JPH1177878A - Transparent coated molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart not only sufficient abrasion resistance and close adhesiveness but also excellent weatherability by using an active energy beam curable coating compsn. containing a polyfunctional compd. having two or more active energy beam curable polymerizable functional groups, a specific photopolymerization initiator and a specific photopolymerization initiator excepting the photopolymerization initiator. SOLUTION: A transparent coated molding contains the transparent cured material layer of an active energy beam curable coating compsn. provided on at least a part of the surface of a transparent synthetic resin base material. The active energy beam curable coating compsn. contains a polyfunctional compd. having two or more active energy beam curable polymerizable functional groups, a specific photopolymerization initiator C1 having a peak of the max. wavelength in a range of 365-400 nm and a photopolymerization initiator C2 of which the absorptivity coefficient per a mole in the max. absorption wavelength is 10,000 (1/mol/cm) or more (excepting the photopolymerization initiator C1). The coating compsn. is applied to the base material by a dip method to form an uncured material layer which is, in turn, irradiated with an active energy beam to cure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent cured resin formed by irradiating an active energy ray (especially ultraviolet light) on a transparent synthetic resin molding substrate and having excellent abrasion resistance, transparency and weather resistance. The present invention relates to a transparent coated molded article having a material layer.

[0002]

2. Description of the Related Art In recent years, transparent synthetic resin materials have been used as transparent materials in place of glass. Above all, aromatic polycarbonate resins are excellent in crush resistance, transparency, light weight, ease of processing and the like, and are utilized in various fields as materials for large-area transparent members such as outer walls and arcades by utilizing their features. Further, use as a window material in place of glass in buildings and automobiles is also being studied. However, there are drawbacks that the weather resistance is insufficient for use as a substitute for glass, and that the hardness of the surface of the molded product is not sufficient, and the molded product is easily damaged and abraded.

Hitherto, many attempts have been made to improve the scratch resistance and abrasion resistance of the surface of an aromatic polycarbonate resin molded product. One of the most common methods is to apply a polyfunctional compound having two or more polymerizable functional groups such as an acryloyl group in the molecule to the surface of the molded product, and to cure it with an active energy ray such as heat or ultraviolet rays, and to prevent scratching. There is a method of obtaining a molded article having a transparent cured product layer having excellent heat resistance and abrasion resistance. According to this method, the coating liquid is relatively stable, and particularly excellent in productivity because it can be cured by ultraviolet rays. Even when a molded product is subjected to bending, no crack is generated in the cured product film and the surface is not scratched. And abrasion resistance can be improved. However, since the cured product film is composed only of an organic substance, it is necessary to add a large amount of an ultraviolet absorber under severe conditions such as long-term outdoor use.

[0004] However, there is a limitation in using an ultraviolet curable compound and an ultraviolet absorber in combination. In other words, if a large amount of the ultraviolet absorber is used, the ultraviolet absorber absorbs the ultraviolet ray during the irradiation of the ultraviolet ray during curing, and the curability of the essential curable compound becomes insufficient. If the curability of the curable compound is insufficient, various inconveniences such as insufficient scratch resistance and abrasion resistance of the surface and insufficient adhesion to the molded product surface occur. Therefore, various methods have been devised, such as shifting the absorption wavelength of the ultraviolet light and the absorption wavelength of the photoinitiator, but in the coexistence of the ultraviolet light absorber, the surface from the interface with the surface of the molded article to the surface is hardened uniformly and sufficiently. Has not been reached.

On the other hand, as a method for imparting a higher surface hardness to the surface of a molded product, there is a method in which a metal alkoxide is applied to a substrate and cured by heat. Silicon-based compounds are widely used as metal alkoxides, and although a cured product film with excellent abrasion resistance can be formed, the productivity is low due to the high temperature required for curing the metal alkoxide. Since the adhesion between the film and the substrate is poor, there are disadvantages such as easy peeling and cracking of the cured film.

As a method for imparting higher surface hardness to the surface of a molded product, a mixture of a polyfunctional compound having an acryloyl group and colloidal silica is applied to the surface of the molded product, and the mixture is irradiated with active energy rays such as ultraviolet rays. There is a method of forming a transparent coating layer having excellent scratch resistance and abrasion resistance by curing (JP-A-61-181809). By using colloidal silica in combination with a polyfunctional compound, it is possible to achieve both high surface hardness and high productivity.

In such a method, a technique using colloidal silica surface-modified with a vinyl-functional silane, an acrylic-functional silane, an epoxy-functional silane, an amino-functional silane, or the like (JP-A-1-188509, JP-A-1-31)
5403, JP-A-2-64138, JP-A-5-9317
0, JP-A-5-117545) is also disclosed. However, even when such a polyfunctional compound containing colloidal silica is used, the abrasion resistance of the surface and the adhesion to the substrate are often insufficient as described above.

[0008]

The present invention seeks to overcome the aforementioned disadvantages. That is, even in the presence of an ultraviolet absorber, the curability at the interface with the surface of the molded product is ensured, and the curability of the surface is also ensured, so that sufficient surface abrasion resistance and adhesion to the molded product surface are obtained. It is another object of the present invention to provide a molded article having a transparent cured layer having excellent weather resistance.

[0009]

Means for Solving the Problems The inventors of the present invention have studied as a purpose of solving the above problems, and as a result, have found that an active energy ray-curable coating composition using two kinds of specific photopolymerization initiators in combination is used. A transparent coated molded article on which the cured product layer was formed was found. The present invention is the following invention relating to this transparent coated molded article. The active energy ray-curable coating composition may contain an ultraviolet absorber or colloidal silica.

In a transparent molded article comprising a transparent synthetic resin molded substrate and a transparent cured layer of an active energy ray curable coating composition provided on at least a part of the surface of the transparent synthetic resin molded substrate, an active energy ray-curable Polyfunctional compound having two or more active energy ray-curable polymerizable functional groups, a photopolymerization initiator (C1) having a maximum absorption wavelength peak at 365 to 400 nm, and a mole per mole at the maximum absorption wavelength. The extinction coefficient is 10,000 (l / m
ol / cm) or more, which is a coating composition containing a photopolymerization initiator (C2) [excluding the photopolymerization initiator (C1)].

In the surface of the transparent cured resin layer (hereinafter, referred to as a cured material layer) of the present invention, which is in contact with the transparent synthetic resin molding substrate (hereinafter, referred to as a contact surface), it is longer than the absorption wavelength region of a commonly used ultraviolet absorber. By using the photoinitiator (C1) having the peak of the maximum absorption wavelength on the wavelength side, good deep curability of the coating composition can be obtained, and thus good substrate adhesion can be obtained. By using a photoinitiator (C2) having a very high extinction coefficient on the exposed surface of the cured product layer, it is hardly affected by oxygen at the time of irradiating ultraviolet rays, and curing of the polyfunctional compound on the exposed surface is sufficient. And a high surface hardness is obtained as a result. Therefore, from the interface of the base material to the exposed surface of the entire cured product layer, the sufficient curing of the polyfunctional compound proceeds even in the presence of an ultraviolet absorber for maintaining weather resistance, and good substrate adhesion and abrasion resistance are obtained. It has the feature of realizing.

