JPH0812937A - Coating resin composition - Google Patents

Abstract

PURPOSE:To provide a one-pack coating resin compsn. having excellent storage stability and low-temp. curability. CONSTITUTION:A coating resin compsn. characterized by comprising (a) a resin contg. at least one siloxy group and at least one alkoxysilyl group in its molecule, (b) a compd. contg. at least two isocyanate groups in its molecule., and (c) a catalyst for dissociating a siloxy group as indispensable components. The compsn. may further contain (d) a resin contg. at least one isocyanate group and at least one alkoysilyl group in its molecule, (e) a compd. contg. at least two siloxy groups in its molecule., and (c) a catalyst for dissociating a siloxy group as indispensable components.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel and useful coating resin composition. More specifically, it relates to a multi-component coating resin composition obtained by introducing an alkoxysilyl group into a curing system containing a hydroxyl group protected in the form of a siloxy group and an isocyanate group. The resin composition of the present invention is particularly suitable for use in automobile repair.

[0002]

2. Description of the Related Art At present, in the field of automobile repair, a two-pack type coating composed of a combination of an acrylic polyol and a polyfunctional isocyanate curing agent is widely used from the viewpoints of room temperature curing property, finish property, weather resistance and the like. . However, the two-component type is inferior in workability because the main agent and the curing agent must be blended at the painting site. The excess or deficiency of the blending amount of the curing agent affects the coating film performance. Due to its high viscosity, there is a problem that a large amount of diluting solvent must be used. In order to solve these problems, a siloxy group-containing vinyl polymer is used in place of the conventional hydroxyl group-containing vinyl polymer, and a one-pack type resin composition comprising this and a polyfunctional isocyanate curing agent is prepared. Although such methods have been proposed (for example, Japanese Patent Application Laid-Open Nos. 3-250016 and 1-96264, etc.), such a resin composition has insufficient curability at room temperature and low temperature and is required to have quick drying property. It is not practical for automobile repair. Furthermore, in recent years, coating film damage due to acid rain has become a problem, and improvement in acid resistance has been demanded.
In the system comprising a combination of the above-mentioned hydroxyl group- or siloxy group-containing resin and a polyfunctional isocyanate curing agent, the acid resistance is insufficient, and thus such required performance cannot be satisfied.

[0003]

