JPH0987578A - Curable coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable coating compsn. improved in compatibility, clarity, and finished appearance by compounding a specific hydroxylated polyester resin, a polyepoxide, a silicon compd., a chelate compd., and an org. solvent. SOLUTION: This compsn. is prepd. by dissolving or dispersing, in an org. solvent, 5-94wt.% hydroxylated polyester resin having a number average mol.wt. of 1,000-30,000, a glass transition point of -40 to 60 deg.C, a solubility parameter of 10.0-12.0, and a hydroxyl value of 2-20mgKOH/g, 5-94wt.% polyepoxide having a number average mol.wt. of 120-20,000, 0.1-50wt.% silicon compd. having 1-20 Si atoms in the molecule and represented by the formula (wherein R<1> is H or a 1-3C alkyl; R<2> is an aryl, an aralkyl, or a 4-24C monovalent hydrocarbon group having an ether bond and/or an ester bond; (a) is 0.10-3.95; and (b) is 0.05-1.95 provided a + b is 4 or lower), and 0.01-10wt.% chelate compd. of at least one metal selected from among Al, Ti, Zr, and Sn.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a novel curable resin composition.

[0002]

2. Description of the Related Art A curable resin composition prepared by blending a metal chelate compound with a mixture of a hydroxyl group-containing resin, a polyepoxide and an organosilane compound has been disclosed in JP-A-2-73825.

The composition of this publication exhibits excellent curability, but when a polyester resin is used as the hydroxyl group-containing resin, the compatibility between the polyester resin and the organosilane compound is poor and the composition is transparent and uniform and has an excellent finished appearance. It was difficult to obtain a cured coating film.

The present invention is to develop a curable resin composition which, when a polyester resin is used as a hydroxyl group-containing resin, is capable of forming a cured coating film having good compatibility, transparency, and uniformity and an excellent finished appearance. It was intended.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to solve the above problems, and as a result, a hydroxyl group-containing polyester resin, a polyepoxide, a silicon compound having a specific organic group, a metal chelate compound, and The composition containing an organic solvent has good compatibility, is transparent, and is uniform.
The inventors have found that a cured coating film having an excellent finished appearance can be formed and completed the present invention.

That is, according to the present invention, (a) a hydroxyl group-containing polyester resin having a solubility parameter value (sp value) in the range of 10.0 to 12.0, (b) a polyepoxide, (c) the following rational formula [1]: And one silicon atom in one molecule
To 20 silicon compounds SiO _{(4- (a + b)) / 2} (OR ¹ ) _a (OR ² ) _b [1] (In the formula, R ¹ represents an alkyl group having 1 to 3 carbon atoms or a hydrogen atom. , R ² is an aryl group, an aralkyl group, or an ether bond and / or an ester bond, and has 4 to 4 carbon atoms.
It represents 24 monovalent hydrocarbon groups. a is 0.10 to 3.9
5 and b represent a number of 0.05 to 1.95, and the sum of a and b is 4 or less. ), (D) at least one selected from aluminum chelate compounds, titanium chelate compounds, zirconium chelate compounds, and tin chelate compounds.
The present invention provides a curable coating composition containing a chelate compound of type (e) and an organic solvent (e).

In the composition of the present invention, the hydroxyl group-containing polyester resin (a) is particularly limited as long as it has a solubility parameter value (sp value) of 10.0 to 12.0 and a hydroxyl group-containing polyester resin. From the viewpoint of curability, durability of the resulting coating film, water resistance of the coating film, etc., it is generally preferable that the hydroxyl value is in the range of 2 to 200 mgKOH / g, and in the range of 2 to 120 mgKOH / g. Is more preferable. It is difficult to produce a polyester resin having an sp value of less than 10.0, and if the sp value exceeds 12.0, the compatibility with the silicon compound as the component (c) becomes poor.

In the present invention, the solubility parameter value (s
p-value) is based on R. in Polym. Eng. Sci. (Polymer Engineering Science), 14 , [2] 147 (1974).
It is a value calculated from the following formula by F. Fedors.

[0009]

[Equation 1]

The acid value of the polyester resin (a) is usually 0 to 3 from the viewpoint of curability and water resistance of the resulting coating film.
It is preferably 0 mgKOH / g, more preferably 0 to 20 mgKOH / g.

Further, the polyester resin (a) preferably has a number average molecular weight of 1,000 to 30,000 in view of the durability of the resulting coating film and the solid content of the coating. Is more preferably in the range of 20,000 to 20,000, and even more preferably in the range of 2,500 to 8,000.

The polyester resin (a) has a glass transition temperature (hereinafter sometimes abbreviated as "Tg") of -40 to 60 from the viewpoints of hardness and processability of the resulting coating film.
It is preferably in the range of ℃, and more preferably in the range of -10 to 30 ℃. The polyester resin (a) in the composition of the present invention is a polyester resin containing a hydroxyl group, and is an oil-free polyester resin, an oil-modified alkyd resin, or a modified product of these resins, for example, a urethane-modified polyester resin or a urethane-modified alkyd resin. Or the like.

The oil-free polyester resin is mainly an esterified product of a polybasic acid and a polyhydric alcohol.
Examples of polybasic acids include phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4
′ -Diphenylmethanedicarboxylic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexane-1,3,5-tricarboxylic acid, trihydrotricarboxylic acid Mellitic acid, dihydropyromellitic acid, endomethylenehexahydrophthalic acid, methylendomethylenehexahydrophthalic acid, maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, pimelic acid, suberic acid, Examples thereof include sebacic acid, dimer fatty acid (dimer acid), trimellitic acid, pyromellitic acid, and acid anhydrides of these acids. These polybasic acids can be used alone or in admixture of two or more.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexanediol and 1,4-. Examples thereof include dihydroxymethylcyclohexane, 1,3-dihydroxymethylcyclohexane, glycerin, trimethylolethane, trimethylolpropane and pentaerythritol. These polyhydric alcohols alone
Alternatively, two or more kinds can be mixed and used. Also, lactones such as ε-caprolactone and γ-valerolactone can be used in these reactions. These esterification reactions can be performed by a known method.

