JP2002361807A - Antistaining polycarbonate sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antistaining polycarbonate sheet constituted by providing a photocatalytically active material layer on a polycarbonate substrate and having good durability excellent in long-term weatherability and interlaminar bonding properties. SOLUTION: The antistaining polycarbonate sheet comprises a laminate having a polycarbonate substrate and the weatherable layer, an organic-inorganic composite gradient film and a photocatalytically active material layer successively provided on the substrate. A layer containing an acrylic polymer having a weatherable component in its molecule is used as the weatherable layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifouling polycarbonate plate, and more particularly, to a laminate in which a weather-resistant layer, an organic-inorganic composite gradient film and a photocatalytic active material layer are sequentially provided on the surface of a polycarbonate substrate. The present invention relates to a polycarbonate plate having excellent weather resistance, transparency, interlayer adhesion, etc., exhibiting a photocatalytic function, and imparting excellent antifouling properties.

[0002]

2. Description of the Related Art A photocatalytically active material (hereinafter, sometimes simply referred to as a photocatalyst) is excited when irradiated with light having an energy equal to or more than its band gap to generate electrons in a conduction band and to generate positive electrons in a valence band. Holes are created. Then, generated electrons are superoxide anion by reducing surface oxygen (· O ₂ ^-) with to produce, holes oxidize surface hydroxyl groups to produce the hydroxyl radical (· OH), these reactive It is known that active oxygen species exhibit a strong oxidative decomposition function and decompose organic substances attached to the surface of a photocatalyst with high efficiency. Applying such photocatalytic functions, for example, deodorization, antifouling, antibacterial, sterilization, and furthermore, decomposing / removing various substances that are a problem on environmental pollution in wastewater and waste gas are being studied. I have.

[0003] Another function of the photocatalyst is that when the photocatalyst is photoexcited, for example, International Patent Publication No. 96/2.
As disclosed in Japanese Patent No. 9375, it is also known that the surface of the photocatalyst exhibits superhydrophilicity in which the contact angle with water becomes 10 degrees or less. Applying the superhydrophilizing function of such a photocatalyst, for example, to prevent pollution from soot contained in automobile exhaust gas for noise barriers on highways, lighting in tunnels, street lights, etc., or body coats and side panels of automobiles Use of a photocatalyst for a film for a mirror, an antifogging property, a self-cleaning window glass, and the like has been studied.

As such a photocatalyst, compounds having various semiconductor properties such as titanium dioxide,
Metal oxides such as iron oxide, tungsten oxide and zinc oxide, and metal sulfides such as cadmium sulfide and zinc sulfide are known. Among them, titanium dioxide, particularly anatase type titanium dioxide is a practical photocatalyst. Useful as This titanium dioxide exhibits excellent photocatalytic activity by absorbing light of a specific wavelength in the ultraviolet region included in daily light such as sunlight.

When a layer made of a photocatalyst is provided on an organic substrate such as plastic, if the photocatalyst is directly coated, there is a problem that the organic substrate is inevitably deteriorated in a short time due to the photocatalysis. Therefore, for example, when a photocatalytic layer is provided on a plastic substrate, as described in JP-A-2001-38858, for example, in order to prevent deterioration of the plastic substrate due to photocatalysis and to improve adhesion to the plastic substrate. Is usually provided with an intermediate layer made of a silicone resin or an acrylic-modified silicone resin. However, even if such an intermediate layer is used, since the intermediate layer has an organic substituent, the resistance to photocatalysis is not sufficient,
There is a problem that the plastic substrate deteriorates in a relatively short period of time, for example, about 1 to 3 years.

On the other hand, the present inventors have previously proposed various uses as a novel functional material, for example, a coating film, an adhesive between an organic material and an inorganic or metal material, and an organic base material and a photocatalytic coating film. The composition in the thickness direction, which is useful for applications such as an intermediate film that prevents deterioration of the organic base material and an intermediate film that improves the adhesion between the organic base material and the inorganic or metallic material layer, is provided between them. An organic-inorganic composite gradient material that changes continuously has been found (Japanese Patent Application No. 11-264592).

This organic-inorganic composite gradient material is an organic-inorganic composite material containing a chemical bond of an organic polymer compound and a metal compound, and the content of the metal compound is increased in the thickness direction of the material. It has a component gradient structure that changes continuously,
It is a novel material useful for the above various applications.

When such a gradient material is provided as an intermediate film between the plastic substrate and the photocatalyst layer, the adhesion between the plastic substrate and the photocatalyst layer is excellent, and the surface is almost a metal compound. Has good adhesion, and the intermediate film is hardly deteriorated by the photocatalytic action, so that the plastic substrate can be protected.

However, when the plastic substrate is a polycarbonate plate, the polycarbonate substrate has poor weather resistance. Therefore, when the photocatalyst layer is provided on the surface thereof via the organic-inorganic composite gradient film, the photocatalyst layer and the organic-inorganic substrate are not provided. Since the thickness of each of the composite gradient films is about 100 nm, ultraviolet rays reach the substrate and cause yellowing or whitening of the substrate in about one year. On the other hand, those having weather resistance imparted to the polycarbonate plate itself are known, but these are generally additive-type ones in which a weathering agent having a low molecular weight and no chemical bond with the substrate is simply kneaded in the substrate. Because
The bleeding of the weathering agent occurs over time, or the substrate surface is not uniformly covered with the weathering agent, and has a structure in which the weathering agent is scattered. In the same place, it is also severely deteriorated by ultraviolet rays,
When a coating film such as a photocatalyst layer or an intermediate film thereof is provided, peeling of the coating film at the interface between the intermediate film and the substrate has been induced.

[0010]

SUMMARY OF THE INVENTION Under such circumstances, the present invention is to provide a photocatalytic layer on a polycarbonate substrate, and a good antifouling property having excellent long-term weather resistance and excellent interlayer adhesion. It is an object to provide a polycarbonate plate.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to develop the above-mentioned antifouling polycarbonate plate having good durability, and as a result, a weather-resistant component has been formed on the polycarbonate substrate in the molecule. It has been found that the object can be achieved by sequentially providing a weather-resistant layer containing an acrylic polymer having an organic-inorganic composite gradient film and a photocatalytic active material layer, and based on this finding, the present invention has been completed. .

