JP2000273399A - Ultraviolet-curable film-forming composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum-powder-containing ultraviolet-curable film- forming composition having excellent storage stability, and giving a coating film being excellent in performances such as processability, adhesion, hardness, and scratch resistance and having metallic appearance. SOLUTION: Provided are an ultraviolet-curable film-forming composition comprising 100 pts.wt. (A) photopolymerizable binder component, 1-30 pts.wt. (B) aluminum powder having a mean particle diameter of 1-50 μm, 0.1-30 pts.wt. (C) photopolymerization initiator, and 0.1-10 pts.wt. (D) organic resin microparticles having a mean particle diameter of 1 nm to 1 μm and a process for producing a coated metallic can comprising applying the composition to a metallic sheet or a resin-film-laminated metallic sheet or to a metallic can fabricated from the metallic sheet or the resin-film-laminated metallic sheet and curing the composition by irradiation with ultraviolet rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to processability, adhesion,
The present invention relates to an aluminum powder-containing ultraviolet-curable film-forming composition having excellent film properties such as hardness and scratch resistance and excellent storage stability.

[0002]

2. Description of the Related Art
UV-curable paints include cationically polymerizable compounds having an epoxy group or vinyl group and a cationically polymerizable initiator containing a cationic polymerization initiator that generates cations upon irradiation with ultraviolet light, and radically polymerizable compounds having a radically polymerizable unsaturated group. Radical polymerization-type paints and the like containing a compound and a radical polymerization initiator that generates radicals upon irradiation with ultraviolet rays are known.

In order to improve the aesthetics of the resulting coating film, a coloring pigment, a brilliant pigment or the like has been added to these UV-curable coating materials, but the coating film has a metallic appearance. Therefore, when aluminum powder which is a brilliant pigment is blended, there is a problem that storage stability becomes extremely poor.

[0004] It is an object of the present invention to provide an aluminum powder which is excellent in film performance such as processability, adhesion, hardness and scratch resistance, excellent in storage stability, and can impart a metallic appearance to the film. The purpose is to obtain an ultraviolet-curable film-forming composition.

[0005]

Means for Solving the Problems The present inventors have found that, in an ultraviolet-curable film-forming composition containing aluminum powder, an aluminum powder having a specific particle diameter is used and organic resin fine particles having a small particle diameter are blended. The present inventors have found that the storage stability of the film-forming composition can be improved without lowering the film performance, and have completed the present invention.

Thus, the present invention relates to (A) 100 parts by weight of the photopolymerizable binder component, and (B) an average particle diameter of 1 to 100 parts by weight.
1 to 30 parts by weight of 50 μm aluminum powder, (C) 0.1 to 30 parts by weight of a photopolymerization initiator, and (D) an average particle diameter of 1
It is intended to provide an ultraviolet-curable film-forming composition containing 0.1 to 10 parts by weight of organic resin fine particles having a particle size of nm to 1 μm.

Further, the present invention provides a method for coating the above-mentioned ultraviolet-curable film-forming composition on a metal plate, a resin film-laminated metal plate or a metal can formed by molding the metal plate or the resin film-laminated metal plate. An object of the present invention is to provide a method for producing a coated metal can characterized by irradiation and curing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the UV-curable film-forming composition of the present invention will be described.

The film-forming composition of the present invention contains the following photopolymerizable binder component (A), aluminum powder (B), photopolymerization initiator (C) and organic resin fine particles (D) as essential components.

Photopolymerizable Binder Component (A) The photopolymerizable binder component, which is the component (A) of the coating composition of the present invention, is a binder component capable of undergoing cationic polymerization or radical polymerization by ultraviolet irradiation and being cured. is there.

The binder component which can be cured by initiating the cationic polymerization can be a compound having a cationically polymerizable group. For example, one of the cationically polymerizable compounds shown in the following (a) to (e): Species or two or more species can be mentioned.

