Abstract: Thermotropic liquid crystalline polymers represented by the formulas as illustrated in FIGS. 1 and 2 wherein m, n, and o represent the number of monomer segments present; and x, y, and z are independently selected from the group consisting of alkyl, substituted alkyl, alkylene, and substituted alkylene.

Abstract: There are provided novel rod-like heterocyclic aromatic copolymers having repeating groups of the formula: ##STR1## wherein n has a value of 0.01 to 0.50, wherein Ar is a para-oriented aromatic group and Q is an aromatic heterocyclic group of the formula: ##STR2## wherein Y is --S--, --O-- or --NR--, wherein R is selected from the group consisting of --H, alkyl having 1 to 4 carbon atoms, and aromatic having 1 or 2 aromatic rings.

Abstract: Films from aromatic polyesters and from aromatic polyestercarbonates are excellently suitable for preparing printing ribbons, in particular for thermal and electrothermal recording processes.

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: Thermotropic, fully aromatic polyesters which have been prepared by polycondensation of p-hydroxybenzoic acid, hydroquinone, 4,4-dihydroxydiphenyl, terephthalic acid and isophthalic acid and which contain specific amounts of the radicals of the compounds mentioned are distinguished by an excellent toughness, very high heat distortion temperature and good processability.

Abstract: This invention provides thermoplastic polymeric materials comprising polycarbonate and polyestercarbonate resins and oriented polymeric compositions thereof which exhibit nonlinear optical properties.

Abstract: This invention relates to moldable polyarylates and in particular to moldable polyarylate compositions which have repeating units derived from bis-(3,5-dimethyl-4-hydroxyphenyl) sulfone (TMBS), optionally a dihydric phenol such as 2,2-bis-(4-hydroxyphenyl)-propane (Bisphenol A) and a mixture of isophthalic acid and terephthalic acid or derivatives thereof. Such polyarylates exhibit improved hydrolytic stability.

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: 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: 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: An aromatic polyester of good processability and heat resistance is prepared by charging starting materials in a reaction vessel, carrying out polycondensation reaction in the vessel until the flow temperature of the produced aromatic polyester falls in the temperature range of from 240.degree. C. to a temperature of 20.degree. C. below the reaction temperature and discharging the reaction product from the vessel in the molten state.The aromatic polyester obtained by the present invention can be used molded into various forms such as fiber, film, etc. In addition, compositions comprising this aromatic polyester and glass fibers, mica, talc, silica, potassium titanate, wollastonite, calcium carbonate, quartz, iron oxide, graphite, carbon fibers, etc. can be used in machine parts, electric and electronic parts and automobile parts because of their excellent mechanical properties, electric properties, chemical resistance and oil resistance.

Abstract: An improved polyarylate resin is provided, which resin comprises the following units (I) to (IV) ##STR1## the units (I) being contained in an amount of from 3 to 30 mole %, the units (II) being contained in amount of not less than 30 mole %, the units (III) being contained in an amount of not less than 30 mole %, and the units (IV) being contained in an amount of not larger than 25 mole %, each based on the total moles of the units (I) to (IV). The polyarylate resin has good mechanical strength, heat resistance, resistance to color change, transparency, moldability and flame retardancy. A resin composition comprising the polyarylate resin, a polyamide and an epoxy resin is also provided.

Abstract: Copolyamides are described comprising: (1) 0.22-0.28 mole fraction units derived from terephthalic acid; (2) 0.2-0.28 mole fraction units derived from paraphenylene diamine; (3) 0.22-0.28 mole fraction units derived from isophthalic acid; and (4) 0.22-0.28 mole fraction units derived from a 3,3'- or 4,4'-diamine of diphenyl methane, diphenylpropane-2,2, diphenyl cyclohexane-1,1, diphenyl ether, diphenyl sulfide, diphenyl sulphone, or benzophenone.

