JPH07168016A - Composition for protective film, substrate provided with color filter and liquid crystal display device using same - Google Patents

Abstract

PURPOSE:To provide a color-filter protective film having a high flattening capability and a sufficient adhesion force with a glass substrate by employing an alicyclic epoxy resin serving as the main component, a multifunctional photopolymerizing polygomer having no aromatic ring, and a reactive diluent in a specific ratio. CONSTITUTION:A composition for a protective film comprises an alicyclic epoxy resin serving as the main component and containing a multifunctional photopolymerizing oligomer, a reactive diluent, an epoxy hardening agent and a photopolymerization initiator; a multifunctional photopolymerizing oligomer having no aromatic ring; and a reactive diluent, the former multifunctional photopolymerizing oligomer having no alicyclic epoxy resin and no aromatic ring as its components. When the alicyclic epoxy resin is 100 parts by weight, the multifunctional photopolymerization oligomer having no aromatic ring is 50 to 200 parts by weight and the reactive diluent is 50 to 200 parts by weight. A color-filter-equipped substrate comprises a substrate 1, colored layers 21R, 21G, 21B formed over the substrate 1, and a protective film 3 formed over the layers, and the above composition is hardened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective film composition, a substrate with a color filter, and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art In recent years, a light receiving display element such as a liquid crystal display element has been remarkable as a substitute for a CRT (cathode ray tube) which has been a mainstream of conventional display devices because of its thinness, lightness and low power consumption. Showing development. A color filter is indispensable in order to obtain a display performance closer to that of a CRT by colorizing this display element, and various materials and methods have been proposed so far.

[0003]

A typical example thereof is a dyed color filter obtained by dyeing a thin film of a polymer such as gelatin with a dye, which has been used in conventional liquid crystal type small color televisions and the like. . This dyed color filter was excellent in terms of transmittance and chromaticity, but some drawbacks have been pointed out as the size of the liquid crystal display device has increased in recent years. That is, there is a lack of uniformity of chromaticity over a large area, a high cost due to the complexity of the process, and a lack of heat resistance and weather resistance due to the use of dyes.

In order to make up for these drawbacks, various color filter manufacturing methods have been proposed in recent years. For example, a pigment is dispersed in a photosensitive resin in advance and patterned by photolithography, a so-called pigment dispersion method, using an inorganic or organic pigment or dye, directly on the substrate by screen, offset, gravure printing, or the like. Examples include a printing method for forming a pattern and an electrodeposition method in which an electrodeposition paint is attached on the electrodes.

However, these color filter-equipped substrates have a problem in that thickness unevenness occurs in each color or between colors (usually 0.1 μm or more). In particular, the above-mentioned pigment dispersion method can form a color filter having a high pattern accuracy, but the thickness unevenness due to the overlap between colors is large. Such thickness unevenness causes a problem that sufficient contrast and gradation cannot be obtained when such a substrate with a color filter is used as one electrode substrate of a liquid crystal display element.

In such a color filter, a transparent protective layer is often formed on the colored layer for the purpose of protecting the colored layer. Basic properties required for the protective layer include adhesion to a transparent electrode (ITO, etc.), patterning property by etching, appropriate hardness, adhesion to glass, adhesion to a sealing material used for a liquid crystal display element, etc. However, at the same time, the protective layer also has a function of flattening the colored layer, and in order to obtain a high-performance display, it is important to use one having a high flattening function. Further, the film thickness uniformity of the protective film itself is also an important performance.

Several materials have been proposed for the protective layer, which are roughly classified into acrylic type, polyimide / polyamide type, and silicone type.

As an acrylic type, Japanese Patent Laid-Open No. 61-171
No. 24, JP-A No. 61-141401, JP-A No. 62-89022, etc., but in general, the above-mentioned flattening function is not sufficient, and in addition, adhesion to a transparent electrode, Also, it has a defect that the patterning property is not sufficient. That is, a transparent conductive film is formed on the protective layer, and a photolithography process and wet etching process are performed.
Although fine processing (patterning) is performed, it is difficult to obtain sufficient adhesion between the protective film / transparent conductive film at this time, and peeling occurs, severe undercutting or side etching during patterning of the transparent conductive film. There was a problem such as occurrence.