(A) Compounds having an epoxy group: dicyclopentadienedioxide, limonenedioxide,
4-vinylcyclohexene dioxide, (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexanecarboxylate, di (3,4-epoxycyclohexyl) adipate, (3,4-epoxycyclohexyl) methyl alcohol, (3 , 4-epoxy-6
-Methylcyclohexyl) methyl-3,4-epoxy-
6-methylcyclohexanecarboxylate, ethylene 1,2-di (3,4-epoxycyclohexanecarboxylic acid) ester, (3,4-epoxycyclohexyl) ethyltrimethoxysilane, phenylglycidyl ether, bisphenol A type epoxy resin, halogenation Bisphenol A type epoxy resin, bisphenol F type epoxy resin, o-, m-, p-cresol novolak type epoxy resin, phenol novolak type epoxy resin, epoxy compounds such as polyglycidyl ether of polyhydric alcohol and the like.

(B) Vinyl compounds: aromatic vinyl compounds such as styrene, α-methylstyrene, p-chloromethylstyrene and vinyltoluene; substituted or unsubstituted compounds such as n-butyl vinyl ether, isobutyl vinyl ether, cyclohexyl vinyl ether and hydroxybutyl vinyl ether Substituted alkyl vinyl ethers; allyl vinyl ether, ethenyl vinyl ether, 1-methyl-2-
Alkenyl vinyl ethers such as propenyl vinyl ether; aryl vinyl ethers such as phenyl vinyl ether and p-methoxyphenyl vinyl ether; alkyl divinyl ethers such as butanediol divinyl ether, triethylene glycol divinyl ether and cyclohexanediol divinyl ether;
Benzene dimethanol divinyl ether, Nm-chlorophenyldiethanolamine divinyl ether, m-
Aralkyl divinyl ethers such as phenylene bis (ethylene glycol) divinyl ether; aryl divinyl ethers such as hydroquinone divinyl ether and resorcinol divinyl ether; and cationic polymerizable nitrogen-containing compounds such as N-vinyl carbazole and N-vinyl pyrrolidone.

(C) Bicycloorthoester compound: 1
-Phenyl-4-ethyl-2,6,7-trioxabicyclo- [2,2,2] -octane, 1-ethyl-4-hydroxymethyl-2,6,7-trioxabicyclo-
[2,2,2] -octane and the like.

(D) Spiro orthocarbonate compound:
1,5,7,11-tetraoxaspiro- [5,5]-
Undecane, 3,9-dibenzyl-1,5,7,11-
Tetraoxaspiro- [5,5] -undecane, 1,
4,6-trioxaspiro- [4,4] -nonane, 2-
Methyl-1,4,6-trioxaspiro- [4,4]-
Nonane, 1,4,6-trioxaspiro- [4,5]-
Decane etc.

(E) Oxetane ring-containing compound:

[0017]

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A compound containing at least one oxetane ring represented by the following formula, for example, 3-ethyl-3-methoxymethyloxetane,
Ethyl-3-ethoxymethyloxetane, 3-ethyl-
3-butoxymethyloxetane, 3-ethyl-3-hexyloxymethyloxetane, 3-ethyl-3-allyloxymethyloxetane, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3- Ethyl-3- (2'-hydroxyethyl) oxymethyloxetane, 3-ethyl-3- (2 '
-Hydroxy-3'-phenoxypropyl) oxymethyloxetane, 3-ethyl-3- (2'-hydroxy-
3'-butoxypropyl) oxymethyloxetane, 3
-Ethyl-3- [2 '-(2 "-ethoxyethyl) oxymethyl] oxetane, 3-ethyl-3- (2'-butoxyethyl) oxymethyloxetane, 3-ethyl-
3-benzyloxymethyloxetane, 3-ethyl-3
-(P-tert-butylbenzyloxymethyl) oxetane, 3-ethyl-3-glycidyloxymethyloxetane, 3-ethyl-3- (3,4-epoxycyclohexylmethyl) oxymethyloxetane, bis (3-ethyloxetanyl- 3-methyl) oxide, a compound having a polymerizable unsaturated group and an oxetane ring [for example, oxetane obtained by radical copolymerization of 3-ethyl-3- (acryloyloxyethyl) oxymethyloxetane as one monomer component] Copolymer having ring; Formula (1) below

[0019]

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(Wherein, A represents a divalent hydrocarbon group having 1 to 23 carbon atoms which may contain a hetero atom such as an oxygen atom).

