JP3096862B2 - Active energy radiation curable coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray-curable coating composition capable of forming a hardened film having abrasion resistance and scratch resistance.

[0002]

2. Description of the Related Art Synthetic resin molded products such as polymethyl methacrylate resin, polycarbonate resin and polyarylate resin are not only lightweight and excellent in impact resistance but also inexpensive as compared with glass. It has various advantages such as easy molding process, and is widely used in many fields by utilizing these advantages. For example, it is used for glazing of automobiles, buses, aircraft, and other public transportation vehicles, or lenses such as headlamp lenses and corner lenses, and lenses for glasses and optical devices. However, these synthetic resin molded products have insufficient surface hardness, and the surface is damaged due to the effects of contact with other objects, impact, scratching, etc. during transportation of the molded product, mounting of parts, or use, and appearance. Is lost, the commercial value is reduced, and the product yield is reduced.

[0003] Therefore, there is a strong demand for improving the surface hardness of the surface of these synthetic resin molded products, and many methods of improving the surface hardness have been proposed. For example,
A coating consisting of a partially condensed reaction product of a silane mixture containing alkyltrialkoxysilane as a main component and colloidal silica is applied to the surface of a molded article, and then heated to form a cured film and improve abrasion resistance. A method or a coating mainly composed of a polyfunctional acrylate having two or more (meth) acryloyloxy groups in one molecule is applied to the surface of a molded article, and then a cured film is formed by irradiation with ultraviolet rays. A method for improving the wear resistance has been proposed.

[0004] In these methods, the former is an excellent method because it has a large effect of improving abrasion resistance. However, since the adhesion to a molded article is poor, a primer coating treatment is required, which increases the cost. Or the processing process becomes complicated, and the heat treatment is long, so that there is a difficulty in productivity. Also, the latter is excellent in productivity because the curing time is extremely short as several seconds to several tens of seconds due to the ultraviolet curing method. In recent years, a method that can be cured even in the air has been proposed, which is an economically extremely useful method. However, the latter UV curing method tends to have a lower level of abrasion resistance than the former thermosetting method, especially when the wear material is abrasive, and the fact that the latter has a clearly lower level of abrasion resistance. Is recognized.

[0005] Methods have been proposed that take advantage of the advantages of the former method and the latter method. That is, Japanese Patent Publication No. 57-500
No. 984 discloses an ultraviolet-curable silicone coating composition containing an acrylic component and colloidal silica. By using ultraviolet rays for curing, the curing time, which was a fundamental problem of silicon-based coating materials, can be greatly reduced, and curing in a short time of several seconds to several minutes is possible, which is advantageous in terms of productivity. The advantage that it becomes.

[0006]

However, it has been found that the silicone coating composition disclosed in Japanese Patent Publication No. 57-500984 has the following problems to be solved. One is the problem of the adhesion of the cured film to the surface of the synthetic resin molded product, and the second is the problem of cracks generated in the cured film in an accelerated exposure test such as a weathering test such as a sunshine weather meter. It is.

[0007] The adhesion of the cured film differs depending on the compounding ratio of the acrylic component and the colloidal silica in the silicone coating material composition, and the adhesion tends to be improved in the direction in which the acrylic component increases. Is shown.
However, an increase in the acrylic component increases the abrasion resistance of the cured film, particularly the degree of abrasion by the abrasive grains, so that it is difficult to obtain sufficient abrasion resistance. Further, regarding the adhesion, it is also recognized that the film thickness dependency is large, and sufficient adhesion is not obtained in a relatively thin region and a relatively thick region, and a sufficient adhesion is obtained only in a narrow region of the film thickness. Adhesion can be obtained, but this is to narrow the range of processing conditions, and it is an issue to expand the allowable range of the film thickness.

