A red color paste for color photoresist and a preparation method thereof
By combining modified pigment Red 177 with antioxidants, the problems of uneven dispersion and unstable storage of red pigment paste in photoresist were solved, achieving high dispersibility and long-term stability, and ensuring the color uniformity and weather resistance of the photoresist.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- MAOMING QINGHE TECH CO LTD
- Filing Date
- 2026-02-11
- Publication Date
- 2026-06-02
AI Technical Summary
The red pigment paste in photoresist is prone to agglomeration due to its nano-sized pigment particles and sensitivity to temperature and light, resulting in poor dispersion stability, which affects coating uniformity and color consistency, and also has a short storage time.
Modified pigment Red 177, tea polyphenols, ascorbic acid and polydimethyldiallylammonium chloride modifiers, combined with antioxidants coated with β-cyclodextrin, are used to construct a dual-stabilized structure of "adsorption-steric hindrance" through ultrasonic dispersion and freeze-drying treatment, which improves dispersibility and stability. Undispersed particles are removed by pressure filtration.
It achieves high dispersion stability and long-term storage of red pigment, avoids color difference and uneven color after photoresist film formation, and extends the weather resistance and color durability of photoresist products.
Smart Images
Figure SMS_2
Abstract
Description
Technical Field
[0001] This invention relates to the field of photoresist technology, and in particular to a red pigment for color photoresist and its preparation method. Background Technology
[0002] The red pigment in photoresist is a key functional material used to manufacture the red pixel portion of the color filter in a liquid crystal display (LCD).
[0003] The drawbacks of red pigment paste for photoresist are: nanoscale pigment particles are prone to aggregation and sedimentation due to their high surface energy, resulting in poor dispersion stability and affecting coating uniformity; during storage or processing, the pigment paste is sensitive to temperature and light, and solvent evaporation or chemical reactions of components can accelerate the decay of the red hue, shortening the effective storage time; finally, after film formation, uneven pigment distribution, particle size differences, or fluctuations in the baking process can directly cause color differences in the film layer, affecting color consistency and display effect. Based on this, the present invention provides a red pigment paste for color photoresist and its preparation method. Summary of the Invention
[0004] The main objective of this invention is to provide a red pigment paste for color photoresist with good dispersibility and long shelf life, which is applied to a red pigment paste for color photoresist and its preparation method.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a red pigment paste for color photoresist, wherein the red pigment paste for color photoresist is composed of the following raw materials in parts by weight: 17-19 parts modified pigment red 177, 56-58 parts propylene glycol methyl ether acetate, 2.2-2.4 parts poly(methacrylic acid-co-acrylate) copolymer, 9-10 parts acrylate resin, 1-1.2 parts styrene-maleic anhydride copolymer, and 0.42-0.56 parts antioxidant.
[0006] The styrene-maleic anhydride copolymer has a maleic anhydride content of 12% and an average molecular weight of 8000. The average molecular weight of acrylate resins is 10,000-15,000; The solid content of the poly(methacrylic acid-co-acrylate) copolymer is 50%. Propylene glycol methyl ether acetate is photolithography grade, with a moisture content ≤50ppm; Furthermore, the preparation of the modified pigment Red 177 includes the following steps: A1. Place Pigment Red 177 into an air jet mill for pulverization. Set the inlet pressure to 0.6-0.8 MPa and the classifier speed to 3000 rpm. Pulverize for 5-8 minutes. Place the pulverized Pigment Red 177 into a vacuum drying oven for drying. Set the vacuum degree to -0.09 MPa and the temperature to 80℃. Dry for 3 hours to obtain dried Pigment Red 177 granules. A2. Place tea polyphenols and ascorbic acid into an agate mortar and grind for 5 minutes. Then pass the mixture through a 400-mesh sieve to obtain the modifier. A3. Add the dried pigment Red 177 particles to a high-speed plow mixer and stir at 1500 rpm for 5 minutes. Add the modifier and stir for 10 minutes. Add polydimethyldiallyl ammonium chloride and stir. Set the temperature to 50℃, increase the speed to 2000 rpm, and stir for 60 minutes to obtain a mixed pigment. Place the mixed pigment in a vacuum drying oven and dry at 60℃ and a vacuum degree of -0.09 MPa for 2 hours. Allow it to cool naturally to 25℃ to obtain the modified pigment Red 177.
