JP2571433B2 - Resin composition for paint - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a resin composition for coatings, and more particularly, to an alcoholic composition which is excellent in durability and weather resistance, and is extremely useful in fields where such coating film properties are particularly required. The present invention relates to a resin composition for a hydroxyl group-containing polysiloxane-containing paint.

2. Prior Art Polysiloxane resins are excellent in heat resistance, water repellency, weather resistance, etc., but are inferior in mechanical strength by themselves. Therefore, they have been devised for use in modifying epoxy resins and acrylic resins to take advantage of their characteristics. However, the conventional method of introducing a polysiloxane resin into an acrylic resin or a polyester resin has been performed by condensing a silanol group or an alkoxy group of the polysiloxane resin with a hydroxyl group of the organic resin. That is, both are cross-linked by the Si—O—C bond, but this bond is susceptible to hydrolysis and the polysiloxane resin is desorbed, and the corrosion resistance, weather resistance, stain resistance, etc., gradually deteriorate. doing. Also, JP-A-58-217515
And JP-B-58-58123 propose modification of a urethane resin with dimethylpolysiloxane having alcoholic hydroxyl groups at both ends, but the surface hardness and mechanical strength are poor due to the low crosslinking density.

In Japanese Patent Publication Nos. 60-1886 and 63-23212, the crosslink density is increased by introducing a plurality of alcoholic hydroxyl groups into the side chain. Can not be obtained.

Problems to be Solved by the Invention If a large amount of silicone resin can be firmly incorporated into the base resin, the durability and weather resistance of the film as a characteristic of the silicone resin can be remarkably improved.
It is expected to be extremely useful for paints, and it is an object of the present invention to obtain such a resin composition.

Means for Solving the Problems According to the present invention, the above object is achieved by the following formula (a): R ¹ _n R ² _m SiO _{(4-nm) / 2} (where R ¹ is hydrogen, an alloxy group, carbon number R ² is selected from the group consisting of an alkoxy group having 1 to 20, an aryl group, a methyl group and an organic group having 2 to 100 carbon atoms; R ² is an organic group having 2 to 100 carbon atoms having a hydroxyl group; m and n are 0 <n <4, 0 <m <
4 and a positive real number satisfying 2 ≦ m + n <4), a number average molecular weight of 200 to 100,000 and a hydroxyl value of 20 to 40
A group consisting of an acrylic resin, an alkyd resin, a polyester resin, an epoxy resin, an aminoplast resin, an acryl-modified alkyd resin, and an acryl-modified polyester resin having an organopolysiloxane content of 3 to 70% by weight and a hydroxyl value of 20 to 300; Hydroxyl-containing resin selected from 97 to
30% by weight, and (c) a crosslinking agent which reacts with one or more hydroxyl groups selected from a polyisocyanate compound, a melamine formaldehyde resin, and a dibasic acid anhydride, wherein (a) and (b) Is achieved by a resin composition for coatings, which may be combined with all or a part of them in advance.

The organopolysiloxane used in the present invention is a hydroxyl group-containing organopolysiloxane having a specific hydroxyl value, which is represented by the above formula, wherein R ¹ is hydrogen, an allyloxy group, an alkoxy group having 1 to 20 carbon atoms, It is selected from the group consisting of an aryl group, a methyl group and an organic group having 2 to 100 carbon atoms, and R ² needs to be an organic group having 2 to 100 carbon atoms having a hydroxyl group. Here, "C2-C2
The term "100 organic groups" means that the chain may contain an ester bond, an ether bond, a urethane bond, a carbon-carbon unsaturated bond, and may have a functional group other than a hydroxyl group. A compound residue having a methylene backbone of 100100 is meant.