The polyimide / polyamide type is described in JP-A-60-78401, JP-A-61-77007 and the like. This is generally superior in adhesiveness to the transparent electrode and patterning property as compared with the acrylic type, but has a drawback that the flattening function is extremely low and the cost is high, so that it is not often used. Absent.

Further, regarding the silicone type, a thermosetting type is described in JP-A-63-218771, but the above-mentioned flattening function is not sufficient, and a sufficient protective film / transparent conductive film is used. It is difficult to obtain the adhesive force between the layers, and peeling may occur during patterning of the transparent conductive film.
It has problems such as severe undercut and side etch.

Further, as another attempt to flatten the surface of the protective layer, it is possible to polish the surface of the protective layer.
It is proposed in Japanese Patent No. 93781, Japanese Unexamined Patent Publication No. 1-206304, and the like.

[0012] However, this requires a polishing process having a low productivity, which is a major factor in increasing the cost. Further, there is a problem that scratches are likely to occur on the protective layer due to polishing.

The present invention is intended to solve the above-mentioned drawbacks of the prior art. The film thickness of the protective film is good, and the flattening ability of the colored layer is excellent. It is a protective layer that has good adhesion, etc., and also has increased adhesion strength between the substrate and the protective film to prevent peeling from the periphery of the protective film and penetration of chemicals and the like between the substrate and the protective film. Therefore, it is intended to obtain a high quality, stable quality, high productivity, low cost substrate suitable for a color filter.

[0014]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that a protective layer made of a specific composition is extremely effective in solving the above problems. I found that.

That is, the present invention comprises the main components (A), (B) and (C) containing the following components (A), (B), (C), (D) and (E). A composition for a protective film, wherein (B) is 50 when (A) is 100 parts by weight.
To 200 parts by weight, and (C) is 50 to 200 parts by weight, to provide a protective film composition,
A substrate with a color filter comprising a substrate, a colored layer formed on the substrate, and a protective layer formed on the substrate, wherein the composition is cured. The present invention provides a liquid crystal display device characterized by using the above-mentioned substrate with a color filter as a substrate with a color filter and at least one substrate constituting a liquid crystal panel.

(A) Alicyclic epoxy resin (B) Polyfunctional photopolymerizable oligomer having no aromatic ring (C) Reactive diluent (D) Epoxy curing agent (E) Photopolymerization initiator Will be described.

The component (A) is an alicyclic epoxy. The alicyclic epoxy is an epoxy having an alicyclic portion in its structure, and particularly preferably the alicyclic portion has about 4 to 8 carbon atoms. An alicyclic epoxy containing a cyclohexane ring is preferable because it is generally easily available.

Among the epoxy resins having good adhesiveness, the alicyclic epoxy resin has a feature that it has good transparency, weather resistance and heat resistance because it has no conjugated system as compared with the aromatic epoxy resin. Further, among the alicyclic epoxy resins, an alicyclic epoxy resin having a structure as shown in Chemical Formula 1 (wherein R is an alkyl portion of a monohydric alcohol such as methanol, ethanol, propanol, butanol or trimethylolpropane, pentaerythritol) Alkyl part of polyhydric alcohol) is desirable because it has a high T _g of the cured product and has good weather resistance, transparency, and electrical characteristics. As such a resin, EHPE-3150, EHPE-1150 (trade name,
Available from Daicel Chemical Industries).

[0019]

[Chemical 1]

One of the notable features of this resin is that the raw material contains no causative substance,
^It can be mentioned that ionic impurities such as ⁺ and Cl ⁻ are very small. This is a very effective feature for preventing the occurrence of display unevenness in a liquid crystal display device due to a substrate with a color filter using this composition.

