JP2007211079A - Design coating material for precoated metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a design coating material for precoated metal, forming a relief pattern and having excellent processability and adhesiveness. <P>SOLUTION: (1) The art coating material for precoated metal contains 50-2,000 pts.mass of a solvent (B) based on 100 pts.mass of the solid component of a styrene-butadiene copolymer resin (A) and (2) an art coating material for precoated metal described in the item (1) wherein the solvent (B) is a ketone-based solvent. (3) A coating film forming method is formed an art coating film for precoated metal on a metal plate which may be subjected to chemical conversion treatment on its surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a designable coating material for a precoat metal which forms a pattern having a concavo-convex feeling and is excellent in workability and adhesion.

  In recent years, in the field of pre-coated metal sheets for building materials and equipment processing, there has been a demand for coated metal sheets having excellent cosmetic properties, and inventions relating to paints containing organic resin fine particles are known (patent documents) 1).

  In addition, there is a paint in which a coating film composed of an acrylate-styrene copolymer and / or a methacrylic ester-styrene copolymer having a specific average particle diameter and a binder exhibits a velvety appearance (Patent Literature). 2).

  In addition, a paint film in which a bead pigment is added to a polyvinyl chloride sol using a specific diluent solvent is applied to a substrate through a polyvinyl chloride resin layer, and a dried film is provided to form a coating film. There is known a method of obtaining (Patent Document 3). In addition, an invention is known which is a non-aqueous dispersion resin composition comprising polymer fine particles having a volume average particle size of 5 to 100 μm, polymer fine particles having a volume average particle size of less than 5 μm, and a dispersing resin. (Patent Document 4).

  Furthermore, a coating material containing an epoxy resin-modified polyester resin, a polyester resin or an acrylic resin, a low-nuclear body methylated melamine resin, and a mixture of a sulfonic acid and an amine is disclosed (Patent Document 5). In addition, a polymer solution in which two or more types of incompatible polymers having an ability to form a coating film are dissolved in an organic solvent, and the coating film is coated and dried on a substrate sheet. An invention relating to a polymer solution in which a concavo-convex pattern is formed on the surface is disclosed (Patent Document 6).

  However, the coating film obtained by the prior art has very fine irregularities and has a uniform coating color, and thus has a tendency to be flat and lack a high-class feeling. When viewed from a distance, the irregularities could not be recognized. Therefore, studies have been made to make the unevenness larger in order to give a higher-class feeling, but it has not been easily achieved by conventional studies.

JP-A-1-152172 JP-A-2-292373 Japanese Patent Laid-Open No. 5-116252 JP 2001-220546 A JP 2002-146280 A JP 2005-298722 A

  The objective of this invention is providing the designable coating material for precoat metals which can form the pattern with a large uneven | corrugated feeling, and can form the coating film which is excellent in workability and adhesiveness.

  As a result of intensive studies to solve the above problems, the present inventors have found that a large uneven pattern is formed by the design coating for precoat metal containing styrene / butadiene copolymer resin (A) and solvent (B). As a result, the present invention has been completed.

  By using the coating composition of the present invention, a precoated steel sheet that forms a pattern with an uneven feeling and is excellent in workability and adhesion can be obtained. The pattern with this concavo-convex feeling can be sufficiently recognized even at a distance (about 10 to 20 m).

The design paint for the precoat metal of the present invention is
A styrene / butadiene copolymer resin (A) and a solvent (B) are included.

Styrene-butadiene copolymer resin (A)
Examples of the styrene / butadiene-based copolymer resin (A) include the following styrene / butadiene-based copolymer resins (a1) and styrene / butadiene-based copolymer resins (a2).

  Styrene / butadiene copolymer resin (a1): The styrene / butadiene copolymer resin (a1) that can be used in the present invention is 5 to 35% by mass of styrene with respect to the total amount of the constituent monomers. , Preferably 20 to 30% by mass, butadiene 95 to 65% by mass, preferably 80 to 70% by mass, and other radical polymerizable unsaturated monomer (1) copolymerizable therewith 0 to 20% by mass. A styrene / butadiene copolymer resin (a1) obtained by copolymerizing a monomer component by an emulsion polymerization reaction or the like.

