Abstract: The present invention discloses a wholly aromatic, melt processable polyester which is comprised of recurring moieties derived from the following compounds: 2,6-naphthalenedicarboxylic acid, 4-hydroxybenzoic acid, an aromatic dihydroxy compound, and 6-hydroxy-2-naphthoic acid. The resulting wholly aromatic polyester is capable of forming a thermotropic melt phase at temperatures below approximately 350.degree. C. and most preferably at temperatures below approximately 290.degree. C.

Abstract: Flame-resistant thermoplastic branched polycarbonates of high molecular weight are prepared from:(1) a carbonate precursor;(2) at least one dihydroxyaromatic compound of formula: ##STR1## where: R is a single bond, or a substituted or non-substituted linear or branched C.sub.1 -C.sub.5 alkylene radical, or a group chosen from O, S, SO.sub.2 and CO;X and Y, which may be the same or different, are H or CH.sub.3 ;m and n, which may be the same or different, are whole numbers from 1 to 4;(3) at least one halogenated pyrimidine compound of formula: ##STR2## where: R.sub.2, R.sub.3, R.sub.4, which may be the same or different, are chlorine or bromine or hydrogen, on condition that at least one is chlorine or bromine;R.sub.1 is chlorine or bromine, or a radical of formula: ##STR3## where Z is NH or S or O; (4) at least one polyfunctional organic compound as branching agent, characterized by possessing at least three equal or different groups chosen from the groups OH, COOH, COCl and SO.sub.2 Cl.

Abstract: The present invention comprises diamantane groups interspersed among benzothiazole groups, benzoxazole groups or benzimidazole groups. This constitutes a rigid-rod polymer with stable cycloaliphatic groups interspersed into the aromatic-heteroaromatic backbone of the rods. The presence of the aliphatic groups decreases crystallinity by adding disorder to the rods thus minimizing interactions between the heteroaromatic groups. The interspersed aliphatic groups act as insulators and thus permit greater relative protonation. Also, the reduced conjugation of the aromatic-heteroaromatic rings reduces the color of the polymers. The preferred method of manufacturing this improved rigid-rod polymer is by condensation of dimethyl diamantanecarboxylate with 2,5-diamino-1,4-benzenedithiol, 1,2,4,5-tetraaminobenzene, or 4,6-diamino-1,3-benzenediol.

Abstract: New aromatic polyesters and polyester-carbonates are prepared by the reaction of bisphenols of the formula ##STR1## wherein R.sup.3 and R.sup.4 independently of each other represent C.sub.1 -C.sub.4 alkyl group or a halogen atom, i and k denote zero or an integer 1 to 4, and X.sub.1 and X.sub.2 represent fluorine by the two-phase boundary process in an aqueous-alkaline phase with iso- or tere-phthaloyl dichloride. The polyesters and polyester carbonates according to the invention can be processed to form shaped articles by extrusion molding or in an extruder, applied in the form of solutions, or spun to fibers from melt or solution.

Abstract: Polyarylene ether-polyalkenamer copolymers are provided by effecting a ring-opening metathesis polymerization (ROMP) of a cycloalkene such as, cyclooctene in the presence of a polyarylene ether having an ester link cycloalkenyl group. An effective amount of a metallic catalyst, such as an osmium or a ruthenium halide, can be used to catalyze the metathesis.

Abstract: Liquid-crystalline, completely aromatic copolyesters are disclosed, which are endowed with a heat stability not lower than 350.degree. C., and are constituted by a succession of repetitive units containing: ##STR1## wherein A and B, which can be either equal to, or different, from, each other, can be either --O-- or --CO-- and one of the following moieties: ##STR2## in which Ar can be 1,4-phenylene, 2-monosubstituted-1,4-phenylene or 4,4'-diphenylene.Also copolyesters also containing amidic bonding groups are disclosed.

Abstract: Aromatic polyester copolymers are provided consisting essentially of dihydroxy-meta-terphenyl units, and bisphenol A units chemically combined with aromatic diacid units such as isophthaloyl units, terephthaloyl units and mixtures thereof. Polyesters have been found to have a high glass transition temperature and stability up to 475.degree. C.