The above oil-free polyester resin can also be obtained by carrying out an ester exchange reaction using a lower alkyl ester of a polybasic acid (eg, methyl ester, ethyl ester) instead of the polybasic acid in the above esterification reaction. be able to. The transesterification reaction of both components can be performed by a known method.

The alkyd resin is obtained by reacting an oil fatty acid by a known method in addition to the acid component and the alcohol component of the oil-free polyester resin, and examples of the oil fatty acid include coconut oil fatty acid and soybean oil fatty acid. , Linseed oil fatty acid, safflower oil fatty acid, tall oil fatty acid, dehydrated castor oil fatty acid, tung oil fatty acid and the like.

The urethane-modified polyester resin is a number average molecular weight of 300 to 10,0 obtained by reacting an acid component and an alcohol component during the production of the oil-free polyester resin or the oil-free polyester resin.
Low molecular weight oil-free polyester resin of about 00,
The polyisocyanate compound is reacted with a known method.

The urethane-modified alkyd resin is a number-average molecular weight of 300 to 1 obtained by reacting the above-mentioned oil-modified alkyd resin or each component in the above-mentioned oil-modified alkyd resin production.
A low molecular weight oil-modified alkyd resin of about 10,000 is reacted with a polyisocyanate compound by a known method. Urethane-modified polyester resin, polyisocyanate compound used in the production of urethane-modified alkyd resin, hexamethylene diisocyanate,
Trimethylhexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), 2,4,6-triisocyanatotoluene, 2-isocyanato Ethyl-2,6-diisocyanatocaproate and the like can be mentioned.

The polyepoxide (b) in the present invention is
It is a cross-linking agent component of the resin (a).

The polyepoxide (b) is a compound having at least about 2 or more epoxy groups in one molecule on average, and the epoxy equivalent is usually preferably about 60 to 10,000, and 65 to 4, It is more preferably 000.

The polyepoxide (b) has a number average molecular weight of about 120 to 20,000, preferably about 240 to 8,000.
Those in the range of 0 are preferred. If the number average molecular weight is less than about 120, it is difficult to obtain it. On the other hand, if the number average molecular weight exceeds about 20,000, a coating composition with a high solid content cannot be obtained, and the molecular weight between crosslinks becomes large, so that the coating film resistance is high. Solvent-based,
It is not preferable because the scratch resistance and the like are reduced.

Specific examples of the polyepoxide (b) include:
For example, glycidyl group-containing monomers such as glycidyl (meth) acrylate and allyl glycidyl ether, 3,4-
Radical polymerizable epoxy monomers such as alicyclic epoxy group-containing monomers such as epoxycyclohexylmethyl (meth) acrylate, and optionally C _1-24 alkyl (meth) acrylate, cycloalkyl (meth) acrylate, aromatic Polymers obtained by radical polymerization reaction of other vinyl monomers such as vinyl monomers; glycidyl ether compounds such as diglycidyl ether, 2-glycidyl phenyl glycidyl ether, 2,6-diglycidyl phenyl glycidyl ether; vinyl cyclohexenedioxide, Compounds containing glycidyl group and alicyclic epoxy group such as limonendioxide; dicyclopentadiene dioxide, bis (2,3-epoxycyclopentyl) ether, epoxycyclohexenecarboxylic acid ethylene glycol Diester, bis (3,4-epoxycyclohexylmethyl) adipate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6 -Methylcyclohexanecarboxylate, Epolide GT30
0 (manufactured by Daicel Chemical Industries, Ltd., trifunctional alicyclic epoxy compound), Epolide GT400 (manufactured by Daicel Chemical Industries, Ltd.,
Tetrafunctional alicyclic epoxy compound), celoxide 208
1, 2082, 2083 (all of which are manufactured by Daicel Chemical Industries, Ltd., a ring-opening ε-caprolactone chain-containing bifunctional alicyclic epoxy compound), Epolide GT301, GT
302, the same GT303 (all of which are manufactured by Daicel Chemical Industries, Ltd., a ring-opening ε-caprolactone chain-containing trifunctional alicyclic epoxy compound), Epolide GT401, the same GT40.
2, the same GT403 (all of which are manufactured by Daicel Chemical Industries Ltd., a ring-opening ε-caprolactone chain-containing tetrafunctional alicyclic epoxy compound) such as an alicyclic epoxy group-containing compound; "Epicoat 1001" (Okaka Shell Epoxy Co., Ltd. Bisphenol A type epoxy resin), cresol novolac type epoxy resin, phenol novolac type epoxy resin and the like. Among these, polyepoxides having two or more alicyclic epoxy groups are particularly desirable because of their excellent low-temperature curability.

The silicon compound (c) in the present invention is a component that reacts with the hydroxyl group in the polyester resin (a) and the epoxy group in the polyepoxide (b), and is represented by the following formula [1]: And 1 to 1 silicon atom in one molecule
It has 20 pieces.

SiO _{(4- (a + b)) / 2} (OR ¹ ) _a (OR ² ) _b [1] (In the formula, R ¹ represents an alkyl group having 1 to 3 carbon atoms or a hydrogen atom, and R ² Is an aryl group, an aralkyl group, or an ether bond and / or an ester bond containing 4 to 4 carbon atoms.
It represents 24 monovalent hydrocarbon groups. a is 0.10 to 3.9
5 and b represent a number of 0.05 to 1.95, and the sum of a and b is 4 or less. ) In the silicon compound (c), (OR ¹ ) has ¹ carbon atom.
Represents an alkoxyl group or a hydroxyl group. 1 carbon atom
As the alkoxyl group of ~ 3, methoxy, ethoxy,
Examples thereof include n-propoxy and isopropoxy groups.

