JP2001040245A - Photocatalytic hydrophilic coating composition and photocatalytic hydrophilic coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of forming a coating film having enough hydrophilicity and antifouling property and excellent in adhesion and resistance to weather, and useful for e.g. anti-fogging use such as mirrors of lavatory and rearview mirrors for vehicles by including a photocatalytic semiconductor material, hard-to-decompose binder and light shield material. SOLUTION: This composition is obtained by including (A) a photocatalytic semiconductor material such as minute particles of anatase-type titanium dioxide, (B) a hard-to-decompose binder consisting of preferably peroxoitanic acid and/or the partial condensate thereof and (C) a light shield material consisting of preferably e.g. rutile-type titanium dioxide minute particles with a particle diameter of 0.001-0.1 μm; wherein the preferable amount of each component to be included based on the whole solid is respectively 20-80 wt.% of the component A, 20-80 wt.% of the component B, and 0.1-50 wt.% of the component C, if the component C is an inorganic minute particle ultraviolet ray shield agent. This composition is useful for building sheathing such as outer walls, exterior surfacing of vehicles such as cars, and the like in the outdoor use where self-cleaning through rainfall is expected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photocatalytic hydrophilic coating composition and a photocatalytic hydrophilic coating film.

[0002]

2. Description of the Related Art In the field of construction and paints, contamination of architectural exterior materials, outdoor buildings and coating films thereof has become a problem due to environmental pollution. Dust and particles suspended in the air accumulate on the roof and outer walls of buildings in fine weather. Sediment is washed away by rainwater as it rains and flows down the building's outer walls. Furthermore, in the rain, the floating dust is carried by the rain and flows down on the outer wall of the building or the surface of the outdoor building. As a result, on the surface,
Pollutants accumulate along the path of rainwater. When the surface dries, striped stains appear on the surface. Dirt on building exterior materials and coatings is due to combustion products such as carbon black,
It consists of pollutants of inorganic substances such as urban dust and clay particles. It is thought that such a variety of contaminants complicates antifouling measures (Yoshinori Tachibana, "Method for Accelerated Testing of Contamination of Exterior Wall Finishing Materials", Proc. No., October 1989, p.
24).

[0003] When the surface of the substrate is hydrophilized, attached water droplets spread uniformly on the surface of the substrate, so that fogging of glass, lenses and mirrors can be effectively prevented, and devitrification by moisture is prevented.
Useful for ensuring visibility in rainy weather. Further, hydrophobic contaminants such as urban dust, combustion products such as carbon black contained in exhaust gas of automobiles, oils and fats, and sealant eluting components are hardly adhered. It is convenient because it can be dropped more easily.

Under these circumstances, hydrophilic resins have been proposed in the field of antifogging paints and exterior antifouling paints (for example, Japanese Utility Model Laid-Open No. 5-68006, "Polymer", Vol. May 1995, p. 307). Also, a surface treatment method for making the surface hydrophilic has been proposed (for example, Japanese Utility Model Laid-Open No. 3-129357). There is a method of highly hydrophilizing the surface of an article by the photoexcitation effect of a semiconductor photocatalyst (Patent Publication No. 275647). According to this method, the surface of the article coated with the photocatalytic semiconductor composition is highly hydrophilized and maintained by irradiation with ultraviolet rays.

On the other hand, as a substrate having a light shielding property, for example, Japanese Patent Application Laid-Open No. 4-224133 describes various glass compositions in which a metal compound is melted and added to glass. A method of providing a surface layer containing a large amount of an ultraviolet shielding agent on the surface of a thermoplastic resin plate is disclosed in, for example, Japanese Patent Publication No.
No. 4,626, JP-A-55-59929, and JP-A-6-31493.

As a coating composition having an ultraviolet shielding function, a benzophenone or benzotriazole-based organic substance known as a transparent and powder having an ultraviolet shielding property is mixed with a synthetic resin to form a coating film. ing. Paints containing these organic ultraviolet shielding agents absorb ultraviolet light, but themselves deteriorate and discolor with it.
There was a concern that bleed-out was easier than resin.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a photocatalytic semiconductor which is irradiated with light having a wavelength greater than the bandgap of the photocatalytic semiconductor to generate a hydrophilic effect on the outermost layer by radicals generated from the photocatalytic semiconductor. An object of the present invention is to solve the problems that an organic compound present on the surface of a coating film and a substrate is decomposed, or the coating film and the substrate are directly decomposed by ultraviolet rays, although an antifouling effect is obtained.

[0008]

The first invention is a photocatalytic hydrophilic coating composition comprising a photocatalytic semiconductor material, a hardly decomposable binder, and a light shielding material. By providing such a photocatalytic hydrophilic coating composition, it is possible to obtain a coating film having sufficient hydrophilicity and antifouling property and having excellent adhesion and weather resistance.

A second invention is the photocatalytic hydrophilic coating composition according to the first invention, wherein the light-shielding material is rutile-type titanium dioxide fine particles having a particle diameter of 0.001 μm or more and 0.1 μm or less. By providing the photocatalytic hydrophilic coating composition according to the present invention, in addition to the effects of the first invention, a coating film that more effectively blocks light having a wavelength of 290 to 390 nm can be obtained, and a coating with high storage stability can be obtained. A composition can be obtained.

A third invention is the photocatalytic hydrophilic coating composition according to the first invention, wherein the light shielding material is zinc oxide fine particles having a particle diameter of 0.001 μm or more and 0.1 μm or less. By providing the photocatalytic hydrophilic coating composition according to the present invention, in addition to the effects of the first invention, it further shields light having a wavelength of 290 to 390 nm, and has a wavelength of 500 to
It is possible to obtain a coating film that transmits light of 800 nm more.

