Abstract: The present invention is a process for making a low color copolymer of ethylene glycol, isosorbide and terephthalic acid or dimethyl terephthalate. This copolymer, poly(ethylene-co-isosorbide) terephthalate, is useful for making bottles, hot-fill containers, films, sheet, fiber, strand and optical article applications. It can also be used to make polymer blends and alloys.

Abstract: Biaxially-drawn polyester film for fabrication which is characterized in that it is a film comprising polyester in which ethylene terephthalate units and/or ethylene naphthalate units are the chief structural component and containing 0.1-2 wt % of a carnauba wax and 1 to 200 ppm of germanium, and the melting point of said film is 180-270° C., the angle of contact to water is 70°-120°, and the planar orientation coefficient is 0.08-0.15. This film shows outstanding release properties following repeated use, use after fabrication and use in an aqueous environment and, furthermore, it exhibits stable properties with little variation and, in particular, following lamination to metal sheet such as steel or aluminium, when used as the inner face of a fabricated metal can, it is outstanding in its non-stick properties to the contents, and provides a combination of heat resistance and processability.

Abstract: By the present invention, there are provided a catalyst for polyester preparation, which comprises a solid titanium compound containing titanium, oxygen, carbon and hydrogen and having a Ti—O bond and which has a maximum solubility in ethylene glycol, as measured when the catalyst is dissolved in ethylene glycol under heating at 150° C., of not less than 3,000 ppm in terms of a titanium atom, a catalyst for polyester preparation, which comprises a titanium-containing solution wherein a contact product of a hydrolyzate of a titanium halide or a hydrolyzate of a titanium alkoxide with a polyhydric alcohol is dissolved in ethylene glycol in an amount of 3,000 to 100,000 ppm in terms of a titanium atom, a process for preparing a polyester using the catalyst, and a polyester prepared by the process.

Abstract: The present invention provides poly(trimethylene terephthalate) copolymerized with ester-forming sulfonate and a fiber thereof. The polymer of the present invention is high in melting point, small in loss of melting viscosity and has a high molecular weight. The fiber of the present invention is high in toughness, excellent in whiteness and dyeable with a cationic dye, whereby it is useful for clothing, carpets or non-woven sheets, etc.

Abstract: A method of producing an aliphatic polyester, including polycondensing an aliphatic diol and an aliphatic dicarboxylic acid compound, or a prepolymer thereof in the presence of a metal-containing ester interchange catalyst and a phosphorus-containing co-catalyst such as an ammonium, calcium or magnesium salt of hydrogen-containing phosphoric acid or an organic phosphinic acid. An oxycarboxylic acid compound or its prepolymer may also be used as a raw material.

Abstract: A preblended additive composition and process for the preparation of polyester resins useful in the manufacture of plastic containers such as bottles is disclosed. The additive composition includes a cobalt-containing compound that is preblended with a phosphorous compound. The polyester resin, e.g., a PET resin, may be prepared by reacting ethylene glycol with dimethyl terephthalate (DMT) or terephthalic acid (TA) in an esterification reaction. The additive composition may be prepared by quickly dumping the phosphorus compound into the cobalt compound such as cobalt acetate, and the resulting composition is added to the reactor vessel before the polycondensation reaction. On the other hand, the additive composition may be prepared by slowly dumping the phosphorus compound into the cobalt compound over a period of at least 5 minutes. Such preblending substantially eliminates any yellow or blue color, or haze in the product article.

Abstract: To a copolyester reacted essentially by terephthalic acid components and ethylene glycol units, adding 1% to 15 weight % of specific diol unit selected from the group consisting of at least one of 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol and hydroxypivalyl hydroxypivalate; or adding 0 to 1.0 mole % of mulfunctional group components consisting of at least one or more of trimellitic acid, trimellitic anhydride and trimethylol propane; and adding 0.01 to 0.5 weight % of compound represented by the following formula: can improve the color hue of the copolyester, and increase the reaction rate of the copolyester subjecting to solid phase polymerization, therefore improve the color hue of the shaped articles produced therefrom; furthermore, reduce the decline degree of the intrinsic viscosity after melt processing.

