JPH04128802A - Production of color filter - Google Patents

Abstract

PURPOSE:To improve heat resistance, adhesive property, as well as transparency by applying a coating material essentially consisting of a copolymer consisting of a monomer having at least one epoxy groups and a monomer having either of an N-substd. amide group or N-substd. imide group and at least one kind of either of polyvalent carboxylic acid or polyvalent carboxylic anhydride as a curing agent on a colored layer, then curing the coating by heating. CONSTITUTION:After 50g phenyl maleimide, 50g glycidyl methacrylate and 250g cyclohexanone are charged into a triangular round bottomed flask of 1l capacity having a cooling tube, stirrer and thermometer, 1.5g azobis- isobutylonitrile is charged therein after sufficient nitrogen substitution. The temp. of the soln. is raised to 80 deg.C and is continuously stirred for 5 hours, by which the copolymer is obtd. The coating material is obtd. by adding 25g of 12% diglime soln. of trimellitic acid to 100g copolymer soln. and well stirring the soln. The surface of the colored layer 2 of a color filter substrate 1 is coated with this coating material at 1,200rpm by a spin coater and the coating is cured for 60 minutes at 200 deg.C, by which an over coat layer 3 is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a color filter used for colorizing a liquid crystal display.

[Conventional technology]

In recent years, the demand for color filters has increased due to the expansion of applications for liquid crystal displays. A color filter has a colored layer made of natural protein, acrylic resin, and dye or pigment. For the purpose of improving smoothness, an overcoat layer is provided by applying and curing a coating material.

The characteristics required for the overcoat layer are: (1) Transparency (2) Adhesion to color filters (3) Heat resistance (250°C) (4) Chemical resistance (5>Adhesion with ITO (transparent electrode film) (6) Adhesion with sealing material, etc.)

[Problem to be solved by the invention]

Conventional coating materials for forming overcoat layers include thermosetting acrylic resins, urethane resins, epoxy resins, silica-based inorganic coating materials, and the like. However, conventional acrylic and urethane resins have low heat resistance and adhesion, and epoxy resins have IT○ (indium-
There have been problems with lack of reliability, such as the tendency for cracks to occur after vapor deposition (tin-oxide) and poor adhesion with silica-based coating materials, and there has been no coating material that can satisfy the above characteristics. Therefore, the credibility of a color filter using this as an overcoat layer was not sufficient.

An object of the present invention is to provide a method for manufacturing a color filter having an overcoat layer having good heat resistance, adhesion, and transparency.

[Means to solve the problem]

That is, the present invention provides a method for producing a color filter having a colored layer on a transparent substrate and an overcoat layer provided on the colored layer, the method comprising a monomer having at least one epoxy group and an N- The main components are a copolymer consisting of a monomer having either an The above-mentioned problem was solved by forming an overcoat layer by applying a coating material onto the colored layer and then heating and curing the coating material.

[Effect]

The color filter manufacturing method of the present invention involves applying a coating material into which either an amide or imide group has been introduced to a part of the copolymer during the manufacturing process to provide an overcoat layer. Not only does it have better heat resistance than a color filter coated with acrylic resin and has an overcoat layer, but it also has a high affinity with the color filter material's natural kumbaku, acrylic resin, dyes, and pigments, so it has excellent adhesion. Excellent.

Incidentally, there is usually a concern that amide/imide groups cause yellow coloring, but surprisingly this did not cause any problems.

[The main components of the coating material used to form the overcoat layer related to the method for manufacturing a color filter in the detailed description of the invention are a monomer having at least one epoxy group and a monomer having an N-substituted amide or N-substituted imide group. It consists of a copolymer consisting of a monomer having any of the above, and at least one of a polyvalent carboxylic acid or a polyvalent carboxylic acid anhydride as a curing agent.

A monomer having at least one epoxy group (hereinafter referred to as (a)
) as glycidyl (meth)acrylate,
3.4 Epoquin butyl (meth)acrylate, etc. As a crosslinking component, it is possible to use a resin having a hydroxyl group in addition to an epoxy group, but it is possible! Monomers with N-N substituted amide and N-substituted imide groups (hereinafter referred to as (b)) that have epoxy groups are good because they have problems such as decreased compatibility with solvents and loss of smoothness. N,N-dimethyl (meth)
Acrylamide, (meth)acryloylmorpholine, N
-phenylmaleimide, N-cyclohexylmaleimide, etc. Other amide group-containing monomers include acrylamide, but is it organic unless it is converted to Nfi? There are problems such as a decrease in compatibility with the 800-gold and a loss of smoothness.

