CN112898825A - Submicron-grade large red zirconium silicate coated pigment and preparation method thereof - Google Patents

Abstract

The invention relates to the field of inorganic pigments, in particular to a submicron bright red cadmium sulfoselenide coated zirconium silicate pigment and a preparation method thereof. The obtained coated pigment has good dispersibility and narrow particle size distribution range (the particle size is mainly distributed in the range of 0.15-0.75 micrometer, the average particle size is 0.35-0.50 micrometer), the coated pigment mainly comprises approximately spherical or ellipsoidal particles, the coated pigment presents bright red, and when a CIEL a b system is adopted to represent the performance of the pigment, the L value, the a value and the b value are respectively 54-58, 42-46 and 20-28. The invention can prepare the completely wrapped submicron zirconium silicate wrapped cadmium sulfoselenide bright red pigment by controlling the synthesis process step by step and only adopting single microemulsion, thereby not only reducing the using amount of oil and alcohol substances, but also greatly reducing the using amount of zirconium silicate wrappage and improving the color performance, and being beneficial to reducing the production cost of the wrapped pigment and reducing the environmental protection pressure of the production process.

Description

Submicron-grade large red zirconium silicate coated pigment and preparation method thereof

[ technical field ] A method for producing a semiconductor device

The invention relates to the field of inorganic pigments, in particular to a large red zirconium silicate coated pigment suitable for ink-jet printing and laser 3D printing.

[ background of the invention ]

Ink jet printing technology has been developed as one of the major ceramic decoration technologies, and the development of new ceramic laser printing technology represents a new trend in the development of ceramic decoration technology. Red is one of the three primary colors of ceramic printing decoration, and the lack of bright red ceramic ink greatly affects the ceramic printing decoration for a long timeThe ceramic ink-jet printing decoration effect is improved. Cadmium sulfoselenide (CdSe)_xS_1-x) The pigment is the only inorganic pigment which is known at present and can present bright red, but the pigment is a non-oxide material and is easy to be oxidized and decomposed in an air environment above 500 ℃ to lose red, so the pigment cannot be directly applied to ceramic decoration. By using zirconium silicate (ZrSiO) having excellent high temperature resistance and chemical stability₄) The cadmium sulfoselenide is coated and modified, the stable temperature of the cadmium sulfoselenide in most ceramic glaze materials can be increased to more than 1300 ℃ while the color generation of the pigment is not influenced, and therefore, the zirconium silicate coated cadmium sulfoselenide pigment is widely applied to traditional ceramic glaze decoration. Pigments for ceramic ink-jet printing inks generally require a maximum particle size of less than 1 micron (average particle size of several hundred nanometers) to improve ink stability and satisfy the limitation of printer head pore size and improve print pattern accuracy. For ceramic laser printing, it is required to control the particle size of pigment particles with a large density to several hundred nanometers, and to improve powder flowability, it is also required to have a high shape of pigment particles.

In the current industrial production, the zirconium silicate coated cadmium sulfoselenide pigment is generally prepared by a liquid-phase coprecipitation method, and is calcined at high temperature to obtain the pigment with compact zirconium silicate inclusion, the particle size distribution of the coated pigment particles is wide, the shape of the coated pigment particles is irregular, the particle size of most particles reaches 15-30 microns, and the actual coating rate is very low and is only 8% -10%. When the coating pigment is prepared by the process, after high-temperature calcination, most of cadmium selenide sulfide which is not effectively coated needs to be removed by soaking with a large amount of strong acid, so that the coating pigment can be applied to ceramic decoration, and therefore, the production efficiency is low and the environmental protection pressure is high. The more disadvantageous is that the common encapsulated red pigment needs to be crushed, ground and refined for a long time in order to meet the requirement of ink preparation on particle size, but most zirconium silicate inclusion bodies are damaged in the crushing process, and the exposed cadmium sulfoselenide is decomposed at high temperature so that the pigment can only show light pink and even completely loses red. Therefore, the coating rate of the zirconium silicate coated cadmium sulfoselenide pigment with the core-shell structure is improved, and the integral granularity of the coated pigment is effectively reduced, so that the key technical problem of preparing the scarlet ink for ceramic decoration is always solved.

[ summary of the invention ]

The invention aims to overcome the defects of the prior art and provides a submicron bright red zirconium silicate coated cadmium sulfoselenide pigment and a preparation method thereof. The obtained coated pigment has good dispersibility and narrow particle size distribution range (the particle size is mainly distributed in the range of 0.15-0.75 micrometer, the average particle size is 0.35-0.50 micrometer), the coated pigment mainly comprises approximately spherical or ellipsoidal particles, the coated pigment presents bright red, and when a CIEL a b system is adopted to represent the performance of the pigment, the L value, the a value and the b value are respectively 54-58, 42-46 and 20-28.

