JP5122925B2 - Painted body - Google Patents

Description

  The present invention relates to a coated body having a hydrophilic surface, which is used as an exterior material for a house.

  The exterior material that forms the outer wall of the house is made of a molded article of ceramics material such as cement as a base material, and the surface of the base material is an organic material that is colored by adding pigments and the like to impart design properties. An organic paint film is formed by applying paint.

  Since this organic coating is organic, it deteriorates due to the action of ultraviolet rays, and fading easily occurs. Therefore, in order to protect the organic coating film, an inorganic coating film is formed by applying a silicone-based inorganic coating as a clear topcoat. Since this inorganic coating film is inorganic, deterioration with respect to ultraviolet rays is small, and since it is difficult to transmit ultraviolet rays, the organic coating film can be protected from ultraviolet rays. In particular, an organic coating film can be more effectively protected by blending a UV absorber to make the inorganic coating film UV-blocking.

Recently, a silicone-based inorganic coating containing a photocatalyst has been formed on the clear inorganic coating. The photocatalyst is activated by the irradiation of ultraviolet rays and can decompose dirt adhering to the surface. Moreover, in order to make the surface hydrophilic, the decomposed dirt can be washed away with rain water, etc., and a self-cleaning effect is obtained. It is something that can be done. In addition, when the photocatalyst-containing inorganic coating film formed in this way is directly provided on the organic coating film, the photocatalyst acts on the organic coating film to decompose the organic matter and may deteriorate the organic coating film. Further, by interposing the inorganic coating film between the organic coating film and the photocatalyst-containing inorganic coating film, it is possible to obtain an effect of preventing such deterioration of the organic coating film (see Patent Document 1, etc.). .
JP 2007-168135 A

  However, when applying the photocatalyst-containing inorganic coating on the inorganic coating as described above, the inorganic coating is hydrophobic and the affinity of the photocatalyst-containing inorganic coating to the surface of the inorganic coating is low. It is difficult to uniformly apply the photocatalyst-containing inorganic coating without unevenness on the surface, and it is difficult to uniformly form the photocatalyst-containing inorganic coating film. If the photocatalyst-containing inorganic paint is applied with a thick film thickness, it is possible to form a photocatalyst-containing coating without uneven application, but the photocatalyst-containing inorganic paint contains titanium oxide or the like as a photocatalyst, When a photocatalyst-containing coating film is formed with a thick film thickness, this titanium oxide acts as a pigment to become a white and cloudy coating film, and a clear coating film cannot be formed. Further, when an expensive photocatalyst-containing inorganic coating is applied with a thick film, the cost becomes high. For this reason, it is necessary to apply the photocatalyst-containing inorganic coating with a thin film thickness, and it becomes more difficult to uniformly form the photocatalyst-containing inorganic coating film.

  And when the photocatalyst containing inorganic coating film was not formed uniformly in this way, there existed a problem that a variation might arise in the hydrophilicity of the surface of a coating body.

  This invention is made | formed in view of said point, and it aims at providing the coating body which can form the photocatalyst containing inorganic coating film uniformly, and can obtain the hydrophilic property of the surface stably. To do.

Coated article according to the present invention, the surface of the base material, an organic coating, an inorganic coating, and a photocatalyst-containing inorganic coating was applied in this order, the organic coating, an inorganic coating, a photocatalyst-containing inorganic coating film is formed, the photocatalyst containing inorganic coatings, painted the photocatalyst-containing inorganic coating on the surface of the inorganic coating film contact angle of water was adjusted to 60 ° below the surface treatment formed with a film thickness of 0.1~2μm The inorganic paint is a silicone-based coating agent, the photocatalyst-containing inorganic paint is a silicone-based coating agent containing a photocatalyst, and the surface treatment of the inorganic coating film is a silica vapor deposition treatment. it is characterized in that.

  According to this invention, the wettability of the photocatalyst-containing inorganic coating with respect to the surface of the inorganic coating is improved by treating the surface of the inorganic coating so that the water contact angle is 60 ° or less. A photocatalyst-containing inorganic coating film can be uniformly formed with a thin film thickness of 2 μm.

The present invention, wherein the inorganic coating is a silicone-based coating agents, the photocatalyst-containing inorganic coating is silicone-based coating agent was blended a photocatalyst, said surface treatment of the inorganic coating film, a sheet silica deposition process This process is characterized in that the surface of the inorganic coating film can be made to have a water contact angle of 60 ° or less by this treatment.

  According to the present invention, the wettability of the photocatalyst-containing inorganic coating with respect to the surface of the inorganic coating is improved by treating the surface of the inorganic coating so that the water contact angle is 60 ° or less. A photocatalyst-containing inorganic coating film can be uniformly formed with a thin film thickness of 2 μm, and the hydrophilicity of the surface of the coated body can be stably obtained.

  Hereinafter, the best mode for carrying out the present invention will be described.

  As the base material 1, one formed of a ceramic material can be used. For example, an inorganic filler, a fibrous material, or the like is blended into a hydraulic glue used as a raw material for an inorganic cured body, and molded. It is made by curing and curing later. The hydraulic glue is not particularly limited, and for example, one or more kinds selected from Portland cement, blast furnace cement, blast furnace slag, calcium silicate, gypsum and the like can be used. Also, fly ash, micro silica, silica sand, etc. are used as the inorganic filler, and inorganic fibers such as pulp, synthetic fiber, asbestos, etc., and metal fibers such as steel fibers, etc., are used alone or in combination as a fibrous material. be able to. Molding can be performed by methods such as extrusion molding, cast molding, papermaking molding, press molding, etc. After molding, ceramics used as an exterior material by performing autoclave curing, steam curing, room temperature curing as necessary A system substrate can be produced.

  And the coating body like FIG. 1 can be obtained by forming the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing inorganic coating film 4 on the surface of this base material 1. FIG. By coloring the organic coating film 2 and forming the inorganic coating film 3 and the photocatalyst-containing inorganic coating film 4 transparently, the organic coating film 2 is made up of a coated body, and the organic coating film 2 is deteriorated by ultraviolet rays. While preventing with the inorganic coating film 3, hydrophilicity is provided to the surface with the photocatalyst contained in the outermost photocatalyst containing inorganic coating film 4, and antifouling property can be obtained.

  In the present invention, the organic coating material for forming the organic coating film 2 is not particularly limited, but it is preferable to use an organic coating mainly composed of an acrylic emulsion or an acrylic silicone emulsion. By forming the organic coating film 2 with an acrylic emulsion or an acrylic silicone emulsion in this way, high adhesion between the organic coating film 2 and the inorganic coating film 3 formed thereon can be obtained. .

  As the acrylic emulsion, for example, a core-shell type acrylic emulsion disclosed in JP-A No. 2004-195934 can be used. That is, the core-shell type acrylic emulsion is a copolymer emulsion obtained by copolymerizing a monomer component mainly composed of acrylamide in the presence of a seed emulsion as a core particle.

  Seed emulsions such as acrylic ester, styrene / acrylate ester, acrylonitrile, styrene-butadiene, acrylonitrile-butadiene, acrylate-butadiene, vinyl chloride, vinyl acetate, etc. Molecular emulsions can be used, and they can be used alone or in combination of two or more.

  Moreover, in said monomer component, the unsaturated monomer copolymerizable with acrylamide is contained as needed. As this unsaturated monomer, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-aminoethyl acrylate, acrylic acid 2- (N-methylamino) ethyl, 2- (N, N-dimethylamino) ethyl acrylate, acrylic esters such as glycidyl acrylate, vinyl esters such as vinyl acetate and vinyl propionate, and nitriles such as acrylonitrile Group-containing monomers, unsaturated carboxylic acids such as acrylic acid, maleic anhydride, fumaric acid, itaconic acid, crotonic acid, aromatic vinyl monomers such as styrene, α-methylstyrene, divinylbenzene, N- N-substituted unsaturated carboxylic acid amides such as methylolacrylamide can be selected. That. Among these, it is preferable to use an unsaturated monomer having a functional group such as a carboxyl group, a hydroxyl group, an amino group, a methylol group, or a glycidyl group.

  This core-shell structure acrylic emulsion is produced by a known polymerization technique using a polymerization initiator and a chain transfer agent together with the above-mentioned materials. Such core-shell type acrylic emulsions have various types known so far (see, for example, JP-A-2000-204285), and commercially available products can also be used.

  Among such core-shell type acrylic emulsions, it is preferable to use those having an acid amount in the range of 5 to 15% by weight in the shell portion. By setting the acid amount of the shell portion within this range, the interlayer adhesion strength between the organic coating film and the coating film can be increased. When the acid amount of the shell portion is less than 5% by weight, An improvement in interlayer adhesion strength with the coating film cannot be expected. The same applies when the acid amount of the shell part exceeds 15% by weight.

  Moreover, as an acrylic silicone emulsion, what mix | blended the silicone component with the acrylic emulsion currently disclosed by patent 3347097 can be used, for example.

The acrylic emulsion preferably contains methyl methacrylate and butyl acrylate as resin main components. The organic coating film must satisfy one of the following requirements.
(1) The gel fraction of the organic coating film with respect to the organic solvent is 30% or less.
(2) The Tg (glass transition temperature) of the organic coating film is 50 ° C. or lower.
(3) The contact angle of the top-coated inorganic coating film with the inorganic coating is 40 degrees or less.

  In the case of a coated body in which the organic coating film as described above is formed and the surface thereof is coated with an inorganic coating, the coating film adhesion due to the inorganic coating is extremely excellent as well as the weather resistance. Making the gel fraction of the organic coating film low with respect to the organic solvent as in (1) means that the organic coating film is easily exposed to the organic solvent. Here, the gel fraction is an index of solvent resistance. Specifically, for example, the gel fraction of the organic coating film is obtained by immersing the organic coating film dried (120 ° C., 4 minutes) after application in acetone for 5 hours. It is shown as a weight ratio remaining after the treatment.