In the compound represented by the above formula (1),
As A in the formula, for example, a linear, branched or cyclic alkylene group (particularly, an alkylene group having 1 to 15 carbon atoms such as methylene, ethylene, propylene, butylene, and cyclohexylene), a carbon atom Formulas 4 to 30, preferably 4 to 8 polyalkyleneoxy groups (eg, poly (ethyleneoxy), poly (propyleneoxy) groups, etc.), phenylene groups, xylylene groups, and the following formula (2)

[0022]

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(Where Z is O, S, CH ₂ , N
H, SO, SO ₂ , C (CF ₃ ) ₂ or C (CH ₃ ) ₂
Represents a divalent aromatic hydrocarbon group.

Among the compounds (a) to (e), the compound (a) having an epoxy group (especially an alicyclic epoxy group) and / or the oxetane ring-containing compound (e) are preferably used. Can be.

As the binder component capable of causing radical polymerization and curing, one or more of a radical polymerizable resin and a radical polymerizable vinyl monomer having a radical polymerizable unsaturated group can be used. Can be mentioned.

The above radical polymerizable resin includes an ethylenically unsaturated group-containing resin, and specific examples thereof include the following.

Examples of the ethylenically unsaturated group-containing resin include a resin obtained by condensing (meth) acrylic acid with a polyester, an ethylenically unsaturated group-containing polyurethane resin, an ethylenically unsaturated group-containing epoxy resin, and an ethylenically unsaturated group. Examples include a saturated group-containing phosphorus-containing epoxy resin, an ethylenically unsaturated group-containing acrylic resin, an ethylenically unsaturated group-containing silicon resin, and an ethylenically unsaturated group-containing melamine resin.

The radically polymerizable vinyl monomer includes not only a radically polymerizable unsaturated monomer but also a radically polymerizable unsaturated oligomer, and specific examples thereof include the following.

As the radical polymerizable unsaturated monomer,
For example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, butyl acrylate (n-, i-, t-), hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, acrylic Decyl acrylate, lauryl acrylate, stearyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, butyl methacrylate (n-, i-, t-), hexyl methacrylate Alkyl or cycloalkyl esters of acrylic acid or methacrylic acid such as 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, lauryl methacrylate, stearyl methacrylate and cyclohexyl methacrylate; Acrylic acid methoxybutyl methacrylate methoxybutyl, methoxyethyl acrylate, methoxyethyl methacrylate, ethoxyethyl acrylate,
Esterified products of acrylic acid or methacrylic acid such as an alkoxyalkyl ester of acrylic acid or methacrylic acid such as ethoxybutyl methacrylate and a monohydric alcohol having 1 to 28 carbon atoms: styrene, vinyltoluene,
Vinyl aromatic compounds such as methylstyrene, chlorostyrene and divinylbenzene; carboxyl group-containing monomers such as acrylic acid and methacrylic acid; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate Hydroxyl-containing monomers such as butyl isocyanate, phenyl isocyanate and the above-mentioned hydroxyl-containing monomers, and adducts of phosphoric acid and the above-mentioned hydroxyl-containing monomers;
Examples include unsaturated monomers having a nitrogen-containing heterocycle such as vinylpyrrolidone and vinylpyridine; and other vinyl compounds such as vinyl acetate, vinyl chloride, vinyl isobutyl ether, methyl vinyl ether, acrylonitrile, and 2-ethylhexyl vinyl ether.