A fourth invention is the photocatalytic hydrophilic coating composition according to any one of the first to third inventions, wherein the hardly decomposable binder is peroxotitanic acid and / or a partial condensate thereof. By providing the photocatalytic hydrophilic coating composition according to the present invention, in addition to the effects of the first invention, a coating film that more effectively blocks light having a wavelength of 290 to 390 nm can be obtained, and storage stability can be obtained. Paint composition having a high viscosity can be obtained.

A fifth invention is a photocatalytic hydrophilic coating composition comprising a photocatalytic semiconductor material, a peroxotitanic acid and / or a partial condensate thereof as a hardly decomposable binder and a light shielding material. Thus, by providing the photocatalytic hydrophilic coating composition according to the present invention, the coating composition can be manufactured with fewer steps.

A sixth invention is the photocatalytic hydrophilic coating composition according to any one of the first to fifth inventions, further comprising a hardly decomposable colorant. By providing a hydrophilic coating composition, it is possible to obtain a coating film having excellent light shielding properties, sufficient hydrophilicity, antifouling properties, and further high designability without increasing the number of coating steps of the coating composition. it can.

Further, the photocatalytic hydrophilic coating composition according to the first to sixth aspects of the present invention can be applied to form a photocatalytic hydrophilic coating film. By forming a hydrophilic coating film, a photocatalytic hydrophilic composite material can also be provided.

The base material which can be coated with the photocatalytic hydrophilic coating composition of the invention is, for antifogging applications, a transparent base material such as glass, transparent plastic, lens, prism and mirror.

More specifically, bathroom or toilet mirrors,
Mirrors such as vehicle back mirrors, dental tooth mirrors, road mirrors;
Lenses such as spectacle lenses, optical lenses, camera lenses, endoscope lenses, illumination lenses, lenses for semiconductor manufacturing; prisms; windows of buildings and towers; automobiles, railway vehicles, aircraft, ships, submersibles, Windowpanes for vehicles such as snowmobiles, lowway gondola, amusement park gondola, spaceships; cars, railcars, aircraft, ships, submarines,
Windshields for vehicles such as snowmobiles, snowmobiles, motorbikes, gondolaes in lowways, gondolaes in amusement parks; protective or sporting goggles or masks (including diving masks) Helmet shield; frozen food display case glass; measuring instrument cover glass;
And a film, an emblem, and the like that can be attached to those articles.

As a substrate which can be coated with the photocatalytic hydrophilic coating composition of the present invention, for outdoor use where self-purification by rainfall can be expected, for example, metal, ceramics, glass, plastic, wood, stone, cement, Concrete, fiber, fabric, paper, combinations thereof, laminates thereof, coatings thereof, and the like.

More specifically, building exteriors such as exterior walls and roofs; window frames; exterior and painting of vehicles such as automobiles, rail vehicles, aircraft, ships, bicycles, and motorcycles; window glasses; Signs, soundproof walls, vinyl houses, insulators,
Covers for vehicles, tent materials, reflectors, shutters, screen doors, covers for solar cells, covers for collectors such as solar water heaters, street lights,
Pavement, outdoor lighting, stones and tiles for artificial waterfalls and artificial fountains,
Bridges, greenhouses, outer wall materials, sealers between walls and glass, guard rails, verandas, vending machines, outdoor air conditioners, outdoor benches, various display devices, shutters, toll booths, toll boxes, Roof gutters, vehicle lamp protection covers, dust-proof covers and painting, painting of machinery and articles, exterior and painting of advertising towers,
Structural members, films, patches, and the like that can be attached to such articles.

As a substrate which can be coated with the photocatalytic hydrophilic coating composition of the present invention, in an application where cleaning by water washing can be expected, for example, metal, ceramics, glass, plastic, wood, stone, cement, concrete, etc. −
, Fibers, fabrics, papers, combinations thereof, laminates thereof, coatings thereof, and the like.

More specifically, not only the above-mentioned outdoor use members are included, but also other materials such as building interior materials, window glass,
Housing equipment, toilets, bathtubs, washbasins, lighting fixtures, kitchenware,
Tableware, dish dryer, sink, cooking range, kitchen furniture
Doors, ventilation fans, window rails, window frames, tunnel interior walls, tunnel interior lighting, and films and patches that can be attached to these articles.

Examples of the substrate which can be coated with the photocatalytic hydrophilic coating composition of the present invention include those which can be expected to accelerate drying, such as window sashes, radiating fins for heat exchangers, pavements, bathroom mirrors, and the like. Examples include vinyl house ceilings, vanities, automobile bodies, and films and patches that can be attached to such articles.

The coating composition of the present invention has a wide range of uses other than those described above, such as prevention of snow accumulation and prevention of air bubble adhesion.

In particular, snow-preventing properties are remarkably excellent when a surface layer having a surface roughness of 1 μm or less is provided. For example, roofing materials for snowy countries, antennas, power transmission lines, films that can be adhered to such articles, The present invention is applicable to base materials including patches.

According to a seventh aspect of the present invention, a light beam having a wavelength of 290 to 390 nm is shielded from reaching a boundary portion between a substrate and a coating film.
And a photocatalytic hydrophilic coating characterized in that the surface of the coating exhibits hydrophilicity in response to photoexcitation of the photocatalyst, by providing a photocatalytic hydrophilic coating according to the present invention,
It has sufficient hydrophilicity and antifouling property, and can obtain excellent adhesion and weather resistance.

An eighth invention is a photocatalytic hydrophilic coating film having a transmittance of light having a wavelength of 325 nm of less than 10% and a transmittance of light having a wavelength of 390 nm of 50% or less. By providing such a photocatalytic hydrophilic coating film, in addition to the seventh invention, a coating film having further excellent adhesion and durability can be obtained.

In a ninth aspect, the film thickness of the coating film is 0.0
The photocatalytic hydrophilic coating film according to the seventh or eighth invention, which is 5 μm or more and 10 μm or less, in addition to the seventh invention, by providing the photocatalytic hydrophilic coating film according to the present invention. Further, it is possible to obtain a coating film having a sufficient light shielding function and excellent strength and durability.