[0007] By using a composite modifier of tea polyphenols and ascorbic acid, combined with surface treatment of polydimethyldiallylammonium chloride, the dispersibility of pigments and the stability of color pastes can be improved. Furthermore, the mass ratio of pigment red 177, tea polyphenols, ascorbic acid, and polydimethyldiallylammonium chloride is 68:4:1:232.
[0008] Furthermore, the polydimethyldiallylammonium chloride is a 20% aqueous solution with a molecular weight of 120,000-180,000.
[0009] Furthermore, the purity of the pigment red 177 is ≥99.5%, and the particle size of the pulverized pigment red 177 is 1-3 μm.
[0010] Furthermore, the preparation of the antioxidant includes the following steps: S1. Add deionized water to the reaction vessel and stir. Set the temperature to 40℃ and the speed to 800 rpm. Add β-cyclodextrin and stir for 10 minutes. Add pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] and UV-327 and stir for 15 minutes at 800 rpm to obtain a suspension. S2. Disperse the suspension in an ultrasonic cell disruptor, set the power to 500W, pulse mode, and disperse for 10 minutes. Place the dispersed suspension in a freeze dryer and freeze for 2 hours at -50℃. Set the vacuum degree of the freeze dryer to ≤10Pa and dry for 8 hours to obtain a freeze antioxidant. Place the freeze antioxidant in a planetary ball mill and grind for 30 minutes at 500rpm to obtain an antioxidant.
[0011] β-Cyclodextrin encapsulates two antioxidant components (pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] + UV-327), and combined with ultrasonic dispersion and freeze-drying processes, it can enhance the compatibility of antioxidants with the color paste system; Furthermore, the mass ratio of the deionized water, β-cyclodextrin, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] to UV-327 is 21:0.8:1:1.
[0012] UV-327 is 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole; Secondly, the present invention also provides a method for preparing a red pigment paste for a color photoresist, comprising the following preparation steps: Modified pigment Red 177 was added to a high-speed shear mill, and propylene glycol methyl ether acetate was added and stirred at 3000 rpm for 20 minutes. The speed was then increased to 12000 rpm and stirred for 50 minutes to obtain a slurry. The slurry was then placed in a grinding mill, zirconium beads were added, and the speed was set to 2000 rpm while controlling the temperature to ≤45℃. The milling process was carried out for 3 hours. The zirconium beads were then filtered out using a stainless steel filter. The ground slurry was then added to a reaction vessel, and poly(methacrylic acid-co-acrylate) copolymer was added and stirred at 2000 rpm for 20 minutes. The temperature was then raised to 50℃, and styrene-maleic anhydride copolymer was added and stirred for 30 minutes. An antioxidant was added and stirred at 2000 rpm for 30 minutes. Propylene glycol methyl ether acetate was then added to obtain a mixed slurry. The mixed slurry was then filtered under pressure using a positive pressure filter to obtain a red pigment paste for use in color photoresist.
[0013] The initial addition of propylene glycol methyl ether acetate accounts for 98%-100% of the total mass of propylene glycol methyl ether acetate; Add propylene glycol methyl ether acetate to adjust the slurry viscosity to 100±20 mPa at 25℃. s; Furthermore, the positive pressure filter is supplied with nitrogen gas and set at a pressure of 0.2 MPa, and uses a polytetrafluoroethylene filter membrane with a pore size of 0.22 μm.
[0014] Furthermore, the pore size of the stainless steel filter screen is 50-100μm; The mass ratio of zirconium beads to slurry is 1.5:1; The diameter of the zirconium beads is 0.2 mm.
[0015] The present invention has the following beneficial effects: 1. In this invention, modified pigment Red 177 is added as a core colorant, which can ensure high tinting strength and bright red tone to meet the color requirements of colored photoresist; after airflow pulverization, it is adapted to the fine film formation and high resolution requirements of photoresist; and through modification with tea polyphenols, ascorbic acid and polydimethyldiallylammonium chloride, the surface polarity is optimized, particle agglomeration is greatly reduced, and the dispersion stability in the color paste system is improved.