The invention discloses a submicron zirconium silicate coated cadmium sulfoselenide bright red pigment, which is characterized in that: the chemical composition is as follows: CdSe_xS_1-x@ZrSiO₄(x＝0.22～0.32)，ZrSiO₄With CdSe_xS_1-xThe molar ratio of (A) to (B) is 4-6: 1; when the pigment performance is expressed by a CIEL a b system, the L value, a value and b value are respectively 54-57, 42-46 and 20-28;

the submicron zirconium silicate coated cadmium sulfoselenide bright red pigment is obtained by adopting a single microemulsion method and controlling the synthesis process step by step, and comprises the following specific steps:

(1) mixing sodium sulfide (Na)₂S), selenium (Se) powder, sodium hydroxide (NaOH), Sodium Dodecyl Benzene Sulfonate (SDBS) and Cetyl Trimethyl Ammonium Bromide (CTAB) are dissolved in hot deionized water to obtain a mixed solution A, wherein Se is_xS_1-xThe concentration is 0.5-2 mol/L, SDBS and the mass percentage of CTAB is 0.3-0.8%; will react with Se_xS_1-xEquimolar amounts of cadmium salts (e.g. CdCl)₂、Cd(NO₃)₂Or CdSO₄Etc.) in deionized water to obtain Cd²⁺The concentration of the solution B is 0.5 to 2 mol/L;

(2) stirring and mixing n-octane, n-octanol and fatty alcohol-polyoxyethylene ether according to the mass ratio of 100: 20-25: 22-25 to obtain an oil solution, adding the solution A according to 8-10% of the mass of the oil solution, and fully stirring to obtain an oil/water microemulsion;

(3) dripping the solution B into the microemulsion obtained in the step (2),continuously stirring, fully mixing and reacting for 1-2 h, and generating the CdSe compositely coated by the SDBS and the CTAB in the microemulsion_xS_1-xPrecipitate particles;

(4) dissolving Tetraethoxysilane (TEOS) in an ethanol/water mixed solution to obtain a solution C with TEOS concentration of 1-2 mol/L, and dissolving ZrOCl₂Or Zr (NO)₃)₄·5H₂Dissolving zirconium salt such as O and lithium fluoride (LiF) in deionized water to obtain Zr⁴⁺The solution D with the concentration of 2-3 mol/L, the Si/Zr molar ratio in the solution C and the solution D is 1.1-1.2, and the addition amount of lithium fluoride is ZrSiO theoretically available₄4-6% of the mass;

(5) adding the solution C into the microemulsion obtained in the step (3), fully stirring for 2-3 h to ensure that the tetraethoxysilane is fully hydrolyzed and deposited in a composite surfactant micelle structure in CdSe_xS_1-xThe surface of the particle forms a tightly adsorbed porous structure SiO₂Adding the solution D into the precursor, and continuously stirring for 3-4 h to enable Zr-OH to be adsorbed and deposited on the porous SiO₂Adding an ethanol solution of a polyoxyethylene polyoxypropylene ether segmented copolymer into the precursor structure for demulsification, and finally obtaining a pigment-coated precursor precipitate through centrifugal separation;

(6) and (3) cleaning the precipitate obtained in the step (5) by using deionized water and industrial ethanol once respectively, drying at 80-100 ℃ for 6h, rapidly heating to 500 ℃ at a speed of 20-25 ℃/min, keeping the temperature for 1h, heating to 850-1000 ℃ at a speed of 5 ℃/min, and calcining for 1h to obtain the zirconium silicate coated cadmium sulfoselenide pigment.

Compared with the prior art, the invention has the following advantages:

1. the invention can prepare the completely wrapped submicron zirconium silicate wrapped cadmium sulfoselenide bright red pigment by controlling the synthesis process step by step and only adopting single microemulsion, thereby not only reducing the dosage of oil and alcohol substances, but also greatly reducing the dosage of zirconium silicate wrappage (ZrSiO)₄/CdSe_xS_1-xThe molar ratio is reduced from 10-20: 1 to 4-6: 1) in the prior art, the color development performance is improved, the process of removing a large amount of unencapsulated cadmium selenide by strong acid soaking in the later stage of the traditional method can be avoided, and the production cost of the encapsulated pigment is reducedAnd reduces the environmental protection pressure of the production process.

