JP2000103987A - Coating agent and resin molded product having coating layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating agent capable of forming a coating layer having an excellent appearance and hardness, excellent in abrasion and weather resistances, or the like, and usable without a solvent by using a colloidal silica having a specific shape. SOLUTION: This coating agent contains (A) 50-99 pts.wt. of a monomer (mixture) comprising (i) 50-100 wt.% of a polyfunctional (meth)acrylate monomer having at least two (meth)acryloyloxy groups in the molecule and (ii) 0-50 wt.% of a monofunctional (meth)acrylate monomer copolymerizable with the component (i) and (B) 1-50 pts.wt. of a colloidal silica containing the one in a slender form having 5-20 nm average thickness and 40-300 nm average length in an amount of 5-100 wt.% based on the total weight of the colloidal silica. The component (i) preferably contains at least a urethane (meth)acrylate prepared by reacting a polyisocyanate represented by the formula (R1 is a 1-12C hydrocarbon) with an acrylic or a methacrylic monomer having active hydrogens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a coating agent comprising a polyfunctional (meth) acrylate monomer, if desired, a monofunctional (meth) acrylate monomer, and colloidal silica having a specific shape, and The present invention relates to a resin molded article having a coating layer obtained by curing the coating layer and having excellent abrasion resistance, weather resistance, adhesion to a substrate, and the like.

[0002]

2. Description of the Related Art Resin molded products made from polymethyl methacrylate, polycarbonate, polystyrene, AS resin, etc. are not only lighter and more excellent in impact resistance than glass products, but also have good transparency and molding process. Utilizing various advantages such as easiness, it is used in various fields.

[0003] On the other hand, however, these resin molded products are insufficient in abrasion resistance of the surface, so that the surface is easily damaged by contact, friction, scratching, etc. with other hard objects.
This damage can significantly reduce commercial value or render it unusable in a short period of time. Therefore, there is a strong demand for improving the wear resistance of the surface of these resin molded products.

As a method for improving this point, for example, Japanese Patent Application Laid-Open Nos. 53-102936 and 53-104638.
JP-A-5-97633 and JP-A-54-97633 apply a curing liquid composed of a compound having a plurality of (meth) acryloyloxy groups in a molecule to a molded article, and cure it by heat or active energy rays such as ultraviolet rays. A method for obtaining a molded article having excellent wear resistance is disclosed. This method has the advantage that the curing liquid is relatively inexpensive and the productivity is excellent. However, since the cured film is an organic substance, there is a limit to the wear resistance of the coated molded article.

On the other hand, as a method for imparting higher wear resistance to a molded article, for example, JP-A-48-26822 and JP-A-59-64671 disclose an alkoxysilane compound on the surface of a plastic molded article. A method of applying and curing by heat is disclosed. Also, for example,
JP-A-56-106969 discloses a method 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, in these methods, a solvent is used, so that a drying step is required, and since it is necessary to cure by heat, energy consumption is large and curing takes a long time, which is industrially disadvantageous. Further, volatilization of the solvent in the curing / drying step of the coating film is not preferable from the viewpoint of global environment protection, which has been particularly noted in recent years.

As a method for solving these problems, for example, JP-A-57-131214 and JP-A-3-56514 disclose a compound having a plurality of (meth) acryloyloxy groups in a molecule. There is disclosed a method of applying a curing liquid composed of colloidal silica to a molded article, curing the molded article with active energy rays such as ultraviolet rays, and obtaining a coated molded article having high abrasion resistance. However, this method has a problem in the weather resistance of the coated molded article, and it has not been possible to obtain a coated molded article excellent in a balance between abrasion resistance, weather resistance, and adhesion between the coating layer and the substrate.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a molded article having a coating layer having excellent appearance and hardness, and excellent balance of abrasion resistance, weather resistance, and adhesion to a substrate. An object of the present invention is to provide a colloidal silica-containing coating agent that can be formed on the surface and can be made solvent-free, and a resin molded article having a coating layer obtained by curing the coating agent.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that a very excellent effect can be obtained by using colloidal silica having a specific shape. The present invention has been completed.

That is, the coating agent of the present invention comprises a polyfunctional (meth) acrylate monomer (m-1) having at least two (meth) acryloyloxy groups in the molecule.
50 to 99 parts by weight of a monomer or monomer mixture (M) consisting of 50 to 100% by weight and 0 to 50% by weight of a monofunctional (meth) acrylate monomer (m-2) copolymerizable therewith And 1 to 50 parts by weight of colloidal silica, wherein the colloidal silica has an average thickness of 5 to 20 n.
m, a coating agent comprising colloidal silica in an elongated shape having an average length of 40 to 300 nm in an amount of 5 to 100% by weight based on the total weight of the colloidal silica.

[0010] The resin molded article of the present invention is a resin molded article having a coating layer obtained by curing the coating agent of the present invention.

In the present invention, "(meth) acryloyl" means "acryloyl and / or methacryloyl".

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

The polyfunctional (meth) acrylate monomer (m-1) used in the present invention is a monomer having at least two (meth) acryloyloxy groups in the molecule. The residue binding each (meth) acryloyloxy group in this molecule is not particularly limited, but is generally composed of a hydrocarbon or a derivative thereof. Also, within that residue,
It may contain a tell bond, thioether bond, ester bond, amide bond, urethane bond and the like.