Abstract: A process for preparing a polyarylate by heating in the melt phase in the presence of a 4-dialkylaminopyridine, an acid anhydride which is in the range of stoichiometric amount to 25% molar excess, bisphenol-A and a dicarboxylic acid selected from the group consisting of isophthalic acid and mixtures of isophthalic acid and terephthalic acid wherein the ratio of isophthalic acid to terephthalic acid is in the range of 100:0 to 25:75.

Abstract: A polyarylate is formed by reacting a mixture of a diester of a dihydric phenol, at least one aromatic dicarboxylic acid and an inert diluent comprising a poly(fluorinated alkylene oxide). Polyarylates of improvided color can be formed and the diluent can be easily separated from the polyarylate and reaction byproducts.

Abstract: Process for preparing polyarylates comprising the steps of (a) prepolymerizing a diester of Bisphenol-A with at least one aromatic dicarboxylic acid to form a prepolymer having a melting point of at least about 200.degree. C. and being fluid at the polymerization temperature; followed by (b) polycondensing said prepolymer under agitation until it is substantially transformed into a powdery solid; maintaining said agitation to keep the powdery solid in a polydispersed solid state; and continuing the polymerization below the agglomeration temperature of the polymerizing solid, until the desired molecular weight is reached.

Abstract: Thermotropic liquid-crystalline aromatic polyesters processable in the molten state, comprising units derived from at least one dicarboxylic aromatic acid and from mono- and di-substituted (1-phenyl-ethyl)-hydroquinones in admixture with hydroquinone, and/or hydroquinones substituted with halogen or alky, aryl or cycloalkyl groups.

Abstract: A melt-processable copolyester comprising:a structural unit (I) of the formula (1), ##STR1## a structural unit (II) of the formula (2),--OC--X--CO-- (2)wherein X is at least one member selected from the group consisting of ##STR2## a structural unit (III) of the formula (3)--O--Y--O-- (3)wherein Y is at least one member selected from the group consisting of ##STR3## and a structural unit (IV) of the formula (4)--O--Z--CO-- (4)wherein Z represents at least one member selected from the group consisting of ##STR4## the ratio of the structural unit (IV) (III) to the structural units [(I)+(II)+(III)+(IV)] in total being 5 to 80 mole%, the structural units [(I)+(II)] being substantially equimolar to the structural unit (III), the ratio of the structural unit (I) to the structural units [(I)+(II)] in total being 10 to 90 mole %, and the copolyester having an inherent viscosity (ln .eta..sub.rel)/C, measured in a concentration of 0.16 g/dl in pentafluorophenol at 60.degree. C., of not less than 0.3 dl/g.

Abstract: Disclosed is a crosslinked polyester for a toner, which has an acid value of 5 to 20 mgKOH/g, a flow index of 0.1.times.10.sup.-4 to 300.times.10.sup.-4 ml/sec and a softening point lower than 145.degree. C., the polyester being formed by mixing a dicarboxylic acid component, a diol component and at least one crosslinking component selected from a polyfunctional carboxylic acid component having a trivalency or a higher valency and a polyhydric alcohol component having a trivalency or a higher valency at a mixing ratio represented by the following formula (1), reacting the mixture at a reaction ratio represented by the following formula (2) and subjecting the esterification product to polycondensation and crosslinking.0.8.ltoreq.R.ltoreq.1+5a (1)0.7.ltoreq.P.ltoreq.[R/(1+a)].sup.

Abstract: Thermotropic polyesters containing recurring structural units corresponding to the following formulae ##STR1## can be processed at low temperatures and may be used for the production of moldings, filaments, fibers and films.

Abstract: In a continuous process for the manufacture of aromatic polyesters by polycondensation of mono- or multi-nuclear substituted or unsubstituted diphenols, with halides of aromatic dicarboxylic acids according to the two-phase interface polycondensation process, the first step is to produce continuously a fine pre-emulsion with an organic solvent and from the aqueous phase, consisting of a solution obtained from the diphenols, of an alkaline hydroxide in order to form the diphenates and possibly of a phase transfer catalyst in water or in a mixture of water and of an organic solubilizer. This pre-emulsion is fed in quantities to a dispersion unit jointly with the organo-liquid phase forming the acid chloride solution.

