JPH04151602A - Surface protective material for color filter - Google Patents

Abstract

PURPOSE:To obtain a surface protective material of a color filter having a flatness, excellent in the hardness and the chemical resistance by constituting it with a material consisting of a dicyclopentadiene resin and polythiol, being a solid at a room temp. and being a specified melt viscosity at 200 deg.C. CONSTITUTION:The surface protective material is constituted of a material consisting of the dicyclopentadiene resin and the polythiol, being a solid at a room temp. and being <=5000cPs at a melt viscosity at 200 deg.C. As the dicyclopentadiene resin, the prepolymer of dicyclopentadiene is exemplified and as the polythiol, pentaerythritol tetorakis benzenedithiol, etc., are exemplified. Hence the flat surface protective layer is provided with this on a color filter and besides the product excellent in the film hardness, the heat resistance, the chemical resistance and the clarity is obtained.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a surface protection material for color filters.

[Prior art] Liquid crystal display elements, charge coupled devices (CC
Color filters for solid-state imaging devices such as D) are usually manufactured by methods such as dyeing, printing, and electrodeposition, but generally for the purpose of surface protection and/or when manufactured by dyeing. For the purpose of resist dyeing, a protective layer is formed on top of the red, green, and blue colored layers. Conventionally, acrylic epoxy resins (for example,
JP-A-61-292-604) and chloromethylated polystyrene (JP-A-64-7543) are known as flattening materials that can provide an ideal flat surface by reflowing by heating.

[Problems to be Solved by the Invention] In the above-mentioned liquid crystal display elements and the like, flattening of the color filter surface is required in order to improve display quality. However, the former type of protective material has a problem in that surface irregularities cannot be flattened.

Further, the latter material has problems in that it has a low surface hardness of about HB (pencil hardness) and has low chemical resistance (for example, n-methylpyrrolidone) when used as a protective material for color filters.

[Means for Solving the Problems] The present inventors have developed a color filter with ideal flatness, excellent hardness and chemical resistance, which enables improvement of the display quality of liquid crystal display elements and solid-state image sensors. As a result of intensive study on surface protection materials, the present invention was arrived at.

That is, the present invention is a surface protection material for a color filter, which is made of dicyclopentadiene resin and polythiol, is solid at room temperature, and has a melt viscosity of 5000 cps (centimeter squares) or less at 200°C. .

The surface protection material of the present invention is solid at room temperature.

If it is a liquid at room temperature, it will be difficult to control the coating film thickness during coating. Also, the melt viscosity at 200℃ is usually 1 to 5000c.
ps, preferably 1 to 500 cps.

If it exceeds 5000 cps, it becomes difficult to flatten the surface of the color filter.

Examples of the dicyclopentadiene resin include dicyclopentadiene prepolymers (for example, manufactured by Japan Petrochemical Department).

As a polythiol, pentaerythritol tetrakis (thiogatacholate)
, trimethylolethanetris (β-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropioether), benzenedithiol, and the like.

The weight ratio of the polythiol to the dicyclopentadiene resin is usually in the range of 20:1 to 1:1, preferably in the range of 10:1 to 2:1.

If the weight ratio is outside the range of 20:1 to 1:1, curing will be insufficient and heat resistance, chemical resistance, and hardness will not be good.

In addition to the dicyclopentadiene resin and polythiol components, the surface protection material of the present invention may optionally contain a photoinitiator, a silane coupling agent, and two or more allyl, acryloyloxy, or methacryloyloxy groups. Compounds etc. that can be added can be added.

Examples of the photoinitiator include acetophenone photoinitiators such as 2.2-jethoxyacetophenone and 4-dimethylaminoacetophenone, benzophenone photoinitiators such as benzophenone and Michler's ketone, benzyl, benzoin butyl ether, and benzoin dimethyl ketal. . Preferred among these are benzoin butyl ether and benzoin dimethyl ketal.

The amount of the photoinitiator is usually 0.01 to 10 parts by weight, preferably 0.01 to 10 parts by weight, based on 100 parts by weight of the dicyclopentadiene resin.
It can be added in an amount of 1 to 5 parts by weight. If the amount added is less than 0.01 parts by weight, the function as a photoinitiator will be insufficient. On the other hand, if the amount exceeds 10 parts by weight, the amount of the photoinitiator or its reactant bleed out from the cured coating film of the surface protection material increases, which adversely affects the properties of the surface protection film.

Silane coupling agents include γ-glycidoxypropyltrimethoxysilane, β-(
Epoxy group-containing silane coupling agents such as 3,4-epoxycyclohexyl)ethyltrimethoxysilane, vinyl group-containing silane coupling agents such as vinyltrimethoxysilane, γ-methallyloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, etc. Examples include amino group-containing silane coupling agents such as methoxysilane.

They can also be used by pre-coating the substrate to which the surface protection material is to be applied.

The silane coupling agent can be added in an amount of usually 0.1 to 30 parts by weight, preferably 0.5 to 20 parts by weight, per 100 parts by weight of the dicyclopentadiene resin.

If the amount added is less than 0.1 part by weight, the function as a silane coupling agent will be insufficient. Moreover, if it exceeds 30 parts by weight, the chemical resistance of the surface protection material will decrease.

Examples of compounds containing two or more allyl groups, acryloyloxy groups, or methacryloyloxy groups include trifunctional arylates such as triallyl cyanurate, dimethacrylates modified with 2 moles of bisphenol A ethylene oxide, diacrylates modified with 3 moles of ethylene oxide isocyanurate, and Bifunctional acrylates or methacrylates such as erythritol diacrylate monostearate, pentaerythritol triacrylate, trifunctional acrylates or methacrylates such as isocyanuric acid ethylene oxide 3 mol modified triacrylate, isocyanuric acid ethylene oxide 3 mol modified trimethacrylate, dipentaerythritol penta Examples include acrylates having five or more functional functions such as acrylate and dipentaerythritol hexaacrylate.

