JPH10140083A - Coating material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyurethane-based coating material capable of manifesting good fouling resistance just after forming a coating film. SOLUTION: This coating composition comprises an acrylic polyol, a polyisocyanate compound, a silicate compound and a hydrophilicity imparting agent. The respective amounts of the contained components based on 100 pts.wt. total amount of the acrylic polyol and polyisocyanate compound are 1-20 pts.wt. silicate compound and 0.001-0.1 pt.wt. hydrophilicity imparting agent. The hydrophilicity imparting agent is preferably an amine salt of a carboxylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coating composition, and more particularly to a polyurethane resin-based coating composition containing an acrylic polyol and a polyisocyanate compound.

[0002]

2. Description of the Related Art Polyurethane resin-based paints have been used as heavy anticorrosion paints for buildings such as buildings and plants. Such polyurethane resin-based paints are, of course, required to have a property capable of forming a coating film exhibiting good heavy corrosion protection, but recently, have also been required to have a property capable of simultaneously realizing the stain resistance of the coating film. Have been.

For this reason, various polyurethane resin paints capable of forming a coating film having both good heavy corrosion resistance and good stain resistance have been provided. For example, WO94
/ 06870 discloses a polyurethane resin-based paint containing an acrylic polyol, a polyisocyanate compound and a silicate compound.

[0004]

The coating film formed by using the polyurethane resin paint disclosed in the above-mentioned publications begins to exhibit good stain resistance after a considerable period of time has elapsed after formation. Immediately after the contamination is not good.

[0005] An object of the present invention is to realize a polyurethane resin-based paint which can exhibit good stain resistance immediately after the formation of a coating film.

[0006]

The coating composition according to the present invention contains an acrylic polyol, a polyisocyanate compound, a silicate compound, and a hydrophilicity-imparting agent. Here, with respect to 100 parts by weight of the total amount of the acrylic polyol and the polyisocyanate compound, for example, 1 to 20 parts by weight of the silicate compound and 0.0
It is contained in each of 0.1 to 0.1 parts by weight. The hydrophilicity-imparting agent is, for example, an amine salt of a carboxylic acid.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Acrylic polyol The acrylic polyol used in the present invention is an acrylic resin containing a hydroxyl group as an essential component in a molecule, and is mainly composed of an acrylic monomer and a hydroxyl group-containing polymerizable unsaturated monomer. It is obtained by polymerizing a monomer.

Here, as the acrylic monomer, for example, alkyl esters and cycloalkyl esters of acrylic acid or methacrylic acid, specifically, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, Examples thereof include butyl methacrylate, hexyl acrylate, hexyl methacrylate, octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate.

Examples of the hydroxyl group-containing polymerizable unsaturated monomer include, for example, acrylic acid or methacrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate and hydroxybutyl methacrylate. Hydroxyalkyl esters, alkylene glycol monoacrylates or polyalkylene glycol monoacrylates such as ethylene glycol monoacrylate and polyethylene glycol monoacrylate, hydroxyalkyl vinyl ethers such as hydroxybutyl vinyl ether,
Examples thereof include alcohols such as allyl alcohol and methallyl alcohol, and adducts of the above various monomers with lactones (eg, ε-caprolactone and γ-valerolactone).

The monomer used for producing the acrylic polyol used in the present invention is a polymerizable unsaturated monomer other than the above-mentioned acrylic monomer and hydroxyl group-containing polymerizable unsaturated monomer. The body may be used in combination. Examples of such a polymerizable unsaturated monomer include vinyl aromatic compounds such as styrene and vinyl toluene, perfluorobutylethyl acrylate, perfluorobutylethyl methacrylate, perfluoroisononylethyl acrylate, and perfluoroisononyl. Perfluoroalkyl acrylates such as ethyl methacrylate, perfluorooctylethyl acrylate, perfluorooctylethyl methacrylate or perfluoroalkyl methacrylates, acrylonitriles, methacrylonitriles, olefins, fluoroolefins,
Examples thereof include vinyl esters, cyclohexyl or alkyl vinyl ether olefins, cyclohexyl or alkyl vinyl ethers, and aryl ethers.

