JP3074850B2 - Protective film material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective film material comprising a thermosetting resin composition and suitable for an optical device.

[0002]

2. Description of the Related Art In a display device such as a liquid crystal display device, a dipping process is performed in a solvent, an acid or an alkali solution during a manufacturing process, and the surface of the wiring electrode layer is locally formed when a film is formed by sputtering. Exposed to high temperatures. Therefore, in order to prevent the element from being deteriorated or damaged by such processing, a thin protective film layer having resistance to these processing is provided.

[0003] Such a protective film has high adhesiveness to a substrate or a lower layer and a layer formed thereon, and the film itself is required to be smooth and tough, to be transparent, to have heat resistance and light resistance. It is required to have high performance such as not causing deterioration such as coloring, yellowing and whitening over a long period of time, and excellent water resistance, solvent resistance, acid resistance and alkali resistance. As a protective film material satisfying these characteristics, for example, a thermosetting composition disclosed in JP-A-60-217230 and the like is known.

[0004]

However, for example, in the case of a super twisted nematic (STN) type color liquid crystal display device, the cell is compared with a conventional twisted nematic (TN) type liquid crystal display device. Since the uniformity of the gap is very important, flatness of the substrate surface is required. This is because display unevenness occurs if the substrate surface is not flat.

Conventional protective film layers have been often used mainly for liquid crystal panels of the TN mode, so that their flatness is rarely questioned, and protective films actually formed on color filter substrates are used. Examination of the layer revealed that surface irregularities caused by the production of the color filter were almost completely expressed on the surface of the protective film layer.

Accordingly, the present invention has been made in view of the above-mentioned drawbacks of the prior art, and has as its object to provide a protective film material which can form a protective film having an effect of reducing unevenness on a color filter, and which is particularly suitable for STN. With the goal.

[0007]

According to the present invention, (A) the following general formula (1)

Embedded image [Wherein R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and m represents an integer of 1 to 8]. A polymer containing at least 20% by weight of a structural unit represented by the formula: (Hereinafter referred to as "polymer A"), (B) at least one compound selected from polycarboxylic anhydrides and polycarboxylic acids, (C) acrylic compounds, and (D) alkoxysilano groups. And a compound having an epoxy group. This protective film material can achieve high concentration and low viscosity, has a high ability to flatten the unevenness on the substrate, and has a high crosslink density, so it is excellent in various resistances Layers can be formed.

Component (A) In the protective film material of the present invention, component which is a base component
The polymer A of (A) has the structural unit represented by the general formula (1) as described above. In this general formula (1), m
Is an integer of 1 to 8, preferably 1 to 4. Also R
Is a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. The lower alkyl group may be linear or branched, and may be, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl and n-pentyl. Can be exemplified.

The monomer used to introduce the structural unit represented by the above general formula (1) includes, for example, (meth)
Glycidyl acrylate, α-ethyl glycidyl acrylate, α-n-propyl glycidyl acrylate, α-n-
Glycidyl butyl acrylate, (meth) acrylic acid-
3,4-epoxybutyl, (meth) acrylate-4,5-epoxypentyl, (meth) acrylate-6,7-epoxyheptyl, α-ethylacrylate-6,7-epoxyheptyl and the like. it can. Of these, glycidyl (meth) acrylate is particularly preferred. These monomers can be used alone or in combination of two or more.

The structural unit represented by the general formula (1) introduced from these monomers is contained in the polymer A in an amount of at least 20% by weight in order to effectively perform a crosslinking reaction in the coating film. However, it is particularly preferable that the content is 30 to 70% by weight.

The polymer A may contain structural units other than the structural unit represented by the general formula (1) in an amount of 80% by weight or less, particularly 70 to 30% by weight. Examples of the comonomer for introducing another structural unit include (meth)
Methyl acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopenta (meth) acrylate Esters of (meth) acrylic acid such as phenyl, dicyclopentanyloxyethyl (meth) acrylate, and isobornyl (meth) acrylate; vinyl aromatic compounds such as styrene, α-methylstyrene, p-methylstyrene, and vinylnaphthalene Compounds can be mentioned.

The molecular weight of the polymer A is not particularly limited as long as the solution of the protective film material of the present invention can be applied uniformly, and depends on the thickness of the coating film to be formed, application conditions, purpose and the like. Although it is appropriately selected, it is generally preferable that the weight average molecular weight in terms of polystyrene is in the range of 5,000 to 300,000.
Further, the polymer A used in the present invention may be a random copolymer or a block copolymer of the above-mentioned monomers as long as it has the above-mentioned constitutional unit.

Component (B) In the protective film material of the present invention, the polycarboxylic anhydride or polycarboxylic acid used as the component (B) functions as a curing agent for the polymer A.

