JPH07247434A - Water-dispersible silicone resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition consisting of a specific silicone resin particulate matter, water, a surfactant and a specific silicone resin emulsion, excellent in safety, film-forming property and weather resistance, heat resistance, water resistance and water repellency after curing and useful for coating, etc. CONSTITUTION:This resin composition is composed of (A) 100 pts.wt. of a granulate matter of a polyorganosiloxane resin expressed by average unit of formula I [R is a (substituted)monovalent hydrocarbon group; 0.2<=(n)<2.0] and having 50-250 deg.C softening point, (B) 20-10000 pts.wt. of water, (C) 0.1-10 pts.wt. of a surfactant such as a nonionic surfactant and (D) 0.1-300 pts.wt. of an emulsion of a polyorganosiloxane expressed by an average unit of formula II [R<1> is a (substituted) 1-20C monovalent hydrocarbon group or H; R<2> is OH or a hydrolyzable group; (a) and (b) each is a number satisfying the formulas 0<(a)<3, 0<(b)<2 and 1.9<(a+b)<2.2] and containing OH and a hydrolyzable group in the molecule e.g. a polymer of formula III (P is a polymerization degree). Furthermore, average particle diameter of the component A is preferably 0.1-500mum.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water-dispersed silicone resin composition, and more particularly to a water-dispersed silicone resin composition useful as a coating agent for forming a film having excellent weather resistance, heat resistance and water resistance.

[0002]

TECHNICAL BACKGROUND AND PROBLEMS OF THE INVENTION Silicone resins have been widely used as vehicles for heat-resistant paints and weather-resistant paints because of their excellent weather resistance, heat resistance, water resistance and water repellency. It is also widely used as a coating agent for the purpose of water repellency, moisture resistance, stain resistance, and release. However, in general, silicone resin is a solution of an organic solvent, and when it is used as a vehicle for paint, there is a problem of safety in handling due to flammability and also a problem of environmental pollution due to volatilization of the organic solvent. there were. Therefore, a technique of making a silicone resin into an emulsion using an emulsifier, a technique of introducing a hydrophilic group into a silicone resin to make it water-soluble, and the like are known. However, when using an emulsifier to form an emulsion, it is generally necessary to dilute the silicone resin in an organic solvent, and since a large amount of a surfactant is used, the weather resistance, heat resistance, and water resistance of the resulting coating film are reduced. There is a problem that properties such as water resistance and water repellency are deteriorated. In addition, there is a problem that a film obtained by introducing a hydrophilic group to be water-soluble does not have sufficient heat resistance, weather resistance and the like of the obtained coating film. Further, a silicone aqueous emulsion obtained by polymerizing a polydiorganosiloxane having a hydroxyl group at the terminal in the presence of colloidal silica is known (see JP-A-61-272264). It is difficult to obtain a film with sufficient hardness when used as a coating agent because it is used as a raw material, and if the amount of colloidal silica is increased to obtain hardness, the stability of the resulting emulsion decreases. There was a problem of doing.
Further, an aqueous dispersion of a silicone rubber granule, a silicone rubber granule comprising water and a surfactant (see JP-A-63-309565), and a powdery silsesquioxane emulsion insoluble in an organic solvent. (See JP-A-62-43424), which are aqueous dispersions or emulsions of cured products of silicone, and have sufficient water resistance and repellent properties when used as a coating agent. It was difficult to obtain a water-soluble and durable coating.

[0003]

OBJECT OF THE INVENTION The present invention does not use an organic solvent and is excellent in handling safety and environmental hygiene characteristics, and forms a film excellent in weather resistance, heat resistance, water resistance and water repellency by heat curing. An object of the present invention is to provide a water-dispersed silicone resin composition useful as a coating agent and the like.

