JP3088511B2 - Coating composition and surface-coated article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition for various molded articles capable of forming a coating excellent in abrasion resistance and solvent resistance by irradiating active energy rays in an air atmosphere and such a composition. And an article coated with a cured product of the article.

[0002]

2. Description of the Related Art In recent years, it has been widely used to use a transparent plastic material having high crush resistance as an alternative to a transparent plate glass. However, transparent plastic materials have the disadvantage that their surfaces are softer than glass and are more susceptible to surface wear and scratches.

Heretofore, many attempts have been made to improve the wear resistance of plastics. For example, JP
As disclosed in JP-A-26822 and JP-A-59-64671, there is a method in which an alkoxysilane compound is applied to the surface of a plastic molded product and cured by heat. Further, as disclosed in JP-A-56-106969 and JP-A-2-272204,
A method is also known in which a mixture of colloidal silica and an organic resin is applied to the surface of a plastic molded product and cured by heat. However, these methods need to be cured by heat, and therefore consume a large amount of energy, and require a long time for curing, which is industrially disadvantageous.

As an ultraviolet-curable coating composition, Japanese Patent Publication No. 3-6190 discloses a combination of a polyfunctional acrylate, colloidal silica and an acryloyloxy-functional silane. However, this composition requires the use of an expensive acryloyloxy-functional silane, and the acryloyloxy-functional silane acts as a silane coupling agent and only reinforces the interface between the polyfunctional acrylate and the colloidal silica. Since the particles were not bonded to each other but existed independently, the silica was not formed as a skeleton, and the surface hardness was slightly inferior.

[0005]

As described above, no effective coating composition for imparting abrasion resistance and solvent resistance to the surface of a synthetic resin has been found.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies on the above problems, and as a result, have found that a polymerizable compound having at least two acryloyloxy groups and / or methacryloyloxy groups in the molecule, a colloidal silica, A composition comprising silica fine particles obtained by hydrolyzing and polycondensing alkoxysilane in the presence and tetra (acryloyloxyalkoxy) silane or tetra (methacryloyloxyalkoxy) silane is applied to the surface of various molded articles and cured. As a result, it has been found that scratch resistance and solvent resistance can be imparted to the surface of the synthetic resin.

That is, the present invention relates to (a) a polymerizable compound having at least two acryloyloxy groups and / or methacryloyloxy groups in a molecule, and (b) a colloidal silica having the following general formula (I): SiR ¹ _a R ² _b (OR ³ ) _c (I) (wherein, R ¹ and R ² are a hydrocarbon residue having 1 to 10 carbon atoms which may have an ether bond or an ester bond, Those having no radical polymerizable group or epoxy group, R ³ is a hydrogen atom or a hydrocarbon residue having 1 to 10 carbon atoms, a and b are integers of 0 to 3, c is 4-ab, , And represents an integer of 1 to 4.) A silica-based condensation polymer obtained by hydrolysis and condensation polymerization of a silane compound represented by
An abrasion-resistant ultraviolet-curable coating composition comprising (c) tetra (acryloyloxyalkoxy) silane or tetra (methacryloyloxyalkoxy) silane and (d) a photopolymerization initiator.

Another object of the present invention is an article whose surface is coated with a cured product of such a coating composition.

[0009]

According to the coating composition of the present invention, a silica skeleton of a silica-based polycondensate (b) comprising colloidal silica and a silane compound hydrolyzed and polycondensed on the surface thereof, and a radical polymerizable vinyl compound Semi-IP with polymer
An N (Interpenetrating Network) structure is formed, and tetra (acryloyloxyalkoxy) silane or tetra (methacryloyloxyalkoxy) silane further contributes to densification, so that extremely good surface hardness is exhibited.

The polymerizable compound (a) used in the present invention
Is a cross-linkable polymerizable compound having at least two (meth) acryloyloxy groups (meaning acryloyloxy group and / or methacryloyloxy group, the same applies hereinafter) in a molecule, wherein each (meth) acryloyloxy group is bonded Is a hydrocarbon or a derivative thereof, and the molecule can contain an ether bond, a thioether bond, an ester bond, an amide bond, a urethane bond, or the like.

