JP2000063549A - Thin article having abrasion resistant thin membrane, and optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrathin cured film having a thickness of less than 3 μm and particularly excellent abrasion resistance, transparency, surface smoothness, heat resistance, chemical resistance, durability, and base material. To obtain a thin article having good adhesion. SOLUTION: (A) hydrolyzing (a-1) colloidal silica fine particles (solid content) and (a-2) a specific compound,
Solid content of the photocurable silicone obtained by the condensation reaction,
(B) the total amount of at least one monomer having at least one (meth) acryloyloxy group in one molecule,
(C) a photopolymerization initiator and (D)
After coating a photosensitive coating composition comprising at least one organic solvent on a substrate, the organic solvent (D) contained therein is volatilized, and polymerized and cured by irradiation with light energy. Form a coating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article having improved abrasion resistance on the surface of a substrate, and more particularly, to an ultrathin article having a cured film thickness of less than 3 μm on the surface of the substrate by irradiation of light energy. The present invention relates to a thin article formed with a crosslinked cured film having excellent transparency, surface smoothness, heat resistance, chemical resistance, durability, and adhesion to a substrate, which is particularly excellent in abrasion resistance.

[0002]

2. Description of the Related Art A synthetic resin molded article manufactured from a polymethyl methacrylate resin, a polymethacrylimide resin, a polycarbonate resin, a polystyrene resin, a polyolefin resin, etc. is not only lighter and more excellent in impact resistance than glass products, In recent years, it has been used in various fields such as optical discs, home electric parts, plastic materials for automobiles, and various film materials, taking advantage of various advantages such as good transparency and easy molding.

However, on the other hand, these synthetic resin molded products are
Due to the lack of abrasion resistance of the surface, the surface is easily damaged by contact, friction, scratching, etc. with other hard objects, and the damage generated on the surface significantly lowers its commercial value. Therefore, it is strongly required to improve the wear resistance of the surface of the molded article.

Various methods for improving the above-mentioned drawbacks of synthetic resin molded articles have been studied in the past. For example, a partially hydrolyzed condensate of a silane mixture containing an alkyltrialkoxysilane as a main component and colloidal silica are used. (US Pat. No. 4,006,271) discloses a method of applying a coating consisting of the following to a surface of a molded article and then subjecting the coating to heat treatment to form a crosslinked cured film to improve abrasion resistance. In this method, a high degree of abrasion resistance is obtained, but the adhesion to the surface of the molded product is often insufficient, and a polymer made of an acrylic or silicon-based material is used as a primer to improve the adhesion. Therefore, there is a problem that the process of forming the coating is complicated. Further, since the curing time is long, it is economically disadvantageous and productivity is poor.

As a method for improving this disadvantage, Japanese Patent Application Laid-Open
No. 7,500,984 and U.S. Pat. No. 4,438,462 disclose an ultraviolet-curable coating composed of colloidal silica, an alkoxysilane having a methacryloyloxy group or a glycidyl group functional group, and a non-silyl acrylate on the surface of a molded article. And then irradiating it with ultraviolet light to obtain a wear-resistant synthetic resin molded article.
No. 56 discloses a coating composition substantially free of an organic solvent comprising a hydrolyzate of a silyl acrylate and a silyl acrylate, a polyfunctional acrylate and a photopolymerization initiator, and a production method thereof. Is
A coating composition substantially free of an organic solvent, comprising acrylate-modified colloidal silica, polyfunctional acrylate, and polyfunctional urethane acrylate having a limited structure, is disclosed. These methods are methods of curing a silicon-based coating by ultraviolet irradiation, and have the advantage that the curing time of the coating, which has been a problem in the past, can be significantly shortened. It is advantageous.

[0006]

In recent years, in the field of optical discs and the like, demands for higher density have been made, so that relatively thin base materials have been used, and warpage has occurred in the base materials. It is an important subject to prevent the occurrence of the problem and to maintain the surface smoothness. However, in the above-mentioned conventional method, although a thick coating film having a cured film thickness of 3 to 100 μm can be formed, when applied to a thin-walled substrate such as an optical disc, film, or sheet made of a thin-walled substrate. However, since the film thickness is large, there is a problem that the substrate is warped toward the coating film application side due to the stress accompanying the curing shrinkage. Even if the warpage is very small, it is an important problem, especially when applied to an optical disk with a high density, since it directly leads to a decrease in the performance of the optical disk.

[0007] Curing shrinkage of the coating composition, which causes this warpage, is generally 6% to more than 10% in the case of a radical polymerizable composition. Since it is impossible to reduce the curing shrinkage to 0%, it is necessary to reduce the cured film thickness as much as possible in order to minimize the warpage. However, radical polymerization, in which polymerization is normally initiated by active energy rays such as light, is not performed under a special inert gas atmosphere or under a vacuum unless the oxygen in the air inhibits polymerization. It is difficult to cure a thin film of less than 3 μm with a wear-resistant coating by the method. Further, at present, it is impossible to impart various performances such as abrasion resistance and durability in a state of the thin film in a well-balanced state.

An object of the present invention is to have excellent abrasion resistance,
In addition, the base material surface is coated with a thin cross-linked cured film having a good balance of various properties such as transparency, surface smoothness, heat resistance, chemical resistance, durability and adhesion to the base material. There is no thin article to provide.

[0009]

The inventors of the present invention have conducted intensive studies on the above problems, and as a result, have found that a photocurable silicone obtained by hydrolyzing colloidal silica fine particles and a specific radically polymerizable silane compound and subjecting it to a condensation reaction. By using together with a monomer having at least one (meth) acryloyloxy group in one molecule, a light-sensitive coating material composition that can be cured even in a thin film less than 3 μm is very excellent. The inventors have found that a thin article having performance can be obtained, and have completed the present invention.