The eleventh invention has a wavelength of 500 nm to 800 nm.
The photocatalytic hydrophilic coating film according to any one of the seventh to tenth inventions, which transmits a light beam having a wavelength of nm. It can also be used for substrates that require properties.

Further, a photocatalytic hydrophilic composite material comprising a base material and the photocatalytic hydrophilic coating film according to the present invention can be provided. In this case, the substrate can be applied to various substrates as described above.

[0029]

Next, specific components of the present invention will be described. The wavelength region to be shielded in the present invention is a wavelength having an energy higher than the band gap of anatase type and brookite type titanium dioxide used as a photocatalytic semiconductor material, and is 390 nm or less. Light rays from the sun contain a wide range of ultraviolet rays, but ultraviolet rays shorter than 290 nm are absorbed by stratospheric ozone, so that there is a problem in actual use.
It is a light beam having a wavelength of 290 to 390 nm.

The light shielding in the present invention does not mean that no light beam reaches at the boundary between the base material and the coating film. Even if the light is slightly transmitted, the photocatalytic activity of the photocatalytic semiconductor material is not apparently recognized. This is the level of shielding.

As the light shielding material used in the present invention, an organic ultraviolet absorbing agent, an inorganic ultraviolet shielding agent, and an antioxidant are preferred.

Examples of organic UV absorbers include benzophenone, benzotriazole, cyanoacrylate, triazine, salicylate, indole, and the like.
Examples include oxalic acid anilide type and substituted acrylonitrile type.

As the benzophenone-based ultraviolet absorber,
For example, 2-hydroxy-4-methoxybenzophenone,
2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone,
2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2-hydroxy-4-benzoyloxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfonebenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-5
-Chlorobenzophenone, bis- (2-methoxy-4-
(Hydroxy-5-benzoylphenyl) methane and the like.

Examples of the benzotriazole-based ultraviolet absorber include 2- (2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy- 5-methylphenyl) -5-carboxylic acid butyl ester benzotriazole, 2- (2'-hydroxy-5 '
-Methylphenyl) -5,6-dichlorobenzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5-ethylsulfonebenzotriazole, 2-
(2′-hydroxy-5′-t-butylphenyl) -5
-Chlorobenzotriazole, 2- (2'-hydroxy-5'-t-butylphenyl) benzotriazole,
-(2'-hydroxy-5'-aminophenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-
Dimethylphenyl) benzotriazole, 2- (2′-
Hydroxy-3 ′, 5′-dimethylphenyl) -5-methoxybenzotriazole, 2- (2′-methyl-4 ′)
-Hydroxyphenyl) benzotriazole, 2-
(2′-stearyloxy-3 ′, 5′-dimethylphenyl) -5-methylbenzotriazole, 2- (2′-
(Hydroxy-5-carboxylic acid phenyl) benzotriazole ethyl ester, 2- (2′-hydroxy-3′-
Methyl-5'-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2-
(2′-hydroxy-3′-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2-
(2′-hydroxy-5′-methoxyphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-
Di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-cyclohexylphenyl) benzotriazole, 2- (2'-hydroxy-4 ', 5'-dimethylphenyl) -5 Carboxylic acid benzotriazole butyl ester, 2- (2′-hydroxy-3 ′, 5′-dichlorophenyl) benzotriazole, 2- (2′-hydroxy-4 ′, 5′-dichlorophenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl) -5-ethylsulfonebenzotriazole, 2- (2'-hydroxy-
4'-octoxyphenyl) benzotriazole, 2-
(2'-hydroxy-5'-methoxyphenyl) -5
Methylbenzotriazole, 2- (2′-hydroxy-
5'-methylphenyl) -5-carboxylic acid ester benzotriazole, 2- (2'-acetoxy-5'-methylphenyl) benzotriazole, and the like.

As the cyanoacrylate-based ultraviolet absorber, for example, 2-ethylhexyl-2-cyano-3,3 '
-Diphenyl acrylate, ethyl-2-cyano-3,
3'-diphenyl acrylate and the like.

Examples of the triazine type ultraviolet absorber include 3,5-dialkyl-4-hydroxyphenyl derivatives of triazine, sulfur-containing derivatives of diallyl-4-hydroxyphenyltriazine, hydroxyphenyl-1,
Such triazines containing 3,5-triazine and sulfonic acid groups, aryl-1,3,5-triazines, orthohydroxyaryl-s-triazines and the like are included.

The amount of the organic ultraviolet absorber added in the present invention is preferably in the range of 0.01 to 20% by weight, more preferably 0.1 to 10% by weight, based on the total solid content.
Range. If the addition amount is less than 0.01% by weight, the light absorbing ability at a wavelength of 290 to 390 nm is insufficient, and if it exceeds 20% by weight, the transparency is reduced, the storage stability of the coating composition is reduced, and the film strength is reduced. Cause a decline.

