JP3445831B2 - Silicone resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention relates to a silicone resin composition containing an alkoxy-terminated polyorganosiloxane,
More specifically, it is excellent in storage stability when a catalyst is added, can be used as a coating agent for solvent-free clear paints and enamel paints, and the obtained coating agent is cured at room temperature and heat treatment and The present invention relates to a silicone resin composition which gives a film excellent in solvent resistance, releasability, water / oil repellency, weather resistance and stain resistance.

[0002]

[Background of the Invention and Related Problems] Conventionally, it is common to bake polyorganosiloxane resin having a hydroxyl group bonded to a silicon atom at a high temperature of 150 ° C or higher, sometimes 200 ° C or higher. Recently, a room temperature curable solventless silicone resin composition has been proposed. For example, U.S. Pat. No. 3,350,349 discloses a solventless silicone resin composed of a polyorganosiloxane resin having a hydroxyl group bonded to a silicon atom and an aminoalkylalkoxysilane, and U.S. Pat. A room temperature curable silicone resin composition comprising a polyorganosiloxane resin having a hydroxyl group bonded to an atom and an alkenylacetoxysilane is described. However, both the aminoalkylalkoxysilane and the alkenylacetoxysilane are stored in a solution of a polyorganosiloxane resin having a silicon atom-bonded hydroxyl group, because the resulting mixed solution gels in a short time. It has the drawback of poor stability. Due to this drawback, such a solventless silicone resin composition is subject to a large restriction that the components must be mixed immediately before use, and there is a problem that workability is extremely poor. Further, a coating obtained by curing such a composition at room temperature has poor solvent resistance and has a drawback that it easily swells in xylene, acetone or the like. Further, Japanese Patent Publication No. 56-15827 describes a composition comprising a hydroxyl group-containing polyorganosiloxane resin, an alkoxy group-containing polysiloxane resin, an alkoxysilane, an aminoalkylalkoxysilane and an organic solvent. However, with global environmental issues being emphasized today, in various industrial chemistry fields, particularly in the fields of paints and adhesives, air pollution caused by the emission of volatile organic substances (VOCs), that is, organic solvents, into the atmosphere As a result, problems such as photochemical smog, acid rain, and global warming are becoming more serious. Therefore, in the paint industry, as a measure against this VOC, high solidification of paints and conversion to water-based paints are being promoted, and the range of using aromatic, aliphatic, or chlorine-containing solvents as organic solvents is It tends to be extremely limited. Further, in the above composition, it is shown that an aminoalkylalkoxysilane is blended as a curing catalyst to be used as a one-pack type, but the storage stability when used as a paint is not sufficient,
In addition, there is a problem in that the use time for coating the base material is insufficient.

[0003]

OBJECTS OF THE INVENTION The inventors of the present invention have conducted extensive studies to solve the above-mentioned drawbacks and to provide a silicone resin composition having excellent performance as a coating agent. As a result, a specific alkoxy-terminated polyorganosiloxane composition was obtained. By using a curing catalyst as the main component, it has good storage stability without solvent, and has excellent solvent resistance, mold release, water and oil repellency, weather resistance, and stain resistance. The inventors have found that a coating agent that forms a film can be obtained, and completed the present invention.

[0004]

That is, the present invention is based on the RSiO _3/2 unit (where R
Are the same or different from each other and represent a substituted or unsubstituted monovalent hydrocarbon group) and R ₂ SiO _2/2 units (wherein R represents the same group as described above) (the ratio is R ₂ SiO _{2 / 2} units /
RSiO _3/2 units have a molar ratio of 0.1 to 1.5)
(R ¹ O) _a R _(3-a) SiO _1/2 unit (wherein R is the same group as described above, R ¹ is the same or different from each other, substituted or unsubstituted monovalent hydrocarbon group, a Represents an integer of 2 or 3), and a silicone resin composition comprising an alkoxy-terminated polyorganosiloxane sealed with.

