JP2001259521A - Method for forming hydrophilic film and coated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for simply preparing a hydrophilic film excellent in durability and a coated article in which the hydrophilic film obtained by the method is formed as a top coat layer. SOLUTION: In the method for forming the hydrophilic film, a solution containing an aluminum compound is applied on a base material to form the film, on a petal-shaped alumina film of the base material which is manufactured by being treated with hot water or heated steam and in which the petal-shaped alumina film is formed, a film made from a titanium chelate compound (A) or a film of amorphous titanium oxide (B) and a film of polysiloxane (C) are formed in turn to prepare a double layer film, and the double layer film is irradiated with active energy beams. In the coated article, the hydrophilic film formed by the method is arranged as the top coat layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a novel and useful hydrophilic film and a coated article provided with a hydrophilic film obtained by the method as a top coat layer.

More specifically, a coating solution containing an aluminum compound is applied to a substrate to form a film, and the film is treated with hot water or heated steam. After forming a titanium chelate compound film or an amorphous titanium oxide film and a polysiloxane film on the petal-like alumina film to prepare a multilayer film, irradiating the multilayer film with active energy rays A method for forming a hydrophilic film, and a coated article provided with a hydrophilic film prepared by the method as a top coat layer.

[0003] The hydrophilic film thus prepared is used as a top coat for various outdoor products such as exterior wall materials of buildings, outdoor structures such as bridges and tanks, and vehicles such as automobiles for preventing contamination. Coatings, hydrophilic coatings of fins such as aluminum fins used in outdoor and indoor units for heat exchange such as coolers, anti-fogging coatings of various glasses and mirrors used indoors, and images It can be effectively used for various uses such as a forming medium.

[0004]

2. Description of the Related Art Heretofore, as a method for forming a hydrophilic film, there have been mentioned (1) a method of preparing a polymer by crosslinking a polymer containing a hydrophilic group such as a carboxylate group, a sulfonate group or a polyoxyalkylene group. Or
(2) Japanese Patent No. 2756474 and JP-A-9-579
As described in JP-A No. 12 (1994), after coating a base material with a coating agent composed of metal oxide fine particles having a function as a photo-oxidation catalyst such as crystalline titanium oxide and a binder such as silicone, the substrate is irradiated with light. To make the surface hydrophilic.

However, among such methods, (1)
The hydrophilic film obtained by the method of (1) has a problem of inferior durability. In the method of (2), a coating agent is prepared from fine particles having a function as a photooxidation catalyst obtained by firing at a high temperature in advance and a binder. There is a problem that it has to go through a complicated process of preparing

[0006]

SUMMARY OF THE INVENTION However, the present inventors have started research to eliminate all the various problems in the conventional technology as described above.

Accordingly, an object of the present invention is to provide a method for easily preparing a hydrophilic film having excellent durability, and to provide a hydrophilic film obtained by such a method as a top coat layer. An object of the present invention is to provide a coated article provided.

[0008] In order to solve the above-mentioned problems, the present inventors have
As a result of intensive studies, a coating solution containing an aluminum compound was applied to the base material to form a film, and treated with hot water or heated steam. On the petal-like alumina film, a film of the titanium chelate compound is formed from the titanium chelate compound by drying at room temperature or baking at a relatively low temperature, or a film of amorphous titanium oxide is formed by baking at a low temperature. After forming a multi-layer film by forming a film of polysiloxane thereon, by irradiating the multi-layer film with active energy rays, it is possible to easily obtain a hydrophilic film having excellent durability.
In addition, the coated article provided with the hydrophilic film thus obtained as a top coat layer has various properties and durability derived from surface hydrophilicity such as exposure contamination resistance, anti-fogging property, and water flowability. The inventors have found that the present invention is excellent in performance and convinced that the problems to be solved by the present invention can be solved brilliantly, and have now completed the present invention.

That is, the present invention provides: A titanium chelate compound (A) film or an amorphous titanium oxide (B) film and a polysiloxane (C) film are sequentially formed on the petal-like alumina film on which the petal-like alumina film is formed. A method for forming a hydrophilic film by irradiating the multilayer film with active energy rays after preparing the multilayer film, wherein the petal-like alumina film is formed by applying a coating solution containing an aluminum compound to a substrate, Forming a film, characterized by being prepared by treatment with hot water or heated steam, a method for forming a hydrophilic coating film,

[0010] 2. The above-mentioned polysiloxane (C) film has at least one hydrolyzable group bonded to a silicon atom.
And an organosilane compound and / or a silicate compound having at least one monovalent organic group bonded to a silicon atom, or a hydrolysis product of the organosilane compound and / or the silicate compound. A method for forming a hydrophilic film according to 1 above,

3. The method for forming a hydrophilic film according to 1 or 2, wherein the irradiation of active energy rays reduces the contact angle between the multilayer film and water to 20 degrees or less.

4. The method for forming a hydrophilic film according to the above 1, 2, or 3, wherein the active energy ray is ultraviolet light, and

5. It is intended to provide a coated article provided with a hydrophilic film prepared by the method as described in any one of the above items 1 to 4 as a top coat layer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION
It will be described in detail. First, the hydrophilic film referred to in the present invention refers to a film having a hydrophilicity of about 50 ° or less, preferably 40 ° or less, particularly preferably 20 ° or less as the contact angle with water.

As the substrate used for forming such a hydrophilic film, various known and commonly used substrates can be used. Particularly typical examples of such a base material include various metal base materials, inorganic base materials, plastic base materials, paper, and wood base materials.

[0016] Among these various base materials, typical metal base materials include various metals such as iron, nickel, aluminum, chromium, zinc, tin, copper, and lead; and stainless steel and brass. And alloys of these various metals; various kinds of metals as described above, such as various kinds of surface-treated metals that have been subjected to plating, chemical conversion, and the like.