Examples of the radical polymerizable unsaturated oligomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and 1,3. −
Butylene glycol di (meth) acrylate, 1,4-
Butanediol diacrylate, glycerin di (meth)
Acrylate, glycerin tri (meth) acrylate,
Trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate , Hydroxyisocyanurate tri (meth) acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, glycerol allyloxydi (meth) acrylate, 1,1,1-tris (hydroxymethyl) ethanedi (meth) acrylate , 1,1,1-tris (hydroxymethyl) ethanetri (meth) acrylate [In the present invention, “(meth) acrylate” at the end of each compound is Or methacrylate "means. And di-, tri- and tetra-vinyl compounds; ethylene glycol, glycerin, butylene glycol, trimethylolpropane, pentaerythritol, neopentyl glycol, 1,6
A product obtained by reacting acrylic acid and / or methacrylic acid with an adduct of a polyhydric alcohol such as hexanediol and ethylene oxide or propylene oxide;
Products obtained by reacting acrylic acid and / or methacrylic acid with the above-mentioned adduct of polyhydric alcohol and ε-caprolactone; and phosphorus-containing polymerizable unsaturated oligomers.

The radical polymerizable unsaturated monomer and the radical polymerizable unsaturated oligomer can be used alone or in combination of two or more.

Aluminum Powder (B) The aluminum powder (B) that can be used in the present invention is:
Aluminum powder that can be used for paints and can give a metallic appearance to the coating, and has an average particle size (D ₅₀ )
Can be used without particular limitation as long as the particle size is 1 to 50 μm. Further, the surface of the aluminum powder (B) may be untreated or may have been subjected to a surface treatment such as an oleic acid treatment, a stearic acid treatment, and a resin coating treatment.

Photopolymerization Initiator (C) The photopolymerization initiator (C) is blended in the composition of the present invention in order to accelerate the curing of the composition of the present invention by irradiation with ultraviolet rays.

When the photopolymerizable binder component (A) is cationically polymerizable, the photopolymerization initiator (C) includes:
A cationic photopolymerization initiator that generates a cation by ultraviolet irradiation to initiate polymerization is used. Examples of the cationic photopolymerization initiator include, for example, compounds represented by the following formula.

[0035] _{^{Ar 2 I + · X - (}} I) [ In the formula, Ar represents an aryl group such as phenyl group,
X ^- is PF ₆ ^-, SbF ₆ ^- or AsF ₆ ^- the _{^{representative] Ar 3 S + · X -}} (II) [ wherein, Ar and X ^- is the same as defined above]

[0036]

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Wherein R represents an alkyl group having 1 to 12 carbon atoms or an alkoxyl group having 1 to 12 carbon atoms, and n represents 0 to
Represents an integer of 3 and X ⁻ has the same meaning as described above]

[0038]

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[0039] [wherein, Y ^- is PF ₆ ^-, SbF ₆ ^- or AsF ₆ ^- or SbF ₅ (OH) ^- represents a]

[0040]

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Wherein X ⁻ has the same meaning as described above.

[0042]

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Wherein X ⁻ has the same meaning as described above.

[0044]

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[Wherein, X ^- has the same meaning as described above]

[0046]

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[0047] [In the formula, R ¹ represents an aralkyl group or Aarukeniru group having a carbon number of 3 to 9 of 7 to 15 carbon atoms, R ²
Represents a hydrocarbon group having 1 to 7 carbon atoms or a hydroxyphenyl group, R ³ represents an alkyl group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, and X ⁻ has the same meaning as described above. Having

[0048]

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[In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 12 carbon atoms or 1 to 12 carbon atoms.
Represents an alkoxyl group of the formula

[0050]

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Wherein R ¹ and R ² have the same meaning as described above.

[0052]

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Commercially available photocationic polymerization initiators include:
For example, Silacure UVI-6970, UVI-6
974, UVI-6990 (all, manufactured by Union Carbide, USA), Irgacure 261 (manufactured by Ciba-Geigy), CIT-1682 (Nippon Soda Co., Ltd.)
Manufactured), PHOTOINITIATOR (photo initiator) 2074
(Rhone Poulin).
The compounding amount of the photocationic polymerization initiator is usually 0.1 to 30 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the cationically polymerizable photopolymerizable binder component (A). used.

When the photopolymerizable binder component (A) is radically polymerizable, the photopolymerization initiator (B) is excited by irradiation with ultraviolet rays to generate radicals, and the film-forming binder (A) A) photo-radical polymerization initiator for initiating the curing of ()) is used.