The polyfunctional (meth) acrylate monomer (m-
As 1), for example, an ester obtained from a polyhydric alcohol and (meth) acrylic acid or a derivative thereof, or an esterified product obtained from a polyhydric alcohol, a polycarboxylic acid and (meth) acrylic acid or a derivative thereof And linear esterified products.

Specific examples of the ester obtained from a polyhydric alcohol and (meth) acrylic acid or a derivative thereof include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylate such as tetraethylene glycol di (meth) acrylate, 1,
4-butanediol di (meth) acrylate, 1,6-
Hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 3-acryloyloxy-2-hydroxypropyl (meth) acrylate, trimethylolpropanetri (meth) acrylate, trimethylolethanetri (meth) Acrylate,
Examples include pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and glycerin tri (meth) acrylate.

Further, as an ester obtained from a polyhydric alcohol and (meth) acrylic acid or a derivative thereof, the following general formula (III)

[0017]

Embedded image (Wherein, M represents at least three (meth) acryloyloxy groups and the remainder represents a hydroxyl group, and n represents a positive integer of 1 to 4).

Specific examples of the compound represented by the general formula (III) include dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, tripentaerythritol tetra (meth)
Examples include acrylate, tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, and tripentaerythritol hepta (meth) acrylate.

The linear esterified product obtained from a polyhydric alcohol, a polycarboxylic acid and (meth) acrylic acid or a derivative thereof is obtained by reacting a hydroxyl group of the polyhydric alcohol with a polycarboxylic acid and (meth) acrylic acid. It is obtained by reacting a mixture such that both carboxyl groups are finally equal in amount. Among the saturated or unsaturated polyester poly (meth) acrylates thus obtained, particularly preferred are, for example,
Malonic acid / trimethylolethane / (meth) acrylic acid, malonic acid / trimethylolpropane / (meth) acrylic acid, malonic acid / glycerin / (meth) acrylic acid,
Malonic acid / pentaerythritol / (meth) acrylic acid, succinic acid / trimethylolethane / (meth) acrylic acid, succinic acid / trimethylolpropane / (meth) acrylic acid, succinic acid / glycerin / (meth) acrylic acid, succinic Acid / pentaerythritol / (meth) acrylic acid, adipic acid / trimethylolethane / (meth) acrylic acid, adipic acid / trimethylolpropane / (meth) acrylic acid, adipic acid / glycerin / (meth) acrylic acid, adipic acid / Pentaerythritol / (meth) acrylic acid, glutaric acid / trimethylolethane /
(Meth) acrylic acid, glutaric acid / trimethylolpropane / (meth) acrylic acid, glutaric acid / glycerin /
(Meth) acrylic acid, glutaric acid / pentaerythritol / (meth) acrylic acid, sebacic acid / trimethylolethane / (meth) acrylic acid, sebacic acid / trimethylolpropane / (meth) acrylic acid, sebacic acid / glycerin / ( (Meth) acrylic acid, sebacic acid / pentaerythritol / (meth) acrylic acid, fumaric acid / trimethylolethane / (meth) acrylic acid, fumaric acid / trimethylolpropane / (meth) acrylic acid, fumaric acid / glycerin / (meth) ) Acrylic acid, fumaric acid / pentaerythritol / (meth) acrylic acid, itaconic acid / trimethylolethane / (meth) acrylic acid, itaconic acid / trimethylolpropane / (meth) acrylic acid, itaconic acid / glycerin / (meth) Acrylic acid, itaconic acid / pentaerythritol / (Meth) acrylic acid, maleic anhydride / trimethylolethane / (meth) acrylic acid, maleic anhydride / trimethylolpropane / (meth) acrylic acid, maleic anhydride / glycerin / (meth) acrylic acid, maleic anhydride / Pentaerythritol / (meth) acrylic acid and the like.

The polyfunctional (meth) acrylate monomer (m-
Other specific examples of 1) include trimethylolpropane toluylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate,
A diisocyanate compound such as 4,4′-methylenebis (cyclohexylisocyanate), isophorone diisocyanate, hexamethylene diisocyanate, or a compound represented by the following general formula (I) obtained by trimerization

[0021]

Embedded image (Wherein R ¹ each independently represents a hydrocarbon group having 1 to 12 carbon atoms) and a (meth) acrylic monomer having an active hydrogen [for example, 2-hydroxyethyl ( (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-methoxypropyl (meth) acrylate, 1,2,3-propanetriol-1,3-di (meth) acrylate, 3
-Acryloyloxy-2-hydroxypropyl methacrylate] and urethane (meth) acrylate obtained by a conventional method, or di (meth) acrylate or tri (meth) acrylate of tris (2-hydroxyethyl) isocyanuric acid Such as poly ((meta)
Examples thereof include (acryloyloxyethyl) isocyanurate, and various conventionally known epoxy poly (meth) acrylates and urethane poly (meth) acrylates.

The polyfunctional (meth) acrylate monomer (m-
The fact that 1) contains a urethane (meth) acrylate obtained by reacting the polyisocyanate represented by the general formula (I) with a (meth) acrylic monomer having an active hydrogen by a conventional method is resistant. It is preferable for obtaining a coated molded article excellent in balance between abrasion, weather resistance and adhesion between the coating layer and the substrate. Also, the following formula (II)

[0023]

Embedded image (Wherein A is the following formula (IIa)

[0024]

Embedded image Represents ) Is more preferably included.