That is, the present invention provides (1) a laminate comprising a polycarbonate substrate and a weather-resistant layer, an organic-inorganic composite gradient film and a photocatalytic active material layer sequentially provided thereon, wherein the weather-resistant layer comprises: An antifouling polycarbonate plate, which is a layer containing an acrylic polymer having a weather-resistant component in the molecule. (2) The above (1), wherein the polycarbonate substrate has a sheet-like or hollow structure.
(3) The organic-inorganic composite gradient film contains a composite in which an organic polymer compound and a metal oxide compound are chemically bonded, and the content of the metal component is It has a component gradient structure that changes continuously in the thickness direction of the film, and substantially consists of only a metal oxide compound component at the interface with the photocatalytic active material layer and is in contact with the weather-resistant layer In the antifouling polycarbonate plate according to the above (1) or (2), which comprises only an organic polymer compound component,

(4) An organic-inorganic composite gradient film comprises (A) an organic polymer compound having a metal-containing group capable of bonding to a metal oxide by hydrolysis in a molecule, and (B) a metal oxide by hydrolysis. (5) The antifouling polycarbonate plate according to the above (1), (2) or (3), which is formed by applying a coating agent obtained by hydrolyzing a metal-containing compound capable of forming a compound. The organic polymer compound of the component (A) comprises (a) an ethylenically unsaturated monomer having a metal-containing group capable of bonding to a metal oxide by hydrolysis, and (b) an ethylenic monomer containing no metal. The antifouling polycarbonate plate according to the above (4), which is obtained by copolymerizing an unsaturated monomer, and the metal-containing compound of the component (6) (B) are represented by the general formula (I) R ¹ _mn M _{^{1 R 2 n ... (I)}} (R 1 in the formula unhydrolysed min Gender group, R ² is a hydrolyzable group, M
¹ is a metal atom, m is the valence of the metal atom M ¹ , n
Is an integer satisfying the relationship 0 <n ≦ m. The present invention provides the antifouling polycarbonate plate according to the above (4) or (5), which is a compound represented by the formula (1) or a condensation oligomer.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polycarbonate substrate used in the antifouling polycarbonate plate of the present invention includes:
Preferable examples include a sheet-like member and a member having a hollow structure. The thickness of the sheet-like polycarbonate substrate is not particularly limited, but is usually 1 to 30 m.
m, preferably in the range of 2 to 20 mm. Examples of the polycarbonate substrate having a hollow structure include a honeycomb-type sandwich plate, a sandwich plate having a structure shown in FIGS. 1A and 1B in the perspective view of FIG. 1, and a grid plate shown in FIG. Can be. The thickness of the polycarbonate substrate having such a hollow structure is not particularly limited, but is usually 2 to 30 m.
m, preferably in the range of 4 to 20 mm.

The polycarbonate substrate may be subjected to a surface treatment by an oxidation method or a concavo-convex method, if desired, for the purpose of improving the adhesion to the weather-resistant layer provided thereon. As the oxidation method, for example, corona discharge treatment,
Oxygen plasma treatment, chromic acid treatment (wet), flame treatment,
Hot air treatment, ozone / ultraviolet irradiation treatment and the like can be mentioned, and examples of the unevenness method include a sand blast method and a solvent treatment method. Among them, the corona discharge treatment is generally preferably used from the viewpoint of effects and operability.

In the present invention, a weather-resistant layer containing an acrylic polymer having a weather-resistant component in the molecule is provided on the surface of the polycarbonate substrate. Examples of the acrylic polymer having a weather-resistant component in the molecule include, for example, an acrylic polymer obtained by reacting the functional group of an acrylic polymer having a functional group with a weathering agent having a functional group capable of reacting with the functional group. It may be one in which a weather-resistant component is introduced in the molecule of the coalescence, or by copolymerizing a weather-resistant agent having a polymerizable vinyl group in the molecule with an acrylic monomer, to thereby form a polymer in the molecule of the acrylic polymer. It may be one in which a weather-resistant component is introduced. Among them, an acrylic polymer having a weather-resistant component in a molecule obtained by the latter copolymerization method is preferable from the viewpoint of ease of production and the like.

Next, the production of an acrylic polymer having a weather-resistant component in the molecule by a copolymerization method will be described.
In this copolymerization method, a weathering agent having a polymerizable vinyl group in the molecule and an acrylic monomer are used as raw material monomers. Here, examples of the weathering agent having a polymerizable vinyl group in the molecule include an ultraviolet absorbing compound and a light-stable compound having a polymerizable vinyl group in the molecule. Examples of the ultraviolet absorbing compound having a polymerizable vinyl group in the molecule include 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-
(2-methacryloyloxyethyl) benzotriazole, 2- (2-hydroxy-5-methylphenyl) -5
-(2-methacryloyloxyethyl) benzotriazole, 2- (2-hydroxy-5-methacryloyloxyethylphenyl) -2H-benzotriazole, 2-
(2-hydroxy-5-methacryloyloxyethylphenyl) -5-chloro-2H-benzotriazole, 2
Such as-(2-hydroxy-5-acryloyloxyethylphenyl) -2H-benzotriazole and 2- (2-hydroxy-3-tert-butyl-5-acryloyloxyethylphenyl) -5-chloro-2H-benzotriazole. Benzotriazole compounds, 2-hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-4- (2-hydroxy-3-methacryloyloxy) propoxybenzophenone, 2-hydroxy-4
Benzophenone compounds such as-(2-methacryloyloxy) ethoxybenzophenone and 2-hydroxy-4-vinyloxycarbonylmethoxybenzophenone are exemplified. Examples of the photostable compound having a polymerizable vinyl group in the molecule include 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,
Hindered amine compounds such as 6-tetramethyl-4-piperidyl methacrylate are exemplified. One of these weathering agents having a polymerizable vinyl group in the molecule may be used alone, or two or more may be used in combination.

On the other hand, examples of the acrylic monomer include (meth) acrylates having 1 to 20 carbon atoms in the alkyl group of the ester portion, specifically, methyl (meth) acrylate, ethyl (meth) acrylate, ( (Meth) propyl acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, Decyl (meth) acrylate, dodecyl (meth) acrylate,
Examples thereof include myristyl (meth) acrylate, palmityl (meth) acrylate, and stearyl (meth) acrylate. One of these may be used alone, or two or more may be used in combination.

In the present invention, a polyfunctional monomer, a monomer having a crosslinkable functional group, and other monomers can be used, if desired, in addition to the above-mentioned monomers. Here, examples of the polyfunctional monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. Acrylate, neopentyl glycol adipate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, etc. Is mentioned. One of these may be used alone, or two or more may be used in combination. By using this polyfunctional monomer, a crosslinked structure is formed in the obtained acrylic polymer, and the adhesion and weather resistance can be improved.

