Melt processable thermotropic wholly aromatic polyester comprising both para-oxybenzoyl and meta-oxybenzoyl moieties

Abstract

A wholly aromatic polyester is provided which unlike the aromatic polyesters normally encountered in the prior art is not intractable or difficultly tractable and readily undergoes melt processing with ease. The aromatic polyester of the present invention consists essentially of the recurring units (a) p-oxybenzoyl moiety, (b) m-oxybenzoyl moiety, (c) 2,6-dicarboxynaphthalene moiety, and (d) symmetrical dioxy aryl moiety (as defined), and is free of units which possess ring substitution. The resulting polyester exhibits a melting point below approximately 310.degree. C., and preferably below 300.degree. C. The ability of the wholly aromatic polyester readily to undergo melt processing can be attributed to its atypical inherent propensity to form a thermotropic melt phase at relatively low temperatures. The wholly aromatic polyester may be formed by a variety of procedures including a slurry polymerization technique (as defined) or a melt polymerization technique. The presence of the meta-oxybenzoyl moiety in the wholly aromatic polyester (as described) has been found to render the polymer melt processable at even lower temperatures than if this component were omitted.

Dependencies are inferred from the claim text.