Such an alcoholic hydroxyl group-containing polysiloxane used in the present invention is, for example, Is reacted with a siloxane represented by an alkylene mmol in the presence of a platinum acid catalyst, And further reacted with n moles of alkeneoxytrialkylsilane in the presence of a platinum acid catalyst, followed by an addition reaction, And the hydrolysis First, a cyclic siloxane (R ₃ has 1 to ₃ carbon atoms which may contain an ether and / or ester bond in the chain)
100 alkylene chains) and then subjecting the resulting cyclic siloxane to ring-opening polymerization with heat or / and a catalyst to obtain an alcoholic hydroxyl group-containing polysiloxane. As the catalyst, for example, concentrated sulfuric acid, alkali metal hydroxide and silanolate, quaternary ammonium hydroxide and the like can be used. At the time of polymerization, a siloxane compound represented by the formula (R ′) ₃ —Si—O—Si— (R ′) ₃ (wherein R ′ is an alkyl group having 1 to 3 carbon atoms, which may contain a hydroxyl group) It can also be blended.

The method for producing other alcoholic hydroxyl group-containing polysiloxane is represented by the formula Is reacted with a polysiloxane represented by the formula in the presence of a platinum acid catalyst in the presence of an alkeneoxytrimethylsilane in the presence of a platinum acid catalyst. And then hydrolyzed to give a compound of the formula And a method for preparing a compound represented by the formula: Further, the chain length of the alcoholic hydroxyl group is extended by ring-opening addition of ε-caprolactone to the obtained alcoholic hydroxyl group using a catalyst such as tetrabutyl titanate, for example, to form a phase with an acrylic resin or a polyester resin. Improved solubility can be renewed.

Among the compounds represented by the formula R ¹ _n R ² _m SiO _{(4-nm) / 2} , particularly preferred organopolysiloxanes are HOCH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ ) _p R ³ _q SiO _{(4-p−q) / 2} (where p and q are 0 <p ≦ 2, 0 <q ≦ 2 and 1 <p +
A positive real number satisfying q <3, and R ³ is a compound represented by an unsubstituted or substituted monovalent hydrocarbon group).

Above all, the structural formula A _x R _3-x SiO (R ₂ SiO) _y (RASiO) ₂ OSiR _3-x A _x (where x is 0 or 1, y and z are respectively 1 ≦ y ≦ 20,
A real number that satisfies 1 ≦ z ≦ 10, R is a methyl group or a phenyl group, A is HOCH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ group) Furthermore, those containing 10 to 50 mol% of a phenyl group as R are particularly preferable.

 Specifically, the following compounds are particularly preferably used.

(In the above formula, Me represents a methyl group and Ph represents a phenyl group.) The number average molecular weight of such an organopolysiloxane is 200
The range of 〜100,000 is suitable, preferably 500-20,000. If it is less than 200, sufficient mechanical strength of the surface does not occur,
If it is more than 100,000, the compatibility with the hydroxyl group-containing resin and the crosslinking agent deteriorates, and a sufficient cured coating film cannot be obtained, which causes a problem.

The hydroxyl value of such organopolysiloxane (JIS
K) is preferably in the range of 20 to 400, more preferably 50 to 200. If the hydroxyl value is 20 or less, it does not sufficiently react with the curing agent, does not show surface curability, and the surface mechanical properties are deteriorated.If it is 200 or more, the compatibility with the hydroxyl group-containing resin and the crosslinking agent is deteriorated, and sufficient curing is performed. A problem arises because a coating film cannot be obtained.

In the present invention, the hydroxyl group-containing resin, which is one of the components to be combined with the above-described alcoholic hydroxyl group-containing polysiloxane, is not particularly limited as long as the hydroxyl value is 20 to 300, and various types of resins can be used. Examples of suitable resin types include acrylic resins, alkyd resins, polyester resins, epoxy resins, aminoplast resins, acryl-modified alkyd resins, and acryl-modified polyester resins.

Among them, acrylic resin obtained by copolymerizing (meth) acrylic acid, (meth) acrylic acid ester and the like with hydroxyalkyl (meth) acrylate, epoxy resin obtained from bisphenol A and epichlorohydrin,
A polyester resin or the like obtained from a polycarboxylic acid and a polyol polycondensate is preferably used.

In the present invention, the crosslinking agent used in combination with the alcoholic hydroxyl group-containing polysiloxane and the hydroxyl group-containing resin described above can be any compound having a functional group that reacts with a hydroxyl group in the molecule, and may be an organopolysiloxane and an organic resin. , Organopolysiloxanes and organic resins. Specific examples include a polyisocyanate compound, a melamine formaldehyde resin, and a dibasic acid anhydride. Such a crosslinking agent crosslinks an alcoholic hydroxyl group-containing polysiloxane and a hydroxyl group-containing resin at room temperature or under heating.