(The ratio of (a) to (b) is preferably 20-55 parts by weight. If (a) is more than 55 parts by weight, the adhesiveness will not improve, and if it is less than 20 parts by weight, crosslinking will be insufficient, resulting in poor chemical resistance, The hardness decreases.The molecular weight of the copolymer is 5000~
200,000, preferably 10,000 to 50,000.

If the molecular weight is 200,000 or more, crosslinking will proceed too much, resulting in insufficient adhesion, and if it is less than 5,000, the crosslinking density will be low and durability will be impaired.

Furthermore, the curing agent is a polycarboxylic acid that reacts with an epoxy group, and includes bifunctional acids such as succinic acid, adipic acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, and hexahydrophthalic acid, trimeri-nodonic acid, and trimenone. Examples include trifunctional acids such as acids, and tetrafunctional carboxylic acids such as pyromellitic acid and 12.5.6-titracarboquinlunaphthalene. Among these, tri- to tetrafunctional aromatic polycarboxylic acids and their anhydrides are preferred from the viewpoint of crosslinking density and compatibility with the resin.

The amount added is 10% of the copolymer of (a)
The amount ranges from 1 to 100 parts by weight, preferably from 10 to 40 parts by weight. If the amount added exceeds 100 parts by weight, the adhesion between the overcoat layer and the color filter will decrease, and the stability of the coating material will also deteriorate. Also 1
If it is less than 1 part by weight, the crosslinking density will not increase sufficiently, causing problems in chemical resistance and toughness.

In addition to the above-mentioned components (a) to (C), the coating material can be supplemented with S1 cambringing agent to further improve adhesion, and methyltrimethoxysilane, vinyltrimethoxysilane, etc. Silane, T-methacryloyloxypropyltrimethoxysilane, T-glycidoxypropyltrimethoxysilane, β-(3,4-epoxychlorohexyl)ethyltrimethoxysilane, T-glycidoxypropylmethyljethoxysilane, etc. It will be done.

The coating material forming the overcoat layer can be obtained by uniformly mixing the above-mentioned components.

As a method for mixing these components, it is preferable to mix these components by dissolving them in a suitable solvent.

Examples of solvents that can uniformly dissolve the coating material include ketones such as methyl isobutyl ketone, cyclohexanone, and isophorone, ethers such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dioxane, propylene glycol monomethyl ether, and propylene glycol monoethyl ether, butyl acetate, Esters such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethyl lactate are prohibited.

In particular, ethylene glycol monoethyl ether acetate and diethylene glycol dimethyl ether are preferred from the viewpoint of solubility and coating properties.

The order in which the components of the coating material are mixed is not particularly limited. Further, the solution concentration of the coating material is not particularly limited, but is appropriately selected depending on the purpose of use and the method of coating the transparent substrate. -10~ for boat fishing
It is used at about 40% by weight.

The coating material obtained in the above manner is applied to
As shown in the figure, it is applied to a substrate consisting of a transparent BA substrate and a colored layer 2, etc. to an arbitrary thickness using a roll coater, spin coater, etc. and cured at 150 to 250'C for about 30 minutes to 5 hours. Overcoat layer 3 and colored layer 2
Color filters can be protected without compromising color tone or transparency.

The present invention will be specifically explained below using examples.

[Example 1] 50 g of phenylmaleimide, 50 g of glycidyl methacrylate, and 250 g of cyclohexanone were charged into a 111-volume three-diameter round bottom flask equipped with a cooling tube, a stirrer, and a thermometer.
After sufficiently purging with nitrogen, 1.5 g of azobisisobutyronitrile was added, the temperature of the solution was raised to 80°C, and the mixture was stirred for 5 hours to obtain a copolymer. The weight average molecular weight of this copolymer was 40,000 in terms of polystyrene.

To 100 g of the copolymer solution obtained here, 25 g of a 12% solution of diglyme 'f4 of trimellitic acid was added and stirred thoroughly to obtain a coating material.

This coating material was coated on the colored layer of the previously prepared color filter substrate using a spin coater at 120 rpm, and then cured at 200° C. for 60 minutes to obtain an overcoat layer. The obtained color filter has excellent smoothness (02 μm
(Below) There were no external abnormalities. Results of film thickness measurement by contact type 1. It was I IJm.

