Pigment color paste for yellow photoresist

Abstract

The invention belongs to the field of liquid crystal display, and particularly relates to pigment paste for yellow photoresist. The pigment color paste for the yellow photoresist comprises a yellow pigment, resin and a solvent, the yellow pigment comprises a yellow organic pigment and a dispersing agent. The pigment paste for the yellow photoresist prepared by the method has excellent dispersity and stability, so that a higher contrast ratio can be obtained on the performance of an optical filter, and the performance improvement effect is remarkable.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of liquid crystal display, and particularly relates to a yellow photoresist pigment color paste. BACKGROUND

[0002] Color paste is one of the core materials for preparing color photoresist, and its performance directly determines the resolution, color saturation and yield of the final product of the photoresist. Color paste is mainly composed of pigments, resins, solvents and other functional additives, and needs to meet the comprehensive requirements of high temperature resistance, chemical resistance, high color saturation and high transmittance. At present, color paste is mainly applied to the manufacturing process of color filters of liquid crystal displays, and color display is realized through red, green and blue three primary color pixels. In the color paste, the preparation of yellow (pigment) color paste is particularly crucial. If only conventional organic pigments or yellow pigments obtained by ordinary kneading treatment are used, and then the color paste is prepared by grinding and dispersing, it is often difficult to meet the requirement of contrast ratio of 10000 or more. As a colorant, the pigment is one of the main factors affecting the performance of the color paste, and must fully exert its coloring power and brightness to achieve excellent spectral properties. Therefore, during the preparation of the color paste, the pigment particles must be dispersed in the color paste in a fine, uniform and stable state as much as possible. Chinese Patent Application CN117511247A discloses a dispersant applied to high-temperature dispersion ink for improving dispersion stability, but there is no report on its application in photoresist color paste. Since there are significant differences between photoresist color paste and high-temperature dispersion ink in medium composition, process environment and performance requirements, the technical personnel in the field usually cannot predict the feasibility and technical effect of migrating the ink system dispersant to the photoresist color paste, resulting in that there is still room for improvement in the dispersion technology for yellow (pigment) color paste. SUMMARY

[0003] The application aims to provide a yellow photoresist pigment color paste.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows: A yellow photoresist pigment color paste, comprising yellow pigment, resin and solvent; the yellow pigment comprises yellow organic pigment and dispersant. The structure of the dispersant is shown in Formula I:

[0005] In the formula, X is selected from C3-C20 alkyl which is unsubstituted or substituted by at least one substituent, C3-C6 cycloalkyl, C3-C6 heterocyclyl; the substituent is C1-C6 alkyl or phenyl. In the heterocyclyl, the heteroatom is S, N or O.

[0006] The mass ratio of yellow pigment, resin and solvent is 1:2~4:2~4; The resin is selected from one or more of aliphatic polyurethane acrylate, styrene acrylate resin, and polyurethane acrylate.

[0007] The solvent is selected from one or more of ethylene glycol, propylene glycol, glycerol, ethylene glycol monomethyl ether, ethylene glycol methyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol methyl ether acetate, methanol, ethanol, acetone, and cyclohexanone.

[0008] The amount of dispersant used in yellow pigments is 0.01-50% of the mass of the yellow organic pigment.

[0009] The yellow organic pigment is selected from one of PY93, PY110, PY128, PY138, PY139, PY150, and PY151.

[0010] The preparation method of the yellow pigment is as follows: mix and knead the yellow organic pigment, inorganic salt, solvent and dispersant at 0~60℃ for 2~12 hours; after kneading, put the mixture into 60℃ water to precipitate, stir and filter, wash the filter cake to make the pH of the filtrate 7 and the conductivity 50μs / cm, and then dry and crush the filter cake to obtain the yellow pigment.

[0011] The inorganic salt is one or more of sodium chloride, potassium chloride, and sodium sulfate; the dosage is 5 to 20 times that of the yellow organic pigment (w / w). The solvent is one or more of ethylene glycol, diethylene glycol, propylene glycol, and glycerol.