[0004]

The present inventors have conducted extensive studies to achieve the above object, and as a result, have obtained a dispersion of polyorganosiloxane having a softening point of 50 to 250 ° C. as fine particles in water and an emulsion of polyorganosiloxane. By mixing
It was found that a water-dispersed silicone resin composition useful as a coating agent can be obtained, and the present invention has been completed. That is, the present invention is (A) the general formula R _n SiO _{(4-n) / 2} (wherein R represents the same or different substituted or unsubstituted monovalent hydrocarbon group, n is 0.2 ≦ n <2.0 Of the polyorganosiloxane resin having a softening point of 50 to 250 ° C. 100 parts by weight (B) Water 20 to 10,000 parts by weight (C) Surfactant 0.1 to 10 parts by weight ( D) General formula

[0005]

[Chemical 2]

(Wherein R ¹ is the same or different, substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or hydrogen atom, R ² is a hydroxyl group or a hydrolyzable group, and a and b are , 0
<A <3, 0 <b <2, and 1.9 <a + b <2.2. The present invention relates to a water-dispersed silicone resin composition comprising 0.1 to 300 parts by weight of an emulsion of polyorganosiloxane containing at least one hydroxyl group or hydrolyzable group in one molecule represented by the formula (1).

The particles of the polyorganosiloxane resin as the component (A) of the present invention are dispersed in the water as the component (B) to form a uniform water-dispersed silicone resin composition, which is cured by heating to obtain a good composition. It is the main component that forms the film. This polyorganosiloxane is represented by the above general formula, in which R represents an identical or different substituted or unsubstituted monovalent hydrocarbon group, and R represents a methyl group, an ethyl group or an isopropyl group. , Alkyl groups such as t-butyl group, octyl group, lauryl group and stearyl group, alkenyl groups such as vinyl group and allyl group, phenyl group, tolyl group, aralkyl group such as naphthyl group and vinylphenyl group, cyclopentyl group, cyclohexyl A monovalent hydrocarbon group such as a cycloalkyl group such as a group or an epoxy group,
Examples include monovalent hydrocarbon groups substituted with amino groups, methacryloxy groups, carboxyl groups, cyano groups, polyoxyalkylene groups, mercapto groups, hydroxy groups, halogen atoms, etc., but the heat resistance and water repellency of the resulting coating film. From
An unsubstituted monovalent hydrocarbon group is preferable, and particularly has 1 to 4 carbon atoms.
Alkyl groups or phenyl groups are preferred. Further, in the formula, n is a number satisfying 0.2 ≤ n <2.0, and when n is smaller than 0.2, the obtained coating becomes brittle and the water repellency also deteriorates. If n is larger than 2.0, the hardness of the obtained coating film will be insufficient and the durability will be reduced. Preferably 1.0 ≦
n <1.8. The component (A) of the present invention takes such a value of n, contains a unit such as RSiO _3/2 and SiO _4/2 unlike the polyorganosiloxane when n is 2 or more, and is generally branched. Have a structure. Further, the component (A) of the present invention preferably contains a silanol group, and the silanol group content at that time is 0.01% by weight or more since a good dispersion in water is obtained and good curability is obtained. It is preferably 20% by weight or less from the viewpoint of durability and water repellency of the obtained coating. It is particularly preferably 0.1 to 5% by weight. The component (A) of the present invention is required to have a softening point of 50 to 250 ° C, preferably 80 to 150 ° C. If the softening point is lower than 50 ° C, it becomes difficult to obtain particulate matter due to adhesion and the like, and if it is higher than 250 ° C, it becomes difficult to obtain a good cured film. Of the present invention
The component (A) is a granular material, and one of the features of the present invention is that it is dispersed in water as a granular material. The average particle size of the granules is preferably 0.01 to 500 μm, particularly preferably 0.1 to 30 μm. By using such a granular material, a good water-dispersed composition can be obtained without using an organic solvent, and a cured film formed from the composition also has good characteristics. The granules of component (A) can be obtained by using the polyorganosiloxane resin alone and using a ball mill, etc., but by mixing with the component (B) and other components and dispersing using a sand grinder or the like. At the same time, it is possible to make a granular material. The polyorganosiloxane resin of component (A) is
1 of organotrichlorosilane, diorganodichlorosilane, triorganochlorosilane or tetrachlorosilane, or alkoxysilane corresponding to these
It can be obtained by hydrolyzing two or more species. The size of the molecular weight is not particularly limited as long as it has such a polymerization degree as to exhibit the above-mentioned softening point. When hydrolyzed with an alkoxysilane, a polyorganosiloxane resin in which a silanol group produced and a remaining alkoxy group coexist may be obtained, but even if such a resin is used, it may be used if it has the above softening point. Is possible.

