JP2003165929A - Energy-curable coating composition containing a photocatalyst capable of forming a low-contamination coating film, the coating film, a substrate coated with the coating film, and a method for preventing contamination - Google Patents

Abstract

(57) Abstract: A photocatalyst-containing energy-ray-curable coating composition capable of forming a coating film having a function of easily decomposing stains and a function of reducing contamination with high production efficiency, a coating film formed from the composition, Provided are a coated substrate coated with a coating film and an antifouling method for the substrate using the composition. SOLUTION: (A) Photocatalyst particles, (B) energy ray-curable urethane (meth) acrylate resin, and (C) energy ray-curable polysiloxane-modified urethane (meth)
A photocatalyst-containing energy ray-curable coating composition comprising an acrylate resin; a coating film formed from the composition; a coated substrate coated with the coating film; Antifouling method of the substrate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating composition, a coating film formed from the composition, a coated substrate coated with the coating film, and a method for antifouling a substrate using the composition, More specifically, a photocatalyst-containing energy ray-curable coating composition capable of forming a coating film having an easily decomposing function and a low-pollution function with high production efficiency, a coating film formed from the composition, and a coating film coated with the coating film. The present invention relates to a coated substrate, and a method for antifouling a substrate using the composition.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Since building materials such as roofing materials, shutters, and outer wall materials are used outdoors, they are severely contaminated by wind and rain and human beings, and such building materials have excellent pollution resistance. Is required. In addition, the same applies indoors, where it is difficult for such stains to adhere to the kitchen, kitchen, bathroom, etc. Interior wall materials that are easy to drop are required.

In order to achieve such an object, conventionally, there has been adopted a method of preventing the adhesion of dirt by providing a fluorine-based or silicone-based resin coating having excellent water repellency and oil repellency on the surface of a substrate. ing. However, with such a method, a small amount of dirt may remain even after the dirt adhered to the wall material is wiped off or washed away, and the dirt may be harder to remove due to the accumulation of the small quantity of dirt. It was

On the other hand, there has been proposed an antifouling method in which dirt is decomposed by forming a film containing photocatalyst particles such as titanium dioxide and titanium peroxide on the surface of a base material. This method uses a mechanism in which a photocatalyst is activated by ultraviolet rays or the like to generate radical active species from water and oxygen in the air and decompose dirt such as oil. However, in a place where dirt is particularly severe, the rate of pollution is high, and a method that depends only on the decomposition action of dirt by a photocatalyst is not always sufficient.

Under these circumstances, in Japanese Patent Laid-Open No. 2000-96800, a coating film containing an oil repellent substance and photocatalyst particles is formed on the surface of the substrate, and the surface of the coating film is coated with the above-mentioned repellent material. Both the oily substance and the photocatalyst particles are exposed, at least a part of the photocatalyst particles are exposed so that a part of the particles are in contact with the outside air, and the arithmetic mean roughness of the coating film surface. Ra is a stylus type measuring device (JIS B
0601) proposes an antifouling building material having a thickness of 200 nm or less. In the publication, the oil repellent substance includes an oil repellent substance containing an alkyl group and / or a fluoroalkyl group, specifically, a polysiloxane compound such as dimethylsiloxane, a fluorine compound or a polymer thereof, Examples of the photocatalyst particles include titanium oxide, zinc oxide, tin oxide, iron oxide, copper oxide and the like. Further, the coating film of the publication discloses a mode in which a binder is contained. As a method of forming such a coating film, a substrate is coated with the binder, and the photocatalyst particles are dispersed before being completely cured. A method of forming a coating film by mixing a liquid and a resin containing an oil repellent substance separately or simultaneously is mentioned.
Here, examples of the resin containing an oil-repellent substance include oil-repellent urethane resin paints, and examples of the binder include a resin that can be a cured film by heat, a catalyst, electromagnetic waves, or hydrolysis,
Specific examples include phthalic acid resin, chlorinated rubber resin, epoxy resin, phenol resin, acrylic silicone resin, methacrylate resin, polyurethane resin and the like.

Since the coating film described in the above publication contains the oil repellent substance and the photocatalyst particles as described above, the antifouling property is improved. However, the catalyst particle dispersion liquid used for the building material described in this publication is insufficient in that it takes time to dry the coating film because of its thermosetting property, production efficiency is poor, and cost is high. Further, there is still room for improvement in terms of the antifouling property of the coating film.

It should be noted that the publication does not disclose any coating composition containing photocatalyst particles, urethane (meth) acrylate resin and silicone-modified urethane (meth) acrylate resin as used in the present application.

[0008]

It is an object of the present invention to solve the above problems and to provide a photocatalyst-containing energy ray curable composition capable of forming a coating film having an easily decomposing function and a low pollution function with high production efficiency. It is an object of the present invention to provide a coating composition, a coating film formed from the composition, a coated substrate coated with the coating film, and an antifouling method for a substrate using the composition.

[0009]

SUMMARY OF THE INVENTION A photocatalyst-containing energy ray-curable coating composition according to the present invention comprises (A) photocatalyst particles, (B) an energy ray-curable urethane (meth) acrylate resin, and
(C) energy ray-curable polysiloxane-modified urethane (meth) acrylate resin, and (D) (meth) acrylate-based monomer or (E) photopolymerization initiation, if necessary. An agent may be included.

The energy ray-curable polysiloxane-modified urethane (meth) acrylate resin (C) contains at least a unit derived from a hydroxyl group-containing polysiloxane (c1), a unit derived from a polyisocyanate (c2), and a hydroxyl group. A unit derived from the contained (meth) acrylate (c3) is preferably contained. Component (A) (solid content) is 1 to 100 parts by weight in total of component (A) (solid content), component (B) and component (C).
8 parts by weight, 5 to 60 parts by weight of component (B), and 32 to 90 parts by weight of component (C) are preferably contained, and more preferably component (A) (solid content).
Is preferably contained in an amount of 3 to 5 parts by weight, the component (B) in an amount of 10 to 45 parts by weight, and the component (C) in an amount of 50 to 70 parts by weight.