The present invention is characterized in that, as described above, the coating composition has sufficient curability even in the presence of an ultraviolet absorber. Is preferably contained. further,
The coating composition of the present invention may contain colloidal silica having an average particle size of 200 nm or less. The addition of colloidal silica is extremely effective in improving the abrasion resistance of the surface of the cured product layer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The transparent synthetic resin molding base material in the present invention is a molded product having a predetermined shape obtained by molding a transparent synthetic resin, and the type of the synthetic resin is not limited. A preferred synthetic resin of the base material is a thermoplastic resin, and for example, a transparent thermoplastic synthetic resin such as an aromatic polycarbonate resin, an acrylic resin, and a polystyrene resin is preferable. Among them, aromatic polycarbonate resins are preferred. The shape of the transparent synthetic resin molding substrate is not particularly limited, but is preferably a sheet or film such as a flat plate or a corrugated plate. Further, a sheet-shaped material or the like may be subjected to secondary processing such as bending, or may be formed into a shape corresponding thereto. The transparent synthetic resin molded base material having a preferable shape is a sheet-shaped base material, and a flat base material is particularly preferable. Further, the thickness of the sheet-like substrate is preferably 1 to 100 mm from the required performance of mechanical properties such as rigidity.

The transparent synthetic resin molded substrate in the present invention may be a multilayer structure having a transparent synthetic resin layer as described above. For example, a laminate of an aromatic polycarbonate resin and a transparent thermoplastic acrylic resin may be used. The laminate can be produced by laminating sheets or films of an aromatic polycarbonate resin and a transparent thermoplastic acrylic resin, or can be produced by co-extrusion. The cured product layer can be formed on either the surface of the aromatic polycarbonate resin or the surface of the transparent thermoplastic acrylic resin.

Here, the transparent thermoplastic acrylic resin is a homopolymer of alkyl (meth) acrylate or a copolymer thereof, or a copolymer of such a monomer with another monomer. It may be. Further, a mixture of these polymers and another polymer may be used. More preferably, it is a polymethyl methacrylate-based resin having excellent weather resistance (a homopolymer of methyl methacrylate or a copolymer with another copolymerizable monomer mainly containing methyl methacrylate). When using a laminate of an aromatic polycarbonate resin and a transparent thermoplastic acrylic resin, it is preferable to form a cured layer on the surface of the transparent thermoplastic acrylic resin, and to protect the aromatic polycarbonate resin with a transparent thermosetting resin. It is also preferable to add an ultraviolet absorber to the plastic acrylic resin.

In the present invention, the cured product layer may have one or more intermediate layers between the cured product layer and the surface of the base material. The intermediate layer is preferably made of a cured product of the active energy ray-curable coating composition. The coating composition of the intermediate layer may be a composition equivalent or similar to the coating composition of the present invention, or may be another active energy ray-curable coating composition. For example, as the photopolymerization initiator in the coating composition for the intermediate layer, only one of the photopolymerization initiator (C1) and the photopolymerization initiator (C2) is used, or any one of the photopolymerization initiator and another photopolymerization initiator is used in combination. Or a photopolymerization initiator (C
Photopolymerization initiators other than 1) and (C2) may be used.

The photopolymerization initiator (C1) having a maximum absorption wavelength peak at 365 to 400 nm in the coating composition is defined as having a maximum absorption wavelength peak called λ _max of 365 to 400 nm.
Refers to a photopolymerization initiator present at 400 nm. Examples of the photopolymerization initiator (C1) include an acylated organic phosphorus-based polymerization initiator in which an acyl group is bonded to a phosphorus atom, such as an acylphosphine oxide-based polymerization initiator, and a thioxanthone-based photoinitiator. Specific examples of the thioxanthone-based photoinitiator include 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone. is there. When these thioxanthone-based photoinitiators are used, the cured film may become yellowish in color if the amount is too large. Therefore, it is preferable to adjust the amount to prevent such a coloration.

The acylated organophosphorus polymerization initiator includes:
There are acylphosphine oxide-based photopolymerization initiators, acylphosphinate-based polymerization initiators, acylphosphonate-based polymerization initiators, and the like. As the acylphosphine oxide-based photopolymerization initiator, a compound represented by the following formula (1) is used. As the acylphosphinate-based polymerization initiator, a compound represented by the following formula (2) is used. As the acylphosphonate-based polymerization initiator, Is preferably a compound represented by the following formula (3).

[0019]

R ¹ -C (= O) -P (= O) R ² R ³ (1) R ¹ -C (= O) -P (= O) R ² (OR ⁴ ) · (2) R ¹ -C (= O) -P (= O) (OR ⁴ ) ₂ ... (3)

In the formulas (1), (2) and (3), R
¹ and R ⁴ each independently represent an alkyl group having 8 or less carbon atoms, a phenyl group, a benzyl group, or a substituted phenyl group or substituted benzyl group having 15 or less carbon atoms. R
² and R ³ each independently represent an alkyl group having 8 or less carbon atoms, an acyl group having 15 or less carbon atoms, a phenyl group, a benzyl group, or a substituted phenyl or substituted benzyl group having 15 or less carbon atoms. As the acyl group having 15 or less carbon atoms, an alkanoyl group having 8 or less carbon atoms, a benzoyl group,
And a substituted benzoyl group having 12 or less carbon atoms is preferred.
Here, as the substituent of the substituted phenyl group, the substituted benzyl group, and the substituted benzoyl group, an alkyl group having 4 or less carbon atoms, an alkoxy group having 4 or less carbon atoms, a halogen atom and the like are preferable, and the number of substituents is preferably 3 or less.

As the acylated organophosphorus polymerization initiator,
Particularly, an acylphosphine oxide-based photopolymerization initiator is preferable. Examples of such an acylated organic phosphorus-based photopolymerization initiator include the following compounds. 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoyldiphenylphosphine oxide, 2,6-dimethylbenzoyldiphenylphosphine oxide, bis (2,6
-Dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphinate, methyl
2,4,6-trimethylbenzoylphenylphosphinate, isopropyl 2,4,6-trimethylbenzoylphenylphosphinate, dimethyl 2,4,6-trimethylbenzoylphosphonate, diethylbenzoylphosphonate.

The photopolymerization initiator (C1) is used in an amount of 0.02 to 10 parts by weight based on 100 parts by weight of the polyfunctional compound. Of these, the thioxanthone-based photopolymerization initiator is preferably used in a range of 0.02 to 5 parts by weight to avoid coloring of the cured film. Excessive amounts of both the thioxanthone-based and acylphosphine oxide-based photopolymerization initiators are not preferred because cracks may occur after curing and the weather resistance may be reduced. On the other hand, if the compounding amount is extremely small, poor curing and poor adhesion to the substrate are caused, which is not preferable.

As the photopolymerization initiator (C2), any one can be used as long as it has an extinction coefficient per mol at the maximum absorption wavelength (usually represented by ε) of 10,000 (l / mol / cm) or more. . However, the photopolymerization initiator (C2) is a compound other than the photopolymerization initiator (C1), and the photopolymerization initiator has the characteristics of both the photopolymerization initiator (C1) and the photopolymerization initiator (C2). If satisfactory, such photoinitiators are considered photoinitiators (C1) in the present invention.

When the ultraviolet-curable coating composition is cured by ultraviolet irradiation, oxygen is present near the surface of the coating composition, so that the radicals supplied from the initiator are consumed in the reaction with oxygen, and the ultraviolet-curable coating composition is sufficiently cured. Not supplied to the coating composition, poor curing of the polyfunctional compound is likely to occur. Therefore, by blending a photopolymerization initiator capable of generating a large amount of active radicals upon irradiation with ultraviolet light, the radicals are sufficiently distributed to the ultraviolet-curable coating composition even when the consumption of radicals by oxygen occurs. Surface hardness is obtained.