[0016] 2. In this invention, an antioxidant is added. The antioxidant is made by coating pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] with UV-327 via β-cyclodextrin. The hindered phenolic component can effectively inhibit thermo-oxidative aging and prevent the performance of the pigment paste from degrading due to oxidation during high-temperature film formation. UV-327 can block the degradation of the pigment paste by ultraviolet light and prevent the red tone from fading. After β-cyclodextrin coating, ultrasonic dispersion and freeze-drying, the compatibility between the antioxidant and the pigment paste system is greatly improved, and there will be no problem of antioxidant precipitation, which will avoid affecting the performance of the photoresist. Ultimately, it will extend the storage life of the pigment paste and the weather resistance of the photoresist product, making the red tone more durable.
[0017] 3. In this invention, modified pigment red 177, poly(methacrylic acid-co-acrylate) copolymer, and polydimethyldiallyl ammonium chloride are added. The three work synergistically. The modified groups on the surface of modified pigment red 177 can form a stable adsorption with the cationic groups of polydimethyldiallyl ammonium chloride. Combined with the steric hindrance effect of poly(methacrylic acid-co-acrylate) copolymer, a dual stable structure of "adsorption-steric hindrance" is constructed. This synergistic effect can inhibit the agglomeration of pigment particles and allow the pigment to be uniformly dispersed in propylene glycol methyl ether acetate solvent. Ultimately, it can ensure that the color paste is uniform and delicate, and avoid color difference or pattern blurring after the photoresist film is formed. Detailed Implementation
[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0019] It should be noted that all raw materials used in the following experiments are commercially available.
[0020] Example 1: A red pigment paste for color photoresist, wherein the red pigment paste for color photoresist is composed of the following raw materials in parts by weight: 17 parts modified pigment red 177, 56 parts propylene glycol methyl ether acetate, 2.2 parts poly(methacrylic acid-co-acrylate) copolymer, 9 parts acrylate resin, 1 part styrene-maleic anhydride copolymer and 0.42 parts antioxidant.
[0021] The preparation of modified pigment Red 177 includes the following steps: A1. Place Pigment Red 177 into an air jet mill for pulverization. Set the inlet pressure to 0.6-0.8 MPa and the classifier speed to 3000 rpm. Pulverize for 5-8 minutes. Place the pulverized Pigment Red 177 into a vacuum drying oven for drying. Set the vacuum degree to -0.09 MPa and the temperature to 80℃. Dry for 3 hours to obtain dried Pigment Red 177 granules. A2. Place tea polyphenols and ascorbic acid into an agate mortar and grind for 5 minutes. Then pass the mixture through a 400-mesh sieve to obtain the modifier. A3. Add the dried pigment Red 177 particles to a high-speed plow mixer and stir at 1500 rpm for 5 minutes. Add the modifier and stir for 10 minutes. Add polydimethyldiallyl ammonium chloride and stir. Set the temperature to 50℃, increase the speed to 2000 rpm, and stir for 60 minutes to obtain a mixed pigment. Place the mixed pigment in a vacuum drying oven and dry at 60℃ and a vacuum degree of -0.09 MPa for 2 hours. Allow it to cool naturally to 25℃ to obtain the modified pigment Red 177.
[0022] The mass ratio of Pigment Red 177, tea polyphenols, ascorbic acid, and polydimethyldiallyl ammonium chloride is 68:4:1:232.
[0023] Polydimethyl diallyl ammonium chloride is a 20% aqueous solution with a molecular weight of 120,000-180,000.
[0024] Pigment Red 177 has a purity of ≥99.5% and a particle size of 1-3μm after pulverization.
[0025] The preparation of antioxidants includes the following steps: S1. Add deionized water to the reaction vessel and stir. Set the temperature to 40℃ and the speed to 800 rpm. Add β-cyclodextrin and stir for 10 minutes. Add pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] and UV-327 and stir for 15 minutes at 800 rpm to obtain a suspension. S2. Disperse the suspension in an ultrasonic cell disruptor, set the power to 500W, pulse mode, and disperse for 10 minutes. Place the dispersed suspension in a freeze dryer and freeze for 2 hours at -50℃. Set the vacuum degree of the freeze dryer to ≤10Pa and dry for 8 hours to obtain a freeze antioxidant. Place the freeze antioxidant in a planetary ball mill and grind for 30 minutes at 500rpm to obtain an antioxidant.
[0026] The mass ratio of deionized water, β-cyclodextrin, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and UV-327 was 21:0.8:1:1.
