JP2001031893A - Coating composition containing aluminum pigment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum pigment-containing coating composition which has a high solid content, can form a coating film having excellent bright appearance and coating performances, and has excellent mechanical stability for a long period. SOLUTION: This aluminum pigment-containing coating composition comprises 100 pts.wt. of a thermosetting binder component, (C) 5 to 200 pts.wt. of an aluminum pigment having an average particle diameter (D50) of 7 to 30 μm, and (D) inorganic particles having an average particle diameter of 1 nm to 5 μm in an amount of 5 to 50 pts.wt. per 100 pts.wt. of the aluminum pigment. The thermosetting binder component comprises (A) 40 to 95 pts.wt. of a polyol having a number-average mol.wt. of 300 to 4,000 and a hydroxyl group value of 30 to 600 KOH mg/g and (B) 5 to 60 pts.wt. of an amino resin cross-linking agent which comprises a methyletherized amino resin and/or an amino resin etherized with a mixture of methyl ether with butyl ether, and has a mono- nuclear unit content of >=40 wt.% and one or less imino group per nucleus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum pigment-containing coating composition having excellent mechanical stability and capable of forming a coating film having excellent glitter even after a lapse of mechanical operation, and a paint finish using the composition. The present invention relates to a method and a coated metal plate or a coated metal can on which a coating of the composition has been formed.

[0002]

2. Description of the Related Art Conventionally, there has been developed a practical method for obtaining a metallic glitter such as an aluminum can by applying a paint to a steel can or a metal can coated with a white film (including a white coat). I didn't.

[0003] A gravure ink containing aluminum pigment is back-printed on a transparent polyester (PET) film,
A metal glitter can be obtained by thermally laminating the back-printed surface and a steel can (mainly a three-piece can) via an adhesive.
Generally, a large amount of an organic solvent is contained, and there are problems in working environment and global environment.

[0004] In order to obtain a metallic luster such as an aluminum can has, it is conceivable to apply a paint containing an aluminum pigment. However, in order to obtain a desired metallic glitter, an aluminum pigment having a large particle diameter (usually, an aluminum pigment) is usually used. 7 μm or more)
Must be used. However, aluminum pigments having a large particle size have poor mechanical stability with respect to such a share in a paint supply (circulation) device or a coating device, and the luster is reduced over time when the machine is operated using these devices. There was a problem of going. This mechanical stability can be improved by diluting the paint with an organic solvent to reduce the aluminum pigment concentration in the paint,
As described above, dilution with an organic solvent has problems in working environment and global environment.

[0005] An object of the present invention is to form a coating having a metallic glitter such as that of an aluminum can on an object to be coated such as a steel can or a metal can coated with a white film (including a white coat) and an organic solvent. And to provide a coated metal plate and a coated metal can excellent in metallic glitter using the coating composition.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a coating composition containing a specific crosslinkable binder component, an aluminum pigment having a specific particle size and specific inorganic fine particles, and a coating composition containing the same. The present inventors have found that the above objects can be achieved by using the composition, and have completed the present invention.

Thus, the present invention provides (A) a number average molecular weight of 300 to 4,000, a hydroxyl value of 30 to 600 KOH mg
/ G of 40 to 95 parts by weight of a polyol component and at least one amino resin selected from (B) a methyl etherified amino resin and a mixed etherified amino resin of methyl ether and butyl ether, and a mononuclear substance content (C) average particles based on 100 parts by weight of a thermosetting binder component composed of 5 to 60 parts by weight of an amino resin crosslinking agent having an average of 1 or less imino groups per nucleus in an amount of 40% by weight or more. ₅ to 200 parts by weight of an aluminum pigment having a diameter (D ₅₀ ) in the range of 7 to 30 μm, and (D) having an average particle diameter of 1 nm to 5 μm with respect to 100 parts by weight of the aluminum pigment (C). Inorganic fine particles within the range of 5 to 50
It is intended to provide a coating composition characterized by containing parts by weight.

[0008] The present invention also provides a coating finishing method, which comprises coating the above-mentioned coating composition on a substrate, and then applying a clear coating on the coated or uncured coating film. Things.

Further, the present invention provides a coated metal plate excellent in glitter, comprising a coating film of the coating composition formed on a substrate and a clear coating film formed on the coating film of the coating composition. A coated metal can is provided.

