Abstract: A composition useful for molding into articles such as food containers, soft drink bottles, cured structural plastics and the like, comprising molding or fiber grade linear or unsaturated polyester or polycarbonate having copolymerized therein a total of from 1.0 to about 5,000 ppm, of the reactant residue moieties of one or a mixture of bis-methine reactants of the formulaM.sup.1 .dbd.HC--Ar.sup.1 --CH.dbd.M.sup.2whereinAr.sup.1 is an unsubstituted or substituted 1,4-phenylene radical; andM.sup.1 and M.sup.2 are the same or different and each is a disubstituted methylene group having the structure ##STR1## wherein R.sup.1 is ##STR2## and R.sup.2 is ##STR3## wherein R.sup.3 is hydrogen, allyl or an unsubstituted or substituted alkyl, cycloalkyl or phenyl radical;X is a divalent alkylene, cycloalkylene or phenylene radical or a combination thereof which may include within the divalent chain one or two atoms or radicals selected from ##STR4## wherein R.sup.

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: An aqueous dispersion comprising a polyester having repeat units from at least one difunctional sulfomonomer containing at least one metal sulfonate group attached to an aromatic nucleus wherein the functional groups are carboxyl or hydroxyl, and a polymer having a majority of repeat units from vinyl acetate, wherein this polymer is formed from monomers polymerized in an aqueous dispersion of said polyesters.

Abstract: Flat heather polyester yarns that provide soft pleasing fabrics that can easily be brushed (or napped) to enhance their aesthetics, on account of their unusually low tenacity, that consist essentially of cationic dyeable polyester filaments with homopolymer filaments, and corresponding spin-oriented feed yarns that may be processed into such flat yarns by draw-warping.

Abstract: Flat polyester yarns that provide soft pleasing fabrics that can easily be brushed (or napped) to enhance their aesthetics, on account of their unusually low tenacity, that consist essentially of cationic dyeable polyester filaments, and corresponding spin-oriented feed yarns that may be processed into such flat yarns by draw-warping.

Abstract: An aqueous coating composition is provided for thermoplastic films comprising(i) from 1 to 10 weight percent based upon the total weight of the coating composition, of a sulfonated copolyester consisting essentially of the polyester condensation product of the following monomers or their polyester-forming equivalents:(A) about 65 to 95 mole percent of isophthalic acid;(B) about 0 to 30 mole percent of at least one aliphatic dicarboxylic acid of the formula HOOC(CH.sub.2)--.sub.n COOH, wherein n ranges from about 1-11;(C) about 5 to about 15 mole percent of at least one sulfomonomer containing an alkali metal sulfonate group attached to a dicarboxylic aromatic nucleus; and(D) stoichiometric quantities of about 100 mole percent of at least one copolymerizable aliphatic or cycloaliphatic alkylene glycol having about from 2 to 11 carbon atoms,(ii) from 0.

Abstract: Novel thermoplastic polymers of relatively high glass transition temperatures are characterized by five-carbon moieties having a keto group in the 3-position alternating with bis(benzoheterocyclic) moieties. The polymers are produced by reaction of a keto-C.sub.5 source, selected from 4-oxoheptanedioic acid compounds or a 1,6-dioxa [4.4] spirodilactone, with a bis(ortho-phenylene amine) compound. Further cyclization of the initial polymer product or reaction of a bis(ortho-phenylenediamine) provides a polymer having a hexacyclic repeating unit.

Abstract: Disclosed is a water-dissipatable polyester containing a sulfonate group and at least 10 mole percent of a multifunctional or branch-inducing moiety. The polyester is useful to prepare coatings such as paints.

Abstract: Novel polyarylate polymers comprise alternating moieties derived from an aromatic dicarboxylic acid halide, from a hydroxyaryl-substituted 1,6-diaza [4.4] spirodilactam and, optionally, from a di(hydroxyphenyl) compound. The polyarylate polymers are thermoplastic polymers characterized by relatively high glass transition temperatures.