Examples of the monomer having a crosslinkable functional group in the molecule include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
3-hydroxypropyl (meth) acrylate, (meth)
Hydroxyacrylic esters of (meth) acrylic acid such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, acrylamide, methacrylamide, N
Acrylamides such as -methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethyl (meth) acrylate Aminopropyl, monoalkylaminoalkyl (meth) acrylates such as monoethylaminopropyl (meth) acrylate, acrylic acid, methacrylic acid, crotonic acid,
And ethylenically unsaturated carboxylic acids such as maleic acid, itaconic acid and citraconic acid. One of these monomers may be used alone, or two or more thereof may be used in combination. By using a monomer having a crosslinkable functional group in the molecule, a crosslink point which reacts with a crosslinkable compound described later can be formed in the obtained acrylic polymer.

On the other hand, examples of other monomers include vinyl esters such as vinyl acetate and vinyl propionate; olefins such as ethylene, propylene and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; styrene; -Styrene monomers such as methylstyrene, diene monomers such as butadiene, isoprene and chloroprene; nitrile monomers such as acrylonitrile and methacrylonitrile; N, N-dimethylacrylamide; N, N-dimethylmethacryl N, N-dialkyl-substituted acrylamides such as amides are exemplified. These may be used alone, or
Two or more kinds may be used in combination.

The above-mentioned weathering agent having a polymerizable vinyl group, an acrylic monomer and various monomers used as desired are subjected to radical copolymerization in a known manner, that is, in the presence of a radical polymerization initiator, so that the weathering agent is formed in the molecule. An acrylic polymer having a hydrophilic component is obtained. The content of the weather-resistant component in the acrylic polymer is preferably from 0.1 to 50% by weight, particularly preferably from 1 to 30% by weight, in view of weather resistance and other physical properties.

Specific examples of preferable commercial products of such an acrylic polymer include “U-double UV-G300”, “UV-G101”, and “UV-G101” manufactured by Nippon Shokubai Co., Ltd.
-G10 "and" the same UV-G714 ".

In the present invention, in order to form a weather-resistant layer on the polycarbonate substrate, first, the acrylic polymer and optionally a crosslinkable compound are dissolved in a suitable solvent to prepare a coating solution. At this time, various additives such as a lubricant, an antistatic agent, an antiblocking agent, a surfactant, a softener, a plasticizer, and a coloring agent can be added as long as the object of the present invention is not impaired.

Examples of the crosslinkable compound include isocyanate compounds, melamine compounds, urea compounds,
Epoxy compounds, amine compounds, amide compounds,
Examples include an aziridine compound, an oxazoline compound, a silane coupling agent, a metal chelate compound, a metal alkoxide, and a metal salt. When an acrylic polymer is crosslinked using these crosslinkable compounds, those having a crosslinking point are used as the acrylic polymer. The formation of the crosslinked structure improves the adhesion and weather resistance as described above.

Examples of suitable solvents include aromatic hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; Alcohol solvents such as -2-propanol, 1-ethoxy-2-propanol and 2-methyl-1-propanol. These may be used alone,
Two or more kinds may be used in combination.

The coating solution thus obtained is applied to a conventionally known method, for example, a dip coating method, a spin coating method,
Coating on polycarbonate substrate using spray coating, bar coating, knife coating, roll coating, blade coating, die coating, gravure coating, etc. Can be formed. The thickness of the weather-resistant layer is selected in the range of usually 2 to 20 μm, preferably 2 to 10 μm.

The weather-resistant layer thus formed contains an acrylic polymer having a weather-resistant component introduced into the molecule by a chemical bond. Therefore, the weather-resistant layer is simply a mixture of the weather-resistant component and the acrylic polymer. Unlike the layer containing, the weather-resistant component is suppressed from bleeding out or volatilizing, and is uniformly distributed, so it has excellent weather resistance,
And its life is long. In addition, the surface of the weather-resistant layer can be subjected to a corona discharge treatment for the purpose of improving the adhesion to the organic-inorganic composite gradient film provided thereon.

In the antifouling polycarbonate plate of the present invention, the organic-inorganic composite gradient film is formed on the weather-resistant layer provided on the polycarbonate substrate in this manner. The organic-inorganic composite gradient film contains a composite in which an organic polymer compound and a metal oxide compound are chemically bonded, and a component in which the content of a metal component continuously changes in the thickness direction of the film. It has an inclined structure. Such a composite gradient film together with (A) an organic polymer compound having a metal-containing group capable of bonding to a metal oxide by hydrolysis (hereinafter sometimes referred to as a hydrolyzable metal-containing group) in a molecule. , (B)
It can be formed using a coating agent obtained by subjecting a metal-containing compound capable of forming a metal oxide by hydrolysis to a hydrolysis treatment.

The organic polymer compound having a hydrolyzable metal-containing group of the component (A) includes, for example, (a) an ethylenically unsaturated monomer having a hydrolyzable metal-containing group, and (b) a metal. Can be obtained by copolymerizing ethylenically unsaturated monomers.

The ethylenically unsaturated monomer having a hydrolyzable metal-containing group (A) or (a) is a compound represented by the following general formula (II):

[0032]

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(Wherein R ³ is a hydrogen atom or a methyl group,
A is an alkylene group, preferably an alkylene group having 1 to 4 carbon atoms, and R ⁴ is a hydrolyzable group or a non-hydrolyzable group, at least one of which is hydrolyzed to form (B)
It must be a hydrolyzable group capable of components chemically bonded, and when R ⁴ is plural, each R ⁴ may be the mutually the same or different, M ² is silicon, titanium, zirconium, indium, tin, metal atoms such as aluminum, k is the valence of the metal atom M ^2. )).

In the general formula (II), examples of the hydrolyzable group of R ⁴ which can be chemically bonded to the component (B) by hydrolysis include, for example, a halogen atom such as an alkoxyl group, an isocyanate group, a chlorine atom, an oxy group. Halogen group,
An acetylacetonate group, a hydroxyl group and the like are mentioned. On the other hand, as the non-hydrolyzable group which does not chemically bond to the component (B), for example, a lower alkyl group is preferably mentioned.

