JP3319326B2 - Primer composition and transparent coated article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer composition capable of improving the adhesion between an organic resin substrate such as polycarbonate and a silicon-based coating agent and improving the weather resistance and durability of the substrate. And a transparent coated article excellent in weather resistance and durability in which a primer layer of the primer composition is formed on an organic resin substrate and a transparent coating layer of a silicon-based coating agent is formed.

[0002]

2. Description of the Related Art Conventionally, an organic resin base material which is lightweight, easy to process, and excellent in impact resistance is apt to be scratched on its surface, and has abrasion resistance, hardness and chemical resistance. However, there is proposed a technique for forming a surface protective layer (silicone hard coat layer, hereinafter referred to as a hard coat layer) comprising a hydrolyzate of alkoxysilane and colloidal silica on the surface thereof. The layer has poor adhesion to the organic resin substrate. Therefore, generally, a primer layer is interposed.

However, when the article coated with the hard coat layer via the primer layer is used for a structure or the like which is directly exposed outdoors, the hard coat layer itself is deteriorated by ultraviolet rays irradiated from sunlight. However, it is known that the organic resin base material and the primer layer decompose, degrade and peel off, and thus have extremely poor durability.

[0004] Therefore, various proposals have been made to improve the durability of the coated article, and two proposals can be typically given. One is to include an ultraviolet absorbing compound in the hard coat layer and / or the primer layer, and the other is to impregnate the ultraviolet absorbing compound on the side of the organic resin substrate coated with the primer layer. In either method, ultraviolet rays are cut by an ultraviolet absorbing compound to prevent deterioration of the substrate.

However, in the former method, when an ultraviolet absorbing compound is contained in the hard coat layer, an organic ultraviolet absorbing compound or a silane-modified ultraviolet absorbing compound is contained in a polysiloxane solution for forming the hard coat layer. To form a hard coat layer having ultraviolet absorbing ability by dissolving it and applying and curing it on the substrate. However, its content is limited, and decomposition of the organic resin or primer layer of the substrate If the hard coat layer contains an ultraviolet absorbing compound in an amount necessary to completely prevent deterioration, the hardness and abrasion resistance of the hard coat layer are reduced, and the performance as a hard coat film is unsatisfactory. become. When the hard coat layer contains an inorganic ultraviolet absorbing compound such as titanium oxide, the film hardness tends to increase, but when a thin film having a thickness of 30 μm or less is formed, an amount that imparts a sufficient ultraviolet absorbing ability is provided. Incorporation of the above inorganic compound into the film significantly impairs the film forming property and flexibility of the film. On the other hand, when adding an organic ultraviolet absorbing compound to the primer layer,
If the primer layer contains an amount of an ultraviolet absorbing compound necessary to completely prevent the deterioration of the base material, the adhesion between the base material and the hard coat layer is reduced.

Therefore, a method is generally adopted in which both the hard coat layer and the primer layer contain an ultraviolet absorbing compound. However, even when a large amount of an ultraviolet absorbing compound is contained to such an extent that deterioration can be completely prevented, the properties of the hard coat layer and the primer layer are surely deteriorated. That is, in the method of adding a known ultraviolet absorbing compound to the primer layer, the adhesion to the substrate and the hard coat layer is significantly impaired, and the hard coat layer cannot be completely prevented from being peeled off by long-term exposure.

On the other hand, a method of impregnating an ultraviolet absorbing compound on the surface of the organic resin substrate which is in contact with the primer layer has been proposed in Japanese Patent Publication No. 4-28735. Is remarkably changed, and this is not preferable because it lowers the adhesion to the primer layer.

Further, since the ultraviolet absorbing compounds used in each of the above methods are all organic compounds,
It is mainly composed of elements such as carbon, hydrogen, oxygen, and nitrogen.
Specifically, benzophenone derivatives, benzotriazole derivatives, triazine derivatives, cyanoacrylate derivatives and the like are used. However, these organic UV absorbing compounds have excellent compatibility with organic resins, but the compounds themselves decompose and deteriorate due to long-term outdoor exposure,
In addition to the drawback that the ultraviolet absorption capacity of each layer is reduced, when the layer is formed, it is necessary to heat it to about 80 to 120 ° C. for curing, it may be thermally decomposed or sublimated and scattered. In some cases, the expected ultraviolet shielding effect cannot be achieved.

Further, JP-A-6-82604, JP-A-8-2604
No. 48204 discloses a urethane elastomer and inorganic fine particles such as titanium oxide, a primer layer composed of an organoalkoxysilane, but the urethane elastomer has poor water resistance, and particularly has a remarkable problem in hot water adhesion. There was also a problem with the dispersibility of the inorganic fine particles.