  The organic coating and inorganic coating have a low gel fraction, that is, low solvent resistance. The organic solvent in the top coating of the inorganic coating swells and dissolves the organic coating at the interface with the organic coating. This means that the organic coating film and the inorganic coating film are welded to obtain a strong physical adhesion, and the situation is strong against changes over time. The gel fraction of the organic coating is preferably 30% or less, more preferably 0%, or an approximation thereof, so that the inorganic coating with the inorganic coating is strongly adhered. Sex can be obtained.

  It is possible to lower the gel fraction with respect to the organic solvent by selecting the resin component in the organic paint and adjusting the composition and the ratio thereof. For example, in an acrylic emulsion prepared with molecular weights of approximately the same level, methyl methacrylate (MMA) and butyl acrylate (BA) are included in the resin main component, that is, 50% by weight or more of the resin component. The ratio of the components and the mutual ratio of methyl methacrylate (MMA) and butyl acrylate (BA) are adjusted. In order to lower the gel fraction, it is generally appropriate that the ratio of methyl methacrylate (MMA) and butyl acrylate (BA) as main components is MMA / BA = 1 to 2 as a weight ratio. More preferably, MMA / BA = 1.1 to 1.6. When the ratio of methyl methacrylate (MMA) exceeds 2, the gel fraction cannot be expected to be reduced to 30% or less, and a substantial improvement in adhesion cannot be obtained. On the other hand, when the weight ratio is less than 1, the strength, durability, etc. of the coating film as a coated body tend not to be sufficient. Further, in the range of the weight ratio MMA / BA = 1.1 to 1.6, the gel fraction is substantially 0, and excellent adhesion can be obtained. It should be noted that the proportion of methyl methacrylate (MMA) and butyl acrylate (BA) as the main component of the resin is preferably 60% by weight or more, and blending of acrylate or methacrylate as the other component is appropriate. Is possible.

  Further, as shown in (2), when the Tg is set to a low level of 50 ° C. or lower, the organic coating film is softened and the interface with the inorganic coating film tends to be in a fused state, resulting in a physically strong result. A coated product having adhesiveness can be obtained.

  Further, as in (3), the adhesiveness between the organic coating film and the inorganic coating film can be improved also by reducing the contact angle of the top coating inorganic coating to the organic coating film to 40 degrees or less. The small contact angle with respect to the inorganic coating film means that the wettability is good, that is, the inorganic coating can be uniformly applied to the organic coating film, and the pores generated by drainage of the organic coating film, etc. It means that the inorganic paint penetrates into (pores) and the like, an anchoring effect is obtained and stabilized, and the adhesion is improved.

  Thus, in order to make a contact angle small, a silicone component is mix | blended with an acrylic emulsion, and it uses as an acrylic silicone emulsion. When blending the silicone component into the acrylic emulsion, the proportion of the total resin component is suitably in the range of 5 wt% to 20 wt%. If the amount is less than 5% by weight, no substantial effect is obtained. On the other hand, if the amount exceeds 20% by weight, the performance deteriorates in terms of water resistance.

  An organic paint can be obtained by blending various components as needed into the acrylic emulsion or acrylic silicone emulsion obtained as described above.

  For example, an emulsifier and a dispersant can be appropriately blended in the emulsion. Low molecular emulsifiers and reactive emulsifiers can be preferably used. However, from the viewpoint of coating film adhesion, it is desirable to suppress the use of low molecular emulsifiers that cause poor adhesion as a free soap, so the proportion of low molecular emulsifier is less than 50% and reactive emulsifier is 50% or more. Is desirable. In addition, pigments, fillers, mineral oil-based antifoaming agents, thickeners, paraffin-based water repellents, and the like can be appropriately blended in the emulsion. Examples of pigments include organic pigments such as carbon black, quinacridone, naphthol red, cyanine blue, cyaning ray, and hansa yellow, and inorganic pigments such as titanium oxide, barium sulfate, bengara, calcium carbonate, alumina, iron oxide, and composite metal oxides. Examples of fillers include general silica powder, barium sulfate, sand, and resin beads. The particle size of the pigment or filler is not particularly limited. The blending of components other than the resin component is preferably 5% by weight or less with respect to the entire emulsion.

Then, in the present invention, the inorganic coating composition forming the inorganic coating film 3, Ru with shea recone based coating agent. As this silicone type coating agent, what is disclosed by patent 3243442, patent 3193382, and Unexamined-Japanese-Patent No. 9-249822 can be used, for example.

The silicone-based coating agent disclosed in Japanese Patent No. 3243442 is
(A): General formula R ¹ _n SiX _4-n (1)
(In the formula (1), R ¹ is the same or different alkyl group, cycloalkyl group, alkenyl group, halogen-substituted hydrocarbon group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4- A monovalent hydrocarbon group having 1 to 8 carbon atoms selected from the group consisting of an epoxycyclohexylethyl group and a γ-mercaptopropyl group, n is an integer of 0 to 3, X is an alkoxy group, an acetoxy group, an oxime group, A hydrolyzable group selected from the group consisting of an enoxy group, an amino group, an aminoxy group and an amide group.
An organosilane obtained by partially hydrolyzing a hydrolyzable organosilane represented by the formula (I) in colloidal silica dispersed in an organic solvent or water under the condition that 0.001 to 0.5 mol of water is used per 1 mol of X. Silica dispersion oligomer solution of
(B): the average compositional formula _{^{R 2 a Si (OH) b}} O (4-a-b) / 2 (2)
(In the formula (2), R ² is the same or different alkyl group, cycloalkyl group, alkenyl group, halogen-substituted hydrocarbon group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4- A monovalent hydrocarbon group having 1 to 8 carbon atoms selected from the group consisting of an epoxycyclohexylethyl group and a γ-mercaptopropyl group, wherein a and b are 0.2 ≦ a ≦ 2, 0.0001 ≦ b ≦, respectively. 3 and a number satisfying the relationship of a + b <4.)
And a polyorganosiloxane containing 1 to 30 mol% of phenyl groups based on the total R ² groups in R ² of the component, and
(C): A catalyst that accelerates the condensation reaction between the component (A) and the component (B) is an essential component, and the component (A) contains 5 to 95% by weight of silica as a solid content. At least 50 mol% is an organosilane having n = 1, and 99 to 1 part by weight of component (B) is blended with 1 to 99 parts by weight of component (A).

  The silica-dispersed oligomer as the component (A) is a main component of a base polymer having a hydrolyzable group as a functional group to be subjected to a curing reaction during film formation. This was done by adding one or more hydrolyzable group-containing organosilanes represented by the general formula (1) to colloidal silica dispersed in an organic solvent or water, and adding water in colloidal silica or separately. It is obtained by partially hydrolyzing the hydrolyzable organosilane with water.

The group R ¹ in the hydrolyzable organosilane represented by the general formula (1) is an alkyl group, a cycloalkyl group, an alkenyl group, a halogen-substituted hydrocarbon group, a γ-methacryloxypropyl group, or a γ-glycidoxypropyl. A monovalent hydrocarbon group having 1 to 8 carbon atoms selected from the group consisting of a group, 3,4-epoxycyclohexylethyl group and γ-mercaptopropyl group, for example, methyl group, ethyl group, propyl group, butyl group Alkyl groups such as pentyl group, hexyl group, heptyl group and octyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aralkyl groups such as 2-phenylethyl group and 3-phenylpropyl group; phenyl group and tolyl group Aryl groups such as vinyl groups, alkenyl groups such as allyl groups, chloromethyl groups, γ-chloropropyl groups, , 3,3-trifluoropropyl groups such as halogen-substituted hydrocarbon groups and γ-methacryloxypropyl groups, γ-glycidoxypropyl groups, 3,4-epoxycyclohexylethyl groups, γ-mercaptopropyl groups, etc. A hydrocarbon group etc. can be illustrated. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of easy synthesis or availability.

  X of the hydrolyzable group is a hydrolyzable group selected from the group consisting of an alkoxy group, an acetoxy group, an oxime group, an enoxy group, an amino group, an aminoxy group, and an amide group. Alkoxy groups are preferred because of their availability and ease of preparing silica-dispersed oligomer solutions.

  Particularly, tetramethoxysilane, tetraethoxysilane and the like can be exemplified as tetraalkoxysilane of n = 0, and methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, n = 1 as organotrialkoxysilane, Examples thereof include phenyltrimethoxysilane, phenyltriethoxysilane, and 3,3,3-trifluoropropyltrimethoxysilane. Examples of n = 2 diorganodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane, and n = 3 triorganoalkoxysilane. Examples thereof include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, and dimethylisobutylmethoxysilane. Furthermore, organosilane compounds generally called silane coupling agents are also included in the alkoxysilanes.

  Of these hydrolyzable organosilanes represented by the general formula (1), 50 mol% or more is required to be a trifunctional one represented by n = 1. They are more preferably 60 mol% or more, most preferably 70 mol% or more. If this is less than 50 mol%, sufficient coating film hardness cannot be obtained, and the dry curability tends to be poor.

  The colloidal silica in the component (A) is essential for increasing the hardness of the cured film of the silicone-based coating agent. As such colloidal silica, water-dispersible or non-aqueous organic solvent-dispersible colloidal silica such as alcohol can be used. Generally, such colloidal silica contains 20 to 50% by weight of silica as a solid content, and the amount of silica can be determined from this value. Moreover, when using water dispersible colloidal silica, the water which exists as components other than solid content can be used for a hydrolysis of the organosilicon compound of (A) component. These are usually made from water glass, but such colloidal silica is readily available commercially. The organic solvent-dispersed colloidal silica can be easily prepared by replacing the water of the water-dispersible colloidal silica with an organic solvent. Such an organic solvent-dispersed colloidal silica can also be easily obtained as a commercial product, like the water-dispersed colloidal silica. Examples of the organic solvent in which colloidal silica is dispersed include, for example, lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol; ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, and the like. And ethylene glycol derivatives; derivatives of diethylene glycol such as diethylene glycol and diethylene glycol monobutyl ether, diacetone alcohol, and the like, and one or more selected from the group consisting of these can be used. In combination with these hydrophilic organic solvents, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, and the like can also be used.