In the present invention, the monofunctional (meth) acrylate monomer (m-2) optionally used is a (meth) acrylate copolymerizable with the polyfunctional (meth) acrylate monomer (m-1). It is a monomer having one acryloyloxy group. The residue bonded to the (meth) acryloyloxy group in this molecule is not particularly limited, but is generally composed of a hydrocarbon or a derivative thereof. In addition, an ether bond, a thioether bond, an ester bond,
An amide bond, a urethane bond and the like may be contained.

The monofunctional (meth) acrylate monomer (m-
Specific examples of 2) include methyl (meth) acrylate,
Ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, tridecyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxymethyl (Meth) acrylate, 2-hydroxyethyl (meth)
Acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate,
Glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethyl carbitol (meth) acrylate, 2-hydroxy-3
-Chloropropyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3
-Tetrafluoropropyl (meth) acrylate, 1
H, 1H, 5H-octafluoropentyl (meth) acrylate, phenyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyl (meth)
Acrylate, cyclohexyl (meth) acrylate and the like can be mentioned.

The monomer or monomer mixture (M) used in the present invention is a polyfunctional (meth) acrylate monomer (m-
1) Consist of 50 to 100% by weight and monofunctional (meth) acrylate monomer (m-2) 0 to 50% by weight. If the proportion of the monofunctional (meth) acrylate monomer (m-2) exceeds 50% by weight, sufficient hardness of the coating layer cannot be obtained.

The colloidal silica used in the present invention is a colloidal silica having a specific shape, that is, an average thickness of 5 to 20.
The colloidal silica having an elongated shape having an average length of 40 to 300 nm is at least 5% by weight based on the total weight of the colloidal silica. When the average thickness of the elongated colloidal silica is less than 5 nm, the hardness of the coating layer decreases. On the other hand, when the average thickness exceeds 20 nm, the appearance of the coating layer deteriorates. On the other hand, if the average length is less than 40 nm, it becomes impossible to obtain a coated molded article having an excellent balance between abrasion resistance, weather resistance and adhesion between the coating layer and the substrate. On the other hand, when the average length exceeds 300 nm, the appearance of the coating layer deteriorates.

The ratio of the length to the thickness of the elongated colloidal silica is preferably 3 or more, more preferably 5 or more. The elongated shape may be curved or branched.

The fine particle form of the colloidal silica can be observed by a transmission electron microscope after diluting the colloidal silica with a solvent, dropping it on a metal mesh provided with a collodion film, and drying. The average thickness and average length of colloidal silica were measured using an electron microscope at a magnification of about 200,000 times, and the thickness and length of 30 randomly selected colloidal silicas were measured. , Thickness, and length.

Among all the colloidal silicas, the proportion (content) of the elongated colloidal silica is as follows:
It is 5 to 100% by weight based on the total weight of colloidal silica. If this amount is less than 5% by weight, it becomes impossible to obtain a coated molded article having an excellent balance between abrasion resistance, weather resistance and adhesion between the coating layer and the substrate. The content of the elongated colloidal silica is preferably 50 to 100% by weight.

When the content of the elongated colloidal silica is less than 100% by weight, that is, when colloidal silica of another shape is used in combination, the shape and particle size of the colloidal silica are not particularly limited, and various colloidal silicas can be used. It may be used as desired.

The content of colloidal silica is 1 to 50 parts by weight based on 100 parts by weight of the coating agent. If the content is less than 1 part by weight, sufficient hardness of the coating layer cannot be obtained. On the other hand, if the content exceeds 50 parts by weight, the adhesion between the coating layer and the base material becomes poor, and when a solventless coating agent is used, the viscosity becomes very high, and good coatability is obtained. Can not be obtained.

The colloidal silica used in the present invention is an acrylic-functionalized colloidal silica whose surface is modified with a hydrolyzate of a silane compound copolymerizable with a monomer or a monomer mixture (M). Agent stability,
It is preferable in terms of the hardness of the coating layer and the like.

Examples of the silane compound copolymerizable with the monomer or monomer mixture (M) include, for example, γ- (meth) acryloyloxypropyl trialkoxysilane and the like represented by the following general formula (IV):

[0036]

Embedded image (In the formula, R ² is H or CH ₃ , R ³ and R ⁴ are each independently H or an alkyl group having 1 to 10 carbon atoms, R ⁵ is an alkylene group having 1 to 10 carbon atoms, s is 0 or 1 , T represents 1 or 2), a di (meth) acryloyloxydialkoxysilane, a primary or secondary amino group-containing silane or a mercapto group-containing silane and a polyfunctional (meth) acrylate monomer. Examples include a silane compound having a (meth) acryloyloxy group in a molecule obtained by the Michael addition reaction. Note that these silane compounds function as a polymerizable silane coupling agent, but when they are used, a non-polymerizable silane coupling agent can be used in combination.