Examples of the metal-containing group represented by -M ² R ⁴ _k-1 in the general formula (II) include, for example, trimethoxysilyl, triethoxysilyl, tri-n-propoxysilyl, triisopropoxy Silyl group, tri-n-butoxysilyl group, triisobutoxysilyl group, tri-sec-
Butoxysilyl group, tri-tert-butoxysilyl group, trichlorosilyl group, dimethylmethoxysilyl group, methyldimethoxysilyl group, dimethylchlorosilyl group, methyldichlorosilyl group, triisocyanatosilyl group, methyldiisocyanatosilyl group, etc. Trimethoxytitanium group, triethoxytitanium group, tri-n-propoxytitanium group, triisopropoxytitanium group, tri-n-butoxytitanium group, triisobutoxytitanium group, tri-sec-butoxytitanium group, tri-ter
t-butoxy titanium group, trichloro titanium group,
Further, trimethoxy zirconium group, triethoxy zirconium group, tri-n-propoxy zirconium group, triisopropoxy zirconium group, tri-n-butoxy zirconium group, triisobutoxy zirconium group, tri-sec-butoxy zirconium group, tri- −tert
-Butoxyzirconium group, trichlorozirconium group, or even dimethoxyaluminum group, diethoxyaluminum group, di-n-propoxyaluminum group, diisopropoxyaluminum group, di-n-butoxyaluminum group, diisobutoxyaluminum group, -Sec-butoxyaluminum group, di-tert-butoxyaluminum group, trichloroaluminum group and the like. The ethylenically unsaturated monomer of the component (a) contains 1
Species may be used, or two or more may be used in combination.

On the other hand, as the metal-free ethylenically unsaturated monomer as the component (b), for example, a compound represented by the general formula (II)
I)

[0037]

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(Wherein R ⁵ is a hydrogen atom or a methyl group,
X is a monovalent organic group. An ethylenically unsaturated monomer represented by the formula (III-a):

[0039]

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(Wherein, R ⁵ is the same as described above, and R ⁶ represents a hydrocarbon group), or an ethylenically unsaturated monomer represented by the general formula (III-a) General formula (III-b) as an ethylenically unsaturated monomer and an adhesion improver optionally added

[0041]

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(Wherein R ⁷ is a hydrogen atom or a methyl group;
R ⁸ represents an epoxy group, a halogen atom or a hydrocarbon group having an ether bond. )) And a mixture with the ethylenically unsaturated monomer represented by the formula (1).

In the ethylenically unsaturated monomer represented by the general formula (III-a), the hydrocarbon group represented by R ⁶ is a linear or branched alkyl group having 1 to 10 carbon atoms. A cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and various butyl groups, a pentyl group, a hexyl group, an octyl group, and a decyl group. Examples of the cycloalkyl group having 3 to 10 carbon atoms include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and a cyclooctyl group.
Examples of the aryl group of 0 include a phenyl group, a tolyl group,
Examples of the aralkyl group having 7 to 10 carbon atoms such as a xylyl group, a naphthyl group, and a methylnaphthyl group include a benzyl group, a methylbenzyl group, a phenethyl group, and a naphthylmethyl group.

Examples of the ethylenically unsaturated monomer represented by the general formula (III-a) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. , Hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth)
Acrylate and the like. These may be used alone or in combination of two or more.

In the ethylenically unsaturated monomer represented by the general formula (III-b), the epoxy group represented by R ⁸ , the halogen atom or the hydrocarbon group having an ether bond may have 1 to 10 carbon atoms. A linear or branched alkyl group, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. As the halogen atom for the above substituent, a chlorine atom and a bromine atom are preferable. Specific examples of the above-mentioned hydrocarbon group include the aforementioned general formula (III-
The same groups as those exemplified in the description of R ⁶ in a) can be mentioned.

Examples of the ethylenically unsaturated monomer represented by the general formula (III-b) include glycidyl (meth) acrylate, 3-glycidoxypropyl (meth) acrylate, and 2- (3,4 -Epoxycyclohexyl) ethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-bromoethyl (meth) acrylate and the like can be preferably mentioned.

The ethylenically unsaturated monomers represented by the above general formula (III) include styrene, α-methylstyrene, α-acetoxystyrene, m
-, O- or p-bromostyrene, m-, o- or p-chlorostyrene, m-, o- or p-vinylphenol, 1- or 2-vinylnaphthalene, etc., further having an ethylenically unsaturated group Stabilizer for polymerizable polymer,
For example, antioxidants, ultraviolet absorbers, light stabilizers and the like having an ethylenically unsaturated group can also be used. These may be used alone or in combination of two or more.

When the ethylenically unsaturated monomer represented by the general formula (III-a) and the ethylenically unsaturated monomer represented by the general formula (III-b) are used in combination, It is preferred to use the latter ethylenically unsaturated monomer in a proportion of 1 to 100 mol% with respect to the ethylenically unsaturated monomer.

The (a) component ethylenically unsaturated monomer having a hydrolyzable metal-containing group and the (b) component metal-free ethylenically unsaturated monomer in the presence of a radical polymerization initiator Under the radical copolymerization, (A)
An organic polymer compound having a hydrolyzable metal-containing group as a component is obtained.

On the other hand, the metal-containing compound (hydrolyzable metal-containing compound) capable of forming a metal oxide by hydrolysis of the component (B) is represented by the following general formula (I): R ¹ _mn M ¹ R ² _n (I) Wherein R ¹ is a non-hydrolyzable group, R ² is a hydrolyzable group,
¹ is a metal atom, m is the valence of the metal atom M ¹ , n
Is an integer satisfying the relationship 0 <n ≦ m. Or a condensation oligomer thereof.

The above formula (I), when R ¹ is more than one, a plurality of R ¹ may be the same or different and when R ² is plural, R ² is a same Or different. Preferred examples of the non-hydrolysable group represented by R ¹ include an alkyl group, an aryl group, and an alkenyl group. Examples of the hydrolysable group represented by R ² include a hydroxyl group, an alkoxyl group, an isocyanate group, and chlorine. Examples include a halogen atom such as an atom, an oxyhalogen group, and an acetylacetonate group. Also,
Examples of the metal atom represented by M ¹ include silicon, titanium, zirconium, indium, tin, and aluminum.

Examples of the compound represented by the general formula (I) or the condensation oligomer thereof include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, Isobutoxysilane, tetra-sec
-Butoxysilane, tetra-tert-butoxysilane and the like, and the corresponding tetraalkoxytitanium and tetraalkoxyzirconium, furthermore, trimethoxyaluminum, triethoxyaluminum, tri-
Metal alkoxides such as n-propoxyaluminum, triisopropoxyaluminum, tri-n-butoxyaluminum, triisobutoxyaluminum, tri-sec-butoxyaluminum, tri-tert-butoxyaluminum, or metal alkoxide oligomers, for example, commercially available alkoxy Silane oligomers "methyl silicate 51", "ethyl silicate 40" (all trade names manufactured by Colcoat), "MS-51", "MS"
-56 "(all trade names manufactured by Mitsubishi Chemical Corporation) and the like, and also tetraisocyanatosilane, methyltriisocyanatosilane, tetrachlorosilane, methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxy. Silane, methyltriisopropoxysilane, phenyltrimethoxysilane,
Phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltriisopropoxysilane, dimethyldimethoxysilane, dimethyltriethoxysilane, dimethyldi-n-propoxysilane, dimethyldiisopropoxysilane and the like can be mentioned. As the component, a metal alkoxide is preferable. In the present invention, one kind of the hydrolyzable metal-containing compound may be used alone, or two or more kinds thereof may be used in combination.