The water as the component (B) of the present invention is for obtaining a uniform, water-dispersible silicone resin composition by dispersing or dissolving the particulate matter of the component (A) and other components. The water is not particularly limited as long as it is water. The amount of the component (B) water to be added is 20 to 10,000 parts by weight, preferably 50 to 5,000 parts by weight, based on 100 parts by weight of the siloxane resin as the component (A). If it is more than 10000 parts by weight, it is difficult to form a film, and if it is less than 20 parts by weight, it is difficult to disperse the component (A) well.

The surfactant as the component (C) has a function of uniformly dispersing the particulate matter of the component (A) in water and improving the storage stability of the aqueous dispersion composition. As such a surfactant, there are the following nonionic surfactants, anionic surfactants, and cationic surfactants. Among these, nonionic surfactants are preferably used. Nonionic surfactants include polyoxyalkylene alkyl ether, polyoxyalkylene alkylphenol, polyoxyalkylene alkyl ester, polyoxyalkylene sorbitan ester, polyethylene glycol, polypropylene glycol, diethylene glycol trimethylnonanol ethylene oxide adduct. Is exemplified. As the anionic surfactant, hexylbenzenesulfonic acid, octylbenzenesulfonic acid, decylbenzenesulfonic acid, dodecylbenzenesulfonic acid, cetylbenzenesulfonic acid, alkylbenzenesulfonic acid such as myristylbenzenesulfonic acid, CH
₃ (CH ₂ ) ₆ CH ₂ O (C ₂ H ₄ O) ₂ SO ₃ H, CH ₃ (CH ₂ ) ₈ CH ₂ O (C ₂ H ₄ O) ₈ SO ₃
H, CH ₃ (CH ₂ ) ₁₉ CH ₂ O (C ₂ H ₄ O) ₂ SO ₃ H, CH ₃ (CH ₂ ) ₈ CH ₂ C ₆ H ₄ O
Examples thereof include sulfuric acid ester of polyoxyethylene monoalkyl ether such as (C ₂ H ₄ O) ₂ SO ₃ H, and alkylnaphthylsulfonic acid. As the cationic surfactant, octyltrimethylammonium hydroxide, dodecyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide, octyldimethylbenzylammonium hydroxide, decyldimethylbenzylammonium hydroxide, dioctadecyldimethylammonium hydroxide, beef tallow trimethyl. Examples include ammonium hydroxide, quaternary ammonium hydroxides such as coconut oil trimethylammonium hydroxide, and salts thereof. Polyether-modified silicone is also exemplified as the surfactant. Among these, the polyether-modified silicone is preferably used because of its good effect. The blending amount of the component (C) surfactant is
The amount of component (A) is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, based on 100 parts by weight. From the viewpoint of obtaining good dispersibility, it is preferably 0.1 part by weight or more, and from the viewpoint of heat resistance and water resistance of the obtained cured film, it is preferably 10 parts by weight or less.

The component (D) of the present invention is an emulsion of polyorganosiloxane containing at least one hydroxyl group or hydrolyzable group in one molecule, and has good film-forming property and substrate Provides good adhesion to the like. In the above general formula representing the polyorganosiloxane of the component (D), R ¹ is the same or different and is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom.
Examples of the valent hydrocarbon group include the same groups as the above R, but from the viewpoint of film forming property, an alkyl group, particularly a methyl group is preferable, and from the viewpoint of adhesion to a substrate, heat crack resistance, etc.,
Amino group-containing group, epoxy group-containing group and alkenyl group-containing group are preferable, and vinylphenyl group is particularly preferable. Examples of the hydrolyzable group of R ² include alkoxy groups such as methoxy group, ethoxy group, propoxy group and butoxy group, and acyloxy group, amino group, aminoxy group, oxime group, ketoxime group, amide group, alkenyloxy group. To be done. From the viewpoint of easy handling, R ² is preferably a hydroxyl group or an alkoxy group, and particularly preferably a hydroxyl group. The structure of this polyorganosiloxane may be linear, branched, or cyclic, and in the general formula showing the polyorganosiloxane of component (D), a and b are 0 <a <3, 0 <b < 2, 1.9 <
As long as a + b <2.2 is satisfied, 2.0 ≦ a + b <2.2 is preferable and a linear one is preferable from the viewpoint of heat crack resistance. The molecular weight of the polyorganosiloxane of component (D) is 1,00 because of its good film-forming properties and heat crack resistance.
0 to 1,000,000, particularly 10,000 to 600,000 are preferred.
The component (D) is an emulsion of the polyorganosiloxane described above and is prepared using a surfactant and water.Examples of the surfactant are the same as those of the component (C). Surfactants and cationic surfactants are preferred. Surfactant is polyorganosiloxane
5 to 100 parts by weight, preferably 10 to 50 parts by weight per 100 parts by weight
Used by weight. Water is polyorganosiloxane 1
50 to 1000 parts by weight, preferably 100 to 30 parts by weight
Used 0 parts by weight. The emulsion of the component (D) of the present invention can be obtained by a known method. For example,