  In the component (A), colloidal silica is contained in the range of 5 to 95% by weight as the silica content. More preferably, it is 10 to 90 weight%, Most preferably, it is the range of 20 to 85 weight%. If the content is less than 5% by weight, the desired film hardness cannot be obtained, and if it exceeds 95% by weight, it is difficult to uniformly disperse silica, and component (A) may cause problems such as gelation. .

  The silica-dispersed oligomer of component (A) can be usually obtained by partially hydrolyzing a hydrolyzable group-containing organosilane in water-dispersed colloidal silica or organic solvent-dispersed colloidal silica. The amount of water used relative to the hydrolyzable organosilane is preferably 0.001 to 0.5 mol of water with respect to 1 mol of the hydrolyzable group (X). When the ratio is less than 0.001 mol, a sufficient partial hydrolyzate cannot be obtained, and when it exceeds 0.5 mol, the stability of the partial hydrolyzate is deteriorated. The method of partial hydrolysis is not particularly limited, and a hydrolyzable organoalkoxysilane and colloidal silica may be mixed and added with a necessary amount of water, and at this time, the partial hydrolysis reaction proceeds at room temperature. You may heat to 60-100 degreeC in order to accelerate a partial hydrolysis reaction. Furthermore, hydrochloric acid, acetic acid, halogenated silane, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, toluene for the purpose of promoting partial hydrolysis reaction Organic acids such as sulfonic acid and oxalic acid and inorganic acids may be used as the catalyst.

  In order to obtain the component (A) stably in the long term, the pH of the liquid is 2.0 to 7.0, preferably 2.5 to 6.5, more preferably 3.0 to 6.0. It is good to do. If the pH is outside this range, the amount of water used is 0.3 mol or more per 1 mol of the group (X), and the long-term performance deterioration of the component (A) is remarkable. When the pH of the component (A) is outside this range, it may be adjusted by adding a basic reagent such as ammonia or ethylenediamine if it is more acidic than this range. Adjustment may be performed using an acidic reagent such as acetic acid. However, the adjustment method is not particularly limited.

The silanol group-containing polyorganosiloxane of the component (B) represented by the average composition formula (2) is an important component. (2) In the formula, as R ² , the same as R ¹ in the formula (1) is exemplified, but preferably an alkyl group having 1 to 4 carbon atoms, a vinyl group, a γ-glycidoxypropyl group, Substituted hydrocarbon groups such as γ-methacryloxypropyl group and 3,3,3-trifluoropropyl group, more preferably methyl group. Further, in the formula, a and b are numbers satisfying the above relationship, respectively, and if a is less than 0.2 or b exceeds 3, there is a problem such as a crack in the cured film, and a exceeds 2 When it is 4 or less or when b is less than 0.0001, curing does not proceed well.

Further, ^{R 2} is 1 to 30 mol% of the total ^{R 2} groups phenyl group, preferably it to contain 5 to 20 mol%, the resulting coating film having excellent gloss, leveling. If the number of phenyl groups is less than 1 mol% based on the total R ² groups, the desired gloss cannot be obtained, and if it exceeds 30 mol%, the gloss decreases and the coating film becomes soft.

  Such a silanol group-containing polyorganosiloxane can be prepared by a known method using a large amount of methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or a mixture of one or more of the corresponding alkoxysilanes. It can be obtained by hydrolysis with water. When a silanol group-containing polyorganosiloxane is obtained by hydrolysis with a known method using alkoxysilane, a trace amount of alkoxy groups that are not hydrolyzed may remain. That is, a polyorganosiloxane in which a silanol group and a trace amount of an alkoxy group coexist may be obtained, but such a polyorganosiloxane may be used.

  The curing catalyst which is the component (C) accelerates the condensation reaction between the component (A) and the component (B) and cures the coating. Examples of such catalysts include metal salts of carboxylic acids such as alkyl titanates, tin octylate and dibutyltin dilaurate, dioctyltin dimaleate; amine salts such as dibutylamine-2-hexoate, dimethylamine acetate, and ethanolamine acetate; Quaternary ammonium salts of carboxylic acids such as tetramethylammonium acetate; amines such as tetraethylpentamine; N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyl Amine-based silane coupling agents such as dimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum compounds such as aluminum alkoxide and aluminum chelate; alkali catalysts such as potassium hydroxide; tetraisopropyl titane , Tetrabutyl titanate, titanium tetraacetylacetonate and other titanium compounds, methyltrichlorosilane, dimethyldichlorosilane, trimethylmonochlorosilane, and other halogenated silanes. In addition to these, component (A) and component (B) There is no particular limitation as long as it is effective for the condensation reaction with.

  The blending ratio of the component (A) and the component (B) is 99 to 1 part by weight of the component (B) with respect to 1 to 99 parts by weight of the component (A), more preferably 5 to 95 parts by weight of the component (A). The component (B) is 95 to 5 parts by weight, and most preferably the component (B) is 90 to 10 parts by weight with respect to the component (A) 10 to 90 parts by weight (provided that the component (A) and the component (B) The total of the components is 100 parts by weight). When the component (A) is less than 1 part by weight, the room temperature curability is inferior and sufficient film hardness cannot be obtained. On the other hand, when it exceeds 99 parts by weight, the curability is unstable and a good coating film is obtained. There may not be.

  Moreover, it is preferable that the addition amount of (C) component is 0.0001-10 weight part with respect to 100 weight part in total of (A) component and (B) component. More preferably, it is 0.0005-8 weight part, Most preferably, it is 0.0007-5 weight part. If it is less than 0.0001 part by weight, it will not be cured at room temperature. Moreover, when it exceeds 10 weight part, heat resistance and a weather resistance will worsen.

  This silicone-based coating agent can be used by diluting with various organic solvents for ease of handling. The type of the organic solvent can be selected according to the type of the monovalent hydrocarbon group or the molecular weight of the component (A) or the component (B). Examples of such organic solvents include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol shown as dispersion solvents for colloidal silica; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl acetate. Examples include ethylene glycol derivatives such as ether; derivatives of diethylene glycol such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or two or more selected from the group consisting of these can be used. . Examples of solvents that can be used in combination with these hydrophilic organic solvents include toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and methyl ethyl ketoxime.

  As a method for storing this silicone-based coating agent, it is common to take a three-packed form in which the components (A), (B), and (C) are stored, but the components (A) and (C) It is also possible to separate the mixed component and the component (B) into two package types and mix them at the time of use, or mix all the components and store them in one container. However, when mixing and storing (A) component and (C) component, it is preferable to add (C) component after adjusting the pH of (A) component to 2-7, and also (A) component The amount of water used per 1 mol of the hydrolyzable group (X) of the organoalkoxysilane is preferably 0.3 mol or less.

  In addition, this silicone-based coating agent has properties such as leveling agents, thickeners, pigments, dyes, aluminum paste, glass frit, metal powder, antioxidants, matting agents, and UV absorbers as necessary. It can be added within a range that does not affect.

Next, the silicone-based coating agent disclosed in Japanese Patent No. 3193932 is
General formula R ¹ _n SiX _4-n (3)
(In formula (3), R ¹ represents the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, n represents an integer of 0 to 3, and X represents a hydrolyzable group)
In a state where 0.001 to 0.5 mol of water is used per 1 mol of X1 in a state where fine particle oxide is dispersed in a particle size of 0.2 to 3 μm, the hydrolyzable organosilane represented by To what was obtained by hydrolysis,
General formula OH (R ² ₂ SiO) _m H (4)
(In formula (4), R ² represents the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and m represents 1 or more.)
A silicone diol-containing fine particle oxide-dispersed oligomer (component D) containing 5 to 30% by weight of a silicone diol component having a weight average molecular weight of 10,000 or less represented by:
Average composition formula R ³ _a Si (OH) _b O _{(4-ab) / 2} (5)
(In the formula (5), R ³ represents the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and a and b are 0.2 ≦ a <2.0, 0,. (A number satisfying the relationship of 0001 ≦ b ≦ 3 and a + b <4)
A polyorganosiloxane (E component) containing a silanol group in the molecule represented by:
Each component of the catalyst (F component) is contained.

  The silicone diol-containing fine particle oxide-dispersed oligomer of component D is the main component of a base polymer having a hydrolyzable group X as a functional group that is subjected to a curing reaction during film formation. This is obtained by adding a silicone diol represented by the above general formula (4) to one or more hydrolyzable organosilanes represented by the above general formula (3). It can be obtained by partially hydrolyzing the hydrolyzable organosiloxane by adding a necessary amount of water while dispersing the fine particle oxide or after completing the fine particle oxide dispersion. The silicone diol may be added before hydrolyzing the hydrolyzable organosilane, at the time of hydrolysis, or after hydrolysis.

Here, the group R ¹ in the hydrolyzable organosilane represented by the general formula (3) represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, such as a methyl group or an ethyl group. Group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and other alkyl groups; cyclopentyl group, cyclohexyl group and other cycloalkyl groups; 2-phenylethyl group, 2-phenylpropyl group, 3-phenylpropylene Aralkyl groups such as ruthel groups; aryl groups such as phenyl groups and tolyl groups; alkenyl groups such as vinyl groups and allyl groups; halogen substitutions such as chloromethyl groups, γ-chloropropyl groups, and 3,3,3-trifluoropropyl Hydrocarbon group; and γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, γ-medium It may be exemplified substituted hydrocarbon group such as mercaptopropyl group. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of easy synthesis or availability.

