JP2001347216A - Coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating method capable of drying at a room temperature or a relatively low temperature and forming an inorganic top coated film excellent in adherability, coating film hardness, coloring by pigments and retrained film thickness. SOLUTION: A method for coating an inorganic type top coating paint containing a following mixture of condensation reactants as resin components on an undercoated film after having formed the undercoated film from the undercoating paint selected from an epoxy resin type paint and an acrylic pilicon type paint on a material to be coated: the mixture of the condensation reactants comprising (A) 100 parts by weight of an alkylarylpolysiloxane having a weight average molecular weight of 500-6,000 and an alkoxy group content of 0-30 wt.%, (B) 0-30 parts by weight of an alkyltrialkoxysilane, (C) 0.1 200 parts by weight of a mono- and/or di-alkoxysilane and further (D) 0.1-200 parts by weight of an epoxy group containing silane based on the total weight of (A), (B) and (C) components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a coating method using an inorganic top coat.

[0002]

2. Description of the Related Art Inorganic paints have high hardness and are excellent in adhesion, water resistance, stain resistance, and weather resistance. Wood, cement, slate,
It is used as a coating agent for mortar and other inorganic ceramic substrates. Conventionally, these inorganic paints have had to cure a coating film by heat energy by heating.

[0003] Under such circumstances, there has been an increasing demand for inorganic coatings which can be cured at room temperature or at a relatively low temperature. Organosiloxane-type inorganic paints that cure at room temperature are disclosed in, for example, JP-A-6-240207 and JP-A-10-060377.

[0004] The organosiloxane type inorganic paint described in JP-A-6-240207 is composed of a silica-dispersed oligomer solution of an organosilane, a silanol group-containing polyorganosiloxane, and a curing catalyst. Therefore, there is a problem that it is difficult to secure a necessary film thickness.

The organosiloxane type inorganic paint described in JP-A-10-060377 comprises a silanol-containing polyorganosiloxane, a glycidoxypropyl group-containing silane, a silane having at least two hydrolyzable groups, and a curing catalyst. However, there is a problem that the pigment dispersion stability is poor and coloring is difficult.

Further, a coating film obtained from an inorganic coating material has a problem that adhesion to an alkali base material such as cement, mortar, slate or the like or an organic coating film is not sufficient.

An object of the present invention is to provide a coating method which can be dried at room temperature or at a relatively low temperature, and which can form an inorganic top coat having excellent adhesiveness, coating film hardness, colorability with a coloring pigment, film thickness retention and the like. It is to provide.

[0008]

Means for Solving the Problems The present inventors have conducted various studies in order to achieve the above object, and as a result, have found that a dried undercoat film of epoxy resin paint or acrylic silicone paint is coated on the substrate. A specific alkylarylalkoxypolysiloxane, an alkyltrialkoxysilane and / or a condensate thereof, a mono- and / or di-alkoxysilane, and an epoxy group-containing alkoxysilane as a resin component. The present inventors have found that the above objects can be achieved by applying an inorganic overcoating material, and have completed the present invention.

That is, according to the present invention, an undercoat selected from an epoxy resin-based paint and an acrylic silicone-based paint is applied on an object to be coated, dried to form an undercoat, and a) the following rational formula ^{_{R 1 a R 2 b (R}} 3 O) c SiO ( in _{4-abc) / 2} formula, R ¹ represents an alkyl group having 1 to 8 carbon atoms, R ² is an aryl group, R ³ is Represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, where a is 0.1 ≦ a ≦ 2.0, and b is 0.1 ≦ b
≦ 2.0, b / a is 0.2 ≦ b / a ≦ 2.0, c is 0.1 ≦ c ≦ 1.0, and (a + b + c) is 4
And the weight average molecular weight is in the range of 500 to 6,000, and the alkoxyl group content is in the range of 0 to 30% by weight based on the polysiloxane. and alkylaryl polysiloxane 100 parts by weight, (B) the following general formula R ⁴ Si (oR ⁵⁾ ₃ wherein, R ⁴ and R ⁵ are the same or different, represents an alkyl group having 1 to 8 carbon atoms, in illustrated condensates 0-200 parts by weight of alkyltrialkoxysilane and / or the alkyltrialkoxysilane and, (C) the following general formula R ⁶ _d Si (oR ⁷⁾ in _(4-d) formula is, R ⁶ are the same or Differently represents an alkyl group or aryl having 1 to 8 carbon atoms, R ⁷ is the same or different and represents an alkyl group having 1 to 8 carbon atoms, and d represents 2 or 3, mono- and / or Or di-alkoxy 0.1 to 200 parts by weight of silane, the alkylarylpolysiloxane (A), the alkyltrialkoxysilane and / or
Alternatively, based on a total of 100 parts by weight of the condensate (B) of the alkyltrialkoxysilane and the mono- and / or di-alkoxysilane (C), (D) the following general formula: R ⁸ R ⁹ _n Si (OR ¹⁰ ) In the formula _(3-n) , R ⁸ is a monovalent organic group containing an epoxy group, n R ⁹ are the same or different, and are an alkyl group having 1 to 8 carbon atoms;
R ¹⁰ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and n represents an integer of 0 to 2;
The present invention provides a coating method characterized by applying an inorganic top coat containing, as a resin component, a condensation reaction product with 0.1 to 200 parts by weight of an epoxy group-containing silane represented by the following formula:

[0010] In the present invention, the inorganic top coating composition may contain an amino group-containing alkoxysilane based on 1 equivalent of the epoxy group of the condensation reaction product, and the active hydrogen of the amino group may be 0.1 to 0.1%.
The present invention provides the above coating method, wherein the coating material contains 3.0 equivalents.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The coating method of the present invention will be described below in detail. In the coating method of the present invention, an undercoat selected from an epoxy resin-based paint and an acrylic silicone-based paint is applied on an object to be coated, dried to form an undercoat, and then a specific undercoat is formed on the undercoat. Apply inorganic top coat.

The object to be coated is iron, aluminum,
Metal substrates such as stainless steel, galvanized steel plates, zinc alloy-plated steel plates (plated with alloys such as iron-zinc, nickel-zinc, and aluminum-zinc), and tin plates; plastic substrates; glass, cement, slate, Inorganic ceramic substrates such as mortars and tiles; and coated substrates obtained by coating these substrates with coating films.

In the method of the present invention, the undercoat paint to be applied on the object is selected from an epoxy resin paint and an acrylic silicone paint.

As the epoxy resin-based paint, there can be mentioned a known epoxy resin-based paint as a sealer or an undercoat, and typical examples thereof include an epoxy-amine resin-based paint and an epoxy urethane resin-based paint. And the like.

As the acrylic silicone paint, (1)
Polymer of a monomer mixture comprising an alkoxysilyl group-containing polymerizable unsaturated monomer or polysiloxane macromonomer such as γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, and other polymerizable unsaturated monomers ;
(2) A paint containing, as a resin component, a condensation polymer obtained by subjecting an alkoxysilyl group-containing organopolysiloxane and a hydroxyl group-containing acrylic resin to a dealcoholization reaction. The acrylic silicone-based paint may contain, for example, a curing agent such as a polyisocyanate compound.

The undercoat paint contains, in addition to the binder component, an organic solvent, pigments such as color pigments, extender pigments, rust-preventive pigments, and other paint additives such as a curing catalyst, a coating surface adjuster, and an anti-drip agent. Can be.

The organic solvent that can be contained in the undercoat paint can be used without any particular limitation as long as it can dissolve or disperse the resin in the undercoat paint. However, in the method of the present invention, the surface of the substrate on which the undercoat paint is applied has deteriorated. In the case of the old paint film surface, when the undercoat paint is applied over the old paint film, it is necessary that lifting of the old paint film does not occur, and for that, the aliphatic hydrocarbon solvent and the boiling point It is preferable that the composition contains at least 95% by weight of a hydrocarbon solvent selected from high-boiling aromatic hydrocarbon solvents having a temperature of 150 ° C. or higher, based on the total amount of the organic solvent in the undercoat paint.

Specific examples of the above-mentioned aliphatic hydrocarbon solvents and high-boiling aromatic hydrocarbon solvents include, for example, VM & P
Naphtha, Mineral Spirit, Solvent Kerosene, Aromatic Naphtha, Solvent Naphtha, Solvesso 100, Solvesso 150, Solvesso 200 [“Solvesso” is a registered trademark of Esso Oil Co., Ltd.], Swazol 310, Swazol 1000, Swazol 1500 [“Swazol” is Cosmo Aliphatic or aromatic hydrocarbons having a relatively low dissolving power, such as n-butane, n-hexane, n-heptane, n-octane, isononane, n-decane, n-dodecane And aliphatic hydrocarbons such as cyclopentane, cyclohexane and cyclobutane. In this case, the organic solvent in the undercoat paint is most preferably an aliphatic hydrocarbon-based solvent or a high-boiling aromatic hydrocarbon-based solvent, but the organic solvent includes an aliphatic hydrocarbon-based solvent and a high-boiling-point solvent. It may contain 5% or less, preferably 3% or less of other organic solvents other than the aromatic hydrocarbon solvent. When the amount of the other organic solvent increases, lifting of the old coating film easily occurs at the time of recoating.

The above-mentioned undercoat paint is dried after application to form an undercoat film. The drying conditions can be appropriately set according to the kind of the undercoat paint and the like. It can be cured by curing or the like.

In the method of the present invention, the inorganic top coat applied on the undercoat film includes the following alkylarylalkoxypolysiloxane (A), alkyltrialkoxysilane condensate (B) and epoxy group-containing alkoxysilane (C). As a resin component.

Alkylarylalkoxypolysiloxa
(A) Alkylarylalkoxypolysiloxane ( hereinafter sometimes abbreviated as “polysiloxane (A)”) as a component (A) is a polysiloxane containing an alkyl group, an aryl group and an alkoxy group. In the formula, R ¹ represents an alkyl group having 1 to 8 carbon atoms, R ² represents an aryl group, R ³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and a represents 0.1 ≦ a. ≦ 2.0, b is 0.1 ≦ b
≦ 2.0, b / a is 0.2 ≦ b / a ≦ 2.0, c is 0.1 ≦ c ≦ 1.0, and (a + b + c) is 4
Is a polysiloxane represented by the following formula:

Since the polysiloxane (A) has an aryl group in the above-mentioned quantitative range, it has excellent film-forming properties.