That is, the present invention provides (A) (a-1) 40 to 90 parts by weight of colloidal silica fine particles (solid content);
(A-2) The following general formula (I)

Embedded image (Wherein X is a methacryloyloxy group, acryloyloxy group, or vinyloxy group, R ¹ is a linear or branched alkyl group having 0 to 8 carbon atoms, and R ^{2 and} R ³ are 1 to 8 carbon atoms.
A is a positive integer of 1 to 3, b is a positive integer of 0 to 2, and a + b is a positive number of 1 to 3. A) (solid content) of 10 to 60
Parts by weight (provided that the total amount of the components (a-1) and (a-2) is 100 parts by weight) and the solid content of the photocurable silicone obtained by the condensation reaction is 10 to 70 parts. % By weight, and (B) at least one kind of a monomer having at least one (meth) acryloyloxy group in one molecule.
(C) with respect to 100 parts by weight of the total amount of 0 to 90% by weight.
After applying a photosensitive coating composition comprising 0.01 to 10 parts by weight of a photopolymerization initiator and 30 to 2000 parts by weight of at least one kind of an organic solvent (D) on a substrate, the organic solvent (D A) a thin article having a cured film with a thickness of less than 3 μm, which is volatilized and polymerized and cured by irradiation with light energy;
(A) (a-1) Colloidal silica fine particles (solid content) 4
0 to 90 parts by weight, and (a-3) the following general formula (II)

Embedded image (Wherein, X is a methacryloyloxy group, acryloyloxy group, or vinyloxy group; R ¹ is a linear or branched alkyl group having 0 to 8 carbon atoms; R ² is a linear or branched alkyl group having 1 to 8 carbon atoms; A is a positive integer of 1 to 3; b is a positive integer of 0 to 2; a + b is a positive number of 1 to 3; Object (solid content)
10 to 60 parts by weight (provided that the component (a-1) and the component (a-
3) The total amount of the components is 100 parts by weight), a solid content of 10 to 70% by weight of the photocurable silicone obtained by hydrolysis and condensation reaction, and at least one component (B) per molecule. (C) 0.01 to 10 parts by weight of a photopolymerization initiator, based on 100 parts by weight of a total amount of 30 to 90% by weight of at least one kind of a monomer having a (meth) acryloyloxy group;
(D) After applying a photosensitive coating composition comprising at least one kind of organic solvent of 30 to 2,000 parts by weight on a substrate,
A thin article having a cured film having a film thickness of less than 3 μm, an optical disc, and a thin article having a wear-resistant thin film having a thickness of less than 1.5 mm, wherein the organic solvent (D) contained is volatilized and polymerized and cured by irradiation with light energy. Goods.

In the present invention, "(meth) acrylate" means "acrylate and / or methacrylate", and "(meth) acryloyloxy group" means "acryloyloxy group and / or methacryloyloxy group", respectively. I do.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. First, with respect to the thin article having the abrasion-resistant thin film of the present invention, first, a photosensitive coating material composition (hereinafter, abbreviated as a coating composition) for forming the abrasion-resistant thin film will be described.

[0013] The thin article and the optical disk of the present invention are characterized in that the abrasion-resistant coating applied to their surfaces is formed of a coating composition containing a photocurable silicone (A).

The process for producing the component (A) is carried out in the presence of the colloidal silica fine particles of the component (a-1) and the hydrolyzate of the monomer represented by the general formula (I). Is azeotropically distilled together with a non-polar solvent such as toluene under normal pressure or reduced pressure, and after replacing the dispersion medium with a non-polar solvent, the reaction is carried out under heating.

Hereinafter, the method for producing the component (A) will be described in detail. Here, the term “colloidal silica fine particles of the component (a-1) and the presence of the hydrolyzate of the monomer represented by the general formula (I)” means that the components (a-1) and (a-2) are mixed. After that, a hydrolysis catalyst is added, and the monomer represented by the general formula (I) is hydrolyzed by a conventional method such as stirring at room temperature or under heating. The hydrolyzate of component (a-2) obtained by the reaction (a
-3) and (a-1) in the presence of the hydrolyzate obtained by mixing the components.

In both of the above methods, the method for producing the hydrolyzate is based on 1 mole of the monomer represented by the general formula (I) in the presence or absence of an organic solvent such as an alcohol solvent. In the case of the method, in the presence of the component (a-1), 0.5 to 6 mol of water or 0.001 to
A hydrolysis catalyst such as a 0.1 N hydrochloric acid or acetic acid aqueous solution may be added, and the alcohol produced by the hydrolysis may be removed from the system while stirring under heating.

The subsequent condensation reaction may be performed as follows. Specifically, in the presence of the hydrolyzate obtained by the above-described method, (a-
1) By adding the component, first, colloidal silica fine particles (a
-1) The azeotropic distillation of the water generated in the condensation reaction with the dispersion medium in 1) at a temperature of 60 to 100 ° C, preferably 70 to 90 ° C under normal pressure or reduced pressure, to obtain a solid content of 50 to 90% by weight. I do. Next, a non-polar solvent such as toluene is added into the system, and the non-polar solvent, water, and the dispersion medium of the colloidal silica fine particles are further azeotropically distilled at a temperature of 60 to 150 ° C., preferably 80 to 130 ° C. While maintaining the solid content concentration at 30 to 90% by weight, preferably 50 to 80% by weight, the solid content is adjusted to 0.1% by weight.
The mixture is stirred for 5 to 10 hours to perform a condensation reaction. At this time, a catalyst such as water, an acid, a base or a salt may be used for the purpose of accelerating the reaction. Thereby, the photocurable silicone (A) is obtained.

