| 摘要 |
PURPOSE:To improve the adhesive property of the titled medium to a magnetic layer and to enhance the abrasion resistance and durability by forming a top coat layer incorporated with a vinyl chloride copolymer having <=200 polymerization degree and contg. >=2wt% OH group on the magnetic layer. CONSTITUTION:A vinyl chloride-vinyl acetate-vinyl alcohol copolymer, a vinyl chloride-vinyol propionate-vinyl alcohol copolymer, a vinyl chloride-acrylic ester copolymer, and a vinyl chloride-vinylidene chloride copolymer each having <=200 polymerization degree and contg. >=2wt% OH group are examplified as the vinyl copolymer having <=200 polymerization degree and contg. >=2wt% OH group, and a single copolymer or the mixture of >=2 kinds of copolymers is used. An isocyanate compd., an epoxy compd., and an ethyleneimine compd. each having respectively, in one molecule, >=2 cross-linking functional groups such as an isocyanate group or an epoxy group or an ethyleneimine ring are preferably used as a curing agent to be used jointly with the vinyl chloride copolymer. |