[0011]

[Chemical 3]

The polyorganosiloxane represented by or a polymer bonded to these silicon atoms

[0013]

[Chemical 4]

An example is a method in which a polyorganosiloxane substituted with a group such as is mixed with a surfactant and water to form an emulsion in an emulsifier. Alternatively, a polyorganosiloxane emulsion can also be obtained by mixing a cyclic polysiloxane monomer such as octamethylcyclotetrasiloxane with a surfactant and water, emulsifying it, and polymerizing it using an acid or base catalyst. it can. When emulsion polymerization is performed using such a cyclic polysiloxane monomer, an aminosilane such as γ-aminopropylmethyldiethoxysilane or an epoxysilane such as γ-glycidoxypropylmethyldimethoxysilane is added. Thus, an emulsion of polyorganosiloxane having an amino group or an epoxy group can be obtained. Further, p-vinylphenylmethyldimethoxysilane can be used to obtain an emulsion of polyorganosiloxane having a p-vinylphenyl group. In the present invention, such
The component (D) can form a film only with the components (A), (B), and (C) without any special blending.However, film formability, adhesion to the substrate, and heat cracking of the film Sex, flexibility,
It is necessary to incorporate the component (D) in order to improve durability.

The amount of component (D) blended is 100 parts by weight of component (A) as an emulsion of polyorganosiloxane.
The amount is 0.1 to 300 parts by weight, preferably 1.0 to 200 parts by weight. If it is less than 0.1 part by weight, it is not effective in imparting the heat crack resistance of the film, and if it exceeds 300 parts by weight, the heat-curing property is deteriorated and the useful coating agent aimed at by the present invention cannot be obtained.

The composition of the present invention may contain a catalyst, inorganic particles, a pigment and the like as other components. The catalyst acts as a catalyst when the component (A) is cured by heating, and enables curing at a lower temperature, shortens the curing time, and is effective in improving the curability. Examples of such a catalyst include metal salts of carboxylic acids such as alkyl titanates, tin octylate and dibutyltin dilaurate, dioctyltin dimaleate; dibutylamine-2-
Amine salts such as hexoate, dimethylamine acetate, ethanolamine acetate; carboxylic acid quaternary ammonium salts such as tetramethylammonium acetate; amines such as tetraethylpentamine; N-β-aminoethyl-γ-aminopropyltrimethoxy Silane, N-β
-Amine-based silane coupling agents such as aminoethyl-γ-aminopropylmethyldimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid, hydrochloric acid; aluminum compounds such as aluminum alkoxides and aluminum chelates; alkalis such as potassium hydroxide Examples of the catalyst include titanium compounds such as tetraisopropyl titanate, tetrabutyl titanate, and titanium tetraacetylacetonate. Other than these, the catalyst is not particularly limited as long as it serves as a catalyst for the condensation curing reaction of the component (A). The amount of the catalyst blended is preferably 0.01 to 5 parts by weight, more preferably 0.5 to 2.5 parts by weight, based on 100 parts by weight of the component (A). (A)
The component is hardened by heating without adding a catalyst,
It is preferably 0.01 parts by weight or more because good curability is obtained, and cracks are less likely to occur in the obtained cured coating and the adhesion to the substrate is good, so 5 parts by weight or less is preferable. Water-soluble catalysts
It may be dissolved as it is in water which is the dispersion medium of the present invention,
A water-insoluble and liquid one may be dispersed as an emulsion, and a water-insoluble and solid substance may be dispersed as a granular material in the same manner as the component (A).