With respect to the use amount of each of the above-mentioned components, it can be blended over a wide range of 97 to 30% by weight of a hydroxyl group-containing resin with respect to 3 to 70% by weight of an alcoholic hydroxyl group-containing polysiloxane, and preferably the former is 5 to 40% by weight. %, The latter 95 to 60% by weight. When the content of the alcoholic hydroxyl group-containing polysiloxane is less than 3% by weight, the characteristics of the polysiloxane are not sufficiently exhibited. When the amount exceeds 70% by weight, the compatibility with the hydroxyl group-containing resin becomes poor, and the coating film hardness is lowered. Are found to be insufficient, and both are found to be undesirable. The functional group of the cross-linking agent reacts with the hydroxyl group in the polysiloxane and the hydroxyl group-containing resin to perform three-dimensional cross-linking, thereby improving the mechanical strength.However, the amount of the cross-linking agent is necessary for the polysiloxane and the hydroxyl group-containing resin. The amount is not particularly limited.

In the present invention, a specific amount of an organopolysiloxane and a specific amount of a hydroxyl group-containing resin are used in combination. However, the whole or a part thereof may be reacted and bonded in advance.

This is achieved by, for example, reacting a compound having an unsaturated double bond with a functional group other than a hydroxyl group, for example, a compound such as maleic anhydride with trisiloxane having a hydroxyalkyl group, and incorporating a component having an unsaturated double bond. Alternatively, both can be combined by means of addition polymerization with an acrylic or vinyl monomer.

Thus, in the present invention, unlike the conventional surface conditioning silicone oil, the amount of polysiloxane in the resin composition can be adjusted relatively easily, and a large amount can be firmly incorporated into the resin composition. Therefore, a novel crosslinked product which retains the water repellency for a long period of time and has further excellent weather resistance and durability can be obtained. In the case of a conventional silicone-modified acrylic resin or polyester resin, a modification method is to heat a silanol group or alkoxy group-containing organopolysiloxane and a hydroxyl group-containing organic resin in the presence of a catalyst such as alkyl titanate and zinc octylate. Although the polysiloxane was incorporated into the organic resin by the Si-OC bond, the polysiloxane was easily hydrolyzed. However, in the present invention, the cross-linking was carried out by the reaction between the respective hydroxyl groups of the polysiloxane and the organic resin and the functional groups of the crosslinking agent. The bond at the cross-linking point is hardly hydrolyzed by an ester bond, an ether bond, or a urethane bond, so that the properties of the polysiloxane, i.e., gas and ion permeability, heat resistance, and water repellency are not impaired. Can provide crosslinked products with excellent corrosion resistance, weather resistance, stain resistance, etc. It is.

Therefore, the resin composition of the present invention is extremely useful as a resin vehicle of a paint which is a highly nonvolatile type and can provide a coating film having excellent durability, weather resistance and corrosion resistance.

Hereinafter, the present invention will be described with reference to examples. Unless indicated otherwise, parts and percentages are by weight.

Production Example 1: Synthesis of polysiloxane resin solution A Xylol (10 parts), maleic anhydride (4 parts), and dibutyltin oxide (0.5 part) were reacted at 130 ° C. for 1 hour to obtain a polysiloxane resin solution A. The reaction was tracked by oxidation measurement to confirm that the reaction was completed.

