| 摘要 |
<p>1448457 Magnetic recording media BASF AG 14 Nov 1973 [15 Nov 1972] 52790/73 Headings C3P and C3R A magnetic recording medium has a non- magnetic base and a coating comprising a magnetic pigment and a binder containing 30-90% by weight of a polyurethane substantially free of isocyanate groups and soluble in a volatile organic solvent, derived from a linear aliphatic polyester or polyether, and a C 6-24 diisocyanate, and 10-70% by weight of a copolymer of at least 50% vinyl chloride and 5-50% of a monoester of a C 2-4 aliphatic diol and (meth)- acrylic acid. Preferably the polyurethane is formed from a polyester derived from aliphatic C 4-6 dicarboxylic acids and C 4-10 aliphatic diol, or from a polyether derived from a C 3-6 aliphatic diol or a C 3-6 cyclic ether. Optionally a polyisocyanate may be added to the magnetic layer. In examples the polyurethane is derived from adipic acid, 1,4-butanediol, and diphenylmethane-4,4<SP>1</SP>-diisocyanate or from polyoxytetramethylene, diphenylmethane - 4,41 - diisocyanate, and 1,4-butanediol; the copolymer is formed from vinyl chloride with propanediol monoacrylate; the magnetic pigment is acicularγ-iron(III) oxide and an isocyanate formed from 1,1,1-trimethylolpropane and toluylene diisocyanate may also be added. The coating compositions are prepared in a mixture of tetrahydrofuran and dioxane, the compositions also containing lecithin and polydimethyl siloxane.</p> |
| 申请人 |
BASF AG, 6700 LUDWIGSHAFEN |
发明人 |
MOTZ, HERBERT, DR., 6700 LUDWIGSHAFEN;BACHMANN, RUDOLF, DR., 6710 FRANKENTHAL;HARTMANN, HANS JOERG, DR., 6713 FREINSHEIM |
