PLATES, METHODS FOR MAKING SUCH PLATES AND FLUID PASTE

专利摘要:
plate, method for making a plate, slurry, gasket compound, acoustic panel and method for making a pregelatinized starch. the present invention relates to a product (e.g. panels), slurry and methods relating to a pregelatinized starch having a mid-range viscosity (i.e., from about 20 centipoise to about 700 centipoise), and an extruded pregelatinized starch.
公开号:BR112015008774B1
申请号:R112015008774-4
申请日:2013-10-14
公开日:2021-07-20
发明作者:Chris C. Lee；Cesar Chan；Yijun SANG；Weixin D. Song
申请人:United States Gypsum Company；
IPC主号:

专利说明:

CROSS REFERENCE TO RELATED ORDER
[1] This application claims the benefit of US Provisional Patent Application No. 61/717,588, filed October 23, 2012, US Non-Provisional Patent Application No. 13/835,002, filed March 15, 2013 and Continuation Application -in-Part US No. 14/044,582, filed on October 2, 2013, all prior patent applications which are incorporated into the addendum by reference in their entirety. FUNDAMENTALS OF THE INVENTION
[2] Hardened gypsum (i.e., calcium sulfate dihydrate) is a well-known material that is used in many products, including panels and other construction and remodeling products. One such panel (often referred to as gypsum board), in the form of a hardened gypsum core, is sandwiched between two cover sheets (eg, paper coated board) and is commonly used in drywall construction for walls. interiors and roofs of buildings. One or more dense layers, often referred to as “skim coats” (skim coats), may be included on both sides of the core, usually at the central interface of the paper.
[3] During board manufacture, stucco (ie, calcined gypsum in the form of calcium sulfate hemidrate and/or calcium sulfate anhydrite), water and other ingredients as appropriate are mixed, typically in a pin mixer such as term is used in the technique. A slurry is formed and discharged from the mixer onto a moving conveyor, loading a cover sheet with one of the thin coatings (if present) already applied (often upstream of the mixer). The slurry is spread over the paper (with a thin coating optionally included on the paper). Another cover sheet, with or without thin coating, is applied over the slurry to form the sandwich structure of desired thickness with the aid of, for example, a forming plate or the like. The mixture is molded and allowed to harden to form hardened (i.e., rehydrated) gypsum by reacting the calcined gypsum with water to form a matrix of crystalline hydrated gypsum (i.e., calcium sulfate dihydrate). It is the desired hydration of the calcined gypsum that allows the formation of the interlocking matrix of the hardened gypsum crystals, thereby providing resistance to the gypsum structure in the product. Heat is needed (eg, in an oven) to expel the remaining free (ie unreacted) water to produce a dry product.
[4] The excess water that is carried out represents an inefficiency in the system. Energy input is required to remove water, and the manufacturing process is slowed down to accommodate the drying step. However, reducing the amount of water in the system proved very difficult without compromising other critical aspects of the commercial product, including the strength and weight of the board.
[5] It will be recognized that this description of the fundamentals was created by the inventors to assist the reader and should not be taken as a reference to the state of the art nor as an indication that any of the problems indicated have been properly recognized in the art. While the principles described may, in some respects and embodiments, alleviate problems inherent in other systems, it will be recognized that the scope of the protected innovation is defined by the appended claims and not by the claimed invention's ability to solve any specific problem noted here. BRIEF SUMMARY OF THE INVENTION
[6] In one aspect, the present invention provides slab comprising hardened gypsum core. The core may comprise an interlocking matrix of gypsum crystals. The board can be arranged between two cover sheets (eg formed from paper). The hardened gypsum core is formed of a slurry comprising water, stucco and at least one pregelatinized starch characterized as having an "average" viscosity (i.e., having a viscosity of approximately 20 centipoise to about 700 centipoise) when the starch is subjected to conditions according to the VMA method, as set out in example 1 below, with the starch in water in an amount of 15% by weight of the total starch and water. Thus, the VMA method is used to determine whether the starch has the characteristic of medium viscosity when subjected to the conditions of the VMA method. This does not mean that starch should be added to the gypsum paste under these conditions. Instead, when adding the starch to the paste, it can be in wet forms (at different concentrations of starch in water) or dry and does not need to be fully gelatinized or otherwise under the conditions defined in the VMA method, in accordance with the modalities of invention. As used herein, "pregelatinized" means any degree of gelatinization.
[7] In another aspect, the present invention provides slurry comprising water, stucco and at least one pregelatinized starch, having an average viscosity of about 20 centipoise to about 700 centipoise where the viscosity is measured in accordance with the VMA method. Slurry is sometimes referred to as "gypsum slurry" as gypsum forms in it as water reacts with stucco. As the stucco in the slurry reacts with water, gypsum, ie calcium sulfate dihydrate, begins to form. The slurry can be used to make board as well as other gypsum products.
[8] In another aspect, the present invention provides a method of making the plate. Water, stucco and at least one pregelatinized starch, characterized by medium viscosity according to the VMA method, are mixed together to form a slurry. Starch can be added in wet or dry form. Pregelatinized starch does not need to be fully gelatinized when added to the slurry and does not need to be under the conditions defined in the VMA method. The slurry is disposed between a first layer and a second layer to form a wet assembly that is a precursor to the panel. In this regard, as used herein, by "arranged between" it will be understood that the thin coating can optionally be applied or included between the core and one or both of the plies, such that it will be understood that a ply may include thin lining. The panel is cut to form a board. The board is dry. After drying, final sizing (eg cutting) and processing can take place as desired. Starch can be chemically modified (in any order with respect to a pregelatinization step) in some modalities prior to inclusion in the slurry. In some embodiments, the pregelatinized starch is partially gelatinized when added to the paste, with the remaining gelatinization taking place in the drying step (eg, in an oven). Starch becomes fully gelatinized in the oven in some ways.
[9] In another aspect, the joint compound comprises calcium carbonate and at least one pregelatinized starch, wherein the starch has a viscosity of about 20 centipoise to about 700 centipoise and where the viscosity is measured accordingly. with the VMA method. In some embodiments, the joint compound further comprises calcined gypsum, water and/or set retarder.
[10] In another aspect, acoustic panel comprises an acoustic component comprising fiber and at least one pregelatinized starch, wherein the starch has a viscosity of approximately 20 centipoise to about 700 centipoise, wherein the viscosity is measured accordingly with the VMA method, and wherein the panel has a Noise Reduction Coefficient of at least about 0.5 in accordance with ASTM C 423-02. In some embodiments, the fibers comprise mineral wool.
[11] In another aspect, the invention provides a board comprising a core of hardened gypsum disposed between two cover sheets, the core formed from a slurry comprising water, stucco and at least one pregelatinized starch, where the starch has a cold water solubility of greater than about 30%, and in which the hardened gypsum core has a greater compressive strength than a hardened gypsum core made with a starch having a cold water solubility of less than about 30%.
[12] In another aspect, the present invention provides a method of making a board comprising mixing at least water, stucco and at least one pregelatinized starch to form a slurry, by disposing the slurry between a first cover sheet and a second cover sheet to form a wet mount by cutting the wet mount into a board and drying off the board. Starch has a cold water solubility of greater than about 30%, and the hardened gypsum core has a greater compressive strength than a hardened gypsum core made with a starch having a cold water solubility of less than about 30% .
[13] In another aspect, the present invention provides a method of making a pregelatinized starch comprising mixing at least water and pregelatinized starch to make a wet starch, disposing the wet starch in an extruder with a mold at a temperature of about 90°C or greater and dry the starch. Pregelatinized starch has a cold water solubility greater than about 30%. BRIEF DESCRIPTION OF THE FIGURES
[14] FIG. 1 is a viscogram developed from a viscograph, illustrating starch viscosity in different states, where the x axis is time and the y axis overlaps torque (major y axis, left) and temperature (secondary y axis, right) in accordance with the embodiments of the invention.
[15] FIG. 2 is a line graph showing compressive force (y-axis) with a specified density (x-axis) for example 13 cubes in accordance with embodiments of the invention. DETAILED DESCRIPTION OF THE INVENTION
[16] Embodiments of the present invention are based, at least in part, on the inclusion in a gypsum slurry of a pregelatinized starch characterized as having "medium" viscosity (eg, from about 20 centipoise to about 700 centipoise ). Although the viscosity characteristic is determined as the starch is placed under certain conditions, in accordance with the VMA methodology described in this document, it will be understood that pregelatinized starch need not be added to the slurry under these conditions. Surprisingly and unexpectedly, it has been found that the inclusion of medium viscosity pregelatinized starch confers a combination of significant benefits, such as with respect to starch efficiency (e.g., so less starch can be used), strength improvements. product and water demand, for example, in unison in some modalities. In accordance with the embodiments of the invention, the benefits, including with respect to starch efficiency, water demand, starch and/or strength represent a considerable improvement and advancement over starches known for use in gypsum slurries such as starch non-gelatinized (raw) or pregelatinized (cooked) starches with viscosity below 20 centipoise, or above 700 centipoise, measured according to the VMA method. These discoveries confer considerable advantages, including, but not limited to, reducing raw material cost, increasing manufacturing efficiency, and increasing product strength, for example, enabling a lighter weight product with sufficient strength properties.
[17] Starches are classified as carbohydrates and contain two types of polysaccharides, namely linear amylose and branched amylopectin. Starch granules are semi-crystalline, for example, as seen under polarized light, and are insoluble at room temperatures. Gelatinization is the process in which starch is placed in water and heated ("cooked") so that the crystalline structure of the starch granules is melted and the starch molecules dissolve in water, resulting in good dispersion. It has been found that, when transforming a starch granule into gelatinized form, initially the starch granule provides low viscosity in water because the starch granules are insoluble in water. As the temperature increases, the starch granule swells and the crystal structure melts at the gelatinization temperature. Peak viscosity is when the starch granule has maximum swelling. More heating will break down the starch granules and dissolve the starch molecules in water, with a precipitous drop in viscosity. Upon cooling, the starch molecule will reassociate to form a 3-D gel structure, with viscosity increasing due to the gel structure. See, for example, FIG. 1, discussed below. Some commercial starches are sold in a pregelatinized form, while others are sold in a granular form. In accordance with some embodiments of the present invention, the commercial granular form undergoes at least some degree of gelatinization so that it is pregelatinized prior to addition of the gypsum slurry (typically in a mixer, e.g., the pin mixer).
[18] To achieve the desired average viscosities according to embodiments of the invention, the starch molecule can be modified, for example, to hydrolyze glycosidic bonds between glucose units to achieve the desired molecular weight. For example, such modifications can include acidic modifications, enzyme modifications, and/or other methods. For example, other approaches to achieving low viscosity include, for example, mechanical energy extrusion or modification of the starch molecule to include more linear amylose units. For example, in the case of Tackidex K720, low viscosity is achieved by mechanical energy extrusion, plus amylose units (~ 35%) and hydroxypropylation. Modification can take place before or after gelatinization takes place. In the case of enzyme modifications, it is generally preferred that the modification takes place after the gelatinization step. The most commonly used starch converting enzyme is a-amylase (alpha-amylase). The enzymatic hydrolysis reaction can be stopped either by adjusting the pH or by heating. In the case of acid modifications, it is generally preferred that the modification take place prior to gelatinization as it tends to be more efficient and less expensive. To prepare acid-modified starches, it will be appreciated that the aqueous suspension of unmodified starch can be treated with, for example, a small amount of a strong acid such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid or the like. By adjusting the reaction time, the degree of depolymerization can be modified. For example, when adequate fluidity is achieved, for example as determined by in-process laboratory controls, a mild alkali is introduced to neutralize the acid and stop hydrolysis. Thus, acid-modified starches can be prepared in various fluidities. Furthermore, acid modified starches can be used directly after neutralization without further purification or can be purified to remove salts. The end use of acid modified starches can determine the convenience of purification. For example, a starch composition modified by sulfuric acid and neutralized by calcium hydroxide can contain sodium and calcium sulfate ions, which can be added to a slurry of stucco and water. Since the stucco already has sodium and calcium sulfate ions, it may not be necessary to purify the starch modified by sulfuric acid prior to addition to the paste. Thus, considerations for determining the convenience of purification include, for example, the identity of the acid and alkali and whether it is desirable to add ions other than sulfate or calcium ions to the slurry.
[19] Pregelatinized starches exhibiting the characteristic of medium viscosity according to the invention offer significant benefits to the strength of the product (eg the panel). Since starch contains glucose monomers containing three hydroxy groups, starch provides many sites for hydrogen bonding to gypsum crystals. While not wishing to be bound by any particular theory, it is believed that the molecular size of pregelatinized starch which exhibits the characteristic of medium viscosity allows optimal mobility of the starch molecules to align the starch molecules with the gypsum crystals to facilitate the good binding of starch to gypsum crystals to strengthen the resulting crystalline gypsum matrix, eg through hydrogen bonds. Pregelatinized starch with non-average viscosities, which would have longer chain lengths and higher molecular weight (very high viscosity) and shorter chain lengths and lower molecular weights (very low viscosity), respectively, do not provide the same combination of benefits . It is also believed that, with respect to starch efficiency, when the starch molecules sufficiently bind to the gypsum crystals, additional starch does not add a significant benefit because the crystals are already bound so that there is no longer any site of gypsum crystal for starch to adhere or bond. In this sense, due to the ideal bond between gypsum crystals and the medium viscosity pregelatinized starch molecules, in fact the strength of the gypsum crystal matrix is enhanced and less starch is needed to promote this strength compared to conventional starches.
[20] Pregelatinized starch exhibiting the characteristic of medium viscosity also offers advantages over water demand. Adding starch to the gypsum slurry requires that additional water be added to the gypsum slurry in order to maintain a desired level of slurry fluidity. This is because starch increases the viscosity and reduces the fluidity of the gypsum slurry. Thus, the use of starch in conventional systems has resulted in an increase in water demand such that even more excess water would be needed in the gypsum slurry. Surprisingly and unexpectedly, pregelatinized starch, having the characteristic of medium viscosity according to the present invention, requires less water so that the effect on water demand in the gypsum slurry is reduced, especially compared to conventional starches. Furthermore, due to the efficiency of the inventive pregelatinized starch having the characteristic of medium viscosity, such that less starch can be used, the positive impact on water demand can be even more significant in terms of some embodiments of the invention. This low water demand provides considerable efficiency during manufacturing. For example, excess water requires energy input for drying. Line speed must be slowed down to accommodate drying. Thus, by reducing the water load on the gypsum slurry, less energy and cost resources can be seen, as well as faster production rates. In some embodiments, the increase in water demand in a gypsum slurry is less than the increase in water demand required by other starches such as pregelatinized starch with a viscosity above 700 centipoise (eg, around 773 centipoise).
[21] Any suitable starch can be selected so long as it can meet the average viscosity characteristic of the invention, for example, by modification or otherwise. As used herein, "starch" refers to a composition that includes a starch component. As such, the starch can be 100% pure starch or it can have other components such as those commonly found in flours such as protein and fiber, while the starch component makes up at least about 75% by weight of the starch composition. The starch may be in the form of a flour (e.g., corn flour) containing starch, such as a flour having at least about 75% starch by weight of the flour, for example, at least about 80%, at least about 85%, at least about 90%, at least about 95%, etc.). By way of example and not limitation, the starch may be in the form of a starch-containing corn meal; corn starch such as, for example, Clinton® 260 (ADM), Supercore® S23F (GPC), Amidon M-B 065R (Roquette); a pea starch such as, for example, acid-modified acetylated starch such as Clearam LG 7015 (Roquette); alkylated starch such as hydroxyethylated starch, such as, for example, Clineo® 714 (ADM), Coatmaster® K57F (GPC) or hydroxypropylated starch, such as, for example Tackidex® K720 (Roquette); as well as oxidized starch such as Clinton® 444 (ADM); or any combination of these.
[22] Gypsum slurry is typically formed inside a pin mixer. However, the way in which ingredients are introduced into the mixer may vary. For example, various combinations of components can be pre-mixed before entering the blender, for example one or more dry ingredients and/or one or more wet ingredients can be pre-mixed. By "added to slurry", as used herein, it is to be understood that ingredients can be pre-mixed in any suitable way prior to entry into the blender where the slurry is formed as set forth herein.
[23] Pregelatinized starch having the medium viscosity characteristic of the invention can be included in the gypsum slurry in a wet or dry form. If in a wet form, starch can be included in any suitable concentration and could be mixed with other wet ingredients. Although viscosity is measured according to the VMA method set out in example 1 while in water in an amount of starch of 15% by weight of the total starch and water, this does not necessarily mean that the starch added to the paste is fully gelatinized or in conditions described in the VMA method, or which must be in a 15% solution in accordance with embodiments of the present invention. Rather, the viscosity feature of starch is characterized under these particular conditions to determine whether the starch meets the viscosity criteria of embodiments of the invention and to allow comparison of the viscosity characteristic of different starches under standard circumstances.
[24] Thus, as used here, "pre-gelatinized" means that the starch has some degree of gelatinization before it is included in the gypsum slurry. In some embodiments, the pregelatinized starch can be partially gelatinized when included in the slurry, but becomes fully gelatinized when exposed to elevated temperature, for example, the oven to the drying step to remove excess water. In some embodiments, the pregelatinized starch is not fully gelatinized, even on leaving the oven as long as the starch meets the characteristic of medium viscosity when under the conditions according to the VMA method.
[25] Differential Scanning Calorimetry (DSC) and Viscographic are two different methods for describing starch gelatinization. The degree of gelatinization of starch can be determined by, for example, thermogram from DSC, for example using peak area (crystal melting) for calculation. A viscogram (from a viscograph) is less desirable for determining the degree of partial gelatinization, but it is a good tool for obtaining data such as change in starch viscosity, maximum gelatinization, gelatinization temperature, gelling, viscosity during scanning, viscosity at end refrigeration etc. For the degree of gelatinization, DSC measurements are made in the presence of excess water, particularly at or above 67% by weight. If water content of starch/water mixture is less than 67%, gelatinization temperature will increase when water content decreases. Starch crystals are difficult to melt when available water is limited. When the water content of the starch/water mixture reaches 67%, gelatinization temperature will remain constant no matter how much more water is added to the starch/water mixture. Gelatinization start temperature indicates the gelatinization start temperature. Gelatinization end temperature indicates the gelatinization end temperature. Gelatinization enthalpy represents the amount of crystal structure melted during gelatinization. Using enthalpy from a starch DSC thermogram, the degree of gelatinization can be indicated.
[26] Different starches have different gelatinization onset temperature, end temperature, and gelatinization enthalpy. Therefore, different starches can become fully gelatinized at different temperatures. It will be understood that a starch is fully gelatinized when the starch is heated beyond the final gelatinization temperature in excess water. Also, for any special starch, if the starch is heated below the end-of-gelatinization temperature, the starch will be partially gelatinized. Thus, partial rather than total gelatinization will occur when starch in the presence of excess water is heated below the final gelatinization temperature, for example as determined by DSC. Complete gelatinization will occur when starch in the presence of excess water is heated above the final gelatinization temperature, for example as determined by DSC. The degree of gelatinization can be adjusted in different ways, such as, for example, by heating the starch below the final gelatinization temperature to form the partial gelatinization. For example, if the total gelatinization enthalpy of a starch is 4 J/g, when the DSC shows the starch gelatinization enthalpy to be only 2 J/g, it means that 50% of the starch has been gelatinized. Fully gelatinized starch would not have the DSC thermogram gelatinization peak (enthalpy = 0 J/g) when measured by DSC.
[27] As noted, the degree of gelatinization can be any suitable amount, such as about 50% or more etc. However, lower degrees of gelatinization will come closer to granular starch and may not take full advantage of the strength enhancement, better (more complete) dispersion, and/or reduced water demand of some embodiments of the invention. Thus, in some embodiments, it is preferable that there is no greater degree of gelatinization, for example, at least about 60%, at least about 70%, at least about 80%, at least about 90% at least about 95%, at least about 97%, at least about 99%, or complete gelatinization (100%). Starch with a lesser degree of gelatinization can be added to the slurry with additional gelatinization (eg at 100%) taking place in the oven. For the purpose of slurry addition, by "fully gelatinized," it will be understood that the starch is sufficiently cooked at or above its gelatinization temperature or to otherwise achieve complete gelatinization, as seen from DSC techniques. Although a small degree of retrogradation upon cooling can be expected, starch will still be understood to be "fully gelatinized" for addition to gypsum slurry in some modalities as those skilled in the art will recognize. In contrast, for the purposes of the VMA method discussed in this document, such retrogradation is not acceptable when measuring viscosity.
[28] In some embodiments, the average viscosity of pregelatinized starch can be from about 20 centipoise to about 700 centipoise, such as from about 20 centipoise to about 500 centipoise or about 30 centipoise to about 200 centipoise. In embodiments of the invention, the viscosity of pregelatinized starch when tested under the VMA method can be, for example, as listed in tables 1A, 1B and 1C below. In tables, an "X" represents the range "from about [corresponding value in top row] to about [corresponding value in leftmost column]". The values indicated represent the viscosity of pregelatinized starch in centipoise. For ease of presentation, it will be understood that each value represents "about" that value. For example, the first "X" in Table 1A is the range "about 20 centipoise to about 25 centipoise." The ranges in the table are between and including the starting and ending points. Table 1A

