Abstract: Disclosed is a process for preparing polyesters of dimethyl terephthalate with 1,4-cyclohexanedimethanol using a catalyst comprising a titanium alkoxide and an alkaline earth metal salt.

Abstract: Process for the preparation of polyaromatic compounds in which an aromatic dichloro compound, optionally in the presence of an anhydrous aprotic solvent, is reacted with metallic zinc, manganese or magnesium in the presence of a catalyst system of(1) from 0.1 to 25 mol-% (based on the dihalogen compound) of a nickel salt, nickel complex salt or nickel complex,(2) from 2 to 100 mol per mol of nickel in (1) of a triarylphosphine and optionally(3) from 0.1 to 10 mol per mol of nickel (1) of a halide, sulphate or phosphate of an alkali metal, alkaline earth metal, zinc, magnesium or manganese.

Abstract: A process for producing a copolyester by copolymerizing the monomers from the ester interchange of at least two lower dialkyl esters of dicarboxylic acid and glycol using a novel catalyst system. The novel catalyst composition includes from about 20 ppm to about 150 ppm manganese; from about 50 ppm to about 350 ppm lithium; preferably from about 10 ppm to about 70 ppm cobalt; and from about 200 ppm to about 400 ppm antimony, all amounts being based upon the expected yield of the copolyester. The novel process to make copolyester includes the step of employing an effective catalytic amount of manganese and lithium in an ester interchange reaction where the lower dialkyl esters and glycol produce a monomer mixture; and using an effective catalytic amount antimony in a copolycondensation reaction of the monomers.

Abstract: The invention provides novel polyesters, fibers and films, nonwovens from the fibers and disposable products of the polyesters such as diapers from the nonwovens. The products are degradable under the conditions typically existing in waste composting processes, have low ingredient costs and yet provide strength and toughness properties adequate for end uses such as in disposable diapers. The polyesters are based upon polyethylene terephthalate copolymerized with diethylene glycol and a 5-sulfoisophthalic acid.

Abstract: The present invention pertains to polymeric whitening agents which contain both a fluorescent portion and a hydrophilic portion. These copolymers may be used on certain substrates, such as polyester or soiled cottons, for a greater brightening than previously known.

Abstract: Disclosed are copolyesters comprising an acid component of 4,4'-biphenyldicarboxylic acid and a glycol component comprising 1,6-hexanediol and ethylene glycol. Injection-molded bars of the coplyesters exhibit unusually high stiffness and tensile strength compared to polyesters described in the art.

Abstract: Disclosed is a polymer and process for producing the polymer using a complex of titanium alkoxide with an alkali or alkaline earth metal salt.

Abstract: A process is disclosed for preparing adhesives from polyethylene terephthalate which comprises reacting a trimellitic acid polyester ether with polyethylene terephthalate to prepare a nonlinear copolymer with crosslinking characteristics suitable for use as an adhesive either as a hot-melt adhesive or as a pressure-sensitive adhesive.

Abstract: A novel catalyst system, a process for using the novel catalyst system, and a product made from the process is described. The novel catalyst system is specific for producing polyethylene terephtalate made from reacting terephthalic acid and ethylene glycol, wherein the catalyst system includes antimony; cobalt and/or zinc, and at least one of zinc, magnesium, manganese or calcium. The antimony is generally present from about 150 ppm to about 650 ppm. The cobalt and/or zinc is usually present from about 5 ppm to about 60 ppm, and the zinc, magnesium, manganese or calcium, as the third component, is generally present from about 10 ppm to about 150 ppm. The amounts of all catalyst components are based on the theoretical yield of the polymer. Using the novel catalyst system to produce PET drastically reduces the polymerization time without sacrificing color and clarity of the polymer produced.

