Abstract: The invention relates to amorphous and crystalline fibers, particularly binder fibers, made from polyesters and the polyesters themselves. The polyesters of the invention are generally formed from a glycol component, such as a five carbon glycol, and a dicarboxylic acid component. The polyesters may be formed into a variety of products, for example fibers, composites and other molded articles. Preferably the polyesters are binder fibers for nonwovens, textile and industrial yarns and fabrics.

Abstract: The invention relates to fibers, particularly binder fibers, made from copolyesters and the copolyesters themselves. The copolyesters of the invention are generally formed from 1,3- or 1,4-cyclohexanedimethanol, ethylene glycol and isophthalic acid or esters thereof and at least one dicarboxylic acid selected from terephthalic acid, naphthalenedicarboxylic acid, 1,3- or 1,4-cyclohexanedicarboxylic acid or esters thereof. Such copolyesters may be formed into a variety of products, especially binder fibers for nonwoven fabrics, textile and industrial yarns, and composites.

Abstract: A biodegradable polyester is formed by carrying out esterification and polycondensation with a carboxylic acid monomer group comprising at least one aliphatic dicarboxylic acid containing 2 to 14 carbon atoms and at least one aromatic or alicyclic carboxylic acid, and at least one glycol in the presence of a composite catalyst comprising a titanium compound, a zinc compound, an antimony compound and a phosphorous compound. The composite catalyst significantly improves the reaction rate of polyester polymerization as well as increases the production amounts of the polyester, as compared with conventional catalysts. The polyester is high in molecular weight, excellent in thermal and mechanical properties by virtue of the introduction of the aromatic or alicyclic carboxylic acid or its derivative, in addition to showing good biodegradability. This polyester can replace preexisting, expensive aliphatic polyesters.

Abstract: A polyester resin comprising a polyester resin chip (A) and a polyester resin fine particle (B) which has the same composition as the (A) and which passes through a 10.5 mesh screen in a proportion of 0.1-300 ppm, wherein a cyclic trimer increases in a proportion of not more than 0.30 wt % upon melting at a temperature of 290.degree. C. for 60 minutes; a polyester resin characterized in that a cyclic trimer increases in a proportion of not more than 0.30 wt % upon melting at a temperature of 290.degree. C. for 60 minutes, and the contents of Na, Ca, Mg and/or Si in the polyeser resin is 0.001-5 ppm and the total of these contents is not more than 10 ppm; and production methods thereof.

Abstract: An organic oligomer binder produced by depolymerizing virgin, scrap, recycled or reclaimed polyethylene terephthalate via an alcoholysis reaction with branched glycols and esterifiing the resulting polyol oligomer with polybasic carboxylic acids and/or anhydrides.

Abstract: A branched radial block copolymer including the reaction product of a dendritic macromolecular initiator, and one or more chain extending monomers.

Abstract: A catalyst composition is disclosed. The composition comprises a titanium compound, a complexing agent, a solvent, and optionally a cocatalyst. The cocatalyst can be a cobalt/aluminum catalyst, an antimony compound, or combinations thereof. Also disclosed is a process for producing the composition. The process comprises combining a titanium compound, a complexing agent, a solvent, and optionally a cocatalyst. Further disclosed is a process for using the composition which comprises contacting a carbonyl compound, in the presence of the composition, with an alcohol under a condition suitable for esterification, transesterification, polymerization, or combinations thereof.

Abstract: The invention provides a process that can be used for producing a bis-glycolate ester of 5-sulfo isophthalate metal salt. The process comprises contacting a 5-sulfo isophthalate a metal salt or a dialkyl ester of 5-sulfo isophthalate metal salt, in the presence of a catalyst, with a glycol. The catalyst comprises (1) a titanium compound, a solubility promoter, a phosphorus source, and optionally a solvent, (2) a titanium compound, a complexing agent, a phosphorus source, and optionally a solvent, a sulfonic acid, or combinations thereof, or (3) combinations of (1) and (2). The solubility promoter can be selected from the group consisting of ortho silicates, ortho zirconates and combinations thereof. The phosphorus source is selected from the group consisting of a phosphonic acid, a phosphinic acid, a phosphine, and combinations of two or more thereof. The complexing agent can be selected from the group consisting of hydroxycarboxylic acids, aminocarboxylic acids, and combinations thereof.