Abstract: Liquid crystalline side-chain polyesters prepared by polycondensing a dicarboxylic acid or a derivative thereof with a diol of a certain general formula. Of such diols the essence is that they have a delocalized .pi. electron system to which both an electron donor group and an electron acceptor group are coupled directly (D.pi.A-system). Because of the structure of the diol to which the D.pi.A-system is linked the polyesters exhibit excellent Tg and Tc values. The polyesters are to be used in optical waveguides or for optical data storage.

Abstract: High molecular weight thermotropic aromatic copolyesteramides which can be molded/extruded into a wide variety of useful shaped articles having improved thermomechanical properties are comprised of recurring structural units of the formulae (I), (III) and (IV), and optionally (II), wherein:(I) represents the structure: ##STR1## in which R.sub.1 is a methyl or ethyl radical or a chlorine or bromine atom, with the proviso that the units (I) may be identical or different,(II) represents the structure: ##STR2## (III) represents the structure: ##STR3## in which n is an integer from 2 to 6, with the proviso that the units (III) may be identical or different,(IV) represents the structure: ##STR4## the molar ratio of the units (I) relative to the sum of the units (II)+(III) ranges from 0.95 to 1.

Abstract: Thermotropic polyester imides having recurrent structural units corresponding to the following formulae: ##STR1##

Abstract: Disclosed herein are (1) a film of a liquid crystalline wholly aromatic polyester which is non-oriented and transparent, which film can be prepared by dissolving a liquid crystalline wholly aromatic polyester in a solvent, casting the resulting solution to form a film and volatirizing the solvent from the film as cast and (2) a film of a liquid crystalline wholly aromatic polyester which is oriented and polarizing, which film can be prepared by orienting the above-mentioned non-oriented film by drawing or heating.

Abstract: Aromatic polyesters based on diphenols and iso- and/or terephthalic acid are produced by transesterification of esters of the diphenols with the aromatic dicarboxylic acids in the melt by first reacting the aromatic dicarboxylic acids with a stoichiometric excess of the diphenol esters to form oligomers and then condensing the resulting oligomers to the aromatic polyesters with elimination and removal by distillation of diphenol ester.

Abstract: A high modulus polyester molded article is obtained by molding an aromatic polyester which comprises at least one structural unit selected from the following structural units (I) to (III), the structural units (II)+(III) being less than 10 mol % of the structural units (I)+(II)+(III), and which is capable of forming anisotropic melt: ##STR1## wherein X represents at least one group selected from ##STR2## Y represents at least one group selected from ##STR3## and Z represents at least one group selected from ##STR4##

Abstract: High molecular weight thermotropic copolyesters and copolyesteramides which can be molded/extruded into a wide variety of useful shaped articles having improved thermomechanical properties are comprised of recurring structural units of the formulae (I), (II), (III) and (IV), wherein ##STR1## in which the symbol A is an oxygen atom or the NH group; the molar ratio of the units (I) relative to the sum of the units (II)+(III) ranges from 0.95 to 1.05;the amount of the units (II) in the mixture of (II)+(III) ranges from 20 to 90 mol % and that of the units (III), on the same basis, ranges from 80 to 10 mol %;the amount of the units (IV), expressed relative to the amount of the units (I), ranges from 25 to 300 mol %; andsaid copolyesters and copolyesteramides have a flow temperature ranging from 200.degree. to 350.degree. C.