Examples of the photoradical polymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, 2-methylbenzoin, benzyl, benzyldimethylketal, diphenylsulfide, tetramethylthiuram monosulfide, diacetyl, eosine, and thionin. , Michler's ketone, anthracene, anthraquinone, chloranthraquinone, methylanthraquinone, acetophenone, α-hydroxyisobutylphenone, p-isopropyl-α-hydroxyisobutylphenone, α-α'-dichloro-4-phenoxyacetophenone, 1-hydroxy-1 -Cyclohexyl acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone,
Methylbenzoylformate, 2-methyl-1- [4
-(Methylthio) phenyl] -2-morpholinopropanone-1, thioxanthone, benzophenone, 2,4,
6-trimethylbenzoyldiphenylphosphine oxide and the like can be mentioned. These photoradical polymerization initiators can be used alone or in combination of two or more. The amount of the photo-radical polymerization initiator is based on 100 parts by weight of the radical-polymerizable photo-polymerizable binder component (A).
Usually, it is used in the range of 0.1 to 30 parts by weight, preferably 0.5 to 5 parts by weight.

In order to accelerate the photopolymerization reaction by these photopolymerization initiators, a photosensitization accelerator may be used in combination with the photopolymerization initiator. Examples of photosensitizers that can be used in combination include tertiary amines such as triethylamine, triethanolamine and dimethylaminoethanol; alkylphosphines such as triphenylphosphine; and thioethers such as β-thiodiglycol. Agents.
These photosensitizers can be used alone or in admixture of two or more. The compounding amount of the photosensitizer is 0.1 to 100 parts by weight of the sum of the radical polymerizable resin and the radical polymerizable vinyl monomer. A range of 1 to 10 parts by weight is preferred.

Organic Resin Fine Particles (D) The organic resin fine particles as the component (D) in the composition of the present invention have an average particle diameter of 1 nm to 1 μm, preferably 50 to 50 μm.
0 nm. Examples of the resin species of the organic resin fine particles (D) include polyethylene, polypropylene, polytetrafluoroethylene; nylon such as nylon 11 and nylon 12; modified polyethylene such as carboxylic acid-modified polyethylene; modified polypropylene such as maleated polypropylene; Silicon rubber, acrylic resin, urethane resin, phenol resin, and the like can be given. Of these,
Acrylic resins are preferred, among which, in the presence of a reactive emulsifier having a polymerizable unsaturated group such as an allyl group, using a water-soluble polymerization initiator such as a water-soluble azoamide compound as a polymerization initiator, Internally crosslinked organic compound obtained by emulsion polymerization of a polymerizable unsaturated monomer component containing a polyfunctional monomer such as divinylbenzene or 1,6-hexanediol di (methacrylate) containing two or more unsaturated unsaturated groups. Resin fine particles are preferred.

The average particle diameter of the organic resin fine particles (D) is 1 n
If it is less than m, the effect of modifying the surface of the aluminum powder is small, and the effect of improving the storage stability is insufficient. On the other hand, if the average particle size exceeds 1 μm, adsorption on the aluminum surface becomes difficult, and the storage stability becomes poor. The improvement effect is not sufficient.

The photopolymerizable coating composition of the present invention comprises, in addition to the above essential components, the photopolymerizable binder component (A), aluminum powder (B), photopolymerization initiator (C) and organic resin fine particles (D). If necessary, a modified resin such as a polyol resin, a phenol resin, an acrylic resin, a polyester resin, a polyolefin resin, and a polybutadiene resin; a fragrance, a solvent, and the like may be contained.

The coating composition of the present invention can be prepared by mixing the above-mentioned components, mixing and stirring to obtain a uniform coating composition. For example, each component is mixed and heated if necessary (for example, up to about 50 ° C.)
Then, it can be prepared by stirring with a stirrer such as a dissolver until it becomes uniform, for example, for about 1 to 30 minutes.

