JP2000186250A - Inorganic coating composition, its preparation, and method for preventing staining of substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inorganic coating composition excellent in adhesiveness and durability by compounding a polyorganosiloxane having Si-bonded hydroxyl groups, a specific hydrolyzable organosilane compound or its hydrolyzate, a hydrophilic organic solvent, water, and a metal chelate or a metal alcoholate. SOLUTION: This composition contains (A) a polyorganosiloxane having repeating units represented by formula I and at least 1 wt.% Si-bonded hydroxyl groups, (B) a hydrolyzable organosilane compound represented by formula II or its hydrolyzate in an amount of 0.2-1.0 equivalent per equivalent of hydroxyl groups of ingredient A, (C) a hydrophilic organic solvent in such an amount that the concenration of ingredient A is 20-50 wt.%, (D) water in an amount of 0.2-2 equivalents per equivalent of alkoxy groups, and (E) a metal chelate in an amount of 0.01-10 pts.wt. per 100 pts.wt. sum of ingredients A and B, In the formulas, R is a monovalent hydrocarbon group; R' is a 1-8C hydrocarbon group; a is 0.8-1.8: b is 0-3: and X is a hydrolyzable group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is suitable for preventing contamination of the surface of a plastic molded product and the surface of a coating film of a painted product such as a ferrous or non-ferrous metal product such as an automobile, a vehicle, and a machine product, a wood product, and a plastic product. The present invention relates to a highly durable inorganic coating composition which is effective for preventing contamination of the surface of a substrate such as iron or non-ferrous metal, glass or ceramics, fiber and wood, a method for producing the same, and a method for preventing contamination of the substrate.

[0002]

2. Description of the Related Art When a titanium oxide having a photocatalytic action is irradiated with light having a wavelength having energy equal to or greater than its band gap, electrons are accumulated in a conduction band and holes are generated in a valence band. It is well known that organic substances are decomposed by a strong redox effect caused by electrons and holes generated by photoexcitation.

[0003] Attempts to utilize the photocatalytic action of this titanium oxide industrially have been widely carried out, and in particular, efforts are being made in antifouling, antibacterial, air purification and water purification. Many have been made.

[0004] As a method for immobilizing titanium oxide fine particles on a substrate, many methods have been reported for applying a coating composition mixed with a hardly decomposable binder. However, when the substrate is made of an organic resin such as a plastic molded article or a cured coating applied to the top coat of an automobile or a plastic molded article, thermal decomposition, 150 ° C. or less to avoid thermal deformation, preferably It is necessary to cure at a low temperature of 120 ° C. or less, and adhesion must also be considered.

[0005] When the substrate is plastic, it is necessary to devise a method in which the photocatalytic action of titanium oxide does not reach the substrate in order to maintain durability. In particular, when applied to a coating film for an automobile outer panel or a coating film of a plastic part such as a bumper that requires long-term durability, securing the durability as a coating system is the biggest issue. Therefore, as a binder for immobilizing titanium oxide, an organic resin which itself may be photodegraded is not suitable, and in many cases, a hardly decomposable inorganic binder is used.

Furthermore, there has been reported a method in which a film formed of a hardly decomposable coating material containing no titanium oxide is used as a barrier layer, and a film containing titanium oxide is formed thereon.

For example, a method in which a hydrolysis product of a hydrolyzable organometallic compound is used as a binder (JP-A-4-174679, JP-A-8-141503, JP-A-8-141503)
164334, JP-A-9-40872, JP-A-9-2
48467 and Japanese Patent No. 2756474), but most use an organic silane compound or an organic titanium compound as the organic metal compound. In particular, when the base material is a cured coating film made of acrylic melamine resin, polyester melamine resin, etc., a binder using a tetrafunctional organic silane compound is excellent in adhesion, solvent resistance, abrasion resistance, etc., but a thick film Occasionally it is easily broken, and in the case of a trifunctional or bifunctional organic silane compound, adhesion is poor.

When a film is formed by a sol-gel method using an organic silane compound, the film forming temperature is 15 ° C.
The film formed in a relatively low temperature range of 0 ° C. or less has a granular structure or a honeycomb shape, is extremely porous, and has a low continuous film-forming ability. It is a matter of course that titanium oxide having a photocatalytic action is directly immobilized on a plastic base material as a binder, but it is used on a plastic base material as a primer, on which titanium oxide containing a photocatalytic action is contained. When a film of an inorganic coating material is formed, it cannot be used because the photo-oxidation effect extends to the lower plastic substrate, and abnormalities such as discoloration and chalking occur after several months of outdoor exposure. That is, even when used as a primer, the barrier effect is poor.

In the case of organic titanium compounds, most are alkoxides. However, when the base material is a cured coating film made of acrylic melamine resin, polyester melamine resin, or the like, the formed film has poor adhesion and a low refractive index. The large size causes design problems such as excessive gloss and interference fringes.

