公开(公告)号：EP0123258A3

公开(公告)日：1985-09-18

申请号：EP84104340

申请日：1984-04-17

Applicant: TORAY INDUSTRIES, INC.

Inventor： Tanaka, Kazuhiro ,  Kawakami, Ken-ichi ,  Yoshii, Toshiya

IPC: G11B05/82 ,  G11B05/70 ,  G11B05/64 ,  B32B27/08

CPC classification number: G11B5/825 ,  G11B5/7315 ,  Y10S428/90 ,  Y10S428/91 ,  Y10T428/24372 ,  Y10T428/24612 ,  Y10T428/24942 ,  Y10T428/24975 ,  Y10T428/26 ,  Y10T428/264 ,  Y10T428/265 ,  Y10T428/31786 ,  Y10T428/31797 ,  Y10T428/31938

Abstract: @ A magnetic recording disk which comprises (1) a three-layered laminate consisting of a core layer of a biaxially oriented polyolefinfilm which has a birefringence of not more than 0.01 and an amorphous-region orientation coefficient of not more than 0.2 and two outer layers of a biaxially oriented polyester film adhered to said core layer, and (2) a magnetic layer formed on at least one side of the laminate. The magnetic recording disk of the invention undergoes only slight dimensional changes with variations in humidity and temperature, and the dimensional changes are isotropic in the plane. The disk therefore has an excellent electromagnetic properties such as output fluctuation and outbreak of dropouts caused by the environmental change.

公开(公告)号：EP0054269A3

公开(公告)日：1983-08-10

申请号：EP81110352

申请日：1981-12-11

Applicant: TEIJIN LIMITED

Inventor： Kadokura, Sadao ,  Tomie, Takashi ,  Naoe, Masahiko

IPC: G11B05/64 ,  G11B05/84 ,  G11B05/70

CPC classification number: G11B5/64 ,  G11B5/851 ,  Y10S428/90 ,  Y10T428/31678

Abstract: Magnetic recording medium conventionally utilizes the in-plane magnetization mode, but, recently, the perpendicular magnetization mode utilizing the perpendicular anisotropy of an hcp cobalt alloy layer, in which C axis is oriented normal to the layer surface, is proposed. The known perpendicular magnetic recording medium has been produced by an RF sputtering, but such medium is of too low flexibility to use it in the form of a magnetic tape. In addition, the production rate of the perpendicular magnetic recording medium by RF sputtering is very low. The perpendicular magnetic recording medium is very flexible due to particle pattern (Figures 10, 12 and 13) completely distinct from the conventional columnar pattern (Figures 8 and 11). In addition, the production rate is high, because the base (20) is located beside a space between the targets (T,, T 2 ) of a sputtering device and further the magnetic field is generated perpendicularly to the sputtering surfaces (T 1s , T 25 ) by a field coil (31) or magnets (32,33). The present invention makes it possible to commercially produce the perpendicular magnetic recording medium, especially in the tape form.