Abstract: Cross-linked aqueous dispersions and emulsions and method for producing casts of any desirable shape therefrom the dispersions comprising a water dissipatable polymer in an amount from 18 to 30 percent by weight based on the total weight of the composition; water in an amount from 67 to 30 percent by weight based on the total weight of the composition; a source of multivalent metallic ions in an amount of 0.1 to 5 percent by weight based on the total weight of the composition; and humectant in an amount from 0.1 to 40 percent by weight based on the total weight of the composition and the emulsions comprising a water dissipatable polymer in an amount from 18 to 30 percent by weight based on the total weight of the composition; water in an amount from 67 to 80 percent by weight based on the total weight of the comosition; emollient oils in an amount from 0.1 to 25 percent by weight based on the total weight of the composition; a source of multivalent metallic ions in an amount from 0.

Abstract: A process for producing a copolyester by copolymerizing the monomers from the ester interchange of a lower dialkyl ester of terephthalic acid and glycol and the direct esterification of a dicarboxylic acid and glycol using a novel catalyst system. The novel catalyst composition includes from about 20 ppm to about 150 ppm manganese; from about 50 ppm to about 350 ppm lithium; preferably from about 10 ppm to about 70 ppm cobalt; and from about 200 ppm to about 400 ppm antimony, all amounts being based upon the expected yield of the copolyester.

Abstract: There is disclosed a copolyester which comprises at least four compositions of: (A) terephthalic acid, and/or its ester forming derivative (terephthalic acid component) and isophthalic acid and/or its ester forming derivative (isophthalic acid component) with a molar ratio of 30/70 to 70/30; (b) 5 to 15 mole % of a dicarboxylic acid having sulfonate group and/or its ester forming derivative based on the all dicarboxylic acid components; (C) an alicyclic dicarboxylic acid and/or its ester forming derivative; and (D) 50 mole % of ethylene glycol based on the all glycol components; and a polyester film which comprises a subbing layer containing the copolyester provided on at least one side of a polyester film base.

Abstract: An aqueous printing ink or its semi-aqueous or non-aqueous concentrate exemplified as comprising a substantially homogeneous system of the components:(1) from about 4 to about 80 weight % of one or more polyester materials having an acid component of from about 75 to about 84 mole % isophthalic acid and conversely from about 25 to about 16 mole % 5-sodiosulfoisophthalic acid, and having a glycol component of from about 45 to about 60 mole % diethylene glycol and conversely from about 55 to about 40 mole % 1,4-cyclohexanedimethanol or ethylene glycol or mixtures thereof;(2) from about 0 to about 60 weight % of pigment material;(3) from substantially none to about 90 weight % of water; and(4) from about 0.25 to about 5 weight % of a diacyl-glycerophospholipid.

Abstract: The properties of polyesters, in particular the tracking index and the antistatic properties, can be improved by the addition of a salt of an alkane sulphonic acid.

Abstract: An aqueous printing ink or its semi-aqueous or non-aqueous concentrate exemplified as comprising a substantially homogeneous system of the components:(1) from about 4 to about 80 weight % of one or more polyester materials having an acid component of from about 75 to about 84 mole % isophthalic acid and conversely from about 25 to about 16 mole % 5-sodiosulfoisophthalic acid, and having a glycol component of from about 45 to about 60 mole % diethylene glycol and conversely from about 55 to about 40 mole % 1,4-cyclohexanedimethanol or ethylene glycol or mixtures thereof;(2) from about 0 to about 60 weight % of pigment material;(3) from substantially none to about 90 weight % of water; and(4) from about 0.25 to about 5 weight % of a diacyl-glycerophospholipid.

Abstract: A method of preparing water-dispersed polymer blends, comprising the steps of:(i) preparing an aqueous polymerization mixture by adding to water, a sulfonate group-containing polyester or polyesteramide, one or more .alpha.,.beta.-unsaturated monomers and a polymerization initiator; and(ii) polymerizing said polymerization mixture to provide said water-dispersed polymer blend.Also disclosed is an aqueous dispersion of a polymer blend, comprising an aqueous dispersion having a solids content of about 30% to 65% of a polyester or polyesteramide blend comprising a sulfonate group-containing polyester or polyesteramide and a polymer comprising repeat units from one or more .alpha.,.beta.-unsaturated monomers.