There is also a method of forming a silicone resin film using a polyorganosiloxane excellent in forming a dense continuous film as a binder (see Japanese Patent Application Laid-Open No. Hei 7-171408). Is poor, and at a low temperature of 150 ° C. or less, the curing property is poor.
It is difficult to obtain a film excellent in solvent resistance, chemical resistance and the like.

As a coating composition, there has been proposed a composition containing a polyorganosiloxane and a hydrolyzable trifunctional organic silane compound (see JP-A-5-140507). Compound 3
When only a functional organic silane compound is used, the adhesiveness and curability are generally inferior, and among the trifunctional silane compounds, when a mercapto group-containing silane compound having a specifically good adhesiveness is used, the curability is inferior. The weather resistance becomes extremely poor.

As described above, when the base material is plastic, it is necessary to first select a binder when immobilizing titanium oxide having a photocatalytic action, and when long-term durability is required, it is important to select a primer. However, there are still problems in the prior art in terms of adhesion to a substrate, low-temperature curability, and long-term durability.

[0013]

SUMMARY OF THE INVENTION The present invention provides a hardly decomposable inorganic coating composition having excellent adhesion and durability, and a method for producing the same. A method for preventing contamination of a substrate, which comprises immobilizing titanium oxide having a photocatalytic action on a substrate, and in particular, in a plastic substrate, using the inorganic coating composition as a primer, and oxidizing contained in an upper layer. An object of the present invention is to provide a method of preventing contamination of a substrate, which is excellent in durability, which protects a plastic substrate from the photocatalytic action of titanium, and an article obtained by the method.

[0014]

According to the present invention, (A)
A repeating unit represented by the general formula _: RaSiO _{(4-a) / 2} (wherein, R represents a monovalent substituted or unsubstituted hydrocarbon group, and a is 0.8 to 1.8). A polyorganosiloxane having a structural unit and having at least 1% by weight of a hydroxyl group bonded to a silicon atom, (B) a general formula R ′ _b SiX _{(4-b) wherein} R ′ is the same or different monovalent Represents a substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, b represents an integer of 0 to 3, and X represents a hydrolyzable group.) Or a hydrolyzable organic silane compound represented by the formula: An inorganic coating composition comprising: (C) a hydrophilic organic solvent, (D) water, and (E) a metal chelate compound and / or a metal alcoholate.

According to the present invention, there is also provided a method for preventing contamination of a substrate, comprising disposing an inorganic coating layer comprising the above inorganic coating composition and a titanium oxide sol having a photocatalytic action on the surface of the substrate. Is done.

According to the present invention, a film of the inorganic coating composition is formed on the surface of a base material, and after using this as a primer, a coating layer containing titanium oxide having a photocatalytic action is provided. A method for preventing contamination of a substrate is provided.

According to the present invention, there is also provided an article which is excellent in adhesion and durability and has been subjected to a method capable of preventing contamination for a long period of time.

[0018]

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

The polyorganosiloxane of the component (A) is preferably resinous from the viewpoint of film-forming properties. R in the polyorganosiloxane is an organic group having 1 to 8 carbon atoms, such as methyl, ethyl or propyl. Preferred are an alkyl group such as phenyl; an aryl group such as phenyl; and a haloalkyl group such as chloromethyl. A in the polyorganosiloxane
Is from 0.8 to 1.8, and preferably from 1.0 to 1.6. If the ratio is less than 0.8, the storage stability is poor. If it exceeds 0.8, the curing rate is low, so that the resulting film has poor curability and does not exhibit sufficient solvent resistance.

The polyorganosiloxane of the component (A)
It has a number average molecular weight of 1,000 to 30,000 and has a hydroxyl group of 1% by weight or more, preferably 3% by weight or more. If it is less than 1% by weight, the curability becomes insufficient,
Solvent resistance cannot be obtained.

In the component (B), R ′ in the hydrolyzable organic silane compound represented by the general formula R ′ _b SiX _(4-b) is a substituted or unsubstituted monovalent monovalent having 1 to 8 carbon atoms. A hydrocarbon group, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group; an aryl group such as a phenyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group; Γ-chloropropyl group, 3,3,3-trifluoropropyl group, γ
-Methacryloxypropyl group, γ-glycidoxypropyl group, mercaptopropyl group, 3,4-epoxycyclohexylmethyl group, γ-aminopropyl group and the like.

As the hydrolyzable group X, an alkoxy group,
Examples thereof include an acetoxy group, an oxime group, and an aminoxy group, and an alkoxy group is preferable in terms of availability.

Wherein b in the formula is an integer of 0 to 3,
Specific examples of bifunctional, trifunctional, and tetrafunctional alkoxysilanes include, when b = 0, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, and the like. b
= 1, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxy Silane, γ
-Glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltri Ethoxysilane, γ-aminopropyltrimethoxysilane,
γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane and the like can be mentioned. When b = 2, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, γ-
Glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-amino Propylmethyldiethoxysilane and the like can be mentioned.
When b = 3, trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane,
Dimethylisobutylmethoxysilane and the like can be exemplified.

