01.11.10
Patent No. U.S. 7,468,401 B2
PPG Industries has received a patent for a process for manufacturing a powder coating composition comprised of the steps of providing a base composition comprised of non-leafing pigment particles and a polymeric binder; mixing the base composition at an elevated temperature; adding flake-like, color effect pigment particles into the base composition to produce a pigment composition, the pigment composition has an initial particle size distribution with fine particles; heating the pigment composition to a temperature to achieve a second particle size distribution substantially without fine particles, wherein the temperature is more than 2°F greater than the TG of the pigment composition; mixing the pigment composition produced in the previous step at the temperature for a predetermined time period; and cooling the pigment composition to produce the powder coating composition.
PPG Industries has received a patent for a process for manufacturing a powder coating composition comprised of the steps of providing a base composition comprised of non-leafing pigment particles and a polymeric binder; mixing the base composition at an elevated temperature; adding flake-like, color effect pigment particles into the base composition to produce a pigment composition, the pigment composition has an initial particle size distribution with fine particles; heating the pigment composition to a temperature to achieve a second particle size distribution substantially without fine particles, wherein the temperature is more than 2°F greater than the TG of the pigment composition; mixing the pigment composition produced in the previous step at the temperature for a predetermined time period; and cooling the pigment composition to produce the powder coating composition.