[0012] A method for preparing a yellow pigment paste for photoresist involves adding the yellow pigment, acrylic resin, solvent, and 0.5mm zirconium beads into a sealed container and placing it in a high-speed shaker for 90 minutes. Then, the 0.5mm zirconium beads are replaced with 0.1mm zirconium beads and shaken for another 90 minutes. Finally, the zirconium beads are filtered out to obtain the yellow pigment paste for photoresist.

[0013] The advantages of this invention are: 1. The pigment paste for yellow photoresist of the present invention uses dispersants Y1~Y8, which can significantly improve the thermal storage stability of the pigment paste.

[0014] 2. The present invention adds dispersants Y1~Y8 to the kneading process, which significantly improves the brightness and contrast of the color paste.

[0015] 3. The yellow photoresist pigment paste prepared by the method of the present invention has excellent dispersibility and stability, which can achieve higher contrast in the performance of the filter and significantly improve its performance. Detailed Implementation

[0016] The following specific embodiments are used to further illustrate the present invention, but the present invention is by no means limited to these examples. Various modifications can be made within the scope defined by the claims.

[0017] The yellow organic pigment in the example is commercially available. The solvent, resin, additives, and deionized water are also commercially available. The dispersant was prepared according to the method described in Examples 9-18 of patent CN117511247A, and its structure is as follows.

[0018] Y-1 Y-2 Y-3 Y-4 Y-5 Y-6 Y-7 Y-8 The raw materials and specifications required for this invention are as follows: Diethylene glycol: CAS: 111-46-6; Propylene glycol monomethyl ether acetate, CAS: 108-65-6; PY93, PY110, PY128, PY138, acrylic resin Joncryl 690 (BASF), and dispersant Disponer W-920 (Elementis) are commercially available products.

[0019] The instruments used for performance testing of this invention are: contrast meter: CT-1-STB1, Tsubosaka Electric, Japan; step tester: Dektak XT, Bruker Corporation; nanoparticle size analyzer: Omni, Brukerhaven Instruments, USA; surface tension meter: Brookfield BZY-2. Unless otherwise specified, the weight parts in this invention refer to the weight parts of the active ingredient, i.e., the weight parts of the non-volatile components.

[0020] Example 1 Preparation of yellow pigment: 100g P.Y.138, 800g pulverized NaCl, 180g diethylene glycol, and 2g dispersant Y-1 were mixed in a kneader and kneaded at 60℃ for 6 hours. After kneading, the resulting mixture was placed in 60℃ warm water to precipitate the pigment. After stirring for 1 hour, the mixture was filtered, and the filter cake was repeatedly washed with deionized water until the pH of the filtrate was 7 and the conductivity was 50μs / cm. The filter cake was then vacuum dried at 60℃ and crushed to obtain the yellow pigment.

[0021] Preparation of pigment paste PYL-1: 12g of the yellow pigment prepared above, 25g of acrylic resin Joncryl 690, 62g of propylene glycol methyl ether acetate and 50mL of 0.5mm zirconium beads were added to a sealed container and placed in a high-speed shaker for 90min. The 0.5mm zirconium beads were then replaced with 0.1mm zirconium beads and shaken for another 90min. The zirconium beads were then filtered out to obtain pigment paste PYL-1.

[0022] Example 2 Compared with Example 1, the dispersant was replaced with 5g Y-2, the organic pigment was replaced with PY93, and the mixture was kneaded at 50°C for 8 hours. The amounts of other raw materials and the operation of each step were the same as in Example 1. A yellow pigment paste PYL-2 was obtained.

[0023] Example 3 Compared with Example 1, the dispersant was replaced with 20g Y-3, and the organic pigment was replaced with PY151; the kneading was carried out at 50°C for 8 hours, and the amounts of other raw materials and the operation of each step were the same as in Example 1. A yellow pigment paste PYL-3 was obtained.

