| 摘要 |
PURPOSE:To obtain a magnetic layer having superior dispersibility, wear resistance and heat resistance of magnetic powder, and excellent adhesion to a base, by providing the magnetic layer using a binder which consists of a specific ternary copolymer, thermoplastic saturated polyester resin and trifunctional low-molecular weight isocyanate. CONSTITUTION:With a ternary copolymer of 200-600 polymerization degree consisting of 70-80wt% vinyl chloride, 1-25wt% vinyl propionate and 5-20wt% vinyl alcohol, thermoplastic polyester of 10,000-30,000 molecular weight having free OH group and free COOH group is mixed in 9:1-1:9 proportion to the said copolymer to obtain a binder. Further, a binder obtained by adding 3-50wt% trifunctional low-molecular weight isocyanate to the said mixture is used to form a magnetic layer. |
