| 摘要 |
PURPOSE:To obtain the title starting material capable of being molded and carbonized without binder and suitable for use in the production of a material having low electric resistance and high thermal shock resistance by mixing heavy oil with carbonaceous or graphitic powder and a nitrating agent and subjecting the mixture to specified heat treatment and vacuum treatment. CONSTITUTION:Heavy oil such as coal tar is kneaded with paste of 20-40wt.% fine carbonaceous and/or graphitic powder basing on the amt. of the heavy oil. The paste is prepd. by mixing the powder with a solvent dissolving the heavy oil, e.g., creosote oil. The amt. of the solvent used is 1-2 times the amt. of the powder. The kneaded material is mixed with <=20wt.% nitrating agent such as nitric acid basing on the amt. of the heavy oil and the mixture is heated to 400 deg.C under a reduced pressure of <=300mmHg with stirring in a nonoxidizing atmosphere to remove tar oil. The pressure is then returned to ordinary pressure and reduced again and this operation is carried out once or more. The pressure is finally reduced to <=300mmHg and the mixture is heated to 500 deg.C. |