A total of 1 of the above components (B) and (C)
It is preferable that the component (D) is contained in the range of 1 to 50 parts by weight and the component (E) is contained in the range of 0.5 to 10 parts by weight with respect to 00 parts by weight. The coating film of the present invention is characterized in that it is formed from the coating composition as described above,
In the coating film of the present invention, an undercoat layer and / or an intermediate coating layer formed of the energy ray-curable resin composition are formed between the coating film layer formed of the above coating composition and the substrate. It may be a laminated coating film.

The coated substrate of the present invention is characterized by being coated with a coating film formed from the above coating composition. The contamination prevention method of the present invention is characterized by coating the surface of a substrate with a coating film formed from the above coating composition.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The coating composition of the present invention, a coating film formed from the composition, a coated substrate coated with the coating film, and a method for preventing contamination of a substrate using the composition. (Also called an antifouling method) will be specifically described. Photocatalyst-containing energy ray curable coating composition The photocatalyst-containing energy ray curable coating composition of the present invention is
As essential components, (A) photocatalyst particles, (B) energy ray-curable urethane (meth) acrylate resin and (C) energy ray-curable polysiloxane-modified urethane acrylate resin are contained, and if necessary,
(D) (meth) acrylate-based monomer or (E)
It contains a photopolymerization initiator. Hereinafter, each component in the composition will be sequentially described. (A) Photocatalyst particles As the photocatalyst particles (A), those described in JP-A Nos. 11-1659 and 2000-42480 can be widely used. For example, oxides of various metals,
Examples thereof include sulfides, and oxides of various metals are particularly preferably used.

Specific examples of various metal oxides include:
Titanium oxide, iron oxide, tungsten oxide, zirconium oxide, tin oxide, bismuth oxide, ruthenium oxide, zinc oxide, strontium titanate, cadmium oxide, indium oxide, silver oxide, manganese oxide, copper oxide, vanadium oxide and other various metals Examples thereof include oxides and various metal chalcogenites (selenium and tellurium compounds).

These substances used as photocatalyst particles, including titanium oxide, have the property of easily adsorbing surface hydroxyl groups because the metal element and oxygen are present on the surface.
Examples of sulfides of various metals include cadmium sulfide and
Examples thereof include zinc sulfide, copper sulfide, molybdenum sulfide, tungsten sulfide, antimony sulfide, and bismuth sulfide.

These photocatalyst particles may be used alone or in combination of two or more kinds. Among these, titanium oxide (titanium dioxide, TiO ₂ ) is harmless,
It is preferable from the viewpoint that it is chemically stable and can be obtained at low cost. Therefore, as the photocatalyst particles (A), titanium oxide (TiO 2) is contained in the component (A) (solid content).
₂ ) as a main component, that is, 5 to 10 when the component (A) (solid content) is 100% by weight.
Those contained in an amount of 0% by weight, preferably 50 to 100% by weight are particularly preferably used from the viewpoint of high photocatalytic activity, safety and the like.

The titanium oxide will be described in more detail below. In the present invention, as the titanium oxide, any of anatase (anatase) type, rutile type, and brookite type can be used, but from the viewpoint of photocatalytic activity, anatase type and rutile type are preferable, and anatase type is particularly preferable. Such titanium oxide can be produced by a known method and is on the market.

The rutile type titanium oxide can be sintered at a high temperature, and a coating film having excellent strength and abrasion resistance can be obtained. On the other hand, as for anatase type titanium oxide, a sol or a slurry in which extremely fine particles are dispersed is commercially available and can be easily obtained. Such anatase type titanium oxide sol or slurry is previously dispersed in a solvent such as water, an acid such as hydrochloric acid or nitric acid, an alcohol, an organic solvent such as toluene, or a mixed solution thereof, and is dispersed in a paint. Since it has good properties and compatibility with other compositions, a very thin coating film can be easily formed.

In order to improve color stability and physical properties,
Anatase-type titanium oxide having a strong photocatalytic activity may be used in combination with rutile-type or brookite-type pigmentary titanium oxide that is generally used for paints and has less photoactivity than anatase-type titanium oxide. As these photocatalyst particles, those having an average particle diameter of usually 1 to 30 nm, preferably 2 to 20 nm, more preferably 5 to 10 nm are desirable, and among photocatalysts having such particle diameter, anatase-type titanium dioxide particles are also preferable. Is desirable.

The smaller the average particle size of the photocatalyst for activating the cured coating film, the stronger the photocatalytic activity of the coating film. However, if it is smaller than the above range, the surface area of the photocatalyst fine particles increases, and the basic physical properties of the coating film are increased. For example, the weather resistance tends to decrease. In addition, when two or more types having a small average particle size are used in combination (composite), the surface area of the particles themselves becomes large, and as a result, the gloss of the coating film decreases and the hiding property also decreases. The luster tends to be limited.

Specific examples of the photocatalyst particles include trade name "TKS-251" (manufactured by Teika Co., Ltd.) and the like. In the present invention, a component (second component) capable of further improving the photocatalytic function may be contained together with these photocatalyst particles (A). Examples of such a second component include V, Fe, Co, Ni, Cu, Z
Examples include metals and / or metal compounds such as n, Ru, Rh, Pd, Ag, Pt, and Au. Examples of the metal compound include oxides, hydroxides, oxyhydroxides, sulfates, halides, nitrates, and metal ions.

The mechanism of soil decomposition of the photocatalyst particles of the present invention will be briefly described by taking titanium oxide as an example. In the present invention, since the above titanium oxide is used alone or in combination with other photocatalytic substances, when a coating film is formed using the coating composition of the present invention, the titanium oxide on the surface of the coating film is an ultraviolet ray described later. Ordinary light irradiation (eg wavelength 400n
photo-excited by photocatalytic action, electron-hole pairs are generated in titanium oxide by photocatalysis, and oxygen molecules and water molecules react with the electron-hole pairs to generate superoxide ions (superoxides) having high oxidizing power. Ions), hydrogen peroxide, hydroxyl radicals, and other active oxygen. Due to the generated active oxygen, organic contaminants on the surface of the coating film,
It is considered that the surface of the coating film will have good stain resistance, etc., because it will be oxidized / decomposed and fall off / scatter / dead.

