| 摘要 |
PURPOSE:To improve surface characteristic and mechanical strength and to obtain excellent running durability by incorporating a curing agent contg. specific isocyanate or a mixture composed of a polyisocyanate contg. the resultant product of said isocyanate and polyhydric alcohol into a binder and using such binder for the back layer of a magnetic recording medium. CONSTITUTION:Isophorone diisocyanate, the resultant product of the isophorone diisocyanate and trimethyrol propane or a mixture composed thereof and the other polyisocyanate compd. is used as a curing agent for a binder resin such as polyester or phenoxy resin for the back coat layer of the magnetic recording medium. Carbon black, MoS, etc. may be further incorporated into said layer in order to improve conductivity, wear resistance, lubricity, etc. The magnetic recording medium with which chipping and exfoliation of the back layer arise hardly and which decreases drop-out and has good running durability is thus obtd. |