The alkoxy-terminated polyorganosiloxane used in the present invention is composed of a trifunctional siloxane unit (RSiO _3/2 unit) and a bifunctional siloxane unit (R ₂ SiO _2/2 unit), and has 2 or 3 terminals. A polyorganosiloxane sealed with a siloxane unit having an alkoxy group ((R ¹ O) _a R _(3-a) SiO _1/2 unit), which is the main component of the silicone resin composition of the present invention. Is. Here, in the formula of the siloxane unit, R's represent mutually the same or different substituted or unsubstituted monovalent hydrocarbon groups, and as R's, a methyl group, an ethyl group, a propyl group, a t-butyl group, 2-
Ethylhexyl group, dodecyl group, 1-isobutyl-3,5
-Dimethylhexyl group, alkyl group such as octadecyl group, vinyl group, allyl group, propenyl group, butenyl group,
Butadienyl group, alkenyl group such as hexadienyl group, cyclopentyl group, cycloalkyl group such as cyclohexyl group, cyclopentenyl group, cyclohexenyl group, cycloalkenyl group such as cyclo-2,4-hexadienyl group, phenyl group, tolyl group, mesityl group Group, xylyl group, aryl group such as naphthyl group, benzyl group, phenylethyl group, aralkyl group such as styryl group, and chloromethyl group in which hydrogen atom of these groups is substituted with halogen atom, 3,3,3 -Trifluoropropyl group,
3,3,4,4,5,5,5-heptafluoropentyl group, perchlorophenyl group, 3,4-dibromo-1-chlorohexyl group, 2,2,2-trifluorotolyl group, 2,4- Examples thereof include a dibromobenzyl group, a difluoromonochlorovinyl group, a 2,3,3-trifluoro-2-chlorocyclobutyl group and a 2-iodocyclohexenyl group. Among these,
An alkyl group, an allyl group, and a fluoroalkyl group are preferable, and a methyl group and a phenyl group are particularly preferable, because the resulting coating has good releasability and water repellency. Further, R ¹ is exemplified by the same groups as R, among which a methyl group, an ethyl group, since good curability and storage stability of the resulting composition can be obtained.
An isopropyl group and an n-butyl group are preferable, and an ethyl group is particularly preferable. In the siloxane unit having an alkoxy group, a representing the number of alkoxy groups is 2 or 3
By containing an alkoxy-terminated polyorganosiloxane sealed with such a siloxane unit, the composition of the present invention can obtain good storage stability even when a curing catalyst is added, A coating with properties is obtained. The ratio of RSiO _3/2 units to R ₂ SiO _2/2 units is R ₂
The molar ratio represented by SiO _2/2 unit / RSiO _3/2 unit is 0.1 to 1.
5, especially in the range of 0.5 to 1.0, the durability and stain resistance of the obtained coating film are good, which is preferable.