As these polymerizable compounds (a), the following general formulas (II) to (IV)

[0012]

Embedded image (In the formula, at least two of Y ¹¹ , Y ¹² , Y ¹³ ,... Y ^p2 , Y ^p3 , and Y ¹⁴ are an acryloyloxy group and / or a methacryloyloxy group, and the rest is a hydrogen atom, a hydroxyl group, an amino group, an alkyl group. Group or substituted alkyl group, p is 1 to
5 is represented. )

[0013]

Embedded image (Wherein, R ⁴ is a hydrogen atom or a methyl group, and R ⁵ is 2-20
R ⁶ is a residue of an aliphatic hydrocarbon having 2 carbon atoms or a derivative thereof, R ⁶ is a residue of an aliphatic or aromatic hydrocarbon having 2 to 20 carbon atoms or a derivative thereof, q is 1
Represents an integer of ２０20. )

[0014]

Embedded image (Wherein R ⁷ is a hydrogen atom or a methyl group, r is 2 to 20)
And s represents an integer of 1 to 50. It is preferable to use at least one selected from the compounds represented by the formula (1).

The compound represented by the general formula (II) is a mono- or polypentaerythritol poly (meth) acrylate (meaning acrylate or methacrylate, the same applies hereinafter).
And polymethylolalkane poly (meth) acrylate, for example, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipenta Erythritol hexa (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tetrapentaerythritol octa (meth)
Acrylates and trimethylolpropane tri (meth) acrylate are exemplified.

The compound represented by the general formula (III) basically comprises a hydroxyl group of a dihydric alcohol, a dihydric carboxylic acid and (meth) acrylic acid (meaning acrylic acid and / or methacrylic acid, the same applies hereinafter). It can be obtained by reacting a mixture such that both carboxyl groups are finally equal in amount. Particularly preferred is a compound represented by the general formula HO
Glycols represented by —R ⁵ —OH or derivatives thereof (α), dicarboxylic acids represented by the general formula HOCO—R ⁶ —COOH, their acid chlorides, anhydrides, or esters (β) and (meth) ) Acrylic acid or their acid chlorides or esters (γ) with (α) :( β):
(Γ) = q + 1: q: a compound obtained by reacting at a ratio of 2 to 2.2 (molar ratio).

The compound (α) includes, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol having an average molecular weight of about 300 to 1,000, propylene glycol, dipropylene glycol, 1,3-
Propanediol, 1,3-butanediol, 2,3-
Butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2,
2'-thiodiethanol, 1,4-cyclohexane dimethanol and the like. As the compound (β), for example, aliphatic dicarboxylic acids such as succinic acid, adipic acid and sebacic acid; alicyclic dicarboxylic acids such as tetrahydrophthalic acid and 3,6-endomethylenetetrahydrophthalic acid;
Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; thiodiglycolic acid, thiodivaleric acid,
It is possible to use diglycolic acid, such as diglycolic acid, which contains a heteroatom in its main chain, or acid chlorides, anhydrides, and esters thereof. Among the compounds represented by the general formula (III), particularly preferable compounds are di (meth) compounds having q of 1 to 10, particularly 1 to 5, synthesized from ethylene glycol, phthalic acid and acrylic acid or methacrylic acid.
Acrylate.

The compound represented by the general formula (IV) is a poly (alkylene glycol) di (meth) acrylate,
For example, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate having an average molecular weight of about 300 to 2,000, propylene glycol di (meth) acrylate , Dipropylene glycol di (meth)
Examples include acrylate, propanediol di (meth) acrylate, butanediol di (meth) acrylate, pentanediol di (meth) acrylate, and hexanediol di (meth) acrylate.

Among the polymerizable compounds (a) used in the present invention, a particularly preferred crosslinkable polymerizable compound is a compound represented by formula (II).

The silica-based polycondensate (b) used in the present invention is prepared by reacting the following general formula (I): SiR ¹ _a R ² _b (OR ³ ) _c (I) in the presence of colloidal silica. ¹ , R ² is a hydrocarbon residue having 1 to 10 carbon atoms which may have an ether bond or an ester bond; R ³ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms;
An integer of 1 to 3, c is 4-ab, and represents an integer of 1 to 4. Is a condensation polymer obtained by hydrolysis and condensation polymerization of most of the OR ³ groups of the silane compound represented by
On its outer surface there are OR ³ groups or OR ³ groups and OH groups.

