JPH03277646A - Curable composition and article coated therewith - Google Patents

Abstract

PURPOSE:To obtain a curable compsn. giving a coated article improved in acid resistance, stain resistance, weatherability, hardness, mar resistance, and durability in boiling water by compounding an alkoxysilylated acrylic polymer. an acrylic resin, and a curing catalyst. CONSTITUTION:(Meth)acrylic acid and a deriv. thereof are copolymerized with an alkoxysilylated monomer to give an alkoxysilylated acrylic polymer having a silicon equivalent of 600 or lower, a number-average mol.wt. of 1,000-30,000, and a glass transition point of -30 to 100 deg.C. 100 pts.wt. said polymer is compounded with 3-300 pts.wt. acrylic resin having a glass transition point of 30 deg.C or lower and a number-average mol.wt. of 1,000-100,000, a curing catalyst in an amt. of 0.1-20 pts.wt. based on 100 pts.wt. solid content of the sum of the polymer and acrylic resin, and, if necessary, an alkoxysilylated and/or silanolated silicon compd., dehydration(-accelerating) agent, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to various coatings such as building exteriors, automobiles, industrial machinery, steel furniture, home appliances, plastics, etc.
In particular, the present invention relates to a curable composition suitable for use in coatings that require durability, and a coated product coated with the same.

[Conventional technology]

Recently, acrylic polymers with alkoxysilyl groups (
Acrylic polymers (alkoxysilyl group-containing acrylic polymers) are hardenable at room temperature or under heat, and their cured products have excellent adhesion and weather resistance to concrete, glass, steel plates, aluminum, etc., and are used for exterior building materials, automobiles, etc. It has been reported that it is useful as a coating agent for commercial purposes, etc. (see JP-A-54-36395, etc.).

[Problem to be solved by the invention]

By the way, when using an alkoxysilyl group-containing acrylic polymer as a coating material, in order to satisfy required physical properties such as hardness, blocking resistance, and scratch resistance, it is necessary to adjust the silicon equivalent of the alkoxysilyl group-containing acrylic polymer. It is preferable to have a small value, that is, to increase the content of alkoxysilyl groups.

However, it has been found that in this case, the durability of Coating '1M in boiling water becomes poor, causing problems such as gloss and cracking in the coating film.

Conventionally, when an alkoxysilyl group-containing acrylic polymer was used alone, it was difficult to balance the physical properties, and therefore the applications to which it could be applied were limited.

Therefore, improving the above-mentioned balance of physical properties has been a particularly big problem in the top coating of automobiles.

There are two types of top paint finishes for automobiles: metallic color finishes and solid color finishes.

Among these, in the case of a metallic color finish, after applying a metallic base coat, a clear paint is applied using a wet-on-wet method, and the coating is heated and cured using a two-coat one-bake method.

However, in the case of metallic color finishing, acrylic melamine resin paint is used as the clear paint, so the resulting paint film has problems in performance such as scratch resistance, acid resistance, stain resistance, etc., and improvements are desired. was.

On the other hand, in the case of solid color finishing, alkyd melamine resin paints are used, and in the past, the method of heating and curing in a one-coat, one-bake method was generally used. As requirements for physical properties such as scratch resistance, acid resistance, and stain resistance have become stricter,
A method of painting a clear paint over a solid color has been proposed.

However, even with this method, a satisfactory coated product has not yet been obtained.

If an alkoxysilyl group-containing acrylic polymer is used alone as a top coat clear paint, a painted product with excellent acid resistance, stain resistance, and weather resistance can be obtained, but as mentioned above, hardness, scratch resistance, etc. However, it is not possible to improve the balance of physical properties with spring water durability.

The present invention was made in view of the above circumstances, and its purpose is not only to provide excellent acid resistance, stain resistance, and weather resistance, but also to improve hardness, scratch resistance, and spring water durability. The object of the present invention is to provide a coated article with an excellent balance of physical properties and a curable composition required for its production.

[Means for Solving the Problems] The curable composition according to the present invention for achieving the above object comprises an alkoxysilyl group-containing acrylic polymer (A) having a silicon equivalent of 700 or less, a glass transition point of 700 or less, 'Tg
J) is composed of an acrylic resin (B) and a curing catalyst (C) at a temperature of 30°C or less, and the coated product according to the present invention is coated with a paint containing metallic powder and/or color pigment. A painted product coated with a top coat clear paint, the top coat clear paint containing the curable composition according to any one of claims 1 to 3 as a main component.

The curable composition of the present invention provides a cured product that has excellent weather resistance, chemical resistance, water resistance, etc. In particular, it has excellent surface hardness compared to acrylic melamine paint, which is commonly used as a clear paint. It has the excellent characteristics of having both scratch resistance and water conduction durability.