Specific examples of the aryl group and aralkyl group represented by R ² include aryl groups such as phenyl, toluyl and xylyl, aralkyl groups such as benzyl and phenethyl (alkyl groups substituted with an aryl group) and the like. Can be mentioned.

Further, an ether bond represented by R ² and /
Or, as the monovalent hydrocarbon group having 4 to 24 carbon atoms containing an ester bond, an aliphatic group is a hydrocarbon group containing an ether bond and / or an ester bond in the group, an aliphatic group,
It may be any of alicyclic, aromatic, and mixed hydrocarbon groups.

Specific examples of the group represented by (OR ² ) include:
An aryloxy group such as phenoxy and tolyloxy; an aralkyloxy group such as benzyloxy and phenethyloxy; a group containing an ether bond represented by the following formula [2]; an ester represented by the following formula [3] or [4] A group containing a bond; examples thereof include a group containing an ether bond and an ester bond represented by the following formula [5].

[0028] _{-O- (C k H 2k -O)} p -R ³ (2) formula (2), k is 1-7 integer, p is an integer from 1 to 9, R
³ represents an alkyl group having 1 to 8 carbon atoms, an aryl group or an aralkyl group.

Specific examples of the group represented by the formula [2] include:
Butoxyethyloxy, phenoxyethyloxy, -O
- (C ₂ H ₄ O) a group represented by the ₂ -C ₄ H ₉ and the like.

[0030]

Embedded image

(In the formula, k and R ³ have the same meanings as described above.)

[0032]

Embedded image

(In the formula, j represents an integer of 1 to 5, q represents an integer of 1 to ³ , and R ³ has the same meaning as described above.) The ester represented by the formula [3] or the formula [4] Specific examples of the bond-containing group include compounds represented by the following formula.

[0034]

Embedded image

[0035]

Embedded image

(In the formula, r represents an integer of 2 to 9, and k and R ³ each have the same meaning as described above.) A group containing an ether bond and an ester bond represented by the above formula [5]. Specific examples of the compound include compounds represented by the following formula.

[0037]

Embedded image

The group represented by (OR ² ) is preferably a group represented by the formula [4] among the groups represented by the above [2] to [5], in which j is 5 Some are particularly preferred.

Examples of the silicon compound (c) include silicon monomers represented by the following formula [6]; condensates of the silicon monomers with each other; tetraalkoxysilane or tetra tetrasilane represented by the following formula [7]. Co-condensation product with condensate of alkoxysilane; ether exchange of the above tetraalkoxysilane or its condensate with monovalent hydroxyl group-containing hydrocarbon represented by R ² OH (R ² has the same meaning as above) Examples thereof include a reaction product obtained by the reaction; and a ring-opening addition reaction product of the above-mentioned tetraalkoxysilane or its condensate with a lactone compound.

(R ¹ O) _m —Si— (OR ² ) _n [6] (In the formula, R ¹ is the same or different and has the same meaning as described above, and R ² is the same or different and is the same as above. It has the same meaning. M is an integer of 2 or 3, n is an integer of 1 or 2, and the sum of m and n is 4.) Specific examples of the silicon monomer represented by the above formula [6] Is triethoxyphenoxysilane, trimethoxyphenoxysilane, triethoxybenzyloxysilane, triethoxy (phenethyloxy) silane, diethoxydiphenoxysilane, dimethoxy-di (butoxyethyloxy) silane, diethoxy-di (butoxyethyloxy) silane. , Trimethoxy (butoxyethyloxy) silane, triethoxy (butoxyethyloxy) silane,
Dimethoxy-di (phenoxyethyloxy) silane, diethoxy-di (phenoxyethyloxy) silane, trimethoxy (phenoxyethyloxy) silane, triethoxy (phenoxyethyloxy) silane, dimethoxy-
Di [2- (acetoxy) pentyloxy] silane, diethoxy-di [2- (acetoxy) pentyloxy] silane, trimethoxy-2- (acetoxy) pentyloxysilane, triethoxy-2- (acetoxy) pentyloxysilane, dimethoxy- Di [2- (ethoxy) pentyloxy] silane, diethoxy-di [2- (ethoxy)
Examples thereof include pentyloxy] silane, trimethoxy-2- (ethoxy) pentyloxysilane, and triethoxy-2- (ethoxy) pentyloxysilane.

Si- (OR ¹ ) ₄ [7] (In the formula, R ¹ is the same or different and has the same meaning as described above.) The tetraalkoxysilane represented by the above formula [7] is tetraalkoxysilane. Methoxysilane, tetraethoxysilane, tetrapropoxysilane, dimethoxydiethoxysilane,
Dimethoxydipropoxysilane etc. can be mentioned.

As the condensate of tetraalkoxysilane, for example, as a commercially available product, "Colcoat ES40" (trade name, tetraethyl silicate manufactured by Colcoat, 1 to 1) is used.
0-mer, average about 5-mer), "Colcoat MS51" (Colcoat company, trade name, 1-tetramethyl silicate)
Octamer, average about 4 mer) and the like.

In order to obtain a condensate of the silicon monomers represented by the above formula [6] and a cocondensate of the silicon monomer and the tetraalkoxysilane represented by the above formula [7] or a condensate thereof, ) The condensation reaction can be performed by a conventional method. For example, it can be hydrolyzed and condensed by heating in the presence of a predetermined amount of water.

