JP3025587B2 - Coating composition and surface-coated molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition capable of forming a coating film having excellent abrasion resistance and solvent resistance by irradiating ultraviolet rays or the like, and a cured film of the coating composition. The present invention relates to a surface-coated molded product such as a coated synthetic resin molded product.

[0002]

2. Description of the Related Art In recent years, a transparent plastic material having high crush resistance has been widely used as an alternative to a transparent glass sheet. However, transparent plastic materials have the serious drawback that they have a soft surface compared to glass, so they are easily worn and susceptible to scratching.

Therefore, many attempts have been made to improve the wear resistance of plastic materials. One of the most common of these methods is described in, for example, JP-A-53-1.
No. 02936, No. 53-104638, No. 54-97
No. 633, etc., a compound having a plurality of acryloyloxy groups or methacryloyloxy groups in a molecule is applied to the surface of a synthetic resin molded product, and cured with an active energy ray such as heat or ultraviolet rays to obtain a resist. There is a method of obtaining a surface-coated molded article having excellent scratch resistance. This conventional method,
The curing liquid is also relatively inexpensive and has excellent productivity. But,
Since this coating film is an organic material, there is a limit in abrasion resistance at present.

On the other hand, in order to impart a higher surface hardness to a molded product, for example, JP-A-48-26822 and JP-A-59-64
There is a method of applying an alkoxysilane compound to the surface of a plastic molded article and curing it by heat, as described in JP-A-6771. Further, for example, Japanese Patent Application Laid-Open No. Sho 56-10696
9, a method of applying a mixture of colloidal silica and an organic resin to the surface of a plastic molded product and curing the mixture with heat as described in JP-A-2-272204 or the like.
However, these methods require a drying step because a solvent is used. In particular, this solvent drying step has a problem in terms of global environmental protection, which has been receiving attention in recent years. Further, the appearance of the coated molded article is liable to cause a problem, and it needs to be cured by heat, so that the energy consumption is large and the curing takes a long time, which is industrially disadvantageous.

[0005] Japanese Patent Publication No. 1-55307 and Japanese Patent Publication No. 3
No. 2168, Japanese Patent Publication No. 3-6190, JP-A-59-2
04669, JP-A-62-256874, JP-A-2
-28267, JP-A-2-64138, JP-A-4-
No. 18423, JP-B No. 62-21815 and the like describe a coating composition comprising colloidal silica, an alkoxysilane having an acryl group or a methacryl group, and a polyfunctional acrylate. These compositions can be used in the absence of a solvent, if necessary, and can impart considerably excellent surface hardness to the resin molded product.
However, due to the hydrophilic properties derived from the structure of the acryl group and methacryl group in the alkoxysilane compound, hydrolysis easily occurs at the interface between the colloidal silica and the alkoxysilane in this film, and the weather resistance and water resistance of the film are poor. There was a problem of being damaged.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art. That is, an object of the present invention is to provide a coating composition which can be applied without using a solvent, and which has excellent abrasion resistance, scratch resistance, weather resistance and water resistance by curing, and has a high surface hardness and a good appearance. An object of the present invention is to provide a coating composition capable of forming a coating film, and a molded product whose surface is coated with a cured product of the coating composition.

[0007]

The present invention relates to (a) a cross-linkable polymerizable compound (a) having at least two acryloyloxy groups and / or methacryloyloxy groups in a molecule;
-1) or a mixture comprising at least 50% by weight of the crosslinkable polymerizable compound (a-1) and a compound (a-2) copolymerizable therewith,
(B) General formula (I):

[0008]

Embedded image (Wherein, R ¹ is a hydrogen atom or a methyl group, R ² is an alkyl group or a phenyl group having 1 to ³ carbon atoms, R ³ is a hydrogen atom or a hydrocarbon residue having 1 to 10 carbon atoms, and n is 0 to 2 A silica particle whose surface is modified with a hydrolyzate of a silane compound represented by the following formula: and (c) a photopolymerization initiator.

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

[0010]

In the coating composition of the present invention, the surface of the silica particles (b) is modified with the hydrolyzate of the silane compound represented by the general formula (I), so that the component (a)
Silica particles (b) can be dispersed therein at a high concentration,
The above object such as improvement of abrasion resistance can be achieved. Furthermore, the silane compound represented by the general formula (I) also has an excellent action due to the following groups.