Abstract: Applicant has discovered processes for preparing polyglycerols and polyglycerol esters in high yield and with minimal formation of cyclic polyglycerols and cyclic polyglycerol esters. Furthermore, the processes of this invention produce a high proportion of linear polyglycerols and polyglycerol esters. The linear polyglycerols have very desirable physical characteristics, including a clear appearance at melt, a desirable Gardner color, a mild odor, and a bland taste. The polyglycerols and polyglycerol esters prepared by the method of the present invention are well suited for use as cosmetic and food additives. Since few, if any, cyclic polyglycerols and polyglycerol esters are formed by the processes of this invention, costly and time consuming distillation steps to remove such by-products are not needed.

Abstract: Disclosed is an improved promoter system for curing resin compositions based on unsaturated polyesters. The promoter system contains at least one primary promoter which is a metallic compound, such as a cobalt salt, and at least one co-promoter which is an alkyl alkanolamine. Such an alkyl alkanolamine is usually an amino (C2-C4) alcohol, and it is present at 1-15 mole of amine per mole of equivalent cobalt metal. The use of alkyl alkanolamine reduces the level of the cobalt promoter in curing formulations with no deleterious effects on the curing performance, which leads to reduced color formation in finished products.

Abstract: Disclosed is a flame retardant polybutyleneterephthalate resin prepared be copolymerizing a phosphorus-based flame retardant represented by the following formula I and a butyleneterephthalate unit: wherein R1 and R2 are different or the same and are methyl or butyl including a hydroxyl group.

Abstract: A process for producing a polyester that comprises 1 to 90 wt. % poly(alkylene ether) glycol. The process comprises the step of copolymerizing (i) a preformed polyester polymer having an inherent viscosity of at least 0.4 dL/g, (ii) a poly(alkylene ether) glycol, and (iii) a dicarboxylic acid or anhydride, to obtain a polyester comprising 1 to 90 wt. % poly(alkylene ether glycol).

Abstract: A random polytrimethylene ether ester prepared by polycondensation of 1,3-propanediol reactant and about 10 to about 0.1 mole % of aliphatic or aromatic diacid or diester, as well as its manufacture and use thereof.

Abstract: A polyester resin produced by polycondensing a dicarboxylic acid component containing an aromatic dicarboxylic acid or its ester-forming derivative as the main component and a diol component containing ethylene glycol as the main component in the presence of at least an antimony compound and a phosphorus compound, via an esterification reaction or an ester exchange reaction, which is characterized in that the amount of antimony eluted when immersed in hot water of 95° C. for 60 minutes in the form of particles having a number average particle weight of 24 mg, is not more than 1 &mgr;g per 1 g of the polyester resin, as antimony atoms (Sb).

Abstract: An alicyclic (meth)allyl ester monomer obtained by a specific production process. An alicyclic (meth)allyl ester compound for plastic lenses, which can be obtained by a simple and easy production process and which can endure a long-term storage, is produced using the monomer, and a plastic lens is obtained using the compound.

Abstract: A 2-cyanoacrylate composition is disclosed which is excellent in surface curability and clearance curability and effective in shortening the time required for bonding operation. The 2-cyanoacrylate composition contains a Lewis acid metal salt which comprises a specific metal and the conjugate base of an acid having oxygen and in which the metal is bonded to the conjugate base through an oxygen atom and a compound having clathrating ability.

Abstract: A method of producing sulfonated polyester compounds suitable for use as a soil releasing agent and/or textile sizing agent in which a sulfonated acid or ester is reacted with a hydroxy-containing compound to form a sulfonated hydroxy terminated ester which then undergoes a transesterification reaction with a poly(ethylene) terephthalate based polyester followed by polycondensation to form the desired sulfonated polyester compound.

