JPH10363A - Formation of coating film having photochemical activity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a multifunctional coating film having a deodorizing function and an antibacterial function and excellent in antifouling function and atmosphere purifying function. SOLUTION: A coating composition prepared by mixing at least one kind of hydrolyzable silicon compd. selected from a group consisting of a hydrolyzable silyl group-contg. vinyl copolymer, the hydrolyzate of an organosilane and the partial condensate of of the organosilane or a solvent-soluble fluororesin and the titanium oxide having photocatalytic activity and having 45-85 PWC is applied on the surfaced substrate to form a coating film, the surface is rubbed to obtain an active face on the surface layer, and a coating film having photochemical activity is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a multifunctional coating film having a deodorizing function, an antibacterial function, an antifouling function and an air purifying function.

[0002]

2. Description of the Related Art Conventionally, there is no paint having a function of deodorizing and antibacterial at the same time as a paint applied to a ceiling, an inner wall, a floor or the like of a house or a building. Paints containing ethylenediaminetetraacetic acid and alum, as antibacterial paints, paints containing silver silica gel antibacterial agents, etc. are known, but paints that have both deodorant function and antibacterial function have not been established. It was the current situation.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a method for forming a multifunctional coating film which has both a deodorizing function and an antibacterial function, and is also excellent in an antifouling function and an air purifying function. With the goal.

[0004]

Means for Solving the Problems The present inventors have conducted research to solve the above-mentioned problems, and as a result, a photocatalyst was applied to a hydrolyzable silicon compound or a solvent-soluble fluororesin on a substrate subjected to a base treatment. By applying a paint containing a specific amount of active titanium oxide, polishing the surface, and exposing the surface to an active surface, it is known that it has excellent deodorizing function, antibacterial function, antifouling function, and air purification function. Obtained. The present invention has been completed based on such findings.

More specifically, the present invention relates to (A) a hydrolyzable silyl group-containing vinyl copolymer, a hydrolyzate of an organosilane and a partial condensation of a hydrolyzate of an organosilane, At least one hydrolyzable silicon compound or a solvent-soluble fluororesin selected from the group consisting of titanium oxide having photocatalytic activity (B) and a PWC of 45 to 85; This is a method for forming a coating film having photochemical activity, characterized in that an active surface is exposed on the surface layer by coating, forming a coating film, and further polishing the surface.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

In the method of forming a coating film having photochemical activity according to the present invention, the substrate is not particularly limited, such as a metal plate, an inorganic plate, a wooden plate, and a plastic substrate, the surface of which is preliminarily treated. . As a metal plate, for example,
Various metal plates such as a steel plate, an aluminum plate, a stainless steel plate, and a titanium plate are exemplified. Of these, examples of steel sheets include cold-rolled steel sheets, hot-rolled steel sheets, galvanized steel sheets, alloy galvanized steel sheets,
Zinc-iron alloy-plated steel sheet, zinc-aluminum alloy-plated steel sheet, aluminum-plated steel sheet, chromium-plated steel sheet, nickel-plated steel sheet, zinc-nickel alloy steel sheet, tin-plated steel sheet, etc. Pickling, alkali degreasing, polishing, chromate treatment, phosphoric acid treatment, zinc phosphate treatment, blast treatment, composite oxide film treatment, etc., alone or in combination, pre-coating treatment, if necessary, polyester, epoxy, urethane The primer is coated with a roll coater, curtain flow coater, roller curtain coater, electrostatic coating machine, blade coater, die coater, etc., and then left at room temperature, or a hot air furnace, induction heating furnace, combined heating furnace with induction heating and hot air, It is cured and dried in a near-infrared furnace, far-infrared furnace, active energy ray irradiation furnace, etc. according to a conventional method. Obtained by coating to a thickness of about ~30μm. Examples of inorganic boards include slate boards, wood chip cement boards, pulp cement boards, asbestos cement boards, lightweight aggregate-mixed cement boards, foamed concrete boards, glass fiber reinforced cement boards, and calcium silicate boards used for exterior wall materials and interior materials. Examples thereof include a plate, a magnesium carbonate plate, and other hydraulic plate materials, which are obtained by applying a urethane-based, epoxy-based, vinyl-based sealer, or the like. As a wooden board,
Filling treatment, polishing treatment, wood sealer application, and the like are included. Examples of the plastic base material include a primer coating for various plastics.

The hydrolyzable silicon compound used in the present invention is a hydrolyzable silyl group-containing vinyl copolymer, a hydrolyzate of organosilane and a partial condensate of a hydrolyzate of organosilane. These are selected, and these can be used alone or in combination of two or more.

