FOAM ELEMENT IN WHICH INCORPORATES CELLULOSE.

专利摘要:
The invention relates to a foam element provided with a hydrophilic substance incorporated into the foam in the form of cellulose, the structure of which is based on the crystalline modification of cellulose-II, and to a foam element incorporating the cellulose having a reversible ability to absorb moisture. A proportion of the cellulose is between 0.1% by weight and 10% by weight. A humidity value of the foam corresponding to equilibrium humidity in a first ambient atmosphere is increased during use in a second ambient atmosphere. The moisture absorbed by the cellulose II after use evaporates again during a period ranging from 1 hour to 16 hours until the initial value of the humidity of the foam corresponding to the humidity of balance of the first ambient atmosphere is restored.
公开号:BE1019634A3
申请号:E2010/0032
申请日:2010-01-21
公开日:2012-09-04
发明作者:Josef Innerlohinger；Manfred Marchgraber
申请人:Eurofoam Gmbh；
IPC主号:

专利说明:

FOAM ELEMENT IN WHICH IS INCORPORATED FROM THE
CELLULOSE
The invention relates to a foam element having a hydrophilic agent in the form of cellulose incorporated in the foam, and to a foam element replaced by cellulose having a reversible capacity to absorb moisture, as described in Claims 1 to 3.
At present, foams are used or used in many areas of daily life. For many of these applications, the foams are in contact with the body and are generally simply separated by one or more intermediate layers of textiles. Most of these foams are made from synthetic polymers such as polyurethane (PU), polystyrene (PS), synthetic rubber, etc., which, in principle, do not show adequate water absorption capacity. Especially when the mosses are in contact with the body for a long period of time or during an energetic physical effort, there is the appearance of an unpleasant physical sensation due to the large amount of moisture that is not absorbed. Therefore, for most applications, it is necessary that hydrophilic properties are provided to these foams.
This can be done in a variety of ways. One possibility, as described in patent application DE 199 30 526 A, for example, is to give the foam the structure of a flexible hydrophilic polyurethane foam. This is achieved by reacting at least one polyisocyanate with at least one compound containing at least two bonds that react with isocyanate in the presence of sulfonic acids containing one or more hydroxyl groups, and / or their salts and / or polyalkylene ethers. glycol catalysed by monools. These foams are used for the manufacture of household sponges or hygiene articles.
Another possibility is described in patent application DE 101 16 757 A1, based on an open-celled aliphatic polymeric hydrophilic foam having a separate additional layer made from cellulose fibers in which a hydrogel is housed, which serves as storage medium.
The patent EP 0 793 681 B1 and the German translation of the patent DE 695 10 953 T2 describe a process for the production of flexible foams, for which hyperabsorbent polymers (SAPs), also known as hydrogels, are employed. The SAPs that are used can be premixed with the prepolymer, which makes the process very simple for the foam manufacturer. These SAPs can be selected from SAPs grafted with starch or cellulose using acrylonitrile, acrylic acid or acrylamide as the unsaturated monomer, for example. These SAPs are marketed by Höchst / Cassella under the brand name SANWET IM7000.
The text of patent WO 96/31555 A2 describes a foam with a cellular structure; this foam also contains hyperabsorbent polymers (SAPs). According to this embodiment, SAP can be made from a synthetic polymer or, alternatively, from cellulose. The foam employed in this embodiment is intended to absorb moisture and fluids and retain them in the foam structure.
The text of patent WO 2007/135069 A1 describes shoe soles having properties that absorb water. According to this embodiment, the water-absorbing polymers are added before proceeding to the foaming stage of the plastic. These water-absorbing polymers are generally manufactured by polymerizing an aqueous monomeric solution and then optionally crushing the hydrogel. The water-absorbing polymer and the dry hydrogel made therefrom are then milled and screened once they have been produced, and the particle sizes of the dry and screened hydrogel are preferably lower at 1000 pm and preferably above 10 pm. In addition to the hydrogel, a filler may also be added and blended prior to the foaming process, in which case the organic fillers that may be employed include coal black, melamine, rosin and cellulose fibers, polyamide, polyacrylonitrile, polyurethane or polyester based on the principle of aromatic and / or aliphatic dicarboxylic acid esters and carbon fibers, for example. All substances are added to the reaction mixture separately from one another to produce the foam element.
With respect to their properties, prior art foams are designed to be able to store and retain the moisture they absorb over a long period of time. Absorbed moisture and absorbed water are not restored to the original state due to evaporation of moisture in the ambient atmosphere over a period of up to 24 hours, such as explained in WO 2007/135069 Al.
This rate of evaporation is much too slow in normal applications, such as in the case of mattresses, shoe insoles or car seats, for example, which are used for several hours a day and therefore , which have less than 24 hours to evaporate the absorbed moisture. In this context, one can speak of equilibrium moisture and the value of humidity is that at which the foam is in equilibrium with the humidity contained in the ambient atmosphere.
Likewise, the underlying purpose of the present invention is to provide a foam element which contains a material to improve moisture control in terms of evaporation rate but which is also easy to produce at the time of the invention. manufacture of the foam.
This object is achieved by the present invention by means of the features which are defined in claim 1. The advantage of the features defined in claim 1 lies in the fact that the addition of cellulose to the structure of the foam gives it Ability to absorb moisture and fluids sufficiently. important; however, moisture or absorbed fluids vaporize very quickly in the ambient atmosphere from the state induced by use, thereby restoring equilibrium moisture. The use of cellulose-II makes it possible to avoid having to use a material with a fibrous structure, which makes it easier to pour and which makes it possible to prevent the fibers from getting caught between them. The evaporation time depends on the desired purpose or area of application of the foam element and equilibrium moisture should be restored, if possible, within 16 hours of use in the case of mattress, for example. In the case of shoe soles or insoles of shoes, this time can be even shorter. For this reason, a certain amount of cellulose is added as a hydrophilic substance, which is added and mixed at the same time as one of the foam-forming components during the foam manufacturing process. Not only does cellulose provide sufficient storage capacity, but it also causes rapid evaporation of moisture absorption when returning to an ambient environment. Depending on the proportion of added cellulose, the absorption capacity and evaporation rate of the foam element can be easily adapted to suit a range of different applications.
