JPH0931399A - Coating composition and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyacrylic or a polyester coating composition excellent in stain resistance. SOLUTION: This coating composition comprises an acrylic resin having hydroxyl groups or hydrolizable silyl groups, or a polyester resin having hydroxyl groups, a partially hydrolyzed condensate of an alkoxysilane, a polkyalkylene glycol, and an organic solvent as a solvent, the amount of the partially hydrolyzed condensate being 2 to 100 pts.wt. per 100 pts.wt. of the acrylic resin or polyester resin, and the amount of the polyalkylene glycol 1 to 100 pts.wt. per 100 pts.wt. of the partially hydrolyzed condensate of the alkoxysilane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic or polyester-based coating composition having excellent stain resistance, and the coating composition of the present invention is significantly stain resistant as compared with conventional coating compositions. A coating film with improved properties is obtained.

[0002]

BACKGROUND OF THE INVENTION Acrylic paints and polyester paints are general-purpose paints used in a wide range of industrial fields such as automobiles, machines, construction, and civil engineering. However, especially when used outdoors, there is a problem that the initial landscape is always damaged by exposure to pollutants. For example, in outdoor structures such as buildings, road bridges, and chemical plants, local rain line stains frequently occur, and even in the case of washable paint such as automobiles and trains, rain stain stains are generated. There was a problem that it could not be completely removed. As a countermeasure against contamination, there is a method of hardening a coating film, and as a method of hardening an acrylic paint or a polyester paint, a method of adding silica sol described in JP-A-4-292677 or JP-A 6-2
There is a method of adding a silicate oligomer to an acrylic resin having a hydrolyzable silyl group introduced therein, which is disclosed in 40199. According to these methods, the adhered pollutants can be forcibly cleaned, but in outdoor structures that cannot be cleaned frequently, they are practically ineffective, and further improvements have been demanded.

[0003]

The present inventors have completed the present invention as a result of extensive studies to solve the above-mentioned problems. That is, the present invention is an acrylic resin having a hydroxyl group or a hydrolyzable silyl group, which is soluble in an organic solvent described below, or a polyester resin having a hydroxyl group, which is soluble in an organic solvent described below, a partial hydrolysis condensate of an alkoxysilane, and a polyalkylene glycol. And an organic solvent, the content of the partially hydrolyzed condensate of the alkoxysilane is 2 to 100 parts by weight per 100 parts by weight of the acrylic resin or the polyester resin, and the content of the polyalkylene glycol is the alkoxysilane. The coating composition is 1 to 100 parts by weight per 100 parts by weight of the partial hydrolysis-condensation product, and the coating composition is the above-mentioned coating composition in which the polyalkylene glycol is polyethylene glycol.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The acrylic resin in the present invention has a hydroxyl group or a hydrolyzable silyl group, and includes one having both a hydroxyl group and a hydrolyzable silyl group. The acrylic resin having a hydroxyl group is a) obtained by polymerizing an acrylic monomer having a hydroxyl group, alone or with another copolymerizable monomer, or b) a monomer having a hydroxyl group other than the acrylic monomer and a hydroxyl group. It can be obtained by copolymerizing an acrylic monomer not having the above with a copolymerizable monomer, if necessary. Examples of the acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate (meth)
Acrylic acid and ethylene glycol, ethylene oxide,
Examples thereof include monomers obtained by reacting with a polyhydric alcohol such as propylene glycol, propylene oxide, butylene glycol, cyclohexanedimethanol, glycerin and trimethylolpropane. Examples of the monomer having a hydroxyl group other than the acrylic monomer include 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, allyl alcohol, cinnamic alcohol, and N-methylol (meth) acrylamide.
Compounds obtained by ring-opening addition of ε-caprolactone to these monomers having a hydroxyl group, and further unsaturated carboxylic acids such as maleic acid, fumaric acid, crotonic acid and itaconic acid, and ethylene glycol, ethylene oxide, propylene glycol, propylene oxide. Examples thereof include monomers obtained by reacting with polyhydric alcohols such as, butylene glycol, cyclohexanedimethanol, glycerin, and trimethylolpropane. As the acrylic monomer having no hydroxyl group, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic Examples thereof include trifluoroethyl acid salt, pentafluoropropyl (meth) acrylate, (meth) acrylonitrile, glycidyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylamide, acrylic acid and methacrylic acid.

