JP2000080321A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition which is improved in transparency, gloss, build retention, mechanical strength, acid resistance, solvent resistance and long-term weatherability by comprising a copolymer of specific UV absorbing monomer, cycloalkyl group-containing unsaturated monomer and hydroxyl group-containing monomer. SOLUTION: A monomer composition obtained by mixing 0.1 to 30 wt.% of a UV absorbing monomer of formula I, 5 to 98.9 wt.% of a cycloalkyl group- containing unsaturated monomer, and 1 to 45 wt.% of a hydroxyl group- containing monomer, is subjected to copolymerization in the presence of a polymerization initiator at room temperature to 200 deg.C to obtain a copolymer having a weight average molecular weight of 2,000 to 300,000. A polyisocyanate compound (modified material) is compounded in the copolymer. In the formulas, R1 represents H or a 1-8C hydrocarbon group, R2 represents linear or branched 1-6C alkylene, R3 represents H or methyl, X represents H, a halogen, a 1-8C hydrocarbon group, 1-4C alkoxy, cyano or nitro, R10 represents H or a 1-2C hydrocarbon group, and Z represents cycloalkyl which may have a substituent group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention is excellent in transparency, gloss, stickiness, mechanical strength, acid resistance, solvent resistance, etc., and also has gloss retention and discoloration resistance in long-term outdoor use. And a coating composition capable of forming a coating film having excellent long-term weather resistance.

[0002]

2. Description of the Related Art A coating composition comprising a hydroxyl group-containing polymerizable composition and a crosslinking agent comprising a polyisocyanate compound capable of reacting with a hydroxyl group has been known. This coating composition has good drying properties, cures even at room temperature, and has excellent chemical properties such as acid resistance and solvent resistance. In particular, when an acrylic polyol is used as the polymerization composition containing a hydroxyl group, gloss,
Excellent in beauty such as transparency and durability, and can form a coating film with excellent chemical properties. It is often used outdoors as an automobile repair agent, building material, woodworking material, etc. .

[0003] Such coating compositions include, for example, unsaturated monomers containing a cycloalkyl group, unsaturated monomers containing a hydroxyl group, unsaturated monomers containing an acidic functional group, and the like. A coating composition in which a polyisocyanate compound is blended with a hydroxyl group-containing compound obtained by copolymerizing another unsaturated monomer has been reported (JP-A-5-28748).

However, when used for a long period of time, the coating film formed by the above-mentioned conventional coating composition has a problem that the ultraviolet light deteriorates the gloss and the transparency, and the weather resistance is poor.

[0005] In order to solve the above-mentioned problems, a polymer composition containing a copolymer of an ultraviolet absorber or an ultraviolet stabilizer having a polymerizable skeleton and a monomer containing a hydroxyl group has been proposed. A composition has been used. Such coating compositions include, for example, UV-stable monomers, cycloalkyl-containing unsaturated monomers, hydroxyl-containing unsaturated monomers, UV-absorbing monomers, and others. A hydroxyl-containing compound obtained by copolymerizing an unsaturated monomer of
A coating composition containing a polyisocyanate compound has been reported (JP-A-6-207142).

[0006]

However, in the above-mentioned conventional coating composition, an acrylic ester of a benzophenone derivative is used as an ultraviolet absorbing monomer, but an ultraviolet absorbing copolymer obtained therefrom is used. Is not sufficient to absorb the long wavelength region (320 nm to 400 nm) where the integrated energy is relatively large in the ultraviolet region of sunlight on the ground, since the maximum absorption wavelength is relatively short. A coating composition having sufficient long-term weather resistance cannot be obtained.

[0007] The present invention has been made in view of the above-mentioned conventional problems, and its objects are to provide transparency, gloss, durability, and the like.
Excellent mechanical strength, acid resistance, solvent resistance, etc.
Provide a paint composition capable of forming a coating film having excellent long-term weather resistance such as gloss retention and discoloration resistance in outdoor use for a long period of time, which is particularly excellent in ultraviolet absorption in the wavelength region of 300 nm to 400 nm. It is in.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a coating composition to achieve the above object, and have found that a UV-absorbing monomer having a specific structure and a UV-absorbing monomer having a specific structure have a specific structure. Including a copolymer obtained by copolymerizing a monomer composition containing a cycloalkyl group-containing unsaturated monomer and a hydroxyl group-containing monomer, and the specific structure in the monomer composition The coating composition having a content of a cycloalkyl group-containing unsaturated monomer having a content of from 5% by weight to 98.9% by weight has transparency, gloss, stickiness, mechanical strength, and acid resistance. Coating with excellent UV resistance in the wavelength range of 300 to 400 nm, and excellent long-term weather resistance such as gloss retention and discoloration resistance for long-term outdoor use. It has been found that a film can be formed, and the present invention has been completed.