The inorganic substrate is mainly composed of inorganic materials such as silicates such as cement, calcium silicate, etc., gypsums, asbestos, ceramics and the like. What is concrete, cement mortar, gypsum plaster, dolomite plaster, lightweight cellular concrete (ALC), asbestos cement board, glass fiber reinforced calcium silicate board, gypsum board,
Examples include various fired products of various clays such as pottery, porcelain, alumina panels, and tiles, and various materials such as glass.

Representative plastic substrates include polystyrene, polycarbonate, polymethyl methacrylate, ABS resin, polyphenylene oxide,
Films and molded products of various thermoplastic resins such as polyurethane, polyethylene, polyvinyl chloride, polypropylene, polybutylene terephthalate, and polyethylene terephthalate; unsaturated polyester resins, phenolic resins,
Examples include crosslinked films and crosslinked molded articles obtained from various thermosetting resins such as crosslinked polyurethane, crosslinked acrylic resin, and crosslinked saturated polyester resin.

The petal-like alumina film according to the present invention is a fine pore-like structure in which alumina having a petal-like structure is randomly aggregated by the surface layer portion of the alumina film being peptized by hot water or heated steam. Is referred to as a film having a void. Such a substrate having a petal-like alumina film was formed by applying a coating solution prepared from various aluminum compounds to the substrate to form a gel film of the aluminum compound, and then forming a gel film of the aluminum compound. It can be obtained by treating the substrate with hot water or heated steam, preferably by immersing it in hot water. According to this method, a petal-like alumina film can be formed without passing through a step of firing at a high temperature, so that it is suitable for plastics having insufficient heat resistance.

Specific examples of the aluminum compound used in preparing such a coating solution include aluminum trimethoxide, aluminum triethoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum trioxide. sec
-Butoxide, aluminum tri-tert-butoxide, various aluminum alkoxides such as oligomers of aluminum alkoxide obtained by partially hydrolyzing various aluminum alkoxides as described above, aluminum nitrate, aluminum sulfate and the like. No. Particularly preferred among these are aluminum alkoxides.

In preparing the coating solution, as a stabilizer
Β-ketoester compounds as described below as representative chelating agents in titanium chelate compounds,
β-diketone compounds or alkanolamines can be added.

In preparing the coating solution, a diluting solvent can be used. Typical examples of the diluting solvent include various compounds described below as those which can be used when preparing a coating agent containing the titanium chelate compound (A). Among these various compounds, it is particularly preferable to use alcohols from the viewpoint of the stability of the coating solution.

A mixture of an aluminum alkoxide, a stabilizer and a solvent can be used as it is as a coating solution. A mixture obtained by adding water to the mixture and partially hydrolyzing an alkoxy group bonded to an aluminum atom can also be used as the coating liquid. The amount of water added when preparing a coating solution by adding water to partially hydrolyze the alkoxy group can be set relatively freely, but generally, 1 to 1 mole of water is added to 1 mole of aluminum alkoxide. What is necessary is just to add about 4 mol.

The coating solution thus prepared may be added with a catalyst for promoting the hydrolysis of the alkoxy group or for promoting the dehydration condensation. Representative examples of such catalysts include nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, ammonia and the like. The amount of such a catalyst to be added may be about 0.0001 to 1 mol per 1 mol of the aluminum compound.

If necessary, a water-soluble organic polymer can be added to the coating solution containing the above-mentioned aluminum compound. When a substrate coated with a gel film of an aluminum compound obtained by applying a coating solution containing a water-soluble organic polymer is immersed in, for example, hot water, the water-soluble organic polymer contained in the gel film can be easily removed. It elutes and the reaction surface area between the gel membrane and the hot water increases. For this reason, the petal-like alumina film can be formed at a low temperature in a short time. Also, by changing the type and molecular weight of the water-soluble organic polymer to be added, it becomes possible to control the shape of the formed petal-like alumina film.

Representative examples of the water-soluble polymer include polyvinyl pyrrolidone, polyvinyl alcohol, polymethyl vinyl ether, polyethylene glycol, polypropylene glycol and the like. Of these, polyether glycols such as polyethylene glycol and polypropylene glycol are particularly preferable because of their excellent elution properties from the gel film when immersed in hot water. And the addition amount of such polyether glycols is
0.1 to 10 based on the weight of alumina calculated assuming that all aluminum compounds are converted to alumina
% By weight.

In order to form a gel film using a coating solution containing no stabilizer among the above-mentioned coating solutions, the coating atmosphere should be a dry air atmosphere or an inert gas atmosphere such as dry nitrogen. preferable. And it is preferable that the relative humidity of such a dry atmosphere be 30% or less.

As a coating method for forming a gel film from the above-mentioned coating solution, there are various well-known and commonly used methods. Representative examples thereof include dipping, spin coating, spraying, printing, and flow. A coating method and a method using these in combination are exemplified. The thickness of the obtained gel film can be controlled by, for example, adjusting the pulling speed in the dipping method, adjusting the substrate rotation speed in the spin coating method, adjusting the concentration of the coating solution, and the like.

The aluminum compound gel film formed on the substrate by the method described above may be dried at room temperature for about 30 minutes. Further, if necessary, it can be dried at a higher temperature, usually 100 ° C. or lower. The substrate provided with the gel film of the aluminum compound thus prepared is treated with hot water or heated steam to obtain a substrate provided with a petal-like alumina film. The temperature of the hot water when immersing in hot water is preferably about 50 to 100 ° C. The temperature of the hot water is appropriately determined according to the heat resistance of the substrate, but the lower the temperature, the longer it takes to completely form the petal-like alumina film.