Acrylic resins having a hydrolyzable silyl group include a) an acrylic monomer having a hydrolyzable silyl group, which is polymerized alone or with a copolymerizable monomer, and b) a monomer having a hydrolyzable silyl group. It is obtained by copolymerizing a monomer, an acrylic monomer, and a copolymerizable monomer as required, or c) adding a hydrosilane compound to an acrylic resin having a carbon-carbon double bond. As the acrylic monomer having a hydrolyzable silyl group,
(Meth) acrylic acid trimethoxysilane and (meth)
Acrylic acid triethoxysilane etc. are mentioned. Examples of the monomer having a hydrolyzable silyl group include vinyloxypropyltrimethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane. Examples of the acrylic monomer include those exemplified above for the acrylic resin having a hydroxyl group. Also, carbon-
It can also be produced by a method in which a hydrosilane compound such as trimethoxysilane and triethoxysilane is added to an acrylic resin having a carbon double bond in the presence of a Group VIII transition metal. The acrylic resin having a carbon-carbon double bond is prepared by a conventional method using an allyl monomer such as allyl (meth) acrylate and diallyl phthalate and other monomers copolymerizable with these allyl monomers. It can be obtained by homopolymerization or copolymerization.

Other monomers copolymerizable with the acrylic and allyl monomers having a hydroxyl group or a hydrolyzable silyl group are styrene, α-methylstyrene, maleic acid, fumaric acid and itacone. Examples thereof include acids, vinyl acetate and vinyl propionate.

The acrylic resin of the present invention is produced by a solution polymerization method using a peroxide radical initiator such as t-butylperoxyacetate or an azo radical initiator such as azobisisobutyronitrile. preferable. In solution polymerization, the molecular weight may be adjusted by using a chain transfer agent such as dodecyl mercaptan. The polymerization solvent can be used without particular limitation as long as it is a solvent which does not react with the monomer used, such as aromatic type, ketone type, ester type and alcohol type.

The polystyrene-reduced number average molecular weight of the acrylic resin in the present invention is preferably 1,000 to 5
10,000, more preferably 2,000-20,
000. The glass transition temperature is preferably -50 to
70 degreeC, More preferably, it is -20-50 degreeC.
Moreover, when it contains a hydroxyl group, it is 20 to 300 mg KO.
A hydroxyl value of H / g is preferable, and in the case of containing a hydrolyzable silyl group, the monomer unit having a hydrolyzable silyl group is preferably 3 to 50 mol% with respect to the entire copolymer.

The polyester resin in the present invention has a hydroxyl group. Examples of the polyester resin having a hydroxyl group include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodiumsulfoisophthalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid. ,
Polybasic acids such as dimer acid, trimellitic acid, pyromellitic acid and benzophenone tetracarboxylic acid, and ethylene glycol, propylene glycol, 1,3-
Propanediol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, 1,8
-Nonanediol, 3-methylpentanediol, neopentyl glycol, dimethylol pentane, dimethylol heptane, 1,4-cyclohexane dimethanol,
Carbonate diol, polycaprolactone diol,
Polyphenols such as ethylene oxide adduct of bisphenol A, ethylene oxide adduct of bisphenol S, glycerin, polyglycerin, trimethylolpropane, pentaerythritol, polycaprolactone triol and polycaprolactone tetraol. It can be obtained by condensing the compounds by a conventional method under the condition of excess hydroxyl groups. Also, as other polybasic acids, linseed oil, tung oil, dehydrated castor oil, soybean oil, safflower oil, tall oil,
It is possible to use oils and fats such as coconut oil and castor oil. It is preferable to use only

The polyester resin having a hydroxyl group is obtained by subjecting the ester compound of the polybasic acid to the condensation reaction with the polyol, and then subjecting the polyester compound to one or more kinds of the polybasic acid. Can also be obtained.

The polyester resin of the present invention is produced, for example, by the following method. That is, a polyester oligomer is obtained by charging the raw materials of the above polybasic acids and polyols and a catalyst such as antimony trioxide and subjecting them to polycondensation reaction at 160 to 230 ° C. under normal pressure. When a polybasic acid ester compound is used in the above reaction,
The polycondensation reaction is carried out after the condensation reaction with the resins. The polyester oligomer obtained by the above method was treated under reduced pressure for 2
A polyester resin is obtained by performing a polycondensation reaction in a temperature range of 20 to 300 ° C. for 1 to 15 hours.