JP-A-1-149778 and JP-A-3-628
No. 2 discloses a primer composition comprising an acrylic resin and an organic ultraviolet absorber. However, the primer composition is decomposed or deteriorated by long-term outdoor exposure, or sublimation of the ultraviolet absorber by heat at the time of curing the coating film. There is a problem that can not be cut sufficiently. In addition, when the amount of the ultraviolet absorber added is increased, problems such as a decrease in adhesiveness and a decrease in transparency of the film occur.

JP-A-8-67767 discloses a primer composition for a sealing material comprising a polyisocyanate and cerium oxide fine particles. This is a primer composition for a sealing material, which comprises an acrylic resin and a vinyl resin. There is no suggestion about a system resin.

In recent years, it has been pointed out that ultraviolet rays having a wavelength of 320 to 400 nm, which is called a UVA region on the long wavelength side, have a bad effect on human bodies. There is a concern that this will have a significant impact. Nevertheless, the organic UV-absorbing compounds described above only use those that mainly absorb UV rays of 280 to 320 nm called the UVB region, and proposals for taking measures to block ultraviolet rays in the UVA region have been proposed. Almost not done.

The present invention has been made in view of the above circumstances, and in particular, has excellent ultraviolet absorbing ability in the UVA region of 320 to 400 nm, and maintains good adhesion to an organic resin base material and a hard coat layer, and is suitable for outdoor use. Composition capable of dramatically improving the durability of the coating composition and a transparent coating layer (hard coat layer) formed of a silicon-based coating agent on an organic resin substrate via a primer layer of the primer composition It is intended to provide a coated article.

[0014]

Means for Solving the Problems and Embodiments of the Invention The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that a binder resin containing a thermosetting acrylic resin having a trialkoxysilyl group has been obtained. , 320-400 nm
By mixing titanium oxide or zinc oxide fine particles that absorb ultraviolet light and an organic compound that absorbs ultraviolet light having a wavelength of 280 to 400 nm, this is applied to an organic resin base material such as polycarbonate and cured by heating. The primer layer formed by
It excels in the ability to block ultraviolet rays in the A region, and also has excellent transparency in the visible light region, maintains the adhesion as a primer layer, and is transparent with an organic resin base material and a silicon-based coating agent. The present inventors have found that they can improve the adhesion to a coating layer (hard coat layer), weather resistance, and durability, and have accomplished the present invention.

That is, according to the present invention, a binder resin containing a thermosetting acrylic resin having a trialkoxysilyl group is added to a titanium oxide absorbing 320 to 400 nm ultraviolet rays.
0.1 to 30% by weight of fine particles of zinc or zinc oxide with respect to the binder resin, and 0.1 to 30% by weight of an organic compound which absorbs ultraviolet light having a wavelength of
Provided is a primer composition for a silicon-based coating agent applied on an organic resin substrate, characterized in that the primer composition is blended at 20% by weight. Further, the present invention provides a transparent coated article formed by forming a primer layer of the above primer composition on an organic resin substrate and forming a transparent coating layer of a silicon-based coating agent on the primer layer. In this case, the silicon-based coating agent, in the following average compositional formula _{^{(I) R 5 p Si (}} OR 6) q O (4-pq) / 2 (I) ( wherein, R ⁵ is an unsubstituted or substituted monovalent hydrocarbon A hydrogen group, R ⁶ represents a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group;
q is 0.7 ≦ p ≦ 1.6, 0 ≦ q ≦ 3.3, 0.7 ≦
It is a number that satisfies p + q <4. It is preferable to use a siloxane resin represented by the formula (1) as a main component.

Hereinafter, the present invention will be described in more detail.
The primer composition of the present invention is obtained by blending at least one binder resin selected from a (meth) acrylic resin and a vinyl resin with an inorganic compound that absorbs ultraviolet light having a wavelength of 320 to 400 nm.

Here, as the binder resin, one of (meth) acrylic resin and vinyl resin can be used alone or in combination of two or more. These resins may be thermoplastic or thermosetting, and include, for example, polymers obtained by radical polymerization of a monomer having a polymerizable unsaturated group such as methyl methacrylate (MMA) in an organic solvent, and emulsion-polymerized emulsions. Can be.

In this case, as a monomer that can be used to form the (meth) acrylic resin, a monomer containing a polymerizable (meth) acrylic group is used, and specific examples include the following. However, the present invention is not limited to this. _{CH 2 = CHCOOCH 3 CH 2 =} C (CH 3) COOCH 3 CH 2 = CHCOOCH 2 CH 2 OH CH 2 = C (CH 3) COOCH 2 CH 2 OH CH 2 = CHCOOCH 2 CH 2 CH 3 CH 2 = C ( _{CH 3) COOCH 2 CH 2 CH} 3 CH 2 = CHCONHCH 3 CH 2 = C (CH 3) CONHCH 3 CH 2 = CHCON (CH 3) 2 CH 2 = C (CH 3) CON (CH 3) 2 CH 2 = CHCONHCH ₂ OH CH ₂ ＣC (CH ₃ ) CONHCH ₂ OH

[0019]

Embedded image (R ¹ represents a hydrogen atom or a methyl group, R ² represents a monovalent hydrocarbon group having 1 to 6 carbon atoms (eg, an alkyl group, an alkenyl group, a phenyl group, etc.), a is an integer of 1 to 3, b is 0 Or 1.)