Abstract: A copolyesterimide composed of bis-trimellitimide units, 2,6-naphthalenedicarboxylic acid units, hydroquinone units and p-hydroxybenzic acid units. This copolyesterimide is melt-processable, and excels in heat resistance and mechanical properties.

Abstract: Novel thermotropic aromatic copolyesters comprise the following recurring structural units: ##STR1## and are prepared by polycondensing p-(p-hydroxyphenoxy)-benzoic acid with an aromatic or cycloaliphatic diacid, a diphenol and, optionally, p-hydroxybenzoic acid.

Abstract: The present invention features a highly oriented, triazine superstructural network, whose structural alignment is magnetically induced in the liquid crystalline phase during the curing process of its liquid crystalline cyanate ester precursor. High mechanical strength cross-linked network structures are prepared from a new class of liquid crystalline dicyanate compounds. Optionally ring substituted di-(4-hydroxyphenyl)-terephthalate is synthesized as a precursor in the preparation of highly structured triazine networks. The orientation of the triazine networks has been accomplished by magnetically aligning the liquid crystalline phase of the precursor during the curing reaction.

Abstract: Macrocyclic polyarylate oligomers containing a mixture of isophthalate and terephthalate moieties are prepared by reaction of a mixture of isophthaloyl and terephthaloyl chloride with one or more bisphenols under specific reaction conditions. They are characterized by a reduced degree of crystallinity and therefore lower processing temperatures than the corresponding isophthalate oligomers.

Abstract: Polyesters and polyester carbonates ofa) aromatic diphenols,b.sub.1) aliphatic and/or cycloaliphatic and/or aromatic dicarboxylic acids and optionallyb.sub.2) carbonic acid,containingb.sub.1) in a quantity of 0.1 to 100 mol-% andb.sub.2) in a quantity of 0 to 99.9 mol-%, based on (b.sub.1 +b.sub.2), in which 0.

Abstract: Provided is a para-ordered aromatic heterocyclic copolymer having repeating units of the formula --(--Q--Ar--).sub.m --(--Q--Ph--).sub.n -- wherein Q is ##STR1## wherein X is --O--, --NH-- or --S--, m is 0.05 to 0.50 and n is 1.

Abstract: The invention relates to novel aryl carbonate cyanoaryl ether copolymers.

Abstract: The present invention provides for hybrid polybenzimidazole and polybenzimidazolone polymers which are characterized as containing both imidazole and imidazolone structural units in the polymer chain. These polymers are characterized as containing at least one recurring monomer unit containing the structure of the formula: ##STR1## wherein Ar is a tetravalent aromatic moiety derived from an aromatic tetraamine and Ar.sub.1 is a trivalent aromatic moiety derived from a trifunctional acid, an acid anhydride or amine-reactive derivatives thereof, said polymers further characterized by an inherent viscosity of at least about 0.01 dl/g measured as a 0.5% solution in N-methyl pyrrolidone at 25.degree. C.The polymers of this invention exhibit many of the advantageous properties of both polybenzimidazole and polybenzimidazolone polymers. They are characterized as being extremely resistant to chemical attack such as by solvents, acids and bases.

Abstract: A thermoplastic, liquid-crystalline, wholly aromatic polyimide ester comprising(a) at least one structural unit derived from an aromatic dicarboxylic acid,(b) at least one structural unit derived from a substituted hydroquinone having an aralkyl substitutent group in its benzene nucleus, andat least one structural unit selected from (c) structural units derived from carboxy-N-(carboxyphenyl)phthalimides and (d) structural units derived from carboxy-N-(hydroxyphenyl)phthalimidesis able to be molded by injection molding, has excellent dimensional stability and dimensional accuracy in both flow direction and a direction making a right angle with the flow direction, and is also excels in strength, elastic modulus, and heat resistance.

Abstract: This invention relates to thermotropic liquid crystalline polyester compositions containing recurring units derived from 2-methylhydroquinone, terephthalic acid, 2,6-napthalenecarboxylic acid, and hydroquinone, characterized as having a heat distortion temperature of greater than 200.degree. C. and improved elongation. The inclusion of a reinforcing/filling agent selected from the group consisting of glass reinforcing agents, glass fillers, carbon metasilicate, calcium carbonate, talc, titanium dioxide, and calcined aluminum silicate in said compositions, and also in those same compositions lacking recurring units of hydroquinone, results in an improvement in the elongation of said compositions. The inclusion of carbon fiber into these compositions results in no significant decrease in the elongation of said compositions. The compositions are useful as films, fibers, and shaped articles.

