A method for producing powdered pigment

Abstract

The present invention discloses a method for producing a novel powder pigment. The method specifically comprises the following steps: (1) applying a photonic crystal emulsion to the surface of a supporting substrate, and forming an opal-structured photonic crystal after drying; (2) applying a ceramic precursor material to the opal-structured photonic crystal, and sintering the resulting material after curing to form an inverse opal-structured photonic crystal; and (3) crushing the inverse opal-structured photonic crystal to form a powder, thereby obtaining a photonic crystal powder pigment. The inverse opal-structured photonic crystal powder pigment obtained by the present invention can impart richer colors and metallic luster to inks. Furthermore, due to the addition of the ceramic precursor, the crushed photonic crystal pigment has excellent strength and hardness, thereby improving the mechanical properties of the ink coating.

Description

Technical Field

[0001] The invention belongs to the technical field of pigment preparation, and particularly relates to a method for preparing a novel powdered pigment. Background Art

[0002] Pigments refer to highly dispersible colored, black or white powders that are insoluble in water and organic solvents. They can be widely used in inks, coatings, plastics, rubber, ceramics and other fields, giving products special decorative and functional properties.

[0003] Pigments are categorized into organic and inorganic pigments. Organic pigments can be divided into azo pigments, phthalocyanine pigments, heterocyclic pigments, lake pigments, dyes, fluorescent brighteners, and fluorescent pigments, depending on their structure. Inorganic pigments are typically metal oxides, sulfides, sulfates, chromates, molybdates, and other salts, as well as carbon black. Inorganic pigments generally have better thermal and light stability than organic pigments, but their tinting strength is inferior. Furthermore, they have a higher relative density and poorer dispersion stability than organic pigments.

[0004] With the development of science and technology, people's consumption demand for special colors, anti-counterfeiting requirements for commercial packaging, special functional needs in various fields, etc., have led to the gradual development of special pigments such as pearlescent pigments, liquid crystal pigments, color-changing pigments, and metallic pigments that have coloring effects different from traditional pigments.

[0005] As a photonic bandgap material, photonic crystals achieve diffraction of light through their periodic arrangement. While the material itself is colorless, they selectively reflect incident light, achieving observable rainbow-like bright colors. At the same time, their colors have a distinct metallic luster. Summary of the Invention

[0006] The purpose of the present invention is to provide a novel photonic crystal powder pigment having the characteristics of excellent heat stability, light stability, low density, solvent resistance, high strength and high hardness, and a method for preparing the same, as well as applying the same to the preparation of inks or coatings. By adjusting the microsphere particle size and sintering process, an inverse opal structure of different air ball sizes can be obtained. The different air ball sizes will cause the photon band gap color to change, so that the pigment can adjust the reflection wavelength from long-wavelength red to short-wavelength purple. The photonic crystal powder pigment of the present invention can be added to the ink or coating of the prior art in the form of a blend, and the added ink or coating can be a colorless system or a colored system. After the photonic crystal pigment of the present invention is added, its ink or coating system can also show the color of the photonic crystal structure.

[0007] The preparation method of the novel powder pigment is as follows:

[0008] (1) Coating a photonic crystal emulsion on the surface of a supporting substrate to form an opal-structured photonic crystal after drying;

[0009] (2) coating a ceramic precursor material on the opal structure photonic crystal, curing it, and sintering it to form an inverse opal structure photonic crystal;

[0010] (3) The photonic crystals with an inverse opal structure are crushed to form powders to obtain photonic crystal powder pigments.

[0011] The photonic crystal emulsion is a monodisperse organic polymer emulsion with a solid content of 5-60wt%, wherein the organic polymer is selected from one or more of polystyrene, vinyl acetate resin, polyacrylate, polyurethane, and polystyrene-acrylic acid; the particle size of the organic polymer is 150-800nm, and the monodispersity index is ≤0.05.

[0012] The supporting substrate is a glass plate, a metal plate, a ceramic plate or a plastic plate.

[0013] The thickness of the opal-structured photonic crystal obtained in step (1) is 1-40µm, preferably 2-20µm. When the photonic crystal layer is too thin, the photonic band gap intensity is weakened due to the small number of three-dimensional photonic crystal layers, resulting in a weaker structural color. When the photonic crystal layer is too thick, a large number of drying stress cracks will be formed during the coating and drying, resulting in a large number of ground crack-type defects in the three-dimensional photonic crystal, which seriously affects the overall arrangement regularity.