[0011]

Embedded image (In the formula, R ¹ represents a hydrogen atom or a methyl group.) That is, since the above group copolymerizes well with the component (a), the polymer of the component (a) is strongly bonded to the silica particle surface, The cured film will exhibit high surface hardness. What is more remarkable is that the above group exhibits good hydrophobicity and therefore has excellent hydrolysis resistance, which is a problem when a silane compound having an acrylic group or the like is used in a coating composition in the prior art. Thus, the weather resistance and the water resistance of the coated film can be improved.

Hereinafter, the present invention will be described in detail.

Component (a) in the coating composition of the present invention
Are cross-linked polymerizable compounds having at least two acryloyloxy groups and / or methacryloyloxy groups (hereinafter abbreviated as (meth) acryloyloxy groups) in the molecule.
(a-1). This component (a) is composed of at least 50% by weight of a crosslinkable polymerizable compound (a-1) and a compound (a) copolymerizable therewith.
-2).

A crosslinked polymerizable compound having at least two (meth) acryloyloxy groups in the molecule (a-1)
Is a group in which the residue other than (meth) acryloyloxy is a hydrocarbon or a derivative thereof, and the molecule may contain an ether bond, a thioether bond, an ester bond, an amide bond, a urethane bond, or the like.

As the crosslinkable polymerizable compound (a-1), for example, an ester compound obtained from a polyhydric alcohol and (meth) acrylic acid or a derivative thereof, or a polyhydric alcohol and a polycarboxylic acid and (meth) An ester compound obtained from acrylic acid or a derivative thereof is exemplified. As the polyhydric alcohol, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, having an average molecular weight of about 3
00 to about 1000 polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol (that is, 2,2-dimethyl-1,3-propanediol), 2-ethylhexyl-1,3-hexanediol, 2,2′-thiodiethanol, 1,4-cyclohexane Dihydric alcohols such as dimethanol; trimethylolpropane (ie, 1,1,1-trimethylolpropane), pentaglycerol (ie, 1,1,1-trimethylolethane), glycerol, 1,2,4-butanetriol Trihydric alcohols such as 1,2,6-hexanetriol; Other examples include pentaerythritol (that is, 2,2-bis (hydroxymethyl) -1,3-propanediol), diglycerol, dipentaerythritol, and the like.

As an example of the crosslinkable polymerizable compound (a-1) obtained as a poly (meth) acrylate of a polyhydric alcohol, the following general formula (II):

[0017]

Embedded image (In the formula, n represents an integer of 0 to 4, and four or more Xs in the molecule, two or more of which represent a (meth) acryloyloxy group, and the rest each independently represent a hydrogen atom or a hydroxyl group. , An amino group, an alkyl group or a substituted alkyl group.).

The compound represented by the general formula (II) is
Specifically, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaglycerol tri (meth) acrylate,
Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate Acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, and tripentaerythritol hepta (meth) acrylate.

The crosslinkable polymerizable compound (a-1) is a polyhydric alcohol poly (meth) other than the compound of the above general formula (II).
Acrylates, such as diethylene glycol di (meth)
Acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin tri (meth) acrylate And so on.

When an ester compound obtained from a polyhydric alcohol and (meth) acrylic acid is used as the crosslinkable polymerizable compound (a-1), particularly preferred ester compounds are diethylene glycol di (meth) acrylate and triethylene glycol di ( (Meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaglycerol triacrylate And dipentaglycerol pentaacrylate.

The ester compound obtained from a polyhydric alcohol, a polycarboxylic acid and (meth) acrylic acid or a derivative thereof which can be used as the crosslinkable polymerizable compound (a-1) is basically a polyhydric alcohol. By reacting a mixture such that the hydroxyl groups of the above and the carboxyl groups of both the polyvalent carboxylic acid and the (meth) acrylic acid are finally equivalent. Among these ester compounds, preferred are polyhydric alcohols such as dihydric alcohols, trihydric alcohols, and mixtures of dihydric alcohols and trihydric alcohols. And esterified products obtained using the above. When a mixture of a trihydric alcohol and a dihydric alcohol is used, the molar ratio between the trihydric alcohol and the dihydric alcohol may be arbitrarily selected. The molar ratio of the dicarboxylic acid and the (meth) acrylic acid when used together is such that the carboxyl group of the dicarboxylic acid is 2 mol or less per 1 mol of the carboxyl group of (meth) acrylic acid. Is preferred. If the divalent carboxylic acid is in excess of the above range, the viscosity of the resulting ester may be too high, which may cause difficulty in forming a coating film.

