JP3184846B2 - Colored paint composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel colored coating composition.

[0002]

2. Description of the Related Art Conventionally, from room temperature to 100 ° C.
As a composition which can be cross-linked and cured at a relatively low temperature, a composition in which a curing catalyst such as a tin compound is blended with an acrylic resin containing an alkoxysilane group is known (JP-A-58-13).
No. 6606).

[0003] However, the above-mentioned conventional composition has a disadvantage that, although excellent in low-temperature curability, chemical resistance, water resistance, etc., the mechanical properties of the coating film and the storage stability of the coating material are not always sufficient. . That is, when high mechanical properties such as impact resistance, bending resistance, etc. are required, the amount of the curing catalyst,
There is a limit only by controlling the kind, the content of the alkoxysilane group, the molecular weight of the acrylic resin, and the like. Therefore, there are drawbacks in that the application is limited and the storage stability of the paint and the weather resistance are not sufficient. Further, the above composition has a drawback that, when coating on a vertical surface, the coating tends to droop (generally called sagging) where the film thickness is large. This lack of suitability for thick film coating has been a major obstacle in practical use, such as the necessity of recoating to obtain a predetermined film thickness and the poor finish of the coated surface. In addition, to obtain suitability for thick film coating, polyamide resin, organic bentonite,
When the anti-sagging agent such as polyethylene oxide is blended, there is a problem that the gloss of the obtained coating film is remarkably reduced.

Further, a polymer containing a vinyl compound having an alkoxysilane group as a monomer component is used as a dispersion stabilizer resin, and a radical polymerizable unsaturated monomer is polymerized in an organic liquid in the presence of the resin. A curable composition in which a curing catalyst is added to a non-aqueous dispersion of polymer particles obtained is known (see JP-A-1-95116).

[0005] Although this composition improves the mechanical properties of the coating film, which is the above-mentioned problem, when a coloring pigment is blended to obtain a colored coating, the above-mentioned non-aqueous dispersion can disperse the pigment well. There was a problem that it was not possible.
There was also a problem that a high gloss coating film could not be obtained.

Accordingly, the present inventors have been able to form a coating film having low-temperature curability, good storage stability, and excellent coating surface conditions, chemical resistance, water resistance, weather resistance and mechanical properties. As a result of intensive studies, a colored coating composition capable of achieving both a large sagging limit film thickness and the formation of a high gloss colored coating film has been achieved as a result of the present invention.

That is, the present invention relates to (a) general formula [1]

[0008]

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[In the formula, A represents —COO— or a phenylene group. R ₁ is a hydrogen atom or a methyl group; R ₂ is a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms; R ₃ and R ₄
Are the same or different and each represents a phenyl group, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, and R ₅ represents an alkyl group having 1 to 10 carbon atoms. n is 1 to 10
Indicates an integer of 0. An acrylic polymer having an alkoxysilane group-containing vinyl compound represented by the following as an essential monomer component:

(B) An acrylic polymer containing an alkoxysilane group-containing vinyl compound represented by the general formula [1] as an essential monomer component is used as a dispersion stabilizer resin, and is radically polymerizable in an organic liquid in the presence of the resin. A non-aqueous dispersion of polymer particles insoluble in the organic liquid obtained by polymerizing an unsaturated monomer, (c) monoalkyl phosphoric acid, monoalkyl phosphorous acid, dial
Selected from killed phosphorous acid, tin-containing compounds and basic compounds
A curable composition containing a curing catalyst which is a single compound or a mixture of two or more compounds, and (d) a color pigment, wherein the mixing ratio of the acrylic polymer (a) and the non-aqueous dispersion (b) is the former / the latter Wherein the solid content weight ratio is 30/70 to 70/30.

In the present invention, the acrylic polymer as the component (a) contains a specific alkoxysilane group-containing vinyl compound represented by the above general formula [1] as an essential monomer component. In the above general formula [1], as the divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms represented by R ₂ , a linear or branched alkylene group such as methylene, ethylene, propylene, 1,2- Butylene, 1,3
-Butylene, 2,3-butylene, tetramethylene, ethylethylene, pentamethylene, hexamethylene and the like. 1 to ₃ carbon atoms represented by R ₃ and R ₄
As the alkyl group of 6, a linear or branched alkyl group such as methyl, ethyl, n-propyl, isopropyl,
n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-
Hexyl, you can isohexyl group, R ₅
As the alkyl group having 1 to 10 carbon atoms represented by, in addition to the above alkyl group, n-heptyl, 1-methylpentyl, 2-methylhexyl, n-octyl, n-nonyl,
n-decyl and the like.

As the alkoxy group having 1 to 10 carbon atoms represented by R ₃ and R ₄ , a linear or branched alkoxy group, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec. -Butoxy, tert-butoxy, n-pentoxy, isopentoxy, n-hexyloxy, isohexyloxy, n-octyloxy and the like. In the general formula [1], n is an integer of 1 to 100, but n is 2
At this time, R ₃ and R ₄ may be the same or different.