Abstract: The invention relates to a method for producing polyesters with a reduced content of free acetaldehyde from terephthalic acid and ethylene glycol via a catalyzed polycondensation in the melt and also the use of this method. The method is based thereby on the usage of highly active polycondensation catalysts, on the deactivation of these catalysts by the addition of phosphorous-containing inhibitors and the addition of acetaldehyde-bonding substances. The entire polycondensation is thereby implemented at temperatures beneath 280° C.

Abstract: In the process of the present invention for producing an aliphatic poly(ester carbonate), maleic anhydride, a C2-20 glycol and hydrogen are reacted in the presence of a hydrogenating catalyst. By this process, an aliphatic poly(ester carbonate) having practically satisfactory moldability and physical properties is produced in a short period of time by a simplified method as compared to conventional production processes.

Abstract: A manufacturing method of the copolyester containing 2,6-ethylene naphthalate unit (EN) by using 2,6-naphthalenedicarboxylic acid (NDA), purified terephthalic acid (PTA), and ethylene glycol (EG) to proceed with esterification or by using dimethyl 2,6-naphthalenedicarboxylate (NDC), dimethyl terephthalate (DMT), EG, and transesterification catalyst to proceed with transesterification reaction or by PTA process. While the esterification reaction reaches 85˜98 percent of esterification ratio, NDC, EG, and transesterification catalyst are added to proceed with transesterification reaction. The monomer obtained from previous procedure is added with polymerization catalyst thereafter to proceed with polycondensation reaction to produce copolyester of which the viscosity is increased through solid state polymerization. Then, the copolyester is ejected to be blow-molded so as to produce the one-way bottle which can meet the requirement of pasteurization.

Abstract: An alicyclic (meth)allyl ester monomer obtained by a specific production process. An alicyclic (meth)allyl ester compound for plastic lenses, which can be obtained by a simple and easy production process and which can endure a long-term storages, is produced using the monomer, and a plastic lens is obtained using the compound.

Abstract: A composition that can be used as catalyst is disclosed. The composition comprises, or is produced by combining, (A) a titanium compound; (B) either (i) a complexing agent, (ii) a combination of a complexing agent, hypophosphorous acid or a salt thereof, and optionally a solvent, a zirconium compound, or both, (iii) combinations thereof; (C) a phosphorus compound; and optionally a solvent. Also disclosed is a process that can be used for producing a polyester. The process comprises contacting, in the presence of an esterification or transesterification or polycondensation catalyst composition and a phosphorus compound, a carbonyl compound and an alcohol under a condition suitable for esterification, transesterification, or polymerization. Further disclosed is a process to make polyester with reduced insoluble particles or solids using a phosphorus compound other than the commonly used phosphoric acid.

Abstract: A manufacturing method of the copolyester containing 2,6-ethylene naphthalate unit (EN) by using 2,6-naphthalenedicarboxylic acid (NDA), purified terephthalic acid (PTA), and ethylene glycol (EG) to proceed with esterification or by using dimethyl 2,6-naphthalenedicarboxylate (NDC), dimethyl terephthalate (DMT), EG, and transesterification catalyst to proceed with transesterification reaction or by PTA process.

Abstract: The present invention deals with the certain castor polyesters that give high gloss when applied to the skin. Said ester are the reaction of the hydroxyl group of castor oil with less than one equivalent of a fatty acid then in a subsequently step the remainder of an equivalent of a diacid.

Abstract: Disclosed is a method for preparing saturated polyester used in various molded products, such as films, synthetic fibers, vessels and housings. In particular, the method improves mechanical properties, including tensile strength or impact resistance, of saturated polyester. In DMT method or TPA method, the saturated polyester is synthesized through transesterification or esterification and polycondensation, in which metal compounds, such as metal acetate compounds, metal hydroxides, and metal oxides, are added in the larger amounts upon synthesis, and thus crystalline internal grains are formed, thereby improving the mechanical properties. As such, the metal compound can be used alone or in combination with a phosphorous-based compound.