The alkoxysilyl group-containing acrylic polymer (A) in the present invention is an acrylic polymer having an alkoxysilyl group at the terminal or side chain for crosslinking in an amount such that the silicon equivalent is 700 or less.

In the present invention, the silicon equivalent of the alkoxysilyl group-containing acrylic polymer (A) is limited to 700 or less. This is because when the silicon equivalent exceeds 700, the surface hardness of the coating film decreases, and the scratch resistance tends to decrease. A particularly preferred silicon equivalent is 300-650.

Here, the silicon equivalent refers to the number average molecular weight of the acrylic polymer (A) per mole of alkoxysilyl group. Therefore, the smaller the silicon equivalent, the greater the amount of alkoxysilyl groups contained in the acrylic polymer (A).

The number average molecular weight of the alkoxysilyl group-containing acrylic polymer (A) is preferably within the range of 1000 to 30000, and preferably 2000 to It is more preferably within the range of 25,000. In addition, alkoxysilyl group-containing acrylic polymers (
A) has a Tg of 130 to 10 from the viewpoint of the necessary physical properties of the coating film.
Preferably, the temperature is within the range of 0°C.

The alkoxysilyl group-containing acrylic polymer (A) can be obtained, for example, by polymerizing acrylic acid, methacrylic acid, and derivatives thereof and a monomer having an alkoxysilyl group.

The monomers of acrylic acid, methacrylic acid, and derivatives thereof are not particularly limited, and examples include (meth)acrylic acid, methyl (meth)acrylate, and ethyl (meth)acrylate.
Acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate
Acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, trifluoroethyl (meth)acrylate, pentafluoropropyl (meth)acrylate, perfluorocyclohexyl (meth)acrylate, (meth)acrylonitrile, glycidyl (meth)acrylate, dimethyl Aminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate,
(meth)acrylamide, α-ethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide,
NN dimethylacrylamide, N-methylacrylamide, acryloylmorpholine, 2-hydroxyethyl (
meth)acrylate, 2-hydroxypropyl(meth)
Acrylate, N-methylol (meth)acrylamide, phosphoric acid ester group-containing compound that is a condensation product of hydroxyalkyl esters of (meth)acrylic acid, etc. and phosphoric acid or phosphoric acid esters, manufactured by Toagosei Chemical Industry Co., Ltd. Aronix 5700, Placeel FA-1, PIaccel FA- manufactured by Daicel Chemical Industries, Ltd.
4, PIaccel FM-1, Placel F 4 and containing urethane bonds and siloxane bonds (meth)
An example is acrylate.

The alkoxysilyl group-containing acrylic polymer (A) may contain urethane bonds or siloxane bonds in its main chain in an amount not exceeding 50 parts by weight per 100 parts by weight of the polymer (A). It may also contain monomers other than (meth)acrylic acid derivatives.

Monomers other than the above (meth)acrylic acid derivatives are not particularly limited, and examples include aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, styrene sulfonic acid, 4-hydroxystyrene, and vinyltoluene; Acids, unsaturated carboxylic acids such as fumaric acid and itaconic acid, their salts (alkali metal salts, ammonium salts, amine salts, etc.), their acid anhydrides (maleic anhydride, etc.), or them and carbon atoms 1 to 20 Esters of unsaturated carboxylic acids such as diesters or half esters with linear or branched alcohols; vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate, and diallyl phthalate; amino group-containing compounds such as hinylpyridine and aminoethyl vinyl ether. Vinyl compounds; amide group-containing vinyl compounds such as itaconic acid diamide, crotonamide, maleic acid diamide, fumaric acid diamide, tovinylpyrrolidone; 2-hydroxyethyl vinyl ether, methyl vinyl ether, cyclohexy J-levinyl ether, vinyl chloride, vinylidene chloride, Other vinyl compounds include chloroprene, propylene, butadiene, isoprene, fluoroolefin maleimide, N-vinylimidazole, vinyl sulfonic acid, and the like.

The alkoxysilyl-containing monomer may be any monomer having an alkoxysilyl group, that is, a group containing a silicon atom having an alkoxy group bonded to a silicon atom, such as CH3 CHs "CHSI(OCHI)I CHI IICHSI( OCTo)s CH.

CH, snow CHCOO(CHs)s S[(OCRl)i
CHI Tomi CHCOO (CH,), 5i (QC!11)
.

C.I.

CH= ”C(CHs)COO(CHz)-5i(O
CRs)zCH,=C(CM,)Coo(CHI)!
5l(QC!!,)jHx CHz = C(CL)Coo(CHz)x 5t(O
Examples include vinyl monomers such as CJs)z, and (meth)acrylates having an alkoxysilyl group at the end via a urethane bond or a siloxane bond.

