公开(公告)号：JPS60138721A

公开(公告)日：1985-07-23

申请号：JP24982684

申请日：1984-11-28

Applicant: BASF AG

Inventor： KURISUTEIINE GIYUTONAA ,  PEETAA HAIRUMAN ,  UDO KURUMAN ,  DEIITAA MAIYAA ,  BUERUNAA GURAU

IPC: G11B5/66 ,  G11B5/64 ,  G11B5/72

公开(公告)号：JPH02292725A

公开(公告)日：1990-12-04

申请号：JP9418190

申请日：1990-04-11

Applicant: BASF AG

Inventor： HORUSUTO PURATSUTSU ,  PEETAA ENGERUHARUTO ,  FURIIDORITSUHI ZOMAAMAN ,  ARUBERUTO KOORU ,  YURUGEN KURAUSUMAN ,  RAINHORUTO BAURU ,  PEETAA HAIRUMAN ,  HERUMAN RORAA

IPC: G11B5/84 ,  G11B5/842

Abstract: PURPOSE: To improve the recording properties of a magnetic recording medium by producing a dispersion in a mixing and pulverizing machine filled with pulverizing balls having a specific diameter and density. CONSTITUTION: The dispersion is produced in the mixing and pulverizing machine filled with the pulverizing balls having a diameter of 0.2 to 3.0mm and a density of 3.6 to 3.9g/cm . The dispersion is post-treated in a ball mill including pulverizing balls having a diameter larger than 2.0mm and a density larger than 4.2g/cm . The dispersion is so produced that the viscosity of the resulted dispersion, measured at 25 deg.C is at least 50mPas and that the added particulate magnetic material has at least 14m /g as the surface layer measured by a BET method. Consequently, the stable dispersion is produced without increasing a dispersant ratio and/or stabilizer ratio by using the known effective dispersion assembly. As a result, the magnetic properties are intrinsically improved and the recording properties of the resulted magnetic recording medium are improved.

公开(公告)号：JPH01196728A

公开(公告)日：1989-08-08

申请号：JP31663688

申请日：1988-12-16

Applicant: BASF AG

Inventor： MIHIYAERU HITSUTSUFUERUTO ,  TOOMASU FUREHIEN ,  PEETAA HAIRUMAN ,  FUORUKAA KOTSUHO ,  KURUTO DERU ,  HANSUUYOOAHIMU HOFUMAN ,  UBUE NOBUATSUKU

IPC: G11B5/72 ,  G11B5/84

Abstract: PURPOSE: To improve wear resistance and corrosion resistance by forming a hydrogen-contg. amorphous carbon protective layer by vapor deposition while adding a hydrocarbon gas. CONSTITUTION: A ferromagnetic metal thin layer such as Co-P and a carbon protective layer (A) are formed on a nonmagnetic carrier to obtain the medium of the title. The layer (A) is a hydrogen-contg. amorphous carbon layer of 5-100nm thickness formed by vapor deposition which uses a carbon target, while simultaneously adding a hydrocarbon gas which is decomposed by the vapor deposition plasma to change into a vapor deposition gas. As for the vapor deposition, a carbon target DC magnetron vapor deposition method is preferably used, and acetylene is added by (1:0.05) to (1:1) partial pressure to the sputtering gas such as Ar.