The inorganic particles make it easier for the component (A) to form a coating film, enhance the strength of the coating film, and further improve the stability and dispersibility of the aqueous dispersion composition when used in combination with a surfactant. Show the effect. As such inorganic particles,
Examples of the powder include silica, mica, clay, kaolin, barite, aluminum hydroxide, aluminum oxide, calcium carbonate, magnesium carbonate, barium sulfate and aluminum. In addition, these powders are treated with organosilane,
It may be surface-treated with organosiloxane, organosilazane or the like. The shape of the particles may be either spherical or amorphous, but the average particle diameter is preferably 30 μm or less. Among these, silica is preferable, and fumed silica and wet silica are particularly preferably used because the composition has good stability, the transparency of the coating film is good, and the colorability at the time of compounding the pigment is good. The blending amount of the inorganic particles is preferably 1 to 9,000 parts by weight, and particularly preferably 10 to 500 parts by weight with respect to 100 parts by weight of the component (A). The amount is preferably 1 part by weight or more from the viewpoint of obtaining a good effect, and is preferably 9000 parts by weight or less from the viewpoint of film formability and strength.

The pigment is added when the composition of the present invention is used as a paint or the like, but it also has the effect of improving the dispersibility and stability of the composition. Zinc oxide as a pigment,
Iron oxide, cadmium red, carbon black, graphite, ceramic black, chromium oxide, cobalt green, gine green, cadmium yellow, titanium oxide, titanium-based yellow pigment, cobalt blue, konjac,
Examples thereof include phthalocyanine blue and those obtained by surface-treating these with a silane coupling agent or the like. The amount of the pigment to be blended may be adjusted according to the desired degree of color, but from the characteristics of the obtained coating, it is recommended that 100 parts by weight of component (A) be used.
It is preferably 100 parts by weight or less.

The composition of the present invention further comprises, if necessary, a leveling agent, an antifoaming agent, a thickener, a dye, an antioxidant, an ultraviolet absorber, and an extender such as aluminum paste, glass frit and metal powder. Resins such as acrylic resin, urethane resin, epoxy resin, melamine resin, and silicone-acrylic resin can also be blended. If necessary, a small amount of water-soluble organic solvent can be used.

The composition of the present invention is obtained by simultaneously blending the components (A) to (D) and, if necessary, other components and uniformly dispersing them using a ball mill, a triple roll, a sand grinder or the like. To be The component (A) and the other components may be granulated in advance, but in this step in which pulverization is possible, the granulation may be performed simultaneously with the dispersion. In addition, even if the components other than water as the component (B) are mixed at the same time, dry pulverized and mixed with a ball mill, etc., the component (B) is added and the composition is prepared using another high-speed stirrer or the like. Good. Furthermore, (D)
The composition of the present invention may be prepared by separately preparing an emulsion of the components, preparing an aqueous dispersion composition from the other components by the above-mentioned method, and mixing these. A cured coating can be obtained by applying the composition of the present invention to various substrates by a method such as spray coating, dip coating, roller coating, flow coating or casting method and heating.

[0021]

The water-dispersed silicone resin composition of the present invention is obtained by dispersing a specific silicone resin in water as granules, and further blending an emulsion of a specific organopolysiloxane in the dispersion liquid. Since it does not need to be used, it is excellent in handling safety and environmental hygiene characteristics, and by heat curing it forms a film excellent in weather resistance, heat resistance, water resistance, water repellency, and heat crack resistance. Therefore, the water-dispersed silicone resin composition of the present invention,
A surface protective agent that forms a film that imparts weather resistance, water resistance, water repellency, etc. to a metal such as aluminum, stainless steel, copper, iron, duralumin or a wall material made of glass, cement, gypsum, or the like It is useful as a paint that gives the appearance.

[0022]