The silyl group-containing vinyl copolymer comprises at least one ethylenically unsaturated monomer having at least one group of the general formula (I):> C ＝ C <;
And a copolymer containing at least one silyl group-containing monomer.

RSiX _n R ¹ _(3-n) (II) (wherein, R is a monovalent organic group containing a vinyl group, R ¹ is an alkyl group having 1 to 10 carbon atoms, an aryl group or an aralkyl group) , X is a hydrolyzable group selected from the group consisting of halogen, alkoxy, alkoxyalkoxy, acyloxy, ketoximate, amino, acid amide, aminooxy, mercapto, and alkenyloxy groups, and n is an integer of 1 to 3.) Examples of the silyl group-containing monomer include γ-methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, and vinyl-tris (2-methoxyethoxysilane).

Examples of the ethylenically unsaturated monomers suitable for producing the silyl group-containing vinyl copolymer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, and 2-ethylhexyl. Alkyl acrylates such as acrylate, butyl methacrylate, 2-methylhexyl methacrylate and lauryl methacrylate; vinyl aromatic hydrocarbons such as styrene, vinyl toluene and α-methyl styrene; vinyl halides such as vinyl chloride; vinylidene halides such as vinylidene chloride Conjugated dienes such as butadiene and isoprene; vinyl esters of saturated fatty acids having 1 to 12 carbon atoms, vinyl acetate and vinyl propionate; and these may be used alone or in combination of two or more. Can.

In producing the silyl group-containing vinyl copolymer of the present invention, the ethylenically unsaturated monomer and the silyl group-containing monomer can be used in any ratio.
The silyl group-containing monomer is preferably used in a ratio of 0.5 to 25 mol%, and the ethylenically unsaturated monomer is preferably used in a ratio of 99.5 to 75 mol%. When producing this copolymer, a conventionally known method can be used. The molecular weight of the silyl group-containing vinyl copolymer is from 3,000 to 1,000,000.
It is preferably set to 0, especially 10,000 to 300,000.

The hydrolyzate of the organosilane used in the present invention is a compound represented by the following general formula (III-A), (III-B) or (IV).

[0014] _{^{R 2 Si (OR 3) 3}} (III-A) Si (OR 3) 4 (III-B) R 2 2 Si (OR 3) 2 (IV) ( wherein, R ² is C 1 -C ~ 8 organic groups, R
³ is an alkyl group having 1 to 4 carbon atoms, each R ² ,
R ³ may be the same or different. In the present invention, a partially condensed compound of the compound represented by formula (III-A), (III-B) or (IV) can be used. In the present invention, the hydrolyzate of organosilane or a partial condensate thereof is one component acting as a binder. The polycondensed molecular weight of the partially condensed compound is from 1,000 to 5,000, preferably from 1,500 to 3,000.

When this hydrolyzate or its partial condensate is used, it is preferable to use a solvent solution having a solid content of 10 to 80% by weight.

The above general formula (III-A), (III-B) or (I
Specific examples of the organic group R ² in V), methyl group, ethyl group, n- propyl group, i- propyl, i-
Alkyl group such as butyl group, γ-chloropropyl group, vinyl group, 3,3,3-trifluoropropyl group, γ-glycidoxypropyl group, γ-methacryloxypropyl group,
γ-mercaptopropyl group, phenyl group, 3,4-epoxycyclohexylethyl group and the like. Specific examples of the alkyl group R ³ include a methyl group, an ethyl group, and n-
Propyl group, i-propyl group, n-butyl group, sec-
There are a butyl group and a tert-butyl group.

Specific examples of the organosilane represented by the general formula (III-A) are as follows: methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n
-Propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane Ethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane,
γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyl Triethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethyltriethoxysilane, i-butyltrimethoxysilane, i-butyltriethoxysilane and the like, particularly methyltrimethoxysilane and methyl Triethoxysilane is preferred.

Specific examples of the organosilane (alkyl silicate) represented by the general formula (III-B) include tetramethyl silicate, tetraethyl silicate, tetra-n-propyl silicate, tetra-i-propyl silicate and tetra-silicate. n-butyl silicate, tetra-i-
Butyl silicate, tetra-sec-butyl silicate, and the like. Specific examples of the organosilane (IV) include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-i-propyldimethoxysilane,
Examples include di-i-propyldiethoxysilane, di-i-propyldimethoxysilane, di-i-propyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like, with dimethyldimethoxysilane and diethyldiethoxysilane being particularly preferred. In the present invention, these hydrolyzable silicon compounds can be used alone or in combination of two or more.