Independently of what is said above, the object of the invention can also be achieved on the basis of the features which are defined in claim 2. The advantage of the features defined in claim 2 lies in the fact that the addition of cellulose to the structure of the foam provides it with a sufficiently high capacity for absorbing moisture and fluids; however, moisture or absorbed fluids vaporize very quickly in the ambient atmosphere from the state induced by use, thereby restoring equilibrium moisture. Because of the special combination of cellulose-II addition and density values obtained, there is a very high absorption of water vapor and moisture absorption. Due to the significant value of temporary storage of moisture, or water, which can be absorbed into the foam element during use, the user is sure to experience a pleasant and dry sensation during the 'use. As a result, the body does not come into direct contact with moisture.
Independently of what is said above, the object of the invention can also be achieved on the basis of the features which are defined in claim 3. The advantage of the features defined in claim 3 lies in the fact that the addition of cellulose to the structure of the foam provides it with a sufficiently high capacity for absorbing moisture and fluids; however, moisture or absorbed fluids vaporize very quickly in the ambient atmosphere from the state induced by use, thereby restoring equilibrium moisture. Because of the special combination of cellulose-II addition and density values obtained, there is a very high absorption of water vapor and moisture absorption. As a result, the moisture absorbed by the foam element evaporates quickly while it remains comfortable to use. This is the case even after it has absorbed a significant amount of moisture, it can be used again even after a relatively short time and a dry foam element is quickly ready for a new use. .
An additional advantage lies in another embodiment given in claim 4, characterized in that depending on the structure of the foam resulting from the plastic foam, the length of the fibers can be determined so as to ensure optimum transport of moisture, which allows for both rapid absorption and rapid evaporation after use.
An exemplary embodiment defined in claim 5 is also advantageous since it makes it possible to achieve a much more precise distribution of the cellulose particles in the foam structure; therefore, the foam element can be easily adapted to suit different applications.
The exemplary embodiment defined in claim 6 makes it possible to improve the particle delivery capacity. The specific surface is increased due to the structure of the surface, which is irregular and not completely smooth which makes it possible to witness an exceptional adsorption behavior on the part of the cellulose particles.
Another embodiment as defined in claim 7 provides the possibility of using these particles without obstructing the fine orifices of the nozzle, even when using said CO 2 foam manufacturing process.
A further advantage lies in another exemplary embodiment given in claim 8 since a spherical shape is avoided and an uneven surface having no fraying of fibrous type or fibrils is obtained. A rod-shaped model is avoided and this contributes to efficient distribution within the foam structure.
As a result of the embodiment of claim 9, the cellulose may be added and moved during the manufacturing process at the same time as at least one other additive, which means that only the following must be taken into account: a single additive when mixed with a reaction component.
A further advantage lies in another embodiment of claim 10, since a foam element can be obtained which can be used for a variety of different applications.
On the basis of another embodiment described in claim 11, it is possible to achieve better moisture transport inside the foam element.
The use of the foam element for a variety of different applications is also advantageous because it improves wearing comfort during use and the subsequent drying time is also faster. This is particularly advantageous in the case of different types of seats and mattresses, as well as for the types of applications in which the body transpires.
In order to allow a clearer understanding of the invention, it will now be explained in more detail below with reference to the accompanying drawings.
These drawings are simplified diagrams that illustrate the following:
Fig. 1 is a first graph illustrating the moisture absorption between two predefined climates based on different samples and different sampling points;
Fig. 2 is a second graph illustrating the different moisture absorption capabilities of conventional foam and foam replaced by cellulose particles;
Fig. 3 is a third graph illustrating the different rates of evaporation of moisture from conventional foam and foam replaced by cellulose particles;
Fig. 4 is a bar graph illustrating the absorption of water vapor by conventional plastic foam and plastic foam replaced by cellulose particles.
First of all, it should be noted that the identical parts described in the various exemplary embodiments are indicated by identical reference numbers and that the identical component names and descriptions given in this patent text can be transposed in terms of meanings to like parts that have the same reference numbers or the same component names. In addition, the positions chosen in the context of the description, such as vertex, bottom, side, etc., relate to the drawing which can be specifically described and can be transposed in terms of meanings to a new position when the we proceed to the description of another position. The individual features or combinations of features from the various exemplary embodiments illustrated and described can be constructed as independent inventive solutions or as solutions provided by the invention per se.
All figures referring to ranges of values in this description shall be interpreted to include any or all of the partial ranges, in which case, for example, the range of 1 to 10 shall be understood to include all partial ranges. from the lower limit of 1 to the upper limit of 10, ie all partial ranges having as their starting point the lower limit of 1, or more, and ending with the upper limit of 10, or less, eg 1 to 1.7, or 3.2 to 8.1 or 5.5 to 10.
A more detailed explanation is first given for the hydrophilic substance, provided in cellulose form, incorporated in the plastic foam, particularly in the foam element made therefrom. Similarly, the foam element is made from the plastic foam and the hydrophilic substance incorporated therein. The plastic foam can in turn be manufactured from a suitable mixture of components which can be foamed together, preferably in liquid form, by a method known for a long time.