The problem to be solved by the present invention is to provide a resin composition which is a one-pack type and has a low viscosity and which is excellent in storage stability, low temperature curability and acid resistance. is there.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a resin obtained by introducing an alkoxysilyl group into either a siloxy group-containing resin or an isocyanate group-containing resin. It was found that the use of the composition was extremely effective, and the present invention was completed. That is, the present invention provides "1. (a) a resin containing at least one siloxy group and at least one alkoxysilyl group in one molecule, (b)
A resin composition for coating, which comprises a compound containing at least two isocyanate groups in one molecule and (c) a siloxy group dissociation catalyst as an essential component. 2. The resin (a) is obtained by copolymerizing a vinyl monomer containing a siloxy group, an alkoxysilyl group-containing vinyl monomer, and a vinyl monomer copolymerizable with these monomers. The resin composition for coating according to item 1, which is a resin. 3. Resin (a) is a siloxy group-containing vinyl monomer 5
.About.99% by weight, 1 to 95% by weight of an alkoxysilyl group-containing vinyl-based monomer, and 0 to 94% by weight of another vinyl-based monomer, which is a resin described in item 1 or 2. Resin composition. 4. The resin (a) has a weight average molecular weight of 1,000 to 20.
Any one of 1 to 3 which is 50,000 resins
The resin composition for coating described in the item. 5. The coating resin composition according to any one of items 1 to 4, wherein the compound (b) is a resin further containing at least one siloxy group in one molecule. 6. The compound (b) is a resin obtained by copolymerizing an isocyanate group-containing vinyl-based monomer and another vinyl-based monomer copolymerizable with the monomer, any one of 1 to 5 above. The resin composition for coating described in the item. 7. The compound (b) is a resin obtained by copolymerizing an isocyanate group-containing vinyl-based monomer, a siloxy group-containing vinyl-based monomer, and another vinyl-based monomer copolymerizable with these monomers. The coating resin composition according to any one of items 1 to 6. 8. The compound (b) comprises 5 to 99% by weight of an isocyanate group-containing vinyl monomer and other vinyl monomers 1 to 9
The coating resin composition according to any one of items 1 to 7, which is 5% by weight and 0 to 94% by weight of the siloxy group-containing vinyl monomer. 9. The compound (b) has a weight average molecular weight of 1,000 to 2
Item 9. The coating resin composition according to any one of items 1 to 8, which is a resin of 0,000. 10. (D) a resin containing at least one isocyanate group and one alkoxysilyl group in one molecule,
(E) A compound containing at least two siloxy groups in one molecule, and (c) a siloxy group dissociation catalyst as essential components. 11. The resin (d) is an isocyanate group-containing vinyl monomer, an alkoxysilyl group-containing vinyl monomer,
Weight-average molecular weight of 1,000 to 200,000 obtained by copolymerizing these monomers with other vinyl-based monomers
The coating resin composition according to item 10, which is 0 resin. 12. The resin (d) comprises 5 to 99% by weight of an isocyanate group-containing vinyl monomer, 1 to 95% by weight of an alkoxysilyl group-containing vinyl monomer, and 0 to other vinyl monomers.
Item 10 or 11 which is a resin obtained by copolymerizing 94% by weight.
The resin composition for coating described in the item. 13. The coating resin composition according to any one of items 10 to 12, wherein the compound (e) is a resin further containing at least one isocyanate group in one molecule. 14. The compound (e) is a resin having a weight average molecular weight of 1,000 to 200,000 obtained by copolymerizing a vinyl monomer containing a siloxy group and another vinyl monomer, 1
The coating resin composition according to any one of items 0 to 13. 15. The compound (e) is a resin obtained by copolymerizing a vinyl monomer containing a siloxy group, a vinyl monomer containing an isocyanate group, and another vinyl monomer, and The resin composition for coating according to any one of items. 16. The compound (e) was copolymerized with 5 to 99% by weight of a vinyl monomer containing siloxy groups, 1 to 95% by weight of other vinyl monomers, and 0 to 94% by weight of vinyl monomers containing an isocyanate group. The resin composition for coating according to any one of items 10 to 15, which is a resin. 17． As a resin component, a compound (f) containing two or more functional groups of one kind selected from a siloxy group, an isocyanate group and an alkoxysilyl group in one molecule is further added.
Item 20. The coating resin composition according to any one of items 1 to 19, which comprises at least one species. 18. The content of the alkoxysilyl group in the resin composition is the composition amount as a compound and a vinyl monomer containing the alkoxysilyl group used, and the content of the siloxy group contains the siloxy group used. The composition amount as a vinyl-based monomer and a compound is 1 to 40% by weight and 5 to 60% by weight, respectively, with respect to the solid content in the resin composition. Coating resin composition. 19. 19. The coating resin composition according to any one of items 1 to 18, wherein the isocyanate group and the hydroxyl group in the resin composition have an equivalent ratio of NCO / OH = 0.5 to 2.0. 20. 20. The coating resin composition according to any one of items 10 to 19, wherein the siloxy group dissociation catalyst is 0.01 to 10% by weight based on the solid content of the resin composition. 21. The coating resin composition according to any one of items 1 to 20, to which a water binder that traps water is added. Regarding The present invention will be described in detail below.

[0005]

[Action]

In the present invention, the siloxy group has the following formula (I) and formula (I)

[0007]

Embedded image

(Wherein R ₁ , R ₂ and R _{3, which} may be the same or different, each represents an alkyl group having 1 to 18 carbon atoms, a phenyl group or an allyl group), and an alkoxy group. The silyl group has the following formula (II) and formula (II)

[0009]

Embedded image

(In the formula, R ₄ represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, R ₅ represents an alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group, and n is 2 or 3). Is what is shown.

In the present invention, the resin (a) containing at least one siloxy group and at least one alkoxysilyl group in a molecule is usually a vinyl-based monomer having each of these reactive functional groups and It can be obtained by copolymerizing with another vinyl-based monomer that is copolymerizable by a conventional method such as a solution polymerization method in the presence of a radical polymerization initiator.