[0020]

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A monomer or polymer containing an unsaturated group copolymerizable with the above-mentioned monomer may be used for the purpose of copolymerization as long as the object of the present invention is not impaired.

The vinyl-based monomer forming the vinyl-based resin includes an alkoxysilyl group-containing monomer represented by the following formula.

[0023]

Embedded image (R ² has the same meaning as described above, and c is 0 or 1.)

Examples of the alkoxysilyl group-containing monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane and the like. In addition, other vinyl monomers containing no silicon atom other than the above silane can be used.

In the present invention, as the resin component, an acrylic resin having a trialkoxysilyl group as described below can be suitably used. Therefore, a (meth) acrylic monomer containing a trialkoxysilyl group can be used. A polymerized or copolymerized product can be suitably used, which is cured by heating to form a denser film and is advantageous for enhancing the adhesion to a substrate or a coating layer.

[0026]

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Specific examples of the above (meth) acrylic monomer containing a trialkoxysilyl group include methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, acryloxypropyltrimethoxysilane, and acryloxypropyltriethoxysilane. Examples include silane.

In the primer composition of the present invention , fine particles of titanium oxide or zinc oxide are blended in the binder resin as an inorganic compound that absorbs ultraviolet rays of 320 to 400 nm. As such an inorganic compound, 320 to 400 nm
No particular limitation is imposed on the inorganic ultraviolet absorbing compound that absorbs ultraviolet light, but metal oxide fine particles having a relatively small band gap, sulfides, and microcrystals containing a rare earth element are preferred. That is, when light having a specific wavelength or less is irradiated, electrons in the valence band are excited in the conduction band, and a compound capable of generating conduction electrons and holes is preferable. It is effective to use a compound capable of converting to energy that does not deteriorate. Specifically, as these compounds, titanium oxide, zinc oxide,
Cerium oxide, tin oxide, tungsten oxide, zinc sulfide, can be cited cadmium sulfide, considering the dispersibility and the like, can be preferably used titanium oxide, oxide zinc.

The above inorganic compound is used as fine particles,
From the viewpoint of dispersibility, it is recommended to use those having a primary particle size of 1000 nm or less, preferably 300 nm or less. If the primary particle size exceeds 1000 nm, the dispersibility may be reduced, the fine particles of the inorganic compound may settle, or the visible light transmittance of the cured film may be significantly reduced.

Since the dispersibility of the fine particles of the inorganic compound greatly affects the ability to absorb ultraviolet rays and the transparency of the cured film, the secondary particle size of the fine particles of the inorganic compound due to aggregation becomes large. It is preferable to perform a treatment to prevent the following, in this case, a treatment method, silicon oxide,
Examples include surface treatment with various metal oxides such as aluminum oxide and zirconium oxide. In addition, in order to improve the ultraviolet absorbing ability of the inorganic compound fine particles, in order to quickly return the excited inorganic compound fine particles which have generated electrons and holes by absorbing light, iron or other materials such as iron are used. A method of doping with a metal to form a composite oxide and supplementing with a redox system is also effective.

In the present invention, the aforementioned 320 to 40
0.1 to 30% by weight, especially 5 to 2% by weight of the inorganic compound fine particles absorbing ultraviolet light of 0 nm with respect to the binder resin described above.
5% by weight is blended. When the amount is less than 0.1% by weight, the ultraviolet ray shielding effect is extremely low. When the amount exceeds 30% by weight, when the primer composition is obtained as a cured film, the cured film cannot have sufficient strength. It is not suitable because the adhesion to the material and the coating layer is deteriorated.

The primer composition of the present invention can be mixed with the binder resin in the form of a powder or the sol in which the inorganic compound is dispersed in a dispersion medium.

As the dispersion medium for the sol, known solvents can be mentioned, for example, water, alcohols such as methanol, ethanol, isopropanol, n-butanol and isobutanol, methyl ethyl ketone, methyl isobutyl ketone and the like. Ketones and the like can be used. When an organic solvent is used as the dispersion medium for the sol, it is also effective to treat the inorganic compound fine particles with a known silane-based coupling agent, titanate-based coupling agent, or the like in order to enhance the dispersibility. . In addition, as a method for improving the dispersibility of the inorganic compound fine particles, a known dispersant, surfactant or the like can be added to the sol.

