JPH09249850A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material which can form a coating layer excellent in the balance between its deep drawability and its hardness, and in adhesion, lubricity, hygiene and resistance to boiling water, particularly provide a coating material suitable for can coating. SOLUTION: This coating composition comprises (A) 100 pts.wt. of a polyester resin with a number-average molecular weight of 10,000-100,000, a static glass transition point of 10-120 deg.C, a hydroxyl value of 1-15mgKOH/g and an acid value of <=10 and (B) 1-20 pts.wt. of an epoxy resin with a number-average molecular weight of <=1,000, (C) 1-20 pts.wt. of an amino resin and (D) 0.1-10 pts.wt. of a lubricant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition capable of forming a coating film having an excellent balance between deep drawing workability and hardness, excellent adhesion, lubricity, hygiene and boiling water resistance, particularly can coating. A coating composition suitable for use.

[0002]

2. Description of the Related Art Conventionally, as paints for can inner / outer surfaces, lid inner / outer surfaces, and cap inner / outer surfaces which require high workability, amino-alkyd resins, amino-polyester resins, vinyl-amino resins, vinylorgano Resin-based paints such as sol are used.

However, a coating film obtained from an amino-alkyd resin- or amino-polyester resin-based coating material has a difficulty in balancing deep-drawing processability and hardness, and is a vinyl-amino resin or vinyl-organosol resin. A coating film obtained from a paint of a type has problems in hygiene and boiling water resistance when used on the inner surface of a can.

Therefore, the inventors of the present invention can form a coating film having an excellent balance between deep drawing workability and hardness, excellent adhesion, lubricity, hygiene and boiling water resistance, and can be used on the inner surface of a can. As a result of intensive research to obtain a coating composition, it has been found that the above object can be achieved by a coating obtained by compounding a specific polyester resin as a resin component with a liquid epoxy resin, an amino resin and a lubricant in a predetermined amount, thereby completing the present invention. Came to.

[0005]

That is, the present invention provides:
(A) Number average molecular weight 10,000 to 100,000, static glass transition temperature 10 to 120 ° C., hydroxyl value 1 to 15 mg
(B) 1 to 20 parts by weight of an epoxy resin having a number average molecular weight of 1,000 or less, (c) 1 to 20 parts by weight of an amino resin, and (d) to 100 parts by weight of a polyester resin having a KOH / g and an acid value of 10 or less. ) A coating composition comprising 0.1 to 10 parts by weight of a lubricant.

[0006] The present invention also provides: The present invention provides a coating composition for can coating according to item 1.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester resin which is the component (a) in the composition of the present invention is a hydroxyl group-containing polyester resin, and is an oil-free polyester resin, an oil-modified alkyd resin, or a modified product of these resins, For example, any of urethane-modified polyester resin, urethane-modified alkyd resin, epoxy-modified polyester resin, epoxy-modified alkyd resin, etc. may be used.

The above oil-free polyester resin is mainly an esterified product of a polybasic acid and a polyhydric alcohol.
Examples of polybasic acids include adipic acid, isophthalic acid,
Examples thereof include terephthalic acid, sebacic acid, maleic acid, fumaric acid and trimellitic acid. These polybasic acids can be used alone or in admixture of two or more. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, trimethylolethane, trimethylolpropane,
Examples include 1,4-butanediol and neopentyl glycol. These polyhydric alcohols can be used alone or in combination of two or more. The esterification reaction of both components can be performed by a known method.

The above oil-free polyester resin can also be obtained by performing a transesterification reaction using a lower alkyl ester of a polybasic acid (for example, methyl ester, ethyl ester, etc.) instead of the polybasic acid in the esterification reaction. be able to. The transesterification reaction of both components can be performed by a known method.

The alkyd resin is obtained by reacting an oil fatty acid by a known method in addition to the acid component and alcohol component of the oil-free polyester resin, and examples of the oil fatty acid include coconut oil fatty acid and soybean oil fatty acid. , Linseed oil fatty acid, safflower oil fatty acid, tall oil fatty acid, dehydrated castor oil fatty acid, tung oil fatty acid and the like.