Typical examples of the siloxy group-containing vinyl monomer are, for example, trimethylsiloxyethyl (meth) acrylate, trimethylsiloxypropyl (meth) acrylate, trimethylsiloxybutyl (meth) acrylate and triethylsiloxyethyl (meth). )
Examples thereof include trialkylsiloxyalkyl (meth) acrylates such as acrylate, triethylsiloxypropyl (meth) acrylate, and triethylsiloxybutyl (meth) acrylate, but not limited to these, the hydroxyl group in the hydroxyl group-containing vinyl monomer is commonly known. Any compound can be used as long as it is a compound converted into a siloxy group by the silylating agent. That is, hydroxyethyl (meth) acrylate to which ε-caprolactone is added, polyoxyalkylene glycol (meth) acrylates converted into siloxy groups with a silylating agent such as trimethylchlorosilane and t-butyldimethylchlorosilane, respectively. Can also be used.

Typical examples of the alkoxysilyl group-containing vinyl monomer include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth).
Acryloyloxypropyldimethoxymethylsilane,
γ- (meth) acryloyloxypropyltriethoxysilane, styrylethyltrimethoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltriacetoxysilane and the like can be mentioned.

Typical examples of other vinyl monomers copolymerizable with the above-mentioned vinyl monomer having a reactive functional group are, for example, styrene, α-methylstyrene, vinyltoluene and α-chloro. Vinyl aromatic compounds such as styrene; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (n-, i-, t-)
Butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n
-Acrylic acid or methacrylic acid having 1 to 2 carbon atoms such as octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and cyclohexyl (meth) acrylate.
4 alkyl ester or cycloalkyl ester; acrylic acid or methacrylic acid having 2 to 1 carbon atoms such as methoxybutyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxybutyl (meth) acrylate
Alkoxyalkyl ester of 8; perfluoroalkyl (meth) acrylate such as perfluorobutylethyl (meth) acrylate, perfluoroisononylethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate; CF ₂ ═CF ₂ , CHF = CF
₂ , general formula CX such as CH ₂ = CF ₂ , CC ₁ F = CF _2
2 = CX ₂ (wherein X is the same or different and is H, C
I, Br, F, an alkyl group or a haloalkyl group is shown.
However, at least one F is contained in the formula. And a so-called macromonomer having a copolymerizable double bond at one end, which is a polymer of one or more of these monomers and has a reactive functional group. Examples of the monomer that can be copolymerized with the vinyl monomer having a group. These can be appropriately selected and used according to the desired physical properties.

Examples of the solvent used for solution polymerization of the above monomer mixture include alkylbenzene derivatives such as benzene, toluene and xylene; ethyl acetate, propyl acetate, amyl acetate, methoxybutyl acetate, methyl acetoacetate, ethyl acetoacetate, Acetate ester solvents such as methyl cellosolve acetate, cellosolve acetate, diethylene glycol monomethyl ether acetate and carbitol acetate;
Ether solvents such as dioxane, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol diethyl ether; acetone,
Examples of the solvent include ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, which may be used alone or in combination of two or more.

As the radical polymerization initiator, benzoyl peroxide, di-t-butyl hydroperoxide, t-butyl hydroperoxide, cumyl peroxide,
Peroxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, t-butylperoxybenzoate, lauryl peroxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate; α, α′-azo Examples thereof include azo compounds such as bisisobutyronitrile, α, α′-azobis-2-methylbutyronitrile, azobisdimethylvaleronitrile and azobiscyclohexanecarbonitrile.

The proportion of each of the above monomers used is 5 to 99% by weight of siloxy group-containing vinyl monomer, preferably 10 to 6
0% by weight, alkoxysilyl group-containing vinyl monomer 1 to
95% by weight, preferably 3-40% by weight, and other vinyl monomers 0-94% by weight, preferably 0-87% by weight
The range of is suitable.

The resin (a) obtained by an ordinary radical solution polymerization method using the above vinyl-based monomer, solvent and polymerization initiator has a weight average molecular weight of 1,000 to 200,000.
It is preferably 0, more preferably 2,000 to 100,000. When the weight average molecular weight is less than 1,000, it is difficult to obtain a satisfactory drying property, and the weather resistance and durability of the resulting coating film tend to decrease. On the other hand, 200,
If it is more than 000, the finished appearance is deteriorated, which is not preferable.