Hereinafter, the present invention will be described in detail.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the coating composition of the present invention will be described. The coating composition of the present invention is a coating composition capable of forming a coating film having metallic glitter, and has the following (A):
Contains the components (B), (C) and (D) as essential components.

Polyol Component (A) The polyol component (A) in the composition of the present invention has a number average molecular weight of 300 to 4,000, preferably 5 to 4,000.
In the range of from 0.00 to 2,000 and a hydroxyl value of from 50 to 6
00KOHmg / g, preferably 100-400KOH
mg / g and an acid value of 5 KO.
It is preferred that it is Hmg / g or less. In the present invention, the number average molecular weight is measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The polyol component has a number average molecular weight of 300.
If less, the curability, coating film hardness, and processability decrease,
If it exceeds 4,000, the viscosity increases and the mechanical stability of the aluminum pigment described below in the composition deteriorates. In addition, it is preferable that the hydroxyl value of the polyol component is within the above range from the viewpoint of curability, coating film hardness, processability, adhesion, and the like.

As the polyol component (A), for example,
Examples thereof include polyester polyol, polyether polyol, and acrylic polyol.

[0015] Commercial products of the polyol component (A) include:
As the polyester polyol, for example, Adecan New Ace F18-62, F7-68, Y9-10, Y52-13, F1212-5, YG-108, YG-226, YG-240, YG-240 −111, Y
G-510, YT-651 (all of which are manufactured by Asahi Denka Kogyo Co., Ltd., trade names); FLEXOREZ148, 1
88 (all, manufactured by King Industries, USA) (TONE0200, 0201, 02)
10, 2221, 0230, 0249, 030
1, 0305, 0310 (all, manufactured by Union Carbide Co., USA, trade name, polycaprolactone polyol); Praxel 205, 208, 21
0, 212, 220, 230, 303, 30
5, 308, 312, and 320 (all, manufactured by Daicel Chemical Industries, Ltd., trade name, polycaprolactone polyol). Examples of the polyether polyol include ADEKA polyether P. −
700, P-1000, BPX-33, G-70
0, G-1500, G-3000B, T-400
(These are all manufactured by Asahi Denka Kogyo Co., Ltd., trade names); BA
8 glycol, BA10 glycol (all of these are trade names of Nippon Emulsifier Co., Ltd.); PTMG650, PTM
G850, PTMG1000, PTMG1300, PT
MG1500, PTMG2000, PTMG3000
(All mentioned above, manufactured by Mitsubishi Kasei Corporation, trade names).

Amino Resin Crosslinking Agent (B) The amino resin crosslinking agent which is the component (B) in the composition of the present invention is a crosslinking agent capable of reacting with the polyol component (A) to form a cured film, At least one amino resin selected from the group consisting of a fluorinated amino resin and a mixed etherified amino resin of methyl ether and butyl ether, and having a mononuclear content of 40% by weight or more, preferably 45 to 80% by weight, and triazine The number of imino groups per ring nucleus is one or less. When the content of the mononuclear body is less than 40% by weight, the viscosity tends to be high and the mechanical stability of the aluminum pigment (C) tends to be reduced. If the amount of imino groups per nucleus exceeds one, the processability and adhesion of the resulting cured film tend to deteriorate.

Examples of the methyl etherified amino resin having a mononuclear body content of 40% by weight or more and an average of one imino group per nucleus of one or less include Cymel 300, Cymel 301, Cymel 303 and Cymel 350. (All of which are manufactured by Mitsui Cytec Co., Ltd., methyl etherified melamine resin, trade name); Nicaraq MW-30M, Nikalac MW-30, Nikarac MW-24X (all of which are manufactured by Sanwa Chemical Co., Ltd., methyl Nikarac SB-401 (manufactured by Sanwa Chemical Co., Ltd., methyl etherified benzoguanamine resin)
(Product name).

Examples of the mixed etherified amino resin of methyl ether and butyl ether having a mononuclear content of 40% by weight or more and an imino group content of one or less per nucleus include Cymel 232, 235 and 236. , 238, 28
5 (all above, manufactured by Mitsui Cytec Co., Ltd., mixed etherified melamine resin of methyl ether and butyl ether, trade name); Niclac MX-45 (manufactured by Sanwa Chemical Co., Ltd., mixed ether of methyl ether and butyl ether) Melamine resin, trade name); Nikarac BX-4
000 (manufactured by Sanwa Chemical Co., Ltd., mixed etherified benzoguanamine resin of methyl ether and butyl ether,
(Product name).