Since the polysiloxane (A) has an aryl group in the above-mentioned quantitative range, it is excellent in film-forming properties. The polysiloxane (A) has a weight average molecular weight (in terms of polystyrene) of 500 to 6,000, particularly 700 to 4,000.
000 and an alkoxyl group content of 0
It is preferably in the range of 0 to 30% by weight, in particular 0 to 25% by weight.

Commercial products of the polysiloxane (A) include:
For example, SH-6018, DC3074, DC303
7, SR2402 (all, products of Toray Dow Corning Co., Ltd.); KR9218, X-40-9220 (all, products of Shin-Etsu Chemical Co., Ltd.), TSR165, X
Examples thereof include R-31B1763 and XR-31B1410 (both are products of Toshiba Silicone Co., Ltd.).

Alkyl trialkoxysilane and / or
The alkyltrialkoxysilane condensate (B) The component (B) used in the production of the coating resin composition of the present invention is the following alkyltrialkoxysilane and / or a condensate of the alkyltrialkoxysilane. Any of an alkoxysilane, a condensate thereof, and a mixture of an alkyltrialkoxysilane and a condensate thereof may be used.

The alkyltrialkoxysilane which can be the component (B) is a compound represented by the following general formula R ⁴ Si (OR ⁵ ) ₃ , wherein R ⁴ and R ⁵ are the same or different and have 1 to 1 carbon atoms.
8, preferably 1 to 4 alkyl groups.

Specific examples of the above alkyltrialkoxysilanes include, for example, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane,
Butyltrimethoxysilane, hexyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, methyltripropoxysilane, propyltripropoxysilane, methyltributoxysilane, etc. . These alkyl trialkoxysilanes can be used alone or in combination of two or more.

The condensate of the alkyltrialkoxysilane which can be the component (B) is a condensate of the above-mentioned alkyltrialkoxysilane, and has a weight average molecular weight of 300 to 3,000, particularly 500 to 2,000. It is preferable that the content of the alkoxyl group is 20% by weight or more, preferably 25 to 50% by weight based on the condensate. In producing the condensate, the alkyl trialkoxysilane can be condensed by using alone or in combination of two or more.

Mono- and / or dialkoxysilane
(C) The mono- and / or di-alkoxysilane as the component (C) for producing the resin composition of the present invention is represented by the following general formula: R ⁶ _d Si (OR ⁷ ) _(4-d) ⁶ is the same or different and represents an alkyl group or aryl having 1 to 8, preferably 1 to 4 carbon atoms, and R ⁷ is the same or different and represents an alkyl group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. , D represents 2 or 3.

Specific examples of the above-mentioned mono- or di-alkoxysilane include, for example, methoxytrimethylsilane, methoxytriethylsilane, methoxymethyldiethylsilane, ethoxytrimethylsilane, ethoxytriethylsilane, ethoxytriphenylsilane, propoxytrimethylsilane, propoxy Monoalkoxysilanes such as tripropylsilane and butoxytributylsilane; dimethoxydimethylsilane, dimethoxydiethylsilane, dimethoxydiphenylsilane, diethoxydimethylsilane,
Diethoxydiethylsilane, diethoxydiphenylsilane, dipropoxydimethylsilane, dipropoxydiethylsilane, dipropoxydipropylsilane, dipropoxydiphenylsilane, dibutoxydimethylsilane, dibutoxydiethylsilane, dibutoxydibutylsilane, dibutoxydiphenylsilane And the like. These mono- or di-alkoxysilanes can be used alone or in combination of two or more.

The above mono- and / or di-alkoxysilane has the effect of imparting flexibility to the coating film and improving the crack resistance of the coating film.

Epoxy group-containing silane (D) The epoxy group-containing silane (hereinafter sometimes abbreviated as "epoxysilane (D)"), which is the component (D) used in the production of the resin composition of the present invention, comprises: the following general formula _{^{R 8 R 9 n Si (oR}} 10) in _(3-n) wherein the monovalent organic group R ⁸ is containing an epoxy radical, n pieces of R ⁹ may be the same or different, 1 to carbon atoms 8, preferably 1 to 4 alkyl groups, R ¹⁰ being the same or different,
A hydrogen atom or an alkyl group having 1 to 8 carbon atoms, preferably 1
Represents an alkyl group of from 4 to 4, and n represents an integer of from 0 to 2.

Specific examples of the epoxysilane (D) include, for example, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, γ-
Glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyl (methyl) dimethoxysilane, γ-glycidoxypropyl (dimethyl) methoxysilane, γ-glycidoxypropyl (ethyl ) Dimethoxysilane, 3,4-epoxycyclohexylmethyltrimethoxysilane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be mentioned. These epoxy group-containing alkoxysilanes can be used alone or in combination of two or more.

The condensation reaction product contained as a resin component of the inorganic top coat used in the method of the present invention comprises the above polysiloxane (A), alkyl trialkoxysilane and / or its condensate (B), -And / or di-
It is obtained by a condensation reaction between alkoxysilane (C) and epoxysilane (D).

