Bonding plastics with water-based polyurethane primer

US5972158A · kind A · utility

Assignee

• Kenkel Kommanditgeselschaft auf Aktien · DE

Inventors

• Horst Hoffmann · Pentling, DE
• Hans-Georg Kinzelmann · Pulheim, DE
• Hans-Peter Kohlstadt · Velbert, DE

Key dates

• Filing date: Oct 15, 1996
• Grant date: Oct 26, 1999
• Expiry date: Oct 15, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31587
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process of bonding a plastic is provided. The process comprises applying to a plastic surface an aqueous dispersion of a hydroxyl-functional polyurethane prepolymer obtained by: PA1 (1) reaction of: PA2 a polyol component containing a polyester polyol, PA2 a compound selected from the group of compounds containing groups capable of salt formation and at least two isocyanate-reactive groups, PA2 an isocyanate component in a stoichiometric excess, at least 20% by weight of said component consisting of tetramethyl xylylene diisocyanate, and PA1 (2) subsequent dispersion in water and at least partial reaction of the remaining NCO groups with an aminoalcohol and, optionally, subsequent chain extension. The process further comprises drying said applied aqueous dispersion to form a primer and bonding said plastic surface having said primer to a part to be joined thereto. The process is particularly useful for priming plastics such as polyvinyl chloride.