That is, the coating composition of the invention according to claim 1 has the general formula (1)

[0010]

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(Wherein R ¹ is a hydrogen atom or a group having 1 to 1 carbon atoms)
8 represents a hydrocarbon group, R ² represents a linear or branched alkylene group having 1 to 6 carbon atoms, R ³ represents a hydrogen atom or a methyl group, X represents a hydrogen atom or a halogen group. , A hydrocarbon group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group), and a general formula (2)

[0012]

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(Wherein R ¹⁰ is a hydrogen atom or a group having 1 to 1 carbon atoms)
2 represents a hydrocarbon group, Z represents a cycloalkyl group which may have a substituent) and a hydroxyl group-containing monomer. And a content of the cycloalkyl group-containing unsaturated monomer in the monomer composition in the range of 5% by weight to 98.9% by weight. It is characterized by being within.

According to a second aspect of the present invention, there is provided a coating composition according to the first aspect of the present invention, wherein R ¹ and X are represented by the general formula (1).
At least one of them is a hydrogen atom.

According to a third aspect of the present invention, there is provided a coating composition according to the first or second aspect, wherein the monomer composition is represented by the general formula (1): 3)

[0016]

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(In the formula, R ⁶ represents a hydrogen atom or a cyano group, R ⁷ and R ⁸ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms, and R ⁹ represents a hydrogen atom or a carbon atom. Represents a hydrocarbon group of the formulas 1 to 18, Y represents an oxygen atom or an imino group) and / or a general formula (4)

[0018]

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Wherein R ⁶ represents a hydrogen atom or a cyano group, R ⁷ and R ⁸ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms, and Y represents an oxygen atom or an imino group. ) Is further included.

According to a fourth aspect of the present invention, there is provided a coating composition according to any one of the first to third aspects, wherein the copolymer comprises It is characterized in that a crosslinking agent having two or more functional groups capable of reacting with a hydroxyl group in one molecule is blended.

According to a fifth aspect of the present invention, there is provided a coating composition according to the fourth aspect, wherein the crosslinking agent comprises a polyisocyanate compound or a modified product thereof. It is characterized by:

Hereinafter, the present invention will be described in detail. The copolymer according to the present invention comprises an ultraviolet absorbing monomer represented by the general formula (1), a cycloalkyl group-containing unsaturated monomer represented by the general formula (2), and a hydroxyl group-containing monomer. It is obtained by copolymerizing a monomer composition containing a monomer. The above monomer composition may contain, as necessary, an ultraviolet light-stable monomer represented by the general formula (3) and / or an ultraviolet light-stable monomer represented by the general formula (4). May be included. Moreover,
A monomer other than the above monomers may be included.

The ultraviolet absorbing monomer represented by the general formula (1) according to the present invention (hereinafter, referred to as ultraviolet absorbing monomer (1)) is a substituent represented by R ¹ in the formula. There is constituted a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, R ²
Is a linear or branched alkylene group having 1 to 6 carbon atoms, the substituent represented by R ³ is a hydrogen atom or a methyl group, and the substituent represented by X is Benzotriazoles whose group is a hydrogen atom, a halogen group, a hydrocarbon group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group.

Specific examples of the ultraviolet absorbing monomer (1) include, for example, 2- [2'-hydroxy-5 '-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2-
[2'-hydroxy-5 '-(methacryloyloxypropyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyhexyl) phenyl] -2H-benzotriazole, 2- [2 '-Hydroxy-3'-
t-butyl-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-
t-butyl-3 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-
(Methacryloyloxyethyl) phenyl] -5-chloro
-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-methoxy-2
H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyethyl) phenyl ] -5-t-butyl-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-nitro-2H-benzotriazole, and the like, but are not particularly limited. Not something. One of these ultraviolet absorbing monomers (1) may be used alone, or two or more thereof may be appropriately mixed and used.

[0025] The general formula of the present invention (2) cycloalkyl groups containing represented by an unsaturated monomer (hereinafter referred to as a cycloalkyl group-containing monomer (2)) are those wherein in R ¹⁰ It is a compound in which the substituent represented by a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms is constituted, and the substituent represented by Z is constituted by a cycloalkyl group which may have a substituent.

Specific examples of the cycloalkyl group-containing unsaturated monomer include, for example, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, and cyclododecyl (meth) acrylate. ) Acrylate and the like, but are not particularly limited. As the cycloalkyl group-containing monomer, only one type may be used, or two or more types may be appropriately mixed and used.

Specific examples of the hydroxyl group-containing monomer according to the present invention include, for example, hydroxyethyl (meth)
Acrylate, hydroxypropyl (meth) acrylate, caprolactone-modified hydroxy (meth) acrylate (for example, Placcel FM, manufactured by Daicel Chemical Industries, Ltd.), mono (meth) acrylate of polyester diol obtained from phthalic acid and propylene glycol, etc. And a monomer having a hydroxyl group, but are not particularly limited. As the hydroxyl group-containing monomer, only one type may be used, or two or more types may be appropriately mixed and used.

According to the present invention, represented by the general formula (3)
UV-stable monomer (hereinafter referred to as UV-stable monomer)
(Described as (3)) is a compound represented by the formula:⁶The substituent represented by is hydrogen
Consisting of an atom or a cyano group,⁷, R⁸Indicated by
The substituents are each independently a hydrogen atom or carbon number 1-2
R comprises⁹The substituent represented by is hydrogen
Composed of an atom or a hydrocarbon group having 1 to 18 carbon atoms;
The substituent shown is composed of an oxygen atom or an imino group
Piperidines. R above⁷, R⁸A substituent represented by
Specifically, for example, a hydrogen atom, a methyl group or
An ethyl group, ⁹The substituent represented by is specifically
Represents, for example, a methyl group, an ethyl group, a propyl group,
Propyl group, butyl group, isobutyl group, t-butyl group, pen
Tyl, hexyl, heptyl, octyl, nonyl
Group, decyl group, undecyl group, dodecyl group, tridecyl
Group, tetradecyl group, pentadecyl group, hexadecyl
Group, heptadecyl group, octadecyl group and the like.

