• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Spinel pigment. The present invention provides a complex oxide comprising cobalt, aluminum and titanium characterized in that the oxygen, cobalt, aluminum and titanium ions are arranged with one another forming at least one spinel structure. The complex oxide of the invention has a low bioaccessibility and cession of the elements that conform it according to ASTM D5517, and OECD-29. The invention also provides a composition containing the complex oxide of the invention. Also, the invention provides a process for the preparation of the complex oxide of the invention. The complex oxide provided by the present invention can be used for the decoration of surfaces, in particular of ceramics, glasses, plastics, enamels of sheet metal or cast iron and cements. (Machine-translation by Google Translate, not legally binding)
    公开号:ES2711378A1
    申请号:ES201731274
    申请日:2017-10-31
    公开日:2019-05-03
    发明作者:Pla Rafael Mena；Sergio Sereni
    申请人:Colorobbia Espana SA；
    IPC主号:
    专利说明:

    [0001] Spinel Pigment
    [0002]
    [0003] FIELD OF THE INVENTION
    [0004] The present invention relates to a complex oxide of cobalt, aluminum and titanium, characterized in that the cobalt, aluminum and titanium ions are arranged between themselves forming at least one spinel structure, as well as a method of preparing said complex oxide . The invention also relates to a composition containing said oxide, and to its use for application on surfaces.
    [0005]
    [0006] BACKGROUND OF THE INVENTION
    [0007] In the field of enamels, cobalt pigments are appreciated for the characteristic blue tone they give to the products where they are applied. However, the high toxicity of cobalt causes a high impact on the environment when it is released from the pigment.
    [0008]
    [0009] In the state of the art, one of the best known blue pigments is the cobalt blue pigment of formula CoAl2O4 (CAS 1345-16-0, CI Pigment blue 28), which is obtained from the calcination at high temperature of oxide of cobalt (II) and aluminum oxide (III), and crystallization thereof forming the spinel structure. It is believed that the characteristic blue color of this pigment is due to the tetrahedral coordination of the Co (II) ions in the spinel. Furthermore, said pigment can contain modifying elements that vary the hue of the blue color without affecting the structure of the pigment, such as for example Li2O, MgO, SiO2, TiO2 or ZnO.
    [0010]
    [0011] Another well-known pigment is the cobalt blue of formula Co2SiO4 (CAS 68187-40-6, CI Pigment blue 73), which is obtained from the calcination at high temperature of cobalt (II) oxide and silicon oxide (IV ), and crystallization of them forming the olivine structure. Said pigment may contain modifying elements that vary the hue of the blue color without affecting the structure of the pigment, such as for example Al2O3, B2O3, CaO, PbO or ZnO.
    [0012] The pigment Co2SiO4 (CAS 68187-40-6, CI Pigment blue 73) with higher content of Co in composition has a coloration power much higher than CoAl2O4 (CAS 1345-16-0, CI Pigment blue 28), but its level of cession of free cobalt is also very superior and therefore also its toxicity.
    [0013]
    [0014] Several studies have tried to synthesize pigments of similar coloration tones but with a lower content of cobalt and therefore with lower coloring power. Thus, for example, Zou [RSC Adv., 2015, 5, 87932-87939] disclosed a pigment formed by rutile particles TiO2 coated with CoAl2O4 spinel. M.Bouchard and A. Gambardella [J. Raman Spectroscopy, 2010, 41, 1477-1485] also disclosed other known pigments where it had been attempted to reduce the toxicity of the cobalt blue pigments by partially substituting the cobalt content for other metals such as Zn to form the mixed spinel ZnCoAl2O4.
    [0015]
    [0016] However, despite the efforts made to date, there is still a need for the development of new pigments to maintain the coloring power of the cobalt blue pigment Co2SiO4 (CAS 68187-40-6, CI Pigment blue 73) without constituting a threat to the environment.
    [0017]
    [0018] OBJECT OF THE INVENTION
    [0019] The present invention provides a new cobalt pigment of blue coloration that has a reduced solubility of the elements that comprise it. In particular, the pigment of the invention has a low yield of cobalt, which remains anchored in the structure, avoiding producing an ecological impact due to its release to the environment.
    [0020]
    [0021] Although in the state of the art cobalt and aluminum oxides of formula CoAl2O4 with spinel structure are known to have a low yield of the elements that compose it, said oxides do not have the cobalt content as high as the pigment Co2SiO4 and therefore Its coloring power is lower. To date, no cobalt complex oxides with a cobalt content similar to that of the Co2SiO4 pigment have been described and they show a low yield of the elements that comprise it. In this sense, the present invention provides a complex oxide of cobalt, aluminum and titanium with a similar cobalt content as the pigment Co2SiO4 where said elements are arranged in order to form at least one spinel structure and surprisingly have a low yield of the elements that make it up Likewise, the complex oxide of the invention has a low bioavailability of the elements that conform it according to the ASTM D5517 standard, since it has a reduced solubility of the ions that make it up in comparison with other pigments with the same cobalt content, such as pigment Co2SiO4, and therefore producing a limited impact on the environment.