The component (B) is a polyfunctional photopolymerizable oligomer having no aromatic ring. The polyfunctional photopolymerizable oligomer has a photosensitive group that can be polymerized or crosslinked by irradiation with light, and has advantages such as highly efficient use of energy, shortening of curing time, and provision of patterning property. Also,
As compared with the monomer, there are few sites that react, so there is an advantage that curing shrinkage is small and adhesiveness is good.

Specifically, the polyfunctional photopolymerizable oligomer means an acryloyl group, a methacryloyl group, a vinyl group,
It is an oligomer having a plurality of carbon-carbon unsaturated bonds such as allyl groups at the terminal or side chain. For example, epoxy (meth) acrylate, epoxidized oil (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate, vinyl / (meth) acrylate, silicon (meth) acrylate, polybutadiene ( (Meth) acrylate and the like. Polyfunctional (meth) acrylates are preferred because of their relatively high photopolymerization rate. further,
From the viewpoint of heat resistance, it is preferable to use polyester (meth) acrylate. Specific examples of such polyester (meth) acrylate are as follows. M-7100, M-8030, M-8060, M-
8100, M-8530, M-8560, M-9050
(Product name, manufactured by Toagosei Kagaku).

Particularly, an oligomer having no aromatic ring has good transparency, light resistance and heat resistance because the coloring caused by the formation of a conjugated system is suppressed.

The average molecular weight of such an oligomer is 30.
0 or more is preferable, and if it is smaller than this, there is a possibility that curing shrinkage is large and adhesive strength is inferior.

The polyfunctional photopolymerizable oligomer as the component (B) has a content of 50 to 50 when the amount of the component (A) is 100 parts by weight.
If the amount is more than 200 parts by weight, the adhesion to glass will be poor, and if the amount is less than this, the film thickness uniformity may be significantly deteriorated. A more preferred range is 75 to 125 parts by weight.

The component (C) is a reactive diluent. Since the reactive diluent has a low viscosity and a high dilution performance, it is possible to dilute the highly viscous component (A) or component (B) to adjust the viscosity to a practical value for coating. Generally, since the evaporation rate is low, the change in viscosity during coating can be suppressed and good coatability can be obtained. Further, these react with at least one of the component (A) and the component (B) and remain as a film, so that deterioration of flatness due to film reduction can be suppressed and a highly flat film shape can be realized.

In order to ensure a low viscosity of 100 cP or less for the entire composition, a reactive diluent having a low viscosity of 200 or less is preferable.

As such a reactive diluent, a polyfunctional photopolymerizable monomer, a monofunctional photopolymerizable monomer, a monomer capable of reacting with an epoxy or the like can be used. Among these, examples of usable polyfunctional photopolymerizable monomers include trimethylolpropane poly (meth) acrylate, pentaerythritol poly (meth) acrylate, hexanediol poly (meth) acrylate, 1,4-butanedioldi ( (Meth) acrylate, diethylenediol di (meth)
Acrylate, neopentyl glycol di (meth) acrylate, hydroxypivalic acid ester neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, and the like. However,
Considering that the viscosity is extremely low as compared with the components (A) and (B), the hardness does not become too high, and phase separation due to a rapid increase in crosslink density during photocuring is prevented, monofunctional light is considered. More preferred are polymerizable monomers and monomers capable of reacting with epoxy.

Specifically, the monofunctional photopolymerizable monomer is a compound having only one photopolymerizable functional group such as acryloyl group, methacryloyl group, vinyl group, allyl group in the molecule. The monomer having at least one functional group capable of reacting with an epoxy group in the molecule is, for example, an amino group,
Examples thereof include monomers and acid anhydrides having a functional group capable of reacting with an epoxy group such as a mercapto group, a carboxyl group, a hydroxyl group, and an epoxy group in a molecule.