The tetraalkoxysilane and / or its condensate is subjected to an ether exchange reaction with the monovalent hydroxyl group-containing hydrocarbon represented by R ² OH (which may contain an ether bond and / or an ester bond). By (S
A part of the i-OR ¹ ) bond can be replaced with a (Si-OR ² ) bond.

Examples of the monovalent hydroxyl group-containing hydrocarbons represented by R ² OH include phenol; hydroxyl group-containing aryl compounds such as cresol; aralkyl alcohols such as benzyl alcohol; (poly) ethylene glycol;
(Poly) propylene glycol, 1,1-dimethyl-
A hydroxyl group at one end of a (poly) alkylene glycol such as 1,3-propylene glycol is represented by R ³ OH (R ³ has the same meaning as above) and has 1 to 8 carbon atoms.
A hydroxyl group-containing etherified product obtained by etherifying with a valency alkanol, phenols or aralkyl alcohol (corresponding to the introduction of the group of the above formula [2]); a hydroxyl group at one end of alkylene glycol such as ethylene glycol and propylene glycol is represented by R ³ COOH R ³ has the same meaning as described above) and a hydroxyl group-containing esterified product obtained by esterification with a monocarboxylic acid having 2 to 8 carbon atoms (corresponding to the introduction of the group of the above formula [3]); ε-caprolactone, etc. The lactones of ( ³ ) are ring-opened with the compound represented by R ³ OH as an initiator and polymerized as necessary (corresponding to the introduction of the group of the above formula [4]); The hydroxyl group at one end of R ³ COOH
And a hydroxyl group-containing compound having an ether bond and an ester bond formed by esterification with a monocarboxylic acid having 2 to 8 carbon atoms (corresponding to introduction of the group of the above formula [5]).

The reaction of the tetraalkoxysilane and / or its condensate with the above-mentioned monovalent hydroxyl group-containing hydrocarbons is required by a conventional method, for example, by mixing these components or dropping the latter into the former. In the presence of an ether exchange catalyst such as tris (acetylacetonato) aluminum, n-butyltin trioctanoate, etc.
It can be carried out by reacting for 1 to 10 hours under heating at 0 ° C.

The amount of the catalyst used is about 0.001 to 1% by weight, preferably 0.003 to 10% by weight based on the total amount of the tetraalkoxysilane and / or its condensate and the above monovalent hydroxyl group-containing hydrocarbon compound. It is about 0.1% by weight.

A ring-opening addition reaction of the above-mentioned tetraalkoxysilane and / or its condensate with a lactone compound gives an (Si-OR ² ) bond having an ester group in which a part of the (Si-OR ¹ ) bond is ring-opened. Can be replaced with

Examples of the lactone compound include γ
-Valerolactone, δ-valerolactone, ε-caprolactone, α-methyl-β-propiolactone, β-methyl-β-propiolactone, 3-n-propyl-δ-valerolactone, 6,6-dimethyl- δ-valerolactone, β-propiolactone, γ-butyrolactone, δ-
Examples include caprolactone. Of these, ε-caprolactone is particularly desirable.

The ring-opening addition reaction of tetraalkoxysilane and / or its condensate with the above-mentioned lactone compound can be carried out by a conventional method by mixing the two or by dropping the latter into the former. This reaction is usually preferably carried out in the presence of a lactone compound ring-opening addition catalyst. Examples of the ring-opening addition catalyst that can be used here include organotin compounds such as n-butyltin trioctanoate, dibutyltin dilaurate, dimethyltin dichloride, dibutyltin dichloride and dibutyltin diacetate; stannous chloride, chloride Tin halide compounds such as stannic tin; organic zirconium compounds; organic titanium compounds such as tetrabutyl titanate, tetrabutoxy titanate, tetraethyl titanate;
Examples thereof include Lewis acids such as boron trifluoride, aluminum trichloride, zinc chloride and titanium chloride; fluoride salts such as tetrabutylammonium fluoride, cesium fluoride, potassium fluoride and rubidium fluoride. It is not limited to. These catalysts can be used alone or in combination.
A mixture of two or more species can be used.

The amount of the catalyst used is about 0.01 to 10% by weight, preferably 0.2 to about 10% by weight based on the total amount of the tetraalkoxysilane and / or its condensate and the lactone compound.
It is about 4.0% by weight.

The above ring-opening addition reaction can be suitably carried out without a solvent or in the presence of a solvent inert to the reaction, in a temperature range of usually about 80 to 200 ° C, preferably about 100 to 180 ° C. . The reaction time is usually about 1 to 20 hours.

Examples of the above-mentioned inert solvent include hydrocarbon solvents such as toluene, xylene, hexane and heptane, ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as acetone and methyl ethyl ketone, dichloromethane and chloroform. The halogenated hydrocarbon solvent and the like may be used, and these may be used alone or in combination of two or more kinds. It is not desirable to use a large amount of a solvent active in the reaction, for example, a solvent containing a hydroxyl group, because the modification rate of the lactone decreases.

In the silicon compound (c), the number of silicon atoms in one molecule is 1 to 20, preferably 4 to 8.
When the number of silicon atoms exceeds 20, the compatibility with the polyester resin decreases and it becomes impossible to obtain a transparent and uniform cured coating film.

Generally, the silicon compound (c) preferably has a number average molecular weight in the range of 200 to 3,000,
More preferably, it is in the range of 500 to 2,000.

R ¹ in the above formula [1] representing the silicon compound (c) is a reactive group for reacting to form a crosslinked coating film, and the alkoxyl group as R ¹ has 3 carbon atoms.
If it exceeds, reactivity decreases and curability becomes insufficient. Further, when the type of the group represented by R ² in the above formula [1] is out of the range or the number of carbon atoms is less than the specified range, the compatibility with the polyester resin is lowered and a transparent and uniform cured coating film is obtained. On the other hand, when the number of carbon atoms exceeds 24, the hardness of the obtained coating film decreases.