Coating Method The coating material on which the coating composition of the present invention can be formed by painting or the like includes, for example, tin, aluminum, tin-free steel, iron, zinc, copper, galvanized steel sheet,
Metal sheets such as alloy-plated steel sheets of zinc and other metals; Chemically treated metal sheets obtained by subjecting these metals to phosphate treatment or chromate treatment; Polyesters such as polyethylene terephthalate to these metal sheets or chemically treated metal sheets Resin, polyolefin resin such as polyethylene and polypropylene,
Resin film-laminated metal plates formed by laminating resin films such as polyamide resin, epoxy resin, and polyvinyl chloride; molded products such as cans formed by processing these metal plates, chemical conversion-treated metal plates or resin film-laminated metal plates; Wood, plastics, concrete and the like can be mentioned.

The film-forming composition of the present invention is particularly suitable as a base coat paint for the outer surface of a can. The coated surface of the above-mentioned object is preferably a metal plate which is formed into a can after coating and becomes the outer surface of the can. The surface of a chemical conversion-treated metal plate or a resin film-laminated metal plate; the outer surface of a can formed by molding a metal plate, a chemical conversion-treated metal plate or a resin film-laminated metal plate into a can.

The film-forming composition of the present invention can be applied by a method such as roll coating, spray coating, brush coating, bar coating, roller coating, and silk screen printing.

The film thickness of the film-forming composition of the present invention may be appropriately selected within a range where a good film appearance can be obtained, and is usually in a range of about 2 to 20 μm as a dry film thickness. For use in applications, a range of about 2-8 μm is preferred. After applying the coating, if the coating contains a solvent, the solvent is removed by heating or the like, and then the coating is cured by ultraviolet irradiation. The irradiation conditions are appropriately selected according to the type and thickness of the applied coating forming composition. do it. Usually, the wavelength of the light beam to be irradiated is appropriately in the range of 200 to 450 nm, and an irradiation source having a wavelength with high sensitivity can be appropriately selected and used.

Examples of the irradiation source of the ultraviolet ray include a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a carbon arc, a metal halide lamp, sunlight, and the like. 1000
mj / cm ^2, it is suitable in the range of particular 50 to 500 mJ / cm ^2.

After curing by irradiation with ultraviolet rays, the coating film may be heated if necessary. By heating, unreacted substances in the coating film can be reduced, and the coating film can be cured by light irradiation or the distortion of the coating film caused by molding can be reduced. In some cases, this heating can improve the hardness and adhesion of the coating film. The heating is usually performed for 1
It can be carried out at an ambient temperature of 50 to 250 ° C. for 1 to 30 minutes. When the composition of the present invention is applied to a substrate for cans and cured by irradiating ultraviolet rays, and then ink coating and clear paint coating are performed, the composition is also heated by heat during drying of the ink and baking of the clear paint coating film. You can also.

[0067]

EXAMPLES The present invention will be described more specifically with reference to examples. Hereinafter, “parts” and “%” are both based on weight.

Production Example 1 of Ultraviolet Curable Film-Forming Composition Production Example 1 Production of Organic Resin Fine Particles 1 equipped with a stirrer, a thermometer, a cooling pipe and a heating mantle
To a liter flask, 3536.5 parts of deionized water and 51 parts of "Eleminol JS-2" (Note 1) were added, and the temperature was raised to 90 ° C while stirring. In this, "VA-08
20 "of an aqueous solution of 12.5 parts of" 6 "(Note 2) dissolved in 500 parts of deionized water was added. After 15 minutes while maintaining the inside of the flask at 90 ° C., 50 parts of a mixture of 470 parts of styrene, 470 parts of n-butyl acrylate and 60 parts of 1,6-hexanediol diacrylate were added, and the mixture was stirred for 30 minutes. After that, dropping of the remaining total amount (950 parts) of the monomer mixture and the total remaining amount of the aqueous solution of “VA-086” was started. The dropping of the monomer mixture was performed over 3 hours, and the dropping of the aqueous solution of “VA-086” was performed over 3.5 hours. After the dropping of the aqueous solution of “VA-086” was completed, the mixture was heated for 30 minutes and maintained at 90 ° C., cooled to room temperature, taken out using a filter cloth, and dispersed in an aqueous gelled organic resin fine particle aqueous solution having a solid content of 20%. I got The particle diameter of the organic resin fine particles in the aqueous dispersion was about 69 nm as measured by Nanoizer N-4 manufactured by Coulter Corporation.
The aqueous dispersion was dried on a stainless steel vat in an electric hot air dryer at 60 ° C. to obtain organic resin fine particles (1) as solid resin powder.