[0008] Regarding the problem of cracks occurring in the accelerated exposure test, the performance required for the coating composition is not only improved in the abrasion resistance of the synthetic resin molded product, but also strongly required in the weather resistance improvement. Although a high degree of weather resistance is required in applications, the wear-resistant synthetic resin molded article obtained by using the above-mentioned silicone coating material composition does not have a sufficient level of weather resistance and has a sunshine weather meter. In an accelerated exposure test such as-, cracks were observed in the cured film, and there remains a problem with respect to weather resistance such as an increase in haze value and an increase in yellowness. An object of the present invention is to provide an active energy ray-curable silicone coating material composition that solves the above problems.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies on the improvement of adhesion and weather resistance of a cured film of a silicone coating material composition to a synthetic resin molded product, and found that a colloidal silica component and a vinylsilane compound were used. The present inventors have found that an active energy ray-curable coating composition in which three components of polyfunctional (meth) acrylate are blended in a specific ratio can solve the above-mentioned problems, and have completed the present invention.

The gist of the present invention is as follows: (a) 5 to 70% by weight of colloidal silica composed of silica particles having a primary particle size of 1 to 200 millimicrons;

[0011]

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(Wherein, R ₁ is a single bond or a substituted or unsubstituted divalent hydrocarbon group, R ₂ is a monovalent hydrocarbon group or a hydrogen atom, R ₃ is a substituted or unsubstituted monovalent hydrocarbon group. Yes, a
Is an integer of 1 to 3, b is an integer of 0 to 2, a + b is an integer of 1 to 3) 1 to 50% by weight of a hydrolyzate and / or a partial condensation reaction product of a silane compound represented by the following formula: A polyfunctional monomer having two or more acryloyloxy groups and / or methacryloyloxy groups [provided that the following formula:

[0013]

Embedded image

(Wherein at least one of Y is CH ₂ ＣC
H-COO- group or a _{CH 2 = C (CH 3)} -COO- group
And the remainder is a CH ₂ ＣＨCH—COO (CH ₂ ) _n OCO— group
Or a CH ₂ ＣC (CH ₃ ) —COO (CH ₂ ) _m OCO— group
And m and n are integers of 1 to 8. )
One molecule containing at least 20% by weight or more of a monomer
Two or more acryloyloxy groups and / or
Polyfunctional monomer or monomer mixture having acryloyloxy group
Excluding compounds. ] 20 to 80 wt%, (d) a photopolymerization initiator 0.1 to 5% by weight, consisting of city [However, (a),
(B), (c) and (d): 100% by weight] Active energy ray-curable coating composition.

The present invention will be described in detail. First, each component will be described. (A) About a component. The colloidal silica (a) component composed of silica particles having a primary particle diameter of 1 to 200 millimicrons used in the present invention is obtained by using ultrafine particles of silicic anhydride as a colloid solution. Colloidal silica in the form of powder containing no dispersion medium can also be used in the present invention. Examples of the dispersion medium of colloidal silica include alcohols such as water, methanol, ethanol, iso-propanol, n-butanol and n-propanol, and polyvalents such as ethylene glycol. Alcohols,
Polyhydric alcohol derivatives such as ethyl cellosolve and butyl cellosolve; ketones such as methyl ethyl ketone, methyl isobutyl ketone and diacetone alcohol; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and tetrahydrofurfuryl Although there are monomers such as acrylate and general organic solvents, alcohols having an alkyl group having 1 to 4 carbon atoms are particularly preferred in the present invention.

As these colloidal silicas, commercially available ones manufactured by a known method can be used. For example, water-dispersed colloidal silica (trade name: Snortex), methanol-dispersed colloidal silica (trade name: methanol silica sol), iso-propanol dispersed colloidal silica (trade name) commercially available from Nissan Chemical Industries, Ltd. IPA-ST), a methanol-dispersed colloidal silica (trade name: OSCA) commercially available from Catalyst Chemicals, Inc.
L1132), iso-propanol dispersed colloidal silica (trade name: OSCAL1432), and the like. Examples of the powdered colloidal silica include OSCAP commercially available from Catalyst Chemicals, Inc. Although the colloidal silica of the present invention can be taken in an acidic or basic form, it is more preferable to use an acidic form in the method for producing the coating composition of the present invention.

