High compressive strength pitch based carbon fiber

Abstract

The pitch based carbon fiber has a uniform crystal structure in which substantially all crystal fibriles constituting the fiber have the thickness ranging from 30 to 200% of the average thickness Lav. Uniform stress distribution over uniform crystal fibriles can be obtained. This permits suppresion of non-linearity of the compressive modulus of elasticity of carbon fiber to greatly improve the compressive strength thereof. Typically, a compressive strength of 100 to 170 kg/mm.sup.2 can be obtained with a tensile modulus of elasticity of 50 ton/mm.sup.2. Such carbon fiber can be obtained by securing uniformity of molecular weight distribution of the liquid crystal pitch and also uniformity of the orientation of the liquid crystal constituent molecules by the application of multi-stage high shear spinning.

Dependencies are inferred from the claim text.