Examples of the divalent carboxylic acid or its derivative used in the synthesis of the above-mentioned ester compound include aliphatic dicarboxylic acids such as succinic acid, adipic acid and sebacic acid; tetrahydrophthalic acid, 3,6-endomethylenetetrahydrophthalic acid Alicyclic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, etc .; thiodiglycolic acid, thiodivalic acid, diglycolic acid, maleic acid, fumaric acid, itaconic acid, and their chlorides Products, anhydrides and esters.

Specific examples of the above ester compounds used as the crosslinkable polymerizable compound (a-1) include malonic acid / trimethylolethane / (meth) acrylic acid, malonic acid / trimethylolpropane / (meth) acrylic acid, malonic acid, 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 /
Pentaerythritol / (meth) acrylic acid, adipic acid / glycerin / (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 / pentane Risuritoru / (meth) acrylic acid, itaconic acid / trimethylolethane / (meth) acrylic acid, itaconic acid / trimethylolpropane / (meth) acrylic acid, itaconic acid / pentaerythritol /
Saturated or unsaturated polyester polyacrylate or polymethacrylate by a combination of compounds such as (meth) acrylic acid, maleic anhydride / trimethylolethane / (meth) acrylic acid, maleic anhydride / glycerin / (meth) acrylic acid, etc. .

Further, as the crosslinkable polymerizable compound (a-1), for example,
If toluylene triisocyanate, the following general formula (III)

[0025]

Embedded image (In the formula, R ⁴ represents an alkylene group.)
Compound, hexamethylene diisocyanate, tolylene diisocyanate, diphenylethane diisocyanate, xylene diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), isophorone diisocyanate or trimethylhexamethylene diisocyanate
And polyisocyanates such as bets, the acrylic monomer having an active hydrogen, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxy-3-methoxypropyl (meth) acrylate, N- methylol (meth) acrylamide, N -Hydroxy (meth) acrylamide
And urethane (meth) acrylate obtained by reacting 1 mol or more of an acrylic monomer per 1 mol of isocyanate groups by a conventional method; and poly (tri (meth) acrylate) such as tris (2-hydroxyethyl) isocyanuric acid. [(Meth) acryloyloxyethyl] isocyanurate.

Component (a) in the coating composition of the present invention
May be a mixture of 50% by weight or more of the crosslinkable polymerizable compound (a-1) and the compound (a-2) copolymerizable therewith as described above. As the copolymerizable compound (a-2), for example, a compound having one (meth) acryloyloxy group in the molecule is used. Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) Acrylate, tridecyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) Acrylate, 1,4-butylene glycol mono (meth) acrylate, ethoxyethyl (meth) acrylate, ethyl carbitol (meth) acrylate, 2-hydroxy-3-chloropropyl (meth) Acrylate, (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxypropyl (meth) acrylamide, 2,2,2-trifluoroethyl (meth) acrylate, 2, 2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H,
5H-octafluoropentyl (meth) acrylate,
N-hydroxybutyl (meth) acrylamide, hydroxymethyl diacetone (meth) acrylamide, N-hydroxyethyl-N-methyl (meth) acrylamide,
The following general formula (IV) or (V)

[0027]

Embedded image (In the general formulas IV and V, n represents 1 to 10, X represents a (meth) acryloyloxy group, R ⁵ represents an alkyl group,
It represents a substituted alkyl group, a phenyl group, a substituted phenyl group, a benzyl group or a substituted benzyl group. )), And the like.

The mono (meth) acrylate represented by the general formula (IV) or (V) includes, for example, methoxydiethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, butoxyethylene Glycol (meth) acrylate and the like.

Further, as the copolymerizable compound (a-2), for example, β- (meth) acryloyloxyethyl hydrogen phthalate, β- (meth) acryloyloxyethyl hydrogen succinate, β- (meth) acryloyloxypropyl hydrogen succinate And various known epoxy (meth) acrylates and urethane (meth) acrylates.