Specific examples of the UV-stable monomer (3) include, for example, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloyl Amino-2,2,6,6-tetramethylpiperidine, 4-
(Meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6
-Pentamethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-
Examples include crotonoyloxy-2,2,6,6-tetramethylpiperidine and 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, but are not particularly limited. As the UV-stable monomer (3), only one kind may be used, or two or more kinds may be appropriately mixed and used.

The UV-stable monomer represented by the general formula (4) according to the present invention (hereinafter referred to as UV-stable monomer (4)) is a compound represented by the substituent represented by R ⁶ in the formula. Is a hydrogen atom or a cyano group, and the substituents represented by R ⁷ and R ⁸ are each independently a hydrogen atom or a carbon atom having 1 to 2 carbon atoms.
And the substituent represented by Y is a piperidine comprising an oxygen atom or an imino group.

Specific examples of the above-mentioned ultraviolet light-stable monomer (4) include, for example, 1- (meth) acryloyl-4-
(Meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1 -Crotonoyl-4-crotonoyloxy-2,2,6,6
-Tetramethylpiperidine and the like, but are not particularly limited. As the UV-stable monomer (4), only one kind may be used, or two or more kinds may be appropriately mixed and used.

Further, the above-mentioned monomers (that is, the ultraviolet-absorbing monomer (1), the cycloalkyl group-containing monomer (2), the hydroxyl group-containing monomer, and the ultraviolet-stable monomer (3).
The monomers other than (4)), that is, other monomers (hereinafter, referred to as other monomers) optionally contained in the monomer composition, share the monomer composition. The coating composition containing the copolymer obtained by polymerization may be any compound that does not impair the required physical properties.

Specific examples of the other monomers include carboxyl group-containing unsaturated monomers such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid and maleic anhydride; vinyl sulfone Sulfonic acid group-containing unsaturated monomers such as acid, styrene sulfonic acid and sulfoethyl (meth) acrylate; 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxypropyl acid phosphate, 2- (meth) Acidic phosphate unsaturated monomers such as acryloyloxy-3-chloropropyl acid phosphate and 2-methacryloyloxyethylphenylphosphoric acid; methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, isopropyl (meth)
Alkyl (meth) acrylates such as acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate An epoxy group-containing unsaturated monomer such as glycidyl (meth) acrylate; a nitrogen-containing unsaturated monomer such as (meth) acrylamide, N, N'-dimethylaminoethyl (meth) acrylate, vinylpyridine and vinylimidazole; Halogen-containing unsaturated monomers such as vinyl chloride and vinylidene chloride; styrene,
Examples include aromatic unsaturated monomers such as α-methylstyrene and vinyltoluene; vinyl esters such as vinyl acetate; vinyl ethers; unsaturated cyanide compounds such as (meth) acrylonitrile, but are not particularly limited. As the other monomer, only one kind may be used as necessary, or two or more kinds may be appropriately mixed and used.

The content of each of the above monomers in the monomer composition is not particularly limited, but the content of the ultraviolet absorbing monomer (1) is 0.1 to 30% by weight. It is preferably in the range, more preferably in the range of 1% to 20% by weight, particularly preferably in the range of 2% to 15% by weight.

If the amount of the UV-absorbing monomer (1) in the monomer composition is less than 0.1% by weight, the UV-absorbing ability of the obtained coating composition is insufficient, which is not preferable. On the other hand, when the amount of the UV-absorbing monomer (1) is more than 30% by weight, the gloss and the feeling of holding of the coating film formed from the coating composition are insufficient, and the appearance becomes ugly. In addition, the solvent resistance and the chemical resistance are inferior, which is not preferable.

The content of the cycloalkyl group-containing monomer (2) in the monomer composition is preferably in the range of 5% by weight to 98.9% by weight, and more preferably in the range of 5% by weight to 80% by weight. More preferably, it is particularly preferably in the range of 10% by weight to 70% by weight.

When the amount of the cycloalkyl group-containing monomer (2) in the monomer composition is less than 5% by weight, the gloss and the feeling of holding of the coating film formed from the coating composition are reduced. It is not preferable because it is insufficient or the synergistic effect with the ultraviolet absorbing monomer (1) is weakened, and the weather resistance is not sufficiently exhibited. On the other hand, when the amount of the cycloalkyl group-containing monomer (2) is more than 98.9% by weight, the contents of the ultraviolet absorbing monomer (1) and the hydroxyl group-containing monomer become too small, and It is not preferable because the weather resistance of the coating film formed from the composition for use becomes insufficient and the solvent resistance and chemical resistance are poor.

The content of the hydroxyl group-containing monomer in the monomer composition is preferably in the range of 1% by weight to 45% by weight, more preferably in the range of 2% by weight to 40% by weight.
Particularly preferred is in the range of from 35% to 35% by weight.

