Process for the production of multicoat protective and/or decorative coatings on substrate surfaces

US5370910A · kind A · utility

Assignee

• Basf Lacke & Farben Aktiengesellschaft · DE

Inventors

• Hans-Dieter Hille · Bensberg, DE
• Stefan Wieditz · Sylvania, US
• Arnold Dobbelstein · Cologne, DE
• Horst Muller · Cologne, DE

Key dates

• Filing date: Feb 26, 1992
• Grant date: Dec 6, 1994
• Expiry date: Feb 26, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D175/04
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a basecoat/clearcoat process in which the basecoat composition used contains as a film former a polyurethane resin which can be prepared by preparing an intermediate from PA1 (A) a mixture obtained from 10 to 90 mol % of linear polyether diols and 90 to 10 mol % of polyester diols, PA1 (B) diisocyanates, PA1 (C) compounds which contain two groups reactive toward isocyanate groups, at least some of these compounds having at least one group capable of forming anions, and the free isocyanate groups of the said intermediate are then reacted with PA1 (D) polyols containing at least three hydroxyl groups, and the reaction product obtained in this manner is transferred into an aqueous base, wherein PA2 a) the polyester diol is prepared from diols and an acid component which consists of 60 to 100 % by weight of aliphatic dicarboxylic acids of more than 18 carbon atoms and of 40 to 0 % by weight of aliphatic dicarboxylic acids of 2 to 18 carbon atoms, PA2 b) the equivalent ratio of the NCO groups to the total of the OH groups of (A) and the reactive groups of (C) is 2:1 to 1.05:1 and PA2 c) the equivalent of the OH groups of the component (D) to the NCO groups of th…