It is preferable to use particles having a particle size of 1 to 200 millimicrons, particularly preferably 5 to 80 millimicrons. If the particle size is less than 1 millimicron, the stability of the dispersion state is poor and it is difficult to obtain a product having a constant quality. If the particle size exceeds 200 millimicrons, the transparency of the coating film is poor, and You can only get big things.

The colloidal silica used in the present invention remarkably improves the abrasion resistance and surface hardness of the cured film, and exhibits an excellent effect particularly in the abrasion test using abrasive grains as an abrasive. However, when a film is formed solely of colloidal silica, the adhesion to the surface of the molded article is extremely poor, so that the film is cracked or the film is peeled off, so that it cannot be used practically alone. The mixing ratio of colloidal silica is 5% in 100% by weight of the coating composition.
It is from 70 to 70% by weight, preferably from 10 to 60% by weight, particularly preferably from 15 to 50% by weight. If the compounding ratio is less than 5% by weight, the abrasion resistance of the cured film, particularly the abrasion resistance due to the abrasive grains, becomes insufficient. On the other hand, if it exceeds 70% by weight, cracking and adhesion of the cured film occur. A decrease may be observed.

Regarding the component (b). The hydrolysis product of the vinylsilane compound represented by the general formula 1 and / or the partial condensation reaction product (b) component is, for example, vinyltrimethoxysilane, vinyltriethoxysilane,
Vinyl methyl dimethoxy silane, vinyl methyl diethoxy silane, vinyl tris (2-methoxy ethoxy) silane, vinyl triacetoxy silane, vinyl ratramethylene trimethoxy silane, vinyl octamethylene trimethoxy silane, and the like; For example, it can be obtained by a conventional method such as stirring in the presence of hydrochloric acid at a temperature lower than room temperature to a reflux temperature for about 1 to 10 hours. Among the vinylsilane compounds, vinyltrimethoxysilane is particularly preferable because it has excellent polymerization activity under active energy rays, particularly ultraviolet irradiation, and has a large effect of expressing the abrasion resistance of the cured film.

When the component (b) of the present invention is used in combination with the component (a) and the component (c) described later, the adhesiveness of the cured film is greatly improved, and it is sufficient in a wide range of film thickness. It is possible to obtain excellent adhesion. Further, when used in combination with the component (c), the effect of preventing the occurrence of cracks during accelerated exposure is increased, and the combined use with the component (c) is also essential in the present invention for improving the weather resistance. The proportion of the component (b) used is 1 in 100% by weight of the coating composition.
It is from 50 to 50% by weight, preferably from 3 to 40% by weight, particularly preferably from 5 to 35% by weight. If the use ratio is less than 1% by weight, turbidity occurs in the cured film, making it difficult to form a transparent film in appearance, and further, a decrease in adhesion of the cured film and generation of cracks in an accelerated exposure test are observed. Become like
On the other hand, if it is used in an amount exceeding 50% by weight, the curability becomes insufficient, so that wrinkles are generated in the film, and even if it can be cured, only a low level of abrasion resistance is obtained.

Regarding the component (c). Multifunctional monomer (c) having two or more acryloyloxy groups and / or methacryloyloxy groups in one molecule
The components are manufactured by a well-known method and are also commercially available. Examples thereof include polyol (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, and urethane (meth). Acrylate, polyether (meth) acrylate, melamine (meth) acrylate
And alkyd (meth) acrylate, silicon (meth) acrylate and the like. These compounds are specifically described in "UV / EB Curing Handbook-Raw Materials" issued by the Society of Polymer Publishing.