A silane compound obtained by a Michael addition reaction of a primary or secondary amino group-containing silane with a polyfunctional (meth) acrylate monomer is, for example, represented by the following reaction formula (V)

[0038]

Embedded image (Wherein R ⁷ is H or CH ₃ , R ⁸ is an alkylene group, R ⁶
And R ⁹ are alkyl groups, R ¹⁰ and R ¹¹ are H or C
H ₃ and Y are a divalent or higher valent hydrocarbon group or a hydrocarbon group having a substituent, and may contain an ether bond, an ester bond, or a urethane bond. b represents an integer of 1 to 5, and z represents an integer of 0 to 2. ) Is a compound synthesized according to the reaction mechanism shown in).

A silane compound obtained by a Michael addition reaction of a mercapto group-containing silane with a polyfunctional (meth) acrylate is described, for example, by the following reaction formula (VI):

[0040]

Embedded image (Wherein, R ⁶ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and b are the same as those in the aforementioned reaction formula (V), and y represents an integer of 0 to 2). It is a compound synthesized according to the mechanism.

Specific examples of the primary or secondary amino group-containing silane used in the Michael addition reaction to obtain the silane compound include N- (2-aminoethyl-3-aminopropyl) trimethoxysilane and 3-aminopropyl Triethoxysilane, 3-aminopropyltrimethoxysilane and the like.

Specific examples of the mercapto group-containing silane used in the Michael addition reaction to obtain the silane compound include γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltrimethoxysilane.
Mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-mercaptopropylethyldiethoxysilane, γ-mercaptopropylbutyldimethoxysilane, δ- Mercaptobutyltrimethoxysilane, δ-mercaptobutylmethyldimethoxysilane, δ-mercaptobutylethyldimethoxysilane, δ
-Mercaptobutylmethyldiethoxysilane, δ-mercaptobutylethyldiethoxysilane, γ-mercaptoisobutyltrimethoxysilane, γ-mercaptoisobutylmethyldimethoxysilane, γ-mercaptobutyltrimethoxysilane, γ-mercaptobutylmethyldimethoxysilane, γ -Mercapto-2-hydroxypropyltrimethoxysilane, γ-mercapto-2-hydroxypropyltriethoxysilane, γ-mercapto-2-hydroxypropylmethyldimethoxysilane, γ-mercapto-2-hydroxypropylethyldiethoxysilane, γ- Mercaptopropyldimethylmethoxysilane,
γ-mercaptopropyldiethylethoxysilane, β-
Mercaptoethyltrimethoxysilane, β-mercaptoethyltriethoxysilane, γ-mercaptopropyltriaminosilane and the like.

Specific examples of the polyfunctional (meth) acrylate monomer used in the Michael addition reaction to obtain the silane compound include polyfunctional (meth) acrylate monomers (m-
The various monomers mentioned above as specific examples of 1) can be similarly mentioned.

By using these silane compounds, it is possible to obtain an acrylic-functionalized colloidal silica whose surface is modified with its hydrolyzate. Here, "the surface is modified with the hydrolyzate" means that the hydrolyzate of the silane compound is held by a condensation reaction on a part or all of the surface of the colloidal silica, and the surface characteristics are thereby reduced. It means that it has been modified. Further, the compound in a state where the condensation reaction of the hydrolyzate of the silane compound has advanced,
Also included is retained colloidal silica.

This surface modification can be easily performed by hydrolyzing the silane compound in the presence of colloidal silica, or by causing a hydrolysis and condensation reaction.

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

A solvent can be used in the hydrolysis reaction system of the silane compound in order to carry out the reaction mildly and uniformly. The solvent is desirably a solvent that can dissolve the reactant silane alkoxide, water, and a catalyst. Specific examples of the solvent include water, alcohols such as methanol, ethanol, and isopropyl alcohol; ketones such as acetone and methyl isobutyl ketone; ethers such as tetrahydrofuran and dioxane; The amount of the solvent used is not particularly limited as long as the reactants can be uniformly dissolved. However, it is preferable to suppress the reaction amount to an appropriate amount so that the reaction rate does not significantly decrease.

The hydrolysis and condensation reaction of the silane compound is preferably performed at a temperature of about room temperature to about 120 ° C. for about 30 minutes to about 24 hours, more preferably at a temperature of about room temperature to about the boiling point of the solvent.
Perform for about 10 to 10 hours.

When acrylic-functionalized colloidal silica having a modified surface is obtained by hydrolysis of the silane compound, the amount of the silane compound used is 0.1 to 500 parts by weight with respect to 100 parts by weight of the colloidal silica (solid content). And more preferably 0.5 to 200 parts by weight.

Various additives such as an ultraviolet absorber, a light stabilizer, a surface smoothing agent, a surfactant, a heat stabilizer, and a storage stabilizer can be added to the coating agent of the present invention, if necessary. In particular, when weather resistance is required for a resin molded product obtained by applying and curing the coating agent of the present invention, it is preferable to add an ultraviolet absorber and / or a light stabilizer to the coating agent.

