Application of photoresist dispersing agent

Abstract

The invention relates to the field of liquid crystal display, in particular to application of a photoresist dispersing agent. The photoresist dispersing agent is used for preparing the blue pigment for the color photoresist; the blue pigment for the color photoresist comprises a blue organic pigment and a photoresist dispersing agent; wherein the blue organic pigment is P.B.15: 6. According to the invention, effective adaptation of the dispersing agent for high-temperature dispersing ink in a photoresist system is creatively realized, the application range of the dispersing agent is expanded, and a brand new solution is provided for construction of a high-performance photoresist pigment dispersing system.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal displays, and more specifically to the application of a photoresist dispersant. Background Technology

[0002] The key component for achieving color display in liquid crystal displays (LCDs) is the color filter, whose performance directly determines the quality of the display's color images. Color filters are typically fabricated using color photoresist, making photoresist a core material affecting their performance. To meet the requirements of high-quality displays, color photoresist must possess characteristics such as high temperature resistance, good chemical resistance, high color saturation, and high transmittance. Color photoresist is generally prepared from color pastes, and the core component of color pastes is pigment. Therefore, the physical and chemical properties of the photoresist pigments fundamentally affect the overall performance of the photoresist. Currently, there are still technical bottlenecks in the preparation of high-contrast (e.g., contrast ratio greater than 10000) color pastes. The core problem stems from the shortcomings of existing pigments in terms of miniaturization, homogenization, and dispersion stability. Therefore, during pigment processing, it is essential to make the pigment particles as fine, uniform, and stable as possible to fully utilize the pigment's inherent coloring strength and color vibrancy, thereby obtaining ideal spectral performance.

[0003] Currently, photoresist pigments mainly utilize high-grade organic pigments, relying on dispersion processing to obtain pigment dispersions. However, this process suffers from pigment agglomeration, leading to increased particle size, uneven dispersion, and negatively impacting lithography accuracy and yield. To improve pigment dispersion in the system, dispersants are often used; however, their effectiveness is typically highly specific to a particular system, exhibiting poor cross-system compatibility. For example, Chinese patent application CN117511246A discloses a blue dye derivative suitable as a dispersant in high-temperature direct-injection blue disperse dye inks. While this dispersant demonstrates good dispersibility and thermal stability in high-temperature inkjet printing, its design goals and application scenarios differ fundamentally from those of photoresist systems. High-temperature direct-injection ink systems and photoresist systems differ significantly in chemical compatibility, process matching, and performance focus. To date, no published literature or technical data demonstrates that a dispersant can directly achieve equivalent or superior technical effects in both high-temperature direct-injection ink systems and photoresist systems. Summary of the Invention

[0004] The purpose of this invention is to provide an application of a photoresist dispersant.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An application of a photoresist dispersant, used in the preparation of a blue pigment for color photoresists; The structure of the photoresist dispersant is shown in Formula I:

[0006] Among them, R1, R2, R3, R4, and R5 can be the same or different and are selected from H, -NO2, -CN, -Br, -SO3H, -SO2NH2, -SO2H, or -COOH; R6, R7, R8, and R9 may be the same or different and may be selected from H, -OCH3, -OC2H5, -NHCOCH3, or -NHCOC2H5; X and Y can be the same or different and are selected from -C2H5 or -C2H4OCOCH3; Furthermore, R1, R2, R3, R4, and R5 must be selected from at least -SO3H, -SO2NH2, -SO2H, or -COOH.

[0007] The blue pigment used in the colored photoresist comprises a blue organic pigment and a dispersant.

[0008] The blue organic pigment may be selected from, but is not limited to, PB15:6.

[0009] The amount of photoresist dispersant used is 0.01-50% (w / w) of the amount of blue organic pigment.

