JPH09316397A - Composition for forming coating film and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition improved in dripping and dispersion of stability of pigment and giving coating films having high hardness and being excellent in adhesion, etc., by mixing a condensate of a silicone resin with an organoalkoxysilane with a hydrophilic organic solvent and colloidal silica. SOLUTION: This composition consists essentially of a silicone resin being a silanol-group-containing organopolysiloxane represented by the average compositional formula: Ra Si(OH)b O(4-a-b)/2 ((a) is 0.5-1.5; (b) is 0.01-1; and R is a 1-9C monovalent organic group) and having an average molecular weight of 500-100,000 (in terms of the polystyrene), a substance obtained by polycondensing a hydrolyzate of an organoalkoxysilane in the presence of an acidic water-dispersed colloidal alumina, a hydrophilic organic solvent and acidic colloidal silica and/or a hydrophilic organic solvent dispersed colloidal silica. This composition is improved in resistance to dripping occurring in thick coating and pigment dispersibility and can give high-gloss coating films excellent in adhesion, water resistance, heat resistance, weatherability, chemical resistance, etc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to high hardness and adhesion,
The present invention relates to a film forming composition capable of forming a highly glossy film excellent in water resistance, heat resistance, weather resistance, chemical resistance and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a siloxane bond (Si-OS) has been used.
The resin with i) has, due to its high binding energy,
The coating film made of the resin has excellent durability. Many paints containing a resin using this bond in the main chain have been proposed. For example, as the resin, a silicone resin (prior art 1), a hydrolyzate of an organoalkoxysilane (prior art 2), and Japanese Patent Laid-Open No. Sho 53-53. -130732 as described above, a composite of colloidal silica and an organoalkoxysilane hydrolyzate (prior art 3), or JP-A-62-3215.
A composite of colloidal alumina and organoalkoxysilane hydrolyzate as described in 7 (prior art 4) and the like has been proposed.

However, the silicone resin of Prior Art 1 generally has a low crosslink density, and due to the degree of freedom of siloxane bonds, it is difficult to obtain a high hardness coating from a coating material containing the resin as a coating forming component. Further, the coating material containing the organoalkoxysilane hydrolyzate of Conventional Technique 2 as a film-forming component can increase the cross-linking density to obtain a high-hardness film, but the adhesion of the film to the substrate and crack resistance are difficult. The coating composition of the prior art 3 which contains a composite with colloidal silica as a film-forming component in order to improve these is also recognized to be improved, but there is a problem in the balance between high hardness, adhesion and crack resistance. was there.

The inventors of the present invention have made a detailed study on the coating material of the prior art 4, which contains a complex of colloidal alumina as a film-forming component. As a result, the inventors found that the shape of the colloidal alumina (feather-like) relaxes the stress in the film. Perhaps because of this, it is possible to achieve both hardness and crack resistance, but chemical resistance, boiling resistance,
It was found that there was a problem with the smoothness of the coating.

Further, the coating compositions of the prior arts 2 and 3 generally have a low viscosity of the composition, and have problems such as sagging when applied and dispersibility of the pigment. Although the use of colloidal alumina improved these points considerably, the prevention of liquid sagging and the dispersion stability of the pigment at the time of thickening the film were still insufficient.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and imparts sufficient thixotropy to a coating composition to prevent liquid sagging when a thick film is applied. Dispersion stability of the pigment is dramatically improved, and a film forming composition capable of forming a highly glossy film having high hardness and excellent adhesion, water resistance, heat resistance, weather resistance, chemical resistance, and the like. The purpose is to provide a manufacturing method.

[0007]

The present invention provides a film-forming composition containing the following components (A), (B), (C) and (D) as essential components, and a method for producing the same. To do. Component (A): average composition formula _Ra Si (OH) _b O
_{(4-ab) / 2} (where a is a positive number of 0.5 to 1.5, b is a positive number of 0.01 to 1 and R is a monovalent organic group having 1 to 9 carbon atoms). A silicone resin which is an organopolysiloxane having a silanol group in the molecule and has a polystyrene-reduced weight average molecular weight of 500 to 100,000. Component (B): A substance obtained by hydrolyzing and polycondensing an organoalkoxysilane in the presence of acidic water-dispersed colloidal alumina. Component (C): hydrophilic organic solvent. Component (D): acidic colloidal silica and / or hydrophilic organic solvent dispersed colloidal silica.