Abstract: High molecular weight thermotropic aromatic copolyesteramides which can be molded/extruded into a wide variety of useful shaped articles having improved thermomechanical properties are comprised of recurring structural units of the formulae (I), optionally (II), (III) and (IV), wherein: ##STR1## in which R.sub.1 is a methyl or ethyl radical or a chlorine or bromine atom, with the proviso that the units (I) may be identical or different; ##STR2## the molar ratio of the units (I) relative to the sum of the units (II)+(III) ranges from 0.95 to 1.05;the amount of the units (II) in the mixture of (II)+(III) ranges from 0 to 80 mol % and that of the units (III), on the same basis, ranges from 100 to 20 mol %;the amount of the units (IV), expressed relative to the amount of the units (I), ranges from 5 to 100 mol %; andsaid copolyesteramides have a flow temperature ranging from 200.degree. to 350.degree. C.

Abstract: The invention relates to aromatic polyesters containing units with two carbonyl groups and having liquid crystalline properties. The aromatic polyesters are characterized in that the polyesters contain heterocyclic units with two carbonyl groups. Preferably these units are derived from furandicarboxylic acid. The aromatic polyesters show a considerable reduction in melting temperature, rendering the polyester more processable.

Abstract: In a process for the preparation of aromatic polyesters by polycondensation of diphenols with chlorides of aromatic dicarboxylic acids by the two-phase interfacial polycondensation process, in which a dispersion as the reaction mixture is prepared from an aqueous phase, which contains the diphenolate formed with the aid of alkali metal hydroxide, and an organic-liquid phase containing the acid chlorides, this dispersion is passed, in the apparatus which is intended for carrying out the process and which comprises a reaction kettle and a dispersing device included with the latter in a circulation, through the dispersing device and the reaction kettle, the acid chloride dissolved in a largely anhydrous chlorinated solvent being continuously fed into this circulation at a point which, in the direction of flow, is upstream of the dispersing device.

Abstract: An aromatic ester carbonate resin comprised of:(i) at least one recurring structural unit represented by the formula ##STR1## (ii) at least one recurring structural unit selected from structural units represented by the formulae ##STR2## or mixtures thereof; and (iii) at least one recurring structural unit represented by the formula ##STR3## (iv) at least one recurring structural unit selected from structural units represented by the formulae ##STR4## or mixtures thereof; wherein R is independently selected from halogen, monovalent hydrocarbon radicals, or monovalent hydrocarbonoxy radicals,W is selected from divalent hydrocarbon radicals, ##STR5## A is the divalent residue of at least one polymerized conjugated alkadiene and has a weight average molecular weight of at least about 600,m is independently selected from integers having a value of from 0 to 4, andb is either zero or one, andwherein B is the divalent residue of an ester precursor.

Abstract: Wholly aromatic thermotropic polyesters are based on(A) 30 to 60 mol % of 4-hydroxybenzoic acid,(B) 20 to 35 mol % of terephthalic acid and(C) 20 to 35 mol % of a mixture of(C.sub.1) trimethylhydroquinone and(C.sub.2) resorcinolthe molar ratio of C.sub.1 :C.sub.2 being within the range from 0.4:1 to 0.7:1 and the molar ratio of B:C within the range from 0.9:1 to 1.1:1.

Abstract: A wholly aromatic polyester consisting essentially of:(a) from 2 to 50 equivalent % of a 3,3'-biphenyldicarboxylic acid residue;(b) from 10 to 40 equivalent % of a dicarboxylic acid residue excluding the residue of 3,3'-bisphenyldicarboxylic acid;(c) from 10 to 52 equivalent % of a dioxy compound residue of the formula: ##STR1## wherein R.sup.2 is a group of the formula ##STR2## wherein R.sup.6 is a C.sub.1 -C.sub.4 alkyl group or a phenyl group and n is 0 or an integer up to 4, ##STR3## wherein X is as defined above, ##STR4## wherein X is as defined above, and/or ##STR5## and (d) from 0 to 80 equivalent % of an oxycarboxylic acid residue of the formula: ##STR6## wherein R.sup.3 is a bivalent aromatic hydrocarbon group or R.sup.4 --X--R.sup.5, wherein R.sup.4, R.sup.5 and X are as defined above, said polyester having a melt viscosity of at least 50 poise as measured at 275.degree. C. at 100 sec.sup.-1.

