Coating powders on the basis of thermoplastic polyesters

US4054681A · kind A · utility

Assignee

• Dynamit Nobel GmbH · DE

Inventors

• Klaus Bruning · Bensberg, DE
• Karl Sturm
• Siegfried Hahn · Hennef (Sieg), DE

Key dates

• Filing date: Nov 20, 1975
• Grant date: Oct 18, 1977
• Expiry date: Nov 20, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D167/02
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

An improvement in a process for coating a substrate by a powder coating process wherein a polyester powder is applied to said substrate which improvement comprises using as the polyester powder a partially crystalline powder of a polyester condensation product of an acid component comprising an acid or ester of at least terephthalic acid and a diol component at least 50 molar percent of which is 1,4-butanediol; a polyester coating powder which is a partially crystalline polyester of an acid component at least part of which is an acid or ester of terephthalic acid and a diol component at least 50 molar percent of which is 1,4-butanediol, said powder having a glass transition temperature between -20.degree. and +50.degree. C., measured as the attenuation maximum in accordance with Deutsche Industrie Norm 53,445 a reduced n.sub.red viscosity of at least 0.6, measured in a 1 weight percent solution of a mixture of 60 parts by weight phenol and 40 parts by weight phenol and 40 parts by weight 1,1,2,2-tetrachloroethane at 25.degree. C. and a melting maximum, determined by differential thermoanalysis, of about 150.degree. to 200.degree. C.