When such a petal-shaped alumina film is provided,
Very effective for applications that use patterned coated articles that have both highly water-repellent parts and highly hydrophilic parts because they can further increase the water repellency of the multilayer coating before irradiation with active energy rays. It is.

Further, in the present invention, a substrate obtained by coating a known and commonly used coating material on the above-described various substrates in advance to form a film may be used as the substrate. Typical paints used for forming such a film include acrylic resin paints, polyester resin paints, alkyd resin paints, epoxy resin paints, polyurethane resin paints, and fluoroolefin polymer paints. Various types such as paints, water glass paints, alkyl silicate paints, and polysiloxane paints can be mentioned. These paints may be in any form such as an organic solvent solution type, an organic solvent dispersion type, an aqueous dispersion type, a non-solvent type or a powder type.

In the method of the present invention, a film made of a titanium chelate compound (A) or a film of amorphous titanium oxide (B) is formed as a first layer on a substrate. Among such films, various known and commonly used titanium chelate compounds (A) can be used as the titanium chelate compound (A) used in preparing the film composed of the titanium chelate compound (A).

Representative chelating agents in the titanium chelate compound (A) include β-diketone compounds such as acetylacetone, dipyrroylmethane, trifluoroacetylacetone, hexafluoroacetylacetone, benzoylacetone and dibenzoylmethane. Methyl acetoacetate, ethyl acetoacetate, allyl acetoacetate, benzyl acetoacetate, acetoacetate-iso-
Propyl, tert-butyl acetoacetate, iso-butyl acetoacetate, 2-methoxyethyl acetoacetate,
Β-ketoester compounds, such as methyl 3-keto-n-valerate, etc .;
Examples thereof include alkanolamines such as diethanolamine and triethanolamine.

The above-mentioned titanium chelate compound (A)
Various known methods can be used as a method for preparing the compound. However, it is particularly convenient to react a known and commonly used titanium alkoxide with various chelating agents as described above.

Typical titanium alkoxides used at that time include titanium tetramethoxide, titanium tetraethoxide, titanium tetraisopropoxide, titanium tetra-n-
Butoxide, titanium tetra-sec-butoxide, titanium tetra-tert-butoxide or oligomers of titanium alkoxide obtained by partially hydrolyzing the above-mentioned various titanium alkoxides.

Specific examples of the titanium chelate compound (A) obtained from the above various titanium alkoxides and a chelating agent include titanium mono (acetylacetonate) tri-n-butoxide, titanium tetrakis ( Acetylacetonate), titanium tetrakis (ethylacetoacetate), titanium bis (acetylacetonate) diisopropoxide, titaniumbis (ethylacetoacetate) di-n
-Butoxide, titanium mono (benzoylacetonate) tri-n-butoxide and the like.

Among these titanium chelate compounds (A), those containing an alkoxy group bonded to at least one titanium atom in one molecule are particularly preferred from the viewpoint of film-forming properties. That is, the titanium chelate compound (A) used in the present invention is particularly preferably a compound in which at least one chelating agent and at least one alkoxy group are bonded in one molecule.

In preparing the film comprising the titanium chelate compound (A), first, for example, a method in which the various chelate compounds (A) prepared in advance as described above are dissolved in various solvents or the above-mentioned various methods are used. Chelating compound (A) by a method of adding a chelating agent to an organic solvent solution of titanium alkoxide
Is prepared.

The titanium chelate compound (A)
As a solvent used for preparing a coating agent containing, various known and commonly used solvents can be used. Typical examples thereof include methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, sec-butyl alcohol, ethylene glycol and ethylene glycol-mono-n. Alcohols such as -propyl ether; n
-Various aliphatic or alicyclic hydrocarbons such as hexane, n-octane, cyclohexane, cyclopentane and cyclooctane;

Various aromatic hydrocarbons such as toluene, xylene and ethylbenzene; such as ethyl formate, ethyl acetate, n-butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate and ethylene glycol monobutyl ether acetate , Various esters; various ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; dimethoxyethane;
Various ethers such as tetrahydrofuran, dioxane, diisopropyl ether; chloroform, methylene chloride, carbon tetrachloride. Various chlorinated hydrocarbons such as tetrachloroethane; N-methylpyrrolidone;
Aprotic polar solvents such as dimethylformamide, dimethylacetamide, and ethylene carbonate;

In preparing the coating agent used in the present invention by the above-mentioned method or the above-mentioned method, among the above-mentioned various solvents, alcohols are used as an essential component from the viewpoint of the stability of the coating agent. Is particularly preferred. In preparing the coating agent containing the titanium chelate compound (A) by these methods, water may be added as necessary to partially hydrolyze the alkoxy group bonded to the metal. As described above, the amount of water to be added is preferably an amount within a range in which at least one alkoxy group bonded to a metal remains per molecule, as described above.

In the coating agent containing the titanium chelate compound (A), the hydrolysis of the alkoxy group or the dehydration condensation reaction of the hydroxyl group bonded to the titanium atom is promoted. A catalyst can be added to facilitate the formation.

Representative examples of such catalysts include various inorganic acids such as nitric acid, hydrochloric acid, sulfuric acid, and phosphoric acid; various organic acids such as p-toluenesulfonic acid, monoisopropyl phosphate and acetic acid; and ammonium hydroxide. side,
Various inorganic bases such as sodium hydroxide and potassium hydroxide; various tin carboxylate salts such as dibutyltin diacetate and tin octylate; naphthenic acids of various metals such as iron, cobalt, manganese and zinc Metal carboxylate salts such as salts and octylates;

Various amine compounds such as 1,8-diazabicyclo [5.4.0] undecene-7 (DBU), tri-n-butylamine or dimethylbenzylamine, imidazole, 1-methylimidazole; tetramethyl Various quaternary ammonium salts such as ammonium salts, tetrabutylammonium salts, and trimethyl (2-hydroxypropyl) ammonium salts, and salts each having chloride, bromide, carboxylate, hydroxide, or the like as a counter anion. And the like.