According to the present invention, the components (A) to (D) are used as essential components of the film-forming composition, thereby imparting sufficient thixotropy to the composition and applying the solution when a thick film is applied. The anti-sagging property and the dispersion stability of the pigment are remarkably improved, and a highly glossy film having high hardness and excellent adhesion, water resistance, heat resistance, weather resistance and chemical resistance can be formed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Each component constituting the composition of the present invention will be described in detail. (A) a silicone resin as the component, the average composition formula _{R a Si (OH) b O} (4-ab) / 2 ( provided that a 0.5 to 1.5 positive number, b is 0.01 to 1 , R is a monovalent organic group having 1 to 9 carbon atoms, and has a silanol group in the molecule, and a polystyrene-equivalent weight average molecular weight of 500 to 10
It is a silicone resin of 10,000.

R in the above average composition formula is, for example, an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group or a butyl group, or a fluoroalkyl group such as a 3,3,3-trifluoropropyl group. , Aryl groups such as phenyl group, other γ-chloropropyl group, vinyl group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, β- (3,4-epoxycyclohexyl) ethyl group, N- (β -Aminoethyl) -γ-aminopropyl group, γ-aminopropyl group, γ-mercaptopropyl group and the like.

The component (A) is obtained by hydrolyzing and polycondensing the corresponding chlorosilane or alkoxysilane. In the composition of the present invention, the component (A) functions as a binder and also has good adhesion and resistance to a substrate. It greatly contributes to the development of chemical properties.

This silicone resin is used for gel permeation chromatography (apparatus: HLC802 manufactured by Tosoh Corporation).
0, column: Tosoh TSKgel G4000H + TS
KgelG2000H, solvent: tetrahydrofuran, column temperature: 40 ° C., solvent flow rate: 1 ml / min, siloxane concentration: 1% tetrahydrofuran solution), and polystyrene conversion weight average molecular weight (hereinafter simply referred to as molecular weight) is 5
Must be in the range of 00-100,000,
It is preferably in the range of 3,000 to 20,000, more preferably in the range of 5,000 to 10,000. If the molecular weight is less than 500, the shrinkage of the coating film upon curing becomes too large, the crack resistance of the coating film decreases, and the molecular weight is 100,0.
If it exceeds 00, the coating becomes soft.

It is important that this silicone resin contains a silanol group (Si-OH). This silanol group is a group that crosslinks and cures by reacting silanol groups with each other or a terminal silanol group or an alkoxysilyl group of an organoalkoxysilane condensate to be described later during curing after forming a film.

In the hydrolysis and polycondensation of chlorosilane, the terminals of the obtained silicone resin are all silanol groups, but in the hydrolysis and polycondensation of alkoxysilane, the terminals of the obtained silicone resin are silanol groups and alkoxysilyl groups. It becomes a mixture of. A small amount of alkoxysilyl groups remains, but this is not a problem. When alkoxysilane is used as a raw material, it is hydrolyzed with a large amount of water and the generated alcohol is distilled off, or a liquid-liquid heterophasic reaction using a low polar solvent such as toluene is used to terminate the terminal silanol. It can be an excess of groups.

If the silicone resin is within the above-mentioned molecular weight range, it is possible to use a varnish for paints, electric varnishes or silanol group-containing modification intermediates commercially available from silicone manufacturers. Specifically, TS
R127B, TSR160 (Toshiba Silicone), KR2
12, KR216, KR311 (Shin-Etsu Chemical Co., Ltd.), SH
6018 (Toray Dow Corning Silicone) and the like. These silicone resins are supplied in the form of being dissolved in an organic solvent such as toluene or xylene, or as a flake-like solid. Even if they are diluted or dissolved with a hydrophilic organic solvent described later, they may be used. Good.

Further, the average composition formula R _a Si (OH) _b
As R in O _{(4-ab) / 2} , various organic groups can be selected as described above, but in consideration of availability, synthesis, etc., R is a methyl group or a phenyl group. Methyl groups are most preferable, if the hardness and weather resistance of the coating are important. Also, the smaller the value of a (called the degree of functionality) in the formula, the harder the film formed, but if it is less than 0.5, the film becomes extremely brittle, and
If it exceeds 1.5, the curability of the coating tends to be poor. It is preferably 0.8 to 1.2, more preferably 1.0.

Since a compound in which b exceeds 1 is unlikely to exist stably, b is selected in the range of 1 or less. When the carbon number of R is large, 1) it becomes difficult to polymerize, and 2) the durability and hardness of the obtained coating film deteriorate. Therefore, the carbon number of R is 1-9.