As such a monomer used as a reactive diluent, there are (1) a photopolymerizable substance which does not react with epoxy, (2) a photopolymerizable substance which can react with epoxy, and (3) a photopolymerizable substance. And (Ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, styrene are examples of (1), and styrene oxide, butyl glycidyl ether, glycidyl phenyl are examples of (2). Examples of ether, glycidyl isopropyl ether, epoxy cyclohexene epoxide, glycidol, (3) are (meth)
Examples thereof include acrylic acid, glycidyl (meth) acrylate, vinyl glycidyl ether, allyl glycidyl ether, vinylcyclohexene epoxide, and epoxycyclohexyl (meth) acrylate. The reaction diluent (3) is particularly preferable. As the component (C), such monomers can be used alone or in combination.

The reactive diluent as the component (C) is 50 to 200 parts by weight when the amount of the component (A) is 100 parts by weight, and if it is more than this, the hardness of the protective film is low and the heat resistance and chemical resistance are high. May decrease, and if less than this (A)
Phase separation of the component and the component (B) may easily occur. A more preferred range is 75 to 125 parts by weight.

In the present invention, the above components (A) to (C) are the main components. Specifically, it means that the total weight of these three components occupies 80% or more, preferably 90% or more of the total weight of the components (A) to (E). If the total weight is less than this, heat resistance and stability to light are reduced. There is a risk that it will worsen.

Examples of combinations of the main components (A), (B) and (C) are as follows.

(1) (A) alicyclic epoxy (B) polyfunctional photopolymerizable oligomer having no aromatic ring (C) a monofunctional photopolymerizable oligomer having photopolymerizability and having no group capable of reacting with epoxy Reactive diluent composed of functional photopolymerizable monomer (2) (A) Alicyclic epoxy (B) Polyfunctional photopolymerizable oligomer having no aromatic ring (C) No photopolymerizability and reacting with epoxy Reactive diluent composed of a monomer having a group to be obtained (3) (A) Alicyclic epoxy (B) Polyfunctional photopolymerizable oligomer containing no aromatic ring (C) Photopolymerizable epoxy group Examples thereof include a reactive diluent composed of a monomer having a group capable of reacting with.

An epoxy curing agent as the component (D) and a photopolymerization initiator as the component (E) are added to the composition.

Epoxy curing agents include polyamine-based curing agents, acid anhydride-based curing agents, polyamide-based curing agents, latent curing catalysts, etc., but latent curing catalysts in which the curing reaction occurs only at high temperatures considering the pot life. Are preferred, and examples include boron trifluoride monoethylamine and the like.

The epoxy curing agent as the component (D) has an appropriate amount depending on the combination of the epoxy and the curing agent, and is usually compounded so that the heat distortion temperature of the cured product becomes the highest. When boron trifluoride monoethylamine is used, it is preferably 1 to 15 parts by weight, and more than this, when the total of epoxy-containing components contained in the components (A) and (C) is 100 parts by weight. If so, there is a possibility that an inconvenience may occur such that adhesiveness and heat resistance are deteriorated.

A radical polymerization initiator can be used as the photopolymerization initiator which is the component (E). Examples thereof include 2-hydroxy-2-methyl-1-phenylpropan-1-one, chloroacetophenone, diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- (4-methylthiophenyl)-.
2-morpholino-propan-1-one, benzoin ether, benzyl dimethyl ketal, benzophenone, methyl-o-benzoyl benzoate, thioxanthone,
Examples include glyoxy ester. Also, a suitable sensitizer such as 4,4-bis (diethylamino) benzophenone for the photopolymerization initiator benzophenone may be added.

The photopolymerization initiator which is the component (E) has a total of 100 photopolymerizable components contained in the components (B) and (C).
The amount is preferably 1 to 20 parts by weight, and if it is less than this, the curing speed may be too slow, and if it is more than this, the heat resistance and the stability to light may deteriorate. . More preferably 5 to 15
Parts by weight.

Further, this system includes a silane coupling agent (γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane).
Aminopropyltrimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, etc.) (A)
When the total amount of components (E) to (E) is 100 parts by weight, 0.5 to 10 parts by weight can be added. This has the effect of improving the adhesive force between the protective film layer and the glass substrate.

Further, an antioxidant (such as butylhydroxytoluene), a light stabilizer, a defoaming agent and a leveling agent can be added to this system.