2. The present invention is in CdSe_xS_1-xIn the synthesis process, anionic surfactant Sodium Dodecyl Benzene Sulfonate (SDBS) and cationic surfactant Cetyl Trimethyl Ammonium Bromide (CTAB) are simultaneously introduced, and the synthesized CdSe can be obtained by the composite action of the two surfactants_xS_1-xThe micelle is taken as a template, a silicon oxide precursor (Si-OH) obtained after hydrolysis can be closely adsorbed and deposited on the micelle to form a porous network structure, a zirconium oxide precursor (Zr-OH) obtained after hydrolysis in the subsequent process is further adsorbed and deposited in the porous network structure, and thus, the surface of the particle is provided with surfactant molecular micelle with high adsorption density and compact combination, and the micelle is further taken as a template, so that the zirconium oxide precursor (Zr-OH) obtained after hydrolysis in the subsequent process is further adsorbed and deposited in the porous network structure, thereby the_xS_1-xThe surface of the particle forms a tightly adsorbed wrapper precursor, and Zr and Si elements are uniformly distributed, which is helpful to promote ZrSiO in the high-temperature calcination process₄And (4) synthesizing.

3. The ethanol solution of the polyoxyethylene polyoxypropylene ether segmented copolymer is adopted to replace common acetone for demulsification, so that the dispersibility of the coating pigment precursor precipitate and the coating pigment obtained by calcination after demulsification can be improved, and the cost can be reduced.

4. According to the technical scheme, in the heating and calcining process of the coating pigment precursor, a rapid heating system (20-25 ℃/min) is adopted at the temperature below 500 ℃, so that organic matters in the coating precursor can be rapidly burnt out, the coating collapses and shrinks rapidly, and the reduction of CdSe in the heating process is facilitated_xS_1-xIn contact with air, ZrSiO₄The density of the wrapping layer is improved synthetically.

5. The zirconium silicate coated cadmium sulfoselenide pigment provided by the invention is bright red, has good dispersibility and narrow particle size distribution range (the particle size of the particles is mainly distributed in the range of 0.15-75 micrometers, and the average particle size is 0.35-0.50 micrometers), mainly comprises approximately spherical or ellipsoidal particles, and can simultaneously meet the technical requirements of ceramic ink-jet printing and laser printing.

[ description of the drawings ]

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings, in which:

FIG. 1 is a TEM photograph of a zirconium silicate-coated cadmium sulfoselenide pigment (synthesized by keeping the temperature at 900 ℃ for 1 hour);

FIG. 2 is an XRD spectrum of a zirconium silicate coated cadmium sulfoselenide pigment (synthesized by heat preservation at 900 ℃ for 1 hour);

[ detailed description ] embodiments

The first embodiment is as follows:

preparation of ZrSiO₄Encapsulation of CdSe_xS_1-xPigment, wherein x is 0.3, ZrSiO₄/CdSe_xS_1-xThe molar ratio is 5: 1. First Na₂S, Se powder, NaOH, SDBS and CTAB are dissolved in hot water to solution A, wherein Se is_xS_1-xThe mass percentage of concentration of 1mol/L, SDBS and CTAB are both 0.6%, and the pH value of the solution is adjusted to 13 by NaOH; will react with Se_xS_1-xEquimolar amount of Cd (NO)₃)₂Dissolving the Cd in deionized water to obtain Cd²⁺The concentration of the solution B is 2 mol/L. Stirring and mixing n-octane, n-octanol and fatty alcohol-polyoxyethylene ether according to the mass ratio of 100:22:23 to obtain an oil solution, adding the solution A according to 10% of the mass of the oil solution, and fully stirring to obtain the oil/water microemulsion. Then dropwise adding the solution B into the microemulsion and continuously stirring for 2 hours to ensure that the CdSe is obtained_xS_1-xAfter the synthesis reaction process is fully carried out, 1mol/L ethyl orthosilicate (TEOS) alcohol aqueous solution is dripped, the mixture is continuously stirred for 2 hours, and then 2mol/L ZrOCl is dripped₂And LiF (Si/Zr molar ratio is controlled to be 1.1, lithium fluoride content is ZrSiO)₄4 percent of the mass), continuously stirring for 4 hours, adding an ethanol solution of 10 percent polyoxyethylene polyoxypropylene ether segmented copolymer for demulsification, and finally obtaining the pigment-coated precursor precipitate through centrifugal separation.

Washing the precipitate with deionized water and industrial alcohol, drying at 100 deg.c for 6 hr, heating to 500 deg.c at 25 deg.c/min for 1 hr, heating to 900 deg.c at 5 deg.c/min and calcining for 1 hr to obtain the zirconium silicate coated cadmium sulfoselenide pigment. The particle size distribution is mainly distributed in the range of 0.2-0.6 micron, the average particle size is 0.4 micron, the values of L, a and b are respectively 56, 46 and 25, the red pigment presents bright red, and the red value a of the existing ink-jet printing coating red pigment is only 20-30 generally. FIG. 1 is a TEM of the coated pigment obtained by the present inventionA photo; FIG. 2 is an XRD pattern of the coated pigment, showing that the resulting coated pigment consists mainly of zirconium silicate crystal phase and CdSexS1-x crystal phase, and compared with the existing coated pigment, CdSe_xS_1-xThe diffraction peak intensity of the crystal phase is obviously improved because the content of the inclusion is greatly reduced by adopting the technology of the invention.