Abstract: An aromatic polyester consisting of 40-70 mol % of unit I derived from p-hydroxybenzoic acid, 1-8 mol % of unit II derived from m-hydroxybenzoic acid or isophthalic acid, 6-36 mol % of units III and IV derived from terephthalic acid and 2,6-naphthalene dicarboxylic acid, respectively, and 10-40 mol % of unit V derived from a symmetrical dihydroxy compound can be melt molded at a temperature of up to 330.degree. C. into an article having improved mechanical and thermal properties. An aromatic polyesteramide consisting of components I to V and unit VI having an anilino group is also provided. A filled composition is obtained by blending the polyester or polyesteramide with an inorganic filler. A magnetic resin composition is obtained by blending the polyester or polyesteramide with a magnetic powder.

Abstract: A novel wholly aromatic thermotropic liquid crystal polyester consisting essentially of 4-oxybenzoyl unit, terephthaloyl unit, 4,4'-dioxydiphenyl unit and 4,4'-dioxydiphenyl ether unit has a relatively low transition temperature to liquid crystal as well as good flow characteristics, and has thereby good melt-formability. The polyester gives melt extruded fibers and melt extruded films having superior mechanical strengths and elastic moduli, and also gives injection-molded products having superior strengths, excellent thermal characteristics, elastic moduli and impact strengths.

Abstract: A polyester resin for toner, which consists essentially of (a) from 5 to 60 equivalent %, based on the entire carboxylic acid components, of at least one member selected from the group consisting of tribasic and higher polybasic carboxylic acids, anhydrides thereof and lower alkyl esters thereof, (b) at least one member selected from the group consisting of dicarboxylic acids and lower alkyl esters thereof, (c) at least one aromatic diol and (d) at least one aliphatic diol, and which has a softening temeprature of from 100.degree. to 170.degree. C., a glass transition temperature (Tg) of from 50.degree. to 70.degree. C., an acid value of from 0.5 to 10 mgKOH/g and a gel content of from 3 to 40%.

Abstract: A composition useful for molding into articles such as food containers, soft drink bottles, cured structural plastics and the like, comprising molding grade linear or unsaturated polyester or polycarbonate having reacted or copolymerized therein the residue of one or a mixture of methine reactants of the formula ##STR1## wherein R.sup.1 is hydrogen or an unsubstituted or substituted alkyl, alkenyl, cycloalkyl or aryl radical;A.sup.1 is an unsubstituted or substituted phenylene radical;A.sup.2 is an unsubstituted or substituted 1,4-phenylene radical;R.sup.2 is hydrogen or an unsubstituted or substituted alkyl, cycloalkyl or aryl radical;R.sup.3 is cyano or ##STR2## and R.sup.4 is one of the substituents which R.sup.3 can represent or an unsubstituted or substituted carbamoyl, alkanoyl, aroyl, alkylsulfonyl, arylsulfonyl, aryl or aromatic heterocyclic radicals.

Abstract: Aromatic polyesters based on phenoxyterephthalic acid, a method of manufacturing the same, and applications of the same. The inventive polyesters are based on phenoxyterephthalic acid, one or more other aromatic dicarboxylic acids, a dihydroxyaryl compound (with 2 OH groups attached to an aromatic ring), and an hydroxyaromatic carboxylic acid, are partially crystalline, form an anisotropic melt phase, and are processible at up to 360.degree. C. The polyesters may be used for manufacturing pieces formed by molding, extrusion, or other standard forming techniques.

