JP3130542B2 - Curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a curable composition used for various coatings such as architectural exteriors, automobiles, industrial machines, steel furniture, household appliances, plastics, etc., especially for coatings requiring durability. Composition.

[0002]

2. Description of the Related Art Conventional thermosetting paints are those in which melamine is used as a crosslinking agent, such as alkyd melamine, acrylic melamine, epoxy melamine, etc. The problem was left unresolved.

[0003] In order to solve these problems, the present inventors have found a crosslinking method using a polyol resin and a hydrolyzable silyl group-containing resin which is completely different from the conventional crosslinking method using a polyol resin and a melamine resin. (See Japanese Patent Application Laid-Open No. 1-141952).

However, when a mixture of these polyol resins and a polymer containing a hydrolyzable silyl group is used without using a curing catalyst, the curing speed is low when heated at room temperature or a relatively low temperature. If a high rate of paint curing is required, heating to a high temperature is required, consuming a large amount of energy.

[0005] Such a defect can be improved generally by blending the curing catalyst immediately before use to increase the curing speed of the coating film even at a relatively low temperature.
Once a curing catalyst is added, these paints, coatings, adhesives, sealants or coupling agents cure in a short time, so the pot life is short and cannot be used before the painting is finished There is a case. It is necessary to keep the pot life sufficiently long from the viewpoint of the painting process and workability.

In order to maintain sufficient adhesion to a metal substrate in conventional thermosetting paints and other paints,
After applying the undercoat or primer to the metal substrate,
There are many systems that apply these paints. However, considering workability and the like, it is desirable to develop a paint that is applied directly to a metal substrate and adheres without coating with a primer or primer.

As described above, it is technically difficult to simultaneously provide sufficient pot life and performance of direct adhesion to a metal substrate.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to solve these problems, and as a result, have found that a mixture of a hydroxyl group-containing acrylic resin and an alkoxysilyl group-containing acrylic copolymer, by combining an acrylic resin containing a group and a curing catalyst, sufficiently maintain the pot life, I was able to improve the adhesion.
In addition, the curability of these compositions by baking is good, which is better than the curability of the composition filed in the patent application. Thus, a curable composition having both pot life and adhesion properties was found, and the present invention was completed.

Accordingly, the present invention will have a (A) a hydroxyl group the general formula (I):

Embedded image ( Wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms, R ² is a hydrogen atom
Or an alkyl group having 1 to 10 carbon atoms, an aryl group and
Monovalent hydrocarbon selected from the group consisting of aralkyl groups
A represents 0, 1 or 2)
Not acrylic resin, (B) general formula (I)

[0010]

An alkoxysilyl group-containing acrylic copolymer containing a group represented by the formula: (C) having an acid value of 30 to 700 mgKOH / g,
Carboxyl group-containing acrylic copolymer having no group represented by (I), (D) Ri Do a curing catalyst and (E) a dehydrating agent and (F) 1 or more alkyl alcohols, (A) component / ( B) The components are 9/1 to 1/9 by weight,
100 parts by weight of component (A) and component (B) (hereinafter referred to as parts)
5 to 70 parts (solid content) of component (C) based on (solid content)
(D) component 0.1 to 20 parts, (E) component 100 parts or less, (F) component 100
Parts or less, but one of the components (E) and (F)
If only using Write, it relates to a curable composition Ru 0.5 to 100 parts der.

[0012]

Examples Having a hydroxyl group as the component (A) used in the present invention.
And the general formula (I):

Embedded image (Wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms, R ² is a hydrogen atom
Or an alkyl group having 1 to 10 carbon atoms, an aryl group and
Monovalent hydrocarbon selected from the group consisting of aralkyl groups
A represents 0, 1 or 2)
No acrylic resin (hereinafter, an acrylic resin having a hydroxyl group
(Also referred to as (A)) is a component used to develop coating properties such as hardness immediately after baking and solvent resistance, and the main chain thereof is substantially composed of an acrylic copolymer chain. The weather resistance, chemical resistance, water resistance, etc. of the cured product are improved.

The hydroxyl group-containing acrylic resin (A) can be obtained, for example, by copolymerization of a hydroxyl group-containing vinyl monomer with acrylic acid, methacrylic acid, derivatives thereof and the like.

Examples of the hydroxyl group-containing vinyl monomer contained as the copolymer component include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, and N-methylol (meth) acrylamide. Alonix 5700, 4-hydroxystyrene manufactured by Toa Gosei Chemical Industry Co., Ltd., HE-10, HE-20, HP-1 manufactured by Nippon Shokubai Chemical Industry Co., Ltd.
0 and HP-20 (both terminally acrylate oligomers having hydroxyl groups), Prenmer PP series (polypropylene glycol methacrylate), Prenmer PE series (polyethylene glycol monomethacrylate), Prenmer PEP series (polyethylene Glycol polypropylene glycol methacrylate), Prenemer AP-400 (polypropylene glycol monoacrylate), Prenemer AE-350 (polyethylene glycol monoacrylate), Prenemer NKH-5050
(Polypropylene glycol polytrimethylene monoacrylate) and premer GLM (glycerol monomethacrylate), and ε-caprolactone-modified hydroxyalkyl vinyl monomers obtained by reacting a hydroxyl group-containing vinyl compound with ε-caprolactone.