When the amount of the hydroxyl group-containing monomer in the monomer composition is less than 1% by weight, the number of active hydroxyl groups contained in the obtained copolymer decreases, and the crosslinking density decreases. Is not preferable because the coating film performance cannot be obtained. On the other hand, when the amount of the hydroxyl group-containing monomer is more than 45% by weight, the polymerization stability becomes poor and the water resistance of the obtained coating film is undesirably reduced. Further, the storage stability after blending the polyisocyanate compound or a modified product thereof is deteriorated, which is not preferable.

The amount of the ultraviolet absorbing monomer (1), the amount of the cycloalkyl group-containing monomer (2) in the monomer composition,
And by setting the amount of the hydroxyl group-containing monomer to the above range, the obtained coating composition can form a coating film having good mechanical properties and various physical properties such as acid resistance and long-term weather resistance. it can.

The UV-stable monomers (3) and (4) are used, if necessary, in a total content of the monomer composition in a range of 20% by weight or less, but 0.1% by weight or more. By doing so, the UV stability of the obtained coating composition becomes sufficient and long-term weather resistance is realized. The weight ratio of the UV-stable monomer (3) to the UV-stable monomer (4) is not particularly limited, and both may be used or only one may be used. It is particularly preferable to use only the UV-stable monomer (3).

When the above monomer composition is obtained, an ultraviolet absorbing monomer (1), a cycloalkyl group-containing monomer (2),
Hydroxyl-containing monomer, UV-stable monomer (3)
The method of mixing (4) and other monomers is not particularly limited. That is, the method for preparing the monomer composition is not particularly limited.

The polymerization method for copolymerizing the monomer composition is not particularly limited, and various polymerization methods known in the art, such as a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, and the like. Although a polymerization method or the like can be employed, a solution polymerization method is preferably employed.

Solvents that can be used when the monomer composition is copolymerized by employing the solution polymerization method include, for example, toluene, xylene, and other high-boiling aromatic solvents; ethyl acetate, butyl acetate Solvent such as methyl ethyl ketone and methyl isobutyl ketone; aliphatic alcohol solvents such as isopropanol, n-butanol and iso-butanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and diethylene glycol mono Examples thereof include an organic solvent such as an alkylene glycol monoalkyl ether solvent such as ethyl ether and water, but are not particularly limited. However, in the coating composition of the present invention, when a crosslinking agent comprising a polyisocyanate compound or a modified product thereof is blended with the copolymer, among the above-mentioned solvents, aliphatic alcohol solvents, alkylene glycol monoalkyl Ether solvents or solvents that exhibit activity toward isocyanate groups, such as water, are not preferred. One of these solvents may be used alone, or two or more of them may be appropriately mixed and used. Further, the amount of the solvent used is not particularly limited.

When copolymerizing the monomer composition, a polymerization initiator can be used. Examples of the polymerization initiator include, for example, 2,2'-azobis- (2-methylbutyronitrile), t-butylperoxy-2-ethylhexanoate, 2,2'-azobisisobutyronitrile And ordinary radical polymerization initiators such as benzoyl peroxide and di-t-butyl peroxide, but are not particularly limited. Further, the amount of the polymerization initiator used is not particularly limited.

When the monomer composition is copolymerized, the reaction temperature is not particularly limited, but is preferably in the range of room temperature to 200 ° C, more preferably in the range of 40 ° C to 140 ° C. . The reaction time may be appropriately set according to the reaction temperature, the composition of the monomer composition to be used, the type of the polymerization initiator, and the like so that the polymerization reaction is completed.

Further, when copolymerizing the monomer composition, lauryl mercaptan, 2-mercaptoethanol, carbon tetrachloride,
A chain transfer agent such as carbon tetrabromide or a regulator may be used. That is, the molecular weight of the obtained copolymer is determined by the reaction time, the reaction temperature, or the composition of the monomer composition to be used, the type of the polymerization initiator, and the like. It can be adjusted using. The weight average molecular weight (Mw) of the copolymer thus obtained is from 2,000 to 30.
It is preferably 0,000, more preferably 8,000 to 100,000.

The crosslinking agent according to the present invention is not particularly limited as long as it comprises a compound having two or more functional groups capable of reacting with a hydroxyl group in one molecule, and only one kind may be used. Alternatively, two or more kinds may be appropriately mixed and used. When a polyisocyanate compound having two or more isocyanate groups in one molecule or a modified product thereof is used as the compound, a two-part crosslinkable room temperature-curable coating composition that cures at room temperature or a relatively low heating temperature is used. It is suitably obtained.

The polyisocyanate compound or a modified product thereof is not particularly limited as long as it has two or more isocyanate groups in the molecule.
Trimethylene diisocyanate, 1,6-hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, metaxylylene diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), and derivatives of these diisocyanates Adduct polyisocyanate compounds such as trimethylolpropane adducts, burettes, isocyanurates and the like can be mentioned. In addition, only one type may be used, or two or more types may be appropriately mixed and used.

The blending amount of the polyisocyanate compound or its modified product with respect to the copolymer in the coating composition of the present invention is not particularly limited.