Production Example 2: Synthesis of Silicone-Modified Acrylic Resin Solution B 70 parts of xylol, 20 parts of styrene in a reaction solution kept at 110 ° C., Praxel FM-1 (manufactured by Daicel Chemical Industries, 2-hydroxyethyl methacrylate and ε-caprolactone) Adduct) 38 parts, methyl methacrylate 25 parts, methacrylic acid 2
-A mixed solution of 15 parts of ethyl exyl, 2 parts of methacrylic acid and 2 parts of azobisisobutyronitrile was added dropwise over 3 hours, and 1
After aging for 0.5 hour, 0.5 part of t-butylperoxy 2-ethylhexanonate and 30 parts of xylol were added dropwise over 30 minutes to obtain an acrylic resin solution after aging for 2 hours. After cooling, KR-9218
(Methylphenylmethoxypolysiloxane manufactured by Shin-Etsu Chemical Co., Ltd.) 30 parts and TBT-100 (tetrabutyl titanate) 0.2 part as a condensation catalyst are charged and heated and stirred. The reaction temperature was kept constant at 140 ° C, and the amount of methanol distilled off was the theoretical amount of methanol (the methoxy group of the polysiloxane was 100%).
% Removal of methanol when reacted with active hydrogen of base resin)
Cool down to 70% of the volume. The resulting varnish was used as a silicone-modified acrylic resin solution B.

Production Example 3: Synthesis of acrylic resin solution A 70 parts of toluene part, 20 parts of styrene, 30 parts of methyl methacrylate, 30 parts of n-butyl acrylate, and 30 parts of 2-hydroxyethyl methacrylate in a reaction solution kept at 110 ° C. , A mixed solution of 3 parts of methacrylic acid and 3 parts of t-butylperoxy 2-ethylhexanonate was added dropwise over 3 hours, and after aging for 1 hour, 0.5 part of t-butylperoxy 2-ethylhexanonate was added. 30 parts of toluene was added dropwise over 30 minutes, and after aging for 2 hours, an acrylic resin solution A was obtained.

Production Example 4: Synthesis of polyester resin solution A 36 parts of hexhydrophthalic acid, 42 parts of trimethylolpropane, and 50 parts of neopentyl glycol in a reaction vessel equipped with a heating device, a stirrer, a reflux device, a water separator, a rectification tower, and a thermometer.
Parts, 56 parts of 1,6-hexanediol, and heat.
When the raw materials are melted and agitation becomes possible, agitation is started.
Heat to 0 ° C. The temperature is raised at a constant rate from 210 ° C. to 230 ° C. over 2 hours, and the generated condensed water is distilled out of the system.
When the temperature reaches 230 ° C, keep the temperature constant and adjust the resin acid value.
Cool at 1.0. After cooling, add 153 parts of isophthalic acid,
Heat up to 190 ° C. The temperature is raised at a constant rate from 190 ° C. to 210 ° C. over a period of 3 hours, and the condensed water generated is distilled out of the system. When the temperature reaches 210 ° C., 3 parts of xylol are added to the reaction vessel, the condensation is switched to the presence of a solvent, and the mixture is cooled at a resin acid value of 20.0. After cooling, 51 parts of xylol, cellosolve acetate 13
Add 9 parts and add oil-free polyester resin varnish A
I got

Production Example 5: Synthesis of Acrylic Resin Solution B 80 parts of xylol, 15 parts of styrene, 25 parts of methyl methacrylate in a reaction solution kept at 120 ° C., Plaxel FM-1
(1: 1 adduct of 2-hydroxyethyl methacrylate and ε-caprolactone, manufactured by Daicel Chemical Co., Ltd.) 27 parts, 3 parts of methacrylic acid, 15 parts of 2-ethylhexyl methacrylate, 15 parts of ethyl methacrylate, azobisisobutyro A mixed solution of 2 parts of nitrile was added dropwise over 3 hours, and after aging for 1 hour, 0.5 part of t-butylperoxy-2-ethylhexanoate and 20 parts of xylol were added dropwise over 30 minutes. B was obtained.

Example 1 0.4 parts of xylol, 15 parts of acrylic resin solution A, 12 parts of Super Beckamine 114-60 (Melamine formaldehyde resin solution, manufactured by Dainippon Ink), 5 parts of methyl isobutyl ketone
After mixing the parts, the mixture was applied on a tin plate and baked at 140 ° C. for 30 minutes to obtain a crosslinked coating film. A contact angle of the crosslinked coating film with water, a xylol and methyl ethyl ketone rubbing test and a weather resistance test were performed. The results are shown in Table 1.