Abstract: A catalyst composition is disclosed. The composition comprises a titanium compound, a phosphorus compound, an amine, a solvent and optionally a cocatalyst in which the phosphorus compound has a formula selected from the group consisting of (R.sup.1 O).sub.x (PO)(OH).sub.3-x, (R.sup.1 O).sub.y (P.sub.2 O.sub.3)(OH).sub.4-y, and combinations thereof; the amine is a tertiary amine; each R.sup.1 is independently a linear or branched alkyl radical containing from 1 to about 20 carbon atoms per radical; x is 1 or 2; and y is 1, 2, or 3; and the cocatalyst can be a cobalt/aluminum catalyst, an antimony compound, or combinations thereof. Also disclosed is a process for producing the composition. The process comprises combining a titanium compound, a phosphorus compound, a solvent, an amine, a solvent, and optionally a cocatalyst. The phosphorus compound, amie, and solvent are the same as those disclosed above.

Abstract: A method for producing polybutylene terephthalate comprising continuously esterifying a dicarboxylic acid component consisting essentially of terephthalic acid with a diol component consisting essentially of 1,4-butanediol followed by polycondensing the resulting oligomer, wherein the esterification is effected in a molar ratio, P, of the diol component to the dicarboxylic acid component to fall between 1.1 and 1.6, in the presence of a combination of an organic titanium compound and an organic tin compound that satisfies the following requirement:amount of organic titanium compound (mol %).ltoreq.0.08.times.P-0.07where P=molar ratio of diol component to dicarboxylic acid component, and is followed by the polycondensation.

Abstract: Polyesters are prepared by the reaction of a dicarboxylic acid, preferably an aromatic acid such as terephthalic acid, or an ester or ester-forming derivative thereof with a dihydroxy compound such as 1,4-butanediol in the presence of a catalyst composition comprising the combination of a titanium-based compound such as tetra-n-butyl titanate, a zirconium-based compound such as zirconium tetrakis(2,4-pentanedionate) and a phosphate-forming compound such as sodium dihydrogen phosphate. This catalyst composition affords polyesters having relatively low melt viscosities in short reaction times and does not produce an excessive level of undesirable reaction by-products.

Abstract: A process for preparing polyethylene naphthalate polymer by using a composite catalyst. The process comprises the steps of esterifying a dicarboxylic acid containing 2,6-NDCA, a dicarboxylic ester containing 2,6-NDC or derivatives thereof, with ethylene glycol or a glycol containing ethylene glycol to produce esterification polymers containing bis(beta-hydroxyethyl)naphthalate; continuously polycondensing the obtained esterification polymers to prepare a polymers of polyethylene naphthalate; and wherein the process includes using a composite polymerization catalyst, said composite polymerization catalyst comprising a titanium compound, a phosphorous compound and optionally an antimony compound. The process can considerably reduce both the esterification time and the polycondensation time and provides a good color and excellent physical characteristics.

Abstract: The invention provides non-antimony containing polymerization catalysts for the condensation of polyesters. The catalyst is in the form of a clear chlorine and/or bromine containing solution of a metal glycoxide and a metal glycolate having a pH in the range of from 0 to about 1, and containing chlorine and/or bromine atoms at a number ratio of chlorine and/or bromine to total metal cations in the catalyst ranging from about 0.5:1 to about 3:1. Polyesters produced with this catalyst have improved melt elasticity, and higher melt viscosity. The former property is desirable for the preparation of large and complex shaped polyester containers, and the latter property is desirable for melt spinning of industrial grade fibers and tire cords.

Abstract: A process which can be used in oligomerization, polymerization, or depolymerization such as, for example, the production of a polyester is provided. The process comprises contacting a carbonyl compound, in the presence of a composition, with an alcohol. The catalyst comprises a catalyst having the formula of M.sub.x Ti.sup.(III) Ti.sup.(IV).sub.y O.sub.(x+3+4y)/2 wherein M is an alkali metal, Ti.sup.(III) is titanium in the +3 oxidation state, Ti.sup.(IV) is titanium in the +4 oxidation state, x and y are numbers greater than or equal to zero wherein if x equals zero, y is a number less than 1/2.