  Examples of the hydrolyzable group X in the hydrolyzable organosilane represented by the general formula (3) include an alkoxy group, an acetoxy group, an oxime group, an enoxy group, an amino group, an aminoxy group, and an amide group. . Alkoxy groups are preferred because of their availability and ease of preparing fine particle oxide-dispersed oligomer solutions.

  Such hydrolyzable organosilanes include mono-, di-, tri-, and tetra-functional alkoxysilanes in which n in the general formula (3) is an integer of 0 to 3, Examples include acetoxysilanes, oxime silanes, enoxysilanes, aminosilanes, aminoxysilanes, and amidosilanes. Alkoxysilanes are preferred because they are readily available and easy to prepare a fine particle oxide-dispersed oligomer solution.

  In particular, tetramethoxysilane, tetraethoxysilane, and the like can be exemplified as the n = 0 tetraalkoxysilane, and the methyltrialkoxysilane, methyltriethoxysilane, methyltrimethoxysilane, and the like can be exemplified as the n = 1 organotrialkoxysilane. Examples thereof include isopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Examples of n = 2 diorganodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane, and n = 3 triorganoalkoxysilane. Examples of silane include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, and dimethylisobutylmethoxysilane. An organosilane compound generally called a silane coupling agent can also be used as alkoxysilanes.

  Of the hydrolyzable organosilanes represented by the general formula (3) as described above, 50 mol% or more is preferably trifunctional with n = 1. More preferably, it is 60 mol% or more, and most preferably 70 mol% or more. When the trifunctional compound of n = 1 is less than 50 mol%, it is difficult to obtain a sufficient film hardness and the dry curability may be easily deteriorated.

  The fine particulate oxide in the component D is essential for controlling the gloss of the coating composition and acts as a matting agent. Examples of the fine particle oxide include silicon oxide, aluminum oxide, titanium oxide, etc., and those whose surfaces are subjected to silica treatment, alumina treatment, coupling treatment, etc. for the purpose of enhancing dispersibility. Can be used.

  Then, the particulate oxide is directly dispersed in the hydrolyzable organosilane represented by the general formula (3), and the hydrolyzable organosilane is partially hydrolyzed with a necessary amount of water to prepare the component D. However, for the purpose of increasing the degree of dispersion of the powdered fine particle oxide, it is dispersed with an organic solvent such as alcohol, and the hydrolyzable organosilane is partially hydrolyzed with a necessary amount of water to prepare the component D. Also good. Examples of the organic solvent include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol and isobutanol; ethylene glycol derivatives such as ethylene glycol, ethylene glycol monobutyl ether and ethylene glycol monoethyl ether; diethylene glycol, And diethylene glycol derivatives such as diethylene glycol monobutyl ether; and diacetone alcohol. One or two or more selected from the group consisting of these can be used, but in combination with these hydrophilic organic solvents, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, Methyl ethyl ketoxime can also be used.

  The particle diameter of the fine particle oxide dispersed in the hydrolyzable organosilane oligomer of component D is in the range of 0.2 to 3 μm. When the particle diameter is less than 0.2 μm, it is difficult to control the gloss, and when the particle diameter exceeds 3 μm, the film formability may be impaired. In the component D, the fine particle oxide is contained in the range of preferably 5 to 30% by weight, more preferably 8 to 25% by weight as the solid content. When the content is less than 5% by weight, it is difficult to control the gloss, and when it exceeds 30% by weight, there is a possibility that inconveniences such as impaired film formability may be caused.

The silicone diol in component D is essential for obtaining a stable gloss of the coating composition. The compounding ratio in the D component of the silicone diol represented by the general formula (4) is 5 to 30% by weight. If it is less than 5% by weight, it is difficult to obtain long-term gloss stability, and if it exceeds 30% by weight, curing of the coating film may be delayed. The weight average molecular weight of the silicone diol component is 10,000 or less, preferably 5000 or less, more preferably 1000 or less. A silicone diol component having a weight average molecular weight exceeding 10,000 has poor compatibility with the resin and is difficult to use. Here, R ^{2 in} the general formula (4) of the silicone diol can be used without particular limitation as long as it is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms. The hydrocarbon group similar to R < ¹ > in the said Formula (3) can be mentioned.

  The organosilane oligomer of component D can be obtained by partially hydrolyzing the hydrolyzable organosilane of the general formula (1). The amount of water used relative to the hydrolyzable organosilane is 0.001 to 0.5 mol of water relative to 1 mol of the hydrolyzable group X. When the amount of water used is less than 0.001 mol, a sufficient partial hydrolyzate cannot be obtained, and when the amount of water used exceeds 0.5 mol, the stability of the partial hydrolyzate becomes poor. The method of partial hydrolysis is not particularly limited, and a hydrolyzable organosilane and a necessary amount of water may be added and blended. At this time, the partial hydrolysis reaction proceeds at room temperature, but the partial hydrolysis reaction is promoted. Therefore, heating may be performed at a temperature of 60 to 100 ° C. Furthermore, hydrochloric acid, acetic acid, halogenated silane, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, toluene for the purpose of promoting partial hydrolysis reaction An inorganic acid such as sulfonic acid or oxalic acid or an organic acid may be used as a catalyst.

  In order to obtain long-term stable performance, the silicone diol-containing fine particle oxide-dispersed oligomer of component D has a pH of the liquid in the range of 2.0 to 7.0, more preferably pH 2.5 to 6.5. It is better to adjust to the range, even more preferably to the range of pH 3.0 to 6.0. When the pH is out of this range, the long-term performance deterioration of the D component may be remarkable particularly when the amount of water used is 0.3 mol or more with respect to X1 mol. If the pH of component D is outside this range, a basic reagent such as ammonia or ethylenediamine may be added to adjust the pH when it is acidic from this range, and hydrochloric acid, nitric acid, What is necessary is just to adjust pH using acidic reagents, such as an acetic acid. The adjustment method is not particularly limited.

The silanol group-containing polyorganosiloxane of E component whose average composition formula is represented by the above formula (5) is an important component constituting one of the characteristics of the silicone coating agent. In formula (5), R ³ may be the same as R ¹ in formula (3), preferably an alkyl group having 1 to 4 carbon atoms, a phenyl group, a vinyl group, γ- Substituted hydrocarbon groups such as a glycidoxypropyl group, γ-methacryloxypropyl group, and 3,3,3-trifluoropropyl group, more preferably a methyl group and a phenyl group. In the formula (5), a and b are numbers satisfying the relations 0.2 ≦ a <2.0, 0.0001 ≦ b ≦ 3, and a + b <4, respectively, and a is less than 0.2 or b is If it exceeds 3, there are disadvantages such as causing cracks in the cured film, and if a is more than 2.0 and 4 or less, or if b is less than 0.0001, there is an inconvenience that curing does not proceed well.

  Examples of such a silanol group-containing polyorganosiloxane of formula (5) include, for example, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or one or a mixture of two or more alkoxysilanes corresponding thereto. Can be obtained by hydrolysis with a large amount of water by a known method. When a silanol group-containing polyorganosiloxane is obtained by hydrolysis using a known method using alkoxysilane, a trace amount of alkoxy groups that are not hydrolyzed may remain. That is, a polyorganosiloxane in which a silanol group and a trace amount of an alkoxy group coexist may be obtained, but such a polyorganosiloxane may be used.

  The F component catalyst serves as a curing catalyst for accelerating the condensation reaction between the D component and the E component and curing the coating. Examples of such catalysts include metal salts of carboxylic acids such as alkyl titanates, tin octylate and dibutyltin dilaurate, dioctyltin dimaleate; amine salts such as dibutylamine-2-hexoate, dimethylamine acetate, and ethanolamine acetate; Quaternary ammonium salts such as tetramethylammonium acetate, amines such as tetraethylpentamine; N (-β-aminoethyl) -γ-aminopropyltrimethoxysilane, N (-β-aminoethyl) -γ -Amine-based silane coupling agents such as aminopropylmethyldimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum compounds such as aluminum alkoxide and aluminum chelate; alkali catalysts such as potassium hydroxide; tetraisopropyl tita And titanium compounds such as tetrabutyltitanate and titanium tetraacetylacetonate, and halogenated silanes such as methyltrichlorosilane, dimethyldichlorosilane, and trimethylmonochlorosilane. There is no particular limitation as long as it is effective for the condensation reaction.

  The mixing ratio of the D component and the E component is preferably 70 to 30 parts by weight of the E component with respect to 30 to 70 parts by weight of the D component, more preferably 60 to 40 parts by weight of the E component with respect to 40 to 60 parts by weight of the D component. (However, the total amount of D component and E component is 100 parts by weight). When the D component is less than 30 parts by weight, it is difficult to control the gloss of the resulting inorganic coating film, and when the E component exceeds 70 parts by weight, the film formability of the inorganic coating film may be impaired. By changing the blending ratio of the D component and the E component in the above range, the gloss of the inorganic coating film can be easily adjusted. When the blending ratio is adjusted so as to increase the D component, the inorganic coating film The glossiness of the inorganic coating film can be increased by adjusting the blending ratio so as to reduce the D component.

  Moreover, it is preferable that the addition amount of the catalyst of F component is 0.0001-10 weight part with respect to a total of 100 weight part of D component and E component. More preferably, it is 0.0005-8 weight part, Most preferably, it is 0.0007-5 weight part. If the addition amount of the F component catalyst is less than 0.0001 parts by weight, it may not be cured at room temperature, and if the addition amount of the F component catalyst exceeds 10 parts by weight, the heat resistance and weather resistance of the resulting inorganic coating film May be worse.

  The silicone-based coating agent prepared as described above can be used after being diluted with various organic solvents for ease of handling. The type of the organic solvent is selected according to the type or molecular weight of the D component or E component monovalent hydrocarbon group. Examples of such an organic solvent include those shown as dispersion solvents for fine particle oxides, etc. 1 type or 2 types or more selected from the group consisting of these can be used.