Example 2 Instead of 0.4 parts of xylol Except for using 0.4 parts of xylol, a processed coating film was obtained using acrylic resin solution A, melamine resin solution and methyl isobutyl ketone in exactly the same manner as in Example 1. In addition, a similar test was performed. The results are shown in Table 1.

Example 3 Crosslinking was carried out in exactly the same manner as in Example 1 except that acrylic resin solution A, melamine resin solution and methyl isobutyl ketone were used, except that 0.4 parts of xylol was replaced by 2 parts of the polysiloxane resin solution A obtained in Production Example 1. A coating was obtained. In addition, a similar test was performed. The results are shown in Table 1.

Example 4 After mixing 1 part of xylol, 20 parts of acrylic resin solution B, 6 parts of Dismodur N3390 (manufactured by Sumitomo Bayern, isocyanate resin solution) and 5 parts of methyl isobutyl ketone, the mixture was applied on a tin plate and baked at 90 ° C. for 30 minutes. A crosslinked coating film was obtained. The same test as in Example 1 was performed. The results are shown in Table 1.

Example 5 Except for using 20 parts of a polyester resin solution A instead of 20 parts of an acrylic resin solution, exactly the same as in Example 4
A crosslinked coating film was obtained. In addition, a similar test was performed. The results are shown in Table 1.

Production Example 6: Synthesis of silicone-modified acrylic resin solution C 25 parts of polysiloxane resin solution A obtained in Production Example 1,
Xylol 65 parts, styrene 1 in the reaction solution kept at 110 ℃
5 parts, 2-hydroxyethyl methacrylate 14 parts, methyl methacrylate 25 parts, 2-ethylhexyl methacrylate 23
Parts, methacrylic acid 3 parts, azobisisobutyronitrile 2.
0 parts of the mixed solution was added dropwise over 3 hours, and after aging for 1 hour, t
0.5 parts% of -butylperoxy 2-ethylhexanonate and 30 parts of xylol were added dropwise over 30 minutes, and after aging for 2 hours, a silicone-modified acrylic resin solution C was obtained.

Example 6 A crosslinked coating film was obtained in exactly the same manner as in Example 4 except that the silicone-modified acrylic resin solution G was used instead of 1 part of xylol and 20 parts of the acrylic resin solution B. The same test as in Example 1 was performed. The results are shown in Table 1.

Example 7 A crosslinked coating film was obtained using 1 part of xylol, 20 parts of a polyester resin solution A, 12 parts of Super Beckamine 114-60, and 5 parts of methyl isobutyl ketone. The same test as in Example 1 was performed. The results are shown in Table 1.

Example 8 Instead of 0.4 parts of xylol A crosslinked coating film was obtained using an acrylic resin solution A, a melamine resin solution and methyl isobutyl ketone in exactly the same manner as in Example 1 except that 0.8 parts of xylol was used.
In addition, a similar test was performed. The results are shown in Table 1.

Comparative Example 1 Acrylic resin solution A10 parts, Super Beckamine 114-60
After well mixing 3.5 parts, a crosslinked coating film was prepared in the same manner as in Example 1, and various tests were performed. The results are shown in Table 1.

Comparative Example 2 Acrylic resin solution A15 parts, commercially available dimethylsiloxane (number average molecular weight: about 2000) 2 parts, and melamine resin solution 12 parts were mixed well, then a crosslinked coating film was prepared in the same manner as in Example 1 and various tests were performed. Was. The results are shown in Table 1.

Comparative Example 3 After mixing 15 parts of silicone-modified acrylic resin B and 6.5 parts of Super Beckamine 114-60, the mixture was applied on a tin plate.
Baking was performed at 140 ° C. for 30 minutes to obtain a crosslinked coating film. The same test as in Example 1 was performed. The results are shown in Table 1.

Production Example 7 Production of polysiloxane resin solution B A mixture of 20 parts of xylol, 40 parts of ε-caprolactone, 0.15 part of tetrabutyl titanate and 10 parts of xylol was added to 13 parts.
The reaction was carried out at 0 ° C. for 6 hours to obtain a polysiloxane resin solution B having a resin content of 80%. The number average molecular weight of the obtained polysiloxane was about 2100.