Among the above alkoxysilanes, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, γ-glycidoxypropyl Trimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ
-Mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and the like are preferred. These alkoxysilanes can be used alone or in combination of two or more.

The ratio of the component (B) to the component (A) is such that the hydroxyl group in the polyorganosiloxane of the component (A) is 1
0.2 to 10 equivalents, preferably 0.5 to
It is 8.0 equivalents. If it is less than 0.2 equivalent, the low-temperature curability is poor, and the adhesion is also reduced. If it exceeds 10 equivalents, the film is liable to crack at the time of thick film, and the continuous film forming property is reduced.
The kind of the hydrophilic organic solvent of the component (C) is methanol, ethanol, isopropyl alcohol, n-butanol,
Alcohols such as isobutanol; ethylene glycol derivatives such as ethylene glycol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol tert-butyl ether, and ethylene glycol monoethyl ether; propylene glycol monomethyl ether and propylene glycol monomethyl ether Propylene glycol derivatives such as pionate; other diethylene glycol derivatives and diacetone alcohol; and one or more selected from these can be used. In combination with these hydrophilic organic solvents, ethyl acetate, butyl acetate, isobutyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene and the like can be used.

The amount of the component (C) used is such that the polyorganosiloxane as the component (A) has a solid content of 20 to 50% by weight,
Preferably, the amount is 30 to 40% by weight. If it exceeds 50% by weight, the storage stability of the solution is poor, and if it is less than 20% by weight, the degree of freedom of the composition of the diluting solvent at the time of coating is narrowed, which may hinder the coating.

Next, regarding the water as the component (D), (B)
0.2 to 2 equivalents, preferably 0.5 to 1.5 equivalents, per equivalent of alkoxyl group contained in the organic silane compound of the component.
Used in equivalent proportions. If it exceeds 2 equivalents, the storage stability of the reaction composition deteriorates, and if it is less than 0.2 equivalent,
Hydrolysis of the organic silane compound becomes insufficient and sufficient curability cannot be obtained.

Next, as the metal chelate compound of the component (E), aluminum acetylacetonate, aluminum bisethylacetoacetate monoacetylacetonate, aluminum-di-n-butoxide-monoethylacetoacetate, aluminum-di-isopropoxide Aluminum chelate compounds such as monomethyl acetoacetate; titanium chelate compounds such as titanium acetylacetonate and titanium tetraacetylacetonate;
In addition, chromium acetylacetonate, cobalt acetylacetonate, tin acetylacetonate, iron (II
I) acetylacetonate, manganese acetylacetonate, nickel acetylacetonate and the like. Examples of metal alcoholates include tetraisopropyl titanate, tetra-n-butyl titanate, tetra-2-ethylhexyl titanate, tetraethoxyzirconium, tetrapropoxyzirconium, tetraisopropoxyzirconium, tetrabutoxyzirconium, triethoxyaluminum, and triisopropoxy. Aluminum and the like can be mentioned. These metal chelate compounds and metal alcoholates can be used alone or in combination of two or more.

Component (E) is used in an amount of 0.01 to 1 based on 100 parts by weight of the total of components (A) and (B).
0 parts by weight, preferably 0.1 to 5 parts by weight. 0.0
If the amount is less than 1 part by weight, the curability is reduced, and the solvent resistance cannot be obtained. If the amount exceeds 10 parts by weight, storage stability and weather resistance may decrease, and coloring such as yellowing of the film may occur.

In order to obtain the inorganic coating composition of the present invention, it is necessary to hydrolyze the organosilane compound as the component (B). In this case, hydrochloric acid is used to promote the hydrolysis reaction. Inorganic acids and organic acids such as acetic acid, chloroacetic acid, citric acid, formic acid, propionic acid, oxalic acid and maleic acid can be used as the catalyst. The hydrolysis reaction temperature is room temperature, preferably 40 ° C. or higher, more preferably 50 to 80 ° C., and the reaction time is 0.5 to 3 hours, preferably 1 to 2 hours.

The component (E) can be blended together with the components (A) to (D) and added with the above-mentioned hydrolysis catalyst, if necessary, and preferably mixed in advance. The components (A) to (D) are mixed and heat-treated at 40 ° C. or higher, and after hydrolyzing the organosilane compound of the component (B), the component (E) is added and the mixture is further heated at 40 ° C. or higher. By performing the treatment, the self-condensation of the component (A) or the component (B) is suppressed, the formation of a microgel which causes the occurrence of lumps in the film is suppressed, and the hydroxyl group-containing polyorganosiloxane of the component (A) and (B) A) A co-condensation product with the component organosilane compound can be obtained.