The above-mentioned organic ultraviolet shielding agent may be added with an optional antioxidant, for example, a hindered amine light stabilizer to enhance the ultraviolet protection function. The hindered amine light stabilizer is designed to capture and stop various radicals generated on the coating film and the substrate surface, although the effect as an ultraviolet absorber is not so expected. Here, as the hindered amine light stabilizer, for example, bis-
(2,2,6,6-tetramethylpiperidin-4-yl) -sebacate, bis- (1,2,2,6,6-pentamethylpiperidin-4-yl) -sebacate, di-
(1,2,2,6,6-pentamethylpiperidine-4-
Yl) (3,5-di-t-butyl-4-hydroxybenzyl) -butylmalonate, 4-benzoyl-2,2,
6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 3-n
-Octyl-7,7,9,9-tetramethyl-1,3,
8-triazaspiro (4.5) -decane-2,4-dione, tris- (2,2,6,6-tetramethylpiperidin-4-yl) -nitrilotriacetate, 1,2-bis- (2,2 , 6,6-Tetramethyl-3-oxopiperazin-4-yl) -ethane, 2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21-oxodispiro (5.1.11) .2) Hen Eikosan, 2, 4
-Dichloro-6-t-octylamino-s-triazine and 4,4'-hexamethylenebis- (amino-2,2,
Polycondensation product 1 with 6,6-tetramethylpiperidine)
-(2-hydroxyethyl) -2,2,6,6-tetramethyl-4-hydroxypiperidine and a polycondensation product of succinic acid, 4,4'-hexamethylenebis- (amino-
2,2,6,6-tetramethylpiperidin-4-yl)
Polycondensation product of 1,2-dibromoethane with tetrakis- (2,2,6,6-tetramethylpiperidine-4-
Yl) 1,2,3,4-butanetetracarboxylate, tetrakis- (1,2,2,6,6-pentamethylpiperidin-4-yl) 1,2,3,4-butanetetracarboxylate, 4,4-Dichloro-6-morpholino-s-triazine and 4,4'-hexamethylenebis-
(Amino-2,2,6,6-tetramethylpiperidine)
A polycondensation product with N, N ′, N ″, N ′ ″-tetrakis ((4,6-bis- (butyl-2,2,6,6-
Tetramethylpiperidin-4-yl) -amino-s-triazin-2-yl) -1,10-diamino-4,7-
Diazadecane, mixed (2,2,6,6-tetramethylpiperidin-4-yl / β, β, β ′, β′-tetramethyl-
3,9- (2,4,8,10-tetraoxaspiro (5.5) -undecane) diethyl) 1,2,3,4-
Butanetetracarboxylate, mixed (1, 2, 2,
6,6-pentamethylpiperidin-4-yl / β, β,
β ′, β′-tetramethyl-3,9- (2,4,8,1
0-tetraoxaspiro (5,5) -undecane) diethyl) 1,2,3,4-butanetetracarboxylate, octamethylenebis- (2,2,6,6-tetramethylpiperidine-4-carboxylate) , 4,4'-
Ethylenebis- (2,2,6,6-tetramethylpiperazin-3-one), N-2,2,6,6-tetramethylpiperidin-4-yl-n-dodecylsuccinimide,
N-1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl-n-dodecylsuccinimide, 1-
Acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro (4,5) -decane-
2,4-dione, di- (1-octoxy-2,2,6,
6-tetramethylpiperidin-4-yl) -sebacate, di- (1-cyclohexyloxy-2,2,6,6
-Tetramethylpiperidin-4-yl) -succinate, 1-octyloxy-2,2,6,6-tetramethyl-4-hydroxypiperidine, poly- (6-t-octylamino-s-triazine-2,4 -Diyl) (2-
(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) -imino) -hexylmethylene- (4- (1-cyclohexyloxy-2,2,
6,6-tetramethylpiperidin-4-yl) -imino), 2,4,6-tris- (N- (1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-
4-yl) -n-butylamino) -s-triazine and the like.

Examples of the inorganic ultraviolet shielding agent include, for example, at least one selected from titanium oxide, cerium oxide, zinc oxide, iron oxide, tin oxide, zirconium oxide, vanadium oxide, lead oxide, ammothin oxide, and indium oxide. be able to. The structure of the fine particles containing an inorganic material having ultraviolet absorbing properties is not particularly limited, and other than the fine particles composed only of the inorganic materials having ultraviolet absorbing properties,
Fine particles obtained by coating the surface of the core particles with an inorganic material having an ultraviolet absorbing property, resin fine particles containing an inorganic material having an ultraviolet absorbing property, and the like can be given. The core particles are made of silica, mica, resin, or the like, and may or may not have ultraviolet absorption.

In the case of using an inorganic fine particle ultraviolet ray shielding agent having photocatalytic activity such as anatase type titanium dioxide, Zn, Al, Mg, Li, Na,
Cu, Ca, Pb, V, Nb, Ta, As, W, Cr,
Doping with a metal element such as Fe, Co, or Ni, or coating the surface with an inert hydrated metal (hydroxide) such as Al, Si, or Zr may improve weather resistance.

As other inorganic ultraviolet shielding agents in the present invention, amorphous titanium oxide precursor compounds such as peroxotitanic acid or a partial condensate thereof, titanium lactate, and titanium triethanolamine are also suitable. Peroxotitanic acid and / or a partial condensate thereof are more preferred because of easy handling.

The amount of the inorganic fine particle ultraviolet shielding agent in the present invention varies depending on the metal oxide to be added and is not particularly limited.
A range of 0% by weight is preferred. If the addition amount is less than 0.1% by weight, the ultraviolet absorbing ability becomes insufficient, and if it exceeds 50% by weight, the transparency, the film strength is reduced, and the hydrophilicity is poor.

When an inorganic fine particle ultraviolet shielding agent is used for a member requiring transparency, the average particle diameter of the light shielding material is as follows:
0.1 μm or less, preferably 0.05 μm or less,
More preferably, it is 0.03 μm or less. When the average particle diameter of the light-shielding material exceeds 0.1 μm, absorption in the visible region starts, and the transparency decreases.

In order to maintain a high transmittance at a wavelength of 400 to 800 nm, it is effective to make the composition into ultrafine particles, but the stability of the coating composition deteriorates, the scattering ability of ultraviolet rays is impaired, There is also a problem that the overall ultraviolet absorbing ability is reduced.

When long-term weather resistance is required, the light shielding material is preferably an inorganic material. Use of an organic ultraviolet shielding agent causes a problem that the life is short.

The lower limit of the thickness of the photocatalytic hydrophilic coating film in the present invention is at least 0.05 μm, preferably 0.1 μm.
m or more, more preferably 0.5 μm or more. When the film thickness is less than 0.05 μm, the light shielding ability becomes insufficient. In that case, it is possible to have a sufficient light shielding ability by increasing the amount of the light shielding material to be added. The strength of the
It is not preferable in terms of transparency.