Furthermore, in order to increase the hardness of the cured film, silica sol, alumina sol and the like can be added to the above composition in an amount of 0 to 40% by weight, preferably 1 to 15% by weight. Finally, the hardness of the cured film is preferably pencil hardness HB or more, and more preferably 3H or more.

The composition described above is preferably diluted with a solvent in order to improve coatability. Examples of the solvent include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, carbitol, methyl carbitol, and NMP. It is illustrated.

The above-mentioned solvent is added to the other components in a total amount of 10
When the amount is 0 parts by weight, it is preferably 20 to 800 parts by weight. If the amount is less than this, the film thickness becomes too thick, and if it exceeds this amount, the film thickness becomes too thin.

The thickness of the protective layer is 0.5 to 100 after curing.
It may be about μm. If it is thinner than this, the flattening performance is insufficient, and if it is thicker than this, the transparency may be lowered, or cracks or the like may occur, resulting in a reduction in strength. In particular, it is preferable that the thickness is 1 to 50 μm, and further 1.5 to 10 μm, because sufficient flatness can be obtained.

The substrate used in the present invention is not particularly limited. Examples thereof include organic sheets of polyethylene terephthalate, polyester, diacetate, etc., and transparent substrates such as various glass plates. The thickness of the substrate is selected according to the purpose and is not particularly limited. When a glass substrate is used for a liquid crystal display device, about 0.3 mm to 1.5 mm is usually used.

The color filter in the present invention may be formed by any method other than the above pigment dispersion method. The color filter pattern is not particularly limited, and may be, for example, a stripe pattern, a mosaic pattern, a delta pattern, or the like. In addition, in order to improve the contrast, a light-shielding pattern such as a black matrix may be formed between the patterns, and the formation of the black matrix may be performed by a vapor deposition method of metallic chromium or the like.
The black photosensitive resist may be patterned by photolithography.

The method of manufacturing the electrode substrate with the color filter according to the present invention will be described below in the case where the pigment dispersion method is adopted.

First, a light shielding layer called a black matrix is formed on a transparent substrate such as glass or plastic. This light-shielding layer is provided in the liquid crystal element of the TFT system in order to maintain the characteristics of the transistor or prevent the deterioration of the contrast, and may be formed of a metal chromium thin film having an excellent light-shielding property.

In a simple matrix drive represented by an STN (Super Twisted Nematic) type liquid crystal element, the contrast of these elements is originally T.
The black matrix is often omitted, formed by superimposing the three primary colors, or formed of a colored resist in order to reduce the cost as compared with the FT method and to pursue cost reduction.

Next, a colored resist containing a dye such as a pigment and a photosensitive resin is applied on the substrate and exposed through a photomask having a predetermined pattern, and then the unexposed portion is removed by development. Form a color pattern. PVA as an oxygen barrier film overlaid on the colored resist layer during exposure
You may use together a (polyvinyl alcohol) layer. This operation is repeated twice with another color to form a color filter of three primary colors.

A layer made of the above composition is formed thereon. As the method, various coaters such as a roll coater, an air knife coater, a blade coater, a rod coater, a bar coater and a spin coater can be used.

Curing of the composition layer can be carried out by irradiating active energy rays such as ultraviolet rays, visible rays, electron rays and the like from a high pressure mercury lamp, a xenon lamp or the like. Patterning may be performed through a photomask, irradiation may be performed, and an unexposed portion may be removed with a solvent or the like to form a pattern.

Next, an electrode layer is formed on the protective layer. The electrode layer is made of aluminum, chromium or the like.
Further, the transmissive display needs to be light transmissive, and it is generally preferable to use indium tin oxide (ITO) or tin oxide, but the present invention is not limited to this. Further, the electrode layer may be patterned corresponding to the display, or may be a solid electrode when used as a common electrode. The method for forming the electrode layer is not particularly limited to this, but from the viewpoint of making the layer thickness uniform, a vapor deposition method, a sputtering method, or the like is preferably used.