The above-mentioned condensation reaction product is, for example, the above-mentioned polysiloxane (A), alkyl trialkoxysilane and / or its condensate (B), mono- and / or di-alkoxysilane (C) and epoxy silane (D) Is heated in the presence of a reaction catalyst and water without removing the alcohol from the reaction system to convert a part of the alkoxy group bonded to Si into a hydroxyl group (silanol group) bonded to Si and partially condense After forming a siloxane bond, that is, after hydrolysis and partial condensation, the product can be produced by heating to cause a condensation reaction while removing the alcohol outside the system.

The condensation reaction product is, for example, a polysiloxane (A) and an alkyl trialkoxysilane and / or
Alternatively, a mixture of the condensate (B) and the mono- and / or di-alkoxysilane (C) is heated in advance in the presence of a reaction catalyst and water without removing the alcohol from the reaction system, thereby obtaining (A) After converting a part of the alkoxyl group bonded to Si in the components (B) and (C) into a hydroxyl group (silanol group) bonded to Si and partially condensing to form a siloxane bond, After decomposition and partial condensation, the product can also be produced by adding epoxysilane (D) to the product and subjecting it to a condensation reaction while heating to remove distillates such as alcohol from the system.

In the above reaction, the reaction conditions are not particularly limited, but the reaction is carried out without removing the alcohol from the reaction system in the presence of the reaction catalyst and water without removing the alcohols (A), (B) and (C). ) And, if necessary, converting a part of the alkoxy group bonded to Si in the component (D) into a hydroxyl group (silanol group) bonded to Si and partially condensing to form a siloxane bond, ie, hydrolysis. In the case of partial condensation, the mixture is usually stirred at room temperature to 100 ° C. for 5 minutes to 24 hours, particularly at 40 to 80 ° C. for 10 minutes to 12 hours without removing the alcohol.
1 hour to 24 hours while removing alcohol and the like generated by the reaction at 0 to 300 ° C. (preferably 80 ° C. to 250 ° C.).
It is preferable to carry out the condensation reaction for a time.

In producing the above condensation reaction product, the above polysiloxane (A), alkyl trialkoxysilane and / or its condensate (B), mono- and / or di-alkoxysilane (C) and epoxysilane (D )) Are as follows. The amount of the alkyl trialkoxysilane and / or the condensate thereof (B) is 0 to 100 parts by weight of the polysiloxane (A).
It is preferably 200 parts by weight, particularly from 0 to 100 parts by weight, from the viewpoint of room temperature curability, adhesion of the obtained coating film, and coating film hardness. The amount of the mono- and / or di-alkoxysilane (C) is 0.1 to 200 parts by weight, particularly 1.0 to 1 part by weight, based on 100 parts by weight of the polysiloxane (A).
The amount within the range of 00 parts by weight is preferable from the viewpoints of room temperature curability, adhesion of the obtained coating film, cracking resistance, and coating film hardness.

The amount of the epoxysilane (D) is as follows:
Based on a total of 100 parts by weight of polysiloxane (A), alkyl trialkoxysilane and / or condensate (B) thereof, and mono- and / or di-alkoxysilane (C),
It is preferably from 0.1 to 200 parts by weight, particularly from 1 to 100 parts by weight, from the viewpoint of room temperature curability, pot life and adhesion of the coating film.

As the reaction catalyst in the above condensation reaction,
Metal alkoxide compounds, metal chelate compounds, metal ester compounds, inorganic acids, organic acids, basic compounds and the like are used.

Examples of the metal alkoxide compound include aluminum trimethoxide, aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, and aluminum tri-n-oxide.
Butoxide, aluminum triisobutoxide, aluminum trisec-butoxide, aluminum tritert-
Aluminum alkoxides such as butoxide; tetramethyl titanate, tetraethyl titanate, tetra-n-
Propyl titanate, tetraisopropyl titanate,
Titanium alkoxide such as tetra n-butyl titanate, tetraisobutyl titanate, tetra tert-butyl titanate, tetra n-hexyl titanate, tetraisooctyl titanate, tetra n-lauryl titanate; tetraethyl zirconate, tetra n-propyl zirconate, tetraisopropyl Zirconate, tetra n-butyl zirconate, tetra sec-butyl zirconate, tetra tert-butyl zirconate, tetra n-pentyl zirconate, tetra tert-pentyl zirconate, tetra tert-hexyl zirconate, tetra n-heptyl zirconate Zirconium alkoxides such as tert., Tetra n-octyl zirconate and tetra n-stearyl zirconate; dibutyltin dibutoxide; and the like. For example, tris (ethylacetoacetate) aluminum, tris (n-propylacetoacetate) aluminum, tris (isopropylacetoacetate) aluminum, tris (n)
-Butylacetoacetate) aluminum, isopropoxybis (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, tris (proponylacetonato) aluminum, diisopropoxypropionylacetonatoaluminum, acetylacetonatobis (propionylacetone) Nato) aluminum,
Monoethyl acetoacetate bis (acetylacetonato) aluminum, acetylacetonatoaluminum
Aluminum chelate compounds such as di-sec-butylate, methyl acetoacetate aluminum di-tert-butylate, bis (acetylacetonato) aluminum mono-sec butyrate, di (methyl acetoacetate) aluminum mono-tert-butylate; diisopropoxy bis (Ethyl acetoacetate) titanate, diisopropoxy bis (acetylacetonato) titanate,
Titanium chelate compounds such as di-n-butoxybis (acetylacetonato) titanate; zirconium chelate compounds such as tetrakis (acetylacetonato) zirconium, tetrakis (n-propylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; dibutyl Examples of the metal ester compound include dibutyltin diacetate, dibutyltin di (2-ethylhexylate), dibenzyltin di (2-ethylhexylate), and dibutyltin. Tin ester compounds such as tin dilaurate and dibutyltin diisooctyl maleate;

