Process for preparing coating powder compositions and their use for making coatings

US5981696A · kind A · utility

Assignee

• Herberts Gesellschaft mit beschrankter Haftung · DE

Inventors

• Dietrich Saatweber · Wuppertal, DE
• Karin Maag · Inzlingen, DE
• Wolfgang Diener · Wuppertal, DE
• Peter Klostermann · Sprockhövel, DE
• Thomas Berger · Hirschau, DE

Key dates

• Filing date: Feb 10, 1997
• Grant date: Nov 9, 1999
• Expiry date: Feb 10, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D5/03
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The invention concerns a process for preparing coating powder compositions in which one or a plurality of base resins and one or a plurality of hardeners, each of which is in solid form, is dissolved with a low-molecular compound above its critical pressure and critical temperature. This low-molecular compound is inert with respect to the base resins and hardeners and is in gaseous form under normal operating conditions with respect to pressure and temperature. The pressure of the resultant solution is then reduced, for example, by spraying. The resultant coating powder composition can be sprayed directly onto a substrate to be coated. Coating powders can also be recycled according to the process of the invention.