Representative examples of the ε-caprolactone-modified hydroxyalkyl vinyl monomer include, for example, those represented by the formula:

[0016]

Embedded image

(Wherein, R is H or CH ₃ , n is an integer of 1 or more). Placcel FA-1 (R = H, n = 1) manufactured by Daicel Chemical Industries, Ltd. , Placcel FA-4 (R
= H, n = 4), Placcel FM-1 (R = CH 3, n = 1) and Placce
l FM-4 (R = CH ₃ , n = 4), TONE M-100 (R =
H, n = 2) and TONE M201 (R = CH ₃ , n = 1). By using an ε-caprolactone-modified hydroxyalkyl vinyl monomer as the hydroxyl group-containing vinyl monomer, the impact resistance and flexibility of the coating film can be improved.

These hydroxyl-containing vinyl monomers have the following structure:
Seeds may be used, or two or more kinds may be used in combination.

The derivative of acrylic acid or methacrylic acid copolymerizable with the hydroxyl group-containing vinyl monomer is not particularly limited, and specific examples thereof include, for example, methyl (meth)
Acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoro Propyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, (meth) acrylonitrile, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylamide, α-ethyl (meth) ) Acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine, N-methylol (meth) Acrylamide, AS-6, AN-6 is a macromer made of Toagosei Chemical Industry (Ltd.), AA-
6, condensation products of hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids such as AB-6, AK-5, hydroxyalkyl esters of (meth) acrylic acid and phosphoric acid or phosphoric acid esters Examples include phosphoric ester group-containing vinyl compounds and (meth) acrylates containing urethane bonds or siloxane bonds.

The copolymer may contain a segment formed by a urethane bond or a siloxane bond in the main chain within a range not exceeding 50% (% by weight, the same applies hereinafter). A segment derived from a monomer other than the acid derivative may be included. The monomer is not limited, and specific examples thereof include styrene and α-
Aromatic hydrocarbon-based vinyl compounds such as methylstyrene, chlorostyrene, styrenesulfonic acid, and vinyltoluene; unsaturated carboxylic acids such as maleic acid, fumaric acid, and itaconic acid, and salts thereof (alkali metal salts, ammonium salts, amines) Salts thereof), their anhydrides (such as maleic anhydride), or esters of unsaturated carboxylic acids such as diesters or half-esters thereof with linear or branched alcohols having 1 to 20 carbon atoms; vinyl acetate, Vinyl ester and allyl compounds such as vinyl propionate and diallyl phthalate; vinyl compounds containing an amino group such as vinyl pyridine and aminoethyl vinyl ether; itaconic acid diamide crotonamide, maleic acid diamide;
Amide group-containing vinyl compounds such as fumaric diamide and N-vinylpyrrolidone; methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride,
Chloroprene, propylene, butadiene, isoprene,
Other vinyl compounds such as fluoroolefin maleimide, N-vinylimidazole, vinylsulfonic acid and the like can be mentioned.

The acrylic resin (A) having a hydroxyl group is preferably produced by a solution polymerization method using an azo radical initiator such as azobisisobutyronitrile from the viewpoint of ease of synthesis.

In the solution polymerization, the molecular weight can be adjusted by using a chain transfer agent such as n-dodecyl mercaptan, t-dodecyl mercaptan or n-butyl mercaptan, if necessary.

The polymerization solvent is not particularly limited as long as it is a non-reactive solvent. The acrylic resin (A) having a hydroxyl group may be a non-aqueous dispersion type in which polymer particles insoluble in a non-polar organic solvent such as heptane and pentane are dispersed. The molecular weight of the acrylic resin (A) having a hydroxyl group is not particularly limited and may be any commonly used one. However, the physical properties of the coating such as durability (the coating formed from the composition of the present invention) may be used. From the viewpoint of physical properties of the film), the number average molecular weight is preferably from 1,500 to 40,000, more preferably from 3,000 to 25,000, and
It is preferable to have a hydroxyl group enough to crosslink sufficiently,
Hydroxyl value is 10 ~ 30 from the viewpoint of physical properties of coating such as strength and durability
It is preferably 0 mgKOH / g, more preferably 30-150 mgKOH / g.

Acrylic resin having such a hydroxyl group
(A) may be used alone or in combination of two or more.

The alkoxysilyl group-containing acrylic copolymer (hereinafter also referred to as an alkoxysilyl group-containing acrylic copolymer (B)) as the component (B) used in the present invention has a general formula at the terminal and / or the side chain. (I) :

[0026]

Embedded image

A polymer having at least one, and preferably two or more, alkoxysilyl groups represented by the following formula:

In the above formula, R ¹ is an alkyl group having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. When the number of carbon atoms exceeds 10, the reactivity of the alkoxysilyl group decreases, and when R ¹ is other than an alkyl group, for example, a phenyl group or a benzyl group, the reactivity also decreases. Specific examples of R ¹ include, for example, methyl, ethyl, n-propyl, iso-propyl, n-
Butyl group, iso-butyl group and the like.

In the above formula, R ² is a hydrogen atom or a monovalent hydrocarbon group selected from the group consisting of alkyl, aryl and aralkyl groups having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms.

Specific examples of the alkyl group having 1 to 10 carbon atoms, which is one kind of R ² , include the same groups as those of R ^1, and specific examples of the aryl group include, for example, a phenyl group. Specific examples of the aralkyl group include a benzyl group.

In the above formula, a represents 0, 1 or 2.