In the present invention, examples of the compound represented by the general formula [1] wherein A is —COO— include, for example, γ- (meth) acryloyloxyethyltrimethoxysilane, γ- (meth) acryloyloxypropyl Trimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropyltripropoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ
-(Meth) acryloyloxypropylmethyldiethoxysilane, γ- (meth) acryloyloxypropylmethyldipropoxysilane, γ- (meth) acryloyloxybutylphenyldimethoxysilane, γ- (meth) acryloyloxybutylphenyldiethoxysilane, γ
-(Meth) acryloyloxybutylphenyldipropoxysilane, γ- (meth) acryloyloxypropyldimethylmethoxysilane, γ- (meth) acryloyloxypropyldimethylethoxysilane, γ- (meth) acryloyloxypropylphenylmethylmethoxysilane, γ -(Meth) acryloyloxypropylphenylmethylethoxysilane,

[0014]

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And the like.

The compound represented by the general formula [1] in which A is a phenylene group includes, for example,

[0017]

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And the like.

Among the compounds represented by the general formula [1], in particular, γ-acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltri-n-butoxysilane, γ-acryloyl Oxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyl n-butoxysilane and the like are preferred.

In the present invention, the acrylic polymer as the component (a) comprises, as an essential monomer component, at least one of the vinyl compounds having an alkoxysilane group represented by the general formula [1]. It is a polymer obtained by copolymerizing a reactive monomer. The use ratio of the essential monomer can be selected from a wide range, but is usually 1% by weight or more, preferably about 5 to 30% by weight based on the monomer used.

The other polymerizable monomer used as needed in the polymer can be appropriately selected according to the performance required for the coating film. Other monomers that can be preferably used include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tertbutyl (meth) acrylate ,
Alkyl or cyclo (meth) acrylic acid such as 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, etc. Alkyl esters; alkoxyalkyl esters of (meth) acrylic acid such as methoxybutyl (meth) acrylate, methoxyethyl (meth) acrylate, and ethoxybutyl (meth) acrylate; aromatic alcohols such as benzyl (meth) acrylate and (meth) acryl Esters with acids; adducts of hydroxyalkyl esters of glycidyl (meth) acrylate or (meth) acrylic acid with monocarboxylic compounds such as capric acid, lauric acid, linoleic acid, oleic acid, (T) an adduct of acrylic acid with a monoepoxy compound such as "Cajura E10" (manufactured by Shell Chemical); vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene, and p-tert-butylstyrene. Group compounds; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) acrylic acid, crotonic acid, maleic acid, Α, β-ethylenically unsaturated carboxylic acids such as maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, citraconic acid; glycidyl group-containing compounds such as glycidyl (meth) acrylate, vinyl glycidyl ether, allyl glycidyl ether; (Meth) acrylamide, N, N-dimethyl Le (meth) acrylamide, N- alkoxymethyl (meth)
Carboxamide compounds such as acrylamide, diacetone acrylamide, N-methylol (meth) acrylamide; p-styrenesulfonamide, N-methyl-p
-Sulfonamide group-containing compounds such as styrene sulfonamide and N, N-dimethyl-p-styrene sulfonamide; "Biscoat 8F", "Biscoat 8FM", "Biscoat 3F", "Biscoat 3FM" (all of Osaka Organic Chemicals) Co., Ltd., having a fluorine atom in the side chain (meta)
Acrylates), perfluorocyclohexyl (meth) acrylate, and fluorine-containing compounds such as perfluorocyclohexylethylene.

The acrylic polymer as the component (a) preferably contains at least 30% by weight of a total of acrylic acid or methacrylic acid esters among monomer components from the viewpoint of weather resistance and the like. , 50% by weight or more.

The polymerization for producing the acrylic polymer as the component (a) is usually carried out using a radical polymerization initiator. Examples of usable radical initiators include, for example, 2,
Azo-based initiators such as 2'-azobisisobutyronitrile and 2,2'-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide, tert-butyl peroxyoctoate, tert- Peroxide initiators such as butyl peroxy-2-ethylhexanoate are exemplified, and these initiators are generally used in an amount of about 0.2 to 10 parts by weight per 100 parts by weight of a monomer used for polymerization, preferably It can be used in the range of 0.5 to 5 parts by weight. It is appropriate to use a reaction temperature in the polymerization generally in the range of about 60 to 160 ° C, and the reaction is usually completed in about 1 to 15 hours.

The molecular weight of the acrylic polymer as the component (a) is usually about 5,000 to 100,0 by weight average molecular weight.
About 00 (about 1,000 to 60,000 in number average molecular weight)
Degree), preferably about 5,000 to 5 in weight average molecular weight.
It is in the range of about 0000. When the weight average molecular weight is less than about 5,000, water resistance and weather resistance are insufficient, and when the weight molecular weight exceeds about 100,000, the viscosity becomes extremely high and handling may be difficult. Not preferred.