Examples of the inorganic acid include nitric acid, hydrochloric acid, phosphoric acid, and halogenated silane, and examples of the organic acid include acetic acid,
Examples include formic acid, propionic acid, maleic acid, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, glutaric acid, glycolic acid, maleic acid, toluenesulfonic acid, oxalic acid, and the like. As the basic compound, ammonia, methylamine, ethylamine, propylamine,
Butylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine and the like.

These reaction catalysts can be used alone or in combination of two or more.

The amount of the reaction catalyst used is (A), (B),
It is usually preferred that the amount be in the range of 0.0001 to 5 parts by weight based on 100 parts by weight of the total of the components (C) and (D). The amount of water is usually in the range of 0.02 to 1.0 mol based on 1 equivalent of the alkoxysilyl group in the total of the components (A), (B), (C) and (D). It is preferred that there be.

The condensation reaction product obtained by the above condensation reaction has an epoxy equivalent of 300 to 5,000, particularly 500 to 5,000.
4,000 and a weight average molecular weight (in terms of polystyrene) of 1,000 to 400,000, especially 2,000 to
In the infrared absorption spectrum, [absorption based on silanol group (3400c
m- ¹ ) / absorption based on siloxane (around 1080 cm- ¹ )] of 0.05 or less, preferably 0.03
The following is preferable from the viewpoint of pigment dispersion stability.

The inorganic top coat used in the method of the present invention contains the above condensation reaction product as a resin component, and usually further contains a curing agent. Examples of the curing agent include an amino group-containing alkoxysilane. Specific examples of the amino group-containing alkoxysilane include N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane,
-Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and the like. These compounds can be used alone or in combination of two or more.

When an amino group-containing alkoxysilane is used as a curing agent in the inorganic top coat, the mixing ratio of the condensation reaction product and the amino group-containing alkoxysilane is determined by the following formula: the number of equivalents of amino group active hydrogen / The ratio of the number of equivalents of the epoxy group in the dealcoholization condensation reaction is 0.1
It is preferable that the ratio be in the range of from 3.0 to 3.0, particularly from 0.3 to 2.0, from the viewpoint of the curability and the pot life of the obtained top coat.

The above inorganic top coating composition may further comprise, in addition to the dealcoholization condensation product and the amino group-containing alkoxysilane,
Further, if necessary, a curing catalyst; iron oxide, titanium oxide,
Color pigments such as carbon black, cyanine blue, cyanine green and quinacridone red, extenders such as calcium carbonate, talc, clay, silica, barium sulfate and mica; organic solvents; and other additives can be contained.

The curing catalyst promotes the curing reaction between the condensation reaction product and the amino group-containing alkoxysilane. Specific examples of the curing catalyst include aqueous alkali metals such as sodium hydroxide and potassium hydroxide. Oxides; hydrochloric acid,
Inorganic acids such as sulfuric acid and phosphoric acid; organic acids such as acetic acid and paratoluenesulfonic acid; quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide and tetrabutylammonium hydroxide; dibutylamine-2 Amine salts such as hexoate, dimethylamine acetate, ethanolamine acetate; quaternary ammonium salts of carboxylic acids such as tetramethylammonium acetate; amines such as butylamine, octylamine, triethylenediamine, t-butylamine, tetraethylpentamine; Aluminum alkoxides, aluminum chelates; organic titanium compounds such as tetraisopropyl titanate, tetrabutyl titanate, and titanium tetraacetylacetonate; dibutyltin diacetate And organic acid tin ester compounds such as dibutyltin dilaurate; imidazole derivatives such as imidazole, 1-methylimidazole, 2-methylimidazole and 4-methylimidazole; piperidine, piperazine, pyrrolidine and the like; potassium fluoride, sodium fluoride , Tetrabutylammonium fluoride,
Benzyltrimethylammonium fluoride can be mentioned. These curing catalysts can be used alone or in combination of two or more.

When the curing catalyst is blended, the blending amount is 0.0001 to 5 based on 100 parts by weight of the total of the condensation reaction product and the amino group-containing alkoxysilane.
It is preferably in the range of parts by weight.

In the method of the present invention, the method of applying the above-mentioned top coat on the undercoat film is not particularly limited, and examples thereof include brush coating, air spray coating, airless spray coating, roll coater, and the like. The coating can be performed using a flow coater or the like, and the coating film thickness is not particularly limited, but is usually preferably in the range of 5 to 60 μm. This inorganic top coat can be cured at room temperature, and the cured coating film exhibits excellent performance, but may be subjected to forced drying or heat curing.

