| 摘要 |
PURPOSE:To decrease starting torque at and under a high temp. and high humidity by using sulfonic acid metal base-contg. polyurethane compounded with a lubricating agent added with fatty acid of 12-18C at a specific ratio of the entire lubricating agent as a binder. CONSTITUTION:A magnetic layer in which magnetic powder, binder and lubricating agent are incorporated is formed on a nonmagnetic base. The binder consists essentially of the polyurethane resin contg. the sulfonic acid metal base at 10-1,000equiv./10<6>g polymer and the lubricating agent contains the fatty acid of 12-18C. The agent preferably contains the fatty acid of 12-18C, branch fatty acid ester of <=10 deg.C m.p., and ester of butyl cellosolve and fatty acid of 12-18C. The durability at and under the low temp. up to the high temp. and high humidity is thereby improved and the starting torque at and under the high temp. and high humidity is sharply improved. |