In the present invention, the non-aqueous dispersion of the polymer particles as the component (b) is obtained by polymerizing a radically polymerizable unsaturated monomer in an organic liquid in the presence of a dispersion stabilizer resin. It is a non-aqueous dispersion of polymer particles insoluble in liquid.

The dispersion stabilizer resin used for the production of the component (b) is an acrylic polymer containing an alkoxysilane group-containing vinyl compound represented by the general formula [1] as an essential monomer component. The acrylic polymer as a component can be used alone, or two or more copolymers having different copolymer compositions and molecular weights can be used in combination. Further, if necessary, other dispersion stabilizer resins, For example, it can be used in combination with a small amount of a butyl etherified melamine-formaldehyde resin or an alkyd resin.

As the organic liquid used in the production of the component (b), the dispersed polymer particles formed by the polymerization are not substantially dissolved, but the dispersion stabilizer resin and the radical polymerizable unsaturated monomer are used. Organic liquids that are good solvents for the body are included. Specific examples of such organic liquids include aliphatic hydrocarbons such as hexane, heptane and octane; aromatic hydrocarbons such as benzene, toluene and xylene; methyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, octyl alcohol and the like. Alcohols, ethers such as cellosolve, butyl cellosolve, and diethylene glycol monobutyl ether; ketones such as methyl isobutyl ketone, diisobutyl ketone, methyl ethyl ketone, methylhexyl ketone, and ethyl butyl ketone; ethyl acetate, isobutyl acetate, amyl acetate, and 2-ethylhexyl acetate And the like. These organic liquids can be used alone or in combination of two or more. However, generally, the organic liquid is mainly composed of an aliphatic hydrocarbon, and an aromatic hydrocarbon, an alcohol, an ether, or the like. , Ketones or esters are preferably used.

In the production of the component (b), the radically polymerizable unsaturated monomer which is subjected to polymerization to form polymer particles has excellent polymerizability, and a polymer formed from the monomer is used. Higher solubility parameter than dispersion stabilizer resin (SP
Value) and generally the SP of the polymer
The value is preferably in the range of about 8.0 to 9.5. In the present invention, the “solubility parameter (SP value)” can be theoretically calculated by the following equation. SP value: δ δ × 100 = (δ a × A) + (δ b × B) + (δ c ×
C) + {(where, δ: solubility parameter of the copolymer, δ _a , δ _b , δ _c }: monomers a, b, c}
溶解, solubility parameter of A, B, C ‥‥‥: weight% of copolymer of monomers a, b, c ‥‥‥)

As the above-mentioned radical polymerizable unsaturated monomer, those listed as other polymerizable monomers used as needed in the production of the component (a) can be used, and the above-mentioned general formula [1] ] Can also be used. These radically polymerizable unsaturated monomers can be used alone or in combination of two or more. As the radically polymerizable unsaturated monomer forming the polymer particles, an alkyl ester of acrylic acid or methacrylic acid having 8 or less, preferably 4 or less, styrene, (meth) acrylonitrile and the like are particularly preferable.

It is also possible to copolymerize a vinyl monomer having two or more polymerizable unsaturated groups such as ethylene glycol diacrylate and divirbenzene, or to react with and bond to each other in addition to the polymerizable unsaturated groups. At least two types of polymerizable unsaturated monomers each having a complementary functional group are copolymerized as a part of the monomer component, and the complementary functional groups are allowed to react with each other. Can be crosslinked. By crosslinking the inside of the polymer particles, the stability of the non-aqueous dispersion of the polymer particles can be generally improved. Examples of the combination of the complementary functional groups include (1) an epoxy group / carboxyl group, (2) a hydroxyl group / isocyanate group, and (3)
Examples include combinations of epoxy group / amino group, (4) isocyanate group / amino group, (5) alkoxysilyl group / hydroxyl group, and (6) epoxy group / phosphate group. Taking as an example a combination of monomers that is a combination of complementary functional groups in the case of the above (1), an epoxy group-containing monomer such as glycidyl acrylate and glycidyl methacrylate and a carboxyl group such as acrylic acid and methacrylic acid A combination with the contained monomer is exemplified.

The radically polymerizable unsaturated monomer is usually polymerized using a radical polymerization initiator. Examples of usable radical polymerization initiators include, for example, 2,2′-
Azo initiators such as azobisisobutyronitrile and 2,2'-azobis (2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, tert-butyl peroctoate, tert-butyl peroxy- Examples thereof include peroxide initiators such as 2-ethylhexanoate. These polymerization initiators are generally used in an amount of about 0.2 to 10 parts by weight, preferably about 0.1 to 10 parts by weight, per 100 parts by weight of monomers used for polymerization. It can be used within the range of 5 to 5 parts by weight.