[0014] The ceramic precursor material is selected from one or more of phenolic resin, silicone resin, epoxy resin, polyphenyl resin, polysiloxane, polysilazane, boron-modified phenolic resin, and boron-modified silazane.

[0015] The sintering temperature is 300-1300° C., and the sintering environment is air, argon, ammonia or nitrogen atmosphere.

[0016] The particle size of the photonic crystal powder pigment is less than 30 microns.

[0017] The photonic crystal powder pigment prepared by the above method is used in the preparation of ink or coating.

[0018] The present invention uses an inverse opal structure sintered at high temperature as the main structure of the photonic crystal pigment. By sintering a ceramic precursor, the strength and hardness of the photonic crystal pigment are guaranteed, and at the same time, it obtains more excellent solvent resistance. The inverse opal structure obtained by sintering further reduces the pigment density. Compared with solid photonic crystal pigments, it can significantly reduce its pigment density and improve the dispersion stability of the photonic crystal pigment in ink or coating. The inverse opal pigment after sintering and crushing of the present invention is a flaky structure. After being combined with ink or coating, the photonic crystal pigment doped in the coating is in a short-range ordered and long-range disordered structural state, which can give the ink or coating a special photonic crystal structure color. The artificially synthesized photonic crystal powder pigment imitating natural structural color provided by the present invention can be widely used in the existing ink and coating fields because of its excellent heat stability, light stability, low density, solvent resistance, high strength and high hardness. DETAILED DESCRIPTION

[0019] Example 1:

[0020] (1) The surface of the glass substrate was cleaned and degreased, and then a photonic crystal emulsion (300 nm polystyrene photonic crystal emulsion, solid content 50%, PDI 0.05) was coated using an RDS20 wire rod. After natural drying for 10 min, an opal structure photonic crystal coating with a thickness of 10 μm was formed;

[0021] (2) Using an RDS20 wire rod, a polysiloxane ceramic precursor material dispersion (50% solid content, n-hexane as the dispersion solvent) was applied to the surface of the opal-structured photonic crystal. After coating, the sample surface became uniform and transparent, and then cured for 5 h under natural conditions with a humidity of 50%.

[0022] (3) The cured sample (polystyrene photonic crystal covered with polysiloxane) was placed in a muffle furnace and heated at a heating rate of 3°C / min to 500°C, kept at this temperature for 2 hours, and then naturally cooled to room temperature. During the heating process, the polystyrene was ablated and removed, leaving the polysilazane material, forming a photonic crystal with an inverse opal structure.

[0023] (4) The sample was crushed and ground in a mortar to form a powder smaller than 30 μm to obtain a blue photonic crystal powder pigment.

[0024] Example 2

[0025] (1) On the surface of the high-temperature resistant glass substrate, a photonic crystal emulsion (450nm polymethacrylate photonic crystal emulsion, solid content 30%, PDI 0.04) was coated with an RDS30 wire rod. After natural drying for 30 minutes, an opal-structured photonic crystal with a thickness of 20µm was formed.

[0026] (2) On the surface of the opal structure photonic crystal, a boron-modified phenolic resin ceramic precursor material was coated using an RDS20 wire rod. After coating, the sample surface became uniform and transparent. After being placed at room temperature for 10 minutes, it was thermally cured at 150°C for 0.5 hours.

[0027] (3) The sample was placed in a tube furnace and heated at a heating rate of 3°C / min in an argon environment to 550°C, kept at this temperature for 2 h, and then naturally cooled to room temperature to form a photonic crystal with an inverse opal structure.

[0028] (4) Crushing and grinding the above sample into powder to obtain yellow photonic crystal powder pigment.

[0029] Example 3

[0030] (1) Using an Iwata HP-CP (0.3 mm) airbrush and a small pressure pump, spray photonic crystal emulsion (400 nm polyurethane photonic crystal emulsion, solid content 20%, PDI 0.03) on the surface of a high-temperature resistant stainless steel substrate. After natural drying for 30 minutes, opal-structured photonic crystals were formed.