The silica-based polycondensate (b) has a polymer content of the polymerizable compound (b) even at a silica concentration such that gelation occurs when only colloidal silica is dispersed in the polymerizable compound (a). a) It is possible to disperse evenly in it. That is, according to the present invention, it is possible to uniformly disperse silica at a high concentration in the coating composition,
It is possible to impart a high degree of wear resistance to the cured film.

As the colloidal silica used in the present invention, various commercial products can be used. The particle size of the colloidal silica is usually 1 nm to 1 μm, but is not particularly limited. However, the preferred particle size is 10 nm
５００500 nm. The dispersion medium of the colloidal silica is not particularly limited, but usually, water; alcohols such as methanol and isopropyl alcohol; cellosolves; dimethylacetamide and the like are used. Particularly preferred dispersion media are alcohols, cellosolves and water.

Examples of the silane compound represented by the general formula (I) used in the present invention include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane,
Tetrabutoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,
Phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, methylethyldiethoxysilane, methylphenyldimethoxysilane, trimethylethoxysilane, methoxyethyltriethoxysilane, acetoxyethyltriethoxysilane, diethoxyethyldiethoxy Silanes and their partial hydrolysates. Preferred silane compounds are those represented by R ¹ and R in the general formula (I).
² , R ³ is a silane compound having 1 to 4 carbon atoms. When R ¹ , R ² , and R ³ are hydrocarbon residues having 4 or less carbon atoms, steric hindrance is small, so that hydrolysis and polycondensation rates are increased, and colloidal silica particles are bonded to each other. A silica skeleton is easily formed, which is preferable. Particularly preferred silane compounds are tetraalkoxysilanes in which c is 4 in the general formula (I). The tetraalkoxysilane is used alone or in consideration of the stability of the coating composition before curing. It is preferable to use a mixture of trialkoxysilane or dialkoxysilane in which c is 3 or 2.

In order to derive a silica-based condensed polymer (b) obtained by hydrolyzing and condensing a silane compound represented by the general formula (I) in the presence of colloidal silica, a compound represented by the general formula (I) is used. May be used alone, or a silane compound represented by the general formula (I) and a component capable of co-condensing therewith may be used in combination. Examples of the component capable of co-condensing with the silane compound include a metal alkoxide, an organic metal salt, and a metal chelate. The use ratio of the cocondensable component is preferably 0 to 100 parts by weight with respect to 100 parts by weight of the silane compound represented by the general formula (I).
0 to 50 parts by weight is more preferred.

Examples of the cocondensable metal alkoxide, organic metal salt and metal chelate include, for example, titanium tetraethoxide, titanium tetraisopropoxide, zirconium tetraethoxide, zirconium tetra-n-butoxide, aluminum triisopropoxide, Examples include zinc acetylacetonate, lead acetate, and barium oxalate.

In the hydrolysis and polycondensation reaction of the silane compound, water must be present in the reaction system.
In general, the effect of the proportion of water in the reaction system on the reaction rate is not particularly significant. However, when the proportion is extremely small, hydrolysis is too slow to obtain a condensation polymer.

As a catalyst for performing the hydrolysis reaction of the silane compound, an inorganic acid or an organic acid can be used. As the inorganic acid, for example, hydrohalic acid such as hydrochloric acid, hydrofluoric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like are used. Examples of the organic acid include formic acid, acetic acid, oxalic acid, acrylic acid, methacrylic acid and the like.

In the hydrolysis reaction system of the silane compound, a solvent can be used to carry out the reaction mildly and uniformly. As the solvent, a solvent capable of dissolving the reactant silane alkoxide, water and a catalyst is desirable. Examples of such a solvent include water; alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; ketones such as acetone and methyl isobutyl ketone; and ethers such as tetrahydrofuran and dioxane. As the solvent, the above-described dispersion medium of colloidal silica may be used as it is, or a new necessary amount may be added. The amount of the solvent to be used is not particularly limited as long as the reactant can be uniformly dissolved, but if the concentration of the reactant is too low, the reaction rate may be significantly reduced. The hydrolysis and polycondensation reaction of the silane compound is carried out at a temperature of about room temperature to about 120 ° C. for about 30 minutes to about 24 hours, preferably at about room temperature to about the boiling point of the solvent for about 1 to about 10 hours. Done.