[0010] The preparation method of the blue pigment for color photoresist is as follows: a blue organic pigment, an inorganic salt, a solvent and the photoresist dispersant are kneaded together. After kneading, the mixture is placed in water at 60°C to precipitate. After stirring, the mixture is filtered to obtain a filter cake. The filter cake is washed, dried and crushed to obtain the blue pigment for color photoresist.

[0011] The inorganic salt is one or more of sodium chloride, potassium chloride, and sodium sulfate; The solvent is one or more of ethylene glycol, diethylene glycol, propylene glycol, and glycerol; The kneading conditions are: kneading at 0~60℃ for 2~15 hours.

[0012] The filter cake was rinsed to make the pH of the filtrate 7 and the conductivity 50 μs / cm. The filter cake was then vacuum dried at 60℃ and crushed to obtain the blue pigment for color photoresist.

[0013] The blue pigment used in the color photoresist is used to prepare the pigment paste for the color photoresist.

[0014] The pigment paste for color photoresist includes the blue pigment, resin, and solvent for color photoresist; the mass ratio of the blue pigment, resin, and solvent for color photoresist is 1:2~10:2~10.

[0015] The resin is selected from acrylic resins; the acrylic resin is one or more of aliphatic polyurethane acrylate, styrene acrylic resin, and polyurethane acrylate.

[0016] The solvent is selected from 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.

[0017] The present invention has the following advantages and beneficial effects: 1. Breaking through technical barriers and providing new material application paths: This invention creatively realizes the effective adaptation of dispersants for high-temperature dispersed inks in photoresist systems, expands the application range of dispersants, and provides a brand-new solution for the construction of high-performance photoresist pigment dispersion systems.

[0018] 2. Significantly improves the stability of color paste and system: Photoresist dispersants can significantly improve the viscosity stability and long-term storage stability of color paste, while effectively maintaining the process applicability of system viscosity.

[0019] 3. Optimize optical performance and process compatibility: Photoresist dispersants improve the dispersion state of pigments, which directly promotes the improvement of the optical performance of the final filter. Specifically, this is reflected in the significant improvement of key indicators such as brightness and contrast, thus providing a material basis for the fabrication of liquid crystal displays. Detailed Implementation

[0020] 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.

[0021] The blue organic pigment used in the examples is commercially available. The solvent, resin, and deionized water are also commercially available. The photoresist dispersant was prepared according to the method described in Examples 11-18 of Chinese patent application CN117511246A, and its structure is as follows.

[0022] Photoresist dispersant B-1 Photoresist dispersant B-2 Photoresist dispersant B-3 Photoresist dispersant B-4 Photoresist dispersant B-5 Photoresist dispersant B-6 Photoresist dispersant B-7 Photoresist dispersant B-8 Photoresist dispersant B-9 The raw materials and specifications required for the embodiments of the present invention are as follows: Diethylene glycol: CAS: 111-46-6; Propylene glycol monomethyl ether acetate, CAS: 108-65-6; PB15:6, tetrahydrorosin; Dispersant DISPERBYK-163 (BYK) is a commercially available product. Dispersants B-1, B-2, B-3, B-4, B-5, B-6, B-7, B-8, and B-9 are in-house manufactured.

[0023] The instruments used for performance testing in this embodiment of the invention are: Contrast meter, CT-1-STB1, Tsubosaka Electric, Japan; Step tester, Dektak XT, Bruker Corporation; Nanoparticle size analyzer, Omni, Brukerhaven Instruments, USA; Viscometer: Brookfield DV2TLVTJ0. Unless otherwise specified, the weight parts in the embodiments of this invention refer to the weight parts of the active ingredient, that is, the weight parts of the non-volatile components.

[0024] Example 1 Preparation of blue pigment for color photoresist: 100g PB15:6, 800g pulverized NaCl, 180g diethylene glycol, and 4g dispersant B-1 were mixed in a kneader and kneaded at 60℃ for 8 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 blue pigment.

[0025] Examples 2-9 According to the components and conditions in Table 1, the blue pigments for color photoresists in Examples 2 to 9 were prepared according to the preparation method of Example 1.