Component (b) in the coating composition of the present invention
Are silica particles whose surface is coated with a hydrolyzate of a silane compound represented by the general formula (I). Here, "the surface is modified with the hydrolyzate" means that the hydrolyzate of the silane compound is held on a part or the whole of the surface of the silica particles, and thereby the surface characteristics are modified. Means that. In addition, the silica particles in which the condensation reaction of the hydrolyzate has progressed are also included. Typically, this surface modification in the present invention can be easily performed by hydrolyzing a silane compound in the presence of silica particles, or by causing a hydrolysis and condensation reaction.

As the silica particles, for example, colloidal silica can be used. The average particle size of silica is usually 1 nm to 1
Although it is μm and is not particularly limited, a preferable average particle diameter is 10 nm to 500 nm. When colloidal silica is used, the dispersion medium is not particularly limited, but water; alcohols such as methanol, ethanol, isopropyl alcohol, and n-butanol; cellosolves; dimethylacetamide, xylene, and the like are usually used. Particularly preferred dispersion media are alcohols, cellosolves and water.

Examples of the silane compound represented by the general formula (I) include, for example, p-vinylphenyltrimethoxysilane, p-vinylphenyltriethoxysilane, p-vinylphenyltriisopropoxysilane, p-vinylphenylmethyldimethoxysilane , P-vinylphenylmethyldiethoxysilane, p-vinylphenylethyldimethoxysilane, p-vinylphenylpropyldimethoxysilane, p-vinylphenylphenyldimethoxysilane,
p-vinylphenyldimethylmethoxysilane, o-vinylphenyltrimethoxysilane, o-vinylphenylmethyldimethoxysilane, m-vinylphenyltrimethoxysilane, o-vinylphenylmethyldimethoxysilane, p-isopropenylphenyltrimethoxysilane,
p-isopropenylphenylmethyldimethoxysilane,
m-isopropenylphenyltrimethoxysilane, m-
Examples thereof include isopropenylphenylmethyldimethoxysilane and the like and a mixture thereof.

Preferred silane compounds are p-vinylphenyltrimethoxysilane, p-vinylphenyltriethoxysilane, p-vinylphenylmethyldimethoxysilane, p-vinylphenylmethyldiethoxysilane, and p-vinylphenyldimethylmethoxysilane. And more preferred silane compounds are p-vinylphenyltrimethoxysilane and p-vinylphenylmethyldimethoxysilane.

When colloidal silica is used as the silica particles, the silane compound represented by the general formula (I) is mixed in a dispersion of colloidal silica and hydrolyzed with water in the system or newly added water. Silica particles (b) whose surface is modified with this hydrolyzate are obtained. As a catalyst for performing the hydrolysis reaction of the silane compound, an inorganic acid or an organic acid can be used. As the inorganic acid, for example, hydrohalic acid such as hydrochloric acid, hydrofluoric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like are used. Examples of the organic acid include formic acid, acetic acid, oxalic acid, acrylic acid, methacrylic acid and the like.

In the hydrolysis reaction system of the silane compound, a solvent can be used in order to carry out the reaction mildly and uniformly. The solvent is desirably one that can make the silane alkoxide, which is a reactant, water and a catalyst compatible. Specific examples include water; alcohols such as methanol, ethanol, and isopropyl alcohol; ketones such as acetone and methyl isobutyl ketone; and ethers such as tetrahydrofuran and dioxane. As the solvent, the above-described dispersion medium of colloidal silica may be used as it is, or may be newly added in a necessary amount. The amount of the solvent to be used is not particularly limited as long as the reactant can be uniformly dissolved, but if the concentration of the reactant is too low, the reaction rate may be significantly reduced. The hydrolysis and condensation reaction of the silane compound is carried out at a temperature of about room temperature to about 120 ° C. for 30 minutes to 24 hours.
The reaction is carried out for about 1 hour, preferably at about room temperature to about the boiling point of the solvent for about 1 to 10 hours.

The mixing ratio in the component (b) is not particularly limited, but the silane compound represented by the general formula (I) is preferably used in an amount of 5 to 200 parts by weight per 100 parts by weight of silica particles (solid content in the case of colloidal silica). Parts by weight, more preferably 25 to 100 parts by weight. The mixing ratio of the component (a) to the component (b) is not particularly limited, but the component (a) is preferably added to 100 parts by weight of the silica particles (solid content in the case of colloidal silica) in the component (b). ~
1000 parts by weight, more preferably 20 to 200 parts by weight.