When these organosilanes of the general formulas (III-A), (III-B) and (IV) are used in combination, the mixing ratio (III-A) to (III-B) in terms of organosilane ( Weight ratio)
00: 0 to 30 (that is, (III-B) may not be contained in some cases), and the mixing ratio (weight) of (IV) to the total amount of (III-A) and (III-B) in terms of organosilane. Ratio) is 100: 5-1.
It is preferably 50, especially 100: 10 to 120.
When the mixing ratio of the organosilane of the general formula (IV) is larger than the above range, the formed coating film is liable to crack, and conversely, when smaller than the above range, the curability decreases,
And the hardness of the coating film tends to decrease.

In the present invention, a hydrolyzate of the organosilane or a partial condensate thereof is used, and water is added to perform the hydrolysis and the partial condensation. The amount of water to be added is generally 0.1 to 1.0 mol, especially 0.15 to 0 mol, per equivalent of the alkoxy group of the organosilane of the general formulas (III-A), (III-B) and (IV). It is preferable to use 0.7 mol. If the number of moles of water is smaller than the above range, storage stability tends to be deteriorated, and if the number of moles of water is larger than the above range, curing and drying tends to be slow. Further, a production accelerator may be used to produce such a condensate of organosilane.

Such an accelerator is represented by the general formula (V):
A compound represented by M (OR) _x , a mineral acid, or the like can be used. In the general formula (V), M is Ti, Al,
A metal such as B and Zr, R is an alkyl group having 2 to 5 carbon atoms, and x is an integer of 2 to 4.

Specific examples of the general formula (V) include tetra-i-propoxytitanium, tetra-n-butoxytitanium, tri-i-propoxyaluminum, and mono-sec.
-Butoxy-di-i-propoxyaluminum, diethoxyboron, di-n-propoxyboron, tetra-n-
Butoxyzirconium and the like, and mineral acids such as hydrochloric acid and sulfuric acid. The addition amount is preferably in the range of 0.05 to 2.0 parts by weight based on 100 parts by weight of the organosilane. The solvent-soluble fluororesin used in the present invention includes a fluoroolefin and a hydroxyl group or a glycidyl group. Copolymers containing vinyl ether as the main component, copolymers containing fluoroolefin and vinyl ester as the main component, and those having a carboxyl group in a part of these copolymers. Specific examples of the resin include a copolymer containing fluoroolefin, cyclohexyl vinyl ether, alkyl vinyl ether and hydroxyalkyl vinyl ether as essential components; a copolymer containing fluoroolefin, cyclohexyl vinyl ether and glycidyl vinyl ether as essential components; Copolymer obtained by reacting a dibasic acid anhydride with a copolymer of phenyl ether and hydroxyvinyl ether and partially carboxylated; at least one perhaloolefin selected from tetrafluoroethylene and chlorotrifluoroethylene; A hydroxyl group-containing copolymer obtained by hydrolyzing a copolymer of vinylidene, vinyl ester and another monomer; at least one perhaloolefin selected from tetrafluoroethylene and chlorotrifluoroethylene, α-olefin, hydroxyalkyl A copolymer comprising vinyl ether and another comonomer; a copolymer comprising one or more of chlorotrifluoroethylene, tetrafluoropropyl vinyl ether and a vinyl ether having a hydroxyl group, a glycidyl group or an amino group as a functional group; Difluo Copolymers of ethylene and a monomer having a functional group such as a hydroxyl group, a glycidyl group or a carboxyl group and a copolymer of tetrafluoroethylene or chlorotrifluoroethylene, and the like. Examples of such commercially available products are Lumiflon 200, Lumiflon 400, and Lumiflon 500. , Lumiflon 554 and the like (these are trade names of Asahi Glass Co., Ltd.) and combinations thereof.

The solvent-soluble resin of the present invention can be used alone or in a low-polarity organic solvent such as xylene or toluene. However, if necessary, a mixture of other organic solvents may be used. It is possible. Other organic solvents include cyclic ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbons such as benzene, toluene and xylene; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. Nitrogen-containing solvents such as dimethylformamide, dimethylacetamide and pyridine; halogen-containing solvents such as 1,1,1-trichloroethane and trichloroethylene.

The solvent-soluble fluororesin of the present invention can be produced by solution polymerization in the presence of a usual radical initiator.

The titanium oxide having photocatalytic activity used in the present invention is a TiO ₂ sol applied to a substrate material to form a thin film, and an aqueous solution of a metal salt having a catalytic function or a suspension of fine metal powder is formed on the thin film. Is applied or impregnated, and then at a temperature below the phase transition point to rutile-type TiO ₂ at 800
The metal is immobilized on an anatase TiO ₂ thin film by heat treatment at a temperature of not more than ℃.

