Carbonaceous pitch, production thereof and carbon fibers therefrom.

摘要

A carbonaceous pitch suitable for production of high tensile strength, high modulus of elasticity fibers comprises 2 to 20 wt % of n-heptane-soluble component and 15 to 45 wt % of n-heptane-insoluble/benzene-soluble component. The balance is preferably only benzene insolubles comprising quinoline-solubles and quinoline-insolubles The pitch has a softening point up to 320 DEG C and an anisotropic phase content of at least 90 vol %.
<??>The pitch may be prepared by thermally cracking and polycondensing a heavy hydrocarbon oil or tar, precipitating anisotropic phase at 400 to 440 DEG C without substantial increase in molecular weight, separating and subjecting the anisotropic phase to heat treatment in inert atmosphere.
<??>Carbon fibers may be produced by spinning the pitch at 280 to 370 DEG C, rendering the fibers infusible by heating in oxidising atmosphere and then carbonising. Tensile strengths of 3 GPa and modulus in tension of 200 GPa are possible.