The urethane-modified polyester resin is known as a polyisocyanate compound, which is a low molecular weight oil-free polyester resin obtained by reacting an acid component and an alcohol component in the production of the oil-free polyester resin. It was made to react by the method of. Urethane-modified alkyd resin is
The above-mentioned alkyd resin, or a low molecular weight alkyd resin obtained by reacting each component during the production of the alkyd resin,
The polyisocyanate compound is reacted with a known method. Examples of the polyisocyanate compound used for producing the urethane-modified polyester resin and the urethane-modified alkyd resin include hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′- Methylene bis (cyclohexyl isocyanate), 2,4,6-triisocyanatotoluene and the like can be mentioned.

The epoxy-modified polyester is obtained by reacting the oil-free polyester resin or the oil-free polyester resin obtained by reacting the acid component and the alcohol component in the production of the oil-free polyester resin with an epoxy compound by a known method. It is a thing. The epoxy-modified alkyd resin is obtained by reacting the above-mentioned alkyd resin or a low-molecular-weight alkyd resin obtained by reacting each component during the production of the above-mentioned alkyd resin with a polyisocyanate compound by a known method.

Epoxy compounds used in the production of epoxy-modified polyester resin and epoxy-modified alkyd resin include butyl glycidyl ether, octyl glycidyl ether, glycidyl laurate, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol. Aliphatics such as diglycidyl ether, polypropylene glycol diglycidyl ether, butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, diglycerin tetraglycidyl ether Epoxy compound; dicyclopentadiene dioxide, epoxy cyclo Alicyclic epoxy compounds such as cyclohexene carboxylic acid ethylene glycol diester; polyphenol compound and an epoxy compound obtained by reaction between epichlorohydrin, diglycidyl phthalate,
Examples thereof include aromatic or heterocyclic epoxy compounds such as triglycidyl isocyanurate.

Examples of the polyphenol compound which can be used for producing the epoxy compound obtained by the reaction of the above polyphenol compound and epichlorohydrin include, for example, bis (4-hydroxyphenyl) -2,2-propane, 4,
4'-dihydroxybenzophenone, bis (4-hydroxyphenyl) -1,1-ethane, bis (4-hydroxyphenyl) -1,1-isobutane, bis (4-hydroxy-tert-butyl-phenyl) -2,2 -Propane,
Bis (2-hydroxynaphthyl) methane, 1,5-dihydroxynaphthalene, bis (2,4-dihydroxyphenyl) methane, tetra (4-hydroxyphenyl)-
1,1,2,2-ethane, 4,4'-dihydroxydiphenyl sulfone, phenol novolac, cresol novolac and the like can be mentioned.

Commercially available epoxy compounds obtained by the reaction of a polyphenol compound and epichlorohydrin are, for example, Epicoat 100 manufactured by Shell Chemical Co.
1, 1, 1004, 1007 and the like.

The above polyester resin has a number average molecular weight of 10,000 to 100,000, a glass transition temperature of 10 to 120 ° C., and a hydroxyl value of 1 from the viewpoint of processability of the obtained coating film, coating film hardness, alcohol resistance and the like. ~ 15mgKOH / g, acid value 1
It is necessary that the number average molecular weight is 15,0 or less.
00-40,000, glass transition temperature (Tg point) 40-
It is preferably 100 ° C., a hydroxyl value of 3 to 10 mgKOH / g, and an acid value of 5 or less. If the number average molecular weight is less than 10,000, the processability is poor. On the other hand, if the number average molecular weight is more than 100,000, the viscosity of the obtained coating composition becomes high and handling becomes difficult. When the Tg point is less than 10 ° C, the hardness of the obtained coating film becomes low, while when it exceeds 120 ° C, the workability of the obtained coating film deteriorates. If the hydroxyl value and the acid value are out of the above ranges, the workability and hardness cannot be balanced.

In the present invention, the glass transition temperature (Tg)
Is measured by differential thermal analysis (DSC), and the number average molecular weight is measured by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene.

The epoxy resin which is the component (b) in the composition of the present invention has a number average molecular weight of 1,000 or less and has at least one, and preferably two or more epoxy groups in the molecule, Epoxy equivalent is 100 to 50
It is preferably in the range of 0.