That is, when a coating film formed from the coating composition of the present invention containing such photocatalyst particles (A) is irradiated with light, the photocatalyst particles (A) are activated. Specifically, Japanese Unexamined Patent Publication No. 2000-42480 [0015] to
As described in the paragraph [0016], when the thickness of the coating film is about 0.1 μm, for example, on the surface of the coating film side,
When the photocatalyst particles are activated for 2 to 3 hours by irradiation with sunlight (about ² to 3 mW / cm ^{2 in} illuminance), the photocatalyst particles come to exhibit stain resistance and the like.

The photocatalyst particles (A) (solid content) are usually 1 to 8 parts by weight, preferably 1 to 8 parts by weight, based on 100 parts by weight of the total of the component (A) (solid content), the component (B) and the component (C). It is desirable that the content is 2 to 6 parts by weight, more preferably 3 to 5 parts by weight. When the compounding amount of titanium oxide is within the above range, the stain resistance is excellent, the coating film physical properties such as durability and surface hardness are excellent, and the coating film tends not to crack during curing. (B) Energy ray curable urethane (meth) acrylate
The resin energy ray-curable urethane (meth) acrylate resin (B) is obtained by reacting, for example, polyisocyanate, a hydroxyl group-containing (meth) acrylate, and, if necessary, a polyol other than a hydroxyl group-containing (meth) acrylate. the resulting, acryloyl group as a functional group in the molecule (CH ₂ = CHCO-) or methacryloyl group _{(CH 2 = C (CH 3} ) -CO-), a urethane bond (-
NH.COO-).

The polyisocyanate is not limited in carbon number as long as it does not impair the effects of the present invention. For example, the total carbon number is 4 to 20, preferably 6 to 1.
5, more preferably 8 to 12 linear or branched isocyanate-group-containing chain saturated hydrocarbon,
An isocyanate group-containing cyclic saturated hydrocarbon and an isocyanate group-containing aromatic hydrocarbon can be used. Specifically, a straight chain saturated hydrocarbon containing an isocyanate group such as tetramethylene diisocyanate and hexamethylene diisocyanate [HDI], and a saturated saturated chain hydrocarbon containing an isocyanate group such as 2,2,4-trimethylhexamethylene diisocyanate [TMHMDI]. Isocyanate group-containing cyclic saturated hydrocarbons such as hydrogen, isophorone diisocyanate [IPDI], methylenebis (4-cyclohexylisocyanate) [HMDI], hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, hydrogenated toluene diisocyanate, p-phenylene diisocyanate [PPDI] , 3,3'-dimethyldiphenyl-
4,4′-diisocyanate [TODI], 1,3-xylene diisocyanate [XDI], dianisidine diisocyanate [DADI], tetramethylxylene diisocyanate [TMXDI], 1,5-naphthalene diisocyanate [NDI], tolylene diisocyanate [TDI] ] A diisocyanate group-containing aromatic hydrocarbon such as 4,4-diphenylmethane diisocyanate [MDI] can be used. The polyisocyanate may be modified with isocyanurate or the like in order to improve heat resistance and the like. Examples of the isocyanurate modified include isocyanurate-modified toluene diisocyanate and the like. As the polyisocyanate other than the above, polyfunctional isocyanates such as dimethyltriphenylmethane tetraisocyanate, triphenylmethane triisocyanate, and NCO group-containing acrylate may be used. Furthermore, such polyisocyanates may be used alone or in combination of two or more.

Among the above polyisocyanates,
Particularly, hexamethylene diisocyanate is preferable. As the hydroxyl group-containing (meth) acrylate, a (meth) acrylate having at least one hydroxyl group, preferably 2 to 5, and more preferably 3 to 4 hydroxyl groups can be used. Further, such a hydroxyl group-containing (meth) acrylate does not limit the carbon number as long as the effect of the present invention is not impaired, but the carbon number is 2 to 20, preferably 6 to 15, and more preferably 9 to. It is desirable to have 11 saturated or unsaturated hydrocarbon moieties, which may be branched or straight chain, alicyclic hydrocarbon moieties, or aromatic hydrocarbon moieties. Note that an ether bond (C—O—C bond) may be included in part of the hydrocarbon moiety.

Specifically, 2-hydroxyethyl acrylate [HEA], 2-hydroxyethyl methacrylate [HEMA], 2-hydroxypropyl acrylate [HPA], glycidol dimethacrylate [GDM].
A], pentaerythritol tri (meth) acrylate [PETA], dipentaerythritol penta (meth)
Acrylate, dipentaerythritol tetra (meth)
Examples thereof include acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol di (meth) acrylate and the like. In addition to the above, modified products such as polycaprolactone-modified 2-hydroxyethyl (meth) acrylate may be used. These hydroxyl group-containing (meth) acrylates may be used alone or in combination of two or more.

Among the above-mentioned hydroxyl group-containing (meth) acrylates, dipentaerythritol diacrylate is preferable. As the polyol other than the above-mentioned hydroxyl group-containing (meth) acrylate that is used as necessary, known polyols such as polyether polyol, polyester-based polyol, and polyolefin-based polyol can be used, and specifically, polyoxyethylene. Examples thereof include glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, polycaprolactone polyol and alkylene diol. Such polyols may be used alone or in combination of two or more.

Among the above-mentioned polyols, polyoxyethylene glycol is preferable. The energy ray-curable urethane (meth) acrylate resin (B) has a viscosity at 25 ° C. of 3000 to 12000 cps, preferably 4000 to 9000 cp.
s, more preferably 5000 to 8000 cps. Such an energy ray-curable urethane (meth) acrylate resin (B) can be produced by a conventionally known method, and as a commercially available product, specifically, KAYARAD ARC-87 (Japan Kayaku Co., Ltd., SHIKO UV-1700B (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like are preferably used.

