METHOD FOR FORMING EXCELLENT MULTI-LAYER COATING FILM

• US 20150217332A1
• Filed: 04/18/2013
• Published: 08/06/2015
• Est. Priority Date: 08/28/2012
• Status: Active Grant

• Current Assignee: Mazda Motor Corporation, Nippon paint automotive coatings co., ltd. (Rainbow Light Limited)
• Original Assignee: Mazda Motor Corporation, Nippon Paint Company Limited (Rainbow Light Limited)
• Inventors: Fujii, Hiroaki, Kubota, Hiroshi, Nakano, Sakura, Aoki, Yoshiko, Shinoda, Masafumi, Tsuneoka, Tatsuo, Hirano, Fumi
• Granted Patent: US 9,737,906 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B05D 1/38 with intermediate treatment intermediate treatment per se B05D3/00
• CPC Class Codes: B05D 3/0254 After-treatment
• CPC Class Codes: B05D 5/063 Reflective effect B05D5/067 takes precedence
• CPC Class Codes: B05D 5/066 achieved by multilayers
• CPC Class Codes: B05D 5/068 achieved by multilayers B05D5/066 takes precedence
• CPC Class Codes: B05D 7/14 to metal, e.g. car bodies involving a chemical reaction between the metal and the coating C23
• CPC Class Codes: B05D 7/57 the last layer being a clear coat
• CPC Class Codes: C09D 201/00 Coating compositions based on unspecified macromolecular compounds
• CPC Class Codes: C09D 5/28 for wrinkle, crackle, orange-peel, or similar decorative effects
• CPC Class Codes: C09D 7/41 Organic pigments; Organic dyes

Abstract

The purpose of the present invention is to obtain a method for forming an excellent multi-layer coating film of high chroma and brightness and a rich color. With the method, color mottling does not occur easily in the coating film and the design obtained is homogeneous even without strict control of variations in film thickness during coating. The method for forming the excellent multi-layer coating film comprises: forming a metallic base coating film on the surface of the object to be coated by applying a metallic base coating containing a shiny material; then forming a color base coating film by applying a color base coating; subsequently forming a clear coating film by applying a clear coating on the color base coating film; and heat-curing the metallic base coating film, the color base coating film and the clear coating film obtained. In the method, the light reflectance of the metallic base coating film is in a specified range and the light transmittance of the single color base coating film obtained by heat-curing the color base coating film as a single film is adjusted to a specified range.

Claims

1. A process for forming an excellent multi-layer coating film comprising the steps of:

(1) applying a metallic base coating composition to a coating substrate to form a metallic base coating film, wherein the metallic base coating composition comprises a coloring pigment and a luster pigment,

(2) applying a color base coating composition to the metallic base coating film obtained by the step (1) to form a color base coating film, wherein the color base coating composition comprises a coloring pigment and does not comprises a luster pigment,

(3) applying a clear coating composition to the color base coating film obtained by the step (2) to form a clear coating film, and

(4) simultaneously heating and curing the metallic base coating film, the color base coating film and the clear coating film formed in the steps (1), (2) and (3) to form a multi-layer coating film, wherein

a single layer of the metallic base coating film obtained by heating and curing of the metallic base coating film in the step (1) has light reflectance of from 45 to 50% in a wavelength range of 650 to 700 nm and light reflectance of not more than 20% in wavelength ranges of 410 to 440 nm and 510 to 590 nm, and

a single layer of the color base coating film obtained by heating and curing of the color base coating film in the step (2) has light transmittance of from 50 to 70% in a wavelength range of 400 to 700 nm, light transmittance of from 88 to 92% in a wavelength range of 650 to 700 nm and light transmittance of from 20 to 60% in wavelength ranges of 410 to 440 nm and 510 to 590 nm.

2. A process for forming an excellent multi-layer coating film according to claim 1, wherein the coloring pigment in the metallic base coating composition and the coloring pigment in the color base coating composition are the same coloring pigment.

3. A process for forming an excellent multi-layer coating film according to claim 2, wherein the coloring pigment is a perylene pigment.