Examples of the epoxy resin (b) include various epoxy resins such as bisphenol A type, bisphenol F type and novolac type. Specific examples thereof include Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 154 [ Above, all manufactured by Yuka Shell Epoxy Co., Ltd.], Araldite 502, Araldite 6005 [all above manufactured by Ciba], Dow 33
2, Dow 331 [The above are all manufactured by Dow Chemical Co.]
And the like.

The amino resin which is the component (c) in the composition of the present invention includes amino components such as melamine, urea, benzoguanamine, acetoguanamine, steroganamin, spiroguanamine, dicyandiamide and formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like. The methylolated amino resin obtained by the reaction with the aldehyde component of. The methylol group of this methylolated amino resin has 1 to 6 carbon atoms.
The above-mentioned amino resins also include those etherified with lower alcohols.

The above-mentioned amino resin is preferably a lower alkyl etherified melamine resin or a lower alkyl etherified benzoguanamine resin obtained by etherifying a part or all of the methylol groups of a methylolated melamine resin or a methylolated benzoguanamine resin. As the lower alcohol used for the above etherification, methyl alcohol, ethyl alcohol, isobutyl alcohol and n-butyl alcohol are preferable, and these alcohols can be used alone or in combination of two or more for etherification.

Specific examples of the above melamine resin include, for example, U-Van 20SE, 225 [above, all manufactured by Mitsui Toatsu Co., Ltd.], Super Beckamine J820-60, L-117-60, L-109. -65, 47-50
Butyl etherified melamine resins such as 8-60, L-118-60, G821-60 [all of which are manufactured by Dainippon Ink and Chemicals, Inc.]; Cymel 300, 30;
3, 325, 327, 350, 730, 73
6, 738 (all manufactured by Mitsui Cytec Co., Ltd.), melan 522, 523 (all manufactured by Hitachi Chemical Co., Ltd.),
Nikarac MS001, MX430, MX650
[Sanwa Chemical Co., Ltd.], Sumimar M-55, M
-100, the same M-40S [Sumitomo Chemical Co., Ltd.], Regimin 740, the same 747 [all are Monsanto Co.] methyl etherified melamine resins; Cymel 232, the same 26
6, the same XV-514, the same 1130 [all are manufactured by Mitsui Cytec Co., Ltd.], Nikarac MX500, the same MX60
0, the same MS95 [all manufactured by Sanwa Chemical Co., Ltd.], Regimin 753, the same 755 [all manufactured by Monsanto],
Examples thereof include a mixed etherified melamine resin of methyl ether and butyl ether such as Sumimar M-66B (manufactured by Sumitomo Chemical Co., Ltd.).

Specific examples of the benzoguanamine resin include Cymel 1123 (a mixed etherified benzoguanamine resin of methyl ether and ethyl ether) and Cymel 1123-10 (a mixed ether of methyl ether and butyl ether) manufactured by Mitsui Cytec Co., Ltd. Benzoguanamine resin), Cymel 1128 (butyl etherified benzoguanamine resin), Mycoat 102 (methyl etherified benzoguanamine resin) and the like.

The lubricant which is the component (d) in the composition of the present invention is added to impart lubricity to the coating film, and specifically, it is a plant wax, an animal wax,
Mineral wax, petroleum wax, fatty acid ester wax, etc. can be mentioned, and these are 1 type or 2 types.
A mixture of more than one species can be used.

Examples of plant waxes include carnauba wax, cotton wax, and wax. Animal waxes include lanolin wax, gallow wax, and beeswax. Petroleum waxes include paraffin wax, microcrystalline wax, and wax. Examples include petrolatum, mineral waxes include ozokerite and montan wax, and petroleum waxes include polyethylene wax.

As the above fatty acid ester wax,
Fatty acid sucrose ester An esterification product of polyglycerin ether and fatty acid can be mentioned. Examples of the fatty acid sucrose ester include those disclosed in JP-A-6-293865. A monoester, diester or triester in which at least one of the eight hydroxyl groups present in sucrose is esterified with a fatty acid. The above polyester or a mixture of two or more of these esters.