The value of a in the above formula [1] representing the silicon compound (c) is 0.10 to 3.95, preferably 0.7.
5 to 2.00, the value of b is 0.05 to 1.95,
It is preferably 0.50 to 1.50. The value of a is 0.1
When it is less than 0, the reactivity is lowered and the curability becomes insufficient,
On the other hand, when it exceeds 3.95, the amount of R ² is inevitably reduced, the compatibility with the polyester resin is lowered, and a transparent and uniform cured coating film cannot be obtained. When the value of b is less than 0.05, the compatibility with the polyester resin decreases, and a transparent and uniform cured coating film cannot be obtained. On the other hand, when it exceeds 1.95, the reactivity of the silicon compound decreases. Further, the sum of a and b in the formula [1] is 4 or less, but it is preferable that it is in the range of 1.5 to 2.5 for compatibility with the polyester resin and prevention of undesired gel-like substances. It is preferable from the point.

The chelate compound (d) in the composition of the present invention is a chelate compound selected from an aluminum chelate compound, a titanium chelate compound, a zirconium chelate compound and a tin chelate compound, and is a curing catalyst for the components (a) to (c). Is used as.

The chelate compound (d) is preferably a chelate compound containing a compound capable of forming a keto / enol tautomer as a chelate ligand.

Examples of the compound capable of forming the keto-enol tautomer include β-diketones (acetylacetone etc.), acetoacetic acid esters (methyl acetoacetate etc.),
Malonates (ethyl malonate, etc.), Ketones having a hydroxyl group at the β-position (diacetone alcohol), Aldehydes having a hydroxyl group at the β-position (such as salicylaldehyde), Esters having a hydroxyl group at the β-position (methyl salicylate) ) Etc. can be used. Particularly, β-diketones and acetoacetic acid esters are preferable.

As the chelate compound (d), an aluminum chelate compound is particularly preferable from the viewpoint of metal species,
Suitable aluminum chelate compounds include tris (acetylacetonato) aluminum, tris (propionylacetonato) aluminum, tris (propionylpropionato) aluminum, tris (butyrylacetonato) aluminum, benzoylacetonatobis (acetylacetonato). ) Aluminum, bis (benzoylacetonato) / acetylacetonato aluminum, tris (benzoylacetonato) aluminum, tris (ethylacetoacetato) aluminum, tris (propylacetoacetato) aluminum, tris (butylacetoacetato) aluminum, Monoethylacetoacetato-bis (acetylacetonato) aluminum, monoacetylacetonato-bis (ethylacetoacetato) aluminum, etc. Door can be.

A typical example of the titanium chelate compound is diisopropoxy bis (ethylacetoacetate).
Examples include titanium and diisopropoxy bis (acetylacetonato) titanium. Typical examples of the zirconium chelate compound include tetrakis (acetylacetonato) zirconium and tetrakis (ethylacetoacetato) zirconium. Typical examples of the tin chelate compound include bis (acetylacetonato) monobutyltin octanoate, bis (acetylacetonato) monobutyltin acetate, bis (benzoylacetonato) monobutyltin octanoate, and bis (benzoylacetonato) monobutyltin acetate. Can be mentioned.

In the composition of the present invention, the above (a) to
The blending amount of the component (d) is not particularly limited,
Usually, each component has the following blending ratio with respect to the total weight of the components (a) to (d), and thus the finished appearance of the coating film is obtained,
It is preferable from the viewpoint of coating film performance such as curability and water resistance.

Component (a): 5-94% by weight, more preferably 14-75% by weight, Component (b): 5-94% by weight, more preferably 10-
75% by weight, (c) component: 0.1 to 50% by weight, more preferably 0.5 to 30% by weight, (d) component: 0.01 to 10% by weight, further preferably 0.1 to 5% by weight %.

The organic solvent (e) in the composition of the present invention is
It is a component for dissolving or dispersing the components (a) to (d). As the organic solvent (e), the above (a) to (d)
There is no particular limitation as long as it dissolves or disperses the components, and a conventional organic solvent can be appropriately selected and used.

Specific examples of the organic solvent (e) include aromatic hydrocarbons such as toluene and xylene, acetone,
Examples thereof include ketone systems such as methyl ethyl ketone and methyl isobutyl ketone, ester systems such as ethyl acetate, propyl acetate and butyl acetate, and alcohol systems such as ethylene glycol monobutyl ether.

The organic solvent (e) is blended so that the solid content of the resin composition is usually in the range of about 10 to 90% by weight.

The composition of the present invention has the above-mentioned (a) to (e).
In addition to the components, a silane coupling agent can be added if necessary. The use of the silane coupling agent has the advantage of improving the adhesion to the substrate without impairing the curability. Examples of silane coupling agents include epoxycyclohexylethyltrimethoxysilane, glycidoxypropyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, phenyltrimethoxysilane, phenethyltrimethoxysilane, and the like.

When the silane coupling agent is added to the composition of the present invention, the components (a), (b),
It is used within the range of 10 parts by weight based on 100 parts by weight of the total of the components (c) and (d).

Further, in addition to the above, if necessary, a curing catalyst, a coloring pigment, an extender pigment, an ultraviolet absorber, an ultraviolet stabilizer, a fluidity adjusting agent and other additives for paints may be added.

The composition of the present invention can be applied directly to a base material such as metal or plastic, or to a coated base material obtained by applying a coating material such as a primer to these base materials.

The coating film thickness is about 1 to 100 μm as a dry film thickness.
It is preferably in the range of about 10 to 50 μm, and the curing conditions are such that heating at a temperature of about 60 to 260 ° C. cures in about 30 seconds to 180 minutes.