The polystyrene-reduced number average molecular weight of the polyester resin in the present invention is preferably 1,000 to
50,000, more preferably 2,000 to 2
10,000 can be used. The glass transition temperature is preferably −50 to 70 ° C., more preferably −20.
５０50 ° C. Further, the polyester resin in the present invention may contain a small amount of hydroxyl groups,
A hydroxyl value of 00 mgKOH / g is more preferable.

Partial hydrolysis condensate of alkoxysilane in the present invention (hereinafter referred to as alkoxysilane condensate)
Is a self-condensation product of an alkoxysilane having two or more hydrolyzable alkoxy groups in one molecule and having a condensation degree of 2
All that is required is the above. Such an alkoxysilane condensate is
For example, it is commercially available from Colcoat Co., Ltd. and can be easily synthesized by the following method. That is, an alkoxysilane is dissolved in an organic solvent, or an alkoxysilane is dissolved in an organic solvent solution of the acrylic resin or polyester resin and / or polyethylene glycol, and an inorganic acid such as hydrochloric acid or acetic acid or p-toluenesulfonic acid is used. After adjusting the pH to about 1 to 4 by adding the above organic acid, 0.05 to 3 equivalents of water relative to the alkoxy group is added and hydrolyzed at 30 to 80 ° C. for 1 to 8 hours to give an alkoxy. A silane condensate is obtained.

As described above, the coating composition of the present invention containing the acrylic resin or polyester resin, the alkoxysilane condensate, the polyalkylene glycol and the organic solvent as essential components can be used in the organic solvent solution of the acrylic resin or the polyester resin. The alkoxysilane condensate is mixed with the polyalkylene glycol, or the alkoxysilane is hydrolyzed in the organic solvent solution of the acrylic resin or the polyester resin and / or the polyalkylene glycol to synthesize the alkoxysilane condensate. It can be manufactured by a method or the like. In particular, when the alkoxysilane is hydrolyzed in a solution of an acrylic resin or a polyester resin and / or a polyalkylene glycol in an organic solvent, a hydroxyl group of the acrylic resin or the polyester resin and / or the polyalkylene glycol and the alkoxysilane Since the alkoxy groups are trapped, the effect of improving the storage stability of the alkoxysilane condensate can be obtained. In this method, there is no particular limitation on the amount of the acrylic resin or polyester resin and / or alkylene glycol that is present during the hydrolysis of the alkoxysilane, and even if the total amount of each component constituting the composition of the present invention is present. Alternatively, a partial amount may be present.
When a partial amount is present, the remaining components will be added and blended after hydrolysis.

Alcoholic solvents are suitable as the organic solvent when the alkoxysilane is hydrolyzed in the absence of the acrylic resin or polyester resin and ethylene glycol, and examples thereof include methanol and ethanol. ,
In addition to alcohols such as isopropanol, propanol, butanol and diacetone alcohol, glycol ethers such as propylene glycol monomethyl ether and ethylene glycol monobutyl ether can be used. In addition to alcohols, ketone-based, ester-based or aromatic-based solvents can be used, but from the viewpoint of stability of the alkoxysilane condensate to be formed, it is preferable to use at least 10% by weight or more of all alcohol solvents. . On the other hand, as the organic solvent when the alkoxysilane is hydrolyzed in the coexistence of the acrylic resin or the polyester resin and / or the polyalkylene glycol, the organic solvent in the composition of the present invention is preferably used, and specific examples thereof include As described later.

The alkoxysilanes usable in the present invention include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane and vinyl. Triethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane and γ -Hydroxypropyltrimethoxysilane and the like can be mentioned. The amount of alkoxysilane condensate used is
The amount is 2 to 100 parts by weight, preferably 5 to 80 parts by weight, per 100 parts by weight of the acrylic resin or the polyester resin. If the amount of the condensate used is less than 2 parts by weight, the effect of stain resistance cannot be obtained, while if it exceeds 100 parts by weight, the stability of the coating composition is deteriorated.

In a coating film comprising the coating composition of the present invention containing the alkoxysilane condensate as a component, the alkoxy groups remaining in the alkoxysilane condensate are gradually hydrolyzed by moisture in the atmosphere. In addition, the coating film is more densely crosslinked and cured. Alkoxysilane condensation of a metal alkoxide condensate having the same properties as an alkoxysilane condensate, that is, a partial hydrolysis condensate of a metal alkoxide consisting of an element of Group 3 or 4 of the periodic table such as aluminum, titanium and zirconium. You may use together with a thing.