Abstract: The invention relates to mixtures of cationic benzene carboxylate polymers, a method for their preparation and use, which polymers are defined by the formula ##STR1## wherein R and R' are selected from the group consisting of alkyl or alkenyl having from 1 to 20 carbon atoms, aryl, ##STR2## with the proviso that at least one of R and R' is quaternized; Q is hydrogen, SO.sub.3 -alkali metal, SO.sub.3 H, COOH or COO-alkali metal, between about 55% and about 90% of Q in said mixture being hydrogen and between about 10% and about 45% of Q in said mixture being other than hydrogen;a and b each have a value of from 1 to 200, except that the sum of a+b is at least 25;X is hydrogen, lower alkyl or mixtures thereof in random or block distribution when a and/or b is greater than 3;c has a value of from 2 to 10,000;R.sub.1, R.sub.2 and R.sub.3 each contain from 1 to 22 carbon atoms and are alkyl, hydroxy alkyl or alkylamido lower alkyl;R.sub.5 is ##STR3## --OH, --OCOR.sub.1 or --OR.sub.1 ; R.sub.6 is hydrogen or --COR.

Abstract: New polyesters are provided, having advantageous utility as dual function binder/charge agents in electrostatographic toner particles. The new polyesters contain a quaternary phosphonium salt comprising a cationic portion and an anionic portion, wherein the cationic portion comprises a phosphonium atom directly covalently bonded to at least one aryl moiety substituted with a group containing an ester linkage to the rest of the polyester, and wherein the anionic portion of the salt comprises an arylsulfonate moiety in which the aryl group is unsubstituted or is substituted with one or more alkyl, halide, or group having an ester linkage to the rest of the polyester.

Abstract: Coating compositions suitable for use as coatings or inks for metallic foils, such as aluminum foil, as well as for use on other materials, such as papers and plastics resin films, are disclosed. These compositions comprise a water dispersible polyester resin, an alkylated amino resin, a water dispersible epoxy resin and water. They may optionally include a pigment and other optional modifying ingredients. These compositions, being water-based, provide improved environmental compatibility and may be dried under relatively low temperatures without objectional ammonia residue odor.

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## whereinR.sup.1 is an unsubstituted or substituted alkyl, cycloalkyl or aryl radical;A is an unsubstituted or substituted 1,4-phenylene radical;R.sup.2 is hydrogen or an unsubstituted or substituted alkyl, alkenyl, cycloalkyl or aryl radical;R.sup.3 is cyano, ##STR2## or an unsubstituted or substituted carbamoyl, alkanoyl, aroyl, alkylsulfonyl, arylsulfonyl, aryl or aromatic heterocyclic radicals. The methine residues are present in the polymer as an integral part of the polymer chain and absorb ultraviolet radiation in the range of about 250 to about 390 nm. The residues are non-extractable from the polymer and stable at the conditions at which the polymers are manufactured and processed.

Abstract: An aqueous coating composition is provided for thermoplastic films comprising(i) from 1 to 10 weight percent, based upon the total weight of the coating composition, of a sulfonated copolyester consisting essentially of the polyester condensation product of the following monomers or their polyester-forming equivalents:(A) about 65 to 95 mole percent of isophthalic acid;(B) about 0 to 30 mole percent of at least one aliphatic dicarboxylic acid of the formula HOOC(CH.sub.2)--.sub.n COOH, wherein n ranges from about 1-11;(C) about 5 to about 15 mole percent of at least one sulfomonomer containing an alkali metal sulfonate group attached to a dicarboxylic aromatic nucleus; and(D) stoichiometric quantities of about 100 mole percent of at least one copolymerizable aliphatic or cycloaliphatic alkylene glycol having about from 2 to 11 carbon atoms,(ii) from 0.

