公开(公告)号：JPH06176346A

公开(公告)日：1994-06-24

申请号：JP21605493

申请日：1993-08-31

Applicant: BASF MAGNETICS GMBH

Inventor： HERUMUUTO YAKUSHIYU ,  KURAUSU DEIITAA SHIYOOMAN ,  MIHIYAERU FUITSUTSUFUERUTO ,  HERUMAN RORAA ,  RAINHORUTO BAURU ,  EDOBUIN ROOTOFUSU

IPC: C09D5/23 ,  C09D175/00 ,  C09D175/04 ,  G11B5/70 ,  G11B5/706 ,  G11B5/73

Abstract: PURPOSE: To obtain a magnetic recording medium which contains main chromium dioxide as a magnetic material and does not have the drawbacks of drop-outs in copying by a sprinter process method. CONSTITUTION: The magnetic memory medium consists of a nonmagnetic substrate and a magnetic layer applied thereon. This magnetic layer is obtd. by applying a dispersion prepd. by uniformly dispersing at least 40wt.% acicular ferromagnetic chromium dioxide in a polymer binder consisting of polyurethane as a base on the substrate, then drying the coating. The magnetic layer in particular has an inside surface area of 5 to 30m /cm and the pigment concn. PVC per volume attains 45 to 65%. The magnetic recording medium is thus made adaptable to the sprinter process of rapid copying.

公开(公告)号：JPH06203369A

公开(公告)日：1994-07-22

申请号：JP27941793

申请日：1993-11-09

Applicant: BASF MAGNETICS GMBH

Inventor： MIHIYAERU BOBURITSUHI ,  GUREEGORU BUROTO ,  HERUMAN RORAA

IPC: G11B5/72 ,  C09D5/23 ,  C09D175/14 ,  G11B5/73 ,  G11B5/735 ,  G11B5/84 ,  G11B5/704

Abstract: PURPOSE: To ensure high thermal stability and moisture resistance by forming a backing coat on a face of a substrate opposite to the principal face. CONSTITUTION: A poly(meth)acrylate having

公开(公告)号：JPH0628663A

公开(公告)日：1994-02-04

申请号：JP11827293

申请日：1993-05-20

Applicant: BASF MAGNETICS GMBH

Inventor： HERUMAN RORAA ,  PEETAA ENGERUHARUTO ,  RAINHORUTO BAURU ,  MIHIYAERU BOBURITSUHI ,  BUERUNAA RATSUERU ,  BUERUNAA RENTSU ,  RUDORUFU ZUYUTEINGAA

IPC: G11B5/66 ,  G11B5/73 ,  G11B5/733 ,  G11B5/735 ,  G11B5/704

Abstract: PURPOSE: To prepare a dispersion liquid to form a back layer which shows no decrease in gloss or increase in roughness, nor decrease in mechanical characteristics such as wear resistance by completing dispersion under specified technical conditions and then maintaining the stable state. CONSTITUTION: The magnetic recording carrier consists of a nonmagnetic base tape, a magnetic layer formed on the principal surface of the base tape, and a back coating layer comprising a polymer binder, nonmagnetic filler and supporting pigment. The back layer contains 15 to 40vol.% precipitated silica to the whole volume. The precipitated silica contains 98 to 99.5 % SiO2 and has pH=5 to 7 and 90 to 650m /g specific surface area. The surface of the silicate is covered with a polyurethane by 0.05 to 0.25g/m coating amt. This polyurethane has 40000 to 120000 average mol.wt. Mw and contains 10 to 100mg equiv. phosphate groups per 1kg of polyurethane.

公开(公告)号：JPH06195683A

公开(公告)日：1994-07-15

申请号：JP20617093

申请日：1993-08-20

Applicant: BASF MAGNETICS GMBH

Inventor： AUGUSUTO REENAA ,  NORUBERUTO SHIYUNAIDAA ,  HERUMAN RORAA ,  BUERUNAA BARUTSU ,  BUERUNAA RENTSU ,  ARUBERUTO KOORU ,  RAINHARUTO SHIYUTORANSUKII