The alkoxysilyl group-containing acrylic polymer (A) is disclosed in, for example, JP-A-54-36395 and JP-A-57-3610.
From the viewpoint of ease of synthesis, an azo radical initiator such as 2,2''-azobisisobutyronitrile is used. It is most preferable to manufacture by solution polymerization method.

In solution polymerization, n-dodecylmercaptan, t-dodecylmercaptan, n-butylmercaptan, T-mercaptopropyltrimethoxysilane,
T-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, T-mercaptopropylmethyljethoxysilane, (HsCO)s 5t-5-5-5i (OCHx)z,
By using a chain transfer agent such as (CH,0), 5i-5, -5t(CH3)3, the molecular weight can be adjusted.

In particular, if a chain transfer agent having an alkoxysilyl group in the molecule, such as T-mercaptopropyltrimethoxysilane, is used, an alkoxysilyl group can be introduced at the end of the molecule.

Hydrocarbon II is used as polymerization cutting for solution polymerization.
C) toluene, xylene, n-hexane, cyclohexane, etc.), acetic acid ester II (ethyl acetate, butyl acetate, etc.), alcohol I! (methanol, ethanol, isopropanol, n-butanol, etc.), ether 11 (
Ethyl cellosolve, butyl cellosolve, cellosolve acetate, etc.), ketone I! (Methyl ethyl ketone, ethyl acetoacetate, acetylacetone, diacetone alcohol, methyl isobutyl ketone, acetone, etc.) are exemplified, but the solvent is not particularly limited as long as it is a non-reactive solvent.

In the present invention, the alkoxysilyl group-containing polymer (A)
may be used alone or in combination of two or more as necessary.

Acrylic resin (B) with Tg of 30°C or less in the present invention
Similarly to the alkoxysilyl group-containing polymer (A), the main chain is substantially composed of an acrylic polymer chain, and from this point of view as well, the thermosetting composition of the present invention has excellent weather resistance. It exhibits properties such as durability, chemical resistance, and water resistance.

In the present invention, the Tg of the acrylic resin (B) is 30°C.
Limited to: This is V! This is to give the membrane durability against boiling water. Particularly preferable Tg is 20°C to 30°C.
within the range of ℃.

In addition, the glass transition point (Tgm) of the obtained copolymer when two or more types of monomers are used is calculated from the following Fox formula.

FoxO formula: 1 mi Tgm ΣTgi where, Tgi: glass transition point of i component, mi: i
is the weight fraction of the components.

The number average molecular weight of the acrylic resin (B) is determined from ■000 to too
It is preferably within the range of ooo, and more preferably within the range of 2,000 to 50,000.

The method for synthesizing the acrylic resin (B) is not particularly limited, and is exactly the same as the method for synthesizing the acrylic polymer (A) from the alkoxysilyl radical described above.

Examples of the seven acids used include (meth)acrylic acid,
Methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate 1, trifluoroethyl (meth)acrylate ) 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,
Phosphate group-containing compound which is a condensation product of hydroxyalkyl esters of (meth)acrylic acid, etc. and phosphoric acid or phosphoric acid esters, Toagosei Chemical Industry Co., Ltd.
Aronix 5700 manufactured by Daicel Chemical Industries, Ltd., Placel FA-1, Placel FA-4 manufactured by Daicel Chemical Industries, Ltd.
, Placel FM-1, PIaccel FM-
4 and containing urethane bonds and siloxane bonds (meth)
Examples include acrylate.

The acrylic resin (B) may contain a urethane bond or a siloxane bond in its main chain in an amount not exceeding 50 parts based on 100 parts by weight of the resin (B), and (meth)
It may also contain monomers other than acrylic acid derivatives.

Monomers other than the above (meth)acrylic acid derivatives are not particularly limited, and include aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, and vinyltoluene; maleic acid , unsaturated carboxylic acids such as fumaric acid and itaconic acid, their salts (alkali metal salts, ammonium salts, amine salts, etc.), their acid anhydrides (maleic anhydride, etc.), or combinations thereof with carbon atoms having 1 to 20 carbon atoms. Esters of unsaturated carboxylic acids such as diesters or half esters with linear or branched alcohols; vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate, diallyl phthalate; amino group-containing vinyls such as vinyl pyridine and aminoethyl vinyl ether Compounds: Vinylation of amide bases such as itaconic acid diamide, crotonamide, maleic acid diamide, fumaric acid diamide, N-vinylpyrrolidone, etc. 11: 2-hydroxyethyl vinyl ether, methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene , propylene, butadiene, isoprene, fluoroolefins, maleimides, N-vinylimidazole, vinyl sulfonic acid, and other vinyl compounds.

As the polymerization method, a solution polymerization method using an azo radical initiator such as 2.2''-azobisisobutyronitrile is easy, as in the case of synthesis of the alkoxysilyl group-containing acrylic polymer (A). Preferable from this point of view.