Since the primer composition of the present invention uses the above-mentioned inorganic compound as an ultraviolet absorbing compound, the life as an ultraviolet absorbing agent is semi-permanent.
Although it can be used for a long period of time and can maintain its ultraviolet absorbing ability, an ultraviolet absorbing organic compound is added to the primer composition for the purpose of further enhancing the ultraviolet absorbing ability.

Here, as the ultraviolet absorbing organic compound that can be used, a compound that absorbs ultraviolet rays having a wavelength of 280 to 400 nm can be suitably used. The amount of the organic compound used is 0.1 to 20% by weight based on the binder resin. And particularly preferably 1 to 18% by weight. When the content exceeds 20% by weight,
When a cured film is formed, adhesion to a substrate or a coating layer is deteriorated, and the weather resistance of each layer cannot be maintained due to deterioration of the ultraviolet absorbing organic compound itself, which is not suitable in some cases.

The ultraviolet absorbing organic compound is not particularly limited, but in the present invention, from the viewpoint of availability and cost, the benzophenone derivative (1) and the benzotriazole derivative (1) 2), a compound having a triazine derivative (3) or a derivative thereof.

[0037]

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Here, R ^{1 to} R ⁴ are each a hydrogen atom or a group having 1 carbon atom.
To 18 organic groups, and examples of the organic group include an unsubstituted or substituted monovalent hydrocarbon group such as an alkyl group.

Specific examples of the ultraviolet absorbing organic compound include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and 2- (2-hydroxy-benzophenone). 5-methylphenyl) benzotriazole,
2- (2-hydroxy-5-t-octylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, 4- (2
-Acryloxyethoxy) -2-hydroxybenzophenone polymer, 2- (2-hydroxy-4-hexyloxyphenyl) -4,6-diphenyltriazine and the like, but are not limited thereto. Not something.

Further, the primer composition of the present invention may contain known additives, diluents and curing catalysts in addition to the above essential components. As the diluent, water or an organic solvent can be used, and as the organic solvent, alcohols, ketones, esters, ethers, and the like can be given.
Specifically, alcohols such as methanol, ethanol, isopropanol and isobutanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and isobutyl acetate; aromatic compounds such as toluene and xylene; Solvents and the like, and as the curing catalyst, alkyl titanates, aluminum alkoxides, aluminum chelates, dibutyluzudiooctate, dibutyluzudyllaurate, and the like can be mentioned, the amount of which is a catalytic amount, usually a binder 0.00 to 100 parts by weight of resin
It is 1 to 10 parts by weight.

The primer composition of the present invention is used for primer treatment when forming a coating layer (hard coat layer) with a silicon-based coating agent on an organic resin substrate. When forming the primer layer on the organic resin substrate, spray coating the primer composition on the organic resin substrate,
It is applied by an appropriate method such as roll coating, dip coating, spin coating, etc.
A method in which the binder resin is cured by heating at 0 ° C. for 10 minutes to 2 hours can be suitably employed. In this case, the thickness of the primer layer is not particularly limited.
It is preferably from 30 to 30 μm, particularly preferably from 1 to 20 μm.

The organic resin base material is not particularly limited, but a transparent plastic molded product is suitably used from the viewpoint of obtaining the transparent coated article according to the second invention of the present invention. Organic resin base materials such as polycarbonate resin and acrylic resin are suitable, but are not particularly limited.

Further, as the silicon-based coating agent,
The following average compositional formula _{^{(I) R 5 p Si (}} OR 6) q O (4-pq) / 2 as a main component, a siloxane resin represented by the formula (I) is preferably used.

Here, R ⁵ is an unsubstituted or substituted monovalent hydrocarbon group, preferably having 1 to 18 carbon atoms, particularly 1 to 8 carbon atoms, and specifically includes methyl, ethyl, propyl, butyl, Alkyl groups such as hexyl, cyclohexyl and octyl, alkenyl groups such as vinyl, allyl, propenyl and butenyl, aryl groups such as phenyl, aralkyl groups such as benzyl and ethylphenyl, and a part of these carbon atom-bonded hydrogen atoms or All are halogen atoms such as chlorine, bromine and fluorine, cyano groups, and monovalent hydrocarbons containing epoxy groups such as alkoxy groups having 1 to 6 carbon atoms, γ-glycidoxyalkyl groups, and 3,4-epoxycyclohexylalkyl groups. Group, monovalent hydrocarbon group containing (meth) acrylic group such as (meth) acryloxyalkyl group, monovalent hydrocarbon group containing amino group such as aminoalkyl group And those substituted with an organic functional group such as a mercapto group-containing monovalent hydrocarbon group such as a hydrogen atom group or a mercaptoalkyl group.