Abstract: This invention relates to thermotropic liquid crystalline polyester compositions containing recurring units derived from hydroquinone, 4-4'-dihydroxybiphenyl, terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 4-hydroxybenzoic acid which are characterized as having melting points less than 365.degree. C., breaking elongations greater than or equal to 1.5%, and heat distortion temperatures greater than 200.degree. C.This invention further relates to the same compositions containing 20 to 40 weight percent of at least one glass reinforcing/filling agent and which are characterized as having melting points less than 365.degree. C., breaking elongations greater than or equal to 2.0%, and heat distortion temperatures greater than 230.degree. C.The compositions are useful as films, fibers, and shaped or molded articles.

Abstract: A composition and method of making macrocyclic aryl ether ketones useful in the preparation of high molecular weight resins. Macrocyclic aryl ether ketone compositions having structural units of the formula ##STR1## wherein n is an integer from about 2 to about 20, are prepared by contacting a dihalo compound of the formula ##STR2## wherein X is a halogen with a compound of the formulaHO--A--OHin the presence of a dipolar aprotic solvent and a base, wherein A is a bridged biphenyl group selected from the group including formulas--A.sup.1 --Y--A.sup.2 -- and (I) ##STR3## wherein each A.sup.1 and A.sup.2 is a single ring divalent aromatic radical, Y is a bridging radical in which one or two atoms separate from A.sup.2, R.sup.1 is independently C.sub.1-4 primary of secondary alkyl or halo, and n.sub.1 is 0 to about 3.

Abstract: Thermoplastic polyarylate compositions suitable for molding are formed from isophthalic acid, terephthalic acid or mixtures thereof, a bisphenolic compound such as bisphenol A and from about 5 to 10 mole % relative to the monomeric charge of 2-hydroxy-6-naphthoic acid.

Abstract: Aromatic polyamides of the invention are polyamides comprising a recurring unit ##STR1## and a recurring unit [--NH--Ar.sub.1 --NH--] and copolyamides comprising a recurring unit ##STR2## and a recurring unit [--NH--Ar.sub.2 --NHCO--Ar.sub.3 --CO--] wherein Ar.sub.1 and Ar.sub.2 are, for example, phenylene group, naphthylene group, biphenylene group, and 4,4'-methylenediphenylene group and Ar.sub.3 is, for example, phenylene group, naphthylene group and biphenylene group in which both the bonding chains extend in the coaxial direction or in the parallel direction to axis.The aromatic polyamide of the invention has high glass transition temperature and has heat resistance, high strength, and high elasticity and besides is soluble in various solvents and is excellent in spinnability and film-formability. The aromatic polyamide is molded into fibers or films and can be utilized as electric insulating materials, laminates, varnishes, fabrics, synthetic papers, etc.

Abstract: A conjugated system-containing organic high molecular compound is described, which contains a recurring unit represented by the following structural formula (I) and has a number-average molecular weight of 1,000 or more: ##STR1## wherein m represents an integer of from 2 to 10; n represents an integer of from 1 to 23; B and B' respectively represent --NHCO-- and --CONH--, --CONH-- and --NHCO--, ##STR2## --A-- is selected from the group consisting of ##STR3## wherein R.sup.1-4 and R.sup.5-8 each independently is selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an amino group, an alkylamino group having 1 to 5 carbon atoms, a hydroxyl group, an alkoxyl group having 1 to 5 carbon atoms, a cyano group, a nitro group, and groups of the following formulae (a), (b), and (c), provided that the groups of --A-- may be the same or different: ##STR4## wherein R.sup.9-12, R.sup.13-16, and R.sup.

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: A transparent polyester-ester amide having a permanently antistatic property is obtained by copolymerizing (a) an aminocarboxylic acid, a lactam, or a salt derived from a diamine and a dicarboxylic acid; (b) a diol of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are an ethylene oxide or propylene oxide group, Y is covalent bond, alkylene, alkylidene, cycloalkylidene, arylalkylidene, O, SO, SO.sub.2, CO, S, CF.sub.2, C(CF.sub.3).sub.2 or NH, X is H, alkyl, halogen, sulfonic acid or salt thereof, l is 0 or an integer of 1-4, and m and n an integer of 1-15; (c) a poly(alkylene oxide)glycol or a diol of the formula:HO--R.sup.3 --OH (IV)wherein R.sup.3 is alkylene, alkylidene, cycloalkylidene or arylalkylidene; and (d) a dicarboxylic acid; wherein the content of the polyether-ester units is 10 to 90 wt. %.