Among these polyfunctional monomers, those which are preferable as the component (c) include bis (acryloxyethyl) hydroxyethyl isocyanurate, 1,4-butanediol diacrylate, and glycerol diacrylate. ,
1,6-hexanediol diacrylate, neopentyl glycol diacrylate, neopentyl glycol diacrylate hydroxypivalate and urethane acrylates, from dibasic acid, dihydric alcohol and acrylic acid Di (meth) acrylates such as polyester (meth) acrylate to be synthesized; trimethylolpropane tri (meth) acrylate, tris ((meth) acryloxyethyl) isocyanurate, pentaerythritol tri ( Tri (meth) acrylates such as (meth) acrylate; dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate Acrylate, ditrimethylolpropanetetra (meth) acrylate, dibasic acid Trivalent or tetravalent alcohol - le and (meth) polyester synthesized from acrylic acid (meth)
(Tetra, penta or hexa) (meth) acrylates such as acrylate and the like. One of these monomers may be used alone, or two or more thereof may be used in combination.

The component (c), while interacting with other components, mainly imparts toughness and flexibility to the cured film, thereby preventing cracking of the cured film and improving adhesion. When the coating material composition is prepared from the components (a) and (b) without using the component (c), only a turbid cured film is obtained, and the internal stress of the film is reduced. Cracks due to the occurrence tend to occur, and a practical wear-resistant synthetic resin molded product cannot be obtained. Among the components (c), bis-
A combined system of (acryloxyethyl) hydroxyethyl isocyanurate and 1,6-hexanediol diacrylate or a combined system of tris (acryloxyethyl) isocyanate and 1,6-hexanediol diacrylate is used.
The component (c) used in the present invention is particularly preferable because it has a large effect of improving adhesion and excellent weather resistance due to accelerated exposure, particularly excellent transparency, gloss retention and yellowing resistance.

The proportion of the component (c) used is determined according to the coating composition 10
It is 20 to 80% by weight, preferably 30 to 75% by weight, particularly preferably 40 to 70% by weight in 0% by weight. When the use ratio is less than 20% by weight, the transparency of the cured film is deteriorated and cracks are observed. On the other hand, when it is used in excess of 80% by weight, the wear resistance of the cured film, especially the wear resistance due to abrasive grains It is not preferable because the property is lowered.

Regarding the component (d). When ultraviolet rays are used as the active energy rays, it is preferable to incorporate a small amount of the photopolymerization initiator (d) into the coating composition in consideration of practical curing. Specific examples of the photopolymerization initiator include benzophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, ptyloin, toluoin, benzyl, benzophenone, p-methoxybenzophenone, Diethoxyacetophenone, α, α-dimethoxy-α-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylaminobenzophenone), 2-hydroxy-2-methyl-1-
Phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-methyl-1- [4- (methylthio ) Phenyl)
Carbonyl compounds such as -2-morpholino-propan-1-one; sulfur compounds such as tetramethylthiuram disulphide and tetramethylthiuram monosulfide; azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile Azo compounds such as benzoyl peroxide and di-tert-butyl peroxide; acyl phosphine compounds such as 2,4,6-trimethylbenzoyl diphenyl phosphine oxide. These may be used alone or in combination of two or more. The amount of the photopolymerization initiator added to the coating composition was 10
It is 0.1 to 5% by weight in 0% by weight. When the amount of the photopolymerization initiator is too large, the weather resistance of the cured film tends to be lowered and coloring tends to occur.

The active energy ray-curable coating composition of the present invention comprises the above-mentioned components (a), (b), (c) and (d), and if necessary, an ultraviolet absorber and a light stabilizer. , Antioxidants, stabilizers such as thermal polymerization inhibitors; surfactants such as leveling agents, defoamers, thickeners, anti-settling agents, pigment dispersants, antistatic agents, anti-fogging agents; A curing catalyst selected from alkalis, salts and the like may be blended in an appropriate amount and used.