  Examples of the other radical polymerizable unsaturated monomer (1) include alkyl acrylates such as methyl acrylate, alkyl methacrylates such as methyl methacrylate, vinylcyan and divinylbenzene such as acrylonitrile, monoethylene glycol dimethacrylate, polyethylene glycol dimethacrylate. C1-C24 alkyl or cycloalkyl esters such as These may be used alone or in combination of two or more.

  Styrene-butadiene copolymer resin (a2): In the presence of the styrene-butadiene copolymer resin (a1), the following monomer (i) (Note 1) is added to the emulsion polymerization reaction and graft polymerization. A styrene-butadiene copolymer resin (a2) obtained by the reaction can also be used. The styrene / butadiene copolymer resin (a1) is 40 to 80 parts by mass (solid content), preferably 50 to 75 parts by mass (solid content), and the following monomer (i) (Note 1) 60 to 20 parts by mass, preferably 50 to 25 parts by mass.

  (Note 1) Monomer (i): Aromatic vinyl monomer 20 to 80% by mass, preferably 40 to 60% by mass, alkyl methacrylate 80 to 20% by mass, preferably 60 to 40% by mass and the same. It consists of 0-20 mass% of other radically polymerizable unsaturated monomers (2) which can superpose | polymerize.

Examples of the other radical polymerizable unsaturated monomer (2) include vinylcyan such as divinylbenzene, monoethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, acrylonitrile, and alkyl acrylate such as ethyl acrylate or butyl acrylate. These can be used alone or in combination of two or more.

  Commercially available products of the above styrene / butadiene copolymer resins (a1) include Kane Ace B-11A, B-12, B-22, B-28, B-31, B-51, B-56 and B-58 (manufactured by Kaneka Corporation). Examples of commercially available styrene / butadiene-based copolymer resins (a2) include Kane Ace M-511 and M-521 (manufactured by Kaneka Corporation), and one or more of these are selected. Can be used.

Solvent (B)
The solvent (B) used in the paint is used for the purpose of dissolving a part or all of the styrene / butadiene copolymer resin (A) and imparting a film forming property during coating and a flow property during baking. .
For example, hydrocarbon solvents such as high boiling point petroleum hydrocarbons such as toluene and xylene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone; ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate, diethylene glycol mono Ester solvents such as ethyl ether acetate; alcohol solvents such as methanol, ethanol and butanol; ether alcohol solvents such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether and diethylene glycol monobutyl ether; water, etc. Can be used alone or in admixture of two or more.

Among these, ketone solvents and ether alcohol solvents are preferable from the viewpoint of forming a uniform and uneven pattern, and cyclohexanone is a particularly preferable example.
As a usage-amount of a solvent (B), 50-2,000 mass parts with respect to 100 mass parts of solid content of a styrene butadiene type copolymer resin (A), Preferably it is 300-1,500 mass parts, Furthermore, Preferably about 500-1,000 mass parts is preferable also from the surface which ensures the film forming property at the time of coating, and the flow property of the coating film at the time of baking.

  In the design coating material for the precoat metal of the present invention, in addition to the styrene / butadiene copolymer resin (A) and the solvent (B) described above, the purpose of the coating film performance such as coating film hardness and adhesion is as appropriate. Hydroxyl-containing resins such as polyester resins, acrylic resins, epoxy resins and polyurethane resins, cross-linking agents such as melamine resins and blocked isocyanate compounds, bright materials such as colored pigments, aluminum pastes and pearl pigments, and extender pigments such as silica fine powder Well-known materials such as organic resin powder, inorganic aggregate, antifoaming agent, leveling agent, lubricity imparting agent, ultraviolet absorber, and pigment dispersant can also be used.

  Examples of the color pigment include color pigments commonly used in the paint field for pre-coated metals, such as white pigments such as titanium white and zinc white; blue pigments such as cyanine blue and indanthrene blue; cyanine green and patina. Green pigments; organic red pigments such as azo and quinacridone, red pigments such as Bengala; organic yellow pigments such as benzimidazolone, isoindolinone, isoindoline and quinophthalone, yellow such as titanium yellow and yellow lead Examples of pigments include black pigments such as carbon black, graphite and pine smoke; bright pigments such as aluminum powder, copper powder, nickel powder, titanium oxide-coated mica powder, iron oxide-coated mica powder, and bright graphite.

