POLYESTER OF 6-HYDROXY-2-NAPHTHOIC ACID, PARA-HYDROXYBENZOIC ACID, TEREPHTHALIC ACID AND RESORCINE, ABLE TO MANUFACTURE FORMED PRODUCT WITH IMPROVED IMPACT STRENGTH BY MELT PROCESS

摘要

A novel thermotropic polyester is provided which has been found to exhibit an optically anisotropic melt phase at a temperature which enables it readily to undergo melt processing to form quality molded articles, fibers, etc., which exhibit substantial flexibility. For instance, molded articles can be prepared having an unusually high impact strength, toughness, and high extension in addition to other highly satisfactory mechanical properties. The polyester of the present invention contains recurring 6-oxy-2-naphthoyl and p- oxybenzoyl moieties in addition to terephthaloyl moieties and meta-dioxyphenylene moieties in the proportions indicated. Such meta-dioxyphenylene moieties are non- symmetrical in structure. The hydrogen atoms present upon the aromatic rings of these moieties optionally may be at least partially substituted (as described). The wholly aromatic polyester is capable of forming the desired optically anisotropic melt at a temperature below approximately 350° C. and in a particularly preferred embodiment at a temperature below approximately 325° C.