When such catalysts are added, they are used in an amount of 0.0001 to 10 based on 100 parts by weight of the chelate compound (A) contained in the coating agent.
Parts by weight, preferably in a range of 0.0005 to 3 parts by weight, particularly preferably 0.0005 to 1 part by weight.
A range of parts by weight is appropriate.

Further, the coating agent containing the titanium chelate compound (A) can be used as a clear coating agent containing no coloring agent, and various known or commonly used organic or inorganic pigments or pigments can be used. It can also be used as a coating agent containing a dye. Further, such a coating agent, if necessary, a leveling agent, a rheology control agent, an ultraviolet absorber, an antioxidant or a plasticizer, various known and commonly used additives, or an acrylic resin, a vinyl resin or Various resins such as a polyurethane resin can also be blended and used.

Then, a coating is formed on the substrate by a known and commonly used method and dried at room temperature or forcibly dried or baked at a temperature of about 60 to 400 ° C. for a time for which the chelate bond remains. do it. Typical coating methods applied at that time include dipping, spin coating, nozzle flow coating, spraying, reverse coating, flexo, printing, flow coating, bar coating, and air coating. Various methods such as a spray method and an airless spray method are mentioned.

Next, a method for forming a film of amorphous titanium oxide on a substrate will be described. As such a method, various known and commonly used methods can be applied. For example, various compounds such as titanium alkoxides or titanium carboxylate such as titanium tetraacetate to generate titanium hydroxide by hydrolysis, among the solvents described above,
A coating agent obtained by dissolving in a water-soluble solvent such as methanol, ethanol or isopropanol and then adding water to perform partial hydrolysis or complete hydrolysis is applied to a substrate by various coating methods as described above, and dried. To form titanium hydroxide. Further, if necessary, a method of baking at a temperature up to about 400 ° C. to convert the titanium oxide into amorphous titanium oxide, and forming a film from the titanium chelate compound (A) on the base material as described above, In this case, a method in which the chelate bond is thermally decomposed to convert it into amorphous titanium oxide by heating may be applied.

When the above-mentioned method is applied, various catalysts as exemplified as those which can be added when preparing the coating agent containing the chelate compound (A) can be added when preparing the coating agent.

The thickness of the titanium chelate compound (A) film or the amorphous titanium oxide film thus formed is 0.5 nm to 10 μm from the viewpoint of exhibiting a high degree of hydrophilicity and crack resistance.
It is preferable to set to about.

The polysiloxane (C) film was formed on the titanium chelate compound (A) film or the amorphous titanium oxide (B) film formed on the petal-like alumina film of the substrate as described above. By forming, a multilayer film is prepared. Various known and commonly used methods can be applied to the formation of the polysiloxane (C) film. Specific examples of such a method include a method of applying a silane-based coating agent containing, as an essential component, a silane compound having at least one hydrolyzable group bonded to a silicon atom and hydrolyzing and condensing the silane compound. A polysiloxane-based coating agent containing, as an essential component, a previously prepared hydrolyzate of a silane compound having at least one hydrolyzable group bonded to a silicon atom or a polysiloxane which is a hydrolyzed condensate of the silane compound And further proceeding with condensation.

Examples of the silane compound used in the above-mentioned or the following method include an organosilane compound having at least one hydrolyzable group bonded to a silicon atom and at least one organic group bonded to a silicon atom, and various kinds of silane compounds. Silicate compounds.

In such an organosilane compound, the hydrolyzable group bonded to the silicon atom includes an alkoxy group, a substituted alkoxy group, an alkenyloxy group, an iminooxy group, an aryloxy group, an aralkyloxy group, a halogen atom and a hydrogen atom. And a group forming a hydroxyl group bonded to a silicon atom by hydrolysis, that is, a silanol group. Representative examples of the organic group bonded to the silicon atom include an alkyl group, a substituted alkyl group bonded with various substituents via a silicon-carbon bond, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. Various organic groups such as groups can be mentioned.

Representative of the alkyl groups among the above organic groups
Typical are methyl group, ethyl group, n-butyl
Group, iso-butyl group, n-octyl group, n-dodecyl
Group, n-octadecyl group, n-eicosyl group, n-tri
An alkyl group having 1 to 30 carbon atoms such as an acosyl group;
Can be Representative examples of the substituent alkyl group include 3
-Glycidoxypropyl group, 3- (meth) acryloyl
Oxypropyl group, 3-ureidopropyl group, 3-iso
A cyanatopropyl group, a 3-dimethylaminopropyl group
3-substituted propyl group; 3,3,3-trifluoro
Propyl group, 4,4,4-trifluorobutyl group, CF
_Three(CF_Two)_TwoCH_TwoCH_Two-, CF_Three(CF_Two)_ThreeCH_TwoCH_Two-, CF_Three(CF _Two)₇CH_TwoCH
_Two-, CF_Three(CF_Two)₉CH_TwoCH_Two-, CF_Three(CF_Two)₁₁CH_TwoCH_Two-, CF_Three(CF_Two)
₁₃CH_TwoCH_Two-, CF_Three(CF_Two)_FifteenCH_TwoCH_Two-, CF_Three(CF_Two)₁₇CH_TwoCH_Two-, C
F_Three(CF_Two)_{twenty one}CH_TwoCH_Two-, CF_Three(CF_Two)_{twenty five}CH_TwoCH_Two-, CF_Three(CF_Two)₂₇CH_Two
CH_TwoAlkyl groups substituted by various fluorine atoms such as-; 2
-Cyclohexylethyl group, 3,4-epoxycyclo
Alkyl substituted by cyclohexyl such as xylethyl
Examples include a kill group.