The above energy ray curable urethane (meta)
Since the acrylate resin (B) has an active acryloyl group or methacryloyl group, it is cured by irradiation with energy rays. The energy ray-curable urethane (meth) acrylate resin (B) is the component (A).
(Solid content), component (B) and component (C) total 100
5 to 60 parts by weight, preferably 8 to 10 parts by weight,
It is desirable that the content is 50 parts by weight, more preferably 10 to 45 parts by weight. When the amount of the energy ray-curable urethane (meth) acrylate resin (B) is within the above range, the coating film properties such as durability, hardness, stain resistance and scratch resistance tend to be excellent. (C) Energy ray curable polysiloxane-modified urethane
Acrylate resin The energy ray-curable polysiloxane-modified urethane (meth) acrylate resin (C) is a resin in which the functional group in the polysiloxane and the functional group in the urethane (meth) acrylate resin are chemically reacted and bonded.

The energy ray-curable polysiloxane-modified urethane acrylate resin (C) used in the present invention is
Units derived from at least hydroxyl group-containing polysiloxane (c1), units derived from polyisocyanate (c2), and hydroxyl group-containing (meth) acrylate (c3)
And a unit derived from
It may contain a unit derived from a polyol component (c4) other than 3), and at least an acryloyl group (CH ₂ ═CHCO—) or a methacryloyl group (CH ₂ ═C (CH ₃ )) as a functional group in the molecule. It has a -CO-) and a urethane bond (-NH.COO-).

Examples of the hydroxyl group-containing polysiloxane (c1) include hydroxyl group-containing dimethyl polysiloxane. The unit derived from such a hydroxyl group-containing polysiloxane is 5 to 50% by weight, preferably 8 to 2% when the total amount of the component units in the component (C) is 100% by weight.
It is desirable that the content is 0% by weight, more preferably 10 to 15% by weight.

The polyisocyanate (c2) is not limited in carbon number as long as it does not impair the effects of the present invention, but has 4 to 20 carbon atoms, preferably 6 to 1 carbon atoms.
5, more preferably 8 to 12 linear or branched isocyanate-group-containing chain saturated hydrocarbon,
An isocyanate group-containing cyclic saturated hydrocarbon and an isocyanate group-containing aromatic hydrocarbon can be used, and specific examples thereof include those described in the description of the component (B). Such polyisocyanates may be used alone or in combination of two or more kinds. As the polyisocyanate (c2) component, isocyanurate modified products and NCO group-containing (meth) acrylates are preferably used among the above-mentioned components, and it is particularly preferable to use these in combination.

The NCO group-containing (meth) acrylate has at least one NCO group, preferably 1 or more.
A (meth) acrylate having 5 to 5, more preferably 1 to 2 can be used. The NCO group-containing (meth) acrylate does not limit the number of carbon atoms unless the effect of the present invention is impaired, but the number of carbon atoms excluding the number of carbon atoms in the NCO group is 2 to 20, preferably 2 to 15. More preferably, it preferably has 2 to 10 saturated or unsaturated hydrocarbon moieties which may be branched or straight chain, alicyclic hydrocarbon moieties, or aromatic hydrocarbon moieties. Specific examples thereof include isocyanatoethyl (meth) acrylate, isocyanatopropyl (meth) acrylate, and isocyanatobutyl (meth) acrylate. Such NCO group-containing (meth) acrylates may be used alone or in combination of two or more kinds. Among the above, isocyanatoethyl (meth) acrylate is preferable.

The above-mentioned hydroxyl group-containing (meth) acrylate (c
3) has at least one hydroxyl group, preferably 2 to
(Meth) acrylate having 5 and more preferably 2 to 4 can be used. The hydroxyl group-containing (meth) acrylate does not limit the number of carbon atoms unless the effects of the present invention are impaired, but the number of carbon atoms is 2 to 2.
0, preferably 6 to 15, more preferably 9 to 11 branched or straight chained saturated or unsaturated hydrocarbon moieties, alicyclic hydrocarbon moieties, or aromatic hydrocarbon moieties It is desirable to have In addition, an ether bond (C—O—C bond) is formed in a part of the hydrocarbon moiety.
May be included. Specific examples thereof include the same as those described in the description of the component (B). Such a hydroxyl group-containing (meth) acrylate may be used alone or in combination of two or more kinds, and among them, dipentaerythritol tetraacrylate is preferable.

The above-mentioned hydroxyl group-containing (meth) acrylate (c
Examples of the polyol component (c4) other than 3) are the same as those described in the description of the component (B). Such polyols may be used alone or in combination of two or more kinds. Among the above, the component (c4) is preferably polycaprolactone polyol, and specific examples thereof include those obtained by ring-opening polymerization of ε-caprolactone or methylvalerolactone. The polycaprolactone polyol usually has a molecular weight of 550 to 550.
It is preferably 4,000, preferably 1,000 to 2,000, and has a hydroxyl value of 240 to 30, preferably 100 to 50.

The units (c2) to (c4) are the hydroxyl group-containing polysiloxane (c1) in the energy ray-curable polysiloxane-modified urethane (meth) acrylate resin (C).
When the unit is 100 parts by weight, the polyisocyanate (c2) unit is 200 to 500 parts by weight, preferably 300 to 400 parts by weight, and the hydroxyl group-containing (meth) acrylate (c3) unit is 200 to 800 parts by weight. Parts, preferably 300 to 500 parts by weight, when the polyol component (c4) unit other than the (c3) unit is included (c
4) The unit is 50 to 300 parts by weight, preferably 100 to
It is desirable that the content is 200 parts by weight.