In solution polymerization, the molecular weight can be adjusted using a chain transfer agent such as n-dodecylmercaptan, t-dodecylmercaptan, n-butylmercaptan, etc., if necessary.

Polymerization cutting in solution polymerization is not particularly limited as long as it is a non-reactive solvent.

The acrylic resin (B) in the present invention may be a non-aqueous dispersion type resin in which insoluble polymer particles are dispersed in an aqueous solvent. Such acrylic resin (B) may be used alone, or two or more types may be used in combination as necessary.

The blending amount of the acrylic resin (B) is 3 to 300 parts per 100 parts of the alkoxysilyl group-containing acrylic polymer (A).
If the amount of acrylic resin (B) is less than 3 parts, the resistance to spring water of the paint film will decrease, and if it exceeds 300 parts, the paint film will deteriorate. There is a tendency for water resistance, chemical resistance, etc. to decrease.

Each component of the alkoxysilyl group-containing polymer (A) and acrylic resin (B) may be copolymerized with a polar additive in order to improve the adhesion, surface hardness, and scratch resistance of the coating film. is preferable, and such polar monomers are preferably monomers having active hydrogen such as carboxylic acid groups, amide groups, amino groups, and hydroxyl groups.

The curing catalyst (C) in the present invention includes organic tin compounds such as dibutyltin dilaurate, dibutyltin simalate, dioctyltin dilaurate, dioctyltin simalate, tin octylate; phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate; Monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate,
Phosphoric acid or phosphate esters such as dibutyl phosphate, dioctyl phosphate, didecyl phosphate; propylene oxide, butylene oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic glycidyl ether, γ-glycidoxypropyltrimethoxysilane, T-glycidyl Cydoxypropyltriethoxysilane, T-glycidoxypropylmethyldimethoxysilane 1, Cardura E manufactured by Yuka Shell Epoxy Co., Ltd.; Epicoat 828, Ebico-41001 manufactured by Yuka Shell Epoxy Co., Ltd.
Addition reaction products of epoxy compounds such as phosphoric acid and/or monoacidic phosphate esters; titanate compounds; organoaluminum compounds; acidic compounds such as maleic acid and P-toluenesulfonic acid; hexylamine, di-2-
Amines such as ethylhexylamine, N,N-dimethyldodecylamine, morpholine, dodecylamine; mixtures or reactants of these amines and acidic phosphoric acid esters;
Examples include alkaline compounds such as sodium hydroxide and potassium hydroxide, saturated or unsaturated polycarboxylic acids, anhydrides of saturated or unsaturated polycarboxylic acids, and reactive silicon compounds.

Among these exemplified curing catalysts (C), organic tin compounds,
Acidic phosphoric acid esters, mixtures or reactants of acidic phosphoric acid esters and amines, saturated or unsaturated polyhydric carboxylic acids or their acid anhydrides, reactive silicon compounds, organic titanate compounds, aluminum compounds or mixtures thereof. It is preferred because of its high catalytic activity.

Especially when using organometallic compounds such as organotin compounds, organotitanate compounds, organoaluminum compounds, etc.
When a β-diketone compound is used in combination, the stability of the composition in closed and open states can be significantly improved.

This seems to be because the β-diketone compound has a certain interaction with the curing catalyst. In addition, after the coating is used, the β-diketone compound evaporates during drying and curing and is removed from the system, so that almost no phenomenon of inhibiting the crosslinking reaction is observed.

As the β-diketone compound, acetylacetate can be obtained.The curing catalyst (C) may be used alone,
Two or more types may be used in combination if necessary.

The amount of the curing catalyst (C) is not particularly limited, but it is usually 0.1 parts per 100 parts of dry solid content of the alkoxysilyl group-containing acrylic polymer (A) and acrylic resin (B).
-20 parts are preferable, and 0.1-10 parts are more preferable.

If the amount of the curing catalyst (C) is less than 0.1 part, the curability tends to decrease, and if it exceeds 20 parts, the physical properties of the coating film tend to decrease.

If a silicon compound having an alkoxysilyl group and/or a silanol group (hereinafter sometimes abbreviated as "silicon compound") is further added to the curable composition consisting of the above (A), (B) and (C), , it is possible to further improve the adhesion, hardness, scratch resistance, solvent resistance, etc. of the resulting coating film.

Suitable examples of the silicon compound include alkoxysilane compounds, partially hydrolyzed condensates or reactants of alkoxysilane compounds, and mixtures thereof.

