Method for determining the surface gloss of a colour standard

Patent metadata

Field	Value
Publication number	US-9417187-B2
Application number	US-201514799771-A
Country	US
Kind code	B2
Filing date	Jul 15, 2015
Priority date	Nov 28, 2011
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

The invention relates to a method for determining the gloss of a colour standard comprising the following steps:
A) experimentally determining reflection spectra R(exp) of the colour standard, comprising a first reflection spectrum and a second reflection spectrum, with an integrating sphere colour measurement instrument, wherein said first reflection spectrum is obtained at (A1) d/8°—geometry with the specular component included, and said second reflection spectrum is obtained at (A2) d/8°—geometry with the specular component excluded, and B) converting reflection spectra data of the experimentally determined reflection spectra R(exp) of the colour standard to gloss values by: B1) acquiring the difference reflection spectrum ΔR of the experimentally determined reflection spectrum R(exp) with the specular component included (A1) and the reflection spectrum R(exp) with the specular component excluded (A2), and B2) determining the gloss values corresponding to said difference reflection spectrum ΔR with the assistance of previously prepared calibration curves, representing the functional relationship between the difference reflection spectrum ΔR and the gloss values measured at one or more gloss angles.

First claim

What we claim is:

1. A method for determining a gloss of a colour standard, said method comprising the steps of:
A) experimentally determining a reflection spectrum R(exp) of the colour standard, comprising a first reflection spectrum and a second reflection spectrum, with an integrating sphere colour measurement instrument, wherein said first reflection spectrum is obtained at
(A1) d/8°—geometry or 8°/d—geometry with a specular component included; and

said second reflection spectrum is obtained at
(A2) d/8°—geometry or 8°/d—geometry with the specular component excluded; and

B) converting reflection spectra data of the experimentally determined reflection spectrum R(exp) of the colour standard to a gloss value by:
B1) acquiring a difference reflection spectrum ΔR of the experimentally determined reflection spectrum R(exp) with the specular component included (A1) and the experimentally determined reflection spectrum R(exp) with the specular component excluded (A2); and
B2) determining the gloss value corresponding to said difference reflection spectrum ΔR with the assistance of a previously prepared calibration curve representing a functional relationship between the difference reflection spectrum ΔR and the gloss value measured at one or more gloss angles.

2. The method of claim 1 , wherein said colour standard is a matt solid colour standard.

3. The method according to claim 1 , wherein an X, Y, and Z colour position, or an L*, a*, and b* colour position, are derived from the reflection spectrum R(exp), and wherein the X, Y, and Z colour position or the L*, a*, and b* colour position is used in addition to the reflection spectra to determine the gloss value.

4. The method according to claim 1 , wherein an X, Y and Z colour position, or an L*, a*, and b* colour position are measured, and wherein the X, Y, and Z colour position or the L*, a*, and b* colour position is used in addition to the reflection spectra to determine the gloss value.

5. The method according to claim 1 , wherein the reflection spectrum R(exp) is measured with a spectrophotometer with the d/8°—geometry or with the 8°/d—geometry.

6. The method according to claim 1 , wherein the reflection spectrum R(exp) is acquired over a wavelength range of from about 400 nanometers (nm) to about 700 nm.

7. The method according to claim 1 further comprising:
standardizing paint using the gloss value.

8. The method according to claim 1 further comprising:
using the gloss value in an original equipment manufacturer automotive coating.

9. The method according to claim 1 further comprising:
using the gloss value in a refinish coating.

10. A method for determining a gloss of a colour standard, said method comprising the steps of:
A) experimentally determining a colour position of the colour standard, wherein said colour position comprises:
(A1) a specular included colour standard; and
(A2) a specular excluded colour standard; and

B) converting the experimentally determined colour position of the colour standard to a gloss value by:
B1) acquiring a difference colour standard of the experimentally determined colour position with the specular included colour standard (A1) and the specular excluded colour standard (A2); and
B2) determining the gloss value corresponding to said difference colour standard with the assistance of a previously prepared calibration curve representing a functional relationship between the difference colour standard and the gloss value measured at one or more gloss angles.

11. The method of claim 10 wherein experimentally determining the colour position of the colour standard comprises experimentally determining an X, Y, and Z colour position of the colour standard.

12. The method of claim 10 wherein experimentally determining the colour position of the colour standard comprises experimentally determining an L*, a*, and b* colour position of the colour standard.

13. A method for producing a coating composition having one or more matting agents, said method comprising the steps of:
i) determining a gloss value of a colour standard by:
A) experimentally determining a reflection spectrum R(exp) of the colour standard, comprising a first reflection spectrum and a second reflection spectrum, with an integrating sphere colour measurement instrument, wherein said first reflection spectrum is obtained at
(A1) d/8°—geometry or 8°/d—geometry with a specular component included; and

said second reflection spectrum is obtained at
(A2) d/8°—geometry or 8°/d—geometry with the specular component excluded; and

B) converting reflection spectra data of the reflection spectrum R(exp) of the colour standard to the gloss value by:
B1) acquiring a difference reflection spectrum ΔR of the reflection spectrum R(exp) with the specular component included (A1) and the reflection spectrum R(exp) with the specular component excluded (A2); and
B2) determining the gloss value corresponding to said difference reflection spectrum ΔR with the assistance of a previously prepared calibration curve representing a functional relationship between the difference reflection spectrum ΔR and the gloss value measured at one or more gloss angles;

ii) determining a colour recipe for said coating composition based on said colour standard; and
iii) producing said coating composition based on said colour recipe.

14. The method of claim 13 , wherein said colour standard is a matt solid colour standard.

15. The method of claim 13 , wherein said coating composition is an original equipment manufacturer automotive coating composition, a refinish coating composition, or a combination thereof.

Assignees

• Axalta Coating Systems Ip Co

Inventors

• Kettler Wilhelm
• Jelen Peter
• Korten Oliver

Classifications

• G01J3/0251

  Colorimeters making use of an integrating sphere · CPC title

• G01N21/57 Primary

  Measuring gloss · CPC title

• G01N2201/065

  Integrating spheres · CPC title

• G01J3/504

  Goniometric colour measurements, for example measurements of metallic or flake based paints · CPC title