PREPARATION OF PITCH RESIN WITH HEAT RESISTANCE FROM COAL TAR

The reaction of coal tar with benzaldehyde as cross linking agent and P toluenes sulfonic acid as catalyst was a positive ion typed polycondensation catalyzed by proton. The B stage pitch resin was turned into C stage pitch resin by heat treatment. The excellent heat resistance (400 ℃)for the C stage pitch resin is similar to that for polyimide, but the heat resistance (at the temperature over 800 ℃) for the C stage pitch resin is better than that of polyimide. Moreover the cost of the pitch resin is lower than that of polyimide. Therefore, the pitch resin is a kind of resin that has a more wide prospect.