    [0022]
    [0023] Therefore, in a first aspect the present invention is directed to a complex oxide comprising cobalt, aluminum and titanium, characterized in that the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged together forming at least one structure of spinel, and where said complex oxide presents a bioavailability of the elements that make it less than 1% according to the bioavailability norm ASTM D5517, and a yield lower than 0.2% according to the OECD-29 assignment regulation.
    [0024]
    [0025] In a second aspect the invention is directed to the composition comprising the complex oxide of the invention. Also, the invention also relates to the composition when said composition is a pigment, and to the use of said pigment for the manufacture of an ink, an Inkjet ink, an enamel, or a serigraphic or pigmentary paste.
    [0026]
    [0027] In other aspects, the invention also relates to the ink, to the enamel, to the serigraphic or pigmentary paste that comprise the composition when said composition is a pigment.
    [0028]
    [0029] In another aspect the invention relates to the ceramic product comprising the complex oxide of the invention or the composition comprising the complex oxide of the invention.
    [0030]
    [0031] Another aspect of the invention relates to a method for preparing the complex oxide of the invention comprising:
    [0032] a) provide Al2O3, Co3O4 and TiO2 or precursors thereof,
    [0033] b) mixing the oxides or precursors of the oxides of step a) to obtain a mixture comprising 55% Co3O4 and 45% by weight of the mixture Al2O3 and TiO2, and
    [0034] c) calcining the mixture of oxides or precursors of the oxides of stage b) to obtain a complex oxide of cobalt, aluminum and titanium where the ions of Oxygen, cobalt, aluminum and titanium of said complex oxide are arranged among themselves forming at least one spinel structure.
    [0035]
    [0036] The invention also provides the process for preparing the pigment comprising the steps described for the preparation of the complex oxide.
    [0037]
    [0038] The complex oxide of the invention, as well as the composition comprising the complex oxide of the invention can be used for the surface and volume application of different materials. Thus, another additional aspect of the invention relates to a printing process comprising the application of the pigment, the ink, the enamel or the screen or pigment paste on a surface, as well as the use of the complex oxide of the invention for the application in ceramics, glasses, plastics, enamels of sheet metal or cast iron and cements, as well as for the decoration of ceramics.
    [0039]
    [0040] FIGURES
    [0041] FIGURE 1 shows the X-ray diffraction diagrams of various Co, Al and Ti oxide pigments: P1 shows a crystalline spinel structure corresponding to the Co-Ti pigment; P2 and P3 show two spinel structures one of Co-Ti and one of Co-Ti-Al; P4 and P5 show the structure of the pigment containing the complex oxide of the spinel structure of Co-Ti-Al, and; P6 to the spinel pigment Co-Al.
    [0042]
    [0043] FIGURE 2 shows the X-ray diffraction diagram of an oxide of the invention of Co-Ti-Al with spinel structure.
    [0044]
    [0045] FIGURE 3 shows the X-ray diffraction diagram of the oxide of the invention prepared in example 7. Figure 3 also shows a table showing the bioavailability and yield values of the complex oxide obtained in example 7, and of a Co-Si complex oxide with the same cobalt content.
    [0046]
    [0047] FIGURE 4 shows the calorimetric values of several ceramic applications of the pigment P7, as opposed to a complex oxide oxide of Co-Si with an olivine structure with the same cobalt content.
    [0048] FIGURE 5 shows the granulometric distribution of the pigment of example 1.
    [0049]
    [0050] DETAILED DESCRIPTION OF THE INVENTION
    [0051] The present invention provides a complex oxide comprising cobalt, aluminum and titanium, wherein the oxygen, cobalt, aluminum and titanium ions of said oxide are arranged in between, forming at least one spinel structure. The complex oxide of the invention has a low solubility of the elements that comprise it. In addition, the complex oxide provided by the present invention has a bioavailability of the elements that make it less than 1% according to the bioavailability norm ASTM D5517, and a yield lower than 0.2% according to the OECD cession regulation. Thus, in a first aspect the present invention is directed to a complex oxide comprising cobalt, aluminum and titanium, characterized in that the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged together forming at least one spinel structure and where said complex oxide presents a bioavailability of the elements that conform it less than 1% according to the bioavailability norm ASTM D5517, and a yield lower than 0.2% according to the OECD-29 assignment regulation. In particular, the complex oxide of the invention shows a low yield of cobalt in comparison with other pigments with a similar content of this element, according to the bioaccessibility regulations (ASTM D5517 of 2007) and assignment (OECD-29 of 2001). It is believed that the complex oxide structure of the invention could keep cobalt fixed to the structure, limiting its release to the environment, and thus reducing the contaminating impact on the environment by the release of said metal.
    [0052]
    [0053] The results of bioaccessibility (ASTM D5517) and transfer (OECD-29) of the complex oxide (Co-Al-Ti) of example 7 belonging to the invention and of another complex oxide of Co-Si are shown in the table of figure 3. with a similar content of cobalt. In particular, the table shows that while the complex oxide of Co-Si has a solubility of 26.8%, the complex oxide of the invention has a solubility of 0.52% according to the ASTM D5517 bioavailability (2007). Also, according to OECD-29 (December 29, 2001), the complex oxide of the invention has a transfer value of 0.119 mg / l in acid pH, and 0.08 mg / l in basic pH, while in the same conditions for the complex oxide of Co-Si, the transfer values in acid pH are 1.695 mg / l, and in basic pH 0.791 mg / l. These results show that the complex oxide of the invention has a low yield of the elements that conform it according to the reference standard.
