US 7,466,415 B2
Method of producing matched coating composition and device used therefor
Mark Alan Gibson, Bloomfield Township, Mich. (US); David Lee Griffus, Grand Blanc, Mich. (US); Allan Blase Joseph Rodrigues, Bloomsfield Hills, Mich. (US); and Michelle Grace Ward, Troy, Mich. (US)
Assigned to E.I. du Pont de Nemours & Company, Wilmington, Del. (US)
Appl. No. 10/552,200
PCT Filed May 06, 2004, PCT No. PCT/US2004/014371
§ 371(c)(1), (2), (4) Date Oct. 06, 2005,
PCT Pub. No. WO2004/101689, PCT Pub. Date Nov. 25, 2004.
Claims priority of provisional application 60/468595, filed on May 07, 2003.
Prior Publication US 2006/0181707 A1, Aug. 17, 2006
Int. Cl. G01J 3/46 (2006.01)
U.S. Cl. 356—402 27 Claims
OG exemplary drawing
 
1. A method for producing a matched coating composition for a specified end-use, said method comprising:
(i) measuring reflectances of a target portion of a target coating at a set of preset wavelengths with a spectrophotometer of a coating characterizing device to plot a target spectral curve of said target portion, wherein said target coating is on an undamaged portion of an auto body, plastic substrate, marine substrate, and aluminum substrate;
(ii) calculating target color (L,a,b or L,C,h) values of said target portion from said target spectral curve of said target portion;
(iii) selecting one or more preliminary colorant combinations from a stored list of known colorants in accordance with a combinatorial selection criteria to match with said target color values, wherein said stored list of known colorants comprises pigments, dispersions, tints, dyes, metallic flakes or a combination thereof, and wherein said combinatorial selection criteria comprise avoiding shading with complementary colorants and preferring colorant combinations with a fewer number of pigments than a greater number of pigments;
(iv) determining concentration of each said known colorant in each of said preliminary colorant combinations in accordance with color matching criteria wherein said concentration of each said known colorant is optimized for optimal match of color values of each of said preliminary colorant combinations with said target color values;
(v) balancing said preliminary colorant combinations to allow for presence of non-colorant components in said matched coating composition to generate one or more viable combinations optimized in accordance with mixing and regulatory criteria developed for said specified end-use;
(vi) selecting an optimal viable combination from said viable combinations in accordance with an acceptability equation for said specified end-use, said optimal viable combination having an optimal acceptability value for said specified end-use wherein said known colorants and non-colorant components when mixed in accordance with said optimal viable combination produce said matched coating composition that when applied as a matched coating visually matches with appearance of said target coating, wherein said acceptability equation is a summation of acceptability factors multiplied by a weight assigned to each said acceptability factor, wherein said acceptability factors comprise color difference, metamerism, closeness of spectral curve match, durability or cost; and
(vii) displaying on a screen of a monitor of said device said optimal viable combination.