公开(公告)号：DE19626824A1

公开(公告)日：1998-01-08

申请号：DE19626824

申请日：1996-07-03

Applicant: EMTEC MAGNETICS GMBH

Inventor： WEINGART FRANZ DR ,  BURKHARDT UWE ,  BAUER STEPHAN DR ,  REICH WOLFGANG DR ,  KOHL ALBERT ,  KRESS RIA DR ,  TRAUB HANSJOERG DR ,  LOCH WERNER DR

IPC: C08G18/83 ,  G11B5/702 ,  C08L75/04 ,  C08L75/06 ,  C08L75/08 ,  C08L75/12 ,  C09D175/04

Abstract: A magnetic recording material contains a layer comprising a magnetic pigment and a polyurethane binder (I) prepared by reacting an isocyanate (II) with a chain extender (V).(II) are (a) prepolymers prepared by reacting (A1) a polyvalent alcohol (III) containing more than one hydroxyl group per molecule capable of reacting with (II), with (A2) an aromatic or aliphatic polyvalent isocyanate (IV), or (b) compounds (IV). The ratio of reactive hydroxyl groups in (III) to the isocyanate groups in (IV) is less than 1. (V) are prepared by reacting (a) a polyvalent alcohol (VI) with either (b1) a compound (VII) containing an epoxy group and an additional functional group which is reactive with alcohols, forming a compound (VIII) which is reacted with an alpha,beta-olefinic unsaturated carboxylic acid (IX) to form a compound (X), or (b2) a compound (IX) to form a compound (X), and then (c) reacting (X) with an amine (XI) containing at least one prim. amino group which can react with olefinic bond in (IX). The sum of reactive amino and hydroxyl groups in (V) is greater than the number of isocyanate groups in (II).