Examples of the organic resin powder include particulate or fibrous powders such as fluorine resin, acrylic resin, polyurethane, phenol resin, silicon resin, polypropylene, and polyamide such as nylon 11 and nylon 12.
In addition to the styrene / butadiene copolymer resin (A) and the solvent (B), the design coating material for the precoat metal of the present invention is appropriately dispersed by adding a hydroxyl group-containing resin, a crosslinking agent, a pigment, and an additive. From the viewpoint of safety, a master batch can be produced by mixing uniformly by kneading with a disper or the like to obtain the intended designable paint.

Method for Forming Coating Film The designable paint of the present invention comprises (1). A method for forming a coating film, in which the present designable paint is directly applied to the material, (2). A method of forming a coating film by applying the present design coating material onto the primer coating film via a primer coating material; (3). A primer paint is applied to the material, at least one colored base paint formed on the primer coating is applied, the designable paint of the present invention is applied on the colored base coating, and a clear paint is further applied. The design properties can be effectively expressed by a method for forming a coating film formed by coating a coating film.

  In addition, there is no restriction | limiting in particular as a coating method of the designable coating material for precoat metals of this invention, Curtain coating, roll coating, dip coating, spray coating, etc. are possible, and the coating-film thickness after drying is normal. The coating is performed so as to be in the range of 5 to 70 μm, preferably 30 to 50 μm.

  The curing condition of the designable coating material of the present invention is usually a material reaching maximum temperature of 120 to 260 ° C., preferably 150 to 240 ° C., for 15 seconds to 30 minutes, preferably about 30 seconds to 3 minutes.

  Material: Cold rolled steel sheet, hot dip galvanized steel sheet, electrogalvanized steel sheet, alloy-plated steel sheet such as iron-zinc, nickel-zinc, zinc-aluminum, aluminum plate, stainless steel plate, copper plate, copper-plated steel plate, tin Examples thereof include metals such as plated steel sheets, plastics, wood, and cement. When painting on metals, the metal surface, which is the material to be coated, may be painted as it is if it is not contaminated with oil or other pollutants, but it is well known for improving adhesion and corrosion resistance with the coating film. It is desirable to apply a metal surface treatment. These known surface treatment methods include phosphate surface treatment, titanium surface treatment chromate surface treatment, and coating treatment with a chromic acid coating agent.

  Primer paint: When coating film quality is required, it is preferable to apply the paint composition of the present invention after applying the primer paint after the metal surface treatment. As the primer, a known primer used in the field of colored color steel sheet coating, industrial machine coating, metal part coating, etc. can be applied, and is appropriately selected depending on the type of material to be coated and the type of metal surface treatment. Resin-based primers, polyester resin-based primers, and modified primers thereof are preferable, and polyester resin-based primers are preferable when workability is particularly required.

  Colored base paint: Colored base paint is a hydroxyl group-containing resin such as polyester resin, acrylic resin, epoxy resin, polyurethane resin, cross-linking agent such as melamine resin or blocked isocyanate compound, luster material such as color pigment, aluminum paste, pearl pigment, Use conventionally known materials such as extender pigments such as silica fine powder, organic resin powder, inorganic aggregate, antifoaming agent, leveling agent, lubricity imparting agent, ultraviolet absorber, pigment dispersant, etc. Can do. The film thickness of the colored coating film is usually 8 to 50 μm, preferably 10 to 25 μm.

  Clear paint: The clear paint contains a resin component composed of a base resin and a crosslinking agent, and appropriately contains a curing catalyst, an amine compound, and a glittering powder. If necessary, a solvent, a lubricity imparting agent, an ultraviolet absorber, It contains ultraviolet stabilizers, antifoaming agents, coating surface conditioners, inorganic fine powders such as silica fine powders, and the like. Examples of the glitter powder include aluminum powder, copper powder, nickel powder, titanium oxide-coated mica powder, iron oxide-coated mica powder, and glitter graphite. The blending amount of the glittering powder may be an amount within a range that gives the coating surface appearance a glittering feeling and allows the design coating film of the present invention to be seen through the clear coating film. The film thickness of the clear coating film is usually 1 to 50 μm, preferably 5 to 25 μm.