The energy ray-curable polysiloxane-modified urethane (meth) acrylate resin (C) has a viscosity at 25 ° C. of 3000 to 12000 cps, preferably 40.
00 to 9000 cps, more preferably 5000 to 80
00 cps is desirable. The energy ray-curable polysiloxane-modified urethane (meth) acrylate resin (C) can be produced by a conventionally known method, or a commercially available one can be used. Specifically, such a component (C) includes a hydroxyl group-containing polysiloxane (c1) and a polyisocyanate (c2).
And a hydroxyl group-containing (meth) acrylate (c3) and a polyol (c4) may be co-condensed if necessary, or polyisocyanate (c2) and a hydroxyl group-containing (meth) acrylate (c3), If necessary, it may be produced by reacting a urethane (meth) acrylate resin obtained by co-condensing the polyol (c4) with a hydroxyl group-containing polysiloxane.

Examples of the products put on the market include U
VS-520 (manufactured by Otake Meishin Chemical Co., Ltd.) and the like can be mentioned. The energy ray-curable polysiloxane-modified urethane (meth) acrylate resin (C) is the above-mentioned component (A).
(Solid content), component (B) and component (C) total 100
32 to 90 parts by weight, preferably 4 parts by weight
It is desirable that the content is 4 to 80 parts by weight, more preferably 50 to 70 parts by weight. When the amount of the energy ray-curable polysiloxane-modified urethane (meth) acrylate resin (C) is in the above range, the coating film properties such as oil repellency, durability, hardness, stain resistance, and water repellency tend to be excellent. . (D) (Meth) acrylate-based monomer The photocatalyst-containing low-staining energy-curable coating composition of the present invention further contains a (meth) acrylate-based monomer (D) in addition to the components (A) to (C). It may have been done.

Used in the present invention as needed (meta)
As the acrylate-based monomer (D), for example,
1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol diacrylate, 2 (2-ethoxyethoxy) ethyl acrylate, tetrahydrofurfuryl Acrylate, 2-phenoxyethyl acrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, 1,3-butylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, hydroxypivalate neopentyl glycol. Examples include diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, etc. it can. Further, such a (meth) acrylate-based monomer may be a lactone-modified product such as an acrylate of ε-caprolactone-modified dipentaerythritol.

The above-mentioned (meth) acrylate-based monomer (D) can be used as a reactive diluent alone or in combination of two or more. Among the above, 1,9-nonanediol diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and ε-caprolactone-modified dipentaerythritol acrylate are preferable, and 1,9-nonanediol diacrylate and dipentaerythritol are particularly preferable. Erythritol pentaacrylate and dipentaerythritol hexaacrylate are preferably used in combination.
When dipentaerythritol pentaacrylate or dipentaerythritol hexaacrylate is used as the (meth) acrylate-based monomer (D), the acrylic group density can be particularly improved, and a coating film with high surface hardness tends to be obtained. Further, when 1,9-nonanediol diacrylate is used, the coating composition tends to have excellent solubility in a solvent.

(Meth) acrylate monomer (D)
Is usually in the range of 1 to 50 parts by weight, preferably 10 to 30 parts by weight, more preferably 15 to 25 parts by weight, based on 100 parts by weight (solid content) of the components (B) and (C). It is desirable to use. (E) Photopolymerization initiator As the photopolymerization initiator (E) used in the present invention, specifically, benzoin-based photopolymerization such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether. Initiator: benzyl dimethyl ketal (also known as 2,2-dimethoxy-2-phenylacetophenone), diethoxyacetophenone, 4-phenoxydichloroacetophenone,
4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, 2-hydroxy-2-methyl-1-
Phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-
(4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenylketone, 2- Acetophenone-based photopolymerization initiators such as methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1; benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone , 4-benzoyl-4'-methyldiphenyl sulfide, 3,3'-dimethyl-4-methoxybenzophenone and other benzophenone-based photopolymerization initiators; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4 -Dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-die Examples thereof include thioxanthone photopolymerization initiators such as tylthioxanthone and 2,4-diisopropylthioxanthone. Among them, benzyl dimethyl ketal and 1-hydroxycyclohexyl phenyl ketone are preferably used.

The photopolymerization initiator (E) as described above is generally used in an amount of 0.5 to 10 parts by weight, preferably 100 parts by weight (solid content) of the components (B) and (C). Two
It is desirable to use in an amount of from 5 to 5 parts by weight, more preferably from 3 to 4 parts by weight. Other components In the photocatalyst-containing energy ray-curable coating composition according to the present invention, (A) the photocatalyst particles, (B) the energy ray-curable urethane (meth) acrylate resin, and (C) the energy ray-curable polysiloxane. Modified urethane acrylate resin, (D) (meth) acrylate-based monomer, (E)
In addition to the photopolymerization initiator, if necessary, a polymerization inhibitor, a non-reactive diluent, a matting agent, a defoaming agent, an anti-settling agent,
A leveling agent, a dispersant, a heat stabilizer, an ultraviolet absorber and the like can be added within a range that does not impair the object of the present invention.

Preparation of coating composition and coating film The photocatalyst-containing energy ray-curable coating composition according to the present invention is prepared by mixing the above-mentioned components with a conventionally known apparatus such as a mixer, a disperser, and a stirrer. -It can be obtained by stirring. Examples of such an apparatus include a mixing / dispersion mill, a mortar mixer, a roll, a paint shaker,
A homogenizer etc. are mentioned.

The photocatalyst-containing energy ray-curable coating composition according to the present invention can be used as an intermediate coating, but is preferably used as a top coating and can be coated on the surface of a substrate by a conventionally known method. . As the base material, specifically, an inorganic decorative board, metal, concrete,
Examples include wood boards, plastics, resin films, glass, enameled panels, tiles, cement, ceramics and paper materials. Specific examples of the inorganic decorative board include fiber-reinforced cement board, calcium silicate board, slate board, perlite cement board, ALC, GRC, and ceramic siding. As the plastic substrate, fiber reinforced plastic, acrylic resin, polycarbonate resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polypropylene (P
P), acrylic butadiene styrene copolymer (ABS)
Film-like sheets and molded products of resins, vinyl chloride resins, epoxy resins, phenol resins and the like can be mentioned.