[0026] Table 1

[0027] Application Example 1 Preparation of pigment paste PbL-1: 15g of the blue pigment for color photoresist prepared in Example 1, 50g of acrylic resin (solid content 40%), 65g 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 again for 90min. The zirconium beads were then filtered out to obtain pigment paste PYL-1.

[0028] Application Examples 2-9 Following the preparation method of Application Example 1, the blue pigment for the color photoresist prepared in Example 1 was replaced with the blue pigment for the color photoresist prepared in Examples 2 to 9 (see Table 2) to obtain color pastes PYL-2 to PYL-9.

[0029] Table 2

[0030] Comparative Example 1 The difference from Example 1 is that dispersant B-1 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 1. The prepared pigment is then used to prepare blue pigment paste PBL-1D according to the same resin, solvent and pigment preparation method as in Example 1.

[0031] Comparative Example 2 The difference from Example 2 is that dispersant B-2 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 2. The prepared pigment is then used to prepare blue pigment paste PBL-2D according to the same resin, solvent and pigment preparation method as in Application Example 1.

[0032] Comparative Example 3 The difference from Example 3 is that dispersant B-3 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 3. The prepared pigment is then used to prepare blue pigment paste PBL-3D according to the same resin, solvent and pigment preparation method as in Application Example 1.

[0033] Comparative Example 4 The difference from Example 4 is that dispersant B-4 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 4. The prepared pigment is then used to prepare blue pigment paste PBL-4D according to the same resin, solvent and pigment preparation method as in Application Example 1.

[0034] Comparative Example 5 The difference from Example 5 is that dispersant B-5 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 5. The prepared pigment is then used to prepare blue pigment paste PBL-5D according to the same resin, solvent and pigment preparation method as in Application Example 1.

[0035] Comparative Example 6 The difference from Example 6 is that dispersant B-6 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 6. The prepared pigment is then used to prepare blue pigment paste PBL-6D according to the same resin, solvent and pigment preparation method as in Application Example 1.

[0036] Comparative Example 7 The difference from Example 7 is that dispersant B-7 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 7. The prepared pigment is then used to prepare blue pigment paste PBL-7D according to the same resin, solvent and pigment preparation method as in Application Example 1.

[0037] Comparative Example 8 The difference from Example 8 is that dispersant B-8 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 8. The prepared pigment is then used to prepare blue pigment paste PBL-8D according to the same resin, solvent and pigment preparation method as in Application Example 1.

[0038] Comparative Example 9 The difference from Example 9 is that dispersant B-9 is not added. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 9. The prepared pigment is then used to prepare blue pigment paste PBL-9D according to the same resin, solvent and pigment preparation method as in Application Example 1.

[0039] Comparative Example 10 The difference from Example 1 is that the dispersant is replaced with tetrahydrorosin. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 1. The prepared pigment is then used to prepare blue pigment paste PBL-10D according to the same resin, solvent and pigment preparation method as in Example 1.

[0040] Comparative Example 11 The difference from Example 1 is that the dispersant is replaced with DISPERBYK-163. The pigment is prepared according to the same blue organic pigment, inorganic salt, solvent and preparation method as in Example 1. The prepared pigment is then used to prepare blue pigment paste PBL-11D according to the same resin, solvent and pigment preparation method as in Example 1.

[0041] The following performance indicators were measured for the pigment pastes used in the photoresists of Application Examples 1-9 and Comparative Examples 1-11 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.

[0042] 2. Viscosity: Select the rotor, add an appropriate amount of color paste into the cylinder, install and fix it, set the temperature, speed and other parameters, start the measurement, and read the value.

[0043] 3. Contrast Ratio: 1 mL of blue pigment was spin-coated onto a glass slide at 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 a 230°C oven for 30 minutes. Colorimetry (x, y), luminance (Y), and contrast ratio were measured.