As already explained above, in the patent specification WO 2007/135 069 A1, the cellulose fibers are added in addition to the polymer which absorbs water in the form of an extra charge. These are intended to increase the mechanical properties of the foam when necessary. In this regard, however, it has been discovered that the addition of fibrous additives makes it more difficult to transform the initial mixture to be foamed due to changes in fluidity. For example, the fibrous cellulose particles mixed with the polyol component, especially prior to the foaming step, make it more viscous, which makes it more difficult or impossible to mix with another component, know the isocyanate at the level of the gauging head of the foaming unit. They may also complicate the spread of the reaction component on the conveyor belt of the foam forming unit. Fibrous cellulose particles may also tend to adhere to the conveyor belts of the reaction mixture, forming deposits.
Therefore, it is simply possible to add fibrous additives within certain limits. The smaller the amount of fibrous additives, as a proportion, especially the shortened cellulose fibers, the lower the water absorption capacity when added to the foam. It can be expected that even the addition of small amounts of fibrous cellulose powders increases the viscosity, especially of the polyol component. Although, in principle, it is possible to convert these mixtures, the modified viscosity during processing must be taken into account.
Cellulose and the yarns, fibers or powders made therefrom are generally obtained by processing and grinding the cellulose or, alternatively, wood and / or annuals with the aid of a generally known method.
Depending on the nature of the production process, powders of different qualities (purity, size, etc.) are obtained. All these powders have in common a fibrous structure because the natural cellulose of any size shows a marked tendency to form these fibrous structures. Even MCC (microcrystalline cellulose), which can be described as spherical, is still made from pieces of crystalline fiber.
Depending on the microstructure, a distinction is made between different types of cellulose structure, especially cellulose-I and cellulose-II. These differences between these two types of structures are described in detail in the relevant literature and can also be seen using X-ray technology.
A substantial portion of the cellulose powders consist of cellulose-I. The production and use of cellulose-I powders are protected by a large number of patents. Many technical details of the grinding processes are also protected, for example. Cellulose-I powders are of a fibrous nature, which does not contribute much to a number of applications and may even be an obstacle. For example, fibrous powders often cause the fibers to cling to each other. They are also associated with a limited ability to flow freely.
Cellulose powders based on cellulose-II are currently very difficult to find on the market. These cellulose powders having this structure can be obtained either from a solution (usually viscose) or by grinding the cellulose-II products. Such a product may consist of cellophane, for example. These fine powders whose grain size is 10 pm or less can also be obtained in very small quantities only.
Spherical, non-fibrillated cellulose particles having a particle size in the range of from 1pm to 400μm can be produced from a solution of non-derived cellulose in a mixture or an organic substance and from water.
This solution is cooled below its hardening temperature and the solidified cellulose solution is then milled. Subsequently, the solvent is washed and the milled particles are dried. The subsequent grinding is generally carried out in a crusher.
This is particularly advantageous if at least the following individual additives are incorporated into the pre-prepared cellulose solution prior to its cooling and curing. This additive can be selected from the group comprising pigments, inorganic substances such as titanium oxide for example, particularly substoichiometric titanium dioxide, barium sulfate, ion exchangers, polyethylene, polypropylene, polyester, carbon black, zeolite, activated carbon, polymeric hyperabsorbents or flame retardants. They are then incorporated simultaneously into the cellulose particles produced. They can be added at different times during the production of the solution but under no circumstances can they be added before curing. In this regard, from 1% by weight to 200% by weight of additives may be incorporated, based on the amount of cellulose. It has been discovered that these additives are not removed during washing but remain in the cellulose particles and strongly retain their function. For example, if activated carbon is incorporated, its active surface area, which can be measured using the BET method, for example, is also preserved intact in the finished particles. The additives present on the surface of the cellulose particles as well as those present inside these particles are also fully preserved. This can be considered particularly beneficial since only small amounts of additives must be incorporated into the pre-prepared cellulose solution.
The advantage is that it is only necessary to add the cellulose particles already containing the functional additives to the reaction mixture so as to produce the foam element. While in the past all the additives were added separately and individually to the reaction mixture, it is now simply necessary to take into account one type of additive when setting up the foam manufacturing process. This avoids uncontrollable fluctuations in the suitability of many of these different additives.
The consequence of this approach is that a single cellulose powder is obtained, which is made of particles having a cellulose - II structure. The cellulose powder has a particle size in a range whose lower limit is 1 μτη and the upper limit is 400 μm for a mean particle size of x50 characterized by a lower limit of 4 μm and an upper limit of 250 μm in the case of a monomodal particle size distribution. The cellulose powder or particles have particles whose shape is approximately spherical, characterized by an irregular surface and crystallinity within a range whose lower limit is 15% and the upper limit is 45% based on the method of Raman. The particles also have a specific surface (Adsorption-N2, BET) characterized by a lower limit of 0.2 m 2 / g and an upper limit of 8 m 2 / g for a bulk density with a lower limit of 250 g / l and a upper limit of 750 g / 1.
The structure of Cellulose II is produced by dissolving and re-precipitating the cellulose, and the particles are very different from particles made from cellulose without a dissolution stage.
The size of the particles in the range cited above whose lower limit is 1 μm and the upper limit is 400 μπι with a particle distribution characterized by a value x50 characterized by a lower limit of 4 μm, especially 50 μm, and an upper limit of 250 μm, most preferably 100 μm, is naturally affected by the procedure used for grinding during the grinding process. However, this distribution of the particles can be obtained particularly easily if one opts for the specific production method based on the hardening of a solution of non-agglomerating cellulose and because of the mechanical properties provided to the hardened cellulose compound. The application of shear forces to a hardened cellulose solution under identical grinding conditions gives rise to different but fibrous properties.