The proportion of the dispersion stabilizer resin to be used in the above polymerization can be selected from a wide range according to the kind of the resin and the like. The amount of the saturated monomer is suitably about 5 to 240 parts by weight, preferably 40 to 150 parts by weight. Further, the total concentration of the dispersion stabilizer resin and the radical polymerizable unsaturated monomer in the organic liquid is generally 30 to 7
It is suitable that the content is about 0% by weight, preferably 30 to 60% by weight. The polymerization can be carried out by a method known per se, and the reaction temperature at the time of the polymerization is usually suitably in the range of about 60 to 160 ° C, and the reaction is usually completed in about 1 to 15 hours.

Thus, a stable non-aqueous dispersion is obtained in which the liquid phase is a liquid in which the dispersion stabilizer resin is dissolved in the organic liquid, and the solid phase is polymer particles obtained by polymerization of a radical polymerizable unsaturated monomer. The particle size of the polymer particles is usually about 0.1 to 1.0.
μm range. When the particle size is smaller than this range, the viscosity of the varnish increases, while when the particle size is larger than this range, the particles swell or aggregate during storage, which is not preferable.

In the present invention, the storage stability and mechanical properties can be further improved by combining the dispersion stabilizer resin and the polymer particles in the non-aqueous dispersion. Even when the particles are bonded, there is almost no change in the dispersion state in appearance, and the particle size of the polymer particles is also within the above range.
As a method of bonding the dispersion stabilizer resin and the polymer particles, for example, in the stage of manufacturing the dispersion stabilizer resin in advance, hydroxyl group, acid group, acid anhydride group, epoxy group, methylol group, isocyanate group, amide group, amino A monomer component having a functional group such as a group is partially copolymerized, and further a hydroxyl group, an acid group, an acid anhydride group, an epoxy group, which reacts with the above functional group as a monomer component forming a polymer particle, It can be carried out by using a monomer having a functional group such as a methylol group, an isocyanate group, an amide group, or an amino group. Examples of these combinations include an isocyanate group and a hydroxyl group, an isocyanate group and a methylol group, an epoxy group and an acid (anhydrous) group, an epoxy group and an amino group, an isocyanate group and an amide group, and an acid (anhydrous) group and a hydroxyl group. .

Examples of the monomer having such a functional group include (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride,
Α, β-ethylenically unsaturated carboxylic acids such as fumaric acid and citraconic acid; glycidyl group-containing compounds such as glycidyl (meth) acrylate, vinyl glycidyl ether, allyl glycidyl ether; (meth) acrylamide;
Carboxamide compounds such as N-dimethyl (meth) acrylamide, N-alkoxymethylated (meth) acrylamide, diacetone acrylamide, N-methylol (meth) acrylamide; p-styrenesulfonamide, N-methyl-p-styrene Sulfonamide, N, N
-Sulfonamide-containing compounds such as -dimethyl-p-styrenesulfonamide; amino-containing compounds such as tert-butylaminoethyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate and phosphoric acid or phosphoric acid ester Group-containing compounds, such as glycidyl (meth) acrylate, and other compounds having a glycidyl group, and phosphoric acid-containing compounds such as phosphoric acid esters added to the glycidyl group; 2-acrylamido-2-methyl- Sulfonic acid group-containing compounds such as propanesulfonic acid; equimolar adducts of isophorone diisocyanate or tolylene diisocyanate with hydroxy (meth) acrylate; isocyanate groups such as m-isopropenyl-α, α-dimethylbenzyl isocyanate and isocyanoethyl methacrylate Include compounds Rukoto can.

Another method for bonding the dispersion stabilizer resin and the polymer particles is to polymerize a radical polymerizable unsaturated monomer in the presence of a dispersion stabilizer resin having a polymerizable double bond. Can do it. The polymerizable double bond is introduced into the dispersion stabilizer resin by, for example, using an acid group-containing monomer such as carboxylic acid, phosphoric acid, or sulfonic acid as a copolymerization component of the resin, and adding glycidyl (meth) ) The reaction can be carried out by reacting a glycidyl group-containing unsaturated monomer such as acrylate or allyl glycidyl ether. However, it is needless to say that a glycidyl group is contained in the resin and an acid group-containing unsaturated monomer is added thereto. It can also be done by reacting the body. These reactions can be performed under conventionally known conditions.

Further, as another method for bonding the dispersion stabilizer resin and the polymer particles, a non-aqueous dispersion in which functional groups which do not react with each other are introduced into the dispersion stabilizer resin and the polymer particles is prepared. It can also be carried out by blending a binding agent that binds the two with this.

Specifically, for example, a hydroxyl group-containing unsaturated monomer alone or in the form of a mixture with another unsaturated monomer is polymerized in the presence of a hydroxyl group-containing dispersion stabilizer resin and an organic liquid, and both of them are polymerized. After the production of a non-aqueous dispersion containing
At about -100 ° C, the reaction can be carried out for about 1-5 hours.