Abstract: The present invention relates to a polyester resin produced by polymerizing a dicarboxylic acid component comprising mainly an aromatic dicarboxylic acid or its ester forming derivative, and a diol component comprising mainly ethylene glycol in the presence of a catalyst containing a titanium compound, which polyester resin contains titanium atoms (Ti) in an amount of 0.002 to 1.0 mole based on one ton of the polyester resin and has the following properties: Intrinsic viscosity ([&eegr;], dl/g)≧0.70 Hunter's “b” value≦4 Acetaldehyde content (AA0, ppm)≦5.0.

Abstract: The invention relates unsaturated polyester resins for the manufacture of subzero flexible, weather-resistant products. The liquid unsaturated polyester resin comprises a linear unsaturated polyester obtained by reacting 5-30 mol % of one or more ethylenically unsaturated dicarboxylic acids (A), 20-45 mol % of one or more other aliphatic or aromatic acids (B) and 40-60 mol % of two or more polyhydric alcohols and 30-60 wt % of one or more reactive monomers. The linear unsaturated polyesters have a cone and plate viscosity (I.C.I.) of 2 ps/125° C.-20 ps/125° C. and a molecular weight Mw of 20,000-100,000. The invention also relates to a process for the manufacture of such unsaturated polyester resins and to the use of them in applications wherein good adhesion to supporting material and flexibility at ambient and especially at low temperatures are needed.

Abstract: A composition that can be used as catalyst is disclosed. The composition comprises, or is produced by combining, (A) a titanium compound; (B) either (i) a complexing agent, (ii) a combination of a complexing agent, hypophosphorous acid or a salt thereof, and optionally a solvent, a zirconium compound, or both, (iii) combinations thereof; (C) a phosphorus compound; and optionally a solvent. Also disclosed is a process that can be used for producing a polyester. The process comprises contacting, in the presence of an esterification or transesterification or polycondensation catalyst composition and a phosphorus compound, a carbonyl compound and an alcohol under a condition suitable for esterification, transesterification, or polymerization. Further disclosed is a process to make polyester with reduced insoluble particles or solids using a phosphorus compound other than the commonly used phosphoric acid.

Abstract: The present invention provides a manufacturing method of copolyester for low acetaldehyde content of PET bottles. The polyethylene terephthalate (PET) polymer is added with an appropriate modifier in order to decrease the production of acetaldehyde caused by pyrolysis side reaction during the blow molding process of PET bottles. The modifier comprises stabilizer and primary antioxidant, wherein the stabilizer is an inorganic phosphorous compound with an addition quantity of 0.003˜0.5 weight % based on the weight of the total copolyester copolymer and the primary antioxidant is a hindered phenolic antioxidant containing Ca+2 with an addition quantity of 0.005˜5.0 weight % based on the weight of the total copolyester copolymer. The present invention owns an improving effect of decreasing the production of side product—acetaldehyde at least 30% than those without the addition of said modifier.

Abstract: A composition that can be used as catalyst is disclosed. The composition comprises, or is produced by combining, (A) a titanium compound; (B) either (i) a complexing agent, (ii) a combination of a complexing agent, hypophosphorous acid or a salt thereof, and optionally a solvent, a zirconium compound, or both, (iii) combinations thereof; (C) a phosphorus compound; and optionally a solvent. Also disclosed is a process that can be used for producing a polyester. The process comprises contacting, in the presence of an esterification or transesterification or polycondensation catalyst composition and a phosphorus compound, a carbonyl compound and an alcohol under a condition suitable for esterification, transesterification, or polymerization. Further disclosed is a process to make polyester with reduced insoluble particles or solids using a phosphorus compound other than the commonly used phosphoric acid.