Table 1B
Table 1C


[29] Thus, the viscosity of pregelatinized starch can have a range between and including any of the endpoints stipulated above in tables 1A, 1B or 1C.
[30] Pregelatinized starch having the characteristic of medium viscosity in accordance with the embodiments of the present invention can surprisingly and unexpectedly be included in the slurry in a relatively low amount (solids/solids basis) and still achieve significant improvement in resistance on the board. Therefore, in preferred embodiments of the invention, pregelatinized starch having the characteristic of medium viscosity is included in the gypsum slurry in an amount that is about 5% or less by weight of the stucco (e.g., approximately 0.1 % to about 5%) or even less, such as about 3% or less by weight of the plaster. For example, pregelatinized starch can be included in an amount of from about 0.1% to about 4% by weight of the plaster, about 0.1% to about 3%, about 0.1% to about 2%, about 0.1% to about 1.5% etc. It has been found that increasing the amount of medium viscosity starch in the slurry beyond these ranges does not improve strength as effectively as strength levels may stagnate somewhat when adding even more starch in some modalities. However, larger amounts of starch can be used if desired, especially where decreased strength return is accepted. For example, although not preferred, in some embodiments, amounts of starch greater than about 5% can be used, for example, from about 0.1% to about 10% by weight of the plaster.
[31] In embodiments of the invention, the amount of pregelatinized starch can be, for example, as listed in tables 2A and 2B below. In the table, an "X" represents the range "from about [corresponding value in top row] to about [corresponding value in leftmost column]". The values indicated represent the amount of starch in percent by weight of the plaster. For ease of presentation, it will be understood that each value represents "about" that value. For example, the first "X" is the range "from "approximately 0.1% starch by weight of the stucco, to about 0.25% of the starch by weight of the stucco. The ranges in the table are between and including the starting points and end. Table 2A

Table 2B

[32] Thus, the amount of pregelatinized starch may have a range between and including any of the endpoints stipulated above in tables 2A or 2B.
[33] Pregelatinized starches having the characteristic of medium desired viscosity can be combined with other starches in accordance with embodiments of the invention. For example, pregelatinized starches exhibiting the average desired viscosity characteristic can be combined with other starches to increase both core strength and paper core binding, particularly if an increase in water demand is accepted. Thus, in some embodiments of the invention, gypsum slurry may include one or more pregelatinized starches having the characteristic of medium viscosity, as well as one or more other types of starches. Other starches can include, for example, pregelatinized starch, having a viscosity below 20 centipoise and/or above 700 centipoise. One example is pregelatinized corn starch (for example, having a viscosity of more than 700 centipoise such as centipoise about 773). The other starches can also be in the form of, for example, non-pregelatinized starches, such as acid-modified starches, as well as alkylated starches, for example, ethylated starches, which are not gelatinized etc. The combination of starches can be pre-mixed (eg in a dry mix, optionally with other components such as stucco etc., or in a wet mix with other wet ingredients) before addition to the gypsum paste, or they can be included in the gypsum folder, one at a time, or any variation thereof. Any suitable proportion of pregelatinized starch having the characteristic of medium viscosity and other starch may be included. For example, the starch content of pregelatinized starch with the characteristic of medium viscosity as a percentage of the total starch content to be added to the gypsum slurry can be, for example, at least about 10% by weight, as per at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least , about 90%, at least about 95%, at least about 99%, at least about 100%, or any range in between). In exemplary embodiments, the ratio of pregelatinized starch having the medium viscosity characteristic to another starch can be about 25:75, about 30:70, about 35:65, about 50:50, about 65: 35, about 70, about 75:25 etc.
[34] In some embodiments, the invention includes a pregelatinized starch having cold water solubility. Pregelatinization, a process that makes starch soluble in cold water, usually requires cooking starch in an additional amount of water. In certain cases, it is not desirable to prepare pregelatinized starch by this method. Extrusion, a combination of heating and mechanical cutting, is an energy efficient method that can be used to produce low moisture pregelatinized starch. Extrusion of starches can generate extruded pregelatinized starches that are soluble in cold water. Cold water solubility is defined as having any amount of solubility in water at room temperature (25°C). It has been found that starches exhibiting cold water solubility can provide significant strength benefits to gypsum products (eg, panel). Cold water soluble starches of the present invention have a cold water solubility greater than about 30% and, when added to a hardened gypsum core, can increase the strength of the gypsum core. The solubility of pregelatinized starch in water is defined as the amount of starch that dissolves in water at room temperature divided by the total amount of starch and can be measured using the method of example 14.
[35] In some embodiments, the cold water solubility of pregelatinized starch is about 30% to about 75%. In other embodiments, the cold water solubility of extruded pregelatinized starch is from about 50% to about 75%. In embodiments of the invention, the cold water solubility of extruded pregelatinized starch may be, for example, as listed in Table 2C. In the table, an "X" represents the range "from about [matching value in top row] to about [matching value in leftmost column]." The values shown represent the cold water solubility of extruded pregelatinized starch (Table 2C). For ease of presentation, it will be understood that each value represents "about" that value. For example, the first "X" in Table 2C is the range "from about 30% to about 35%". The ranges in the table are between and including the starting and ending points. Table 2C