Examples of the esterified product of polyglycerin ether and fatty acid include those disclosed in JP-A-7-138501. The polyglycerin ether in this esterified product is 4 to 4% of glycerin.
It is an etherified product of glycerin which is a 12-mer. The degree of esterification is such that 1/3 or more of the number of hydroxyl groups in polyglycerin ether is esterified.

The fatty acid in the esterified product of fatty acid sucrose ester and polyglycerin ether and fatty acid is preferably saturated or unsaturated fatty acid having 11 to 23 carbon atoms, and specific examples thereof include lauric acid, oleic acid, myristic acid and palmitic acid. , Stearic acid, behenic acid and the like.

Of these lubricants, the melting point is 25 to 15
It is preferable to use a wax having a temperature of 0 ° C. (more preferably 40 to 130 ° C.) such as carnauba wax, lanolin wax, paraffin wax, polyethylene wax, and fatty acid ester wax. These waxes may be in any form such as emulsion type, dispersion type and dissolution type.

By incorporating a lubricant into the coating composition of the present invention, it is possible to impart slipperiness to the surface of the coating film obtained from this composition and to reduce the frictional resistance of the coated surface.
Molding processability is improved and corrosion resistance after processing is also improved.

In the composition of the present invention, the mixing ratio of the polyester resin (a), the epoxy resin (b), the amino resin (c) and the lubricant (d) is such that the polyester resin (a) 10
The proportions of the components (b), (c) and (d) with respect to 0 parts by weight are in the following ranges in terms of solid content ratio.

Epoxy resin (b): 1 to 20 parts by weight, preferably 5 to 15 parts by weight, amino resin (c): 1 to 20 parts by weight, preferably 3 to 10 parts by weight, lubricant (d): 0 .1 to 10 parts by weight, preferably 0.3 to 5 parts by weight.

When the compounding amount of the epoxy resin (b) is less than 1 part by weight with respect to 100 parts by weight of the polyester resin (a), the adhesion of the obtained coating film becomes insufficient, and after the boiling water immersion test, for example, boiling water is used. The adhesion of the coating film after dipping for 1 hour in water is reduced, while when the blending amount exceeds 20 parts by weight, the color of the coating film obtained is large, and the extraction amount in the retort treatment is large and the hygiene is deteriorated. .

When the compounding amount of the amino resin (c) is less than 1 part by weight with respect to 100 parts by weight of the polyester resin (a),
The hardness of the obtained coating film is insufficient and the hardness of the coating film decreases. On the other hand, when the compounding amount exceeds 20 parts by weight, the processability of the obtained coating film decreases and the adhesion of the coating film after immersion in boiling water decreases. Sex decreases.

If the blending amount of the lubricant (d) is less than 0.1 parts by weight with respect to 100 parts by weight of the polyester resin (a), the slipperiness of the resulting coating film will be deteriorated, and for example, if the draw ratio exceeds 50%. When a severe process such as drawing is performed, the coating film is scratched and a smooth coated surface cannot be obtained. On the other hand, if the blending amount of the lubricant (d) exceeds 10 parts by weight, the flexibility of the obtained coating film is lowered, and the continuity of the coating film is impaired when severe processing is performed.

The form of the composition of the present invention is not particularly limited, but usually, the components (a), (b), (c) and (d) are dissolved or dispersed in an organic solvent. It is a thing. Examples of the organic solvent include (a),
An organic solvent capable of dissolving or dispersing the components (b), (c) and (d) is used. Specific examples include, for example, aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as cyclohexanone and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, alcohol solvents such as ethanol and butanol, and ethylene glycol. Examples thereof include ether alcohol solvents such as monoethyl ether and ethylene glycol monobutyl ether, and these can be used alone or in admixture of two or more.

In addition to the above-mentioned components, the composition of the present invention may contain known coloring pigments for coating materials; extender pigments; additives such as defoaming agents and coating surface adjusting agents; curing catalysts and the like.

The composition of the present invention can be applied to the outer surface and / or the inner surface of a can on which a metal plate or a metal plate is processed and then baked to form a coating film suitable for can coating.