Further, when a polyisocyanate compound or a modified product thereof is blended with the copolymer, the coating composition of the present invention may have a hydroxyl group and an isocyanate group in the copolymer other than the copolymer and the crosslinking agent. Known catalysts for promoting the urethanization reaction of dilauric acid
organotin compounds such as n-butyltin and tertiary amines),
Various coating additives such as an organic solvent, a filler, a leveling agent, a plasticizer, a stabilizer, a dye, and a pigment may be appropriately included.

As the above-mentioned pigments, inorganic pigments and organic pigments can be used. Examples of the inorganic pigment include white pigments such as titanium oxide, antimony trioxide, zinc white, lithopone, and lead white; and color pigments such as carbon black, graphite, molybdenum red, red iron oxide, yellow iron oxide, and yellow flower. . Examples of the organic pigment include azo compounds such as benzidine and Hansa Yellow; and phthalocyanines such as phthalocyanine blue. One of these pigments may be used alone, or two or more of them may be appropriately mixed and used. The paint composition according to the present invention can also be used as a colored paint by dispersing various pigments by a known pigment dispersion method, and is excellent in dispersibility of a pigment such as carbon black. It is also excellent in color mixing stability in the composite pigment system.

The method of compounding the copolymer, crosslinking agent and various additives for obtaining the coating composition of the present invention is not particularly limited.

As described above, the coating composition according to the present invention comprises a simple composition containing an ultraviolet absorbing monomer (1), a cycloalkyl group-containing monomer (2), and a hydroxyl group-containing monomer. (2) a copolymer comprising a copolymer obtained by copolymerizing a monomer composition, and the cycloalkyl group-containing monomer (2) in the monomer composition
Is in the range of 5% by weight to 98.9% by weight.

Further, in the coating composition according to the present invention, the ultraviolet absorbing monomer (1) is represented by the following general formula (1):
At least one of the substituents represented by R ¹ and X is a hydrogen atom.

As a result, excellent transparency, gloss, durability, mechanical strength, acid resistance, solvent resistance, etc.
It is particularly excellent in ultraviolet absorption in the wavelength region of ~ 400 nm, and coloring caused by the ultraviolet absorbing monomer (1) hardly occurs.
In addition, it is possible to provide a coating composition capable of forming a coating film having excellent long-term weather resistance such as gloss retention and discoloration resistance in long-term outdoor use.

Further, the coating composition according to the present invention comprises:
The above monomer composition comprises an ultraviolet light-stable monomer (3) and / or
Alternatively, the composition further includes an ultraviolet-stable monomer (4). As a result, due to the synergistic effect of the UV-absorbing monomer (1) and the UV-stable monomers (3) and (4), the UV-absorbing ability and the UV-stability are sufficiently exhibited.
A coating film having more excellent long-term weather resistance can be formed.

In addition, the coating composition according to the present invention comprises:
A cross-linking agent comprising a polyisocyanate compound or a modified product thereof is blended with the above copolymer. Thereby, it is possible to obtain a two-part crosslinking type cold-curable coating composition having excellent drying properties and excellent coating workability.

The object to which the above coating composition can be applied is not particularly limited. Examples of the object to be coated include various plastics such as ABS (acrylonitrile-butadiene-styrene) resin, FRP (fiber reinforced plastic), PET (polyethylene terephthalate), polystyrene, polypropylene, polycarbonate, and acrylic resin; various metals; glass And the like. By applying the coating composition of the present invention to the surface of these objects to form a coating film, the objects to be coated can be protected from ultraviolet rays. That is, the coating composition of the present invention is used for plastic molded products, home appliances,
Widely used as UV-absorbing coating agent for steel products, large structures, automobiles (for solid color coatings for new vehicles and repairs and for clear tops of metallic color coatings), construction, building materials, woodworking, etc. can do.

[0060]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. In the Examples and Comparative Examples, “parts” means “parts by weight”, and “%” means “% by weight”.
Is shown.

Example 1 A four-necked flask equipped with a thermometer, a nitrogen gas inlet tube, a dropping funnel, a condenser and a stirrer was charged with 25 parts of xylene as a solvent and 25 parts of butyl acetate.
And heated to 100 ° C. On the other hand, 0.1 part of 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole (hereinafter referred to as benzotriazole (A)) as an ultraviolet absorbing monomer (1), 46.9 parts of cyclohexyl methacrylate as a cycloalkyl group-containing monomer (2), 2.5 parts of hydroxyethyl methacrylate as a hydroxyl group-containing monomer, 0.5 part of methacrylic acid as another monomer, and 2,2 as a polymerization initiator A mixed solution obtained by mixing 0.5 part of 2'-azobisisobutyronitrile (hereinafter, referred to as an initiator (a)) was put into a dropping funnel. Thereafter, the mixed solution was added dropwise at 100 ° C. over 2 hours while stirring under a nitrogen gas stream, and further added at 100 ° C.
While maintaining the temperature for 4 hours to effect copolymerization. Table 1 summarizes the main reaction conditions.

After completion of the reaction, the viscosity of the obtained copolymer solution was measured by a Gardner foam viscometer.
⁺ (Viscosity standard solution symbol) and the non-volatile content is 49.8
%Met. The weight average molecular weight (Mw) of the obtained copolymer was 15,000.