Abstract: An improved process for the preparation of high molecular weight, linear polyester resins comprises reacting an aromatic dicarboxylic acid with an excess of an alkane diol under conditions effective to reach the clearing point of the reaction; pre-condensing the cleared reaction mixture under conditions effective to produce oligomers having an intrinsic viscosity measured in 60/40 phenol/1,1,2,2-tetrachloroethane at 25° C. of less than about 0.70 deciliters/gram and a carboxylic acid end group level of less than or equal to about 100 milliequivalents per kilogram; and polycondensing the oligomer under conditions effective to produce a linear polyester resin having an intrinsic viscosity less than or equal to about 2.0 dl/g as measured in 60/40 phenol/1,1,2,2-tetrachloroethane by weight at 25° C. and a carboxylic acid end group level of about 10 to about 40 milliequivalents per kilogram.

Abstract: The invention relates to a process for the preparation of a copolyether ester built up of hard polyester segments of repeating units derived from at least one alkylene glycol and at least one aromatic dicarboxylic acid or an ester thereof and soft segments derived from at least one polyalkylene oxide glycol, which comprises polymerization by condensation in the melt of at least one aromatic dicarboxylic acid, at least one alkylene glycol and at least one polyalkylene oxide glycol, in the presence of a catalyst based on a combination of titanium and a bivalent metal in a single compound or several compounds, characterized in that the molecular ratio of Ti:bivalent metal is at most 1.6, preferably at most 1.5. The invention leads to a substantial shortening of the polycondensation time in the melt or a higher degree of polymerization of the copolyether ester. The solid-phase post-condensation can also be shortened substantially.

Abstract: A process for producing a polyester that comprises 65 to 90 wt. % poly(alkylene ether) glycol. The process comprises the step of copolymerizing a preformed polyester polymer having an inherent viscosity of at least 0.4 dL/g and a poly(alkylene ether) glycol, to obtain said polyester comprising said 65 to 90 wt. % poly(alkylene ether glycol).

Abstract: A perfluorodicarboxylic fluoride of the formula: F—CO—CF2—O—Rf—O—CF2—CO—F or perfluorodiketone of the formula: R1—CO—Rf—CO—R1 wherein Rf is a perfluoroalkylene group and R1 is a C1-8 perfluoroalkyl group is mixed with an alkali metal fluoride in an aprotic polar solvent to form an initiator solution. Hexafluoropropene oxide is fed to the initiator solution for polymerization, obtaining difunctional hexafluoropropene oxide polymers of high purity.

Abstract: The production of linear polyester by the interchange of ester radicals or esterification and polycondensation of multivalent alcohols with multivalent carboxylic acids takes place by means of catalysts. In order that the catalyst features the lowest possible content of catalytically active metal compound, the carrier substance that forms the heterogeneous phase comprises particles of the finest grain and of porous structure and features a surface of great inner, reactive and/or coordinated centers, whereby a catalytically active metal compound is adsorbed in the pores.

Abstract: This invention is related to a process for preparing polyester polymers using a composite catalyst comprises the steps of 1) esterifying naphthalene dicarboxylic acid or a dicarboxylic acids containing NDCA or ester derivatives thereof, with ethylene glycol or glycols containing ethylene glycol or derivatives thereof to produce esterified compounds or its low molecular weight polymers; and then 2) continuously polycondensing the obtained esterification product to produce polyester polymers; and wherein the process includes using a composite polymerization catalyst which was prepared by reacting titanium compounds and cobalt compounds in the solution containing at least one alcohol. The process yields high quality polyester polymers having a good color and excellent physical properties. The process can considerably reduce both the esterification time and the polycondensation time.

Abstract: The present invention provides novel hydrogel-forming, self-solvating, absorbable polyester copolymers capable of selective, segmental association into compliant hydrogels upon contacting an aqueous environment. Methods of using the novel polyester copolymers of the invention in humans are also disclosed for providing a protective barrier to prevent post-surgical adhesion, treatment of defects in conduits such as blood vessels, and controlled release of a biologically active agent for modulating cellular events such as wound healing and tissue regeneration or therapeutic treatment of diseases such as infection of the periodontium, dry socket, bone, skin, vaginal, and nail infections.