An organic or inorganic coating or film may be previously formed on the surface of such a base material. Examples of the organic coating used include coatings of epoxy resin, phenol resin, unsaturated polyester resin, fluororesin, urea resin, silicone resin, acrylic silicone resin, methacrylate resin, polyurethane resin, melamine resin, and the like, and inorganic coatings. Examples thereof include alkali silicate type, phosphoric acid type and boric acid type coatings.
Needless to say, the base material used in the present invention is not limited to those exemplified above.

The above-mentioned base material may be surface-treated in advance. For example, when a porous base material such as a wood material or a paper material is used, the base material is previously subjected to a sealing treatment. And / or undercoating to fill the coating and /
Or it is desirable to form a colored undercoat film,
Particularly in the case of an alkaline inorganic porous substrate, it is desirable to previously perform a sealer treatment for the purpose of preventing alkali leaching on the substrate surface. Further, before coating the photocurable resin composition, for example, printing may be performed for patterning on the colored undercoat coating film.

The photocatalyst-containing energy ray-curable coating composition of the present invention can be applied, for example, by a flow coater, roll coater, spraying method, airless spray method, air spray method, brush coating, roller coating, iron coating, dipping method. , A pulling method, a nozzle method, a winding method, a sinking method, a coating method, a patching method, etc., and may be automated or manually painted. More specifically,
It is carried out using a coating machine such as a rubber or sponge roll coater, a spray coater, a flow coater and a vacuum coater. These coating machines can be used alone or in combination of two or more.

When the coating composition of the present invention is used as an overcoat, an undercoat is used for the purpose of improving the adhesion between the coating composition of the present invention and a substrate and improving the design. It is preferable to provide a layer and an intermediate coating layer, and such an undercoat layer and an intermediate coating layer are not particularly limited as long as they are generally used for this purpose, but an energy ray-curable type, particularly an ultraviolet ray curable type coating material. Is preferably used, and examples thereof include UV-curable unsaturated polyester resin paints and UV-curable acrylic resin paints.
Specifically, Aulex No. 1 which is a UV-curable urethane acrylate resin paint manufactured by China Paint Co., Ltd. 230-5
Etc.

When the coating composition of the present invention is overcoated on the surface of a base material coated with such an undercoat layer and an intermediate coat, the undercoat layer and the intermediate coat layer in a semi-cured state are semi-cured. It is preferable to apply the coating. Specifically, for example, when the coating composition of the present invention is overcoated on an intermediate coating layer, the coating composition of the present invention is overcoated on a semi-cured intermediate coating layer and completely cured ( Full cure) is preferable. As described above, when the present composition is applied onto the semi-cured state, the adhesion between the present composition and the intermediate coating layer tends to be significantly improved.

The photocatalyst-containing energy ray-curable coating composition of the present invention is preferably used by diluting it with a solvent from the viewpoint of coatability. As the solvent that can be used, for example, ethanol, methanol, toluene, xylene, ethyl acetate, volatile organic solvents such as methyl isobutyl ketone can be used, from the viewpoint of low pollution, safety to the human body, etc. Ethanol and methanol are preferably used. The amount of the solvent used is generally 3 to 30% by weight, preferably 5 to 20% by weight, and more preferably the solid content of the photocatalyst-containing energy ray-curable coating composition in the prepared coating liquid. Is preferably contained in an amount of 10 to 15% by weight. The coating composition of the present invention has excellent coating properties when diluted with a solvent in such an amount,
Further, after coating, the photocatalyst particles are exposed from the surface of the dried coating film, and there is a tendency that the effect of decomposing contaminants by the photocatalyst particles is sufficiently obtained.

The coating amount of the photocatalyst-containing energy ray-curable coating composition is somewhat different depending on the type of base material used and the application. For example, in the case of a wood floor base material, it is usually 0.3 to 1.5 g in a wet state. / Measure ² , preferably 0.5-
It is desirably 1.0 g / scale ^2. In addition, 1 shaku is
It is 10/33 of 1m. Further, in the present invention, in order to more effectively obtain the pollutant decomposition action of the photocatalyst particles, it is preferable to coat the surface of the coating film formed after coating so that the photocatalyst particles (A) are exposed. In order to expose the coating film surface, it is desirable that the thickness of the coating film after drying is smaller than the diameter of the photocatalyst particles. Therefore, the dry film thickness of the photocatalyst-containing energy ray-curable coating composition of the present invention depends on the particle size of the photocatalyst particles (A), but is generally 0.01 to 4 μm, preferably 0.1 to 2 μm. More preferably, it is applied so as to have a thickness of 0.5 to 1 μm.

A typical schematic view of a cross section of a coating film obtained by coating the substrate with the coating composition of the present invention is shown in FIG. FIG. 1 shows a state in which the coating composition of the present invention is applied after the intermediate coating 3 is applied to the substrate surface 4. In the coating film of the present invention, since the photocatalyst particles 1 are exposed from the surface of the coating film 2 as shown in FIG. 1, the photocatalyst particles 1 can sufficiently receive light, and are easily decomposed by pollution.

The number of times the photocatalyst-containing energy ray-curable coating composition is applied is not particularly limited and may be applied once or twice or more. On the coating surface of the photocatalyst-containing energy ray-curable coating composition coated on the surface of the substrate surface or the intermediate coating layer as described above, electron rays, ultraviolet rays, energy rays such as visible rays, preferably ultraviolet rays or visible rays. By curing the coating film in the wet state by irradiating with, it is possible to easily obtain a cured coating film (coating film) having low stain resistance and excellent stain removability.

When irradiating with ultraviolet rays or visible rays,
It can be carried out by a conventionally known irradiation method, for example, a high-pressure mercury lamp is a single lamp of 20 to 120 W / cm,
The belt speed can be 1 to 20 m / min, preferably 30 to 40 W / cm with one lamp, and the belt speed is preferably 3 to 5 m / min. Further, the above conditions can be appropriately adjusted depending on the number of lights or the like. For example, the belt speed can be increased by increasing the number of lights or the capacity of W / cm.