The molecular weight (number average molecular weight) of the acrylic polyol used in the present invention is usually from 2,000 to 10
000 is preferred, and 3,000 to 40,000 is more preferred. When the molecular weight is less than 2,000, the weather resistance and stain resistance of the coating film obtained from the coating composition of the present invention may be reduced. Conversely, if it exceeds 100,000, the compatibility between the acrylic polyol and the other components contained in the coating composition of the present invention is reduced, and as a result, the curing of the coating film becomes non-uniform and the coating film has a high resistance. Contamination may be reduced.

The hydroxyl value of the acrylic polyol is as follows:
Usually, 10 to 400 is preferable, and 50 to 200 is more preferable. If the hydroxyl value is less than 10, the curability of the coating composition of the present invention may be reduced. Conversely, if it exceeds 400, the water resistance and stain resistance of the coating film obtained from the composition of the present invention may be reduced.

The acrylic polyol used in the present invention generally has a nonvolatile content (NV) of 10 to 90% by weight,
Preferably, it is set to 40 to 70% by weight.

Polyisocyanate Compound The polyisocyanate compound used in the present invention is not particularly limited as long as it is a compound having two or more isocyanate groups in a molecule, and various known compounds are available. Specifically, tolylene diisocyanate (TD
I), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI),
Meta-xylylene diisocyanate (MXDI), hexamethylene diisocyanate (HDI), hydrogenated MDI,
Hydrogenated TDI, hydrogenated XDI, isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMDI), dimer acid diisocyanate (DDI), and their alcohol-modified products and aggregates (isocyanurate and burette) can be used. . Among such polyisocyanate compounds, preferred is an isocyanurate of hexamethylene diisocyanate (for example, Nippon Polyurethane Co., Ltd.) in that it can impart good durability to a coating film obtained by the coating composition of the present invention. Trade name "Coronate HX" manufactured by Kogyo Co., Ltd.).

Silicate Compound The silicate compound used in the present invention is represented by the following general formula (1) and a partially hydrolyzed condensate thereof.

[0016]

Embedded image

In the formula, R ¹ and R ² are selected from the group consisting of an alkyl group, an aryl group and an aralkyl group.
And a monovalent hydrocarbon group. Here, the alkyl group preferably has 1 to 10 carbon atoms, and more preferably has 1 to 4 carbon atoms. Examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, i
Examples thereof include a so-propyl group, an n-butyl group, and an iso-butyl group. The aryl group preferably has 6 to 9 carbon atoms, such as a phenyl group. Further, as the aralkyl group, those having 7 to 9 carbon atoms are preferable, and examples thereof include a benzyl group. When the number of carbon atoms constituting the above-mentioned alkyl group, aryl group and aralkyl group exceeds the above-mentioned range, the reactivity of the silicate compound may decrease, and as a result, the silicate compound is obtained by the coating composition of the present invention. The stain resistance of the coating film may be reduced.

The above R ¹ and R ² may be the same or different from each other.

A in the general formula (1) is an integer of 0 to 3. However, a is preferably 0 because the curability of the coating film formed by the coating composition of the present invention can be enhanced.

Specific examples of the silicate compound represented by the above general formula (1) include, for example, tetramethyl silicate, tetraethyl silicate, tetra n-propyl silicate, tetra iso-propyl silicate, tetra n-butyl silicate and tetra iso Tetraalkyl silicate such as -butyl silicate, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, octadecyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, methyltrisec-octyloxysilane And trialkoxysilanes such as methyltriphenoxysilane, methyltriisopropoxysilane and methyltributoxysilane.