Abstract: An aromatic group containing copolyester resin composition which has good biodegradability and physical properties, wherein; (i) 0.1 wt % to 30 wt % of an aliphatic prepolymers having number average molecular weight of from 300 to 30,000; (ii) one or a plurality of aromatic dicarboxylic acid (or an acid anhydride thereof which containing aromatic group in the molecule; (iii) one or a plurality of aliphatic (including cyclic type) dicarboxylic acid (or an acid anhydride thereof); and (iv) one or a plurality of aliphatic (including cyclic type) glycol, wherein the copolyester resin has number average molecular weight of from 30,000 to 90,000, weight average molecular weight of from 100,000 to 600,000, melting point of from 70° C. to 150° C., and melt index of from 0.1 to 50 g/10min. (190° C., 2,160 g), and the process for preparing and/or producing the same.

Abstract: The present invention relates to a manufacturing method for decreasing the cyclic oligomer content in polyester which effectively restrains the production of the cyclic oligomer in ester chips and further decreases the amount of regenerated cyclic oligomer at the melting process stage by adding the additive, during the process of manufacturing polyethylene terephthalate, with the following structure:

Abstract: A method of producing an aliphatic polyester, including polycondensing an aliphatic diol and an aliphatic dicarboxylic acid compound, or a prepolymer thereof in the presence of a metal-containing ester interchange catalyst and a phosphorus-containing co-catalyst such as an ammonium, calcium or magnesium salt of hydrogen-containing phosphoric acid or an organic phosphinic acid. An oxycarboxylic acid compound or its prepolymer may also be used as a raw material.

Abstract: This invention relates to a method for manufacturing polyesters, in particular, to using a lithium titanyl oxalate as the catalyst for such reaction to provide fast reactions with excellent color properties for the resulting polyester. The present invention provides an improved method of producing polyester by the polycondensation of polyester forming reactants wherein the improvement comprises utilizing, as the polycondensation catalyst, lithium titanyl oxalate. The improved process produces a polyester of improved color versus other titanyl oxalate catalysts and a novel polyester without the presence of antimony.

Abstract: This invention relates to a method for manufacturing polyesters, in particular, to using a lithium titanyl oxalate as the catalyst for such reaction to provide fast reactions with excellent color properties for the resulting polyester. The present invention provides an improved method of producing polyester by the polycondensation of polyester forming reactants wherein the improvement comprises utilizing, as the polycondensation catalyst, lithium titanyl oxalate. The improved process produces a polyester of improved color versus other titanyl oxalate catalysts and a novel polyester without the presence of antimony.

Abstract: The present invention is based upon the discovery that nontitanyl oxalates can enhance the catalytic functionality of titanyl oxalate catalysts. This invention provides a novel catalytic composition containing a titanyl oxalate catalyst and a metallic oxalate catalyst enhancer and optionally containing a metallic cocatalyst such as an antimony based catalyst. A synergistic relationship has been discovered between titanyl oxalate catalyst and the catalyst enhancer. A synergistic relationship has also been discovered between the titanyl oxalate catalyst, catalyst enhancer and a metallic cocatalyst such as antimony oxide or antimony triacetate.

Abstract: The invention relates to a process for the preparation of polyesters of a glycol and a dicarboxylic acid which comprises the following steps:

Abstract: For the production of polyesters and copolyesters, coprecipitates are used individually or in a mixture as polycondensation catalysts, the coprecipitates being prepared by simultaneous hydrolytic precipitation of a titanium compound and a metallic compound of a metal selected from the groups IA, IIA, VIIIA, IB, IIB, IIIB, and IVB, whereby the titanium compound and the metallic compound are, independently of one another, an alkylate, alcoholate, or carboxylate of titanium or the metal, respectively, and the molar ratio of the titanium compound to the metallic compound is ≧50:50 mol/mol. The coprecipitates exhibit a higher catalytic activity than Sb2O3 which results in a prefered amount of usage of only 10 to 100 ppm with respect to the esters or oligoesters to undergo polycondensation.