R ⁶ is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group. The monovalent hydrocarbon group preferably has 1 to 8 carbon atoms, particularly 1 to 6 carbon atoms. Examples thereof include an alkyl group, an alkenyl group, and an aryl group, and particularly include an alkyl group having 1 to 4 carbon atoms, and may be an alkoxy-substituted alkyl group.

P and q are 0.7 ≦ p ≦ 1.6 and 0 ≦ q ≦
3.3, a number that satisfies 0.7 ≦ p + q <4. That is, the value of p needs to be 1.6 or less in order to obtain a film having sufficient hardness, and 0.7 or more in order to obtain a film in which cracks hardly occur during curing. ≦ p ≦ 1.
6, preferably a number satisfying 0.8 ≦ p ≦ 1.5.
Further, the value of q needs to be 3.3 or less as the sum of the number of alkoxy groups or silanol groups serving as crosslinking points, and 0 ≦ q ≦ 3.3, preferably 0.1 ≦ q <3. When the value of q exceeds 3.3, volume shrinkage at the time of curing increases, and cracks easily occur in the coating film. Furthermore, 0.7 ≦ p + q <4, particularly 0.8 ≦ p + q <3.

Incidentally, the value of q can actually be determined by measuring the ²⁹ Si NMR spectrum of the siloxane resin.

The siloxane resin can be obtained by a known method, and is not particularly limited. Specifically, a siloxane resin obtained by hydrolyzing and condensing 2 to 4 functional silane compounds at a specific ratio is used. Can be manufactured as a main component,
These have a silanol group or a hydrolyzable group that can undergo a condensation reaction, and are cured at room temperature or by heat treatment.

Here, the hydrolyzable silane as a raw material is
Formula _{^{(II) R 5 m Si (}} OR 6) n (II) ( wherein, R ^5, R ⁶ are as defined above, 0 ≦ m ≦ 2,2
≦ n ≦ 4, m + n = 4. ), And the following hydrolyzable silanes can be exemplified.

Methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-t-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, n-propyltrimethoxysilane, n-propyltrimethoxysilane Propyltriethoxysilane, n-propyltriisopropoxysilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane , Tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane,
Phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, trimethoxyhydrosilane, triethoxyhydrosilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ -Glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxy Silane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ
-Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane,
Examples include γ-mercaptopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, and partially hydrolyzed products thereof.

Among these, dimethyldimethoxysilane, methyltrimethoxysilane, tetramethoxysilane, dimethyldiethoxysilane, methyltriethoxysilane, tetraethoxysilane, and dimethyldimethoxysilane, methyltrimethoxysilane, tetramethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane can be suitably used.

It is preferable to use trifunctional silane in order to maintain good film appearance and film formability such as hardness and smoothness of the film, and the above-mentioned trifunctional silane should be contained in an amount of 10 mol% or more. Is preferred.

The siloxane resin can be obtained by mixing and hydrolyzing the hydrolyzable silane and water in the presence of a hydrolyzable catalyst. As the hydrolyzable catalyst, a conventionally known catalyst can be used. However, it is preferable to use a catalyst which shows an acidity of pH 2 to 5 when it comes into contact with water, particularly, an acidic hydrogen halide, a carboxylic acid, a sulfonic acid, an acidic or weak acid. Examples thereof include acidic inorganic salts and solid acids such as ion exchange resins. Specific examples include hydrogen fluoride, hydrochloric acid, nitric acid, sulfuric acid, acetic acid, organic acids represented by maleic acid, methylsulfonic acid, and cation exchange resins having a sulfonic acid group or a carboxylic acid group on the surface. . The amount of the hydrolyzable catalyst used is 0.001 to 5 per mol of the hydrolyzable group on the silicon atom.
It is preferably set to mol.

The amount of water used for the hydrolysis is 0.05 to 50 mol, preferably 0.2 to 30 mol, per mol of the hydrolyzable group contained in the silane or siloxane resin used as the raw material. The use of is recommended.

In the above reaction, alcohol, ketone,
A polar solvent such as an ester may be used as the solvent.

The coating agent may further contain silica. Silica has an average particle size of 0.1.
What disperse | distributed the fine silica of 1-500 nm, preferably 1-200 nm in organic solvents, such as water or alcohol, is used suitably. In this case, the pH of the silica dispersion is preferably 2 to 7 from the viewpoint of the stability of the coating composition. Examples of such a silica dispersion include Snowtex-O, methanol silica sol (Nissan Chemical Co., Ltd.)
), Catroid-S, Oscar (manufactured by Catalysis Kasei)
And the like.

The solid concentration in the silica dispersion is 5 to 5.
40% by weight is preferred. Further, the silica solid content is preferably 1 to 200 parts by weight with respect to 100 parts by weight of the siloxane resin, and if it exceeds 200 parts by weight, crack resistance and flexibility of the coating film may be reduced. .

