Graft polymers, containing polyvinyl acetal groups, on polyurethane grafting substrates, processes for the preparation thereof, and the use thereof

US5034475A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Matthias Kroggel · Kelkheim, DE
• Karl J. Rauterkus · Kelkheim, DE
• Hans D. Hermann · Bad Soden am Taunus, DE

Key dates

• Filing date: Oct 19, 1989
• Grant date: Jul 23, 1991
• Expiry date: Oct 19, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F8/48
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Polymers with polyvinyl acetal groups, which contain acetalized polyvinyl alcohol groups on polyurethane grafting substrates and which are prepared from graft polymers, containing vinyl alcohol groups on polyurethane grafting substrates, by reaction with aldehydes according to known methods. The aldehydes used can be any known aldehydes capable of acetalization reactions. The polyurethane grafting substrates contain at least 2 urethane groups in the molecule and units from diisocyanates and diols, and polymer radicals of units of vinyl carboxylates having 3 to 20 carbon atoms and/or hydrolysis products thereof and, if appropriate, further monomer units are grafted onto the polyurethane grafting substrates. The proportion of vinyl alcohol units in the hydrolyzed or partially hydrolyzed graft polymers before the acetalization is >10% by weight. In the acetalized polymer, the content of residual unacetalized vinyl alcohol units is >7.5 mol %, relative to the molar content (=100 mol %) of vinyl alcohol units in the starting graft polyvinyl alcohol before acetalization. The graft polyvinyl acetals may be used as a constituent of coating compositions, as a coating agent constituent for t…