    [0054] In the context of the present invention, the term "oxide" refers to a chemical compound formed by at least one metal cation and one oxygen atom (O2-). In particular, the term "complex oxide" refers to a chemical compound that contains two or more metal cations and oxygen oxides. The "complex oxide" of the invention refers to an oxide containing cobalt, aluminum and titanium cations and oxygen anions. In the complex oxide of the invention, the cobalt, aluminum and titanium metal ions are arranged together to form at least one spinel structure. In the present application the term "Co-Al-Ti" refers to the complex oxide of the invention where the ions of Co, Al and Ti are arranged together forming a spinel structure.
    [0055]
    [0056] In the spinel structure the oxygen ions are located in the vertices of a cubic subnetwork centered on the faces (FCC) of spatial group Fd3m, originating octahedral and tetrahedral holes. In the spinel structure, the bivalent cation ions occupy the tetrahedral holes of the oxygen network, while the trivalent cations occupy the octahedral holes. Thus in the complex oxide of the invention, the cobalt ions would occupy the tetrahedron voids, while the aluminum and titanium ions would occupy the octahedral voids of the structure. In particular, in the complex oxide of the invention where aluminum, cobalt and titanium are arranged together to form at least one spinel structure, the aluminum and titanium ions indistinctly occupy the available octahedral voids of the spinel structure.
    [0057]
    [0058] The structure of the complex oxide of the invention has been characterized by X-ray diffraction. The technique of X-ray diffraction is based on using an X-ray beam with a wavelength of the order of the interatomic distances of the samples to be studied, so that the diffraction phenomena of these rays are produced in directions and with specific intensities for each type of crystalline substance, not obtained in the amorphous ones (eg, frit). The X-Ray Diffraction measurements that appear in the present application have been taken with an X-ray diffraction equipment (DRX) of the PANalytical brand for powdered materials. The equipment used has a copper X-ray tube. In addition, measurements were made at a voltage of 45kV, intensity of 40mA, and a divergent gap of 5mm. The acquired information allows by means of the comparison with JCPDS files to identify the crystalline substances present in the sample to be analyzed.
    [0059] The quantification of the phases present by XRD can become very complex, especially if some have low crystallinity. However, by combining the results of XRD with those of X-ray fluorescence it is possible to make an approximation known as "rational analysis" or on the other hand with the method "Rietveld".
    [0060]
    [0061] Figure 1 shows the X-ray diagram of different oxide pigments of Co, Al and Ti with spinel structure of the examples of the application. In particular in the pigments P2 (example 2), P3 (example 3), P4 (example 4) and P5 (example 5) the complex oxide of the invention is detected. Also, in P2 and P3 CoTiO3 is also detected. On the contrary, in the diagrams corresponding to P1 and P6 the complex oxide of the invention is not detected, but an oxide of Co-Ti with spinel structure and CoTiO3 in P1, and a complex oxide of Co and Al with spinel structure in P6.
    [0062]
    [0063] In FIG. 2, the diffraction maxima of a complex oxide of the invention of the pigment P4 of example 4 of the application are shown. The maxima detected correspond to the spinel Co-Ti-Al, where the content of titanium is majority with respect to aluminum, and the spinel Co-Al-Ti, where the aluminum ion is majority with respect to titanium. The detected diffraction maxima corresponding to the Spinel Co-Ti-Al are found at the following positions 20: 18.43, 30.29, 35.70, 43.37, 53.79, 57.32 and 63.06, while the spinel maxima Co-Al-Ti are in positions 20: 18.92, 31.12, 36.65, 44.56, 48.92, 55.37, 59.01 and 64.84 .
    [0064]
    [0065] In another particular embodiment, the complex oxide of the invention has the formula [Co2 +] [Co3 + Al3 + Ti3 +] 2O4. When the complex oxide of the invention has said formula, the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged together to form a spinel structure, where half of the octahedral holes are occupied by aluminum ions, and the another half by titanium ions.