In the present invention, if necessary, SiO ₂ , TiO ₂ , Si ₃ may be formed above or below the electrodes on the substrate.
An insulating film such as N ₄ , an active element such as a TFT, an MIM, a thin film diode, a retardation film, a polarizing film, a reflecting film, a photoconductive film, or the like may be formed.

Further, in the case of a liquid crystal display, an alignment film is formed on the electrode-attached substrate, if necessary. This may be obtained by rubbing an organic resin film of polyimide, polyamide, polyvinyl alcohol, or the like, may be obliquely vapor-deposited of SiO, or may be used by applying a vertical alignment agent.

Further, as a method of manufacturing a liquid crystal display element, a method which is usually used can be adopted. That is,
One of the pair of substrates is the electrode substrate with the color filter, the other is a substrate with an electrode that is appropriately patterned, and a liquid crystal alignment film is formed on the substrate as necessary,
Next, the electrode surfaces of the pair of substrates are opposed to each other, the peripheral portions are sealed, and the liquid crystal is sealed inside. This makes it possible to obtain a color liquid crystal display having high definition.

From the viewpoint of application, the substrate with a color filter of the present invention includes a liquid crystal display surface, a cathode ray tube display surface, a light receiving surface of an image pickup tube, and the like. Further, since a color filter having extremely small thickness unevenness can be obtained, it is particularly preferable for a liquid crystal element in which the accuracy of the substrate spacing is strict.

The reason why an extremely high leveling ability is obtained as in the present invention is presumed as follows.

It is considered that the film immediately after being applied on the substrate has fluidity, and the coating film surface is very flat due to its leveling property regardless of the unevenness of the surface of the color filter below. Generally, when this is cured or dried by heat, the film shrinks as the solvent evaporates, polymerizes, or crosslinks, and the surface shape gradually approaches the shape of the color filter, resulting in poor flatness.

In the present invention, it is possible to prevent the deterioration of the flatness by irradiating the light before the solvent is evaporated to advance the curing in a short time, maintain the flat coating film surface. Since the polyfunctional acrylate oligomer that plays this role has many photosensitive acrylate groups, it is effective because the photoreaction efficiency is good.

Further, since the addition of the reactive diluent reduces the viscosity, it is not necessary to add a large amount of the solvent as in the conventional composition. Therefore, the film shrinkage due to the evaporation of the solvent is reduced to further improve the flatness. It is the present invention that has made it possible to obtain

The protective layer of the present invention has a very high adhesive force with glass and has high reliability. It is considered that this adhesive force has the effect of the polarity of the functional group in the epoxy resin or the reactive diluent, the effect of reducing the curing shrinkage rate of each component, and the like. Further, by using a silane coupling agent, it is possible to further improve the adhesion to glass.

In the substrate with color filter of the present invention,
Since it is not necessary to polish the surface of the color filter in the subsequent process, the quality is improved by eliminating the generation of foreign matter and scratches due to polishing, and the production time of the color filter is shortened, the cost is reduced, and the cleanness is improved. The effect of can be obtained.

After the composition is applied to the entire surface, a negative pattern of a photomask is overlaid, exposed and cured, and developed with a developing solution to form a resin pattern having a desired shape. With this configuration, when the liquid crystal is sealed while the electrode substrate with the color filter and the substrate with the electrode pattern facing the color filter are overlapped with each other, the protective layer in the sealed portion can be selectively removed. It is possible to improve the adhesive effect of the seal.

[0066]

EXAMPLES A method for manufacturing a color filter according to the present invention will be described with reference to FIGS.

First, a chromium film having a thickness of 100 nm was formed on the transparent glass substrate 1 by the magnetron sputtering method. A photomask is used on this to form a pattern with a photosensitive resist, and then the chromium film is etched to form a light shielding pattern (FIG. 1A).

Next, in the same manner, red 21R and green 21
G and blue 21B colored patterns are sequentially formed between the light blocking patterns (FIG. 1B).

The compositions shown in Table 1 were prepared as examples. A silicone-based leveling agent (manufactured by Shin-Etsu Chemical) was used as the leveling agent in the table.