The copolycondensation of the hydroxyl group-containing polyorganosiloxane (A) and the organic silane compound (B) results in a dense polyorganosiloxane having a high continuous film-forming property. And low-temperature curability.

The thus obtained inorganic coating composition of the present invention hardly causes cracks and forms a cured film excellent in curability, adhesion and durability at a relatively low temperature of 150 ° C. or less, Hardly affected by humidity during curing.

In order to prevent contamination of the substrate surface using the inorganic coating composition, it is effective to utilize the organic substance resolution of titanium oxide fine particles having a photocatalytic action. In this case, (1) a mixture of titanium oxide fine particles mixed with the inorganic coating composition of the present invention is directly applied, or (2) a cured film of the inorganic coating composition is used as a primer, particularly when the substrate is plastic. And applying thereon a mixture of an inorganic coating composition and titanium oxide fine particles as an overcoat, or (3)
Using the cured film of the inorganic coating composition as a primer,
Various contamination prevention methods are possible, such as forming a coating layer formed by mixing titanium oxide fine particles with a condensate of the hydrolyzable organic silane compound (B) as a binder.

Here, the rutile type titanium oxide sol according to claim 4, which is a feature of the present invention, will be described in detail.

When utilizing the photocatalytic action of titanium oxide,
Normally, anatase type titanium oxide is used, but in the case of anatase type, photocatalytic action is strong, but in the case of a plastic substrate, durability is a problem, and practical use in fields requiring long-term durability is extremely difficult. It is. In order to ensure long-term durability, along with the choice of inorganic binder,
The type of titanium oxide is important.

The inorganic coating composition according to the present invention provides a primer composition as a binder for immobilizing titanium oxide fine particles or as a barrier layer against photocatalysis, and the titanium oxide according to claim 4 is a rutile type titanium oxide. It has a crystalline form and is much more durable than anatase-type titanium oxide. Moreover, although the photocatalysis is slightly lower than that of the anatase type,
It has sufficient organic substance resolution to prevent contamination of the substrate surface, and is used in the form of a sol of a composite colloid with tin oxide.

The production method is to add hydrogen peroxide to a gel or sol of hydrated titanium oxide to dissolve the hydrated titanium oxide,
Next, the obtained solution was mixed with titanium oxide / tin oxide =
It is obtained by heating in the presence of a tin compound in an amount of 1.5 to 14. Here, the gel of hydrated titanium oxide can be obtained by adding an alkali to an aqueous solution of a titanium salt such as titanium chloride or titanium sulfate, neutralizing the resultant, and washing the sol. It can be obtained by a conventionally known method such as removing anions through an ion exchange resin or hydrolyzing a titanium alkoxide.

As the tin compound, tin salts such as tin chloride and tin nitrate, stannates such as potassium stannate, and other tin oxides and hydroxides are used. The addition amount of the tin compound is in the range of titanium oxide / tin oxide = 1.5 to 14, preferably 2 to 10. If it is less than 1.5, the crystal structure is deviated from the rutile structure to become anatase-type titanium oxide, and if it exceeds 14, the crystal structure is different from the rutile-type structure. The solution to which the tin compound has been added is hydrolyzed by heating to a temperature of 60 ° C. or higher, preferably 80 ° C. or higher, to obtain a desired colloidal sol of rutile-type titanium oxide and tin oxide. At this time, the stability of the resulting rutile-type titanium oxide sol can be increased by heating and hydrolyzing the mixed aqueous solution of the titanic acid solution and the tin compound in the presence of a silicon compound. As the silicon compound, an alkali metal silicate, a silicate solution obtained by removing alkali metal from an aqueous solution of an alkali metal silicate, silica gel, silica sol, or the like is used. The addition amount of the silicon compound is 5 to 20 parts by weight based on 100 parts by weight of the total of titanium oxide and tin oxide.

The sol thus obtained has an average particle size of the rutile-type titanium oxide / tin oxide composite colloid or the rutile-type titanium oxide / tin oxide / silicon oxide composite colloid in the range of 5 to 100 nm. , Very uniform particles are dispersed. The composite colloid also has a structure in which the surface of the composite colloid is coated with silica, silica-alumina, silica-zirconia, or the like, and a titanium oxide sol having extremely excellent durability can be obtained.

In the coating agent containing titanium oxide, the mixing ratio of the coating film forming component and titanium oxide is 20 to 30 as solids per 100 parts by weight of the coating film forming component.
0 parts by weight, preferably 50 to 200 parts by weight. 20
When the amount is less than part by weight, the photocatalytic action of titanium oxide becomes small, and the practicality is poor in terms of the pollution prevention function. 300
When the amount is more than the weight part, the adhesive strength with the base material is reduced, the abrasion resistance is reduced, and it is easy to fall off.