As described above, the surface of the colloidal silica fine particles having a hydrophilic surface is coated with a (meth) acryloyl-functional silicone to make the photocurable silicone (A) hydrophobic.
By using, the compatibility with the polyfunctional acrylate used in combination in the coating composition used in the present invention is improved, and the transparency of the obtained crosslinked cured film is improved.

Here, (a-1) to (a-3) used for obtaining the component (A) of the coating composition used in the present invention.
The components will be described.

Regarding the component (a-1) The colloidal silica fine particles which are the component (a-1) are obtained by dispersing ultrafine silica particles having a primary particle diameter in the range of 1 to 200 nm in water or an organic solvent. belongs to.

Examples of the dispersion medium used for dispersing the ultrafine particles of silicic anhydride include water; alcohol solvents such as methanol, ethanol, isopropanol, n-propanol, isobutanol and n-butanol; and ethylene glycol and the like. Polyhydric alcohol solvents; polyhydric alcohol derivatives such as ethyl cellosolve and butyl cellosolve; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and diacetone alcohol; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate and the like Monomers.

Among them, alcohol solvents having 3 or less carbon atoms are particularly preferable in the reaction step with the component (a-2) or the component (a-3).

The colloidal silica fine particles (a-1)
Can be produced by a known method, but is also commercially available. In the present invention, the primary particle diameter of the component (a-1) is preferably in the range of 1 to 200 nm, and 5 to 8
A range of 0 nm is particularly preferred. This primary particle diameter is 1 nm
If the average particle size is less than 200 nm, gelation is likely to occur in the reaction step with the component (a-2) or the component (a-3), and the intended coating composition cannot be obtained. If it exceeds, the transparency of the cured film tends to decrease.

The colloidal silica fine particles (a-1) can remarkably improve the abrasion resistance of the cured film, and particularly have a great effect of improving the abrasion resistance against fine particles such as silica sand. But,
When colloidal silica is used alone as a cured coating, the adhesion to the surface of the synthetic resin molded product is poor.

Component (a-2) The monomer represented by the above general formula (I) (hereinafter abbreviated as silane compound), which is component (a-2), is preliminarily mixed with colloidal silica fine particles (a-1). By reacting
(B) A component that improves compatibility with the polyfunctional (meth) acrylate that is the component.

As the component (a-2), a silane compound having an acryloyloxy group, a methacryloyloxy group or a vinyl group which exhibits polymerization activity upon irradiation with light energy is used. By using this silane compound,
A photocurable silicone capable of forming a chemical bond with the polyfunctional (meth) acrylate of the component (B) can be formed, and toughness can be imparted to the obtained cured film. Furthermore, by using the colloidal silica fine particles (a-1) and (a-2) in combination, it is possible to further improve the wear resistance of the obtained cured film, and in particular, the wear resistance to metal fibers such as steel wool. The effect of improving the properties can be increased.

In the present invention, the component (a-2) includes
As specific examples, for example, 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 2-methacryloyloxyethyltrimethoxysilane, 2-acryloyloxyethyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane 3-acryloyloxypropyltriethoxysilane, 2-methacryloyloxyethyltriethoxysilane, 2-acryloyloxyethyltriethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, vinyltrimethoxysilane And at least one silane compound selected from vinyltriethoxysilane and the like.

Among the above, 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane At least one silane compound selected from ethoxysilane is particularly preferred in that it has excellent reactivity with the component (a-1).

In another embodiment of the present invention, the component (a-3) is replaced with the monomer (a-2) represented by the general formula (II) instead of the component (a-2). Decomposed products can be used. Specific examples of the component (a-3) include a hydrolyzate of at least one silane compound selected from the silane compounds of the component (a-2). As described above, the method for producing the hydrolyzate of the component (a-2), which is the component (a-3), includes adding a hydrolysis catalyst to the silane compound in the presence or absence of an organic solvent, The alcohol generated by hydrolysis may be removed from the system while stirring at room temperature or under heating.

In the present invention, the non-polar solvent used in the production of the photocurable silicone (A) is selected based on the dielectric constant, dipole efficiency or hydrogen bonding parameter. It also includes a polar solvent. For example, a nonpolar solvent having a dielectric constant at 20 ° C. in the range of 2 to 10 is a preferable solvent in the present invention.

Specific examples of the nonpolar solvent include, for example, hydrocarbons such as benzene, toluene, xylene, ethylbenzene and cyclohexane; halogenated hydrocarbons such as trichloroethylene and tetrachloroethylene; Ethers such as butyl ether; ketones such as methyl isobutyl ketone; esters such as n-butyl acetate, isobutyl acetate, ethyl acetate and ethyl propionate; polyhydric alcohols such as 1-methoxy-2-propanol and ethylene glycol monobutyl ether Derivatives and the like can be mentioned. Further, an unsaturated ethylenic compound, for example, a monomer having one or more (meth) acryloyloxy groups in one molecule can be used as the non-polar solvent.

Among these non-polar solvents, hydrocarbons, aromatic hydrocarbons or polyhydric alcohol derivatives can be used in view of the reaction between the component (a-1) and the component (a-2). Preferred, particularly preferred non-polar solvents,
Examples thereof include toluene and 1-methoxy-2-propanol.