As the photopolymerization initiator (C2), for example, the following compounds are preferred. [] Shows the ε and lambda _max of the compound in the. 2,2-dimethoxy-2-phenylacetophenone [ε = 12000 l / mol / cm, λ
_max = 252 nm], 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one [ε
= 18600 l / mol / cm, λ _max = 305 n
m], 4 ′, 4 ″ -diethylisophthalophenone [ε =
38300 l / mol / cm, λ _max = 264n
m], 3,3 ′, 4,4′-tetrakis (t-butylperoxycarbonyl) benzophenone [ε = 20,000
1 / mol / cm, λ _max = 260 nm].

The photopolymerization initiator (C2) is used in an amount of 0.02 to 10 parts by weight based on 100 parts by weight of the polyfunctional compound. Again, if excessive amounts are added, cracks will occur after curing,
It is not preferable because the weather resistance may be reduced. Also,
If the compounding amount is extremely small, poor curing and poor adhesion to the substrate are undesirably caused.

The coating composition of the present invention preferably contains an ultraviolet absorber. When the coating composition contains an ultraviolet absorber, the content is preferably 50 parts by weight or less based on 100 parts by weight of the polyfunctional compound having two or more active energy ray-curable polymerizable functional groups. When the amount exceeds 50 parts by weight, the ultraviolet absorbent tends to bleed on the surface of the cured film, and the curability of the coating composition may be reduced. The lower limit of the amount of the ultraviolet absorber is not particularly limited, but in order to exhibit the effect of containing the ultraviolet absorber, 0.1% is required.
It is preferable that the amount be not less than part by weight. A more preferred usage amount of the ultraviolet absorber is 1 to 20 parts by weight based on 100 parts by weight of the polyfunctional compound.

As the ultraviolet absorber, various ultraviolet absorbers can be used, and for example, a known or well-known ultraviolet absorber such as a commercially available one can be used. Examples of such an ultraviolet absorber include a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, a salicylic acid-based ultraviolet absorber, and a phenyltriazine-based ultraviolet absorber. Further, a polymerizable ultraviolet absorber can be used as a part or all of the ultraviolet absorber. The use of the polymerizable ultraviolet absorber has an effect that even if a relatively large amount of the ultraviolet absorber is added to the composition, the surface of the ultraviolet absorber is not significantly reduced in bleeding, scratch resistance and the like.

The polymerizable UV absorber is a polymerizable UV-ray-absorbing agent having at least one polymerizable functional group similar to the active energy ray-curable polymerizable functional group in the polyfunctional compound described below and a skeleton having an ultraviolet absorbing ability. It is an ultraviolet absorber. As the polymerizable functional group, a (meth) acryloyl group described below is preferable. In particular, a compound having a benzotriazole skeleton or a benzophenone skeleton as a skeleton having an ultraviolet absorbing ability and having a structure in which an organic group having a (meth) acryloyl group is bonded to these skeletons is preferable as the polymerizable ultraviolet absorber.

In the present specification, an acryloyl group and a methacryloyl group are collectively referred to as a (meth) acryloyl group. The same applies to expressions such as (meth) acryloyloxy group, (meth) acrylic acid, and (meth) acrylate.

In the coating composition, the polymerizable ultraviolet absorber is a polyfunctional compound or a monofunctional compound having two or more active energy ray-curable polymerizable functional groups.
Although it can be regarded as a species, in the present invention, the polymerizable ultraviolet absorber is not included in any of the category of the polyfunctional compound or the monofunctional compound, and is a component included in the category of the ultraviolet absorber.

The following are specific examples of the ultraviolet absorber, but are not limited thereto. Octyl 3- ｛3- (2H
-Benzotriazol-2-yl) -5-t-butyl-
4-hydroxyphenyl} propionate, 2- (3,
5-di-tert-pentyl-2-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-
3,5-di-t-butylphenyl) benzotriazole, 2- (2-hydroxy-3-t-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2-
(2-hydroxy-3,5-di-t-butylphenyl)
-5-chlorobenzotriazole, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, pt-butylphenyl salicylate.

2- {2-hydroxy-5-((meth) acryloyloxy) phenyl} benzotriazole, 2
-{2-hydroxy-3-methyl-5-((meth) acryloyloxy) phenyl} benzotriazole, 2-
{2-hydroxy-5- (2- (meth) acryloyloxyethyl) phenyl} benzotriazole, 2- {2
-Hydroxy-5- (3- (meth) acryloyloxypropyl) phenyl} benzotriazole, 2-hydroxy-4- (meth) acryloyloxybenzophenone, 2-hydroxy-4- (2- (meth) acryloyloxyethoxy) benzophenone , 2-hydroxy-4
-(2-acryloyloxypropoxy) benzophenone, 2,2'-dihydroxy-4- (meth) acryloyloxybenzophenone.

The active energy ray-curable polymerizable functional group in the polyfunctional compound having two or more active energy ray-curable polymerizable functional groups includes unsaturated (meth) acryloyl, vinyl, allyl, etc. It is a group or a group having the same, and is preferably a (meth) acryloyl group. That is, as the polyfunctional compound, a compound having at least two polymerizable functional groups selected from an acryloyl group and a methacryloyl group is preferable. Among them, an acryloyl group which is more easily polymerized by ultraviolet rays is preferable. That is, among these groups and compounds, those having an acryloyl group as described above are preferable, for example, an acryloyloxy group, acrylic acid,
Acrylate and the like.

The polyfunctional compound has 2 per molecule.
It may be a compound having two or more kinds of active energy ray-curable polymerizable functional groups in total, or a compound having two or more kinds of the same active energy ray-curable polymerizable functional groups. The number of active energy ray-curable polymerizable functional groups in one molecule of the polyfunctional compound is 2 or more, and the upper limit is not particularly limited. Usually, 2 to 50 pieces are suitable, and 2 to 30 pieces are particularly preferable.

Preferred compounds as polyfunctional compounds are compounds having two or more (meth) acryloyl groups.
Among them, a compound having two or more (meth) acryloyloxy groups, that is, a polyester of a compound having two or more hydroxyl groups such as polyhydric alcohol and (meth) acrylic acid is preferable.

[0037] In the coating composition, two or more kinds of polyfunctional compounds may be contained as the polyfunctional compound. Further, together with the polyfunctional compound, a monofunctional compound having one polymerizable functional group that can be polymerized by an active energy ray may be included. As the monofunctional compound, a compound having a (meth) acryloyl group is preferable, and a compound having an acryloyl group is particularly preferable.

When the monofunctional compound is used in a coating composition, the proportion of the monofunctional compound with respect to the total of the polyfunctional compound and the monofunctional compound is not particularly limited, but is preferably 0 to 60% by weight. Appropriate. If the proportion of the monofunctional compound is too large, the hardness of the cured coating film may decrease and the abrasion resistance may be insufficient. A more preferable ratio of the monofunctional compound to the total of the polyfunctional compound and the monofunctional compound is 0 to 30% by weight.

The polyfunctional compound may be a compound having various functional groups or bonds other than the polymerizable functional group. For example, it may have a hydroxyl group, carboxyl group, halogen atom, urethane bond, ether bond, ester bond, thioether bond, amide bond, and the like. In particular, a (meth) acryloyl group-containing compound having a urethane bond (so-called acryl urethane) and a (meth) acrylate compound having no urethane bond are preferable. Hereinafter, these two polyfunctional compounds will be described.