The above-mentioned TiO ₂ sol means that anatase-type TiO ₂ having an average particle size of about 0.01 to 0.05 μm is contained in an aqueous solution of an acid such as nitric acid or hydrochloric acid or a basic aqueous solution such as ammonia in a sol state by several%. ~ Tens of percent are present. Examples of metals having a catalytic function include Cu, Ag, and F.
e, Pd, Pt, etc., and the salt may be a seed salt, a sulfate, an acetate, or the like.

The polishing of the coating film surface in the coating film forming method of the present invention includes polishing with abrasive paper, mechanical polishing with various sanders such as a level sander, a wide belt sander and the like.

The coating composition of the present invention comprises the component (A)
It is composed of the component (B) and is blended so that the PWC is 45 to 85, preferably 50 to 80.

Here, the PWC is Pigment Wen.
It is light concentration (pigment weight concentration) and is calculated by the following formula.

[0030]

When the PWC is less than 45, the photocatalytic effect is not sufficiently exhibited. Conversely, if it exceeds 85, the film-forming properties decrease,
Undesirably, cracks and peeling occur.

It is possible to replace 10 to 50% by weight of the photocatalytically active titanium oxide of the present invention with at least one selected from the group consisting of activated carbon, silica gel, zeolite and calcium phosphate. Examples of the calcium phosphate include α-tricalcium phosphate, β-tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, and hydroxyapatite, with hydroxyapatite being particularly preferred.

If the replacement ratio is less than 10% by weight, no replacement effect is observed. Conversely, if it exceeds 50% by weight, the photocatalytic effect will be reduced, which is not preferable.

The coating composition of the present invention can be used as a coating by blending various pigments, organic solvents or additives as necessary with the coating composition described above.

As the pigment, pigments that are usually used for paints can be used as they are. Specifically, titanium oxide, zinc oxide, iron oxide, colored inorganic pigments such as graphite, phthalocyanine blue, colored organic pigments such as benzidine yellow, quartz powder, alumina oxide, extender pigments such as precipitated barium sulfate, stainless powder, Representative examples include metal powders such as zinc powder, aluminum powder, bronze powder, and mica powder.

Examples of the organic solvent include hydrocarbon solvents such as toluene and xylene; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone; Representative examples include alcohol solvents such as butanol.

Examples of the additives include additives known as ordinary paint additives such as a surface conditioner, a dispersant, an ultraviolet absorber, a thickener, and a reaction control catalyst.

The coating material thus obtained is applicable not only to various metal materials such as steel plate, stainless steel plate and aluminum plate, but also to coating of inorganic materials such as mortar, concrete and glass, plastic and wood.

As the coating method, conventionally used methods such as air spray, airless spray, electrostatic spray, shower coating, dip coating, brush coating, and roll coating can be employed as they are.

[0040]

The method for forming a coating film of the present invention has a deodorizing function,
It has both antibacterial and antifouling functions, as well as an air purification function.

Now, the present invention will be described in further detail with reference to Examples.

[0042]

EXAMPLES In the examples, "parts" and "%" are shown on a weight basis. <Preparation of Hydrolysis Condensate Solution of Organoalkoxysilane> 40 parts of methyltriethoxysilicate and 54 parts of isopropyl alcohol were stirred and mixed at 40 ° C., and then 0.3 parts of 0.1N hydrochloric acid and 5.7 parts of water were added thereto. Was added dropwise over 90 minutes. After the dropwise addition, the mixture was further stirred at 40 ° C. for 4 hours, and hydrolyzed condensate solution of methyltriethoxysilicate having a nonvolatile content of 40% [hereinafter referred to as hydrolyzed condensate A-1]
That] was obtained. The polystyrene equivalent weight average molecular weight of the condensate was 10,000.

<Preparation of Tetraalkoxysilicate Hydrolysis Condensate Solution> Tetraethoxysilicate [“Ethylsilicate 40” (trade name, manufactured by Nippon Colcoat)] 3
5 parts and 61 parts of isopropyl alcohol were stirred and mixed at 40 ° C., and then a mixture of 1 part of 1N hydrochloric acid and 3 parts of water was added dropwise over 90 minutes. After the dropwise addition, the mixture was further stirred at 40 ° C. for 4 hours, and a solution of a hydrolytic condensate of tetraethoxysilicate having a nonvolatile content of 35% [hereinafter referred to as a hydrolytic condensate A-2]
That] was obtained. The polystyrene equivalent weight average molecular weight of the condensate was 13,000.