    [0066]
    [0067] In a particular embodiment, the oxygen, cobalt, aluminum and titanium ions of the complex oxide of the invention are arranged together to form two spinel structures. In a preferred embodiment, the oxygen, cobalt, aluminum and titanium ions of the complex oxide of the invention are arranged in order to form two spinels of Co2 (Ti1-x Alx) O4 and Co (Al2-y). Tiy) O4, where "x" is between 0.01 and 0.25, and "y" is between 0.01 and 0.15. In a more preferred embodiment, the oxygen, cobalt, aluminum and titanium ions of the complex oxide of the invention are arranged between each other forming two spinels of Co2 (Ti1-x Alx) O4y of Co (Al2- and Tiy) O4, where "X" is between 0.18 and 0.20, and "y" is between 0.05 and 0.10. In the spinel of Co2 (Ti1-x Alx) O4the Ti ions are partially substituted by Al ions, while in the spinel Co (Al2-yTiy) O4, the titanium ions partially replace the aluminum ions. The inventors have observed that the presence of both titanium and aluminum ions in the crystal structure can cause the deformation of the crystal lattice due to the difference in size of both elements
    [0068]
    [0069] In a more preferred embodiment the complex oxide of the invention contains between 60 and 70% of the spinel Co2 (Ti1-x Alx) O4, and between 30 and 40% of the spinel of Co (Al2- and Tiy) O4, where "x" is between 0.01 and 0.25, preferably between 0.18 and 0.20, and "and" is between 0.01 and 0.15, preferably between 0.05 and 0.10. More preferably, the complex oxide of the invention contains 65% of the spinel Co2 (Ti1-x Alx) O4 and 35% of the spinel Co (Al2- and Tiy) O4, where "x" is between 0.01 and 0, 25, e "y" is between 0.01 and 0.15.
    [0070]
    [0071] In addition to the spinel structure present in the complex oxide of the invention, the oxygen, cobalt, aluminum and titanium ions may be arranged to form other oxide structures, such as CoTiO3 perovskite structures (see for example P2 and P3 in the figure 1) or that corresponding to Co (Ti2-z Alz) O5, with structure of type "Pseudobrookite".
    [0072]
    [0073] In a preferred embodiment the complex oxide of the invention would contain:
    [0074] - between 60 and 70% of the spinel Co2 (Ti1-x Alx) O4, where x is between 0.01 and 0.25, preferably between 0.18 and 0.20,
    [0075] - between 30 and 40% of the spinel of Co (Al2- and Tiy) O4, where "y" is between 0.01 and 0.15, preferably between 0.05 and 0.10 and
    [0076] - between 0 and 5% of Co (Ti2-z Alz) O5, where z would be between 0.01 and 1.99
    [0077]
    [0078] More preferably, the complex oxide of the invention would contain:
    [0079] - 65% of the spinel Co2 (Ti1-x Alx) O4, where x is between 0.01 and 0.25, preferably between 0.18 and 0.20,
    [0080] - 30% of the spinel of Co (Al2- and Tiy) O4, where "y" is between 0.01 and 0.15, preferably between 0.05 and 0.10 and
    [0081] - 5% Co (Ti2-z Alz) O5, where z is between 0.01 and 1.99.
    [0082]
    [0083] The complex oxide of the invention may also include impurities such as Fe, Si, P, Na, Ni, Mg, and Ca. These impurities are believed to come from the complex oxide precursor raw materials of the invention. Thus, for example, the impurities of Fe, Si and P are often associated with Ti precursors, the impurities of Na, Ni, Mg, Fe and Ca to Co precursors; and the impurities of Si, Na, Fe, Ca to precursors of Al.
    [0084]
    [0085] In addition, the complex oxide of the invention may contain modifiers. In the context of the present invention the term "modifier" or "modifying element" is used to refer to any precursor substance that introduces a metal into the complex oxide of the invention without modifying the crystalline structure of the complex oxide. Examples of modifying elements include Li2O3, MgO, SiO2, SrO2, ZnO, CaO, Cr2O3, Fe2O3, NiO, Sb2O5, B2O3, ZrO2, MnO2, SnO2 and WO3. Modifying elements are often used in pigments to produce variations in the properties of the pigment color, such as hue or intensity of color.
    [0086]
    [0087] Composition
    [0088] In one aspect the present invention provides a composition comprising the complex oxide of the invention. The composition comprising the complex oxide of the invention can be solid or liquid.
    [0089]
    [0090] The complex oxide of the invention provides a blue coloration that allows its use as a pigment. Thus, in a particular embodiment, the composition of the invention comprising the complex oxide of cobalt, aluminum and titanium, characterized in that the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged together forming at least one spinel structure and, where said complex oxide presents a bioavailability of the elements that conform it less than 1% according to the bioavailability norm ASTM D5517, and a yield less than 0.2% according to the OECD-29 assignment regulation, it is a pigment.
    [0091] The composition or pigment of the invention may also comprise at least one modifier. In particular, the modifiers are incorporated into the composition of the invention to vary the final tonality of the coloration of the composition without affecting the crystalline structure of the complex oxide of the invention. Thus, when the composition of the invention is a pigment it is possible to achieve variations in the hue of the coloration of the pigment using modifiers. In a particular embodiment, the composition of the invention further comprises at least one modifier selected from Li2O3, MgO, SiO2, SrO2, ZnO. OaO, Or 2 O 3 , Fe 2 O 3 , NiO, Sb 2 O 5 , B 2 O 3 , ZrO 2 , MnO 2 , SnO 2 and ^ VO 3 .
    [0092]
    [0093] In addition, the composition or pigment of the invention may contain a carrier or diluent. The composition or pigment of the invention can be used for the manufacture of inks or enamels of digital application. In a particular embodiment the composition of the invention comprises the complex oxide of the invention diluted in inorganic diluents. Examples of inorganic diluents suitable for the composition of the invention include silica, clays, feldspars, nephelines, calcium carbonate, alumina, kaolins, zinc oxide and others.