The shape of the particles employed is approximately spherical. These particles have a crystallographic ratio (l: d) whose lower limit is 1 and the upper limit is 2.5f. They have an irregular surface but do not show any fraying of fibrous type or any fibril under a microscope. It is absolutely not about spheres with a smooth surface. This form is also not particularly suitable for the desired applications.
The bulk density of the cellulose powders described in the present, which is between a lower limit of 250 g / l and an upper limit of 750 g / l, is significantly greater than that of fibrillar particles known in the art. The bulk density has significant processing advantages as it also improves the compactness of the cellulose powder described herein and, among other things, results in better flowability, miscibility within the range of different environments and in reducing the problems occurring during storage.
In short, it can be said that the resulting cellulose powder particles are able to flow more freely due to their spherical structure and induce almost no change in viscosity due to their structure. Characterization of particles using the particle sizing device widely used in industry is also easier and meaningful because of the spherical shape. The structure of the irregular surface and which is not completely smooth gives rise to a larger surface area, which contributes to the extraordinary adsorption behavior of the powder.
Regardless of what is said above, it is also possible to mix a pure cellulose powder, or particles thereof, with other cellulose particles, which also contain incorporated additives whose lower limit is 1% by weight and the upper limit is 200% by weight in proportion to the amount of cellulose. These individual additives can also be selected from the group comprising pigments, inorganic substances such as titanium oxide, for example, especially substoichiometric titanium dioxide, barium sulfate, ion exchangers, polyethylene, polypropylene, polyester, activated carbon, polymeric hyperabsorbers and flame retardants.
Depending on the foam manufacturing process used to produce the foams, the spherical cellulose particles have been found to be particularly useful in comparison to fibrous cellulose particles, especially in the case of C02 foam manufacturing. The manufacture of C02 foam can be carried out using the Novaflex-Cardio process or by similar methods, for example, for which nozzles are used whose orifices are particularly fine. Crude and fibrous particles could immediately block the jet holes and cause other problems. For this reason, the high degree of fineness of spherical cellulose particles is particularly advantageous in the context of this specific foam manufacturing process.
The foam member and the production approach of the foam member proposed by the present invention will now be explained in more detail with reference to a number of examples. These are constructed, as far as possible, as exemplary embodiments of the invention; however, the invention is in no way limited by the scope of these examples.
Figures referring to moisture as% by weight refer to the mass or weight of the entire foam element (plastic foam, cellulose particles and water or moisture).
Example 1; The foam member to be produced may be made from a plastic foam such as polyurethane foam, for example, and a full range of different options and methods of manufacture may be used. These foams generally have an open cell structure. This can be done using a "QFM" foaming machine marketed by Hennecke, and the foam is produced in a continuous process using a high-pressure gauging device. All the necessary components are accurately metered under the control of a computer via controlled pumps and are mixed using the stirring principle. In this particular case, one of these components is the polyol, which is replaced by the cellulose particles described above. Since the cellulose particles are mixed with a reaction component, the polyol, various adjustments must be made to the formula, such as water, catalysts, stabilizers and TDI so as to strongly neutralize the effect of cellulose powder incorporated for production and subsequent physical values obtained.
A possible foam based on the invention is produced with 7.5% by weight of spherical cellulose particles. To do this, a spherical cellulose powder is first produced which can then be added to a reaction component of the foam to be produced. In terms of quantity, the proportion of cellulose relative to the total weight of the foam, in particular of the plastic foam, may be in a range whose lower limit is 0.1% by weight, especially 5% by weight, and the upper limit is 10% by weight, especially 8.5% by weight.
Example 2 (Comparative Example):
In order to allow comparison with Example 1, a foam member is made from a plastic foam that is produced without the addition of cellulose powder or cellulose particles. It can be a standard foam, an HR foam or a viscose foam, each consisting of a known formula and then being foamed.
The first objective is to determine if the cellulose particles are uniformly distributed in all layers of the resulting foam element in terms of height. This is accomplished by determining said moisture equilibrium based on the water intake by the foams in a standard climate at 20 ° C and 55% hr. and in another standardized climate at 23 ° C. and 93% hr. To do this, samples of the same size are taken from foam blocks manufactured as specified in Examples 1 and 2 at three different heights. the water intake in the two standardized climates described above is measured. In this respect, 1.0 m represents the top layer of the foam block, 0.5 m the middle layer and 0.0 m the bottom layer of the foam from which the samples are taken from the replaced plastic foam by cellulose particles. The total height of the block is about 1 m. The cellulose-free plastic foam of Example 2 is used for comparison.
Table 1:
As can be seen from these figures, the foam replaced by cellulose particles absorbs significantly more moisture than the cellulose-free foam, both in the standard climate and in the other climate standardized with moisture of physical balance. There is also a relatively good correlation for the measurement results for the different points from which the samples are taken (top, middle, bottom), which leads to the conclusion that there is a homogeneous distribution of samples. cellulose particles in the foam element produced.
Table 2 below shows the mechanical properties of the two foams manufactured as described in Examples 1 and 2. It clearly appears that the type of foam made from the cellulose particles has mechanical properties which are comparable to the foam which is not replaced by cellulose particles. This involves problem-free processing of the reaction components, especially if they incorporate the spherical cellulose particles.
Table 2:
The foam having added cellulose particles should have the following desired values for the two desired types of foam:

