Manufacture of thin layers of polyurethane elastomers

US4013806A · kind A · utility

Assignee

• BASF SE

Inventors

• Otto Volkert · Bad Dürkheim, DE
• August Wigger · Waldsee, DE
• Manfred Zuerger
• Peter Richter · Karlstein, DE

Key dates

• Filing date: Dec 4, 1973
• Grant date: Mar 22, 1977
• Expiry date: Dec 4, 1993

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F283/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the manufacture of thin layers based on polyurethane elastomers. A liquid reaction mixture essentially consisting of (A) polyesters, polyethers, polyester urethanes or polyether urethanes, all of which contain at least two hydroxyl groups in the molecule, and diisocyanates or (B) prepolymers obtained from the hydroxyl-containing compounds mentioned under (A) above with an excess of diisocyanates, said prepolymers containing at least two isocyanate groups in the molecule, and at least one of the compounds mentioned under (A) above which are capable of reacting with isocyanates, to which reaction mixture a minor quantity of substantially compatible monomers having at least two photocrosslinkable C--C multiple bonds and optionally a photopolymerization initiator have been added, is applied to a substrate to form a coating thereon, which coating is then gelled by irradiation and finally thermocured. The process of the invention is particularly suitable for the continuous manufacture of uniformly thin layers of soft polyurethane elastomer showing narrow tolerance limits.