IPC: C08K3/08 ,  C08K3/02 ,  C09D5/23 ,  G11B5/708

Abstract: PURPOSE: To suppress the wear of a head by forming a magnetic layer contg. a fine powdery org. hydrophobic pigment insoluble in a solvent used and having >90 deg.C m.p. by 0.1-8wt.% of the amt. of a magnetic material. CONSTITUTION: A magnetic dispersion liq. contg. a fine powdery org. hydrophobic pigment, PE or PP having a mol.wt. of 500-7,000 as a binder and an anisotropic magnetic material in an org. solvent is prepd. The pigment is insoluble in the solvent and has >=90 deg.C m.p. and a fine powdery spherical pigment having 90 deg.C m.p. is advantageously used. The pigment is contained by 0.1-8wt.% of the amt. of the magnetic material. A nonmagnetic substrate is coated with the dispersion liq., the anistropic magnetic material is oriented in a magnetic field and the resultant magnetic layer is solidified. The objective medium producing no harmful effect on mechanical properties is obtd. without deteriorating magnetic properties.

公开(公告)号：JPH06176349A

公开(公告)日：1994-06-24

申请号：JP20616993

申请日：1993-08-20

Applicant: BASF MAGNETICS GMBH

Inventor： AUGUSUTO REENAA ,  NORUBERUTO SHIYUNAIDAA ,  HERUMAN RORAA ,  BUERUNAA BARUTSU ,  BUERUNAA RENTSU ,  ARUBERUTO KOORU

IPC: C09D183/04 ,  C09D5/23 ,  C10M107/04 ,  C10M107/06 ,  C10M107/50 ,  C10N40/18 ,  G11B5/708 ,  G11B5/71

Abstract: PURPOSE: To obtain a magnetic recording medium which exhibits lower head wear, less water absorption and improved scratching flaw resistance even at and under a high temp., fluctuating temp. load and atm. humidity and improved use characteristics, such as lessened oscillation, at the time of tape travel and is not damaged and degraded in its magnetic properties. CONSTITUTION: The dispersion of an anisotropic magnetic material and ordinary additives is prepd, in the polymer binder soln. in an org. solvent. This dispersion is applied in a laminar form on a substrate with which the magnetization is infeasible. Further, the anisotropic magnetic material is oriented in a magnetic field and the applied magnetic layer is solidified, by which the magnetic layer is obtd. The magnetic layer formed in such a manner includes org. hydrophobic supporting pigments of fine powder and highly viscous polysiloxane.

公开(公告)号：JPH05135346A

公开(公告)日：1993-06-01

申请号：JP12021092

申请日：1992-05-13

Applicant: BASF MAGNETICS GMBH

Inventor： HERUMAN RORAA ,  PEETAA HAIRUMAN ,  MIHIYAERU HITSUTSUFUERUTO ,  DEIITAA SHIYUTOTSUKUBURUGAA ,  BUERUNAA RATSUTSUERU ,  RAINHORUTO BAURU ,  PEETAA ENGERUHARUTO ,  EDOBUIN ROOTOFUSU ,  BUERUNAA GURAU ,  BUERUNAA RENTSU

IPC: C09D5/23 ,  C09D127/04 ,  C09D127/06 ,  C09D175/00 ,  C09D175/04 ,  G11B5/73 ,  G11B5/735

Abstract: PURPOSE: To obtain a magnetic recording medium having good wear resistance by applying a magnetic layer on the main surface on one side of a web-like nonmagnetic substrate and applying a high mol.wt. binder and nonmagnetic additives on the rear surface layer on the opposite side of the main surface. CONSTITUTION: This magnetic recording medium consists of the web-like nonmagnetic substrate, the magnetic layer applied on the main surface on one side of this substrate and the rear surface layer formed on the opposite side of the main surface of the substrate from the high mol.wt. binder and nonmagnetic additives. The rear surface layer is formed by dispersing an org. polymer and a mixture composed of 2.5 to 25vol.% filler, 0.5 to 3vol.% auxiliary pigment and 1 to 10vol.% polyolefin of spherical particles having an average grain size of 1 to 1000μm at a density of 0.9 to 1.0 in the shape of the spherical particles. In addition, the resulted dispersion is applied on the front surface of the substrate existing on the opposite side of the magnetic layer at a layer thickness of such extent that a layer thickness of 0.1 to 2.0μm arises after the solidification of the rear surface layer. As a result, the magnetic recording medium having the excellent wear resistance and wear on the rear surface layer of the magnetic recording medium and simultaneously having transparency to light is obtd.