(Note 1) "Eleminol JS-2": trade name, manufactured by Sanyo Chemical Co., Ltd., aqueous solution of sulfosuccinic allyl group-containing anionic reactive emulsifier, solid content 39%.

(Note 2) "VA-086": trade name, water-soluble azoamide polymerization initiator, manufactured by Wako Pure Chemical Industries, Ltd.
2'-Azobis [2-methyl-N- (2-hydroxyethyl) -propionamide].

Example 1 20 parts of 3-ethyl-3-hydroxymethyloxetane (denoted as “OXA” in Table 1 below), Cyracure U
VR-6110 (Note 3) 80 parts, Alpaste 0620
MS (Note 4) 15 parts, Cyracure UVI-6990
(Note 5) 5 copies, PHOTOINITIATOR 2074 (Note 6) 1
Parts, 0.5 parts of Kayacure DETX-S (Note 7) and 3 parts of the organic resin fine particles (1) obtained in Production Example 1 were mixed and stirred to obtain a uniform UV-curable film-forming composition.

(Note 3) Silacure UVR-6110:
Trade name, manufactured by Union Carbide, USA, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.

(Note 4) Alpaste 0620MS: trade name, manufactured by Toyo Aluminum Co., Ltd., leafing type aluminum paste, average particle size about 14 μm.

(Note 5) Cyracure UVI-6990:
Trade name, US, manufactured by Union Carbide Corporation, PF ₆ ^- triallyl sulfonium salt photoacid generator having.

(Note 6) PHOTOINITIATOR 2074: trade name, manufactured by Rhone Poulin, diallyliodonium salt-based photoacid generator.

(Note 7) Kayacure DETX-S: trade name, manufactured by Nippon Kayaku Co., Ltd., a thioxanthone-based photoradical generator.

Examples 2 to 5 and Comparative Examples 1 to 6 The same procedures as in Example 1 were carried out except that the composition was changed as shown in Table 1 below. I got

(Note) in Table 1 represents the following meanings. (* 1) Aronix M-101: manufactured by Toagosei Co., Ltd.
Trade name, polymerizable unsaturated compound which is a phenol / ethylene oxide modified acrylate, having one polymerizable unsaturated group in the molecule. (* 2) Aronix M-315: manufactured by Toagosei Co., Ltd.
Trade name, triacrylate of ethylene oxide modified product of isocyanuric acid.

(* 3) Alpaste 7670NS: trade name, manufactured by Toyo Aluminum Co., Ltd., non-leafing type aluminum paste, average particle size about 15 μm. (* 4) Asahi Kasei Aluminum Paste HR-6601: a non-leafing type aluminum paste manufactured by Asahi Kasei Corporation with a resin-coated surface, average particle size of about 16 μm. (* 5) Lucirin TPO: trade name, manufactured by BASF (B.S.F.), acylphosphine-based photoradical generator.

Test of the film-forming composition For each of the film-forming compositions obtained in the above Examples and Comparative Examples, the initial viscosity immediately after production, the storage stability, and the initial and after storage film performance, coating workability, Further, the color tone of the coating solution after storage was tested based on the test method described later. The test results are shown in Table 1 below.

Preparation of Test Coated Plate Each of the film-forming compositions obtained in the above Examples and Comparative Examples was applied to a tin-free steel plate having a thickness of 0.20 mm to a thickness of 12 μm.
Homo PET (polyethylene terephthalate) sheets were thermocompressed to PET steel sheets, each of which was dried so as to have a dry film thickness of 5 μm. Ultraviolet irradiation was performed using a metal halide lamp (160 W / cm) from a distance of 10 cm from the coated plate. Ultraviolet irradiation was performed so that the energy dose became 150 mJ / cm ^2, and the coating film was cured to obtain a test coated plate.
Test coating plates were prepared using each of the film-forming compositions immediately after production and those stored for 8 weeks at 30 ° C. in a closed state in a dark place.