As the partially hydrolyzed condensate of the silicate compound represented by the general formula (1), a product obtained by adding water to the above-mentioned tetraalkylsilicate or trialkoxysilane and condensing it according to a conventional method is used. obtain. Specific examples of such a partially hydrolyzed condensate include, for example, “MSI51” (trade name, manufactured by Colcoat Co., Ltd.)
"ESI28", "ESI40", "HAS-"
1 "and" HAS-10 "(all are partially hydrolyzed condensates of tetraalkyl silicate), Shin-Etsu Chemical's trade name" AFP-1 "(partially hydrolyzed condensate of trialkoxysilane) and "MS-56" (a partially hydrolyzed condensate of tetramethylsilicate) manufactured by Mitsubishi Chemical Corporation can be mentioned.

The above-mentioned various silicate compounds may be used alone or in combination of two or more.

Among the above-mentioned various silicate compounds, preferred are tetramethyl silicate and tetraethyl silicate, and their partially hydrolyzed and condensed products in terms of stain resistance. In particular, the partially hydrolyzed and condensed products of tetramethyl silicate are preferred. Are preferred.

The hydrophilicity-imparting agent used in the present invention imparts hydrophilicity to the coating film of the coating composition of the present invention, and enhances the stain resistance of the coating film immediately after formation of the coating film. It is a component of. As such a hydrophilicity-imparting agent, for example, amine salts of carboxylic acids, particularly long-chain amine salts of long-chain carboxylic acids are preferably used.

Here, carboxylic acids include, for example, butanoic acid, pentanoic acid, hexanoic acid, 2-ethylhexanoic acid, maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, succinic acid, phthalic acid Acids, trimellitic acid, pyromellitic acid and benzoic acid can be mentioned. Among them, preferred long-chain carboxylic acids include maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, succinic acid, phthalic acid, trimellitic acid and pyromellitic acid.

On the other hand, examples of amines which form salts with the above-mentioned carboxylic acids include primary amines such as hexylamine, myristylamine and dodecylamine, dimethylamine, dimethyldodecylamine, distearylamine and di (2- Secondary amines such as ethylhexyl) amine; and tertiary amines such as dimethyloctylamine, dimethyldecylamine, dibutyllaurylamine, dimethylmyristylamine, dimethylpalmitylamine, dimethylstearylamine, dimethyldodecylamine, triethylamine and trioctylamine. be able to. Among them, preferred long-chain amines include dibutyl laurylamine, hexylamine, dimethyldodecylamine and dodecylamine.

The combination of the above-mentioned carboxylic acid and amine is not particularly limited. However, in the present invention, dibutyl laurylamine salt of 2-ethylhexanoic acid is used as a hydrophilicity-imparting agent in terms of adhesion. It is preferable to use them.

The above-mentioned hydrophilicity-imparting agents may be used in combination of two or more.

Blending Ratio The coating composition of the present invention has a mixing ratio (A: B) of the above-mentioned acrylic polyol (A) and the above-mentioned polyisocyanate compound (B) in a solid content weight ratio of 85:15 to 60:
Preferably, it is set to 40. If the ratio of the acrylic polyol is higher than this ratio, the curing of the coating film may be insufficient. Conversely, when the proportion of the acrylic polyol is smaller than this proportion, the coating film becomes hard and cracks may occur.

Further, the coating composition of the present invention contains 1 to 20 parts by weight of the above-mentioned silicate compound with respect to 100 parts by weight (in terms of solid content) of the above-mentioned acrylic polyol and the above-mentioned polyisocyanate compound. Preferably 2 to 10
Parts by weight) and 0.001 to 0.001 of the above-mentioned hydrophilicity-imparting agent.
0.1 parts by weight (preferably 0.002 to 0.05 parts by weight).

If the content of the silicate compound is less than 1 part by weight, the coating film of the present invention may not exhibit good stain resistance. Conversely, if it exceeds 20 parts by weight, cracks may occur in the coating film.