[0027] Secondly, the present invention also provides a method for preparing a red pigment paste for a color photoresist, comprising the following preparation steps: Modified pigment Red 177 was added to a high-speed shear mill, and propylene glycol methyl ether acetate was added and stirred at 3000 rpm for 20 minutes. The speed was then increased to 12000 rpm and stirred for 50 minutes to obtain a slurry. The slurry was then placed in a grinding mill, zirconium beads were added, and the speed was set to 2000 rpm while controlling the temperature to ≤45℃. The milling process was carried out for 3 hours. The zirconium beads were then filtered out using a stainless steel filter. The ground slurry was then added to a reaction vessel, and poly(methacrylic acid-co-acrylate) copolymer was added and stirred at 2000 rpm for 20 minutes. The temperature was then raised to 50℃, and styrene-maleic anhydride copolymer was added and stirred for 30 minutes. An antioxidant was added and stirred at 2000 rpm for 30 minutes. Propylene glycol methyl ether acetate was then added to obtain a mixed slurry. The mixed slurry was then filtered under pressure using a positive pressure filter to obtain a red pigment paste for use in color photoresist.
[0028] Nitrogen gas was introduced into the positive pressure filter, and the pressure was set to 0.2 MPa. A polytetrafluoroethylene filter membrane with a pore size of 0.22 μm was used.
[0029] The pore size of the stainless steel filter screen is 50-100μm; The mass ratio of the zirconium beads to the slurry is 1.5:1; The zirconium beads have a diameter of 0.2 mm.
[0030] Example 2, a red pigment paste for color photoresist, wherein the red pigment paste for color photoresist is composed of the following raw materials in parts by weight: 18 parts modified pigment red 177, 57 parts propylene glycol methyl ether acetate, 2.3 parts poly(methacrylic acid-co-acrylate) copolymer, 9.5 parts acrylate resin, 1.1 parts styrene-maleic anhydride copolymer and 0.49 parts antioxidant.
[0031] The preparation of modified pigment Red 177 includes the following steps: A1. Place Pigment Red 177 into an air jet mill for pulverization. Set the inlet pressure to 0.6-0.8 MPa and the classifier speed to 3000 rpm. Pulverize for 5-8 minutes. Place the pulverized Pigment Red 177 into a vacuum drying oven for drying. Set the vacuum degree to -0.09 MPa and the temperature to 80℃. Dry for 3 hours to obtain dried Pigment Red 177 granules. A2. Place tea polyphenols and ascorbic acid into an agate mortar and grind for 5 minutes. Then pass the mixture through a 400-mesh sieve to obtain the modifier. A3. Add the dried pigment Red 177 particles to a high-speed plow mixer and stir at 1500 rpm for 5 minutes. Add the modifier and stir for 10 minutes. Add polydimethyldiallyl ammonium chloride and stir. Set the temperature to 50℃, increase the speed to 2000 rpm, and stir for 60 minutes to obtain a mixed pigment. Place the mixed pigment in a vacuum drying oven and dry at 60℃ and a vacuum degree of -0.09 MPa for 2 hours. Allow it to cool naturally to 25℃ to obtain the modified pigment Red 177.
[0032] The mass ratio of Pigment Red 177, tea polyphenols, ascorbic acid, and polydimethyldiallyl ammonium chloride is 68:4:1:232.
[0033] Polydimethyl diallyl ammonium chloride is a 20% aqueous solution with a molecular weight of 120,000-180,000.
[0034] Pigment Red 177 has a purity of ≥99.5% and a particle size of 1-3μm after pulverization.
[0035] The preparation of antioxidants includes the following steps: S1. Add deionized water to the reaction vessel and stir. Set the temperature to 40℃ and the speed to 800 rpm. Add β-cyclodextrin and stir for 10 minutes. Add pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] and UV-327 and stir for 15 minutes at 800 rpm to obtain a suspension. S2. Disperse the suspension in an ultrasonic cell disruptor, set the power to 500W, pulse mode, and disperse for 10 minutes. Place the dispersed suspension in a freeze dryer and freeze for 2 hours at -50℃. Set the vacuum degree of the freeze dryer to ≤10Pa and dry for 8 hours to obtain a freeze antioxidant. Place the freeze antioxidant in a planetary ball mill and grind for 30 minutes at 500rpm to obtain an antioxidant.
[0036] The mass ratio of deionized water, β-cyclodextrin, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and UV-327 was 21:0.8:1:1.