A silicone resin in which R is a methyl group and a is 1.0 is called monomethyl silicone resin or methylsilsesquioxane, which is obtained by hydrolysis and polycondensation of methyltrichlorosilane or methyltrialkoxysilane. can get. Among commercially available silicone resins, those commercially available as varnishes for bonding mica for electrical use correspond to this, and specific examples thereof include TSR127B and YR337 of Toshiba Silicone.
0 and the like.

The component (B) is hydrolyzed and polycondensed in the presence of acidic water-dispersed colloidal alumina, and contains the colloidal alumina and organoalkoxysilane condensate. The component (B) is obtained by adding an organoalkoxysilane to acidic water-dispersed colloidal alumina and reacting it. Hydrolysis and polycondensation of the organoalkoxysilane proceed by the water contained in the acidic water-dispersed colloidal alumina to obtain the desired alkoxysilane condensate. In the constituent component of the present invention, the component (B) functions as a binder and contributes greatly to the heat resistance, crack resistance and hardness of the coating.

The acidic water-dispersed colloidal alumina in the component (B) usually contains 5 to 25% by weight of alumina, pseudo-boehmite, boehmite or the like, and has a pH of 2.5 to 6.
It is dispersed in acidic water of 0 and contains acetic acid, nitric acid, hydrochloric acid, etc. as stabilizers. This colloidal alumina can be easily obtained, for example, by hydrolyzing, polymerizing and grain-growing aluminum alkoxide, distilling off the generated alcohol, and adding a stabilizer to disperse it. , For example,
AS-1, AS-2, AS-3 manufactured by Catalysts & Chemicals Industry, alumina sol 100, 200, 520 manufactured by Nissan Chemical Industries, and ASK110, 120 manufactured by Sumitomo Aluminum can also be used.

The organoalkoxysilane (hereinafter referred to as organoalkoxysilane (B)), which is a raw material for the organoalkoxysilane condensate in the component (B), has the general formula R _x Si (OR ′) _4-x (x is 0, 1 or 2) is preferable, and R is a monovalent organic group having 1 to 9 carbon atoms, and examples thereof include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group and butyl group. ,
Fluoroalkyl groups such as 3,3,3-trifluoropropyl group, aryl groups such as phenyl group, and γ-
Chloropropyl group, vinyl group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, β- (3,4-
Epoxycyclohexyl) ethyl group, N- (β-aminoethyl) -γ-aminopropyl group, γ-aminopropyl group, γ-mercaptopropyl group and the like can be mentioned.

The R'group in the alkoxy group is an alkyl group having 1 to 5 carbon atoms or an alkoxyalkyl group, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, Examples thereof include isobutyl group, s-butyl group, methoxyethyl group and ethoxyethyl group. The following can be illustrated as specific examples of these organoalkoxysilanes (B).

Tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane. Methyltrimethoxysilane, methyltriethoxysilane, methyltrin-propoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrin-propoxysilane, ethyltriisopropoxysilane, n-propyltrimethoxysilane , N-propyltriethoxysilane, n-propyltrin-propoxysilane, n-propyltriisopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrin-propoxysilane, phenyltriisopropoxysilane. Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-propoxysilane, dimethyldiisopropoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldi-n-propoxysilane, diethyldiisopropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane , Diphenyldi-n-propoxysilane, diphenyldiisopropoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, methylphenyldi-n-propoxysilane, methylphenyldiisopropoxysilane.

Γ-chloropropyltrimethoxysilane,
γ-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane. γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N- (β-aminoethyl) -γ-
Aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltriethoxysilane, N
-(Β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane,
3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane.

These compounds may be used alone or 2
Mixtures of more than one species may be used. Of these organoalkoxysilanes (B), considering the hardness and weather resistance of the coating film, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane are preferable, and further have crack resistance. Considering these, methyltrimethoxysilane and methyltriethoxysilane are most preferable, and those obtained by condensing organoalkoxysilane (B) containing 50 mol% or more, preferably 70 mol% or more of these are preferable.

The mixing amount of the organoalkoxysilane (B) and colloidal alumina is 5 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the organoalkoxysilane (B) in terms of solid content. Parts by weight. With less colloidal alumina,
The hardness and crack resistance of the resulting coating are poorly balanced, and when the content is more than this, the storage stability of the composition is poor, and the coating loses transparency, which is not preferable.

The compounding ratio of the component (A) and the component (B) is (A) / (B) = 1/99 to 50/5 in terms of solid content.
It is preferably 0, more preferably 10/90 to
It is 30/70. If the amount of component (A) is less than this range, the water resistance of the resulting coating film will be poor. On the other hand, if it exceeds this range, problems will occur in terms of adhesion and hardness of the resulting coating film, which is not preferable.