The alkoxy-terminated polyorganosiloxane of the present invention is obtained by reacting a hydroxyl group-containing polyorganosiloxane resin produced by a conventionally known method with an alkoxysilane. The hydroxyl group-containing polyorganosiloxane resin used here is a cyclic group having a hydrolyzable group consisting of two silanes, three silanes and a bifunctional siloxane unit corresponding to the siloxane unit of the alkoxy-terminated polyorganosiloxane of the present invention. It can also be obtained by mixing siloxane and hydrolyzing and condensing, or by further hydrolyzing and condensing each silane or siloxane separately, and then mixing and condensing each of the obtained condensates. Can also be obtained. Examples of the hydrolyzable group of the silane as a raw material include a halogen atom, an alkoxy group, an acetoxy group, an oxime group, an aminoxy group, an amino group, an amide group, and the like. Ethoxy groups are preferred. Examples of the cyclic siloxane include hexaorganocyclotrisiloxane, octaorganocyclotetrasiloxane, and decaorganocyclopentasiloxane. Particularly, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and the like are preferably used. It
The alkoxy-terminated polyorganosiloxane used in the present invention is obtained by reacting the hydroxyl group-containing polyorganosiloxane resin obtained as described above with an alkoxysilane having 3 or 4 alkoxy groups to obtain (R ¹ O) _a R _(3-a) S
It is obtained by encapsulating with iO _1/2 units (where a is an integer of 2 or 3). Examples of the alkoxysilane having 3 or 4 alkoxy groups include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, methyltri (methoxyethoxy) silane, vinyltrimethoxysilane,
Trialkoxysilanes such as allyltrimethoxysilane, allyltriethoxysilane, and 3,3,3-trifluoropropyltrimethoxysilane, orthosilicates such as methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and hexyl orthosilicate are exemplified. Since the hardness and releasability of the coating film obtained when the composition of the present invention is cured become preferable,
Methyltrimethoxysilane, methyltriethoxysilane, methylorthosilicate, ethylorthosilicate are preferable, and 3,3,3-trifluoropropyltrimethoxysilane is preferable because the resulting coating has good water repellency. used. The alkoxy-terminated polyorganosiloxane is obtained by reacting a hydroxyl group-containing polyorganosiloxane resin with an alkoxysilane as described above, and the amount of these raw materials to be compounded is such that the terminals are efficiently blocked and the hydroxyl group-containing polyorganosiloxane is used. Since the organosiloxane resin is less likely to gel, it is preferable to use 30 parts by weight or more of alkoxysilane per 100 parts by weight of the hydroxyl group-containing polyorganosiloxane resin. In order to obtain a good resin yield when obtaining the resin, it is preferably 70 parts by weight or less. In particular, it is preferably 40 to 60 parts by weight.

A catalyst is preferably used in the reaction of the hydroxyl-containing polyorganosiloxane resin and the alkoxysilane. Examples of such a reaction catalyst include hydroxides, oxides, or basic metal salts of alkali metals or alkaline earth metals, specifically, alkaline earth metals such as calcium hydroxide and magnesium hydroxide. Hydroxides, chlorides of alkaline earth metals such as calcium chloride and magnesium chloride, oxides of alkaline earth metals such as calcium oxide and magnesium oxide, and basic metal salts such as basic zinc carbonate and basic magnesium carbonate. It can be illustrated. Further, as other catalysts, aluminum chelate compounds, organic titanium compounds, organic tin compounds, aminoalkylalkoxysilanes, ammonium salts and the like can be used. Examples of the aluminum chelate compound include aluminum ethyl acetoacetate diisopropylate, aluminum tris (ethyl acetate) aluminum tris (ethyl acetonate), and aluminum bisethyl acetoacetate monoacetyl acetonate. Examples of the organic titanium compound include tetraisopropoxy titanium, tetra-n-butoxy titanium, and tetrakis (2-ethylhexoxy) titanium. Organic tin compounds include dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctoate, stannous octoate, stannous naphthenate, stannous oleate, stannous isobutyrate, stannous linoleate, stearic acid Stannous, stannous benzoate, stannous naphthoate,
Stannous laurate, stannous o-timate, stannous β-benzoylpropionate, stannous crotonic acid, stannous tropate, stannous p-bromobenzoate, stannous palmitooleate Examples include tin, stannous cinnamate, and tin salts of carboxylic acids such as stannous phenylacetate. As the aminoalkylalkoxysilane, γ-aminopropyltrimethylmethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N- ( Examples include β-aminoethyl) -γ-aminopropylmethyldimethoxysilane and γ- (dimethylamino) propyltrimethoxysilane. Examples of the ammonium salt include salts of acids and amines, examples of the acid include acetic acid and formic acid, and examples of the amine include allylamine, 2-ethylhexylamine, 3-ethoxypropylamine, diisobutylamine, 3-diethylaminopropylamine and di-amine. 2-ethylhexylamine, dibutylaminopropylamine, tri-n-octylamine,
Examples thereof include t-butylamine, s-butylamine, propylamine, 3-methoxypropylamine and the like. Among these reaction catalysts, it shows good catalytic activity even at a temperature of 100 ° C or lower, is industrially easy to synthesize, and can be sublimated by heating at 200 ° C or lower after the reaction is completed. Ammonium salts are preferable, and diisobutylammonium salt of formic acid and t-butylammonium salt of formic acid are particularly preferable because the storage stability of the agent becomes good. In the case of ammonium salt,
The amine and the acid may be separately added to the reaction system to form a salt in the system. The amount of the reaction catalyst added is such that the hydroxyl group-containing polyorganosiloxane resin 1
With respect to 00 parts by weight, 1 part by weight or more is preferable, and 30 parts by weight or less is preferable, and 3 to 25 parts by weight is particularly preferable because the curability of the obtained coating agent is good.