Examples of the UV absorber include benzotriazole, benzophenone, benzoate and cyanoacrylate UV absorbers. Specific examples thereof include 2- (2′-hydroxy-5′-tert-
Butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-
Butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-tert-
Butylphenyl) -5-chlorobenzotriazole, 2
-(2'-hydroxy-5'-methylphenyl) benzotriazole, 2,2-methylenebis [4- (1,1,3,3
-Tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone , 2-hydroxy-
4-n-octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4- Dodecyloxybenzophenone, phenyl salicylate, p-tert-butylphenyl salicylate, 3
-Hydroxyphenylbenzoate, phenylene-1,
3-benzoate, 2-ethylhexyl-2-cyano-
3,3′-diphenyl acrylate and ethyl-2-cyano-3,3′-diphenyl acrylate. The amount of the ultraviolet absorber added is preferably 10 parts by weight or less based on 100 parts by weight of the coating agent from the viewpoint of the hardness of the coating layer and the like.

Specific examples of the light stabilizer include tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl)
1,2,3,4-butanetetracarboxylate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl)
1,2,3,4-butanetetracarboxylate, 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine, 1- [2- [3- (3,5-di-t-butyl) -4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6
-Tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis (1,2,2,6 , 6-Pentamethyl-4-piperidyl)
Sebacate and dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate polycondensate. The addition amount of the light stabilizer is preferably 3 parts by weight or less based on 100 parts by weight of the coating agent from the viewpoint of the hardness of the coating layer and the like.

The method for applying the coating agent of the present invention to the surface of a substrate includes spray coating, bar coating, roller coating, casting, dipping, air knife coating, flow coating, and brush coating. And the like.

Further, a coating agent is applied to a glass plate or a stainless steel plate and cured, and then a mold is formed by using the glass plate or the stainless steel plate. It is also possible to obtain a resin molded product having the same.

Further, a resin molding having a coating layer can be obtained by applying a coating agent inside the mold and curing the resin, and then injecting the molten resin into the mold and cooling it.

Although the coating agent of the present invention can be used without containing an organic solvent, it is preferable to use an organic solvent after adjusting the viscosity if necessary according to the coating method.

The organic solvent can be uniformly mixed with the polyfunctional (meth) acrylate monomer (m-1), the monofunctional (meth) acrylate monomer (m-2), and the polymerization initiator. Further, a solvent capable of uniformly dispersing the coating agent itself can be suitably used. The boiling point at normal pressure is 50 ° C.
Not less than 200 ° C. and a viscosity at room temperature (25 ° C.) of 1
Organic solvents of 0 mPa · s or less are preferred.

Specific examples of the organic solvent include methanol,
Alcohols such as ethanol, isopropyl alcohol, normal propyl alcohol, normal butyl alcohol and isobutyl alcohol; aromatic hydrocarbons such as benzene, toluene and xylene; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; dioxane and ethylene glycol mono Ethers such as ethyl ether and ethylene glycol monobutyl ether; esters such as methyl acetate, ethyl acetate and butyl acetate;
N-dimethylformamide; and the like. These organic solvents can be used alone or as a mixture of two or more.

The temperature of the substrate surface when applying the coating agent to the substrate surface is preferably in the range of 20 to 120 ° C.
When this temperature is 20 ° C. or higher, the adhesion between the coating layer and the substrate surface tends to be improved. On the other hand, if this temperature is 120
When the temperature is lower than or equal to ° C., the appearance of the coating layer tends to be improved.

The thickness of the coating layer is preferably from 0.5 to 20 μm. When this thickness is 0.5 μm or more,
The wear resistance of the coating layer tends to be improved. On the other hand, when the thickness is 20 μm or less, flexibility is improved, and cracks due to deformation tend to hardly occur.

As the resin molded article serving as the base material, for example,
Examples of the molded article include polymethyl methacrylate, a copolymer containing methyl methacrylate as a main component, polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, polycarbonate, polyvinyl chloride resin, and polyester resin.

The method for curing the coating agent of the present invention includes thermal curing, ultraviolet curing, and electron beam curing.

When curing is carried out by heat curing or ultraviolet curing, a polymerization initiator may be added to the coating agent. Specific examples of the polymerization initiator used for heat curing include lauroyl peroxide, benzoyl peroxide, propionoyl peroxide, tertiary butyl peroxylaurate, dicumyl peroxide, ditertiary butyl peroxide, cumene hydroperoxide. Peroxide initiators such as 2,2′-azobisisobutyronitrile, 1,1′-azobis-1-cyclopentanonitrile, dimethyl-2,2′-azobisisobutyrate,
1'-azobiscyclohexanecarbonitrile, 4,4 '
Azo-based initiators such as -azobis-4-cyanovaleic acid, 2,2'-azobis-2-benzylpropionitrile; and the like.

Specific examples of the polymerization initiator used for ultraviolet curing include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, butyroin, toluoin, benzyl, benzophenone, and p-methoxybenzophenone. 2,2-diethoxyacetophenone, α, α-dimethoxy-α-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylamino) benzophenone, 2-hydroxy-2- Methyl-1-phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoyldiethoxyphosphine oxide, thioxanthone, 2-chlorothioxa Tons, 2,4-dichloro thioxanthone, 2-methyl thioxanthone, 2,4-dimethyl thioxanthone, 2-isopropyl thioxanthone, 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, and the like.

These polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator added is based on 100 parts by weight of the coating agent.
0.01 to 10 parts by weight is preferred.

[0066]

The present invention will be described below in detail with reference to examples. In the following description, “parts” means “parts by weight” unless otherwise specified.
Is shown. Measurement and evaluation of various physical properties in the examples were performed by the following methods.

