A color photoresist based on a photoresist monomer and a color filter

Abstract

The present invention discloses a color photoresist and a color filter based on a novel photoresist monomer. Based on 100 parts by weight, the color photoresist comprises: 5-8 parts of a photoresist monomer; 8-11 parts of a pigment dispersion; 7-9 parts of an alkali-soluble resin; 0.4-0.8 parts of a photoinitiator; 74-79 parts of a solvent; 0.3-0.4 parts of an additive; the color filter comprises a glass substrate containing a black matrix, and the color filter is prepared by coating the color photoresist on the glass substrate. The present invention effectively improves the overall performance of the color photoresist by designing and synthesizing a photoresist monomer and applying it to the color photoresist, and the color filter prepared under certain process conditions has good moldability and high thermal stability.

Description

Technical Field

[0001] The present invention belongs to the field of liquid crystal displays, and particularly relates to a color photoresist and a color filter based on a photoresist monomer. Background Art

[0002] In recent years, displays have entered thousands of households, and there has been a qualitative leap in their development. Currently, the mainstream display types are mainly the following several types: thin film transistor liquid crystal display (TFT-LCD), organic light-emitting diode (OLED), and micro light-emitting diode (Micro LED).

[0003] Among them, color filters are widely used in display technology. It can screen out light of specific wavelengths to form different colors. The current color filter technology has some problems in aspects such as image quality, durability, and production cost. The preparation components and processes of color photoresists directly affect the performance of color filters and displays. Color photoresists contain pigments, alkali-soluble resins, photoresist monomers, photoinitiators, solvents, and additives. As an indispensable component in photopolymerization, the monomer plays a cross-linking role and has a decisive influence on the performance of the entire photoresist.

[0004] Existing photoresist monomers usually adopt n-butyl acrylate group, isobutyl acrylate group, isooctyl acrylate, DPHA, DPEA-12, etc. Different monomers contain different numbers of carbon-carbon double bond functional groups, which directly affect the cross-linking process of color photoresists and play an important role in the resolution, line roughness, and adhesion on color filters.

[0005] Regarding the number of functional groups, when low-functional group monomers are cross-linked and cured in photoresists, the cross-linking density is low, and the shrinkage of the color photoresist film is small, resulting in high toughness and flatness. At the same time, its chemical resistance and adhesion are poor, and the cured part is easily developed away during development; when the number of functional groups increases, a cross-linked network structure is formed during curing and cross-linking, which increases the cross-linking density, enhances its adhesion, strength, and chemical resistance, preventing the cured part from being easily developed away during development. At the same time, there is also a phenomenon of increasing film shrinkage rate, which will affect the surface roughness of the film;

[0006] Therefore, there is a mutually restrictive relationship between the performance of existing photoresists and the color filters prepared therefrom, and the overall performance of color photoresists and the moldability and thermal stability of color filters cannot meet the ideal requirements. Summary of the Invention

[0007] Objective of the Invention: To solve the problems of poor performance of color photoresist and poor moldability and thermal stability of color filters, a color photoresist and a color filter based on a photoresist monomer are provided. By designing and synthesizing a photoresist monomer and applying it to the color photoresist, the overall performance of the color photoresist is effectively improved, and the color filter prepared under certain process conditions has good moldability and high thermal stability.

[0008] Technical Solution: To achieve the above objective, the present invention provides a color photoresist based on a photoresist monomer, which, based on 100 parts by weight, comprises the following components in parts by weight:

[0009]

[0010] Further, the structural general formula of the photoresist monomer is:

[0011]

[0012] Wherein, R is a different linking group containing C, H, and O.

[0013] Further, the photoresist monomer comprises monomer A and monomer B, and the structural formulas are respectively:

[0014]

[0015] Using the photoresist monomer in the form of a mixture of monomer A and monomer B can better adjust the performance of the color photoresist.

[0016] Further, the pigment dispersion is one or more of Red-254, Green-36, Yellow-158, and Blue15:6, the alkali-soluble resin is an alkyl methacrylate, the photoinitiator is one or more of triazine, benzoin, and benzophenone, the solvent is one or more of propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, and 3-methoxybutyl acetate, and the additive is one of a silane coupling agent, a leveling agent, and an antifoaming agent.