In the present invention, the compound (b) is a compound or resin containing at least two isocyanate groups in one molecule, and may be a resin further containing at least one siloxy group in some cases. Representative examples of the compound containing at least two isocyanate groups in one molecule used as the component (b) include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; hydrogenated xylyl Cycloaliphatic diisocyanates such as diisocyanate or isophorone diisocyanate; organic diisocyanates themselves such as aromatic diisocyanates such as tolylene diisocyanate and 4,4'-diphenylmethane diisocyanate, or these organic diisocyanates and polyhydric alcohols, low molecular weight Examples thereof include an adduct with polyester or water, a cyclized polymer of the above-mentioned organic diisocyanates, and an isocyanate / biuret body. As an example of those typical commercial products, "Bernock D-75
0, -800, DN-950, -970 or 15-
455 "[above, products of Dainippon Ink and Chemicals, Inc.]," Desmodur L, N, HL, IL, or N3390 "[Products of Bayer AG, West Germany]" Sumijour N-3200 or N-3500 "[Sumitomo Bayer Urethane Co., Ltd.], "Takenate D-102,
-202, -110N or 123N "[Takeda Pharmaceutical Co., Ltd. product]," Coronate L, HL, EH or 203 "[Japan Polyurethane Industry Co., Ltd. product] or" Duranate 24A-90CX "[Asahi Kasei Co., Ltd. product], etc. There is.

The resin used as the above component (b) is
Usually, an isocyanate group-containing vinyl-based monomer and another vinyl-based monomer copolymerizable therewith, and optionally a siloxy group-containing vinyl-based monomer are added in the same manner as the resin (a). It can be obtained by copolymerization by a conventional method such as a solution polymerization method in the presence of a radical polymerization initiator.

Typical examples of the above isocyanate group-containing vinyl monomer include, for example, isocyanate ethyl (meth) acrylate, isocyanate propyl (meth) acrylate, and meta-isopropenyl-α, α.
-Such as dimethylbenzyl isocyanate,
Not limited to this, an addition product of a hydroxyl group-containing vinyl monomer such as hydroxyethyl (meth) acrylate and a polyfunctional isocyanate compound such as isophorone diisocyanate can also be used.

Other vinyl-based monomers copolymerizable with the above-mentioned isocyanate group-containing vinyl-based monomers and siloxy group-containing vinyl-based monomers which are used as required include those of the above resin (a). The siloxy group-containing vinyl-based monomers and other vinyl-based monomers listed in the structural units can be used.

The proportion of each of the above-mentioned monomers used is from 5 to 99% by weight of the vinyl monomer containing an isocyanate group, preferably 1
0-60% by weight, and other vinyl monomers 1-95
% By weight, preferably 0-40% by weight, and further 0-94% by weight of siloxy group-containing vinyl monomer, preferably 0-8.
A range of 0% by weight is suitable.

The resin (b) has a weight average molecular weight of 1,0.
00 to 200,000, and further 2,000 to 100,0
It is preferably in the range of 00. When the weight average molecular weight is less than 1,000, it is difficult to obtain a satisfactory drying property,
Further, the weather resistance and durability of the obtained coating film tend to be lowered. On the other hand, if it is larger than 200,000, the finished appearance is deteriorated, which is not preferable.

In the present invention, the resin (d) is a resin containing at least one isocyanate group and at least one alkoxysilyl group in each molecule, while (e) contains at least two siloxy groups in one molecule. The compound may be a low molecular weight compound or a resin, and in the case of a resin, a resin further containing at least one isocyanate group may be used. In these resins, a vinyl-based monomer having each of these reactive functional groups and another vinyl-based monomer copolymerizable therewith are usually used as a radical polymerization initiator in the same manner as the resin (a). It can be obtained by copolymerization in the presence of a conventional method such as a solution polymerization method. Examples of the above-mentioned reactive functional group-containing vinyl monomers and other vinyl monomers copolymerizable with them include the reactive functional groups listed in the constitutional units of the resin (a) and the resin (b). It can be appropriately selected and used from the contained vinyl-based monomers and other vinyl-based monomers.

The proportion of each monomer used in the resin (d) is 5 to 99% by weight, preferably 10 to 60% by weight, of an isocyanate group-containing vinyl monomer, and 1 to 60% of an alkoxysilyl group-containing vinyl monomer. 95% by weight, preferably 3-4
A suitable range is 0% by weight and 0 to 94% by weight of other vinyl monomers, preferably 0 to 87% by weight.

On the other hand, the proportion of each monomer used in the resin (e) is 5 to 99% by weight of the siloxy group-containing vinyl monomer,
Preferably from 10 to 60% by weight and from 1 to 95% by weight of other vinyl-based monomer, preferably from 10 to 40% by weight, and further from 0 to 94% by weight of isocyanate group-containing vinyl-based monomer,
It is preferably within the range of 0 to 80% by weight.