Specific examples of the alkoxysilyl group represented by the above general formula include, for example, groups contained in an alkoxysilyl group-containing monomer described later.

Acrylic copolymer containing alkoxysilyl group
In (B), since the main chain is substantially composed of an acrylic copolymer chain, the cured product has improved weather resistance, chemical resistance, water resistance, and the like. Further, since the alkoxysilyl group is bonded to a carbon atom, the cured product has improved water resistance, alkali resistance, acid resistance, and the like.

Acrylic copolymer containing alkoxysilyl group
(B) If the number of alkoxysilyl groups in one molecule is less than one, the solvent resistance of the coating film obtained from the composition of the present invention tends to decrease.

Acrylic copolymer containing alkoxysilyl group
The number average molecular weight of (B) is from 1,000 to 30,000, particularly preferably from 3,000 to 25,000, from the viewpoint of physical properties such as durability of a coating film obtained from the composition of the present invention.

Acrylic copolymer containing alkoxysilyl group
(B) can be obtained, for example, by copolymerizing acrylic acid, methacrylic acid, a derivative thereof and the like with an alkoxysilyl group-containing monomer.

The acrylic acid or methacrylic acid derivative is not limited, and specific examples thereof include, for example, methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate,
Benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, (meth) acrylonitrile, glycidyl (meth) acrylate, dimethylaminoethyl (Meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine, 2 -Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N-methylol (meth) acrylamide, Alonix M-5700 manufactured by Toa Gosei Chemical Industry Co., Ltd. AS-6 is a macromer of Toagosei Chemical Industry (Ltd.), AN-6, AA-6, AB-6,
AK-5, Placcel FA-1, Plac manufactured by Daicel Chemical Industries, Ltd.
α, β- such as cel FA-4, Placcel FM-1, Placcel FM-4, hydroxyalkyl esters of (meth) acrylic acid
Examples include a vinyl compound having a phosphate ester group, which is a condensation product of a hydroxyalkyl ester of an ethylenically unsaturated carboxylic acid and phosphoric acid or a phosphoric ester, or a (meth) acrylate containing a urethane bond or a siloxane bond. When a hydroxyl group-containing monomer is used, its amount is preferably small (for example, 2% or less in the copolymer).

The alkoxysilyl group-containing monomer is not particularly limited except that it is a monomer having a polymerizable unsaturated double bond and having an alkoxysilyl group. Specific examples thereof include, for example, CH ₂ CHCHSi ( CH ₃ ) (OCH ₃ ) ₂ , CH ₂ CHCHSi (OCH ₃ ) ₃ , CH ₂ CHCHCOO (CH ₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂ , CH ₂ CHCHCOO (CH ₂ ) ₃ Si ( _{OCH 3) 3, CH 2 =} C (CH 3) COO (CH 2) 3 Si (CH 3) (OCH 3)
_{2, CH 2 = C (CH} 3) COO (CH 2) 3 Si (OCH 3) 3,

[0039]

Embedded image

CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ , CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₃ Si (CH ₃ ) (OC ₂
H _{5) 2,}

[0041]

Embedded image

Further, CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₂ -O- [CO (CH ₂ ) ₅ O
] ₃ --CO (CH ₂ ) ₅ -O-CO-NH- (CH ₂ ) ₃ Si (OCH ₃ ) ₃ , CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₂ -O-CH ₂ CH ( OH)-CH ₂
-O--(CH ₂ ) ₃ Si (CH ₃ ) ₂ -O- [Si (CH ₃ ) ₂ -O] _n -Si
(CH ₃ ) ₂ --(CH ₂ ) ₃ -O-CH ₂ -CH (OH) -CH ₂ -NH- (CH ₂ ) ₃ Si (
(Meth) acrylates having an alkoxysilyl group at a terminal such as OCH ₃ ) ₃ via a urethane bond or a siloxane bond.

The proportion of units derived from the alkoxysilyl group-containing monomer in the alkoxysilyl group-containing acrylic copolymer (B) is from 5 to 90% in view of the curability of the composition and the durability of the coating film. Preferably, 11-70% is more preferred.

In the copolymer, a segment formed by a urethane bond or a siloxane bond may be contained in the main chain within a range of not more than 50% and derived from a monomer other than the (meth) acrylic acid derivative. May be included. The monomer is not limited, and specific examples thereof include aromatic hydrocarbon-based vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, and vinyltoluene; maleic acid, fumaric acid, Unsaturated carboxylic acids such as itaconic acid, salts thereof (alkali metal salts, ammonium salts, amine salts, etc.), their acid anhydrides (maleic anhydride, etc.), or linear chains having 1 to 20 carbon atoms or Esters of unsaturated carboxylic acids such as diesters or half esters with branched alcohols; vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; vinyl compounds containing amino groups such as vinyl pyridine and aminoethyl vinyl ether; Acid diamide, crotonamide, maleic acid Amide, fumaric acid diamide, amide group-containing vinyl compounds such as N- vinyl pyrrolidone; 2-hydroxyethyl vinyl ether, methyl vinyl ether, cyclohexyl vinyl ether,
Other vinyl compounds such as vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin, maleimide, N-vinylimidazole, and vinylsulfonic acid.