According to the method of the present invention, it is possible to form an inorganic overcoating film which can be dried at room temperature or a relatively low temperature, is excellent in adhesion, coloring by a color pigment, film thickness retention, gloss and weather resistance. .

[0053]

The present invention will be specifically described below with reference to examples. In the following, “parts” and “%” indicate “parts by weight” and “% by weight”, respectively, unless otherwise specified.

Production Example 1 Production of Condensation Reaction Liquid (a) "DC3074" (manufactured by Dow Corning Toray Silicone Co., Ltd., alkylarylalkoxysilane) was placed in a reaction vessel equipped with a thermometer, a thermostat, a stirrer, and a distilling tube. Oligomer, phenyl group content (about 1 equivalent of organic group, the same applies hereinafter) about 50 equivalent%, methoxy group content about 17%,
(Weight average molecular weight about 1600) 100 parts, "XR31B-
1410 "(manufactured by Toshiba Silicone Co., Ltd., partial condensate of alkyl trialkoxysilane, methoxy group content of about 45 to 45)
50 parts by weight, weight average molecular weight of about 500), 40 parts of trimethylmethoxysilane, 20 parts of γ-glycidoxypropylmethyldimethoxysilane, 0.2 parts of diisopropoxybisacetylacetonato titanium, and 10 parts of methyl alcohol. After the temperature was raised to 60 ° C., a mixture of 10 parts of water and 0.8 part of a dimethylamine solution was added dropwise, and the mixture was stirred at 60 ° C. for 2 hours. Thereafter, the mixture was heated to 130 ° C. while removing the distilling solvent, and stirring was continued at the same temperature for 6 hours to produce a condensation reaction liquid (a). The condensation reaction liquid (a) has a nonvolatile content of 9
1%, the weight average molecular weight was about 12,000, and the epoxy equivalent was 2,200. In addition, the infrared absorption spectrum (I
In R), the ratio of the absorbance of the absorption of silanol (absorption at 3400 cm ^-1 ) / the absorption of siloxane (absorption at 1080 cm ^-1 ) was 0.01.

Production Example 2 Production of Condensation Reaction Product Liquid (b) In a reaction vessel equipped with a thermometer, a thermostat, a stirrer, and a distilling tube, 100 parts of “DC3074” (described above) and “XR3
1B1410 "(described above), 20 parts of methyltrimethoxysilane, 50 parts of dimethyldimethoxysilane, 50 parts of γ-glycidoxypropylmethyldimethoxysilane, 0.2 parts of diisopropoxybisacetylacetonato titanium,
After 10 parts of isopropyl alcohol was charged and the temperature was raised to 50 ° C., a mixture of 8 parts of water and 0.8 part of a dimethylamine solution was added dropwise, and the mixture was stirred at 60 ° C. for 2 hours. Thereafter, the mixture was heated to 120 ° C. while removing the distilling solvent, and stirring was continued at the same temperature for 3 hours to produce a condensation reaction liquid (b). The condensation reaction liquid (b) has a nonvolatile content of 89% and a weight average molecular weight of about 6,7.
00, the epoxy equivalent was 1200. In addition, in the infrared absorption spectrum (IR), the absorption of silanol (34
Absorbance of siloxane / absorbance (10 cm- ¹ )
The absorbance ratio (absorption at 80 cm ^-1 ) was 0.02.

Production Example 3 Production of Condensation Reaction Liquid (c) In a reaction vessel equipped with a thermometer, a thermostat, a stirrer, and a rectification tube, 100 parts of “DC3074” (described above), 30 parts of xylene, and “SH6018” ( 15 parts of a silanol group-containing alkylarylpolysiloxane (manufactured by Dow Corning Toray Silicone Co., Ltd.) and stirred at 50 ° C.
6018 ", 30 parts of γ-glycidoxypropylmethyldimethoxysilane, dimethyldimethoxysilane 1
5 parts, 10 parts of methyl alcohol, 0.3 part of diisopropoxybisacetylacetonato titanium and 5.5 parts of water were charged, and stirring was continued at 70 ° C. for 6 hours. Thereafter, the temperature was raised to about 150 ° C. while removing the distilling solvent, and the temperature was gradually raised and heating was continued so that the solvent vapor temperature of the rectification tube was maintained at 60 ° C. to 70 ° C. When the solvent distilled at 70 ° C. or less disappeared, heating was stopped to produce a condensation reaction liquid (c). The condensation reaction product liquid (c) has a nonvolatile content of 82%, a weight average molecular weight of about 28,000, an epoxy equivalent of 1,100, and absorbance of silanol (absorption of 3400 cm ^-1 ) / absorbance of siloxane (absorption of siloxane). The absorbance ratio (at 1080 cm ^-1 ) was 0.01.