Next, a polyfunctional isocyanate (Sumidur N-320) as a crosslinking agent was added to this copolymer solution.
0; manufactured by Sumitomo Bayer Urethane Co., Ltd.) with an equivalent ratio of isocyanate groups to hydroxyl groups in the copolymer of 1: 1.
The following amounts were weighed and blended to obtain a coating composition.

Further, the obtained coating composition was diluted by adding a thinner of xylene: butyl acetate = 1: 1,
The viscosity of the mixture was adjusted to a viscosity that allowed air spraying. As a result, a clear paint was obtained.

The resulting clear paint is applied by air spray to a white plate obtained by applying a two-component urethane resin enamel on a zinc phosphate treated steel plate, and applying the paint so that the dry film thickness becomes about 30 μm. Was painted on the surface of a white plate. Thereafter, the white plate was forcibly dried at 80 ° C. for 60 minutes to prepare a test piece for a fluorescent UV condensation test (QUV test).

Then, using this test piece, a 60 ° gloss value and a yellowing degree (hereinafter, referred to as Δb value) were measured. The measurement was carried out based on JIS K 5400-1979, and as a measuring device, a UB-1 (UVCON) manufactured by Toyo Seiki Seisaku-sho, Ltd. was used. As a measurement condition, a cycle of irradiating 70 ° C. × 4 hours and wet 50 ° C. × 4 hours as one set was repeated, and the initial and QUV
After 2000 hours, the 60 ° gloss value and the degree of yellowing were measured, and the gloss retention after 2000 hours of QUV (hereinafter referred to as GR) was determined. As a result, the initial 60 ° gloss value was 93,
The GR after V 2000 hours was 93%, and the Δb value was 8.

An acid resistance test was performed as follows.
The evaluation was made in four stages of “excellent” to “good” to “normal” to “poor”. That is, a 5 w / v% aqueous solution of sulfuric acid was spotted on the test piece, left at 60 ° C. for 30 minutes, and visually observed. In this case, no abnormality was observed in the coating film (four-level evaluation “excellent”). Table 2 summarizes these measurement results.

Example 2 The amount of benzotriazole (A) in Example 1 was changed from 0.1 part to 1.0 part, the amount of cyclohexyl methacrylate was changed from 46.9 parts to 28.5 parts, and the amount of hydroxyethyl methacrylate was changed from 2.5 parts to 20.0 parts. To
Except having changed each, the same reaction and operation as Example 1 were performed, and the copolymer solution was obtained. Table 1 summarizes the main reaction conditions.

After completion of the reaction, the viscosity of the obtained copolymer solution was measured by a Gardner foam viscometer, and it was Z (viscosity standard solution symbol), and the nonvolatile content was 50.1%. Also, the weight average molecular weight (M
w) was 14,000.

Next, the same operation as in Example 1 was performed to obtain a coating composition. Further, the same operation as in Example 1 was performed to prepare a test piece, and the initial 60 ° gloss value, QUV 200
Measurement of Δb value and GR after 0 hour and acid resistance test were performed. Table 2 summarizes these measurement results.

Example 3 A four-necked flask similar to the four-necked flask of Example 1 was charged with 25 parts of xylene and 25 parts of butyl acetate as a solvent and heated to 100 ° C. On the other hand, 15.0 parts of benzotriazole (A), 14.6 parts of cyclohexyl methacrylate, 8.0 parts of hydroxyethyl methacrylate, 0.5 part of initiator (a), 0.5 part of methacrylic acid as other monomer, n-butyl acrylate
The mixture obtained by mixing 1.5 parts was placed in a dropping funnel. Thereafter, the mixture is stirred under a stream of nitrogen gas for 1 hour.
The mixture was added dropwise at 00 ° C. over 2 hours, and further stirred for 4 hours while maintaining the temperature at 100 ° C. to carry out copolymerization to obtain a copolymer solution. Table 1 summarizes the main reaction conditions.

After completion of the reaction, the viscosity of the obtained copolymer solution was measured by a Gardner foam viscometer.
(Viscosity standard liquid symbol) and the non-volatile content is 50.0%
Met. The weight average molecular weight (Mw) of the obtained copolymer was 13,000.

Next, the same operation as in Example 1 was performed to obtain a coating composition. Further, the same operation as in Example 1 was performed to prepare a test piece, and the initial 60 ° gloss value, QUV 200
Measurement of Δb value and GR after 0 hour and acid resistance test were performed. Table 2 summarizes these measurement results.

Example 4 A four-necked flask similar to the four-necked flask of Example 1 was charged with 25 parts of xylene and 25 parts of butyl acetate as a solvent, and heated to 100 ° C. On the other hand, 5.0 parts of benzotriazole (A), 34.5 parts of cyclohexyl methacrylate, 8.0 parts of hydroxyethyl methacrylate, and 0.5 part of methacrylic acid as another monomer
Part, 0.5 part of initiator (a) and 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine (hereinafter referred to as piperidine (C)) as ultraviolet-stable monomer (3)
The mixture obtained by mixing 2.0 parts was put in a dropping funnel. Thereafter, the mixture is stirred for 100 hours under a nitrogen gas stream.
The mixture was added dropwise at 2 ° C. over 2 hours, and further stirred for 4 hours while maintaining the temperature at 100 ° C. to carry out copolymerization to obtain a copolymer solution. Table 1 summarizes the main reaction conditions.