Acrylic copolymer containing alkoxysilyl group
(B) is described in, for example, JP-A-54-36395 and JP-A-57-36109.
JP-A-58-157810 can be produced by the method shown in JP-A-58-157810, etc., but from the viewpoint of ease of synthesis and the like by a solution polymerization method using an azo-based radical initiator such as azobisisobutyronitrile. It is most preferred to manufacture.

In the solution polymerization, n-
Dodecyl mercaptan, t-dodecyl mercaptan, n-butyl mercaptan, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane,
γ-mercaptopropylmethyldiethoxysilane, (H ₃ C
_{O) 3 Si-SS-Si-} (OCH 3) 3, (CH 3 O) 3 Si-S 8 - Si
The molecular weight can be adjusted using a chain transfer agent such as (OCH ₃ ) ₃ . In particular, when a chain transfer agent having an alkoxysilyl group in the molecule, for example, γ-mercaptopropyltrimethoxysilane, an alkoxysilyl group can be introduced into the terminal of the silyl group-containing acrylic copolymer.

The polymerization solvent used in the solution polymerization includes hydrocarbons (toluene, xylene, n-hexane, cyclohexane, etc.), acetates (ethyl acetate, butyl acetate, etc.), alcohols (methanol, ethanol, isopropanol, etc.). n-butanol, etc., ethers (ethyl cellosolve, butyl cellosolve, cellosolve acetate, etc.), ketones (methyl ethyl ketone, ethyl acetoacetate, acetylacetone, diacetone alcohol,
There is no particular limitation as long as it is a non-reactive solvent such as methyl isobutyl ketone and acetone.

Such an alkoxysilyl group-containing polymer
(B) may be used alone or in combination of two or more.

The proportion of the alkoxysilyl group-containing polymer (B) used is such that the weight ratio of component (A) / component (B) is from 9/1 to 1/1.
9 is preferable, and 8/2 to 2/8 is more preferable. (A)
If the ratio of component / (B) exceeds 9/1, the water resistance of the coating film obtained from the composition of the present invention tends to decrease, and 1/9
If the amount is less than the above range, the feature of blending the component (A) tends to be insufficient.

The acid value of the component (C) used in the present invention is from 30 to
700mgKOH / g, represented by hydroxyl group and general formula (I)
A carboxyl group-containing acrylic copolymer having no group (hereinafter, also referred to as a carboxyl group-containing acrylic copolymer (C)) has a sufficient pot life and improves workability.
It is a component used to develop coating properties such as adhesion and curability immediately after baking, and its main chain is substantially composed of an acrylic copolymer chain. And water resistance are improved.

Acrylic copolymer having a carboxyl group
(C) can be obtained, for example, by copolymerizing a carboxyl group-containing vinyl monomer with a derivative of acrylic acid or methacrylic acid.

[0052]

Embedded image

The acrylic acid or methacrylic acid derivative copolymerizable with the carboxyl group-containing vinyl monomer is not particularly limited, and specific examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate,
Benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, (meth) acrylonitrile, glycidyl (meth) acrylate, dimethylaminoethyl (Meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine, Toa Examples include macromers AS-6, AN-6, AA-6, AB-6, AK-5, and (meth) acrylates containing a urethane bond or a siloxane bond, manufactured by Synthetic Chemical Industry Co., Ltd.

The copolymer may contain a segment formed by a urethane bond or a siloxane bond in the main chain within a range not exceeding 50 %, and is derived from a monomer other than the (meth) acrylic acid derivative. May be included. The monomer is not limited, and specific examples thereof include, for example, aromatic hydrocarbon-based vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, and vinyltoluene; vinyl acetate, vinyl propionate, diallyl Vinyl ester and allyl compounds such as phthalate; vinyl group-containing vinyl compounds such as vinyl pyridine and aminoethyl vinyl ether; itaconic diamide, crotonamide, maleic diamide,
Amide group-containing vinyl compounds such as fumaric diamide and N-vinylpyrrolidone; methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride,
Chloroprene, propylene, butadiene, isoprene,
Other vinyl compounds such as fluoroolefin maleimide, N-vinylimidazole, vinylsulfonic acid and the like can be mentioned.

The acrylic resin having a carboxyl group is
It is preferable to produce by a solution polymerization method using an azo radical initiator such as azobisisobutyronitrile from the viewpoint of ease of synthesis.

In the solution polymerization, the molecular weight can be adjusted by using a chain transfer agent such as n-dodecyl mercaptan, t-dodecyl mercaptan, or n-butyl mercaptan, if necessary.

Polymerization solvents used in the solution polymerization include hydrocarbons (toluene, xylene, n-hexane, cyclohexane, etc.), acetates (ethyl acetate, butyl acetate, etc.), alcohols (methanol, ethanol, isopropanol, etc.). n-butanol, etc., ethers (ethyl cellosolve, butyl cellosolve, cellosolve acetate, etc.), ketones (methyl ethyl ketone, ethyl acetoacetate, acetylacetone, diacetone alcohol,
There is no particular limitation as long as it is a non-reactive solvent such as methyl isobutyl ketone and acetone.

Acrylic copolymer having a carboxyl group
There is no particular limitation on the molecular weight of (C), and any commonly used one can be used, but the number average molecular weight is 1,50.
It is preferably from 0 to 40,000, more preferably from 3,000 to 25,000, from the viewpoint of coating properties such as durability. The glass transition temperature is not particularly limited, but is preferably -20 to 120 ° C, more preferably 70 to 100 ° C, from the viewpoint of coating properties such as adhesion and durability. ~ 700mgKOH
/ g, more preferably 50 to 200 mgKOH / g, from the viewpoint of physical properties such as pot life and adhesion.

