PREPARATION OF SPUN PITCH FOR CARBON FIBER

摘要

PURPOSE:To prepare the titled pitch having a uniform molecular weight distribution and a low melting point, by heat treating an aromatic oil-soluble component obtained by bringing a heated carbonaceous raw material into contact with a specified aromatic oil and separating optically anisotropic substances for recovery. CONSTITUTION:0.1-3pts.wt. aromatic oil (e.g. naphthalene oil) having a boiling point or an initial boiling point of 150 deg.C or higher is added to 1pt.wt. product with an optically anisotropic substance content of 10% or higher obtained by heat treating a carbonaceous raw material at 350-500 deg.C under normal pressure -10kg/cm<2>G for 5-20hr. The mixture is heated to 400 deg.C or lower and an aromatic oil-soluble component is separated. The separated component is heat treated at 350-500 deg.C under normal pressure -10kg/cm<2>G for 2min-20hr to obtain a product which contains 10-90% optically anisotropic substance. The product is left to stand at 300-400 deg.C for 0.2-10hr to separate the optically anisotropic substance by sedimentation due to specific gravity.