  This silicone coating agent is generally stored in a three-packed form in which the D component, the E component, and the F component are stored separately, but the mixed component of the D component and the F component, the E component, The two may be divided into two package types, and the two may be mixed at the time of use. Alternatively, all the components may be mixed and stored in one container. However, when the D component and the F component are mixed and stored, it is preferable to adjust the pH of the D component to 2 to 7 and then add and mix the F component. It is preferable to use a solution in which the amount of water used is 0.3 mol or less with respect to 1 mol of the hydrolyzable group.

  In addition, this silicone-based coating agent does not affect the properties of leveling agents, thickeners, pigments, dyes, aluminum paste, glass frit, metal powder, antioxidants, UV absorbers, etc. as necessary. It can be added within the range.

Next, JP-A-9-249822 discloses two types of silicone coating agents. One of the two types of silicone coating agents (hereinafter referred to as silicone coating agent (1))
General formula (R ¹ ) _m Si (OR ² ) _4-m (6)
(In the formula (6), ^{R 1} each represent a methyl group, an ethyl group or a phenyl group, ^{R 2} is .m each represents an alkyl group having 1 to 8 carbon atoms is 0, 1 or 2.)
An ultraviolet absorber is blended with a silicon alkoxide-based coating agent mainly composed of a silicon compound represented by formula (1) and / or a partial hydrolyzate thereof.

The silicon alkoxide mainly composed of the silicon compound represented by the general formula (6) and / or a partial hydrolyzate thereof is a mixture mainly composed of the following compounds (i), (ii) and (iii): Can be obtained by diluting with an appropriate solvent, adding a necessary amount of a curing agent and a catalyst, followed by hydrolysis and condensation polymerization, having a weight average molecular weight Mw of 500 to 3000 in terms of polystyrene, and a molecular weight distribution Mw / Mn ( Mn preferably has a number average molecular weight) of 1.1 to 3.0. More preferably, Mw = 600 to 3000 and Mw / Mn = 1.2 to 1.8. When the weight average molecular weight and the molecular weight distribution are smaller than these ranges, the curing shrinkage during the condensation polymerization becomes large, and cracks tend to occur in the coating film after baking. Also, when the weight average molecular weight and molecular weight distribution are larger than this range, the reaction is too slow and hard to cure, or even when cured, the coating tends to be soft, or the leveling properties of the coating tend to be very poor. There is.
(I): 20 to 200 parts by weight of a silicon compound and colloidal silica represented by m = 0 in the general formula (6) (ii): 100 parts by weight of a silicon compound represented by m = 1 in the general formula (6) (iii ): 0 to 80 parts by weight of a silicon compound represented by m = 2 in the general formula (6) As these silicon compounds, alkoxysilanes in the later-described formula (7) can be used. Further, the component (i) colloidal silica (colloidal silica) is used by dispersing the fine particle silica component in water, an organic solvent such as methanol, or a mixed solvent thereof, as long as they are colloidal. There are no particular restrictions on the solvent type. In addition, the compounding quantity of the colloidal silica of component (i) is a weight part also including a dispersion medium.

  Although it does not specifically limit as said hardening | curing agent used as needed in a silicone type coating agent (1), For example, inorganic acids, such as hydrochloric acid, phosphoric acid, a sulfuric acid, formic acid, an acetic acid, chloroacetic acid An acidic catalyst such as a dilute solution of an organic acid such as a basic catalyst described later can be used alone or in combination of two or more. Further, when colloidal silica is used as the component (i), the colloidal silica exhibits acidity, so that it becomes a catalyst, and nothing is required as an acidic catalyst.

  As the catalyst used as necessary in the silicone-based coating agent (1), a basic catalyst is used. The basic catalyst is not particularly limited. For example, amines such as triethanolamine; γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, etc. Aminosilanes; salts of inorganic acids (eg, hydrochloric acid, nitric acid, phosphoric acid, etc.) or organic acids (eg, formic acid, acetic acid, propionic acid, etc.), such as ammonia, trimethylamine, triethylamine, n-butylamine, or inorganic or organic acids Examples thereof include metathesis salts of salts and quaternary ammonium salts. These types and addition amounts are not limited at all.

  In addition to the above-mentioned components, the silicone-based coating agent (1) may optionally contain a filler other than colloidal silica (for example, inorganic filler such as alumina sol or fumed silica), a colorant, a diluting solvent, a thickening agent. 1 or more types of various additives, such as an agent, can be mix | blended. Although it does not specifically limit as this dilution solvent, For example, alcohols, such as methanol, ethanol, isopropanol (IPA); Cellosolves, such as ethylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc. can be mentioned, These are 1 type or Two or more kinds can be used in combination.

  The silicone-based coating agent (1) can be stably used within the aforementioned molecular weight range by adjusting its pH value to 3.8 to 6.0. If the pH value is outside this range, the silicone-based coating agent (1) becomes less stable, and the usable period after preparing the silicone-based coating agent (1) may be limited. Here, the pH value adjusting method is not particularly limited. For example, when the pH value becomes less than 3.8 when the raw material of the silicone-based coating agent (1) is mixed, the basic range such as ammonia may be used. What is necessary is just to adjust to the inside pH value, and what is necessary is just to adjust to the said predetermined range using acidic reagents, such as hydrochloric acid, when pH value exceeds 6.0. Depending on the pH value, the reaction does not proceed conversely with a small molecular weight, and if it takes time to reach the molecular weight range, the silicone coating agent (1) is heated to promote the reaction. Alternatively, the pH value may be lowered with an acidic reagent and the reaction may be advanced, and then returned to a predetermined pH value with a basic reagent.

  Even when the pH value is adjusted as described above, or even when the pH value is not adjusted, the condensation reaction is promoted by adding a basic catalyst to the silicone-based coating agent (1) during use or at least during use. Since the number of crosslinking points in the coating film can be increased, it is possible to stably obtain a coating film having good crack resistance. Further, by promoting the crosslinking reaction, the curing time can be shortened or the curing temperature can be lowered, which is economical.

Of the two types of silicone coating agents disclosed in JP-A-9-249822, the other silicone coating agent (hereinafter referred to as silicone coating agent (2)) is:
Formula (R ³ ) _n SiX _4-n (7)
(In Formula (7), R ³ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, X represents a hydrolyzable group, and n is an integer of 0 to 3. )
A silica-dispersed oligomer solution of organosilane (G) obtained by partially hydrolyzing the hydrolyzable organosilane represented by the formula (I) with colloidal silica dispersed in an organic solvent and / or water;
Average composition formula (R ⁴ ) _d Si (OH) _e O _{(4-de) / 2} (8)
(In Formula (8), R ⁴ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and d and e are 0.2 ≦ d ≦ 2.0 and 0.0001 ≦, respectively. (It is a number that satisfies the relationship of e ≦ 3 and d + e <4.)
A polyorganosiloxane (H) containing a silanol group in the molecule represented by:
Of the curing catalyst (I),
A silicon alkoxide coating agent containing three components (G), (H), and (I) as essential components is blended with an ultraviolet absorber.

  The silica-dispersed oligomer of component (G) used in the silicone-based coating agent (2) is a main component of a base polymer having a hydrolyzable group X as a functional group that is subjected to a curing reaction during film formation. This is achieved by adding one or more hydrolyzable organosilanes represented by the above general formula (7) to colloidal silica dispersed in an organic solvent, water, or a mixed solvent thereof, to form colloidal silica. It can be obtained by partially hydrolyzing the hydrolyzable organosilane with water therein or water added separately.

R ³ in the hydrolyzable organosilane represented by the general formula (7) is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, Alkyl groups such as butyl group, pentyl group, hexyl group, heptyl group and octyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aralkyl groups such as 2-phenylethyl group and 3-phenylpropyl group; phenyl group and tolyl Aryl groups such as vinyl groups; alkenyl groups such as vinyl groups and allyl groups; halogen-substituted hydrocarbon groups such as chloromethyl groups, γ-chloropropyl groups, and 3,3,3-trifluoropropyl groups; γ-methacryloxypropyl groups Substituted hydrocarbon such as γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, γ-mercaptopropyl group, etc. It can be exemplified, and the like. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of easy synthesis or availability.

  Examples of the hydrolyzable group X in the general formula (7) include an alkoxy group, an acetoxy group, an oxime group, an enoxy group, an amino group, an aminoxy group, and an amide group. Among these, an alkoxy group is preferable because it is easily available and a silica-dispersed oligomer solution (G) can be easily prepared. Examples of the hydrolyzable organosilane include mono-, di-, tri-, and tetra-functional alkoxysilanes in which the n in the general formula (7) is an integer of 0 to 3, acetoxy Examples thereof include silanes, oxime silanes, enoxysilanes, aminosilanes, aminoxysilanes, and amidosilanes. Among these, alkoxysilanes are preferable because they are easily available and the silica-dispersed oligomer solution (G) is easy to prepare.

  In particular, tetramethoxysilane, tetraethoxysilane, and the like can be exemplified as the n = 0 tetraalkoxysilane, and the methyltrialkoxysilane, methyltriethoxysilane, methyltrimethoxysilane, and the like can be exemplified as the n = 1 organotrialkoxysilane. Examples thereof include isopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Examples of n = 2 diorganodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane. Further, examples of the triorganoalkoxysilane with n = 3 include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, and dimethylisobutylmethoxysilane. Organosilane compounds generally called silane coupling agents can also be used as alkoxysilanes.

  Of these hydrolyzable organosilanes of the general formula (7), 50 mol% or more is preferably a trifunctional compound represented by n = 1. More preferably, it is 60 mol% or more, and most preferably 70 mol% or more. When the trifunctional compound with n = 1 is less than 50 mol%, it is difficult to obtain a sufficient coating film hardness, and the dry curability tends to be inferior.