Abstract: Melt-processable polyesteramides capable of exhibiting melt-phase anisotropy at temperatures of approximately 360.degree. C. and lower are disclosed. The polyesteramides contain certain essential 2,2'-substituted biphenylene radicals and repeating units which provide ester and amide linkages. The polyesteramides exhibit melt processability suitable for processing into films and fibers.

Abstract: The preparation of aromatic polyesters based on diphenols and iso- and terephthalic acid is carried out by solventfree transesterification of esters of the diphenols with the aromatic dicarboxylic acids, the esters of the diphenols being initially reacted with teriphthalic acid alone and subsequently reacted with isophthalic acid after at least 80% of the terephthalic acid has undergone reaction.

Abstract: Thermotropic, fully aromatic polyesters, which consist essentially of(a) repeating units of the formula ##STR1## in proportions of 20 to 70 mole percent, (b) units of the formula ##STR2## in proportions of 10 to 40 mole percent, (c) one or both units of the formula ##STR3## wherein X=C.dbd.O or --O--, in proportions of 0 to 15 mole percent, (d) units of the formula(s) ##STR4## in proportions of 0 to 33 mole percent, and (e) units of the formula ##STR5## in proportions of 2 to 40 mole percent, have high Vicat B temperatures and can be thermoplastically processed at temperatures below 400.degree. C.

Abstract: Novel aromatic polyethers excellent in heat resistance and soluble in various organic solvents are obtained by introducing 9,9-biphenylfluorene group, optionally together with another divalent aromatic group, into the structural units of a polyether derived from either diphenyl ketone or diphenyl sulfone.

Abstract: A polyetherimide ester polymer comprised of the reaction products of:(i) a diol component comprising at least one low molecular weight diol and at least one high molecular weight diol;(ii) at least one dicarboxylic acid or an ester forming reactive derivative thereof; and(iii) a set of reactants selected from(a) (1) at least one high molecular weight poly(oxy alkylene)diamine, and (2) at least one tricarboxylic acid or its derivative, or(b) at least one high molecular weight polyoxyalkylene diimide diacid.The polymer of this invention exhibits improved flexibility; and the diol component (i) contains an amount of high molecular weight diol at least effective to improve the flexibility of the polymer.

Abstract: Aromatic polyesteramides exhibiting melt processability are disclosed. The polyesteramides comprise certain essential repeating units of the formulas ##STR1## wherein X is alkyl, alkoxy, trifluoromethyl, halogen or nitro. The polyesteramides exhibit melt anisotropy. Films and fibers combining a balance of properties suited to high strength service can be provided from the melt-processable polyesteramides.

Abstract: In the present invention disclosed are high-molecular-weight, soluble, thermoplastic branched polycarbonates endowed with improved properties, and suitable to blow-moulding fabrication.Such polycarbonates are characterized by the presence, in their structure, of units deriving from the following double-ring aromatic compounds: ##STR1## wherein R.sub.1 indicates H, --COCL, --SO.sub.2 Cl; R.sub.2, R.sub.3 and R.sub.4, equal to or different from each other, indicate --COCl or SO.sub.2 Cl.The above-said compounds are directly used in the syntheses.

Abstract: A method for preparation of very pure anhydride copolymers with high yield. The anhydride copolymers, consisting of aromatic and aliphatic diacids are formed by melt condensation of individually prepared, pure, isolated prepolymers. The method of preparation is characterized by high yield, reproducibility, polymer purity and controlled composition, and is a short and convenient procedure. The polyanhydrides produced by the disclosed method are particularly well suited to biomedical applications requiring low levels of toxic or inflammatory contaminants and physical and mechanical properties which closely conform to manufacturing specifications.

Abstract: Thermoplastic copolyester-carbonate resins are described, having included in their polymer chains, a moiety of the formula: ##STR1## The resins are useful intermediates for branched or cross-linked molding compositions.

Abstract: Films from aromatic polyesters and from aromatic polyestercarbonates are excellently suitable as electrically insulating films, for example as dielectric for capacitors and as conductor track films.