[36] While not wishing to be bound by any particular theory, it is believed that a combination of mechanical and thermal energy during extrusion is responsible for the cold water solubility of starch. It is believed that when starch is extruded, the hydrogen bonds between the starch molecules are broken. When extruded starch is dissolved in water, the starch forms hydrogen bonds with water molecules. After the pregelatinization process, the extruded pregelatinized starch molecules are free to hydrogen bond with the gypsum crystals, thus giving greater strength to the gypsum product. In this sense, because starches exhibiting cold water solubility improve the strength of the gypsum board, less starch is needed compared to conventional starches.
[37] The extruded water-soluble pregelatinized starches of the present invention may have any suitable cold water viscosity according to the cold water viscosity test method (CWVA) (see example 16). In some embodiments, the cold water soluble starch has a viscosity of approximately 20 centipoise to about 300 centipoise. Pregelatinized starches with the viscosity scale of the present invention require less water so that the effect on water demand in gypsum slurries is reduced. In embodiments of the invention, the viscosity of the extruded pregelatinized starch may be, for example, as listed in Table 2D. In the table, an "X" represents the range "from about [matching value in top row] to about [matching value in leftmost column]." The values indicated represent the viscosity of pregelatinized starch in centipoise (Table 2D). For ease of presentation, it will be understood that each value represents "about" that value. For example, the first "X" in Table 2D is the range "from about 20 centipoise to about 40 centipoise." The ranges in the table are between and including the starting and ending points. 2D table

[38] In another aspect, the present invention provides a method of preparing an extruded pregelatinized starch having cold water solubility. An extruded pregelatinized starch is prepared by mixing at least water and starch to make a wet starch, extruding the wet starch through an extruder and drying the starch. An extruder is a machine commonly used to melt and process polymers. The starch of the present invention is pregelatinized in an extruder such as a Wenger TX 52 Twin Screw extruder. In general, an extruder comprises a feed hopper for delivering the feed material, a preconditioner comprising heat jackets for conditioning polymer with plasticizer (e.g. water), modular extruder head comprising heating zones and an assembly of mold. The mold assembly generally comprises a plate, spacer and mold head. For the present invention, starch and water are pre-mixed and fed into an extruder. In some embodiments, additional water can be added to the extruder. During extrusion, a combination of heating elements and mechanical distortion melts and pregelatinizes the starch. After extrusion, the pregelatinized starch is dried to sufficient moisture and then ground into a powder. Although the extruder mold can be of any sufficient temperature, the mold temperature generally exceeds the melting temperature of the starch crystals. In embodiments of the invention, the temperature of the extruder can be, for example, as listed in table 2E. In the table, an "X" represents the range "from about [matching value in top row] to about [matching value in leftmost column]." The values shown represent the extruder temperature (Table 2E). For ease of presentation, it will be understood that each value represents "about" that value. For example, the first "X" in Table 2E is the range "from about 90°C to about 100°C". The ranges in the table are between and including the starting and ending points. Table 2E Starting Point for Extruder Temperature Range (°C)

[39] The water content of wet starch during extrusion is also an important parameter for cold water solubility. Moist starch can have any water content, but it usually has a water content of less than about 25%. In some embodiments, wet starch has a water content of about 12% to about 25%. It has been found that when a starch has a lower moisture content, the extrusion process produces a pregelatinized starch with greater cold water solubility. While not wishing to be bound by any particular theory, it is believed that the presence of less water leads to greater friction during extrusion. Increased friction can increase the disturbance of the autohydrogen bond in starch. Pregelatinized starch produced from extrusion using a starch with a water content of less than about 25% may have a cold water solubility of greater than about 30%. In embodiments of the invention, the water content of the wet starch may be, for example, as listed in table 2F. In the table, an "X" represents the range "from about [matching value in top row] to about [matching value in leftmost column]." The indicated values represent the moisture content (%) of wet starch by weight of stucco (Table 2F). For ease of presentation, it will be understood that each value represents "about" that value. For example, the first "X" in Table 2F is the range "from about 12% to about 13%". The ranges in the table are between and including the starting and ending points. Table 2F

[40] In yet another aspect, the present invention provides a method of preparing a panel comprising a core comprising a pregelatinized starch having cold water solubility. Water, stucco and at least one pregelatinized starch with a cold water solubility greater than about 30% are mixed together to form a slurry. Starch can be suitably prepared as described in this document. Starch with cold water solubility can be included in the stucco slurry in the amounts described herein. In some embodiments, the cold water soluble starch is included in the stucco slurry in an amount of from about 0.1% to about 5% by weight of the stucco. The pregelatinized starch of the present invention can be added in wet or dry form, but is preferably added as a dry powder. The particle size of the cold water soluble starch can be any size. In some embodiments, the particle size is approximately 100 microns to about 400 microns. In embodiments of the invention, the particle size of the pregelatinized starch can be, for example, as listed in Table 2G. In the table, an "X" represents the range "from about [matching value in top row] to about [matching value in leftmost column]." The values indicated represent the particle size of the pregelatinized starch in centipoise (Table 2G). For ease of presentation, it will be understood that each value represents "about" that value. For example, the first "X" in Table 2G is the range "from about 100 microns to about 125 microns". The ranges in the table are between and including the starting and ending points. Table 2G