Further, an ultraviolet absorbing compound can be blended in the coating agent.

As the ultraviolet absorbing compound, the same inorganic compounds and organic compounds as the metal oxide fine particles exemplified in the primer composition can be used. The compounding amount is
1 to 3 with respect to 100 parts by weight of the above siloxane resin.
It is preferably 00 parts by weight. When the amount exceeds 300 parts by weight, the role of the siloxane resin as a binder becomes insufficient, and the properties as a coating layer and the adhesion to a primer layer are remarkably reduced, which may not be suitable.

As the metal oxide fine particles, titanium oxide fine particles conventionally used in conventionally known high-refractive-index spectacle lenses, conuclear fine particles of titanium oxide and other metal oxide fine particles, and other metal oxide fine particles. And the like, which can be used as an inorganic compound having ultraviolet absorbing properties. Specifically, titanium oxide (TiO ₂ ), cerium oxide (Ce)
O ₂ ), tin oxide (SnO ₂ ), zirconium oxide (Zr
O ₂ ), antimony oxide (Sb ₂ O ₅ ), iron oxide (Fe ₂ O)
₃ ), titanium oxide doped with iron oxide or zirconium oxide, rare earth oxide, and the like, but are not limited thereto.

The coating agent may contain a diluent, a curing catalyst and the like. In this case, as a diluent for diluting the composition, water, a known organic solvent, or the like can be used. Examples of the organic solvent include alcohols, ketones, esters, and ethers. Specifically, alcohols such as methanol, ethanol, isopropanol and isobutanol, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and isobutyl acetate, aromatic compounds such as toluene and xylene, and mixed solvents thereof And the like.

Further, as the curing catalyst, conventionally known curing catalysts can be used, for example, lithium hydroxide,
Basic compounds such as sodium hydroxide, potassium hydroxide, sodium methylate, sodium acetate, sodium formate, potassium acetate, potassium formate, potassium propionate, tetramethylammonium chloride and tetramethylammonium hydroxide; n-hexylamine; Tributylamine, diazabicycloundecene,
Ethylenediamine, hexanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, ethanolamines, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane Amine compounds such as γ- (2-aminoethyl) -aminopropylmethyldimethoxysilane; titanium compounds such as tetraisopropyl titanate and tetrabutyl titanate; aluminum triisobutoxide;
Aluminum compounds such as aluminum triisopropoxide, aluminum acetylacetonate, aluminum perchlorate and aluminum chloride; tin compounds such as tin acetylacetonate and dibutyltin octylate; cobalt octylate, cobalt acetylacetonate, iron acetylacetonate and the like And acidic compounds such as phosphoric acid, nitric acid, phthalic acid, p-toluenesulfonic acid, and trichloroacetic acid.

Further, a combination of an acid and a basic compound serving as a buffer for adjusting the pH, for example, acetic acid and sodium acetate, disodium hydrogen phosphate and citric acid may be added. In addition, for the purpose of giving excellent coating performance,
Pigments, dyes, leveling agents, storage stabilizers and the like can also be used.

As a method for forming a coating layer using the above-mentioned coating agent, a known method can be employed. Specifically, the coating layer is applied by a method such as spray coating, roll coating, dip coating, spin coating, and the like. Air drying or room temperature to 150 ° C, 10
A method of curing the siloxane resin by heating for minutes to 2 hours can be employed.

The thickness of the coating layer made of the above coating agent is not particularly limited, but may be in the range of 0.1.
It is preferably from 001 to 50 μm.

The transparent coated article formed by forming a transparent coating layer of the above coating agent on the above-mentioned organic resin base material via a primer layer of the above primer composition has an adhesive property of the base material, the primer layer and the coating layer. It is excellent. In addition, in the coated article of the present invention, the primer layer is excellent in ultraviolet absorbing ability, deterioration by ultraviolet rays is prevented as much as possible, and deterioration and interfacial peeling of each layer and substrate are prevented as much as possible. The primer layer and the coating layer have high transparency and can be used for a long time without causing discoloration such as yellowing. For example, plastic molding such as a plastic lens which requires transparency is required. It can be suitably used as a primer for a product.

[0067]

According to the primer composition of the present invention, it is possible to form a primer layer having excellent transparency especially in the UVA region and high transparency, and to impair the adhesion to the substrate and the coating layer. In addition, coated articles obtained by using this primer composition are not subject to degradation / deterioration of the UV absorbing compound itself due to long-term exposure while maintaining the conventional surface abrasion resistance and chemical resistance. It is excellent in ultraviolet absorption in the UVA region of 320 to 400 nm, in particular, and has excellent durability in which transparency is maintained for a long time.