Example 9 A crosslinked coating film was obtained using the acrylic resin solution A, the melamine resin solution and methyl isobutyl ketone in exactly the same manner as in Example 1 except that 2 parts of the polysiloxane resin solution was used instead of 0.4 parts of xylol. A similar test was performed. The results are shown in Table 1.

The test method of each test item in Table 1 is as follows.

60 ° specular gloss: Measured according to the method specified in JIS-K5400 6.7.

Contact angle to water: The contact angle of the cured coating film surface to water was measured by a conventional method.

Rubbing test: A rubbing test was carried out 50 times in each case with xylol and methyl ethyl ketone by a conventional method, and the coating film surface after rubbing was visually evaluated. The criteria for the visual evaluation were as follows.

◎… No abnormality ○… Almost no abnormality △… Coating surface slightly opaque ×… Coating surface turbidity Salt spray resistance: Implemented continuously for 10 days according to the method specified in JIS-K5400 7.8. Was visually evaluated.

 The criteria for the visual evaluation were as follows.

◎… No abnormalities ○… Small swelling △… Small swelling Accelerated weatherability: Irradiated with a sunshine weatherometer for 2000 hours, visually evaluate the condition of the painted surface, measure 60 ° specular gloss, The gloss retention after irradiation with respect to gloss (%) was determined.

 The criteria for the visual evaluation were as follows.

◎: No abnormality ○: Almost no abnormality △: Partial chalking ×: Intense choking Example 10 Average Composition Formula Polysiloxane 20 parts, Acrylic A-801
160 parts of an acrylic resin (Dai Nippon Ink Co., Ltd., hydroxyl value 50, non-volatile content 50%) and 40 parts of TYPAQUE R-820 (titanium oxide, manufactured by Ishihara Sangyo Co., Ltd.) were dispersed in a ball mill and burnt D-950. (Dainippon Ink Co., Ltd. polyisocyanate) 54 parts was added, spray-coated on an iron plate to a film thickness of about 30μ, cured at room temperature for one week, the physical properties of the coating film was measured, and the result Are shown in Table 2.

Example 11 20 parts of the same polysiloxane as in Example 10 and Acrylic A-430-60 (an acrylic resin manufactured by Dainippon Ink and Chemicals, Inc.)
133 parts, Super Beckamine L-127-60
A coating film was prepared in the same manner as in Example 10 using 55 parts (Melamine formaldehyde resin manufactured by Dainippon Ink Co., Ltd.) and 40 parts of Taipaque R-820, and cured by heating at 150 ° C. for 30 minutes. Was measured, and the results are shown in Table 2.

Example 12 As in Example 10, 20 parts of polysiloxane, 100 parts of methyl isobutyl ketone, 80 parts of Epicoat 1001 (epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.), and 30 parts of phthalic anhydride were added to 14 parts.
After reacting at 0 ° C. for 2 hours, 30 parts of xylene was added, and after cooling, 40 parts of Taipaque R-820 was added, and a coating film was prepared in the same manner as in Example 10 and was cured by heating at 180 ° C. for 30 minutes. rear,
The physical properties of the coating film were measured, and the results are shown in Table 2.

Example 13 A reaction vessel equipped with a heating device, a stirrer, a reflux device and a thermometer was charged with 20 parts of the same polysiloxane as in Example 10, 1.2 parts of maleic anhydride, 0.04 part of dibutyltin oxide, and 25 parts of xylene, Incubate at 90 ° C for 1 hour.
Next, 35 parts of xylene and 20 parts of methyl isobutyl ketone are added, and the temperature is raised to 110 ° C. 40 parts of methyl methacrylate and 2-ethylhexyl methacrylate 25
, A mixed solution of 12 parts of 2-hydroxyethyl methacrylate, 3 parts of methacrylic acid and 1.2 parts of t-butylperoxy 2-ethylhexanoate was added dropwise over 3 hours. After aging for 1 hour, t-butylperoxy was added. 0.2 parts of 2-ethylhexanoate and 20 parts of xylene were added dropwise over 30 minutes, and the mixture was aged for 2 hours to obtain a resin solution A.