As the polyalkylene glycol, water-soluble polyalkylene glycol represented by polyethylene glycol, polypropylene glycol and polytetraethylene glycol is preferably used, and more preferably polyethylene glycol. The polyalkylene glycol has a number average molecular weight of 200 to 3,
000 is preferable, and 200 to 2,000 is more preferable.
0. When the number average molecular weight of the polyalkylene glycol is less than 200, the hardness of the coating film is likely to decrease, while when it exceeds 3,000, the polyalkylene glycol is difficult to dissolve in the organic solvent for coating material. The amount of polyalkylene glycol used is 1 to 100 parts by weight per 100 parts by weight of the alkoxysilane condensate. If the amount of polyalkylene glycol used is less than 1 part by weight, the effect of stain resistance cannot be obtained, and if it exceeds 100 parts by weight, the weather resistance decreases. A particularly preferred amount of use is 1 to 50 on the same basis.
Parts by weight.

As the organic solvent in the present invention, an organic solvent generally used in the paint field can be used, and specifically, ethyl acetate, butyl acetate, toluene, xylene, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, Examples thereof include ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, isopropanol, butanol and cyclohexanol.

The coating composition of the present invention can be used without using a curing agent, but if desired, a curing agent such as polyisocyanate and amino resin may be used in combination. The use of a curing agent is a preferred method because it cures the coating film more densely and further improves the stain resistance. Examples of the polyisocyanate include aliphatic compounds such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate, cyclic compounds such as xylylene diisocyanate and isophorone diisocyanate, aromatic compounds such as tolylene diisocyanate and 4,4′-diphenylmethane diisocyanate. Can be mentioned.
Furthermore, multimers of the above polyisocyanates, such as dimers, trimers or prepolymers, and burettes and ureas derived from polyisocyanate compounds can also be preferably used. More preferred are non-yellowing polyisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate. The preferred amount of the polyisocyanate used is an amount that provides 0.6 to 1.2 equivalents of isocyanate groups with respect to the hydroxyl groups of the acrylic resin or polyester resin. Examples of the amino resin include urea resin, melamine resin and benzoguanamine resin, and melamine resin is preferable in terms of compatibility and durability.

In the coating composition of the present invention, in addition to the above-mentioned curing agents, pigments and other additives usually added to coatings can be used. Examples of the pigment include inorganic pigments such as titanium oxide, iron oxide, yellow lead and calcined pigment, organic pigments such as carbon black, quinacridone red and phthalocyanine blue, and other additives include ultraviolet absorbers and antioxidants. , Curing catalysts, surface conditioners, silane coupling agents and matting agents.

[0022]

EXAMPLES The present invention will be described more specifically below with reference to Synthesis Examples, Examples and Comparative Examples. (Synthesis example) a) Synthesis of acrylic resin (A-1) A reactor equipped with a stirrer, a cooler, and a nitrogen inlet tube was charged with 133 parts of xylene and 133 parts of butyl acetate and heated to 80 ° C. To this, 2-hydroxyethyl methacrylate 6
A mixture of 0 parts, 27.5 parts of methyl methacrylate, 187.5 parts of isobutyl methacrylate, and 4.1 parts of azobisisobutyronitrile was dissolved and added dropwise over 2 hours. Furthermore, 1.2 parts of azobisisobutyronitrile was added, the temperature was raised to 85 ° C., and the mixture was further stirred for 4 hours to synthesize an acrylic resin having a theoretical hydroxyl value of 94. The solid content of the obtained acrylic resin solution was 50%. Further, the number average molecular weight in terms of polystyrene by gel permeation chromatography was 15,000, and the weight average molecular weight was 63,000. Furthermore, the Tg measured by DSC was 55 ° C.

B) Synthesis of acrylic resin (A-2) A reactor equipped with a stirrer, a cooler and a nitrogen inlet tube was charged with 133 parts of xylene and 133 parts of butyl acetate and heated to 80 ° C. 25 parts of γ-methacryloxypropyltrimethoxysilane, 75 parts of butyl acrylate, 75 parts of methyl methacrylate, 100 parts of isobutyl methacrylate,
A mixture of 4.1 parts of azobisisobutyronitrile dissolved therein was added dropwise over 2 hours. Furthermore, 1.2 parts of azobisisobutyronitrile was added, the temperature was raised to 85 ° C., and stirring was continued for 4 hours to synthesize an acrylic resin having a hydrolyzable silyl group. The solid content of the obtained acrylic resin solution was 50%. The polystyrene-equivalent number average molecular weight by gel permeation chromatography is 18,000, and the weight average molecular weight is 71.0.
It was 00. Furthermore, the Tg measured by DSC is 45 ° C.
Met.