[0068]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to adjustment examples, examples, and comparative examples, but the present invention is not limited to the following examples. In the following examples,% indicates% by weight.

[Preparation Example 1] In a 2 L flask, 30 g of commercially available polymethyl methacrylate (PMMA) resin powder and 570 g of methyl isobutyl ketone were added, and the mixture was completely dissolved by heating and stirring at 80 ° C for 2 hours. Solution A (resin concentration 5.1%) was obtained.

[Preparation Example 2] 500 g of diacetone alcohol was placed in a 5 L flask and heated to 80 ° C. under a nitrogen atmosphere. Then, 600 g of methyl methacrylate, 100 g of ethyl acrylate, γ-methacryloxypropyltrimethoxysilane were added. A mixture of 20 g and 2.5 g of AIBN was dropped, and polymerization was carried out at 100 ° C. or lower.

After the polymerization was completed, 400 g of diacetone alcohol was added, and the mixture was stirred at room temperature for 1 hour.
1568 g of a 3.2% resin solution were obtained.

50 g of the obtained resin solution was diluted with 365 g of diacetone alcohol to obtain an acrylic resin solution B having a solid concentration of 5.2%.

[Preparation Example 3] In a 2 L flask, 356 g (2.0 mol) of methyltriethoxysilane and 100 g of isopropyl alcohol were placed, and the system was cooled to 10 ° C. or less by ice cooling.
(8.0 mol) was added dropwise over 20 minutes to hydrolyze methyltriethoxysilane. After reacting for 2 hours, stirring was continued at room temperature, and the mixture was stirred for 15 hours to complete the hydrolysis of methyltriethoxysilane to obtain a siloxane resin.

When the structure of the obtained siloxane resin was measured by ²⁹ Si nuclear magnetic resonance spectrum ( ²⁹ Si NMR), it showed three broad signals, and these chemical shifts were (a) δ = −46 to −46. 48 ppm, (b) δ = −
54 to -58 ppm, (c) δ = -62 to -68 ppm
, Respectively, which belonged to the silicon atom of the structural unit represented by the following chemical formulas (a), (b) and (c).

[0075]

Embedded image (Note that Me represents a methyl group, OX in the above formula is a hydroxyl group or a residual ethoxy group, and all the silicon atoms in (c) represent silicon atoms converted into siloxy groups. Calculation was made from the respective signal intensity ratios. The molar ratio of each structure is (a):
(B): (c) = 21: 52: 27. )

From the above, it was confirmed that the unit (a) was 21 mol%, the unit (b) was 52 mol%, and the unit (c) was 27 mol%, based on all T units. From the above results, the average composition formula of the obtained siloxane resin was determined as follows. (CH ₃ ) _1.0 Si (OX) _0.94 O _1.03 (X = H or CH ₃ CH ₂ −) Further, 7.6 g of 2,4-dihydroxybenzophenone as an organic ultraviolet absorber and isobutanol were added to the siloxane solution. 164 g and 191 g of methanol-dispersed silica sol (methanol silica sol (solid content: 30%), manufactured by Nissan Chemical Co., Ltd.) were added, and the silica solid content concentration was 21.
A 1% hard coat liquid C was obtained.

[Preparation Example 4] A siloxane hydrolyzate was obtained in the same manner as in Preparation Example 3, and 7.6 g of 2,4-dihydroxybenzophenone, 164 g of isobutanol, and titanium oxide-methanol dispersed instead of methanol-dispersed silica sol were used. By adding 191 g of sol (solid content 30%), a hard coat liquid D having a solid content concentration of 21.5% was obtained.

[0078]

[0079]

[0080]

[0081]

[0082]

Examples 1 and 2 , Comparative Examples 1 to 4 As the binder resin, the acrylic resin solutions A and B obtained in Preparation Examples 1 and 2, a methanol dispersion of titanium oxide fine particles as an inorganic ultraviolet absorber , Zinc oxide fine particles (FIN
EX-75, manufactured by Sakai Chemical Industry Co., Ltd., average particle size 10n
m), 2,4-dihydroxybenzophenone, 2- (3,5-di-t-amyl-2-) as an organic ultraviolet absorber
Hydroxyphenyl) benzotriazole (TINUV
IN328, manufactured by Ciba Geigy), methyl isobutyl ketone, methanol, and diacetone alcohol as the diluting solvents in the ratio shown in Table 1 to obtain a primer composition (Example P-
1 , 2 and Comparative Examples Q-1 to 4) were obtained.

Comparative Example 5 Using the silica used in Preparation Example 3, a primer composition having the composition shown in Table 1 (Comparative Example Q-5) was obtained.