Production Example 4 Production of Inorganic Topcoat (A) 109.9 parts of a condensation reaction liquid (a) having a non-volatile content of 91% obtained in Production Example 1 was added to “Taipec CR-93” (manufactured by Ishihara Sangyo Co., Ltd.). , Trade name, titanium white) 100 parts and toluene 1
0 parts were added and mixed, and pigment was dispersed using a paint shaker to obtain a paint base (A-1). Separately, 3.0 parts of γ-aminopropyltriethoxysilane and 0.1 part of dibutyltin diacetate were mixed to obtain a coating curing agent (C). Immediately before painting, the paint base (A
-1) 219.9 parts and 3.1 parts of the above-mentioned curing agent for coating (C) were mixed to prepare an inorganic top coating (A), which was used for coating.
The inorganic top coat (A) had good coloring properties.

Production Example 5 Production of Inorganic Overcoat (B) 112.4 parts of the condensation reaction liquid (b) having a non-volatile content of 89% obtained in Production Example 2 was added to “Taipec CR-93” (manufactured by Ishihara Sangyo Co., Ltd.). , Trade name, titanium white) 100 parts and toluene 1
0 parts were added and mixed, and pigment was dispersed using a paint shaker to obtain a paint base (B-1). Immediately before the coating, 222.4 parts of the base for coating (B-1) and 3.1 parts of the curing agent for coating (C) were mixed to prepare an inorganic top coating (B), which was used for coating. The inorganic top coating (B) had good coloring properties.

Production Example 6 Production of Inorganic Topcoat (C) 122.0 parts of a condensation reaction liquid (c) having a non-volatile content of 82% obtained in Production Example 1 was added to “Taipec CR-93” (manufactured by Ishihara Sangyo Co., Ltd.). , Trade name, titanium white) 100 parts and toluene 1
0 parts were added and mixed, and the pigment was dispersed using a paint shaker to obtain a paint base (C-1). Immediately before coating, 232.0 parts of the above-mentioned base for coating (C-1) and 3.1 parts of the above-mentioned curing agent for coating (C) were mixed to prepare an inorganic top coating (C), which was used for coating. The inorganic top coat (C) had good coloring properties.

Example 1 A multi-tile concrete primer EPO (trade name, manufactured by Kansai Paint Co., Ltd., epoxy-amine resin-based primer) was coated on a mortar board having a size of 150 × 70 × 20 mm at 120 g / m ^2. Is applied in a room at a temperature of 20 ° C. and a humidity of 65% RH.
After drying on a day, the inorganic overcoating material (A) obtained in Production Example 4 was brush-coated so as to have a coating amount (dry coating film weight) of 100 g / m ² , and a temperature of 20 ° C. and a humidity of 65% RH. 10 indoors
After drying for days, a coated plate was obtained.

Example 2 A coated plate was prepared in the same manner as in Example 1 except that the inorganic top coating (B) obtained in Production Example 5 was used instead of the inorganic top coating (A). Obtained.

Example 3 A coated plate was prepared in the same manner as in Example 1 except that the inorganic top coat (C) obtained in Production Example 6 was used instead of the inorganic top coat (A). Obtained.

Example 4 In Example 1, “Ales Silicon” (trade name, manufactured by Kansai Paint Co., Ltd., acrylic silicone resin paint) was used instead of “Multi-tile concrete primer EPO”.
Was carried out in the same manner as in Example 1 except for using, to obtain a coated plate.

Example 5 As an overcoat, "Alesletan" (manufactured by Kansai Paint Co., Ltd.)
Product name, acrylic urethane resin-based top coating) is coated on the surface of a coated plate that has been baked for three years at a bakery in Okinoerabu, Okinawa Prefecture. Primer EPO 12
After brushing to a coating amount (paint weight) of 0 g / m ² and drying in a room at a temperature of 20 ° C. and a humidity of 65% RH for one day,
The inorganic top coat (A) obtained in Production Example 4 was 100 g /
It was brush-coated so as to have a coating amount (paint weight) of m ² and dried in a room at a temperature of 20 ° C. and a humidity of 65% RH for 10 days to obtain a coated plate.

Example 6 A coated plate having on its surface a coating film of "SD Super Marine Topcoat" (trade name, manufactured by Kansai Paint Co., Ltd., trade name, long oil phthalate resin-based topcoat, conforming to JIS K5516 2 types) as a topcoat Was used as a base material for three years at a backyard in Okinoerabu, Okinawa Prefecture, and "Esco Mild NB" (Kansai Paint Co., Ltd., trade name, weak solvent type epoxy resin paint ) Was applied with a brush so as to give a coating amount (paint weight) of 120 g / m ² , dried in a room at a temperature of 20 ° C. and a humidity of 65% RH for 1 day, and then the inorganic top coat (obtained in Production Example 4). A) was applied with a brush so as to give a coating amount (paint weight) of 100 g / m ² , and the temperature was 20 ° C. and the humidity was 65.
The coated plate was dried for 10 days in a room of% RH to obtain a coated plate.

Comparative Example 1 The procedure of Example 1 was repeated, except that “Allethretan” was used in place of the inorganic top coat (A).

Comparative Example 2 A coated plate was prepared in the same manner as in Example 1 except that the mortar plate was directly coated with the inorganic top coat (A) without applying the “multi-tile concrete primer EPO”. Obtained.

Comparative Example 3 The procedure of Example 6 was repeated, except that the inorganic top coat (A) was applied directly on the coating film of the substrate without applying “Esco mild NB”. I got a board.