The hydrophilic organic solvent as the component (C) is added to adjust the solid content concentration and viscosity of the resulting composition, and the components (A) and (B) are mixed. It is essential to do. Specifically, water-dispersible colloidal alumina and a lipophilic silicone resin are mixed. The compounding amount of this hydrophilic organic solvent is ((A) +
50 to 50 parts by weight of the solid content of component (B)).
It is mixed in a proportion of 1,000 parts by weight, preferably 100 to 500 parts by weight, but the viscosity and solid content concentration of the appropriate composition may vary depending on the coating method, required film thickness, etc. The blending amount can be adjusted so that the physical properties can be obtained.

If the amount of the component (C) is too small, the stability of the resulting composition may be deteriorated or the smoothness of the coating film formed may be impaired. The film thickness obtained by coating becomes extremely thin, which is inefficient, and the desired physical properties of the film may not be obtained.

Examples of the hydrophilic organic solvent include lower alcohols, polyhydric alcohols such as glycols, ether alcohols, and certain ketones and ethers. The following are mentioned as a specific example of a hydrophilic organic solvent.

Methanol, ethanol, n-propanol, isopropanol, t-butanol, ethylene glycol, propylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, hexylene glycol, 2, 3-hexanediol, 2,4-heptanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether,
Propylene glycol monoethyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether,
Dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, furfuryl alcohol, tetrahydrofuran, dioxane, acetone.

These hydrophilic organic solvents may be used alone or in combination of two or more. When the curing temperature of the coating is low, adding a large amount of solvent with a high boiling point may impair the curability of the coating.In such cases, use a lower alcohol such as methanol, ethanol, or isopropanol. It is preferable to use a solvent having a low boiling point as the main solvent.

The component (D), acidic colloidal silica and / or hydrophilic organic solvent-dispersed colloidal silica, is
Coexistence with colloidal alumina in the composition of the present invention imparts structural viscosity (thixotropy) to the composition. Further, when a filler which is the component (E) described later is added, it has a function of remarkably enhancing the dispersion stability.

The acidic colloidal silica usually means pH =
10 to 4 in the acidic region, which is a metastable region of silicic acid around 2
It is a dispersion of 0% by weight of silica. The particle size is generally several nm to several tens of nm, and specifically, Cataloid SN of Catalysts & Chemicals Industry, Snowtex O of Nissan Chemical Industries, Snowtex OL, Silicadoll 20A of Nihon Kagaku Kogyo, Silicadoll. 30A etc. are mentioned.

The hydrophilic organic solvent-dispersed colloidal silica is a colloidal silica dispersed in a hydrophilic organic solvent such as a lower alcohol, and is usually 10 to 40% by weight.
Including silica, and the particle size is generally several nm to several tens nm.
It is. This hydrophilic organic solvent dispersed colloidal silica is
Add a hydrophilic organic solvent to the acidic colloidal silica,
It can be easily obtained by distilling off water. Specific examples thereof include Oscar 1132 and Oscar 1432 manufactured by Catalysts & Chemicals Industry, and methanol silica sol and isopropanol silica sol manufactured by Nissan Chemical Industries.

The blending amount of the component (D) is preferably 1 part by weight to 50 parts by weight per 100 parts by weight of the component ((A) + (B)) in terms of solid content, and 5 parts by weight or more. More preferably. If the compounding amount of colloidal silica is larger or smaller than the above range, the above thixotropy may not be sufficiently exhibited.

The colloidal silica may be blended as it is, or may be diluted with the component (C) and blended as it is, but it is more preferable to coat the surface of the colloidal silica with an organoalkoxysilane before blending. . By coating the surface of the colloidal silica with the organoalkoxysilane, the (A) component, the (B) component, the (A) component and the (B) component when the (C) component is mixed with the (D) component, The affinity of the composition is increased, the stability of the composition is improved, and it is possible to prevent the colloidal silica from becoming unstable depending on the type of the catalyst such as a basic catalyst when the curing catalyst described below is added.

The surface can be coated easily by adding organoalkoxysilane to colloidal silica, and optionally adding water or a hydrolysis catalyst and heating. The amount of the organoalkoxysilane compounded at the time of this surface coating is 5 to 1 in terms of the solid content of the organoalkoxysilane with respect to 100 parts by weight of the solid content of the colloidal silica.
00 parts by weight is preferred. If the amount is less than this range, the surface coating is not performed well, and if the amount exceeds the above range, the amount of the organoalkoxysilane in the composition is relatively increased, and the amount of the organoalkoxysilane in the composition is relatively increased. There is a risk that cracking and adhesion will be compromised.