The (meth) acryloyl group-containing compound having a urethane bond (hereinafter referred to as acrylic urethane) includes, for example, (1) a compound (X1) having a (meth) acryloyl group and a hydroxyl group and a compound (X1) having two or more isocyanate groups ( (2) a reaction product of the compound (X1) with the compound (X2) having two or more hydroxyl groups and a polyisocyanate;
(3) a reaction product of the compound (X3) having a (meth) acryloyl group and an isocyanate group with the compound (X2),
and so on. It is preferable that these reaction products have no isocyanate group. However, hydroxyl groups may be present. Therefore, in the production of these reaction products, it is preferable that the total number of moles of hydroxyl groups of all reaction raw materials is equal to or larger than the total number of moles of isocyanate groups.

The compound (X1) having a (meth) acryloyl group and a hydroxyl group may be a compound having one (meth) acryloyl group and one hydroxyl group.
A compound having two or more (meth) acryloyl groups and one hydroxyl group, a compound having one (meth) acryloyl group and two or more hydroxyl groups, and a compound having two or more (meth) acryloyl groups and two or more hydroxyl groups each Good. As a specific example, for example, 2-hydroxyethyl (meth) acrylate, trimethylolpropanedi (meth)
Examples include acrylate, trimethylolpropane mono (meth) acrylate, and pentaerythritol di (meth) acrylate. These are monoesters of a compound having two or more hydroxyl groups and (meth) acrylic acid or polyesters having one or more hydroxyl groups.

Further, the compound (X1) may be a ring-opening reaction product of a compound having at least one epoxy group with (meth) acrylic acid. The reaction between the epoxy group and the (meth) acrylic acid causes the ring opening of the epoxy group to form an ester bond and a hydroxyl group, resulting in a compound having a (meth) acryloyl group and a hydroxyl group. Alternatively, the compound having one or more epoxy groups may be ring-opened to form a hydroxyl group-containing compound, which may be converted to a (meth) acrylate.

As the compound having one or more epoxy groups, a polyepoxide called an epoxy resin is preferable. Examples of the polyepoxide include compounds having two or more glycidyl groups (glycidyl-type polyepoxide) such as polyhydric phenols-polyglycidyl ether (for example, bisphenol A-diglycidyl ether) and compounds having an alicyclic epoxy group (alicyclic type). Polyepoxide) is preferred. Further, a reaction product of a (meth) acrylate having an epoxy group and a compound having a hydroxyl group or a carboxyl group can be used as the compound (X1). Examples of the (meth) acrylate having an epoxy group include glycidyl (meth) acrylate.

Specific examples of the polyepoxide include the following polyepoxides. Bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether, tetrabromobisphenol A-diglycidyl ether, glycerin triglycidyl ether, novolak polyglycidyl ether, vinylcyclohexene dioxide, dicyclopentadiene dioxide.

Other specific examples of the compound (X1) include the following compounds. 2-hydroxypropyl (meth) acrylate, 1,3-propanediol mono (meth) acrylate, 1,4-butanediol mono (meth) acrylate, 2-butene-1,4-diol mono (meth) acrylate, 1, 6-hexanediol mono (meth) acrylate, glycidol di (meth)
Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol mono (or penta) (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, bisphenol A-diglycidyl ether and (meth) acryl Reaction product with acid.

The polyisocyanate may be an ordinary monomeric polyisocyanate, a multipolymer or modified polyisocyanate, or a prepolymer compound such as an isocyanate group-containing urethane prepolymer. .

Examples of the multimer include a trimer (modified isocyanurate), a dimer, and a carbodiimide modified product.
Examples of the modified form include a urethane modified form, a buret modified form, an allonate modified form, and a urea modified form obtained by modification with a polyhydric alcohol such as trimethylolpropane.
Examples of prepolymers include isocyanate group-containing urethane prepolymers obtained by reacting polyols such as polyether polyols and polyester polyols described below with polyisocyanates. These polyisocyanates can be used in combination of two or more.

Specific examples of the monomeric polyisocyanate include the following polyisocyanates (the names in [] are abbreviated). 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, methylene bis (4-phenyl isocyanate) [MDI], 1,5-
Naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, trans-cyclohexane-1,4-diisocyanate, xylylene diisocyanate [XDI], hydrogenated XDI, hydrogenated MDI, lysine diisocyanate, α, α, α ',
α'-tetramethylxylene diisocyanate, trimethylhexamethylene diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate , Bicycloheptane triisocyanate.

As the polyisocyanate, a non-yellowing polyisocyanate (polyisocyanate having no isocyanate group directly bonded to an aromatic nucleus) is particularly preferable. Specific examples include aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, and aromatic polyisocyanates such as xylylene diisocyanate. As described above, polymers and modified products of these polyisocyanates are also preferable.

Examples of the compound (X2) having two or more hydroxyl groups include polyhydric alcohols and polyols having a higher molecular weight than polyhydric alcohols. As the polyhydric alcohol, a polyhydric alcohol having 2 to 20 hydroxyl groups is preferable, and a polyhydric alcohol having 2 to 15 hydroxyl groups is particularly preferable. The polyhydric alcohol may be an aliphatic polyhydric alcohol, an alicyclic polyhydric alcohol or a polyhydric alcohol having an aromatic nucleus. Examples of the polyhydric alcohol having an aromatic nucleus include an alkylene oxide adduct of a polyhydric phenol and a ring-opened polyepoxide having an aromatic ring such as a polyhydric phenol-polyglycidyl ether.

Examples of the high molecular weight polyol include polyether polyol, polyester polyol, polyether ester polyol, polycarbonate polyol and the like. Further, a hydroxyl group-containing vinyl polymer can also be used as the polyol. These polyhydric alcohols and polyols can be used in combination of two or more.

Specific examples of the polyhydric alcohol include the following polyhydric alcohols. ethylene glycol,
1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 2,2,4 -Trimethyl-1,3-pentanediol, cyclohexanediol, dimethylolcyclohexane, trimethylolpropane, glycerin, tris (2-hydroxyethyl) isocyanurate, tris (2-hydroxypropyl) isocyanurate, pentaerythritol, ditrimethylolpropane, Dipentaerythritol, 3,9-bis (hydroxymethyl)-
2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5. 5] Undecane, ring-opened product of bisphenol A-diglycidyl ether, ring-opened product of vinylcyclohexene dioxide.

Specific examples of the polyol include the following polyols. Polyether polyols such as polyethylene glycol, polypropylene glycol, bisphenol A-alkylene oxide adduct, and polytetramethylene glycol. Aliphatic polyols such as polybutadiene diol and hydrogenated polybutadiene diol; Poly ε-
Caprolactone polyol. Adipic acid, sebacic acid,
A polyester polyol obtained by reacting a polybasic acid such as phthalic acid, maleic acid, fumaric acid, azelaic acid, glutaric acid and the above polyhydric alcohol. A polycarbonate diol obtained by reacting 1,6-hexanediol with phosgene.

Examples of the hydroxyl group-containing vinyl polymer include a copolymer of a hydroxyl group-containing monomer such as allyl alcohol, vinyl alcohol, hydroxyalkyl vinyl ether and hydroxyalkyl (meth) acrylate and a hydroxyl group-free monomer such as olefin. . Examples of the compound (X3) having a (meth) acryloyl group and an isocyanate group include 2-isocyanatoethyl (meth) acrylate and methacryloyl isocyanate. In addition,
Compounds having a polymerizable functional group other than the (meth) acryloyl group can be used in the same manner.
Or 4-isopropenyl-α, α-dimethylbenzyl isocyanate.