The resin (d) and the resin (e) each preferably have a weight average molecular weight of 1,000 to 200,000, more preferably 2,000 to 100,000. When the weight average molecular weight is less than 1,000, it is difficult to obtain a satisfactory drying property, and the weather resistance of the resulting coating film,
Durability tends to decrease. On the other hand, if it is larger than 200,000, the finished appearance is deteriorated, which is not preferable.

The compound containing at least two siloxy groups in one molecule, which is used as the component (e), is a known silylating agent containing a hydroxyl group of a compound containing at least two hydroxyl groups in one molecule. Any compound can be used as long as it is a compound converted into a siloxy group. Typical of these compounds are, for example, dihydric alcohols such as ethylene glycol, propylene glycol, 1,2-butanediol, 1,3-butanediol, and 2,3-butanediol; Polylactone diols obtained by adding lactones such as ε-caprolactone to polyhydric alcohols; trivalent or higher alcohols such as glycerin, trimethylolpropane and pentaerythritol; lactones such as ε-caprolactone to these trivalent or higher alcohols Examples thereof include compounds obtained by converting polylactone polyols to which a group has been added into siloxy groups with a silylating agent such as trimethylchlorosilane and t-butyldimethylchlorosilane.

As the resin component of the present invention, only the resin (a) and the compound (b) or the resin (d) described above is used.
And the compound (e) is sufficient, but a compound containing two or more functional groups each selected from a siloxy group, an isocyanate group, and an alkoxysilyl group in one molecule, if necessary. At least one of f) is used as the components (a) and (b), or (d) and (e) above.
The components may be appropriately selected and added.

The compound used as the component (f) and containing at least two isocyanate groups in one molecule may be a low molecular weight compound, such as the isocyanate compounds listed in the description of the compound (b) and the isocyanate group-containing compounds. Resins obtained by copolymerizing vinyl monomers with other vinyl monomers such as styrene and (meth) acrylic acid esters can be used. As the compound used as the component (f) and containing at least two siloxy groups in one molecule, the compounds listed in the description of the compound (e) and the siloxy group containing listed in the description of the resin (a) are contained. Resins obtained by copolymerizing vinyl monomers with other vinyl monomers such as styrene and (meth) acrylic acid esters can be used. Furthermore, as the compound used as the component (f) and containing at least two alkoxysilyl groups in one molecule, the alkoxysilyl group-containing vinyl monomer listed in the description of the compound (a) is styrene, ( Resins obtained by copolymerization with other vinyl monomers such as (meth) acrylic acid esters can be used. The above resins (a), (b), (d), (e) and (f) are also non-aqueous dispersion type resins (N) containing these resins as dispersion stabilizers.
on aqueous dispersion; NA
It may be used in the form of D). The above resins (a) and (b)
Or the compounding ratio of the resins (d) and (e) (including the component (f) when used if necessary) is appropriately determined depending on the content of the reactive functional group contained in the resin composition. You can choose.

The content of the alkoxysilyl group in the composition of the present invention is the composition of the alkoxysilyl group-containing vinyl monomer used in the resin and the compound (f) as the alkoxysilyl group-containing compound. It is preferably in the range of 1 to 40% by weight, more preferably 3 to 30% by weight, based on the total solid content. If it is less than 1% by weight, the curability at low temperature tends to be insufficient and the acid resistance tends to be poor. on the other hand,
If it exceeds 40% by weight, the cured coating film tends to become brittle.

The siloxy group content in the composition of the present invention is the siloxy group-containing vinyl monomer used in the resin and the compound amount of the compound (f) as the siloxy group-containing compound. It is preferably in the range of 5 to 60% by weight, more preferably 10 to 50% by weight based on the solid content. 1
If it is less than 0% by weight, the cross-linking density of the coating film tends to be low and the physical properties of the coating film tend to deteriorate. On the other hand, even if it exceeds 50% by weight, further improvement in performance cannot be expected.

The siloxy group in the composition of the present invention is hydrolyzed by water in the air after coating to form a hydroxyl group. Therefore, the composition amount of the isocyanate group-containing vinyl monomer used in the resin composition and the compound (f) as the isocyanate group-containing compound is such that the hydroxyl groups generated from the isocyanate groups and the siloxy groups in the entire resin composition have an equivalent ratio. It is preferable that NCO / OH is in the range of 0.5 to 2.0.