[0037] Secondly, the present invention also provides a method for preparing a red pigment paste for a color photoresist, comprising the following preparation steps: Modified pigment Red 177 was added to a high-speed shear mill, and propylene glycol methyl ether acetate was added and stirred at 3000 rpm for 20 minutes. The speed was then increased to 12000 rpm and stirred for 50 minutes to obtain a slurry. The slurry was then placed in a grinding mill, zirconium beads were added, and the speed was set to 2000 rpm while controlling the temperature to ≤45℃. The milling process was carried out for 3 hours. The zirconium beads were then filtered out using a stainless steel filter. The ground slurry was then added to a reaction vessel, and poly(methacrylic acid-co-acrylate) copolymer was added and stirred at 2000 rpm for 20 minutes. The temperature was then raised to 50℃, and styrene-maleic anhydride copolymer was added and stirred for 30 minutes. An antioxidant was added and stirred at 2000 rpm for 30 minutes. Propylene glycol methyl ether acetate was then added to obtain a mixed slurry. The mixed slurry was then filtered under pressure using a positive pressure filter to obtain a red pigment paste for use in color photoresist.
[0038] Nitrogen gas was introduced into the positive pressure filter, and the pressure was set to 0.2 MPa. A polytetrafluoroethylene filter membrane with a pore size of 0.22 μm was used.
[0039] The pore size of the stainless steel filter screen is 50-100μm; The mass ratio of the zirconium beads to the slurry is 1.5:1; The zirconium beads have a diameter of 0.2 mm.
[0040] Example 3: A red pigment paste for color photoresist, wherein the red pigment paste for color photoresist is composed of the following raw materials in parts by weight: 19 parts modified pigment red 177, 58 parts propylene glycol methyl ether acetate, 2.4 parts poly(methacrylic acid-co-acrylate) copolymer, 10 parts acrylate resin, 1.2 parts styrene-maleic anhydride copolymer and 0.56 parts antioxidant.
[0041] The preparation of modified pigment Red 177 includes the following steps: A1. Place Pigment Red 177 into an air jet mill for pulverization. Set the inlet pressure to 0.6-0.8 MPa and the classifier speed to 3000 rpm. Pulverize for 5-8 minutes. Place the pulverized Pigment Red 177 into a vacuum drying oven for drying. Set the vacuum degree to -0.09 MPa and the temperature to 80℃. Dry for 3 hours to obtain dried Pigment Red 177 granules. A2. Place tea polyphenols and ascorbic acid into an agate mortar and grind for 5 minutes. Then pass the mixture through a 400-mesh sieve to obtain the modifier. A3. Add the dried pigment Red 177 particles to a high-speed plow mixer and stir at 1500 rpm for 5 minutes. Add the modifier and stir for 10 minutes. Add polydimethyldiallyl ammonium chloride and stir. Set the temperature to 50℃, increase the speed to 2000 rpm, and stir for 60 minutes to obtain a mixed pigment. Place the mixed pigment in a vacuum drying oven and dry at 60℃ and a vacuum degree of -0.09 MPa for 2 hours. Allow it to cool naturally to 25℃ to obtain the modified pigment Red 177.
[0042] The mass ratio of Pigment Red 177, tea polyphenols, ascorbic acid, and polydimethyldiallyl ammonium chloride is 68:4:1:232.
[0043] Polydimethyl diallyl ammonium chloride is a 20% aqueous solution with a molecular weight of 120,000-180,000.
[0044] Pigment Red 177 has a purity of ≥99.5% and a particle size of 1-3μm after pulverization.
[0045] The preparation of antioxidants includes the following steps: S1. Add deionized water to the reaction vessel and stir. Set the temperature to 40℃ and the speed to 800 rpm. Add β-cyclodextrin and stir for 10 minutes. Add pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] and UV-327 and stir for 15 minutes at 800 rpm to obtain a suspension. S2. Disperse the suspension in an ultrasonic cell disruptor, set the power to 500W, pulse mode, and disperse for 10 minutes. Place the dispersed suspension in a freeze dryer and freeze for 2 hours at -50℃. Set the vacuum degree of the freeze dryer to ≤10Pa and dry for 8 hours to obtain a freeze antioxidant. Place the freeze antioxidant in a planetary ball mill and grind for 30 minutes at 500rpm to obtain an antioxidant.