Abstract: Photosensitive iodonium polymers are provided useful as positive photoresists. The iodonium polymers can be converted to polymeric diaryl iodonium polyfluorometal and metalloid salts by a metathesis reaction. These polymeric iodonium polyfluorometal and metalloid salts can be used as a catalyst in combination with a copper compound cocatalyst to make heat curable compositions with cationically polymerizable materials such as an epoxy resin.

Abstract: A linear rodlike polyester of controlled rigidity and packing density which melts below 350.degree. C. and consists essentially of recurring units of the formula (1) ##STR1## in which A, B, C and D are the same or different cyclic moieties selected from the group consisting of 1,4-phenylene and 1,4-cyclohexylene; n is Zero or 1; Z.sup.1, Z.sup.2 and Z.sup.3 are the same or different and are selected from the group of bivalent links consisting of the covalent bond (--) and of linkages --COO--, --OOC--, --CH.sub.2 CH.sub.2 --, --CH.sub.2 O--, --OCH.sub.2 --, --OCH.sub.2 CH.sub.2 O--, --OCH.sub.2 OCH.sub.2 -- and --CH.sub.2 OCH.sub.2 O--; X.sup.1, X.sup.2, X.sup.3 and X.sup.

Abstract: Water-dispersible polymeric material such as polyesters and poly(ester-amides) containing water-solubilizing sulfonate groups and having reacted onto or into the polymer backbone from about 0.01 to about 40 mol % based on the total of all reactant hydroxy, carboxy or amino equivalents, of colorant comprising one or more heat stable organic compounds initially having one or more condensable groups, the polymeric material comprising the reaction residues of organic monomers and said colorant compounds containing one or more reactive groups condensable under polymerization conditions. This material is useful, for example, for printing inks or other coatings which are desireably applied from an aqueous system.

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 styrylbenzazole reactants of the formula: ##STR1## wherein A is the residue of a benzene ring of a benzoxazole, benzothiazole or benzionidazole radical; X is --O--, --S-- or --N(R.sup.2)--; Ph is a phenylene radical; and R.sup.1 is halogen or --Y--R.sup.2 in which Y is --O-- or --N(R.sup.2)-- and each R.sup.2 is hydrogen, alkenyl or an unsubstituted or substituted alkyl, cycloalkyl or aryl radical.

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: Oligomeric esters and mixtures thereof useful as soil release agents in consumer laundering and fabric care compositions are disclosed. Preferred oligomers have the formulae ##STR1## wherein E is ##STR2## wherein the R substituents may be the same or different and are members selected from the group consisting of --CH.sub.2 CH(CH.sub.3)--, --CH(CH.sub.3)CH.sub.2 --and --CH.sub.2 CH.sub.2 --, n is an integer from 1 to 30 and x is an integer from 0 to about 20 provided that when E is ##STR3## x is at least 1. Mixtures of the oligomers having one and two NaO.sub.3 S(CH.sub.2 CH.sub.2 O).sub.n --substituents are particularly effective and formulable soil release agents in detergent compositions.

Abstract: A five-component copolyester not described in the prior art literature which comprises at least five components, i.e. (a) two aromatic dicarboxylic acid components composed of a major amount of an isophthalic acid component and a minor amount of another dicarboxylic acid component, (b) a diol component composed of an ethylene glycol component and optionally another diol component, (c) an aromatic monohydroxy-monocarboxylic acid component and (d) a polyfunctional compound component having at least three functional groups. The copolyester has excellent melt moldability, mechanical strength, transparency and gas-barrier property in a well balanced combination, and shows improved properties over conventional copolyesters containing a major amount of isophthalic acid as a dicarboxylic acid component.

Abstract: There is disclosed acrylate-terminated oligomers which are radiation-curable and which can be pigmented with magnetizable power to cure on electron beam exposure to provide superior magnetic recording structures. These oligomers include sulfonic acid groups which improve pigment wetting and which can be included in amide-containing compounds.