In the present invention, alcohols, ketones,
In a suitable polar solvent such as ether, the above (A)
A mixture of the organic polymer compound as the component and at least one hydrolyzable metal-containing compound as the component (B) is prepared by using an acid such as hydrochloric acid, sulfuric acid, or nitric acid, or a cation exchange resin as a solid acid. Hydrolysis treatment at a temperature of 100 ° C., preferably 20 to 60 ° C., and in the case of using a solid acid, after removing it, further, if necessary, distilling off or adding a solvent and suitable for coating. The viscosity is adjusted to prepare a coating agent comprising a coating solution. If the temperature is too low, hydrolysis does not proceed, while if it is too high, the hydrolysis / polymerization reaction proceeds too quickly, making control difficult, and as a result, the gradient of the resulting gradient coating film may be reduced.

Depending on the type of the inorganic component, even after the coating liquid is prepared, hydrolysis and polycondensation may gradually progress and the coating conditions may fluctuate. Therefore, a solid dehydrating agent insoluble in the coating liquid may be used. For example, addition of anhydrous magnesium sulfate or the like can prevent a decrease in pot life. In this case, the coating liquid is used for coating after removing the dehydrating agent.

Next, a coating agent comprising the coating solution thus obtained was applied on the weather-resistant layer provided on the polycarbonate substrate to an average thickness after drying of 40 to 300 n.
m, a coating film by a known means such as a dip coating method, a spin coating method, a spray coating method, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, and a gravure coating method. And a known drying process, for example, a heating and drying process at a temperature of about 40 to 150 ° C., to form a desired organic-inorganic composite gradient film.

When the average thickness of the composite gradient film is less than 40 nm, the function as an intermediate film is not sufficiently exhibited, and it is difficult to obtain a durable antifouling polycarbonate plate.
If it exceeds m, it is difficult to form a gradient film.

In the organic-inorganic composite gradient film thus formed, the surface layer has a metal component content of almost 100% in the composite film and gradually decreases in the direction of the weather-resistant layer. It becomes almost 0% near the base material. That is, in the organic-inorganic composite gradient film, the surface in contact with the weather-resistant layer is substantially composed of only the organic polymer compound component, and the other open system surface is composed of only the metal oxide-based compound component. .

To confirm such a tilted structure, for example, the surface of the tilted film is sputtered to scrape the film, and the content of carbon atoms and metal atoms on the film surface is determined over time by X-ray photoelectron spectroscopy. This can be done by measuring.

The content of the metal component in the composite gradient film is not particularly limited, but is usually 5 in terms of metal oxide.
%, Preferably from 20 to 98% by weight, particularly preferably from 50 to 90% by weight. The degree of polymerization and molecular weight of the organic polymer compound are not particularly limited as long as they can be formed into a film, and may be appropriately selected according to the type of the polymer compound and desired physical properties of the gradient film.

The surface of the organic-inorganic composite gradient film can be subjected to a corona discharge treatment for the purpose of improving the adhesion with the photocatalytic material layer provided thereon.

In the antifouling polycarbonate plate of the present invention, a photocatalytically active material layer is provided on the organic-inorganic composite gradient film thus formed. The photocatalytic active material used for this photocatalytic active material layer is not particularly limited, and conventionally known photocatalytic materials such as titanium dioxide, strontium titanate (SrTiO ₃ ), barium titanate (B
aTi ₄ O ₉ ), sodium titanate (Na ₂ Ti)
₆ O ₁₃ ), zirconium dioxide, α-Fe ₂ O ₃ , tungsten oxide, K ₄ Nb ₆ O ₁₇ , Rb ₄ Nb ₆ O ₁₇ , K ₂ Rb ₂
Nb ₆ O ₁₇ , cadmium sulfide, zinc sulfide, and the like can be given. One of these may be used alone, or 2
Although a combination of more than one species may be used, among these,
Titanium dioxide, particularly anatase-type titanium dioxide, is useful as a practical photocatalytically active material. This titanium dioxide exhibits excellent photocatalytic activity by absorbing light of a specific wavelength in the ultraviolet region included in daily light such as sunlight.

The photocatalytic active material layer in the present invention may contain a conventionally known photocatalyst promoter together with the above photocatalytic active material, if desired, for the purpose of promoting photocatalytic activity. Examples of the photocatalyst accelerator include platinum,
Platinum group metals such as palladium, rhodium and ruthenium are preferred. These may be used alone,
Two or more kinds may be used in combination. The amount of the photocatalyst promoter to be added is usually selected in the range of 1 to 20% by weight based on the total weight of the photocatalyst active material and the photocatalyst promoter from the viewpoint of photocatalytic activity.

The method for forming the photocatalytically active material layer on the organic-inorganic composite gradient film is not particularly limited, and various methods can be used. For example, a PVD method (physical vapor Phase deposition method), a dry method such as a metal spraying method, and a wet method using a coating liquid.

As the dry method, the metal spraying method is particularly preferable because the apparatus and the operation are simple. This metal spraying method is a method in which a photocatalytic active material is melted by using a gas combustion flame, is made into fine particles, and is sprayed on the composite gradient film to form a photocatalytic active material layer. In this method, when a photocatalyst accelerator is used together with the photocatalyst active material, a mixture of the photocatalyst active material and the photocatalyst accelerator may be melted and sprayed on the composite gradient film, or first, the photocatalytic active material may be melted. May be sprayed on the composite gradient film, and a melt of the photocatalyst promoter may be further sprayed thereon.

On the other hand, in the method using a coating liquid, a coating liquid comprising a photocatalytically active material and a dispersion containing an inorganic binder such as a photocatalyst accelerator and colloid particles used as needed in a suitable solvent. The coating solution is prepared on a composite gradient film by a known method such as dip coating, spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, and die coating. For example, a method of forming a photocatalytically active material layer by applying by a gravure coating method or the like and then drying naturally or by heating and drying can be used.
When a photocatalyst accelerator is used, for example, a coating solution containing a photocatalytic active material and an inorganic binder such as colloid particles used as desired is applied onto the composite gradient film, and a photocatalytic active material coating film is formed. A plastic film having a coating film of a photocatalytic active material formed on the composite gradient film is immersed in an aqueous solution containing metal ions of a photocatalyst accelerator from which dissolved oxygen has been removed, and irradiated with light to emit the metal ions. The photocatalytically active material layer can be formed by providing a photocatalyst accelerator layer on the photocatalytically active material coating by a photodeposition method in which is deposited on the coating film surface.