    [0094]
    [0095] In the context of the present invention, ink means a liquid medium that can contain one or more pigments. One aspect of the invention relates to the ink comprising the composition of the invention, wherein said composition is a pigment.
    [0096]
    [0097] In the context of the present invention, enamel is understood as the coating on a substrate produced by the melting of a powder on a substrate through a heating process at a high temperature. Therefore, one aspect of the invention relates to the enamel comprising the composition of the invention, wherein said composition is a pigment. Example 7 of the present application shows enamels of the invention comprising the pigment of the invention.
    [0098]
    [0099] Also, the invention also relates to a serigraphic paste, pigment paste or ink for InkJet type printing applications comprising the composition of the invention when said composition is a pigment, and certain additives. In the context of the present invention, pigment paste is understood as a paste comprising at least one pigment and a medium which is usually a resin. The pigment paste can also contain other additives such as wetting and dispersing agents. Also, serigraphic paste is understood as a paste comprising at least one pigment and a medium suitable for screen printing (serigraphic vehicle). Thus, one aspect of the invention relates to a pigmentary or serigraphic paste comprising the composition of the invention wherein said composition is a pigment.
    [0100]
    [0101] In a particular embodiment, the pigment of the invention has the form of solid particles. When the pigment of the invention has the form of solid particles, the optical response of the pigment of the invention may vary depending on the particle size of the pigment of the composition of the invention. The following table shows the colorimetric variations (Hunterlab Colorquest Sphere) of a ceramic application (transparent enamel) at 5% with the pigment of the invention Co-Ti-Al of example 7 (P7) and with different sizes of particle (Malvern model Mastersizer2000 ).
    [0102]
    [0103]
    [0104]
    [0105]
    [0106] Another aspect of the invention relates to the ceramic product comprising the complex oxide of the invention or the composition comprising the complex oxide of the invention. Preferably, the ceramic product comprises the composition of the invention in the form of enamel, paint, or any other type of coating.
    [0107] The detection and the quantitative analysis of the pigments of the invention have been carried out by means of a X-ray fluorescence spectrometry equipment by dispersion of wavelengths. By means of this technique, the material that is wanted to be measured with X-rays is stimulated, producing a phenomenon of fluorescence that allows detecting the specific wavelengths of each element. The separation of the wavelengths is achieved by using an analyzer crystal that acts as a diffraction filter. The crystal selects the appropriate wavelengths according to the Bragg Law. The system used in the present invention is of the brand PANalytical, and has an X-ray tube with a source of Rhodium at a power of 2.7Kw, and with a measurement time of 17 minutes.
    [0108]
    [0109] Process
    [0110] One aspect of the invention relates to a process for preparing the complex oxide of the invention comprising the following steps:
    [0111]
    [0112] a) provide Al 2 O 3 , Co 3 O 4 and TiO 2 or precursors thereof,
    [0113] b) mixing the oxides or precursors of the oxides of step a) to obtain a mixture comprising 55% Co 3 O 4 and 45% by weight of the mixture Al 2 O 3 and TiO 2 , and
    [0114] c) calcining the mixture of oxides or precursors of the oxides of step b) to obtain a complex oxide of cobalt, aluminum and titanium where the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged together forming at least a spinel structure.
    [0115]
    [0116] In step a) of the process of the invention Al 2 O 3 , Co 3 O 4 and TiO 2 or precursors thereof are provided. In the context of the present invention "precursor" is understood as any element or compound that generates the oxides Al 2 O 3 , Co 3 O 4 and TiO 2 when calcining. Examples of precursors in the process of the invention include carbonates, oxides, hydrated oxides, metals, sulfates, chlorides, etc. In particular, commonly used Co 3 O 4 precursors include Co (OH) 2 or CoCO 3 . Also, commonly used precursors of TiO 2 include TiH 4 O 4.
    [0117]
    [0118] According to step b) of the process of the invention, the oxides or precursors of the oxides of step a) are mixed to obtain a mixture comprising 55% Co 3 O 4 and 45% by weight of the mixture Al 2 O 3 and TiO 2 ,
    [0119]
    [0120] The mixing techniques that can be used in step b) of the process of the invention are known in the state of the art. Some examples of mixing techniques that can be used in this stage include dry mixing techniques, such as the use of intensive mixers, mills, etc .; or mixing techniques by humid route through the use of agitation tanks or mills. When the mixture is produced by wet mixing techniques, furthermore, a subsequent drying step of the mixture is required.
    [0121]
    [0122] In step b) the amount of oxides or precursors necessary to achieve a mixture comprising 55% Co 3 O 4 and 45% of the mixture Al 2 O 3 and TiO 2 is mixed. In a particular embodiment the content of Al 2 O 3 is at least 21%, and the content of TiO 2 is between 1 and 24%. In a preferred embodiment the mixture of step b) contains 21% Al 2 O 3 , 24% TiO 2 and 55% Co 3 O 4 . The amounts of oxides or precursors required to achieve said concentrations of metal oxides depend on the oxide or precursor used, and are known to those skilled in the art or easily calculable by routine work in the laboratory.
