Magnetic recording media
AssigneeNippon Zeon Co., Ltd.
InventorsMasahiro Yamakawa, Eitaro Nakamura
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Abstract
A copolymer useful for magnetic paints is provided which is composed of (1) at least 60% by weight of vinyl chloride units (2) 0.1 to 4.0% by weight, as a sulfur- or phosphorus-containing strong acid group, of strong acid group-containing monomer units, (3) at least 0.1% by weight, as the hydroxyl groups, of units of a monomer which gives a side chain represented by the formula --X--OH wherein X is an organic group, and (4) 0 to 20% by weight of units of another monomer.
Claims15
A magnetic recording media comprising a polyester substrate and a magnetic layer coated on said substrate, said magnetic layer comprising a polyisocyanate cross-linked vinyl chloride copolymer binder and a magnetic powder dispersed in said binder, said vinyl chloride copolymer comprising
- (1) at least 60% by weight of vinyl chloride subunits,
- (2) 0.1 to 4.0% by weight, as a sulfur- or phosphorus-containing strong acid group, of strong acid group-containing monomer subunits,
- (3) at least 0.1% by weight, as the hydroxyl groups, of subunits of a monomer which gives a side chain represented by the formula --X--OH wherein X is an organic group selected from the group consisting of C.sub.n H.sub.2n, OC.sub.n H.sub.2n, COOC.sub.n H.sub.2n and CONHC.sub.n H.sub.2n, where n is an integer of 1 to 4, and
- (4) 0 to 20% by weight of subunits of another monomer selected from the group consisting of vinyl esters of carboxylic acids, vinyl ethers, vinylidene halides, unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, esters of unsaturated carboxylic acids, olefins, unsaturated nitriles and aromatic vinyl compounds.
Dependencies are inferred from the claim text.