[0044] Table 3. Comparison of pigment stability

[0045] Table 4. Comparison of Viscosity Indicators

[0046] Table 5. Comparison of luminance Y and contrast at a fixed y value

[0047] Y: Luminance; CR: Contrast Ratio Comparing the data in Table 3-5, we can see that: The initial average particle size (D50) of the color pastes described in Application Examples 1-9 is not significantly different from that of Comparative Examples 1-11. After heat storage, the particle size of Application Examples 1-9 shows little change from the initially measured particle size, indicating good stability. In contrast, the particle size of Comparative Examples 1-11 increases significantly after heat storage, indicating that Application Examples 1-9 have better heat storage stability than Comparative Examples 1-11. After adding photoresist dispersant, the viscosity of the color pastes in the application examples is consistently within 5-10 cP, which is within the normal operating range. However, the viscosity of the comparative examples fluctuates considerably, and most are outside the applicable range. Therefore, photoresist dispersant can significantly improve the viscosity stability of the color pastes. Based on the brightness Y data at a fixed y value, the addition of photoresist dispersant during the kneading process in Application Examples 1-9 significantly improves the brightness and contrast of the color pastes.

[0048] In summary, the photoresist dispersant of this invention can significantly improve the viscosity stability and long-term storage stability of color pastes, while effectively maintaining the process applicability of the system viscosity. This directly promotes the improvement of the final optical performance of the filter, specifically manifested in significant improvements in key indicators such as brightness and contrast, thus providing a material basis for the fabrication of liquid crystal displays.

Claims

1. An application of a photoresist dispersant, characterized in that: The photoresist dispersant is used to prepare blue pigment for color photoresists; the structure of the photoresist dispersant is shown in Formula I: Among them, R1, R2, R3, R4, and R5 can be the same or different and are selected from H, -NO2, -CN, -Br, -SO3H, -SO2NH2, -SO2H, or -COOH; R6, R7, R8, and R9 may be the same or different and may be selected from H, -OCH3, -OC2H5, -NHCOCH3, or -NHCOC2H5; X and Y can be the same or different and are selected from -C2H5 or -C2H4OCOCH3; Furthermore, R1, R2, R3, R4, and R5 must be selected from at least -SO3H, -SO2NH2, -SO2H, or -COOH.

2. The application of the photoresist dispersant according to claim 1, characterized in that: The blue pigment used in the colored photoresist comprises a blue organic pigment and a photoresist dispersant; wherein the blue organic pigment is PB15:

6.

3. The application of the photoresist dispersant according to claim 2, characterized in that: The amount of photoresist dispersant used is 0.01-50% of the mass of the blue organic pigment.

4. The application of the photoresist dispersant according to claim 2, characterized in that: The preparation method of the blue pigment for color photoresist is as follows: a blue organic pigment, an inorganic salt, a solvent and the photoresist dispersant are kneaded together. After kneading, the mixture is placed in water at 60°C to precipitate. After stirring, the mixture is filtered to obtain a filter cake. The filter cake is washed, dried and crushed to obtain the blue pigment for color photoresist.

5. The application of the photoresist dispersant according to claim 4, characterized in that: The kneading conditions are: kneading at 0~60℃ for 2~15 hours.

6. The application of the photoresist dispersant according to claim 4, characterized in that: The filter cake was rinsed to make the pH of the filtrate 7 and the conductivity 50 μs / cm. The filter cake was then vacuum dried at 60℃ and crushed to obtain the blue pigment for color photoresist.

7. The application of the photoresist dispersant according to claim 2, characterized in that: Blue pigment is used to prepare pigment paste for color photoresist.

8. The application of the photoresist dispersant according to claim 7, characterized in that: The pigment paste for color photoresist includes the blue pigment, resin, and solvent for color photoresist; the mass ratio of the blue pigment, resin, and solvent for color photoresist is 1:2~10:2~10.

9. The application of the photoresist dispersant according to claim 8, characterized in that: The resin is selected from acrylic resins; the solvent is selected from 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.

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