    [0123] The inventors have found that surprisingly for a specific content of Co 3 O 4 when the content of Al 2 O 3 is decreased, and that of TiO 2 is increased, the spinel structure Co 2 TiO 4 is generated progressively decreasing at the same time the formation of the invention pigment. In the same way, when the content of Al 2 O 3 is increased against TiO 2 , the spinel CoAl 2 O 4 is generated while decreasing the formation of the inventive pigment.
    [0124]
    [0125] In step c) of the process of the invention, the mixture of step b) of the oxides or precursors of the oxides is calcined to obtain a complex oxide of cobalt, aluminum and titanium where the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged together forming at least one spinel structure. The calcination of the mixture of oxides or precursors of step b) occurs inside ovens. Examples of furnaces that can be used in the calcination stage include static or dynamic furnaces. In addition, the calcination process can be a continuous or intermittent process. Examples of ovens that can be used in the process of the invention when the calcination process is continuous include rotary kilns and calciners, tunnel kilns and roller kilns. When the calcination process is intermittent some examples of ovens that can be used include box ovens or muffles or intermittent rotary kilns. Also, the calcination temperature, as well as the residence time or the duration of the process may vary depending on the precursors used. In a particular embodiment, in step c) the mixture is calcined at a temperature comprised between 750 ° C and 1350 ° C between 1 and 5 hours.
    [0126] Optionally, the calcination step can be carried out in the presence of other reaction-enhancing additives, such as, for example, fluxing substances. These reaction-promoting additives are usually used to reduce the temperature necessary for calcination to occur. Examples of suitable fluxing substances in the process of the invention include halides, halides, nitrates, sulfates or alkali and alkaline earth carbonates. Other examples of fluxing materials include molybdenum, bismuth or boron oxides.
    [0127]
    [0128] The process of the invention can further include an additional washing step by which any soluble substance foreign to the complex oxide of the invention is removed, followed by a subsequent drying step.
    [0129]
    [0130] The particle size of the complex oxide obtained by the process of the invention can also be reduced as appropriate. The reduction of particle size can be carried out by grinding techniques known in the state of the art. In particular, it is preferred that the particle size reduction occurs by dry or wet route, with an additional drying step being necessary in the latter case.
    [0131]
    [0132] The invention also relates to the complex oxide obtained by the process of the invention.
    [0133]
    [0134] In a particular embodiment, the composition of the invention comprising the complex oxide is prepared by a process comprising steps a), b) and c) of the process for obtaining the complex oxide of the invention described above.
    [0135]
    [0136] In another particular embodiment, the pigment of the invention comprising the complex oxide is prepared by a process comprising steps a), b) and c) of the process for obtaining the complex oxide of the invention described above.
    [0137]
    [0138] Industrial application
    [0139] The complex oxide of the invention can be used as a pigment to color substrates of a different nature, such as ceramics, ceramic enamels, glasses, plastics, resins, paints, etc., either by mass application (directly or by means of the preparation). of an ink or pigment paste), or by the surface printing of an ink or printing powder and by different techniques such as screen printing, inkjet, laser etc ... Thus, one aspect of the invention relates to a printing process comprising the application of the pigment, the ink, the enamel or the silk-screen or pigment paste of the invention on a surface. In a particular embodiment, the pigment application of ink, enamel or silk-screen or pigment paste on a surface is carried out by Inkjet printing. In another aspect, the invention relates to the use of the pigment of the invention in the manufacture of an ink, an inkjet printing ink, an enamel or a serigraphic or pigmentary paste.
    [0140]
    [0141] The complex oxide of the invention keeps the cobalt of high toxicity fixed to the structure, limiting the release of said element from the surface on which it is applied to the environment, and thus reducing the contaminating impact by the release of said metal. The table of figure 3 demonstrates the low solubility of a complex oxide of the invention against another complex oxide used in ceramics with the same cobalt content.
    [0142]
    [0143] In particular, the complex oxide or the composition of the invention can be applied to surfaces of ceramic materials. Likewise, the complex oxide or the composition of the invention can also be used for the coloring of glasses, plastics, enamels of sheet metal or cast iron and cements. The complex oxide of the invention provides a very variable coloration hue, being able to develop tonalities from deep blue to dark green on the surface where it is applied. In this sense, an aspect of the invention relates to the use of complex oxide for application in ceramics, glass, plastics, enamels of sheet metal or cast iron and cements. In a preferred embodiment, the complex oxide or the composition of the invention are applied as enamel for the ceramic coating, as for example in sanitary porcelain enamels. More preferably the ceramics are tiles, bricks, tiles, toilets, pavements or decorative elements. A particular embodiment refers to the use of the composition for the decoration of ceramics.
    [0144]
    [0145] The complex oxide or composition of the invention can be used to produce bulk coloration of the product to which it is applied.
    [0146]
    [0147] The invention also relates to the inkjet printing or inkjet ink containing the complex oxide of the invention. In this sense, the inkjet or inkjet printing ink that contains the complex oxide of the invention can be applied on the surface of a product, preferably by a suitable printing system.
