| 摘要 |
PURPOSE:A molding composition that is obtained by mixing petroleum cracking pitch and powdery graphite, thus giving diaphragms for speaker with high specific modulus and large internal loss. CONSTITUTION:A crude oil-cracked pitch obtained as a residue after the separation of the gaseous product containing acetylene, ethylene and others from the cracked product of crude oil or its fraction at a temperature of higher than 900 deg.C is kneaded with powdery graphite of 0.1-50mu particle sizes such as scaly graphite in a kneader or rollers under heating up to an extent of 200 deg.C to give said molding composition. Or the above pitch is dissolved in a solvent and then may be mixed with the powdery graphite. Especially, the quinoline insoluble component is removed from the above pitch and the residue is heated to 400-450 deg.C to form liquid crystals, which is crushed. When this product is mixed with the powdery graphite, the composition shows high elasticity and strength. |