Examples of the alkoxysilane compounds include methyl silicate, methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, T-methacryloxypropyltrimethoxysilane, r -Acryloxypropyltrimethoxylan, T-glycidoxypropyltrimethoxylan, T
Mercaptopropyltrimethodixylan, T-aminopropyltrimethodixylan, N-β-aminoethyl-T
-Propyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dibutyldimethoxysilane, diphenyldimethoxysilane, vinylmethyldimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, trimethylmethoxysilane, triethylmethoxysilane, triphenylmethoxysilane, ethyl Silicates, methyltriethoxysilane, ethyltriethoxysilane, butyltriethoxysilane, octyltriethoxysilane, dodecyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltriethoxysilane, γ
-Acryloxypropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, T-mercaptopropyltriethoxysilane, γ-7minopropyltriethoxysilane, N-β-aminoethyl-Tpropyltriethoxysilane, dimethyl Jetoxysilane, diethyljethoxysilane, dibutyljethoxysilane, diphenyljethoxysilane, γ-methacryloxypropylmethyljethoxysilane, trimethylethoxysilane,
Examples include triethyl ethoxysilane and triphenylmethoxysilane.

The partially hydrolyzed condensate of the above alkoxysilane compound is
The above alkoxysilane compounds are used singly or in combination,
It can be easily obtained by adding a required amount of water, adding a small amount of a condensation catalyst such as hydrochloric acid or sulfuric acid if necessary, maintaining the reaction system at room temperature to 100°C, and carrying out condensation while removing the alcohol produced.

Examples of partially hydrolyzed condensates of alkoxysilane compounds include methyl silicate 47, methyl silicate 51, methyl silicate 55, manufactured by Nippon Colcoat Co., Ltd., which are partially hydrolyzed condensates of methyl silicate and have a methoxysilyl group. Methyl silicate 58
, methyl silicate 60, and commercially available compounds having a methoxysilyl group that are partially hydrolyzed condensates such as methyltrimethoxysilane and dimethyldimethoxysilane include AFPl and AFP-2 manufactured by Shin-Etsu Chemical Co., Ltd.
, AFP-6, KR213, KR217, KR9218
i TSR165, TR3357 manufactured by Toshiba Silicone Corporation;
Y-1587, FZ-3701, F manufactured by Nippon Unicar Co., Ltd.
Z-3104 is mentioned.

In addition, as a commercially available compound which is a partially hydrolyzed condensate of ethyl silicate and has an ethoxysilyl group, for example, ethyl silicate 40 manufactured by Nippon Coal Coat Co., Ltd., RAS
-1, HAS-6, and RAS-10.

Reactants of the alkoxysilane compound mentioned above include a reaction product 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 oxide, epichlorohydrin, epoxy Soybean oil, its oil extraction Epikote 828 and Epicoat 1 manufactured by Shell Epoxy Co., Ltd.
Reaction product with a compound containing an epoxy group such as 001; a silane coupling agent containing an epoxy group and ethylamine, diethylamine, triethylamine, ethylenediamine,
Aliphatic amines such as hexanediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, aromatic amines such as aniline and diphenylamine, alicyclic amines such as cyclopentylamine and cyclohexylamine, and amines such as ethanolamine. An example is a reaction product with.

The silanol group-containing silicon compound is not particularly limited, and includes trimethylsilanol, triethylsilanol, tripropylsilanol, tributylsilanol, triphenylsilanol, diphenylmethylsilanol, diphenylethylsilanol, dimethylsilanediol, diethylsilanediol, dipropylsilanediol, Dibutylsilanediol, diphenylsilanediol, methylphenylsilanediol (hereinafter, blank) R=OH or phenyl group CH.

HO÷S i -0+TH Hs Hx Examples include.

The above silicon compounds may be used alone or in combination of two or more, if necessary.

The amount of the silicon compound is not particularly limited, but it is usually 0.0 parts per 100 parts of the total amount of the alkoxysilyl group-containing acrylic polymer (A) and acrylic resin (B).
The amount is preferably within the range of 1 to 100 parts, and more preferably within the range of 0.1 to 70 parts. The amount of silicon compound is 0.0
If the amount is less than 1 part, the effect of addition will not be sufficiently expressed, and if the amount is less than 1 part,
If it exceeds 0 parts, the physical properties of the coating film tend to deteriorate.

When using T-glycidoxyprobyltrimethoxysilane, T-glycidoxyprobyltriethoxysilane, etc. as examples of the curing catalyst (C) as the silicone compound, the amount of the alkoxysilyl Group-containing acrylic polymer (A) and acrylic resin (B)
It is preferable that the amount is 30 parts or less per 100 parts of total volume.

It should be noted that a dehydrating agent may be further added to the curable composition according to the present invention, and by incorporating the dehydrating agent, stability over a long period of time can be improved, and there is no problem even if the remaining composition is reused at a later date. It can ensure stability without any problems.