1) Adhesion to substrate The sample coating layer was cut 11 times at intervals of 1 mm into the coating layer of the sample at intervals of 1 mm to form 100 grids, and the cellophane tape was adhered well. The number N of squares when the coating layer remained without being peeled off when it was suddenly peeled in the direction of 45 ° was determined and expressed as N / 100.

2) Appearance The haze value (%) of the sample was measured with a haze meter.

3) Abrasion resistance According to the Taber abrasion test method, CALIBR manufactured by Taber Co., Ltd.
Using an ASE CS-10F wear wheel, a wear test was performed on the coating layer of the sample at 500 rotations under a load of 500 g per wheel, and the haze value of the worn portion was measured with a haze meter. The haze was measured at four points on the track of the wear cycle, and the average value was calculated. The Taber abrasion (%) was expressed by (haze after Taber test)-(haze before Taber test). Was.

4) Weather resistance Sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.)
Exposure to the coating layer of the sample was carried out at 63 ° C. and in the presence of rain, and the appearance of the sample after exposure for 1000, 2000 and 2500 hours was visually observed. , And those that did not occur were evaluated as ○.

Example 1 170 parts of isopropanol,
1,6-hexanediol diacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd .; hereinafter, abbreviated as “C6DA”) 155
Parts, 50 parts of γ-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., trade name KBM-803),
A mixture of 0.9 parts of triphenylphosphine (hereinafter abbreviated as “TPP”) was stirred at room temperature for 72 hours. Then, elongated colloidal silica dispersed in isopropanol (solid content 15% by weight, average thickness 10n)
m, average length 200 nm) While stirring 145 parts, 36 parts of the above mixture and 0.01 N hydrochloric acid aqueous solution were added thereto.
6 parts were added, and the mixture was further stirred at 80 ° C. for 4 hours. Thereafter, 103 parts of C6DA was added, the mixture was stirred uniformly, and volatile components were removed by degassing under reduced pressure to obtain a filler dispersion liquid (A).

Next, this filler dispersion (A) 100
Parts, 2.8 parts of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF, trade name Lucirin TPO; hereinafter abbreviated as "TPO") as a photopolymerization initiator and benzophenone (Wako Pure Chemical Industries, Ltd.) 1 part; 2- (2'-hydroxy-5'-tert-butylphenyl) benzotriazole (Ciba Geigy, trade name Tinuvin PS) 6 parts as an ultraviolet absorber;
In addition, 1 part of bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (manufactured by Sankyo Co., Ltd., trade name: SANOL LS770) is added as a light stabilizer, and the coating agent (B) is dissolved by stirring. Prepared.

Next, the coating agent (B) was prepared by setting the surface temperature to 30 ° C., 40 ° C., and 50 ° C. for a length of 300 m.
m, 300 mm in width and 2 mm in thickness were applied to a polycarbonate plate (manufactured by Mitsubishi Rayon Co., Ltd., trade name: Dialite P). Then, a 50 μm-thick biaxially stretched polyethylene terephthalate film (hereinafter abbreviated as “PET film”) was placed thereon, and the thickness of the coating layer was set to 8 μm using a rubber roll. Then, with the PET film as the upper surface, a position 150 mm away from a metal halide lamp having an output of 120 W / cm ² was set at 3.0 m / mi.
The composition was passed at a speed of n to cure the first stage. Next, the PET film was peeled off, with the coated surface facing upward, under a high-pressure mercury lamp with an output of 120 W / cm ² and a distance of 150 mm.
At a speed of 3.0 m / min to form a coating layer. Table 1 shows the evaluation results of the obtained plates.

[Embodiment 2] In the embodiment 1, the C6DA
Instead of adding 103 parts, a polyester acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., hereinafter abbreviated as "TAS") obtained by a condensation reaction of trimethylolethane / succinic acid / acrylic acid (molar ratio 2: 1: 4). A coating layer was formed on a plate in the same manner as in Example 1 except that 43 parts) and 60 parts of C6DA were added, and the results shown in Table 1 were obtained.

[Embodiment 3] In the embodiment 1, the C6DA
Instead of adding 103 parts, 65 parts of TAS, and C6
A filler dispersion (C) was obtained in the same manner as in Example 1 except that 38 parts of DA was added.

Next, the filler dispersion (C) 100
Parts, 30 parts of isopropanol, 30 parts of toluene,
2.8 parts of TPO, 1 part of benzophenone, 6 parts of 2- (2'-hydroxy-5'-tert-butylphenyl) benzotriazole, and bis (2,2,6,6-tetramethyl-
One part of 4-piperidyl) sebacate was added and dissolved by stirring to prepare a coating agent (D).

Next, the coating agent (D) was applied to a column with a surface temperature of 45 ° C. by a flow coating method.
It was applied to a polycarbonate plate having a thickness of 00 mm, a width of 300 mm, and a thickness of 2 mm so that the thickness of the coating layer was 8 μm, and was left at room temperature for 5 minutes. Then, with the coating surface as the upper surface, under a metal halide lamp with an output of 120 w / cm ² ,
After passing through a position of 50 mm at a speed of 3.0 m / min, first-stage curing was performed. Then, with the coated surface facing upward, under a high pressure mercury lamp with an output of 120 w / cm ² , distance
It passed through the 0 mm position at a speed of 3.0 m / min to form a coating layer, and the results shown in Table 1 were obtained.