Aluminum pigment (C) The aluminum pigment which is the component (C) in the composition of the present invention imparts metallic glitter to the coating film to be formed, and has an average particle diameter (D ₅₀ ) of 7 to 30 μm. , Preferably 1
Aluminum pigment in the range of 0 to 20 μm.
If the particle size of the aluminum pigment is less than 7 μm, the metallic glitter tends to be inferior, while if it exceeds 30 μm, the mechanical stability of the aluminum pigment tends to decrease.

The aluminum pigment (C) may be untreated or surface-treated such as oleic acid, stearic acid or resin coating. The aluminum pigment (C) may be either a non-leafing type or a leafing type, or may be a colored aluminum pigment having a colored surface.

Commercially available aluminum pigments (C) include non-leafing types such as Alpaste TD120T, TD180T, TD200T, and TD200T.
D280T, 5620NS, 5640NS, 56
90N, UF300, TCR3040, TCR3
080, TCR3130, TCR2020, TC
R2060, TCR2150 (all of which are manufactured by Toyo Aluminum Co., Ltd., trade names); SAP620N, SA
P630N, SAP640N, SAP650N, SAP
710N, SAP715N, SAP720N, SAP7
26N, LB582, LB584, LB586 (or more,
Each of them can be exemplified by Showa Aluminum Powder Co., Ltd.).
AP130 (all above, Showa Aluminum Powder Co., Ltd.)
Manufactured). Examples of the colored aluminum pigment include, for example, friend color 500RG,
500BG, 500SI, 500RE, 500
OR, 500GR and 500BL (all of which are manufactured by Showa Aluminum Powder Co., Ltd.).

Inorganic Fine Particles (D) The inorganic fine particles which are the component (D) in the composition of the present invention include:
The aluminum pigment (C) is blended for the purpose of improving mechanical stability in a coating material, and has an average particle diameter of 1 nm to 5 μm, preferably 3 nm to 1 μm,
More preferably, inorganic fine particles having a size in the range of 5 to 100 nm can be used without any particular limitation. If the average particle size is less than 1 nm, the viscosity of the coating material increases and the coating workability deteriorates. On the other hand, if the average particle size exceeds 5 μm, the effect of improving the sufficient mechanical stability cannot be obtained, and the mechanical force is considerably applied. After carrying out or circulating by means of a pump or a pump, it becomes impossible to form a coating film having excellent glitter.

Examples of the type of the inorganic fine particles (D) include silica fine particles, barium sulfate, calcium carbonate, talc, mica, clay and the like.

Commercially available inorganic fine particles (D) include SYLYSIA (Sylysia) 25 as silica fine particles.
0, 256, 310, 320, 350, 35
8, 430, 431, 435, 436, 44
0, 445, 530, 540, 550, 73
0, 740 (both are Fuji Silysia Chemical Ltd.)
SYLOPHOBIC 100, 200 (all of which are manufactured by Fuji Devison Chemical Co., Ltd., trade names); AEROSIL (Aerosil) 130, 200, 200V, 200CF, 200FAD , 300, 300CF, 380, R972, R974, RX200, RY200,
R202, R805, R812, and OX50 (all, manufactured by Nippon Aerosil Co., Ltd., trade names); Admafine SO-C1, SO-C2, SO-C3,
SO-C5 (all above, Admatex Corporation)
Product name).

Commercially available inorganic fine particles (D) other than silica fine particles include Varifine BF-1, BF-10 and BF-10.
Same BF-20, Same BF-1L, Same BF-10 ・ P, Same B
F-2 (both are made by Sakai Chemical Industry Co., Ltd., trade name,
Barium sulfate fine powder); LMS-300, LMS-20
0, LMS-100, LMP-100, LMG-10
0, LMR-100 (all, manufactured by Fuji Talc Industries, Ltd., trade name, talc); ASP-072, ASP
-100, ASP-200, ASP-170, ASP-
600 (all, manufactured by ENGELHARD (Engelhard), trade name, talc); and A-11 (Tsuchiya Kaolin Industries, Ltd., trade name, mica powder).

The coating composition of the present invention contains the above-mentioned polyol component (A), amino resin crosslinking agent (B), aluminum pigment (C) and inorganic fine particles (D) as essential components.

