Multilayer coating systems containing a gel-like base layer and a polyurethane topcoat, and their production and use

US6762243B2 · kind B2 · utility

Assignees

• BAYER HEALTHCARE LLC · DE
• TechnogelGmbH & Co. · DE

Inventors

• Adolf Stender · Duderstadt, DE
• Claus Kobusch · Meerbusch, DE
• Wolfram Küttner · Bensberg, DE

Key dates

• Filing date: Jul 27, 2001
• Grant date: Jul 13, 2004
• Expiry date: Jul 27, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31551
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to a coating system containingI) anhydrous, gel-like, high molecular weight polyurethane compositions, which may contain active substances, based on(1) 15 to 62 wt. %, based on the weight of 1) and 2), of a high molecular weight covalently crosslinked polyurethane matrix and(2) 38 to 85 wt. %, based on the weight of 1) and 2), of a liquid dispersing agent firmly bound in the matrix by secondary valence bonds, wherein the liquid dispersing agent contains one or more polyhydroxyl compounds having a number average molecular weight of 1000 to 12000 and an OH number of 20 to 112, wherein the dispersing agent is substantially free from hydroxyl compounds having a molecular weight below 800, andII) solvent-containing, solvent-free and/or aqueous polyurethane topcoats.