PURPOSE: To improve the traveling performance and durability by forming a back layer contg. fine SiO2 particles and carbon black dispersed in a mixed binder consisting of thermoplastic polyester and nitrocellulose on one side of a support having a ferromagnetic metallic thin film on the other side.
CONSTITUTION: A back layer of 1.0W0.2μm thickness is formed on one side of a nonmagnetic support having a ferromagnetic metallic thin film on the other side for a recording medium. The back layer contains 50W300pts.wt. mixture of fine SiO2 particles with carbon black dispersed in 100pts.wt. mixed binder consisting of 90W30pts.wt. thermoplastic polyester and 10W70pts.wt. nitrocellulose. The preferred weight ratio of SiO2: carbon black is 100:(50W20). A tape having superior corrosion resistance as well as said characteristics and suitable for use as an audiotape, a videotape, a tape for a computer or the like is obtd.
MURAI MIKIO
SUZUKI TAKASHI
ENOMOTO SUSUMU