The content of the hydrophilicity-imparting agent is 0.001.
When the amount is less than part by weight, the coating film formed by the coating composition of the present invention is hard to exhibit good stain resistance immediately after formation, and it takes a long time for the coating film to exhibit good stain resistance. May be required. Conversely, when the amount exceeds 0.1 part by weight, the time until the composition of the present invention gels is shortened, and as a result, cracks may easily occur in a coating film obtained by the composition of the present invention. is there.

The coating composition of the present invention may contain, in addition to the above essential components, a tin catalyst as a curing catalyst, a coloring pigment, a diluent, an ultraviolet absorber, a light stabilizer, and an anti-sagging agent, if necessary. And various additives such as an antifoaming agent and a leveling agent. When a tin catalyst is used, the content is 100 parts by weight (in terms of solid content) of the above-mentioned acrylic polyol and the above-mentioned polyisocyanate compound.
Is preferably set to 0.001 to 0.1 part by weight. The content of the pigment is 15 to 40% by weight based on the weight of the coating film obtained by the coating composition of the present invention.
It is preferable to set the content of the other additives to 0.1 to 10% by weight of the coating liquid described later.

Method for Preparing the Coating Composition The coating composition of the present invention usually comprises a coating liquid containing the above-mentioned acrylic polyol and a hydrophilicity-imparting agent as main components and the above-mentioned polyisocyanate compound and a silicate compound as main components. It can be prepared by preparing two liquids with a curing agent and mixing both. The tin catalyst described above,
Pigments and other additives are usually added to the coating liquid side.

The coating composition of the present invention thus prepared is not particularly limited, but may be used, for example, as a paint for an outer wall of a building or a heavy-duty anticorrosive paint for a steel structure such as a bridge or a plant. Used. When the coating composition of the present invention is applied to such an object to be coated, for example, a normal method such as dipping, spraying, or brushing is adopted, and the coating composition is left at room temperature for a predetermined period or heated. To be cured. The coating film formed in this manner can exhibit not only good anticorrosion properties as in the case of a conventional polyurethane resin-based heavy anticorrosion paint, but also can exhibit good stain resistance immediately after formation.

[0036]

【Example】Production Example 1 (Synthesis of acrylic polyol)  35 parts by weight of butyl acetate, 20 parts by weight of styrene,
12 parts by weight of 2-hydroxyethyl acrylate, butyl methacrylate
24 parts by weight of chill and 4 parts by weight of methyl methacrylate
Product made by Kayaku Akzo Co., Ltd.
Using Kayaester O (5 parts by weight) in the usual manner
Ril polyol was synthesized.

The obtained acrylic polyol has a nonvolatile content of 60% by weight, an acid value of 4, and a number average molecular weight of 3,50.
0, the glass transition temperature was 50 ° C., and the hydroxyl value was 80.

Production Example 2 (Synthesis of acrylic polyol) 20 parts by weight of styrene, 15 parts by weight of 2-ethylhexyl methacrylate and 2-hydroxyethyl methacrylate 1
5 parts by weight of xylene 30 parts by weight and cyclohexanone 17
Acrylic polyol was synthesized by a conventional method using 3 parts by weight of "Kayaester O" (trade name, manufactured by Kayaku Akzo Co., Ltd.) as a polymerization initiator.

The obtained acrylic polyol has a nonvolatile content of 50% by weight, an acid value of 0, and a number average molecular weight of 5,000.
0, the glass transition temperature was 50 ° C., and the hydroxyl value was 120.

Example (Preparation of coating composition ) 55 parts by weight of titanium oxide (trade name "CR-97" manufactured by Ishihara Sangyo Co., Ltd. ) as a pigment and 15 parts by weight of the acrylic polyol obtained in Production Example 2 The glass beads were mixed and mixed for 1 hour using a desktop sand grind mill to prepare a pigment dispersion paste. The total amount of the pigment dispersion paste was 0.01 parts by weight of a hydrophilicity-imparting agent composed of 40 parts by weight of 2-ethylhexanoic acid and 60 parts by weight of dibutyl laurylamine, and 30 parts by weight of the acrylic polyol obtained in Production Example 1. And mix well.
A coating liquid was obtained.