The condensation of the silica-based condensed polymer (b) obtained by hydrolyzing and condensing the silane compound represented by the general formula (I) in the presence of colloidal silica is carried out by hydrolysis and condensation of the silane compound. After the polymerization, it is preferable to add the polymerizable compound (a) and tetra (acryloyloxyalkoxy) silane or tetra (methacryloyloxyalkoxy) silane (c), and to carry out the method by distilling off the solvent. If the solvent is completely distilled off without adding the polymerizable compound (a) or the like, the condensation polymerization of the silane compound proceeds excessively, and the stability of the coating composition of the present invention tends to be impaired.

In the present invention, (c) tetra (acryloyloxyalkoxy) silane or tetra (methacryloyloxyalkoxy) silane is an essential component.
As tetra (acryloyloxyalkoxy) silane or tetra (methacryloyloxyalkoxy) silane, tetra (acryloyloxyethoxy) silane is usually used, which is synthesized from tetrachlorosilane and 2-hydroxyethyl acrylate. By using tetra (acryloyloxyalkoxy) silane or tetra (methacryloyloxyalkoxy) silane, the polyfunctional acrylate and colloidal silica are chemically bonded to each other for densification, and the surface hardness is further improved.

Further, in the present invention, a compound having one α, β-ethylenically unsaturated bond in various molecules may be used, and is used for improving the uniformity of the coating composition. Is preferred. One α, β- in the molecule
Particularly preferred as the compound having an ethylenically unsaturated bond is a compound having at least one of a hydroxyl group, a cyclic ether bond and a chain ether bond in a molecule,
These are particularly excellent in polymerization activity in air. Examples of the compound having at least one of a hydroxyl group, a cyclic ether bond, and a chain ether bond in a molecule include, for example, 2-
Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl (meth)
Acrylate, tetrahydrofurfuryl (meth) acrylate, ethoxyethyl (meth) acrylate, ethyl carbitol (meth) acrylate, butoxyethyl (meth) acrylate, 1,4-butylene glycol (meth) acrylate, dipropylene glycol (meth) acrylate And the like.

In the present invention, it is essential to use a photopolymerization initiator. As the photopolymerization initiator, a wavelength of 2000
Radical generators that can be activated in the range of up to 5000 angstroms are effective, and generally carbonyl compounds, azo compounds, peroxides, sulfur compounds, halides, quinone compounds and the like can be used. In addition, two or more kinds can be used in combination. The compounding amount of the photopolymerization initiator is preferably from 0.01 to 10 parts by weight based on 100 parts by weight of the radical-polymerizable monomer mixture.

Further, as disclosed in JP-B-63-28094, the coating composition of the present invention can be used without reducing the appearance of the cured film, such as transparency and smoothness. For the purpose of improving the adhesion to the material, an alkyl (meth) acrylate polymer may be added.
As the (meth) acrylic acid alkyl ester polymer,
It is preferable that the intrinsic viscosity [η] (g / l), which is a measure of the molecular weight of the polymer, is in the range of 0.01 to 0.30, and that the alkyl (meth) acrylate has an alkyl group having 1 to 8 carbon atoms. It is selected from homopolymers of the selected monomers or copolymers thereof.

Specific examples of the alkyl (meth) acrylate polymer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and amyl methacrylate. , Hexyl methacrylate, octyl methacrylate, 2-ethyl-
1-hexyl (meth) acrylate, 3-pentyl acrylate, 3-methyl-1-hexyl (meth) acrylate, a-methyl 1-hexyl (meth) acrylate,
Examples include a homopolymer of 3-methyl-1-butyl acrylate or a copolymer thereof. These polymers may be used alone or in a combination of two or more.

The amounts of the various components in the present invention are not particularly limited, but preferably, the solid content of colloidal silica is 10%.
5 to 200 parts by weight, more preferably 25 to 100 parts by weight, of a silane compound represented by formula (I) based on 0 parts by weight, a polymerizable compound having at least two (meth) acryloyloxy groups in a molecule (A) 5 to 1000 parts by weight, preferably 20 to 200 parts by weight, tetra ((meth) acryloyloxyalkoxy) silane (c) 1 to 50 parts by weight, more preferably 5 to 30 parts by weight.