  As the colloidal silica used in the component (G), water-dispersible or non-aqueous organic solvent-dispersible colloidal silica such as alcohol can be used, and the colloid used in the silicone-based coating agent (1) described above. The same silica gel can be used. Generally, such colloidal silica contains 20 to 50% by weight of silica as a solid content, and the amount of silica can be determined from this value.

  When water-dispersible colloidal silica is used, water present as a component other than the solid content can be used for hydrolysis of the component (G). Water-dispersible colloidal silica is usually made from water glass, but such colloidal silica is readily available commercially. The organic solvent-dispersible colloidal silica can be easily prepared by replacing the water of the water-dispersible colloidal silica with an organic solvent. Such an organic solvent-dispersible colloidal silica can be easily obtained as a commercial product in the same manner as the water-dispersible colloidal silica. Examples of the organic solvent in which the colloidal silica is dispersed include, for example, lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether acetate. Examples include ethylene glycol derivatives; diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or two or more selected from the group consisting of these can be used, but in combination with these hydrophilic organic solvents, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, Methyl ethyl ketoxime can also be used.

  The colloidal silica in the component (G) is essential for increasing the hardness of the cured film of the silicone coating agent (2). In the component (G), the colloidal silica is preferably contained in the range of 5 to 95% by weight as the silica solid content. More preferably, it is 10 to 90 weight%, Most preferably, it is the range of 20 to 85 weight%. If the content is less than 5% by weight, the desired film hardness cannot be obtained, and if it exceeds 95% by weight, it is difficult to uniformly disperse the silica, which may cause inconveniences such as gelation in the component (G). .

  The silica-dispersed oligomer of organosilane as component (G) is usually a partial hydrolysis of hydrolyzable organosilane of general formula (7) in at least one of water-dispersible colloidal silica and organic solvent-dispersible colloidal silica. Can be obtained. The amount of water used relative to the hydrolyzable organosilane is preferably 0.001 to 0.5 mol of water with respect to 1 mol of the hydrolyzable group. If the amount of water used is less than 0.001 mol, a sufficient partial hydrolyzate cannot be obtained, and if the amount of water used exceeds 0.5 mol, the stability of the partial hydrolyzate may be deteriorated. There is. The method of partial hydrolysis is not particularly limited, and a hydrolyzable organosilane and colloidal silica may be mixed and mixed with a necessary amount of water. At this time, the partial hydrolysis reaction proceeds at room temperature. In order to promote the partial hydrolysis reaction, it may be heated to 60 to 100 ° C. Furthermore, hydrochloric acid, acetic acid, halogenated silane, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, toluene for the purpose of promoting partial hydrolysis reaction An inorganic acid such as sulfonic acid or oxalic acid or an organic acid may be used as a catalyst.

  The silica-dispersed oligomer of organosilane as component (G) has a liquid pH value in the range of 2.0 to 7.0, more preferably 2.5 to 6.5, in order to obtain long-term stable performance. It is better to adjust to a range of pH 3.0 to 6.0, even more preferably in the range of 3.0 to 6.0. When the pH value is out of this range, the long-term performance deterioration of the component (G) may be significant particularly when the amount of water used is 0.3 mol or more with respect to X1 mol. If the pH value of the component (G) is outside this range, the pH value may be adjusted by adding a basic reagent such as ammonia or ethylenediamine when the pH value is more acidic than this range. What is necessary is just to adjust pH value using acidic reagents, such as hydrochloric acid, nitric acid, and an acetic acid. The adjustment method is not particularly limited.

The (H) component silanol group-containing polyorganosiloxane used in the silicone-based coating agent (2) has an average composition formula represented by the above formula (8), and R ⁴ in the formula (8) is: it can be exemplified the same as ^{R 3} above (7) wherein 5 to 50 wt% in ^{R 4} is a phenyl group. If the phenyl group is less than 5% by weight, the elongation of the coating film is reduced and cracks are likely to occur, and if it exceeds 50% by weight, curing may be too slow. The other R ⁴ is preferably an alkyl group having 1 to 4 carbon atoms, a vinyl group, a γ-glycidoxypropyl group, a γ-methacryloxypropyl group, a γ-aminopropyl group, 3,3,3-trifluoropropyl. Substituted hydrocarbon groups such as groups, more preferably alkyl groups of methyl and ethyl groups. In the formula (8), d and e are numbers satisfying the relations 0.2 ≦ d ≦ 2.0, 0.0001 ≦ e ≦ 3, and d + e <4, respectively, and d is less than 0.2 or e is If it exceeds 3, there are disadvantages such as cracks in the cured film, and if d is more than 2 and 4 or less, or if e is less than 0.0001, curing does not proceed well.

  Such a silanol group-containing polyorganosiloxane (H) of the formula (8) is, for example, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or one or two alkoxysilanes corresponding thereto. The above mixture can be obtained by hydrolyzing with a large amount of water by a known method. In order to obtain a silanol group-containing polyorganosiloxane, when it is hydrolyzed by a known method using alkoxysilane, an unhydrolyzed alkoxy group may remain in a trace amount. That is, a polyorganosiloxane in which a silanol group and a trace amount of an alkoxy group coexist may be obtained, but such a polyorganosiloxane may be used.

  The molecular weight of the silanol group-containing polyorganosiloxane as the component (H) is preferably 700 to 20000. The molecular weight here is a weight average molecular weight in terms of standard polystyrene by GPC (gel permeation chromatography) measurement. When the molecular weight is less than 700, the curability of the formed coating film is slow and cracks are likely to occur. When it exceeds 20000, there is a possibility that the coating film formed from the silicone-based coating agent (2) to which the pigment is added has no gloss and the smoothness is also deteriorated.

  The curing catalyst of the component (I) used in the silicone-based coating agent (2) accelerates the condensation reaction between the component (G) and the component (H) and cures the film. Examples of such catalysts include metal salts of carboxylic acids such as alkyl titanates, tin octylate and dibutyltin dilaurate, dioctyltin dimaleate; amine salts such as dibutylamine-2-hexoate, dimethylamine acetate, and ethanolamine acetate; Carboxylic acid quaternary ammonium salts such as tetramethylammonium acetate; amines such as tetraethylpentamine; N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyl Amine-based silane coupling agents such as dimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum compounds such as aluminum alkoxide and aluminum chelate; alkali catalysts such as potassium hydroxide; tetraisopropyl titanate; There are titanium compounds such as trabutyl titanate and titanium tetraacetylacetonate, and halogenated silanes such as methyltrichlorosilane, dimethyldichlorosilane, and trimethylmonochlorosilane. In addition to these, (G) component and (H) component There is no particular limitation as long as it is effective for the condensation reaction.

  The mixing ratio of the component (G) and the component (H) is 99 to 1 part by weight of the component (H) with respect to 1 to 99 parts by weight of the component (G), preferably 5 to 95 parts by weight of the component (G). In contrast, 95 to 5 parts by weight of component (H), more preferably 90 to 10 parts by weight of component (H) with respect to 10 to 90 parts by weight of component (G) (provided that component (G) and component (H)) Total amount of 100 parts by weight). When the component (G) is less than 1 part by weight, the room temperature curability is inferior and sufficient film hardness cannot be obtained. On the other hand, when the component (G) exceeds 99 parts by weight, the curability is unstable and a good film may not be obtained.

  Moreover, it is preferable that the addition amount of the curing catalyst of (I) component is 0.0001-10 weight part with respect to a total of 100 weight part of (G) component and (H) component. More preferably, it is 0.0005-8 weight part, Most preferably, it is 0.0007-5 weight part. If the addition amount of the curing catalyst (I) is less than 0.0001 parts by weight, it may not be cured at room temperature, and if the addition amount of the curing catalyst (I) exceeds 10 parts by weight, the heat resistance and weather resistance of the film may be reduced. It may get worse.

  You may add a pigment, a matting agent, a filler, etc. to the silicone type coating agent (1) or (2) prepared as mentioned above. Examples of pigments to be added include organic pigments such as carbon black, quinacridone, naphthol red, cyanine blue, cyanine green, and hansa yellow, titanium oxide, barium sulfate, petal, calcium carbonate, alumina, iron oxide red, and composite metal oxide. An inorganic pigment such as a product is good, and one or two or more selected from these groups can be used in combination. Among these, inorganic pigments are preferable for improving weather resistance. Moreover, silica powder, barium sulfate, etc. can be used as a filler, and it can be used combining 1 type (s) or 2 or more types chosen from the group enumerated above. The particle diameter of the pigment or filler is not particularly limited, but is preferably about 0.01 to 4 μm in average particle diameter.

  The amount of pigment added is not particularly limited because the concealability varies depending on the type of pigment, but in the case of an inorganic pigment, a range of 15 to 80 parts by weight with respect to 100 parts by weight of the resin solid content is preferable. When the amount is less than 15 parts by weight, the concealability cannot be sufficiently obtained, and when it exceeds 80 parts by weight, the smoothness of the coating film may be deteriorated. The pigment can be dispersed by an ordinary method, and a dispersant, a dispersion aid, a thickener, a coupling agent, and the like can be used at that time.

  And an ultraviolet-absorbing coating agent can be obtained by adding an ultraviolet absorber to a silicone type coating agent (1) or (2). Examples of ultraviolet absorbers include organic ultraviolet absorbers such as benzotriazole compounds such as 2 (2′hydroxy-5-methylphenyl) benzotriazole, benzophenone compounds such as 2,4-dihydroxybenzophenone, and particulate zinc oxide. And an inorganic ultraviolet absorber such as fine particle titanium oxide can be used, and an organic ultraviolet absorber and an inorganic ultraviolet absorber can be used in combination.