The upper limit of the thickness of the photocatalytic hydrophilic coating film in the present invention is 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less. 10μ thickness
When m exceeds m, the strength of the coating film is significantly reduced, and the transparency at a wavelength of 400 to 800 nm is also reduced.

When the inorganic fine particle ultraviolet shielding agent of the present invention is mixed with the coating composition, any dispersing agent can be used. When dispersing in an aqueous solvent, as an aqueous dispersant,
For example, high molecular weight polycarboxylic acid salt, styrene / maleic acid copolymer salt, naphthalene / sulfonic acid formalin condensate, long chain alkyl organic sulfonic acid salt, lignin sulfonic acid salt, polyphosphoric acid, polysilicic acid Salts, long-chain alkylamine salts, polyethylene glycol derivatives, sorbitan fatty acid esters, and the like can be used, and one or more kinds can be used.

Examples of the organic solvent-based dispersant include a cationic surfactant, a nonionic surfactant, and an anionic surfactant.

The photocatalytic semiconductor materials used in the present invention include TiO2, ZnO, SnO2, SrTiO2.
3, CdS, CdO, CaP, InP, In2O3, C
aAs, BaTiO3, K2NbO3, Fe2O3, T
a2O5, WO3, SaO2, Bi2O3, NiO, C
u2O, SiC, SiO2, MoS2, MoS3, In
Pb, RuO2, CeO2 and the like can be mentioned.
Among them, titanium oxide is preferable. Among titanium oxides, the anatase type and the brookite type are more preferable as the crystal form.

The average particle diameter of the photocatalytic semiconductor particles is 1 to 10
It is preferably 0 nm, more preferably 1 to 50 nm. When the particle size is in the above range, the hydrophilicity can be sufficiently exerted, and the surface to which the composition is applied can be prevented from losing transparency due to scattering of visible light by the particles. In particular, when high transparency, smoothness, and durability are required for the photocatalytic hydrophilic coating film, it is preferable to use an optical semiconductor having an average particle diameter of 10 nm or less. When long-term storage stability is required for the composition of the present invention, it is preferable to use optical semiconductor fine particles having an average particle size of 10 nm or more.

The addition amount of the photocatalytic semiconductor material in the present invention is preferably in the range of 5 to 90% by weight, more preferably 20 to 80% by weight, based on the total solid content. If the addition amount is less than 5% by weight, the photocatalytic activity is not sufficient, and the expected hydrophilicity and antifouling property cannot be obtained. On the other hand, if it exceeds 90% by weight, the film strength is significantly reduced.

As the hardly decomposable binder in the present invention,
Hydrolyzable silane, alkyl silicate, polyorganosiloxane, acrylic silicone resin, silica, colloidal silica, water-soluble silica, silanol, water glass, silicon compounds such as thiium silicate, potassium silicate, zinc phosphate, aluminum phosphate , Hydroxyapatite, phosphates such as calcium phosphate, heavy phosphates,
Cement, lime, gypsum, feldspar, glaze, plaster,
Enamel frit, layered oxide, clay, borate, aluminosilicate, borosilicate, organic titanate, alumina, titania, peroxotitanic acid, partial condensate of peroxotitanic acid, organic zirconium compound, zirconium chloride, zirconium nitrate , Zirconium oxide chloride,
Inorganic compounds such as zirconia, and organic compounds such as fluorine-based polymers and fluorine-based monomers can be used.

Here, the hydrolyzable silane includes methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, methyltripropoxysilane, ethyltripropoxysilane, n-propyltrimethoxysilane and n-propyltrimethoxysilane. -Propyltriethoxysilane, n-propyltripropoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, isopropyltripropoxysilane, methyltributoxysilane, ethyltributoxysilane, n-propylbutoxysilane, isopropylbutoxysilane, phenyltrisilane Methoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltributoxysilane, γ-glycidoxypropyltrimethoxysilane, γ -Glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltripropoxysilane, β- (3 4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane,
γ-mercaptopropyltriethoxysilane, trifluoropropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, trifluoropropyltriethoxysilane, phenylmethyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane Hydrolyzable organosilanes such as silane, diethyldiethoxysilane, phenylmethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetra-n-propoxysilane, tetrabutoxysilane, tetramethoxysilane And tetraalkoxysilanes such as dimethoxydiethoxysilane.

Here, as the alkyl silicate, methyl silicate, ethyl silicate, propyl silicate
And butyl silicate can be used.

Here, the polyorganosiloxane includes
The above-mentioned hydrolyzable silanes, alkyl silicates, their (partial) hydrolysates, hydrolyzates / condensates, etc. can be used.

The acrylic silicone used herein is a resin having at least one silicon group in one molecule whose main chain is composed of a silyl group-containing vinyl polymer or copolymer and which is bonded to a hydrolyzable group at a molecular terminal or a side chain. Can be used.

Here, as the cement, an early-strength cement,
Uses Portland cement such as ordinary cement, moderate heat cement, sulfate resistant cement, white cement, oil well cement, geothermal well cement, mixed cement such as fly ash cement, high sulfate cement, silica cement, blast furnace cement, alumina cement etc. it can.

As the plaster, gypsum plaster, lime plaster, dolomite plaster and the like can be used.

The fluorine-based polymer includes polyvinylidene fluoride, polyvinyl fluoride, polychlorinated ethylene trifluoride, polytetrafluoroethylene, polytetrafluoroethylene-propylene hexafluoride copolymer, ethylene-polytetrafluoroethylene. Crystalline fluororesins such as fluorinated ethylene copolymer, ethylene-chlorinated ethylene trifluoride copolymer, ethylene tetrafluoride-perfluoroalkylvinyl ether copolymer, perfluorocyclopolymer, vinyl ether fluoroolefin Non-crystalline fluororesins such as copolymers and vinyl ester-fluoroolefin copolymers, various fluororubbers and the like can be used.