In the present invention, such a coating composition is applied to the surface of various molded articles and polymerized and cured. It is preferable to use a coating composition diluted with an organic solvent in order to perform uniform coating at the time of coating. Organic solvents are
It is necessary to satisfy conditions such as mixing with the coating composition to form a uniform solution, having a boiling point at normal pressure of 50 ° C. or more and 200 ° C. or less, and a viscosity at normal temperature of 10 centipoise or less. . Specifically, ethanol, isopropyl alcohol, normal propyl alcohol, alcohols such as normal butyl alcohol, benzene, aromatic hydrocarbons such as toluene, acetone, ketones such as methyl ethyl ketone, ethers such as dioxane, ethyl acetate,
Esters such as butyl acetate; N, N-dimethylformamide; and the like.
A mixture of more than one species can be used. The amount of these solvents used is 95 to 90 parts by weight based on the coating composition.
It is preferably 10 parts by weight.

In the coating composition of the present invention,
If necessary, surface smoothing agent, surfactant, UV absorber,
Alternatively, an additive such as a storage stabilizer can be appropriately added and used.

Examples of the method of applying the coating composition to the surface of various molded articles include a brush coating method, a casting method, a roller coating method, a bar coating method, a spray coating method, an air knife coating method, a dipping method and the like. But is not particularly limited. Among these, the dipping method is particularly preferable from the viewpoint of workability and productivity.

The coating amount of the coating composition on the surface of various molded articles is suitably applied so that the film thickness becomes 1 to 30 μm. When the film thickness is less than 1 μm,
If the film has a poor abrasion resistance and the film thickness exceeds 30 μm, the cured film is liable to crack or the like, which is not preferable.

According to the present invention, as a molded article having a film formed on its surface, a known synthetic resin molded article can be used. In particular, polymethyl methacrylate, a copolymer containing methyl methacrylate as a main component, polystyrene, Styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, polycarbonate, cellulose acetate butyrate resin, polyacryl diglycol carbonate resin, polyvinyl chloride resin, and polyester resin are preferred.

[0041]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

"Parts" and "%" in Examples and Comparative Examples indicate "parts by weight" and "% by weight", respectively. The evaluation of the film performance in the examples was performed by the following method.

Wear resistance # 000 steel wool was mounted on the tip of a cylinder having a diameter of 25 mm, brought into contact with a horizontally placed sample surface, rotated 5 times (20 rpm) under a load of 0.6 kg, and visually observed the degree of scratches. ,
Evaluation was made according to the following criteria. 〇: There is almost no scratch on the sample surface. Δ: The surface of the sample is slightly scratched. X: The sample surface is severely scratched.

Adhesion A cross-cut cellophane tape peel test was performed on the crosslinked cured film. That is, 11 cut lines of the coating reaching the substrate at 1 mm intervals were inserted in the coating in each of the vertical and horizontal directions.
100 squares of mm ² were made, cellophane tape was stuck on it, and it was rapidly removed. 〇 ・ ・ ・ ・ ・ ・ 剥離 無 し 無 し 無 し 剥離 無 し 無 し ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・. Δ: Number of peeling lines 1 to 50 ×: Number of peeling lines: 51 to 100

Reference Example 425 parts by weight of tetrachlorosilane was added to 100 parts of methylene chloride.
1300 parts by weight of 2-hydroxyethyl acrylate was added to a solution dissolved in 0 parts by weight, and the solution was stirred at a temperature of 10 ° C.
It was dropped while keeping below. After completion of the dropwise addition, the solution was stirred at room temperature for 3 hours, and thereafter, volatile components were completely distilled off under reduced pressure to obtain tetra (acryloyloxyethoxy) silane.

Example 1 156 parts by weight of tetraethoxysilane, isopropyl alcohol-dispersed colloidal silica (silica content: 30% by weight, trade name OSCAL-143, manufactured by Kasei Kagaku Kogyo KK)
2) 600 parts by weight, 54 parts by weight of deionized water and 0.5 part by weight of 36% hydrochloric acid were charged into the flask, and heated at 80 ° C. for 1 hour with stirring.

Thereafter, the product was cooled to around room temperature, and 65 parts by weight of dipentaerythritol pentaacrylate was added.
65 parts by weight of tetraethylene glycol diacrylate,
And tetra (acryloyloxyethoxy) silane 36
After the addition of parts by weight, water and organic solvent present in the system were distilled off at a temperature of 20 to 40 ° C. under a pressure of 10 to 150 mmHg until the solid content became 50% by weight.

