Wholly aromatic polyester composition, process for production thereof, and production therefrom of a film-like or fibrous article of a wholly aromatic polyester

Claim 1

A process for producing a film-like or fibrous article of a wholly aromatic polyester, which comprises (1) melt-molding a wholly aromatic polyester composition comprising (a) 100 parts by weight of a wholly aromatic polyester containing as a main component at least one compound selected from the group consisting of aromatic dicarboxylic acids, aromatic dihydroxy compounds and aromatic hydroxycarboxylic acids, and (b) from 5 to 300 parts by weight of a low-molecular-weight compound being substantially non-reactive with the wholly aromatic polyester and having a boiling point of at least about 200° C. under atmospheric pressure and a molecular weight of not more than 1,000, selected from the group consisting of imide compounds, isocyanurate compounds and diphenyl or the formula ##STR9## wherein A represents --O--, --SO 2 --, --CO-- or are alkylene group, an the phenyl groups may be substitutes, into an unstretched film-like or fibrous article, and (2) removing at least a major portion of the low-molecular-weight compound from the unstretched film-like or fibrous article by extraction with an organic solvent capable of dissolving the low-molecular-weight compound but substantially incapable of dissolving the wholly aromatic polyester under the extracting conditions; or stretching the unstretched film-like or fibrous article, and after, as desired, the stretched article is heat-set, removing at least a major portion of the low-molecular-weight compound from the stretched article by extraction with an organic solvent having the same properties as above.