The inorganic binder used as needed in the preparation of the coating solution is not particularly limited as long as it can exhibit the function as a binder.
Conventionally known compounds, for example, oxides and hydroxides of metals such as silicon, aluminum, titanium, zirconium, magnesium, niobium, tungsten, tin, and tantalum, or a composite of two or more metals selected from the above metals Oxides and composite hydroxides can be used. One kind of this inorganic binder may be used, or two or more kinds may be used in combination. The coating liquid may contain other conventionally known additional components used in the coating liquid for forming the photocatalytic active material layer, such as a silicone resin, a modified silicone resin, and a silane coupling agent. .

In the antifouling polycarbonate plate of the present invention, the thickness of the photocatalytic active material layer is usually 5 nm to 2 μm.
Is selected in the range. When the thickness is less than 5 nm, the photocatalytic function is not sufficiently exhibited. When the thickness exceeds 2 μm, the effect of improving the photocatalytic function is not recognized for the thickness. The preferred thickness is 10 nm to 2 μm, especially 20 nm to 1 μm
Is preferable.

In the antifouling polycarbonate plate of the present invention, a photocatalytically active material layer is formed on an organic-inorganic composite gradient film provided on a polycarbonate substrate with a weather-resistant layer interposed therebetween. , Substantially at the interface with the photocatalytically active material layer, consisting only of the metal oxide compound component,
In addition, since the surface in contact with the weather-resistant layer is composed only of the organic polymer compound component, the adhesion between the substrate and the composite gradient film and the adhesion between the photocatalytically active material layer and the composite gradient film are extremely good. Further, at the interface with the photocatalytic active material layer, the composite gradient film is substantially composed of only the metal oxide compound component, so that the deterioration of the composite gradient film due to the photocatalytic function of the photocatalytic active material layer is suppressed.

Further, since the weather-resistant layer is provided between the polycarbonate substrate and the composite gradient film, it is possible to effectively suppress the deterioration of the polycarbonate substrate due to the ultraviolet light transmitted through the photocatalytic active material layer and the composite gradient film. it can. In addition, since the deterioration of the surface of the weather-resistant layer due to ultraviolet rays is small, the photocatalytically active material layer and the composite gradient film do not fall off the substrate for a long period of time, and the antifouling property is maintained.
When the photocatalytic active material layer is provided directly on the weather-resistant layer without using the composite gradient film, the weather-resistant layer deteriorates in a short period of time due to the photocatalytic action of the photocatalytic active material layer.

The antifouling polycarbonate plate of the present invention having such a constitution has a weather resistance of 1800 hours or more in an accelerated weathering test by a carbon arc type sunshine weather meter and maintains the antifouling performance for a long time. Can be. FIG. 2 is a cross-sectional view showing an example of the configuration of the antifouling polycarbonate plate of the present invention. The antifouling polycarbonate plate 10 has an organic-inorganic composite on the surface of a polycarbonate substrate 1 via a weather-resistant layer 2. It has a structure in which a gradient film 3 is provided, and a photocatalytically active material layer 4 is further formed thereon.

The antifouling polycarbonate plate of the present invention is suitably used as a traffic member such as a sound insulation plate of a railway or a highway, a building member such as a carport roof, a window, a partition plate of a simple house, and a daylighting plate.

[0072]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The characteristics in each example were determined according to the following methods. (1) Inclination of interlayer film Using an XPS apparatus “PHI-5600” (manufactured by ULVAC-PHI, Inc.), argon sputtering (4 kV)
Was performed at intervals of 3 minutes to scrape the film, the content of carbon atoms and metal atoms on the film surface was measured by X-ray photoelectron spectroscopy, and the inclination was examined.

(2) Weather resistance of product The polycarbonate plate with a photocatalyst film is JIS K7
Accelerated weathering test (light source: 225 W / m ² , cycle: irradiation 102) by a carbon arc type sunshine weather meter test method [testing machine: sunshine weather meter “S300” manufactured by Suga Test Instruments Co., Ltd.]
1 hour, 2 hours 1 cycle of irradiation + rainfall 18 minutes, black panel temperature: 63 ± 3 ° C., relative humidity: 55 ± 5%), observing the surface condition as follows, haze value, water contact angle And the degree of yellowing was measured. Pass / fail was determined in (a) to (d) below, and the test time when any one or more exceeded a specified value was taken as the deterioration time of the product.

(A) Surface Condition Surface Profile Measurement Microscope “VF-75” manufactured by KEYENCE CORPORATION.
00, the surface condition was observed at a magnification of 1250, and the presence or absence of peeling or cracking of the coating film was confirmed, and evaluated according to the following criteria. ：: No peeling of coating film and no cracks ×: One or both of peeling and cracking of coating film

(B) Haze value A haze value was measured according to JIS K7361 using a haze meter “NDH2000” manufactured by Nippon Denshoku Co., Ltd. In order to maintain the initial transparency, the degree of increase in the haze value relative to the initial value is preferably less than 5%.

(C) Water contact angle Elma Sales Co., Ltd. contact angle measuring instrument "G-1-1000"
Was measured in an atmosphere at a temperature of 25 ° C. and a relative humidity of 50%. For maintaining the antifouling property, the contact angle is preferably less than 10 °.

(D) Yellowing degree Visible ultraviolet spectrophotometer “UV210” manufactured by Shimadzu Corporation
Using "0", the measurement was performed in accordance with JIS K7103.
It is preferable that the degree of increase (ΔYI) of the YI value with respect to the initial stage is less than 3% because yellowing is small.

Example 1 120 g of titanium tetraisopropoxide was added to ethanol 1
A mixed solution of 25 g of concentrated hydrochloric acid, 5 g of water and 50 g of ethanol was slowly added dropwise to the solution dissolved in 00 g while stirring. This solution is stirred at room temperature for 6 hours, and the inorganic component liquid (a)
I got After dissolving 0.1 g of 2,2'-azobisisobutyronitrile in a mixed solution of 10.9 g of methyl methacrylate and 1.36 g of γ-methacryloxypropyltrimethoxysilane, the mixture is stirred at 75 ° C. for 3 hours with stirring. The reaction was performed to obtain a copolymer (A) having a weight average molecular weight of about 70,000 in terms of polystyrene by gel permeation chromatography (GPC). This copolymer 1.0
g in 100 ml of methyl isobutyl ketone and 1
An organic component solution (b) having a concentration of 0 g / L was obtained.