As a comparative example, the composition shown in Table 2 and a commercially available product (Comparative Example 4, "JSS-71" manufactured by Japan Synthetic Rubber) were used.
5 ”) was prepared. Here, the components in the table are: EHPE-3150: Alicyclic epoxy, manufactured by Daicel Chemical Industries Epicoat 152: Novolac epoxy, manufactured by Yuka Shell Aronix M-8030: Oligoester acrylate, manufactured by Toagosei Chemical Co., Ltd. PETA, TMPTA: penta Mixture of erythritol triacrylate and trimethylolpropane triacrylate, Shin Nakamura Chemical Co., Ltd. Seloxide 2000: vinyl cyclohexene epoxide, Daicel Chemical Industries, Ltd. CYCLOMER M-100: epoxy cyclohexyl methacrylate, Daicel Chemical Industries, Ltd. Epoxy curing agent: boron trifluoride monoethylamine (Hashimoto Kasei Co., Ltd.) Photopolymerization initiator: 2-hydroxy-2-methyl-1-phenylpropan-1-one (Darocur 1173, manufactured by Merck) Coupling agent: γ-glycy Trimethoxysilane (KBM-403, Shin-Etsu Chemical Co., Ltd.) Leveling agent: silicone-based, is manufactured by Shin-Etsu Chemical.

This composition was applied onto the above-mentioned colored pattern with a spin coater to give a protective film 3 having a thickness of about 2 after curing.
The entire surface was coated so as to have a thickness of μm (FIG. 1 (c)). Then, it was irradiated with ultraviolet light using a high pressure mercury lamp and heated at 200 ° C. for 30 minutes to be completely cured.

The physical properties of the color filters manufactured by the methods of the above Examples and Comparative Examples were evaluated. The appearance was evaluated as ◯ when no whitening or peeling occurred on the substrate surface or edge face coated with the protective film, and as x when it occurred. The coating properties were evaluated by using a sodium lamp with visual evaluation, and those with almost no unevenness were evaluated as ◯, and those with some unevenness were evaluated as Δ. The flatness was examined by using a surface roughness meter for the effect of improving the unevenness of the surface before and after forming the coating layer on the colored layer. The unevenness improvement rate was evaluated as x when less than 40%, and ◯ when 40% or more. Further, the adhesion with glass was evaluated by a cross-cut tape test after boiling in water for 10 hours. The adhesive strength was evaluated as ◯ when it was not peeled at all, Δ when partially peeled, and x when it was completely peeled. For transparency, a protective film was formed on a glass substrate, and the transmittance including glass was measured at 400 nm with an air reference. The transmittance of 86% or more was evaluated as ◯, and the transmittance of less than 86% was evaluated as x.

The results are shown in Table 3 (Example) and Table 4 respectively.
(Comparative example).

[0074]

[Table 1]

[0075]

[Table 2]

[0076]

[Table 3]

[0077]

[Table 4]

As is clear from the comparison between the example and the comparative example, the protective film of the color filter of the present invention has very good coatability and achieves film thickness uniformity capable of supporting higher performance display. is doing. This is considered to be mainly due to the effect of the reactive diluent, and is particularly clear in comparison with Comparative Example 3. Further, it is considered that the reactive diluent contributes to the improvement of the compatibility of the component (A) and the component (B) without causing any phenomenon such as whitening in the examples.

As is clear from the comparison between Example 3 and Comparative Example 1, transparency is better when an alicyclic epoxy resin is used as the component (A) than an aromatic epoxy resin.

As is clear from the comparison between Example 4 and Comparative Example 2, as the component (B), the polyfunctional photopolymerizable oligomer has better adhesiveness than the polyfunctional photopolymerizable monomer. It is considered that this is because the oligomer has a lower shrinkage rate during photocuring and a smaller internal stress than the monomer.

In the embodiment, extremely high flatness is realized. This is considered to be a manifestation of the flatness retention by photo-curing and the solvent reduction effect by using the reactive diluent.