The following tests were conducted on the overcoat layer of the color filter produced as described above. First 400-700
The transmittance in the entire nm range was measured, and it was confirmed that the transmittance was 95% or more in the entire range. A 1 microscopic spectrophotometer manufactured by Olympus Corporation was used as the measuring device. Next, the adhesion between the overcoat layer and the color filter was examined.

After a 5-hour pre-shark test at 120°C2at+n, a base grain test (JIS K
-5400), no peeling was observed at all. In addition, an aqueous solution of 5XNaOH15XHzso, N
? No abnormalities were found regarding changes in film thickness, changes in transmittance, or adhesion after immersion in IP (N-methylpyrrolidinone) for 30 minutes at room temperature.

Furthermore, ITo (indium-
Tin-oxide) was vapor-deposited and its suitability for ITO was examined, but no abnormalities such as cranking or peeling were observed. Good results were also obtained regarding adhesion to the sealant.

From the above results, the overcoat layer of the color filter obtained by the manufacturing method of the present invention has transparency, heat resistance,
It was confirmed that the adhesiveness and ITO suitability were excellent.

[Example 2] Same as Example 1, GMA (glycidyl methacrylate) 0g acryloylmorpholine 40gECA (
ethylene glycol monoethyl ether acetate)
250 g AIBN (azobisisobutyronitrile) 1,2 g These were charged to obtain a copolymer. The weight average molecular weight of this copolymer was 80,000 in terms of polystyrene.

After obtaining a coating material in the same manner as in Example 1, spin coating was performed on a color filter substrate in the same manner as in Example 1 to form an overcoat layer. The same test as in Example 1 was conducted and the results shown in Table 1 were obtained.

[Example 3] Same as Example 1, GMA (glycidyl methacrylate) 0g cyclohexylmaleimide 50gECA
(ethylene glycol monoethyl ether acetate))
250 g AIBN (azobisisobutyronitrile) 1 g These were charged to obtain a copolymer. The weight average molecular weight of this copolymer was 40,000 in terms of polystyrene.

After obtaining a coating material in the same manner as in Example 1, spin coating was performed on a color filter substrate in the same manner as in Example 1 to form an overcoat layer. The same test as in Example 1 was conducted and the results shown in Table 1 were obtained.

[Comparative Example 1] In the same manner as in Example 1, 00 g of GMA (glycidyl methacrylate), 250 g of ECA (ethylene glycol monoethyl ether acetate), and 1 g of AIBN (azobisisobutyronitrile) were charged to obtain a copolymer. The weight average molecular weight of this copolymer was 50,000 in terms of polystyrene.

After obtaining a coating material in the same manner as in Example 1, spin coating was performed on a color filter substrate in the same manner as in Example 1 to form an overcoat layer. The same test as in Example 1 was conducted and the results shown in Table 1 were obtained.

[Comparative Example 2] In the same manner as in Example 1, 5 g of GMA (glycidyl methacrylate), 15 g of phenylmaleimide, 250 g of cyclohexanone, and 1 g of AIBN (abisisobutyronitrile) were charged to obtain a copolymer. The weight average molecular weight of this copolymer was 60,000 in terms of polystyrene.

After obtaining a coating material in the same manner as in Example 1, spin coating was performed on a colored layer on a transparent substrate in the same manner as in Example 1 to form an overcoat layer. The same test as in Example 1 was conducted and the results shown in Table 1 were obtained.

(The following is a blank space) [Effects of the invention] The color filter manufactured by the manufacturing method of the present invention has the following properties:
Since the coating material forming the overcoat layer has either amide or imide groups, it has the necessary physical properties, toughness, hardness, light resistance, transparency, melting resistance, adhesion, and sealing agent. The adhesion properties are also extremely excellent for practical use.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of a color filter. 1...Transparent substrate 2...Colored layer 3...Overcoat layer 4...Blank matrix patent application Person Toppan Printing Co., Ltd. Representative Kazuo Suzuki

Claims (1)

[Claims] (1) A method for producing a color filter having a colored layer on a transparent substrate and an overcoat layer provided on the colored layer, which comprises a monomer having at least one epoxy group and an N-substituted amide or A coating material mainly composed of a copolymer consisting of a monomer having any of N-substituted imide groups and at least one type of polyvalent carboxylic acid or polyvalent carboxylic acid anhydride is applied on the colored layer. A method for manufacturing a color filter, which comprises forming an overcoat layer by heating and curing after coating.