Representative examples of the cycloalkyl group include cyclopentyl and cyclohexyl groups. Representative examples of the aryl group include a phenyl group, a p-tolyl group, and a 1-naphthyl group.
Representative aralkyl groups include 2-phenylethyl and 1-phenylethyl groups. Representative examples of the alkenyl group include a vinyl group and an isopropenyl group.

At least one of the above hydrolyzable groups
Containing at least one organic group and at least one organic group
An alkoxy group or a hydrolyzable group in the compound
Is representative of those containing substituted alkoxy groups.
Methyltrimethoxysilane, methyltriethoxy
Silane, methyltri (2-methoxyethoxy) silane,
n-butyltrimethoxysilane, n-octyltrimeth
Xysilane, n-dodecyltrimethoxysilane, n-o
Kutadecyl trimethoxysilane, n-docosyl trimet
Xysilane, n-eicosyltrimethoxysilane, n-
Triacosyltrimethoxysilane, ethyltrimethoxy
Silane, ethyltriethoxysilane, ethyltri-n-
Butoxysilane, n-propyltrimethoxysilane, n
-Butyltrimethoxysilane, n-butyltriethoxy
Silane, phenyltrimethoxysilane, phenyltrie
Toxoxysilane, phenyltri-n-butoxysilane,
Nyltrimethoxysilane, vinyltriethoxysilane,
Vinyltri-n-butoxysilane, vinyltris (2-
Methoxyethoxy) silane or allyltrimethoxy
Silane, 2-trimethoxysilylethyl vinyl ether
, 2-triethoxysilylethyl vinyl ether, 3
-Trimethoxysilylpropyl vinyl ether, 3-to
Liethoxysilylpropyl vinyl ether, 3- (meth
TA) acryloyloxypropyltrimethoxysilane,
3- (meth) acryloyloxypropyltriethoxy
Silane, 3-glycidoxypropyltrimethoxysila
3,3,3, -trifluoropropyltrimethoxy
Silane, 4,4,4-trifluorobutyltrimethoxy
Silane, CF_Three(CF_Two)_TwoCH_TwoCH_Two-Si (OCH_Three)_Three, CF_Three(CF_Two)_ThreeCH_TwoCH_Two
-Si (OCH_Three)_Three, CF_Three(CF_Two)₇CH_TwoCH_Two-Si (OCH_Three)_Three, CF_Three(CF_Two)₉CH
_TwoCH_Two-Si (OCH_Three)_Three, CF_Three(CF_Two)₁₁CH _TwoCH_Two-Si (OCH_Three)_Three, CF_Three(CF
_Two)₁₃CH_TwoCH_Two-Si (OCH_Three)_Three, CF_Three(CF_Two)_FifteenCH_TwoCH_Two-Si (OCH_Three)_Three,
CF_Three(CF_Two)₁₇CH_TwoCH_Two-Si (OCH_Three)_Three, CF_Three(CF_Two)_{twenty one}CH_TwoCH_Two-Si (OC
H_Three)_Three, CF_Three(CF_Two)_{twenty five}CH_TwoCH_Two-Si (OCH_Three)_Three, CF_Three(CF_Two)₂₇CH_TwoCH_Two
-Si (OCH_Three)_Three, 3,4-epoxycyclohexyltrimeth
Various organotrialkoxysilas such as xysilane
Types;

Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi (2-methoxyethoxy) silane, dimethyldi-n-butoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyl Diethoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, diphenyldimethoxysilane,
Diphenyldiethoxysilane, diphenyldi-n-butoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, vinylmethyldimethoxysilane, 2- (methyldimethoxysilyl) ethyl vinyl ether, 3- (methyldimethoxysilyl) propyl vinyl ether, - (meth) acryloyloxy propyl methyl dimethoxy silane, 3-glycidoxypropyl _{methyldimethoxysilane, CF 3 (CF 2) 7} CH 2 CH 2 -Si (CH 3) (OC
_{H 3) 2, CF 3 (} CF 2) 9 CH 2 CH 2 -Si (CH 3) (OCH 3) 2 , such as, various diorgano dialkoxysilane; trimethylmethoxysilane, triethyl silane, tert- butyl dimethyl methoxysilane, cyclohexyl dimethyl _{methoxysilane, CF 3 (CF 2) 7} CH 2 CH 2 -Si (CH 3) 2 (OCH 3) , such as, tri organo mono alkoxysilanes are exemplified.

As the organosilane compound containing various groups other than an alkoxy group or a substituted alkoxy group as a hydrolyzable group, the above-mentioned various alkoxysilane compounds may be substituted by an alkoxy group or a substituted alkoxy group. And various compounds into which a hydrolyzable group has been introduced.

Among the various organosilane compounds described above, it is particularly preferable to use a silane compound containing two or three hydrolyzable groups as a main component in view of the durability of the hydrophilic film. . In addition, those containing an alkoxy group or a substituted alkoxy group are particularly preferable as the hydrolyzable group from the viewpoint of easy handling.

Representative examples of the silicate compound as one of the silane compounds used in the above-mentioned method or the following method include tetramethyl silicate, tetraethyl silicate, tetra-n-butyl silicate, tetra-2-ethylhexyl silicate , Tetra-
various silicates containing an alkoxy group having about 1 to 18 carbon atoms, such as n-octyl silicate, tetra-n-dodecyl silicate and tetra-n-octadecyl silicate; tetra-2-methoxyethoxy silicate;
Various alkyl silicates such as tetra-3-methoxypropyl silicate; aralkyl silicates such as benzyl silicate and 2-phenylethyl silicate; The organosilane compound and the silicate compound described above can be used alone,
Both can be used together.