Next, in the method for preventing contamination of a substrate according to the present invention, a cured film of the inorganic coating composition according to the first aspect is used as a primer, and the component of the third aspect is further provided thereon. Among them, a method of providing a coating layer composed of components (B) to (F) is used. In this case, a binder composition composed of an organic silane compound can be obtained by a conventionally known method. That is, (B) according to claim 1
A hydrophilic organic solvent of the component (C) and water of the component (D) are added to the components to hydrolyze the organic silane compound. At this time,
Inorganic or organic acids such as hydrochloric acid, acetic acid, chloroacetic acid, citric acid, formic acid, propionic acid, oxalic acid and maleic acid can be used as catalysts. This hydrolysis reaction
It may be performed at normal temperature or by heating to 40 ° C. or higher.
After the hydrolysis, after aging for 12 hours or more at room temperature, a binder composition can be obtained by adding the metal chelate compound of the component (E). A film of the condensation product can be obtained.

When a condensation product consisting of only an organic silane compound is used as a binder for titanium oxide, it is important that the thickness of the film be 1.0 μm or less in order to prevent the occurrence of cracks. When a tetrafunctional silane such as tetraethoxysilane is used in an equivalent number exceeding 70% of the equivalent number of the organic silane compound, for example, care must be taken since cracks are easily generated in the film.

In order to obtain a cured film at a lower temperature and in a shorter time, the coating film forming composition used in the present invention may contain, in addition to a metal chelate compound and a metal alkoxide, amines, organic metal salts, and the like, if necessary. Among curing catalysts such as organic acids or anhydrides thereof, Lewis acids and metal halide compounds,
Only those which do not impair the storage stability of the film-forming composition may be used in combination with the film-forming composition. Furthermore, coloring pigments, extender pigments, glitters, dyes, etc. can be blended according to the necessity of design, and thickeners, defoaming agents,
A leveling agent, an anti-bake agent and the like can also be compounded. For the purpose of improving the film performance, an ultraviolet absorber, a light stabilizer and the like, as well as a storage stabilizer and a pH adjuster can be compounded.

The inorganic coating composition of the present invention,
The coating composition containing titanium oxide can be applied by a usual application method, and various application methods such as brush coating, spray coating, dip coating, flow coating, and roll coating can be employed. Further, it can be diluted with an organic solvent as required, and the dilution ratio is not particularly limited.

The thickness of the film after drying is not particularly limited.
For example, the thickness may be 0.01 to 30 μm. However, in order to have good durability and abrasion resistance of the film, no design defects such as gloss and interference fringes, and no cracks, preferably 0 to 30 μm. It is preferable that the thickness be 0.05 to 10 μm.

The drying temperature after coating is 50 to 15
The temperature is 0 ° C., but preferably 80 to 120 ° C., and there is no thermal deformation of the plastic, and good curability can be obtained in a short time.

As the substrate, plastic, ferrous or non-ferrous metal, glass or ceramics, fiber, wood, etc. are used. Particularly, as the plastic substrate, polycarbonate, polymethyl methacrylate and its copolymer, polystyrene, polychlorinated Vinyl, ABS resin,
Various plastic moldings made of polyurethane, polyolefin resin, cellulose acetate, polyethylene terephthalate, unsaturated polyester, etc., and ferrous or non-ferrous metal products such as automobiles, vehicles and machine products, wood products and plastic moldings, etc. A cured coating film formed and having a glass transition temperature of 50 to 130 ° C. is suitable.

[0049]

Industrial Applicability The inorganic coating composition of the present invention, the method for producing the same, and the method for preventing contamination of a substrate are based on the photocatalytic action of a binder or titanium oxide for immobilizing photocatalytic titanium oxide particles on a substrate. It is intended to provide a primer composition for protecting a material, a method for immobilization, and an immobilized substrate.

The method for preventing contamination according to the present invention comprises the steps of removing harmful substances by utilizing the organic substance decomposition action of photocatalytic titanium oxide;
It is also useful as a highly safe method for various environmental measures other than pollution prevention, such as antibacterial / antifungal and odor removal.

[0051]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. “Parts” and “%” in the description are based on weight.

Production Example of Inorganic Coating Composition (A) Production Example 1 2 equipped with a reflux condenser, stirrer, thermometer and dropping funnel
In a liter four-necked flask, add isobutanol 440
Parts, isopropyl alcohol 230 parts, dimethyl-type polyorganosiloxane having a hydroxyl group content of 6% and a molecular weight of 3,200, 283 parts, tetraethoxysilane 42
And 149 parts of γ-glycidoxypropylmethyldiethoxysilane were added thereto, and 36 parts of a 0.01 N hydrochloric acid aqueous solution was added dropwise with stirring. The mixture was heated at 60 ° C. for 1 hour while maintaining the liquid temperature, and then heated. 4 parts of aluminum acetylacetonate was added, and the mixture was further heated at 60 ° C. for 1 hour. The solid content concentration of the obtained inorganic coating composition (A-1) was 32.
8% and the viscosity was 102 cps. The solid content was calculated by heating the sample at 120 ° C. for 30 minutes and measuring the remaining amount. The viscosity was measured at 60 rpm with a B-type viscometer.
The value at the time of m is shown.

