JPS60110444A - Powdered body coated metallic plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a coated metal plate for searching and processing.

Prior Art Examples of conventional methods for painting metal surfaces are as follows.

(1) Painting with a solvent-based paint This method consists of many steps: chemical conversion treatment of the metal surface, undercoating with a thickness of 5 to 10 μm, high-temperature baking, top-coating, and high-temperature baking. This method requires long and complicated steps and is difficult to produce multiple colors.

(2) Polyacrylic acid-based aqueous emulsion coating type pretreatment This method uses a polyacrylic acid-based aqueous emulsion paint to apply an undercoat, and then applies a topcoat as a post-treatment. , the secondary adhesion of the paint is insufficient.

(3) Combination with dissolvable paint undercoat 9 This method not only requires high-temperature baking, but also reduces the scratch hardness of the topcoat surface if the coating is softened with emphasis on workability.

When metal plates manufactured by these conventional methods are subjected to embossing, they can only be embossing at a shallow depth of several meters to 10 mm at most.

OBJECT OF THE INVENTION In view of the current situation as described above, it is an object of the present invention to provide a coated metal plate that can be searched for.

Structure of the Invention In order to achieve the above object, the present inventors have conducted extensive research and found that resin particles, particularly microgel-like resin particles, are dispersed or used as a pretreatment agent for metal coating processes. The molecular weight of polyethylene, polypropylene, etc. is 1
500 to 3000 polyolefin wax, fluororesin powder such as vinylidene fluoride resin, vinyl fluoride resin, fluorinated ethylene resin, etc. alone or water-soluble resin such as polyester resin, acrylic resin, etc. to help dispersion in the processing agent. It has been found that when used in appropriate combination with the particles, the coating strength is improved because the particles act as an elastic aggregate, and the coating can withstand high processing. Furthermore, when fine silica powder is added as a filler to the pretreatment agent, the coating becomes white, making it possible to apply a thin film when applying a powder coating with weak hiding power, and improving physical properties such as workability. They discovered this and arrived at the present invention.

That is, the present invention provides resin particles, particularly emulsion-type microgel-like resin particles or polyolefin wax,
This is a powder-coated metal plate characterized in that a coating type pretreatment agent containing a fluororesin is applied to a metal plate, and then a powder coating is applied over it.

The constituent elements of the present invention will be explained in detail below.

(Resin particles) In the present invention, resin particles refer to particles obtained by emulsion polymerization of α,β-monoethylenically unsaturated monomers using, for example, any of the following emulsifiers (a), (b), and (9). The internal gelling emulsion has a diameter of 0.1 to 3 μm, but is not limited thereto.

(a) Polyacrylic acid (b) A copolymer of acrylic acid and a hydrophilic monomer other than acrylic acid, such as methacrylic acid, acrylamide, etc. (c) Polyacrylic acid and the copolymer 3 described in (b) above
- The resin particles in the present invention are in a mixture with a high glass transition temperature (15~
(approximately 110°C), it can be mixed with phosphoric acid etc. as a pre-treatment agent, and even when a metal plate is chemically treated with this pre-treatment agent, the resin particles will not form a film and the resin will be The particles can independently form convex portions.

In the present invention, it is necessary to blend the internal gelling emulsion containing the resin particles in an amount of about 5 to 30% by weight of the pretreatment agent.

If the blending ratio of resin particles is less than 5% by weight, it is impossible to carry out the search, and even if it exceeds 30% by weight, no increase in effectiveness can be expected.

(Pre-treatment agent) The pre-treatment agent of the present invention can contain phosphoric acid and/or fine silica powder of the resin particles.

(Chemical conversion treatment) 4. To chemically treat raw metal with the pretreatment agent of the present invention, apply the pretreatment agent of the present invention to the raw metal using a roll coater, or add the raw metal in the pretreatment agent. The pretreatment agent may be coated on the surface of the raw metal to a thickness of about 0.1 to 0.3 μm by immersion or the like, and then dried at a temperature of about 100°C.