Abstract: Disclosed are polyesterether bonding compositions comprising repeating units from trans-1,4-cyclohexanedicarboxylic acid, a difunctional sulfomonomer, a polyetherglycol, and 1,4-cyclohexanedimethanol.

Abstract: A fiber composed of a polyester having at least a part of terminals blocked with the residue of at least one specific metal sulfonate compound, where the amount of the blocked terminals is 1.3 to 4.0 mol % based on the dicarboxylic acid component of the polyester and the alkali dissolution speed constant is 3.3.times.10.sup.-9 to 6.5.times.10.sup.-9 cm/sec. This polyester has a good dyeability with a cationic dye and is excellent in the heat resistance and alkali resistance. The polyester fiber can be spun at a high speed or super high speed and can be false-twisted at a high temperature.

Abstract: Disclosed are polyesterether bonding compositions comprising repeating units from trans-1,4-cyclohexanedicarboxylic acid, a difunctional sulfomonomer, a polyetherglycol, 1,4-butanediol or 1,4-cyclohexanedimethanol and ethylene glycol.

Abstract: Disclosed are copolyester adhesives containing small amounts of at least one difunctional sulfonate metal salt such as 5-sodiosulfoisophthalate. Such copolyesters permit a wider bonding temperature range with fabrics and provide increased bond strengths on metal substrates.

Abstract: A primer coated, oriented polyester film material is provided wherein the primer is applied in an aqueous medium comprising a water dispersible copolyester consisting essentially of the condensation product of components A, B, C, and D or their polyester forming equivalents as follows:(A) about 60 to 75 mole percent of terephthalic acid;(B) about 15 to 25 mole percent of at least one dicarboxylic acid of the formula HOOC(CH.sub.2).sub.n COOH, wherein n ranges from about 1-11;(C) greater than from about 6 up to about 15 mole percent of at least one sulfomonomer containing an alkali metal sulfonate group attached to a dicarboxylic aromatic nucleus, and(D) stoichiometric quantities, i.e., about 100 mole percent of at least one aliphatic or cycloaliphatic alkylene glycol copolymerizable therewith having about from 2 to 11 carbon atoms.The copolyester priming layer may be applied to the polyester film at any suitable stage during manufacture of the film, i.e., before or during the stretching operations.

Abstract: Polyester compositions which are dispersible or soluble in water based systems can be very valuable as adhesives, coatings, paints, and the like. The use of water based solvent systems eliminates recovery and toxicity problems normally related with many organic solvents. The polyester compositions of this invention have an increased affinity for water based systems by the incorporation therein salts of organic sulfonic acid monomers and by carboxyl terminating these polyesters to a very substantial degree. The water based systems in which these modified polyesters are useful contain an alcohol in addition to water.

Abstract: An ethylene terephthalate copolymer modified with an alicyclic sulfonate is disclosed which is useful in the production of biaxially oriented containers.

Abstract: A flexible monofilament surgical suture having unique handling and knot tying characteristics. Said suture comprises a drawn and oriented monofilament of a poly(polymethylene terephthalate, isophthalate or cyclohexane-1,4-dicarboxylate-co-dimerate), having the following combination of mechanical properties:Tensile strength--at least about 60,000 psiKnot strength --at least about 35,000 psiYoung's modulus--between about 80,000 and 280,000 psiElongation --from about 20% to 80%.

Abstract: Disclosed are polyesters prepared from hetero-atom-containing dicarboxylic acids and hetero-atom-containing diols. These polyesters have low permeability to oxygen and carbon dioxide and are useful in packaging applications such as for food and beverages.

Abstract: Absorbable, radiation sterilizable polymers, useful as sutures and other medical and surgical devices, are produced from polyesters of substituted benzoic acid, dihydric alcohols, and glycolide and/or lactide.