The photopolymerization initiator (c) in the coating composition of the present invention is not particularly limited as long as it can cause a polymerization reaction of the component (a). Specifically, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether,
Carbonyl compounds such as benzoin isobutyl ether, acetoin, butyroin, toluoin, benzyl, benzophenone and p-methoxybenzophenone; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; azobisisobutyronitrile, azobis-2,4 Azo compounds such as dimethylvaleronitrile; peroxide compounds such as benzoyl peroxide and di-tert-butyl peroxide; phosphine oxide compounds such as trimethylbenzoyldiphenylphosphine oxide and benzoyldiethoxyphosphine oxide. These polymerization initiators may be used alone or in combination of two or more. The amount of the photopolymerization initiator (c) is preferably 0.01 to 10 parts by weight based on 100 parts by weight of the component (a).

The coating composition of the present invention may be basically provided as containing no organic solvent, but may be provided as containing an organic solvent (d) if necessary. As the organic solvent (d), the component (a) and the photopolymerization initiator (c) can be uniformly mixed, and the component (b)
Is used. Boiling point at normal pressure is 5
It is suitable that it satisfies conditions such as 0 ° C. or more and 200 ° C. or less and a viscosity at room temperature (25 ° C.) of 10 centipoise or less. Specifically, alcohols such as ethanol, isopropyl alcohol, normal propyl alcohol, normal butyl alcohol, and isobutyl alcohol; aromatic hydrocarbons such as benzene and toluene; ketones such as acetone and methyl ethyl ketone; ethers such as dioxane; Esters such as ethyl acetate and butyl acetate;
N, N-dimethylformamide and the like, and these organic solvents can be used alone or in combination of two or more.

Further, in the coating composition of the present invention, various additives such as a surface smoothing agent, a surfactant, an ultraviolet absorber, and a storage stabilizer can be appropriately added and used as necessary. .

The method for obtaining the coating composition of the present invention is not particularly limited. For example, a colloidal silica dispersion is mixed with a silane compound represented by the general formula (I) and, if necessary, water or a catalyst. Then, the reaction was carried out under the reaction conditions described above, the component (a) was mixed into the liquid after the reaction, and then the dispersion medium of colloidal silica and the volatile matter generated by the hydrolysis reaction of the silane compound were removed. Particular preference is given to adding the initiator (c) and, if necessary, other additives.

Examples of the method of applying the coating composition to the surface of various molded articles include a brush coating method, a casting method, a roller coating method, a bar coating method, a spray coating method, an air knife coating method, a dipping method and the like. Although it is mentioned, it is not particularly limited. The amount of the coating composition to be applied to the surface of the molded article is suitably applied so that the film thickness becomes 1 to 30 μm. When the film thickness is less than 1 μm, the abrasion resistance is poor, and when the film thickness exceeds 30 μm, cracks and the like tend to easily occur in the cured film, which is not preferable. By irradiating the coating film formed by such a method with ultraviolet rays or the like and curing it, a good cured coating film can be formed.

According to the present invention, the molded articles having a film formed on the surface thereof are various known molded articles which are required to have improved surface abrasion resistance and the like. In particular, synthetic resin molded articles are typically exemplified, for example, polymethyl methacrylate, a copolymer having methyl methacrylate as a main component, polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, polycarbonate, and cellulose acetate. Butyrate resin, polyacrylic diglycol carbonate resin, polyvinyl chloride resin, polyester resin and the like are preferable.

[0043]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the examples. The measurement and evaluation of various physical properties in the examples were performed by the following methods.

1) Scratch resistance No. 000 steel wool was attached to a 25φ circular pad,
The pad was placed on the surface of a sample held on a reciprocating abrasion tester table and subjected to 100 reciprocal scratches under a load of 1000 g. After washing this sample, the haze value was measured with a haze meter. The steel wool abrasion resistance (%) is represented by (haze value after abrasion)-(haze value before abrasion).

2) Abrasion resistance According to the Taber abrasion test method, CS-10F wear wheels and 50
The haze value was measured with a haze meter when the weights of 0 g were combined and rotated 100 times. The haze value was measured at four points around the orbit of the wear cycle, and the average value was calculated. The Taber abrasion (%) is represented by (haze value after Taber test)-(haze value before Taber test).