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

Production Example 1 Styrene-butadiene copolymer resin No. 1 1
In a polymerization vessel equipped with a stirrer, 200 parts of deionized water, 1.5 parts of sodium oleate, 0.002 part of ferrous sulfate, 0.005 part of ethylenediamine 4-acetic acid · 2Na salt, sodium formaldehyde sulfoxide 0. 2 parts, 0.2 parts of tripotassium phosphate, 57 parts of butadiene, 23 parts of styrene, 1.0 part of divinylbenzene and 0.1 part of diisopropylbenzene hydroperoxide were polymerized at 50 ° C. for 10 hours, and the polymerization addition rate Was confirmed to be 95% or more, 20 parts of butadiene and 0.05 part of diisopropylbenzene hydroperoxide were added, and after further polymerizing for 7 hours, water was dried and a styrene / butadiene copolymer was obtained. Resin No. 1 was obtained.

Production Example 2 Styrene / butadiene copolymer resin No. 1 2 (graft polymerization type)
Styrene-butadiene copolymer resin No. 1 obtained in Production Example 1. 1 part 70 parts (solid content), deionized water 200 parts, ferrous sulfate 0.002 parts, ethylenediamine 4-acetic acid 2Na salt 0.004 parts, sodium formaldehyde sulfate 0.1 part and potassium chloride 1.5 parts To this, 15 parts of methyl methacrylate and 0.1 part of cumene hydroperoxide were continuously added at 70 ° C. over 3 hours. The polymerization was further continued for 1 hour, and then water was dried. Styrene-butadiene copolymer resin No. 2 was obtained.

Production Example 3 Styrene-butadiene copolymer resin No. 3 (graft polymerization type)
Styrene-butadiene copolymer resin No. 1 obtained in Production Example 1. 1 part 70 parts (solid content), deionized water 200 parts, ferrous sulfate 0.002 parts, ethylenediamine 4-acetic acid 2Na salt 0.004 parts, sodium formaldehyde sulfate 0.1 part and potassium chloride 1.5 parts Then, 13 parts of methyl methacrylate and 0.1 part of cumene hydroperoxide were continuously added over 3 hours at 70 ° C., and polymerization was further continued for 1 hour. Subsequently, 2 parts of butyl acrylate and 0.02 part of cumene hydroperoxide were continuously added over 20 minutes, and polymerization was further continued for 30 minutes. Thereafter, 15 parts of styrene and 0.1 part of cumene hydroperoxide were continuously added over 3 hours, and the polymerization was further continued for 1 hour to complete the polymerization, and then water was dried to obtain a styrene / butadiene copolymer. Resin No. 3 was obtained.

Production Example 4 Production Example of Polyester Resin 740 parts of phthalic anhydride and isophthalic acid in a reaction vessel using a normal polyester resin production device equipped with a heating device, a stirrer, a reflux device, a water separator, a rectifying tower, a thermometer, etc. 498 parts, 145 parts adipic acid, 735 parts neopentyl glycol and 236 parts 1.6-hexanediol were charged and heated. After the raw material was melted, stirring was started, the reaction temperature was raised to 230 ° C., and the condensed water produced by maintaining at 230 ° C. for 2 hours was distilled out of the system through a rectifying column. Subsequently, 90 parts of xylol was added to the reaction vessel and the reaction was continued by switching to the solvent condensation method. When the acid value reached 5, the reaction was terminated and cooled. After cooling, 1414 parts of xylol was added to obtain a polyester resin A solution having a solid content of 60%. The obtained resin had a hydroxyl value of 79 mgKOH / g and a number average molecular weight of about 1,300.

Production Example 1 of Designable Paint
Styrene-butadiene copolymer resin No. 1 obtained in Production Example 1. 100 parts of cyclohexane 1 and 900 parts of cyclohexane non were heated and stirred at 60 ° C. for 1 hour with a disper. 1 was obtained.