Abstract: A polymeric antistatic agent suitable for use in a polyester fiber, the antistatic agent is a polyester containing azelaic acid units and 2,2-dimethyl-1,3-propanediol units, and capped polyether units where the cap is ##STR1## and X is 12 to 16. The antistatic agent preferably contains tetra alkyl phosphonium isophthalate units. Polyester fibers containing these antistatic agents is also disclosed.

Abstract: Disclosed is a process for preparing sulfo-modified polyesters having an inherent viscosity of about 0.3 to about 0.9 and characterized by an improved planar stretch ratio relative to a given inherent viscosity, an improved rate of acetaldehyde generation relative to a given planar stretch ratio and increased buildup of melt viscosity. The process comprises the steps of (a) reacting (1) a dicarboxylic acid component comprising at least about 85 mole % terephthalic acid and about 0.1 to about 5.0 mole % of a difunctional sulfo-monomer, and (2) a glycol component comprising at least about 85 mole % ethylene glycol, the reaction being conducted in the presence of a catalyst system comprising a titanium compound and an organic salt of an alkali metal, (2) polycondensing the reaction product of step (1) in the presence of a phosphate ester until a polymer having the desired I.V. is obtained.

Abstract: The invention relates to a thread with a proportion of a basic-dyeable, texturized polyester filament which contains a metal sulphonate containing the structural unit ##STR1## where M is equal to Na or K and a compound A containing structural units --(CH.sub.2).sub.y -- and/or --O--(C.sub.x.sbsb.1 H.sub.2x.sbsb.1 O).sub.y.sbsb.1 -- where x.sub.1 .gtoreq.2, y.gtoreq.20 and x.sub.1 y.sub.1 .gtoreq.20.The basic-dyeable polyester filament contains 1.0 to 5.0 mol % of metal sulphonate units and between 0.5 and 12% by weight of compound A.

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: This invention relates to new emulsifiable polyester waxes which are linear polyester waxes which are end capped with polyfunctional organic anhydrides. The emulsifiable polyester waxes are generally amorphous or semicrystalline solids with melting points less than about 100.degree. C. These polyester waxes are useful in preparing clear emulsions which can be applied to surfaces to form protective and decorative films or coatings.

Abstract: Amorphous sulfopolyesters which are the esterification product of glycols and dicarboxylic acids and, optionally, hydroxycarboxylic acids, of which at least about 35 mole percent are ortho-dicarboxylic acids.

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 base fabric for a pressure-sensitive adhesive tape comprising as the warp a flat yarn of polyester fibers containing a specific residue in the molecular chain. A pressure-sensitive adhesive tape obtained from this base fabric is easy to tear in the crosswise direction and has a smooth torn edge.

Abstract: A novel compound having the formula: ##STR1## wherein: R is alkyl containing from 1 to 10 carbon atoms; andM is a monovalent cation, selected from the group consisting of alkali metal and ammonium, has been synthesized in high yield by hydrogenating the corresponding arylsulfonate in a solvent which simultaneously prevents hydration of the sulfonate group and hydrolysis of the ester functions. The compound is useful in preparing condensation polymers having ionic groups. In particular, these condensation polymers comprise additional polymerized copolymerizable dicarboxylic acids and diols, diamines or hydroxyamines, to yield polyesterionomers useful in dye imbibition photohardenable imaging materials for forming positive dye images.

Abstract: Disclosed are copolymers having molecular weight from 2,000 to 10,000 and comprising a copolymer of ethylene glycol, polyethylene glycol having an average molecular weight of from 200 to 1000 aromatic dicarboxylic acid containing only carbon, hydrogen, and oxygen atoms and alkali metal salt of a sulfonated aromatic dicarboxylic acid containing only carbon, oxygen, hydrogen and sulfur atoms. The copolymers are useful for preparing anionic textile treating compositions.