The average weight by volume or density of the entire foam element is within the range of which the lower limit is 30 kg / m3 and the upper limit is 45 kg / m3.
Fig. 1 indicates the percent moisture of the foam for samples of the same type but taken at different locations from the foam member as described above. The moisture of the foam as [%] is shown on the y-axis. The proportion of cellulose powder or cellulose particles added, in this example, is 10% by weight and the cellulose particles are the spherical cellulose particles described above. These different individual samples, with and without additives, are represented on the abscissa axis.
The foam moisture measurement points of the individual samples shown as circles represent the initial value and the measurements shown in square form are obtained for the same sample but after a day of moisture uptake. The lower initial values are determined for the standard climate described above and the other value shown for the same sample represents moisture uptake in the other standardized climate after 24 hours at 23 ° C and 93% h. r .. The abbreviation hr refers to the relative humidity or humidity in the air and is given in%.
Fig. 2 represents moisture uptake over a period of 48 hours, with time values (t) being plotted on the x-axis by [h]. The initial state of the body of the sample is again that of the standard climate of 20 ° C and 55% hr. defined above. The other climate standardized at 23 ° C and 93% hr. is intended to represent a climate based on use or on the body climate so as to determine the period during which the moisture of the foam increases in% by weight. The moisture values of the foam are shown on the y-axis as [%].
The first line graph 1 whose measurement points illustrated in circles represent a foam element with a predefined size of the sample based on Example 2 without the addition of cellulose particles or cellulose powder.
The other line graph 2 whose measurement points illustrated in the form of squares represents the foam moisture of a foam member to which 7.5% by weight of cellulose particles or cellulose powder is added. The cellulose particles again consist of the spherical cellulose particles described above.
The 48-hour moisture graph illustrates that the physical balance moisture of "mosses" in the "body climate" is reached after only a short time. It can thus be concluded that the foam replaced by cellulose particles is capable of absorbing twice as much moisture in 3 hours as a foam based on Example 2 to which cellulose particles are not added.
Moisture measurements are obtained by storing the pieces of foam with a volume of about 10 cm3 in a dryer whose humidity in the air is determined (using a saturated KN03 solution) and 93% hr), having previously been used to dry the samples. The samples are removed from the dryer after a set period of time and the weight gain (= water intake) is measured. Fluctuations in moisture uptake can be explained by sample handling as well as a slight lack of homogeneity in the samples.
Fig. 3 illustrates the drying behavior of a foam element to which cellulose particles are added based on Example 1 compared to a foam based on Example 2 to which no cellulose particles are added. For comparison purposes, both samples were first conditioned in the "body climate" for 24 hours. It is again a temperature of 23 ° C and a relative humidity of 93%. Moisture values of the foam are plotted on the y-axis as [%] and the time (t) in [min] is plotted on the abscissa. The specified percent values for foam moisture are given in percent by weight based on the weight or weight of all foam elements (plastic foam, cellulose particles and water or moisture).
The measurement points illustrated in circles are again related to the foam element based on Example 2 to which no cellulose particles are added representing a corresponding line 3 which represents the decrease in moisture. The measurement points illustrated in the form of squares are determined for the foam element to which cellulose particles are added. Another corresponding line 4 also represents the evidence of a rapid evaporation of moisture. The proportion of cellulose particles is again 7.5% by weight.
It is obvious that the equilibrium moisture of 2% is already restored after a period of about 10 minutes. This is much faster than in the case of a foam of the prior art that requires several hours to evaporate a comparable amount of water.
When the foam element replaced by cellulose particles based on the crystalline modification of cellulose-II is conditioned in the "body climate" for a period of 24 hours and then exposed to the "standard climate", it initially absorbs a carbon content. in moisture greater than 5% by weight and the moisture content is reduced by at least 2 (two)% over a period of 2 min after being introduced into the "standard climate".
Fig. 4 is a bar graph showing the absorption of water vapor "Fi" based on Hohenstein in [g / m2] and these values are plotted on the ordinate axis.
The period during which water vapor is absorbed from the standard climate of 20 ° C and 55% hr. defined above and in the standardized climate of 23 ° C and 93% hr. also defined above (application climate and body climate) for the two measured values obtained is 3 (three) hours. The samples are "B" type foam samples described above. A first bar graph 5 illustrates a "B" type foam without cellulose or added cellulose particles. The value measured in this case is about 4.8 g / m2. The foam replaced by cellulose, on the other hand, indicates a larger value of about 10.4 g / m 2 and this can be represented on another bar graph 6. This other value is, therefore, greater than a value of 5 g / m2 based on Hohenstein.