It is particularly preferable that the hardly decomposable binder contains a silicon compound. As a silicon compound,
The above-mentioned silicon-based compounds are exemplified. More preferably, a siloxane bond ({Si-O-Si}) is a main component, and hydrolyzable silane, polyorganosiloxane, alkyl silicate, silica, colloidal silica, water glass, lithium silicate, silica Potassium acid and the like.

The non-degradable binder in the present invention is preferably an amorphous titanium oxide precursor compound such as peroxotitanic acid or a partial condensate thereof. These can sufficiently function not only as a hardly decomposable binder but also as a light shielding material. However, since the hydrophilicity is poor, it is preferable to use a combination with a material having a high hydrophilicity such as colloidal silica. Further, the addition of colloidal silica also has the effect of lowering the refractive index of the coating film and reducing reflection in the visible region.

The amount of the hard-to-decompose binder in the present invention is preferably in the range of 10 to 95% by weight, more preferably 20 to 80% by weight, based on the total solid content. When the addition amount is less than 10% by weight, the film strength of the coating film is significantly reduced. On the other hand, when the content exceeds 95% by weight, the amount of the photocatalytic semiconductor material added becomes small, which is not sufficient to cause photocatalytic activity, and the desired hydrophilicity and antifouling property cannot be obtained.

In the coating composition of the present invention, a coloring agent which does not discolor, deteriorate or decompose even when used in combination with the photocatalytic semiconductor material may be added within a range that does not adversely affect the effects of the present invention.

The colorant is not particularly limited, but can be used for coloring and is selected from inorganic pigments, organic pigments, dyes and the like, and may be used alone or in combination of two or more.

As inorganic pigments, titanium oxide, zinc white,
Metal oxides such as red iron oxide, chromium oxide, cobalt blue and iron black; metal hydroxides such as alumina white and yellow iron oxide; ferrocyanide compounds such as navy blue;
Zinc chromate, lead chromate such as molybdenum red, sulfide such as zinc sulfide, vermilion, cadmium yellow, cadmium red, selenium compound, barite, sulfate such as precipitated barium sulfate, heavy calcium carbonate, sedimentation Carbonates such as calcium carbonate, hydrated silicates, silicates such as clay and ultramarine, carbons such as carbon black, metal powders such as aluminum powder, bronze powder, zinc powder, mica and titanium oxide And pearl pigments.

As the organic pigment, naphthol green B
Nitro pigments such as naphthol S, azo pigments such as lithol red, lake red C, fast yellow and naphthol red; dyed lake pigments such as alkali blue red and rhodamine chelate; phthalocyanine blue, phthalocyanine green Phthalocyanine pigments, condensed polycyclic pigments such as perene red, quinacridone red, dioxazine violet, and isoindolinone yellow.

Examples of the dye include disperse dyes, oil-soluble dyes, basic dyes, direct dyes, and acid dyes.

Further, a leveling agent, a water-soluble resin, a coupling agent, a thickener, a metal powder, a glass powder, and an antibacterial agent may be added as long as the effects of the present invention are not adversely affected.

The method for coating the substrate with the coating composition prepared by the present invention by spraying or spraying it is not particularly limited. For example, a spray coating method, a dip coating method, a flow coating method and the like. -Ting method,
Methods such as spin coating, roll coating, screen printing, bar coater, brush coating, and sponge coating can be used.

The substrate which can be coated with the coating composition of the present invention is an inorganic material, a metal material, an organic material or a composite thereof, and is not particularly limited. For example,
Metal, ceramics, glass, plastic, wood, stone,
Cement, concrete, fiber, fabric, paper, combinations thereof, laminates thereof, coatings thereof, and the like.
Among these, especially when applied to organic polymer resin materials such as acrylonitrile resin, vinyl chloride resin, polycarbonate resin, methyl methacrylate resin, polyester resin, polyurethane resin, etc., it can be protected from decomposition by photocatalytic semiconductor material and exerts effects I do.

The composition according to the invention is applied to the surface of a substrate and subsequently dried or cured into a coating. Drying or curing can be performed by heating, leaving at room temperature, irradiating ultraviolet rays, or the like. The coating film of the present invention cures to the extent that there is no problem in practical use even when left at room temperature. However, if necessary, heating can shorten the curing time and increase the degree of curing.

[0073]

EXAMPLES The present invention will be described more specifically below with reference to examples, but the technical scope of the present invention is not limited to these examples. (Formulation Example 1) As a photocatalytic semiconductor material, a titanium dioxide anatase type fine particle sol solution (TO-24, manufactured by Tanaka Transfer Co., Ltd.)
0) 125.0 parts, a peroxotitanic acid solution (PTA manufactured by Tanaka Transfer Co., Ltd., PTA
-170) The coating composition A was obtained by stirring 411.76 parts of the mixture at room temperature for 30 minutes.

(Formulation Example 2) 125.0 parts of a titanium dioxide anatase type fine particle sol solution (TO-240, manufactured by Tanaka Transfer Co., Ltd.) as a photocatalytic semiconductor material, a peroxytitanic acid as a hardly decomposable binder and a light shielding material 352.94 parts of a solution (PTA-170, manufactured by Tanaka Transfer Co., Ltd.), and 1.2 parts of ion-exchanged water, 0.1 part of propylene glycol as a light shielding material, a dispersant (manufactured by BSF Japan, Pigment Disperser) MD20) A coating liquid of 1.0 part of a titanium dioxide rutile type fine particle powder (TTO-55D, manufactured by Ishihara Sangyo Co., Ltd.) previously dispersed in 0.1 part of the mixture was stirred for 30 minutes to prepare the coating composition B. Obtained.

(Formulation Example 3) As a mixture of a photocatalytic semiconductor material and a hardly decomposable binder, 60.0 parts of a photocatalytic titanium oxide / coating solution (ST-K03, manufactured by Ishihara Sangyo Co., Ltd.) was used as a hardly decomposable binder. , Colloidal silica (Nissan Chemical Industries,
10.0 parts of Snowtex IPA-ST), 1.0 part of titanium dioxide rutile type fine particle powder (TTO-55D, manufactured by Ishihara Sangyo Co., Ltd.) as a light shielding material, 2-propanol 4
The coating composition C was obtained by stirring 29.0 parts of the mixed liquid for 30 minutes.