The silane-based coating agent or polysiloxane-based coating agent used in the present invention can be prepared from the above-described various silane compounds by various known and commonly used methods. That is, the silane compound is dissolved in various solvents as exemplified as those used in preparing the coating agent containing the above-mentioned chelate compound (A), or the silane compound is partially hydrolyzed and condensed in the solvent. For example, a method of causing a hydrolysis, a hydrolysis, or a hydrolysis and condensation can be applied. In preparing these coating agents, various catalysts as described above can also be added.

When such catalysts are added, they are used in an amount of 0.1 to 100 parts by weight of the silane compound or polysiloxane contained in the coating agent.
The range of 0001 to 10 parts by weight is preferably 0.
In the range of 0005 to 3 parts by weight, particularly preferably,
The range of 0.0005 to 1 part by weight is appropriate.

As described above, a polysiloxane-based coating agent is prepared from an organosilane compound and / or a silicate compound. A polysiloxane contains a silicon atom to which a methyl group or a phenyl group is bonded, and has a functional group. Various commercially available silicone resins containing a silanol group or a methoxy group as a group can also be used.

The silane coating agent or polysiloxane coating agent used in the present invention may contain a leveling agent, a rheology control agent,
UV absorbers, antioxidants or plasticizers and various known and commonly used additives, or acrylic resins, vinyl resins, polyester resins, polyurethane resins, etc. can do.

The above-mentioned coating agent used in the present invention can be used as a clear coating agent containing no coloring agent, and various known and commonly used organic or inorganic pigments and dyes can be used. Can also be used as a coating agent containing

The coating agent thus prepared was formed on a substrate by applying various methods as exemplified as those applied when preparing the above-mentioned film comprising the titanium chelate compound (A). It is applied on a film made of a titanium chelate compound (A) or a film of amorphous titanium oxide (B). Then, leave it at room temperature for about 1 to 10 days to dry it,
By forcibly drying or baking at a temperature of about 60 to 300 ° C. for about 1 minute to 3 hours, a film of polysiloxane (C) can be obtained.

As described above, the thickness of the polysiloxane (C) film formed is 0.5 nm to 1 nm in view of exhibiting a high degree of hydrophilicity and crack resistance.
It is preferably set to 0 μm, preferably about 1 nm to 5 μm.

A hydrophilic film can be formed by irradiating the thus obtained multilayer film with an active energy ray. The irradiation conditions such as the type of the active energy ray to be irradiated and the irradiation time are water, With a contact angle of approximately 50 degrees or less, preferably 40 degrees or less, and most preferably 2 degrees or less.
What is necessary is just to set it so that it may become 0 degrees or less.

Such active active energy rays include:
Various known and commonly used materials can be used, and typical ones include visible light, ultraviolet light, excimer laser light, semiconductor laser light, electron beam, and X-ray.

As the radiation source for irradiating the active energy ray, a known and commonly used device capable of generating each active energy ray may be used.
Sunlight can also be used as a source.

Among the various types of active energy rays described above, ultraviolet rays are particularly preferred.

The time for irradiating the active energy ray may be set to an optimum time according to the degree of hydrophilicity to be imparted to the film, the thickness of the film, the intensity of the radiation source, and the like. It may be about 10 hours. However, when using sunlight as a radiation source, it may be possible for the first time to become hydrophilic by exposure for one day to one month.

The mechanism by which the hydrophilic film is formed by the method of the present invention has not been elucidated yet, but the film obtained from the titanium chelate compound (A) or the film of amorphous titanium oxide (B) is photodecomposed. It is presumed that the function is exhibited, and the organic group or the alkoxy group contained in the polysiloxane film of the top coat layer is decomposed to form a hydrophilic silica-based film.

Next, a coated article provided with a hydrophilic film obtained by the method for forming a hydrophilic film of the present invention as a top coat layer will be described.

More specifically, such coated articles include automobiles, motorcycles, trains, bicycles, ships or airplanes or other transportation-related equipment using a metal substrate as a substrate, respectively. Various parts using metal base or plastic base, etc. used for them; TV, radio, refrigerator, washing machine, cooler outdoor unit using metal base, plastic base, etc. as base Fin materials such as aluminum fins for heat exchange installed in indoor units or outdoor units of coolers or computers or other household appliances; various image forming media mainly using metal base materials Glass parts for vehicles such as windshields, rear glasses, side glasses, door mirrors, and glass products such as mirrors or window glasses of buildings.

Various building materials such as various inorganic tiles, metal roof materials, inorganic outer wall materials, metal wall materials, metal window frames, metal doors, and inner wall materials; road sign,
Various outdoor structures such as guardrails, bridges, tanks, chimneys, and buildings; and various coating films coated on various organic films such as polyester resin films, acrylic resin films, polyimide resin films, and fluororesin films. No.

Then, among these various coated articles,
Particularly preferred are various exterior building materials and various outdoor constructions in that the top coat layer is made hydrophilic to improve the exposure and contamination resistance; From the viewpoint, a fin material for heat exchange and various glass products can be mentioned.

As another example of a preferred coated article,
From the viewpoint of taking advantage of the stain resistance and antifogging properties, molded products or films of thermoplastic resins and thermosetting resins such as polycarbonate, polyethylene terephthalate, and unsaturated polyester resins are exemplified.

Further, since a significant hydrophilization can be achieved by irradiation with energy rays, a material for image formation which can make use of the difference in hydrophilicity between an irradiated portion and an unirradiated portion is also one of the useful ones of the coated article of the present invention. One of them.

