Production of carbon artifact precursors

The process for preparing a pitch suitable for carbon artifact manufacture comprising:

• providing cat cracker bottom fractions boiling in the range from about 200.degree. C. to about 550.degree. C. at 760 mm of mercury;
• heating said cat cracker bottom to temperatures in the range of about 200.degree. C. to about 300.degree. C. at pressures ranging from about 250 to 500 microns of mercury to obtain a middle fractions distillate;
• heat soaking said distillate at temperatures in the range from about 390.degree. C. to about 450.degree. C. for times ranging from about 1 minute to about 20 hours to provide an oil-containing pitch;
• and,
• thereafter, vacuum stripping the heat soaked distillate at temperatures below about 400.degree. C. and at pressures ranging from about 1 to 100 mm of mercury for time sufficient to remove at least a portion of the oil present in the oil-containing pitch whereby a pitch suitable for carbon artifact manufacture is obtained.

A process for preparing a pitch suitable for carbon fiber production comprising:

• treating a cat cracker bottom which boils in the range from about 200.degree. C. to about 550.degree. C. to obtain a middle fractions distillate boiling in the approximate range from about 450.degree. C. to about 510.degree. C. at 760 mm of mercury;
• heat soaking the distillate at temperatures in the range from about 390.degree. C. to about 450.degree. C. for times ranging from about 1 minute to about 20 hours;
• and then,
• vacuum stripping said heat treated distillate at temperatures in the range of from about 320.degree. C. to about 380.degree. C. and at pressures ranging from about 1 to about 100 mm of mercury to remove from about 20% to about 60% of the oil present in said pitch;
• treating said so-treated pitch with an organic solvent system having a solubility parameter at 25.degree. C. of between about 8.0 and about 9.5, said treating being at a temperature and with an amount of organic solvent system sufficient to provide a solvent insoluble fraction which is thermally convertible into a deformable pitch containing greater than 75% of an optically anisotropic phase;
• and
• separating said solvent insoluble fraction whereby a pitch suitable for carbon fiber production is obtained.

A process for preparing a pitch suitable for carbon fiber production comprising:

• treating a cat cracker bottom which boils in the range from about 200.degree. C. to about 550.degree. C. to obtain a middle fractions distillate boiling in the range from about 450.degree. C. to about 510.degree. C. at 760 mm of mercury;
• heat soaking the distillate at temperatures in the range from about 390.degree. C. to about 450.degree. C. for times ranging from about 1 minute to about 20 hours;
• and then,
• vacuum stripping said heat treated distillate at temperatures in the range of from about 320.degree. C. to about 380.degree. C. and at pressures ranging from about 1 to about 100 mm of mercury to remove from about 20% to about 60% of the oil present in said pitch;
• adding an organic fluxing liquid to said vacuum stripped pitch to provide a fluid pitch containing insoluble solids suspended therein, said organic fluxing liquid being employed in the range from about 0.5 to 3 parts by weight of liquid per part of pitch;
• filtering said pitch to separate said solids;
• treating said pitch with said separated fluid pitch with an organic solvent system having a solubility parameter at 25.degree. C. between about 8.0 and about 9.5, said treating being at a temperature with an amount of organic solvent system sufficient to provide a solvent insoluble fraction which is thermally convertible into a deformable pitch containing greater than 75% of an optically anisotropic phase;
• and
• separating said solvent insoluble fraction whereby a pitch suitable for carbon fiber production is obtained.