The foam member is made from a plastic foam, and a PU foam is used as the preferred foam. As explained above in connection with the individual diagrams, moisture uptake is determined from said equilibrium moisture representing a "standard climate" at 20 ° C with a relative humidity of 55%. In order to simulate a use, another standardized climate is defined at 23 ° C with a relative humidity of 93%. This other standardized climate is intended to represent the moisture absorbed during use in the body of a human being transpiring, for example a person. The cellulose incorporated in the foam element is intended to disperse the absorbed moisture during a period of use with a lower time limit of 1 hour and the upper time limit is 16 hours again after use and thus restore, in the entire foam element, the equilibrium moisture of the ambient atmosphere. This means that the stored moisture evaporates from the cellulose very quickly after use, which is emitted into the ambient atmosphere and thus allows the foam element to dry.
As mentioned above, it can be said that there is equilibrium moisture when the foam member has been exposed to one of the ambient atmospheres described above to a degree that the moisture value of the The foam element (foam moisture) is in equilibrium with the humidity value in the ambient atmosphere. When the equilibrium moisture level is reached, there is no more moisture exchange between the foam element and the ambient atmosphere around the foam element.
The test methods described above can be carried out so that the foam element is exposed to the first ambient atmosphere characterized by the first climate which is based on the predefined temperature and relative humidity of the air, for example, 20 ° C and 55% rh, until the equilibrium moisture is reached in this ambient atmosphere, after which the same foam element is exposed to a second atmosphere. ambient, modified or different, which is different from the first ambient atmosphere. This second ambient atmosphere has a second climate characterized by a higher temperature and / or relative humidity of the upper air compared to the first climate, for example 23 ° C and 93% of hr. Therefore, the value moisture from the foam increases and moisture is absorbed by the cellulose that is incorporated into the foam. Subsequently, the same element is exposed again to the first ambient atmosphere and, following the lapse of time between 1 hour and 16 hours specified above, the initial value of the moisture of the foam which corresponds to the equilibrium humidity based on the first ambient atmosphere is restored. Consequently, during this time, the moisture absorbed by the cellulose, in the context of the second ambient atmosphere, is evaporated in the ambient atmosphere and, consequently, reduced.
The lower value of 1 hour specified herein depends on the amount of liquid or moisture absorbed but can also be much lower, in which case it can be adjusted within minutes.
Apart from the spherical cellulose particles described above, it is also possible to use cellulose in the form of cut fibers characterized by a fiber length whose lower limit is 0.1 mm and the upper limit is 5 mm. . However, it is also possible to use cellulose in the form of crushed fibers characterized by a particle size whose lower limit is 50 μπι and the upper limit is 0.5 mm.
Depending on the field of application, the foam to be produced has different properties and these are characterized by a range of different physical properties.
The compressive strength at a compression of 40% can be within a range with a lower limit of 1.0 kPa and an upper limit of 10.0 kPa. The elasticity as measured by the ball test may have a value whose lower limit is 5% and the upper limit is 70%. This test method is performed according to EN ISO 8307 and the rebound height and inverse parallel elasticity are determined.
If the produced foam element is made from a polyurethane foam, especially a flexible foam, it can be produced with both a TDI base and an MDI base. However, it is also possible to use other foams, such as polyethylene foam, polystyrene foam, polycarbonate foam, PVC foam, polyimide foam, foam foam, silicon, PMMA foam (polymethyl methacrylate), rubber foam, for example. The importance of moisture uptake will then depend on the raw material and the method used to produce the foam as the reversible ability to absorb moisture is achieved by incorporating or interlocking the cellulose. It is preferable to use open-cell type foams which allow a smooth exchange of air with the ambient atmosphere. It is also essential to ensure that the cellulose added to the foam structure is homogeneously distributed as described above in connection with the tests performed. If the foam does not have an open-celled structure, it can be treated specifically using known methods to obtain open cells.
If polyol is used as the starting material for one of the reaction components, the cellulose can be added prior to the foam manufacturing process. The cellulose can be added by keeping it under agitation or by dispersing it using methods known in the industry. The polyol employed is that which is necessary for the corresponding type of foam and is added in the required amount specified in the formula. However, the moisture content of the cellulose particles must be taken into account when establishing the formula.
The foam member can be used to make individual plastic products and the plastic products can be selected from the group consisting of mattresses, upholstery, pillows.
The exemplary embodiments illustrated as examples represent possible variants of the foam element having a hydrophilic substance in the form of cellulose incorporated into the plastic foam, and it should be noted at this stage that the invention is not limited to these illustrated variants, but rather that these individual variants can be used in different combinations with each other and that these possible variations are within the abilities of those skilled in the art given the technical teaching which is provided. Similarly, all the conceivable variants that can be obtained by combining the individual details of the variants described and illustrated are possible and are included within the scope of the invention.
The basic purpose of independent inventive solutions can be found upon reading the description.
List of reference numbers 1 Line chart 2 Line chart 3 Line chart 4 Line chart 5 Bar chart 6 Bar chart