180 parts of the obtained resin solution and R-820 4
0 parts were dispersed in a ball mill, 54 parts of Burnock D-950 were added, and coating and film formation were carried out in the same manner as in Example 10, and the physical properties of the coating film were measured. The results are shown in Table 2.

Comparative Example 4 200 parts of Acrylic A-801 and Typek R-820
Was dispersed in a ball mill and 50 parts of Vernot D-950 were added.
A part of the coating was prepared in the same manner as in Example 10 and cured at room temperature for one week. The physical properties of the coating were measured, and the results are shown in Table 2.

Comparative Example 5 A mixture of 536 parts of trimethylolpropane, 296 parts of phthalic acid, and 138 parts of adipic acid was subjected to dehydration-condensation polymerization at 200 ° C., and a polyester resin solution adjusted to an acid value of 5 (cellosolve acetate solution,
Non-volatile content 50%, acid value 5) 140 parts, KR-9218 (phenylmethylmethoxypolysiloxane manufactured by Shin-Etsu Chemical Co., Ltd.) 30
Parts and a mixture of 0.3 parts of tetrabutyl titanate at 150 ° C.
After heating for 2 hours at room temperature, 30 parts of cellosolve acetate was added and the mixture was cooled, and 40 parts of Taipaque R-820 was added thereto.
A coating film was prepared in the same manner as described above, and cured by heating at 180 ° C. for 30 minutes, and the physical properties of the coating film were measured. The results are shown in Table 2.

The test method in Table 2 is the same as that in Table 1,
They differ in the following points.

Pencil hardness Salt spray resistance measured according to JIS K 5400 × indicates rust and blister (blister) Accelerated weather resistance After exposure for 1000 hours, gloss was measured to determine gloss retention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirotoshi Umemoto 19-17 Ikedanakamachi, Neyagawa-shi, Osaka Japan Paint Co., Ltd. Inside the Industrial Co., Ltd. (72) Inventor Yoshio Okamura 2- 13-1, Isobe, Annaka-shi, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. (72) Inventor Kenji 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu (56) References JP-A-62-252480 (JP, A) JP-B-48-22173 (JP, B1)

Claims (4)

(57) [Claims] (A) a compound represented by the formula: R ¹ _n R ² _m SiO _{(4-nm) / 2} (where R ¹ is hydrogen, an allyloxy group, an alkoxy group having 1 to 20 carbon atoms, an aryl group, a methyl group, R ² is selected from the group consisting of organic groups having 2 to 100 carbon atoms; R ² is an organic group having 2 to 100 carbon atoms having a hydroxyl group; m and n are 0 <n <4, 0 <m <
4 and a positive real number satisfying 2 ≦ m + n <4), a number average molecular weight of 200 to 100,000 and a hydroxyl value of 20 to 40
A group consisting of an acrylic resin, an alkyd resin, a polyester resin, an epoxy resin, an aminoplast resin, an acryl-modified alkyd resin, and an acryl-modified polyester resin having an organopolysiloxane content of 3 to 70% by weight and a hydroxyl value of 20 to 300; Hydroxyl-containing resin selected from 97 to
(C) a cross-linking agent that reacts with one or more hydroxyl groups selected from (c) a polyisocyanate compound, a melamine formaldehyde resin, and a dibasic acid anhydride; Is a resin composition for coatings, in which all or part of them may be bonded in advance. 2. An organopolysiloxane having the formula (HOCH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ ) _p R ³ _q SiO _{(4-p−q) / 2} (where p and q are 0 <p ≦ 2,0 <P ≦ 2 and 1 <p
The resin composition according to claim 1, wherein the positive real number satisfying + q <3 and R ³ is an unsubstituted or substituted monovalent hydrocarbon group). 3. An organopolysiloxane wherein R ³ is a methyl group,
The resin composition according to claim 2, which is selected from a propyl group and a phenyl group. 4. An organopolysiloxane having the formula (A _X R _3-X SiO (R ₂ SiO) _y (RASiO) _z OSiR _3-x A _x (where x is 0 or 1 and y and z are 1 ≦ 1) y ≦ 20,1
_2. The resin composition according to claim 1, wherein a positive real number satisfying ≤z≤10, R is a methyl group or a phenyl group, and A is a HOCH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ group).