3) Adhesion of coating film The sample was cut by eleven vertical and horizontal lines at 1 mm intervals with a razor blade to make 100 goban eyes, and after adhering a commercially available cellophane tape, it was turned forward by 90 °. The number of squares (x) when the film remains without peeling when the film is rapidly peeled off is indicated by x / 100.

4) Appearance Defects such as banding, spots, cracks, and cloudiness were visually determined and evaluated as follows. …: No noticeable defect. X: Yellowish color or a crack, clouding, or the like having a ΔYI value of 4.0 or more is observed.

5) Weather resistance Sunshine weather meter (WE, Suga Test Instruments Co., Ltd.)
L-SUN-DC type) and black panel temperature 63
After exposure for 2,000 hours at a cycle of rainfall at 12 ° C for 12 minutes and drying for 48 minutes, the appearance was evaluated.

6) Water resistance After immersing the test piece in water of 80 ° C. for 25 days,
The adhesion was evaluated.

Example 1 100 parts by weight of isopropyl alcohol-dispersed colloidal silica (silica content: 30% by weight, trade name OSCAL-1432, manufactured by Kasei Kagaku Co., Ltd.) was added to p-vinylphenyltrimethoxysilane (hereinafter, referred to as "PAL"). 11.2 parts by weight of VPTMS) and 3 parts by weight of a 0.01 N hydrochloric acid aqueous solution were added, and the mixture was stirred at 40 ° C. for 1 hour. Thereafter, 45 parts by weight of 1,6-hexanediol diacrylate (hereinafter abbreviated as C6DA) was added, and all volatile components were distilled off under reduced pressure. Next, 2.4 parts by weight of trimethylbenzoyldiphenylphosphine oxide (hereinafter abbreviated as APO) and 0.8 parts by weight of benzophenone (hereinafter abbreviated as BNP) as a photopolymerization initiator and 2- (2- Hydroxy-5-tert-
5 parts by weight of (butylphenyl) benzotriazole (trade name: Tinuvin-PS, manufactured by Ciba Geigy) were added and dissolved to obtain a coating composition.

This coating composition was coated on a polycarbonate plate (manufactured by Mitsubishi Rayon Co., Ltd., trade name: Dialite, 1 m thick).
m), and tightly pressed with a sponge roll while covering with a polyester film (manufactured by Diafoil Co., Ltd., thickness: 50 μm), and squeezed so that the thickness of the coating film became about 7 μm. Next, a 120 W / cm metal halide lamp adjusted to an irradiation width of 13 cm (with a parallel reflector, an ozone-less type, and a distance of 3 mm from an object)
0 cm) was passed through at a speed of 2 m / min so that the polyester film surface side was irradiated. Next, only the polyester film was peeled off, and further passed under a high-pressure mercury lamp of 120 W / cm (with a parallel reflector, ozone type, irradiation width of 13 cm, distance between the object and the lamp of 30 cm) at a speed of 2 m / min. A resin plate whose surface was protected by a cured film of the coating composition was obtained.

The hardness, adhesion, appearance, weather resistance and water resistance of this resin plate were evaluated according to the above-mentioned methods. Table 2 shows the results.

<Examples 2 to 10 and Comparative Examples 1 to 5> Coating compositions having various compositions shown in Table 1 were prepared in the same manner as in Example 1, and polycarbonate plates (manufactured by Mitsubishi Rayon Co., Ltd.) were prepared.
Applying and curing in the same manner as in Example 1 on a diallite (trade name, 1 mm thick) or a polymethyl methacrylate plate (trade name Acrylite, 1 mm thick, manufactured by Mitsubishi Rayon Co., Ltd.) To obtain a protected resin plate. These resin plates were evaluated in the same manner as in Example 1. Table 2 shows the results.

<Example 11> Colloidal silica dispersed with isopropyl alcohol (silica content: 30% by weight, trade name OSCAL-1432, manufactured by Kasei Kagaku Kogyo KK) 100
11.2 parts by weight of VPTMS and 3 parts by weight of a 0.01 N hydrochloric acid aqueous solution were added to parts by weight, and the mixture was stirred at 40 ° C. for 1 hour.
Thereafter, 40 parts by weight of bis (acryloyloxyethyl) hydroxyethyl isocyanurate (trade name: Aronix M-215, manufactured by Toagosei Co., Ltd.), 10 parts by weight of C6DA, and 60 parts by weight of isobutyl alcohol were added, and the mixture was stirred well. Then, APO was added thereto as a photopolymerization initiator.
2.4 parts by weight, 0.8 parts by weight of BNP, and 5 parts by weight of 2- (2-hydroxy-5-tert-butylphenyl) benzotriazole (trade name: Tinuvin-PS, manufactured by Ciba Geigy) as an ultraviolet absorber are added and dissolved. To give a coating composition.