[0017] Further, the synthesis method of the photoresist monomer comprises the following steps:

[0018] S1: Add 3-[(trifluoromethyl)sulfonyl] acid and 3,3,3-trifluoropropyltrichlorosilane to an ethyl acetate solution at room temperature. After cooling the entire reaction system, carry out a stirring process, dropwise add triethylamine, control the reaction temperature, and after dropping triethylamine, raise the reaction temperature for a stirring process. After the reaction system is treated, intermediate A is obtained;

[0019] S2: Add isopropanol and anhydrous potassium carbonate into the dehydrated N,N-dimethylformamide solution. After cooling the entire reaction system to 0 °C, add intermediate A into the reaction solution, and then raise the temperature to room temperature for reaction. The entire reaction system is processed to obtain product monomer A.

[0020] S3: Add intermediate A, 3,4-dichlorophenylboronic acid, sodium hydroxide, tetrahydrofuran and water into the reaction system in sequence. Add a catalyst, and reflux the reaction solution. After the reaction ends, the reaction solution is post-treated to obtain intermediate B.

[0021] S4: Add isopropanol, imidazole and 4-(dimethylamino)pyridine into the dehydrated dichloromethane solution in sequence. After cooling the entire reaction system to 0 °C, add intermediate B into the reaction solution, and then raise the temperature to room temperature for reaction. The entire reaction system is processed to obtain product monomer B.

[0022] Further, the control range of the reaction temperature in step S1 is 50 - 65 °C, and the reaction temperature in step S3 is 70 - 80 °C.

[0023] Further, the catalyst in step S3 is tetrakis(triphenylphosphine)palladium.

[0024] The photoresist monomer of the present invention can be polymerized with other monomers to obtain a color photoresist resin, which has the functions of improving heat resistance, chemical resistance and stability.

[0025] The photoresist monomer has a carbon-carbon unsaturated double bond, which has a cross-linking effect. When exposed to light or thermal energy, it undergoes a graft copolymerization reaction with the resin.

[0026] The present invention also provides a color filter, which includes a glass substrate with a black matrix. The color filter is prepared by coating the color photoresist provided by the present invention on the glass substrate. The preparation process of the color filter is as follows:

[0027] 1) Spin-coat the color photoresist on the glass substrate with a black matrix.

[0028] 2) Put the glass substrate coated with the color photoresist into a VCD for vacuum treatment.

[0029] 3) Put the glass substrate after vacuum treatment into an oven for drying.

[0030] 4) Put the glass sheet into an exposure machine for exposure treatment.

[0031] 5) Put the exposed glass sheet into a developing machine for development.

[0032] 6) Rinse the glass sheet with an alkaline solution to remove the undeveloped part.

[0033] 7) The glass substrate coated with the color filter is placed in an oven for baking to obtain the color filter.

[0034] In the preparation process of the color photoresist, the mass ratio of each component needs to comprehensively consider various factors, such as color targets, material properties, application scenarios, and process conditions, etc., in order to achieve an ideal color effect, including specific spectral distribution, lightness, and saturation, etc. To meet specific color requirements, the mass ratio between components needs to be selected and adjusted according to the required color targets.

[0035] The photoresist monomers and color photoresists in the present invention obtained through the above preparation method can meet the construction requirements of the color filters in the present invention. The present invention introduces fluorine - and silicon - containing photoresist monomers and makes them into a hybrid - material color photoresist to achieve more excellent performance. The silicon - containing photoresist monomer has better chemical stability because the electron cloud distribution on the silicon atom is relatively stable and not easily disturbed by the external environment. This brings excellent corrosion resistance and heat resistance to it during the manufacturing process. In addition, the silicon - containing monomer can form strong interactions with other polymer molecules, improve the adhesion and adhesiveness of the photoresist, and help prevent phenomena such as peeling or warping during the manufacturing process. At the same time, the distribution of silicon atoms in the polymer chain can affect the propagation speed of light in different media, thereby improving the light - transmission performance of the photoresist.

[0036] On the other hand, the fluorine element of the photoresist monomer can enhance the heat resistance and chemical stability of the copolymer. The low - polarizability fluorine atoms endow the fluorine - containing copolymer with special surface properties and optical properties, thus bringing higher performance and stability to the fluorine - containing photoresist monomer during the manufacturing process. To sum up, by introducing fluorine - and silicon - containing photoresist monomers in the preparation of the color photoresist, the present invention enables it to have more excellent comprehensive performance.