The mixing ratio of the hydroxyl group-containing acrylic resin (A), the alkoxysilyl group-containing acrylic copolymer and the carboxyl group-containing acrylic copolymer (C) depends on the solid content of the components (A) and (B). The solid content of the component (C) is preferably from 5 to 70 parts, more preferably from 10 to 40 parts, per 100 parts, from the viewpoint of the coating properties such as adhesion and durability.

Specific examples of the curing catalyst (D) used as the component (D) used in the present invention include, for example, dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, and dioctyltin dimaleate. And organotin compounds such as tin octylate;
Phosphoric acid or phosphate esters such as phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, didecyl phosphate; propylene oxide, butylene Oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic glycidyl ether, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane,
γ-glycidoxypropylmethyldimethoxysilane,

[0061]

Embedded image

Addition products of epoxy compounds such as Cardura E manufactured by Yuka Shell Epoxy Co., Ltd., Epikote 828 and Epikote 1001 manufactured by Yuka Shell Epoxy Co., and phosphoric acid and / or monoacid phosphate. Organic titanate compounds; organic aluminum compounds, organic zirconium compounds; maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, succinic acid, phthalic acid, trimellitic acid, pyromellitic acid, and their acid anhydrides And acidic compounds such as paratoluenesulfonic acid; amines such as hexylamine, di-2-ethylhexylamine, N, N-dimethyldodecylamine and dodecylamine;
Mixtures or reactants of these amines and acid phosphates; alkaline compounds such as sodium hydroxide and potassium hydroxide.

Among these curing catalysts (D), organotin compounds, acid phosphates, mixtures or reactants of acid phosphates and amines, saturated or unsaturated polycarboxylic acids or acid anhydrides, Silicon compound,
An organic titanate compound, an organic aluminum compound or a mixture thereof is preferred because of its high activity.

More preferably, organotin compounds, acidic phosphoric acid esters, and mixtures or reactants of acidic phosphoric acid esters and amines are preferred.

These materials have a sufficiently long pot life, good curability during baking, and good direct adhesion to a metal substrate.

These curing catalysts (D) may be used alone or in combination of two or more. (D) Component usage
Is usually 0.1 to 20 parts, preferably 0.1 to 10 parts, per 100 parts of the solid content of the components (A) and (B). If the amount of the component (D) is less than 0.1 part, the curability tends to decrease, and if it exceeds 20 parts, the appearance of the coating film tends to decrease.

The composition of the present invention contains at least one of a dehydrating agent (component (E)) and an alkyl alcohol (component (F)).

Specific examples of the dehydrating agent (E) include, for example, methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, methyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyl Trimethoxysilane, methyl silicate,
Examples include hydrolyzable ester compounds such as ethyl silicate. These hydrolyzable ester compounds are
It may be added before the polymerization of the alkoxysilyl group-containing acrylic copolymer (B), after the polymerization, or during the polymerization.

The amount of the dehydrating agent used is usually 100 parts or less, preferably 50 parts or less based on 100 parts of the solid content of the components (A) and (B), and the dehydrating agent is used alone without using an alkyl alcohol. In such a case, the amount is usually 0.5 to 100 parts, preferably 1 to 50 parts.

When a dehydrating agent is used together with a dehydration accelerator, the effect can be further enhanced.

Preferred specific examples of the dehydration accelerator include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid;
Organic acids such as formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid, p-toluenesulfonic acid, acrylic acid and methacrylic acid; metal salts of carboxylic acids such as alkyl titanates and lead octylate; tin octylate and dibutyl Tin dilaurate,
Carboxylic acid-type organotin compounds such as dioctyltin maleate; sulfide-type and mercaptide-type organotin compounds such as monobutyltin sulfide and dioctyltin mercaptide; organotin oxides such as dioctyltin oxide;
Organotin compounds by reaction of organotin oxide with ester compounds such as ethyl silicate, ethyl silicate 40, dimethyl maleate and dioctyl phthalate; tetraethylenepentamine, triethylenediamine, N-β-aminoethyl-γ-aminopropyltri Amines such as methoxysilane; alkali catalysts such as potassium hydroxide and sodium hydroxide, but are not limited thereto. Of these, organic acids, inorganic acids and organic tin compounds are particularly effective.

These dehydration accelerators are used with respect to 100 parts of the dehydration agent.
Usually, 0.0001 to 20 parts, preferably 0.001 to 10 parts is used. When a compound which is also the component (D) is used as a dehydration accelerator, an additional 0.1
To 20 parts, preferably 1 to 10 parts.

The alkyl alcohol used in the composition of the present invention
call

[0074]

Preferred specific examples of ( (F) component ) include alcohols having 1 to 10 carbon atoms in the alkyl group, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, and the like. Isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol, octyl alcohol, cellosolve and the like are used.

The amount of the alkyl alcohol (component (F)) to be used is generally 100 parts or less, preferably 50 parts or less, per 100 parts of the solid content of the components (A) and (B). When the solvent is used alone without using, usually 0.5 to 1
00 parts, preferably 2 to 50 parts.

