Magnetic recording medium containing magnetic material dispersed in a polyurethaneurea-polyurethane binder

US5552229A · kind A · utility

Assignee

• BASF Magnetics GmbH · DE

Inventors

• Gregor Brodt · Heppenheim, DE
• Attila Vass · Foster City, US
• Werner Loch · Erpolzheim, DE
• August Lehner
• Werner Lenz · Bad Dürkheim, DE
• Norbert Schneider · Schorndorf, DE

Key dates

• Filing date: Sep 29, 1994
• Grant date: Sep 3, 1996
• Expiry date: Sep 29, 2014

Classification

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

Abstract

In magnetic recording media consisting of a nonmagnetic substrate and at least one magnetizable layer firmly applied thereon and based on magnetic material dispersed in a binder mixture which contains at least one hydroxyl-containing, preferably low molecular weight polyureaurethane and one polyurethaneurea (meth)acrylate, the polyurethaneurea (meth)acrylate is obtained by reacting a poly(meth)acrylate having up to 2 terminal OH groups per mol and a molecular weight of from 200 to 50,000 with a mixture of aliphatic polyisocyanates having an average functionality of from 3.0 to 6.0 NCO groups per mol, consisting of from 0.1 to 10% by weight of a diisocyanate, from 30 to 80% by weight of a triisocyanate and from 20 to 60% by weight of an isocyanate having a functionality of from 4 to 10, with the proviso that from 1.2 to 3.0 NCO groups react per OH group and the remaining NCO groups are converted into substituted terminal urea groups with a polyfunctional amine or with a mixture of different polyfunctional amines.