Abstract: Polyesters, especially poly(ethylene terephthalate) and poly(butylene terephthalate), having a substantial proportion of free carboxylic acid groups are caused to react with polyepoxy compounds, especially poly(O- or N-epoxyalkyl-substituted) cyclic amides, imides and amidates and preferably triglycidyl isocyanurate, in the presence of various amines or salts as catalysts. The preferred catalysts are fatty acid salts such as sodium sterate. The products have very high melt viscosities and are useful in such operations as blow molding.

Abstract: Quick-crystallizing polyester compositions comprising a mixture consisting or consisting essentially of a polyester thermoplastic resin and of 0.1-10% by weight of a nucleant selected from polymeric-base salts, or mixtures of salts, of alkali metals or alkaline-earth metals of the formula:M--(OOC--C.sub.6 H.sub.4 --COO--CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2).sub.m (OOC--Z--COOY).sub.n (ABRX) (1)whereinM is an alkali or alkaline-earth metal;Y is a group --CH.sub.2 CH.sub.2 --,--(CH.sub.2).sub.4 -- or --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --;Z is a group --C.sub.6 H.sub.4 --, or a group --(CH.sub.2).sub.q --, q being an integer from 7 to 10;A is an anion selected from the group consisting of carboxylate, sulphonate, sulphinate, phosphonate, phosphinate;B may be a single bond or a group selected from the group consisting of --CH.dbd.CH--, --CH.sub.2 --, --CH.sub.2 CH.sub.2 --;R is an arylene radical containing from 1 to 3 aromatic rings or a heterocyclic ring;X is a hydrogen atom or a group --COOM or --COO(CH.

Abstract: Transesterification curing of ester polymers and hydroxyl polymers is effected by the inclusion of a transesterification catalyst comprising a catalytic amount of epoxy resin and certain inorganic salts.

Abstract: A process of polymerizing a polymerizable material in an inert organic liquid medium, in which the polymer formed from the monomer or monomers is insoluble, comprising dispersing the polymerizable material in the organic liquid in the presence of a finely, divided particulate material comprising an inorganic portion insoluble in the organic liquid medium and in combination therewith, preferably by covalent or ionic bonding, hydrocarbon chains containing at least 8 carbon atoms, the hydrocarbon chains being soluble in the organic liquid medium and heating the mixture to polymerize the polymerizable material to a required degree of polymerization. The process provides a means of stabilizing dispersion polymerizations which need to be carried out at very high temperatures to effect the polymerization.

Abstract: A process for producing a linear polyester comprising a main structural unit of an aromatic dicarboxylic acid ester of an alkylene glycol, particularly, comprising a polyethylene terephthalate or polytetramethylene terephthalate unit, is provided. In the process of the invention, the polycondensation reaction is conducted in the presence of a niobic acid catalyst that is obtained by heat-treating a hydrated niobium compound at the temperature range between 80.degree. C. and 400.degree. C. The process of the invention is also effecitvely applied to the manufacture of an elastomeric polyester comprising a polyalkylene terephthalate as a hard segment and a polyalkylene glycol as a soft segment.

Abstract: An esterification process particularly for the preparation of rosin esters, polyesters and polymeric esters wherein aliphatic or aromatic carboxylic acids are reacted with appropriate alcohols in the presence of catalytic amounts of a mixture of a calcium hydroxyaryl phosphonate and an organosilicon heterocycle, the presence of said mixture serving to reduce the time necessary for complete esterification and to provide esters with increased oxidation stability and better color.

Abstract: Polycoester of the formula IE--CO--R--CO--O--R.sup.1 --O--CO--R--CO).sub.n E.sup.1 (I)in whichR is 60 to 85 mol % 1,3-phenylene radicals, 5 to 20 mol % tetramethylene radicals and 10 to 20 mol % for example radicals of the formula IIa ##STR1## R.sup.1 is 60 to 95 mol % ethylene radicals (--CH.sub.2 CH.sub.2 --), 0 to 28 mol % 2,2-dimethyl-1,3-propylene radicals and 5 to 12 mol % polyoxyethylene radicals having an average molecular weight up to 600 andR.sup.2 denotes for example SO.sub.3 H andE, E.sup.1 denote for example --OH andn is a sufficiently large number that the polycoester has an average molecular weight between 15,000 and 40,000, are used in the form of their aqueous solutions as sizing agents.