The siloxy groups in the composition of the present invention are hydrolyzed by water in the air after coating to form hydroxyl groups. In the present invention, the siloxy group dissociation catalyst (c) is an essential component for promoting this hydrolysis reaction. Typical examples of the compound used as the siloxy group dissociation catalyst (c) are, for example, phosphoric acid and its acidic esters, phosphites; sulfonic acids such as paratoluenesulfonic acid and naphthalenedisulfonic acid, and amine salts thereof; Examples thereof include carboxylic acids such as trichloroacetic acid and trifluoroacetic acid, and acidic compounds such as amine salts thereof. When the composition of the present invention is stored for a long period of time, it is desirable to store the catalyst in a container separate from the resin component.

The siloxy group dissociation catalyst (c) is added in an amount of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the solid content of the resin composition. . If it is less than 0.01% by weight, the curability will decrease,
If it exceeds 10% by weight, the water resistance of the coating film tends to be poor.
The composition of the present invention comprises the resin component described above and a siloxy group dissociation catalyst, and a known conventional urethane-forming catalyst such as an organotin compound such as dibutyltin dilaurate in order to accelerate the reaction between the generated hydroxyl group and the isocyanate group. It may be added in advance.

In addition, a water-binding agent that traps water may be added to the composition of the present invention in order to prevent hydrolysis of siloxy groups and ensure long-term storage stability. Trialkyl orthoformates such as trimethyl orthoformate, triethyl orthoformate, and tributyl orthoformate; and trialkyl orthoacetates such as trimethyl orthoacetate, triethyl orthoacetate, and tributyl orthoacetate can be used as the water-binding agent.
Further, for improving the physical properties, a fibrin resin such as cellulose acetate butyrate or an epoxy resin may be blended and used. Further, if necessary, pigments (eg, aluminum paste, pearl powder, graphite, metallic pigments such as MIO, titanium oxide, organic and inorganic coloring pigments such as carbon black, extender pigments, etc.), organic solvent, ultraviolet absorber, It may contain additives for paints such as an antioxidant, a surface conditioner and a dispersant. The composition of the present invention thus obtained can be used as a one-pack type coating which can be coated by simply adjusting the coating viscosity with a diluting solvent.

As the method for coating the composition of the present invention, known methods in the field of coating coating such as spray coating, brush coating, roller coating and the like can be used. Usually, the dry film thickness is about 10 to 80 μm, preferably about 20 to 50 μm. To be done. The composition of the present invention is a multi-component composition comprising a resin / compound containing a siloxy group, an alkoxysilyl group, and an isocyanate group, and is a one-pack type having a low viscosity, storage stability, low temperature curability, and acid resistance. It is a coating resin composition that is excellent in use and is extremely useful particularly in the field of automobile repair paints.

[0039]

The present invention will be described below in detail with reference to examples. Manufacturing of reactive functional group-containing resin

Production Example 1 A reactor was equipped with a thermometer, a thermostat, a stirrer, a reflux condenser, and a dropping pump. After 60 parts by weight of xylene was charged and heated to 110 ° C. with stirring, the monomers shown in Table 1 were used. Further, 103 parts by weight of the mixture of the polymerization initiator was added dropwise at a constant rate over 3 hours by using a dropping pump while maintaining the temperature at 110 ° C. After completion of dropping, the temperature was maintained at 110 ° C. for 1 hour, and stirring was continued. Then, a solution prepared by dissolving 0.5 parts by weight of an additional polymerization initiator in 5 parts by weight of xylene was added dropwise at a constant rate over 1 hour, and the reaction was terminated at 110 ° C. for 1 hour. The obtained siloxy group- and alkoxysilyl group-containing resin solution was a uniform and transparent solution having a nonvolatile content of 60% by weight and a Gardner viscosity MN. The weight average molecular weight of this resin was 15,000.

Production Examples 2 to 9 The same procedure as in Production Example 1 was carried out except that the mixture of the monomer and the polymerization initiator and the additional polymerization initiator in the Production Example 1 were mixed as shown in Table 1. A group-containing resin solution was obtained.
The properties of the obtained resin and resin solution are shown in Table 2.

[0042]

[Table 1]

(Note) Polymerization initiator: α, α'-azobis-
2-Methylbutyronitrile Additional polymerization initiator: α, α′-azobis-2-methylbutyronitrile

[0044]

[Table 2]

Examples and Comparative Examples Reactive functional group-containing resin solutions and catalysts obtained in Production Examples,
Furthermore, the polyisocyanate compound (Note 1) was mixed and stirred in the composition shown in Table 3 to prepare a clear coating.