The compound containing two or more allyl, acryloyloxy, or methacryloyloxy groups is usually 0.1 to 50 parts by weight, preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the dicyclopentadiene resin. It can be added within the range of 100%.

If the amount added is less than 0.1 part by weight, the hardness due to the addition,
Effects such as improving chemical resistance become insufficient. Furthermore, if the amount exceeds 50 parts by weight, the surface protective film may shrink significantly during curing and cracks may occur.

By blending these compounds in such ranges, the formed coating film has further improved flatness, adhesion to the substrate, chemical resistance, and hardness.

The surface protection material of the present invention is usually used by uniformly mixing the above-mentioned components in a solvent. The solvent is not particularly limited as long as it dissolves these components and does not react with them; specific examples include esters (ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, ethyl acetate, Butyl acetate, isobutyl isobutyrate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, etc.), ethers (ethylene glycol diethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, butyl ether, diisoamyl ether, diethylene glycol, ethylene Examples include glycol monomethyl ether, etc.), ketones (methyl isobutyl ketone, cyclohexanone, etc.), halogenated hydrocarbons (1,2-ethylene dichloride, dichlorobenzene, etc.), and mixed solvents thereof.

There are no restrictions on the above mixing method, and all the components may be mixed in the solvent at once, or if necessary, each component
The surface protection material of the present invention can also be obtained by separately dissolving a species or two or more species in the same or different solvents to prepare two or more solutions, and then mixing these solutions. In addition, the concentration in the case of a solution-like surface protection material is not particularly limited and is appropriately selected depending on the purpose of use and application method, but it is usually preferably about 10 to 80% by weight based on the total constituent components. .

It is also possible to form a solvent-free mixture, for example, by sufficiently mixing them in a heated molten state, solid state, etc., it is possible to obtain the surface protection material of the present invention with a uniform composition, similar to solution mixing.

Examples of methods for applying the surface protection material of the present invention onto color filters include applying the surface protection material of the present invention in solution or heated molten state onto the color filter using spin cord coating, roll coating, or bar coater coating. The coating is usually applied to a coating thickness of 0.2 to 10 μm by methods such as , spray coating, and printing. Subsequently, the coating film is heated at 100 to 250°C using an infrared lamp, hot plate, clean oven, etc. to melt and flow it to obtain a flattened surface. An ideally flat surface protective film can be formed on the color filter by curing with an ultraviolet lamp or far ultraviolet lamp to improve hardness.

[Examples] Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited thereto.

Example 1 10 g of dicyclopentadiene resin (manufactured by Nippon Petrochemical, softening temperature 100°C), 3 g of pentaerythritol tetrakis (thioglycolate), and 40 g of ethylene glycol monoethyl ether acetate were mixed and dissolved uniformly, and the pore size was determined. After filtering with a 0.2 μm filter, the following composition 1 for surface protection material was prepared.

In addition, ethylene glycol monoethyl ether acetate was distilled off under reduced pressure from Composition 1 for surface protection material.
When the melt viscosity was measured at 00°C, it was 50 cps.

As shown in Figure 1, a glass substrate with an RGB color filter with a thickness of 3 μm (Figure 2 above) was then heated at 200°C for 5 minutes (Figure 3), followed by a high-pressure mercury lamp. The film was cured by irradiating it with ultraviolet light for 1 minute. (FIG. 4) As a result, a surface protective film layer flattened to 0.1 μm was obtained.

This film showed sufficient coating hardness with a pencil hardness of 4H.
Furthermore, Example 2 shows no cracks or coloring during IT○ vapor deposition, good heat resistance, and visible light (400 to 800 nm). -mercaptopropyl ether). The melt viscosity of the prepared Composition 2 for surface protection material, in which ethylene glycol monoethyl ether acetate was distilled off under reduced pressure, was measured at 200° C. and found to be 40 cps. As a result of the experiment, exactly the same results as in Example 1 were obtained, and a surface protective film layer with good hardness, heat resistance, transparency, and chemical resistance and flattened to 0.1 μm was obtained.

[Effects of the Invention] The surface protection material of the present invention provides an ideally flat surface protection film layer on a color filter, and further improves film hardness, heat resistance,
Both chemical resistance and transparency were good.

This is extremely useful for improving the display quality of liquid crystal display elements and solid-state image sensors.

[Brief explanation of drawings]

1st to 4th rI! J is an explanatory diagram (cross-sectional view) of a method of using the surface protection material of the present invention.・Color filter ・Glass substrate ・Coated surface protection material ・Surface protection material leveled and flattened by heating ・Surface protection material cured by ultraviolet rays Engraving of drawings (no change in content) Procedural amendment (method) % formula % Invention Name Relationship to the Case of Person Who Corrects Surface Preservatives for Color Filters Patent Applicant Residence 11-1 Danno Honmachi, Higashiyama-ku, Kyoto City 1991
The first drawing attached to the application on May 7th is 1. As shown in the attached sheet (no change in content) (Figure 1, Figure 2, Figure 3, Figure 4)

Claims (1)

[Claims] 1. Made of dicyclopentadiene resin and polythiol, it is solid at room temperature and has a melt viscosity of 5000 at 200°C.
A surface protection material for color filters characterized by a cps (centipoise) or less.