Further, from the viewpoints of uniform solubility, dispersion stability, adhesion to a substrate, and smoothness and uniformity of a coating film, an organic solvent may be used in the coating composition. Good. The organic solvent is not particularly limited, and an organic solvent that satisfies the desired performance as described above may be used. Further, two or more organic solvents may be used in combination. The usage ratio of this organic solvent is 0 to 2000 parts by weight based on 100 parts by weight of the coating composition. Its usage is 2
If it exceeds 000 parts by weight, only a thin film can be obtained, so that abrasion resistance and scratch resistance are not sufficient. Also, by blending a mono (meth) acrylate having one (meth) acryloyloxy group in one molecule into a coating composition, the above-mentioned desired performance can be satisfied similarly to the organic solvent. You can also. Examples of such a mono (meth) acrylate include methyl methacrylate, ethyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate,
Examples thereof include low-viscosity mono (meth) acrylates such as glycidyl acrylate, 2-hydroxyethyl acrylate, and tetrahydrofurfuryl acrylate.

In order to further improve the weather resistance of the cured film, benzophenone, benzotriazole, phenyl salicylate, phenyl benzoate,
An ultraviolet absorber having a maximum absorption wavelength derived from a cyanoacrylate compound in the range of 240 to 380 nm or a hindered amine light stabilizer can also be added. It is more preferable to add both components in combination. This addition further improves the weather resistance of the coating, such as, for example, yellowing resistance of the coating due to exposure, retention of gloss and transparency, crack resistance, and retention of adhesion to a synthetic resin substrate.

Next, the method of using the active energy ray-curable coating composition will be described. The coating composition of the present invention,
Although it can be used for various applications conventionally known as an application field of a coating material, in particular, a coating having excellent wear resistance is formed on the surface of a synthetic resin molded product to produce a wear-resistant synthetic resin molded product. It is very effective when you do. That is, a step of applying the coating composition of the present invention to the surface of a synthetic resin molded article, curing the composition by irradiation with active energy rays, and forming a film having a thickness of 1 to 30 μm on the surface is employed. This makes it possible to easily form a practically effective film excellent in various properties on the surface of the synthetic resin molded product.

The method of applying the coating composition of the present invention to the surface of a synthetic resin molded article includes coating methods such as dip coating, brush coating, flow coating, spray coating, and spin coating.
Of these, the dip coating method is preferable from the viewpoint of the coating workability of the coating composition and the smoothness and uniformity of the coating film, and the spray coating method is preferable from the viewpoint of adaptability to the shape of the molded product. The supply amount of this coating composition is such that the thickness of the cured film is 1 to 3.
The supply may be appropriately adjusted so as to be in the range of 30 μm, preferably 3 to 15 μm.

As a method of curing the coating composition of the present invention, a method of irradiating an active energy ray such as an electron beam, an α-ray, a γ-ray, a β-ray, an ultraviolet ray, etc. which is taken out from an electron beam accelerator of 20 to 2000 kV. Is adopted. It is preferable to use ultraviolet rays having a wavelength of 100 to 400 nm from the viewpoint of being easily cured economically. When ultraviolet rays are used, it is desirable to add a photopolymerization initiator to the coating composition as described above. As a source of ultraviolet rays, a method of irradiating ultraviolet rays with a wavelength of 100 to 400 nm using an ultraviolet lamp from the viewpoint of practicality and economy is preferable. Specific examples of the ultraviolet lamp include a low-pressure mercury lamp, a medium-pressure mercury lamp, A high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp and the like can be mentioned. The atmosphere at the time of curing by irradiation with ultraviolet rays may be ordinary air or an inert gas such as nitrogen or argon. In addition, for the purpose of improving the adhesion of the film, etc., before irradiation with ultraviolet rays, 20 to 120
The heat treatment may be performed for 1 to 60 minutes in a temperature range of ° C.