Examples In order to make the present invention easier to understand, examples are shown below, but the following examples are not intended to limit the present invention.

(Pre-treatment agent) In the following examples, the following pre-treatment agent (1) and pre-treatment agent (2) were used.

(Note) ``I BMI100 varnish was manufactured as follows.

A flask equipped with a stirrer, reflux condenser, thermometer, and two addition funnels was charged with the following liquids.

Deionized water 150 parts by weight Aqueous methacrylic acid copolymer solution 120 parts by weight [The above aqueous methacrylic acid copolymer solution is obtained by copolymerizing methacrylic acid and 2-hydroxyethyl methacrylate at a weight ratio of 8:2. This is an aqueous solution of a water-soluble copolymer (concentration 25% by weight, copolymer molecule J1s 6,000). ] While stirring the contents of the above flask, raise the temperature to 80~80℃.
The temperature was raised to 85°C. Then, the following monomer mixture was added dropwise from one dropping funnel, and the following catalyst solution was added dropwise from the other dropping funnel over a period of 3 hours at 80 to 85°C.

(Monomer mixture) Methyl methacrylate 50 parts by weight Styrene 27 parts by weight 2-hydroxyethyl methacrylate 10 parts by weight n-butyl methacrylate 10 parts by weight Ethylene glycol dimethacrylate 3 parts by weight (catalyst liquid) Ammonium persulfate 2 parts by weight After dropping 50 parts by weight of deionized water, add 80 to 85 parts by weight to further complete the polymerization reaction.
Aging was performed at ℃ for about 2 hours. The resulting emulsion had a solid content of 300%, a pH of 1.6, and a particle size of 0.
A uniform stable emulsion of 55 μm was formed, and the particles in this emulsion did not dissolve in xylene.

Middle 2 Product name of silica gel manufactured by Nippon Aerosil Co., Ltd. (chemical treatment) The above-mentioned pretreatment agent was applied to a 0.5-thick aluminum killed steel plate using a roll coater and dried. The coating and drying conditions were as shown in Table 1 below.

(Powder Coating) Nitzpe Precord 300 (trade name of Nippon Paint Co., Ltd.) containing polyester resin, blocked isocyanate, pigment, etc. was applied using an electrostatic powder coating machine.

Table 1 In Table 1, ■ indicates excellent results, ◯ indicates good results, and × indicates poor results.

(Note) 3rd year of junior high school The product name of Nippon Paint Co., Ltd.'s coating type pretreatment agent. This product does not contain resin particles.

Fist 4 Sample steel plate 40m long x 40 wag x depth 4
I searched for the square shape of 0 sea bream. The radius of curvature between the bottom surface and the side walls is Fi6 tm , and the radius of curvature between the side walls is 8.
5■ Closed.

Middle 5th grade We did a gopan test on a part with a radius of curvature of 8.5m.

Junior High School 6: After being immersed in boiling water for 4 hours, the eye test was carried out.

Skewer 7 After applying red oil-based ink and black oil-based ink, it was wiped off with methanol, and the remaining state of the ink was observed.

(Evaluation) If you compare the results of Cytest with a comparative example using a pretreatment agent that does not contain resin particles and the product of the present invention, the product of the present invention has excellent primary adhesion, secondary adhesion, and stain resistance. It was excellent.

Import of the invention The present invention provides for the first time a pre-coated metal plate for searching. This dramatically expands the applications of pre-coated metal sheets.

Applicant: Nippon Paint Co., Ltd. Agent: Patent Attorney Minoru Isaka −11= Continuation of page 1

Claims (2)

[Claims] (1) A coating type pretreatment agent containing resin particles with a glass transition point of 15 to 110°C is applied to a metal plate, and then a powder coating is applied over it. Powder coated metal sheet. (2) Claim 1, wherein the resin particles having a glass transition point of 15 to 110°C are microgels that reduce labor costs.
Powder-coated metal plates as described in Section.