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis-(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: The present invention relates to aromatic compounds corresponding to formula (I) ##STR1## to their production and to their use as modifiers for thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyester carbonates and/or thermoplastic aromatic polyesters.

Abstract: Polyimides useful in multilayer electronic devices containing the 4,4'-bis(4-amino-2-trifluoromethylphenoxy) biphenyl moiety have low dielectric constants, low moisture uptake, high thermal degradation stability, low glass transition temperature.

Abstract: A novel polyester is provided which forms an anisotropic melt phase in combination with good heat resistance and melt-processability. The polyester is formed from a combination of appropriate concentrations of four essential constituent units (as described). In a particularly preferred embodiment the polyester is derived from p-acetoxybenzoic acid, 4,4'-diacetoxydiphenyl, 2,2-propylidenebis(1,4-phenylene), and terephthalic acid. The resulting polyester is well suited to injection molding to form superior three-dimensional articles, fibers and films.

Abstract: The present invention relates to aromatic compounds corresponding to formula (I) ##STR1## to their production and to their use as modifiers for thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyester carbonates and/or thermoplastic aromatic polyesters.

Abstract: Amorphous polyamide compositions are provided which are transparent and have improved glass transition and thermal decomposition temperatures. The polyamide compositions of the present invention can be prepared as the polymeric condensation product of a diamine component comprising neopentyldiamine, and a diacid component comprising an aromatic dicarboxylic acid.

Abstract: The invention relates to a class of copolymers capable of forming an optically anisotropic melt comprising recurring structural units (a) independently each occurrence selected from the group consisting of Formula I; recurring structural units (b) independently each occurrence selected from the group consisting of Formulas II and III; recurring structural units (c) independently each occurrence selected from the group consisting of Formula IV and optionally recurring structural units (d) independently each occurrence selected from the group consisting of Formula V: ##STR1## wherein R independently each occurrence is a chemically inert substituent.

Abstract: Disclosed is a process for the preparation of poly(ester-carbonates) wherein (1) an aromatic diol, (2) methyl phenyl carbonate and (3) an alkyl carboxylate ester component selected from an aromatic dicarboxylate ester, a hydroxy aromatic carboxylate ester or a mixture thereof are contacted in the presence of a transesterification/polycondensation catalyst under transesterification/polycondensation conditions of pressure and temperature.

Abstract: There is provided a para-ordered, rigid-rod aromatic heterocyclic copolymer having repeating groups of the formula:--Ba--Ar).sub.x (Ba--Fl).sub.1.0-xwherein x has a value of 0.50 to 0.99, Fl is a 2,7-fluorene moiety, Ar is a para-ordered arylene group and Ba is a benzazole group of the formula: ##STR1## wherein Y is S or O.

Abstract: An aromatic polyester superior in heat resistance and melt-moldability is obtained by carrying out the polycondensation reaction withComponent A consisting of at least one compound having the formula, ##STR1## wherein R.sub.1 is hydrogen, formyl, acetyl, propionyl or benzoyl, and R.sub.2 is hydrogen, a C.sub.1 -C.sub.6 alkyl or a C.sub.6 -C.sub.18 aryl, or a mixture containing not less than 50% by mole of said compound,Component B consisting of at least one compound having any one of the formulas, ##STR2## wherein R.sub.3 is hydroxyl, a C.sub.1 -C.sub.6 alkyloxy, a C.sub.6 -C.sub.18 aryloxy or halogen, or a mixture containing not less than 50% by mole of said compound, andComponent C consisting of at least one compound having the formula,R.sub.4 O--A.sub.1 --OR.sub.4wherein A.sub.1 is a divalent aromatic residue, and R.sub.4 is hydrogen, acetyl, propionyl or benzoylin a reaction vessel at a temperature of 270.degree. C. to 380.degree. C.

