Process for preparing pulverulent coating composition based upon polyamide having at least 10 aliphatically bound carbon atoms per carbonamide group

US4687838A · kind A · utility

Assignee

• Huls Aktiengesellschaft · DE

Inventors

• Salih Mumcu · Marl, DE
• Helmut Winzer · Kevelaer, DE

Key dates

• Filing date: Mar 18, 1986
• Grant date: Aug 18, 1987
• Expiry date: Mar 18, 2006

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2377/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention concerns an improved precipitation process in the manufacture of coating powders based on polyamides having at least ten aliphatically bound carbon atoms per carbonamide group. Rapid cooling takes place with stirring mainly by distilling the ethanol solvent until the temperature of precipitation is set in the range from 90.degree. to 113.degree. C. With the beginning of the saturation limit (about 125.degree. C.), the temperature difference between the coolant in the jacket and the solution inside is maintained at most at .+-.3.degree. C. The solution is maintained during the precipitation stage at constant temperature (isothermal procedure) by further distillation of the ethanol.