Method for forming multilayer coating film

Patent metadata

Field	Value
Publication number	US-2020398308-A1
Application number	US-201816962032-A
Country	US
Kind code	A1
Filing date	Dec 27, 2018
Priority date	Jan 16, 2018
Publication date	Dec 24, 2020
Grant date	—

Abstract

A method for forming a multilayer coating film, the method including the following steps (1) to (3): (1) applying a colored paint (X) to a substrate to form a colored coating film whose lightness L* value in the L*a*b* color space is 5 or less, (2) applying an effect pigment dispersion (Y) to the colored coating film formed in step (1) to form an effect coating film, and (3) applying a clear paint (Z) to the effect coating film formed in step (2) to form a clear coating film, wherein the effect pigment dispersion (Y) contains water, a rheology control agent (A), and a flake-effect pigment (B), the flake-effect pigment (B) being an effect pigment in which a transparent or translucent base material is coated with a metal oxide, and the effect pigment dispersion (Y) having a solids content of 0.1 to 15 mass %; the obtained multilayer coating film has a Y value (Y5) of 50 or more, the Y value (Y5) representing a luminance in the XYZ color space based on spectral reflectance when light illuminated at an angle of 45 degrees with respect to the multilayer coating film is received at an angle of 5 degrees deviated from specular reflection light in the incident light direction; and the obtained multilayer coating film has a lightness L* value (L*25) of 25 or less in the L*a*b* color space when light illuminated at an angle of 45 degrees with respect to the multilayer coating film is received at an angle of 25 degrees deviated from specular reflection light in the incident light direction.

First claim

1 . A method for forming a multilayer coating film, the method comprising the following steps (1) to (3):
(1) applying a colored paint (X) to a substrate to form a colored coating film whose lightness L* value in an L*a*b* color space is 5 or less, (2) applying an effect pigment dispersion (Y) to the colored coating film formed in step (1) to form an effect coating film, and (3) applying a clear paint (Z) to the effect coating film formed in step (2) to form a clear coating film, wherein
the effect pigment dispersion (Y) contains water, a rheology control agent (A), and a flake-effect pigment (B), the flake-effect pigment (B) being an effect pigment in which a transparent or translucent base material is coated with a metal oxide, the effect pigment dispersion (Y) having a solids content of 0.1 to 15 mass %,
the obtained multilayer coating film has a Y value (Y5) of 50 or more, the Y value (Y5) representing a luminance in an XYZ color space based on spectral reflectance when light illuminated at an angle of 45 degrees with respect to the multilayer coating film is received at an angle of 5 degrees deviated from specular reflection light in the incident light direction, and
the obtained multilayer coating film has a lightness L* value (L*25) of 25 or less in the L*a*b* color space when light illuminated at an angle of 45 degrees with respect to the multilayer coating film is received at an angle of 25 degrees deviated from specular reflection light in the incident light direction.

2 . The method for forming a multilayer coating film according to claim 1 , wherein the flake-effect pigment (B) contains an effect pigment that has a black color.

3 . The method for forming a multilayer coating film according to claim 1 , wherein the content of the flake-effect pigment (B) is 1 to 90 parts by mass, per 100 parts by mass of the total solids content in the effect pigment dispersion (Y).

4 . The method for forming a multilayer coating film according to claim 1 , wherein the effect pigment dispersion (Y) further contains a surface adjusting agent (C).

5 . The method for forming a multilayer coating film according to claim 1 , wherein the colored paint (X) contains carbon black.

6 . The method for forming a multilayer coating film according to claim 1 , wherein the clear paint (Z) is a two-component clear paint that contains a hydroxy-containing resin and a polyisocyanate compound.

Assignees

• Kansai Paint Co Ltd

Inventors

• Okazaki Hirokazu
• Kuramochi Tatsuo
• Sakai Kenji
• Narita Nobuhiko

Classifications

• B05D2202/10

  based on Fe · CPC title

• B05D7/572 Primary

  all layers being cured or baked together · CPC title

• B05D1/36

  Successively applying liquids or other fluent materials, e.g. without intermediate treatment · CPC title

• B05D5/06 Primary

  to obtain multicolour or other optical effects (B05D5/02 takes precedence) · CPC title

• C09D7/61

  inorganic · CPC title