Abstract: Aromatic thermoplastic polyarylates containing structural units derived from a bisphenol of cyclohexanone, preferably 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, and an aromatic dicarboxylic acid or mixture of such acids, are provided which exhibit improved oxygen barrier properties.

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: A wholly aromatic polyester is composed of naphthalene dicarboxylic acid units comprising 5 to 95 mole % of the unit having the formula (1) and 95 to 5 mole % of the unit having the formula (2) and aromatic diol units having the formula (3). It is improved in heat resistance and may be blended with a filler.

Abstract: Provided herein are an aromatic polyester having superior physical properties which is composed of the following units ##STR1## an aromatic polyester amide formed by introducing a prescribed amount of amide linkage into said aromatic polyester; filament thereof; and a composition formed by adding an inorganic filler or magnetic powder to said polymers.

Abstract: Aromatic copolyesters comprise 10 to 90 mol % of the repeating unit (I) and 90 to 10 mol % of the repeating unit (II): ##STR1## wherein Y.sup.1 and Y.sup.2 may be the same or different and are, for example, a lower alkylene group, a lower alkylidene group or a carbonyl group, Ar is, for example, a phenylene group or a naphthylene group, and m or n is zero or one, and the copolyesters have high glass transition temperature, heat resistance, modulus, moulding processability and mechanical strength and are useful for shaped articles in mechanical, electrical or medical applications.

Abstract: An organic polyarylate containing a repeating unit represented by the formula; ##STR1## wherein X is at least one member selected from the group consisting of --O--, --S--, --SO.sub.2 --, --CO--, alkylene, alkenylene and following formulas; ##STR2## and R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, and R.sub.7 respectively show a hydrogen atom, a halogen atom or a C.sub.1 -C.sub.10 alkyl group; said polyarylates having an inherent viscosity of at least 0.2 dl/g measured at 25.degree. C. in a solution of 1 g of the polarylate in 100 ml of a mixture of 50% by weight of phenol and 50% by weight of 1,1,2,2-tetrachloroethane.

Abstract: A copolyester having an intrinsic viscosity, measured in o-chlorophenol at 25.degree. C., of 0.3 to 1.5 dl/g and being derived from dicarboxylic acid units composed of 95 to 60 mole % of isophthalic acid units and 5 to 40 mole % of 2,6-naphthalenedicarboxylic acid units and dihydroxy compound units composed of 95 to 70 mole % of ethylene glycol units and 5 to 30 mole % of 1,3-bis(2-hydroxyethoxy)benzene units; a gas barrier imparting agent composed of the copolyester; a polyester composition composed of (A) a polyethylene terephthlate and (B) the copolyester; and a film, a preform and a container composed of the polyester composition. Also provided are a polyester laminated structure, a stretched laminated structure, a preform and a laminated blow-molded article each composed of (C) a polyalkylene terephthalate layer and (D) a copolyester layer composed of the copolyester or the polyester composition.

Abstract: The invention relates to a class of polyesters and copolyesters which display optical anisotropy in the molten state and to the shaped articles, fibers and films obtained from the optically anisotropic melts. The copolyesters consisting essentially of recurring structural units (a) independently each occurrence selected from the group consisting essentially of Formula I; recurring structural units (b) independently each occurrence selected from the group consisting of Formulas II and III; recurring structural units (c) independently each occurrence selected from the group consisting of Formula IV and optionally recurring structural units (d) independently each occurrence selected from the group consisting of Formula V: ##STR1## wherein R independently each occurrence is selected from the group consisting of hydrogen, halo, lower alkyl, methoxy and phenyl; R' independently each occurrence is selected from the group consisting of hydrogen, halo, methoxy and phenyl; and R" comprises lower alkyl.

Abstract: Novel liquid crystal polyesters can be formed by reaction of bis(hydroxyalkoxy)biphenyls (including the novel bis(2-hydroxybutoxy)biphenyl) with terephthaloyl chloride.

Abstract: Disclosed herein are a coppolymerized polyester produced by copolymerizing a dicarboxylic acid component (A) comprising(a) 10 to 90 mol % of isophthalic acid or an ester forming derivative thereof,(b) 10 to 60 mol % of a phenylenedi(oxyacetic acid) represented by the formula [I]: ##STR1## (wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atom, an alkoxy group having 1 to 6 carbon atom, a phenyl group, a chlorine atom, a bromine atom or a fluorine atom), or as ester forming derivative thereof, and(c) 0 to 45 mol % of a naphthalenedicarboxylic acid or an ester forming derivative thereof, anda diol component (B); and a polyester composition containing the copolymerized polyester.

