PURPOSE: To prepare the title pitch having a high softening point in a high yield while inhibiting the formation of a low molecular component, by elevating the temp. of charged pitch at a slow rate in an inert gas and conducting heat treatment of the pitch by heating the same at a predetermined temp. under reduced pressure.
CONSTITUTION: Stock pitch is fed into a hermetically sealed vessel. The vessel is pressurized with an inert gas, such as gaseous N2, to a pressure of 1W5kg/cm2, and the temperature is slowly raised to 350W500°C at a rate of 10°C/min or less. Then, the pressure within the hermetically sealed vessel is decreased to 20mmHg or less, and the pitch is maintained at the above- mentioned temp. for 30min or less for heat treatment thereof. Thus, there is obtd. the title pitch having a benzene insoluble of 60W95wt% and a mesophase carbonaceous content of 95W100wt% and having a high softening temp., e.g., 300W400°C, in a yield as high as 50% or more.
NISHIZAWA SETSU
TAKAHASHI TOMOJI
KOMATSU NOBUYUKI
YUMITORI SHUJI
