JP2001294800A - Coating material and base plate coated with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material which gives an irregular surface showing an excellent heat resistance and adhesion and shows a highly efficient light- reflecting property and a fine flat effect, and a base plate such as an LCD- reflective plate, etc., obtained by applying this. SOLUTION: The coating material comprises a solution containing 5 to 30 wt.% resin component (A) essentially comprising an acrylic resin component (A1) or an epoxy resin component (A2) comprising an epoxy resin and a hardener, 30 to 80 wt.% solvent (B) and 1 to 30 wt.% filler (C). Here, the light transmittance at a wavelength of 500 nm of the solution at a width of 1 cm is >=60%. The base plate has a coating film having an irregular form wherein the surface roughness Ra of the coating film surface is from 0.05 to 0.2 μm, which is obtained by applying this coating material onto a base plate at a film thickness of >=0.3 μm and subsequently curing it through heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating material and a substrate coated with the coating material. More specifically, the present invention relates to a coating material suitable for forming surface irregularities having both alkali resistance and heat resistance, and a substrate obtained by applying the coating material and having a fine irregular surface on a coating film surface.

[0002]

2. Description of the Related Art In recent years, it has been demanded to form various irregularities on a substrate for the purpose of improving adhesion and diffuse reflection of light. Conventionally, polishing of a substrate, addition of a filler to a resin composition, and formation of unevenness of a pattern by photolithography using a photocurable resin have been performed, but the manufacturing process is complicated and costly. The problem of difficulty was raised.

[0003] In addition, a resin composition to which various fillers have been added in order to easily form irregularities has been proposed, but when the specific gravity of the filler is heavier than the resin composition, precipitation occurs,
If the particle size of the filler is large, a uniform coating film cannot be obtained,
Good unevenness could not be obtained. It is also known to use a transparent pigment such as silica as a filler (Japanese Unexamined Patent Publication No. 11-315249). However, simply using these silicas causes irregular reflection of the silica and turbidity. However, there is a problem that the silica precipitates during storage and unevenness in film thickness occurs during coating.

On the other hand, in photolithography using a photocurable resin, an acrylic resin was conventionally used, but the heat resistance of the cured film and the adhesion during alkali immersion are insufficient. Peeling and deformation occurred.

[0005]

SUMMARY OF THE INVENTION As described above, the present invention provides a coating material having heat resistance, alkali resistance, storage stability, and applicability and capable of forming unevenness of a coating film. The present invention provides a substrate having a good surface unevenness obtained by applying the same.

[0006]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems, the present inventors have found that high performance has been achieved by highly dispersing a specific filler in a specific resin composition. The present inventors have found that a coating material can be obtained, and that a substrate having good surface unevenness can be obtained by a simple manufacturing method using only this coating material and heat treatment, thereby completing the present invention.

That is, the present invention provides a resin component (A) having an acrylic resin component (A1) or an epoxy resin component (A2) composed of an epoxy resin and a curing agent (A) in an amount of 5 to 30% by weight and a solvent (B) in an amount of 30 to 30%. 80% by weight and filler (C)
It is composed of a solution containing 1 to 30% by weight as an essential component, and the light transmittance of the solution in a width of 1 cm is 500 n.
It is a coating material characterized by being 60% or more in m. In addition, the present invention is obtained by applying this coating material on a substrate at a thickness of 0.3 μm or more and then curing by heat treatment, and the surface roughness Ra of the coating film surface is 0.05 to 0.2 μm.
This is a substrate having a coating film having an uneven shape in the range of m.

Hereinafter, the present invention will be described in detail. The coating material of the present invention comprises a resin component, a solvent, and a filler, which essentially contain an acrylic resin component or an epoxy resin component, and a thermal polymerization initiator and the like.

