高強度ならびに高圧縮強度奄有する新規ピッチ系炭素繊維の調製

抄録

Modifications of decant oil (DCO) were carried out to prepare carbon fiber with higher tensile modulus and compressive strength. DCO was hydrogenated using Ni/Mo catalyst to different extent of 6 to 18mol/kg. The hydrogenated DCO was further heat-treated at 420°C for 2h under 1MPa to prepare mesophase pitch with 30% anisotropic content. Thus prepared mesophase pitch, pitch-A which was derived from H3-DCO (18mol/kg added H₂) was failed to be spun into fiber form. It was found that the series of solvent extraction operations to remove lighter and heavier fractions (pitch-B) of pitch-A was effective to achieve the smooth spinning of fiber. It was indicated by DSC and high temperature ¹³C-NMR that pitch-A consisted of two phases at the spinning temperature. Such evidences were not found for pitch-B. The carbon fiber prepared from pitch-B showed lower Lc (crystallite size along C-direction) and higher recoil strength, which correspond to compressive strength, than the conventional pitch based carbon fiber made from mesophase pitch with 100% anisotropy at the same tensile modulus.