In the step of producing the component (A), the solid concentration during the reaction is preferably in the range of 30 to 90% by weight. If this solid content is less than 30% by weight, that is, if the solvent exceeds 70% by weight, the reaction between the component (a-1) and the component (a-2) or (a-3) becomes insufficient, The cross-linked cured film obtained by using the coating composition using the above tends to have poor transparency. On the other hand, if the solid content exceeds 90% by weight, the condensation reaction occurs rapidly, and problems such as the reaction system being in a gelled state occur.

The temperature during the condensation reaction for obtaining the component (A) is preferably in the range of 60 to 150 ° C. This is because when the reaction temperature is lower than 60 ° C., the reaction does not proceed sufficiently and a longer reaction time is required. On the other hand, when the reaction temperature is higher than 150 ° C., reactions other than silanol condensation occur,
Or a problem such as formation of a gel occurs.

In the production of the component (A) in the present invention, the solid content of the component (a-1) in the reaction step and (a-
The weight ratio of the hydrolyzate of component 2) or the solid content of component (a-3) (converted as silanol) is (a-
1) / (a-2) or (a-3) = 40-90 / 10
60, preferably 50-80 / 20-50 (100 in total)
Parts by weight).

When the use ratio is out of the above range, for example,
If the amount of the component (a-1) exceeds 90 parts by weight, problems such as clouding of the reaction system and formation of a gel occur, and cracks tend to occur in the crosslinked cured film. on the other hand,
If the amount of the component (a-1) is less than 40 parts by weight, the abrasion resistance of the cured film tends to decrease.

In a nonpolar solvent, the component (a-1) and the component (a-
By reacting the component (2) or the component (a-3), the curability of the obtained coating composition is improved, a thin film of less than 3 μm can be formed, and the coating composition is transparent and resistant even in an air atmosphere. It becomes possible to form a cured film having excellent wear properties.

A coating composition using a photocurable silicone produced by a method other than the above method has insufficient curability, cannot be cured sufficiently in an air atmosphere, and has a low transparency when formed into a thin film of less than 3 μm. In addition, appearance defects such as deterioration of the cured film are likely to occur, and sufficient abrasion resistance and durability of the cured film cannot be obtained.

The photocurable silicone which is the component (A) of the coating composition used in the present invention is a component for improving the abrasion resistance and durability of the crosslinked cured film. The use ratio of the component (A) is in the range of 10 to 70% by weight, preferably 2%, based on the total amount of the component (A) (solid content) and the component (B).
The amount is in the range of 0 to 60% by weight, more preferably 25 to 55% by weight.

When the use ratio of the component (A) is less than 10% by weight, sufficient effects of improving curability, abrasion resistance and durability cannot be obtained. The occurrence of is now recognized.

Regarding the component (B) At least one (meth) component is present in one molecule of the component (B).
Examples of the monomer having an acryloyloxy group include aliphatic, alicyclic or aromatic mono- or poly (meth)
Acrylates, aliphatic, alicyclic or aromatic urethane poly (meth) acrylates, epoxy poly (meth) acrylates, and polyester poly (meth) acrylates can be used.

Specific examples of these include, for example, methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dicyclopentanyl Mono (meth) acrylate compounds such as (meth) acrylate, dicyclopentenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, and adducts of phthalic anhydride and 2-hydroxyethyl (meth) acrylate ;
1,4-butanediol di (meth) acrylate, 1,
6-hexanediol di (meth) acrylate, 1,9
-Nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol (n = 2 to 15) di (meth) acrylate, polypropylene glycol (n = 2 to 15) Di (meth) acrylate, polybutylene glycol (n = 2 to 15) di (meth) acrylate, 2,2-bis (4- (meth) acryloxyethoxyphenyl) propane, 2,2-bis (4
-(Meth) acryloxydiethoxyphenyl) propane, trimethylolpropane diacrylate, bis (2
-(Meth) acryloxyethyl) -hydroxyethyl-
Di (meth) acrylate compounds such as isocyanurate; trimethylolpropane tri (meth) acrylate, tris (2- (meth) acryloyloxyethyl)
Isocyanurate, tris (2- (meth) acryloyloxypropyl) isocyanurate, bis (2- (meth) acryloyloxyethyl) hydroxyethyl isocyanurate, bis (2- (meth) acryloyloxypropyl) -2-ethoxypropyl isocyanate Nurate,
Multifunctional (meta) such as pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate A) an acrylate compound; an epoxy poly (meth) acrylate such as an epoxy di (meth) acrylate obtained by reacting bisphenol A-type diepoxy with (meth) acrylic acid; 2-hydroxyethyl (trimer of 1,6-hexamethylene diisocyanate) Urethane tri (meth) acrylate obtained by reacting meth) acrylate; urethane di (meth) acrylate obtained by reacting isophorone diisocyanate with 2-hydroxypropyl (meth) acrylate; Urethane hexa (meth) acrylate obtained by reacting long diisocyanate with pentaerythritol tri (meth) acrylate, urethane di (meth) acrylate obtained by reacting dicyclomethane diisocyanate with 2-hydroxyethyl (meth) acrylate, dicyclomethane diisocyanate And poly (n = 6-
15) Urethane poly (meth) acrylate such as urethane di (meth) acrylate obtained by reacting 2-hydroxyethyl (meth) acrylate with a urethanation reaction product with tetramethylene glycol; trimethylolethane and succinic acid, (meth) acrylic Polyester (meth) acrylates such as polyester (meth) acrylate reacted with an acid, and polyester (meth) acrylate such as polyester (meth) acrylate obtained by reacting trimethylolpropane with succinic acid, ethylene glycol, coal and (meth) acrylic acid. be able to.