Examples of the metal plate include beverage cans, cans for canning,
Any metal plate can be used as the lid and the cap, and examples thereof include an aluminum plate, a tin-free steel plate and a tin plate.

The composition of the present invention can be coated by a known coating method such as roll coater coating or spray coating. The coating film thickness is not particularly limited, but the dry film thickness is in the range of 3 to 18 μm. Is preferred. The baking condition of the coating film is usually about 90 seconds to about 330 degrees Celsius for about 5 seconds.
It takes about 30 minutes.

As described above, the cured coating film from the composition of the present invention can be formed on the inner and outer surfaces of the metal plate or the can, lid, and cap processed with the metal plate.

[0042]

EFFECTS OF THE INVENTION The composition of the present invention can form a coating film having an excellent balance between deep drawing workability and hardness and excellent adhesion, lubricity, hygiene and boiling water resistance.
Suitable as a paint for the inside and outside of the lid and the inside and outside of the cap.

[0043]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the following, "parts" and "%" are based on weight.

Production of Polyester Resin Solution Production Example 1 49.8 parts of terephthalic acid, 49.8 parts of isophthalic acid, 34.4 parts of hexahydroterephthalic acid, 28.adipic acid.
Charge 5 parts, neopentyl glycol 99.8 parts, trimethylolpropane 6.8 parts and polycondensation catalyst, heat,
Stirring is carried out while removing the water produced, and the esterification reaction is carried out.
A resin having an acid value of 1.0 and a Tg point of 60 ° C. was obtained. The obtained resin is methyl ethyl ketone / cyclohexanone = 50 /
A polyester resin solution A having a solid content of 30% was obtained by diluting with a mixed solvent of 50.

Production Example 2 37.7 parts of phthalic acid, 66.4 parts of isophthalic acid, 46.2 parts of hexahydrophthalic acid, 6.7 parts of trimellitic acid,
Charge 12.4 parts of ethylene glycol, 78.8 parts of neopentyl glycol, 6.8 parts of trimethylolpropane, and a polycondensation catalyst, heat and stir them to carry out an esterification reaction while removing water produced, and a number average molecular weight. 15,000
0, hydroxyl value 5.0 mgKOH / g, acid value 2.0, Tg point 80
° C resin was obtained. The obtained resin is methyl ethyl ketone /
Diluted with a mixed solvent of cyclohexanone = 50/50 to obtain a polyester resin solution B having a solid content of 30%.

Production Example 3 Polyester resin "TP-220" manufactured by Nippon Gosei Co., Ltd.
(Number average molecular weight 16,000, hydroxyl value 7.0 mgKOH / g
, Acid value 1 or less, Tg point 70 ° C.) was diluted with a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50 to obtain a polyester resin solution C having a solid content of 30%.

Production Example 4 Polyester resin "Byron 10" manufactured by Toyobo Co., Ltd.
3 "(number average molecular weight 22,000, hydroxyl value 5 mgKOH / g
, Acid value 2 or less, Tg point 45 ° C.) was diluted with a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50 to obtain a polyester resin solution D having a solid content of 30%.

Production Example 5 (for comparison) A polyester resin "Unitika Elitel UE-3300" manufactured by Unitika Ltd. (number average molecular weight 8,000, hydroxyl value 18 mgKOH / g, acid value 1 or less, Tg point 45 ° C.) was used. Diluted with a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50 to obtain a polyester resin solution E having a solid content of 30%.

Production Example 6 (for comparison) Polyester resin "Unitika Elitel UE-3230" manufactured by Unitika Ltd. (number average molecular weight 20,000,
A hydroxyl value of 5.0 mgKOH / g, an acid value of 1 or less, and a Tg point of 3 ° C.) were diluted with a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50 to obtain a polyester resin solution F having a solid content of 30%.

Production Example 7 (for comparison) Arakawa Chemical Co., Ltd. polymer resin "Arachid KA-1"
027U "(number average molecular weight 10,000, hydroxyl value 20
mgKOH / g, acid value 3, Tg point 15 ° C.) was diluted with a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50 to obtain a polyester resin solution G having a solid content of 30%.