[0080]

Next, the present invention will be described more specifically with reference examples, examples and comparative examples, but the present invention is by no means limited to these examples. In the following, all parts and percentages are by weight unless otherwise specified. In addition, the measurement of the contact angle with water, which is a measure of hydrophilicity, was about 1.7 on the film.
The measurement was carried out under a temperature condition of 25 ° C. in the atmosphere using a contact angle meter manufactured by Elma Co., Ltd. with a water droplet of μl placed thereon.

Reference Example 1 (Preparation of Coating Agent for Forming Petal-Like Alumina Film) A reaction vessel equipped with a stirrer, a thermometer and a dropping funnel was prepared.
Aluminum tri-sec-butoxide and isopropanol were charged, and ethyl acetoacetate was added with stirring at room temperature. Next, a 0.01 N aqueous nitric acid solution and isopropanol were added, and the mixture was stirred at room temperature for 1 hour to prepare a coating solution for forming a gel film of an aluminum compound. Hereinafter, this coating solution is used as a coating agent (C-1).
Abbreviated. The used molar ratio of each component used here was as follows. Aluminum tri-sec-butoxide: isopropanol: ethyl acetoacetate: water = 1: 20: 1: 1

REFERENCE EXAMPLE 2 (same as above) Aluminum tri-sec-
Butoxide, isopropanol and a number average molecular weight of 60
Polyethylene glycol of No. 0 was charged and stirred at room temperature for 1 hour to prepare a coating solution for forming a gel film of an aluminum compound. Hereinafter, this coating liquid is abbreviated as a coating agent (C-2). The used molar ratio of each component used here was as follows. Aluminum tri-sec-butoxide: isopropanol: polyethylene glycol = 1: 30: 0.1

Reference Example 3 (Preparation of Coating Agent for Forming Titanium Chelate Compound Film) In the same reaction vessel as in Reference Example 1, titanium tetra-n-
Charge 34.0 g (0.1 mol) of butoxide and 92.1 g (2.0 mol) of ethanol,
For 30 minutes. Then a mixture of 10.0 grams (0.1 mole) of acetylacetone and 46.1 grams (1.0 mole) of ethanol was added dropwise over 30 minutes. The mixture was further stirred at 25 ° C. for 2 hours, and then a 1.8N aqueous nitric acid solution of 1.8N was added.
Grams were added and stirred for 1 hour to obtain a coating agent containing a titanium chelate compound bound with acetylacetone as a chelating agent. Hereinafter, this is referred to as coating agent (C-3).

Reference Example 4 (Preparation of Coating Agent for Forming Film of Amorphous Titanium Oxide) In a reaction vessel equipped with a stirrer, a thermometer and a dropping funnel,
34.0 grams (0.1 mole) of titanium tetra-n-butoxide and 92.1 grams (2.0 moles) of ethanol
Mol) and stirred at 25 ° C. for 10 minutes to obtain a uniform solution. Then, 46.1 grams (1.0 mol) of ethanol and 3.3 of 1.2N aqueous hydrochloric acid were added.
A mixture of grams was added dropwise over 30 minutes. The mixture was further stirred at the same temperature for 30 minutes to hydrolyze titanium tetra-n-butoxide.
The coating agent was obtained by polycondensation. Hereinafter, this is referred to as coating agent (C-4).

Reference Example 5 [Preparation of coating agent for forming film of polysiloxane (C)] In a reaction vessel similar to that of Reference Example 1, 41.7 g (0.1 mol) of n-octadecyltriethoxysilane was added. Charge 921.4 grams (20.0 moles) of ethanol, 3
2. While stirring at 0 ° C., a 0.02 N aqueous hydrochloric acid solution was added.
6 grams were added dropwise over 10 minutes. Continue at the same temperature for 5
Stirring was continued for a time to obtain a solution of the silane-based coating agent. Hereinafter, this is referred to as coating agent (C-5).

Reference Example 6 (same as above) In a reaction vessel similar to Reference Example 1, 5 of heptadecafluorodecyltrimethoxysilane [C ₈ F ₁₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ] was added.
6.8 grams (0.1 mole) and 12 of isopropanol
After charging 02.0 g (20.0 mol), 5.4 g of a 0.01 N hydrochloric acid aqueous solution was added dropwise over 10 minutes while stirring at 30 ° C. Subsequently, stirring was continued at the same temperature for 5 hours to obtain a solution of the silane-based coating agent. Hereinafter, this is referred to as coating agent (C-6).

Example 1 A polycarbonate plate (size: 25 mm × 25 mm × 1 m) obtained by sequentially washing with a neutral detergent, water and ethanol
m) was immersed in the coating agent (C-1).
Dip coating was performed at a lifting speed of mm / sec. Next, drying was performed at room temperature for 30 minutes to form a gel film of an aluminum compound. The coated polycarbonate plate thus obtained was immersed in hot water of 60 ° C. for 5 minutes,
A polycarbonate plate having a petal-like alumina film having a thickness of 200 nm was obtained.

The polycarbonate plate having the petal-like alumina film thus produced was used as a substrate, and the coating agent (C-3) containing the titanium chelate compound prepared in Reference Example 3 was dip-coated thereon. The coating was carried out by a method and dried at room temperature for one day to form a titanium chelate compound film. Next, the coating agent (C-5) prepared in Reference Example 5 was applied to the obtained coated polycarbonate plate by a dip coating method, and then dried at room temperature for 7 days to form a polysiloxane film as a top coat. A multilayer coating was obtained.