These monomers may be used alone or in combination of two or more. However, when imparting excellent wear resistance to a thin article, the molecular A compound having two or more (meth) acryloyl groups in (B)
It is preferably used as a component.

Among them, component (B) includes dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and tris (2- ( 2-hydroxyethyl to a trimer of (meth) acryloyloxyethyl) isocyanurate, bis (2- (meth) acryloyloxyethyl) hydroxyethyl isocyanurate, trimethylolpropane tri (meth) acrylate and 1,6-hexamethylene diisocyanate (Meta)
Urethane tri (meth) acrylate obtained by reacting acrylate, urethane hexa (meth) acrylate obtained by reacting isophorone diisocyanate with pentaerythritol tri (meth) acrylate, dicyclomethane diisocyanate and poly (n = 6-15) tetramethylene glycol Urethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tris (2- (meth) acryloxyethyl) isocyanurate, One or more compounds selected from 2,6-hexanediol di (meth) acrylate are particularly preferred.

The proportion of component (B) used is in the range of 30 to 90% by weight based on the total amount of component (A) (solid content) and component (B).

When the amount of the component (B) is less than 30% by weight, the durability of the obtained thin cured film and the adhesion to the substrate are reduced. This is because the reactivity in air tends to decrease. Preferably in the range of 40-80% by weight, more preferably 45-80% by weight.
It is in the range of 75% by weight.

Component (C) The coating composition used in the present invention contains a photopolymerization initiator as the component (C).

Specific examples of the component (C) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, butyroin, toluoin, benzyl, benzophenone, p-methoxybenzophenone, and diethoxy. Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4-bis (dimethylaminobenzophenone),
2-hydroxy-2-methyl-1-phenylpropane-
Carbonyl compounds such as 1-one, 1-hydroxycyclohexylphenyl ketone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one; sulfur compounds such as tetramethylthiuram disulfide and tetramethylthiuram disulfide Azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile; peroxide compounds such as benzoyl peroxide and ditertiary butyl peroxide;
2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl)
Acyl phosphine oxide compounds such as -2,4,4-trimethylpentyl phosphine oxide can be mentioned.

Among them, the photopolymerization initiator (C) includes
One or more compounds selected from benzophenone, 1-hydroxycyclohexylphenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and methylphenylglyoxylate are particularly preferred.

Component (C) is used in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total amount of component (A) (solid content) and component (B). Department. When the use ratio of the component (C) exceeds 10 parts by weight, the crosslinked cured film becomes colored and the weather resistance is reduced. When the use amount is less than 0.01 part by weight, the obtained coating composition cannot be cured.

Component (D) In the present invention, in addition to adjusting the viscosity of the coating composition, aspects such as uniform solubility, dispersion stability, adhesion to the substrate, and smoothness and uniformity of the cured film are considered. Therefore, an organic solvent is used as the component (D). To apply the coating composition used in the present invention to a substrate, brush coating, spray coating, dip coating, spin coating, roll coating, curtain coating, and other ordinary methods can be used. It is desirable. However, since the mixture of the photocurable silicone (A) and the component (B) has a very high viscosity, it is preferable to dilute the mixture with an organic solvent (D) to a viscosity suitable for coating.

The organic solvent (D) is not particularly limited, but may be at least 30 to 2,000 parts by weight based on 100 parts by weight of the total of the component (A) (solid content) and the component (B). What is necessary is just to mix one kind of organic solvent.

As the organic solvent (D), alcohols,
At least one selected from organic solvents such as hydrocarbons, ketones, ethers, esters, polyhydric alcohol derivatives, and halogenated hydrocarbons can be used.

Specific examples of the organic solvent (D) include, for example, alcohol solvents such as isopropyl alcohol, n-butanol, isobutanol, diacetone alcohol, hexane, cyclohexane, toluene, xylene, and the like.
Hydrocarbon solvents such as high boiling aromatic solvents (Swazole 1000 etc.), ketone solvents such as MEK, MIBK, DIBK, cyclohexanone, ether solvents such as ethyl ether, ethyl acetate, n-butyl acetate, amyl acetate, acetic acid Examples include ester solvents such as methoxypropyl and ethoxyethyl acetate, and solvents of polyhydric alcohol derivatives such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methoxypropanol, methoxybutanol, and ethyldiglycol. These may be used alone or as a mixture of two or more.

Among these, the uniform solubility of the coating composition,
From the viewpoints of dispersion stability, adhesion to a substrate, and smoothness and uniformity of a film, (d) as an organic solvent (D)
-1) 10 to 50% by weight of an alcoholic organic solvent, (d-
2) 10 to 50% by weight of an acetate organic solvent, (d-
Particularly preferred is a combination of 3) 5 to 30% by weight of a ketone solvent and 1 to 30% by weight of a (d-4) polyhydric alcohol derivative solvent (when the total amount of the component (D) is 100% by weight).

The amount of the organic solvent (D) used is in the range of 30 to 2000 parts by weight, preferably 50 to 1 part by weight, based on 100 parts by weight of the total of the component (A) (solid content) and the component (B).
It is preferred to add in the range of 000 parts by weight.

The above are the essential components constituting the coating composition used in the present invention. If necessary, an antioxidant, an anti-yellowing agent, a bluing agent, a pigment, a leveling agent, a defoaming agent, Various additives such as a thickener, an antisettling agent, an antistatic agent, an antifogging agent, an ultraviolet absorber, and a light stabilizer may be contained.

In the present invention, the coating amount of the coating composition is preferably such that the thickness of the crosslinked cured film is less than 3 μm, preferably 0.5 to 2.5 μm. When the film thickness is less than 0.3 μm, sufficient abrasion resistance and adhesion to the substrate tend to be poor, and when it exceeds 3 μm, the warpage of the substrate due to curing shrinkage of the coating composition tends to increase. It is in.