[0075] When after the completion of the reaction, the viscosity of the resulting copolymer solution was measured by a Gardner bubble viscometer, Z1 ⁺
(Viscosity standard liquid symbol) and the non-volatile content is 49.9%
Met. The weight average molecular weight (Mw) of the obtained copolymer was 14,000.

Next, the same operation as in Example 1 was performed to obtain a coating composition. Further, the same operation as in Example 1 was performed to prepare a test piece, and the initial 60 ° gloss value, QUV 200
Measurement of Δb value and GR after 0 hour and acid resistance test were performed. Table 2 summarizes these measurement results.

Example 5 A four-necked flask similar to the four-necked flask of Example 1 was charged with 25 parts of xylene as a solvent and 25 parts of butyl acetate, and heated to 100 ° C. On the other hand, a mixed solution obtained by mixing 1.0 part of benzotriazole (A), 29.0 parts of cyclohexyl methacrylate, 20.0 parts of hydroxyethyl methacrylate, and 0.5 part of initiator (a) was put into a dropping funnel. Thereafter, the mixed solution was dropped at 100 ° C. over 2 hours while stirring under a nitrogen gas stream, and further stirred for 4 hours while maintaining the temperature at 100 ° C. to copolymerize, thereby obtaining a copolymer solution. Table 1 summarizes the main reaction conditions.

After the completion of the reaction, the viscosity of the obtained copolymer solution was measured by a Gardner foam viscometer.
(Viscosity standard liquid symbol) and the non-volatile content is 49.9%
Met. The weight average molecular weight (Mw) of the obtained copolymer was 14,000.

Next, the same operation as in Example 1 was performed to obtain a coating composition. Further, the same operation as in Example 1 was performed to prepare a test piece, and the initial 60 ° gloss value, QUV 200
Measurement of Δb value and GR after 0 hour and acid resistance test were performed. Table 2 summarizes these measurement results.

Example 6 A four-necked flask similar to the four-necked flask of Example 1 was charged with 25 parts of xylene as a solvent and 25 parts of butyl acetate, and heated to 100 ° C. On the other hand, a mixed solution obtained by mixing 7.0 parts of benzotriazole (A), 23.0 parts of cyclohexyl methacrylate, 15.0 parts of hydroxyethyl methacrylate, 5.0 parts of piperidine (C) and 0.5 part of initiator (a) was put into a dropping funnel. Thereafter, the mixed solution was dropped at 100 ° C. over 2 hours while stirring under a nitrogen gas stream, and further stirred for 4 hours while maintaining the temperature at 100 ° C. to copolymerize, thereby obtaining a copolymer solution. Table 1 summarizes the main reaction conditions.

[0081] When after the completion of the reaction, the viscosity of the resulting copolymer solution was measured by a Gardner bubble viscometer, Z2 ⁺
(Viscosity standard liquid symbol) and the non-volatile content is 50.0%
Met. The weight average molecular weight (Mw) of the obtained copolymer was 15,000.

Next, the same operation as in Example 1 was performed to obtain a coating composition. Further, the same operation as in Example 1 was performed to prepare a test piece, and the initial 60 ° gloss value, QUV 200
Measurement of Δb value and GR after 0 hour and acid resistance test were performed. Table 2 summarizes these measurement results.

Comparative Example 1 A four-necked flask similar to the four-necked flask of Example 1 was charged with 25 parts of xylene and 25 parts of butyl acetate as a solvent, and heated to 100 ° C. On the other hand, instead of benzotriazole (A) of Example 1, 2- [2'-hydroxy-5 '-(β
-Methacryloyloxyethoxy) -3'-t-butylphenyl] -4-t-butyl-2H-benzotriazole (hereinafter referred to as benzotriazole (B)) 0.1 part, cyclohexyl methacrylate 46.9 parts, hydroxyethyl methacrylate
2.0 parts, methacrylic acid 0.4 part, and initiator (a) 0.5
The mixture obtained by mixing the parts was placed in a dropping funnel. afterwards,
The mixture was added dropwise at 100 ° C. over 2 hours while stirring under a nitrogen gas stream, and further stirred for 4 hours while maintaining the temperature at 100 ° C. to copolymerize, thereby obtaining a copolymer solution. Table 1 summarizes the main reaction conditions.

After completion of the reaction, the viscosity of the obtained copolymer solution was measured with a Gardner foam viscometer.
⁺ (Viscosity standard solution symbol), and the non-volatile content is 50.0
%Met. The weight average molecular weight (Mw) of the obtained copolymer was 15,000.

Next, the same operation as in Example 1 was performed to obtain a paint composition for comparison. Further, the same operation as in Example 1 was performed to prepare a test piece, and the initial 60 ° gloss value, QUA
Measurement of Δb value and GR after 2000 hours of V and acid resistance test were performed. Table 2 summarizes these measurement results.