In 40 ml of methyl isobutyl ketone, 10 ml of the organic component solution (b) and 40 m of 2-ethoxyethanol
After adding 1 l, 10 ml of the inorganic component liquid (a) was added with slow stirring to prepare a coating liquid (c). Acrylic polyol-based Hals hybrid resin [Nippon Shokubai Co., Ltd.
"U-double UV-G300" manufactured by Sumitomo Bayer Urethane Co., Ltd.
00 "], 1.3 g of ethyl acetate and 1-ethoxy-
It was completely dissolved in a mixed solvent with 18 g of 2-propanol to prepare a coating solution (d) for a weather-resistant layer.

As a base material, a polycarbonate plate [“Polycaace EC100” manufactured by Tsutsunaka Plastics Industry Co., Ltd .;
100 mm × 100 mm × 5 mm], and applying the coating solution (d) for the weather-resistant layer to the surface thereof by spin coating (300 rpm).
m, 20 seconds), and then heat-treated in a fine oven at 80 ° C. for 18 hours to form a 3.5 μm thick weatherable layer. Next, the coating liquid (c) is spin-coated (1500 rpm, 20 seconds) on the weather-resistant layer,
Heat treatment was performed at 80 ° C. for 15 hours to form a photocatalyst intermediate film having a thickness of 60 nm. At this time, in order to improve the adhesion between the weather-resistant layer and the photocatalytic interlayer, the weather-resistant layer may be subjected to a corona discharge treatment of about 50,000 J / m ² in advance. Also,
From the XPS measurement results (FIG. 3), it was found that the photocatalyst intermediate film was a film having a gradient.

Next, a photocatalyst solution “STK-211” manufactured by Ishihara Sangyo Co., Ltd. was spin-coated (1500 rpm, 20 seconds) on the photocatalyst intermediate film, and then heat-treated at 80 ° C. for 1 hour to obtain a film having a thickness of 50 nm. Was formed, and a polycarbonate plate with a photocatalyst film was prepared. At this time, in order to improve the adhesion between the photocatalyst layer and photocatalytic intermediate film may be subjected to 10,000 J / m ² about corona discharge treatment photocatalytic intermediate film. Table 1 shows various characteristics.

The polycarbonate sheet with the photocatalytic film was subjected to an accelerated weathering test using a carbon arc type sunshine weather meter. As a result, no peeling or cracking of the photocatalytic film or the intermediate film was observed even after 3000 hours. The degree of increase in haze value relative to the initial value was less than 5% (3.44% compared to the initial value of 0.39%). The water contact angle was 5 °, indicating super hydrophilicity, and ΔYI = 0.21
And no yellowing was observed.

Example 2 Instead of a polycarbonate plate, a hollow core portion was formed by integrally molding a large number of polycarbonate ribs between two polycarbonate substrates instead of a polycarbonate plate in a sandwich manner. A hollow structure polycarbonate plate with a photocatalytic film was produced in the same manner as in Example 1 except that a polycarbonate plate was used. Here, from the XPS measurement results (FIG. 4), it was confirmed that the photocatalyst intermediate film was a film having a gradient. Table 1 shows various characteristics.

As a result of an accelerated weathering test of this polycarbonate plate with a photocatalytic film and a hollow structure using a carbon arc type sunshine weather meter, the result was 3000.
After the lapse of time, there was no peeling or cracking of the photocatalytic film and the intermediate film, and the degree of increase in the haze value was less than 5% (33.10% against 29.08% in the initial stage). The water contact angle was 5 °, indicating superhydrophilicity, and ΔYI = 1.57, indicating no yellowing.

Example 3 A polycarbonate with a photocatalyst film was prepared in the same manner as in Example 1 except that the number of revolutions of the spin coat at the time of forming the weather-resistant layer was 1000 rpm and a weather-resistant layer having a thickness of 1.48 μm was formed. A plate was made. Here, the XPS measurement result (FIG. 5) confirmed that the photocatalyst intermediate film was a film having a gradient. Table 1 shows various characteristics.

The polycarbonate sheet with the photocatalytic film was subjected to an accelerated weathering test using a carbon arc type sunshine weather meter. As a result, almost no peeling or cracking of the coating film was observed after 1800 hours, and the haze value increased. Was less than 5% (5.30% vs. 0.40% initially). The water contact angle is 9 ° and ΔYI = 2.8
3 and yellowing was hardly observed.

Example 4 A polycarbonate plate with a photocatalyst film was prepared in the same manner as in Example 1 except that the following acrylic copolymer A was used as the weathering layer. The thickness of the weather-resistant layer obtained here is 4.25.
μm. In addition, the acrylic copolymer A and the coating liquid
The detailed preparation method of (e) is as follows.

First, 9.12 g of methyl methacrylate,
2.59 g of 2-hydroxyethyl methacrylate, a polymerizable benzotriazole-based UV absorber "RUVA-9"
3 "(manufactured by Otsuka Chemical Co., Ltd.), 1.83 g, polymerizable hindered amine light stabilizer" LA-82 "(manufactured by Asahi Denka Kogyo KK)
After mixing and dissolving 1.86 g and 0.22 g of 2,2'-azobisisobutyronitrile, the mixture is reacted at 75 ° C. for 3 hours to obtain an acrylic copolymer having an ultraviolet absorber and a light stabilizer in the molecule. A was obtained.

Next, 5 g of the acrylic copolymer A and a curing agent
[Sumijur N3 manufactured by Sumitomo Vial Urethane Co., Ltd.
200 "] 1 g of ethyl acetate and 1-ethoxy-2
-Completely dissolved in a mixed solvent with 18 g of propanol,
A coating solution (e) for a weather resistant layer was prepared.

From the XPS measurement results (FIG. 6), it was confirmed that the photocatalyst intermediate film was a film having a gradient. Shows various characteristics
Shown in 1. The polycarbonate sheet with the photocatalyst film was subjected to an accelerated weathering test using a carbon arc type sunshine weather meter. As a result, there was no peeling or cracking of the photocatalyst and the intermediate film even after 3000 hours, and the haze value increased by 5%. (Initial 0.51
5.20% to%). The water contact angle was 8 °, indicating superhydrophilicity, ΔYI = 1.81, and no yellowing was observed.