As the above polyisocyanate compound,
Any compound having two or more isocyanate groups in the molecule can be used. For example, aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, and 4,4'-diphenylmethane diisocyanate or hydrides thereof; hexamethylene diisocyanate , Lysine diisocyanate, aliphatic diisocyanate such as dimer acid (dimer of tall oil fatty acid) diisocyanate; and alicyclic diisocyanate such as isophorone diisocyanate.

In addition to the above combination, the combination of a dispersion stabilizer resin containing acid groups and polymer particles with a polyepoxide, the dispersion stabilizer resin containing epoxy groups and polymer particles and a polycarboxylic acid , A dispersion stabilizer resin containing an epoxy group or an isocyanate group and a combination of polymer particles and a polysulfide compound.

Examples of the polyepoxide used in the above combination include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, epoxy group-containing acrylic resin and the like; polycarboxylic acids such as adipic acid and sebacic acid , Azelaic acid, isophthalic acid, etc .; Examples of polysulfides include pentamethylene disulfide, hexamethylene disulfide, poly (ethylene disulfide) and the like.

As described above, the dispersion stabilizer resin and the polymer particles can be chemically bonded. At this time, various functional groups and polymerizable double bonds are added to the dispersion stabilizer resin and / or the polymerizable double bond. The amount introduced into the conductive particles is preferably in the range of 0.2 to 5 on average in one molecule of the resin and / or the particles. The non-aqueous dispersion thus obtained has excellent storage stability because the dispersion stabilizer resin and the polymer particles are chemically bonded, and the formed coating film is chemically and mechanically. Shows excellent properties.

The curing catalyst which is the component (c) in the composition of the present invention is generally used as a curing catalyst for an alkoxysilyl group, and comprises the components (a) and (b).
An alkoxysilyl group derived from the compound of the general formula [1] in the component is hydrolyzed in the presence of moisture to produce a silanol group, and then the silanol group is dehydrated and condensed to promote a reaction of bonding and crosslinking. And imparts excellent low-temperature curability to the composition.

Specific examples of the curing catalyst of the component (c) include:
For example, p-toluenesulfonic acid, trichloroacetic acid, phosphoric acid, mono-n-propyl phosphoric acid, monoisopropyl phosphoric acid,
Mono-n-butyl phosphoric acid, monoisobutyl phosphoric acid, mono tert
Monoalkyl phosphoric acid such as butyl phosphoric acid, monooctyl phosphoric acid, monodecyl phosphoric acid, di-n-propyl phosphoric acid, diisopropyl phosphoric acid, di-n-butyl phosphoric acid, diisobutyl phosphoric acid, di te
Dialkyl phosphoric acid such as rt butyl phosphoric acid, dioctyl phosphoric acid, and didecyl phosphoric acid, phosphoric acid ester of β-hydroxyethyl (meth) acrylate, mono-n-propyl phosphite, monoisopropyl phosphite, mono-n-butyl phosphite, monoisobutyl phosphite Monoalkyl phosphites such as mono-tert-butyl phosphite, monooctyl phosphite, monodecyl phosphite, di-n
Dialkyl phosphites such as propyl phosphite, diisopropyl phosphite, di-n-butyl phosphite, diisobutyl phosphite, ditertbutyl phosphite, dioctyl phosphite, didecyl phosphite, etc .; tin octylate, dibutyltin diacetate, dibutyl Tin-containing compounds such as tin dioctoate, dibutyltin dilaurate and dibutyltin maleate; butylamine, tert
-Butylamine, dibutylamine, hexylamine, ethylenediamine, triethylamine, isophoronediamine, imidazole, lithium hydroxide, potassium hydroxide,
Basic compounds such as sodium methylate can be mentioned. These can be used alone or as a mixture of two or more. The composition of the present invention is generally provided as a two-pack type, and the base and the curing catalyst are mixed and used immediately before use.

As the color pigment which is the component (d) in the composition of the present invention, organic and inorganic color pigments usually used in the field of paints are used. Specifically, inorganic color pigments such as titanium white, red iron, titanium yellow, molybdenum red, carbon black, graphite, and various calcined pigments; quinacridone red, azo red, phthalocyanine green, phthalocyanine blue, azo yellow, anthra yellow Organic coloring pigments such as pyrimidine yellow, isoindolinone yellow, flavans yellow, perylene maroon, and thioindigo bordeaux.

In the composition of the present invention, the mixing ratio of the acrylic polymer as the component (a) and the non-aqueous dispersion of the polymer particles as the component (b) is expressed by the weight ratio of (a) /
It is necessary that (b) is in the range of 30/70 to 70/30, preferably in the range of 40/60 to 60/40. When the ratio of (a) / (b) is smaller than 30/70 [when (a) is small], there is a problem that the gloss of the obtained coating film is low. On the other hand, when the ratio of (a) / (b) is larger than 70/30, the sagging limit film thickness becomes small and the applicability of thick film coating is lost, and mechanical properties such as impact resistance and flexibility of the coating film are deteriorated. And the ratio of (a) / (b) is greater than 70/30, and (b)
When the ingredients are blended, the reason is not clear,
The problem that the gloss of the coating film is reduced is likely to occur.