(Formulation Example 4) As a mixture of a photocatalytic semiconductor material and a hardly decomposable binder, 60.0 parts of a photocatalytic titanium oxide / coating solution (ST-K03, manufactured by Ishihara Sangyo Co., Ltd.) was used as a hardly decomposable binder. , Colloidal silica (Nissan Chemical Industries,
A mixture of 10.0 parts of Snowtex IPA-ST), 1.0 part of a benzophenone-based ultraviolet shielding agent (Adeka Stab LA-51, manufactured by Asahi Denka Co., Ltd.) and 429.0 parts of 2-propanol as a light shielding material is 30. By stirring for minutes, coating composition D was obtained.

(Formulation Example 5) 125.0 parts of a titanium dioxide anatase type fine particle sol solution (TO-240, manufactured by Tanaka Transfer Co., Ltd.) as a photocatalytic semiconductor material, and a lithium silicate solution (Nippon Chemical Co., Ltd.) as a hardly decomposable binder , Lithium silicate 3
5) A coating composition E was obtained by stirring a mixture of 29.79 parts and 45.21 parts of ion-exchanged water at room temperature for 30 minutes.

(Formulation Example 6) As a mixture of a photocatalytic semiconductor material and a hardly decomposable binder, 60.0 parts of a photocatalytic titanium oxide / coating solution (ST-K03, manufactured by Ishihara Sangyo Co., Ltd.)
A coating composition F was obtained by stirring a mixed solution of 240.0 parts of propanol at room temperature for 30 minutes.

(Formulation Example 7) As a mixture of a photocatalytic semiconductor material and a hardly decomposable binder, 60.0 parts of a photocatalytic titanium oxide / coating solution (ST-K03, manufactured by Ishihara Sangyo Co., Ltd.) was used as a hardly decomposable binder. , Colloidal silica (Nissan Chemical Industries,
A coating composition G was obtained by stirring a mixed liquid of 13.33 parts of Snowtex IPA-ST) and 426.67 parts of 2-propanol for 30 minutes.

(Example 1) A slide glass plate (manufactured by Matsunami Glass Industry Co., Ltd., standard large-size water-green polisher S9) cut to 40 × 40 mm
213, thickness 1.3 mm) was applied with 0.34 g of the coating composition A prepared in Preparation Example 1 by brushing, and dried at room temperature for 3 days to obtain a coated test plate a having a film thickness of 1 μm. Also one
An asbestos cement calcium silicate plate (according to JIS A5418) cut to 50 mm x 65 mm is spray-coated with an epoxy resin-based primer (SK KAKEN, trade name: SK Surf Epo), dried at room temperature for 24 hours, and then acrylic. A urethane paint (Isamu paint, trade name Hi Art 1000) is spray-coated on the asbestos cement calcium silicate plate on which the above-mentioned primer coating has been performed,
Dry at room temperature for 24 hours. Then, 2.07 g of the coating composition A prepared in Formulation Example 1 was applied by brushing, and dried at room temperature for 3 days to obtain a coating test plate a ′ of the coating composition A having a thickness of 1 μm.

(Example 2) In the same manner as in Example 1, 0.68 g of the coating composition A prepared in Preparation Example 1 was added to glass,
The asbestos cement calcium silicate board coated with the primer and the paint is applied with a brush coating of 4.14 g, dried at room temperature for 3 days, and coated with a glass coating test plate b having a thickness of 2 μm and asbestos cement silicate board. A coating test plate b ′ made of a calcium acid plate was obtained.

Example 3 In the same manner as in Example 1, 0.34 g of the coating composition B prepared in Preparation Example 2 was added to glass,
The asbestos cement calcium silicate plate coated with the primer and the paint is applied by brushing with 2.07 g, dried at room temperature for 3 days, and coated with a 1 μm-thick glass coating test plate c and asbestos cement silicate. A coating test plate c ′ made of a calcium acid plate was obtained.

Example 4 In the same manner as in Example 1, 0.22 g of the coating composition C prepared in Preparation Example 3 was added to glass,
The asbestos cement calcium silicate board coated with the primer and the paint is applied with a brush coating of 1.34 g, dried at room temperature for 3 days, and coated with a 1 μm-thick glass coating test plate d and asbestos cement silicate board. A coating test plate d ′ made of a calcium acid plate was obtained.

(Example 5) In the same manner as in Example 1, 0.20 g of the coating composition D prepared in Preparation Example 4 was added to glass,
The asbestos cement calcium silicate plate coated with the primer and the paint is applied with a 1.22 g brush coating, dried at room temperature for 3 days, and coated with a 1 μm-thick glass coating test plate e and an asbestos cement silicate plate. A coating test plate e ′ made of a calcium acid plate was obtained.

(Comparative Example 1) In the same manner as in Example 1, 0.09 g of the coating composition E prepared in Preparation Example 5 was added to glass,
The asbestos cement calcium silicate plate coated with the primer and the paint is applied with a brush coating of 0.55 g, dried at room temperature for 3 days, and a glass coated test plate f having a thickness of 1 μm and an asbestos cement silicate plate. A coating test plate f ′ made of a calcium acid plate was obtained.

Comparative Example 2 In the same manner as in Example 1, 0.24 g of the coating composition F prepared in Preparation Example 6 was added to glass,
1.46 g of an asbestos cement calcium silicate plate coated with a primer and a paint is applied by brush coating, dried at room temperature for 3 days, and a 1 μm-thick glass coated test plate g and an asbestos cement silica plate. A coated test plate g ′ of a calcium acid plate was obtained.