<Preparation of Silyl Group-Containing Vinyl Resin Solution>
After adding and mixing 45 parts of xylene and 40 parts of isobutanol, the mixture was heated to 85 ° C. with stirring. Next, a mixed solution of 50 parts of isobutyl methacrylate, 35 parts of 2-ethylhexyl methacrylate, 15 parts of γ-methacryloxypropylmethoxysilane, and 1.5 parts of azobisisovaleronitrile was added dropwise at 85 ° C. over 3 hours. The temperature was raised to ° C. and maintained for 2 hours to terminate the reaction, thereby obtaining a silyl group-containing vinyl resin solution (hereinafter referred to as vinyl resin B) having a nonvolatile content of 55%. The vinyl resin has a weight average molecular weight of 14,000, and an average of about 7 per polymer molecule.
Has two silyl groups.

<Preparation of paint> The components shown in Table 1 were mixed,
A paint was prepared with a glass shaker using a glass shaker as a dispersion medium.

<Undercoat> Methyl methacrylate / butyl acrylate / 2-hydroxymethyl acrylate =
70/20/10 acrylic copolymer: 10 parts,
Hexamethylene diisocyanate trimethylolpropane adduct: 4 parts, tolylene diisocyanate trimer: 3 parts, titanium white: 15 parts, kaolin: 8 parts, mica: 8 parts, barium sulfate: 4 parts, butyl acetate: 20 parts and xylene: A composition consisting of 28 parts.

Examples 1 to 18 and Comparative Examples 1 to 9 A slate plate (50 × 10 mm, thickness 5 mm) was coated with an undercoat and the curing accelerator (dibutyltin laurate) was added to the coatings shown in Tables 1 to 3. Rate) is added to 100 parts of varnish, and dried at 100 ° C. for 10 minutes to form a coating film having a dry film thickness of about 30 μm. Water-resistant abrasive paper (type DCCS, particle size Polishing was performed using CC-240-CW (manufactured by Sankyo Rikagaku Co., Ltd.), and various tests were performed. The results are shown in Tables 4 to 6. (However, Comparative Examples 2 to 5, 7, and 8 are not polished)

<Acetaldehyde reduction rate> In an atmosphere having an acetaldehyde concentration of 1000 ppm, a sample of 5 cm is irradiated with ultraviolet light at an intensity of 4.0 mW / cm ² using a black light. The gas concentration in the atmosphere is measured at intervals of 15 minutes to determine the reduction rate of acetaldehyde.

<Antibacterial test> Test piece (5 cm × 5 cm)
Was placed on a standard agar medium smeared with 0.3 ml of the bacterial solution prepared in advance, left at 35 ° C. for 24 hours, and the formation of an inhibition zone around the test piece was measured. Based on the JIS-L-1902 halo method, An antibacterial test was performed.

<Test for antifouling property>
One month later, the ΔE value was measured to evaluate the decomposability of the tobacco tar.

As is clear from Tables 4 and 5, Examples 1 to 18 in which the coating film forming method of the present invention was performed had excellent coating film performance.

On the other hand, as is clear from Table 6, PWC was 4
Comparative Examples 1, 5, and 6 having less than 5 had a low reduction rate of acetaldehyde and had a high ΔE value, and Comparative Examples 2 and 7 having a PWC of more than 85 exhibited remarkable cracks and poor film formation. Comparative Examples 3 and 8, in which 50% by weight or more of the photocatalytic titanium oxide were replaced with activated carbon, had a low reduction rate of acetaldehyde and were poor, and Comparative Examples 4, 9 in which no photocatalytic titanium oxide was used showed the formation of a stop band. There was no defect.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

[Table 3]

[0056]

[Table 4]

[0057]

[Table 5]

[0058]

[Table 6]

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C09D 7/12 PSK C09D 7/12 PSK 127/12 PFG 127/12 PFG 143/04 PGL 143/04 PGL 157 / 00 PDM 157/00 PDM 183/04 PMT 183/04 PMT

Claims (2)

[Claims] 1. A group comprising (A) a hydrolyzable silyl group-containing vinyl copolymer, a hydrolyzate of an organosilane, and a partial condensate of a hydrolyzate of an organosilane. At least one hydrolyzable silicon compound or a solvent-soluble fluororesin selected from the group consisting of:
(B) a titanium oxide compound having photocatalytic activity
A method for forming a coating film having photochemical activity, comprising applying a coating composition having a WC of 45 to 85, forming a coating film, and polishing the surface to give an active surface to a surface layer. 2. Titanium oxide having photocatalytic activity of 10 to 10.
2. The method according to claim 1, wherein 50% by weight is replaced with at least one selected from the group consisting of activated carbon, silica gel, zeolite and calcium phosphate.