[0037] It should also be noted here that stable photoresist monomers can effectively improve the adhesion and adhesiveness of the color photoresist, making the color photoresist have better corrosion resistance and heat resistance during the manufacturing process of the color filter, thereby improving the overall performance of the photoresist.

[0038] Beneficial effects: Compared with the prior art, the present invention constructs photoresist monomers and applies them to color photoresists, and uses this color photoresist to make color filters. By introducing special photoresist monomers, the adhesion, adhesiveness, corrosion resistance, and heat resistance of the color photoresist can be improved. The color filter has good moldability and high thermal stability, solves the problems of poor performance and instability of the existing color photoresists and color filters, and improves the service performance of the color filter. Description of the Drawings

[0039] Figure 1 It is the OM diagram of the color filter after the pressure - accelerated aging test;

[0040] Figure 2 It is the UV diagram of the color filter in NMP solution after the chemical resistance test. Detailed implementation manners

[0041] The present invention will be further clarified below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading the present invention, those skilled in the art's various equivalent modifications of the present invention all fall within the scope defined by the appended claims of this application.

[0042] Example 1:

[0043] This example provides a method for synthesizing a photoresist monomer, and the synthesis reaction scheme is as follows:

[0044]

[0045] According to the above synthesis reaction formula, the synthesis of the photoresist monomer successively includes four parts: the synthesis of compound 1-1, the synthesis of compound 1-2, the synthesis of compound 2-1, and the synthesis of compound 2-2. The specific synthesis process is as follows:

[0046] 1. Synthesis of compound 1-1 (intermediate A):

[0047] At room temperature, 3-[(trifluoromethyl)sulfonyl] acid (200.00 g, 0.93 mol) and 3,3,3-trifluoropropyltrichlorosilane (269.53 g, 1.16 mol) were added to an ethyl acetate solution in a 2 L round-bottom flask. After the temperature of the reaction system was lowered to 0 °C, the stirring process was carried out, and triethylamine (147.23 g, 1.46 mol) was added dropwise, controlling the reaction temperature not to exceed 5 °C. Subsequently, after the temperature was raised to 65 °C, the reaction was carried out for 18 h. After the reaction was completed, water was added for quenching, and dichloromethane was added for extraction and washing three times. Then, anhydrous calcium chloride was added to the reaction solution to remove excess moisture. After filtration, a crude product was obtained, and the crude product was subjected to vacuum distillation to obtain product 1-1 (253.01 g). Product 1-1 is intermediate A, with a yield of 65% and a GC purity of 97.89%.

[0048] 2. Synthesis of compound 1-2 (monomer A):

[0049] In a 2 L round-bottom flask, acrylic acid (72.06 g, 1.08 mol) and anhydrous potassium carbonate (169.31 g, 1.23 mol) were added to a dehydrated N,N-dimethylformamide solution (40 ml). After cooling the entire reaction system to 15 °C, intermediate A (200.00 g, 0.49 mol) was added to the reaction solution. The temperature was raised to 50 °C and the reaction was carried out overnight. After the reaction was completed, it was cooled to room temperature. Water and dichloromethane were added to the reaction system for extraction and washing three times. Then, anhydrous calcium chloride was added to the reaction solution to remove excess water. After filtration, a crude product was obtained. Finally, the product monomer 1-2 (173.46 g) was obtained after column chromatography separation. Monomer 1-2 was monomer A, with a yield of 75% and a GC purity of 98.36%.

[0050] 3. Synthesis of compound 2-1 (intermediate B):

[0051] In a 2 L round-bottom flask, intermediate A (200.00 g, 0.49 mol), 3,4-dichlorophenylboronic acid (206.07 g, 1.08 mol), tetrakis(triphenylphosphine)palladium (28.31 g, 0.02 mol), 800 mL of sodium hydroxide aqueous solution (4 mol / L), and 400 mL of tetrahydrofuran were added in sequence. The entire reaction system was heated to 80 °C and refluxed for 24 h. After the reaction was completed, it was cooled to room temperature. The solvent was evaporated. Water and dichloromethane were added to the reaction system for extraction and washing three times, dried with anhydrous magnesium sulfate, filtered, and the filtrate was collected. After evaporating the solvent of the reaction system, the product monomer 1-2 (253.01 g) was obtained after column chromatography separation. Monomer 1-2 was intermediate B, with a yield of 68% and a GC purity of 99.01%.