Abstract: The invention relates to rapidly crystallizing polyester materials and a process for their preparation, in which, in a first stage, the polyester is prepared in the presence of an (alkaline earth) alkali metal or of an (alkaline earth) alkali metal compound, and then, in a second stage, further non-nucleated polyesters and a crystallization accelerator in a adequate amount are, if required, added to this polyester.The polyesters according to the invention are distinguished in particular by reduced molecular weight degradation.

Abstract: A method for preparing aromatic polyols useful for the production of polyurethane and polyisocyanurate polymers involves digesting scrap polyalkylene terephthalate polymers with a digesting agent, typically a low molecular weight polyol. The digestion product is then treated with an alkylene oxide to produce a low viscosity polyol which displays excellent stability over long term storage.

Abstract: A polybutylene terephthalate is manufactured by the steps of polycondensating in the liquid phase terephthalic acid or a lower alcohol ester thereof as the acid component and 1,4-butanediol as the diol component to obtain a prepolymer of polybutylene terephthalate, solidifying the prepolymer and further polymerizing the prepolymer in the solid phase to obtain a polybutylene terephthalate of a higher polymerization degree, 0.001 to 5 percent by weight, based on the prepolymer, of a nucleator being added to the polymerization mixture at any time during a period of from the monomer-mixing stage before the starting of the solid phase polymerization, the solid phase polymerization being conducted in the presence of the nucleator uniformly dispersed in the polymerization mixture. The solid polymerization can be treated subsequently to the liquid polymerization and can proceed in a short time.

Abstract: A polyester having an initial accumulation electric charge of not less than 2.9 .mu.c/mm.sup.2 when determined in a melt state according to the method as hereinabove defined and a heat resistance of not more than 0.210 when determined according to the method as hereinabove defined, which comprises at least one magnesium compound and at least one phosphorus compound solubilized therein in amounts as satisfying the following formulas:30.ltoreq.[Mg].ltoreq.400 (1)0.8.ltoreq.Mg/P.ltoreq.3 (2)wherein [Mg] is the content (ppm) of the magnesium compound in terms of magnesium atom to the polyester and Mg/P is the atomic ratio of the magnesium atom in the magnesium compound to the phosphorus atom in the phosphorus compound.

Abstract: An oriented polyester film comprising ethylene terephthalate as the major repeating unit, which comprises particles of kaolinite and calcium carbonate uniformly dispersed therein, said kaolinite and said calcium carbonate having each an average particle size of 0.05 to 0.8 micron and being contained in such amounts as satisfying the following equations:70.ltoreq.D.times.A.ltoreq.1000 (I)1000.ltoreq.A+B.ltoreq.10000 (II)0.1.ltoreq.B/A.ltoreq.25 (III)wherein D is an average particle size (micron) of calcium carbonate, A is a content (ppm) of calcium carbonate and B is a content (ppm) of kaolinite, said oriented polyester film being excellent in flatness, slipperiness, abrasion resistance, etc. with a small number of coarse particles.

Abstract: Hydrolysis-resistant, thermoplastic molding compositions are made from high-molecular weight, linear polybutylene terephthalate and 0.1-10 mole %, based on the amount of the dicarboxylic acid component of the polyester, of a salt of Formula (A)[(-O.sub.3 S).sub.x R--CO.sub.2.sup.-).sub.2 ]M, (A)whereinM is an alkali or alkaline earth metal cation,R is an aromatic or cycloaliphatic residue or an aliphatic residue of 2-20 carbon atoms in the carbon chain, andx is 0 or 1.

Abstract: Described is a process for improving the color of thermoplastic polymers by contacting the monomer(s) before or during polymerization with an alkali or alkaline earth metal formate.