The coating film according to the present invention is formed from the above-mentioned photocurable resin composition according to the present invention by the method as described above. The coated substrate according to the present invention is a substrate whose surface is coated with this coating. Such a coated substrate is
Suitable for wall materials such as kitchen and bathroom, partition board, etc.

The method for preventing pollution according to the present invention is carried out by coating the surface of a substrate with a coating curtain formed from the above coating composition.

[0058]

EFFECT OF THE INVENTION A coating film comprising the photocatalyst-containing energy ray-curable coating composition of the present invention contains a photocatalyst molecule having an easily decomposing function of stains and a resin component having a low staining property, and therefore is extremely dirty. It is difficult and can be easily removed even if dirt is attached. Further, according to the photocatalyst-containing energy ray-curable coating composition of the present invention, a desired coating film can be simultaneously formed in one step without separately forming a layer containing a photocatalyst molecule and a layer containing a resin component. Therefore, the production efficiency of the coating film is very good.

[0059]

EXAMPLES The present invention will be further described below based on examples, but the present invention is not limited to these examples. The appearance of the coating film, the stain removability, the exposure ratio of the photocatalyst particles to the coating film surface, and the like in Examples and Comparative Examples were evaluated according to the following methods. (1) Appearance of coating film The surface of the coating film formed on the surface of the base material was visually observed as described below to evaluate whether the coating film had gloss, uneven gloss, or rough roll.

<Evaluation Criteria> 3: The gloss of the coating film is good, and there is no glossiness or rough roll. (Pass) 2: The gloss of the coating film is good, but rough rolls are generated. (Failure) 1: The gloss of the coating film is poor, and there are glossiness and rough roll. (Failure) (2) Contamination removal property The coating film surface formed on the surface of the substrate as described below is stained with black magic, and after 1 minute, wiped dry with a tissue paper to prevent the magic film from seeping into the surface. The degree was visually observed, and the stain removability was evaluated according to the following criteria.

<Evaluation Criteria> 3: No stain. (Pass) 2: There is slight stain. (Failure) 1: There is dirt. (Failure) (3) Exposure ratio of photocatalyst particles to coating film surface The ratio of how much photocatalyst particles were exposed to the coating film surface was measured by a silver nitrate reaction.

Silver nitrate reaction A 1% aqueous solution of silver nitrate was dropped on the surface of the coating film, and then left under a BLB lamp for 5 minutes, and the degree of discoloration was measured as a color difference ΔE. <Evaluation Criteria> 3: ΔE> 6 (Failure) 2: 1 ≦ ΔE ≦ 6 (Pass) 1: ΔE <1 (Failure)

[0063]

[Example 1] [Preparation of coating composition]
Gee ray curable urethane (meth) acrylate resin
"KAYARAD ARC-87" (Product name: Urethane
38 weight of acrylate resin, manufactured by Nippon Kayaku Co., Ltd.
Parts, energy ray curable polysiloxane-modified urethane
"UVS-520" as (meth) acrylate resin
(Product name: Polysiloxane modified urethane (meth) acrylic
Rate resin, manufactured by Otake Meishin Chemical Co., Ltd.),
"Irgacure 500" as a photopolymerization initiator
Name; 1-hydroxy-cyclohexyl phenyl ketone +
Benzophenone, Ciba Specialty Chemicals
(Manufactured by Co., Ltd.) as photocatalyst particles by "TKS-2".
51 ”(trade name; solvent-dispersed photocatalyst titanium oxide, TAYCA
15 parts by weight (made by Co., Ltd.) (3 parts by weight when converted to solid content)
Part) and ethanol / methanol as a diluting solvent
Add 650 parts by weight of (2/1) mixed solvent, stir,
A catalyst-containing energy ray curable coating composition was obtained. [Test plate preparation method] As a base material, a sheet made by Nikko Kasei Co., Ltd.
An escort plate (white) was used. Intermediate coating on the substrate surface
"Aurex No. 230-5" (trade name;
UV curable urethane acrylate resin paint, Chinese paint
Roll coater (manufactured by Co., Ltd.) (Mochizuki Kikou Seisakusho Co., Ltd.)
Made by) + Flow coater (made by Iwata Paint Co., Ltd.)
8.5g / measure²At a rate of 30 W / cm
Use one high pressure mercury lamp (Nippon Battery Co., Ltd.)
It was cured at a rate of 5 m / min to a semi-cured state. Next
On top of the semi-cured intermediate coat layer,
The coating composition prepared as described above with a groove roll coater.
-(Manufactured by Mochizuki Kiko Co., Ltd.) (1 g / measure) ²)
Of 80W / cm high pressure mercury lamp
Used to completely cure at a belt speed of 3 m / min (full cure
Then, a test plate was prepared.

The test plate obtained as described above was evaluated by the evaluation method described above. The results are shown in Table 1.

[0065]

Example 2 A coating composition was prepared and tested in the same manner as in Example 1 except that the type of energy-curable urethane acrylate resin in the coating composition was changed to the resin shown in Table 1. A board was prepared and evaluated. The results are shown in Table 1.
Shown in.

[0066]

Example 3 In Example 1, the type of energy-curable urethane acrylate resin in the coating composition was changed to the resin shown in Table 1, and an energy-curable urethane acrylate resin and an energy-curable polysiloxane-modified urethane acrylate resin were used. A coating composition was prepared in the same manner as in Example 1 except that the compounding amount was changed to the amount shown in the table, and a test plate was prepared and evaluated. The results are shown in Table 1.

[0067]

[Example 4] Example 4 except that the amount of the energy-curable urethane acrylate resin and the energy-curable polysiloxane-modified urethane acrylate resin in the coating composition was changed to the amount shown in Table 1 A coating composition was prepared in the same manner as in 1, and a test plate was prepared and evaluated. The results are shown in Table 1.