[41] Pregelatinized starch powder can be added to dry ingredients during stucco slurry manufacture. The slurry is disposed between a first layer and a second layer to form a wet assembly that is a precursor to the panel. The slurry comprises water, stucco and at least one pregelatinized starch; starch with a cold water solubility greater than about 30%. The panel is cut to form a board. The board is dry. After drying, final sizing (eg cutting) and processing can take place as desired. Starch may be chemically modified (in any order with respect to a pregelatinization step) in some ways prior to inclusion in the slurry. The panel of the present invention comprises a hardened gypsum core having greater compressive strength than a hardened gypsum core made without starch.
[42] In addition to the starch component, the paste is formulated to include water, stucco, foaming agent (sometimes referred to simply as "foam") and other additives as desired. The stucco may be in the form of calcium sulfate alpha hemidrate, calcium sulfate beta hemidrate and/or calcium sulfate anhydrite. Stucco can be fibrous or non-fibrous. Foaming agent may be included to form a void air distribution within the continuous crystalline matrix of hardened gypsum. In some embodiments, the foaming agent is composed of a larger portion of the unstable component and a smaller portion of the stable component (eg, where unstable and stable/unstable mixture are combined). The ratio of unstable component to stable component weight is effective to form a void air distribution within the hardened gypsum core. See, for example, U.S. Patents 5,643,510; 6,342,284; and 6,632,550. It has been found that proper void distribution thickness and wall thickness (independent) can be effective to increase strength, especially in the lower density plate (eg, below about 35 pcf (561 kg/m3)). See, for example, U.S. 2007/0048490 and U.S. 2008/0090068. Evaporative water voids, generally having voids of about 5 µm or less in diameter, also contribute to the total void distribution along with the above-mentioned air (foam) voids. In some embodiments, the ratio of void volume with a pore size greater than about 5 microns to voids with a pore size of about 5 microns or less is from about 0.5:1 to about 9: 1, such as, for example, 0.7:1 to about 9:1, about 0.8:1 to about 9:1, about 1.4:1 to about 9:1, about 1.8:1 to about 9:1 , about 2.3:1 to about 9:1, about 0.7:1 to about 6:1, about 1.4:1 to about 6:1, about 1.8:1 to about 6: 1, about 0.7:1 to about 4:1, about 1.4:1 to about 4:1, about 1.8:1 to about 4:1, about 0.5:1 to about 2.3:1, about 0.7:1 to about 2.3:1, about 0.8:1 to about 2.3:1, about 1.4:1 to about 2.3:1, about 1.8:1 to about 2.3:1, etc. In some embodiments, the foaming agent is present in the slurry, for example, in an amount of less than about 0.5% by weight of the plaster such as about 0.01% to about 0.5%. about 0.01% to about 0.4%, about 0.01% to about 0.3%, about 0.01% to about 0.2%, about 0.01% to about 0.1%, about 0.02% to about 0.4%, about 0.02% to 0.3%, about 0.02% to about 0.2%, etc.
[43] Additives such as accelerator (eg wet gypsum accelerator, heat resistant accelerator, climate stabilized accelerator) and retarder are well known and may be included. See, for example, U.S. patents 3,573,947 and 6,409,825. In some embodiments where accelerator and/or retarder are included, the accelerator and/or retarder may each be in the gypsum slurry in an amount on a solid basis of, for example, from about 0% to about 10% in weight of the plaster (for example, approximately 0.1% to about 10%), such as, for example, from about 0% to about 5% by weight of the plaster (for example, about 0.1% to about 5%). Other additives, as desired, may be included, for example, to give strength to allow lighter weight product with sufficient strength, to prevent permanent deformation, to promote green strength, for example, as product hardens on conveyor moving down by a manufacturing line, to promote fire resistance, to promote water resistance, etc.
[44] For example, the slurry may optionally include at least one dispersant to improve the flowability of some modalities. Like starch and other ingredients, dispersants can be included in a dry form with other dry ingredients and/or in a liquid form with other liquid ingredients in the core slurry. Examples of dispersants include naphthalenesulfonates, such as polynaphthalenesulfonic acid and its salts (polynaphthalenesulfonates) and derivatives, which are condensation products of naphthalenesulfonic acids and formaldehyde; as well as polycarboxylate dispersants, such as polycarboxylic ethers, e.g. PCE211, PCE111, 1641, 1641F, or PCE 2641-type dispersants, e.g. MELFLUX 2641F, MELFLUX, 2651F, MELFLUX 1641F, MELFLUX 2500L (BASF) and COATEX dispersants Ethacryl M, available from Coatex, Inc.; and/or lignosulfonates or sulfonated lignin. Lignosulfonates are water-soluble anionic polyelectrolyte polymers, by-products of wood pulp production using sulfite pulping. An example of a lignin useful in practicing the principles of embodiments of the present invention is Marasperse C-21, available from Reed lignin Inc.
[45] Lower molecular weight dispersants are generally preferred. Lower molecular weight naphthalenesulfonate dispersants are favored because they tend to have a lower water demand than higher viscosity, higher molecular weight dispersants. Thus, molecular weights of about 3,000 to about 10,000 (for example, about 8,000 to about 10,000) are preferred. As another illustration, for PCE211 type dispersants, in some embodiments, the molecular weight can be from about 20,000 to about 60,000, which has less lag than dispersants with a molecular weight above 60,000.
[46] An example of a naphthalenesulfonate is DILOFLO, available from GEO Specialty Chemicals. DILOFLO is a 45% solution of naphthalenesulfonate in water, although other aqueous solutions, for example, in the range of about 35% to about 55% solids content by weight, are also readily available. Naphthalenesulfonates can be used in dry solid or powder form, such as LOMAR D, available from GEO Specialty Chemicals, for example. Another exemplary naphthalene sulfonate is DAXAD, available from Hampshire Chemical Corp.
[47] If included, the dispersant may be included in any suitable amount (solids/solids) such as, for example, about 0.1% to about 5% by weight of the plaster, for example about 0. 1% to about 4%, about 0.1% to about 3%, about 0.2% to about 3%, about 0.5% to about 3%, about 0.5% about 2.5%, about 0.5% to about 2%, about 0.5% to 1.5% etc.
[48] One or more phosphate-containing compounds may also optionally be included in the slurry, if desired. For example, phosphate-containing components useful in some embodiments include water-soluble components and may be in the form of an ion, a salt, or an acid, i.e., condensed phosphoric acids, each of which comprises two or more phosphoric acid units. ; condensed salts or phosphate ions, each of which is composed of two or more phosphate units; and monobasic salts or monovalent ions of orthophosphates, as well as a water-soluble acyclic polyphosphate salt. See, for example, U.S. Patents 6,342,284; 6,632,550; 6,815,049; and 6,822.033.
[49] Phosphate compositions according to some embodiments of the invention can increase green strength, resistance to permanent deformation (eg, decay), dimensional stability, etc. Trimetaphosphate compounds can be used, including, for example, sodium trimetaphosphate, potassium trimetaphosphate, lithium trimetaphosphate and ammonium trimetaphosphate. Sodium trimetaphosphate (SMTP) is preferred, although other phosphates may be suitable, including for example sodium tetrametaphosphate, sodium hexametaphosphate having from about 6 to about 27 repeated phosphate units and having the molecular formula Nan+2PnO3n+1, where n=6-27, tetrapotassium pyrophosphate having the molecular formula K4P2O7, dipotassium trisodium tripolyphosphate having the molecular formula Na3K2P3O10, sodium tripolyphosphate having the molecular formula Na5P3O10, tetrasodium pyrophosphate having the molecular formula Na4P2O7, the molecular formula aluminum trimetaphosphate Al(PO3)3, sodium acid pyrophosphate, having the molecular formula Na2H2P2O7, ammonium polyphosphate having 1000-3000 repeated phosphate units and having the molecular formula (NH4)n+2PnO3n+1 where n=1000-3000, or acid polyphosphoric acid having two or more repeating phosphoric acid units and having the molecular formula Hn+2PnO3n+1 where n is two or more.
[50] Phosphate can be included in a dry form or in an in-water form (eg, a phosphate solution of about 5% to about 20%, such as a solution of about 10%). If included, the phosphate may be in any suitable amount (solids/solids basis) such as from about 0.01% to about 0.5% by weight of the plaster, for example from about 0.03% to about 0.4%, from about 0.1% to about 0.3%, or from about 0.12% to about 0.4% by weight of the plaster.
[51] Suitable additives for fire-rated and/or water resistant product may also optionally be included, including, for example, siloxanes (water resistance); fiber; heat sink additives such as aluminum trihydrate (ATH), magnesium hydroxide or the like; and/or high expansion particles (eg, expandable to 300% or more of original volume when heated for about one hour at 1560°F (849°C)). See, for example, co-pending, commonly assigned to U.S. Application No. 13/400,010 (filed February 17, 2012) for description of these and other ingredients. In some embodiments, high expansion vermiculite is included, although other fire resistant materials may be included. The plate of some fire-related products according to the invention may have a thermal insulation index (TI) of about 17 minutes or greater, for example, about 20 minutes or greater, about 30 minutes or greater, about 45 minutes or more, about 60 minutes or more, etc.; and/or a High Temperature Shrinkage (at temperatures of about 1560°F (849°C)) of less than about 10% in the x-y directions and expansion in the z direction greater than about 20%. The fire or water resistance additives may be included in any suitable amount as desired depending on, for example, fire rating, etc. For example, if included, fire or water resistance additives can be in an amount of from about 0.5% to about 10% by weight of the stucco, such as from about 1% to about 10%, about from 1% to about 8%, about 2% to about 10%, about 2% to about 8% by weight of the plaster, etc.
[52] If included, the siloxane is preferably added in the form of an emulsion. The slurry is then shaped and dried under conditions that promote polymerization of the siloxane to form a highly cross-linked silicone resin. A catalyst that promotes the polymerization of the siloxane to form a highly cross-linked silicone resin can be added to the gypsum slurry. In some embodiments, non-solvent methylhydrogen siloxane fluid sold under the name SILRES BS 94 by Wacker-Chemie GmbH (Munich, Germany) can be used as the siloxane. This product is a siloxane fluid that does not contain water or solvents. It is anticipated that from about 0.3% to about 1.0% of the BS 94 siloxane can be used in some embodiments, based on the weight of the dry ingredients. For example, in some embodiments, it is preferred to use from about 0.4% to 0.8% siloxane based on dry weight of stucco.
[53] Slurry formulation can be done with any suitable water/stucco ratio, eg from about 0.4 to about 1.3. However, because pregelatinized starches with the medium viscosity characteristic of the invention reduce the amount of water needed to be added to the slurry to accommodate them, compared to other starches, the slurry can be formulated with a water ratio input /stucco which is inferior in some embodiments than is conventional for other starch-containing gypsum slurries, especially in low weight/density. For example, in some embodiments, the water/stucco ratio can be from about 0.4 to about 1.1, about 0.4 to about 0.9, about 0.4 to about 0.85, about 0.45 to about about 0.85, about 0.55 to about 0.85, about 0.55 to about 0.8, about 0.6 to about 0.9, about 0.6 to about 0.85, about 0.6 to about of 0.8 etc.
[54] Cover sheets can be formed from any suitable basis weight and material. Advantageously, core Board formed from the paste including pregelatinized starch, characterized by medium viscosity provides sufficient strength in the board even with lower base weight sheets such as, for example, less than 45 lbs/MSF (219.7 g/ m 2 of) (eg about 33 lbs/MSF (161 g/m2) to 45 lbs/MSF (from 2 219.7 g/m)) even for lighter board weight (eg having a density of about 35 pcf (561 kg/m 3 of) or below) in some modes. However, if desired, in some embodiments, heavy base weights can be used, for example, to further increase the nail's tensile strength or to improve handling, for example, to facilitate desirable "touch" characteristics for end users. In some embodiments, to increase strength (eg nail tensile strength), especially for the lower density board, one or both cover sheets can be formed from paper and have a basis weight of, per example, at least about 45 lbs/MSF (220 g/m2) (e.g. from about 45 lbs/MSF (220 g/m2) to about 65 lbs/MSF (317 g/m2), about 45 lbs/MSF (220 g/m2) to about 60 lbs/MSF (293 g/m2), about 45 lbs/MSF (220 g/m2) to about 55 lbs/MSF (268 g/m2), about from 50 lbs/MSF (224 g/m2) to about 65 lbs/MSF (317 g/m2), about 50 lbs/MSF (224 g/m2) to about 60 lbs/MSF (293 g/m2) , etc.). If desired, in some embodiments, one cover sheet (eg, the "face" side of the side paper when installed) may have a higher basis weight, for example, to increase nail tensile strength and handling, while the other cover sheet (eg the "back" sheet when the board is installed) may have a slightly lower basis weight if desired (eg basis weight of less than 45 kg/MSF (220 g/m2) per example, from about 33 lbs/MSF (161 g/m2) to 45 lbs/MSF (220 g/m2), for example, about 33 lbs/MSF (161 g/m2) to about 40 lbs/MSF ( 195 g/m2)).
[55] Plate weight is a function of thickness. Since boards are commonly made with varying thickness, board density is used here as a measure of board weight. The advantages of medium viscosity starch in accordance with the embodiments of the invention can be seen across various board densities, eg about 40 pcf (641 kg/m3) or less, for example from about 20 pcf (320 kg/m3) to about 40 pcf (641 kg/m3), from about 24 pcf (384 kg/m3) to about 37 pcf (593 kg/m3) etc. However, preferred embodiments of the invention have particular utility at lower densities, where the enhanced strength provided by the medium viscosity starches of the invention advantageously enables the use of lower weight board with good strength and less water demand than board made from other starches. For example, in some embodiments, plate density can be from about 20 pcf ((320 kg/m3) to about 35 pcf (561 kg/m3), for example, about 24 pcf (384 kg/m3) to about 35 pcf (561 kg/m3), about 24 pcf (384 kg/m3) to about 34 pcf (545 kg/m3), about 27 pcf (432 kg/m3) to about 35 pcf (561 kg/m3), about 27 pcf (432 kg/m3) to about 34 pcf (545 kg/m3), about 30 pcf (481 kg/m3) to about 34 pcf (545 kg/m3), about from 27 pcf (432 kg/m3) to about 30 pcf (481 kg/m3) etc.
[56] The starches of the invention in this document provide strength enhancement to the product according to the invention, which can be especially beneficial at lower weight/density. For example, in some embodiments, board core or other slurry molded in accordance with the 2 inch cube test (no foam) described herein preferably has a compressive strength of at least about 1650 psi (11 .38 MPa), for example, at least about 1700 psi (11.72 MPa), at least about 1750 psi (12.07 MPa), at least about 1800 psi (12.41 MPa), at least about 1850 psi ( 12.76 MPa), at least about 1900 pounds per square inch (13.1 MPa), at least about 1950 pounds per square inch (13.44 MPa), at least about 2000 psi (13.79 MPa), at least about 2050 pounds per square inch (14.13 MPa), at least about 2100 psi (14.48 MPa), at least about 2150 psi (14.82 MPa), at least about 2200 psi (15.17 MPa), at least about 2250 psi (15.51 MPa), at least about 2300 psi (15.86 MPa), at least about 2350 psi (16.2 MPa) etc.
[57] In some embodiments, board according to the invention meets test protocols in accordance with ASTM Standard C473-10 (eg method B). For example, in some embodiments, when the board is molded to a thickness of % inch (1.27 cm), the board has a nail tensile strength of at least about 65 lb (29.5 kg) as determined from according to ASTM C473 (for example, at least approximately 68 lb (30.8 kg), at least approximately 70 lb (31.8 kg), at least approximately 72 lb (32.7 kg) at least approximately 75 lb ( 34 kg), at least about 77 lb (35 kg) etc.). With respect to flexural strength, in some embodiments, when molded into a % inch (1.27 cm) thick slab, the slab has a flexural strength of at least about 36 lb (16.3 kg) in a machine direction (eg, at least approximately 38 lb (17.2 kg), at least about 40 lb (18.1 kg), etc.) and/or at least about 107 lb (48.5 kg) (eg, at least approximately 110 lb (49.9 kg), at least approximately 112 lb (50.8 kg), etc.) in the cross-machine direction as determined in accordance with ASTM C473 standard. Also, in some embodiments, the board can have an average core hardness of at least about 11 pounds (5 kg), as determined in accordance with ASTM C473. Due at least in part to the average viscosity characteristic of embodiments of the invention, these standards can be met with even the lowest density board (e.g., about 35 pcf (561 kg/m3) or less) as described herein.
[58] Product according to embodiments of the invention can be made on typical manufacturing lines. For example, board fabrication techniques are described in, for example, U.S. Patent 7,364,676 and U.S. Patent Application Publication 2010/0247937. Briefly, in the case of gypsum board, the process usually involves unloading a cover sheet onto a moving conveyor. Since the gypsum board is normally formed "face down", this cover sheet is the "face" cover sheet in such arrangements.
[59] Dry and/or wet components of the gypsum slurry are fed to a mixer (eg pin mixer) where they are agitated to form the gypsum slurry. The mixer is composed of a main body and a discharge conductor (eg, a gate-cylinder-boot arrangement as known in the art, or an arrangement as described in U.S. patents 6,494,609 and 6,874,930). In some embodiments, the discharge conduit may include a slurry dispenser with a single feed inlet or multiple feed inlets, such as those described in US Patent Application Publication 2012/0168527 A1 (application No. 13/341,016) and Application Patent Publication 2012/0170403 A1 (application No. 13/341,209), for example. In such embodiments, using a slurry dispenser with multiple feed inlets, the discharge conduit may include a suitable flow divider such as those described in U.S. Patent Application publication 2012/0170403 A1 . Foaming agent may be added to the mixer discharge conduit (e.g., gate as described, e.g., in U.S. Patents 5,683,635 to and 6,494,609) or to the main body if desired. Slurry discharged from the discharge conduit after all ingredients have been added, including foaming agent, is the main gypsum slurry and will form the core of the board. This plate core paste is discharged onto the moving cover sheet.
[60] The cover sheet may have a thin coating in the form of a relatively dense layer of slurry. Also, hard edges, as known in the art, can be formed, for example, from the same paste flux forming the face the thin face coat. In embodiments where the foam is inserted into the discharge conduit, a stream of secondary gypsum slurry can be withdrawn from the mixer body to form the dense thin coating slurry, which can be used to form the thin face and hard edge coating. as known in the art. If included, normally thin face coat and hard edges are deposited onto the moving face cover sheet before the core paste is deposited, usually downstream of the mixer. After being discharged from the discharge conductor, the core slurry spreads, as needed, onto the face cover sheet (optionally with thin coating) and covered with a second cover sheet (usually the "rear" cover sheet) to form a wet assembly in the form of a sandwich structure that is a precursor to the final product. The second cover sheet optionally can support a second coat of cream, which can be formed from the same or different slurry of the secondary (dense) gypsum as for the top coat, if present. Cover sheets can be formed from paper, fibrous mat or other type of material (eg sheet, plastic, glass mat, non-woven material such as a mixture of cellulosic filler and inorganic filler etc.).
[61] The wet assembly thus provided is transmitted to a form station where the product is sized to a desired thickness (eg via forming plate) and to one or more knife sections where it is cut to a desired length . The wet mount is allowed to harden to form the interconnected crystalline matrix of hardened gypsum and excess water is removed using a drying process (eg, transporting the mount through an oven). It is also common in gypsum board manufacturing to use vibration to eliminate large void cavities or air pockets from the deposited slurry. Each of the above steps, as well as processes and equipment for carrying out these steps, are known in the art.
[62] The starch characterized by the average viscosity of the invention can be used in the formulation of various products, such as, for example, gypsum panel, acoustic tile (eg ceiling), joint compound, cellulosic fiber-gypsum products , such as gypsum-wood fiberboard and the like. In some embodiments, such a product can be formed from the paste in accordance with embodiments of the invention.
[63] As such, pregelatinized starch characterized by medium viscosity can have beneficial effects, as described herein, on the product, in addition to paper-coated gypsum board in embodiments of the invention. For example, pregelatinized starch characterized as having a medium viscosity can be used in mat coated products (eg fabrics) where cover sheets are in the form of fibrous mats. Mats can optionally support a finish to reduce water permeability. Other ingredients that may be included in making such a mat-coated product, as well as materials for the fibrous mats and manufacturing methods, are discussed in, for example, U.S. Patent 8,070,895, as well as U.S. Patent Application Publication 2009/0247937.
[64] In addition, the cellulosic-gypsum product may be in the form of cellulosic host particles (eg wood fibers), gypsum, medium viscosity pregelatinized starch and other ingredients (eg, water resistant additives such as as siloxanes) as desired. Other ingredients and manufacturing methods are discussed in, for example, U.S. Patents 4,328,178; 4,239,716; 4,392,896; 4,645,548; 5,320,677; 5,817,262; and 7,413,603.
[65] Pregelatinized starches in this document may also be included in joint compound formulations, including dry and ready-to-mix modalities. The benefit of the invention is not limited to embodiments including calcined gypsum, as medium viscosity pregelatinized starch in accordance with some embodiments may have good binding and strength with other components, e.g., non-fitting components such as calcium carbonate and the like. To inhibit premature setting in some ready-to-mix embodiments, hardened retarder is desirably also included in some embodiments as those skilled in the art will appreciate. For example, U.S. Patents 4,661,161; 5,746,822; and US Patent Application publication 2011/0100844 describe hardened retarders (eg phosphate like tetrasodium pyrophosphate (TSPP), polyacrylic acid and/or its salt or the like) and other ingredients (eg latex emulsion binder, thickener , phosphate, as described herein and the like, or combinations thereof, etc.) which may be useful in accordance with the present invention. Other ingredients and methods of making and using the gasket compound are discussed in, for example, U.S. patents 6,406,537 and 6,805,741; as well as U.S. Patent Application Publication 2008/0305252.