Examples of the polycarboxylic anhydride include itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenylsuccinic anhydride, tricarbanilic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. Aliphatic polycarboxylic dianhydrides such as aliphatic dicarboxylic anhydrides such as hymic acid, 1,2,3,4-butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, and phthalic anhydride Acids, pyromellitic anhydride, trimellitic anhydride, aromatic polycarboxylic anhydrides such as benzophenonetetracarboxylic anhydride, and ester group-containing anhydrides such as ethylene glycol bis trimellitate and glycerin tris trimellitate. Can be. Of these, aromatic polycarboxylic anhydrides are particularly preferred from the viewpoint of heat resistance.

The polycarboxylic acids include, for example, aliphatic polycarboxylic acids such as succinic acid, glutaric acid, adipic acid, butanetetracarboxylic acid, maleic acid and itaconic acid, hexahydrophthalic acid, 1,2-cyclohexane Alicyclic polycarboxylic acids such as dicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, cyclopentanetetracarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, 1,2,5 And aromatic polycarboxylic acids such as 8-naphthalenetetracarboxylic acid. In particular, aromatic polycarboxylic acids are preferred from the viewpoint of reactivity, heat resistance and the like.

These polycarboxylic acid anhydrides or polycarboxylic acids of component (B) can be used alone or in combination of two or more. Usually, 1 to 100 parts by weight per 100 parts by weight of polymer A is used. Parts, especially 3 to 50 parts by weight. If the amount is less than this, the cross-linking density of the formed protective film is not sufficient, and various resistances are reduced. It becomes stable or the adhesion is reduced.

[0017] While acrylic compound component (C) Component (C) also acting as a curing agent, in particular gives a flattening function on the protective film. Such acrylic compounds include monofunctional, bifunctional, and trifunctional or higher polyfunctional compounds, and usually esterified compounds capable of undergoing a radical reaction by heat are used.

As the monofunctional acrylic compound, phenoxy polyethylene glycol (meth) acrylate,
Nonylphenoxy polyethylene glycol (meth) acrylate, nonylphenoxy polypropylene glycol (meth) acrylate, and the like. These include, for example, Aronix M-101, M-111, and M-114 (manufactured by Toa Gosei Chemical Industry Co., Ltd.), It is commercially available under trade names such as V158 and V2311 (manufactured by Osaka Organic Chemical Industry Co., Ltd.).

Examples of the bifunctional acrylic compound include polyethylene glycol di (meth) acrylate, ethylene oxide-modified bisphenol A di (meth) acrylate, and hexamethylene glycol di (meth) acrylate. 210, M-240, M-6200 (manufactured by Toa Gosei Chemical Industry Co., Ltd.),
KAYARAD HDDA, HX-220, R-604, R-629
(Nippon Kayaku Co., Ltd.), V260, V-312, V-335H
P (manufactured by Osaka Organic Chemical Industry Co., Ltd.) and the like.

Examples of the trifunctional or higher polyfunctional acrylic compound include dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropanetri (meth) acrylate, and ditrimethylolpropanetetra (meth) acrylate. And these are, for example, Aronix M-400
M-405, M-450, M-7100, M-803
0, M-8060 (manufactured by Toa Gosei Chemical Industry Co., Ltd.), KAYARAD
TMPTA, DPCA-20, DPCA-30, DPC
A-60, DPCA-120 (Nippon Kayaku Co., Ltd.), VG
It is commercially available under a trade name such as PT (manufactured by Osaka Organic Chemical Industry Co., Ltd.).

Among these acrylic compounds, trifunctional or higher functional acrylic compounds are preferable, and trifunctional or higher functional acrylic compounds not containing an oxyalkylene structure such as oxyethylene are particularly preferable. These are commercially available, for example, Aronix M-400, M-405, M-450, M-450.
7100, M-8030, M-8060 and KAYARAD TMPTA.

These acrylic compounds of the component (C) can be used alone or in combination of two or more. The amount of the acrylic compound is usually 5 to 200 parts by weight, especially 10 to 10 parts by weight, per 100 parts by weight of the component (A). A range of 100 parts by weight is preferred. If the amount is less than the above range, sufficient flatness cannot be obtained, and if the amount is more than the above range, film roughness or phase separation may occur during formation of the protective film, or heat resistance of the film may be reduced.

[0023] Component (D) a compound having an alkoxy silanol groups and epoxy groups of component (D), as well as providing a flattening action on the protective film together with the component (C), to impart adhesion to the protective film.

Examples of such compounds include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ
-Glycidoxypropyldiethoxysilane and the like, which can be used alone or in combination of two or more.