The coated plates obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were tested for initial adhesion and accelerated weather resistance according to the following test methods. The results of these tests are shown in Table 1 below.

Test Method Painted surface condition: The coated surface of the coated plate was visually observed, and the
Evaluations were made for abnormalities such as cracks, peeling, discoloration, and chalking.

Adhesion: JIS K5400 8.5.
2 (1990), according to the grid-tape method,
Six parallel and vertical knife wounds reaching the substrate were made on the coating surface of the coated plate, and 25 squares of 2 mm x 2 mm were created. A cellophane pressure-sensitive adhesive tape was adhered to the grid, and was instantaneously peeled off, and the ratio of the number of cells remaining without peeling out of the 25 cells was described.

Coating film hardness: JIS K5400 8.4.
2 (1990), a pencil scratch test was performed, and evaluation was performed by the blurring method.

Accelerated weathering test: The coated plate was subjected to an accelerated weathering test for 5,000 hours using a sunshine carbon arc weatherometer. The coated surface state and adhesion of the coated plate after the test were evaluated. The test was conducted on the coated surface of the coated plate after the test in the same manner as in the test method of the coated surface, and the adhesion of the coated plate after the test was tested in the same manner as the test method of the adhesiveness.

[0074]

[Table 1]

[0075]

According to the coating method of the present invention, it is possible to form an inorganic topcoat film which can be dried at room temperature or at a relatively low temperature, and is excellent in adhesiveness, hardness of the coating film, coloring by a coloring pigment, and film thickness retention.

In the method of the present invention, by using a weak solvent type epoxy resin-based paint or acrylic silicone-based paint as the undercoat paint, abnormalities such as shrinkage at the time of painting can be prevented even when applied on the deteriorated old paint film. In addition, it is possible to form an inorganic overcoating film having excellent coating surface appearance and coating film performance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 183/06 C09D 183/06 F-term (Reference) 4D075 AE03 AE16 CA13 EB22 EB33 EB43 4J035 BA04 CA01K CA01U CA06K CA06U CA061 CA11K CA11U CA111 EA01 EB03 LB01 4J038 DL032 DL041 DL042 DL051 DL052 GA07 GA09 MA14 NA01 NA12 PB05 PC02 PC03 PC04 PC08

Claims (3)

[Claims] 1. An undercoat selected from an epoxy resin-based paint and an acrylic silicone-based paint is applied on an object to be coated and dried to form an undercoat, and then: (A) rational formula R in _{^{1 a R 2 b (R 3}} O) c SiO (4-abc) / 2 formula, R ¹ represents an alkyl group having 1 to 8 carbon atoms, R ² is an aryl group, R ³ is a hydrogen atom or A represents an alkyl group having 1 to 8 carbon atoms, a represents 0.1 ≦ a ≦ 2.0, and b represents 0.1 ≦ b
≦ 2.0, b / a is 0.2 ≦ b / a ≦ 2.0, c is 0.1 ≦ c ≦ 1.0, and (a + b + c) is 4
And the weight average molecular weight is in the range of 500 to 6,000, and the alkoxyl group content is in the range of 0 to 30% by weight based on the polysiloxane. and alkylaryl polysiloxane 100 parts by weight, (B) the following general formula R ⁴ Si (oR ⁵⁾ ₃ wherein, R ⁴ and R ⁵ are the same or different, represents an alkyl group having 1 to 8 carbon atoms, in illustrated condensates 0-200 parts by weight of alkyltrialkoxysilane and / or the alkyltrialkoxysilane and, (C) the following general formula R ⁶ _d Si (oR ⁷⁾ in _(4-d) formula is, R ⁶ are the same or Differently represents an alkyl group or aryl having 1 to 8 carbon atoms, R ⁷ is the same or different and represents an alkyl group having 1 to 8 carbon atoms, and d represents 2 or 3, mono- and / or Or di-alkoxy 0.1 to 200 parts by weight of silane, the alkylarylpolysiloxane (A), the alkyltrialkoxysilane and / or
Alternatively, based on a total of 100 parts by weight of the condensate (B) of the alkyltrialkoxysilane and the mono- and / or di-alkoxysilane (C), (D) the following general formula: R ⁸ R ⁹ _n Si (OR ¹⁰ ) In the formula _(3-n) , R ⁸ is a monovalent organic group containing an epoxy group, n R ⁹ are the same or different, and are an alkyl group having 1 to 8 carbon atoms;
R ¹⁰ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and n represents an integer of 0 to 2;
A coating method comprising applying a condensation reaction product with 0.1 to 200 parts by weight of an epoxy group-containing silane represented by the formula (1) as a resin component. 2. The inorganic topcoat composition contains an amino group-containing alkoxysilane with respect to 1 equivalent of epoxy group of the condensation reaction product in such an amount that the active hydrogen of the amino group becomes 0.1 to 3.0 equivalent. The coating method according to claim 1, wherein the coating material is a paint. 3. The object to be coated has an old coating film, and is selected from an epoxy resin-based coating material and an acrylic silicon-based coating material as an undercoating material on the old coating film of the object to be coated. 2. An undercoat paint is applied.
Or the coating method of 2.