[0032]

The present invention will be described in more detail with reference to the following examples. Example 1 1 l 4-neck flask with stirrer and condenser
A vessel was charged with 200 g of iso-propyl alcohol-dispersed colloidal silica, 35 g of vinyltrimethoxysilane and 12.8 g of a 0.001 N hydrochloric acid aqueous solution were added with stirring, and the mixture was stirred at room temperature for 1 hour. Next, a mixed solution of 73.5 g of tris (acryloxyethyl) isocyanurate and 31.5 g of 1,6-hexanediol diacrylate was added to the reaction vessel and uniformly dissolved. The temperature of the reaction system was raised, and the reaction was carried out for 5 hours while refluxing volatile components. The resulting reaction solution was added with methylphenylglyoxylate 2.8.
g was added to prepare a coating composition. Using this coating composition
Methacrylic resin with a thickness of 3 mm and 100 x 100 mm
(Product name ACRYPET VH001, color tone clear, Mitsubishi
Rayon Co., Ltd.) Dip coating on injection molded plate to form coating
Then, it was left in a dryer at 80 ° C. for 10 minutes. Then
1,300mg of this in an air atmosphere using a high pressure mercury lamp
/ Cm ² of ultraviolet light energy and a film thickness of 5 μm.
A cured film was formed.

Comparative Example 1 250 g of iso-propyl alcohol-dispersed colloidal silica was charged into the reaction vessel of Example 1, and 3-methacryloxypropyltrimethoxysilane (trade name: A-174, manufactured by Nippon Unicar Co., Ltd.) 37.5 g and 8.2 g of a 0.001 N hydrochloric acid aqueous solution were added, followed by stirring at room temperature for 8 hours. After aging this overnight, trimethylol propane triacrylate
115.1 g and 2-hydroxyethyl acrylate 2
8.8 g was added and stirred at room temperature to obtain a homogeneous solution. 3.6 g of diethoxyacetophenone was added to this solution to prepare a coating composition. This coating composition was treated in the same manner as in Example 1 except that the exposure atmosphere at the time of ultraviolet irradiation was changed to nitrogen to form a crosslinked film having a thickness of 5 μm.

Comparative Example 2 The coating composition of Comparative Example 1 was diluted with iso-propyl alcohol, and treated according to Comparative Example 1 to form a crosslinked film having a thickness of 3 μm. Comparative Example 3 The coating composition of Comparative Example 1 was concentrated by distilling out volatile components with a rotary evaporator. The treatment was carried out according to Comparative Example 1 to form a crosslinked film having a thickness of 10 μm.

Comparative Example 4 Iso-propyl alcohol-dispersed colloid in 1 l of beaker
Dal silica (250 g) is charged, and vinyl
37.5 g of methoxysilane and 0.001N hydrochloric acid aqueous solution
13.7 g was added and the mixture was stirred at room temperature for 8 hours. In this solution
1.5 g of tilphenylglyoxylate was added and the coating composition was added.
I adjusted things. This coating composition was treated in the same manner as in Comparative Example 1 to form a 4 μm-thick crosslinked film.

Comparative Example 5 250 g of iso-propyl alcohol-dispersed colloidal silica and bis- (acryloxyethyl) were added to one liter of beaker.
115.1 g of hydroxyethyl isocyanurate and 1,1
68.8 g of 6-hexanediol diacrylate and 2.9 g of methylphenylglyoxylate were added, and the mixture was stirred at room temperature to prepare a coating composition. Using this coating composition, the actual
The treatment was performed in the same manner as in Example 1 to form a crosslinked film having a thickness of 5 μm.

COMPARATIVE EXAMPLE 6 Vinyltrimethoxysilane 3 was added to a 100 cc beaker.
7.5 g, 13.7 g of a 0.001 N hydrochloric acid aqueous solution and 170 g of iso-propyl alcohol were added, and the mixture was stirred at room temperature for 1 hour. To this, 115.1 g of bis- (acryloxyethyl) hydroxyethyl isocyanurate, 28.8 g of 1,6-hexanediol diacrylate and 3.6 g of methylphenylglyoxylate were added, and the mixture was stirred at room temperature to obtain a coating composition. I adjusted things. Using this coating composition, a treatment was conducted in the same manner as in Example 1 to form a crosslinked film having a thickness of 5 μm.

Evaluation of Each Abrasion-Resistant Synthetic Resin Molded Product Each of the abrasion-resistant synthetic resin molded products obtained in the above Examples and Comparative Examples was evaluated for physical properties. Table 1 shows the results.