As means for curing the coating film of the coating composition applied to the substrate, light energy irradiation, for example, α, β
Irradiation with an active energy ray such as γ-ray or the like may be performed by irradiating the coating film of the coating composition with a known method, and is not particularly limited. For application to thinner thin substrates, it is particularly preferable to use ultraviolet light as a means for curing the coating composition. In this case, as an ultraviolet light source,
An ultraviolet lamp generally used may be used in terms of practicality and economy. Specific examples of the ultraviolet lamp include, for example,
Low pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp,
Senon lamps, metal halide lamps and the like can be mentioned. The atmosphere of light energy irradiation may be in air or in an inert gas such as nitrogen or argon, but is preferably in air from the viewpoint of practicality and economy.

In order to obtain the thin article of the present invention, the organic solvent component (D) contained in the coating composition is applied to the surface of the base material after the coating composition is applied and before the composition is cured by ultraviolet irradiation energy. ) May be subjected to heat treatment at 20 to 120 ° C. for 1 to 60 minutes using an infrared or hot air drying furnace for the purpose of volatilizing and removing the cured film or improving the adhesion of the cured film to the substrate.

As the substrate of the thin article of the present invention, various substrates can be applied. In particular, various types of thermoplastic resins or thermosetting resins which have conventionally been required to have a surface modification such as abrasion resistance and weather resistance have been used. A synthetic resin such as a curable resin may be used.

Specific examples of the substrate include, for example, polymethyl methacrylic resin, polycarbonate resin, polyester resin, polystyrene resin, polyolefin resin, acrylonitrile-styrene copolymer resin, polyamide resin,
Polyarylate resin, polymethacrylimide resin, polyallyl diglycol carbonate resin and the like can be mentioned. In particular, a polymethyl methacrylic resin, a polycarbonate resin, a polystyrene resin, and a polyolefin resin are particularly effective when used as the base material of the present invention because they are excellent in transparency and require strong improvement in abrasion resistance. Further, the thin article in the present invention is not particularly limited, but optical disc molded articles, sheet-shaped molded articles, film-shaped molded articles, lens-shaped molded articles, and casts, extrusions, and presses of various shapes made of these substrates. It is suitable for an article obtained by a molding method or an injection molding method.

[0063]

The present invention will be described in more detail with reference to the following examples. The evaluation in Examples and Comparative Examples was performed by the following method.

1. Appearance (1) Transparency The haze value was measured using a haze meter according to ASTM D-1003. In addition, in the evaluation results in the table, together with the haze value, when the haze value having no optical problem is less than 1, ○ is given, and when the haze value having optical problem is 1 or more, x is given. Is written. (2) After coating and curing the coating composition on the laser reading surface of a CD optical disk (polycarbonate injection molded product) having a warp diameter of 120 mm and a thickness of 1.2 mm of the base material, the degree of warp of the CD optical disk is determined by the optical disk optical system. Mechanical property measurement device (DLD
-3000, manufactured by Japan EM Co., Ltd.), and the difference between the value before forming the cured film and the value after forming the cured film is described. In addition,
In the evaluation results in the table, in addition to the above values, there is no problem in signal reading at all △ mRa (milliradian) = 0 to ± 3, and 許 容 mRa (milliradian) which is an allowable range of signal readingに は is given when = 0 to ± 5, and x is given when △ mRa (milli-radian) = ± 5 which has a problem in signal reading.

2. Abrasion resistance (1) Based on Taber abrasion test ASTM D-1044, wear wheel CS-10
A wear test was performed under the conditions of F, a load of 500 g, and a rotation number of 100 cycles. After abrasion, the samples were washed with a neutral detergent and the haze was measured with a haze meter. In addition, in the evaluation results in the table, in addition to the haze value of the haze value, the abrasion resistance, when the haze increase value after abrasion with respect to before the abrasion is less than 10 which is a practical level, ○ An unacceptable level of 10 or more is indicated by x. (2) Steel wool test # 000 steel wool (Nippon Steel Wool Co., Ltd.
Bonstar (registered trademark)) was mounted on a 1 cm ² circular pad, and the pad was placed on the surface of a sample held on a reciprocating abrasion tester table, and worn for 50 cycles under a load of 1,000 g. This sample was washed with a neutral detergent, and the haze value was measured with a haze meter. In addition, in the evaluation results in the table, together with the haze value of the haze value, the abrasion resistance was evaluated as follows. An unacceptable level of 5 or more is indicated by x.

3. Razor on the surface of the adhesive sample 11 vertical and horizontal 1.5m each
Make scratches that reach the base material at intervals of m, make 100 squares, and press down cellophane tape (25 mm width, made by Nichiban) against the squares, sharply peel upward, and remain on the base material The number of eyes was counted. As for the number of remaining squares, the number of 100 remaining squares indicates good adhesion, and the number of 0-99 indicates that there is a problem in adhesion.

4. Durability test constant temperature and humidity tester (manufactured by Satake Corporation, SC-H65J-4)
(0 type) and an accelerated durability test for 2,000 hours under the test conditions of a temperature of 80 ° C. and a humidity of 85% RH. The appearance of the sample after the test was visually observed,
Further, adhesion and warpage were also evaluated. The evaluation criteria for the appearance (haze value) and the adhesion are the same as those described above, and the evaluation of the degree of warpage conforms to the evaluation of the warpage.