C) Synthesis of polyester resin (P-1) 58.2 parts of dimethyl terephthalate and 15 parts of dimethyl isophthalate were placed in a reactor equipped with a stirrer, a cooler and a nitrogen inlet tube.
5 parts, ethylene glycol 94.2 parts, neopentyl glycol 258 parts, zinc acetate 0.175 parts, antimony trioxide 0.175 parts were charged, and the mixture was heated to 160 to 230 ° C. 5
The condensation reaction was performed over time. After cooling to 180 ° C., 131 parts of adipic acid was added, and a polycondensation reaction was performed while heating to 180 to 230 ° C. over 3 hours. Next, the temperature was raised to 240 ° C. under reduced pressure (10 mmHg), and further 1 mm
The pressure was reduced to Hg, and the reaction was performed for 2 hours. The obtained polyester resin was analyzed by NMR spectrum, and as a result, terephthalic acid / isophthalic acid / adipic acid / ethylene glycol / neopentyl glycol = 7.5 / 20/2
It was 2.5 / 15/35 (molar ratio). The Tg measured by DSC was 0 ° C. The obtained polyester resin was dissolved in a mixed solvent of methyl isobutyl ketone and xylene (mixing ratio 50/50) at a solid content of 40%.

(Synthesis Example of Alkoxysilane Condensate) a) Synthesis of alkoxysilane condensate (B-1) The following raw materials were placed in a 1-liter three-necked flask and heated to 50 ° C. in a nitrogen stream. Tetraethoxysilane 84 g Tetraisopropoxy titanium 86 g Isopropanol 340 g 10% Hydrochloric acid 2 g Next, after adding 16 g of ion-exchanged water and stirring at 50 ° C. for 3 hours, a solution having an alkoxysilane condensate concentration of 9% by weight was obtained. Obtained.

B) Synthesis of alkoxysilane condensate (B-2) The following raw materials were placed in a 1-liter three-necked flask and heated to 70 ° C. in a nitrogen stream. Tetraethoxysilane 260 g Xylene 350 g Isopropyl alcohol 180 g p-Toluenesulfonic acid 0.6 g Next, ion-exchanged water 27 g was added dropwise over 30 minutes, and 70
By stirring at 4 ° C for 4 hours, a solution containing 9% by weight of the alkoxysilane condensate was obtained.

C) Synthesis of alkoxysilane condensate (B-3) The following raw materials were placed in a 200 cc three-necked flask and heated to 70 ° C. in a nitrogen stream to completely remove polyethylene glycol (number average molecular weight: 2,000). Dissolved. Acrylic resin (A-1) solution 50 g Polyethylene glycol 12.5 g Xylene 17 g Butyl cellosolve 18 g After the solution became uniform, the following compounds were added and further stirred at 70 ° C. for 3 hours. Tetraethoxysilane 13 g Methyltriethoxysilane 10 g p-Toluenesulfonic acid 0.01 g Next, a mixed solution of 3.9 g of ion-exchanged water and 3 g of butyl cellosolve was added dropwise over 1 hour, and then the mixture was further stirred at 70 ° C. for 2 hours, A solution having a solid content concentration of 36% by weight and an alkoxysilane condensate concentration of 6% by weight was obtained.

D) Synthesis of alkoxysilane condensate (B-4) The following raw materials were placed in a 200 cc three-necked flask and heated to 50 ° C. in a nitrogen stream to obtain an acrylic resin (A-1) solution and polyethylene glycol (number average). Molecular weight: 1,0
00) was mixed and dissolved. Acrylic resin (A-1) solution 8 g Polyethylene glycol 2 g Propylene glycol monomethyl ether 30 g Butyl cellosolve 26 g After the solution became uniform, the following compound was added and further stirred at 50 ° C. for 1 hour. Tetraethoxysilane 60 g p-toluenesulfonic acid 0.1 g Next, a mixed solution of ion-exchanged water 10 g and butyl cellosolve 10 g was added dropwise over 1 hour, and the mixture was further stirred at 50 ° C. for 2 hours, and the solid content concentration was 20% by weight. Thus, a solution having an alkoxysilane condensate concentration of 16% by weight was obtained.