The present invention will be described in detail below with reference to Examples and Comparative Examples. All "parts" in the examples are "parts by weight".
"%" Means "% by weight", and the viscosity shows a value at 25 ° C. Preparation of component (A) Synthesis example 1 1000 parts of water and 50 parts of acetone were weighed into a flask, and 0.3 mol of methyltrichlorosilane, 0.2 mol of dimethyldichlorosilane and phenyltrichlorosilane were added to the mixed solution.
What melt | dissolved 0.5 mol in 200 parts of toluene was dripped, stirring. After 40 minutes from the completion of dropping, the stirring was stopped, the lower layer hydrochloric acid water separated into two layers was removed, and the water and hydrochloric acid remaining in the upper layer polyorganosiloxane toluene solution were decompressed with excess toluene. After removal, a polyorganosiloxane resin solid (A-1) having an average molecular weight of 5000, a softening point of 90 ° C. and a silanol group content of 4.0% was obtained. This siloxane resin is represented by the general formula (CH ₃ ) _0.7 (C ₆ H ₅ ) _0.5 SiO _1.4 . Synthesis Example 2 Average molecular weight was the same as in Synthesis Example 1 except that 0.2 mol of dimethyldichlorosilane was changed to 0.2 mol of diphenyldichlorosilane and stirring was stopped 120 minutes after completion of dropping.
A polyorganosiloxane resin solid (A-2) having a softening point of 110 ° C. and a silanol group content of 5.0% was obtained. The siloxane resin is represented by the general formula _{(CH 3) 0.3 (C 6} H 5) 0.9 SiO 1.4. Synthesis Example 3 Methyltriisopropoxysilane 1.0 mol and toluene 1
Weigh the mixture with 50 parts into a flask, and add 1% hydrochloric acid solution.
108 parts was added dropwise to this mixture to hydrolyze the methyltriisopropoxysilane. Further, after removing hydrochloric acid water and further removing toluene and the like under reduced pressure in the same manner as in Example 1, the average molecular weight is 12000, the softening point is 105 ° C., and the silanol group content is 1.2%.
A solid polyorganosiloxane resin (A-3) was obtained. This siloxane resin is represented by the general formula (CH ₃ ) _1.0 SiO _1.5 . Synthesis Example 4 Solid polyorganosiloxane resin obtained in Synthesis Example 3
(A-3) 100 parts, toluene 200 parts, trimethylchlorosilane 10 parts and hexamethyldisilazane 50 parts were charged into a flask and heated and stirred. After heating and stirring for 2 hours at the reflux temperature of toluene, ammonia, hydrochloric acid or salts thereof generated by the reaction are removed by washing with water, and toluene is distilled off under reduced pressure to obtain an average molecular weight of 8500, a softening point of 90 ° C and a silanol group content of 0.3. % Polyorganosiloxane resin solids
(A-4) was obtained. This siloxane resin has the general formula (CH ₃ ) _1.03
It is shown by SiO _1.49 .

Preparation of component (D) Synthetic Example 5 400 parts of octamethylcyclotetrasiloxane was placed in 750 parts of distilled water in which 50 parts of dodecylbenzenesulfonic acid were dissolved, and the mixture was stirred for 3 minutes with a homomixer, and then super-mixed. It was emulsified and dispersed by a sonic disperser for 5 minutes. This mixed solution was transferred to a separable flask equipped with a condenser, a nitrogen inlet and a stirrer and heated with stirring and mixing at 90 ° C for 4 hours, then left at room temperature (25 ° C) for 2 hours, and then with triethanolamine. After neutralization, an emulsion (D-1) of polyorganosiloxane as the component (D) was obtained. The obtained organopolysiloxane has an average molecular weight of 2 in terms of polystyrene.
It was 0,000 and was represented by the following general formula.

[0024]

[Chemical 5]

Synthesis Example 6 An emulsion (D-2) of component (D) polyorganosiloxane was obtained in the same manner as in Synthesis Example 5 except that the mixture was heated at 90 ° C. for 6 hours and then left at 5 ° C. for 4 hours. . The obtained organopolysiloxane had an average molecular weight of 100,000 in terms of polystyrene and was represented by the following general formula.

[0026]

[Chemical 6]

Synthetic Example 7 1.5 parts of p-vinylphenylmethyldimethoxysilane and 98.5 parts of octamethylcyclotetrasiloxane were mixed, and this was put into 300 parts of distilled water in which 2.0 parts of dodecylbenzenesulfonic acid was dissolved, and the mixture was mixed with a homomixer to 3 parts. The mixture was stirred for 1 minute, and then emulsified and dispersed by an ultrasonic disperser for 5 minutes. This mixture was transferred to a separable flask equipped with a condenser, a nitrogen inlet and a stirrer, heated with stirring and mixing at 85 ° C for 6 hours, cooled at 15 ° C for 4 hours, and further neutralized with an aqueous sodium carbonate solution, An emulsion (D-3) of the polyorganosiloxane as the component (D) was obtained. The obtained organopolysiloxane had an average molecular weight of 500,000 in terms of polystyrene and was represented by the following general formula.