As the (meth) acrylic acid ester compound having no urethane bond, which is preferable as the polyfunctional compound, a polyester of a compound having two or more hydroxyl groups and a polyester of (meth) acrylic acid similar to the compound (X2) is preferable. . As the compound having two or more hydroxyl groups, the above-mentioned polyhydric alcohols and polyols are preferable. Further, a (meth) acrylate compound which is a reaction product of a compound having two or more epoxy groups and (meth) acrylic acid is also preferable.

The compound having two or more epoxy groups includes the polyepoxide. For example, commercially available epoxy resins such as the glycidyl-type polyepoxide and the alicyclic-type polyepoxide can be used.

Specific examples of the polyfunctional compound containing no urethane bond include the following compounds. (Meth) acrylates of the following aliphatic polyhydric alcohols.
1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-
Hexanediol di (meth) acrylate, carbon number 14
Di (meth) acrylates of long-chain aliphatic diols, 1,3-butanediol di (meth) acrylate,
Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, triglycerol di (meth) acrylate,
Trimethylolpropane tri (meth) acrylate, ditrimethylolpropanetetra (meth) acrylate,
Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and (Meth) acrylate.

The following (meth) acrylates of polyhydric alcohols and polyphenols having the following aromatic or triazine rings: Bis (2- (meth) acryloyloxyethyl) bisphenol A, bis (2- (meth) acryloyloxyethyl) bisphenol S, bis (2- (meth) acryloyloxyethyl) bisphenol F, tris (2
-(Meth) acryloyloxyethyl) isocyanurate, tris (2- (meth) acryloyloxypropyl) isocyanurate, bis (2- (meth) acryloyloxyethyl) -2-hydroxyethyl isocyanurate, bisphenol A dimethacrylate.

The following (meth) acrylates of hydroxyl-containing compounds-alkylene oxide adducts, (meth) acrylates of hydroxyl-containing compounds-caprolactone adducts, and (meth) acrylates of polyoxyalkylene polyols.
Here, EO represents ethylene oxide, and PO represents propylene oxide. Trimethylolpropane-EO adduct tri (meth) acrylate, trimethylolpropane-
PO adduct tri (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, hexa (meth) acrylate of dipentaerythritol-caprolactone adduct Tri (meth) acrylate of tris (2-hydroxyethyl) isocyanurate-caprolactone adduct.

Carboxylic acid esters and phosphoric acid esters having the following (meth) acryloyl groups: Bis (acryloyloxyneopentyl glycol) adipate, di (meth) acrylate of neopentyl glycol hydroxypivalate, di (meth) acrylate of neopentyl glycol hydroxypivalate-caprolactone adduct, bis (2- (meth) acryloyl Oxyethyl) phosphate, tris (2- (meth) acryloyloxyethyl) phosphate.

The following polyepoxide (meth) acrylic acid adduct (provided that one molecule of (meth) acrylic acid is added to each epoxy group of polyepoxide), and glycidyl (meth) acrylate and polyhydric alcohol or polyhydric alcohol Reaction products with carboxylic acids (provided that two or more molecules of glycidyl (meth) acrylate are reacted per molecule of polyhydric alcohol or the like). Bisphenol A-diglycidyl ether (meth) acrylic acid adduct, vinylcyclohexene dioxide- (meth) acrylic acid adduct, dicyclopentadiene dioxide- (meth) acrylic acid adduct, glycidyl (meth) acrylate and ethylene glycol Reaction product of glycidyl (meth) acrylate and propylene glycol; reaction product of glycidyl (meth) acrylate and diethylene glycol; reaction product of glycidyl (meth) acrylate and 1,6-hexanediol; glycidyl (meth) A) reaction products of acrylate and glycerol, reaction products of glycidyl (meth) acrylate and trimethylolpropane, and reaction products of glycidyl (meth) acrylate and phthalic acid.

Alkyl ethers, alkenyl ethers, carboxylic esters and the like of the above (meth) acrylates and compounds having an unreacted hydroxyl group (hereinafter also referred to as "modification"), Compound. Alkyl-modified dipentaerythritol penta (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, allyl etherified product of vinylcyclohexene dioxide- (meth) acrylic acid adduct, Vinylcyclohexene dioxide-
Methyl etherified (meth) acrylic acid adduct, stearic acid-modified pentaerythritol di (meth) acrylate.

As the polyfunctional compound, in the case of acrylic urethane, pentaerythritol or acrylic urethane which is a reaction product of polypentaerythritol or its multimer, polyisocyanate and hydroxyalkyl (meth) acrylate, or pentaerythritol or Acrylic urethane, which is a reaction product of a hydroxyl group-containing poly (meth) acrylate of pentaerythritol and a polyisocyanate, having three or more (preferably 4 to 20) active energy ray-curable polymerizable functional groups, preferable.

As the polyfunctional compound having no urethane bond, pentaerythritol poly (meth) acrylate and isocyanurate poly (meth) acrylate are preferable. A pentaerythritol-based poly (meth) acrylate is a polyester of pentaerythritol or polypentaerythritol with (meth) acrylic acid (preferably an active energy ray-curable polymerizable functional group of 4 to 2).
0). Isocyanurate-based poly (meth) acrylate is tris (hydroxyalkyl)
Polyester of isocyanurate or an adduct obtained by adding 1 to 6 mol of caprolactone or alkylene oxide to 1 mol thereof and (meth) acrylic acid (having 2 to 3 active energy ray-curable polymerizable functional groups thing)
Say. It is also preferable to use these preferable polyfunctional compounds in combination with other polyfunctional compounds having two or more active energy ray-curable polymerizable functional groups (particularly poly (meth) acrylate of polyhydric alcohol).

As the monofunctional compound that can be used together with the polyfunctional compound, for example, a compound having one (meth) acryloyl group in the molecule is preferable. Such a monofunctional compound may have a functional group such as a hydroxyl group and an epoxy group. Preferred monofunctional compounds are (meth) acrylates, ie (meth) acrylates.

Specific examples of the monofunctional compound include the following compounds. Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (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, phenylglycidyl (Meth) acrylic acid adduct of ether.

The coating composition preferably contains an effective amount of colloidal silica having an average particle size of 200 nm or less for increasing the surface hardness of the exposed surface of the cured product layer. The average particle size of the colloidal silica is preferably 1 to 100 nm, particularly preferably 1 to 50 nm. The colloidal silica is preferably the following surface-modified colloidal silica from the viewpoint of improving the dispersion stability of the colloidal silica and the adhesion between the colloidal silica and the polyfunctional compound.

When the colloidal silica is incorporated into the coating composition, the amount of the colloidal silica in the coating composition depends on the amount of the polyfunctional compound (or the monofunctional compound if a monofunctional compound is present) in the coating composition. Total of monofunctional compounds) 10
5 parts by weight or more is suitable for 0 parts by weight, and 10 parts by weight or more is preferable. When the amount is small, the purpose of blending colloidal silica is not sufficiently exhibited. That is, it is difficult to obtain a cured film having a sufficient surface hardness due to the incorporation of colloidal silica. If the amount is too large, haze is likely to be generated in the cured film, and problems such as cracks are likely to occur when the obtained transparent coated molded product is subjected to secondary processing such as hot bending. Therefore, the upper limit of the amount of colloidal silica in the coating composition is preferably 300 parts by weight based on 100 parts by weight of the polyfunctional compound. In a more preferred coating composition, the amount of colloidal silica is 50 to 250 parts by weight based on 100 parts by weight of the polyfunctional compound.