Production Example 2 A 2 equipped with a reflux condenser, a stirrer, a thermometer and a dropping funnel was prepared.
In a liter four-necked flask, add isobutanol 420
Parts, 250 parts of isopropyl alcohol, 340 parts of dimethyl-type polyorganosiloxane having a hydroxyl group content of 5% and a molecular weight of 3,700, and tetraethoxysilane 42
After adding 88 parts of γ-glycidoxypropylmethyldimethoxysilane and 24 parts of methyltriethoxysilane and dripping 36 parts of a 0.01 N hydrochloric acid aqueous solution with stirring,
The solution was heated at 40 ° C. for 1 hour while maintaining the solution temperature, and then 4 parts of aluminum acetylacetonate was added thereto, followed by further addition of 60 parts.
Heated at 0 ° C. for 1 hour. The solid content concentration of the obtained inorganic coating composition (A-2) was 34.2%, and the viscosity was 1
It was 40 cps.

Production Example 3 (for comparison, polyorganosiloxa)
2) equipped with a reflux condenser, stirrer, thermometer and dropping funnel
In a liter four-necked flask, add 284 isobutanol.
Parts, 142 parts of isopropyl alcohol and 283 parts of a dimethyl-type polyorganosiloxane having a hydroxyl group content of 6% and a molecular weight of 3,200, and 1.4 parts of aluminum acetylacetonate under stirring. Heat for 1 hour. The obtained inorganic coating composition (A
-3) The solid concentration is 37.3% and the viscosity is 220.
cps.

Production Example 4 (Comparative, only organic silane compound)
Hydrolysis / condensation product) 2 equipped with a reflux condenser, stirrer, thermometer and dropping funnel
After adding 460 parts of isopropyl alcohol, 186 parts of tetraethoxysilane and 192 parts of γ-glycidoxypropyltrimethoxysilane to a four-necked flask of a little and adding 108 parts of 0.01N hydrochloric acid aqueous solution with stirring, The resulting inorganic coating composition (A-4) was heated for 1 hour while maintaining the liquid temperature at 0 ° C., and then 7.5 parts of aluminum acetylacetonate was added, followed by heating at 60 ° C. for 1 hour. The partial concentration is 29.2%,
The viscosity was 75 cps.

Examples 1-2 and Comparative Examples 1-2 Each of the inorganic coating compositions (A-1) to (A-4) obtained in the above Production Examples 1-4 was diluted with isobutanol to obtain a solid. Coating solutions having a concentration of 20%, 10% and 1% were obtained. Acrylic melamine paint (manufactured by Kansai Paint Co., Ltd., trade name "Magiclon", paint color: black) is applied to a cold-rolled steel sheet having a thickness of 0.7 mm and subjected to chemical conversion treatment, cationic electrodeposition, and intermediate coating. The coating was baked and dried at 140 ° C. for 30 minutes to obtain a plastic substrate, on which the coating solution was spray-coated and dried at 120 ° C. for 25 minutes. Table 1 shows the performance test results.

The test method of the performance test in Table 1 is as follows.

Coating surface condition: The obtained coating was evaluated by visual observation according to the following criteria.

：: glossy, no abnormality in appearance observed

X: Abnormalities such as glossing and cracks are observed.

Adhesion: Evaluated according to the following criteria by a 1 mm square gobang test (cellotape peeling).

○: No peeling at all.

Δ: Peeling was within 1/5 in 100 squares.

×: Peeling of 1/3 or more in 100 squares.

Solvent resistance: Gauze was impregnated with isopropanol and wiped with a finger for 20 reciprocations, and the condition of the coated surface was examined according to the following criteria.

：: There is no scratch or other abnormality.

Δ: Scratches and gloss are observed.

×: The coating melts and falls off.

Hardness: Measured with a microhardness tester (Microhardness tester FM, manufactured by Featurtec). The higher the value, the higher the hardness.