The amount of the compound of component (D) used is generally 0.1 to 200 parts by weight, preferably 5 to 150 parts by weight, per 100 parts by weight of component (A). If less than the range, sufficient adhesion between the protective film and the substrate cannot be obtained,
Further, sufficient flatness cannot be obtained. Further, if it is more than the above range, the alkali resistance and the solvent resistance of the protective film may be reduced.

Other Compounding Agents In the protective film material of the present invention, in addition to the above-mentioned components (A) to (D), if necessary, other compounding agents such as a curing accelerator, a surfactant, and an ultraviolet absorber Etc. can be blended.

The curing accelerator comprises the components (A) and (D) and (B)
It is used for accelerating the reaction with the components, and generally a compound having a heterocyclic structure containing a secondary nitrogen atom or a tertiary nitrogen atom is used. Specific examples include pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, indole, indazole, benzimidazole, isocyanuric acid, and the like. Among these, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-heptadecylimidazole, 4-methyl-2-phenylimidazole,
-Benzyl-2-methylimidazole, 2-ethyl-4
-Methyl-1- (2'-cyanoethyl) imidazole,
Imidazole derivatives such as 2-ethyl-4-methyl-1- [2 '-(3 ", 5" -diaminotriazinyl) ethyl] imidazole and benzimidazole are preferred, and most preferably 2-ethyl- 4-Methylimidazole, 4-methyl-2-phenylimidazole, 1-benzyl-2-methylimidazole are used. These curing accelerators are
It can be used alone or in combination of two or more kinds. It is generally desirable to use 0 to 30 parts by weight, particularly preferably 0.1 to 10 parts by weight, per 100 parts by weight of component (A).

As the surfactant, fluorine-based and silicone-based surfactants can be suitably used. As the fluorine-based surfactant, a compound having a fluoroalkyl or fluoroalkylene group at at least one of terminal, main chain, and side chain is preferable, and specifically,
1,1,2,2-tetrafluorooctyl (1,1,2,2-tetrafluoropropyl) ether, 1,1,2,2-tetrafluorooctylhexyl ether, octaethylene glycol di (1,
1,2,2-tetrafluorobutyl) ether, hexaethylene glycol di (1,1,2,2,3,3-hexafluoropentyl)
Ether, octapropylene glycol di (1,1,2,2-tetrafluorobutyl) ether, hexapropylene glycol di (1,1,2,2,3,3-hexafluoropentyl) ether, sodium perfluorododecyl sulfonate , 1,1,
2,2,8,8,9,9,10,10-decafluorododecane, 1,1,2,2,3,3
-Hexafluorodecane and the like. These commercial products include BM-1000 and BM-1100 (BM Ch
emie), MegaFac F142D, F172, F173
And F183 (manufactured by Dainippon Ink and Chemicals, Inc.).

Examples of the silicone surfactant include Toray silicone DC3PA, SH7PA, D
C11PA, SH21PA, SH28PA, SH29P
A, SH30PA (manufactured by Toray Silicone Co., Ltd.), TS
F-4440, TSF-4300, TSF-4445, TSF-444
6, commercially available products such as TSF-4460 and TSF-4452 (manufactured by Toshiba Silicone Co., Ltd.).

These surfactants can be used alone or in combination of two or more kinds.
Although it differs depending on the type and the type and concentration of each of the components (A) to (D), generally, the range of 0 to 5 parts by weight, particularly 0.001 to 2 parts by weight per 100 parts by weight of the component (A) is suitable. .

Protective film material The protective film material of the present invention can be easily prepared by uniformly mixing the above-mentioned components, and is used in the form of a solution by dissolving it in an appropriate solvent. The solvent to be used is not particularly limited as long as it can dissolve each component uniformly and does not react with each component. However, in general, cellosolve acetate and diglyme are used from the viewpoint of easy formation of a coating film. Are preferred, and ethyl cellosolve acetate, ethyl carbitol acetate, diethylene glycol dimethyl ether and diethylene glycol diethyl ether are particularly preferred. These solvents can be used alone or in combination of two or more. The concentration of the solution of this composition is not particularly limited and can be appropriately selected depending on the purpose of use. However, the solid content is usually used at about 5 to 50% by weight.

In the present invention, a desired protective film can be formed by applying a solution of the above-mentioned protective film material to a predetermined substrate surface and curing it by heating. The method of coating the substrate surface is not particularly limited, and various methods such as a spray method, a roll coating method, and a spin coating method can be employed. The thermosetting conditions of the protective film material of the present invention vary depending on the specific types and mixing ratios of the respective components, but are usually about 150 to 250 ° C. for about 0.2 to 1.5 hours.

