Abstract: A novel 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 fibers, films, molded articles, etc. The polyester contains substantial concentrations of recurring 3-phenyl-4-oxybenzoyl and/or 2-phenyl-4-oxybenzoyl moieties in combination with 4-oxybenzoyl and/or 6-oxy-2-naphthoyl moieties in the proportions indicated. The wholly aromatic polyester is capable of forming the desired anisotropic melt at a temperature below approximately 350.degree. C.

Abstract: A novel polyester is provided which has been found to exhibit an optically anisotropic melt phase which enables it readily to undergo melt processing to form quality fibers, films, molded articles, etc. The polyester of the present invention contains recurring 6-oxy-2-naphthoyl moieties in addition to moieties derived from at least one aromatic diol and at least one aromatic diacid in the proportions indicated. 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 anisotropic melt at a temperature below approximately 400.degree. C., and in a particularly preferred embodiment at a temperature below approximately 320.degree. C.

Abstract: Thermotropic, wholly aromatic polythiolesters exhibit an anisotropic melt. The polythiolesters may be prepared from monomers selected such that all or substantially all of the repeating groups are thiolester groups. Alternatively, the monomers can be selected such that sufficient thiolester groups are present to impart processability to a normally non-tractable polyester. Preparation of the polythiolesters is typically accomplished by melt polymerization of an esterified aromatic mercaptan compound, either alone or with other copolymerizable monomers. The polythiolesters may be melt processed into fibers, films or other types of shaped articles.

Abstract: A thermotropic wholly aromatic polyester is provided which is capable of forming an anisotropic melt phase. This novel polyester displays surprising tractability and may be used as a molding resin or may be melt spun into fibers. The aromatic polyester of the present invention consists essentially of the recurring units (a) 2,6-dioxyanthraquinone moiety, (b) 4-oxybenzoyl moiety, and (c) aromatic diacid moiety. The resulting polyester exhibits a melting point below approximately 375.degree. C., and preferably below approximately 350.degree. C. Fibers which are melt spun from the polyester exhibit unexpectedly good thermal stability. The desirable tractability properties of the polyester are attributed to its anisotropic melt phase, which is due to the inclusion of the 2,6-dioxyanthraquinone moiety in the polymer.

Abstract: A novel 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 fibers, molded articles, etc. The polyester of the present invention contains substantial concentrations of recurring 6-oxy-2-naphthoyl and p-oxybenzoyl moieties in addition to moieties derived from at least one aromatic diol and at least one aromatic diacid in the proportions indicated. 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 anisotropic melt at a temperature below approximately 320.degree. C., and in a particularly preferred embodiment at a temperature below approximately 300.degree. C.

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) 2,6-dioxynaphthalene moiety, and (c) terephthaloyl moiety, and is free of units which possess ring substitution. The resulting polyester exhibits a melting point below approximately 325.degree. C., preferably below 300.degree. C., and most preferably below approximately 290.degree. C. The ability of the wholly aromatic polyester to readily 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.

Abstract: A novel polyester is provided which has been found to exhibit a thermotropic melt phase at a temperature which enables it readily to undergo melt processing to form quality fibers, molded articles, etc. The polyester of the present invention is formed primarily of recurring 6-oxy-2-naphthoyl and p-oxybenzoyl moieties in the proportions indicated. The hydrogen atoms present upon the aromatic rings of these moieties optionally may be at least partially substituted (as described). Also, minor amounts of other ester-forming moieties may be included in the polyester so long as the thermotropic character and ease of melt processability is retained. In a preferred embodiment the wholly aromatic polyester is capable of undergoing melt processing at a temperature below approximately 325.degree. C., and in a particularly preferred embodiment at a temperature of approximately 280.degree. to 300.degree. C.

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.

Abstract: A wholly aromatic polyester is provided which has been found to be highly amenable to melt extrusion to yield high performance fibers. Such fibers following thermal treatment exhibit high tenacity and tensile modulus properties which are well retained at elevated temperatures while exhibiting a low degree of shrinkage. Unlike wholly aromatic polyesters normally encountered in the prior art, the polymer of the present invention is not intractable and may be melt extruded with ease at temperatures below approximately 300.degree. C., and preferably below approximately 280.degree. C. The aromatic polyester of the present invention consists essentially of recurring units (a) p-oxybenzoyl moiety, (b) 2,6-dicarboxynaphthalene moiety, (c) symmetrical dioxy aryl moiety (as defined), and (d) isophthaloyl moiety and/or metal-dioxy phenylene moiety, and is free of units which possess ring substitution.

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) 2,5-dicarboxynaphthalene moiety, and (c) symmetrical dioxy aryl moiety (as defined), and is free of units which possess ring substitution. The resulting polyester exhibits a melting point below approximately 425.degree. C., preferably below 350.degree. C., and most preferably below approximately 330.degree. C. The ability of the wholly aromatic polyester to readily undergo melt processing can be attributed to its atypical inherent propensity to form a thermotropic melt phase which is exhibited in the absence of ring substitution. The particularly effective route for forming the wholly aromatic polyester is via a slurry polymerization technique (as defined).

Abstract: A route is provided for the formation of a polybenzimidazole solid material having an enhanced resistance to undergo the usual color darkening upon exposure to light. A minor concentration of a finely divided pigment found capable of stabilizing the background color inherently manifest by the polybenzimidazole polymer is dispersed in a solution of the polybenzimidazole, and the solvent is removed to produce a polybenzimidazole solid having the pigment substantially uniformly distributed therein. The pigment utilized may be arsenic thioarsenate, copper phthalocyanine, anatase titanium dioxide, or mixtures thereof. Fibers, films, three-dimensional shaped articles, etc. may be formed from the color stabilized polybenzimidazole.