The organoalkoxysilanes available are:
It may be the same as or different from the organoalkoxysilane (B). In particular, organoalkoxysilane (B)
The same as those described above are preferable, and methyltrialkoxysilane is most preferable for the same reason as the component (B).

Although there is no particular limitation on the timing of blending the component (D), addition of the component (D) markedly increases the viscosity of the composition.
If the component (E) described below is added at the stage where the components (B) and (C) have been mixed, it is preferable to add it at the stage of adding the component (E). For example, when colloidal silica is added before the organoalkoxysilane condensation reaction in colloidal alumina, the reaction of the organoalkoxysilane may not occur uniformly due to the increase in viscosity.

The composition of the present invention can also be used by adding a filler as the component (E) to the composition. This filler is added for the purpose of coloring the obtained film, imparting corrosion resistance, imparting heat resistance, and the like, and examples thereof include extender pigments and metal flakes in addition to color pigments such as inorganic pigments and organic pigments. .

The inorganic pigments include white pigments such as titanium white, zinc white, and lithopone, black pigments such as carbon black and sintered spinel black, chromatic pigments such as chromium oxide, iron oxide and manganese oxide, and nitrides. , Carbide pigments and the like. Examples of organic pigments include diazo pigments, naphthol pigments, and phthalocyanine pigments. Examples of extender pigments include kaolin, mica and various metal hydroxides, and examples of metal flakes include iron, copper, aluminum, nickel, zinc and stainless steel.

The amount of these fillers to be blended will vary depending on the intended coating application and its film thickness, but is usually the component (A),
The component (B) and the component (D) are mixed in a proportion of 50 to 1,000 parts by weight based on 100 parts by weight of the total solid content. After mixing the components (A) to (D), the component (E) is added and dispersed by a known method such as a ball mill or a sand mill to obtain a filler-dispersed composition of the present invention.

In the present invention, a hard and highly durable coating is formed by mixing the components (A) to (D) or (A) to (E), but a coating having a higher hardness can be obtained. Therefore, the following component (F) is preferably added after the above mixing. Component (F): R _n Si (OR ′) _4-n (where R,
R'is a monovalent organic group having 1 to 9 carbon atoms, and n is 0 or 1. )
An organoalkoxysilane represented by.

The component (F), organoalkoxysilane (hereinafter referred to as organoalkoxysilane (F)), is
It functions as a cross-linking agent in the curing reaction between the terminal silanol of the organoalkoxysilane polycondensate of the component (B) and the silanol of the silicone resin terminal of the component (A).
For this reason, the organoalkoxysilane (F) is not highly polymerized and is in an oligomeric state (molecular weight 50
0 or less), more preferably in the composition as a monomer. If the molecular weight is larger than this, the function as a cross-linking agent becomes small, and it becomes difficult to contribute to increasing the hardness.
Organoalkoxysilane (F) to enhance crosslinkability
Must have a functionality of 3 or higher.

Specific examples of the organoalkoxysilane (F) include tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, and tetra n-butoxysilane as silanes having a functionality of 4. Examples of the silane having a functionality of 3 include the following.

Methyltrimethoxysilane, methyltriethoxysilane, methyltrin-propoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrin-propoxysilane, ethyltriisopropoxysilane, n-propyl Trimethoxysilane, n-propyltriethoxysilane, n-propyltrin-propoxysilane, n-
Propyltriisopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrin-propoxysilane, phenyltriisopropoxysilane, γ-chloropropyltrimethoxysilane, γ-
Chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, β- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, N- (β-aminoethyl) -γ
-Aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltriethoxysilane,
N- (β-aminoethyl) -γ-aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-
Phenyl-γ-aminopropyltriethoxysilane, γ
-Mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane and the like.

Among these, when selecting a silane with an emphasis on crosslinkability, tetramethoxysilane or tetraethoxysilane having a functionality of 4 and methyltrimethoxysilane or methyltriethoxysilane having a functionality of 3 are suitable. These may be used alone or in combination of two or more.

The weight ratio (F) / ((A) + (B)) of the component (F) to the component ((A) + (B)) is preferably 2.0 or less in terms of solid content. If the amount of the component (F) is larger than this, cracks are likely to occur, and the physical properties of the coating deteriorate rather. Particularly, 1.0 or less is preferable.

The form of addition of the component (F) is such that the component (A) and the component (B) are not highly polycondensed.
After mixing the components, the components (C) and (D), and optionally the component (E), the component (F) is added. For example, it is preferable that the mixture of the components (A), (B), (C), (D) and (E) and the component (D) are separately stored and mixed immediately before coating.