To 100 parts by weight of the above mixed solution, 2.7 parts by weight of 2-hydroxy-4-n-octoxybenzophenone, 0.5 parts by weight of benzoin isobutyl ether, and methyl methacrylate / butyl methacrylate = 50/50.
(Weight ratio) of 0.4 part by weight of the copolymer ([η] = 0.04) was added to prepare a curing liquid.

A 5 mm-thick polymethyl methacrylate resin plate (Acrylite L, manufactured by Mitsubishi Rayon Co., Ltd.) was immersed in the obtained composition, and the plate was pulled up at a speed of 0.5 cm / sec. Was formed. After leaving it for 10 minutes, a high-pressure mercury lamp (2 kw HO-
L21) UV rays from a distance of 20 cm on both sides of the plate
Irradiated for 2 seconds to obtain a surface-treated methacryl plate. Table 1 shows the evaluation results of the obtained methacryl plates.

Example 2 78 parts by weight of tetraethoxysilane, 67 parts by weight of methyltriethoxysilane, 600 parts by weight of isopropyl alcohol-dispersed colloidal silica (silica content: 30% by weight, trade name OSCAL-1432, manufactured by Kasei Kasei Kogyo KK) Parts, 47.3 parts by weight of deionized water and 0.5% of 36% hydrochloric acid
After putting parts by weight into the flask, 80 ° C with stirring
For 1 hour.

Thereafter, the product was cooled to around room temperature, and 65 parts by weight of dipentaerythritol pentaacrylate was added.
65 parts by weight of tetraethylene glycol diacrylate,
And tetra (acryloyloxyethoxy) silane 54
After the addition of parts by weight, all water and organic solvent present in the system were distilled off at a temperature of 20 to 40 ° C. under a pressure of 10 to 150 mmHg.

To 100 parts by weight of the above product, 2.7 parts by weight of 2-hydroxy-4-n-octoxybenzophenone,
0.5 parts by weight of benzoin isobutyl ether and 0.4 parts by weight of a copolymer ([η] = 0.04) of methyl methacrylate / butyl methacrylate = 50/50 (weight ratio) were added to prepare a curing liquid. did.

Using the obtained composition, a methacryl plate having been subjected to a surface treatment in the same manner as in Example 1 was obtained. Table 1 shows the properties of the obtained methacrylic plate.

Example 3 58 parts by weight of tetraethoxysilane, 67 parts by weight of methyltriethoxysilane, 48 parts by weight of dimethyldiethoxysilane, water-dispersible colloidal silica (silica content: 20% by weight, manufactured by Nissan Chemical Industries, Ltd.) Name Snowtex O)
After 900 parts by weight were charged into the flask, the mixture was stirred at room temperature for 1 hour. After adding 1000 parts by weight of cellosolve, the solvent and water were removed at 40 ° C. under reduced pressure. Next, 65 parts by weight of dipentaerythritol pentaacrylate, 65 parts by weight of tetraethylene glycol diacrylate, and 54 parts by weight of tetra (acryloyloxyethoxy) silane were added and dissolved to obtain a transparent acrylic-silica mixture.

To 100 parts by weight of the above product, 2.7 parts by weight of 2-hydroxy-4-n-octoxybenzophenone,
0.5 parts by weight of benzoin isobutyl ether and 0.4 parts by weight of a copolymer ([η] = 0.04) of methyl methacrylate / butyl methacrylate = 50/50 (weight ratio) were added to prepare a curing liquid. did.

Using the obtained composition, a methacrylic plate whose surface was treated in the same manner as in Example 1 was obtained. Table 1 shows the properties of the obtained methacrylic plate.

Examples 4 to 10 and Comparative Examples 1 to 6 Polymerizable compound (a), colloidal silica, silane compound, compound (c), and other additives and amounts were changed as shown in Table 1. A curing liquid was prepared in the same manner as in Example 1,
A methacryl plate having been subjected to a surface treatment in the same manner as in Example 1 was obtained. In Example 9, polycarbonate was used as the substrate.
In Example 10, polystyrene was used as a substrate. Table 1 shows the evaluation results of the obtained methacryl plates.

The evaluation results of polymethyl methacrylate, polycarbonate, and polystyrene resin plates not subjected to surface treatment are shown in Table 1 as Comparative Examples 4 to 6.

