EMTEC magnetics GmbH

US6132880A · kind A · utility

Assignee

• Emtec Magnetics GmbH · DE

Inventors

• Franz Weingart · Leimen, DE
• Christa Hackl · Bad Essen, DE
• Rudiger Krech · Diepholz, DE
• Stephan Bauer · Hochdorf-Assenheim, DE
• Albert Kohl · Laumersheim, DE
• Ria Kress · Ludwigshafen, DE
• Josef Schelble · Munich, DE
• Hans-Ganther Bohrmann · Ludwigshafen, DE

Key dates

• Filing date: Aug 4, 1998
• Grant date: Oct 17, 2000
• Expiry date: Aug 4, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31609
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The thermoplastic, isocyanate-free polyurethane which contains acidic groups, is soluble in tetrahydrofuran, has a molecular weight of from 15,000 to 70,000 and is composed of PA0 A) 1 mol of a polyol having a molecular weight of from 400 to 4000, PA0 B) from 0.3 to 9 mol of a mixture of PA1 B1) if required, a diol of 2 to 18 carbon atoms and PA1 B2) from 0.03 to 0.4 mol of a diol having at least one acidic group, PA0 C) from 0 to 1 mol of a polyol having 3 to 18 carbon atoms and at least 3 OH groups, PA0 D) from 1.25 to 13 mol of a diisocyanate of 6 to 30 carbon atoms and PA0 E) from 0 to 1 mol of a primary or secondary amino alcohol of 2 to 16 carbon atoms, the molar ratio of the OH and any NH groups present in the sum of the components A, B, C and E to the NCO groups of component D being from 0.98 to 1.4, is obtainable by reacting the above components in the melt and is suitable in particular as a binder for magnetic recording media.