Since the composition of the present invention has appropriate thixotropy as described above, the filler does not easily settle and becomes a very stable dispersion. Furthermore, although the composition of the present invention can provide a sufficiently hard coating at room temperature to a low temperature of about 120 ° C. after application, if it is desired to proceed with the curing in a shorter time, the composition is optionally cured. A catalyst may be added.

As the curing catalyst, hydrochloric acid, phosphoric acid, sulfuric acid,
Acids such as formic acid, acetic acid and p-toluenesulfonic acid, alkali hydroxides such as sodium hydroxide and potassium hydroxide,
Ammonia, organic amines, basic curing agents such as quaternary amine salts, organic acid salts such as cobalt, lead and tin, organometallic compounds, metal alkoxides or chelate compounds such as titanium, aluminum and zirconium, silanes having amino groups. A coupling agent or the like is used. The mixing ratio of these curing catalysts is usually 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the composition.

Further, since the composition of the present invention can be cured at a low temperature, it can be applied not only to heat resistant substrates such as metal, glass and ceramics but also to plastics such as acrylic resin, polycarbonate resin and vinyl chloride resin. Coating and film formation can also be performed on the substrate. When forming a clear coating containing no filler on the plastic substrate for surface protection, an ultraviolet absorber may be added to the composition for protecting the underlying substrate. As the ultraviolet absorber, inorganic ultrafine particles such as zinc oxide, titanium oxide and cerium oxide, and organic ultraviolet absorbers such as benzotriazole and benzophenone can be used.

[0054]

The present invention will be described below with reference to examples.
The present invention is not limited to these. The methods for evaluating the composition and the film are as follows.

(Physical properties of the composition) Thixotropy: The fluidity disappears when left standing at 25 ° C. for 1 hour, and the fluidity is expressed again when shaken lightly by hand. Those that do not disappear are defined as "none". Storage stability: The composition is sealed and stored in a constant temperature bath at 50 ° C,
It was taken out and coated every 15 days, and the period during which the gloss and hardness did not change from the physical properties before storage was measured. Pigment dispersion stability: 80 ml of the composition was placed in a 100 ml transparent colorimetric tube and allowed to stand at 25 ° C. for 240 hours. When no pigment sedimentation was observed, “good” was given, and when sedimentation was observed, “precipitation” was given. Yes. ”

(Physical properties of coating film) Appearance: Visually confirmed, and those having no unevenness in film thickness, scratched skin, pinholes, etc. were regarded as "good". Hardness: It was evaluated by the pencil hardness test of JIS-K5400. The results are shown in pencil hardness. Adhesion: JIS-K5400 1 mm-interval cross-cut tape peeling test was performed 3 times, and the average thereof was calculated as the result.
The score can be expressed as a / 100, where a is the number of 100 grids that did not peel. Boil resistance: After boiling for 8 hours in city water, a 1 mm-interval cross-cut tape peeling test was performed 3 times, and the average was calculated as the result. The result can be expressed as a / 100, where a is the number of 100 grids that did not peel. Heat resistance: After heating for 240 hours in an electric furnace at 300 ° C., the appearance was visually confirmed and compared with the state before the test.

Weather resistance: Sunshine weather meter SW
After OM-4000 hours of exposure, the appearance was visually confirmed and compared with the state before the test. Acid resistance: 1 cc of 5% sulfuric acid was dropped on the coating film, and after storing for 240 hours in a petri dish with a lid, the appearance was visually confirmed and compared with the state before the test. Alkali resistance: 1 cc of 5% sodium hydroxide on the coating
After dropping and storing in a petri dish with a lid for 24 hours, the appearance was visually confirmed and compared with the state before the test. Gloss: 60 ° -60 ° Specular gloss was measured at 3 points with a gloss meter, and the average was calculated as the result.

[Synthesis Example] <A-1> 100 g of toluene, 20 g of methyltrichlorosilane and 5 g of methyltrimethoxysilane were mixed,
After keeping the whole reaction vessel at ice temperature, 8 g of ion-exchanged water was added dropwise over about 40 minutes with vigorous stirring, and the mixture was stirred at ice temperature for 30 minutes as it was, then 100 g of ion-exchanged water was added to form a toluene layer. I collected it. The toluene solution was washed with ion-exchanged water until the washing water was not clouded with 0.1N silver nitrate solution, and then vacuum dried to obtain a colorless transparent flake resin. This was dissolved in a solvent of xylene / IPA (isopropanol) = 30/70 volume ratio to obtain a silicone resin solution having a solid content of 25% by weight. The molecular weight of this silicone resin was 6,000.