The resin component (A) used in the present invention essentially contains an acrylic resin component (A1) or an epoxy resin component (A2). Acrylic resin component used in the present invention (A
Examples of 1) include substituted acrylic acids such as acrylic acid and methacrylic acid, and acrylic monomers, oligomers or polymers selected from acrylates such as methyl esters thereof, and polymerizable monomers or oligomers are preferred. Examples of the acrylic resin component include general-purpose acrylates such as methyl methacrylate and methyl acrylate, and polyfunctional acrylates derived from polyfunctional alcohols and polyfunctional epoxy compounds.
Examples thereof include polymers such as acrylic acid and oligomers thereof.

The epoxy resin component (A2) used in the present invention
Is composed of an epoxy resin and a curing agent. Examples of the epoxy resin include a bisphenol A epoxy resin, a bisphenol F epoxy resin, a phenol novolak epoxy resin, and a dihydroxybiphenyl epoxy resin. The epoxy resin component in the present invention includes an epoxy compound. As the curing agent, a curing agent known as a curing agent for an epoxy resin can be used. Examples of such a curing agent include polyfunctional phenols such as novolak type phenol resin and bisphenol A, organic amines, and acid anhydrides.

The acrylic resin component and the epoxy resin component may be used alone or in combination of two or more, and the acrylic resin component and the epoxy resin component may be used in combination. The amount of the resin component (A) used in the present invention is 5 to 30% by weight, preferably 10 to 30% by weight. In addition, resin components other than the essential components, such as other vinyl monomers, oligomers, polymers, and other thermosetting resins, can be blended within a range that does not impair the properties of the coating material of the present invention. It is good to keep it at 40% by weight or less, preferably 20% by weight or less.

Among these acrylic resin components and epoxy resin components, those having a fluorene skeleton are preferably used. As the compound having a fluorene skeleton, those represented by the following formulas 1, 2 and 3 are particularly preferable. By using these resin components, the heat resistance of the resin matrix can be increased. In this case, the proportion of the resin component having a fluorene skeleton is preferably at least 50% by weight, more preferably at least 70% by weight of the resin component. When the acrylic resin component is the main component, trifunctional or higher polyfunctional acrylate is used in an amount of less than 5 to 50% by weight, preferably less than 10 to 30% by weight of the resin component.

[0013]

Embedded image In the above formulas 1 to 3, R represents a hydrogen atom or a carbon number of 1 to 5;
And n represents an integer of 0 to 20.
Y and Z each represent a residue of a polybasic acid. Here, preferably, R is a hydrogen atom. Further, it is preferable that the average (average number of repetitions) of n in Expressions 2 and 3 is 0 to 1.

The solvent (B) used in the present invention includes:
From the viewpoint of solubility and coating properties, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, cyclohexanone, ethylethoxypropionate, butyl acetate, diethylene glycol dimethyl ether, γ-butyrolactone, and the like, and a mixture of these solvents may be used. . The compounding amount of the solvent (B) is 30 to 80% by weight, preferably 40 to 70% by weight.

As the filler (C) used in the present invention, for example, silica, barium sulfate, barium carbonate, alumina and the like can be mentioned, but silica having an average particle diameter of 50 nm or less is most preferable in terms of dispersion. Silica having such a particle size range is commercially available as a silica sol and can be obtained. This silica sol is dispersed in a solvent, and as the solvent, ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and methyl isobutyl ketone are usually used. In the present invention, when a silica sol dispersed in a solvent is used, the solvent content contained in the silica sol is calculated as the solvent (B) in the calculation of the compounding amount.

The average particle size of the filler is desirably 50 nm or less, preferably 20 nm or less. Average particle size of 50
If the thickness exceeds nm, precipitation and separation occur, so that a uniform cured film cannot be obtained, and a transparent solution cannot be obtained. Also,
The unevenness deteriorates depending on the size. However, if the average particle size is too small, a coating film having desired irregularities cannot be obtained, so that the average particle size is preferably 5 nm or more. The compounding ratio of the filler in the coating material is 1 to 30% by weight, preferably 5 to 20% by weight. Content is 1% by weight
If it is less than 30%, sufficient unevenness cannot be obtained, and if it exceeds 30% by weight, a rise in viscosity and the appearance of thixotropy occur, making it impossible to form a uniform film.