Examples of the dehydrating agent in this case include methyl orthoformate,
Examples include hydrolyzable ester compounds such as ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, methyltrimethoxysilane, T-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, methylsilicate, and ethylsilicate. These hydrolyzable ester compounds may be added at any time before, after, or during the polymerization of the alkoxysilyl group-containing acrylic polymer (A).

The amount of the dehydrating agent is not particularly limited, but the preferred amount is the alkoxysilyl group-containing acrylic polymer (A
) is usually 100 parts or less, more preferably 50 parts or less, per 100 parts of solid content. Note that by using a dehydration accelerator in combination, the effect of the dehydration agent can be further enhanced.

Dehydration accelerators include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid; formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid,
p-) Organic acids such as luenesulfonic acid, acrylic acid, and methacrylic acid; Carboxylic acid metal salts such as alkyl titanates and lead octylate; Carboxylic acid type organic tins such as tin octylate, dibutyltin dilaurate, and dioctyltin malate. Compounds; sulfide type and mercaptide type organic tin compounds such as monobutyltin sulfide and dioctyltin mercaptide; organic tin oxides such as dioctyltin oxide; organic tin oxides and ethyl silicate, ethyl silicate 40, dimethyl maleate, dioctyl phthalate, etc. Organotin compounds obtained by reaction with ester compounds; amines such as tetraethylenepentamine, triethylenediamine, N-β-aminoethyl-T-aminopropyltrimethoxysilane; alkaline catalysts such as potassium hydroxide and sodium hydroxide are effective. be. Among these, organic acids, inorganic acids, and organic tin compounds are particularly effective.

Dehydration accelerator is usually o, ooot per 100 parts of dehydrating agent.
-20 parts, preferably o,oot -10 parts are used.

When using a compound that also functions as a curing catalyst (C) as a dehydration accelerator, in addition to the amount of curing catalyst (C), an additional 0.1 to 20 parts, preferably 0.1 to 1
Use an excess of 0 parts.

A solvent may further be added to the curable composition according to the present invention.

In this case, the solvent may be any non-reactive solvent, including aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, etc. used in general paints and coating materials, etc. Examples include ketones, esters, ethers, alcohol esters, ketone alcohols, ether alcohols, ketone ethers, ketone esters, and ester ethers. Among these, solvents containing alkyl alcohol are preferred because they improve the stability of the thermosetting composition according to the present invention.

Such alkyl alcohols are preferably alcohols in which the alkyl group has 1 to 10 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 5ec-7yl alcohol, tert-
Examples include butyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol, octyl alcohol, and cellosolve.

The blending amount of the alcohol is not particularly limited, but is usually 100 parts per 100 parts of dry solid content of the alkoxysilyl group-containing acrylic polymer (A) and acrylic resin (B).
parts, preferably 50 parts or less.

The combined use of alcohols and the dehydration side significantly increases the storage stability when (A), (B) and (C) of the curable composition according to the present invention are mixed and stored.

The amount of the solvent to be blended varies depending on the molecular weights and compositions of (A) and (B) used in the composition of the present invention, and is adjusted in accordance with the practically required solid content concentration and viscosity.

A UV absorber and/or a light stabilizer may be further added to the curable composition according to the present invention.

When using the curable composition according to the present invention as a top coat clear paint, by blending these, -
The weather resistance of the layer can be improved.

As the above-mentioned ultraviolet absorber, various conventionally known ones can be used, but among them, ultraviolet absorbers such as benzophenone type, triazole type, phenyl salicylate type, diphenyl acrylate type, and acetophenone type are preferred.

Various conventionally known light stabilizers can be used as the light stabilizer, such as bis(2,2,6,6-tetramethyl-4
-piperidyl) sebacate, bis(1,2,26,6-
Bentamethyl-4-piperidyl) sebacate, 2-(3
,5-di-tert-butyl-4-hydroxyhensyl)-2-n-butylmalonic acid bis(1,2,2,6,6
-bentamethyl-4-piperidyl), tetrakis (2,
26,6-tetramethyl-4-piperidyl) -1,2
, 3,4 butane tetracarboxylate, tetrakis (
1゜2.2,6.6-bentamethyl-4-piperidyl)
-1,2,3,4-butanetetracarboxylate and the like can be used. These ultraviolet absorbers and light stabilizers may be used alone or in combination of two or more, if necessary.

When used as a top coat clear paint, the weather resistance of the coated object can be further improved by using a UV absorber and a light stabilizer together.

The amount of the ultraviolet absorber to be blended is usually 0.1 to 10 parts, preferably 1 to 5 parts, based on 100 parts of the solid content of the top coat clear paint. In addition, the amount of light stabilizer is usually 0 parts per 100 parts of the solid content of the top coat clear paint.
, 1 to 10 parts, preferably 1 to 5 parts.

