| 摘要 |
<p>1,149,913. Magnetic structures. MINNESOTA MINING & MFG. CO. 18 May, 1966 [1 July, 1965], No. 22180/66. Heading H1H. [Also in Division C7] A dielectric surface is provided with an electroless coating of, e.g. Fe, Ni, Co or alloys thereof to form a magnetic recording medium by first applying a layer of a polymer containing colloidal size particles (less than 1000 Angstroms) the polymer and the particles being such that together, in the absence of other materials, they have a surface resistance of at least 1 x 10<SP>6</SP> ohms per square. The colloidal particles may be Au, Pt, Ag, Rh, Ru, Ir, Fe, Co, Ni and Pd. The dielectric surface may be a polyethylene terephthalate film, and the polymer a vinylidene chloride-acrylonitrile copolymer, a polyester of ethylene glycol and terephthalic acid-isophthalic acid, polyvinyl chloride or chlorinated rubber. Examples are described of electroless cobalt and iron-cobalt solutions containing sodium hypophosphite, sodium potassium tartrate, acid ammonium hydroxide and sulphate.</p> |