Abstract: The invention relates to a novel process for the preparation of compounds of the formula I ##STR1## by polycondensation of a diol of the formula II ##STR2## with a dicarboxylic acid ester of the formula III ##STR3## In the above formulae, the substituents and symbols R.sub.1, R.sub.2, R.sub.3 and n are as defined in claim 1.The process comprises stirring the reaction medium which contains an excess of 2 to 50 mol. %, based on the diol of formula II, of the dicarboxylic acid ester of the formula III, in the presence of at least 0.03 mol. % of a suitable catalyst, until the bulk of the alkanol of the formula R.sub.3 OH formed during the reaction is distilled off, under a pressure of 0.7 to 1.3 bar, and thereafter stirring under a pressure of less than 5 mbar, in the temperature range from 100.degree. to 170.degree. C., and subsequently working up the resultant melt in conventional manner.

Abstract: A polyester fiber having a tenacity of at least 4.0 g/d is formed from a copolyester having a degree of polymerization of from 80 to 100 of which copolyester 1.0 to 2.0 mol % of its acid component has a metal sulfoisophthalic group and 0.5 to 1.9 weight % of which copolyester is provided by a glycol component provided by glycol having a molecular weight of from 400 to 6000. The polyester fiber is readily dyed with basic dyes.The polyester fiber can be prepared by spinning the copolyester at a shear rate of.ltoreq.10.sup.4 sec.sup.-1, a spinning draft ratio of .ltoreq.250, a back pressure of the spinneret of.gtoreq.40 kg/cm.sup.2 and a shear stress of .ltoreq.(Q+0.7).times.10.sup.7 dyne/cm.sup.2, where Q is the mass output rate per single hole (g/min).

Abstract: A flameproof linear polyester is described containing, copolymerized in the molecule, a phosphorus compound of formula: ##STR1## where R is a hydrogen atom, an alkyl group with 1 to 4 carbon atoms or a hydroxyalkyl group, and R' is a hydrogen atom, a hydroxyalkyl group or the group --(CH.sub.2 CH.sub.2 O).sub.n H, where n varies from 1 to 4. Said linear polyester is prepared by firstly forming a low molecular weight precondensate from a dicarboxylic aromatic acid (or a relative lower alkyl diester) and an alkylene glycol, and then polycondensing in the presence of said phosphorus compound, in such a quantity as to obtain a content of phosphorus (expressed as the metal) in the linear polyester of between 0.4 and 0.8% by weight. The linear polyester thus obtained can be formed into articles such as fibres, film, sheets and other articles which, besides being flameproof, possess improved dyeing characteristics.

Abstract: A polyester composition with an excellent high-speed melt-spinning property, comprising(A) 100 parts by weight of a matrix polyester resin comprising at least 80 molar % of an ethylene terephthalate recurring unit, and(B) 0.2 to 7 parts by weight of a dispersoid dispersed in the matrix,the dispersoid being such that, when it is contained in a predetermined amount (w) in a typical matrix polyester resin consisting of a polyethylene terephthalate having an intrinsic viscosity of 0.640, the resultant exemplary polyester composition satisfies the relationship (I): ##EQU1## wherein: .gamma..sub.1 =shearing rate of 0.01 sec.sup.-1 ; .gamma..sub.2 =shearing rate of 5.0 sec.sup.-1 ; .eta..gamma..sub.1 (w)=melt viscosity (poise=1/10 N.multidot.sec.multidot.m.sup.-2) of the exemplary polyester composition at .gamma..sub.1 ; .eta..gamma..sub.1 (0)=melt viscosity of matrix polyester resin at .gamma..sub.1 ; .eta..gamma..sub.2 (w)=melt viscosity of the exemplary polyester composition at .gamma..sub.2 ; and .eta..gamma..

Abstract: Polyester binder fibers consisting of a water-dispersible copolymerized polyester, comprising at least one dicarboxylic acid and/or an esterforming derivative thereof, a glycol and an esterforming sulfonic acid alkali metal salt composition, wherein the total glycol component contained in the above mentioned polyester contains from 5 mole percent to 20 mole percent of a composition represented by the formula H--(OCH.sub.2 CH.sub.2).sub.n --OH, wherein n is an integer of from 2 to 13. The binder fibers are useful especially in a papermaking process.