[0073]

According to the coating composition of the present invention, a specific sp
By using a hydroxyl group-containing polyester resin having a specific value and a specific silicon compound, the compatibility of the polyester resin, the silicon compound and the polyepoxide is significantly improved, and the reaction of the three is effectively performed. As a result, the finished appearance, coating film performance (acid resistance, water resistance,
A coating film having excellent weather resistance and impact resistance can be formed.

[0074]

EXAMPLES The present invention will be described in more detail below with reference to examples. Hereinafter, "parts" and "%" are based on weight.

Production of Polyester Resin Production Example 1 The following components were placed in a flask equipped with a thermometer, a stirrer and a water separator.

Hexahydroterephthalic acid 307 parts Hexahydrophthalic acid 275 parts Trimellitic acid 90 parts 1,4-di (hydroxymethyl) cyclohexane 474 parts 1,6-hexanediol 166 parts Monobutyric acid hydroxide 0.1 parts The material was heated to 240 ° C. over 4 hours with stirring. After maintaining at 240 ° C. for 2 hours, 4% of xylene is added to the total charged amount to promote the removal of condensed water produced as a by-product, and the reaction is further carried out at 240 ° C.
When it reached mgKOH / g, the heating was stopped, and cyclohexanone was added to dilute it to obtain a polyester resin solution (A) having a solid content of about 60%. The obtained resin has a number average molecular weight of 3,
300, hydroxyl value (mg potassium hydroxide value required to neutralize 1 g of resin) 48 mgKOH / g, solubility parameter value (sp value) 10.7, glass transition temperature (Tg point) 14 ° C.
Had.

Production Example 2 Phthalic anhydride 510 parts Adipic acid 215 parts Trimethylolethane 100 parts Neopentyl glycol 440 parts Monobutyltin hydroxide 0.1 parts Manufactured except that the components initially charged in the flask are the above components. The same procedure as in Example 1 was carried out to obtain a polyester resin solution (B) having a solid content of about 60%. The obtained resin had a number average molecular weight of 4,400, a hydroxyl value of 58 mgKOH / g, an sp value of 11.3, and a Tg point of -8 ° C.

Production Example 3 Isophthalic Acid 410 parts Hexahydrophthalic Acid 380 parts Neopentyl Glycol 311 parts Hexanediol 233 parts Monobutyltin Hydroxide 0.1 parts The above components are the components initially charged in the flask, and the acid value is A polyester resin solution (C) having a solid content of about 60% was obtained in the same manner as in Production Example 1 except that the heating was stopped when the amount reached 2 mgKOH / g. The obtained resin had a number average molecular weight of 28,000, a hydroxyl value of 2 mgKOH / g and an sp value of 10.
7. It had a Tg point of 8 ° C.

Production Example 4 Isophthalic acid 239 parts Hexahydrophthalic acid 469 parts Trimethylolpropane 73 parts Neopentyl glycol 336 parts Hexanediol 189 parts Monobutyltin hydroxide 0.1 parts The above components are the components initially charged in the flask. A polyester resin solution (D) having a solid content of about 60% was obtained in the same manner as in Production Example 1 except that. The obtained resin has a number average molecular weight of 1,200, a hydroxyl value of 113 mgKOH / g, sp
It had a value of 11.1 and a Tg point of 1 ° C.

Production Example 5 (for comparison) Isophthalic acid 711 parts Terephthalic acid 178 parts Glycerin 54 parts Neopentyl glycol 306 parts Ethylene glycol 144 parts Monobutyltin hydroxide 0.1 parts The components initially charged in the flask are the above components. A polyester resin solution (E) having a solid content of about 60% was obtained in the same manner as in Production Example 1 except that. The obtained resin had a number average molecular weight of 1,900, a hydroxyl value of 79 mgKOH / g, an sp value of 12.2 and a Tg point of 32 ° C.

Production of Polyepoxide Production Example 6 Polyester resin solution (A) 5,500 obtained in Production Example 1
Parts, 296 parts of a compound represented by the following formula, 2.93 parts of dibutyltin laurate and 197 parts of cyclohexanone were mixed and reacted at 80 ° C. for 3 hours to obtain a polyepoxide solution (d) having a solid content of 60%. The polyepoxide obtained is
It had a number average molecular weight of about 3,900, a hydroxyl value of 26 mgKOH / g, an average of about 2 epoxy groups per molecule, and an epoxy equivalent of 1,950.

[0082]

[Chemical 6]

Production Example 7 Xylene 490 was placed in a flask equipped with a thermometer and a stirrer.
Parts, 137 parts of trimethylolpropane and 462 parts of hexahydrophthalic acid were charged, and then the contents were heated to 130 ° C. over 2 hours while stirring the contents and held at the same temperature for 3 hours to carry out a half-esterification reaction. . Then 60
Cool to ℃ and add tris (acetylacetonate) in it
11 parts of aluminum, 1,584 parts of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and 45 parts of xylene were charged, and the contents were heated to 100 ° C. over 1 hour while stirring, at the same temperature. The reaction was further advanced, and when the acid value reached 1 mgKOH / g, the heating was stopped and the mixture was cooled to obtain a polyepoxide resin solution (e) having a solid content of about 80%. The obtained resin had a number average molecular weight of about 640, a hydroxyl value of 77 mgKOH / g, an average of about 2.5 alicyclic epoxy groups per molecule, and an epoxy equivalent of about 260.

