公开(公告)号：JPH10283627A

公开(公告)日：1998-10-23

申请号：JP34302797

申请日：1997-12-12

Applicant: EMTEC MAGNETICS GMBH

Inventor： KRESS RIA DR ,  KOHL ALBERT ,  LEHNER AUGUST ,  LENZ WERNER DR ,  HITZFELD MICHAEL DR

IPC: C09D5/23 ,  G11B5/702

Abstract: PROBLEM TO BE SOLVED: To provide a magnetic recording medium which has excellent wear resistance, high residual induction, a narrow switching field distribution, is substantially free from the defects of layer surfaces and has excellent magnetic characteristics and more particularly the characteristic to preserve digital data. SOLUTION: This magnetic recording medium has a nonmagnetic substrate and a magnetizable layer contg. ferromagnetic powder and a compsn. of a high-polymer material. In such a case, the compsn. of the high-polymer material contains A) an isocyanate reactive polymer obtd. by bringing a polymer into reaction with a multifunctional nonaromatic isocyanate and introducing an ionic or ionogenic group therein and B) a polymer obtd. by bringing a highpolymer diol into reaction with 2 to 18c diol, polyhydric alcohol, diisocyanate and amino alcohol.

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).

公开(公告)号：DE59505753D1

公开(公告)日：1999-06-02

申请号：DE59505753

申请日：1995-06-30

Applicant: EMTEC MAGNETICS GMBH

Inventor： LEHNER AUGUST ,  KRESS RIA DR ,  KOHL ALBERT ,  HITZFELD MICHAEL DR

IPC: C09D5/23 ,  C09D175/00 ,  C09D175/04 ,  C09D175/14 ,  C09D175/16 ,  G11B5/702

Abstract: Magnetic recording medium has a non-magnetic substrate and magnetisable layer(s) based on magnetic pigments dispersed in a binder mixt., which comprises (a) a mixt. of 3-35% polyurethane-urea (meth)acrylate (I) and 5-97% polyurea-urethane (II) contg. anionic gps.; or (b) a mixt. of 5-25% (I), 15-60% (II) and 15-60% polymeric binder without anionic gps., selected from polyurethane, PVC, polyvinylformal, phenoxy resin, nitrocellulose and/or cellulose ester.

公开(公告)号：DE19651672A1

公开(公告)日：1998-06-18

申请号：DE19651672

申请日：1996-12-12

Applicant: EMTEC MAGNETICS GMBH

Inventor： KRESS RIA DR ,  KOHL ALBERT ,  LEHNER AUGUST ,  LENZ WERNER DR ,  HITZFELD MICHAEL DR

IPC: C09D5/23 ,  G11B5/702 ,  B32B15/08

Abstract: Magnetic recording medium has a non-magnetic substrate and a magnetisable layer containing ferromagnetic pigment and a polymer system, containing 40-100 wt.% polymers (I) and (II), comprising 3-35 wt.% polymer (I) and 5-97 wt.% polymer (II). (I) is obtained by reacting (1) a polymer (III) of (a) 80-100 mole-% 1-25 carbon (C) alkyl or an alpha , beta -unsaturated carboxylic acid, (b) 0-20 mole-% other monomer(s) and (c) a starter and/or regulator giving hydroxyl-(OH) terminated polymer chains, with (2) a non-aromatic polyisocyanate, using 1.2-3.9 mole isocyanate (NCO) groups/mole OH groups in (III); and (3) reacting the product (a) with a compound containing NCO-reactive groups in an amount of 2-7 mole NCO-reactive groups/mole free NCO groups in (III) and (b) then with a compound that reacts with the free reactive groups and introduces ionic or ionogenic groups; or (b) with a compound containing NCO-reactive groups that introduces ionic or ionogenic groups. (II) has a molecular weight of 30 000-2 000 000 and is obtained by reacting (1) 1 mole of a polymeric diol with a number average molecular weight (Mn) of 400-10000 with (2) 0.3-1 mole 2-18 C diol, 0.01-1 mole 3-25 C polyol with NOTLESS 3 OH groups, (4) 1.3-13 mole 6-30 C diisocyanate and (5) 0.09-2 mole 2-16 C amino-alcohol. The ratio of the sum of OH groups in the diols and polyols to NCO groups in the diisocyanate to amino groups in the amino-alcohol is 1:(1.03-1.3):(0.03-0.3).

公开(公告)号：DE19644347C2

公开(公告)日：1999-08-12

申请号：DE19644347

申请日：1996-10-25

Applicant: EMTEC 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: Hydroxyl-containing polyurethanes I are composed essentially of a) a diisocyanate of 6 to 30 carbon atoms (component II), b) a component III comprising alpha ) an aliphatic diol of 2 to 20 carbon atoms or beta ) an aromatic-aliphatic or aromatic-cycloaliphatic diol of 8 to 30 carbon atoms having nonphenolic hydroxyl groups as hydroxyl groups of the diol and c) a polyhydric alcohol having at least 3 hydroxyl groups, 3 to 18 carbon atoms and nonphenolic hydroxyl groups as hydroxyl groups of the alcohol (component IV), the amounts of components II to IV being such that the total number of nonphenolic hydroxyl groups is from 1.1 to 5.0 per isocyanate group of II. The polyurethanes can be used as binders or binder components for pigment-containing coatings, in particular for the production of magnetic recording materials.

公开(公告)号：DE19757670A1

公开(公告)日：1999-07-01

申请号：DE19757670

申请日：1997-12-23

Applicant: EMTEC MAGNETICS GMBH

Inventor： LEHNER AUGUST ,  KOHL ALBERT ,  KRESS RIA DR ,  WUENSCH THOMAS DR ,  WEINGART FRANZ DR

IPC: C09D5/23 ,  C09D175/04 ,  G11B5/702 ,  C08G18/10 ,  C08G18/32 ,  C08G18/65 ,  C08G18/38

Abstract: The present invention relates to a magnetic recording medium, comprising a non-magnetic support and at least one magnetic coating applied thereto, whereby said coating contains at least one finely distributed magnetic material dispersed in a binding agent. Said binding agent contains at least one polyurethane resin (PV, which can be obtained by cross-linking at least one polyisocyanate (A) with at least one polyurethane prepolymer (B) which is free of isocyanate groups and contains at least 3 active hydrogen atoms. The invention is characterised in that the polyurethane prepolymer (B) has at least two hydroxyl groups and at least one primary and/or secondary amino group. The invention also relates to a method for producing a magnetic recording medium, polyurethane prepolymers B) which are free of isocyanate and a method for the production and use thereof.