Examples 2-8
A design paint No. 1 was prepared in the same manner as in Example 1 except that the contents of Table 1 were used. 2-No. 8 was obtained.

(Note 2) Kane Ace 11A: Trade name, styrene / butadiene copolymer resin, manufactured by Kaneka Corporation.

  (Note 3) Kane Ace 22: manufactured by Kaneka Corporation, trade name, styrene-butadiene copolymer resin.

  (Note 4) Kane Ace M-521: Kaneka Co., Ltd., trade name, styrene / butadiene copolymer resin.

(Note 5) GK-13CS: Polyester resin, manufactured by Toyobo Co., Ltd., solid content 51%, number average molecular weight 7,000, hydroxyl value 19 mgKOH / g
(Note 6) Dianal HR-2011: acrylic resin, manufactured by Mitsubishi Rayon Co., Ltd., solid content 50%, hydroxyl value 55 mgKOH / g.

Comparative Example 1
A mixture of 100 parts of a polyester resin A solution 60% solid content obtained in Production Example 4, 10 parts of xylol, 70 parts of titanium white and 5 parts of phthalocyanine blue was dispersed in a shaker.
Next, 42 parts of the polyester resin A solution, 15 parts of Cymel 303 (Note 7), and 0.3 parts of dodecylbenzenesulfonic acid and 1.2 parts of di-n-butylamine were mixed at room temperature. Add 1.5 parts of the reaction mixture, 5 parts of Cyloid 74 (produced by Fuji Devison Co., Ltd., amorphous silica fine powder), 5 parts of DX33-401 (trade name, silicon resin fine particles, produced by Toray Silicone Co., Ltd.), and uniformly The viscosity was adjusted to 80 seconds (Ford Cup # 4, 25 ° C.) with an organic solvent, and the design paint No. 9 was obtained.
(Note 7) Cymel 303: Methyl etherified melamine resin, manufactured by Mitsui Cytec Co., Ltd., solid content of 98% or more.

Comparative Example 2
Arestech AT2100NM Blue (manufactured by Kansai Paint, polyester-melamine resin-based paint for forming a matte paint film with a shrinking pattern) was used.

Paint test board (1)
Using a chromate-treated hot dip galvanized steel sheet with a thickness of 0.5 mm (zinc basis weight 60 g / m ² ), the design paint No. 1-No. 10 was coated with a bar coater so as to have a dry film thickness of 20 μm, and baked and cured for 50 seconds so that the highest temperature reached was 225 ° C. to obtain a test plate. Since these test plates were subjected to the test according to the following test conditions, the results are shown in Table 2.

(Note 8) Pattern unevenness: The three-dimensional effect (large pattern feeling) of the coated surface was visually evaluated at a distance of 1 m.
○: Concavity and convexity are remarkable, and the design is excellent.
Δ: Not noticeable, but has a feeling of unevenness, and has some design.
X: An uneven feeling is not recognized and there is almost no design property.

(Note 9) Adhesiveness: Vertical and horizontal directions orthogonal to each other so that the surface of the coating film on the test plate is reached with a cutter knife in accordance with JIS K-5400 8.5.2 (1990) cross-cut method. 100 squares were created by drawing 11 parallel straight lines at 1 mm intervals. A cellophane pressure-sensitive adhesive tape was adhered to the surface, and the degree of cell peeling when the tape was peeled off was observed and evaluated according to the following criteria.
○: No peeling of the coating film is observed.
Δ: The coating film was slightly peeled, but 90 or more cells remained. ×: The coating film was peeled off, and the number of remaining cells was less than 90.

[Evaluation with multilayer coating system]
Production Example 5 Production Example of Clear Paint Dianal HR-2011 (see note 6) (solid content 70 parts), GK-13CS (see note 5) (solid content 10 parts), Cymel 303 (note 7) (solid content 20 Part) and 0.4 part of Nail Cure 5225 (Note 10) (0.1 part by amount of sulfonic acid) were mixed and stirred to obtain a clear coating composition.

(Note 10) Nature 5225: Made by King Industries, USA, trade name, curing catalyst which is an amine neutralized solution of dodecylbenzenesulfonic acid, content of sulfonic acid compound is about 25%.