In the composition of the present invention, the mixing ratio of the polyol component (A) and the amino resin crosslinking agent (B) is determined based on 100 parts by weight of the thermosetting binder component, which is the total solid content of both components. It is obtained that A) is in the range of 40 to 95 parts by weight, preferably 50 to 80 parts by weight, and the amino resin crosslinking agent (B) is in the range of 5 to 60 parts by weight, preferably 20 to 50 parts by weight. It is suitable from the viewpoint of the curability of the coating film, the hardness of the coating film, the workability and the like.

The amount of the aluminum pigment (C) is as follows:
5 to 2 based on 100 parts by weight of the thermosetting binder component
00 parts by weight, preferably in the range of 50 to 150 parts by weight, and the compounding amount of the inorganic fine particles (D) is 5 to 100 parts by weight of the aluminum pigment (C).
When the amount is within the range of 50 parts by weight, preferably 10 to 30 parts by weight, the viscosity of the obtained coating composition, coating workability (such as mechanical stability of the coating during coating circulation), and the brilliancy of the obtained coating film. It is suitable from the viewpoint of feeling, workability, and the like.

The coating composition of the present invention comprises the above (A)
In addition to the essential components (B), (C) and (D),
If necessary, organic resin fine particles (E), coloring pigments; phenolic resin other than polyol component (A), acrylic resin, polyester resin, alkyd resin, epoxy resin,
Modified resins such as polyolefin resins and polybutadiene resins; and may contain dispersants, defoamers, coating surface conditioners, curing catalysts, fragrances, solvents, and the like.

In the composition of the present invention, the above-mentioned organic resin fine particles (E), which are blended as required, are adsorbed on the surface of the aluminum pigment and are surface-modified to improve the coating workability. Yes, average particle size 1nm ~ 1μ
m, preferably 50-500 nm. Examples of the resin type of the organic resin fine particles (E) include polyethylene,
Polypropylene, polytetrafluoroethylene; Nylon such as Nylon 11 or Nylon; Modified polyethylene such as carboxylic acid-modified polyethylene; Modified polypropylene such as maleated polypropylene; Silicon rubber, acrylic resin, urethane resin, phenol resin, etc. it can. Of these, acrylic resins are preferred,
Among them, in the presence of a reactive emulsifier having a polymerizable unsaturated group such as an allyl group, a water-soluble polymerization initiator such as a water-soluble azoamide compound is used as a polymerization initiator to form two polymerizable unsaturated groups. Divinylbenzene, 1,6-
Internally crosslinked organic resin fine particles obtained by emulsion polymerization of a polymerizable unsaturated monomer component containing a polyfunctional monomer such as hexanediol di (methacrylate) are preferred. The compounding amount of the organic resin fine particles (E) is preferably not more than 40 parts by weight, and more preferably in the range of 1 to 30 parts by weight based on 100 parts by weight of the aluminum pigment (C).

In the composition of the present invention, the above-mentioned coloring pigment to be blended if necessary may be any coloring pigment which can be usually used in the field of coatings, for example, cyanine blue,
Organic coloring pigments such as organic red pigments such as cyanine green, azo-based and quinacridone-based; and inorganic coloring pigments such as titanium white, titanium yellow, red iron black, carbon black, and various calcined pigments.

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.

By coating the coating composition of the present invention on an object to be coated and curing, a coating film having excellent glitter can be obtained.

The coating composition of the present invention is, for example, roll-coated, spray-coated, brush-coated, bar-coated,
It can be coated on a substrate by a method such as roller coating, offset printing, silk screen printing, and the like. The coating film thickness may be appropriately selected within a range where a good coating film appearance can be obtained.
The range is about 20 to about 20 μm, and when used for cans, the range is preferably about 1 to 8 μm. The baking condition of the coating film is not particularly limited as long as the coating film is cured, and is usually at 150 to 300 ° C. for 10 seconds to 2 hours.
Suitably, it is in the range of 0 minutes.

The coating composition of the present invention is particularly suitable as a base coat paint (including a printing paint) for the outer surface of a can, and the coating surface of the object to be coated is preferably formed into a can after coating. The surface of a metal plate, a chemical conversion treated metal plate or a resin film laminated metal plate which is to be the outer surface of the can; the metal plate, the chemical conversion treated metal plate or the resin film laminated metal plate is preferably the outer surface of a can formed by molding into a can. I have.

Next, the paint finishing method of the present invention will be described.