Synthesis of Component (A) Synthesis Example 1 Synthesis of Photo-Curable Silicone (SC-1) Iso-propanol silica sol (dispersion medium; iso-propanol) was placed in a 3-liter four-necked flask equipped with a stirrer, a thermometer and a condenser. -Propanol, SiO2 concentration; 30
Weight%, primary particle diameter; 12 nm, trade name; IPA-S
T, Nissan Chemical Industries, Ltd. (hereinafter abbreviated as IPA-ST) 2,000 parts and 3-methacryloyloxypropyltrimethoxysilane (trade name: TSL-837)
0, Toshiba Silicon Co., Ltd. (hereinafter abbreviated as TSL-8370) weighing 382 parts, raising the temperature with stirring, and starting to reflux the volatile components, 150 parts of pure water was gradually dropped at the same time. After completion of the dropwise addition, hydrolysis was carried out with stirring for 2 hours under reflux. After completion of the hydrolysis, volatile components such as alcohol and water are distilled off under normal pressure, and the solid content (IPA-
600 parts of ST SiO2 and 317 of TSL-8370
When the concentration was about 60%, 600 parts of toluene were added, and alcohol, water and the like were azeotropically distilled together with toluene.

Further, 1,500 parts of toluene was added in several portions, and the solvent was completely replaced to obtain a toluene dispersion system. At this time, the solid content concentration was about 40% by weight.
Further, the reaction was carried out at 110 ° C. for 4 hours while distilling off toluene, and the solid concentration was adjusted to about 60% by weight. Thereafter, 1000 parts of methoxypropanol was further added, and toluene was evaporated and distilled off, followed by solvent replacement to obtain a methoxypropanol dispersion system. The resulting photocurable silicone (hereinafter abbreviated as SC-1) is a yellow, transparent, viscous liquid of Newtonian fluid and has a viscosity of 30 mP at 25 ° C.
-It was s. The solids concentration was 58% by weight in terms of the residue after heating. In addition, heating residue is (weight after heating (g)
/ Weight before heating (g)) × 100 (% by weight) under heating conditions of 105 ° C. for 3 hours.

Synthesis Example 2 Photocurable silicone (SC-
2) Synthesis of Photocurable silicone (hereinafter referred to as SC-2) in the same manner as in Synthesis Example 1 except that 3-acryloyloxypropyltriethoxysilane was used instead of 3-methacryloyloxypropyltrimethoxysilane in Synthesis Example 1. Abbreviated.).

Synthesis Example 3 Photocurable silicone (SC-
3) Synthesis Photocurable silicone (hereinafter abbreviated as SC-3) in the same manner as in Synthesis Example 1 except that vinyltrimethoxysilane was used instead of 3-methacryloyloxypropyltrimethoxysilane in Synthesis Example 1. ) Got.

Example 1 SC-1 was used as the component (A).
86.2 g (50 g as a solid content, 1 as a solvent component)
-Methoxy-2-propanol),
As the component (B), tris (acryloyloxyethyl) isocyanurate (trade name; ARONIX M-31)
5, 20 g of Toa Gosei Chemical Industry Co., Ltd., 20 g of bis (acryloyloxyethyl) hydroxyethyl isocyanurate (trade name; Aronix M-215, manufactured by Toa Gosei Chemical Industry Co., Ltd.), 1,9-nonanediol di 10 g of an acrylate (trade name: Biscoat # 260, manufactured by Osaka Organic Chemical Industry Co., Ltd.), benzophenone, 1.5 g, 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, Ciba Specialty Chemicals (C)) Co., Ltd.) (1.5 g) and 1-methoxy-2-propanol as a component (D), and 155 g (total 294 g, solid content 35 wt%) of the coating composition were prepared. Using this coating composition, a compact disk (CD) injection-molded product (material, polycarbonate, color tone clear, 1.2 mm thick, 120 mm diameter) was applied by spin coating (rotation speed: 4000 rpm, shake-off time: 2 seconds), and 40 After drying for 2 minutes in a hot air drier at 100 ° C., use a high-pressure mercury lamp in an air atmosphere,
Ultraviolet rays of 0 mJ / cm ² (accumulated energy of ultraviolet rays having a wavelength of 320 to 380 nm) are irradiated, and the thickness of the cured film is 1.
C having a wear-resistant thin film of 1 μm formed on the reading surface
D was obtained. Table 2 shows the evaluation results of the performance.

Examples 2 to 8 and Comparative Examples 1 to 6 Each coating composition having the composition shown in Table 1 was prepared. This was applied to a CD injection molded article in the same manner as in Example 1 and cured to obtain a CD having a film thickness shown in Table 1. Table 2 shows the evaluation results of the performance.

REFERENCE EXAMPLE 1 A compact disk (CD) injection-molded article (material, polycarbonate, color tone clear, 1.2 mm thick, which is a base material used in Examples and Comparative Examples)
A 120 mm diameter durability test was performed, and the performance evaluation results are shown in Table 2.

The abbreviations shown in Table 1 represent the following compounds.