Example 4 170 parts of isopropanol,
A mixture of 155 parts of C6DA, 50 parts of γ-mercaptopropyltrimethoxysilane, and 0.9 parts of TPP was stirred at room temperature for 72 hours. Then, isopropanol-dispersed spherical colloidal silica (Nissan Chemical Industries, Ltd.)
(Ag., IPA-ST, solid content 30% by weight), 100 parts of the above mixture was stirred, and 80 parts of the above mixture and 3.6 parts of 0.01N hydrochloric acid were added thereto. Stirred for hours. Thereafter, 130 parts of C6DA was added, the mixture was stirred uniformly, and volatile components were removed by degassing under reduced pressure to obtain a filler dispersion (E).

Next, 50 parts of this filler dispersion (E) and 50 parts of the filler dispersion (A) prepared in the same manner as in Example 1 were mixed to obtain a filler dispersion (F). Thereafter, a coating agent was prepared in the same manner as in Example 1, and a coating layer was formed on the plate. The results shown in Table 1 were obtained.

[Example 5] In Example 1, the C6DA
Instead of adding 103 parts, 23 parts of TAS and tetrahydrofurfuryl acrylate [Osaka Organic Chemical Industry Co., Ltd.
20 parts and 60 parts of C6DA were added.
A coating layer was formed on a plate in the same manner as in Example 1, and the results shown in Table 1 were obtained.

[Embodiment 6] In the embodiment 1, the C6DA
Instead of adding 103 parts, 39 parts of a urethane acrylate represented by the above formula (II) (manufactured by Shin-Nakamura Chemical Co., Ltd .; hereinafter abbreviated as “U-6HA”) and C6DA64
A filler dispersion liquid (G) was obtained in the same manner as in Example 1 except that parts were added.

Next, this filler dispersion (G) 100
To this part, 2.8 parts of TPO and 6 parts of Tinuvin PS were added, and the mixture was stirred and dissolved to prepare a coating agent (H). Thereafter, a coating layer was formed on a plate using this coating agent (H) in the same manner as in Example 1, and the results shown in Table 1 were obtained.

[Embodiment 7] In Embodiment 6, U-6H
Instead of adding A39 parts and C6DA64 parts, U-
A coating layer was formed on a plate in the same manner as in Example 6 except that 29 parts of 6HA, 29 parts of TAS and 45 parts of C6DA were added, and the results shown in Table 1 were obtained.

Example 8 While stirring 145 parts of elongated colloidal silica (solid content: 15% by weight, average thickness: 10 nm, average length: 200 nm) dispersed in isopropanol, γ-methacryloyloxypropyltrimethoxy was added thereto while stirring. Silane (brand name KBM, manufactured by Shin-Etsu Chemical Co., Ltd.)
-503) 4 parts and 1.6 parts of a 0.01 N hydrochloric acid solution were added, and the mixture was stirred at 80 ° C for 4 hours. Then C6DA62
, 30 parts of U-6HA and 30 parts of TAS were added, uniformly stirred, and volatile components were removed by degassing under reduced pressure to obtain a filler dispersion liquid (I).

Next, this filler dispersion (I) 100
To this part, 2.8 parts of TPO and 6 parts of Tinuvin PS were added and dissolved by stirring to prepare a coating agent (J). Thereafter, a coating layer was formed on a plate using this coating agent (J) in the same manner as in Example 1, and the results shown in Table 1 were obtained.

Example 9 A coating agent (K) was obtained in the same manner as in Example 6, except that the amount of Tinuvin PS was changed to 0.5 part.

Next, the coating agent (K) was placed at a height of 300 mm and a width of 300 m at a surface temperature of 50 ° C.
m, 2mm thick acrylic resin plate (Mitsubishi Rayon Co., Ltd.)
Co., Ltd., trade name Acrylite E). Thereafter, in the same manner as in Example 1, a covering layer was formed on the plate by covering the PET film, and the results shown in Table 1 were obtained.

Example 10 Coating Agent (K) 10
0 parts, 45 parts of isopropanol and 1 part of toluene
5 parts were added and dissolved by stirring to prepare a coating agent (L). Hereinafter, in Example 3, except that an acrylic resin plate was used instead of the polycarbonate plate and that the thickness of the coating layer was 12 μm, a coating layer was formed on the plate in accordance with the flow coating method in the same manner as in Example 3. Table 1
Were obtained.

Example 11 100 parts of methyl methacrylate was supplied to a reactor equipped with a cooling pipe, a thermometer, and a stirrer, and heated while stirring to bring the internal temperature to 80 ° C. 0.05 parts of 2'-azobis- (2,4-dimethylvaleronitrile) was added, the mixture was further heated until the internal temperature reached 90 ° C., and the temperature was maintained for 8 minutes. About 22%, viscosity at 20 ° C 1.5 Pa · s
Of methyl methacrylate syrup was prepared.

Further, separately from this, in the first embodiment,
A filler dispersion (M) was obtained in the same manner as in Example 1 except that 39 parts of U-6HA and 45 parts of C6DA were added instead of adding 103 parts of C6DA.