On the other hand, 85 parts by weight of isocyanurate of hexamethylene diisocyanate (trade name "Coronate HX" manufactured by Nippon Polyurethane Industry Co., Ltd.) and a partially hydrolyzed condensate of tetramethyl silicate (trade name manufactured by Mitsubishi Chemical Corporation) MS-56 ″) was mixed with 15 parts by weight to prepare a curing agent.

The coating liquid (A) thus obtained and the curing agent (B) were mixed at a solid content weight ratio (A: B) of 85:15 to prepare a coating composition.

Comparative Example 1 (Preparation of coating composition) A coating composition similar to that of the example was prepared without using a hydrophilicity-imparting agent.

Comparative Example 2 (Preparation of a coating composition) 40 parts by weight of the acrylic polyol obtained in Production Example 1
60 parts by weight of titanium oxide (trade name “CR-97” manufactured by Ishihara Sangyo Co., Ltd.) as a pigment was mixed to prepare a coating liquid. On the other hand, a polyisocyanate compound (trade name "Coronate HX" manufactured by Nippon Polyurethane Industry Co., Ltd.) 7
5 parts by weight and partially hydrolyzed condensate of tetramethylsilicate (trade name “MS-56” manufactured by Mitsubishi Chemical Corporation) 25
A curing agent consisting of parts by weight was prepared. The obtained coating liquid and the curing agent were mixed at the same ratio as in the example to obtain a coating composition.

Evaluation An aluminum plate of Japanese Industrial Standard A1050P was prepared.
The coating compositions obtained in Examples and Comparative Examples 1 and 2 were separately applied thereto so that the dry film thickness became 30 μm. After that, it is cured for 7 days under the environment of temperature 20 ° C and humidity 60%,
A cured coating was obtained. The resulting cured coating film had a water contact angle immediately after curing, and a ΔE after three months of rain exposure.
The values and water contact angles were examined. The test method is as follows. Table 1 shows the results.

(Water contact angle) A water drop of 2 mm is dropped on the coating film, and the product name is “CONTACT” manufactured by Kyowa Interface Science Co., Ltd.
The water contact angle was measured using ANGLE METER CA-Z ". The smaller the water contact angle, the better the stain resistance.

(Raindrop Exposure Test) An exposure rack provided with a roof having grooves at intervals of about 3 mm was prepared. An aluminum coated plate having a size of 9 cm × 30 cm provided with the above-mentioned coating film was vertically arranged on the plate, and rainwater was allowed to flow down the roof through the roof during rainfall. After 3 months, the water contact angle was measured in the same manner as described above, and the ΔE value was measured using Minolta Camera Co., Ltd. product name “CR-310”. The smaller the ΔE value, the smaller the degree of contamination.

[0048]

[Table 1]

[0049]

According to the coating composition of the present invention, the above-mentioned silicate compound and hydrophilicity-imparting agent are added to the acrylic polyol and the polyisocyanate compound. A coating film that can be exhibited can be formed.

Claims (3)

[Claims] 1. A coating composition comprising an acrylic polyol, a polyisocyanate compound, a silicate compound, and a hydrophilicity-imparting agent. 2. The silicate compound is added in an amount of 1 to 20 parts by weight, and the hydrophilicity-imparting agent is added in an amount of 0.001 to 0.1 parts by weight, based on 100 parts by weight of the total amount of the acrylic polyol and the polyisocyanate compound. The coating composition according to claim 1, comprising: 3. The coating composition according to claim 1, wherein the hydrophilicity-imparting agent is an amine salt of a carboxylic acid.