| 摘要 |
1348780 Laminated magnetic material FUJI PHOTO FILM CO Ltd 23 Dec 1970 [29 Dec 1969] 61279/70 Heading B5N A magnetic disc is made by preparing a material comprising a magnetic layer applied to a temporary base, applying this material to both surfaces of a base element with the magnetic layers in contact with the latter, and pressing the resulting assembly so that the magnetic layers adhere to the base element. The temporary bases are exposed and can subsequently be removed. The base element or the magnetic layers may be coated with an adhesive before pressing. The whole assembly may be heated during pressing, which may be effected by a pair of convex resilient members. In one embodiment, several discs are made simultaneously by pressing a stack of alternate discs (3) and temporary bases (1) coated on both sides with magnetic layers (2) (Fig. 4). The temporary base may be provided with a projecting tag which facilitates its removal from the magnetic layer. In Examples (1 and 2) pieces cut from a regenerated cellulose sheet coated successively with (a) a magnetic γ-Fe 2 O 3 or CrO 2 nitrile rubber composition and (b) a phenol/polyurethane adhesive are pressed on to both sides of an aluminium disc; (3) polyethylene terephthalate sheets coated successively with (a) a silicone lubricant and (b) a magnetic γ-Fe 2 O 3 /cellulose acetate-butyrate/styrene-butadiene copolymer composition are pressed on to an aluminium disc coated with polyurethane adhesive. |