The mixing ratio of the curing catalyst as the component (c) in the composition of the present invention is not particularly limited,
Generally, 0.01 to 0.01 parts by weight of the total solid content of the acrylic polymer (a) and the non-aqueous dispersion of the polymer particles (b) is 100 parts by weight.
It is preferably about 10 to 10 parts by weight.

The mixing ratio of the color pigment as the component (d) in the composition of the present invention can be appropriately changed depending on the type of the color pigment, the coating film thickness and the like, and is not particularly limited. It is used in the range of 1 to 150 parts by weight based on 100 parts by weight of the total solid content of (a) and the non-aqueous dispersion of polymer particles (b).

The colored coating composition of the present invention is prepared, for example, by blending an organic solvent as required, dispersing a colored pigment (d) in an acrylic polymer (a) to obtain a pigment paste, It can be easily obtained by mixing the components (b), (c), (d) and, if necessary, the component (a).

In addition to the above components (a), (b), (c) and (d), the colored coating composition of the present invention may further comprise, if necessary, an organic solvent, an extender, a dye, a dehydrating agent and a plasticizer. Etc. can be added. Examples of the plasticizer include known plasticizers, for example, low molecular weight plasticizers such as dimethyl phthalate and dioctyl phthalate, and high molecular weight plasticizers such as a vinyl polymer plasticizer and a polyester plasticizer. It may be dissolved in a radical polymerizable unsaturated monomer at the time of production of the aqueous dispersion and distributed in the dispersed polymer particles of the resulting dispersion, or may be mixed at the time of coating. If necessary, an amino resin, an epoxy resin, a polyisocyanate, or the like generally used as a curing agent may be used in combination. Further, other acrylic resins, alkyd resins, polyester resins, epoxy resins and the like can be blended and used.

The colored coating composition of the present invention can be easily crosslinked and cured by drying at room temperature or heating at a low temperature of 100 ° C. or lower in the presence of moisture. In ordinary temperature drying, the composition is applied after adding water, or the composition is simply exposed to the air after application, and can be sufficiently cured usually in about 8 hours to 7 days without any heating. . In addition, a small amount of moisture required for curing is about the same as the humidity in the air. When water is added before application, an amount of about 0.1 to 1% by weight based on the colored coating composition of the present invention is usually sufficient.

The substrate to which the colored coating composition of the present invention is applied includes a substrate having a surface of a metal such as iron, zinc, and aluminum or an alloy of these metals, wood, concrete, slate, and the like. These surfaces may be subjected to a treatment such as a chemical conversion treatment, a sealer coating, and a primer coating. The coating amount of the colored coating composition of the present invention is not particularly limited, but is usually applied so that the dry film thickness is 25 to 50 μm.

[0053]

According to the composition of the present invention, it has low-temperature curability, good storage stability, and mechanical properties such as a coated surface condition, chemical resistance, water resistance, impact resistance, and bending resistance. Coating film with excellent mechanical properties. In addition, a non-aqueous dispersion of an acrylic polymer (a) and polymer particles, both of which have a large sagging limit film thickness at the time of coating and a high gloss of the resulting coating film, which have been difficult to achieve so far. This was achieved by setting the ratio of (b) to a specific ratio. Further, since the composition of the present invention contains the acrylic polymer (a), the composition can easily disperse the color pigment.

The composition of the present invention contains polymer particles, and the resulting coating film is a photo- and chemically stable coating film having a siloxane bond in the continuous phase. The discontinuous phase is polymer particles, and since the coating film is reinforced by the particles, it is considered that the above-mentioned mechanical properties, weather resistance and the like are excellent. As described above, the composition of the present invention can be easily crosslinked and cured at a low temperature of 100 ° C. or less in the presence of a small amount of moisture, for example, moisture in the air, as described above.

[0055]

The present invention will be described more specifically below with reference to examples and comparative examples. In each case, parts and% are in principle based on weight. Synthesis of Acrylic Polymer Production Example 1 100 parts of xylene was heated to 120 ° C., and a mixture of the following monomer and initiator was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was aged for 2 hours to obtain an acrylic polymer (a-1) solution. Styrene 10 parts n-butyl methacrylate 40 parts methyl methacrylate 35 parts 2-hydroxyethyl methacrylate 5 parts γ-methacryloyloxypropyltrimethoxysilane 10 parts 2,2′-azobisisobutyronitrile 2 parts The obtained acrylic polymer ( a-1) The solution has a nonvolatile content of about 5
0%, viscosity (Gardner viscosity, 25 ° C., the same applies hereinafter) C, and the weight average molecular weight of the acrylic polymer (a-1) was about 10,000.