[0024] Example 4 Compared with Example 1, the dispersant was replaced with 40g Y-4, and the organic pigment was replaced with PY138; the kneading was carried out at 20°C for 10 hours, and the amounts of other raw materials and the operation of each step were the same as in Example 1. A yellow pigment paste PYL-4 was obtained.

[0025] Example 5 Compared with Example 1, the dispersant was replaced with 5g Y-5, and the organic pigment was replaced with PY93; the kneading was carried out at 60°C for 4 hours, and the amounts of other raw materials and the operation of each step were the same as in Example 1. A yellow pigment paste PYL-5 was obtained.

[0026] Example 6 Compared with Example 1, the dispersant was replaced with 30g Y-6, and the organic pigment was replaced with PY93; the kneading was carried out at 0°C for 8 hours, and the amounts of other raw materials and the operation of each step were the same as in Example 1. A yellow pigment paste PYL-6 was obtained.

[0027] Example 7 Compared with Example 1, the dispersant was replaced with 0.1g Y-7, and the organic pigment was replaced with PY138; the kneading was carried out at 40°C for 8 hours, and the amounts of other raw materials and the operation of each step were the same as in Example 1. A yellow pigment paste PYL-7 was obtained.

[0028] Example 8 Compared with Example 1, the dispersant was replaced with 50g Y-8, and the organic pigment was replaced with PY151; the kneading was carried out at 10°C for 12 hours, and the amounts of other raw materials and the operation of each step were the same as in Example 1. A yellow pigment paste PYL-8 was obtained.

[0029] Comparative Example 1 Compared with Example 1, without adding dispersant Y-1, the other pigment preparation formulas and methods, and the color paste preparation formulas and methods are the same as in Example 1, and yellow color paste PYL-1D is prepared.

[0030] Comparative Example 2 Compared with Example 2, without adding dispersant Y-2, the other pigment preparation formulas and methods, and the color paste preparation formulas and methods are the same as in Example 2, and yellow color paste PYL-2D is prepared.

[0031] Comparative Example 3 Compared with Example 3, without adding dispersant Y-3, the other pigment preparation formulas and methods, and the color paste preparation formulas and methods are the same as in Example 3, and yellow color paste PYL-3D is prepared.

[0032] Comparative Example 4 Compared with Example 4, without adding dispersant Y-4, the other pigment preparation formulas and methods, and the color paste preparation formulas and methods are the same as in Example 4, and yellow color paste PYL-4D is prepared.

[0033] Comparative Example 5 Compared with Example 5, without adding dispersant Y-5, the other pigment preparation formulas and methods, and the color paste preparation formulas and methods are the same as in Example 5, and yellow color paste PYL-5D is prepared.

[0034] Comparative Example 6 Compared with Example 6, without adding dispersant Y-6, the other pigment preparation formulas and methods, and the color paste preparation formulas and methods are the same as in Example 6, and yellow color paste PYL-6D is prepared.

[0035] Comparative Example 7 Compared with Example 7, without adding dispersant Y-7, the other pigment preparation formulas and methods, and the color paste preparation formulas and methods are the same as in Example 7, and yellow color paste PYL-7D is prepared.

[0036] Comparative Example 8 Compared with Example 8, without adding dispersant Y-8, the other pigment preparation formulas and methods, and the color paste preparation formulas and methods are the same as in Example 8, and yellow color paste PYL-8D is prepared.

[0037] Comparative Example 9 Referring to Example 1, 2g of dispersant Y-1 was replaced with 2g of dihydrogenated rosin. The other pigment preparation formulas and methods, as well as the color paste preparation formulas and methods, were the same as in Example 1 to prepare yellow color paste PYL-1D.

[0038] Comparative Example 10 Referring to Example 2, 5g of dispersant Y-2 was replaced with 5g of Disponer W-920. The other pigment preparation formulas and methods, as well as the color paste preparation formulas and methods, were the same as in Example 2 to prepare yellow color paste PYL-1D.

