| 摘要 |
A carbonizable material is carbonized at an elevated temperature in an inert atmosphere or in a vacuum, the treatment being interrupted at least once before complete carbonization has occurred and the partially carbonized material being treated with an organic solvent to remove by-products of carbonization therefrom. The material is carbonized to the extent of losing 10 to 75% of its weight by heating, e.g. in an atmosphere of N2, He or A in a furnace or in a vacuum in an autoclave. The by-products deposited on the material are removed by immersing it in the organic solvent or by passing the solvent over the material. Solvents specified are tetrahydrofuran, gasoline, naphtha, benzene, lower alkyl substituted benzenes (e.g. toluene, xylene and ethyl benzene), spirits, light mineral oil, acetone, ether, methyl alcohol, propyl alcohol, butyl alcohol, furfural alcohol, furfural aldehyde, ethyl acetate, methyl acetate, 2-ethoxy ethanol, 2-ethoxy ethyl acetate and dimethyl formamide. Halogenated solvents are preferred, e.g. carbon tetrachloride, trichloroethylene, perchloroethylene, ethylene dichloride, chlorobenzene, dichlorobenzene, ethyl chloride, chloral, dichlorodifluormethane, bromoform and ethylene dibromide. The carbonization is subsequently continued at a higher or lower temperature and for the time desired, e.g. at 2700 DEG C. or higher to produce graphite. There may be several solvent treatment steps between carbonization steps, e.g. 2 of the former and 3 of the latter. The carbonizable material may be initially immersed in a solvent, e.g. a hydrocarbon oil and partially carbonized by heating therein prior to removal from the bath and treatment with a second solvent, such as one of higher volatility and miscible with the first solvent. These steps may be repeated. The carbonizable material is desirably a form of cellulose, e.g. rayon, cotton, linen, wood, paper, straw, ramie, sisal, hemp or flax and may be a single continuous filament, fibres, yarns, or woven or unwoven cloth or tape. Rolls of cloth or ropes of yarn may be carbonized in a solvent bath by a batch or continuous process as illustrated in Figs. 1 and 2, respectively (not shown).
|