Abstract: The present invention relates to a polyester polymerization catalyst, comprising a solution containing an aluminum compound and an alkali compound, with water or an organic solvent or a mixture consisting of water and an organic solvent as the medium, a production method thereof, and a polyester production method, in which the product obtained by the esterification reaction or ester interchange reaction between an aromatic dicarboxylic acid or any of its ester forming derivative and a diol is polycondensed, to produce a polyester, comprising the use of said polymerization catalyst containing an aluminum compound.The present invention can provide a polyester excellent in processability and can overcome such problems as spinneret contamination, filtration pressure rise, filament breaking, film breaking and foreign matter production in the production process of products such as fibers, films, resins and bottles.

Abstract: A poly(ethylene terephthalate) polyester composition which is decreased in the amount of a cyclic trimer of ethylene terephthalate formed in melting, and a method for producing the same.

Abstract: The invention relates to a process for producing polyesters, especially high-molecular polyethylene terephthalate (PET) using titanium-containing catalyst-inhibitor combinations.

Abstract: Degradable polyesters useful in packaging, packing, agricultural, biomedical, and other applications are made by reacting amine-protected glutamic acid with diols or epoxy compounds. The polyesters include a thermoplastic main chain aliphatic polyester, a thermoset heterochain polyester and a thermoset heterochain aromatic polyester. Each of these polyesters can be hydrolyzed into monomers using a biological catalyst such as the enzyme lipase. The thermoplastic main chain aliphatic polyester and the thermoset heterochain polyester can be degraded to respiratory gases and biomass with a mixed culture of Rhizopus, chinesis, Rhizopus delemar, Penecillium pinophilum, Aspergillus niger and Pseudomonas aeruginosa microorganisms. This mixed culture of microorganisms can also be used to degrade other polyesters containing hydrolyzable backbone polyesters.

Abstract: A moldable linear polyester resin consisting essentially of a polyester having the formula: ##STR1## where R is an alkyl from 1 to 6 carbon atoms and n is greater than about 70, said polyester resin being derived from the transesterification reaction of a starting DMCD and a starting CHDM wherein the trans-cis ratio of repeating units derived from DMCD is preferably greater than about 8 to 1, and the trans-cis ratio of repeating units derived from DMCD is preferable greater than about 1 to 1, said polyester resin having crystalline properties with a preferable viscosity greater than 4500 poise and a melting temperature greater than 216 degrees Centigrade.

Abstract: Poly(alkylene arylates) having excellent optical properties are disclosed and can be prepared using an organic titanate-ligand catalyst solution containing organic silicates and/or zirconates and, preferably, certain phosphorus compounds.

Abstract: The present invention provides processes for preparing polyesters. The processes include (a) providing a polymerization medium comprising carbon dioxide, (b) contacting a monomer capable of forming a polyester polymer with the polymerization medium, and (c) polymerizing the monomer in the polymerization medium. The processes of the present invention include preparing polyesters by direct esterification polymerization, transesterification polymerization, melt acidolysis polymerization and acid halide polymerization. As a further aspect, the present invention provides a method of separating the polyester produced from the polymerization medium. Polyester polymers prepared according to the methods of the present invention are also provided.

Abstract: A novel process to produce polyethylene terephthalate (PET) using a specific catalyst stabilizer system is described. The catalyst stabilizer system is specific for producing PET wherein the polycondensation catalyst is a titanium and the stabilizer possesses an irreversible oxidation potential of at least +2.0 volts versus SCE. The novel process results in PET having acceptable color and low acetaldehyde content.

Abstract: The subject is a class of catalyzers to be used in the stage of polycondensation of the synthesis of poly(ethylene terephtalate), consisting of metal and non-metal derivatives in composition with sulfonic acids mixed with titanium compounds so that the final polymer contains a sulfur quantity of 5-60 ppm and a quantity of metals between 2 and 100 ppm.

Abstract: A catalyst composition for use in the preparation of a polyester or copolyester is disclosed. The catalyst composition comprises the combination of (a) a titanium-based compound or zirconium-based compound, and (b) a lanthanide series compound or hafnium. Various titanium-based compounds and lanthanide-based compounds are described. Moreover, in some embodiments, the catalyst composition may further comprise a phosphate-forming compound. Another aspect of this invention is an improved method for preparing a polyester, based, for example, on the two-stage process of ester interchange and polycondensation. The method is carried out in the presence of the catalyst composition described above.