In the method of finishing the coating of the present invention, the above-mentioned coating composition of the present invention is applied on a substrate, and then a clear coating is applied on the coated cured or uncured coating film.

The substrate to be coated in the coating and finishing method of the present invention 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.

As the coating surface of the above-mentioned base material, the surface of a metal plate, a chemical conversion-treated metal plate or a resin film-laminated metal plate which is formed into a can after coating and becomes an outer surface of the can; It is suitable that the resin film laminated metal plate is an outer surface of a can formed by molding into a can.

In the above method, the coating composition of the present invention can be coated on a substrate by the above-mentioned coating method. The coating film thickness may be appropriately selected within a range in which a good coating film appearance can be obtained, and is usually in a range of about 1 to 20 μm as a dry coating film thickness. A range of 1 to 8 μm is preferred.

As the clear paint applied on the coating film coated with the coating composition of the present invention, a clear paint known per se can be used as the top clear paint. Examples of the resin type of the clear paint include an acrylic resin / amino resin type, a polyester resin / amino resin type, an epoxy resin / amino resin type, and an epoxy ester resin / amino resin type. The clear paint may be a color clear paint.

The coating method of the coating composition of the present invention and the clear coating is performed on a cured coating film of the coating composition of the present invention.
A so-called two-coat two-bake system may be used, or a so-called two-coat one-bake system in which the uncured coating film of the coating composition of the present invention is wet-on-wet.

By forming a clear coating film on the coating film of the coating composition of the present invention, the performance as an overall coating film, for example, hardness, scratch resistance, stain resistance, chemical resistance, water resistance, etc. Can be improved.

In the coating finishing method of the present invention, after forming a cured coating film of the coating composition of the present invention, if necessary,
Printing with a printing ink may be performed on the coating film, and then a clear paint may be applied. The type of printing ink and the type of printing ink are not particularly limited, but a thermosetting printing ink can be suitably used. Further, the coating composition of the present invention may be partially applied on a substrate, that is, printed as a printing coating (ink), and a clear coating may be applied on the coating film.

The coated article obtained by the coating finishing method of the present invention has excellent glitter. When the painted article has a curved surface or when the painted article is processed to have a curved surface, the glitter of the coating film becomes more remarkable on the curved surface.

[0046]

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

Production Example 1 Production of Organic Resin Fine Particles 1 equipped with a stirrer, thermometer, cooling pipe and 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 Kasei Co., Ltd., an aqueous solution of a sulfosuccinic allyl group-containing anionic reactive emulsifier, solid content 39%.

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

Example 1 "ADEKA NEW ACE YG-108" (a polyester polyol having a number average molecular weight of about 1,000 and a hydroxyl value of about 120 mgKOH / g, manufactured by Asahi Denka Kogyo KK)
50 parts and "Nikarac MX-45" (manufactured by Sanwa Chemical Co., Ltd., trade name, methyl-butyl mixed etherified melamine resin, solid content 100%) 50 parts (solid content of 50%)
Parts), and 20 parts of AEROSIL 200 (trade name, manufactured by Nippon Aerosil Co., Ltd., silica fine particles, average particle size of about 12 nm) and an organic solvent mixed solution A (Swazol # 1500 ( Note 3) / cyclohexanone / ethylene glycol monobutyl ether = 4
(0/30/30 (weight ratio)), and sand mill dispersion was performed. 107 parts of "Alpaste 5640NS" (trade name, non-leafing type aluminum pigment paste, manufactured by Toyo Aluminum Co., Ltd., average particle diameter of about 14 μm, active ingredient content of 70%) (total amount of active ingredient) 75 parts), Disperbyk-110 (B
9.6 parts (5 parts by weight of the active ingredient, manufactured by YK Chemie, a wetting and dispersing agent having a phosphate group, the active ingredient amount of 52%)
10 parts of organic resin fine particles (1) obtained in Production Example 1 and NAC
URE5225 (King Industries, USA)
Amine salt solution of dodecylbenzene sulfonic acid, curing catalyst, 4 parts of active ingredient (25%) (1 part in active ingredient) were added, stirred, mixed, and diluted with the above organic solvent mixture A to lower the viscosity. 0.7Pa · s (manufactured by Tokimec Co., Ltd.
“TVE-20H” rotational viscometer, 50 rpm, 25 ° C.,
The same was applied to the following) to obtain a coating composition. The solid content of the obtained coating composition was 65%.