The obtained primer compositions were tested according to the following criteria. Table 2 shows the results. After storing the dispersion-stable primer composition at 25 ° C. for one month, the sedimentability of the metal oxide fine particles was visually evaluated according to the following criteria. ：: no sediment (good dispersibility) ×: sediment (poor dispersibility) The membrane transparent primer composition was flow coated on a glass plate,
The coating was obtained by heating and drying at 20 ° C. for 20 minutes, and the transparency of the obtained coating was visually evaluated according to the following criteria. ：: no turbidity (good transparency) ×: turbidity (poor transparency)

[0086]

[Table 1]

[0087]

[Table 2]

Next, Examples 1 and 2 and Comparative Examples 1 to 2 shown in Table 1 were used.
The primer composition prepared in 5 was applied to a polycarbonate plate by a dip coating method, and a primer layer having a thickness of 0.5 to 2 μm was formed under curing conditions of 120 ° C. and 20 minutes.

The hard coat liquids C and D prepared in Preparation Examples 3 and 4 were applied to the surface of the primer layer by dip coating as shown in Table 3, respectively, and cured at 120 ° C. for 1 hour. A coating layer of ８8 μm was formed to obtain a coated article.

[0090]

[Table 3]

A sunshine weather meter (WEL-SUN manufactured by Suga Test Instruments Co., Ltd.) was applied to the obtained coated article.
-HC-B-EM type) and accelerated exposure test to 100
The appearance and adhesion after 0, 3,000 and 5,000 hours were evaluated according to the following criteria. Table 4 shows the results. They were examined visually color change and adhesion state of the primer layer and the coating layer to the substrate by visual appearance. ：: No change ：: Substrate slightly yellowed Δ: Substrate yellowed ×: Substrate yellowed, peeling of coating layer, adhesion Adherence to JIS K-5400, Section 6.15. Eleven vertical and horizontal lines were cut in a grid pattern at 1 mm intervals with a knife, and a cellulo-tape (manufactured by Nichiban) was adhered to each cell, and a peeling test was performed to determine the number of cells that were not peeled.

[0092]

[Table 4]

[0093]

As is clear from Table 2, the primer composition of the present invention was excellent in dispersion stability and did not cause sedimentation of fine particles even after storage for one month.

Further, as is apparent from the results in Table 4, the coated article obtained by the production method of the present invention has a coating of the primer layer, which is higher than that of the coated article containing no metal oxide fine particles. Because of its good transparency and ultraviolet absorption, it adheres well to the hard coat layer (coating layer) and the substrate, and the hard coat layer does not peel off.
Excellent long-term use and weather resistance were observed.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-325507 (JP, A) JP-A-5-78615 (JP, A) JP-A-6-73329 (JP, A) JP-A-57-57 23661 (JP, A) JP-A-2-16048 (JP, A) JP-A-1-149878 (JP, A) JP-A-1-149879 (JP, A) JP-A-3-6282 (JP, A) JP-A-55-160033 (JP, A) JP-A-6-1455387 (JP, A) Table of Japanese Patent Application No. 55-500809 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 1/00-201/10

Claims (6)

(57) [Claims] 1. A binder resin containing a thermosetting acrylic resin having a trialkoxysilyl group,
Titanium oxide or zinc oxide absorbing 400nm ultraviolet light
An organic resin substrate comprising 0.1 to 30% by weight of the fine particles of the above binder resin and 0.1 to 20% by weight of an organic compound absorbing ultraviolet light of 280 to 400 nm with respect to the binder resin. A primer composition for a silicon-based coating agent applied thereon. 2. A primer according to claim 1 Symbol placement organic compound that absorbs ultraviolet light of 280~400nm is a compound or a UV absorbing organic compound selected from a derivative represented by the following general formula (1) to (3) Composition. Embedded image (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group having 1 to 18 carbon atoms.) Wherein to form the primer layer by a primer composition according to the organic resin substrate to Claim 1 or 2, that obtained by forming a transparent coating layer by the silicon-based coating agent on the primer layer A transparent coated article characterized by the following. 4. A silicon-based coating agent, the following average compositional formula _{^{(I) R 5 p Si (}} OR 6) q O (4-pq) / 2 (I) ( wherein, R ⁵ is unsubstituted or monosubstituted R ⁶ represents a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group;
q is 0.7 ≦ p ≦ 1.6, 0 ≦ q ≦ 3.3, 0.7 ≦
It is a number that satisfies p + q <4. 4. The transparent coated article according to claim 3 , which comprises a siloxane resin represented by the following formula as a main component. 5. The transparent coated article according to claim 4, wherein the silicon-based coating agent contains 1 to 200 parts by weight of silica based on 100 parts by weight of the siloxane resin. 6. The silicon-based coating agent comprises 280 to 40.
The compound absorbing 0 nm ultraviolet light is siloxane resin 10
0 parts by weight to contain 0.1 to 300 parts by claim 4
Or the transparent coated article according to 5 .