[0039] The following performance indicators were measured for the pigment pastes used in the photoresists of Examples 1-8 and Comparative Examples 1-10 of this invention: 1. Pigment stability: Take approximately 0.1g of pigment, dilute it with 100ml of propylene glycol monomethyl ether acetate, and test the particle size. After storing the pigment in a 60℃ oven for 6 days, dilute it again using the same method and test the particle size.

[0040] 2. Contrast Ratio: 1 ml of yellow pigment was spin-coated onto a glass slide at speeds of 500 rpm, 1500 rpm, and 2000 rpm respectively. The coated glass slides were then placed on a heating plate and heated at 120°C for 90 seconds, followed by heating in an oven at 230°C for 30 minutes. Colorimetry (x, y), brightness, and CR were measured.

[0041] Surface tension: Surface tension is tested using a fully automatic interfacial tension meter / interfacial tension meter.

[0042] Table 1. Comparison of pigment stability

[0043] Table 2. Comparison of luminance Y and contrast at a fixed y value

[0044] Table 3. Surface tension

[0045] Comparing the data in Table 1 and Table 2, we can see that: The initial average particle size (D50) of the pigments described in Examples 1-8 is not significantly different from that of Comparative Examples 1-9. After heat storage, the particle size of Examples 1-8 does not change much from the initial measured particle size index, indicating that it has good stability. However, the particle size of Comparative Examples 1-8 increases significantly after heat storage, indicating that the heat storage stability of Examples 1-8 is better than that of Comparative Examples 1-8.

[0046] Based on the brightness Y data at a fixed y value, the addition of dispersant in the kneading process in Examples 1-8 significantly improved the brightness and contrast of the pigment.

[0047] As shown in Table 3, the surface tension of the examples is relatively stable, with similar data for each group and very little variation; the comparative examples show larger fluctuations because there is no dispersant to assist in stabilization, which ultimately leads to fluctuations.

Claims

1. A pigment paste for yellow photoresist, characterized in that: The yellow photoresist pigment paste comprises a yellow pigment, resin, and solvent; the yellow pigment comprises a yellow organic pigment and a dispersant. The structure of the dispersant is shown in Formula I: Wherein, X is selected from unsubstituted or substituted C3-C20 alkyl, C3-C6 cycloalkyl, and C3-C6 heterocyclic groups; the following substituents are C1-C6 alkyl and phenyl groups; In this case, the heteroatom in the heterocyclic group is S, N, or O.

2. The pigment paste for yellow photoresist according to claim 1, characterized in that: The mass ratio of yellow pigment, resin, and solvent is 1:2~4:2~4.

3. The pigment paste for yellow photoresist according to claim 1, characterized in that: The resin is selected from acrylic resins; The solvent is selected from one or more of ethylene glycol, propylene glycol, glycerol, ethylene glycol monomethyl ether, ethylene glycol methyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol methyl ether acetate, methanol, ethanol, acetone, and cyclohexanone.

4. The pigment paste for yellow photoresist according to claim 1, characterized in that: The amount of dispersant used in yellow pigments is 0.01-50% of the mass of the yellow organic pigment.

5. The pigment paste for yellow photoresist according to claim 1, characterized in that: The yellow organic pigment is selected from one of PY93, PY110, PY128, PY138, PY139, PY150, and PY151.

6. The pigment paste for yellow photoresist according to claim 1, characterized in that: The preparation method of the yellow pigment is as follows: mix and knead the yellow organic pigment, inorganic salt, solvent and dispersant at 0~60℃ for 2~12 hours; after kneading, put the mixture into 60℃ water to precipitate, stir and filter, wash the filter cake to make the pH of the filtrate 7 and the conductivity 50μs / cm, and then dry and crush the filter cake to obtain the yellow pigment.

Images