[0046] The mass ratio of deionized water, β-cyclodextrin, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and UV-327 was 21:0.8:1:1.
[0047] Secondly, the present invention also provides a method for preparing a red pigment paste for a color photoresist, comprising the following preparation steps: Modified pigment Red 177 was added to a high-speed shear mill, and propylene glycol methyl ether acetate was added and stirred at 3000 rpm for 20 minutes. The speed was then increased to 12000 rpm and stirred for 50 minutes to obtain a slurry. The slurry was then placed in a grinding mill, zirconium beads were added, and the speed was set to 2000 rpm while controlling the temperature to ≤45℃. The milling process was carried out for 3 hours. The zirconium beads were then filtered out using a stainless steel filter. The ground slurry was then added to a reaction vessel, and poly(methacrylic acid-co-acrylate) copolymer was added and stirred at 2000 rpm for 20 minutes. The temperature was then raised to 50℃, and styrene-maleic anhydride copolymer was added and stirred for 30 minutes. An antioxidant was added and stirred at 2000 rpm for 30 minutes. Propylene glycol methyl ether acetate was then added to obtain a mixed slurry. The mixed slurry was then filtered under pressure using a positive pressure filter to obtain a red pigment paste for use in color photoresist.
[0048] Nitrogen gas was introduced into the positive pressure filter, and the pressure was set to 0.2 MPa. A polytetrafluoroethylene filter membrane with a pore size of 0.22 μm was used.
[0049] The pore size of the stainless steel filter screen is 50-100μm; The mass ratio of the zirconium beads to the slurry is 1.5:1; The zirconium beads have a diameter of 0.2 mm.
[0050] Comparative Example 1: The difference between this comparative example and Example 1 is that: The pigment used in this comparative example is modified pigment Red 177.
[0051] Comparative Example 2: The difference between this comparative example and Example 1 is that: The antioxidants in this comparative example do not contain β-cyclodextrin.
[0052] Comparative Example 3 differs from Example 1 in that: This comparative example does not contain mixed slurry and was not pressure filtered.
[0053] Performance testing: The red pigments for color photoresists prepared in Examples 1, 2, 3, Comparative Examples 1, 2, and 3 were tested.
[0054] Performance testing: The relevant properties of the red pigment paste for color photoresist and its preparation method provided in Examples 1-3 and Comparative Examples 1-3 were tested respectively, and the test data are recorded in Table 1 below: Table 1 - Test data of the prepared red pigment for color photoresist Based on the above data, the following conclusions can be drawn: (1) The initial color difference ΔE results of Examples 1-3 are far better than those of Comparative Examples 1-3. The key point is that the examples added modified Pigment Red 177. Pigment Red 177 was modified by tea polyphenols, ascorbic acid and polydimethyldiallylammonium chloride, which optimized the surface polarity, greatly reduced particle agglomeration, and improved the dispersion stability in the color paste system.
[0055] (2) The photostability ΔE of Examples 1-3 is much better than that of Comparative Examples 1-3. The key point is that the examples add β-cyclodextrin, which can coat pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and UV-327. After ultrasonic dispersion and freeze-drying, the compatibility between the antioxidant and the pigment system is greatly improved.
[0056] (3) The clarity of Examples 1-3 is better than that of Comparative Examples 1-3. The key point is that the examples reduce the number of visible microparticles in the pigment paste by adding pressure filtration to trap incompletely dispersed pigment agglomerates, thereby solving the defects such as pinholes and bright spots formed during photolithography coating.
[0057] Through the above demonstrations, the present invention is significantly superior to the control group in terms of initial color difference ΔE, photostability ΔE, and clarity, thus verifying the advanced nature and rationality of the preparation process.
[0058] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0059] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A red pigment for use in color photoresist, characterized in that, The red pigment paste used for color photoresist is composed of the following raw materials in parts by weight: 17-19 parts modified pigment red 177, 56-58 parts propylene glycol methyl ether acetate, 2.2-2.4 parts poly(methacrylic acid-co-acrylate) copolymer, 9-10 parts acrylate resin, 1-1.2 parts styrene-maleic anhydride copolymer, and 0.42-0.56 parts antioxidant.