Abstract: A continuous process for producing polyethylene terephthalate polyester from terephthalic acid and ethylene glycol uses a stabilizer, preferably containing phosphorous, to produce a high quality polyethylene terephthalate polyester which is relatively free of the acetaldehyde and discoloration which are associated with the post-polymerization activity of a polymerization catalyst. The stabilizer is preferably added at or after the end of the polymerization reaction prior to polymer processing to deactivate the polymerization catalyst and can increase the throughput of the polyester without adversely affecting the thermal stability of the polyethylene terephthalate polyester. Alternatively, the late addition of the stabilizer can increase the thermal stability of the polyester without adversely affecting the throughput of the polyethylene terephthalate polyester.

Abstract: A soluble mono-alkyl Stannoic Acid/glycol liquid phase catalyst produced from the reaction of a mono-alkyl Stannoic Acid and a glycol at a temperature of from at least 180.degree. C., and its use in preparing high molecular weight polyester polymers.

Abstract: This invention relates to a process of producing a moldable polyethylene terephthalate or modified polyethylene terephthalate having an inherent viscosity greater than 0.6 dL/g comprising reacting the diacid component with the diol component such that a combination of a titanium-based catalyst and a phosphorus-based catalyst is used during the polycondensation steps.

Abstract: A process for producing an aliphatic polyester carbonate which comprises reacting (1) an aliphatic dicarboxylic acid compound containing succinic acid as a main component, (2) an aliphatic dihydroxy compound containing 1,4-butanediol as a main component, and (3) (a) a polyhydric alcohol having 3 or more hydroxyl groups in a molecule, (b) a polybasic carboxylic acid compound having 3 or more carboxyl groups in a molecule, or (c) a polybasic carboxylic acid having one or more hydroxyl groups in a molecule to obtain an aliphatic polyester oligomer and reacting the obtained aliphatic polyester oligomer and a carbonate compound, wherein the aliphatic polyester carbonate has a melt tension of 1.5 g or more at 190.degree. C.

Abstract: The present invention provides a novel poly(1,3-propylene terephthalate), which is prepared from reacting terephthalic acid and 1,3-propanediol in the presence of an effective catalytic amount of ethylene glycol titanate to undergo esterification to form a monomer; and polymerizing the monomer in the presence of an effective catalytic amount of antimony acetate to obtain poly(1,3-propylene terephthalate). The obtained poly(1,3-propylene terephthalate) (PPT) has an intrinsic viscosity (IV) of 0.65-0.91 dl/g, acid number (--COOH amount) of less than 40 meq/kg, and L*>60. Without adding a pigment, the yellowness b* of PPT is below 9, even below 5. The yellowness b* of PPT even reaches below 3 when a pigment is incorporated.

Abstract: The invention comprises a method for synthesizing polyethylene terephthalate from waste polyethylene terephthalate by cleavage with ethylene glycol and separation of bis(hydroxyethylene) terephthalate from the cleavage mixture with a specific temperature program, recrystallization from water, and esterification and polycondensation with the addition of terephthalic acid.The invention further comprises a method for synthesis of polyethylene naphthalate from waste polyethylene naphthalate in a similar manner.

Abstract: A polyester comprises a dicarboxylic acid moiety comprising terephthalic acid or its ester forming derivative and a diol moiety comprising ethylene glycol and 1,4-cyclohexanedimethanol of 10 to 60 mol % based on the whole diol moiety, the intrinsic viscosity of the polyester being 0.68 to 0.95 dl/g, the "b" value of color tone of the produced pellets of polyester being -5 to 5, the number of the carboxylic acid terminals being not more than 30 eq/ton, and the sum of the numbers of the vinyl terminals, the vinylidene terminals and the methylcyclohexene terminals being not more than 25 eq/ton.

Abstract: An atmospheric pressure process for the continuous production of polyester is disclosed wherein a melt of bis(3-hydroxy propyl) terephthalate, or its low molecular oligomers, obtained by esterifying terephthalic acid or transesterifying dimethyl terephthalate with propylene glycol, is intimately contacted with an inert gas to facilitate polymerization and removal of the reaction by-products. The propylene glycol evolved and the inert gas are recycled.

Abstract: New compounds including bis-.beta.-hydroxy ethyl bibenzoate containing less than 2.5%, and preferably less than 1%, diethylene glycol and a process for the production of the bis-.beta.-hydroxy ethyl bibenzoate by the condensation of 4,4'-biphenyl dicarboxylic acid and ethylene glycol at low temperature and pressure in the presence of a catalyst are disclosed. Use of the compounds to produce polyesters is also disclosed.

