Patent ID: 6800334
Filing Date: 2004-10-05
Classification: C09D

Abstract:
A powder coating composition which incorporates a wax in post-blended form, there being a triboelectric interaction factor &tgr;, between the composition incorporating the wax and the same composition without the wax, of 0.25, the value of &tgr;being given by the relationship&tgr;=&Dgr;E(composition mixture)/&Dgr;E(pure compositions) where&Dgr;E=(&Dgr;L*2+&Dgr;a*2+&Dgr;b*2)1/2 with L*, a* and b* being respectively the z-, x- and y- coordinate variables under the CIE L*a*b*1976 color definition system, &Dgr;E (pure compositions) being determined by color spectrophotometric measurement and &Dgr;E (composition mixture) being determined by mixing the two compositions in equal weight proportions, causing charging of the resulting mixture by tribostatic interaction to establish equilibrium tribostatically charged conditions, directing the charged mixture onto two oppositely charged plates, resulting in a separation of the compositions on the two plates, and then determining &Dgr;E, by color spectrophotometric measurement, between the compositions as applied to the two plates, one or both of the respective initial pure compositions being dyed where appropriate to provide an enhanced &Dgr;E between them to facilitate the determination of &Dgr;E (pure compositions) and &Dgr;E (composition mixture).