It is also preferable to use a filler surface-treated with a coupling agent as the filler. As the coupling agent, a silane coupling agent, a titanate coupling agent, or the like can be used. And those having an epoxy group are desirable. Further, these several kinds can be used in combination. The amount of the coupling agent used is not particularly limited, but is 10 to 200%, preferably 80 to 120% of the theoretical amount of the coupling agent with respect to the specific surface area of the filler. If no coupling agent is used, the adhesion between the cured resin film and the substrate and the alkali resistance may decrease. In such a case, it is preferable to use a filler surface-treated with the coupling agent. The treatment method of the filler with the coupling agent is not particularly limited,
A predetermined coupling agent is added to a solution obtained by mixing a solvent and a filler, and the mixture is stirred to obtain a filler surface-treated with the coupling agent.

The thermal polymerization initiator (D) used in the present invention may be any one which initiates or promotes the thermal polymerization of an acrylic resin component or another thermopolymerizable resin component, and includes an organic amine compound, an imidazole compound, Examples thereof include acid anhydrides and organic phosphines, and the most preferable ones from the viewpoint of storage stability are organic amine compounds and imidazole compounds, and a mixture of several of these can be used. As an organic amine, bisdiethylbenzophenone is preferable, and as an imidazole compound, 2-methylimidazole is preferable in terms of curability and storage stability. The compounding amount of the thermal polymerization initiator in the coating material is 0.01 to 1% by weight,
Preferably 0.02 to 0.2% by weight is advantageous. If the amount used is less than 0.01% by weight, thermosetting properties cannot be exhibited,
If it is 1% by weight or more, the storage stability is deteriorated. The thermal polymerization initiator (D) is not necessarily used, but is preferably used when the resin component contains a thermopolymerizable component such as an acrylic resin component.

The amount of the curing agent, which is an epoxy resin component, is about 1/3 to equivalent weight of the epoxy resin, and the blending amount in the coating material is preferably about 0.01 to 10% by weight. If the amount used is too small, thermosetting properties cannot be expressed,
If the amount is too large, the storage stability deteriorates. The curing agent does not need to be used when a thermosetting component such as an epoxy resin is not contained in the resin component.

The coating material of the present invention has a light transmittance at a wavelength of 1 cm of 60% or more at a wavelength of 500 nm.
It is preferably in the range of 80% or more, more preferably 90% or more. The higher the transmittance, the more it is possible to form a coating film having a fine surface unevenness with less large unevenness. Further, precipitation during storage and generation of unevenness during application are suppressed. The light transmittance can be measured using a spectral transmittance meter.
The measurement is performed by placing the coating material solution in an mx 1 cm cell.

The coating material of the present invention is applied on a smooth substrate such as a glass substrate so as to have a thickness of 0.3 μm or more, and the applied coating material is subjected to a heat treatment using a hot air dryer or the like. Is formed. At the time of application on the substrate, the filler such as silica sol is highly dispersed in the solvent, so that no irregularities are generated. However, at the time of evaporating the solvent by drying, aggregation starts and irregularities are generated.
Drying conditions are not particularly limited, but drying is usually performed at a temperature of normal temperature to 80 ° C for 30 to 5 minutes. Therefore, good unevenness can be formed by simple heating and drying without a complicated manufacturing process such as conventional polishing or photolithography. The substrate having the coating film formed in this manner has a very fine surface unevenness. Specifically, the surface roughness Ra is in the range of 0.05 to 0.2 μm. Here, the uneven shape of the surface of the formed coating film can be controlled by appropriately adjusting the quantitative ratio of each component, the amount of the filler, the particle size of the filler, the heat treatment conditions, and the like.