As the colloidal silica, a surface-unmodified colloidal silica can be used, but preferably a surface-modified colloidal silica is used. The use of surface-modified colloidal silica improves the dispersion stability of the colloidal silica in the composition. It is considered that the average particle size of the colloidal silica fine particles is not substantially changed or slightly increased by the modification, but the average particle size of the obtained modified colloidal silica is considered to be in the above range. The surface modified colloidal silica (hereinafter simply referred to as “modified colloidal silica”) will be described below by taking as an example the case where the modified colloidal silica is used for a coating composition. However, as described above, the modified colloidal silica is used only for the coating composition. It is not limited to.

The unmodified colloidal silica as a raw material of the modified colloidal silica is available in the form of an acidic or basic dispersion. Either form can be used, but if basic colloidal silica is used, the coating composition is dispersed by means such as the addition of an organic acid so that the coating composition does not gel and the silica does not precipitate from the colloidal dispersion. It is preferred to make the body acidic.

Various dispersion media are known as dispersion media of colloidal silica, and the dispersion media of raw material colloidal silica are not particularly limited. If necessary, the modification can be performed by changing the dispersion medium, and the dispersion medium can be changed after the modification. The dispersion medium of the modified colloidal silica is preferably used as it is as a dilution medium (solvent) of the coating composition. The solvent for diluting the coating composition is preferably a solvent having a relatively low boiling point, that is, an ordinary solvent for paint, from the viewpoint of drying properties and the like. For reasons such as ease of production, it is preferable that the dispersion medium of the raw colloidal silica, the dispersion medium of the modified colloidal silica, and the medium of the coating composition are all the same medium (solvent). As such a medium, an organic medium widely used as a solvent for paint is preferable.

As the dispersion medium, for example, the following dispersion medium can be used. water. Lower alcohols such as methanol, ethanol, isopropyl alcohol, n-butanol, t-butanol, 4-hydroxy-4-methyl-2-pentanone and ethylene glycol. Cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve. Dimethylacetamide, toluene, xylene, methyl acetate, ethyl acetate, butyl acetate, acetone and the like. As described above, an organic dispersion medium is particularly preferable as the dispersion medium, and alcohols and cellosolves are more preferable in the organic dispersion medium. Note that an integrated product of colloidal silica and a dispersion medium in which the colloidal silica is dispersed is referred to as a colloidal silica dispersion.

The modification of the colloidal silica is preferably carried out using a compound having a hydrolyzable silicon group or a silicon group having a hydroxyl group bonded thereto (hereinafter, these are referred to as modifiers). It is considered that silanol groups are generated by hydrolysis of the hydrolyzable silicon groups, and these silanol groups react with and bind to silanol groups that are considered to be present on the colloidal silica surface, and the modifier binds to the colloidal silica surface. Two or more modifiers may be used in combination. As described below, a reaction product obtained by previously reacting two kinds of modifiers having reactive functional groups capable of reacting with each other can also be used as the modifier.

The modifying agent may have two or more hydrolyzable silicon groups or silanol groups, a partial hydrolysis condensate of a compound having a hydrolyzable silicon group or a partial condensation of a compound having a silanol group. It may be a thing. Preferably, a compound having one hydrolyzable silicon group is used as a modifying agent (a partially hydrolyzed condensate may be generated during the modification treatment). Further, the modifying agent has an organic group bonded to a silicon atom, and at least one of the organic groups is preferably an organic group having a reactive functional group. Preferred modifiers are compounds represented by the following formula (4). Y _3-n -SiR ⁵ _n R ⁶ (4) where Y is a hydrolyzable group, R ⁵ is a monovalent organic group having no reactive functional group, and R ⁶ is a reactive functional group A monovalent organic group, n represents 0, 1, or 2.

The hydrolyzable group represented by Y includes, for example, a halogen atom, an alkoxy group, an acyloxy group, a carbamoyl group, an amino group, an aminoxy group, a ketoximate group and the like, and an alkoxy group is particularly preferable. As the alkoxy group, an alkoxy group having 4 or less carbon atoms is preferable, and a methoxy group and an ethoxy group are particularly preferable. Note that n
Is preferably 0 or 1. Further, the compound represented in the same manner as in the formula (4) and in which Y is a hydroxyl group is an example of the compound having a silanol group.

1 having no reactive functional group represented by R ⁵
As the valent organic group, a hydrocarbon group having 18 or less carbon atoms such as an alkyl group, an aryl group, and an aralkyl group is preferable.
As the hydrocarbon group, a hydrocarbon group having 8 or less carbon atoms,
Particularly, an alkyl group having 4 or less carbon atoms is preferable. R ⁵ is particularly preferably a methyl group or an ethyl group. Here, the monovalent organic group refers to an organic group bonded to a silicon atom by a carbon atom (the same applies to R ⁶ ).

The monovalent organic group having a reactive functional group represented by R ⁶ includes an alkyl group having a reactive functional group,
A hydrocarbon group having 18 or less carbon atoms such as an aryl group and an aralkyl group is preferred. This organic group may have two or more reactive functional groups. Examples of the reactive functional group include an amino group, a mercapto group, an epoxy group, an isocyanate group, a polymerizable unsaturated group, and a chlorine atom. The polymerizable unsaturated group may be R ⁶ itself (for example, a vinyl group), or a polymerizable unsaturated group which becomes R ⁶ by bonding to an organic group such as a (meth) acryloyloxy group or a vinyloxy group. Is also good.

The amino group may be a primary or secondary amino group. In the case of a secondary amino group, the organic group bonded to the nitrogen atom may be an alkyl group, an aminoalkyl group, an aryl group ( In particular, an alkyl group having 4 or less carbon atoms,
An aminoalkyl group having 4 or less carbon atoms and a phenyl group) are preferred.

Preferred reactive functional groups are amino, mercapto, epoxy and (meth) acryloyloxy. The organic group to which the reactive functional group is bonded is preferably an alkylene group having 8 or less carbon atoms or a phenylene group, excluding the reactive functional group, particularly preferably an alkylene group having 2 to 4 carbon atoms (among them, a polymethylene group). .

Specific examples of the modifying agent include the following compounds when classified according to the type of the reactive functional group. (Meth) acryloyloxy group-containing silanes; 3-
(Meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane and the like.

Amino group-containing silanes; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane,
3-ureidopropyltriethoxysilane, N- (N-
Vinylbenzyl-2-aminoethyl) -3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane and the like.

Mercapto group-containing silanes; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane and the like. Epoxy group-containing silanes; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Such. Isocyanate group-containing silanes; 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatopropylmethyldiethoxysilane and the like.

Examples of the reaction product obtained by previously reacting two types of modifying agents having reactive functional groups capable of reacting with each other include, for example, a reaction product of an amino group-containing silane with an epoxy group-containing silane, Reaction products of group-containing silanes and (meth) acryloyloxy group-containing silanes, reaction products of epoxy group-containing silanes and mercapto group-containing silanes, mercapto group-containing silanes 2
There are reaction products of molecules.

The modification of the colloidal silica is usually carried out by bringing a modifier having a hydrolyzable group into contact with the colloidal silica and hydrolyzing it. For example, it can be modified by adding a modifier to the colloidal silica dispersion and hydrolyzing the modifier in the colloidal silica dispersion. In this case, it is considered that the hydrolyzate of the modifier chemically or physically binds to the surface of the fine particles of colloidal silica to modify the surface. In particular, since silanol groups are usually present on the colloidal silica surface, it is considered that the silanol groups condense with the silanol groups generated by hydrolysis of the modifier to form a surface to which the hydrolysis residues of the modifier are bonded. . It is also considered that the hydrolyzate itself that has undergone a condensation reaction may similarly bind to the surface. Also,
In the present invention, modification can be performed by adding the modifying agent to the colloidal silica dispersion after hydrolyzing the modifying agent to some extent.