<A-2> Toluene 100 g, methyltrichlorosilane 15 g and trichlorophenylsilane 2
After mixing 0 g and keeping the whole reaction vessel at ice temperature, 8 g of ion-exchanged water was added dropwise over about 40 minutes with vigorous stirring, and the mixture was stirred at ice temperature for 30 minutes as it is, and then 100 g of ion-exchanged water was added. Then, the toluene layer was separated. The toluene solution was washed with ion-exchanged water until the washing water was not clouded with 0.1N silver nitrate solution, and then vacuum dried to obtain a colorless transparent flake resin. This was dissolved in a solvent of xylene / IPA = 30/70 volume ratio to obtain a silicone resin solution having a solid content of 25% by weight. The molecular weight of this silicone resin was 4,000.

<A-3> A commercially available monomethyl silicone resin (TSR127B, manufactured by Toshiba Silicone, solid content: 50% by weight) was diluted 2-fold with IPA to obtain a silicone resin solution having a solid content of 25% by weight. The molecular weight of this silicone resin was 10,000.

<A-4> Commercially available methylphenyl silicone resin (TSR117, manufactured by Toshiba Silicone, solid content 50)
(Wt%) was diluted with a solvent of xylene / IPA = 30/70 volume ratio to obtain a silicone resin solution having a solid content of 25 wt%. The molecular weight of this silicone resin was 500,000.

<B-0> On the other hand, aluminum isopropoxide, IPA and water were added to a round flask equipped with a stirrer, a temperature controller and a reflux condenser, and the mixture was reacted under reflux for 24 hours, and then the temperature was changed. The IPA was distilled off while maintaining the temperature while adding water. Then, acetic acid was added to adjust the pH of the solution to 3.0, and the precipitated particles were redispersed by ultrasonic irradiation to obtain a colloidal alumina aqueous dispersion having a solid content concentration of 20% by weight.

<B-1> To a eggplant-shaped flask, 100 parts by weight of methyltrimethoxysilane and 20 parts by weight of IPA were added, stirred and heated to 70 ° C., and the colloidal alumina aqueous solution obtained in <B-0> was then added. Add 50 parts by weight of the dispersion,
After reacting as it was at 70 ° C. for 5 hours, 67 parts by weight of IPA was added to obtain a milky white liquid.

<B-2> 80 parts by weight of methyltrimethoxysilane and 23 parts of tetramethoxysilane were placed in an eggplant-shaped flask.
Add 20 parts by weight of IPA and 20 parts by weight of IPA and stir to 70
After heating to 0 ° C, 50 parts by weight of the colloidal alumina aqueous dispersion obtained in <B-0> was added, and the mixture was reacted at 70 ° C for 5 hours as it was, and then 59 parts by weight of IPA was added to obtain a milky white liquid. It was

<D-1> IPA was added to acidic colloidal silica (manufactured by Nippon Kagaku Kogyo, silica doll 30A, solid content 30% by weight) to obtain solid content 25% by weight.

<D-2> Colloidal silica dispersed in IPA (Catalyst Kasei Kogyo, Oscar 1432, solid content 3)
0% by weight) 100 parts by weight of methyltrimethoxysilane 4
Add 0 parts by weight and 1 part by weight of ion-exchanged water to 70 ° C
After 3 hours of reaction, 58 parts by weight of IPA was added to obtain a surface-coated colloidal silica dispersion liquid.

(Example 1) 10 parts by weight of A-1 solution and B-
90 parts by weight of 1 liquid were mixed and 1 part by weight of aluminum acetylacetonate was added to obtain a composition (coating liquid) of the present invention. This coating liquid was applied to a SUS304 stainless steel plate (2B treatment according to JIS standard) that had been degreased with alkali using a film applicator, and the base material was placed upright and set at room temperature for 5 minutes, then at 120 ° C. Two
Cured for 0 minutes. Table 2 shows the physical properties of the obtained coating film.

(Examples 2 to 7 and Comparative Examples 1 to 4) Table 1
The composition of the present invention (coating liquid) is prepared with the mixed composition shown in
A coating was obtained by the same treatment as in Example 1. Table 2 shows the physical properties of the obtained coating film.