[0031] (2) Use an Iwata HP-CP (0.3 mm) spray brush and a small pressure pump to spray boron-modified silazane ceramic precursor material (50% solid content, n-hexane solution) on the sample surface. After spraying, the sample surface becomes uniform and transparent. After standing at room temperature for 10 minutes, heat cure at 150 ° C for 1 hour.

[0032] (3) The sample was placed in a graphite furnace and heated at a heating rate of 1°C / min to 300°C in a nitrogen environment. The temperature was kept at this temperature for 2 h, and then the temperature was further increased at a heating rate of 1°C / min to 600°C. The sample was then naturally cooled to room temperature to form a photonic crystal with an inverse opal structure.

[0033] (4) Crushing and grinding the above sample into powder to obtain a green photonic crystal powder pigment.

[0034] Example 4

[0035] (1) Using an RDS30 wire rod, a photonic crystal emulsion (240 nm polystyrene-acrylic photonic crystal emulsion, solid content 40%, PDI 0.04) was coated on the surface of the ceramic sheet. After natural drying for 30 minutes, an opal-structured photonic crystal was formed.

[0036] (2) Use an Iwata HP-CP (0.3 mm) spray pen and a small pressure pump to spray a photocurable polysilazane ceramic precursor material (solvent-free system) on the sample surface and cure it with a mercury lamp for 2 minutes. After curing, the sample surface becomes uniform and transparent.

[0037] (3) The sample was placed in a tube furnace and heated at a heating rate of 0.5°C / min to 350°C in an argon environment. The temperature was kept at this temperature for 2 h, and then the temperature was continued to be raised at 1°C / min to 1100°C. The sample was then naturally cooled to room temperature to form a photonic crystal with an inverse opal structure.

[0038] (4) The above sample is crushed and ground into powder to obtain a blue-purple photonic crystal powder pigment.

[0039] Example 5

[0040] (1) Using an RDS40 wire rod, a photonic crystal emulsion (246 nm polystyrene photonic crystal emulsion, solid content 40%, PDI 0.04) was coated on the surface of a clean polytetrafluoroethylene sheet. After natural drying for 30 min, an opal-structured photonic crystal was formed.

[0041] (2) On the surface of the sample, a homemade acetylene polyphenylene resin (30% solid content, ethanol solvent, residual weight greater than 90% at 900°C in nitrogen atmosphere) was coated with an RDS40 wire rod. After coating, the sample was dried at room temperature. After drying, the surface of the sample became uniform and transparent. The temperature was raised to 120°C at 5°C per minute in an oven and kept at this temperature for 1 hour. The temperature was then raised to 150°C at 5°C per minute and kept at this temperature for 2 hours to complete the curing of the acetylene polyphenylene resin. The sample was cooled naturally after curing.

[0042] (3) Peeling the cured sample off the surface of the polytetrafluoroethylene sheet;

[0043] (4) The sample was placed in a tube furnace and heated at a heating rate of 0.5°C / min to 350°C in an argon environment, kept at this temperature for 2 h, and then continued to be heated at a rate of 1°C / min to 900°C, and then naturally cooled to room temperature to form a photonic crystal with an inverse opal structure;

[0044] (5) The above sample is crushed and ground into powder to obtain a blue photonic crystal powder pigment.

[0045] Application Example 1:

[0046] Preparation of heat-curing coatings containing photonic crystal powder pigments:

[0047] (1) Preparation of high temperature curing polyester coating: containing 50% polyester resin, 2% curing agent, 1% coupling agent, 45% solvent, and 2% additives (by mass);

[0048] (2) The blue photonic crystal powder pigment in Example 1 is blended and dispersed with the polyester coating in (1) at a mass ratio of 1:15;

[0049] (3) The blended liquid in (2) was brushed onto a metal plate and baked in an oven at 250°C for 30 min to obtain a coating with high strength, high hardness, and a photonic crystal blue color.

[0050] Application Example 2:

[0051] Preparation of heat-curing coatings containing photonic crystal powder pigments:

[0052] (1) Commercially available transparent UV varnish, which can be quickly cured under a 405nm UV-LED light source;

[0053] (2) The yellow photonic crystal powder pigment in Example 2 is blended and dispersed with the transparent UV varnish in (1) at a mass ratio of 1:10;

[0054] (3) The blended liquid in (2) was brush-coated on a PET sheet and cured under a 405 nm UV LED light source for 0.5 min to obtain a coating exhibiting a photonic crystal effect.