权利要求:
Claims (12)
[1]
A foam member having a hydrophilic cellulose-like substance incorporated in the foam, and a foam member replaced with cellulose having a reversible ability to absorb moisture, characterized in that the cellulose is in the form of a structure based on the crystalline modification of cellulose-II, and in that a proportion of cellulose with reference to the total weight of the foam is selected from a range whose lower limit is 0.1% by weight, most preferably 5% by weight, and the upper limit is 10% by weight, most preferably 8.5% by weight, and in that the moisture value of the foam of the foam element is increased from an initial value of the moisture of the foam which corresponds to an equilibrium humidity of a first ambient atmosphere characterized by a first climate which is based on a predetermined temperature and relative humidity of the air s during use at a humidity value of the foam with reference to a second ambient atmosphere different from the first ambient atmosphere characterized by a second climate which is based on a temperature and / or a relative humidity higher than that of the first climate, and in that the moisture absorbed by the cellulose II incorporated in the foam element after use in the second ambient atmosphere evaporates after a lapse of time, in the first ambient atmosphere, within a range whose limit The lower limit is 1 hour and the upper limit is 16 hours until the initial value of the moisture of the foam corresponding to the equilibrium moisture of the first ambient atmosphere is restored again.
[2]
A foam member having a hydrophilic cellulose-form substance incorporated in the foam, and a foam-replaced foam member having a reversible moisture-absorbing ability, as particularly claimed in claim 1, characterized in that the cellulose is in the form of a structure based on the crystalline modification of cellulose-II, and in that a proportion of cellulose in reference to the total weight of the foam is selected from a range the lower limit of which is 0.1% by weight, most preferably 5% by weight, and the upper limit is 10%, most preferably 8.5% by weight, and the foam element has a density the lower limit of which is 30 kg / m3 and the upper limit is 45 kg / m3, and in that the Hohenstein water vapor intake has a Fi value of greater than 5 g / m2.
[3]
A foam member having a hydrophilic cellulose-like substance incorporated in the foam, and a foam-replaced foam member having a reversible moisture-absorbing ability, as particularly claimed in claim 1 or 2, characterized in that the cellulose is in the form of a structure based on the crystalline modification of cellulose-II, and in that a proportion of cellulose with reference to the total weight of the foam is selected from a range whose lower limit is 0.1% by weight, especially 5%, and the upper limit is 10%, especially 8.5% by weight, and that the foam element has a density whose lower limit is 30 kg / m3 and the upper limit is 45 kg / m3, and that a value that is initially greater than 5% of the foam moisture of the foam element from from the second atmosphere am biante characterized by the second climate is reduced by at least 2% due to the effect of the first ambient atmosphere characterized by the first climate based on a temperature of 20 ° C and a relative humidity of 55% during a period of 2 min.
[4]
Foam element as claimed in one of the preceding claims, characterized in that the cellulose-II is in the form of cut fibers; fibers having a length whose lower limit is 0.1 mm and the upper limit is 5 mm.
[5]
Foam element as claimed in one of the preceding claims, characterized in that the cellulose-II is in the form of crushed fibers; fibers having a particle size of which the lower limit is 50 μm and the upper limit is 0.5 mm.
[6]
Foam element as claimed in one of the preceding claims, characterized in that the cellulose-II is in the form of spherical particles of cellulose.
[7]
Foam element as claimed in claim 6, characterized in that the spherical cellulose particles have a particle size of which the lower limit is 1 μm and the upper limit is 400 μm.
[8]
Foam element as claimed in claim 6 or 7, characterized in that the spherical cellulose particles have a crystallographic ratio (1: d) whose lower limit is 1 and the upper limit is 2.5.
[9]
9. Foam element as claimed in one of the preceding claims, characterized in that the cellulose contains at least one additive selected from the group consisting of pigments, inorganic substances such as titanium oxide, the oxide substoichiometric titanium, barium sulfate, ion exchangers, polyethylene, polypropylene, polyester, carbon black, zeolite, activated carbon, polymeric hyperabsorbents or flame retardants.
[10]
Foam element as claimed in one of the preceding claims, characterized in that the foam is selected from the group consisting of polyurethane foam (PU foam), polyethylene foam, polystyrene foam, foam polycarbonate, PVC foam, polyimide foam, silicon foam, PMMA (polymethyl methacrylate) foam, rubber foam.
[11]
Foam element as claimed in one of claims 1 to 3 or 10, characterized in that the foam has an open-celled foam structure.
[12]
Use of a foam member as claimed in one of claims 1 to 11 in the manufacture of a plastic product, characterized in that the plastic product is selected from the group consisting of mattresses, upholstery of furniture, pillows.