[66] The pregelatinized starches in this document can be used with various types of acoustic panels (eg tile). Starch can be mixed with calcined gypsum, water and other ingredients as desired in some embodiments. However, medium viscosity pregelatinized starch in accordance with some embodiments is not limited to use with calcined gypsum. Medium viscosity pregelatinized starch in some embodiments can provide good bonding between the starch and non-hardening components such as fibers (eg mineral wool and the like). In some embodiments, the panel has a noise reduction coefficient of at least about 0.5 (eg, at least about 0.7 or at least about 1) in accordance with ASTM C423-02. See, for example, U.S. Patents 1,769,519; 6,443,258; 7,364,015; 7,851,057; and 7,862,687 for discussion of ingredients and methods for making acoustic tile.
[67] Some embodiments of the invention may be substantially free of extruded pregelatinized starch or medium viscosity pregelatinized starch. As used herein, "substantially free" can mean either (i) 0% by weight based on the weight of the composition, or (ii) an ineffective or (iii) irrelevant amount of such starch. An example of an ineffective amount is an amount below the threshold amount for achieving the intended purpose of using such a starch, as one skilled in the art would recognize. An immaterial amount may be, for example, below about 5% by weight, such as below about 2% by weight, below about 1% by weight, below about 0.5% by weight, below about of 0.2% by weight, below about 0.1% by weight, or below about 0.0% by weight, as those skilled in the art will appreciate. However, if desired in alternative embodiments, such ingredients may be included in a product, method or slurry.
[68] Thus, in one incarnation, the board comprises a core of hardened gypsum disposed between two cover sheets, the core formed from a slurry composed of water, stucco and at least one pregelatinized starch, in which the Starch has the characteristic of a viscosity of approximately 20 centipoise to about 700 centipoise when the viscosity is measured with starch under the conditions according to the VMA method (see example 1). Having the characteristic does not mean that the starch is added under the conditions of the VMA test, but rather that when the starch is subjected to the VMA test, the characteristic is fulfilled.
[69] In another embodiment, the viscosity characteristic of starch is about 25 centipoise to about 500 centipoise under the conditions according to the VMA method.
[70] In another embodiment, the viscosity characteristic of starch is about 30 centipoise to about 300 centipoise under the conditions according to the VMA method.
[71] In another embodiment, the viscosity characteristic of starch is about 30 centipoise to about 200 centipoise under the conditions according to the VMA method.
[72] In another embodiment, starch is effective in increasing hardened gypsum core core hardness relative to hardened gypsum core without the starch.
[73] In another embodiment, starch requires an increase in the amount of excess water needed to be added to the slurry to maintain the fluidity of the slurry at the same level as it would be without the starch which is less than the increase in the amount of excess. of water required by a starch with a viscosity greater than 700 centipoise (eg 773 centipoise) according to the VMA method.
[74] In another embodiment, starch is an amount of about 0.1% to about 10% by weight of the stucco.
[75] In another embodiment, starch is an amount of about 0.3% to about 4% by weight of the stucco.
[76] In another embodiment, starch is an amount of about 0.5% to about 3% by weight of the stucco.
[77] In another embodiment, starch is acid-modified starch.
[78] In another incarnation, acid-modified starch is acid-modified by sulfuric acid.
[79] In another embodiment, the plate core is characterized as having a compressive strength of at least about 1900 psi (13.1 MPa) (eg, at least about 1950 pounds per square inch (13.45 MPa), at least about about 2000 psi (13.79 MPa), at least about 2050 pounds per square inch (14.13 MPa), at least about 2100 psi (14.48 MPa), at least about 2150 psi (14.82 MPa), at least about 2200 psi (15.17 MPa) etc.) When slurry is molded per 2-inch cube test (absent of any foam).
[80] In another embodiment, slurry has a water/stucco ratio of about 0.4 to about 1.3.
[81] In another incarnation, the water/stucco ratio is from 0.45 to about 0.85.
[82] In another incarnation, the water/stucco ratio is about 0.55 to about 0.8.
[83] In another embodiment, the board has a density of about 24 pcf (384 kg/m3) to about 40 pcf (641 kg/m3).
[84] In another embodiment, the board has a density of about 24 pcf (384 kg/m3) to about 37 pcf (593 kg/m3).
[85] In another embodiment, the board has a density of about 24 pcf (384 kg/m3) to about 35 pcf (561 kg/m3).
[86] In another embodiment, the board has a density of approximately 27 pcf (432 kg/m3) to about 34 pcf (545 kg/m3).
[87] In another embodiment, the board has a density of approximately 30 pcf (481 kg/m3) to about 34 pcf (545 kg/m3).
[88] In another embodiment, the slurry comprises a second type of starch which (a) is not gelatinized, (b) is a pregelatinized starch having the characteristic of a viscosity below 20 centipoise according to the VMA method, or (c) is a pregelatinized starch having a viscosity above 700 centipoise according to the VMA method.
[89] In another embodiment, board has a second type of starch consisting of alkylated starch.
[90] In another embodiment, plaque has a second type of starch that comprises ethylated starch.
[91] In another embodiment, the paste further comprises at least foaming agent consisting of a larger portion of the unstable component and a smaller portion of the stable component, the amount of foaming agent and the component weight ratio unstable and stable component effective to form a void distribution within the hardened gypsum core.
[92] In another embodiment, the foaming agent is in an amount of about 0.1% or less by weight, based on the weight of the plaster.
[93] In another embodiment, the slurry still comprises at least one dispersant.
[94] In another embodiment, the dispersant is naphthalenesulfonate.
[95] In another embodiment, the dispersant is in an amount of from about 0.1% to about 3% by weight, based on the weight of the plaster.
[96] In another embodiment, the naphthalenesulfonate dispersant is in an amount of from about 0.1% to about 3% by weight, based on the weight of the plaster.
[97] In another incarnation, the paste still comprises a polyphosphate.
[98] In another incarnation, the phosphate is sodium trimetaphosphate.
[99] In another embodiment, phosphate is an amount of about 0.5% to about 5% by weight of the stucco.
[100] In another embodiment, sodium trimetaphosphate in an amount of about 0.12% to about 0.4% by weight of the stucco.
[101] In another embodiment, phosphate is water soluble and is present in an amount of about 0.12% to about 0.4% by weight of the stucco.
[102] In another embodiment, at least one cover sheet has a basis weight of at least about 45 lbs/MSF (219.7 g/m2).
[103] In another embodiment, pregelatinized starch is a flour that contains a starch.
[104] In another embodiment, pregelatinized starch is a starch-containing flour (eg, corn flour), such as a flour that contains at least 75% starch by weight of the flour.
[105] In another embodiment, pregelatinized starch is partially pregelatinized.
[106] In another embodiment, when the board is molded to a thickness of about % inch (1.27 cm), the board has a nail tensile strength of at least about 65 pounds (29.5 kg), as determined in accordance with ASTM C473-10 standard.
[107] In another embodiment, when the board is molded to a thickness of about % inch (1.27 cm), the board has a nail tensile strength of at least about 65 pounds (29.5 kg) and a core hardness of at least 11 pounds (5 kg) as determined in accordance with ASTM C473-10 standard.
[108] In another embodiment, when the board is molded to a thickness of about % inch (1.27 cm), the board has a nail tensile strength of at least about 72 pounds (32.7 kg), as determined in accordance with ASTM C473-10 standard.
[109] In another embodiment, when the board is molded to a thickness of about % inch (1.27 cm), the board has a nail tensile strength of at least about 77 pounds (34.9 kg), as determined in accordance with ASTM C473-10 standard.
[110] In another embodiment, the board has a core hardness of at least about 11 lb (5 kg), as determined in accordance with ASTM C473-10 standard.
[111] In another embodiment, a paste is composed of water, stucco and at least one pregelatinized starch, where the starch has a characteristic of a viscosity of approximately 20 centipoise to about 700 centipoise when the viscosity is measured as the starch is subject to the conditions according to the VMA method.
[112] In another embodiment, the product is made from slurry.
[113] In another embodiment, the product is selected from the group consisting of gypsum panel, acoustic tile (eg ceiling), joint composite, gypsum-cellulosic fiber products such as gypsum-wood fiber panel and the like.
[114] In another aspect, the joint compound comprises calcium carbonate and at least one pregelatinized starch, wherein the starch has a viscosity of about 20 centipoise to about 700 centipoise and where the viscosity is measured accordingly. with the VMA method.
[115] In some embodiments, the joint compound further comprises calcined gypsum, water and/or set retarder.
[116] In another embodiment, acoustic panel is composed of an acoustic component composed of fiber and at least one pregelatinized starch, in which the starch has a viscosity of approximately 20 centipoise to about 700 centipoise, in which the viscosity is measured according to the VMA method, and wherein the panel has a noise reduction coefficient of at least about 0.5 according to ASTM C423-02.
[117] In some embodiments, the fibers comprise mineral wool.
[118] In another embodiment, a method of making board comprises (a) mixing at least water, stucco and at least one pregelatinized starch to form a paste, wherein the starch has a characteristic of a viscosity of approximately 20 centipoise a about 700 centipoise when viscosity is measured with starch under conditions according to the VMA method; (b) arranging the slurry between a first cover sheet and a second cover sheet to form a wet assembly; (c) cut the wet assembly into a board; and (d) drying the plate.
[119] In some embodiments, the method comprises adding an amount of water to maintain the fluidity of the slurry at the same level as it would be without the starch, where the amount of water added is less than the amount of water needed when using a pregelatinized starch having a viscosity of more than 700 centipoise in the otherwise same slurry.
[120] In another embodiment, pregelatinized starch is partially gelatinized when added to the paste, with further gelatinization occurring in the drying step.
[121] In another embodiment, pregelatinized starch becomes fully gelatinized in the drying step.
[122] In another embodiment, pregelatinized starch is fully gelatinized when added to the paste or product formulation.
[123] In another embodiment, the method of making the plate further comprises gelatinizing the starch at a temperature equal to or greater than the gelatinization temperature of the starch (at least about 90°C to approximately 95°C) for at least 10 minutes before adding it to the paste or in the product formulation.
[124] In another embodiment, starch is pressure cooked (eg, by superheating at temperatures above about 100°C) to effect gelatinization of the starch prior to inclusion in the gypsum paste or product formulation.
[125] In another embodiment, the amount of added water that must be dried is less than the amount of water dried when using a pregelatinized starch having a viscosity of more than 700 centipoise otherwise the same slurry or other medium for the formulation of product.
[126] In some embodiments, the board comprises a hardened gypsum core disposed between two cover sheets, the core formed from a paste composed of water, stucco and at least one pregelatinized starch; starch with a cold water solubility greater than about 30%; the hardened gypsum core having a greater compressive strength than a hardened gypsum core made with a starch having a cold water solubility of less than about 30%.
[127] In another embodiment, the core has greater compressive strength than a core made without starch.
[128] In another embodiment, starch has a cold water solubility of about 30% to about 75%.
[129] In another embodiment, starch has a cold water solubility of about 50% to about 75%.
[130] In another embodiment, starch has a viscosity of approximately 20 centipoise to about 300 centipoise.
[131] In another embodiment, starch has a particle size of approximately 100 microns to 400 microns.
[132] In another embodiment, starch is an amount of about 0.1% to about 5% by weight based on the weight of the plaster.
[133] In another embodiment, starch is in an amount of about 0.1% to about 3% by weight based on the weight of the plaster.
[134] In another incarnation, the paste still comprises sodium trimetaphosphate.
[135] In another embodiment, the slurry further comprises naphthalenesulfonate dispersant.
[136] In another embodiment, the board has a density of about 24 pcf (384 kg/m3) to about 35 pcf (561 kg/m3).
[137] In some embodiments, the method of making a board comprises (a) mixing at least water, plaster, and at least one pregelatinized starch to form a paste, (b) disposing the slurry between a first sheet of cover and a second cover sheet to form a wet assembly, (c) cutting the wet assembly into a cutting board and (d) drying the board; starch with a cold water solubility greater than about 30%; the hardened gypsum core having a greater compressive strength than a hardened gypsum core made with a starch having a cold water solubility of less than about 30%.
[138] In some embodiments, the method of making a pregelatinized starch comprises (a) mixing at least water and non-pregelatinized starch to make a wet starch, (b) disposing the wet starch in an extruder having a mold at a temperature of about 90°C or greater and (c) drying the starch; pregelatinized starch having a cold water solubility greater than about 30%.
[139] In another embodiment, the extruder mold is at a temperature of about 150°C or higher.
[140] In another embodiment, wet starch has a water content less than about 25% starch by weight.
[141] In some embodiments, the slurry comprises water, stucco and at least one pregelatinized starch; starch with a cold water solubility greater than about 30%.
[142] In another incarnation, slurry has a drop greater than about 6 inches (15.24 cm).
[143] It should be noted that the foregoing are just examples of modalities. Other exemplary embodiments will be apparent from the entire description here. It will also be understood by one of skill in the art that each of these embodiments can be used in various combinations with the other embodiments presented herein.
[144] The following example further illustrates the invention, but of course it should not be construed as limiting its scope in any way. EXAMPLE 1 - VISCOSITY MEASUREMENT METHOD
[145] This example further defines the viscosity measurement test method, referred to as the "VMA method." When viscosity is referred to herein, it is in accordance with the VMA method, unless otherwise indicated. Viscosity is measured using a Discovery HR-2 Hybrid Rheometer (TA Instruments Ltd) with a concentric cylinder, a standard cup (30mm diameter) with vane geometry (28mm diameter) and 42.05mm length.
[146] When starch is obtained, differential scanning calorimetry (DSC) techniques are used to determine whether the starch is fully gelatinized. It should be noted that even if the starch manufacturer identifies the starch as "fully gelatinized", the DSC step must be used to ensure that the starch is fully gelatinized, for example, to confirm that no retrogradation has occurred. One of two procedures is adopted depending on the temperature needed to fully gelatinize the starch, which can also be determined by DSC, as those skilled in the art will appreciate.
[147] Procedure 1 is used where DSC reveals that the starch is either fully gelatinized or has a gelatinization temperature at or below 90°C. Procedure 2 is used where the gelatinization temperature is above 90°C. Since viscosity is measured while the starch is in water, procedure 2 uses pressure cooking in a sealed container to allow for superheating at temperatures above 100°C without causing the water to appreciably evaporate. Procedure 1 is reserved for already fully gelatinized starches or starches with gelatinization temperature up to 90°C because, as discussed below, gelatinization takes place in the rheometer which is an open system and it is not possible to create pressurized conditions for gelatinization. Thus, procedure 2 is followed for starches with higher gelatinization temperatures. Anyway, starch (7.5 g, dry basis) is added to the water for a total weight of 50 g when the viscosity is measured.
[148] In procedure 1, the starch is dispersed in water (15% of the total weight of water and starch starch) and the sample is immediately transferred to a cylindrical cell. The cell is covered with aluminum foil. The sample is heated from 25°C to 90°C at 5°C/min and a shear rate of 200 s-1. The sample is held at 90°C for 10 min at a shear rate of 200 s-1. The sample is cooled from 90°C to 80°C at 5°C/min and a shear rate of 200 s-1. The sample is held at 80°C for 10 min at a shear rate of 0 s-1. Sample viscosity is measured at 80°C and a shear rate of 100 s-1 for 2 min. Viscosity is the average of the measurement from 30 seconds to 60 seconds.
[149] Procedure 2 is used for starches with a gelatinization temperature greater than 90°C. Starch is gelatinized according to methods known in the starch industry (eg pressure cooking). The gelatinized starch water solution (15% of the total weight) is immediately transferred to the measuring cup of the rheometer and equilibrated at 80°C for 10 minutes. Sample viscosity is measured at 80°C and a shear rate of 100 s-1 for 2 minutes. Viscosity is the average of the measurement from 30 seconds to 60 seconds. EXAMPLE 2- VISCOSITY OF STARCH IN DIFFERENT STATES
[150] This example illustrates the viscosity of starch (in 15% solution in water) in different states. The representative starch tested was hydroxyethyl corn starch (Clineo 706, available from ADM). Referring to FIG. 1, the x-axis reflects time, while the y-axis overlaps torque and temperature. The graph demonstrates how viscosity changes as starch is cooked and ultimately gelatinized. Torque measures the force to turn the rotor and is therefore a measure of viscosity. Torque is in Brabender units.
[151] One skilled in the art will easily recognize Brabender units. For example, briefly, a C.W. Brabender Viscograph can be used, for example, a Viscograph-E which uses reaction torque for dynamic measurement. Viscograph-E is commercially available from C.W. Brabender Instruments, Inc., Hackensack, NJ. Please note that as defined in this document, Brabender units are measured using a 16 FL sample cup size. oz (~500 cc), with a 700 cmg cartridge at a RPM of 75. One of skill in the art will also readily recognize that Brabender units can be converted to other viscosity measurements such as centipoise (eg, cP = BU X 2.1, when the measuring cartridge is 700 cmg) or Krebs units, as described there.
[152] The torque (viscosity) and temperature curves, respectively, are labeled in FIG. 1. With respect to temperature, target and actual temperature overlap each other, but there is no significant difference.
[153] As seen from the viscogram of FIG. 1, the granule, ie the physical structure of native starch, is identified as "cold", at low temperature and "hot" above 80°C. At low temperature, before gelatinization, the viscosity does not appreciably change. As the granule is heated, it will absorb water and swell. Starting at the peak of the torque curve, the granule is hot and swollen enough that the granule structure begins to break down and break apart into loose molecules. As the granular structure breaks down, the viscosity decreases until the starch is fully gelatinized, as shown in the trough on the curve. As the curve stagnates in the trough, the solution is cooled. As a result, retrogradation occurs when the gelatinized molecule starts to reassociate and the viscosity starts to increase again. EXAMPLE 3 - CUBE FORMULATION AND COMPRESSION RESISTANCE TEST
[154] This example describes cube compression tests using a 2 inch (5.08 centimeter) cube. In some embodiments, the compression cube test measures a gypsum formulation where the starch and its amount can vary as described in this document. The formulation is formed from a gypsum slurry which is hardened with an inlet to the water/stucco ratio of 1.0, with the amount of starch set to 2% by weight of plaster, unless otherwise indicated.
[155] For starch that requires gelatinization in the laboratory (eg all Clinton series, Clineo series, S23F, LC211, identified below) starch: starch was dispersed in water and heated to boiling for 10 min with continuous stirring. The starch solution was then cooled to 78°F (25.6°C) and transferred to the mixing cup of a Waring blender. 10% sodium trimetaphosphate solution ("SMTP"), dispersant and retarder were weighed into starch solution and mixed. Stucco and HRA were weighed and mixed as a dry mix. The dry mix of stucco and HRA was poured into the starch solution, soaked in water for 10 seconds and mixed at high speed for 10 seconds. 2-inch (5.08 cm) cube molds were filled to a point slightly above the tops of the molds. The excess was scraped off as soon as the gypsum hardened. The cubes were removed from the molds, after which they hardened. The cubes were dried at 110°F (43.3°C) for 48 hours.
[156] Water-soluble starches (eg, extruded hydroxypopyl pea starch, Maltrin M040, Maltrin M100, identified below): starch was dissolved in water at room temperature. Follow the same procedure for starch requiring gelatinization in the laboratory except skipping heating and cooling steps. Alternatively, soluble starch can be prepared in a dry mix with stucco and heat resistant accelerator, then mixed with liquid ingredients (water, SMTP, dispersant and retarder).
[157] For granular starch: starch was weighed into dry mix (stucco and HRA). Water, 10% sodium trimetaphosphate solution, dispersant and retarder were weighed into the mixing cup. The dry mix was poured into water, soaked in water for 10 seconds, mixed at high speed for 10 seconds and the slurry immediately poured into the mold. The damp cube was wrapped in aluminum foil as it hardened. The wrapped cube was heated to 190°C (87.8°C) for 90 min. The cube was unwrapped and dried at 110°F (43.3°C) for 48 hours
[158] The gypsum slurry formulation to form the cube is described below in Table 3. Table 3 Gypsum Slurry Formulation with 2% Starch, 1.0 WSR