Production of Silicon Compound Production Example 8 In a four-necked flask equipped with a cooling tube, a thermometer, a nitrogen blowing tube, a stirrer, and a dropping funnel, "Colcoat ES40" (trade name, tetraethylsilicate manufactured by Nippon Colcoat Co., Ltd.) was placed. The average amount of the pentamer is about 5 and the average number of ethoxy groups is about 12 per molecule.) 744 g and n-butyltin trioctanoate 7 g were charged and the temperature was raised to 140 ° C. Next, 684 g (corresponding to 6 mol) of ε-caprolactone was added dropwise from the dropping funnel over 3 hours, and then the mixture was stirred at the same temperature for 4 hours and cooled to obtain a lactone-modified silicon compound (1). In this compound (1), about 6 out of 12 ethoxy groups on average in one molecule are substituted with a group represented by the following formula, the number average molecular weight by GPC is about 1,600, and a silicon atom 5 in average, and a in the rational formula [1] is 1.
2 and b were 1.2.

[0085]

[Chemical 7]

Production Example 9 In a four-necked flask equipped with a cooling tube, a thermometer, a nitrogen blowing tube, a stirrer, and a dropping funnel, "Colcoat MS51" (trade name, manufactured by Nippon Colcoat Co., Ltd., average of tetramethyl silicate) was added. The tetramer has an average of about 10 methoxy groups in one molecule.) 470 g and n-butyltin trioctanoate 1 g were charged and the temperature was raised to 120 ° C. Then, 342 g (corresponding to 3 mol) of ε-caprolactone was added dropwise from the dropping funnel over 3 hours, and the mixture was stirred at the same temperature for 2 hours and then cooled to obtain a lactone-modified silicon compound (2). In this compound (2), about 3 out of 10 methoxy groups in one molecule are substituted with groups represented by the following formulas, the number average molecular weight by GPC is about 850, and the average of silicon atoms is There are four, a in the rational formula [1] is 1.75,
b was 0.75.

[0087]

Embedded image

Production Example 10 "Colcoat ES40" 744 was placed in a four-necked flask equipped with a cooling tube, a thermometer, a nitrogen blowing tube, a stirrer and a dropping funnel.
1 g, 648 g of benzyl alcohol and 0.1 g of tris (acetylacetonato) aluminum were charged.
276 by stirring for 6 hours at 60 ℃
After removing g of ethanol, the mixture was cooled to obtain a benzyl alcohol-modified silicon compound (3). In this compound (3), about 6 out of 12 methoxy groups in one molecule are substituted with benzyloxy groups, the number average molecular weight by GPC is about 1,100, and the average number of silicon atoms is 5
And the a in the rational formula [1] is 1.2,
b was 1.2.

Production Example 11 "Colcoat ES40" 744 was placed in a four-necked flask equipped with a cooling tube, a thermometer, a nitrogen blowing tube, a stirrer and a dropping funnel.
g, a mixture of 756 g of 3-methoxy-3-methylbutanol and 0.1 g of tris (acetylacetonato) aluminum was charged, and the mixture was stirred at 160 ° C. for 6 hours to carry out a deethanol reaction to remove 276 g of ethanol and then cooled.
A silicon compound (4) modified with 3-methoxy-3-methylbutanol was obtained. In this compound (4), about 6 out of 12 ethoxy groups on average in one molecule are 3-methoxy-3-
It is substituted with a methylbutoxy group, has a number average molecular weight by GPC of about 1,200, has an average of 5 silicon atoms, and in the above-mentioned rational formula [1], a is 1.2 and b is 1 Was 2.

Production Example 12 (for comparison) "Colcoat ES40" 744 was placed in a four-necked flask equipped with a cooling tube, a thermometer, a nitrogen blowing tube, a stirrer and a dropping funnel.
g and n-butyltin trioctanoate 7 g were charged 1
The temperature was raised to 40 ° C. Then, 1,140 g (corresponding to 10 mol) of ε-caprolactone was added dropwise from the dropping funnel over 3 hours, and the mixture was stirred at the same temperature for 4 hours and then cooled to obtain a lactone-modified silicon compound (6). This compound (6)
Is about 10 out of 12 methoxy groups on average in one molecule,
It is substituted with a group represented by the following formula, has a number average molecular weight by GPC of about 1,900, has 5 silicon atoms on average, and a in the rational formula [1] is 0.5. , B
Was 2.0.

[0091]

Embedded image

Example 1 Hydroxyl group-containing polyester resin solution (A) obtained in Production Example 1
Typake CR-95 [made by Ishihara Sangyo Co., Ltd.
Titanium white] 100 parts are mixed and the pigment is dispersed by a ball mill, and then 30 parts of Epolide GT401 (manufactured by Daicel Chemical Industries, a ring-opening ε-caprolactone chain-containing tetrafunctional alicyclic epoxy compound, molecular weight of about 790) is prepared. 10 parts of the silicon compound (1) obtained in Example 7 and benzoylacetonato
1.0 part of bis (acetylacetonato) aluminum was added, cyclohexanone was added, and the mixture was stirred uniformly to obtain a solid content of 6
A 0% coating composition was obtained.

Examples 2 to 16 and Comparative Examples 1 to 6 In Example 1, the polyester resin solutions shown in Table 1 below were used in place of the hydroxyl group-containing polyester resin solution (A), mixing and pigment dispersion were carried out, and then Each coating material was prepared in the same manner as in Example 1 except that the remaining components shown in Table 1 were mixed. The paints of Comparative Examples 4 and 5 had poor paint stability and caused layer separation, so they were not subjected to the test of coating film performance. In addition, the blending amounts of the raw materials in Table 1 are expressed in parts by weight based on the solid content (the metal chelate is the active ingredient amount).

[0094]

[Table 1]

[0095]

[Table 2]

The notes in Table 1 have the following meanings.