[0070]

[Table 1]

[0071]Production example of rutile-type titanium oxide sol (B) Production Example 5 Dilute the titania sulfate solution with pure water to obtain 1
% Aqueous solution was obtained. Keep this aqueous solution at 10 ° C
Add 15% aqueous ammonia with stirring to adjust the pH to 9.5.
Was obtained as a white suspension. The suspension is filtered and washed to obtain a solid content.
Of hydrated titanium oxide gel having a pH of 10.2%
Was. To 530 parts of this cake, 462 parts of 35% hydrogen peroxide water
And 358 parts of pure water, and oxidize by heating at 85 ° C. for 3 hours.
1,350 parts of a 4% titanic acid aqueous solution was obtained as titanium.
Was. Next, the aqueous potassium stannate solution is removed with a cation exchange resin.
375 of 1.6% aqueous stannic acid solution as alkaline tin oxide
Parts, 1,350 parts of the above titanic acid aqueous solution and 3,61 parts of pure water
0 parts were mixed. Furthermore, the average particle size is 7 nm,
57 parts of silica sol having a lica concentration of 15% was mixed.
Thereafter, the mixture was heated at 150 ° C. for 18 hours to obtain a colloid liquid. This
The colloid solution obtained in
After obtaining a titanium oxide sol having a concentration of 20%, ethanol was added.
In addition, extraordinary membrane ("SIP-1013", Asahi Kasei
(Manufactured by Kogyo Co., Ltd., trade name).
% Ethanol as a dispersion medium (B-
1) was obtained. X-ray diffractometer of dispersed particles of this sol
Crystal structure is rutile type, specific surface area is 180m^Two/ G
Met. In addition, the X-ray diffraction was performed by using the sol dispersed particles at 110 ° C.
After drying with Rigaku LAD-IIC type, Cu tube
The measurement was performed under the conditions of a sphere, 35 kV, and 12.5 mA. Also,
Specific surface area, dried sol dispersed particles at 100 ℃ for 10 hours
After that, the specific surface area measuring device (“Multi Soap 12”,
Nitrogen adsorption method (B by Yuasa Ionics, trade name)
ET method). Production example of titanium oxide-containing coating liquid (C) Production Example 6 Made to the inorganic coating composition (A-11) obtained in Production Example 1.
Mix rutile-type titanium oxide sol (B-1) obtained in Preparation Example 5
did. The mixing ratio is the solid content ratio of the inorganic coating composition.
The titanium oxide sol was 100 parts with respect to 100 parts.
The mixture was further diluted with isobutanol to obtain a solid concentrate.
1% titanium oxide-containing coating liquid (C-1)
Was.

Production Examples 7 to 13 In the same manner as in Production Example 6, the types of the inorganic coating composition and the titanium oxide sol were changed, and the oxidization at a solid content of 1% was performed at the compounding amount (solid content) shown in Table 2. The titanium-containing coating liquids (C-2) to (C-8) were obtained.

The titanium oxide sol "ST-K03" of Production Examples 12 and 13 in Table 2 is a trade name of an anatase type titanium oxide sol (titanium oxide concentration: 5%) manufactured by Ishihara Sangyo Co., Ltd.

[0074]

[Table 2]

Working Examples and Comparative Examples of Base Material Example 3 The coated plates (overcoat: acrylic melamine paint, paint color: black) used in Examples 1 and 2 and Comparative Examples 1 and 2 have different paint colors. Two types of white coated plates were used as a plastic substrate, and the titanium oxide-containing coating liquid (C-1) obtained in Production Example 6 was spray-coated thereon, and the coating was performed at 120 ° C for 2 hours.
Dried for 5 minutes. The film thickness was 0.08 to 1 μm. The black paint was used for the finish appearance test in particular, and the white paint was used for the color difference test after exposure and the degree of contamination.

Example 4 The inorganic coating composition (A-1) obtained in Production Example 1 was diluted to a solid content concentration of 7% with the same base material having two kinds of coating colors, black and white, as in Example 3. Spray paint at 120 ℃ 25
After drying for a minute, a primer was obtained.
The titanium oxide-containing coating liquid (C-1) obtained in the above was spray-coated and dried at 120 ° C. for 25 minutes. The thickness of the primer was 0.6 to 1 μm, and the thickness of the titanium oxide-containing film was 0.08 to 0.11 μm.

Examples 5 to 8 and Comparative Examples 3 to 9 Primers of the type shown in Table 3 below and a coating solution containing titanium oxide were used for the base material having the same two coating colors of black and white as in Example 3. Then, a film was formed in the same manner as in Examples 3 and 4. Examples 5 to 8 and Comparative Examples 3 to 8
Table 3 summarizes the performance test results.

Examples 9 to 12 As a substrate, a 0.7 mm thick cold-rolled steel sheet was treated with zinc phosphate (trade name "PB-", manufactured by Nippon Parkerizing Co., Ltd.).
3020 "), and chromate-treated on a 0.3 mm thick aluminum plate (A-1050) (trade name" Alchrome 713 "manufactured by Nippon Parkerizing Co., Ltd.)
And a glass plate (manufactured by Nippon Test Panel Kogyo Co., Ltd., trade name "JISR3202" (float glass)) using a primer of the type shown in Table 3 below and a coating solution containing titanium oxide. A coating was formed in the same manner as in Examples 3 and 4. Table 3 summarizes the performance test results of Examples 9 to 12.

The primer (A-15) used in Comparative Example 8 in Table 3 is a commercially available acrylic silicone resin ("Glaska T8001", trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.).

