Process for preparing polyamide-based, pulverulent coating compositions for high molecular weight post condensation, employing the precipitation procedure

US4711925A · kind A · utility

Assignee

• Huls Aktiengesellschaft · DE

Inventors

• Salih Mumcu · Marl, DE
• Hans J. Panoch
• Joern Rueter · Marl, DE

Key dates

• Filing date: Mar 18, 1986
• Grant date: Dec 8, 1987
• Expiry date: Mar 18, 2006

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2377/00
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A precipitation procedure for preparing pulverulent coating compositions of high molecular weights by post condensation and based on polyamides having at least ten aliphatically bound carbon atoms per carbonamide group. The starting materials are uncontrolled polyamides having a relative solution viscosity of between 1.7 and 2.0 (measured in 0.5% meta cresol solution at 25.degree. C.) and contain not more than 0.2% by weight of phosphoric acid. After the cooling stage of the precipitation step of the polyamides, from 0.3 to 1.2% by weight of phosphoric acid referred to the polyamide are dispersed in the suspension prior to the precipitation in the solution or after the precipitation stage.