The alkoxysilane condensates (B-1 to B-4) synthesized by the above method were subjected to a storage stability test. (Storage stability test) The alkoxysilane condensate was placed in a sample bottle and stored at 40 ° C. The appearance of the liquid was observed after 1 month and 3 months, and it was judged that no turbidity, precipitate formation, gelation, or the like was found.

[Table 1]

The paints of Examples and Comparative Examples containing the acrylic resin, polyester resin, alkoxysilane condensate and the like synthesized by the above method were prepared, and the coating film performance was evaluated by the following method. (Evaluation of coating film performance) After coating the test paint on an A4 size aluminum plate coated with the acrylic urethane white paint so that the dry film thickness is about 20 μ, polyisocyanate is used as a curing agent. If used, 130 ° C /
20 minutes, 180 ° C / 2 when using melamine resin
It was dried under the condition of 0 minutes. When these curing agents were not used, they were dried at room temperature for 1 week. After measuring the initial L value with a color difference meter, two types of inclination angles are set: the angle at which the coated surface is vertical (hereinafter referred to as the vertical surface) and the angle at which the coated surface is upward at 45 degrees (hereinafter referred to as the 45 degree surface). They were selected and exposed southward for 5 months. After the exposure, the L value was measured again, and the difference from the initial L value (ΔL: difference in lightness) was obtained. The smaller the difference in lightness, the better the stain resistance. In addition, the state of streaky contamination on the coated surface after exposure was also visually evaluated.

[0031]

Example 1 Acrylic resin (A-1) solution 20 g (solid content 10 g), alkoxysilane condensate (B-1) solution 1
After mixing 1 g (1 g of pure content), a number average molecular weight of 100
A solution prepared by dissolving 0.5 g of polyethylene glycol of 0 in 10 g of methyl ethyl ketone was added, and further 3.3 g of Coronate HX manufactured by Nippon Polyurethane Industry Co., Ltd. was added as a polyisocyanate curing agent. The evaluation results of the performance of the coating film formed by the above-mentioned paint were as follows. ΔL (vertical plane) = − 1.5; ΔL (45 degree plane) = − 3.0

[0032]

Example 2 Acrylic resin (A-1) solution 20 g (solid content 10 g), alkoxysilane condensate (B-2) solution 5
5 g (pure content 5 g) and 0.5 g of polyethylene glycol having an average molecular weight of 400 were mixed, and further 3.3 g of the same polyisocyanate curing agent as in Example 1 was added to obtain a coating liquid. The evaluation results of coating film performance were as follows. ΔL (vertical plane) = − 1.2; ΔL (45 degree plane) = − 2.5

[0033]

Example 3 The same polysilane as in Example 1 was used for 20 g (solid content: 7.2 g) of an alkoxysilane condensate (B-3) solution containing an acrylic resin (A-1) component and a polyethylene glycol component. A coating liquid was obtained by adding 1.5 g of an isocyanate curing agent. The evaluation results of coating film performance were as follows. ΔL (vertical surface) = − 1.0; ΔL (45 degree surface) = − 3.0

[0034]

Example 4 Acrylic resin (A-2) solution 20 g (solid content 10 g), alkoxysilane condensate (B-1) solution 1
After mixing 1 g (1 g of pure content), a number average molecular weight of 100
A solution of 0.5 g of polyethylene glycol of 0 in 10 g of methyl ethyl ketone was added. The evaluation results of the performance of the coating film formed by the above-mentioned paint were as follows. ΔL (vertical plane) = − 1.0; ΔL (45 degree plane) = − 3.5

[0035]

Example 5 Acrylic resin (A-1) solution 50 g (solid content 25 g), alkoxysilane condensate (B-4) solution 15 g (acrylic resin component 0.4 g, polyethylene glycol component 0.2 g, silica hydrolysis) Product ingredient 2.4g)
Was mixed, and 8.5 g of a polyisocyanate curing agent (Coronate HX) was further added to prepare a coating material. The evaluation results of coating film performance were as follows. ΔL (vertical plane) = − 0.8; ΔL (45 degree plane) = − 3.0

[0036]

Example 6 Polyester resin (P-1) solution 25 g
(Solid content 10 g), alkoxysilane condensate (B-1)
After mixing 11 g of the solution (1 g of pure content), the molecular weight of 2,000
A solution prepared by dissolving 0.5 g of polyethylene glycol of 0 in 10 g of methyl ethyl ketone was added, and 2.8 g of Super Beckamine L-117-60 manufactured by Dainippon Ink and Chemicals, Inc. was further added as a melamine resin to obtain a coating liquid. Got The evaluation results of coating film performance were as follows. ΔL (vertical surface) = − 0.9; ΔL (45 degree surface) = − 2.5 Further, in any of the paints of Examples 1 to 6 described above, almost no streak contamination was observed on the painted surface. .