The coating material of the present invention contains 5 to 30% by weight of the resin component (A), which contains the acrylic resin component or the epoxy resin component, 30 to 60% by weight of the solvent (B), and the filler (C). Is contained as an essential component, and 0.01 to 0.2% by weight of a thermal polymerization initiator (D) is further contained. However, other components may be contained as long as the effects of the present invention are not impaired. For example, a surfactant is preferably used for improving coating properties, and a coupling agent is preferably used for improving adhesion. In this case, the surfactant is 0.01 to 0.10% by weight.
It is preferable to make it contain in the range of.

The method for preparing the coating material is not particularly limited. The acrylic resin component or the epoxy resin component, the solvent, the filler, the thermal polymerization initiator, the surfactant, and the type and amount of the coupling agent are appropriately adjusted. Later, dispersion by roll mill, ball mill, sand mill, planetary mixer, etc.
A method of performing stirring and mixing at 5 to 70 ° C. for about 1 to 50 hours using a mixing apparatus and dispersing the mixture so as to have a uniform composition can be adopted.

[0024]

The present invention will be specifically described below with reference to examples.
In addition, evaluation of various characteristics was measured by the following method. (1) Coating Material Transmittance The coating material was placed in a quartz cell having a cross section of 1 cm × 1 cm, and the transmittance at 500 nm was measured with a Hitachi spectral transmittance meter UBEST-400. (2) Roughness and film transmittance The surface roughness of the formed coating film was measured with a surface roughness meter. The ranking of the evaluation is as follows. The membrane transmittance is 1.3μm
This is the spectral transmittance at the thickness (average in the region of 400 to 800 nm). ：: Ra is in the range of 0.05 to 0.2 μm, and 100 or more irregularities per 1 mm. ×: Ra exceeds 0.2 μm.

(3) Heat Resistance The formed coating film was placed in an oven at 260 ° C. for 3 hours, and the state of the coating film was evaluated. The ranking of the evaluation is as follows. ：: No abnormality in appearance of coating film. ×: Appearance of coating film, peeling and coloring. (4) Adhesion to substrate After applying the coating film, make a cross cut so as to make at least 100 grids, and then perform a peeling test using a cellophane adhesive tape according to JIS Z1522.
The state of the cross cut was visually evaluated. The ranking of the evaluation is as follows. ：: No peeling was observed at all. ×: Peeling is observed even a little.

(5) Coating film hardness Using a pencil hardness tester according to the test method of JIS-K5400, under the condition of a load of 1 kg, the pencil hardness at which the coating film was not scratched was defined as the coating film hardness. The pencil used is "Mitsubishi High Uni".
The ranking of the evaluation is as follows. ：: 4H or more. X: Less than 4H. (6) Chemical resistance The formed coating film was immersed in the following chemicals under the following conditions, and the appearance and adhesion after immersion were evaluated. The ranking of the evaluation is as follows. ：: No abnormality in appearance of coating film. ×: Appearance of coating film, peeling and coloring. (7) Coatability After coating on a glass plate to a thickness of about 1.3 μm and drying, the coating film surface was observed. The ranking of the evaluation is as follows. ：: No abnormality in appearance of coating film. ×: Unevenness and streaks in the appearance of the coating film.

Example 1 A coating material was prepared in the proportions shown in Table 1. At this time, the solvent-dispersed silica sol and the silane coupling agent 1
After preliminarily mixing and surface treating, other components were added, uniformly dispersed and mixed to obtain a coating material. The average particle size of the silica sol is 10 to 15 nm.

Example 2 A coating material was prepared in the same manner as in Example 1 except that the composition of the coating material was changed. Comparative Examples 1 and 2 A coating material was prepared in the same manner as in Example 1, except that the composition of the coating material was changed.