The test method of the performance test in Table 3 is as follows.

Coating state: The obtained coating was evaluated by visual observation according to the following criteria.

：: There is gloss, and no abnormality in appearance is observed.

X: Abnormalities such as glossing and cracks are observed.

Adhesion: Evaluated according to the following criteria by a 1 mm square Gobang test (cellotape peeling).

○: No peeling at all.

Δ: Peeling was within 1/5 in 100 squares.

×: In 100 squares, peeling was 1/3 or more.

Gloss: Specular gloss at an incident angle and a reflection angle of 60 degrees was measured with a gloss meter.

Pollution degree: The test plate (white paint) after one year of outdoor exposure in the central part of Tokyo, where urban pollution is severe, was not washed with water, and the degree of contamination was visually observed and compared with the initial plate according to the following criteria. evaluated.

：: Almost the same as before exposure and no contamination.

Δ: Black spots are slightly noticeable.

X: Black stains are conspicuous and contamination is severe.

Color difference ( ΔL value): The color difference between the test plate (white paint) and the initial plate of the non-washed portion after outdoor exposure for one year in central Tokyo, where urban pollution was severe, was calculated using the SM Color Computer SM.
△ L value (whiteness) was measured by “type-4” (manufactured by Suga Test Instruments Co., Ltd.). This is a numerical value of the degree of contamination, and the larger the negative value, the lower the whiteness and the higher the degree of contamination. The values of Examples 11 and 12 are as follows:
The measurement was made by attaching a blank sheet to the back surface.

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[Table 3]

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[Table 4]

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Katsumi Mitsuishi 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa F-term in Kansai Paint Co., Ltd. 4D075 CA13 CA32 CA34 DA06 DA23 DB01 DB13 DB14 DB31 EA06 EA41 EB43 EC02 EC08 4J038 DL011 DL012 DL031 DL032 HA156 HA216 JA16 JC38 KA04 KA06 MA13 NA05 PA07 PC02 PC06 PC08

Claims (11)

[Claims] (A) A compound represented by the general formula: R _a SiO _{(4-a) / 2} (wherein R represents a monovalent substituted or unsubstituted hydrocarbon group, and a is 0.8 to 1.8) (B) a polyorganosiloxane having a repeating unit represented by the following formula (1) and having at least 1% by weight of a hydroxyl group bonded to a silicon atom: (B) a general formula R ′ _b SiX _(4-b) Represents the same or different monovalent substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, b represents an integer of 0 to 3, and X represents a hydrolyzable group. An inorganic silane compound or a hydrolyzate thereof, (C) a hydrophilic organic solvent, (D) water, and (E) a metal chelate compound and / or a metal alcoholate. 2. After the components (A) to (D) described in claim 1 are mixed and heat-treated at 40 ° C. or more, the component (E) according to claim 1 is added, and further heat-treated at 40 ° C. or more. A method for producing an inorganic coating composition, comprising: 3. The inorganic coating composition according to claim 1, further comprising (F) a titanium oxide sol having a photocatalytic action. 4. Titanium oxide sol (F) having a photocatalytic action
Is added hydrogen peroxide to the hydrated titanium oxide gel or sol to dissolve the hydrated titanium oxide, and then the resulting solution is
Inorganic coating composition of claim 3 wherein the weight ratio is sol composite colloidal rutile type titanium oxide and tin oxide obtained by heating in the presence of an amount of tin compound TiO ₂ / SnO ₂ = 1.5~14 object. 5. A method for preventing contamination of a substrate, comprising forming a film of the inorganic coating composition according to claim 3 on the surface of the substrate. 6. A method according to claim 3, wherein a film of the inorganic coating composition according to claim 1 is formed on the surface of the substrate, and this is used as a primer, and then the coating layer according to claim 3 is provided. Pollution prevention method. 7. After forming a film of the inorganic coating composition according to claim 1 on the surface of a substrate and using this as a primer, it comprises the components (B) to (F) among the components according to claim 3. A method for preventing contamination of a substrate, comprising providing an inorganic coating layer. 8. The method according to claim 6, wherein the primer further contains a coloring material and / or a brilliant material. 9. A plastic molded article whose base material is made of polycarbonate, polymethyl methacrylate and its copolymer, polystyrene, polyvinyl chloride, ABS resin, polyurethane, polyolefin resin, cellulose acetate, polyethylene terephthalate, unsaturated polyester, etc. The method for preventing contamination of a substrate according to any one of claims 5 to 8, wherein 10. The base material is formed by painting iron or non-ferrous metal products such as automobiles, vehicles and machine products, wood products and plastic products, and has a glass transition temperature of 50 to 50.
The coating film according to any one of claims 5 to 8, which is a cured coating film at 130 ° C.
The method for preventing contamination of a base material according to the above item. 11. An article obtained by the method for preventing contamination of a substrate according to any one of claims 5 to 10.