Example two:

ZrSiO was prepared by the same method as in example one₄Encapsulation of CdSe_xS_1-xPigment, wherein x is 0.22, ZrSiO₄/CdSe_xS_1-xThe molar ratio is 6:1, the Si/Zr molar ratio is controlled to be 1.2, and the content of lithium fluoride is ZrSiO₄6% of the mass, and the other preparation methods and procedures are the same as in example one. The obtained coated pigment has particle size distribution of 0.3-0.75 micron, average particle size of 0.5 micron, L, a and b values of 57, 42 and 28, and is bright red.

The above description is only a preferred embodiment of the present invention, and it should be noted that a person skilled in the art can make various changes, modifications, substitutions and alterations to the embodiments without departing from the technical principles of the present invention, and such changes, modifications, substitutions and alterations should also be regarded as the protection scope of the present invention.

Claims (1)

1. A submicron zirconium silicate coated cadmium sulfoselenide bright red pigment is characterized in that: the chemical composition is as follows: CdSe_xS_1-x@ZrSiO₄(x＝0.22～0.32)，ZrSiO₄With CdSe_xS_1-xThe molar ratio of (A) to (B) is 4-6: 1; when the pigment performance is expressed by a CIEL a b system, the L value, a value and b value are respectively 54-57, 42-46 and 20-28;

the submicron zirconium silicate coated cadmium sulfoselenide bright red pigment is obtained by adopting a single microemulsion method and controlling the synthesis process step by step, and comprises the following specific steps:

(1) mixing sodium sulfide (Na)₂S), selenium (Se) powder, sodium hydroxide (NaOH), Sodium Dodecyl Benzene Sulfonate (SDBS) and Cetyl Trimethyl Ammonium Bromide (CTAB) are dissolved in hot deionized water to obtain a mixed solutionLiquid A, wherein Se_xS_1-xThe concentration is 0.5-2 mol/L, SDBS and the mass percentage of CTAB is 0.3-0.8%; will react with Se_xS_1-xEquimolar amounts of cadmium salts (e.g. CdCl)₂、Cd(NO₃)₂Or CdSO₄Etc.) in deionized water to obtain Cd²⁺The concentration of the solution B is 0.5-2 mol/L;

(2) stirring and mixing n-octane, n-octanol and fatty alcohol-polyoxyethylene ether according to the mass ratio of 100: 20-25: 22-25 to obtain an oil solution, adding the solution A according to 8-10% of the mass of the oil solution, and fully stirring to obtain an oil/water microemulsion;

(3) dropwise adding the solution B into the microemulsion obtained in the step (2), continuously stirring, fully mixing and reacting for 1-2 h to generate the CdSe compositely coated by the SDBS and the CTAB in the microemulsion_xS_1-xPrecipitate particles;

(4) dissolving Tetraethoxysilane (TEOS) in an ethanol/water mixed solution to obtain a solution C with TEOS concentration of 1-2 mol/L, and dissolving ZrOCl₂Or Zr (NO)₃)₄·5H₂Dissolving zirconium salt such as O and lithium fluoride (LiF) in deionized water to obtain Zr⁴⁺The solution D with the concentration of 2-3 mol/L, the Si/Zr molar ratio in the solution C and the solution D is 1.1-1.2, and the addition amount of lithium fluoride is ZrSiO theoretically available₄4-6% of the mass;

(5) adding the solution C into the microemulsion obtained in the step (3), fully stirring for 2-3 h to fully hydrolyze ethyl orthosilicate and deposit the ethyl orthosilicate in a composite surfactant micelle structure in CdSe_xS_1-xThe surface of the particle forms a tightly adsorbed porous structure SiO₂Adding the solution D into the precursor, and continuously stirring for 3-4 h to enable Zr-OH to be adsorbed and deposited on the porous SiO₂Adding an ethanol solution of a polyoxyethylene polyoxypropylene ether segmented copolymer into the precursor structure for demulsification, and finally obtaining a pigment-coated precursor precipitate through centrifugal separation;

(6) and (3) cleaning the precipitate obtained in the step (5) by using deionized water and industrial ethanol once respectively, drying at 80-100 ℃ for 6h, rapidly heating to 500 ℃ at a speed of 20-25 ℃/min, keeping the temperature for 1h, heating to 850-1000 ℃ at a speed of 5 ℃/min, and calcining for 1h to obtain the zirconium silicate coated cadmium sulfoselenide pigment.

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