Next, this filler dispersion (M) 100
To this part, 1.5 parts of benzoin ethyl ether (manufactured by BASF) as a photopolymerization initiator and 0.5 part of tinuvin PS as an ultraviolet absorber were added and dissolved by stirring to prepare a coating agent (N).

This coating agent (N) was 610 m long.
m, 460 mm in width and 2 mm in thickness. Next, a PET film was covered thereon, and the thickness of the coating layer was set to 20 μm using a rubber roll. Then, the PET film was passed through a position at a distance of 60 mm at a speed of 0.3 m / min under a chemical lamp (FL-40BL manufactured by Toshiba) with the PET film as the upper surface, and the first-stage curing was performed. Next, the PET film was peeled off, and the coated surface was placed under a high-pressure mercury lamp (H4000L manufactured by Toshiba).
A coating layer was formed by passing through a position at a distance of 60 mm at a speed of 0.3 m / min.

The two SUS plates thus treated are opposed to each other at a distance of 3 mm so that the coating layer is on the inside, and between them, 100 parts of the previously prepared methyl methacrylate syrup is further added with 2,2′-methyl methacrylate. A solution to which 0.05 parts of azobis- (2,4-dimethylvaleronitrile) had been added was injected, the periphery thereof was sealed with a soft vinyl chloride gasket, and the mixture was heated and polymerized at 80 ° C. for 1 hour and then at 130 ° C. for 1 hour. After cooling,
Peeling the resin plate from the SUS plate, 2m thick with a coating layer
m, and the results shown in Table 1 were obtained.

Comparative Example 1 An untreated polycarbonate plate which was the same as the polycarbonate plate used in Examples 1 to 8 and was not coated with a coating agent was similarly evaluated. Table 1 shows the results.

Comparative Example 2 Instead of using 100 parts of the filler dispersion (A) in Example 1, only 100 parts of the spherical colloidal silica filler dispersion (E) prepared in the same manner as in Example 4 was used. A coating layer was formed on a plate in the same manner as in Example 1 except that the results were as shown in Table 1.

Comparative Example 3 170 parts of isopropanol
A mixture of 155 parts of C6DA, 50 parts of γ-mercaptopropyltrimethoxysilane, and 0.9 parts of TPP was stirred at room temperature for 72 hours. Then, isopropanol-dispersed spherical colloidal silica (Nissan Chemical Industries, Ltd.)
(Ag., IPA-ST, solid content 30% by weight), 100 parts of the above mixture was stirred, and 80 parts of the above mixture and 3.6 parts of 0.01N hydrochloric acid were added thereto. Stirred for hours. After that, 76 parts of C6DA and TA
S54 parts were added, the mixture was stirred uniformly, and volatile components were removed by degassing under reduced pressure to obtain a filler dispersion liquid (O). Thereafter, a coating agent was prepared in the same manner as in Example 1, and a coating layer was formed on the plate. The results shown in Table 1 were obtained.

[0097]

[Table 1]

[0098]

As described above, according to the coating agent of the present invention, it has excellent appearance, hardness, abrasion resistance,
A coating layer having an excellent balance between weather resistance and adhesion to a substrate can be formed on the surface of a molded article, and can be made solvent-free.

The resin molded article of the present invention having a coating layer obtained by applying and curing the coating agent has excellent appearance, hardness, abrasion resistance, weather resistance, and the coating layer and substrate. Excellent balance with adhesion. Therefore,
It is very useful for applications requiring such performance, for example, window glass, signboards, lighting fixture covers, optical parts, automobile-related parts, and the like.

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Claims (7)

[Claims] 1. A polyfunctional (meth) acrylate monomer (m-1) having at least two (meth) acryloyloxy groups in a molecule of 50 to 100% by weight and a monofunctional (meth) copolymerizable therewith. ) Acrylate monomer (m-2) 0
50 to 99 parts by weight of a monomer or a monomer mixture (M) consisting of
The colloidal silica has an average thickness of 5 to 20 nm, an average length of 40 to 300 nm, and an elongated colloidal silica of 5 to 100% by weight based on the total weight of the colloidal silica. Characteristic coating agent. 2. A polyfunctional (meth) acrylate monomer (m
-1) is represented by the following general formula (I): Wherein R ¹ independently represents a hydrocarbon group having 1 to 12 carbon atoms, and a (meth) acrylic monomer having active hydrogen. The coating agent according to claim 1, which comprises at least urethane (meth) acrylate. 3. A polyfunctional (meth) acrylate monomer (m
-1) is represented by the following general formula (II): (Wherein A is the following formula (IIa): Represents-. The coating agent according to claim 1, which comprises at least a urethane (meth) acrylate represented by the formula: 4. The coating agent according to claim 1, wherein the ratio of the length to the thickness of the elongated colloidal silica is 3 or more. 5. The colloidal silica according to claim 1, wherein the colloidal silica is an acrylic-functionalized colloidal silica whose surface is modified with a hydrolyzate of a silane compound copolymerizable with the monomer or monomer mixture (M). The coating agent according to any one of the preceding claims. 6. The coating agent according to claim 1, further comprising an organic solvent. 7. A resin molded article having a coating layer obtained by curing the coating agent according to any one of claims 1 to 6.