(A) Component SC-1: Photocurable silicone SC-2 synthesized in Synthesis Example 1 3-acryloyloxypropyltriethoxysilane was used instead of 3-methacryloyloxypropyltrimethoxysilane in Synthesis Example 1. Photocurable silicone SC-3 produced in the same manner as in Synthesis Example 1 except that it is used: In the same manner as in Synthesis Example 1 except that vinyltrimethoxysilane is used instead of 3-methacryloyloxypropyltrimethoxysilane in Synthesis Example 1. Curable silicone

(B) Component (B-1): the following monomer mixture (in a total of 100 g): 40 g of tris (acryloyloxyethyl) isocyanurate (trade name: Aronix M-315, manufactured by Toa Gosei Chemical Industry Co., Ltd.) Bis (acryloyloxyethyl) hydroxyethyl isocyanurate (trade name; ARONIX M-215,
40 g of Toa Gosei Chemical Industry Co., Ltd. 20 g of 1,9-nonanediol diacrylate (trade name: Biscoat # 260, manufactured by Osaka Organic Chemical Industry Co., Ltd.) (B-2): The following monomer mixture (100 g in total) 50 g of urethane acrylate (synthetic product) obtained by reacting 1 mol of isophorone diisocyanate with 2.1 mol of 2-hydroxypropyl acrylate 30 g of dipentaerythritol pentaacrylate (trade name: DPHA, manufactured by Nippon Kayaku Co., Ltd.) -Hydroxybutyl acrylate, 20 g

(C) Component (C-1): The following photoinitiator mixture (in a total of 100 g): benzophenone, 50 g; 1-hydroxycyclohexylphenyl ketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) 50 g (C-2): The following photoinitiator mixture (in a total of 100 g): 2,4,6-trimethylbenzoyldiphenylphosphine oxide (trade name: Lucirin-TPO, B
ASF (manufactured by ASF) 40 g ・ Methylphenylglyoxylate (trade name; Vicure 55, manufactured by Stouffer) 60 g

Component (D): The following organic solvent mixture (total 10)
(D-1): 1-methoxy-2-propanol 100 g (D-2): iso-butyl alcohol 50 g, ethyl acetate 30 g, methyl-isobutyl ketone (MIBK) 2
0g

[0080]

[Table 1]

[0081]

[Table 2]

[0082]

The thin article having a wear-resistant thin film according to the present invention is excellent not only in wear resistance and durability but also in shape accuracy of a thin resin molded article such as an optical disk. It is particularly useful for optical-related members requiring strong abrasion, durability, dimensional accuracy, etc., particularly for optical discs, display-related parts, liquid-crystal-related parts, solar-cell-related parts, and the like.

Continuation of front page    F term (reference) 4F006 AA12 AA15 AA22 AA35 AA36                       AA38 AA39 AB64 AB65 AB66                       AB67 AB68 BA02 CA01 DA04                       EA03                 4J011 AC04 CA01 CA08 CC10 PA13                       PB16 PB40 QA03 QA12 QA13                       QA14 QA15 QA18 QA22 QA23                       QA24 QB03 SA02 SA16 SA19                       SA20 SA22 SA25 SA26 SA32                       SA34 SA42 SA53 SA61 SA76                       SA79 SA83 SA84 VA01 VA10                 4J038 DL031 DL101 FA012 FA241                       GA15 HA446 KA04 KA06                       NA11 PA17 PB08 PB11 PC08

Claims (4)

[Claims] (A) (a-1) 40 to 90 parts by weight of colloidal silica fine particles (solid content), and (a-2) the following general formula (I): (Wherein X is a methacryloyloxy group, acryloyloxy group, or vinyloxy group, R ¹ is a linear or branched alkyl group having 0 to 8 carbon atoms, and R ² and R ³ are 1 to ³ carbon atoms.
8, a is a positive integer of 1 to 3, b is a positive integer of 0 to 2, a + b is 1 to 3,
Is a positive number. ) Monomer (solid content) 10-6
0 parts by weight (provided that the total amount of the components (a-1) and (a-2) is 100 parts by weight), and the solid content of the photocurable silicone obtained by the condensation reaction is 10 to 10 parts by weight. 70
% By weight, and (B) at least one (meth)
With respect to 100 parts by weight of a total amount of 30 to 90% by weight of at least one kind of a monomer having an acryloyloxy group,
(C) A photosensitive coating material composition comprising 0.01 to 10 parts by weight of a photopolymerization initiator and (D) 30 to 2,000 parts by weight of at least one kind of an organic solvent is applied on a substrate, and then the organic solvent is contained. A thin article having an abrasion-resistant thin film, characterized by having a cured film having a thickness of less than 3 μm, which is obtained by volatilizing a solvent (D) and polymerizing and curing by irradiation with light energy. (A) (a-1) 40 to 90 parts by weight of colloidal silica fine particles (solid content) and (a-3) the following general formula (II): (In the formula, X is a methacryloyloxy group, an acryloyloxy group, or a vinyloxy group, R ¹ is a linear or branched alkyl group having 0 to 8 carbon atoms, and R ² is a linear or branched alkyl group having 1 to 8 carbon atoms. A is a positive integer of 1 to 3; b is a positive integer of 0 to 2; a + b is a positive number of 1 to 3; Object (solid content)
10 to 60 parts by weight (provided that the component (a-1) and the component (a-
3) The total amount of the photocurable silicone and the component is 100 parts by weight).
% By weight, and (B) at least one (meth)
With respect to 100 parts by weight of a total amount of 30 to 90% by weight of at least one kind of a monomer having an acryloyloxy group,
(C) A photosensitive coating material composition comprising 0.01 to 10 parts by weight of a photopolymerization initiator and (D) 30 to 2,000 parts by weight of at least one kind of an organic solvent is applied on a substrate, and then the organic solvent is contained. A thin article having an abrasion-resistant thin film, characterized by having a cured film having a thickness of less than 3 μm, which is obtained by volatilizing a solvent (D) and polymerizing and curing by irradiation with light energy. 3. The thin article having a wear-resistant thin film according to claim 1, wherein the thin article having a wear-resistant thin film is an optical disk. 4. A thin article having a wear-resistant thin film according to claim 1, wherein the thickness of the substrate is less than 1.5 mm.