Production Example 2 80 parts of toluene was heated to 110 ° C., and a mixture of the following monomer and initiator was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was aged for 2 hours to obtain an acrylic polymer (a-2) solution. 2-ethylhexyl methacrylate 25 parts Lauryl methacrylate 30 parts n-butyl acrylate 20 parts 2-hydroxyethyl methacrylate 5 parts γ-methacryloyloxypropyltrimethoxysilane 20 parts 2,2′-azobisisobutyronitrile 2 parts The obtained acrylic The polymer (a-2) solution has a nonvolatile content of about 5
5% and viscosity E. The weight average molecular weight of the acrylic polymer (a-2) was about 16,000.

Production of Non-Aqueous Dispersion of Polymer Particles Production Example 3 3 parts of an isocyanate group-containing adduct of 1 mol of isophorone diisocyanate and 1 mol of 2-hydroxyethyl methacrylate were added to 100 parts of an acrylic polymer (a-1) solution. The mixture was heated at 120 ° C. for 2 hours to obtain a polymerizable unsaturated group-containing acrylic polymer solution having a nonvolatile content of about 51%. The obtained polymerizable unsaturated group-containing acrylic polymer solution 80 parts Heptane 80 parts Xylene 23 parts The above mixture was charged into a flask, heated and refluxed, and the following monomers and a polymerization initiator were added dropwise over 3 hours, and the dropwise addition was completed. After aging for another 2 hours. Styrene 15 parts Acrylonitrile 15 parts Methyl methacrylate 70 parts 2,2'-azobisisobutyronitrile 1 part

Thereafter, 80 parts of heptane was removed by depressurization, and 80 parts of xylene was added to obtain a non-aqueous dispersion (b-1) of polymer particles. The resulting dispersion has a nonvolatile content of about 50
%, Viscosity A, and a milky white stable low-viscosity polymer dispersion having a polymer particle diameter of 0.3 to 0.4 μm. This dispersion did not generate any precipitates or coarse particles even after being allowed to stand at room temperature for 3 months.

Production Example 4 3 parts of an isocyanate group-containing adduct of 1 mol of isophorone diisocyanate and 1 mol of 2-hydroxyethyl methacrylate were added to 100 parts of an acrylic polymer (a-2) solution and heated at 110 ° C. for 2 hours. Thus, a polymerizable unsaturated group-containing acrylic polymer solution having a nonvolatile content of about 51% was obtained. The obtained polymerizable unsaturated group-containing acrylic polymer solution 100 parts Cyclohexane 60 parts Toluene 20 parts The above mixture was charged into a flask, heated and refluxed, and the following monomers and a polymerization initiator were added dropwise over 3 hours, and the dropwise addition was completed. After aging for another 2 hours. Styrene 15 parts Methyl methacrylate 42 parts Acrylonitrile 20 parts Glycidyl methacrylate 5 parts Acrylic acid 3 parts 2-hydroxyethyl acrylate 15 parts 2,2'-azobisisobutyronitrile 2 parts

Thereafter, 60 parts of cyclohexane was removed under reduced pressure, and 60 parts of toluene were added. The resulting dispersion had a nonvolatile content of about 55%, a viscosity D, and a particle size of polymer particles of 0.1%.
It was a milky white stable low-viscosity polymer dispersion of 50 to 0.55 µm. The inside of the particles was crosslinked by the reaction between the epoxy group of glycidyl methacrylate and the carboxyl group of acrylic acid. Even when the resulting dispersion was allowed to stand at room temperature for 3 months, no precipitate or coarse particles were generated.

Preparation of Pigment Paste Production Example 5 Raw materials having the following composition were placed in a 4 liter stainless steel container.
The pigment was dispersed in a desktop sand mill for 30 minutes to obtain a pigment paste A. Acrylic polymer (a-1) solution 50 parts Kanekazemurak ZW806Z (Note 1) 4 parts Xylene 6 parts Titanium white CR-93 (Note2) 80 parts (Note1) Kanekazemurak ZW806Z: Kanekachi Chemical Industry Co., Ltd. 2) Titanium white CR-93: white pigment manufactured by Ishihara Sangyo Co., Ltd.

Production Example 6 Raw materials having the following composition were placed in a 4-liter stainless steel container,
The pigment was dispersed in a desktop sand mill for 30 minutes to obtain a pigment paste B. Acrylic polymer (a-2) solution 45.5 parts Kaneka Zemulak ZW806Z 4 parts Xylene 10.5 parts Titanium white CR-93 80 parts

Production Example 7 Raw materials having the following composition were placed in a 4-liter stainless steel container.
The pigment was dispersed in a desktop sand mill for 30 minutes to obtain a pigment paste C. Acrylic polymer (a-1) solution 50 parts Kaneka Zemulak ZW806Z 4 parts Xylene 6 parts Titanium white CR-93 80 parts DISPARON 6900-20X 3 parts

Example 1 A non-aqueous dispersion of 140 parts of the pigment paste A obtained in Production Example 5 and 90 parts of the acrylic polymer (a-1) solution obtained in Production Example 1 and the polymer particles obtained in Production Example 3 ( b-1) 60 parts and 10 parts of xylene were added and uniformly mixed to obtain a paint base.