[0052] 4. Synthesis of compound 2-2 (monomer B):

[0053] In a 2 L round-bottom flask, acrylic acid (115.20 g, 1.60 mol) and anhydrous potassium carbonate (220.81 g, 1.60 mol) were added to a dehydrated N,N-dimethylformamide solution (40 ml). After cooling the entire reaction system to 15 °C, intermediate 2-1 (200.00 g, 0.32 mol) was added to the reaction solution. The temperature was raised to 50 °C and the reaction was carried out overnight. After the reaction was completed, it was cooled to room temperature. Water and dichloromethane were added to the reaction system for extraction and washing three times. Then, anhydrous calcium chloride was added to the reaction solution to remove excess water. After filtration, a crude product was obtained. Finally, the product monomer 2-2 (105.21 g) was obtained after column chromatography separation. Monomer 2-2 was monomer B, with a yield of 43% and a GC purity of 98.46%.

[0054] Example 2:

[0055] In this embodiment, the mixed monomer of monomer A and monomer B obtained in Example 1 is used as a photoresist monomer for preparing a color photoresist. Based on 100 parts by weight, the color photoresist comprises the following components in parts by weight:

[0056]

[0057] In this embodiment, the preparation method of the color photoresist is as follows: The above-mentioned monomer A, monomer B, alkyl methacrylate, benzophenone, propylene glycol monomethyl ether, and silane coupling agent KBM-503 are added into a light-shielding bottle, stirred and shaken evenly for 1 hour until all are dissolved and present a transparent state, and finally red pigment Red-254 is added and stirred to obtain the color photoresist.

[0058] In this embodiment, monomer B has a carbon-carbon unsaturated bond and is grafted onto the resin polymer after copolymerization with alkyl methacrylate.

[0059] Example 3:

[0060] In this embodiment, the mixed monomer of monomer A and monomer B obtained in Example 1 is used as a photoresist monomer for preparing a color photoresist. Based on 100 parts by weight, the color photoresist comprises the following components in parts by weight:

[0061]

[0062] In this embodiment, the preparation method of the color photoresist is as follows: The above-mentioned monomer A, monomer B, alkyl methacrylate, triazine, propylene glycol methyl ether acetate, and leveling agent are added into a light-shielding bottle, stirred and shaken evenly for 1 hour until all are dissolved and present a transparent state, and finally green pigment Green-36 is added and stirred to obtain the color photoresist.

[0063] In this embodiment, monomer B has a carbon-carbon unsaturated bond and is grafted onto the resin polymer after copolymerization with alkyl methacrylate.

[0064] Example 4:

[0065] In this embodiment, the mixed monomer of monomer A and monomer B obtained in Example 1 is used as a photoresist monomer for preparing a color photoresist. Based on 100 parts by weight, the color photoresist comprises the following components in parts by weight:

[0066]

[0067] In this embodiment, the preparation method of the color photoresist is as follows: The above-mentioned monomer A, monomer B, alkyl methacrylate, triazine, propylene glycol methyl ether acetate, and polydimethylsiloxane derivative are added into a light-shielding bottle, stirred and shaken evenly for 1 hour until all are dissolved and present a transparent state, and finally green pigment Green-36 is added and stirred to obtain the color photoresist.

[0068] In this embodiment, monomer B has a carbon-carbon unsaturated bond and is grafted onto the resin polymer after copolymerization with an alkyl methacrylate.

[0069] Example 5:

[0070] In this embodiment, the color photoresist obtained in Example 2 is used to fabricate a color filter, and a color filter based on the color photoresist is provided. The specific preparation process is as follows:

[0071] First, the color photoresist is spin-coated onto a glass substrate with a black matrix at a speed of 325 rpm / s. Then, the glass substrate coated with the photoresist is placed in a VCD for vacuum treatment. Next, to make the photoresist adhere more evenly to the glass substrate, it is placed in an oven at 100 °C for drying. After drying, the glass sheet is then placed in an exposure machine for exposure treatment. After the exposure treatment is completed, the exposed glass sheet is placed in a developer for development. After development, it is rinsed with an alkaline solution for 90 s to remove the undeveloped part. Finally, the glass substrate with the color filter is placed in an oven at 230 °C for half an hour to ensure the firm bonding of the color filter to the substrate, thereby obtaining the color filter.

