公开(公告)号：FR2740776A1

公开(公告)日：1997-05-09

申请号：FR9613318

申请日：1996-10-31

Applicant: BASF MAGNETICS GMBH

Inventor： WUNSCH THOMAS ,  KRESS RIA ,  LOCH WERNER ,  LEHNER AUGUST ,  KOHL ALBERT ,  SCHNEIDER NORBERT ,  BURKHART 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 ,  C09D7/00 ,  G11B5/62

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：DE19516784A1

公开(公告)日：1996-11-14

申请号：DE19516784

申请日：1995-05-11

Applicant: BASF MAGNETICS GMBH

Inventor： BRODT GREGOR ,  WEINGART FRANZ ,  LEHNER AUGUST ,  KOHL ALBERT ,  KRESS RIA ,  SCHELBLE JOSEF ,  SCHNEIDER NORBERT

IPC: C08G18/10 ,  C08G18/62 ,  C08G18/65 ,  C08G18/83 ,  C08L75/00 ,  C08L101/00 ,  C08L101/12 ,  C09D5/23 ,  G11B5/702 ,  G11B5/73 ,  C08L75/04 ,  C09D17/00

Abstract: Polymeric materials (I), suitable for use as dispersing resins, are obtd. by reacting (1) a polymer (II) of (a) 80-100 mole% (1-25C alkyl)-ester of an alpha , beta -unsatd. carboxylic acid, (b) 0-20 mole% other comonomer(s) and (c) a starter and/or regulator to produce OH end gps. on most of the polymer chains with (2) a polyfunctional isocyanate (III) to give a prod. (IV), using a mole ratio of (NCO gps.):(OH gps. in II) = 1.2-3.9, and (3) reacting (IV) with (a) a cpd. contg. NCO-reactive gps., with a ratio of 2-7 moles reactive gps. per mole free NCO gps. in (IV), and then reacting the prod. obtd. (VI) with a cpd. (VII) which reacts with the free reactive gps. to introduce acid gps., or (b) a NCO-reactive cpd. (VIII) which itself enables the introduction of acid gps. Also claimed is (i) this process as such, (ii) pigment prepns. contg. a pigment (pref. a magnetic pigment) and material (I), and (iii) magnetic recording materials contg. magnetic pigments treated with (I).

公开(公告)号：GB2285807A

公开(公告)日：1995-07-26

申请号：GB9500512

申请日：1995-01-11

Applicant: BASF MAGNETICS GMBH

Inventor： WUENSCH THOMAS ,  BRODT GREGOR ,  KRESS RIA ,  SCHNEIDER NORBERT ,  KOHL ALBERT ,  LEHNER AUGUST ,  BALZ WERNER

IPC: C08G18/12 ,  C08G18/61 ,  C08G18/65 ,  C08G18/66 ,  C09D5/23 ,  C09D175/00 ,  C09D175/04 ,  G11B5/702

Abstract: Polymeric materials (I) having an average molecular weight from 4000 to 30,000 are obtainable by reacting 1) A polyurethane (II) comprising a) 1 mol of a diol (III) having an average molecule weight of from 400 to 4000, b) from 0.3 to 9 mol of an aliphatic or cycloaliphatic diol (IV) of 2 to 18 carbon atoms, c) from 0.3 to 9 mol of an aromatic diol (V) of 8 to 30 carbon atoms, d) from 0.01 to 1 mol of a trihydric alcohol (VI) of 3 to 18 carbon atoms, e) from 0.001 to 1 mol of a polyhydric alcohol (VII) of 3 to 14 carbon atoms which contains a tertiary amino group and f) an amount of a diisocyanate (VIII) of 6 to 30 carbon atoms such that the molar ratio of the isocyanate groups to the total number of hydroxyl groups in (III) to (VII) is from 1.05:1 to 1.4:1 with 2) a compound (IX) which contains one or more hydroxyl groups and one or more amino groups reactive toward isocyanate groups, the amount of (IX) being such that the number of reactive amino groups corresponds to the number of isocyanate groups in the polyurethane (II). The materials may be used as crosslinkable binder components for pigment-containing coatings, in particular for the production of magnetic recording materials.

公开(公告)号：DE4233999A1

公开(公告)日：1994-04-14

申请号：DE4233999

申请日：1992-10-09

Applicant: BASF MAGNETICS GMBH

Inventor： LATZEL WERNER DR ,  ENGELHARDT PETER ,  RUDOLF PETER DR ,  SCHWARZ LOTHAR ,  HEILMANN PETER DR ,  ROLLER HERMANN ,  LEHNER AUGUST

IPC: G11B5/73 ,  G11B5/735 ,  G11B5/62 ,  G11B5/72

Abstract: Magnetic recording media with a coating on the reverse side is produced, consisting of a non-magnetic substrate, a magnetic coating on the main side, and, on the other side, a coating made up of a polymer binder, non-magnetic fillers, pigments, dispersing agents and other usual additives. The material for this reverse coating is produced by separately mixing the various solid particles and additives with part of a solution of the binder so as to coat the particles with the organic substances concerned; this mix is next dispersed by means of a ball mill, metered quantities of the dispersion obtained plus the remaining solution of binder are then intensively mixed in a toothed colloid mill against the direction of feed before being applied to the reverse side of the sheeting. ADVANTAGE - The method produces stable dispersions from a wide variety of solid materials. It does so with a high space-time output. Existing types of dispersion can be used without increasing the quantity of dispersion agent. It improves the fault count in the reverse side layer and hence improves the recording quality of the medium.

公开(公告)号：DE4233388A1

公开(公告)日：1994-04-07

申请号：DE4233388

申请日：1992-10-05

Applicant: BASF MAGNETICS GMBH

Inventor： LEHNER AUGUST ,  SCHNEIDER NORBERT ,  BALZ WERNER DR ,  LENZ WERNER DR ,  BOBRICH MICHAEL DR ,  KOHL ALBERT

IPC: C09D5/23 ,  C09D133/04 ,  C09D133/16 ,  G11B5/702 ,  G11B5/708 ,  G11B5/62

Abstract: Magnetic recording substrate comprises a non-magnetic substrate material supporting at least one applied magnetic layer contg. at least 30 wt% ferromagnetic chromium dioxide finely divided in a polymer binding agent and other standard. The content of 0.1-8 wt% (w.r.t. CrO2) perfluoropolyacrylate having a softening pt. greater than 110 deg.C in the magnetic layer. ADVANTAGE - The recording substrates show improved stability to chemical degradation and no less in mechanical properties at high or varying temps. whilst showing no deterioration in magnetic properties.