Abstract: Compounds useful as adhesion promoters for thermally cured thiolene adhesives include a) acrylic or norbornene acid phosphate esters such as ##STR1## b) maleic, acrylic, methacrylic, norbornene dicarboxylic, and fumaric acids and half acid esters and peresters of maleic fumaric and norbornene dicarboxylic acids; and c) norbornene, acrylic or methacrylic silanes having two or three hydrolyzable groups bound to the silicon atom thereof, such as 5-(triacetoxysilyl) norbornene.The adhesion promoters may be employed as surface primers for conventional thiolene compositions. Alternatively the thiolene compositions themselves may be modified by addition of 0.1 to 10% by weight of the adhesion promoter. Preferred thiolene compositions employ norbornene functional ene ingredients.

Abstract: The aromatic polyester and aromatic polyester-amide of the present invention have an excellent heat resistance (soldering resistance) and are excellent in fluidity, and therefore, excellent in moldability, because they show liquid crystallinity in a molten state. In view of mechanical characteristics, the aromatic polyester and aromatic polyester-amide of the present invention have a high modulus of elasticity and are excellent in mechanical strength. In addition, the aromatic polyester and aromatic polyester-amide of the present invention have an advantage that they can be molded at a temperature of 350.degree. C. or below, especially, 320.degree. C. or below.The aromatic polyester and aromatic polyester-amide of the present invention have utility in injection molded articles, films, fibers, etc., due to the above properties thereof.In addition, the aromatic polyester and aromatic polyester-amide of the present invention become molten state at a temperature of 320.degree. C.

Abstract: Fire-retardant polycarbonates, polyester carbonates and polyesters based on dihydroxydiphenyl cycloalkanes ##STR1## in which R.sup.1 and R.sup.2 independently of one another represent hydrogen, halogen, preferably chlorine or bromine, C.sub.1 -C.sub.8 alkyl, C.sub.5 -C.sub.6 cycloalkyl, C.sub.6 -C.sub.10 aryl, preferably phenyl and C.sub.7 -C.sub.12 aralkyl, preferably phenyl-C.sub.1 -C.sub.4 -alkyl, more especially benzyl,m is an integer of 4 to 7, preferably 4 or 5, R.sup.3 and R.sup.4 may be individually selected for each X and, independently of one another, represent hydrogen or C.sub.1 -C.sub.6 alkyl andX is carbon,with the proviso that, at at least one atom X, R.sup.3 and R.sup.4 are both alkyl,the fire-retardant finish being provided by additives and/or comonomers.

Abstract: Copolyimides derived from the reaction product of 3,3'-6 F diamine or 4,4'-6 F diamine, at least one other diamine, and pyromellitic dianhydride can be rendered solvent soluble while at the same time exhibiting an improvement in both mechanical and electrical properties by the inclusion of at least one other dianhydride having a diaryl nucleus in the reaction media. Suitable such dianhydrides include bis (3,4 dicarboxy phenyl) ether dianhydride, 3,3'4,4' benzophenone tetracarboxylic dianhydride, 3,3',4,4' diphenyl tetracarboxylic acid dianhydride and 2,2 bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA). Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N-methyl pyrrolidone, and exhibit excellent film forming properties with improved mechanical and electrical properties as compared to the corresponding homopolyimides. They possess excellent heat stability (Tg's in excess of about 350.degree. C.

Abstract: Thermoplastic polyarylate compositions suitable for molding are formed from isophthalic acid, terephthalic acid or mixtures thereof, a bisphenolic compound such as bisphenol A and from about 5 to 10 mole % relative to the monomeric charge of 2-hydroxy-6-naphthoic acid.

Abstract: Melt-formable thermotropic liquid crystalline polymers containing groups derived from terephthalic acid and a mixture of phenyl hydroquinone, 2-(.alpha.-phenylisopropyl) hydroquinone and, if desired, 2,5 bis (.alpha.-phenylisopropyl) hydroquinone.