Examples 2 to 5 and Comparative Examples 1 to 5 A coating base was obtained in the same manner as in Example 1 except that the types and amounts of the raw materials used were as shown in Table 1 below. The amounts in Table 1 are shown in parts by weight. Comparative Example 6 A pigment paste was obtained in the same manner as in Production Example 5, except that the non-aqueous dispersion (b-1) obtained in Production Example 3 was used instead of the acrylic polymer (a-2) solution. However, the pigment could not be dispersed.

The coating bases obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were tested for storage stability. Further, dibutyltin dilaurate, which is the paint base curing catalyst obtained in each example, was added in the amount shown in Table 1 to obtain a colored paint composition, and the sagging limit film thickness of this composition was measured. The coating composition was applied to a polished mild steel sheet so as to have a dry film thickness of 30 μm, and dried at room temperature for 7 days. The coated film state, gloss, water resistance, alkali resistance, acid resistance, Weather resistance, impact resistance, and bending resistance tests were performed. Also, the gel fraction of the isolated coating film of this coating composition was measured.

Test Method Storage stability: The paint base was stored tightly in a constant temperature room at 40 ° C., and the number of days required for thickening to a pudding was examined. If no significant thickening was observed even after one month, it was evaluated as ○ (good). Sagging limit film thickness: The minimum film thickness (dry film thickness, μm) at which sagging occurs was measured by performing gradient coating of the film thickness.

Painted surface condition: Observed by visual observation, JIS K
It was evaluated according to 5400. A sample having no abnormality was marked with a circle. Gloss: 60 ° gloss and 20 ° gloss of the dry film thickness were measured. Water resistance: The water resistance was examined by immersing the coated surface in tap water at 40 ° C. for 168 hours. A sample having no abnormality was marked with a circle. Alkali resistance: Examined by the state of the coated surface after immersion in a 5% NaOH aqueous solution (25 ° C.) for 24 hours. ○ No abnormality
And Acid resistance: Investigated by the state of the coated surface after immersion in a 10% aqueous HCl solution (25 ° C.) for 24 hours. A sample having no abnormality was marked with a circle. Weather resistance: Using sunshine weather meter
After the test for 1,000 hours, the gloss retention of the coating film was examined.

Impact resistance: Using a Dupont impact tester,
A 500 g weight was dropped on the painted surface at a falling weight height of 50 cm at a 1/2 inch diameter of the shooting point, and it was examined whether the coating film had abnormalities such as cracks and peeling. ○ No abnormalities
And Bending resistance: Using a bending resistance tester (core rod with a diameter of 10 mm)
The test was performed according to IS K5400. A sample having no abnormalities such as cracks and peeling was marked with a circle. Gel fraction: 30 μm dry film thickness of the paint of each example on a tin plate
m and dried at room temperature for 7 days, after which the coating film was peeled off to obtain an isolated coating film. Put the isolated coating film in an equal weight mixture of acetone / methanol maintained at the reflux temperature,
The residual ratio (%) of the coating film after the time extraction was examined.

[0070]

[Table 1]

Claims (2)

(57) [Claims] (A) General formula [1] [In the formula, A represents -COO- or a phenylene group. R ₁
Is a hydrogen atom or a methyl group, R ₂ is a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, R ₃ and R ₄ are the same or different and are a phenyl group, an alkyl group having 1 to 6 carbon atoms or R ₅ represents an alkoxy group having 1 to 10 carbon atoms, and R ₅ represents an alkyl group having 1 to 10 carbon atoms. n shows the integer of 1-100. An acrylic polymer containing an alkoxysilane group-containing vinyl compound represented by the general formula [1] as an essential monomer component; and (b) an acrylic polymer containing an alkoxysilane group-containing vinyl compound represented by the general formula [1] as an essential monomer component. used as a dispersion stabilizer resin, the non-aqueous dispersion of the resin presence radical polymerizable organic liquid unsaturated monomer and insoluble in the organic liquid obtained by polymerizing polymer particles, (c) monoalkyl Phosphoric acid, monoalkylphosphorous acid, dial
Selected from killed phosphorous acid, tin-containing compounds and basic compounds
A curable composition containing a curing catalyst which is a single compound or a mixture of two or more compounds, and (d) a color pigment, wherein the mixing ratio of the acrylic polymer (a) and the non-aqueous dispersion (b) is the former / the latter Characterized in that the solid content weight ratio is 30/70 to 70/30. 2. The colored coating composition according to claim 1, wherein the dispersion stabilizer resin and the polymer particles are chemically bonded in the non-aqueous dispersion (b).