[0046]

[Table 3]

(Note) Dissociation catalyst: Phosphoric acid diisopropyl ester Urethane catalyst: Dibutyltin laurate (Note 1) N-3500 ... Sumitomo Bayer Urethane Co., Ltd., nonvolatile content 100%, NCO content 21.6%,
Hexamethylene diisocyanate isocyanurate type. Next, apply these clear paints to toluene / xylene /
13-14 seconds (Ford Cup # 4 in a thinner having a composition of ethyl acetate / butyl acetate = 50/20/10/20)
/ 25 ° C), and was obtained after spray-painting on a tin plate at room temperature (20 ° C) or on a tin plate obtained by applying a clear coating for a new car on the tin plate and baking and drying it. Table 4 shows the performance test results of the test coated plates.

[0048]

[Table 4]

The test method is as follows. (1) Low temperature curability After coating on a tin plate, keep it horizontal for 20 minutes and then apply temperature 5
The gel fraction of the coating film, which was allowed to stand for 1, 2, and 7 days in a constant temperature and humidity of 60 ° C. and 60% RH, was measured. Method for measuring gel fraction: The coating film was peeled off from the test plate, 5.0 g was put in a Soxhlet extractor, and acetone was refluxed for 6 hours. The weight retention of the coating film after extraction with respect to that before extraction was defined as the gel fraction. (2) Hardness of coating film The Two-Con hardness of the coating film prepared in the same manner as in (1) is Am
erican chain & cable comp
It was measured under a condition of 20 ° C. using a Twocon hardness meter manufactured by any. The higher the value, the harder it is. (3) Acid-resistant clear paint for new cars is applied and baked. After the clear paint of each example is applied on a dried coated plate, it is baked at 60 ° C for 20 minutes, and further 2
40% sulfuric acid was spotted on a coated plate dried at 0 ° C for 7 days, and the state of the coated surface after heating at 85 ° C for 30 minutes was evaluated. ◯: Almost no change on the coated surface Δ: Etching occurred ×: Significant etching occurred (4) Accelerated weather resistance A coated plate prepared in the same manner as in (3) was measured with a sunshine weatherometer to 1000. It was confirmed whether or not the coated surface was changed after the time test. ◯: Almost no change on the coated surface ×: Water marks were observed on the coated surface, resulting in a large reduction in gloss (5) Gasoline resistance A coated plate prepared in the same manner as in (3) was horizontally fixed and folded in four. About 5 cc of regular type gasoline was soaked in (50 × 50 mm) and left on the coated plate for 3 minutes. After that, the gauze was removed, and the state of the coated surface after the gasoline was wiped off with another gauze was evaluated. ◯: Almost no change on the coating surface ×: Deterioration of gloss and softening on the coating surface (6) Storage stability Each sample of which viscosity was adjusted was prepared, and this was sealed and stored at room temperature (20 ° C) for 7 days. The change in viscosity was evaluated. ◯: Almost no change in viscosity Δ: Somewhat thickened ×: Significantly thickened or gelled

[0050]

INDUSTRIAL APPLICABILITY According to the present invention, a resin containing a siloxy group and an alkoxysilyl group or a resin containing an isocyanate group and an alkoxysil group is used to prepare a multi-component resin composition, which is used in combination with a conventional acrylic polyol. A one-pack type low viscosity not obtained with a two-pack type resin composition comprising a combination with a functional isocyanate curing agent or a one-pack type resin composition comprising a siloxy group-containing vinyl polymer and a polyfunctional isocyanate curing agent, It is possible to obtain a coating resin composition which is excellent not only in storage stability and acid resistance but also particularly in low temperature curability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hajime Yushima 4-17-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Kansai Paint Co., Ltd.