Additives such as diluents, anti-cissing agents, pigments such as extender pigments, anti-settling agents, leveling agents, etc. to the curable composition according to the present invention; textile industry such as nitrocellulose, cellulose acetate butyrate; Resins such as epoxy resins, melamine resins, vinyl chloride resins, chlorinated polypropylene, chlorinated rubber, and polyvinyl butyral; fillers and the like may be added.

The curable composition according to the present invention is prepared by cold blending (A) and (B), or by heating blending (hot blending) after mixing, and (C) and/or a silicon compound. Obtained by mixing.

The curable composition according to the present invention can be applied to an object by a conventional method such as dipping, spraying, or brushing, and then cured at a temperature of usually 30'C or higher, preferably 55 to 350C.

An example of applying the curable composition according to the present invention is given below.

First, a paint containing methacrylic powder and/or color pigment is applied to an object to be coated.

Next, a top coat clear paint containing the curable composition according to the present invention as a main component is applied to the coated surface.

In the above case, the paint (base coat) containing methacrylic powder and/or colored pigment is not particularly limited, and examples include amino alkyd resin, oil-free alkyd resin, thermosetting acrylic resin, thermosetting urethane resin, nitrocotton lacquer, Modified acrylic lacquer, straight acrylic lacquer, room temperature curing urethane resin, acrylic enamel resin, oxidation curing alkyd resin, oxidation curing modified (CAB etc.) alkyd resin, room temperature or heat curing fluororesin,
A material containing a hydrolyzable silyl group-containing resin, a composition of the present invention, a mixture thereof, etc. as a main component, and a metallic powder or a colored pigment can be used.

The paint containing the methacrylic powder and/or colored pigment may be any type of paint, such as a solution-type paint using an organic solvent as a medium, a non-aqueous dispersion paint, a multi-component paint, a powder paint, a slurry paint, or a water-based paint. It may be a paint.

The above-mentioned metallic powder and coloring pigment are not particularly limited, and conventionally used ones can be used. As the metallic powder, for example, aluminum powder, copper powder, mica powder can be used, and as the coloring pigment, for example, organic pigments such as phthalocyanine blue, toluidine red, benzidine yellow, titanium oxide, carbon blank, red iron oxide, etc. Inorganic pigments can be used. These metallic powders and coloring pigments may be used alone or in combination of two or more if necessary.

In addition, the weather resistance of the coated object can be further improved by blending the above-mentioned ultraviolet absorber and light stabilizer into the base coat.

Further, the silicon compound described above may be added to the paint containing the metallic powder and/or the colored pigment in order to improve the adhesion between the paint film and the top coat clear paint film.

In this case, the amount of the silicon compound blended is usually 50 parts or less, preferably 20 parts or less, per 100 parts of the paint containing the metallic powder and/or color pigment.

The painted object according to the present invention has a top coat clear paint applied to the coated surface coated with the base coat, for example, a paint containing the metallic powder and/or color pigment is applied to the painted object, After setting for a few minutes, apply a top coat clear paint using a wet-on-wet method and heat cure the 2-coat 1-bake method, or apply a paint containing metallic powder and/or coloring pigment and heat it. It can be manufactured by a two-coat, two-bake method, etc., in which a top coat clear paint is applied after being cured, and then heated and cured.

The top coat clear paint is applied by various conventionally known methods such as dipping, spraying, brushing, using a roll coater or flow coater, and then heated to 30°C or higher, preferably 55 to 350°C. It can be cured by heating.

The thickness of the coating film of the painted object cannot be further defined as it varies depending on the application, but the thickness of the coating film containing metallic powder and/or color pigment is 10 to 10% from the viewpoint of concealment property etc.
The thickness is preferably within the range of 30 μm, and the thickness of the top coat clear coating film is preferably within the range of 20 to 50 μm from the viewpoint of durability.

The coating film obtained by applying the curable composition according to the present invention is
It has excellent physical properties such as hardness, blocking resistance, and scratch resistance, as well as water conduction durability.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on examples, but the present invention is not limited to the following examples in any way, and can be practiced with appropriate modifications within the scope of the gist thereof. It is.

[Production Examples 1 to 3] [Synthesis of alkoxysilyl group-containing acrylic copolymer (A)] 45.9 parts of xylene was placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introduction tube, and a dropping funnel. After the mixture was heated while introducing nitrogen gas, the mixture shown in Table 1 and 2,2°-azobisisobutyronitrile were added dropwise at a constant rate over 5 hours using a dropping funnel.

After the mixture was added dropwise and heated for 2 hours, xylene was added to the cooled resin solution to adjust the solid content to 60%.

Table 1 shows the properties of the obtained resin solution.