[0072] Example 6:

[0073] In this embodiment, the color filter prepared in Example 5 is placed in a pressure steam rewarming test machine. In an environment with a temperature of 120 °C, a humidity of 100%, and an atmospheric pressure of 1 atmosphere, after testing for 6 hours, the photoresist coating on the surface is cut with a blade. Then, a tape is pasted on the cut surface and removed after 60 s. Finally, the surface morphology is observed under an optical microscope, and the OM image as shown in Figure 1 is obtained. Figure 1 No large-area damage or peeling is seen, showing good adhesion and adhesiveness, which also indicates that adding the color photoresist obtained in Example 2 helps to improve the stability of the color filter.

[0074] Example 7:

[0075] The color filter prepared in Example 5 is placed in an oven for heat resistance testing. Corresponding tests are carried out every 5 min. After testing at 230 °C for 10 min, 15 min, 20 min, 25 min, and 30 min respectively, its color coordinates, contrast, and color difference are measured. The specific detection data are shown in Table 1:

[0076] Table 1 - Comparison table of color coordinates, grayscale, and color difference of color filters

[0077]

[0078] According to the data in Table 1, it can be found that the color coordinates, gray scale and color difference measured in the embodiments of the present invention have no obvious difference changes at different times, and △Eab is less than that of the existing color filters, indicating that the color filters exhibit good heat resistance and stability.

[0079] Example 8:

[0080] The color filter prepared in Example 5 was subjected to chemical resistance testing. First, the color filter was cut into 1×5 cm long strips and placed in a glass bottle containing N-methylpyrrolidone (NMP) solution. After being kept at a constant temperature of 80 °C for 40 min, the glass bottle was taken out and the ultraviolet absorption of the solution was tested. The specific test data are as Figure 2 shown, and its maximum absorption value is less than 0.5, indicating good chemical resistance.

Claims

1. A color photoresist based on a photoresist monomer, characterized in that based on 100 parts by weight, it includes the following components in parts by weight: The photoresist monomer includes monomer A and monomer B, and the structural formulas are respectively: The synthesis method of the photoresist monomer includes the following steps: S1: Add 3-[(trifluoromethyl)sulfonyl] acid and 3,3,3-trifluoropropyltrichlorosilane to an ethyl acetate solution at room temperature. After cooling the entire reaction system, carry out a stirring process, dropwise add triethylamine, control the reaction temperature. After dropping triethylamine, raise the reaction temperature and carry out a stirring process. The reaction system is processed to obtain intermediate A; S2: Add isopropanol and anhydrous potassium carbonate to a dehydrated N,N-dimethylformamide solution. After cooling the entire reaction system to 0 °C, add intermediate A to the reaction solution and raise the temperature to room temperature for reaction. The entire reaction system is processed to obtain product monomer A; S3: Add intermediate A, 3,4-dichlorophenylboronic acid, sodium hydroxide, tetrahydrofuran, and water to the reaction system in sequence, add a catalyst, reflux the reaction solution. After the reaction ends, the reaction solution is post-treated to obtain intermediate B; S4: Add isopropanol, imidazole, and 4-(dimethylamino)pyridine to a dehydrated dichloromethane solution in sequence. After cooling the entire reaction system to 0 °C, add intermediate B to the reaction solution and raise the temperature to room temperature for reaction. The entire reaction system is processed to obtain product monomer B.

2. The color photoresist based on a photoresist monomer according to claim 1, characterized in that the pigment dispersion is one or more of Red-254, Green-36, Yellow-158, and Blue15:6, the alkali-soluble resin is an alkyl methacrylate, the photoinitiator is one or more of triazine, benzoin, and benzophenone, the solvent is one or more of propylene glycol methyl ether acetate, propylene glycol monoethyl ether, and 3-methoxybutyl acetate, and the additive is one of a silane coupling agent, a leveling agent, and an antifoaming agent.

3. The color photoresist based on a photoresist monomer according to claim 1, characterized in that the control range of the reaction temperature in step S1 is 50-65 °C, and the reaction temperature in step S3 is 70-80 °C.

4. The color photoresist based on a photoresist monomer according to claim 1, characterized in that the catalyst in step S3 is tetrakis(triphenylphosphine)palladium.

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