It is preferable to add an organosiloxane oligomer obtained by partially hydrolyzing a silane represented by the general formula RSi (OR ¹ ) ₃ to the silicone resin composition of the present invention. By adding such an organosiloxane oligomer, the coating properties and curability of the resulting silicone resin composition will be good, and the storage stability of the composition containing the curing catalyst will be good. . In the above general formula, R ¹ and R ¹ are R represented by an alkoxy-terminated polyorganosiloxane,
The same as R ¹ is exemplified. The organosiloxane oligomer reacts with 1/6 to 1 mol of water based on 1 mol of the alkoxysilane and the alkoxy group represented by the above general formula to partially hydrolyze and then partially condense, and further removes unreacted monomers. It is obtained by The siloxane oligomer thus obtained contains an alkoxy group and does not contain a hydroxyl group. In the present invention, it is preferable to add a material containing an alkoxy group in an amount of 10 to 80% by weight, particularly 40 to 60% by weight. Furthermore, those obtained by co-condensing tetraalkyl silicate, titanic acid ester and the like may be used. The viscosity of siloxane oligomer is 10 to 10,000
It is preferable to use cP, particularly 20 to 2,000 cP, because good coatability can be obtained. Specifically, the following structures are exemplified. (R (R ¹ O) ₂ SiO _1/2 ) _m (R (R ¹ O) SiO _2/2 ) _n (RSiO _3/2 ) _p where m, n and p are the above-mentioned alkoxy group content and viscosity. Is an integer that satisfies. The addition amount of the organosiloxane oligomer is 0.1 to 30 with respect to 100 parts by weight of the alkoxy-terminated polyorganosiloxane because good effects can be obtained.
It is preferably used in the range of 0 parts by weight, particularly 30 to 10 parts by weight.
It is preferable to use 0 part by weight.

Examples of the curing catalyst used in the present invention include aminoalkylalkoxysilanes and organic tin compounds. Specifically, those exemplified as the reaction catalyst of the above-mentioned hydroxyl group-containing polyorganosiloxane resin and alkoxysilane are mentioned. It is similarly exemplified.

The compounding amount of the curing catalyst is preferably 0.01 to 40 parts by weight, particularly 0.1 to 20 parts by weight, based on 100 parts by weight of the alkoxy-terminated polyorganosiloxane. In the present invention, it is preferable to use an aminoalkylalkoxysilane and an organotin compound in combination, good curability can be obtained, adhesion of the cured coating to the substrate becomes good, and the cured coating can be yellowed even at high temperature. Aminoalkylalkoxysilane is 0.1 to 30 parts by weight per 100 parts by weight of alkoxy-terminated polyorganosiloxane because it does not cause discoloration.
It is preferable to use 1 part by weight, especially 1 to 10 parts by weight. Further, since the organotin compound can obtain good curability and storage stability, it is an alkoxy-terminated polyorganosiloxane.
It is preferable to use 0.01 to 10 parts by weight, especially 0.1 to 2 parts by weight per 100 parts by weight.