Table 1 shows the mixing ratio. In Table 1, each component is as follows. Fluorene acrylate: Compound of the above formula 2 Multifunctional acrylate: DPHA manufactured by Nippon Kayaku Co., Ltd. Fluorene epoxy resin: Compound of the above formula 3 BPA epoxy resin: Bisphenol A type epoxy resin (Epicoat 828) Solvent-dispersed silica sol: Nissan Chemical Industries NPC- ST (silica sol content 30%) Silica: SO-25R manufactured by Tatsumori (average particle size: 500 nm) Solvent: propylene glycol monomethyl ether acetate Silane coupling agent 1 and 2: S-510 manufactured by Chisso Corporation Thermal polymerization initiator: Hodogaya Chemicals EAB-F curing agent: Shin Nippon Rika Co., Ltd. Rikashid MH

[0030]

[Table 1]

The coating material obtained as described above was applied to a thickness of about 1.3 μm on a degreased and washed glass plate having a thickness of 1.2 mm, and dried at room temperature to 80 ° C. for 30 to 5 minutes. Thereafter, a sample was prepared by performing a heat drying treatment at 230 ° C. for 30 minutes using a hot air drier. About the obtained sample, coating material transmittance (liquid transmittance), unevenness, film transmittance, heat resistance, adhesion to substrate (adhesion), coating film hardness,
The chemical resistance and applicability were evaluated, and the results are shown in Table 2.

[0032]

[Table 2]

As is clear from the results in Table 2, Example 1
As for No. 2, the target physical properties could be achieved. However, in Comparative Example 1 where the dispersed particle size of the filler was large, the solution transparency, the unevenness,
In Comparative Example 2 in which the applicability was deteriorated, and the dispersed particle size of the filler was large, and the resin component having a fluorene skeleton was not used, the solution transparency, the unevenness, and the applicability were deteriorated, and the heat resistance and adhesion were improved. Insufficiency and surface hardness were observed. From the above results, the resin composition for a coating material of the present invention can provide a coating material having excellent unevenness, heat resistance, transparency, adhesion, hardness, solvent resistance, and the like. It is understood that a substrate having an uneven surface can be easily formed.

[0034]

The coating material of the present invention can easily exhibit irregularities which could not be achieved by the conventional ones, and is excellent in heat resistance and adhesion. For this reason, it can be widely used in applications requiring fine surface irregularities such as the electric and electronic fields.
In particular, it is suitable for LCD reflective substrate applications requiring a highly efficient light reflection performance having a fine surface unevenness and applications where a substrate requiring fine matting is used. A substrate prepared by applying the resin composition for a coating material can be used as an LCD reflective substrate or the like.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shingo Kazama 1 Tsukiji, Kisarazu-shi, Chiba F-term in Nippon Steel Chemical Co., Ltd. Electronic Materials Development Center (reference) 4J038 CG141 CH031 CH051 CH061 DA032 DB061 DB071 HA166 HA286 HA376 HA446 JA25 JA54 JA55 JA63 JA70 JA75 JB01 JB32 JC21 KA03 KA06 KA08 KA09 KA15 MA09 NA12 NA14 NA19 PA19 PB09 PB11

Claims (7)

[Claims] 1. A resin component (A) containing an acrylic resin component (A1) or an epoxy resin component (A2) composed of an epoxy resin and a curing agent as essential components, 5 to 30% by weight, and a solvent (B) 30.
1 to 30% by weight of a filler (C) as an essential component.
A coating material having a light transmittance in a width of not less than 60% at a wavelength of 500 nm. 2. The thermal polymerization initiator (D) is used in an amount of 0.01 to 0.2.
2. The coating material according to claim 1, which contains 0.1% by weight. 3. The coating material according to claim 1, wherein the acrylic resin component or the epoxy resin component is an acrylic resin component or an epoxy resin component having a fluorene skeleton. 4. The coating material according to claim 1, wherein the filler (C) is a silica sol having an average particle size of 50 nm or less. 5. The coating material according to claim 1, wherein the filler (C) has been surface-treated with a coupling agent in advance. 6. The coating agent according to claim 1, wherein the coating agent is a coating agent for forming unevenness. 7. A coating material according to any one of claims 1 to 6, which is applied on a substrate at a thickness of 0.3 μm or more and cured by heat treatment to obtain a coating film having a surface roughness Ra. A substrate having a coating film having an uneven shape in a range of 0.05 to 0.2 μm.