In the case of modifying the surface of colloidal silica with a modifier having a hydrolyzable group, the modifier is added to and mixed with the colloidal silica dispersion and hydrolyzed with water in the system or newly added water. As a result, a modified colloidal silica whose surface is modified with this hydrolyzate is obtained. A catalyst is preferably present in order to effectively promote the hydrolysis reaction of the modifying agent and the reaction between the silanol group on the colloidal silica surface and the modifying agent or its partially hydrolyzed condensate. When modifying with a modifier having a silanol group, a catalyst is preferably present to promote the reaction between the silanol groups.

The catalyst includes an acid and an alkali.
Preferably, an acid selected from inorganic acids and organic acids is used. As the inorganic acid, for example, hydrohalic acid such as hydrochloric acid, hydrofluoric acid and hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like can be used. As the organic acid, formic acid, acetic acid, oxalic acid, (meth) acrylic acid and the like can be used.

The reaction is usually carried out in a solvent in order to make the hydrolysis reaction proceed uniformly. Usually, this solvent is a dispersion medium for the raw colloidal silica dispersion. However, a solvent other than this dispersion medium or a mixed solvent of this dispersion medium and another solvent may be used. The conditions of this solvent include dissolving the modifier,
It is preferably one that is compatible with water and a catalyst and hardly causes aggregation of colloidal silica.

Specifically, water; lower alcohols such as methanol, ethanol, isopropyl alcohol and n-butanol; ketones such as acetone, methyl isobutyl ketone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; Cellosolves such as cellosolve, ethyl cellosolve and butyl cellosolve; dimethylacetamide and the like.

As these solvents, the above-mentioned dispersion medium of colloidal silica may be used as it is, or may be used in place of a solvent other than the dispersion medium. Further, a necessary amount of a solvent other than the dispersion medium may be newly added to the dispersion and used. The reaction temperature is preferably from room temperature to the boiling point of the solvent used, and the reaction time is preferably in the range of 0.5 to 24 hours, depending on the temperature.

In the modification of the colloidal silica, the amount of the modifier used is not particularly limited, but the modifiers 1 to 10 are added to 100 parts by weight of the colloidal silica (solid content in the dispersion).
0 parts by weight is suitable. If the amount of the modifier is less than 1 part by weight, it is difficult to obtain the effect of surface modification. If the amount exceeds 100 parts by weight, a large amount of unreacted modifier or hydrolyzate to condensate of the modifier not supported on the surface of the colloidal silica is generated, and these act as a chain transfer agent during curing of the coating composition. Or acts as a plasticizer for the cured film, and may lower the hardness of the cured film.

The coating composition can be used by diluting it with a solvent for coating on a substrate. Dilution with a solvent is usually essential, and a solvent is used unless the polyfunctional compound is a liquid having a particularly low viscosity. As the solvent, a solvent usually used for a coating composition containing a polyfunctional compound as a curing component can be used. The dispersion medium of the raw material colloidal silica can be used as a solvent as it is. Further, it is preferable to select and use an appropriate solvent depending on the type of the base material. The solvent is removed from the coating composition after applying the coating composition to the substrate and before curing. This solvent removal is commonly referred to as drying.

The amount of the solvent can be appropriately changed depending on the required viscosity of the composition, the desired thickness of the cured film, the drying temperature conditions, and the like. Usually 100% for the curable component in the composition
It is used up to twice the weight, preferably 0.1 to 50 times the weight. Examples of the solvent include solvents such as lower alcohols, ketones, ethers, and cellosolves, which are mentioned as the solvent used for the hydrolysis for modifying the colloidal silica. Other examples include esters such as butyl acetate and diethylene glycol monoacetate, halogenated hydrocarbons, and hydrocarbons. For coating of an aromatic polycarbonate resin having low solvent resistance, lower alcohols, cellosolves, esters, a mixture thereof and the like are suitable.

[0093] In addition to the above basic components, the coating composition may contain various additives as required. For example, in addition to the ultraviolet absorber and the like, an antioxidant, a light stabilizer, a stabilizer such as a thermal polymerization inhibitor, a leveling agent, an antifoaming agent, a thickener,
Surfactants such as an anti-settling agent, a pigment, a dispersant, an antistatic agent, and an anti-fogging agent, and a curing catalyst selected from acids, alkalis and salts may be appropriately blended and used. In particular, use of a light stabilizer is preferable.
-Hindered amine compounds such as tetraalkylpiperidine compounds are preferred.

Ultraviolet rays are particularly preferred as the active energy rays for curing the above composition. However, not limited to ultraviolet rays, electron beams and other active energy rays can be used. Xenon lamps, pulsed xenon lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, carbon arc lamps, tungsten lamps and the like can be used as the ultraviolet light source.

The thickness of the cured product layer in the transparent cured product layer may be of various thicknesses as desired. Usually 1-5
A thickness of 0 μm is appropriate, and particularly preferably a thickness of 2 to 30 μm. When an intermediate layer is present, it is preferable that the thickness of the intermediate layer be this level or even thinner.

The means for forming the uncured layer using the coating composition is not particularly limited, and a known or well-known method can be employed. For example, methods such as a dip method, a flow coat method, a spray method, a bar coat method, a gravure coat method, a roll coat method, a blade coat method, and an air knife coat method can be employed. The composition is applied to a substrate by such a method, and when the composition contains a solvent, it is preferably dried thereafter to form an uncured layer. After the uncured layer is formed, the uncured layer is cured by irradiating with an active energy ray. The irradiation time of the active energy ray can be appropriately changed depending on the type of the active energy ray, the type of the polyfunctional compound in the composition, the type and amount of the photopolymerization initiator, the thickness of the uncured layer, and the like. When the active energy ray is an ultraviolet ray and the polyfunctional compound is a compound having an acryloyl group, the object is achieved by irradiating the compound with a high-pressure mercury lamp, usually for 1 to 60 seconds. Further, for the purpose of completing the curing reaction, heat treatment after irradiation with active energy rays may be added.

[0097]

EXAMPLES The present invention will be described below based on Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to these. Example 2
The measurement and evaluation of various physical properties of Nos. To 7 were performed by the following methods, and the results are shown in Table 2.

[Abrasion resistance] According to the Taber abrasion test method,
A haze meter was used to measure the haze value when the two CS-10F wear wheels were combined with a 500 g weight and rotated 100 times and 500 times, respectively. The haze was measured at four points on the wear cycle track, and the average value was calculated. The abrasion resistance indicates the value (%) of (haze value after abrasion test)-(haze value before abrasion test).

[Adhesion] Adhesion was measured for the sample on which the cured product layer was formed and the sample which had been kept in a thermo-hygrostat at 60 ° C. and 95% relative humidity for one week (the former was the initial adhesion, and the latter was the latter). Is referred to as the adhesion after the moist heat test). For the measurement of adhesion, the sample was cut with a razor blade at 1 mm intervals with 11 cuts each in the vertical and horizontal directions to make 100 grids, and then a commercially available cellophane tape was adhered well.
The test was performed by suddenly peeling off 90 degrees forward. As a result, the number (m) of squares remaining without the coating being peeled off was expressed as m / m.
Represented by 100.

[Weather Resistance] Using a sunshine weather meter, a black panel temperature of 63 ° C. and a cycle of rainfall of 12 minutes and drying of 48 minutes were used for 1000 hours of exposure, and the appearance of each was evaluated.