Abstract: A biaxially stretched polyester film comprising a polyester and zirconium as an internal particle material, produced by polycondensation of terephthalic acid or its esterified derivative and alkylene glycol as the major essential monomeric components in the presence of a polycondensation catalyst, during which zirconium in the form of any compound thereof in an amount of 80 to 2500 ppm in terms of zirconium atom to the polyester as produced being introduced into the reaction system at a stage after the initiation of the reaction and before the intrinsic viscosity of the reaction mixture reaching 0.2, and subjecting the produced polyester to film forming.

Abstract: Novel nucleating agents have been discovered which are effective in polyesters, especially poly(ethylene terephthalate). The novel nucleating agents are copolymers derived from a poly(alkylene terephthalate) and a sulfonate salt.Also provided by this invention are a process for nucleating polyesters, particularly poly(alkylene terephthalates), especially poly(ethylene terephthalate) and the compositions so produced.

Abstract: A process for production of a polyester comprising units of ethylene terephthalate as the major repeating units by supplying terephthalic acid and ethylene glycol continuously or intermittently to bis(beta-hydroxyethyl) terephthalate or its oligomer so as to carry out esterification under a pressure of not more than about 1.0 kg/cm.sup.2, followed by polycondensation, which is characterized in that at least one magnesium compound is incorporated into the reaction system in an amount of about 30 to 400 ppm in terms of Mg to the polyester when the esterification rate in the step of esterification reaches about 20-80% and at least one phosphorus compound is incorporated into the reaction system in an amount as satisfying the following equation (I) at the stage after the esterification rate reaches not less than about 91% and before the termination of the initial condensation in the step of esterification:1.2.ltoreq.Mg/P.ltoreq.20 (I)wherein Mg/P is the atomic ratio of the magnesium atom to the phosphorus atom.

Abstract: In the two stage reaction of terephthalic acid with 1,4-butanediol to produce polybutylene terephthalate in which acid and diol are first subjected to catalytic esterification/oligomerization and the resulting products are thereafter subjected to catalytic polycondensation, the co-production of tetrahydrofuran is significantly reduced by conducting the polycondensation reaction prior to completion of the esterification/oligomerization reaction.

Abstract: The invention is a process for esterifying organic dicarboxylic acid and diol at elevated temperatures and thereafter transesterifying the esterification product in the presence of a diol and a diester at elevated temperatures thereafter polymerizing the transesterification product in a condensation stage to form a polycondensed copolyester having an intrinsic viscosity from 0.2 to 0.9.

Abstract: The use of aluminum sulfate as a dessicant for drying the starting materials used in polymerization reactions employing readily hydrolyzable catalysts is disclosed. The aluminum sulfate is allowed to remain in the reaction mixture during polymerization, and, indeed, may advantageously be allowed to remain in the reaction product without any deleterious effect.

Abstract: A process for preparing a mixture of polyhydroxyl compounds having low molecular weight by catalytically hydrogenating a formose mixture with hydrogen on a metal catalyst. The hydrogenation is carried out at a pH of 7.5 to 12.5 and at elevated temperature and pressure. The formose mixture comprises (i) up to 70 wt. % formose, (ii) up to 1.6 wt. % lead ions and (iii) up to 5 wt. % calcium ions with at least one of (ii) or (iii) being present. The catalyst which is present in an amount of 4-240 wt. % (based on formose solution) is a compound taken from the group consisting of nickel, cobalt and compounds thereof. The mixture of polyhydroxyl compounds made in accordance with the present invention is useful as a starting material in the production of polyether polyols, polyester polyols and polyurethane plastics.