    [0148]
    [0149] In the following the invention is illustrated by examples, which should not be interpreted as limiting the invention, which is defined by the claims.
    [0150]
    [0151] EXAMPLES:
    [0152]
    [0153] Example n ° 1:
    [0154] Using a laboratory scale weigh the formulation identified as P1 with the following components:
    [0155] Co3O4: 55.00 g
    [0156] AhO 3 : 0.00 g
    [0157] TiO 2 : 45.00 g
    [0158]
    [0159] All the materials used in the composition come from typical industrial supplies used in the production of Ceramic Pigments. Below is shown its physical / chemical characteristics:
    [0160]
    [0161] Co3O4:
    [0162] Co 71.0-72.4%
    [0163] Not < 0.0100 %
    [0164] F e < 0.0100%
    [0165] Cu <0.0005%
    [0166] Zn <0.0005%
    [0167] M n < 0.0020%
    [0168] Na <1.6000%
    [0169] M g < 0.0100%
    [0170] Ca < 0.0100 %
    [0171]
    [0172]
    [0173] Cr < 0.0100%
    [0174] Cd <0.0005%
    [0175] Apparent density 0.6 -1.0 g / cm3
    [0176] Average particle size <8.0 ^ m
    [0177] Surface area 2.0 - 5.0 m2 / g
    [0178]
    [0179] Al 2 O 3 :
    [0180]
    [0181]
    [0182]
    [0183]
    [0184]
    [0185] TiO 2 :
    [0186]
    [0187]
    [0188]
    [0189]
    [0190] The intensive mixing of this composition is preceded by a laboratory blade mixer for one minute. The obtained mixture is introduced in an alumina crucible and subjected to a calcination process in an intermittent electric box oven by the following cycle:
    [0191]
    [0192]
    [0193]
    [0194]
    [0195] Once the calcining process is finished, the pigment obtained is subjected to a process of reduction of particle size by wet grinding. This is carried out for 13 minutes in a planetary mill frame using an agate jug of 500 cc volume and with half milling of high density alumina balls of 6mm diameter, according to the following load.
    [0196]
    [0197]
    [0198]
    [0199] Once the grinding process is finished, the pigment is dried by evaporation on ceramic sponge cake and in a laboratory oven. Figure 7 shows the granulometric distribution measured with the Malvern model Mastersizer2000 equipment of the obtained pigment.
    [0200]
    [0201] Example n ° 2:
    [0202]
    [0203] Using a laboratory scale weigh the formulation identified as P2 with the following components:
    [0204] Co 3 O 4 : 55.00 g
    [0205] AfeO * 10.00 g
    [0206] TiO2: 35.00 g
    [0207] Proceed with the same process as for example n ° 1.
    [0208]
    [0209] Example n ° 3:
    [0210]
    [0211] The formulation identified as P3 with the following components is weighed using a laboratory balance:
    [0212] Co 3 O 4 : 55.00 g
    [0213] Al 2 O 3 : 20.00 g
    [0214] TiO 2 : 25.00 g
    [0215] Proceed with the same process as for example n ° 1.
    [0216]
    [0217] Example n ° 4:
    [0218] The formulation identified as P4 with the following components is weighed using a laboratory balance:
    [0219] Co 3 O 4 : 55.00 g
    [0220] Al 2 O 3 : 30.00 g
    [0221] T O 15.00 g
    [0222] Proceed with the same process as for example n ° 1.
    [0223]
    [0224] Example n ° 5:
    [0225]
    [0226] By means of a laboratory scale, the formulation identified as P5 is weighed with the following components:
    [0227] Co 3 O 4 : 55.00 g
    [0228] Al 2 O 3 : 40.00 g
    [0229] TiO 2 : 5.00 g
    [0230] Proceed with identical process that for example n ° 1
    [0231]
    [0232] Example n ° 6:
    [0233]
    [0234] The formulation identified as P6 with the following components is weighed using a laboratory balance:
    [0235] Co 3 O 4 : 55.00 g
    [0236] Al 2 O 3 : 45.00 g
    [0237] TiO 2 : 0.00 g
    [0238] Proceed with identical process that for example n ° 1
    [0239]
    [0240] Example n ° 7:
    [0241]
    [0242] The formulation identified as P7 is weighed using a laboratory scale with the following components:
    [0243] Co 3 O 4 : 55.00 g
    [0244] AhO 3 : 21.00 g
    [0245] T O: 24.00 g
    [0246] Proceed with identical process that for example n ° 1
    [0247] Figure 1 shows the XRD analysis of the resulting Pigments P1 to P6 after the preparation of examples No. 1 to No. 6. This XRD analysis shows that for a Co3O4 content of 55% in the formula, the highest yield in the complex oxide of the invention Co-Ti-Al is obtained for Al2O3 values higher than 20%.
    [0248]
    [0249] Figure 3 shows the XRD analysis of the pigment P7 resulting from the preparation of Example No. 7. In the table of figure 3 the bioaccessibility tests (ASTM D5517) and assignment (OECD-29) for the pigment P7 and another Olivine pigment of Co-Si with the same content of Co3O4 and of majority use in the ceramics sector are detailed.