Each of the test coated plates thus obtained was tested for pencil hardness and adhesion based on the following test methods. The performance test of each test coated plate was performed in a room at 20 ° C.
The test results are shown in Table 1 below.

Test Method Initial Viscosity: The initial viscosity immediately after the production of the film-forming composition was measured at 25 ° C. using a Ford cup # 4.

Storage stability: Stored at 30 ° C. in a dark place in a sealed state for up to 8 weeks. The viscosity was measured at 25 ° C. using a Ford cup # 4 every two weeks after storage. Storage stability is
The viscosity ratio was expressed as a ratio of the viscosity of the composition after storage (seconds after storage) / the viscosity of the initial composition (seconds of the initial period).

Pencil hardness: JIS K54 was applied to each test coated plate.
A pencil scratch test specified in 00 8.4.2 (1990) was performed, and evaluation was performed by a tearing method.

Adhesion: Immediately after ultraviolet irradiation (10 after irradiation is completed)
(Within seconds) A cross cut reaching the substrate was put on the test coated plate with a knife, and a cellophane adhesive tape was closely adhered to the cross cut portion, and the tape was immediately peeled off. ◎: No peeling of the coating film was observed at all. ○: Slight peeling of the coating film was observed. Δ: Significant peeling of the coating film was observed. ×: The peeling of the coating film was remarkable.

Color tone of coating solution: change in color tone of coating solution of film-forming composition stored at 30 ° C. in a closed place in a dark place for up to 8 weeks, compared with color tone of coating solution of film-forming composition immediately after production. Was visually evaluated.

A: no change in color tone of the coating liquid was observed and good metallic feeling was observed. Δ: slight change in color tone of the coating liquid was observed. X: color tone of the coating liquid was significantly changed to black.

Coating workability: The coating workability of the film forming composition stored immediately after production and in a dark place in a closed state at 30 ° C. for up to 8 weeks was tested by a roll coater. The coating conditions were a natural roll coating method, a coating speed of 40 m / min, and a coating thickness of about 5 μm. Evaluation was performed based on the following criteria based on the obtained appearance of the coated surface. The symbol-indicates that the film-forming composition could not be tested due to gelation.

◎: Good appearance of coated surface Δ: Slightly inferior smoothness of coating film X: Significant surface roughness of coating film

[0091]

[Table 1]

[0092]

The ultraviolet-curable film-forming composition of the present invention is a composition containing an aluminum powder, but the storage stability of the aluminum powder is prevented from deteriorating and the storage stability is more excellent than ever. It is. The film-forming composition of the present invention can form a film having a metallic appearance with excellent film performance such as workability, adhesion, hardness, and scratch resistance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 5/00 C09D 5/00 C 7/12 7/12 Z // B65D 1/12 B65D 1/12 Z F-term (reference) 3E033 AA06 BA07 BA13 BB08 3E061 AA15 AB06 AC01 4J011 PA03 PA64 PA66 PA69 PA85 PA95 PA96 PB06 PB25 PB40 QA02 QA03 QA08 QA09 QA13 QA21 QA22 QA23 QB16 RA06 RA10 SA02 SA31 SA83 SA31 SA63 WA02 4J038 CC021 DB061 DB261 HA066 JA74 KA04 KA20 MA02 MA14 PA17 PB04 PC02 PC08

Claims (2)

[Claims] (A) 100 parts by weight of a photopolymerizable binder component, and (B) aluminum powder having an average particle diameter of 1 to 50 μm.
30 parts by weight, (C) 0.1 to 30 parts by weight of a photopolymerization initiator, and (D) organic resin fine particles having an average particle diameter of 1 nm to 1 μm.
An ultraviolet-curable film-forming composition comprising 1 to 10 parts by weight. 2. The ultraviolet-curable film-forming composition according to claim 1, which is applied to a metal plate, a resin film-laminated metal plate or a metal can formed by molding the metal plate or the resin film-laminated metal plate. A method for producing a coated metal can, characterized by irradiating with light.