(Note 3) Swazol # 1500: high boiling aromatic petroleum solvent manufactured by Cosmo Oil Co., Ltd.

Examples 2 to 13 and Comparative Examples 1 to 7 In the same manner as in Example 1, except that the composition was changed to the composition shown in Table 1 below, each component was mixed and the viscosity was adjusted to 0.1. Each coating composition of 7 Pa · s was obtained. The amount of each component in Table 1 is indicated by parts by weight of the active ingredient. In Comparative Example 1, “Elitel UE3350”
(Note 4) was previously dissolved in the organic solvent mixed solution A and then blended. The solid content of each of the obtained coating compositions is described in Table 1.

(Note 4) Elitel UE3350: manufactured by Unitika Ltd., trade name, polyester polyol, number average molecular weight 5,000, hydroxyl value about 25.

[0054]

[Table 1]

[0055]

[Table 2]

(Note) in the above Table 1 has the following meaning.

(Note 5) Plaxel 308: manufactured by Daicel Chemical Industries, Ltd., trade name, polycaprolactone polyol, number average molecular weight: about 850, hydroxyl value: about 195.

(Note 6) Cymel 303: manufactured by Mitsui Cytec Co., Ltd., trade name, methylated melamine resin. (Note 7) Cymel 325: manufactured by Mitsui Cytec Co., Ltd., trade name, imino group type methylated melamine resin, the amount of imino groups per nucleus exceeds one on average.

(Note 8) AEROSIL 300: manufactured by Nippon Aerosil Co., Ltd., trade name, silica fine particles, average particle diameter of about 7 nm. (Note 9) Admafine SO-C2: manufactured by Admatechs Co., Ltd., trade name, silica fine particles, average particle size of about 0.5
μm. (Note 10) Varifine BF-10: Sakai Chemical Industry Co., Ltd.
Made, trade name, barium sulfate fine particles, average particle size about 60n
m. (Note 11) Thylsia 770: Fuji Silysia Chemical Ltd.
Product name, silica fine particles, average particle diameter about 6 μm.

(Note 12) Alpaste 0620MS: trade name, manufactured by Toyo Aluminum Co., Ltd., leafing type aluminum pigment paste, average particle size about 14 μm. (Note 13) SAP620N: Showa Aluminum Powder Co., Ltd.
Product name, non-leafing type aluminum pigment paste, average particle size about 16 μm. (Note 14) SAP2173: Showa Aluminum Powder Co., Ltd.
Product name, non-leafing type aluminum pigment paste, average particle size about 6 μm. (Note 15) LB588: manufactured by Showa Aluminum Powder Co., Ltd.
Trade name, non-leafing type aluminum pigment paste, average particle size about 36 μm.

Mechanical Stability Test of Coating Composition For each coating composition obtained in each of the above Examples and Comparative Examples,
A mechanical stability test during roll coating was performed.
That is, the paint flows down between the pickup roll and the distributor roll via the gear pump, and the paint transferred from the coating roll to the backup roll is scraped off by a doctor blade in contact with the backup roll, and the paint is passed through the gear pump. Using a roll coater having a circulation mechanism in which paint flows down between the pickup roll and the distributor roll, drying is performed on a 0.2 mm-thick tin-free steel plate at the beginning of circulation, 30 minutes and 1 hour after the start of circulation. The film was coated so as to have a film thickness of about 3 μm, and baked by passing through a tunnel-type conveyor oven at an ambient temperature of 210 ° C. for 2 minutes. The coating film appearance of the obtained coated plate was evaluated according to the following criteria. Table 2 shows the test results. ：: Very excellent in brightness unique to aluminum ○: Excellent in brightness unique to aluminum △: Inferior to brightness unique to aluminum ×: There is no bright feeling unique to aluminum, and a dull gray state is exhibited.

Preparation of Test Coated Plate Each of the coating compositions obtained in the above Examples and Comparative Examples was coated with a thickness of 0.1%.
A 20 mm tin-free steel plate and a 12 μm-thick homo PET (polyethylene terephthalate) sheet are thermocompression-bonded to a PET steel plate so as to have a dry film thickness of 3 μm, and a tunnel-type conveyor oven at an ambient temperature of 210 ° C. It was passed through for 2 minutes and baked. After the coated plate has cooled, an acrylic resin /
Melamine resin thermosetting clear paint with dry film thickness of 5μm
And passed through a tunnel-type conveyor oven at an ambient temperature of 210 ° C. for 2 minutes and baked to obtain a test coated plate. The obtained test coated plate was subjected to a pencil hardness, impact workability and adhesion test according to the following test methods. The test results are shown in Table 2 below.