  The organic ultraviolet absorber can be relatively easily dispersed in the silicone coating agent (1) or (2). The addition amount of the organic ultraviolet absorber is not particularly limited, but is in the range of 0.1 to 30% by weight as the solid content with respect to the solid content of the silicone coating agent (1) or (2). Is preferred. If the addition amount is less than 0.1% by weight, the effect of improving the weather resistance due to UV cut becomes insufficient, and if it exceeds 30% by weight, the color of the organic ultraviolet absorber becomes strong, which is not preferable.

  The addition amount of fine particle zinc oxide and fine particle titanium oxide which are inorganic ultraviolet absorbers is not particularly limited, but is 0.1 to 20 with respect to the solid content of the silicone coating agent (1) or (2). A range of% by weight is preferred. If the added amount is less than 0.1% by weight, the effect of improving the weather resistance due to UV cut becomes insufficient, and if it exceeds 20% by weight, it becomes cloudy white.

  Here, the ultraviolet absorber generally has a function of absorbing ultraviolet light and converting it into heat, and the organic ultraviolet absorber has a lifetime because this function is reduced over a long period of time. On the other hand, the lifetime of the inorganic ultraviolet absorber is semi-permanent, and it is preferable to use an inorganic ultraviolet absorber such as fine particle zinc oxide or fine particle titanium oxide as the ultraviolet absorber. However, fine particle zinc oxide and fine particle titanium oxide have poor dispersibility in the silicone-based coating agent (1) or (2), and agglomerate and the coating film becomes cloudy white. is there. In addition, fine zinc oxide and fine titanium oxide powders have a photocatalytic action. When an acrylic resin or alkyd resin having low weather resistance is used, the resin itself deteriorates and long-term storage stability cannot be obtained. For this reason, it is conceivable to use fine zinc oxide or fine particle titanium oxide dispersed in a solvent. However, fine zinc oxide or fine particle titanium oxide settles quickly in the solvent, and it is difficult to improve the dispersibility by this method.

On the other hand, in the hydrolyzable organosilane represented by the general formula (R ³ ) _n SiX _4-n used in the silica-dispersed oligomer solution of organosilane (G), fine zinc oxide and fine titanium oxide are easily dispersed. This dispersion is excellent in transparency and long-term storage stability. Therefore, it is preferable to use the hydrolyzable organosilane in a state in which fine particle zinc oxide or fine particle titanium oxide is added and dispersed. In addition to adding particulate zinc oxide or particulate titanium oxide directly to hydrolyzable organosilane, (R ³ ) _n SiX _4-n hydrolyzable organosilane was prepared by partial hydrolysis in colloidal silica (G ) The silica dispersion oligomer solution of organosilane may be dispersed by adding fine particle zinc oxide or fine particle titanium oxide, and this silica dispersed oligomer solution in which fine particle zinc oxide or fine particle titanium oxide is dispersed is used as a silicone coating agent. By adding to (1) or (2), a coating agent containing fine zinc oxide or fine titanium oxide can be prepared. In this case, the particle size of the primary particles (non-aggregated particles) of fine particle zinc oxide or fine particle titanium oxide is preferably 0.01 μm to 0.5 μm, and the silica-dispersed oligomer solution of organosilane (G) Fine zinc oxide or fine titanium oxide can be dispersed up to about 200 parts by weight with respect to 100 parts by weight (when the amount exceeds 200 parts by weight, the viscosity increases and stirring becomes impossible). The dispersion can be performed using a general mixing apparatus such as a sand mill, a ball mill, or a paint shaker. At this time, an additive aid or filler may be added at a level that does not lower the weather resistance.

Then, in the present invention, the photocatalyst-containing inorganic coating material to form a photocatalyst-containing inorganic coating film 4, Ru with silicone coating agent was blended with the photocatalyst. As this silicone type coating agent, what is disclosed by patent 2767259 can be used, for example. That is,
General formula: Si (OR ¹ ) ₄ (9)
20 to 200 parts by weight of colloidal silica having an organic solvent dispersibility in which the silicon compound and / or colloidal silica is dispersed in a non-aqueous organic solvent,
General formula: R ² Si (OR ¹ ) ₃ (10)
100 parts by weight of a silicon compound represented by
General formula: R ² ₂ Si (OR ¹ ) ₂ (11)
And a photocatalyst-containing coating (in the above formulas (9) to (11), R ¹ and R ² represent a monovalent hydrocarbon group). An agent can be used.

Each silicon compound has a general formula represented by the following formula (12).
General formula: R ² _n Si (OR ¹ ) _4-n (12)
(In formula (12), n = 0 to 3 is shown, and R ¹ and R ² are monovalent hydrocarbon groups.)
R ¹ and R ^{2 in} formula (12) are not limited as long as they represent a monovalent hydrocarbon group, but R ² represents a substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms. For example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and other alkyl groups, cyclopentyl group, cyclohexyl group and other cycloalkyl groups, 2-phenylethyl group, 3-phenylpropylene. Halogens such as aralkyl groups such as ruthel groups, aryl groups such as phenyl and tolyl groups, anikenyl groups such as vinyl and allyl groups, chloromethyl groups, γ-chloropropyl groups, and 3,3,3-trifluoropropyl groups Examples thereof include substituted hydrocarbon groups and substituted hydrocarbon groups such as γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, and γ-mercaptopropyl group. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of ease of synthesis or availability.

As R ¹ in the above formula (12), ^one having an alkyl group having 1 to 4 carbon atoms as a main raw material is used. In particular, tetramethoxysilane, tetraethoxysilane and the like are exemplified as the tetraalkoxysilane of n = 0, and methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane are exemplified as the organotrialkoxysilane of n = 1. , Phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Further, examples of the n = 2 diorganodialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, and the like, and n = 3 triorganoalkoxysilane. Examples thereof include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, dimethylisobutylmethoxysilane and the like.

R ¹ and R ^{2 in the} above formulas (9), (10), and (11) may be the same hydrocarbon group or different.

  Preparation of the silicone-based coating agent includes, for example, diluting a silicon compound represented by the above formulas (9), (10), and (11) with a solvent, adding water or a catalyst as a curing agent, hydrolysis, and It is prepared by performing a polycondensation reaction. The weight average molecular weight (Mw) of these silicon compounds is calculated in terms of polystyrene. In this preparation, the weight average molecular weight (Mw) of the inorganic coating is made 900 or more in terms of polystyrene. When the weight average molecular weight (Mw) is less than 900 in terms of polystyrene, curing shrinkage increases during the polycondensation reaction, and cracks are likely to occur in the baked inorganic coating film.

  The silicone-based coating agent can be used in combination with the silicon compound represented by the above formula (9), or alternatively, colloidal silica as a component. The colloidal silica is an organic solvent-dispersible colloidal silica dispersed in a non-aqueous organic solvent such as alcohol. The colloidal silica contains 20 to 50% by weight of silica as a solid content. The organic solvent-dispersible colloidal silica can be easily prepared by replacing the organic solvent with water. Examples of the organic solvent in which the colloidal silica is dispersed include, for example, lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol, ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether acetate. And ethylene glycol derivatives, diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or more of these are used. Furthermore, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can be used in combination with a hydrophilic organic solvent. In addition, the said compounding quantity of the said colloidal silica is a weight also including a dispersion medium.

  Water is generally used as a curing agent in preparing the silicone coating agent, and the amount of this water is preferably 45% by weight or less, more preferably 25% by weight or less in the silicone coating agent.

  Examples of the organic solvent used in preparing the silicone coating agent include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol, ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl acetate. Examples thereof include ethylene glycol derivatives such as ether, diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or more of these are used. Furthermore, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can be used in combination with a hydrophilic organic solvent.

  When preparing a silicone type coating agent, it is desirable to set pH of a silicone type coating agent to 3.8-6. Within this pH range, the preservability of the silicone-based coating agent is good, and when it is outside this pH range, the period during which application can be performed from the preparation period is limited. The method for adjusting the pH is not limited. For example, when the pH is less than 3.8 when the materials are mixed, the pH may be adjusted by adding a basic reagent such as ammonia. In this case, an acid reagent such as hydrochloric acid may be added for adjustment. Depending on the pH, if the reaction progresses slowly with a small molecular weight, the reaction may be promoted by heating, or after the reaction is advanced by lowering the pH with an acidic reagent, a basic reagent is added. It may be a predetermined pH.

  The silicone-based coating agent can be used as a photocatalytic silicone-based coating agent by containing a photocatalyst. Generally, titanium oxide is used as the photocatalyst. Zinc oxide, tin oxide, iron oxide, zirconium oxide, tungsten oxide, chromium oxide, molybdenum oxide, ruthenium oxide, germanium oxide, lead oxide, cadmium oxide, copper oxide, vanadium oxide, niobium oxide, tantalum oxide, manganese oxide, Cobalt oxide, rhodium oxide, rhenium oxide and the like can also be mentioned. Although the compounding quantity of a photocatalyst is not specifically limited, The range of 20 to 80 weight% is preferable with respect to the dry solid content of a silicone type coating agent.

  Then, after applying a primer treatment on the surface of the ceramic base material 1 as required, an organic coating film 2 containing no photocatalyst is formed by applying an organic paint on the surface and drying and curing it. An inorganic coating film 3 is formed by applying an inorganic coating thereon and drying and curing, and further, a photocatalyst-containing inorganic coating 4 is formed by applying a photocatalyst-containing inorganic coating thereon and drying and curing. It is possible to obtain a coated body as shown in FIG.

  The above coating agents can be applied by various methods such as brush coating method, dipping method, spray coating method, roll coating method, bell method, flow coating method, curtain coating method, knife coating method, etc. In order to easily obtain a coating film having a proper thickness, it is preferable to apply by a spray coating method, a roll coating method, or a bell method using a rotating cup. By forming the coating film with a uniform thickness in this way, it is possible to obtain a uniform elongation at break of the coating film. The film thickness of each coating film is not particularly limited, but the film thickness of the organic coating film 2 is 10 to 200 μm, the film thickness of the inorganic coating film 3 is 2 to 15 μm, and the film thickness of the photocatalyst-containing inorganic coating film 4. Is preferably in the range of 0.1 to 2 μm.