Example 8 After adding a silicone resin solution, an alkoxysilane condensate, colloidal silica (collectively referred to as essential components hereinafter) and a curing agent in the composition of Example 3, 100 parts by weight of the essential components were added. On the other hand, 25 parts by weight of titanium oxide (CR90 manufactured by Ishihara Sangyo Co., Ltd.) was mixed and dispersed in a sand mill to obtain a composition of the present invention. Table 3 shows the physical properties of the obtained composition. This composition was applied to a vertically suspended alkaline degreased SUS304 stainless steel plate (2B treatment according to JIS standard) using an air sprayer so that the dry film thickness would be 40 μm, and the temperature was set as it was for 5 minutes. Cured at 120 ° C. for 20 minutes.
Table 4 shows the physical properties of the obtained coating film.

(Example 9 and Comparative Example 5) As Example 9 and Comparative Example 5, the compositions (coating solutions) shown in Example 5 and Comparative Example 4 of Table 1 were used, respectively, in the same manner as in Example 8. A film was obtained by processing. Table 4 shows the physical properties of the obtained coating film.

(Examples 10 to 12) The organoalkoxysilane of the component (F) was added to the raw compositions shown in Table 5 in Table 5.
The mixture was added at the ratio shown in Table 1 and mixed for 1 hour.
The coating and evaluation were performed in the same manner as in Example 1 and in the same manner as in Example 8 in Example 12. Table 6 shows the results.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

[Table 3]

[0075]

[Table 4]

[0076]

[Table 5]

[0077]

[Table 6]

[0078]

EFFECTS OF THE INVENTION According to the present invention, a composition having an appropriate structural viscosity and thus having excellent anti-dripping property and pigment dispersion stability at the time of coating can be obtained. When formed, a film having high hardness and excellent in crack resistance, water resistance, chemical resistance, heat resistance, and weather resistance can be obtained.

Claims (14)

[Claims] 1. A film-forming composition containing the following components (A), (B), (C) and (D) as essential components. Component (A): average composition formula _Ra Si (OH) _b O
_{(4-ab) / 2} (where a is a positive number of 0.5 to 1.5, b is a positive number of 0.01 to 1 and R is a monovalent organic group having 1 to 9 carbon atoms). A silicone resin which is an organopolysiloxane having a silanol group in the molecule and has a polystyrene-reduced weight average molecular weight of 500 to 100,000. Component (B): A substance obtained by hydrolyzing and polycondensing an organoalkoxysilane in the presence of acidic water-dispersed colloidal alumina. Component (C): hydrophilic organic solvent. Component (D): acidic colloidal silica and / or hydrophilic organic solvent dispersed colloidal silica. 2. The film-forming composition according to claim 1, further comprising a filler as the component (E). 3. The composition ratio of the component (A) and the component (B) is (A) / (B) = 1/99 to 50/50 (weight ratio) in terms of solid content, and ((A) + 100 parts by weight of (B)) and 100 to 500 parts by weight of component (C).
Alternatively, the coating forming composition according to the item 2. 4. The film-forming composition according to claim 1, wherein the silicone resin is a monomethyl silicone resin. 5. The coating forming composition according to claim 1, wherein the organoalkoxysilane is methyltrialkoxysilane. 6. The film-forming composition according to claim 1, wherein the polystyrene-reduced weight average molecular weight of the silicone resin is 3,000 to 20,000. 7. The blending amount of component (D) is 10 to 50 parts by weight based on 100 parts by weight of ((A) + (B)) in terms of solid content. A film forming composition. 8. The film formation according to claim 1, wherein the component (D) is acidic colloidal silica whose surface is coated with an organoalkoxysilane and / or hydrophilic organic solvent-dispersed colloidal silica. Composition. 9. The method according to claim 1, further comprising the following component (F).
The film-forming composition according to any one of claims 1. Component (F): R _n Si (OR ′) _4-n (where R,
R'is a monovalent organic group having 1 to 9 carbon atoms, and n is 0 or 1. )
An organoalkoxysilane represented by. 10. The weight ratio (F) / ((A) + (B)) of the component (F) to the component ((A) + (B)) is 2.0 or less in terms of solid content. 9. The film-forming composition according to item 9. 11. The method for producing a film-forming composition according to claim 1, wherein the component (A), the component (B) and the component (C) are mixed and then the component (D) is added. 12. The method for producing a film forming composition according to claim 2, wherein the components (A), (B) and (C) are mixed and then the components (D) and (E) are added. 13. The method for producing a film-forming composition according to claim 9, wherein the component (A), the component (B), the component (C) and the component (D) are mixed and then the component (F) is added. 14. A component (A), a component (B), a component (C),
The method for producing a film-forming composition according to claim 9, wherein the component (F) is added after the component (D) and the component (E) are mixed.