The multi-layer coating thus prepared was coated with a 250 W ultra-high pressure mercury lamp “UIS-2” manufactured by Ushio Inc.
5102 "(wavelength of irradiation light: 250 to 450 nm), and ultraviolet irradiation was performed for 30 minutes from a distance of 5 cm. The contact angle between the coating and water before the ultraviolet irradiation was very large, 155 degrees, and that after the irradiation was 5 degrees or less, confirming that the coating was highly hydrophilic by the irradiation.

Example 2 A polyethylene terephthalate film (size: 25 mm ×) obtained by sequentially washing with a neutral detergent, water and ethanol.
25 mm x 0.1 mm) was immersed in the coating agent (C-2) in a dry air atmosphere with a relative humidity of 20%.
Dip coating was performed at a lifting speed of 1.0 mm / sec. Next, drying was performed at room temperature for 30 minutes to form a gel film of an aluminum compound. The coated polyethylene terephthalate film thus obtained was immersed in hot water at 60 ° C. for 5 minutes to obtain a polyethylene terephthalate film having a petal-like alumina film having a thickness of 100 nm.

The polyethylene terephthalate film having the petal-like alumina film thus produced was used as a substrate, and the titanium chelate compound-containing coating agent prepared in Reference Example 3 was coated thereon (C-3).
Was applied by a dip coating method and dried at room temperature for one day to form a titanium chelate compound film. Subsequently, the obtained coated polyethylene terephthalate film was coated with the coating agent (C-
6) was applied by a dip coating method, followed by drying at room temperature for 7 days to obtain a multi-layer film having a polysiloxane film formed as a top coat. The multilayer film thus obtained was irradiated with ultraviolet rays using the same apparatus as in Example 1 and under the same conditions as in Example 1. The contact angle between the film and water before UV irradiation is as large as 160 degrees, and
It was 5 degrees or less after irradiation, and it was confirmed that the film was highly hydrophilized by irradiation.

Example 3 A degreased soda lime glass plate of 25 mm × 25 mm × 1 mm was immersed in the coating agent (C-1), and then subjected to dip coating at a pulling speed of 1.0 mm / sec. Next, drying was performed at room temperature for 30 minutes.
A gel film of an aluminum compound was formed. The coated soda lime glass plate thus obtained was immersed in hot water at 60 ° C. for 5 minutes to obtain a soda lime glass plate having a petal-like alumina film having a thickness of 200 nm.

Using the soda-lime glass plate having the petal-like alumina film produced as described above as a base material,
On top of this, the coating agent (C-
4) dip coating to form a film,
Next, baking is performed at 300 ° C. for 30 minutes to obtain a film thickness of 80 n.
m of titanium oxide. When this film was identified by X-ray diffraction, no diffraction peak specific to crystalline titanium oxide was observed, confirming that this film was amorphous titanium oxide.

Next, the glass plate coated with the amorphous titanium oxide prepared in this manner is dipped in the coating agent (C-5) prepared in Reference Example 5 and then pulled up by a dip coating method. A silane-based coating agent was applied thereon. Then, a heat treatment was performed at 250 ° C. for 10 minutes so that
A polysiloxane film having a thickness of nm was formed.

The multilayer film thus obtained was irradiated with ultraviolet rays using the same apparatus as in Example 1 and under the same conditions as in Example 1. The contact angle between the coating and water before the ultraviolet irradiation was as large as 160 degrees, and that after the irradiation was 5 degrees or less, confirming that the coating was highly hydrophilized by the irradiation.

[0096]

The method for forming a hydrophilic film according to the present invention comprises a film of a titanium chelate compound prepared by drying at room temperature or baking at a relatively low temperature or a film of amorphous titanium oxide prepared by baking at low temperature. By irradiating an active energy ray to a multilayer film composed of a polysiloxane film, a highly hydrophilic film excellent in durability can be easily obtained, which is extremely practical.
A coated article provided with such a hydrophilic coating as a top coat layer has excellent performance derived from the hydrophilicity of the coating, such as anti-fogging property, water flow-down property, resistance to exposure contamination, and the like. It is also very useful for use as a coated article having both patterns of a water-repellent portion and a highly hydrophilic portion, and is extremely useful.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Atsunori Matsuda 12-5 Midorigaoka Nakamachi, Kawachinagano City, Osaka Prefecture (72) Inventor Masataka Ooka 6-11-4 Tomigaoka, Nara City, Nara Prefecture F-term (reference) 4D075 AE03 BB46Z BB79Z CA37 DB02 DC01 DC05 DC12 EB01 EB43

Claims (5)

[Claims] 1. A film comprising a titanium chelate compound (A) or a film of amorphous titanium oxide (B) and a film of polysiloxane (C) on a petal-like alumina film on a substrate on which a petal-like alumina film is formed. Are sequentially formed to prepare a multi-layer film, and then a hydrophilic film is formed by irradiating the multi-layer film with an active energy ray. A method for forming a hydrophilic coating film, characterized in that the coating film is formed by forming a coating film by applying the coating film on a substrate and treating with hot water or heated steam. 2. The organosilane as described above, wherein the polysiloxane (C) film has at least one hydrolyzable group bonded to a silicon atom and at least one monovalent organic group bonded to a silicon atom. Compound and / or silicate compound, or the organosilane compound and / or
The method for forming a hydrophilic film according to claim 1, wherein the method is formed from a hydrolysis product of a silicate compound. 3. The method for forming a hydrophilic film according to claim 1, wherein the contact angle between the multilayer film and water is reduced to 20 degrees or less by irradiation with active energy rays. 4. The method for forming a hydrophilic film according to claim 1, wherein the active energy ray is an ultraviolet ray. 5. A coated article comprising a hydrophilic coating prepared by the method according to claim 1 as a top coat layer.