| 摘要 |
PROBLEM TO BE SOLVED: To obtain a carbon sliding material for a hydrostatic air bearing having a moderate rate of air permeability as the air bearing and hardly causing the dusting by an air pressure by impregnating a carbon material having a specific value or above of the quantity of air permeation with a tar pitch or a coal tar and then baking the resultant impregnated carbon material. SOLUTION: A carbon material having >=15 cc/cm<2> .min, preferably 50-300 cc/cm<2> .min rate of air permeability is used as the carbon material. The carbon material prepared by kneading a usual carbon material, i.e., an aggregate such as a coke powder, a graphite powder or a carbon black with a binder such as a coal tar or a tar pitch, pulverizing the kneaded material, molding the pulverized material and baking the molded product can be used as the carbon material. The impregnation of the carbon material with the tar pitch or coal tar is preferably carried out by heating the tar pitch or coal tar at 200-270 deg.C under 8-14 kg/cm<2> pressure. The baking is preferably conducted at 800-1,200 deg.C for 300-500 hr in a reducing atmosphere. |
