Process for producing mesophase pitch

A process for producing a mesophase pitch having a mesophase content of above 90% and a softening point of below 320.degree. C. comprising the steps of:

• (1) heat-treating a pitch forming material at elevated temperatures above about 380.degree. C. for a time sufficient to provide a mixture of mesophase and non-mesophase pitch containing about 20% to about 80% [by weight] of mesophase and a softening point of no greater than 250.degree. C.;
• (2) aging and settling said mesophase portion of said mixture of mesophase and non-mesophase pitch obtained in step (1) by maintaining the mixture in a substantially quiescent condition and at a temperature below the temperature in the heat-treating step , at which temperature the mixture is sufficiently liquid so that the separation of the mesophase and non-mesophase portions of the mixture can be substantially accomplished, [and above about 350.degree. C.] for a time sufficient for the mesophase portion of the mixture to coalesce and accumulate into a substantially lower homogeneous mesophase pitch layer containing at least 90% mesophase and an upper layer comprising the non-mesophase portion of said mixture;
• and
• (3) separating said lower mesophase layer from said upper non-mesophase layer whereby a mesophase pitch which has a mesophase content of above 90% and a softening point below 320.degree. C. is obtained. heat-treated at a temperature in the range of about 380.degree. C. to about 460.degree. C. whereby thermal cracking and polycondensation reactions occur.