MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To lower the coefft. of friction to guide parts and to improve traveling stability by compounding a fine particulate carbon black and graphitized carbon black respectively having specific average particle sizes into a back coat layer. CONSTITUTION:The fine particulate carbon black having 0.01-0.035mum average particle size and the graphitized carbon black having 0.1-0.5mum average particle size are incorporated into the back coat layer. The graphitized carbon black has the graphite layer structure in which the particle surfaces resemble concentrically to the crystal structure of the graphite. One particle thereof has lubricative property in all directions and has an extremely large antifriction effect in coefft. of friction and, therefore, said carbon black lowers both the coeffts. of friction of both materials made of plastic such as polyacetal and metal such as stainless steel to guide pins. Low noises and the excellent traveling stability are thereby obtd. even when this medium is used for apparatus using the guide pins consisting of both the materials in combination.