[0055] Then, the coating composition polycarbonate plate (Mitsubishi Rayon Co., Ltd., trade name diamond light, thickness 1mm) by dip coating at a rate of the 0.3 cm / sec, to form a film, at 80 ° C. Left for 10 minutes, the solvent was evaporated. Next, the point where the polyester film was not covered and the distance between the subject and the lamp when irradiating with a high pressure mercury lamp was set to 15c
Irradiation was carried out in the same manner as in Example 1 except that the m and the passing speed were 1.5 m / min to obtain a resin plate whose surface was protected by a cured film of the coating composition. This resin plate was evaluated in the same manner as in Example 1. Table 2 shows the results.

[0056]

[Table 1] (Abbreviations in Table 1) C6DA: 1,6-hexanediol diacrylate THFA: tetrahydrofurfuryl acrylate DEGDA: diethylene glycol diacrylate TMPTA: trimethylolpropane triacrylate M-215: bis (acryloyloxyethyl) hydroxyethyl isocyanurate ( TAS: Trimethylolethane / acrylic acid / succinic acid (molar ratio 2/4/1) condensate S-1: Isopropyl alcohol dispersed colloidal silica (silica content) 30% by weight, Catalyst Chemical Industry Co., Ltd.
S-2: Water-dispersed colloidal silica (silica content 2)
0 wt%, manufactured by Nissan Chemical Industries, Ltd., trade name: Snowtex O) VPTMS: p-vinylphenyltrimethoxysilane VPDMS: p-vinylphenylmethyldimethoxysilane MPTMS: γ-methacryloyloxypropyltrimethoxysilane APO: trimethylbenzoyl Diphenylphosphine oxide BNP: Benzophenone HOB: 2-hydroxy-4-n-octoxybenzophenone BBE: Benzoin isobutyl ether Tinuvin PS: 2- (2-hydroxy-5-tert-
Butylphenyl) benzotriazole (manufactured by Ciba-Geigy)

[0057]

[Table 2] (Abbreviations in Table 2) PC: polycarbonate PMMA: polymethyl methacrylate

[0058]

The coating composition of the present invention can be applied without using a solvent, and the coating film formed by applying and curing the coating composition has excellent abrasion resistance, scratch resistance, and good appearance. It is. Furthermore, it exhibits excellent weather resistance and water resistance, and is also effective in preventing the occurrence of cracks and the like in the film.

Further, since the surface-coated molded article of the present invention has its surface covered with the above-mentioned cured multi-layered film, various problems such as a decrease in aesthetics due to scratches, which have conventionally been a problem in synthetic resin molded articles, have been encountered. Eliminate problems.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-243939 (JP, A) JP-A-62-169806 (JP, A) JP-A-59-104306 (JP, A) JP-A-57-104306 131214 (JP, A) JP-A-56-32510 (JP, A) "Polymer Paper Collection", Vol. 38, No. 4, p. 201-207, 1981 (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 4/02 C08J 7/04 CA (STN) CAOLD (STN) REGISTRY (STN) WPIDS (STN) Patent file (PATOLIS) )

Claims (3)

(57) [Claims] (1) 50% by weight of a crosslinked polymerizable compound (a-1) having at least two acryloyloxy groups and / or methacryloyloxy groups in a molecule, or the crosslinked polymerizable compound (a-1) A mixture of the above and a compound (a-2) copolymerizable therewith, (b) a general formula (I): (Wherein, R ¹ is a hydrogen atom or a methyl group, R ² is an alkyl group or a phenyl group having 1 to ³ carbon atoms, R ³ is a hydrogen atom or a hydrocarbon residue having 1 to 10 carbon atoms, and n is 0 to 2 (C) a coating composition comprising: a silica particle having a surface modified with a hydrolyzate of a silane compound represented by the formula: and (c) a photopolymerization initiator. 2. The coating composition according to claim 1, further comprising (d) an organic solvent. 3. A molded product having a surface coated with a cured product of the coating composition according to claim 1 or 2.