公开(公告)号：EP0150498A3

公开(公告)日：1987-09-30

申请号：EP84116314

申请日：1984-12-27

Applicant: BAYER AG

Inventor： Ohtsubo, Akio, Prof.

IPC: G11B05/716

CPC classification number: G11B5/716 ,  Y10S428/90 ,  Y10T428/256

Abstract: This invention relates to a two-layer coated recording medium for perpendicular magnetic recording, said medium being composed of
(a) a coated non-oriented perpendicular recording layer containing single-domain particles having multiaxial crystalline anisotropy, and (b) a high permeability layer, with the proviso that the case where the layers (a) and (b) both contain magnetic particles prepared by decomposition of metal carbonyls is excluded.

公开(公告)号：WO1990008380A1

公开(公告)日：1990-07-26

申请号：PCT/JP1990000060

申请日：1990-01-19

Applicant: KONICA CORPORATION ,  NAKANO, Yasushi ,  YASUFUKU, Yoshitaka ,  KOYAMA, Noboru ,  UMEMURA, Masahiro ,  NAMIKI, Takemasa ,  TOBISAWA, Seiichi ,  KAWABE, Shigetoshi ,  NAKAJIMA, Takeshi

Inventor： KONICA CORPORATION

IPC: G11B05/716

CPC classification number: G11B5/716 ,  G11B5/706 ,  G11B5/712 ,  G11B5/714 ,  Y10S428/90 ,  Y10T428/265

Abstract: A magnetic recording medium having a first magnetic layer on a nonmagnetic support member and a second magnetic layer thereon is disclosed. The first magnetic layer contains A parts by weight of at least either Si or Al and 100 parts by weight of a magnetic material, and the second magnetic layer contains B parts by weight of at least either Si or Al in 100 parts by weight of the magnetic material, A being smaller than B. The magnetic recording medium has features that it does not contaminate the carrier rolls while being manufactured; and it causes few running failures when used as a video tape.

Abstract translation: 磁记录介质包括叠加在非磁性介质上的第一和第二磁性层。 第一磁性层每100重量份的磁性材料含有至少Si或Al的A重量份，而第二磁性层含有100重量份的至少Si或Al的B重量份 磁性材料A小于B.该磁记录介质的特征在于，它在制造过程中不会污染输送辊，并且当其用作带时造成最小的故障。 视频。

公开(公告)号：WO1990007775A1

公开(公告)日：1990-07-12

申请号：PCT/JP1990000012

申请日：1990-01-08

Applicant: KONICA CORPORATION ,  NAKANO, Yasushi ,  TOBISAWA, Seiichi ,  KOYAMA, Noboru

Inventor： KONICA CORPORATION

IPC: G11B05/716

CPC classification number: G11B5/714 ,  G11B5/70673 ,  G11B5/708 ,  G11B5/716

Abstract: A magnetic recording medium having a plurality of magnetic layers is disclosed. A first magnetic layer provided on a support member contains a Co-containing η-iron oxide magnetic material having a BET specific surface area of 25 to 40 m2/g and a coercive force (Hc) of 600 to 750 Oe, 0.05 to 0.3 % by weight of silicon with respect to the magnetic material, and 7 to 13 % by weight of carbon black with respect to the magnetic material. A second magnetic layer provided thereon contains a Co-containing η-iron oxide magnetic material having a BET specific surface area of 25 to 70m2/g and a coercive force (Hc) of 750 to 950 Oe, and less than 1 % by weight of carbon black with respect to the magnetic material. It is desired that the first magnetic layer contains phosphoric ester. Further, a binder for the magnetic material should preferably be a polyvinyl chloride containing electronegative functional groups. The magnetic recording medium produces large chroma output and RF output and exhibits well-balanced electromagnetic characteristics and running durability of the tape, so that it is suitably used as a recording material.

公开(公告)号：EP0205239A3

公开(公告)日：1987-11-19

申请号：EP86302893

申请日：1986-04-17

Applicant: AKASHIC MEMORIES CORPORATION

Inventor： Scott, John C. ,  Li, Eric K. ,  Washburn, Hudson A. ,  Viswanathan, Nal T.

IPC: G11B05/66 ,  G11B05/716

CPC classification number: G11B5/851 ,  G11B5/64

Abstract: @ A new high quality, low cost, thin-film magnetic recording member is provided, which has a coercive field strength greater than 650 Oe, a saturation magnetization greater than 10,000 Gauss, and a squareness ratio of 0.9 or larger. The member includes a substrate on which is directly sputter deposited a chromium layer, without the use of an intervening nickel-containing layer between the substrate and the chromium. A nickel-cobalt recording layer is then sputter deposited directly onto the chromium layer. In the preferred mode, the start of that nickel-cobalt deposition begins less than 100 seconds after the chromium deposition is terminated and is followed by the sputtering of a protective layer. Before the chromium deposition, the substrate is preheated to drive off adsorbed gases, and to establish the proper conditions forthe chromium deposition. The substrate is also heated during the time between when the chromium deposition ends and the nickel-cobalt deposition begins.

公开(公告)号：EP0145026A3

公开(公告)日：1986-02-05

申请号：EP84115484

申请日：1984-12-14

Applicant: Saiteku Corporation

Inventor： Takahashi, Yasunori

IPC: G11B05/716 ,  G11B05/66 ,  G11B05/845 ,  G11B05/714

CPC classification number: G11B5/716 ,  G11B5/66 ,  Y10S428/90 ,  Y10T428/256 ,  Y10T428/257

Abstract: A film type multilayer magnetic recording medium comprised of a film applied to a substratum in which coating film needle-shaped magnetic grains are orientated with their longitudinal axes perpendicular to the film surface in a multilayer state and having a film thickness of 1.1 to 2.0 times the average length of the grains, has an excellent property, because the angular ratio (Br Bs) of both horizontal and vertical components respectively are 0.6 or more. As a result, it is possible to attain a high density recording. The film type multilayer magnetic recording medium of the present inventions is manufactured by applying a fluid film forming material, in which neddle-shaped magnetic grains are dispersed to form a coating film having the thickness of 1.1 to 2.0 times the average length of the magnetic grains on a substratum, and then drying or hardening the film forming material in a magnetic field orientated perpendicularly toward the film surface.