[0068]

[Example 5] In Example 1, except that the compounding amounts of the energy-curable urethane acrylate resin, the energy-curable polysiloxane-modified urethane acrylate resin and the photocatalyst particles in the coating composition were changed to the compounding amounts shown in Table 1. A coating composition was prepared in the same manner as in Example 1, and a test plate was prepared and evaluated. The results are shown in Table 1.

[0069]

Comparative Example 1 In Example 1, instead of the energy curable urethane acrylate resin in the coating composition, an energy ray curable polyester resin (trade name “Polylite”) was used.
FG-208 ", manufactured by Dainippon Ink and Chemicals, Inc. was used to prepare a coating composition in the same manner as in Example 1 to prepare a test plate for evaluation. The results are shown in Table 1.

[0070]

Comparative Example 2 A coating composition was prepared in the same manner as in Example 1 except that the energy-curable polysiloxane-modified urethane acrylate resin in the coating composition was not used and the compounding amount was as shown in Table 1. The product was prepared and a test plate was prepared and evaluated. The results are shown in Table 1.

[0071]

[Table 1]

1) "KAYARAD ARC-87"
(Product name: Energy ray curable urethane acrylate resin, manufactured by Nippon Kayaku Co., Ltd.) 2) "Shikou UV-1700B" (Product name: Energy ray curable urethane acrylate resin, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 3) "Shikko UV-6300B" (trade name; energy ray-curable urethane acrylate resin, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 4) "Polylight FG-208" (trade name; energy ray-curable polyester resin, Dainippon Ink and Chemicals) 5) "UVS-520" (trade name; energy ray-curable polysiloxane-modified urethane (meth) acrylate resin, manufactured by Otake Meishin Chemical Co., Ltd.) 6) "IRGACURE 500" (trade name; 1) -Hydroxy-cyclohexyl phenyl ketone + benzophenone,
Ciba Specialty Chemicals Co., Ltd.) 7) "TKS-251" (trade name, solvent-dispersible titanium oxide photocatalyst, Tayca Co., TiO ₂ content: 20 wt%)

[Brief description of drawings]

FIG. 1 shows a schematic cross-sectional view when a photocatalyst-containing low-polluting energy ray-curable coating composition is applied to a substrate.

[Explanation of symbols]

1 Photocatalyst Particles 2 Coating Film (Topcoat Layer) Formed from Photocatalyst-Containing Low Contamination Energy Ray Curable Coating Composition 3 Intermediate Coating Layer 4 Base Material

Continued front page    (72) Inventor Akira Masuda             7 No. 2306 Mikami, Yasu-cho, Yasu-gun, Shiga Prefecture             Inside China Paint Co., Ltd. F term (reference) 4F100 AK25B AK25C AK25J AK51B                       AK51C AK51J AK52J AL01B                       AL01C AL05B AL05C AL08B                       AL08C AT00A BA03 BA07                       BA10A BA10C CA30B CA30C                       CC00B CC00C DE01B DE01C                       GB07 JB14B JB14C JL02                       JL06 JL08B JL08C                 4J038 FA112 FA241 FA281 KA03                       KA04 NA05 PA17

Claims (12)

[Claims] 1. A photocatalyst particle (A), an energy ray curable urethane (meth) acrylate resin (B), and an energy ray curable polysiloxane-modified urethane (meth) (C).
An energy ray curable coating composition containing a photocatalyst, which comprises an acrylate resin. 2. An energy ray-curable polysiloxane-modified urethane (meth) acrylate resin (C), at least a unit derived from a hydroxyl group-containing polysiloxane (c1), and a unit derived from a polyisocyanate (c2), A unit derived from a hydroxyl group-containing (meth) acrylate (c3) is contained.
A photocatalyst-containing energy ray-curable coating composition described in 1. 3. A photocatalyst-containing energy ray-curable coating composition further contains (D) (meth) acrylate-based monomer in addition to the above-mentioned components (A), (B) and (C). The photocatalyst-containing energy ray-curable coating composition according to claim 1 or 2. 4. An energy ray-curable coating composition containing a photocatalyst, in addition to the component (A), the component (B), the component (C) and the component (D) optionally contained therein, further (E) light. A polymerization initiator is contained in the composition.
The photocatalyst-containing energy ray-curable coating composition according to any one of 3 above. 5. The component (A) (solid content) is 1 to 8 parts by weight, and the component (A) (solid content), the component (B) and the component (C) are 100 parts by weight. B) is 5-6
The photocatalyst-containing energy ray-curable coating composition according to any one of claims 1 to 4, wherein 0 part by weight and the component (C) are contained in the range of 32 to 90 parts by weight. 6. The component (A) (solid content) is 3 to 5 parts by weight, and the component (A) (solid content), the component (B) and the component (C) are 100 parts by weight in total, and the component ( B) is 10
45 parts by weight and component (C) are contained in the range of 50 to 70 parts by weight, the photocatalyst-containing energy ray-curable coating composition according to any one of claims 1 to 5. 7. A total of 1 of the component (B) and the component (C).
The photocatalyst-containing energy ray-curable coating composition according to any one of claims 1 to 6, wherein the component (D) is contained in the range of 1 to 50 parts by weight with respect to 00 parts by weight. 8. A total of 1 of the component (B) and the component (C).
Component (E) is contained in the range of 0.5 to 10 parts by weight with respect to 00 parts by weight.
An energy ray-curable coating composition containing a photocatalyst according to any one of 1. 9. A coating film formed from the coating composition according to any one of claims 1 to 8. 10. An undercoat layer formed from an energy ray-curable resin composition and / or a coating layer formed from the coating composition according to any one of claims 1 to 8 and a substrate. A laminated coating film having an intermediate coating layer formed thereon. 11. A coated substrate, which is coated with a coating film formed from the coating composition according to any one of claims 1 to 8. 12. A method for preventing pollution, which comprises coating the surface of a substrate with a coating film formed from the coating composition according to any one of claims 1 to 8.