[Production Examples 4 to 7] [Synthesis of acrylic resin (B)] Instead of 45.9 parts of xylene, 31.3 parts of butyl acetate and 9.5 parts of xylene were charged, and the same formula as in Production Examples 1 to 3 was prepared. 2 and 2,2'-azobisisobutyronitrile were added.

After the mixture was added dropwise and heated for 2 hours, xylene was added to the cooled resin solution to adjust the solid content to 60%.

Table 2 shows the properties of the obtained resin solution.

[Examples 1 to 15 and Comparative Examples 1 to 3] The components shown in Table 3 were mixed to prepare top coat clear paints.

The test piece was a mild steel plate that had been degreased and phosphorylated, coated with an automotive epoxyamide cationic electrodeposited primer and an intermediate coat of surfer, and a commercially available acrylic melamine resin paint (silver metallic base) was applied on top of it. After that, apply Tinuvin 900 to the top coat clear paint shown in Table 3 using a wet-on-wet method.
(manufactured by Ciba Geigy, benzotriazole type ultraviolet absorption W1) and Tinuvin 144 (manufactured by Ciba Geigy, hindered amine light stabilizer) were added at 1 part each to 100 parts of resin solid content, and xylene was added until the viscosity reached a sprayable level. It was diluted and baked for 30 minutes. The dry film thickness of the base coat was about 15 μm, and the dry film thickness of the top coat clear paint was about 30 μm.

Example N11L13.14 is a case where a silicon compound is added to the top coat clear paint, and Example No. 1
No. 5 is a case in which a silicon compound is added to an acrylic melamine resin paint.

The physical properties of the obtained coated product were evaluated by the following method.

The results are also listed in Table 3.

(hardness) Measured in accordance with JIS K 5400.

(Scratch resistance) Apply a paste-like cleanser with a concentration of 60% to the flannel at a ratio of Ig/cd, apply a load of 120g/cj, move it back and forth over the test piece 20 times, and after washing with water, visually inspect the surface condition according to the following criteria. It was evaluated.

O: No change at all O: Slight streaks △: Streaks remained The scratch resistance is level x.

(Adhesion) JIS cellophane tape peel test (2 m x 2 cabinets)
Performed in accordance with K 5400.

Evaluation was made with 25/25 as 10 points and O/25 as 0 points.

(Water conduction test) Each test piece was exposed to water for 3 hours, and changes in appearance were visually evaluated.

○: No change ×: Shiny or cracked In addition, 1) to 5) in the table indicate the following.

1) DR8R Nidioctyl Acid Phosphate (manufactured by Ohe Chemical Industry Co., Ltd.) 2) Firmitsu 0M20: N,N-dimethyldodecylamine (manufactured by Kao Corporation) 3) KR213: Silicone intermediate (manufactured by Shin-Etsu Chemical Co., Ltd.) 4) SH6018 : Silicone intermediate (manufactured by Toray Silicone) 5) KR2 per 100 parts of acrylic melamine resin paint
Table 1 Table 3 (2) As is clear from Table 3, the thermosetting composition and coated product according to the present invention have higher hardness and resistance than conventional ones. It can be seen that it has an excellent balance of physical properties in terms of scratch resistance and shallow water durability.

〔Effect of the invention〕

As explained in detail above, the thermosetting composition and coated article according to the present invention have excellent physical properties such as an excellent balance of hardness, scratch resistance, and shallow water durability. play.

Claims (1)

[Claims] 1. A curable composition comprising an alkoxysilyl group-containing acrylic polymer (A) with a silicon equivalent of 700 or less, an acrylic resin (B) with a glass transition point of 30° C. or less, and a curing catalyst (C) thing. 2. An alkoxysilyl group-containing acrylic polymer (A) with a silicon equivalent of 700 or less, an acrylic resin (B) with a glass transition point of 30°C or less, a curing catalyst (C), and an alkoxysilyl group and/or silanol group. A curable composition consisting of a silicone compound. 3. The curing catalyst (C) is an organic tin compound, an acidic phosphoric acid ester, a mixture or reactant of an acidic phosphoric acid ester and an amine, a saturated or unsaturated polyvalent carboxylic acid, a saturated or unsaturated polyvalent carboxylic acid The curable composition according to claim 1 or 2, which is at least one compound selected from the group consisting of acid anhydrides, reactive silicon compounds, organic titanate compounds, and organic aluminum compounds. 4. A painted product comprising a top coat clear paint applied to a coated surface coated with a paint containing metallic powder and/or colored pigment, wherein the top coat clear paint is according to any one of claims 1 to 3. A coated article containing the curable composition described above as a main component. 5. The coated product according to claim 4, wherein the paint containing the metallic powder and/or the colored pigment contains a silicon compound having an alkoxysilyl group and/or a silanol group. 6. The coated product according to claim 4 or 5, wherein the top coat clear paint contains an ultraviolet absorber and/or a light stabilizer.