Device for predicting gloss of low gloss coating by wet color measurement

摘要

The present invention is directed to a device for process for predicting gloss of a coating resulting from a wet layer of a low gloss coating composition, such as automotive OEM or refinish paint. The device includes measuring reflectance of the layer of the coating composition applied over a test substrate and then allowing the layer to dry and/or cure into a coating. Thereafter, its gloss is measured with a gloss meter. The device is repeated with varying amounts of one or flatting agents added to the composition and the reflectance vs. gloss is plotted on a graph and by using a curve fitting equation a gloss prediction curve is obtained. By measuring the reflectance of a wet layer of a target low gloss coating composition the gloss of a coating that would result from such a layer is then predicted by using the gloss prediction curve. The device is most useful during the manufacture of coating compositions, such as automotive OEM and refinishes paints.

主权项

1. A gloss prediction device comprising:
(a) a test substrate mounted on a driver that is mounted on a support frame; (b) a vessel positioned adjacent to said test substrate such that a coating composition when poured in said vessel can be dispensed as a L0 layer of substantially uniform thickness on surface of said substrate through an opening provided on said vessel; (c) an optical measurement mechanism for projecting on said L0 layer a beam of light of a preset intensity at a preset angle of incidence from a light source; (d) an optical measurement instrument to measure B0 reflectance of said beam reflected from said L0 layer at a preset angle of reflectance; (e) a gloss meter to measure Y0 gloss of a C0 coating at a preset gloss angle resulting from said L0 layer when dried or cured; (f) means for configuring computer readable program code devices to cause a computer to store B0 reflectance of L0 layer and Y0 gloss in a computer usable storage medium of the computer; (g) means for configuring computer readable program code devices to cause said computer to store B1 to Bn reflectance of L1 to Ln layers and Y1 to Yn gloss of C1 to Cn coatings resulting from coating compositions S1 to Sn respectively comprising F1 to Fn parts by weight of one or more flatting agents based on 100 parts by weight of said coating composition, wherein n ranges from 4 to 20; (h) means for configuring computer readable program code devices to cause said computer to subtract said B0 reflectance of said L0 layer from said B1 to Bn reflectance of said L1 to Ln layers to determine ΔB1 to ΔBn of said L1 to Ln layers respectively; (i) means for configuring computer readable program code devices to cause said computer to locate intersecting points on a graph where said ΔB1 to ΔBn of said L1 to Ln layers lying on X-axis of said graph intersect with said Y1 to Yn gloss of said C1 to Cn coatings lying on Y-axis of said graph; (j) means for configuring computer readable program code devices to cause said computer to utilize a curve fitting equation to produce a gloss prediction curve on said graph; (k) means for configuring computer readable program code devices to cause said computer to store a BT reflectance of an LT layer having said substantially uniform thickness and made of a target coating composition comprising said one or more flatting agents, and wherein said BT reflectance is obtained by having said optical measurement mechanism project a beam of light at said preset intensity and at said preset angle of incidence from said light source; (l) means for configuring computer readable program code devices to cause said computer to subtract said B0 reflectance of said L0 layer from said BT reflectance of LT layer to determine ΔBT of said LT layer; (m) means for configuring computer readable program code devices to cause said computer to locate said ΔBT of said LT layer on said X-axis of said graph; (n) means for configuring computer readable program code devices to cause said computer to locate an intersecting point on said gloss prediction curve that intersects with said ΔBT on said X-axis of said graph; (o) means for configuring computer readable program code devices to cause said computer to predict gloss at said preset gloss angle of a target coating that would result from said target layer when dried or cured by locating YT gloss on said Y-axis of said graph that intersects with said intersecting point on said gloss prediction curve that intersects with said ΔBT on said X-axis of said graph; and (p) means for configuring computer readable program code devices to cause said computer to display or print said YT gloss.