[0055] Application Example 3:

[0056] Preparation of heat-curing coatings containing photonic crystal powder pigments:

[0057] (1) Commercially available transparent nail polish can dry naturally at room temperature to harden the conjunctiva;

[0058] (2) Take the blue photonic crystal powder pigment in Example 5 and blend and disperse it with the transparent nail polish in (1) at a mass ratio of 1:20;

[0059] (3) The blended liquid in (2) is applied by brushing on a coated paper board, and the coating is dried naturally after brushing to obtain a coating exhibiting a photonic crystal effect.

[0060] Application Example 4:

[0061] Preparation of heat-curing coatings containing photonic crystal powder pigments:

[0062] (1) White acrylic thermosetting white paint: containing 30% acrylic resin, 63% organic solvent, 5% curing agent, and 2% additives (by mass);

[0063] (2) The green photonic crystal powder pigment in Example 3 was blended and dispersed with the acrylic paint in (1) at a mass ratio of 1:3;

[0064] (3) The blended liquid in (2) is sprayed on the glass surface. After spraying to a certain thickness, it is naturally dried and then cured at 150°C for 30 minutes to obtain a coating showing a green photonic crystal effect.

[0065] The above describes the practicable method of the present invention in detail, but the present invention is not limited thereto. Simple modifications or combinations suitable for the present method within the technical concept of the present invention should be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

[0066] In addition, the various embodiments of the present invention can be arbitrarily combined without contradiction, and as long as they do not violate the concept of the present invention, they should be regarded as the contents disclosed by the present invention.

Claims

1. A method for producing a powder pigment, characterized in that: The specific steps of the production method are: (1) A photonic crystal emulsion was coated on the surface of a ceramic sheet using an RDS30 wire rod, and after natural drying for 30 minutes, an opal structure photonic crystal was formed; the photonic crystal emulsion was a polystyrene-acrylic acid photonic crystal emulsion with a particle size of 240 nm, a solid content of 40%, and a monodispersity index (PDI) of 0.04; (2) On the surface of the sample, use an Iwata HP-CP 0.3mm spray pen with a small pressure pump to spray a photocurable polysilazane ceramic precursor material, a solvent-free system, and cure it with a mercury lamp for 2 minutes. After curing, the sample surface becomes uniform and transparent; (3) The sample was placed in a tube furnace and heated at a heating rate of 0.5°C / min to 350°C in an argon environment. The temperature was kept at this temperature for 2 h, and then the temperature was continued to be raised at 1°C / min to 1100°C. The sample was then naturally cooled to room temperature to form a photonic crystal with an inverse opal structure. (4) The above sample is crushed and ground into powder to obtain a blue-purple photonic crystal powder pigment.

2. A method for producing a powder pigment, characterized in that: The specific steps of the production method are: (1) A photonic crystal emulsion was coated on the surface of a clean polytetrafluoroethylene sheet using an RDS40 wire rod, and after natural drying for 30 minutes, an opal-structured photonic crystal was formed; the photonic crystal emulsion was a polystyrene photonic crystal emulsion with a particle size of 246 nm, a solid content of 40%, and a monodispersity index (PDI) of 0.04; (2) On the surface of the sample, use RDS40 wire rod to coat acetylene polyphenylene resin with ethanol as solvent and 30% solid content. The residual weight is greater than 90% in nitrogen atmosphere at 900℃. After coating, dry at room temperature. After drying, the surface of the sample becomes uniform and transparent. Heat it in an oven at 5℃ per minute to 120℃, keep it warm for 1 hour, and then heat it to 150℃ at 5℃ per minute and keep it warm for 2 hours to complete the curing of acetylene polyphenylene resin. Cool it naturally after curing. (3) Peeling the cured sample off the surface of the polytetrafluoroethylene sheet; (4) The sample was placed in a tube furnace and heated at a heating rate of 0.5°C / min to 350°C in an argon environment, kept at this temperature for 2 h, and then continued to be heated at a rate of 1°C / min to 900°C, and then naturally cooled to room temperature to form a photonic crystal with an inverse opal structure; (5) The above sample is crushed and ground into powder to obtain a blue photonic crystal powder pigment.