2. The red pigment for color photoresist according to claim 1, characterized in that, The preparation of the modified pigment Red 177 includes the following steps: A1. Place Pigment Red 177 into an air jet mill for pulverization. Set the inlet pressure to 0.6-0.8 MPa and the classifier speed to 3000 rpm. Pulverize for 5-8 minutes. Place the pulverized Pigment Red 177 into a vacuum drying oven for drying. Set the vacuum degree to -0.09 MPa and the temperature to 80℃. Dry for 3 hours to obtain dried Pigment Red 177 granules. A2. Place tea polyphenols and ascorbic acid into an agate mortar and grind for 5 minutes. Then pass the mixture through a 400-mesh sieve to obtain the modifier. A3. Add the dried pigment Red 177 particles to a high-speed plow mixer and stir at 1500 rpm for 5 minutes. Add the modifier and stir for 10 minutes. Add polydimethyldiallyl ammonium chloride and stir. Set the temperature to 50℃, increase the speed to 2000 rpm, and stir for 60 minutes to obtain a mixed pigment. Place the mixed pigment in a vacuum drying oven and dry at 60℃ and a vacuum degree of -0.09 MPa for 2 hours. Allow it to cool naturally to 25℃ to obtain the modified pigment Red 177.
3. The red pigment for color photoresist according to claim 2, characterized in that, The mass ratio of pigment red 177, tea polyphenols, ascorbic acid, and polydimethyldiallyl ammonium chloride is 68:4:1:
232.
4. The red pigment for color photoresist according to claim 2, characterized in that, The polydimethyldiallylammonium chloride is a 20% aqueous solution with a molecular weight of 120,000-180,000.
5. The red pigment for color photoresist according to claim 2, characterized in that, The purity of the pigment red 177 is ≥99.5%, and the particle size of the pulverized pigment red 177 is 1-3μm.
6. The red pigment for color photoresist according to claim 2, characterized in that, The preparation of the antioxidant includes the following steps: S1. Add deionized water to the reaction vessel and stir. Set the temperature to 40℃ and the speed to 800 rpm. Add β-cyclodextrin and stir for 10 minutes. Add pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] and UV-327 and stir for 15 minutes at 800 rpm to obtain a suspension. S2. Disperse the suspension in an ultrasonic cell disruptor, set the power to 500W, pulse mode, and disperse for 10 minutes. Place the dispersed suspension in a freeze dryer and freeze for 2 hours at -50℃. Set the vacuum degree of the freeze dryer to ≤10Pa and dry for 8 hours to obtain a freeze antioxidant. Place the freeze antioxidant in a planetary ball mill and grind for 30 minutes at 500rpm to obtain an antioxidant.
7. The red pigment for color photoresist according to claim 6, characterized in that, The mass ratio of deionized water, β-cyclodextrin, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and UV-327 is 21:0.8:1:
1.
8. A method for preparing a red pigment paste for color photoresist, comprising the red pigment paste for color photoresist according to any one of claims 1-7, characterized in that, The preparation steps include: adding modified pigment Red 177 to a high-speed shear mill, adding propylene glycol methyl ether acetate and stirring at 3000 rpm for 20 minutes; increasing the speed to 12000 rpm and stirring for 50 minutes to obtain a slurry; placing the slurry in a grinding mill, adding zirconium beads, setting the speed to 2000 rpm, controlling the temperature ≤45℃, and grinding for 3 hours; filtering out the zirconium beads using a stainless steel filter; adding the ground slurry to a reaction vessel, adding poly(methacrylic acid-co-acrylate) copolymer and stirring at 2000 rpm for 20 minutes; heating the temperature to 50℃, adding styrene-maleic anhydride copolymer and stirring for 30 minutes; adding an antioxidant and stirring at 2000 rpm for 30 minutes; adding propylene glycol methyl ether acetate to obtain a mixed slurry; and using a positive pressure filter to pressurize and filter the mixed slurry to obtain a red pigment paste for color photoresist.
9. The red pigment for color photoresist according to claim 8, characterized in that, The positive pressure filter is supplied with nitrogen gas and set at a pressure of 0.2 MPa. It uses a polytetrafluoroethylene filter membrane with a pore size of 0.22 μm.
10. The red pigment for color photoresist according to claim 8, characterized in that, The pore size of the stainless steel filter screen is 50-100μm; The mass ratio of the zirconium beads to the slurry is 1.5:1; The zirconium beads have a diameter of 0.2 mm.