[0077] When used in combination with the alkyl alcohol ((F) component) pre-Symbol dehydrating agent ((E) component), consisting of (A), (B) component, (D) component and (E) component The storage stability is significantly improved as compared to when the composition is stored. The amount of the solvent exhibiting such effects varies depending on the molecular weight and the composition of the component (A) and the component (B) in the composition of the present invention, and cannot be specified unconditionally. What is necessary is just to adjust so that it may become solid content concentration, viscosity, etc. At this time, a non-reactive solvent such as a general paint,
Aliphatic hydrocarbons used as coating agents,
Aromatic hydrocarbons, halogenated hydrocarbons, alkyl alcohols
Alcohols, ketones, esters,
Ethers, alcohol esters, ketone alcohol
, Ether alcohols, ketone ethers, ketones
Esters and ester ethers may be used in combination.
No.

A hydrolyzable silicon compound can be added to the composition of the present invention in order to improve the coating properties such as adhesion, hardness and solvent resistance. The hydrolyzable silicon compound is a compound having a hydrolyzable silyl group at a terminal or a side chain. Preferred specific examples thereof include, for example, a hydrolyzable silane compound, a partially hydrolyzed condensate, a reaction product thereof, And the like.

Specific examples of the hydrolyzable silane compound include, for example, methyl silicate, methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, octyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, vinyl Trimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-
Aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dibutyldimethoxysilane, diphenyldimethoxysilane, vinylmethyldimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane , Trimethylmethoxysilane, triethylmethoxysilane, triphenylmethoxysilane, ethylsilicate, methyltriethoxysilane, ethyltriethoxysilane, butyltriethoxysilane, octyltriethoxysilane, dodecyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxy Silane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltriethoxysilane, γ-glycidoxypropyl Triethoxysilane,
γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane, N-β-aminoethyl-
γ-aminopropyltriethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, dibutyldiethoxysilane, diphenyldiethoxysilane, vinylmethyldiethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, trimethylethoxysilane,
Examples include triethylethoxysilane and triphenylmethoxysilane.

The partially hydrolyzed condensate of the hydrolyzable silane compound may be prepared, for example, by mixing the silane compound singly or plurally, adding a required amount of H ₂ O, and, if necessary, condensing a condensate such as hydrochloric acid or sulfuric acid. Add a small amount of catalyst, room temperature to 100
° C, and can be easily obtained by proceeding with condensation while removing generated alcohol. For example, examples of the compound containing a methoxysilyl group as a partially hydrolyzed condensate of methyl silicate include methyl silicate 47 and methyl silicate 51 manufactured by Nippon Colcoat Chemical Co., Ltd.
Methyl silicate 55, methyl silicate 58, methyl silicate 60 and the like. Examples of compounds having a methoxysilyl group as a partial hydrolysis condensate such as methyltrimethoxysilane and dimethyldimethoxysilane are Shin-Etsu Chemical Co., Ltd. AFP-1, AFR-2, AFP-6, KR213
, KR217, KR9218; TSR16 manufactured by Toshiba Silicone Co., Ltd.
5, TR3357; Y-1587, FZ-3701 manufactured by Nippon Unicar Co., Ltd.
, FZ-3704 and the like. Examples of the compound containing an ethoxysilyl group as a partially hydrolyzed condensate of ethyl silicate include ethyl silicate 40, HAS-1, HAS-6 and HAS-10 manufactured by Nippon Colcoat Chemical Co., Ltd. .

Examples of the reactant of the hydrolyzable silane compound include a reactant of a silane coupling agent containing an amino group and a silane coupling agent containing an epoxy group; a silane coupling agent containing an amino group and ethylene oxide, butylene. Reaction products of epoxides, epichlorohydrin, epoxidized soybean oil, and other compounds having an epoxy group such as Epicoat 828 and Epicoat 1001 manufactured by Yuka Shell Epoxy Co .; silane coupling agents containing an epoxy group and ethylamine, diethylamine, triethylamine ,
Aliphatic amines such as ethylenediamine, hexanediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine; aromatic amines such as aniline and diphenylamine; alicyclic amines such as cyclopentylamine and cyclohexylamine; and ethanolamines Reaction products with amines and the like can be mentioned.

Such a hydrolyzable silicon compound is represented by 1
Seeds may be used, or two or more kinds may be used in combination.

The amount of the hydrolyzable silicon compound to be used is not particularly limited, but the solid content of the component (A) and the component (B) is 1%.
Usually 0.01 to 100 parts, preferably 0.1 to 30 parts with respect to 00 parts
Department. If the amount of the hydrolyzable silicon compound is less than 0.01 part, the effect of the addition cannot be sufficiently obtained, and if it exceeds 100 parts, the appearance of the coating film obtained from the composition of the present invention tends to decrease.

The composition of the present invention may contain additives such as diluents, pigments (including extenders), ultraviolet absorbers, light stabilizers, anti-settling agents, leveling agents, etc., depending on the application; nitrocellulose, cellulose acetate Cellulose such as butyrate; resins such as epoxy resin, melamine resin, vinyl chloride resin, chlorinated polypropylene, chlorinated rubber, and polyvinyl butyral; and fillers may be added.

Next, a method for preparing the composition of the present invention will be described.