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同族专利:

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公开号 | 公开日

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DE102010000116A1|2010-12-09|

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RU2435800C2|2011-12-10|

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GB2468556A|2010-09-15|

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BRPI1001598A2|2014-01-07|

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ES2357207B1|2012-02-28|

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HU1000036D0|2010-03-29|

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ES2357207A1|2011-04-20|

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AT507849A3|2011-08-15|

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GB2468556B|2011-05-25|

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SE1050066A1|2010-07-23|

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GB2468556A8|2012-03-07|

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ITGE20100005A1|2010-07-23|

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CH700280B1|2014-10-15|

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GB2468556B8|2012-03-07|

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CZ201048A3|2010-08-25|

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US20110319261A1|2011-12-29|

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RU2010101883A|2011-07-27|

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EP2389408A1|2011-11-30|

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HU1000036A2|2012-06-28|

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WO2010083548A1|2010-07-29|

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CN101787200A|2010-07-28|

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FR2941233A1|2010-07-23|

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AT507849B1|2011-09-15|

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CN101787200B|2012-08-08|

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DE102010000116B4|2013-04-04|

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PL390249A1|2010-08-02|

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EP2389408B1|2016-08-24|

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IT1397870B1|2013-02-04|

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CH700280A2|2010-07-30|

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法律状态:
2022-01-10| HC| Change of name of the owners|Owner name: NEVEON AUSTRIA GMBH; AT Free format text: DETAILS ASSIGNMENT: CHANGE OF OWNER(S), CHANGE OF OWNER(S) NAME; FORMER OWNER NAME: EUROFOAM GMBH Effective date: 20211123 |

优先权:

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申请号 | 申请日 | 专利标题

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AT1002009|2009-01-22|

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AT0010009A|AT507849B1|2009-01-22|2009-01-22|FOAM ELEMENT WITH INCLUDED CELLULOSE|

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