    [0250]
    [0251] Figure 4 shows the colorimetric values of several ceramic applications of the pigment P7, compared to a blue pigment of Olivino de Co-Si with the same content of Co3O4 and of majority use in the ceramics sector. The obtained colorimetric values show that the inventive pigment has colorimetric values close to the Olivino co-Si pigment.
    [0252]
    [0253] The process of ceramic application used is detailed below:
    [0254]
    [0255] Proceed as follows:
    [0256]
    [0257] I. In a 500 cc agate jar. of capacity with 235-240 g. of balls (aprox.) of high density alumina (distributed approximately in 80% of balls of 18 mm and 20% of balls of 9 mm) the pigment and enamel corresponding to each application is introduced and water is added to a content in solids 50%
    [0258] II. The mixture is ground for about 5 minutes using a fast planetary mill frame from the laboratory.
    [0259] III. This operation is carried out both for the pigment to be tested (P7) and for the one used as a control reference (Olivino Co-Si).
    [0260] IV. The two grinded compositions are applied (enamelled) in a previously biscuit ceramic piece according to the desired application (patm, gun, tongue, etc.), V. Proceed to the firing of the applied pieces according to the cycle corresponding to each enamel used
    [0261]
    [0262] The colorimetric values were obtained using a Hunterlab Colorquest Sphere Colorimeter, the equipment parameters used in the measurements are the following:
    [0263] • Lamp D 65.
    [0264] • 10 ° inclination angle.
    [0265] • Specular reflectance included.
    [0266] • UV filter included.
    [0267] • CieLab measurement system *
    权利要求:
    Claims (18)
    [1]
    1. Complex oxide comprising cobalt, aluminum and titanium, characterized in that the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged between themselves forming at least one spinel structure, and wherein said complex oxide exhibits a bioavailability of the elements that make up less than 1% according to bioavailability regulation ASTM D5517, and a transfer lower than 0.2% according to the OECD-29 transfer regulations.
    [2]
    2. A complex oxide according to claim 1, characterized in that the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged in order to form two spinel structures.
    [3]
    3. complex oxide according to any of claims 1 or 2 having the formula [Co2 +] [Co3 + Al3 + Ti3 +] 2 O 4.
    [4]
    4. Composition comprising the complex oxide according to any of claims 1 to 3.
    [5]
    5. Composition according to claim 4 further comprising at least one selected from Li2O3, MgO, SiO2, SRO2, ZnO, CaO, Cr2O3, Fe2O3, NiO, Sb2O5, B2O3, ZrO2, MnO 2, SnO 2 and ^ VO3 modifier.
    [6]
    6. Composition according to any of claims 4 or 5, wherein said composition is a pigment.
    [7]
    7. Ink comprising the composition according to claim 6.
    [8]
    8. Enamel comprising the composition according to claim 6.
    [9]
    9. Pigmentary or serigraphic paste comprising the composition according to claim 6.
    [10]
    10. Ceramic product comprising the complex oxide according to any of claims 1 to 3 or the composition according to any of claims 4 to 6.
    [11]
    11. Process for preparing the complex oxide of any of claims 1 to 3 comprising:
    a) provide Al2O3, Co3O4 and TiO2 or precursors thereof,
    b) mixing the oxides or precursors of the oxides of step a) to obtain a mixture comprising 55% Co3O4 and 45% by weight of the mixture Al2O3 and TiO2, and c) calcining the mixture of oxides or precursors of the oxides of step b) to obtain a complex oxide of cobalt, aluminum and titanium where the oxygen, cobalt, aluminum and titanium ions of said complex oxide are arranged together to form at least one spinel structure.
    [12]
    12. Process according to claim 11, wherein the mixture of step b) contains 21% Al2O3, 24% TiO2 and 55% Co3O4.
    [13]
    The method for preparing the pigment according to claim 6, comprising the preparation of the complex oxide according to any of claims 11 or 12.
    [14]
    Printing process comprising the pigment application according to claim 6, of the ink according to claim 7, of the enamel according to claim 8 or of the silk screen or pigment paste according to claim 9, on a surface.
    [15]
    15. Printing process according to claim 14, wherein the application of the pigment, the ink, the enamel or the serigraphic or pigmentary paste on a surface is carried out by Inkjet printing.
    [16]
    16. Use of the complex oxide of cobalt, aluminum and titanium according to any of claims 1 to 3, or of the composition according to claims 4 to 6, for its application in ceramics, glasses, plastics, enamels of sheet metal or cast iron and cements
    [17]
    17. Use of the composition according to any of claims 4 to 6 for the decoration of ceramics.
    [18]
    18. Use of the pigment according to the revindication 6 in the manufacture of an ink, an Inkjet ink, an enamel, or a serigraphic or pigmentary paste.
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    同族专利:
    公开号 | 公开日
    ES2711378B2|2019-10-22|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4390374A|1980-05-28|1983-06-28|Montedison S.P.A.|Rutile pigments coated with trigonal anhydrous alumina and cubic metal aluminate and process|
    US20050049347A1|2003-08-27|2005-03-03|Ferro Corporation|Inorganic pigments|
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