In the present invention, the inorganic coating film 3 is formed on the surface of the organic coating film 2 to form the inorganic coating film 3 as described above, and then the photocatalyst-containing inorganic coating film is coated on the surface of the inorganic coating film 3. Before forming the film 4, the surface of the inorganic coating film 3 is surface-treated, and the hydrophilicity of the surface of the inorganic coating film 3 is adjusted so that the contact angle of water with the surface of the inorganic coating film 3 is 60 ° or less. It is a thing. The method of surface treatment of the inorganic coating film 3 will row by Shi silica deposition process.

As a reference, flame treatment (also referred to as flame treatment) is performed by bringing a flame blown from a burner into contact with the surface of the inorganic coating film 3, and the surface of the inorganic coating film 3 is oxidized to increase hydrophilicity. It is something that can be done. In particular, as described above, when a silicone diol is contained in the inorganic coating material to which the inorganic coating film 3 is applied, if the silicone diol is present on the surface of the inorganic coating film 3 as a bleed, the inorganic diol is caused by the action of the silicone diol. Although the surface of the coating film 3 tends to become hydrophobic, the silicone diol can be removed by performing a frame treatment, and the hydrophilicity of the surface of the inorganic coating film 3 can be increased by eliminating the influence of the silicone diol. It can be done.

  The silica vapor deposition treatment is performed by forming a thin silica vapor deposition film on the surface of the inorganic coating film 3 by physical vapor deposition or chemical vapor deposition of silica (silicon oxide). By forming on the surface of the inorganic coating film 3, the hydrophilicity of the surface of the inorganic coating film 3 can be increased. Also in this case, even if the silicone diol contained in the inorganic coating is present on the surface of the inorganic coating film 3 as a bleed or the like, it can be coated with a silica thin film. The hydrophilicity of the surface of the coating film 3 can be increased.

  In the state in which the inorganic coating film 3 is surface-treated as described above and the hydrophilicity is increased so that the contact angle of water is 60 ° or less, the surface of the inorganic coating film 3 is coated with a photocatalyst-containing inorganic coating, The inorganic coating film 4 is formed. The surface of the inorganic coating film 3 is thus improved in hydrophilicity, and the wettability of the photocatalyst-containing inorganic paint to the surface of the inorganic coating film 3 is improved. The photocatalyst-containing inorganic coating film can be uniformly applied to the surface of the inorganic coating film 3, and the photocatalyst-containing inorganic coating film 4 can be uniformly formed with a thin film thickness.

  The photocatalyst-containing inorganic coating film 4 is formed with an extremely thin film thickness of 0.1 to 2 μm. When the film thickness of the photocatalyst-containing inorganic coating film 4 exceeds 2 μm, the contained photocatalyst acts as a pigment. As a result, the photocatalyst-containing inorganic coating film 4 becomes white and cloudy, the transparency is lowered, and the appearance of the coated body may be impaired. If the film thickness of the photocatalyst-containing inorganic coating film 4 is too thin, the photocatalytic action is lowered and the hydrophilicity of the surface of the coated body becomes insufficient. Therefore, the film thickness of the photocatalyst-containing inorganic coating film 4 is 0.1 μm or more. Is desirable. And in order to form the photocatalyst-containing inorganic coating film 4 with an extremely thin film thickness of 0.1 to 2 μm, the contact angle of water on the surface of the inorganic coating film 3 to which the photocatalyst-containing inorganic paint is applied needs to be 60 ° or less. There is.

  Next, the present invention will be specifically described with reference to examples.

( Reference Example 1)
A core-shell type acrylic emulsion paint (manufactured by Kansai Paint Co., Ltd.) blended with an iron oxide pigment was used as the organic paint.

  Further, “MC-T560” manufactured by Matsushita Electric Works Co., Ltd. was used as the inorganic paint.

  Further, 20 parts by mass of tetraalkoxysilane resin (“NS-2000” manufactured by Matsushita Electric Works Co., Ltd.), 1 part by mass of silica sol (“MT-ST” manufactured by Nissan Chemical Co., Ltd.), 22 parts by mass of photocatalyst (zinc oxide) Then, 78 parts by mass of methanol was blended and mixed by stirring to prepare a photocatalyst-containing inorganic paint.

  Then, the above organic paint was applied to the surface of the cement-made substrate 1 by a spray method, and baked at 150 ° C. for 5 minutes to form an organic coating film 2 having a thickness of 30 μm. Next, the above-mentioned inorganic coating material was applied thereon by a spray method, and baked at 150 ° C. for 7 minutes to form an inorganic coating film 3 having a film thickness of 4 μm.

  After forming the inorganic coating film 3 in this way, the surface of the inorganic coating film 3 is irradiated with a combustion flame of a mixed gas in which LPG gas and air are mixed at a volume ratio of 30: 100 for 2 seconds. 3 surfaces were framed.

  Next, the above-mentioned photocatalyst-containing inorganic coating material is applied on the inorganic coating film 3 by a spray method and baked at 150 ° C. for 1 minute to form a photocatalyst-containing inorganic coating film 4 having a film thickness of 0.5 μm. Got.

(Example 2)
In the same manner as in Reference Example 1, an organic coating film 2 and an inorganic coating film 3 were formed on the surface of the substrate 1.

  After forming the inorganic coating film 3 in this manner, the surface of the inorganic coating film 3 was subjected to silica deposition by vacuum-depositing silica on the surface of the inorganic coating film 3.

Thereafter, in the same manner as in Reference Example 1, a photocatalyst-containing inorganic coating film 4 having a thickness of 0.5 μm was formed on the inorganic coating film 3 to obtain a coated body.

(Comparative Example 1)
A photocatalyst-containing inorganic coating film 4 having a film thickness of 0.5 μm was formed on the inorganic coating film 3 in the same manner as in Reference Example 1, except that the inorganic coating film 3 was not subjected to surface treatment such as frame treatment. A painted body was obtained.

(Comparative Example 2)
A photocatalyst-containing inorganic coating film 4 having a thickness of 3 μm was formed on the inorganic coating film 3 in the same manner as in Reference Example 1 except that the inorganic coating film 3 was not subjected to surface treatment such as flame treatment. Got the body.

About said reference example 1 , Example 2, and Comparative Examples 1-2, after forming the inorganic coating film 3, the contact angle of the water of the surface of the inorganic coating film 3 was measured. For Reference Example 1, after the frame treatment, before applying the photocatalyst-containing inorganic paint, after Example 2, after silica deposition, before applying the photocatalyst-containing inorganic paint, the contact angle of water Measurements were made. The contact angle of water was measured by dropping 4 μL of water on the surface of the inorganic coating film 3 in a horizontal state and measuring the contact angle by the θ / 2 method. The results are shown in Table 1.

Moreover, the hydrophilic property of the surface was evaluated about the coating body obtained by the reference example 1 , Example 2, and Comparative Examples 1-2 as mentioned above. In the evaluation of hydrophilicity, water was sprayed on the surface of the coated body, and “◯” was determined when water was not repelled, and “X” was determined when water was repelled. The results are shown in Table 1.

Further, the coated bodies obtained in Reference Example 1, Example 2 and Comparative Examples 1 and 2 as described above were evaluated by visually observing the appearance, and “○” indicates that the photocatalyst-containing inorganic coating film 4 is transparent. Those that were white and cloudy were judged as “x”. The results are shown in Table 1.

As seen in Table 1, the water contact angle of the inorganic coating film 3 of Reference Example 1 subjected to the frame treatment was 60 °, and the water contact angle of the inorganic coating film 3 of Example 2 subjected to silica deposition treatment was 30 °. Since both have high wettability, even if the photocatalyst-containing inorganic coating 4 is formed with a thin film thickness of 0.5 μm, the surface of the coated body has good hydrophilicity, and the photocatalyst-containing coating 4 is uniformly formed. It has been confirmed. Moreover, in Reference Example 1 and Example 2, since the film thickness of the photocatalyst-containing inorganic coating film 4 was thin, the appearance of the coated body was also good.

  On the other hand, in Comparative Examples 1 and 2 in which the surface of the inorganic coating film 3 was not treated, the contact angle of water was 85 ° and the wettability was low. For this reason, in Comparative Example 1 in which the photocatalyst-containing inorganic coating film 4 is formed with a thin film thickness of 0.5 μm, the hydrophilicity of the surface of the coated body is poor, and the photocatalyst-containing coating film 4 has uneven coating. there were. In Comparative Example 2, since the photocatalyst-containing inorganic coating film 4 is formed with a thick film thickness of 3 μm, the hydrophilicity of the surface of the coated body is good, but the photocatalyst-containing inorganic coating film 4 is white and cloudy, and the appearance is It was something that would be defective.

It is the schematic which shows an example of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Organic coating film 3 Inorganic coating film 4 Photocatalyst containing inorganic coating film

Claims (1)

On the surface of the base material, an organic coating, an inorganic coating, and a photocatalyst-containing inorganic coating was applied in this order, the organic coating, an inorganic coating, a photocatalyst-containing inorganic coating film is formed, the photocatalyst-containing inorganic coatings, surface treatment painted the photocatalyst containing inorganic coating on the surface of the inorganic coating film contact angle of water was adjusted to 60 ° or less by a painted body which is formed with a film thickness of 0.1~2μm ,
A coated body, wherein the inorganic paint is a silicone-based coating agent, the photocatalyst-containing inorganic paint is a silicone-based coating agent containing a photocatalyst, and the surface treatment of the inorganic coating film is a silica vapor deposition treatment .

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