Using the polyester resin solutions having a solid content of 30% obtained in the above Production Examples 1 to 7, coating materials of Examples and Comparative Examples were obtained.

Example 1 Solid content of 3 was obtained by uniformly stirring the following composition in a container.
0% paint was obtained.

[0053] (* 1) Cymel 303: Mitsui Cytec Co., Ltd., methyl etherified melamine resin, solid content about 100%.

(* 2) Epicoat 828: manufactured by Yuka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin, molecular weight about 350, epoxy equivalent about 190.

(* 3) Solvesso 100: A high boiling aromatic hydrocarbon solvent manufactured by Esso Oil Co., Ltd. (* 4) Nacure 5225: (Necure 5225) Dodecyl benzene sulfonic acid type curing catalyst manufactured by King Industries, USA.

Example 2 A solid content of 3 was obtained by uniformly stirring the following composition in a container.
0% paint was obtained.

[0057] (* 5) Epicoat 154: Yuka Shell Epoxy Co., Ltd.
Made, phenol novolac type epoxy resin, molecular weight about 5
00, epoxy equivalent of about 174.

(* 6) Polyethylene wax dispersion: A solvent dispersion of polyethylene wax having a melting point of 100 ° C. and a solid content of 16%.

Example 3 A solid content of 3 was obtained by uniformly stirring the following composition in a container.
0% paint was obtained.

[0060] (* 7) Cymel 325: Mitsui Cytec Co., Ltd., methyl etherified melamine resin, solid content about 80%.

(* 8) Carnauba Wax Dispersion: Ethanolene glycol monobutyl ether dispersion of 10% solids of carnauba wax, melting point of carnauba wax is about 70 ° C.

Example 4 A coating material having a solid content of 30% was obtained in the same manner as in Example 3 except that 0.5 part of Nacure 5225 was added as a curing catalyst to the composition.

Example 5 A solid content of 3 was obtained by uniformly stirring the following composition in a container.
0% paint was obtained.

[0064] (* 9) 50% Epicoat 1001: manufactured by Yuka Shell Epoxy Co., Ltd., "Epicoat 1001" (bisphenol A type epoxy resin, molecular weight about 900, epoxy equivalent about 4)
90) dissolved in methyl ethyl ketone to give a solid content of 50%
Solution.

(* 10) Paraffin wax dispersion:
Paraffin wax ethylene glycol monobutyl ether dispersion of solid content 10%, melting point of paraffin wax is about 70 ℃.

Example 6 A solid content of 3 was obtained by uniformly stirring the following composition in a container.
0% paint was obtained.

Polyester resin solution D 333.3 parts Cymel 303 10.0 parts Epicoat 154 15.0 parts Solvesso 100 55.1 parts Nacure 5225 0.5 parts Fatty acid ester wax dispersion (* 11) 5.0 parts Total 418 .9 parts (* 11) Fatty acid ester wax dispersion: hexaglycerin ether having a degree of polymerization of glycerin 6 and 8 hydroxyl groups in one molecule and lauric acid have a molar ratio of the former to the latter of 1: 6. 10 parts of the esterified product esterified at a ratio of
A lauric acid ester-based wax dispersion liquid added and dispersed in a part.

Comparative Example 1 Stir evenly with the above composition in a container to obtain a solid content of 30.
% Paint was obtained.

Comparative Example 2 Stir evenly with the above composition in a container to obtain a solid content of 30.
% Paint was obtained.

Comparative Example 3 Stir evenly with the above composition in a container to obtain a solid content of 30.
% Paint was obtained.

Comparative Example 4 50% Epicoat 1 prepared by dissolving 7.5 parts of Epicoat 1004 (* 12) in 7.5 parts of cyclohexanone in place of 7.5 parts of Epicoat 154 in Example 2.
15 parts of 004 solution and 2 parts of Solvesso 100
A coating material having a solid content of 30% was obtained in the same manner as in Example 2 except that the amount was changed from 4.5 parts to 17 parts.

(* 12) Epicoat 1004: manufactured by Yuka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin, molecular weight: about 1,400, epoxy equivalent: about 950.

