| 摘要 |
<p>1,271,730. Magnetic recording medium. FUJI PHOTO FILM CO. Ltd. 26 Sept., 1969 [26 Sept., 1968], No. 47477/69. Heading H1H. A magnetic composition comprises a magnetic powder dispersed in a binder comprising at least 50% by wt. of chlorinated polypropylene. Specified magnetic powders areγ-Fe 2 O 3 , Fe 3 O 4 , CrO 2 , Ba ferrite, Zn ferrite and Fe-Co-Ni alloy. The chlorinated polypropylene may have the formula -(C 3 H 6-x Clz) x - where x = 0À27-0À60 and n is 300-800, and the binder may include up to 50% by weight of a compatible resin, e.g. a butylated urea resin, a phenolic or epoxy resin, a maleic acid resin, an acrylonitrile copolymer or an alkyd resin modified by acrylic acid. Examples describe the preparation of recording tapes having a 25 Á thick base of polypropylene, and a 10 Á thick magnetic layer.</p> |