Claims (21)

[Claims] 1. (a) A resin containing at least one siloxy group and at least one alkoxysilyl group in one molecule,
A coating resin composition comprising (b) a compound containing at least two isocyanate groups in one molecule and (c) a siloxy group dissociation catalyst as essential components. 2. The resin (a) comprises a vinyl monomer having a siloxy group, a vinyl monomer having an alkoxysilyl group, and a vinyl monomer copolymerizable with these monomers. The coating resin composition according to claim 1, which is a resin obtained by copolymerization. 3. The resin (a) comprises 5 to 99% by weight of a vinyl monomer containing a siloxy group, 1 to 95% by weight of a vinyl monomer containing an alkoxysilyl group, and 0 to another vinyl monomer.
3. A resin in which 94% by weight is copolymerized.
The resin composition for coating described in 1. 4. The resin (a) has a weight average molecular weight of 1,00.
The resin composition for coating according to any one of claims 1 to 3, which is a resin of 0 to 200,000. 5. The compound (b) is a resin further containing at least one siloxy group in one molecule.
The coating resin composition according to any one of items 1 to 4. 6. The compound (b) is a resin obtained by copolymerizing an isocyanate group-containing vinyl-based monomer with another vinyl-based monomer copolymerizable with this monomer. The coating resin composition according to any one of 5 above. 7. The compound (b) comprises an isocyanate group-containing vinyl monomer and a siloxy group-containing vinyl monomer.
The coating resin composition according to any one of claims 1 to 6, which is a resin obtained by copolymerizing these monomers with another vinyl-based monomer that is copolymerizable. 8. The compound (b) comprises 5 to 99% by weight of an isocyanate group-containing vinyl monomer, 1 to 95% by weight of another vinyl monomer, and 0 to a siloxy group-containing vinyl monomer.
The coating resin composition according to any one of claims 1 to 7, which is 94% by weight. 9. The compound (b) has a weight average molecular weight of 1,0.
It is a resin of 100 to 200,000, 1 to 8.
The resin composition for coating described in any one of 1. 10. (d) A resin containing at least one isocyanate group and one alkoxysilyl group in one molecule, (e) a compound containing at least two siloxy groups in one molecule, and (c) a siloxy group dissociation. A resin composition for coating, which comprises a catalyst as an essential component. 11. The resin (d) comprises an isocyanate group-containing vinyl monomer, an alkoxysilyl group-containing vinyl monomer, and other vinyl monomers copolymerizable with these monomers. Weight average molecular weight of 1,000 to 20
The coating resin composition according to claim 10, which is 50,000 resins. 12. The resin (d) comprises 5 to 99% by weight of an isocyanate group-containing vinyl monomer, 1 to 95% by weight of an alkoxysilyl group-containing vinyl monomer, and other vinyl monomers 0 to 94. A resin obtained by copolymerizing 1% by weight thereof.
The resin composition for coating described in 0 or 11. 13. The compound (e) is a resin which further contains at least one isocyanate group in one molecule,
The resin composition for coating according to any one of claims 10 to 12. 14. The compound (e) is a resin having a weight average molecular weight of 1,000 to 200,000, which is obtained by copolymerizing a vinyl monomer containing a siloxy group and another vinyl monomer. The coating resin composition according to any one of claims 10 to 13. 15. The compound (e) is a resin obtained by copolymerizing a vinyl monomer containing a siloxy group, a vinyl monomer containing an isocyanate group, and another vinyl monomer. Item 15. The coating resin composition according to any one of items 10 to 14. 16. The compound (e) comprises 5 to 99% by weight of a siloxy group-containing vinyl monomer, and another vinyl monomer 1
~ 95% by weight, isocyanate group-containing vinyl monomer 0
The coating resin composition according to any one of claims 10 to 15, which is a resin in which ˜94 wt% is copolymerized. 17. A resin component further comprising at least one compound (f) containing two or more functional groups of one type selected from a siloxy group, an isocyanate group and an alkoxysilyl group in one molecule. The coating resin composition according to any one of claims 1 to 19. 18. The content of the alkoxysilyl group in the resin composition is the composition as a vinyl monomer and a compound containing the alkoxysilyl group used, and the content of the siloxy group is used. The composition amount as a vinyl monomer containing a siloxy group and a compound is 1 to 40% by weight and 5 to 60% by weight based on the solid content in the resin composition, respectively.
The resin composition for coating according to any one of claims 1 to 17. 19. The isocyanate group and the hydroxyl group in the resin composition have an equivalent ratio of NCO / OH = 0.5 to 2.0.
The resin composition for coating according to any one of claims 1 to 18. 20. The coating resin composition according to any one of claims 10 to 19, wherein the siloxy group dissociation catalyst is 0.01 to 10% by weight based on the solid content of the resin composition. 21. A water-binding agent for trapping water is added,
The coating resin composition according to any one of claims 1 to 20.