The protective film formed from the protective film material of the present invention is excellent in flatness as well as various physical properties as apparent from the following examples, and is extremely useful as a protective film for optical devices such as color filters. It is suitable. Next, the present invention will be described in more detail with reference to examples. However, the present invention will be described in more detail, but the present invention is not limited to these examples.

[0034]

Examples 1 to 5 (1) Synthesis of polymer A: The monomers shown in the column of the component (A) in Table 1 were used in the weight ratio shown in the column of the component (A) in the column. The total amount of 100 parts by weight was mixed with 300 parts by weight of ethyl cellosolve acetate, 0.5 parts by weight of azobisisobutyronitrile (AIBN) was added as a polymerization initiator, and the mixture was polymerized at 80 ° C. for 3 hours. A solution having a concentration of 25% by weight of the polymer A was obtained.

(2) Preparation of protective film material; the above polymer solution 1
After diluting 00 parts by weight (polymer A: 25 parts by weight) with 25 parts by weight of ethyl cellosolve acetate, (B) to (D) and other components were added according to the formulation shown in Table 1,
The mixture was sufficiently stirred to obtain a protective film material.

(3) Formation of a protective film; (3-1) Protective film for evaluating various resistances The above protective film material was applied on a glass substrate so as to have a thickness of 2 μm, and was placed in a clean oven at 200 ° C. Thermal protection was performed for 1 hour to form a protective film. (3-2) Protective film for evaluation of adhesion and flatness On a glass substrate (Corning 7059, Douglas Dow Corning), using a gelatin and potassium dichromate solution, striped red, blue, A substrate with three green color filters was created (stripe width 1
50 μm). The surface irregularities of this substrate were examined by α-step (manufactured by Tencor) and found to be 1.0 μm. On this substrate, a protective film material is applied in the same manner as in (3-1) above,
The protective film was formed by thermosetting.

(4) Evaluation of protective film The protective films obtained in the above (3-1) and (3-2) were evaluated as described below, and the results are shown in Table 2.

Adhesion JIS K-5400 (1900) 8.5 out of 8.5 adhesion, according to the 8.5 · 2 cross-cut tape method, 100 pieces were added to the protective film prepared in (3-1) and (3-2) above. A grid was formed with a cutter knife, and the adhesion was evaluated. The adhesion was evaluated based on the number of peeled grids according to the following criteria. ○: 5 or less △: 6 to 49 ×: 50 or more

Surface hardness JIS K-5400 (1990) 8.4 out of 8.4 pencil scratch test
In accordance with 1 test method, the surface hardness of the protective film prepared in (3-1) was evaluated by scuffing the protective film.

20% by weight of a protective film made of acid resistance (3-1) together with the substrate
The evaluation was performed by changing the appearance after immersion in a hydrogen chloride aqueous solution at 40 ° C. for 10 minutes.

10% by weight of the protective film made of alkali resistance (3-1) together with the substrate
The evaluation was performed by changing the appearance after immersion in an aqueous sodium hydroxide solution at 40 ° C. for 60 minutes.

Heat resistance (400-70) before and after heat treatment (250 ° C. for 60 minutes in a clean oven) of the protective film prepared in (3-1)
0 nm). The evaluation criteria are as follows. ：: Within 1% of spectrum change ×: 1% or more of spectrum change

The flatness of the CF substrate having the protective film formed in (3-2) is examined by α-step, and the flattening rate (%) is calculated by the following equation.
Was calculated and evaluated.

[0044]

(Equation 1)

Comparative Example 1 A protective film material was prepared and a protective film was prepared in the same manner as in Example 1 except that the component (C) was not used among the components used in Example 1. An evaluation was performed. Table 2 shows the results.

Comparative Example 2 A protective film material was prepared and a protective film was prepared in exactly the same manner as in Example 1 except that the component (D) was not used among the components used in Example 1. An evaluation was performed. Table 2 shows the results.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

The protective film material of the present invention forms a protective film which is excellent in various resistances and excellent in flatness, for example, to reduce unevenness or steps on the surface of a color filter.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasuaki Yokoyama 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-60-217230 (JP, A) JP-A Heihei 4-53879 (JP, A) JP-A-4-85322 (JP, A) JP-A-4-202418 (JP, A) JP-A-4-300942 (JP, A) (58) Fields investigated (Int. Cl ^7, DB name) C08G 59/40 C08G 59/20 C08G 59/42 C09D 163/00 -. 163/10

Claims (1)

(57) [Claims] (A) The following general formula (1): [Wherein R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and m represents an integer of 1 to 8]. A polymer containing at least 20% by weight of a structural unit represented by the formula: (B) at least one compound selected from a polycarboxylic anhydride and a polycarboxylic acid, (C) an acrylic compound, and (D) a compound having an alkoxysilano group and an epoxy group. Protective film material.