The method of preparation is not particularly limited.
Cold-blending or mixing (A) component and (B) component and then heating (hot blending) them into (E)
And / or (F) component. The composition of the present invention is prepared by mixing and reacting these mixtures with the component (C) and the curing agent component (D). The composition of the present invention prepared in this manner utilizes a crosslinking reaction in which the hydroxyl group of the acrylic resin (A) having a hydroxyl group reacts with the silyl group of the alkoxysilyl group-containing polymer (B). Is clearly distinguished from the technology using melamine as a crosslinking agent.

The composition of the present invention has a sufficiently long pot life, good curability, and excellent direct adhesion to a metal substrate due to the effect of the carboxyl group-containing acrylic resin. Furthermore, storage stability is excellent due to the effects of the dehydrating agent and the solvent.

The composition of the present invention can be used as a coating for various coatings such as architectural exteriors, automobiles, industrial machines, steel furniture, household appliances, plastics, etc., especially for applications requiring durability. It is useful as an agent, and is applied to a substrate by a conventional method such as dipping, spraying, or brushing, and then cured at a temperature of usually 30 ° C. or more, preferably 55 to 350 ° C., to thereby provide a coating film having excellent durability. Can be formed.

Next, the composition of the present invention was prepared based on Examples.
This will be described more specifically.

Production Example 1 [Synthesis of Polymer (B) Containing an Alkoxysilyl Group]
A reaction vessel equipped with a thermometer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel was charged with 45.9 parts of xylene.The temperature was raised to 110 ° C. while introducing nitrogen gas, and a mixture (b) having the following composition was added. Using a dropping funnel, the solution was dropped at a constant speed over 5 hours.

(Mixture (b)) Styrene 12.8 parts Methyl methacrylate 50.1 parts Stearyl methacrylate 6.9 parts γ-methacryloxypropyltrimethoxysilane 30.2 parts Xylene 13.5 parts 2,2′-azobisisobutyronitrile 1.8 parts After completion of the dropwise addition of b), 0.5 parts of 2,2'-azobisisobutyronitrile and 5 parts of toluene were added dropwise at a constant speed over 1 hour. After completion of the dropwise addition, the mixture was aged at 110 ° C. for 2 hours and cooled, and xylene was added to the resin solution to adjust the solid content to 60%.

Table 1 shows the properties of the obtained resin solution (1).

Production Example 2 [Synthesis of Hydroxyl-Containing Acrylic Resin (A)] Xylene 4
31.3 parts of butyl acetate and 9.5 of xylene instead of 5.9 parts
And a mixture having the following composition in the same manner as in Production Example 1.
(a) was added.

(Mixture (a)) Xylene 18 parts Styrene 28.3 parts Methyl methacrylate 7.1 parts N-butyl acrylate 32.5 parts Methacrylic acid 0.3 parts Placcel FM-1 ^{* 1} 31.8 parts 2,2'-azobisiso 1.8 parts of butyronitrile [Note] * 1: 2-hydroxyethyl methacrylate / ε-caprolactone = 1/1 adduct manufactured by Daicel Chemical Industries, Ltd. After the dropping of mixture (a), 2,2′-azo 0.2 parts of bisisobutyronitrile and 3.8 parts of toluene were dropped at a constant speed over 1 hour. After completion of the dropwise addition, the mixture was aged at 110 ° C. for 2 hours and cooled, and xylene was added to the resin solution to adjust the solid content to 60%. Table 1 shows the properties of the obtained resin solution (2).

Production Example 3 [Synthesis of Acrylic Resin (C) Having Carboxyl Group] 36.0 parts of xylene was charged into a reaction vessel equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel.
After the temperature was raised to 110 ° C. while introducing nitrogen gas, a mixture (C) having the following composition was dropped at a constant rate over 5 hours using a dropping funnel.

(Mixture (C)) Styrene 29.5 parts Methyl methacrylate 34.8 parts N-butyl acrylate 25.7 parts Acrylic acid 10.0 parts Toluene 13.5 parts 2,2'-azobisisobutyronitrile 1.8 parts Drop of mixture (C) After completion, 0.2 parts of 2,2'-azobisisobutyronitrile and 5.0 parts of toluene were dropped at a constant speed over 1 hour. After completion of the dropwise addition, the mixture was aged at 110 ° C. for 2 hours and cooled, and xylene was added to the resin solution to adjust the solid content to 60%. Table 1 shows the properties of the obtained resin solution (3).

Production Example 4 [Synthesis of Acrylic Resin (C) Having Carboxyl Group] 36.0 parts of xylene was charged into a reaction vessel equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel.
After the temperature was raised to 110 ° C. while introducing nitrogen gas, a mixture (C) having the following composition was dropped at a constant rate over 5 hours using a dropping funnel.

(Mixture (C)) Styrene 29.5 parts Methyl methacrylate 60.2 parts N-butyl acrylate 0.3 parts Acrylic acid 10.0 parts Toluene 13.5 parts 2,2'-azobisisobutyronitrile 1.8 parts Drop of mixture (C) After the completion, 0.2 parts of 2,2'-azobisisobutyronitrile and 5.0 parts of toluene were dropped at a constant speed over 1 hour. After completion of the dropwise addition, the mixture was aged at 110 ° C. for 2 hours and cooled, and xylene was added to the resin solution to adjust the solid content to 60%. Table 1 shows the properties of the obtained resin solution (4).

Production Example 5 [Synthesis of acrylic resin containing no carboxyl group] 36.0 parts of xylene was charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel. After the temperature was raised to 110 ° C. while introducing the mixture, a mixture (C) having the following composition was dropped at a constant speed over 5 hours by a dropping funnel.