[159] The dried cubes were removed from the oven and cooled at room temperature for 1 hour. Compressive strength was measured using an MTS system (model # SATEC). The load is applied continuously and without a shock at a speed of 0.04 in/min (1.02 mm/min) (with a constant rate between 15 to 40 psi/s (103.4 to 275.8 kPa/s)).
[160] A cube was produced using extruded hydroxypropyl pea starch (Tackidex ® K720 (Roquette)) by dissolving the starch in water at room temperature, where the cube had a strength of 2106 psi (14.52 MPa). A cube was produced using extruded hydroxypropyl pea starch (Tackidex ® K720 (Roquette)), preparing the starch in a dry mix with stucco and heat resistant accelerator, which was then mixed with the liquid ingredients (water, SMTP, dispersant and retarder). ), where the hub had a strength of 2084 psi (14.37 MPa). EXAMPLE 4 - EFFECT OF ADDING GELATINIZED STARCH IN STUCCO PASTE ON STRENGTH
[161] This example compares the effect of adding granular (i.e., non-gelatinized) starch to stucco paste with addition of gelatinized starch to stucco paste on the respective compressive strengths of gypsum formulations. Each starch was placed in a cube test gypsum slurry as described in example 3.
[162] Additional starches are shown in table 4. One of the starches was not acid-modified, while the others were as indicated in table 4, below. Table 4: Effect of Starch State (Granulated or Pre-gelatinized) on Resistance