Abstract: A photosensitive lithographic plate having, on a substrate, a photosensitive layer comprising a photosensitive polyester containing at least (A):(a) an aromatic dicarboxylic acid unit represented by the general formula: ##STR1## where m and n each represents an integer of 0 or 1, with at least one of them being 1,(b) a dicarboxylic acid unit having a sulfonate group, and(c) a diol unit represented by the general formula: ##STR2## represents a hydrogenated benzene ring, R.sup.1 and R.sup.2 each represents an alkylene group of 2-4 carbon atoms, R.sup.3 and R.sup.4 each represents a hydrogen atom or an alkyl group of 1-6 carbon atoms, r and s each represents an integer of from 0 to 3 and t represents an integer of 0 or 1.

Abstract: This invention relates to polyethylene isophthalate (PEI) and copolymers thereof having low cyclic dimer content and process for making same. The invention provides a process for making PEI using protonic acid catalysts which result in a polymer having lower amounts of ring dimer of ethylene isophthalate than has heretofore been known. Strong protonic acids such as sulfuric or phosphoric are utilized as polymerization catalysts to thereby lower the amount of cyclic dimerization which occurs during the polymerization process. Polymers so produced are of a high purity and have reduced manufacturing costs due both to a smaller amount of material being lost as cyclic dimer and because of lower processing costs associated with cleaning cyclic dimer from the processing equipment.

Abstract: Disclosed are colored polyesters having copolymerized therein anthraquinone derivative colorants containing one or more sulfonamido groups. The colored polymers are fast to light and the colorant moieties are not extractable therefrom, rendering from the colored polymers particularly suitable for use in food containers such as molded beverage bottles. The inherent viscosities of these polymers can be varied widely as is well known in the art for different applications. The copolymerizable colorants have the formula ##STR1## wherein R.sub.1 and R.sub.2 are each hydrogen or 1-3 substituents independently selected from alkyl, alkoxy, and the like; and T represents 1-4 independently selected radicals of the formula ##STR2## wherein R.sub.3 is hydrogen or 1-3 substituents such as alkyl, alkoxy and the like; Z is a divalent linking group such as --NH--, --S--, --O--, and alkoxycarbonyl; and Q is hydroxy, carboxy or alkoxycarbonyl.

Abstract: A deep-dyeable polyester fiber of soft hand comprising recurring units consisting mainly of ethylene terephthalate and --SO.sub.3 M groups in which M is an alkali metal, and having a degree of crystallinity .chi..sub..rho. of from 30 to 55%, a degree of orientation .DELTA.n of from 0.06 to 0.12 and .chi..sub..rho. /.DELTA.n of from 350 to 550. The fiber can be produced by heat treating a melt spun, slightly oriented filament under relaxation and then drawing the heat treated filament at a low temperature.

Abstract: An elastomeric copolyester resin having high melt strength and capable of being blow-molded. The copolyester resin is made by adding to the polymerizing or initial mixture small amounts of an alkali salt of a dialkyl sulfoisophthalate. The copolyester resin contains units of terephthalic acid, butane diol, polytetramethylene glycol, and dimer acid.

Abstract: Copolyesters derived from aromatic, cycloaliphatic or aliphatic dibasic acid moieties; aliphatic or cycloaliphatic glycol moieties including at least 10 mole % of 1,6-hexanediol moieties; and 2 to 40 mole % of an alkyl or alkenylsuccinic anhydride moiety. The copolyesters are useful as bonding or coating compositions.

Abstract: Disclosed is the preparation of water-dissipatable polyesters and polyesteramides wherein at least a part of one of the monomeric components from which it is derived is a polycarboxylic acid or polyhydric alcohol which contains a sulfonic acid salt moiety derived from a nitrogen-containing base having an ionization constant in water at 25.degree. C. of 10.sup.-3 to 10.sup.-10. Also disclosed is the use of such polymers as sizes for fibers of glass, ceramics, etc., where the size is removed by burning and little or no ash residue is important.

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).