Comparative Example 5 A coating material having a solid content of 30% was obtained in the same manner as in Example 2 except that the polyester resin solution G was used in place of the polyester resin solution B.

Comparative Example 6 A coating material having a solid content of 30% was obtained in the same manner as in Example 1 except that the lanolin wax was not added and the amount of Solvesso 100 was changed to 23.4 parts.

Comparative Example 7 A coating material having a solid content of 30% was obtained in the same manner as in Example 1 except that the lanolin wax content was 11 parts and the Solvesso 100 content was 49.1 parts.

Preparation of Test Coated Plates The coating materials obtained in the above Examples and Comparative Examples were coated with 0.25 mm thick #
A 5052 aluminum plate was coated so that the dry film thickness was 12 μm, and was baked for 30 seconds with hot air having a wind speed of 18 m / sec and a maximum material reaching temperature (PMT) of 270 ° C. to obtain a test coated plate. The following tests were conducted on the obtained test coated plates. The test results are shown in Table 1 below.

(1) Appearance of coating film: The appearance of the coating film of the test coated plate was visually observed. Those with no abnormalities were marked with a circle.

(2) Adhesion: JIS K-5400
8.5.2 (1990) cross-cutting-A tape of 1.5 mm x 1.5 mm is formed on the coating surface of the test coated plate in accordance with the tape method.
Individual pieces were prepared, an adhesive cellophane tape on the surface thereof was adhered, and the state of the coating film on the squares after rapid peeling was evaluated.

◯: No peeling is observed.

Δ: Peeling is slightly observed.

X: Marked peeling is recognized.

(3) Deep drawing workability: A deep drawing machine with a drawing ratio of 50% was used, a cross cut was put on the processed side surface of the test coated plate, and deep drawing was carried out to remove the coating film on the processed side surface. Was visually observed. The evaluation was performed according to the following criteria.

◯: No peeling is observed.

Δ: Slight peeling is observed.

X: Remarkable peeling is recognized.

(4) Immersion resistance in boiling water: After performing the deep drawing workability test (3) above, the processed article was immersed in boiling water at 100 ° C. for 1 hour, and then the processed side surface was subjected to the above ( The same adhesion test as in 2) was performed. The evaluation criteria are as follows.

◯: No peeling is observed.

Δ: Peeling is slightly recognized.

X: Marked peeling is recognized.

(5) Coating film hardness: JI was applied to the coating film of the test coated plate.
A pencil scratch test specified in SK-5400 84.2 (1990) was performed. The evaluation was performed by the tearing method.

(6) Hygiene: When a test coated plate having a coating area of 100 cm ² was immersed in 100 cc of water at 100 ° C. for 60 minutes, potassium permanganate consumption (ppm) of the extracted water was measured. did.

(7) Lubricity: For the coating film surface of the test coated plate, Egan Slip Tester Model No. 225-
3 (manufactured by Swing Albert Instrument Company) [Egan Slip Tester Model No.225-3 (Thwin
g Albert Instrument Co.)], and the dynamic friction coefficient was measured under the condition of a pulling speed of 10 cm / min.

[0093]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09D 163/00 PKL C09D 163/00 PKL PKQ PKQ (72) Inventor Toshio Wakisaka 4 Higashihachiman, Hiratsuka City, Kanagawa Prefecture Chome 17-1 Kansai Paint Co., Ltd.

Claims (3)

[Claims] 1. (a) Number average molecular weight 10,000 to 10
50,000, static glass transition temperature 10 to 120 ° C., hydroxyl value 1 to 15 mg KOH / g, acid value 10 or less per 100 parts by weight of polyester resin, (b) number average molecular weight of 1.00
A coating composition comprising 1 to 20 parts by weight of an epoxy resin of 0 or less, (c) 1 to 20 parts by weight of an amino resin, and (d) 0.1 to 10 parts by weight of a lubricant. 2. The amino resin (c) is at least one selected from methyl etherified melamine resin and benzoguanamine resin, butyl etherified melamine resin and benzoguanamine resin, mixed etherified melamine resin of methyl ether and butyl ether and benzoguanamine resin.
The coating composition according to claim 1, which is a seed. 3. The coating composition for can coating according to claim 1 or 2.