(Comparative Example 3) In the same manner as in Example 1, 0.20 g of the coating composition G prepared in Formulation Example 7 was added to glass,
The asbestos cement calcium silicate plate coated with the primer and the paint is applied with a brush coating of 1.22 g, dried at room temperature for 3 days, and coated with a glass coating test plate h having a thickness of 1 μm and an asbestos cement silica plate. A coating test plate h ′ of a calcium acid plate was obtained.

(Evaluation) (1) Evaluation of hydrophilicity The hydrophilicity of the prepared test pieces a to h was evaluated by the contact angle with water. 1): The contact angle was measured after standing for 3 days at room temperature after the preparation of the test piece. 2) Following 1), the contact angle after irradiation with a black light blue lamp (manufactured by Sankyo Electric) 0.5 mW / cm 2 for 50 hours was measured. In addition, CX-150 made by Kyowa Interface Science was used for the contact angle measurement.

(2) Evaluation of Transmittance After the prepared test pieces a to h were allowed to stand at room temperature for 3 days after the preparation of the test pieces, a spectrophotometer (manufactured by JASCO Corporation, product number U
best-55) and a wavelength of 300 nm to 900 nm.
Was measured for total light transmittance.

(3) Evaluation of weather resistance The prepared test pieces a ′ to h ′ were prepared at room temperature after preparing the test pieces.
After being left for 3 days, the test piece was tilted southward at 45 degrees, fixed, and subjected to an outdoor exposure test. After standing for 6 months, the film state of the coating and the degree of discoloration were visually evaluated. (1)-
Table 1 shows the evaluation results of (3).

The transmittance of (2) is typically 350 nm,
And the transmittance at 555 nm. The numerical values described above are values obtained by dividing the measured value by the measured value of the slide glass alone in consideration of the shielding ability by the slide glass.

The evaluation results of (3) were as follows. Film state: no change, Δ: slight peeling, ×: considerable peeling Discoloration condition: no change, Δ: slight fading, × considerable fading

[Table 1]

The light-blocking photocatalytic hydrophilic coating of the present invention not only has a light-blocking function and excellent durability, but also has excellent hydrophilicity, so that it has a long-term antifouling property. Can be maintained.

[Brief description of the drawings]

FIG. 1 is a light transmittance curve of Example 2 of the present invention.

FIG. 2 is a light transmittance curve of Comparative Example 1 of the present invention.

Continued on the front page (51) Int. Cl. ⁷ Identification symbol FI Theme coat II (reference) C09D 5/00 C09D 5/00 A 201/00 201/00 C09K 3/18 C09K 3/18 (72) Inventor Kazuo Takahashi Fukuoka Prefecture, Fukuoka Prefecture Kitakyushu City Kokurakita-ku Nakajima 2-chome Nakajima 2-1-1, Tokyu Equipment Co., Ltd. (72) Inventor Shimai Fukuoka Kitakyushu City, Kokurakita-ku 2-1-1 Nakajima Fukuoka Equipment F-term ( Reference) 4D075 CA32 CA37 CB07 DC02 EA02 EA06 EC02 EC11 EC53 4G069 AA04 AA09 BA02B BA02C BA04A BA04B BA04C BA48A BA48C BB04A BB04B BB04C BC35A CA01 CA07 CA10 CA11 DA06 EA08 EB18A01 1 012A011 03A031 HA026 HA066 HA121 HA201 HA211 HA216 HA226 HA296 HA301 HA306 HA331 HA346 HA356 HA371 HA376 HA411 HA441 HA451 HA456 HA461 HA471 HA491 HA521 HA546 HA551 HA561 JA23 JA32 JA64 JB16 JB21 JB30 JB33 JB35 JB36 JB39 JC12 JC13 JC32 JC38 JC33 J08C34 J08 NA03 NA05 NA06 NA 12

Claims (14)

[Claims] 1. A photocatalytic semiconductor material, a hardly decomposable binder,
Photocatalytic hydrophilic coating composition containing light-shielding material 2. The light shielding material has a particle diameter of 0.001.
2. The photocatalytic hydrophilic coating composition according to claim 1, wherein the composition is rutile-type titanium dioxide fine particles having a particle size of 0.1 to 0.1 [mu] m. 3. The light shielding material has a particle diameter of 0.001.
2. The photocatalytic hydrophilic coating composition according to claim 1, which is a zinc oxide fine particle having a particle size of 0.1 to 0.1 [mu] m. 4. The photocatalytic hydrophilic coating composition according to claim 1, wherein the hardly decomposable binder is peroxotitanic acid and / or a partial condensate thereof. 5. A photocatalytic hydrophilic coating composition containing a photocatalytic semiconductor material, a peroxotitanic acid and / or a partial condensate thereof as a hardly decomposable binder and a light shielding material. 6. The photocatalytic hydrophilic coating composition according to claim 1, which further comprises a hardly decomposable colorant. 7. A photocatalytic hydrophilic coating film formed by applying the photocatalytic hydrophilic coating composition according to claim 1. 8. A photocatalytic hydrophilic composite material comprising a base material and the photocatalytic hydrophilic coating film according to claim 7. 9. A wavelength of 290-3 from the boundary between the substrate and the coating film.
A photocatalytic hydrophilic coating film characterized in that a light beam of 90 nm is shielded from reaching and a surface of the coating film exhibits hydrophilicity in response to photoexcitation of a photocatalyst. 10. The transmittance of light having a wavelength of 325 nm is 10
% And the transmittance of light having a wavelength of 390 nm is 5%.
0% or less photocatalytic hydrophilic coating 11. The photocatalytic hydrophilic coating according to claim 9, wherein the thickness of the coating is 0.05 μm or more and 10 μm or less. 12. The photocatalytic hydrophilic coating film according to claim 9, which transmits light having a wavelength of 500 to 800 nm. 13. A photocatalytic hydrophilic composite material comprising a base material and the photocatalytic hydrophilic coating film according to claim 9. 14. A photocatalytic hydrophilic coating composition for forming the photocatalytic hydrophilic coating film according to claim 9.