(* 1) Polyepoxide (a): "Eporide GT401" (manufactured by Daicel Chemical Industries, Ltd., a ring-opening ε-caprolactone chain-containing tetrafunctional alicyclic epoxy compound, molecular weight of about 790) (* 2) Polyepoxide (b) : 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (* 3) polyepoxide (c): "Epicoat 100
1 "(produced by Yuka Shell Epoxy Co., bisphenol A type epoxy resin, number average molecular weight of about 900, epoxy equivalent of about 4)
90) (* 4) Silicon compound (5): "Colcoat ES40"
(Nippon Colcoat, trade name, average pentamer of tetraethyl silicate, having an average of about 12 ethoxy groups in one molecule) (* 5) Aluminum chelate: benzoylacetonato bis (acetylacetonato) aluminum (* 6) Titanium chelate: diisopropoxy bis (ethylacetoacetato) titanium (* 7) Zirconium chelate: tetrakis (ethylacetoacetato) zirconium (* 8) Tin chelate: bis (acetylacetonato) monobutyltin acetate A test coated plate was prepared for each of the coating compositions obtained in the above Examples and Comparative Examples, and various tests were conducted according to the following test methods. The test results are shown in Table 2 below.

Preparation of test coated plate A KP color 86 was applied to an untreated aluminum plate having a thickness of 0.4 mm.
52 Kai Primer (Kansai Paint Co., Ltd., polyester resin-based primer for precoat metal) with a dry film thickness of about 4
Painted to be micron and reached the maximum temperature (PM
A primer-coated plate was obtained by baking for 40 seconds under the condition that T) was 220 ° C. Each of the coating compositions obtained in each of the above Examples and Comparative Examples was applied to this primer-coated plate to give a dry film thickness of about 18
Each test coated plate was obtained by coating so as to have a micron size and baking at an atmospheric temperature of 260 ° C. for 50 seconds. At this time, the material reaching temperature PMT was 220 ° C.

Test method Appearance of coating film: The appearance of the coating film of the test coated plate was visually evaluated according to the following criteria.

B: Abnormality is not recognized. X: Blurring is recognized. Coating surface gloss: JIS K 5400 7.6 (1990).
According to the 60-degree specular glossiness, the reflectance (%) was measured when the incident angle and the light-receiving angle were 60 degrees, respectively.

Pencil hardness: JIS K 5400 8.
The pencil scratching test specified in 4.2 was performed, and the evaluation was performed by the destruction of the coating film.

Workability: In a room at 20 ° C., the test plate was bent 180 ° with the coated surface facing outward, and the T number at which cracks did not occur at the bent portion was displayed. The T number is 0T when 180 ° bending is performed without sandwiching anything inside the bent portion, and 1T when 2 plates with the same thickness as the test plate are sandwiched. The number of sheets was 2T and the number of sheets was 3T.

Solvent resistance: About 1 kg / cm ^{2 on the} coated surface with gauze soaked with methyl ethyl ketone in a room at 20 ° C.
The load was applied to and reciprocated between lengths of about 5 cm. The number of times of reciprocation until the primer coating film is visible is described. When the primer coating film was not visible after 50 round trips, it was indicated as 50 <.

Acid resistance: The test piece was immersed in an aqueous 5% sulfuric acid solution at 60 ° C. for 3 hours, and the coated surface was visually evaluated according to the following criteria.

◯: No abnormality is observed ×: Significant decrease in gloss is observed Adhesion at the bent portion: The test plate is bent 180 ° and 0T bent, and the bent portion is adhered to the bent portion. The remaining degree of the coating film when the tape was attached and immediately peeled off was evaluated.

Further, the coated plate after the test plate was immersed in boiling water for 2 hours was subjected to 0T bending in the same manner as above, and a tape peeling test of the processed portion was carried out to evaluate the residual degree of the coating film. When no or almost no peeling of the coating film is observed ○
The case where the peeling of the coating film was clearly observed was marked with x.

[0107]

[Table 3]

[0108]

[Table 4]

Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication C09D 183/04 PMT C09D 183/04 PMT 183/06 PMU 183/06 PMU (72) Inventor Yoshihiko Aida Hiratsuka, Kanagawa 4-17-1, Higashi-Hachiman, Ichi, Kansai Paint Co., Ltd. (72) Inventor Noboru Tayuki 4-17-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Kansai Paint Co., Ltd. (72) Satoru Ito Higashi-Hachiman, Hiratsuka, Kanagawa 4-17-1 Kansai Paint Co., Ltd.

Claims (6)

[Claims] 1. A hydroxyl group-containing polyester resin having a solubility parameter value (sp value) in the range of 10.0 to 12.0, (b) polyepoxide, and (c) represented by the following rational formula [1]. And a silicon compound having 1 to 20 silicon atoms in one molecule SiO _{(4- (a + b)) / 2} (OR ¹ ) _a (OR ² ) _b [1] (wherein R ¹ is a carbon atom 1 to 3 alkyl groups or hydrogen atoms, R ² is an aryl group, an aralkyl group, or an ether bond and / or an ester bond containing 4 to 4 carbon atoms.
It represents 24 monovalent hydrocarbon groups. a is 0.10 to 3.9
5 and b represent a number of 0.05 to 1.95, and the sum of a and b is 4 or less. ), (D) at least one chelate compound selected from an aluminum chelate compound, a titanium chelate compound, a zirconium chelate compound and a tin chelate compound, and (e) an organic solvent. 2. The hydroxyl value of the polyester resin (a) is 2
The curable coating composition according to claim 1, wherein the curable coating composition is about 200 mgKOH / g. 3. The glass transition temperature of the polyester resin is
It is -40-60 degreeC, It is characterized by the above-mentioned.
The curable coating composition according to. 4. The curable coating composition according to any one of claims 1 to 3, wherein the polyepoxide (b) is an alicyclic polyepoxide. 5. The polyepoxide (b) has a number average molecular weight of 120 to 20,000.
The curable coating composition described. 6. The silicon compound (c) has 4 to 8 silicon atoms in the molecule, and the sum of a and b in the formula [1] is 1.5 to 2.5. The curable coating composition according to any one of claims 1 to 5.