公开(公告)号：JPH06226761A

公开(公告)日：1994-08-16

申请号：JP31810893

申请日：1993-12-17

Applicant: BASF MAGNETICS GMBH

Inventor： RAINHARUTO KURETSUCHIYUMAA ,  ARUBAATO PERUCHIYU ,  YOOZEFU SHIERUBURE

IPC: B29C39/42 ,  B05C9/06 ,  B29L31/34 ,  G11B5/716 ,  G11B5/845 ,  G11B5/848

Abstract: PURPOSE: To prepare a magnetic recording medium by one operating process by using a casting extruder wherein a magnet with a shape of rectangular parallelepiped is arranged in parallel to a layer medium behind the layer medium and an opening part of the extruder exists in facing to the top end edge of the magnet. CONSTITUTION: Two layers are applied on a polyethylene terephthalate layer medium with a thickness of approximately 7 μm in a biaxial casting apparatus with a casting speed of approximately 100 m/min. In this case, the layer thickness of the top side layer is approximately 8 μm and the layer thickness of the bottom side layer is approximately 1.6 μm. Successively, a magnetic recording medium is cut into a width of approximately 8 mm. It is possible thereby to incorporate mainly a metal powder or metal powder alloy which does not spoil technical quality of a recording apparatus into the recording medium as magnetizable particles and to prepare it by one operating process.

公开(公告)号：JPH06198700A

公开(公告)日：1994-07-19

申请号：JP25071893

申请日：1993-10-06

Applicant: BASF MAGNETICS GMBH

Inventor： GEERUHARUTO HIYUBURAA ,  BUORUFUUDEIITAA SHIYUREEAA ,  RAINHARUTO KURECHIYUMAA ,  YOOZEFU SHIERUBURE

IPC: B29C47/02 ,  B05C9/06 ,  G11B5/848

Abstract: PURPOSE: To manufacture a double layer by a wet lap coating method using an extrusion coating machine capable of extremely thinly applying an upper layer containing a magnetizable pigment and a lower lay capable of pref. containing a non-magnetic additive increasing conductivity or reducing light permeability. CONSTITUTION: At least two slot dies for stacking a plurality of layers to apply them to a soft non-magnetic base material by a wet-on-wet system are provided and the upper lip of the common outlet orifice of the slot dies is set back from the lower lip thereof. A magnetic recording medium is produced by an extrusion coating machine constituted so that a right parallelepiped magnet of which the upper end is opposed to an extruder orifice at a distance of 0.1-5 mm is arranged behind a base material in parallel thereto and an uppermost magnetizable layer has a dry thickness of 2.0 μm or more and the lower layer adjacent thereto, pref., a non-magnetic layer has a dry thickness of 0.5 μm or less.