Example 1 (Synthesis Example) 5 parts by weight of 3-mercaptopropyltrimethoxysilane and 50 parts by weight of 0.01N hydrochloric acid were added to 50 parts by weight of colloidal silica dispersed with ethyl cellosolve (silica content: 30% by weight, average particle size: 11 nm). .5 parts by weight were added, heated and stirred at 40 ° C. for 4 hours, and then aged at room temperature for 12 hours to obtain a mercaptosilane-modified colloidal silica dispersion.

Example 2 (Example) In a 300 mL four-necked flask equipped with a stirrer and a condenser, 60 parts by weight of isopropyl alcohol, 60 parts by weight of butyl acetate, 30 parts by weight of ethyl cellosolve, and as a photopolymerization initiator, 2,3,6
1.5 parts by weight of trimethylbenzoyldiphenylphosphine oxide [λ _max = 380 nm], 2-methyl-1
-(4-methylthiophenyl) -2-morpholinopropan-1-one [ε = 18600 l / mol / cm]
1.5 parts by weight, 2- {2-hydroxy-5- (2-acryloyloxyethyl) phenyl} as an ultraviolet absorber
5 parts by weight of benzotriazole and 1 part by weight of bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate as a light stabilizer were added and dissolved. Subsequently, the molecular weight of 2300 obtained by reacting dipentaerythritol polyacrylate with hexamethylene diisocyanate is 1
10 parts by weight of a polyfunctional urethane acrylate having an average number of acryloyl groups per molecule of 15 and 90 parts by weight of tris (2-acryloyloxyethyl) isocyanurate were added to obtain a coating composition.

This coating composition was applied to a transparent aromatic polycarbonate resin plate having a thickness of 3 mm to form a coating film.
It was left in a hot air circulating oven at 10 ° C. for 5 minutes. Then, it is 3,000 in an air atmosphere using a high-pressure mercury lamp.
Ultraviolet rays of mJ / cm ² (integrated energy of ultraviolet rays in a wavelength range of 300 nm to 390 nm) were irradiated to form a cured film having a thickness of 7 μm. Then, the above-mentioned items of scratch resistance, weather resistance and adhesion were evaluated. Table 2 shows the results.

Examples 3 to 4 (Examples) and Examples 5 to 6 (Comparative Examples) In the coating composition of Example 2, the ultraviolet absorber and the photopolymerization initiator were changed as shown in Table 1. This coating composition was applied to a 3 mm-thick polycarbonate plate in the same manner as in Example 2 to form a cured film. Table 2 shows the performance of the cured film.

The abbreviations shown in Table 1 represent the following compounds. UVA1: 2- (3,5-di-t-pentyl-2-
(Hydroxyphenyl) benzotriazole. UVA2:
2- {2-hydroxy-5- (2-acryloyloxyethyl) phenyl} benzotriazole. Initiator A:
2,4-diethylthioxanthone [λ _max = 383n
m]. Initiator B: 2,3,6-trimethylbenzoyldiphenylphosphine oxide. Initiator C: 2-methyl-
1- (4-methylthiophenyl) -2-morpholinopropan-1-one.

Example 7 (Example) In a 300 mL four-necked flask equipped with a stirrer and a condenser, 60 parts by weight of isopropyl alcohol, 60 parts by weight of butyl acetate, 30 parts by weight of ethyl cellosolve, and as a photopolymerization initiator, Initiator B
1.5 parts by weight, 1.5 parts by weight of initiator C, 3 parts by weight of 2- {2-hydroxy-5- (2-acryloyloxyethyl) phenyl} benzotriazole as an ultraviolet absorber,
As a light stabilizer, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (1 part by weight) was added and dissolved. Subsequently, bis (2-acryloyloxyethyl) -2
-Hydroxyethyl isocyanurate (100 parts by weight) was added, and the mixture was stirred at room temperature for 1 hour. Next, Example 1 was added to this reaction vessel.
150 parts by weight of the surface-modified colloidal silica prepared in the above was added, and the mixture was further stirred at room temperature for 0.5 hour to obtain a coating composition.

This coating composition was applied to a transparent aromatic polycarbonate resin plate having a thickness of 3 mm to form a coating film.
It was left in a hot air circulating oven at 0 ° C. for 5 minutes. And
This is 3,000 mJ in an air atmosphere using a high-pressure mercury lamp.
/ Cm ² (ultraviolet integrated energy in the wavelength range of 300 nm to 390 nm) was applied to form a cured film having a thickness of 7 μm. Then, the above-mentioned items of scratch resistance, weather resistance and adhesion were evaluated. The results are described in Table 2.

[0108]

[Table 1]

[0109]

[Table 2]

[0110]

The active energy ray-curable composition is blended with a photopolymerization initiator having a very large molar extinction coefficient to form an exposed surface having a high surface hardness which is less susceptible to oxygen inhibition during ultraviolet curing. In addition, by blending a second photopolymerization initiator having a maximum absorption peak in a long wavelength region as a second photopolymerization initiator, it is possible to form a transparent cured material layer having good deep curability and excellent substrate adhesion. By using two types of photopolymerization initiators as described above, a transparent coated molded article having a cured layer having excellent surface wear resistance and excellent durability and adhesion can be obtained. Further, by adding colloidal silica to the exposed layer, a transparent coated molded article having extremely high abrasion resistance and excellent durability and adhesion can be obtained.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junko Asakura 1150 Hazawa-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Asahi Glass Co., Ltd.

Claims (6)

[Claims] 1. A transparent coated molded article comprising a transparent synthetic resin molded base material and a transparent cured product layer of an active energy ray-curable coating composition provided on at least a part of the surface of the transparent synthetic resin molded base material, A radiation-curable coating composition, a polyfunctional compound having two or more active energy ray-curable polymerizable functional groups, a photopolymerization initiator (C1) having a maximum absorption wavelength peak at 365 to 400 nm, and a mole at the maximum absorption wavelength Absorption coefficient per 10,000 (l / m
ol / cm) or more, which is a coating composition containing a photopolymerization initiator (C2) [excluding the photopolymerization initiator (C1)]. 2. A transparent molded article comprising a transparent synthetic resin molded base material and a transparent cured layer of an active energy ray-curable coating composition provided on at least a part of the surface of the transparent synthetic resin molded base material. A radiation-curable coating composition, a polyfunctional compound having two or more active energy ray-curable polymerizable functional groups, a photopolymerization initiator (C1) having a peak of a maximum absorption wavelength at 365 to 400 nm, and 2,2
-Dimethoxy-2-phenylacetophenone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 4 ', 4 "-diethylisophthalophenone and 3,3', 4,4 ' -Tetrakis (t-
A transparent coated molded article comprising a coating composition containing one or more photopolymerization initiators (C2) selected from (butylperoxycarbonyl) benzophenone. 3. A polyfunctional compound 100 in a coating composition.
The transparent coated molded article according to claim 1 or 2, wherein the ratio of the photopolymerization initiator (C1) and the ratio of the photopolymerization initiator (C2) to parts by weight are both 0.02 to 10 parts by weight. 4. The transparent coated molded article according to claim 1, wherein the photopolymerization initiator (C1) is an acylphosphine oxide-based photopolymerization initiator. 5. The coating composition further comprises a UV absorber.
The transparent coated molded article according to claim 1, 2, 3, or 4. 6. The transparent coated molded article according to claim 1, wherein the coating composition further comprises colloidal silica having an average particle size of 200 nm or less.