[0039]

[Table 1]

Each physical property was evaluated as follows. (1) Abrasion resistance, abrasion resistance, Taber abrasion test, performed according to ASTM D-1044. Wear wheel CS-10F, load 500g, number of wear 5
Worn under the conditions of 00 cycles. The sample was washed with a neutral detergent, and the haze was measured using a haze meter. The abrasion resistance was represented by a haze (%) value of (haze value after abrasion-haze value before abrasion). (2) Adhesion The surface of the sample was cut with a razor to make 11 scratches in each of 1.5 rows and 1.5 rows.
100 squares were formed at intervals of mm, and a cellophane tape (width: 25 mm, manufactured by Nichiban Co., Ltd.) was pressed against the squares and rapidly removed upward. The evaluation of adhesion was shown by “the number of remaining stitches / the total number of stitches”.

(3) Appearance (a) Transparency: Haze value (%) was measured using a haze meter. (B) Crack: visually determined. A sample with no cracks was indicated by 〇, a sample with slight cracks was indicated by △, and a sample with countless cracks was indicated by ×. (4) Weather resistance Sunshine weather meter (WE, Suga Test Machine Co., Ltd.)
(L-SUN-DHC type). Exposure conditions were as follows: exposure time: 1,000 hours, black panel temperature: 63
C., rainfall conditions 12 minutes water spray / 60 minute cycle. The exposed samples were evaluated for the adhesion in the above item (2) and the appearance in the item (3).

[0042]

According to the active energy ray-curable coating composition of the present invention, colloidal silica, a hydrolyzate and / or a partial condensation reaction product of a specific silane compound having a vinyl group and a (meth) acryloyloxy group are used. Since the specific three components of the polyfunctional monomer having the three components interact with each other, when the coating composition is applied to a substrate and cured by irradiation with active energy, particularly severe conditions are applied. Not only is excellent in abrasion resistance and abrasion resistance, but also excellent in adhesion to a substrate, weather resistance and crack resistance are sufficient, and a cured film having excellent transparency can be formed. Thus, when the coating composition of the present invention is used, excellent surface improvement of various synthetic resin molded articles and the like can be easily achieved in a short time, so that it is industrially extremely useful.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // C08F 2/44 C08F 2/50 2/50 G02B 1/10 (56) References JP-A-3-275769 (JP, A (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 4/06 C09D 1/00 C09D 5/00 C09D 183/07 G02B 1/10 C08F 2/44 C08F 2/50 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] (1) 5 to 70% by weight of colloidal silica comprising silica particles having a primary particle diameter of 1 to 200 millimicrons, (b) the following formula: (Wherein, R ₁ is a single bond or a substituted or unsubstituted divalent hydrocarbon group, R ₂ is a monovalent hydrocarbon group or a hydrogen atom, R ₃ is a substituted or unsubstituted monovalent hydrocarbon group, and a Is an integer of 1 to 3, b is an integer of 0 to 2, a + b is an integer of 1 to 3) 1 to 50% by weight of a hydrolyzate and / or partial condensation reaction product of a silane compound represented by the following formula: A polyfunctional monomer having two or more acryloyloxy groups and / or methacryloyloxy groups [ provided that the following formula : ( Wherein, at least one Y is CH ₂ ＣＨCH—COO—
Or a CH ₂ ＣC (CH ₃ ) —COO— group, the remainder being CH ₂
ＣＨCH—COO (CH ₂ ) _n OCO— or CH ₂ ＣC
A (CH ₃ ) —COO (CH ₂ ) _m OCO— group, wherein m and
n is an integer of 1 to 8. ) Less monomer
And 20% by weight or more in one molecule.
Acryloyloxy group and / or methacryloyloxy
Excludes polyfunctional monomers or monomer mixtures having di groups . ]
20 to 80% by weight, (d) 0.1 to 5% by weight of a photopolymerization initiator [provided that (a), (b), (c) and (d)
100% by weight] active energy ray-curable coating composition.