Abstract: The present invention provides a method for preparing polypropylene terephthalate/polyethylene terephthalate (PPT/PET) copolyester, which comprises a group of processes from (a) to (e). Process (a) comprises subjecting bis-2-hydroxyethyl terephthalate (BHET), pure terephthalic acid (PTA) and 1,3-propanediol (1,3-PDO) to undergo esterification reaction to produce BHET and bis-2-hydroxypropyl terephthalate (BHPT), and then subjecting BHET and BHPT to undergo copolymerization reaction. Process (b) comprises subjecting PTA and 1,3-PDO to undergo esterification reaction to produce BHPT, adding BHET, and then subjecting BHET and BHPT to undergo copolymerization reaction. Process (c) comprises subjecting BHET and BEPT to undergo copolymerization reaction. Process (d) comprises subjecting PTA, ethylene glycol (EG) and 1,3-PDO to undergo esterification reaction to produce BHET and BHPT, and then subjecting BHET and BHPT to undergo copolymerization reaction.

Abstract: The present invention is based upon the discovery that nontitanyl oxalates can enhance the catalytic functionality of titanyl oxalate catalysts. This invention provides a novel catalytic composition containing a titanyl oxalate catalyst and a metallic oxalate catalyst enhancer and optionally containing a metallic cocatalyst such as an antimony based catalyst. A synergistic relationship has been discovered between titanyl oxalate catalyst and the catalyst enhancer. A synergistic relationship has also been discovered between the titanyl oxalate catalyst, catalyst enhancer and a metallic cocatalyst such as antimony oxide or antimony triacetate.

Abstract: A process for preparing polytrimethylene terephthalate in which a carbonyl-containing 1,3-propanediol stream is purified for reuse of the 1,3-propanediol. The process involves reacting, under condensation polymerization conditions, terephthalic acid and a molar excess of 1,3-propanediol, with vacuum distillation and condensation of a major portion of the unreacted 1,3-propanediol. To this condensed stream is added a sufficient amount of base to raise the pH to a value greater than 7, and from this base-containing condensate the 1,3-propanediol is distilled and recycled to the polymerization reaction.

Abstract: A polyethylene-2,6-naphthalene dicarboxylate resin contains an antimony compound as a polycondensation catalyst, and has an intrinsic viscosity of 0.55 to 0.75 dl/g, a terminal carboxyl group content of 32 eq/ton or less, an acetaldehyde content of 8 ppm or less and a diethylene glycol component content of 0.8 to 3.0 wt %. A preform and a bottle made of the resin are also described.

Abstract: A polyalkylene naphthalate for a film, which comprises a naphthalenedicarboxylic acid component as a main dicarboxylic acid component and an aliphatic glycol component as a main glycol component, and contains (a) an antimony compound and (b) a quaternary phosphonium sulfonate compound unit having an ester-forming functional group in such amounts that satisfy the following expressions (1) and (2): 0<Sb≦80  (1) 0<S/Sb≦0.4  (2) wherein Sb and S are the molar ratios (mmol %) of the antimony compound and the quaternary phosphonium sulfonate compound unit having an ester-forming functional group to the total of all the dicarboxylic acid components forming the polyalkylene naphthalate, respectively. The film of the present invention has excellent surface flatness and is suitable for use as a base film for a magnetic recording medium. It is also excellent in high-speed winding properties and can be formed into a film stably and produced industrially advantageously.

Abstract: An improved process for Polytetramethylene-Ether-Glycol-Diesters of the formula R—CO—O(CH2—CH2—CH2—CH2—O)n-COR1, in which R and R1 are identical or different and are alkyl radicals or derivatives thereof, by polymerization of tetrahydrofuran in the presence of a heterogeneous polymerization catalyst and in the presence of a carboxylic anhydride. The use of aluminum silicate catalyst composed of acid-activated and calcinated natural halloysite instead of the known catalytic silicates as bentonite, zeolite or kaolinite. The new catalyst with a very long lifetime produces polymers having more uniform properties and narrow molecular weight distribution even with a relative impure monomer.