Comparative Example 1 A coating material was prepared by mixing 20 g of acrylic resin (A-1) solution (solid content 10 g), 1.8 g of polyisocyanate curing agent (Coronate HX) and 17 g of xylene. This example is an example corresponding to Example 3 and does not contain the two components of the alkoxysilane condensate and the polyalkylene glycol. The evaluation results of coating film performance were as follows. ΔL (vertical plane) = − 5.0; ΔL (45 degree plane) = − 11

Comparative Example 2 Acrylic resin (A-1) solution 20 g (solid content 10 g), polyisocyanate curing agent (Coronate HX) 1.8 g, alkoxysilane condensate (tetraalkoxysilane condensate solution, pure content) 21%,
A coating was prepared by mixing 9 g of Colcoat Co., Ltd .; trade name HAS-1). The evaluation results of coating film performance were as follows. ΔL (vertical plane) = − 4.0; ΔL (45 degree plane) = − 10

(Comparative Example 3) Polyester resin (P-1)
3 g of a melamine resin and Super Beckamine L-117-60 were added to 25 g of the solution (solid content 10 g) to obtain a coating liquid. The evaluation results of coating film performance were as follows. ΔL (vertical surface) = − 4.5; ΔL (45 degree surface) = − 10 In addition, in all of the paints of Comparative Examples 1 to 3, rain-like contamination on the vertical surface was remarkable.

According to the comparison between Comparative Example 2 and Example, the coating composition containing an alkoxysilane condensate containing no polyalkylene glycol still has insufficient stain resistance. It is understood that the point is markedly improved by the coating composition of the present invention which also contains polyalkylene glycol as an essential component. Although the action of the polyalkylene glycol in the present invention is not clear, it is presumed that the coating material in which the polyalkylene glycol is present has a property that the contaminants once attached are easily washed away by rainwater or the like.

[0041]

According to the present invention, acrylic paints and polyester paints having excellent stain resistance can be easily obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09D 171/02 PLQ C09D 171/02 PLQ 183/04 PMU 183/04 PMU (72) Inventor Hiroshi Inukai 1 Touna Gosei Co., Ltd. Nagoya Research Institute, 1 Funami-cho, Minato-ku, Nagoya, Aichi

Claims (4)

[Claims] 1. An acrylic resin having a hydroxyl group or a hydrolyzable silyl group, which is soluble in an organic solvent described later, or a polyester resin having a hydroxyl group, which is soluble in an organic solvent described below, a partially hydrolyzed condensate of an alkoxysilane, a polyalkylene glycol and The content of the alkoxysilane partially hydrolyzed condensate is 2 to 100 parts by weight per 100 parts by weight of the acrylic resin or the polyester resin, and the content of polyalkylene glycol is the alkoxysilane part. The coating composition is 1 to 100 parts by weight per 100 parts by weight of the hydrolyzed condensate. 2. The coating composition according to claim 1, wherein the polyalkylene glycol is polyethylene glycol. 3. An acrylic resin having a hydroxyl group or a hydrolyzable silyl group and soluble in an organic solvent described below, or a polyester resin having a hydroxyl group and soluble in an organic solvent described below, and 2 to 100 parts by weight of the acrylic resin or polyester resin.
Using 100 parts by weight of an alkoxysilane which forms a partial hydrolysis-condensation product, 1 to 100 parts by weight of a polyalkylene glycol and an organic solvent per 100 parts by weight of the partial hydrolysis-condensation product, the acrylic resin, polyester resin and In the coexistence of at least one partial amount or total amount of the polyethylene glycol, the alkoxysilane is hydrolyzed in the organic solvent to form a partially hydrolyzed condensate, and the acrylic resin is not allowed to coexist during the hydrolysis.
A method for producing a coating composition, which comprises adding and blending a polyester resin or the polyethylene glycol, if any. 4. The method according to claim 3, wherein the polyalkylene glycol is polyethylene glycol.