Comparative Example 1 A polycarbonate plate with a photocatalytic film was produced in the same manner as in Example 1, except that the weather-resistant layer was not provided on the substrate. Here, the XPS measurement result (FIG. 7) confirmed that the photocatalyst intermediate film was a film having a gradient. Table 1 shows various characteristics.

As a result of an accelerated weathering test of this polycarbonate plate with a photocatalytic film using a carbon arc type sunshine weather meter, cracks and peeling of the coating film were already observed after 300 hours. The degree of increase in the haze value was 5% or more (13.91% compared to 0.39% in the initial stage). The water contact angle was 15 ° and considerable yellowing was observed (ΔYI = 11.26).

Comparative Example 2 In Example 1, a polycarbonate sheet with a weather-resistant layer was not used as the substrate, but instead a polycarbonate sheet with a weather-resistant agent (“Polycaace EC1” manufactured by Tsutsunaka Plastics Industry Co., Ltd.)
00U ", 100 mm x 100 mm x 3 mm), except that a polycarbonate plate with a photocatalyst film was produced in the same manner as in Example 1. Here, the photocatalyst intermediate film is the XP
From the S measurement results (FIG. 8), it was confirmed that the film had a gradient. Table 1 shows various characteristics.

The polycarbonate sheet with the photocatalytic film was subjected to an accelerated weathering test using a carbon arc type sunshine weather meter. As a result, no yellowing was observed after 900 hours (ΔYI = 1.83). Peeling and cracking were observed. The haze value increase was 5% or more (6.51 compared to 0.57% in the initial stage).
%), And the water contact angle was 18 °.

Comparative Example 3 A polycarbonate plate with a photocatalyst film was produced in the same manner as in Example 1, except that the photocatalyst film was directly provided on the weather-resistant layer without providing the photocatalyst intermediate film. Table 1 shows various characteristics.

The polycarbonate sheet with the photocatalyst film was subjected to an accelerated weathering test using a carbon arc sunshine weather meter. As a result, no yellowing was observed after 300 hours (ΔYI = 0.74). The haze value was increased by 5% or more (7.86% from 0.46% in the initial stage), and the water contact angle was 20 °.

[0098]

[Table 1]

[0099]

According to the present invention, a weather-resistant layer containing an acrylic polymer having a weather-resistant component in a molecule, an organic-inorganic composite gradient film and a photocatalytic active material layer are sequentially provided on the surface of a polycarbonate substrate. A polycarbonate plate having excellent weather resistance, transparency, interlayer adhesion, etc., exhibiting a photocatalytic function, and imparting excellent antifouling properties can be obtained. This antifouling polycarbonate plate has antifouling properties and transparency for more than 10 years of actual use.

[Brief description of the drawings]

FIG. 1 shows an antifouling polycarbonate plate of the present invention.
It is a perspective view showing an example of a honeycomb type sandwich structure in a polycarbonate board of a hollow structure used as a substrate.

FIG. 2 shows the configuration 1 of the antifouling polycarbonate plate of the present invention.
It is sectional drawing which shows an example.

FIG. 3 is a graph showing the relationship between the sputtering time and the content of carbon atoms and titanium atoms in the photocatalyst intermediate film formed in Example 1.

FIG. 4 is a graph showing the relationship between the sputtering time and the content of carbon atoms and titanium atoms in the photocatalyst intermediate film formed in Example 2.

FIG. 5 is a graph showing the relationship between the sputtering time and the content of carbon atoms and titanium atoms in the photocatalyst intermediate film formed in Example 3.

FIG. 6 is a graph showing the relationship between the sputtering time and the content of carbon atoms and titanium atoms in the photocatalyst intermediate film formed in Example 4.

7 is a graph showing the relationship between the sputtering time and the content of carbon atoms and titanium atoms in the photocatalyst intermediate film formed in Comparative Example 1. FIG.

FIG. 8 is a graph showing the relationship between the sputtering time and the content of carbon atoms and titanium atoms in the photocatalyst intermediate film formed in Comparative Example 2.

[Explanation of symbols]

 Reference Signs List 1 polycarbonate substrate 2 weather-resistant layer 3 organic-inorganic composite gradient film 4 photocatalytic active material layer 10 antifouling polycarbonate plate

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F100 AA17C AK01C AK45A AK70C AK71C AL01C AR00B AR00C BA04 BA07 BA10A BA10D BA44C DC01A EH46 EH462 EJ42 EJ422 EJ55 EJ552 GB07 GB31 JD20D JL06 JL09 JL11

Claims (6)

[Claims] 1. A laminate comprising a polycarbonate substrate and a weather-resistant layer, an organic-inorganic composite gradient film and a photocatalytically active material layer sequentially provided thereon, wherein the weather-resistant layer comprises:
An antifouling polycarbonate plate comprising a layer containing an acrylic polymer having a weather-resistant component in a molecule. 2. The antifouling polycarbonate plate according to claim 1, wherein the polycarbonate substrate has a sheet shape or a hollow structure. 3. The organic-inorganic composite gradient film contains a complex in which an organic polymer compound and a metal oxide compound are chemically bonded, and the content of a metal component is continuous in the thickness direction of the film. Which has a component gradient structure that changes to substantially, at the interface with the photocatalytically active material layer, consists essentially of a metal oxide-based compound component, and on the surface in contact with the weather-resistant layer, only an organic polymer compound component The antifouling polycarbonate plate according to claim 1, comprising: 4. An organic-inorganic composite gradient film comprising: (A) an organic polymer compound having a metal-containing group capable of bonding to a metal oxide by hydrolysis in a molecule; and (B) a metal oxide by hydrolysis. The antifouling polycarbonate plate according to claim 1, 2 or 3, which is formed by applying a coating agent obtained by hydrolyzing a metal-containing compound that can be formed. 5. The organic polymer compound of component (A),
(A) an ethylenically unsaturated monomer having a metal-containing group capable of bonding to a metal oxide by hydrolysis in a molecule;
The antifouling polycarbonate plate according to claim 4, which is obtained by copolymerizing a metal-free ethylenically unsaturated monomer. 6. The metal-containing compound of the component (B) is represented by the following general formula (I): R ¹ _mn M ¹ R ² _n (I) (wherein R ¹ is a non-hydrolyzable group, and R ² is hydrolyzed) Sex group, M
¹ is a metal atom, m is the valence of the metal atom M ¹ , n
Is an integer satisfying the relationship 0 <n ≦ m. 6. The antifouling polycarbonate plate according to claim 4, which is a compound represented by the formula (1) or a condensation oligomer.