Abstract: A polyester laminated film which comprises a transparent layer and delustered layer(s) laminated at least on one side face of the transparent layer is provided. The transparent layer is formed by a biaxially stretched polyester film mainly composed of polyethylene terephthalate, while the delustered layer is made of an at least uniaxially stretched polyester film which is mainly composed of a polyethylene terephthalate copolymer containing, as a copolymer composition, 1 to 20 mole % of ##STR1## wherein n is an integer from 2 to 140, and x represents ##STR2## and which also contains inert inorganic particles of 0.3 to 20 microns at 3 to 40% by weight.The film of the present invention as described above is roughened on the surface, and is superior in the writability and transcribability by pencils, ink, indian ink, etc., with an excellent transparency, and therefore, very useful for tracing films and the like.

Abstract: Unsaturated esters can be prepared from dicarboxylic acids and dibromoneopentyl glycol with improved resin color in a shorter reaction time with minimal corrosion of metallic reaction vessels and with a net energy saving by the process using an aryl sulfonic acid as the esterification catalyst and following completion of the reaction neutralizing the acid catalyst.

Abstract: A fast crystallizing polyester wherein the polyester has an intrinsic viscosity of greater than 0.3 and at least 90 mole % of the repeating units of the polyester are residues obtained from aromatic diacids or hydroxyacids and aliphatic diols characterized in that at least some of the acid end groups of the polyester have the formula --Y.sup.- M.sup.+ where M is an alkaline metal ion and Y is an anion selected from carboxylate, sulphinate, phosphinate, phosphate, sulphonate, phosphite and borate ions, which ionized end groups have been produced during polymerization of the polyester by either:(a) copolymerizing units derived from materials of formula X--R--Y.sup.- M.sup.+ wherein X is a group capable of being polymerized onto the polyester chain, R is an aliphatic, cycloaliphatic or aromatic group, or(b) polymerizing the polyester in the presence of an alkaline metal salt or corresponding base,the concentration of groups of formula Y.sup.- M.sup.

Abstract: This invention is a method of manufacturing heat-stable polyesters, characterized in that phosphonic acid compounds are added, when heat-stable polyesters with decreased terminal carboxyl groups are manufactured by reacting polyesters and cyclic carbonate compounds in the presence of an alkali halide compound catalyst.

Abstract: Copper powder or a copper compound is mixed with a substantially linear polyester series resin, and the resultant resin composition is formed into a predetermined shape. Thereafter, the resin composition is heated to a temperature above the melting point of the resin in an oxygen-containing atmosphere for cross-linking the polyester series resin.

Abstract: Disclosed is a process for preparing a saturated polyester resin containing ##STR1## groups and having good stability against generation of acetaldehyde at elevated temperatures, which comprises having an alkali metal salt of ethylenediaminetetraacetic acid present in the melt polymerization reaction mixture during formation of such polyester, in an amount up to 0.5 mol percent based on the saturated di- and polycarboxylic acid moieties entering into the polymerization reaction, and products.

Abstract: In the two stage reaction of terephthalic acid with 1,4-butanediol to produce polybutylene terephthalate in which acid and diol are first subjected to catalytic esterification/oligomerization and the resulting products are thereafter subjected to catalytic polycondensation, the co-production of tetrahydrofuran is significantly reduced by conducting the polycondensation reaction prior to completion of the esterification/oligomerization reaction.

Abstract: A polyester fiber having a tenacity of at least 4.0 g/d is formed from a copolyester having a degree of polymerization of from 80 to 100 of which copolyester 1.0 to 2.0 mol % of its acid component has a metal sulfoisophthalic group and 0.5 to 1.9 weight % of which copolyester is provided by a glycol component provided by glycol having a molecular weight of from 400 to 6000. The polyester fiber is readily dyed with basic dyes.The polyester fiber can be prepared by spinning the copolyester at a shear rate of .ltoreq.10.sup.4 sec.sup.-1, a spinning draft ratio of .ltoreq.250, a back pressure of the spinneret of .gtoreq.40 kg/cm.sup.2 and a shear stress of .ltoreq.(Q+0.7).times.10.sup.7 dyne/cm.sup.2, where Q is the mass output rate per single hole (g/min).