In the silicone resin composition of the present invention, if necessary, a small amount of various additives such as a plasticizer, a release agent, a flame retardant, an antioxidant, an ultraviolet absorber, titanium dioxide, carbon black or an oxidation agent is added. You may mix pigments and dyes, such as iron. Similarly, fumed silica, silica airgel, silica gel, and reinforcing silica fillers obtained by treating these with organosilanes, organosiloxanes or organosilazanes, asbestos, crushed fused quartz, aluminum oxide, aluminum silicate, zirconium silicate. , Magnesium oxide, zinc oxide, talc, diatomaceous earth, mica, calcium carbonate, clay, zirconia, glass,
Fillers such as sand, graphite, barium sulfate, zinc sulfate, aluminum powder, sawdust, cork, fluorocarbon polymer powder, silicone rubber powder, and silicone resin powder may be blended. Further, an organic solvent may be added if necessary.

[0012]

The silicone resin composition of the present invention is excellent in storage stability when a curing catalyst is added, and can be used as a solvent-free coating agent, so that it can be preferably used in environmental hygiene. It also shows good curability at room temperature and heat treatment, and the cured film obtained has solvent resistance, releasability,
It is characterized by excellent water repellency, heat resistance, and weather resistance.
The silicone resin composition of the present invention can be used in various coating agents, for example, water, oil, snow, paints, stains, foods,
Coating agent for the purpose of preventing adhesion, peeling or releasing of adhesives, mud, dust, raw rubber, latex, water stains, etc.
A coating agent to protect the surface of various base materials and coated surfaces from the effects of ultraviolet rays, air, water, corrosive gases, acidic and alkaline corrosive liquids, various solvents, etc. Coating properties for improving electrical properties, especially electrical insulation properties, coatings for the purpose of reducing the viscous resistance of the fluid that acts on the interface in contact with the fluid, and imparting water repellency to porous substrates such as concrete and ceramic filters. The intended coating agent is exemplified.
It can be applied to almost any substrate as a coating object, for example, metal, plastic, glass, wood, rubber, mortar, concrete, brick, tile, slate, and the like, and specific objects include automobiles, Ships, molds, cookers, tableware, utility poles, guardrails, road signs, road structures, plant interior and exterior wall surfaces, ozone bath tub surfaces, relays, terminals, glass, spark plugs, printed boards, electrical contacts,
Examples include electric wires, inner and outer surfaces of liquid delivery pipes, bridges, buildings, joints of tiles, various devices and parts, engines, mudguards for cars, window glass, and wall surfaces of reservoirs. Furthermore,
The composition of the present invention can be blended also as a modifier with various resins such as epoxy resin, urethane resin, polyolefin resin, polyester resin, polycarbonate resin, polyamide resin, fluororesin, acrylic resin, phenol resin, and silicone rubber. It is effective in improving moldability, water repellency, water resistance and the like.