Examples 9 to 16, Comparative Example 3, Comparative Example 4
Painting test plate (2)
Chromate-treated hot-dip galvanized steel sheet with a thickness of 0.5 mm (zinc basis weight 60 g / m
² ) A primer coating (epoxy-urethane resin-based primer coating containing a chromate rust preventive pigment) is applied on the top so that the dry film thickness is about 5 μm, and the maximum temperature reached is 225 ° C. It was baked for 50 seconds so as to be cured.
Next, on the coating film, a design paint No. 1-No. 10 was coated with a bar coater to a dry film thickness of 20 μm, and baked for 50 seconds so that the maximum temperature reached was 225 ° C. and cured.
Next, the clear paint obtained in Production Example 5 was applied onto the coating film so that the dry film thickness was about 20 μm, and baked for 60 seconds under the condition that the maximum temperature reached was 230 ° C. 3 A coated test plate was obtained. Since these test plates were subjected to the test according to the following test conditions, the results are shown in Table 3.

Examples 17 to 24, Comparative Example 5 and Comparative Example 6
Paint test plate (3)
Chromate-treated hot-dip galvanized steel sheet with a thickness of 0.5 mm (zinc basis weight 60 g / m
² ) A primer coating (epoxy-urethane resin-based primer coating containing a chromate rust preventive pigment) is applied on the top so that the dry film thickness is about 5 μm, and the maximum temperature reached is 225 ° C. It was baked for 50 seconds so as to be cured.
On this coating film, Arestech AT2000 Blue (trade name, colored base paint, manufactured by Kansai Paint Co., Ltd.) is applied so that the dry film thickness is about 20 μm, and the condition that the maximum temperature reached is 230 ° C. Was baked for 60 seconds to obtain a 3-coat test plate.
Next, on the coating film, a design paint No. 1-No. 10 was coated with a bar coater to a dry film thickness of 20 μm, and baked for 50 seconds so that the maximum temperature reached was 225 ° C. and cured.

  Since these test plates were subjected to the test according to the following test conditions, the results are shown in Table 4.

(Note 11) Workability: When the 1T bending process is performed in which the coated plate surface of the painted plate is folded outward, and the painted plate is folded 180 degrees in a vise without sandwiching anything inside. The coating state of the bent portion was evaluated according to the following criteria. The test was performed at a coated plate temperature of 5 ° C.
◎: Abnormalities such as cracks and peelings are not observed in the coating film ○: Slight cracking is observed in the coating film △: There is considerable cracking in the coating film
X: A crack is recognized remarkably in a coating film.

(Note 12) Corrosion resistance: After the coated plate was cut into a size of 70 × 150 mm, the back surface and the cut surface were sealed with a rust preventive paint. A sealed spray board with a cross-cut reaching the base at almost the center was subjected to a salt spray test. The salt spray test was performed according to JIS Z-2371, the salt spray test time was 500 hours, and the average swelling width of the cross-cut portion was evaluated visually according to the following criteria.
A: No swelling is observed in the crosscut portion
○: The average swelling width on one side from the cut wound is less than 1 mm. Δ: The average swelling width on one side from the cut wound is 1 mm or more and less than 5 mm.
X: The average swelling width of one side from the cut flaw is 5 mm or more.

  A pre-coated metal steel sheet having a pattern with unevenness is obtained.

It is a pattern with an uneven feeling of the present invention. It is a pattern with an uneven feeling of the present invention.

Claims (4)

A design coating material for a precoat metal, comprising 50 to 2,000 parts by mass of the solvent (B) with respect to 100 parts by mass of the solid content of the styrene / butadiene copolymer resin (A). The design paint for a precoat metal according to claim 1, wherein the solvent (B) is a ketone solvent. A coating film forming method comprising forming a design coating film for a precoat metal according to claim 1 or 2 on a metal plate whose surface may be subjected to chemical conversion treatment. 4. At least one undercoat film is formed on a metal plate that may be subjected to chemical conversion treatment on the surface, and the precoat metal for precoat metal according to any one of claims 1 to 3 is formed on the undercoat film. A method for forming a coating film, comprising applying a designable paint and then forming a clear paint film on the designable paint film.

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