(Mixture (C)) Styrene 29.5 parts Methyl methacrylate 43.0 parts N-butyl acrylate 27.5 parts Toluene 13.5 parts 2,2'-azobisisobutyronitrile 1.8 parts After the completion of the dropwise addition of mixture (C), 2 0.2 parts of 2,2'-azobisisobutyronitrile and 5.0 parts of toluene were dropped at a constant speed over 1 hour. After completion of the dropwise addition, the mixture was aged at 110 ° C. for 2 hours and cooled, and xylene was added to the resin solution to adjust the solid content to 60%. Table 1 shows the properties of the obtained resin solution (5).

[0101]

[Table 1]

Examples 1-2 and Comparative Examples 1-2 The acrylic resin having a hydroxyl group (A) obtained in Production Example 2 27.
To 3 parts, 18.0 parts of titanium oxide (CR-90, manufactured by Ishihara Sangyo Co., Ltd.), 2.1 parts of orthoacetic acid methyl ester and 3.6 parts of xylene as a dehydrating agent (E) were added, and the mixture was shaken for 2 hours. 42.7 parts of the obtained alkoxysilyl group-containing polymer (B), 4.2 parts of methanol and 2.1 parts of butanol were added and shaken for 30 minutes to prepare a white enamel. Acrylic copolymer (C) having a carboxyl group in Examples 1 and 2
(Resin solution (3), (4)) 17.5 parts and TN80 as curing agent (D)
1 (Dioctyl Suzu maleate, manufactured by Sakai Chemical Industry Co., Ltd.)
0.84 parts and 38.3 parts of xylene were added, and the mixture was sufficiently stirred, and then directly coated on an aluminum substrate. The comparative example was performed in the same manner as described above using an acrylic resin containing no carboxyl group (resin solution (5)). In addition, the same procedure as above was carried out without adding the acrylic copolymer (C) having a carboxyl group. After baking and drying at 140 ° C. for 20 minutes, adhesion and curability were examined. Further, the pot life of the mixture was also examined. Table 2 shows the adhesion, curability and pot life at that time.
It was shown to.

[0103]

[Table 2]

From the evaluation results shown in Table 2, it can be seen that the composition of the present invention is a composition having improved adhesion to aluminum substrates and others.

[0105]

The composition of the present invention has excellent adhesion to a metal substrate, excellent curability, excellent pot life, and excellent basic properties such as weather resistance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08K 5/521 C08K 5/521 5/56 5/56 5/57 5/57 C08L 43/04 C08L 43/04 C09D 133/00 C09D 133/00 (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 33/14 C08K 5/05 C08K 5/09-5/10 C08K 5/521 C08K 5/56-5/57 C08L 43 / 04 C09D 133/00

Claims (7)

(57) [Claims] (A) A compound having a hydroxyl group and having a general formula (I): (Wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms, R ² is a hydrogen atom or a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, a represents 0, 1 or 2), an acrylic resin having no group represented by the formula (B), an alkoxysilyl group-containing acrylic copolymer containing a group represented by the general formula (I), and (C) an acid value. Is between 30 and 700 mgKOH / g, with hydroxyl and general formula
Carboxyl group-containing acrylic copolymer having no group represented by (I), (D) Ri Do a curing catalyst and (E) a dehydrating agent and (F) 1 or more alkyl alcohols, (A) component / ( B) The components are 9/1 to 1/9 by weight,
100 parts by weight (solid content) of component (A) and component (B)
And 5 to 70 parts by weight (solid content) of component (C), 0.1 component (D)
~ 20 parts by weight, 100 parts by weight or less of component (E), 100 parts by weight of component (F)
Parts or less, provided that either (E) or (F)
On the other hand only the case of not using 0.5 to 100 wt parts der Ru curable composition. 2. A compound having a hydroxyl group as the component (A) and having the general formula
The acrylic resin having no group represented by (I) has a hydroxyl value of 10 to 300 mgKOH / g and a number average molecular weight of 1,500 to 4,
2. The curable composition according to claim 1, wherein the amount is 0.000. 3. An alkoxysilyl group-containing acrylic copolymer as the component (B) has a unit derived from an alkoxysilyl group-containing monomer having a polymerizable unsaturated double bond and an alkoxysilyl group in a molecule of 5 to 5. The curable composition according to claim 1, which is a polymer containing 90% by weight. 4. The carboxyl group-containing acrylic copolymer as the component (C) contains 0.1 to 95% by weight of a unit derived from a carboxyl group-containing monomer having a polymerizable unsaturated double bond and a carboxyl group in the molecule. The curable composition according to claim 1, which is a polymer. 5. The curing catalyst as the component (D) is an organotin compound, an acidic phosphate, a mixture or a reaction product of an acidic phosphate and an amine, a saturated or unsaturated polycarboxylic acid, a saturated or unsaturated Acid anhydrides of polycarboxylic acids, reactive silicon compounds, organic titanate compounds,
The curable composition according to claim 1, which is an organic aluminum compound, an organic zirconium compound, or a mixture thereof. 6. The curable composition according to claim 1, wherein the dehydrating agent as the component (E) is a hydrolyzable ester compound. 7. (E) comprises a hydrolyzable ester compound as a dehydrating agent is a component, is cured composition of claim 1 wherein the al in containing dehydrating accelerator.