| 摘要 |
PURPOSE:To obtain a magnetic coating compd. which maintains high dispersibility, prevents thickening and has excellent reactivity with a crosslinking agent by using a specific hydroxyl group-contg. resin as a binder. CONSTITUTION:The resin which is obtd. by bringing a monobasic acid of <4 PKa into reaction with at least one kind of the epoxy group-contg. resin selected from a PVA resin, polyester resin and butadiene resin having the epoxy and has >=0.5wt% hydroxyl group content is used as the binder component. The PVA resin having the epoxy group is a homopolyer resin having 200-9,000 deg. of polymn. or copolymer resin and chlorinated PVC resin. The PVC resin, polyester resin and butadiene resin are required to contain >=1.5wt% epoxy group. A substantial quantity of the hydroxyl group cannot be added if the content is below the specified ratio. A high temp. or the aid of a catalyst is required for reaction and problems such as deterioration of the resins and the removal of the residual catalyst are liable to arise with a weak acid of >=4 PKa.
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