Abstract: The current process for producing powder coatings can be replaced with a process utilizing supercritical fluids including polymer polymerization, compatibilized blending of powder coating ingredients, and particle size control and classification of the powder coating. Traditionally, powder coating resins are polymerized in solvent based system. Next, the resin is blended with additives in a twin screw extruder at high temperatures. The material is then ground and separated by particle size to form the finished powder coating. This invention replaces the previous process by performing all operations in a supercritical fluid, preferably, carbon dioxide. Polymerization is conducted at any pressure above critical pressure and temperature above critical temperature up to 190°C. Solubility of the polymer in the supercritical fluid allows for control and narrow distribution of the molecular weight and a polydispersity of about 2 or less.

Abstract: The current process for producing powder coatings can be replaced with a process utilizing supercritical fluids including polymer polymerization, compatibilized blending of powder coating ingredients, and particle size control and classification of the powder coating. Traditionally, powder coating resins are polymerized in solvent based system. Next, the resin is blended with additives in a twin screw extruder at high temperatures. The material is then ground and separated by particle size to form the finished powder coating. This invention replaces the previous process by performing all operations in a supercritical fluid, preferably, carbon dioxide. Polymerization is conducted at any pressure above critical pressure and temperature above critical temperature up to 190° C. Solubility of the polymer in the supercritical fluid allows for control and narrow distribution of the molecular weight and a polydispersity of about 2 or less.