[163] This example illustrates the enhanced strength achieved with the entry of pregelatinized starch into a gypsum slurry rather than a granulated starch in accordance with the embodiments of the invention. Granular form provides good fluidity to the stucco paste due to the very low viscosity of granulated starch. However, the granular form does not provide such good strength. Thus, the pregelatinized form is desirable. EXAMPLE 5-VISCOSITY AND COMPRESSION RESISTANCE TO GELATINIZED STARCH
[164] This example illustrates different gelatinized starches that represent a range of viscosities, measured according to the VMA method. The effect on the compressive strength of a gypsum formulation of each of the starches was evaluated, according to the formulation and the cube test defined in example 3. Results showing the viscosity of gelatinized starch and the compressive strength of gypsum cubes formed from slurries comprising the starches are described below in table 5. Table 5: Viscosity and Strength for Gelatinized Starch


[165] Some of the starches were supplied commercially in an already gelatinized form and these starches are marked as gelatinized "during manufacture" in table 5. Other starches were supplied without gelatinization but were then gelatinized in the laboratory as marked "in the laboratory "in table 5. In addition, some of the starches were chemically modified to achieve the indicated viscosity as noted. With respect to extruded hydroxypropyl pea starch, while not wishing to be limited to any particular theory, the low viscosity may be due to starch hydrolysis by high pressure high shear extrusion combined with hydroxypropylation and the high amylose content (35%). Each viscosity indicated is after gelatinization of the starch.
[166] This example demonstrates the suitability of gelatinized starch having a medium viscosity, as defined herein, in a cementitious slurry (eg, gypsum) in accordance with the embodiments of the invention. Medium viscosity starches provide good flowability, as reflected by the starch's viscosity, and also achieve desirable strength properties. Good fluidity results in low water demand in the gypsum slurry. By including less water in the gypsum paste, less excess water must be dried out during fabrication, resulting in improved process efficiency and reduced fabrication costs. EXAMPLE 6 - GELATINIZATION AND VISCOSITY OF ETHYLATED STARCH
[167] This example compares ethylated starches exhibiting a range of viscosities after gelatinization. The effect on the strength of a gypsum formulation, taking into account the addition of gelatinized and granulated (non-gelatinized) starch, respectively, to the stucco paste was also evaluated according to the formulation and the cube test set out in example 3 Results showing the viscosity of gelatinized starch and the compressive strength of gypsum cubes formed from slurries comprising the starches are described below in table 6. Each viscosity indicated is after gelatinization of the starch, but the strength taking into account the addition of granular starch (non-gelatinized starch) in the stucco paste is also included in the data. Table 6: Viscosity and Strength of Ethyl Starches

[168] While not wishing to be bound by any particular theory, ethylation lowers the gelatinization temperature of starch. These ethylated starches can be partially hydrolyzed to the proper viscosity.
[169] This example shows that these ethylated starches having medium viscosity after gelatinization as described herein provide desirable fluidity and strength when included in a gypsum formulation in accordance with embodiments of the invention. EXAMPLE 7 - VARIATION IN AMOUNT OF STARCH IN RESISTANCE
[170] This example compares the effect of gelatinized starch on the strength of a gypsum formulation, across a range of amounts of starch to be placed in the gypsum slurry. The formulation and cube test set out in example 3 were used, except that the amount of starch was varied. The results are shown in Table 7. Table 7: Strength (PSI) vs Starch Content in Gypsum Formulation (wt% stucco)

[171] This example demonstrates that even relatively small amounts of gelatinized starch provide desirable strength properties in the gypsum formulation in accordance with embodiments of the invention. EXAMPLE 8 - FLUIDITY OF THE GIPSITE FOLDER
[172] This example illustrates the effect on gypsum slurry flowability of various gelatinized starches. Each starch was placed in a gypsum formulation according to example 3, except that the water/stucco ratio and the amount of starch were varied. A drop test was used to measure fluidity as follows. The drop was measured by pouring slurry into a 2 inch (5.08 cm) diameter cylinder that is 4" high (10.2 cm) (open at each end and placed end on a smooth flat surface) and leveling the top of the slurry out. This provides a defined volume of slurry for each test. Then the cylinder was immediately lifted and the slurry ran out of the open lower end of the cylinder. The diameter of this amount is measured in centimeters and noted. A more fluid slurry will usually result in a larger diameter amount. The results are shown in Table 8. Table 8. Strength (PSI) vs Starch Content in Gypsum Formulation (wt% Stucco)


[173] This example demonstrates the higher fluidity and lower water demand of gypsum formulations in accordance with the embodiments of the invention. EXAMPLE 9 - ACID-MODIFICATION OF PRE-GELATINIZED CORN FLOUR IN THE DRY STATE
[174] This example demonstrates the reduction in viscosity of pregelatinized cornmeal by acid-modified dry state. Pregelatinized cornmeal (125 g, Bunge Milling) was weighed into a mixing bowl and a Hobart mixer. The top of the cornmeal was sprayed with 1M sulfuric acid (6.2 to 18 g) while mixing at speed 2. The sample was mixed for a further 10 minutes. The sample was transferred to a plastic bottle with a lid and then heated to 80°C for 3h. An equal mole of calcium hydroxide was added, and the sample was mixed for 2 min. The sample was dried at room temperature overnight.
[175] Viscosities of acid-modified pregelatinized cornmeal were measured according to the VMA method as described in example 1. Data are shown in table 9. Table 9
EXAMPLE 10- FORMULATION OF GIPSITE PASTE, RESISTANCE TO CUBE COMPRESSION AND FLUID PASTE FALL TEST
[176] This example describes the cube and sag compression strength using acid-modified starches using different amounts of acid. The gypsum slurry formulation used is shown in table 3. The stucco water ratio (WSR) was 1.0. Sample gypsum cubes were prepared according to the method of example 3. The drop test was followed as described in example 8. Results of the compressive strength test and the drop test are shown in table 10. Table 10

[177] This example demonstrates that reducing the viscosity of pregelatinized cornmeal to a medium level not only generally increases gypsum slurry fluidity, but also generally increases compressive strength. The combination of examples 9 and 10 demonstrates the inverse relationship between starch viscosity and slurry flow. EXAMPLE 11 - ACID-MODIFICATION OF PRE-GELATINIZED CORN FLOUR IN 0.25N SULFURIC ACID SOLUTION
[178] This example describes cube and shear compressive strength using acid-modified starches using different acid exposure times. Pregelatinized cornmeal (31 g) was weighed into a Warren blender containing water (200 g) while mixing took place. The starch solution was transferred to a flask. The blender was rinsed with water (77 g) and the water transferred to the jar. Concentrated sulfuric acid (95-98%, 1.94 ml) was added to the starch solution with stirring. The solution was incubated at 70°C for 60 to 100 min. An equal mole of calcium hydroxide (2.58 g) was then added to the starch solution and stirred for 10 min. The formulation of the gypsum slurry used is shown in table 3. Sample gypsum cubes were prepared according to the method of example 3. The drop test was followed as described in example 8. Compressive strength test results and the drop tests are shown in table 11. Table 11


[179] This example shows that acid-modifying pregelatinized cornmeal in sulfuric acid solution can improve flowability and strength. EXAMPLE 12 - FLUIDITY OF GIPSITE PASTE IN DIFFERENT WATER AND STUCCO RATIO (WSR)
[180] This example illustrates the effect on fluidity of gypsum paste by acid-modifying pregelatinized cornmeal. A drop test was used to measure the flowability as described in example 8. The gypsum slurry formulation used is shown in table 3, except that the water quantity was adjusted according to WSR. The results of the drop test are shown in Table 12. Table 12

[181] This example demonstrates that acid-modified pregelatinized cornmeal can maintain the fluidity of the gypsum slurry even after the water has been reduced by 15%. EXAMPLE 13 - CUBE FORMULATION AND COMPRESSION RESISTANCE TEST
[182] This example describes cube cube compressive strength testing comprising a lab-cooked acid-modified starch. The formulation is formed from a gypsum slurry that has a water/stucco ratio of 1.0 for the control pregelatinized corn starch and 0.9 for laboratory-cooked acid-modified corn starch (Clinton 277), with the amount of starch fixed to 2% by weight of stucco. The formulation used for the control and acid-modified lab-cooked corn starch is shown in Table 13. The cube density was set between 25 and 45 pounds cubic feet (400 kg/m3 and 721 kg/m 33) by addition of foam at different rates.
[183] For the control experiment, pregelatinized cornstarch was weighed into a dry mix, comprising HRA and stucco. Water, 10% sodium trimetaphosphate solution, dispersant and retarder were weighed into the mixing vessel of a Hobart Mixer. The dry mix was poured into the Hobart Mixer container, soaked in water for 15 seconds and mixed at speed II for 30 seconds. For foam preparation, a 0.5% solution of PFM 33 soap was formed and then mixed with air to make the air foam. Foam air was added to the slurry using a foam generator. The foam generator was run at a rate sufficient to obtain the desired plate density. After addition of foam, the slurry was immediately poured to a point slightly above the tops of the molds. The excess was scraped off as soon as the gypsum hardened. The molds had been sprayed with mold release (DW40).
[184] To make acid-modified lab-cooked cornstarch (Clinton 277), acid-modified cornstarch was dispersed in water and heated to boiling for 10 min with continuous stirring. The starch solution was then cooled to 78°F (25°C) and transferred to the vessel of a Hobart Mixer. 10% sodium trimetaphosphate solution, dispersant and retarder were added to the Hobart Mixer container and mixed. The dry mix of stucco and HRA was poured into the starch solution, soaked in water for 15 seconds and mixed at speed II for 30 seconds. For foam preparation, a 0.5% solution of PFM 33 soap was formed and then mixed with air to make the air foam. Foam air was added to the slurry using a foam generator. The foam generator was run at a rate sufficient to obtain the desired plate density. After addition of foam, the slurry was immediately poured to a point slightly above the tops of the molds. The excess was scraped off as soon as the gypsum hardened. The molds had been sprayed with mold release (DW40).
[185] After the cubes had hardened, the cubes were removed from the mold and then dried at 110°F (43°C) for 48 hours. After removing from the oven, the cubes were left to cool at room temperature for 1 hour. Compressive strength was measured using an MTS system (model # SATEC). The load was applied continuously and without a shock at a speed of 0.04 in/min (1.02 mm/min) (with a constant rate between 15 to 40 psi/s (103.4 to 275.8 kPa/s)). Table 13

[186] Traces for the two types of starch are shown in FIG. 2, where density is plotted along the horizontal axis and strength is plotted along the vertical axis. FIG. 2 shows that acid modified lab-boiled corn starch (Clinton 277) with a WSR of 0.9 provides greater compressive strength cubes than pregelatinized corn starch having a WSR of 1.0. This increase in strength was observed for hub densities from 25 lb/ft3 to 40 lb/ft3 (400 kg/m3 to 721 kg/m3). This example suggests that compositions comprising acid modified lab-boiled corn starch (Clinton 277) have greater compressive strength at low density and require less water. EXAMPLE 14 - PRE-GELATINIZED COLD WATER SOLUBLE STARCH AND COMPRESSION RESISTANCE
[187] This example describes a method of forming pregelatinized cold water soluble starch (Clinton 277) using pilot scale extrusion and compressive strength cubes comprising extruded pregelatinized starch.
[188] Accordingly, Clinton 277 acid-modified starch (9% moisture content, 100 kg) and water (4.4 kg) were mixed in a cylinder. The acid-modified starch mixture was added to a Wenger TX 52 Twin Screw extruder. Additional water (8.1 kg) was added to the extruder. The total moisture content in the extruder barrel was 20%. Extrusion conditions are described below in Table 15. The pregelatinized starch was removed from the extruder as a relatively dry, expanded material. The starch was dried until it had a moisture content of about 10% and then ground into a powder. When used to make gypsum products, dry powder can be added to dry ingredients during manufacture. Table 14

[189] The cold water solubility of pregelatinized starch is measured by the following method. A wet starch was formed by adding water (80 mL, room temperature (25°C)) and dry starch (4,000 g) to a stirred beaker. The wet starch was stirred for 20 min and then transferred to a 100 ml graduated cylinder. Water was added up to the 100 mL line, and then the cylinder was inverted three times to mix the slurry. The wet starch was left to stand for 30 min at room temperature. The supernatant (10g) was transferred from the top of the slurry to a tared pan. After the pan was heated overnight (43°C), the remaining solids were weighed. The solubility (%) of starch is established in the equation below.
[190] Solubility (%) = weight of soluble solid/(0.4 x 100)
[191] Pregelatinized extruded cold water soluble starch was used to prepare cubes according to the procedure of example 13. The cubes had a density of 54 lb/ft3 (865 kg/m3). The cold water solubility of extruded starch (Clinton 277) showed a significant impact on cube strength (Table 15). Granular starch is insoluble in water and produces a cube with a compressive strength of 1561 psi (10.76 MPa). However, pregelatinized starches prepared by extrusion were water soluble and yielded cubes with more strength. The compressive strength of the cubes increased as the cold water solubility of the starch increased. In addition, starting with a starch with a lower moisture content (about 10%) resulted in greater water solubility (up to 71%) and yielded a cube with greater compressive strength (1844 psi (12.71 MPa)). Table 15

