| 摘要 |
PURPOSE:To easily obtain the subject carbon fiber sharp in fiber length distribution and very low in aspect ratio without the need for much energy by making infusibilized pitch-based fibers into milled fibers followed by carbonization or graphitization. CONSTITUTION:Optically isotropic coal-based pitch 250 deg.C in softening point is put to melt spinning into pitch fibers, which are then infusibilized in an air atmosphere at max. temp. of 310 deg.C. The resulting infusibilized fibers are made into milled fibers using a pressing machine to produce milled fibers of ca. 100mu, 60mu, and 35mu in fiber lengths, respectively. Then, these milled fibers are either raised in temperature at a rate of 5 deg.C/min to 100 deg.C and treated at this temperature for 30min into carbonized milled fibers, or treated at >=2000 deg.C into graphitized milled fibers, thus easily obtaining at low cost the objective high- quality pitch-based milled carbon fiber of <=8 in aspect ratio with narrow fiber length distribution. |
