| 摘要 |
PROBLEM TO BE SOLVED: To obtain a short carbon fiber aggregate having a high bulk density and improved in thermal conductivity, bending modulus, and bending rigidity in the direction of a fiber length by graphitizing an aggregate prepared by binding short carbon fibers. SOLUTION: Short carbon fibers having a fiber length of 2-20 mm, especially, 3-12 mm and obtained by binding with a size and subsequent cutting are bundled to a bulk density of 450-800 g/l, and the bundled fibers are graphitized by heating to 2,800-3,300 deg.C, desirably, 3,000-3,300 deg.C at a rate of heating of 0.1-200 deg.C/h in an inert gas atmosphere to obtain a short carbon fiber aggregate having a thermal conductivity of 400 W/mK or above (in the direction of length), an impurity ash content of 100 ppm or below, and a d002 value of 3.37-3.35Å(as measured by a powder X-ray analysis). Thermoplastic resin in an amount of 100 pts.wt. is mixed with 30-280 pts.wt., desirably, 35-250 pts.wt. short carbon fiber aggregate to obtain a fiber-reinforced resin composition. This composition has easy handleability and excellent workability and can give a low-void-content molding because it can be molded at a high temperature without evolving a large quantity of gases.
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