[0013]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to this. In the examples, "parts" means "parts by weight" and "%" means "% by weight" unless otherwise specified, and the viscosity indicates a value at 25 ° C. Further, the measurement items of each example were measured by the methods described below, except that the dryness to the touch and the storage stability were 50%.
It was measured by using a test piece obtained by applying a silicone resin paint to a 100 × 0.5 × 0.5 mm mild steel plate so as to be constant and curing the same at room temperature for 1 week.・ Dry to touch According to JIS K 5400. After the coating was applied to the mild steel plate, the center of the coated surface was lightly touched with a fingertip to show the drying time until a coating film was formed in a state where the fingertip was not soiled. -Gloss Conforms to JIS K 5400. Using a specular gloss measurement device, the reflectance was measured when the incident angle and the reflection angle were 20 degrees and 60 degrees, respectively, and shown as a percentage when the gloss of the reference surface of the specular gloss is 100. -Pencil hardness conforms to JIS K 5400. Fix the test piece on a horizontal table with the coated surface facing upward, hold the pencil at an angle of about 45 degrees, and press it against the coated surface as strongly as possible so that the core does not break, and evenly in front of the tester. Extrude about 1 cm at a speed and scratch the coated surface. The hardness symbol of the hardest pencil that does not break on the coated surface is shown. Adhesion: Measured by the cross-cut tape method according to JIS K 5400. Cut 100 pieces of 1 mm ² squares in 1 cm ² against the coated surface of the test piece, press cellophane tape on it, and peel it off, 1
From the number of remaining 00 pieces, it was judged based on the evaluation score with 10 being the best in JIS K 5400. -Impact resistance conforms to JIS K 5400. Using an Erichsen tester, a steel ball was extruded from the back side of the test piece, and the presence or absence of cracking or peeling of the coating film when the test piece was deformed was examined. -Crack resistance A cycle of 1 hour at -10 ° C in boiling water for 2 minutes was defined as one cycle, and the cycle until cracking and peeling of the coating film was shown. Thermal shock resistance The presence or absence of cracking or peeling of the coating film was examined after 100 thermal cycles of -50 ° C to + 150 ° C. -Solvent resistance (rubbing test) A case impregnated with a solvent was reciprocated 100 times under a load of 700 g to check whether the coating film was cracked or peeled. Stain resistance Commercially available lacquer spray was applied to the coating film, left for 24 hours, and then peeled off with gum tape to show the removal rate. -The storage-stable silicone resin composition was placed in a closed container and allowed to stand at room temperature, and after 3 months, the presence or absence of thickening and gelation was examined.

Synthesis Example 1 220 parts of methyltriisopropoxysilane and 150 parts of toluene
Parts were placed in a flask and 108 parts of a 1% hydrochloric acid aqueous solution was added dropwise over 20 minutes to hydrolyze the silane. After 40 minutes from dropping, stirring was stopped, and after separation, the resin layer was washed with water to remove hydrochloric acid, and toluene was further distilled off under reduced pressure to give an average molecular weight of 12000 and a softening point.
Methylpolysilsesquiosan P-1 which is a silanol group-containing 1.2% hydroxyl group-containing polyorganosiloxane resin was prepared at 115 ° C. Further, 700 parts of hexamethylcyclotrisiloxane, 800 parts of acetone and 180 parts of water were placed in a flask, mixed and stirred, 1 part of activated clay was further added, and the mixture was stirred for 3 hours to carry out polymerization. Then, the activated clay was filtered off, and acetone and water were distilled off under reduced pressure to obtain a viscosity of 20 cP and an average molecular weight.
1,200, which is a hydroxyl-containing polyorganosiloxane resin, polydimethylsiloxane Q-1 containing silanol groups at both ends
Was prepared. 60 parts of P-1 and 40 parts of Q-1 were charged into a flask, 55 parts of methyltrimethoxysilane was added and mixed by heating. After cooling, 18 parts of isobutylamine and 6.5 parts of formic acid were added as a catalyst, mixed and stirred, and heated and refluxed for 2 hours to methylen-dimethoxysilylate silanol groups. It was confirmed by FT-IR that the presence of silanol groups had disappeared,
Unreacted methyl trimethoxysilane-generated methanol was distilled off under reduced pressure to obtain a viscosity of 720 cP and heating loss (105 ° C x 60 ° C).
%) To prepare an alkoxy-terminated polyorganosiloxane A-1. The ratio of the trifunctional siloxane unit (T) to the bifunctional siloxane unit (D) in A-1 was D / T = 0.60 calculated from the raw material ratio. The silanol group content is determined by measuring the amount of water generated when the silicone resin is heated at 300 ° C. for 2 hours, by using a coulometric titration water measuring device CA-06.
It was measured using a mold (manufactured by Mitsubishi Kasei Co., Ltd.) and calculated. Synthesis Example 2 P- of Synthesis Example 1 was repeated except that 211 parts of phenyltrichlorosilane was used instead of methyltriisopropoxysilane.
Hydrolysis was performed in the same manner as in Example 1 to prepare phenylpolysilsesquioxane P-2 having a molecular weight of 80,000 and a softening point of 125 ° C. and a silanol group content of 2.0%. Using 60 parts of P-2 and 40 parts of Q-1 of Synthesis Example 1, the silanol group was converted to methyldimethoxysilane in the same manner as in Synthesis Example 1 to obtain a viscosity of 600
An alkoxy-terminated polyorganosiloxane A-2 having a cP and a weight loss upon heating (105 ° C. × 60 minutes) of 1.0% was prepared. The ratio of the trifunctional siloxane unit (T) to the bifunctional siloxane unit (D) in A-2 was calculated from the raw material ratio, and D / T = 0.90.
Met. Synthesis Example 3 To 272 parts (2 mol) of methyltrimethoxysilane, 18 parts (1 mol) of water and 0.5 part of acetic acid as a hydrolysis catalyst were added, mixed and stirred, and hydrolyzed and condensed to have a viscosity of 60 cP.
And an alkoxy group-containing organosiloxane oligomer B-1 having a methoxy group content of 50% was prepared.