Test method Pencil hardness: JIS K5400 was applied to each test coated plate.
A pencil scratch test specified in 4.2 (1990) was performed, and evaluation was performed by a tear method.

Adhesion: JIS K5400 8.5.2.
According to the grid-tape method specified in (1990), 100 squares of 1 mm x 1 mm were formed on the coating surface of the test coated plate, and a cellophane adhesive tape was adhered to the surface and the tape was instantaneously peeled off. The degree of peeling of the coating film was determined according to the following criteria. ：: No peeling of the coating film was observed. Δ: Little peeling of the coating film was observed. ×: The peeling of the coating film was remarkable.

Impact workability: JIS K5400
According to the DuPont impact test specified in 3.2 (1990), the point diameter of the point of impact is 1/2 inch and the weight of the falling weight is 5
Under conditions of 00 g and a drop distance of 30 cm, impact processing was performed from the back side of the coating surface of the test coated plate. The state of cracking of the coating film after the test was visually evaluated based on the following criteria. ：: No cracking of the coating film was observed. Δ: Cracking of the coating film was slightly recognized. ×: Cracking of the coating film was remarkable.

[0066]

[Table 3]

[0067]

[Table 4]

[0068]

Industrial Applicability The coating composition containing the aluminum pigment of the present invention has improved mechanical stability and can maintain excellent glitter of a coating film obtained by long-term stirring and circulation. Further, since the mechanical stability is improved, it is not necessary to use a large amount of a solvent for lowering the viscosity, and the coating can be performed at a high solid content.

Further, the coating method of the present invention makes it possible to form a comprehensive coating film having a metallic appearance with excellent coating film performance such as hardness, adhesion and workability, and excellent glitter.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hideki Yoshihara 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Inside Kansai Paint Co., Ltd. (72) Inventor Motoko Akiyama 4-1-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Seki F-term in Nishi Paint Co., Ltd. (reference) 4D075 AE03 CB04 DA06 DB07 DC42 EA02 EA05 EA43 EB32 EB35 EB45 EB52 EB53 EB55 EB56 EB57 EC01 EC10 EC53 4J038 DA162 DA172 DD001 DD241 GA03 HA066 KA03 KA20 MA14 NA01

Claims (6)

[Claims] (A) a number average molecular weight of 300 to 4,000
0, 40 to 95 parts by weight of a polyol component having a hydroxyl value of 30 to 600 KOH mg / g, and (B) at least one amino resin selected from a methyl etherified amino resin and a mixed etherified amino resin of methyl ether and butyl ether. 5 to 60 parts by weight of an amino resin crosslinking agent having a mononuclear body content of 40% by weight or more and an average of one imino group per nucleus of 1 or less,
(C) ₅ to 200 parts by weight of an aluminum pigment having an average particle diameter (D ₅₀ ) in the range of 7 to 30 μm with respect to 100 parts by weight of the thermosetting binder component comprising A coating composition comprising (D) 5 to 50 parts by weight of inorganic fine particles having an average particle diameter in the range of 1 nm to 5 µm with respect to 100 parts by weight. 2. The polyol component (A) has a melting point of 50 ° C.
The coating composition according to claim 1, which is a polyester resin having a viscosity of 1 Pa · s (Pascal · second) or less at 75 ° C or lower. 3. The inorganic fine particles (D) having an average particle size of 5 n
3. The coating composition according to claim 1, wherein the coating composition is a silica fine powder having a diameter in the range of m to 100 nm. 4. An aluminum pigment (C) 100
The coating composition according to any one of claims 1 to 3, wherein the coating composition contains 1 to 30 parts by weight of organic resin fine particles (E) having an average particle diameter of 1 nm to 1 µm with respect to part by weight. 5. A method comprising applying the coating composition according to claim 1 on a substrate, and then applying a clear coating on the coated or uncured coating film. And paint finish method. 6. A glitter comprising a coating film of the coating composition according to claim 1 formed on a substrate, and a clear coating film formed on the coating film of the coating composition. A coated metal plate or coated metal can with excellent feeling.