Further, when different components (C) are compared in Examples, there are differences in adhesiveness and the like, but the respective properties are generally better than those in Comparative Examples.

Comprehensively judging from these results, an alicyclic epoxy resin as the component (A), a polyfunctional photopolymerizable oligomer as the component (B) and a reactive diluent as the component (C) as in the examples. It was revealed that the use of the composition containing the cured product gave a cured product having good film thickness uniformity and good transparency. Among them, considering the adhesiveness, acrylic acid, allyl glycidyl ether, Celoxide 2000 (trade name, manufactured by Daicel Chemical Industries), epoxycyclohexyl methacrylate, butyl glycidyl ether, styrene oxide, and epoxycyclohexene epoxide are preferable as the component (C), Considering higher flatness and chemical resistance, acrylic acid, allyl glycidyl ether and Celoxide 2000 are preferable.

Next, by the magnetron sputtering method,
The ITO film 40 was formed to a thickness of 0.25 μm (see FIG. 1).
(D)). After applying a line-shaped resist (masking agent) on the ITO film, it was immersed in a hydrochloric acid / ferric chloride-based etching agent to pattern the ITO film.

In the example of the present invention, the change in the resistance value of ITO and the patterning property were satisfactory without any problems.

Example 2 An alignment film obtained by using the electrode substrate with a color filter obtained in Examples 1A and 2 as one substrate and rubbing a polyimide film on the surface together with the other substrate with an electrode. Was formed. A liquid crystal ZLI2293 (trade name, manufactured by Merck) containing a chiral compound was used as a liquid crystal and was sandwiched between the substrates, and
A 0 / twisted 1/240 duty liquid crystal display device was prepared. When this liquid crystal display element was driven, the in-plane color difference was small and the contrast and color reproducibility were good,
It was confirmed that high-quality full-color display was possible.

[0087]

EFFECT OF THE INVENTION By curing the composition as in the present invention, a protective film having an extremely high leveling ability and a sufficient adhesion to a glass substrate can be obtained. This is a protective film most suitable for a substrate with a color filter and has wide application as a hard coating agent.

In the substrate with a color filter of the present invention, since it is not necessary to polish the surface of the color filter in a subsequent step, the quality is improved by eliminating the generation of foreign matters and scratches due to polishing, and the production of the color filter. It is possible to obtain effects such as reduction of time, reduction of cost, and improvement of cleanliness.

Furthermore, by using the electrode substrate with a color filter of the present invention, a high-quality full-color liquid crystal display device having a small in-plane color difference, good contrast and color reproducibility, and extremely high reliability can be obtained. can get.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a manufacturing process of an electrode substrate with a color filter of the present invention.

[Explanation of symbols]

 1: transparent glass substrate 21R, 21G, 21B: colored pattern 3: protective layer 40: ITO film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumiaki Gunji, Inventor 1150, Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Prefecture Asahi Glass Co., Ltd. Central Research Laboratory (72) Takashi Hadano 1160, Matsubara, Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa・ In G Technology Co., Ltd.

Claims (4)

[Claims] 1. The following components (A), (B),
Main components (A), (B) containing (C), (D) and (E),
A protective film composition comprising (C), wherein (A) is 10
(B) is 50 to 200 parts by weight when 0 parts by weight,
(C) is 50-200 weight part, The composition for protective films characterized by the above-mentioned. (A) Alicyclic epoxy resin (B) Polyfunctional photopolymerizable oligomer having no aromatic ring (C) Reactive diluent (D) Epoxy curing agent (E) Photopolymerization initiator 2. The protective film composition according to claim 1, wherein the reactive diluent as the component (C) has an average molecular weight of 200 or less. 3. A substrate and a colored layer formed on the substrate,
In a substrate with a color filter, which comprises a protective layer formed on the protective layer, the protective layer is a protective layer.
A substrate with a color filter, which is obtained by curing the composition for a protective film described above. 4. A liquid crystal display device using the substrate with a color filter according to claim 3 as at least one substrate constituting a liquid crystal panel.