Comparative Example 2 A four-necked flask similar to the four-necked flask of Example 1 was charged with 25 parts of xylene and 25 parts of butyl acetate as a solvent and heated to 100 ° C. On the other hand, benzotriazole (B) 5.0 parts, cyclohexyl methacrylate 34.5 parts, hydroxyethyl methacrylate 10.0 parts, methacrylic acid 0.4 parts, piperidine (C) 2.0
And a mixture obtained by mixing 0.5 part of the initiator (a) were placed in a dropping funnel. Thereafter, the mixed solution was dropped at 100 ° C. over 2 hours while stirring under a nitrogen gas stream, and further stirred for 4 hours while maintaining the temperature at 100 ° C. to copolymerize, thereby obtaining a copolymer solution. Table 1 summarizes the main reaction conditions.

[0087] When after the completion of the reaction, the viscosity of the resulting copolymer solution was measured by a Gardner bubble viscometer, Z1 ⁺
(Viscosity standard solution symbol) and the non-volatile content is 50.1%
Met. The weight average molecular weight (Mw) of the obtained copolymer was 14,000.

Next, the same operation as in Example 1 was performed to obtain a paint composition for comparison. Further, the same operation as in Example 1 was performed to prepare a test piece, and the initial 60 ° gloss value, QUA
Measurement of Δb value and GR after 2000 hours of V and acid resistance test were performed. Table 2 summarizes these measurement results.

[0089]

[Table 1]

[0090]

[Table 2]

As is clear from the results shown in Table 2,
The coating film comprising the coating composition of the present invention has a good gloss retention even after 2000 hours of QUV, and hardly turns yellow. Further, the coating film comprising the coating composition of the present invention has excellent acid resistance. Thereby, the coating composition of the present invention is excellent in transparency, gloss, stickiness, mechanical strength, acid resistance, solvent resistance, etc., and further, absorbs ultraviolet light in a wavelength region of 300 nm to 400 nm. It can be seen that a coating film having excellent long-term weather resistance such as gloss retention and discoloration resistance in outdoor use for a long time can be formed.

[0092]

As described above, the coating composition of the present invention comprises an ultraviolet absorbing monomer represented by the general formula (1) and a cycloalkyl group represented by the general formula (2). Containing unsaturated monomer, a copolymer obtained by copolymerizing a monomer composition containing a hydroxyl group-containing monomer, and the cycloalkyl group-containing unsaturated monomer in the monomer composition In this configuration, the content of the monomer is in the range of 5% by weight to 98.9% by weight.

When the amount of the cycloalkyl group-containing unsaturated monomer represented by the general formula (2) in the above monomer composition is less than 5% by weight, it is formed from the coating composition. It is not preferable because the glossiness and the feeling of holding of the coating film are insufficient, the synergistic effect with the ultraviolet absorbing monomer represented by the general formula (1) is weakened, and the weather resistance is not sufficiently exhibited. On the other hand, when the amount of the cycloalkyl group-containing unsaturated monomer represented by the general formula (2) is more than 98.9% by weight, the ultraviolet absorbent represented by the general formula (1) is used. The contents of the monomer and the hydroxyl group-containing monomer are too small, and the weather resistance of the coating film formed from the coating composition becomes insufficient, and the solvent resistance and the chemical resistance are inferior.

The coating composition of the present invention, having the above-mentioned constitution, is excellent in transparency, gloss, stickiness, mechanical strength, acid resistance, solvent resistance and the like. nm
It is possible to provide a coating composition capable of forming a coating film having excellent long-term weather resistance such as excellent long-term weather resistance such as gloss retention and long-term outdoor use, which is particularly excellent in ultraviolet absorption in the wavelength region. It works.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor ▲ Yoshi ▼ Masaya 5-8 Nishiburi-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. No.5-8 Nippon Shokubai Co., Ltd.

Claims (5)

[Claims] 1. A compound of the general formula (1) (Wherein, R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, R ² represents a linear or branched alkylene group having 1 to 6 carbon atoms, and R ³ represents a hydrogen atom. X represents a hydrogen atom, a halogen group, a hydrocarbon group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group). And the general formula (2) (Wherein, R ¹⁰ represents a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms, and Z represents a cycloalkyl group which may have a substituent). And a copolymer obtained by copolymerizing a monomer composition containing a hydroxyl group-containing monomer, and the cycloalkyl group-containing unsaturated monomer in the monomer composition. Content is 5
A coating composition characterized by being in the range of 9 wt% to 98.9 wt%. 2. In the above general formula (1), R ¹ and X
The coating composition according to claim 1, wherein at least one of them is a hydrogen atom. 3. A method according to claim 1, wherein said monomer composition has the general formula (3): (Wherein, R ⁶ represents a hydrogen atom or a cyano group, R ^7,
R ⁸ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms, and R ⁹ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.
Wherein Y represents an oxygen atom or an imino group) and / or an ultraviolet-stable monomer represented by the general formula (4): (Wherein, R ⁶ represents a hydrogen atom or a cyano group, R ^7,
R ⁸ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 2 carbon atoms, and Y represents an oxygen atom or an imino group). The coating composition according to claim 1. 4. The method according to claim 1, wherein a cross-linking agent having at least two functional groups capable of reacting with a hydroxyl group in one molecule is blended with the copolymer. The composition for coating according to the above. 5. The coating composition according to claim 4, wherein said crosslinking agent comprises a polyisocyanate compound or a modified product thereof.