[0028]

[Chemical 7]

Synthesis Example 8 Using 5.0 parts of p-vinylphenylmethyldimethoxysilane and 95.0 parts of octamethylcyclotetrasiloxane, 5 ° C.
An emulsion (D-4) of polyorganosiloxane as the component (D) was obtained in the same manner as in Synthesis Example 7 except that the mixture was cooled for 12 hours. The obtained organopolysiloxane had an average molecular weight of 500,000 in terms of polystyrene and was represented by the following general formula.

[0030]

[Chemical 8]

Example 1 100 parts of A-1 as the component (A), 150 parts of water as the component (B),
Polyether-modified silicone oil (Toshiba Silicone Co., Ltd., trade name TSF4440) is used as the component (C) surfactant.
1.0 part of white pigment, 72 parts of white pigment titanium oxide (trade name: R-820, manufactured by Ishihara Sangyo Co., Ltd.) was weighed, pulverized and dispersed with a sand grinder, and the tube cage method according to JIS K 5400 was used.
The particles were dispersed until there were no particles of 15 μm or more. After dispersion, 80 parts of component (D) D-3 was further added to prepare a uniform mixed solution, which was used as a white paint. Spray paint the obtained white paint on an aluminum substrate, leave it at room temperature for 1 hour, and then at 250 ℃
It was heat-cured for 30 minutes to form a film, which was used as a test piece. The coating was 30 μm thick and had a pencil hardness of F. About this test piece, sunshine weatherometer (JIS K 5400
The weather resistance acceleration test was performed for 2000 hours, and the coating film was observed. As a result, almost no change was observed in comparison with the coating film before the test, and good durability was confirmed. Furthermore, using the test piece, a warm water test (immersion at 60 ° C for 10 days) and a boiling water test (3
When the coating film was observed by immersing for a period of time), there was no peeling of the coating film, and almost no change was observed compared with the coating film before the test. Examples 2 to 6 Example 1 under the composition of each component and heat curing conditions shown in Table 1
White paint and test pieces were prepared in the same manner as in. Further, a coating film test was carried out in the same manner as in Example 1. The results are shown in Table 1.
As shown in Table 1, good durability was confirmed.

[0032]

[Table 1]

Comparative Examples 1 and 2 White paints and test pieces were prepared in the same manner as in Examples 1 and 2 except that the component (D) was not blended. Further, a coating film test was carried out in the same manner as in Example 1. The results are shown in Table 2.

[0034]

[Table 2]

Examples 7 and 8 Except that the acid value titanium of the white pigment used in Examples 1 and 3 was changed to a water dispersible type aluminum base (manufactured by Toyo Aluminum Co., Ltd., trade name: Alpaste 0500M). The same procedure as in Example 1 was carried out to obtain an aluminum powder-dispersed coating material. Spray coating the obtained aluminum powder dispersion paint on mild steel plate,
It was heat-cured at 00 ° C. for 30 minutes to form a film, which was used as a test piece. The coating thickness was 30 μm. This test piece at 550 ℃
When a heat resistance test was conducted for 200 hours, the coating was ceramicized but retained without peeling from the substrate.

Claims (2)

[Claims] (A) General formula R _n SiO _{(4-n) / 2} (wherein R represents the same or different substituted or unsubstituted monovalent hydrocarbon group, and n is 0.2 ≦ n <2.0. Of the polyorganosiloxane resin having a softening point of 50 to 250 ° C. 100 parts by weight (B) Water 20 to 10,000 parts by weight (C) Surfactant 0.1 to 10 parts by weight ( D) General formula (Here, R ¹ is the same or different, substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or hydrogen atom, R ² is a hydroxyl group or a hydrolyzable group, and a and b are 0 < a <3, 0 <
It is a number that satisfies b <2 and 1.9 <a + b <2.2. ) A water-dispersed silicone resin composition comprising 0.1 to 300 parts by weight of an emulsion of a polyorganosiloxane containing at least one hydroxyl group or hydrolyzable group in one molecule represented by the formula (1). 2. The water-dispersed silicone resin composition according to claim 1, wherein the granular material of the component (A) has an average particle diameter of 0.1 to 500 μm.