[192] Pregelatinized cold water soluble acid modified starch and pregelatinized corn starch were used to prepare cubes according to the procedure of example 13. The cubes had a density of 29 lb/ft3 (465 kg/ m3). The extruded starch gave greater cube strength than conventional starch (Table 16). The fluidity of gypsum foam slurry containing extruded Clinton 277 was increased by 26% and the compressive strength of the foamed cube containing extruded starch was increased by 19%. Table 16
EXAMPLE 15 - PREPARATION OF PRE-GELATINIZED STARCH BENCH SOLUBLE IN COLD WATER
[193] This example illustrates the cold water solubility of pregelatinized acid-modified starch (Clinton 277) made by bench scale extrusion under various conditions.
[194] Accordingly, acid-modified starch was extruded using a bench scale extruder (Micro 18, Leistritz MIC). Starch and water required for the designated moisture content were mixed, sealed in a plastic bag and balanced overnight. After equilibration overnight, the wet starch was fed to the extruder. The effect of extruder temperature, starch moisture content (before gelatinization), mold opening size and amount of tricalcium phosphate on solubility at 25°C was analyzed (see table 17). On a small scale, additive (tricalcium phosphate) did not affect starch solubility. Factors increasing material fluidity (such as a high moisture content and wide mold opening) were negatively related to starch solubility. Large-scale testing has been found to require higher extrusion temperatures and lower moisture content (eg, example 14). Table 17
EXAMPLE 16 - COLD WATER VISCOSITY TEST METHOD
[195] This example establishes the method of testing cold water viscosity measurements, referred to as the "CWVA method". When cold water viscosity is referred to in this document, it is in accordance with the CWVA method, unless otherwise indicated.
[196] Dry starch (40 g) is weighed into water (25°C) to obtain a total weight of 400 g, stirring at 500 RPM for 10 min. Viscosity is measured using a Discovery HR-2 Hybrid Rheometer (TA Instruments Ltd) with a concentric cylinder and a standard cup (30mm diameter) with vane geometry (28mm diameter) and 42.05mm length. A 50 g solution is transferred to the cylindrical cell. Sample viscosity is measured at 25°C and at a shear rate of 100 s-1 for 1 minute.
[197] The use of the terms "a" and "the" and "at least one" and similar references in the context of describing the invention (especially in the context of the claims below) is to be interpreted in the meaning to cover both the singular and the plural, unless otherwise indicated in this document or in case of clear contradiction by the context. The use of the term "at least one" followed by a list of one or more items (eg "at least one of A and B") should be interpreted to mean an item selected from listed items (A or B) or any combination of two or more of the items listed (A and B), unless otherwise indicated in this document or clearly contradicted by context. The terms "comprising", "having", "including" and "containing" shall be interpreted as open terms (ie, meaning "including, but not limited to") unless otherwise indicated. Recitation of the ranges of values in this document are only intended to serve as a simplified method of referring individually to each separate value included in the range, unless otherwise indicated in this document, and each separate value is incorporated into the descriptive report as if it had been individually cited. in this document. All methods described herein may be carried out in any appropriate order, unless otherwise indicated in this document or in cases of clear contradiction by context. The use of any and all examples, or exemplary language (eg, "as") presented herein, is intended only to further illuminate the invention and does not represent a limitation on the scope of the invention, unless otherwise claimed. No language used in the descriptive report should be interpreted as indicating any element not claimed to be essential to the practice of the invention.
[198] Preferred embodiments of this invention are described herein, including the best mode known to inventors for carrying out the invention. Variations from these preferred embodiments may become apparent to those skilled in the art upon reading the above description. The inventors expect persons of skill to employ such variations as the case may be, and the inventors intend that the invention be practiced other than as specifically described herein. Accordingly, this invention includes all modifications and equivalents to the subject matter recited in the claim added herein as permitted by applicable law. Furthermore, any combinations of the above-described elements in all respective possible variations are encompassed by the invention, unless otherwise indicated herein or otherwise clearly contradicted by the context.

权利要求:
Claims (19)
[0001]
1. Board, CHARACTERIZED by the fact that it comprises: a core of hardened gypsum disposed between two covering sheets, the core formed from a slurry comprising stucco, water and at least one starch modified with pregelatinized acid, in which the pregelatinized acid modified starch has a characteristic of a viscosity of 20 centipoise to 500 centipoise (0.02 Pa.s to 0.5 Pa.s) when the viscosity is measured while the pregelatinized acid modified starch is subjected the conditions according to the VMA method, wherein the pregelatinized acid-modified starch is in an amount of 0.5% to 5% by weight of the plaster; the board having a core hardness of at least 11 lb (5 kg), as determined in accordance with ASTM C473-10.
[0002]
2. Plate according to claim 1, CHARACTERIZED by the fact that the characteristic viscosity of starch modified with pregelatinized acid is from 30 centipoise to 200 centipoise (0.03 Pa^s to 0.2 Pa^s) according to with the VMA method.
[0003]
3. Plate according to claim 1, CHARACTERIZED by the fact that pregelatinized acid-modified starch is effective in increasing the core hardness of the hardened gypsum core relative to the hardened gypsum core without the acid-modified starch pregelatinized.
[0004]
4. Board, according to claim 1, CHARACTERIZED by the fact that the starch is in an amount of 0.5% to 3% by weight of the plaster.
[0005]
5. Plate, according to any one of claims 1 to 3, CHARACTERIZED by the fact that the water/stucco ratio is from 0.55 to 0.8.
[0006]
6. Plate according to claim 1, CHARACTERIZED by the fact that the plate has a density of 24 pcf (384 kg/m3) to 35 pcf (561 kg/m3).
[0007]
7. Plate, according to claim 1, CHARACTERIZED by the fact that the slurry comprises a second type of starch which is (a) non-gelatinized, (b) is a pre-gelatinized starch having the characteristic of a viscosity below 20 centipoise (0.02 Pa.s) according to the VMA method, or (c) is a pregelatinized starch having the characteristic of viscosity above 500 centipoise (0.5 Pa.s) according to the VMA method .
[0008]
8. Plate according to claim 7, CHARACTERIZED by the fact that the second type of starch comprises alkylated starch.
[0009]
9. A board, according to claim 1, CHARACTERIZED by the fact that the slurry further comprises at least foaming agent comprising a larger weight portion of unstable component and a smaller weight portion of stable component.
[0010]
10. Plate, according to claim 1, CHARACTERIZED by the fact that the slurry further comprises naphthalenesulfonate dispersant.
[0011]
11. Plate, according to claim 1, CHARACTERIZED by the fact that the slurry further comprises sodium trimetaphosphate.
[0012]
12. Plate according to claim 1, CHARACTERIZED by the fact that when the plate is converted to a thickness of % inch (1.3 cm), the plate has a nail tensile strength of at least 65 pounds (29 .5 kg) and has a core hardness of at least 11 lb (5 kg) as determined in accordance with ASTM C473 standard.
[0013]
13. Slurry, CHARACTERIZED by the fact that it comprises water, stucco, and at least one starch modified with pregelatinized acid, wherein the starch modified with pregelatinized acid has a viscosity characteristic of 20 centipoise to 500 centipoise (0 .02 Pa.s to 0.5 Pa.s) when the viscosity is measured while the starch is subjected to the conditions according to the VMA method, where the starch modified with pregelatinized acid is in an amount of 0.5% to 3% by weight of the plaster; wherein when the slurry is used to make a board, the board has a core hardness of at least 11 lb (5 kg), as determined in accordance with ASTM C473-10.
[0014]
14. Method for making board, CHARACTERIZED in that it comprises: (a) mixing at least water, stucco, and at least one modified starch with pregelatinized acid to form a slurry, wherein the starch has a characteristic of a viscosity from 20 centipoise to 500 centipoise (0.02 Pa.s to 0.5 Pa.s) when the viscosity is measured according to the VMA method; wherein the pregelatinized acid-modified starch is in an amount of 0.5% to 3% by weight of the plaster; (b) disposing the slurry between a first cover sheet and a second cover sheet to form a wet assembly; (c) cut the wet assembly into a board; and (d) drying the board, the board having a core hardness of at least 11 lb (5 kg), as determined in accordance with ASTM C473-10.
[0015]
15. Board, CHARACTERIZED in that it comprises: a core of hardened gypsum disposed between two cover sheets, the core formed from a slurry comprising stucco, water and at least one extruded pregelatinized starch, wherein the starch Extruded pregelatinized is formed by the modification and extrusion of a wet starch having a water content of less than 25%, wherein the modification at least partially hydrolyses the starch by means of acidic and/or enzymatic modification; the extruded pregelatinized starch having a cold water solubility greater than 30% when measured at 25°C and a cold water viscosity of a slurry of 10% by weight of the extruded pregelatinized starch in water when measured at 25°C C e at a shear rate of 100 s-1 for 1 min is 120 centipoise to 300 centipoise (0.12 Pa^s to 0.3 Pa^s); the board having a core hardness of at least 11 lb (5 kg), as determined in accordance with ASTM C473-10.
[0016]
16. Plate according to claim 15, CHARACTERIZED by the fact that extruded pregelatinized starch has a cold water solubility of 30% to 75%.
[0017]
17. The board according to claim 15, CHARACTERIZED by the fact that the extruded pregelatinized starch is in an amount of 0.1% to 5% by weight based on the weight of the plaster.
[0018]
18. Plate according to any one of claims 15 to 17, CHARACTERIZED by the fact that the plate has a density of 24 pcf (384 kg/m3) to 35 pcf. (561 kg/m3).
[0019]
19. Method of making a board, CHARACTERIZED in that it comprises: (a) mixing at least water, plaster, and at least one extruded pregelatinized starch to form a slurry, wherein the extruded pregelatinized starch is formed by the modification and extrusion of a wet starch having a water content of less than 25%, wherein the modification at least partially hydrolyses the starch by means of acidic and/or enzymatic modification, the extruded pregelatinized starch having a cold water solubility greater than 30% when measured at 25°C and a cold water viscosity of a slurry of 10% by weight pregelatinized starch extruded in water when measured at 25°C and a shear rate of 100 s-1 per 1 min is 120 centipoise to 300 centipoise (0.12 Pa^s to 0.3 Pa^s); (b) disposing the slurry between a first cover sheet and a second cover sheet to form a wet assembly; (c) cut the wet assembly into a board; and (d) drying the plate; starch having a cold water solubility greater than 30%; the board having a core hardness of at least 11 lb (5 kg), as determined in accordance with ASTM C473-10.

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同族专利:

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公开号 | 公开日

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CN105121475B|2018-04-13|

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AU2020200531A1|2020-02-13|

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EP2912071B1|2020-05-27|

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CN106673579B|2020-03-03|

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MX2019013822A|2020-01-15|

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JP6659768B2|2020-03-04|

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RU2015117913A|2016-12-10|

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KR20150077437A|2015-07-07|

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KR102299954B1|2021-09-10|

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US11168030B2|2021-11-09|

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NZ707559A|2019-03-29|

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AU2013335106B2|2018-03-08|

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PE20200087A1|2020-01-15|

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AU2018203602A1|2018-06-14|

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CN106673579A|2017-05-17|

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TW201416225A|2014-05-01|

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HUE051627T2|2021-03-01|

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EP2912071A2|2015-09-02|

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LT2912071T|2020-09-10|

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TWI623418B|2018-05-11|

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PE20151033A1|2015-08-19|

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RU2641350C2|2018-01-17|

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UA118442C2|2019-01-25|

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HRP20201112T1|2020-10-30|

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US20140113128A1|2014-04-24|

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ES2806682T3|2021-02-18|

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CA2887346A1|2014-05-01|

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ZA201503140B|2016-01-27|

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CA3112254A1|2014-05-01|

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EP3650471A1|2020-05-13|

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US9540810B2|2017-01-10|

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US20170073272A1|2017-03-16|

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BR112015008774A2|2017-07-04|

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AU2018203602B9|2021-02-18|

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PT2912071T|2020-07-27|

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CN105121475A|2015-12-02|

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JP2016500639A|2016-01-14|

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WO2014066079A2|2014-05-01|

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US20180339944A1|2018-11-29|

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MY175888A|2020-07-14|

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JP6346186B2|2018-06-20|

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AU2013335106A1|2015-05-21|

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CA2887346C|2021-05-04|

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US10464847B2|2019-11-05|

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MX2015004978A|2015-07-17|

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JP2018150237A|2018-09-27|

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AR093072A1|2015-05-13|

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AU2020200532A1|2020-02-13|

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NZ747277A|2020-03-27|

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UA123320C2|2021-03-17|

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AU2018203602B2|2021-02-11|

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MX369731B|2019-11-20|

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DK2912071T3|2020-07-27|

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CL2015000989A1|2015-09-04|

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WO2014066079A3|2015-10-08|

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PL2912071T3|2020-11-16|

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法律状态:
2018-03-06| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|

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2018-03-13| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|

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2018-03-20| B06I| Publication of requirement cancelled [chapter 6.9 patent gazette]|Free format text: ANULADA A PUBLICACAO CODIGO 6.6.1 NA RPI NO 2462 DE 13/03/2018 POR TER SIDO INDEVIDA. |

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2020-05-26| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|

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2021-02-02| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|

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2021-05-25| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

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2021-07-20| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 14/10/2013, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

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申请号 | 申请日 | 专利标题

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US201261717588P| true| 2012-10-23|2012-10-23|

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US61/717,588|2012-10-23|

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US13/835,002|2013-03-15|

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US14/044,582|2013-10-02|

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US14/044,582|US9540810B2|2012-10-23|2013-10-02|Pregelatinized starch with mid-range viscosity, and product, slurry and methods related thereto|

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PCT/US2013/064776|WO2014066079A2|2012-10-23|2013-10-14|Pregelatinized starch with mid-range viscosity, and product, slurry and methods related thereto|

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