[0059]

[Table 1]

[0060]

[Table 2] Example 9 shows the results of surface treatment using polycarbonate and polystyrene as substrates, and the results of evaluation. Comparative Examples 4, 5, and 6 are evaluation results of polymethyl methacrylate, polycarbonate, and polystyrene, respectively, which were not surface-treated. In each of the Examples and Comparative Examples, 2-hydroxy-4-n-
2.7 parts by weight of octoxybenzophenone, 0.5 parts by weight of benzoin isobutyl ether and 0.4 parts by weight of a copolymer ([η] = 0.04) of methyl methacrylate / butyl methacrylate = 50/50 (weight ratio) Parts are added. Abbreviations in the table are as follows. 2P5A: dipentaerythritol pentaacrylate TEDGA: tetraethylene glycol diacrylate BAEP: 2,2-bis- (4-acryloyloxyethoxyphenylpropane THFA: tetrahydrofurfuryl acrylate OSCAL-1432: isopropyl alcohol-dispersed colloidal silica (trade name, (Silica content: 30% by weight, manufactured by Kasei Kagaku Kogyo Co., Ltd.) Triethoxysilane DMDES: dimethyldiethoxysilane DMDMS: dimethyldimethoxysilane MPTMS: γ-methacryloyloxypropyltrimethoxysilane TAS: tetra (acryloyloxy) ) Silane TMAS: tetra (methacryloyloxy ethoxy) silane IPA: Isopropyl alcohol

[0061]

According to the present invention, a cured film having very good abrasion resistance is formed, and the aesthetic deterioration due to scratches, which has been a problem in using synthetic resin, can be solved. Was.

Continuation of the front page (56) References JP-A-5-302041 (JP, A) JP-A-3-275769 (JP, A) JP-A-3-207765 (JP, A) JP-A-64-69673 (JP) JP-A-5-255349 (JP, A) JP-A-5-209027 (JP, A) JP-B-3-6190 (JP, B2) JP-B-52-39691 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 4/06 C09D 183/00 C08F 299/02 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (5)

(57) [Claims] (1) a polymerizable compound having at least two acryloyloxy groups and / or methacryloyloxy groups in a molecule; (b) in the presence of colloidal silica, the following general formula (I): SiR ¹ _a R ² _b (OR ³ ) _c (I) (wherein, R ¹ and R ² are a hydrocarbon residue having 1 to 10 carbon atoms which may have an ether bond or an ester bond, and a radically polymerizable group and having no epoxy group, an R ³ is a hydrocarbon residue hydrogen atom or a C1-10, a and b is an integer of from 0 to 3, c is 4-a-b, 1 to 4 A silica-based condensation polymer obtained by hydrolyzing and condensation-polymerizing a silane compound represented by the formula (c): tetra (acryloyloxyalkoxy) silane or tetra (methacryloyloxyalkoxy) silane; d) photopolymerization An abrasion-resistant UV-curable coating composition comprising an initiator. 2. The polymerizable compound (a) having at least two acryloyloxy groups and / or methacryloyloxy groups in the molecule, represented by the following general formulas (II) to (IV): (In the formula, at least two of Y ¹¹ , Y ¹² , Y ¹³ ,... Y ^p2 , Y ^p3 , and Y ¹⁴ are an acryloyloxy group and / or a methacryloyloxy group, and the rest is a hydrogen atom, a hydroxyl group, an amino group, an alkyl group. Group or substituted alkyl group, p is 1 to
5 is represented. ) (Wherein, R ⁴ is a hydrogen atom or a methyl group, and R ⁵ is 2-20
R ⁶ is a residue of an aliphatic hydrocarbon having 2 carbon atoms or a derivative thereof, R ⁶ is a residue of an aliphatic or aromatic hydrocarbon having 2 to 20 carbon atoms or a derivative thereof, q is 1
Represents an integer of ２０20. ) (Wherein, R ⁷ is a hydrogen atom or a methyl group, r is an integer of 2 to 20, and s is an integer of 1 to 50). Coating composition. 3. The coating composition according to claim 1, wherein a compound represented by c = 4 and a = b = 0 among the silane compounds represented by the general formula (I) is used. 4. Among the silane compounds represented by the general formula (I), a compound represented by c = 4 and a = b = 0, and c = 3
The coating composition according to claim 1 or 2, wherein a mixture with the compound represented by (2) is used. 5. An article whose surface is coated with a cured product of the coating composition according to claim 1.