公开(公告)号：DE19644347A1

公开(公告)日：1997-05-07

申请号：DE19644347

申请日：1996-10-25

Applicant: BASF MAGNETICS GMBH

Inventor： WUENSCH THOMAS DR ,  KRESS RIA DR ,  LOCH WERNER DR ,  LEHNER AUGUST ,  KOHL ALBERT ,  SCHNEIDER NORBERT ,  BURKHARDT UWE

IPC: C08K3/08 ,  C08G18/10 ,  C08G18/32 ,  C08G18/38 ,  C08G18/64 ,  C08G18/72 ,  C08K3/22 ,  C08L75/00 ,  C08L75/04 ,  C09D5/23 ,  C09D175/00 ,  C09D175/04 ,  G11B5/702 ,  C08G18/30 ,  C09D17/00

Abstract: A hydroxyl-containing polyurethane (I) comprises (a) a 6-30C diisocyanate; (b) a component comprising (i) a 2-20C aliphatic diol or (ii) a 8-30C aromatic-(cyclo)aliphatic diol having non-phenolic hydroxyl groups as the diol hydroxyl groups; and (c) a 3-18C polyhydric alcohol having at least 3 hydroxyl groups and non-phenolic hydroxyl groups as alcohol hydroxy groups. The total number of non-phenolic hydroxyl groups in (I) is 1.1-5.0 per isocyanate group in (a). Also claimed are (1) a binder system curable by crosslinking, which comprises (I) and (d) a polyfunctional isocyanate, and where the ratio of isocyanate groups in (d) to the number of free hydroxyl groups in (I) is 0.3-5.0; and (2) a coated article (preferably a magnetic recording material) obtained by applying a layer of the binder system and subsequently crosslinking. Preferably (b) is a 2-10C aliphatic diol. (c) is a 3-6C polyhydric alcohol having 3-5 hydroxyl groups. The binder system contains non-magnetic or magnetic pigments.

公开(公告)号：DE4330889A1

公开(公告)日：1995-03-16

申请号：DE4330889

申请日：1993-09-11

Applicant: BASF MAGNETICS GMBH

Inventor： WUENSCH THOMAS DR ,  SARTOR KARL-HEINZ ,  SCHULZE AXEL-RUEDIGER DR ,  MUELLER NORBERT DR

IPC: B03C1/005 ,  B29B17/02 ,  C08J11/08 ,  G11B5/84 ,  C08L67/02

Abstract: In order to recover the magnetic powder and the PET from a magnetic recording medium comprising a polyethylene terephthalate layer base and a magnetic layer cast thereon, in which finely divided magnetic powder is finely dispersed in polyurethane binder, finely comminuted magnetic tape waste according to the invention is treated at elevated temperature in organic solvents, an acid soluble therein and alcohols or thio alcohols and optionally surfactants. The magnetic layer stripped off in this way is separated from the layer base by a washing process, and subsequently both layer base and magnetic powder are dried. The materials recovered in this manner can be processed and used in further ways.

公开(公告)号：DE4445173A1

公开(公告)日：1995-07-13

申请号：DE4445173

申请日：1994-12-17

Applicant: BASF MAGNETICS GMBH

Inventor： BRODT GREGOR DR ,  WUENSCH THOMAS DR ,  LEHNER AUGUST ,  KOHL ALBERT

IPC: C08G18/12 ,  C08G18/65 ,  C09D5/23 ,  G11B5/702 ,  C09D175/00

Abstract: Curable binder component (I) with mol. wt. of 25000-150000, useful for pigmented coatings, is prepd. from a polyurethane (II) obtd. by reacting (a) 1 mole diol with a mol. wt. of 400-4000, (b) 0.1-10 mole 2-18 C (cyclo)aliphatic diol, (c) 0.01-10 mole 8-36 C aromatic diol, (d) 0.01-2 mole 3-18C triol and (e) 0.001-8 mole 3-40 C polyol contg. a tert. amino gp. with (f) a 6-34 C diisocyanate, using a molar ratio of NCO gps. in (f) to total OH gps. in (a-e) of (1.05-1.4):1. (I) is prepd. by reacting (II) with a cpd. (III) having OH gp(s). and also NCO-reactive amino gp(s). in such an amt. that the no. of reactive amino gps. in (III) corresponds to the no. of NCO gps. in (II). Also claimed are articles with a coating, esp. a coating contg. a magnetic pigment, and magnetic recording materials contg. (I); and the coating process.