Examples 1 to 6 and Comparative Examples 1 to 3 Silicone resin compositions having the compositions shown in Table 1 (Examples 1 to 1)
6, Comparative Example 1) was prepared and evaluated as the above-mentioned coating material. The results are shown in Table 1. As Comparative Example 2, 50 parts of room temperature curable solventless epoxy paint, Epicoat 828 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.), Epiclon
It was prepared by mixing 50 parts of 830 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) with 1.0 part of the amine catalyst triethylamine. Also, as Comparative Example 3, a moisture-curable urethane coating was used with 100 parts of trimethylolpropane. It was prepared by mixing 5.0 parts of toluylene diisocyanate and evaluated in the same manner.
The results are shown in Table 1.

[0016]

[Table 1]

From the results shown in Table 1, the silicone resin compositions of Examples 1, 2, 3 and 4 of the present invention are compared with Comparative Example 1 containing no alkoxy-terminated polyorganosiloxane, and the solventless epoxy paint and urethane paint. It was found that the product was extremely excellent in hardness and crack resistance of the coating. It also showed good properties in solvent resistance, stain resistance, and storage stability. Furthermore, the enamel paints of Examples 5 and 6 prepared by adding 10 parts of titanium oxide to the compositions of Examples 1 and 2 also had a pencil hardness of 3.
Good results were shown as in Examples 1 and 2 except that H was the same. As described above, it was confirmed that even when the enamel paint was prepared by adding a pigment to the silicone resin composition of the present invention, good properties were exhibited.

Claims (3)

(57) [Claims] 1. An R SiO _3/2 unit (wherein R is a substituted or unsubstituted monovalent hydrocarbon group which is the same or different from each other) and an R ₂ SiO _2/2 unit (wherein R is the same as defined above). Indicates a group)
(The ratio is expressed as R ₂ SiO _2/2 units / RSiO _3/2 units.
Molar ratio is 0.1 to 1.5), ends ^{_{(R 1 O) a R (}} 3-a) SiO
_1/2 unit (wherein R is the same group as described above, R ¹ is the same or different from each other, a substituted or unsubstituted monovalent hydrocarbon group,
a represents an integer of 2 or 3), and contains an alkoxy-terminated polyorganosiloxane. 2. (A) 100 parts by weight of an alkoxy-terminated polyorganosiloxane according to claim 1 (B) represented by the general formula RSi (OR ¹ ) ₃ (wherein R ¹ and R ¹ represent the same groups as described above). A silicone resin composition comprising 0.1 to 300 parts by weight of an organosiloxane oligomer obtained by partial hydrolysis of silane. 3. A coating agent composition containing the silicone resin composition according to claim 1 or 2 as a main component.