Abstract: Water-soluble or water-dispersible and curable polyester resins are suitable as binders in various applications. The resins are reaction products of polyterephthalate, sulfoisophthalates, polyols, polyacids, end acids and crosslinker agents. Waste terephthalates can be utilized. The preferred polyol is pentaerythritol. The resins can also be used as dye levelling agents when dyeing synthetic fibers.

Abstract: New polyester composition for new polyester staple fiber that provides fabrics having a combination of excellent pilling performance, aesthetics and tactility ("hand"). Preferred fibers have non-round cross-sections that are retained, especially such non-round cross-sections having multi-grooved scalloped-oval cross-sections that provide fabrics having outstanding comfort qualities of moisture-management, dryness and comfort, along with minimal pilling.

Abstract: This invention is directed to an improved process for producing a polyester oligomer. The process employs a pipeline reactor, having at least two stages, in which the degree of polymerization of an oligomeric feed material is raised from about 2-10 to about 2-40 and the ratio of carboxyl to hydroxyl end groups in the product is reduced. In a first stage of the process, a monomeric diol or polyol, such as ethylene glycol, is added to a melt of the oligomeric feed material. In a second stage of the process, the molecular weight of the oligomer is increased by removal of volatile reaction by-products, including water and polyol. The oligomer produced by the present invention may be used in making higher molecular weight polyesters.

Abstract: In the production of polyethylene naphthalate of the present invention, the esterification reaction between naphthalenedicarboxylic acid and ethylene glycol is conducted while causing water to be present in a reaction system from a start of reaction, in the presence of at least one catalyst selected from the group consisting of nitric, carboxylic, phosphoric and hydrogenphosphoric acid metal salts and alkyl amines according to necessity, to thereby attain an esterification ratio of 45 to 80%, so that a liquid mixture of naphthalenedicarboxylic acid esterification reaction products containing naphthalenedicarboxylic acid, carboxyl-hydroxyethoxycarbonylnaphthalene and bis(hydroxyethoxycarbonyl)naphthalene is obtained. Subsequently, a crystallized reaction product is separated from this liquid mixture to thereby obtain a mixture of esterification reaction products. Thereafter, this mixture having ethylene glycol added thereto according to necessity is subjected to polycondensation.

Abstract: The present invention provides a method of synthesizing polypropylene terephthalate with no more than 5 ppm acrolein and no more than 3 ppm allyl alcohol. The method comprises direct esterification of terephthalic acid with 1,3-propanediol in the presence of 30 to 200 ppm titanium in the form of an inorganic esterification catalyst containing at least 50 mol % TiO.sub.2 precipitate, blocking the esterification catalyst after esterification by adding 10 to 100 ppm phosphorus in the form of a phosphorus-oxygen compound, and then performing precondensation and polycondensation in the presence of 100 to 300 ppm antimony in the form of a conventional antimony polycondensation catalyst and optional conventional coloring agent.

Abstract: The preparation of polyesters and copolyesters, titanium dioxide precipitates and/or titanium dioxide/silicon dioxide coprecipitates having a composition of TiO.sub.2 :SiO.sub.2 >90:10 mol/mol and/or titanium dioxide/zirconium dioxide coprecipitates having a composition of TiO.sub.2 :ZrO.sub.2 >95:5 mol/mol, which have been obtained by hydrolytic precipitation of the corresponding metal alcoholates formed from mono- or polyhydric alcohols, are proposed as polycondensation catalysts. They offer increased safety for the ecosystem and have a higher catalytic activity than Sb.sub.2 O.sub.3, so that the preferred amount used is only 10 to 100 ppm, based on the esters or oligoesters to be subjected to polycondensation. Their storage stability is good if the catalysts have a water content of from 0 to about 15 weight percent, preferably from 0 to about 5 weight percent based upon the hydrated precipitate or coprecipitate, as determined by Karl Fischer titration.

Abstract: Provided are a polyester resin for use in a toner binder which is excellent in terms of offset resistance and low-temperature fixability, which keeps triboelectric charge stability even in an environment of a high temperature and a high humidity, which has excellent durability, and which is used in a toner that gives vivid image characteristics, a process for producing the same, and a toner using the same. The polyester resin for use in the toner binder is formed by linking at least a part of the crosslinked low-molecular polyesters through a dicarboxylic acid used as a linking agent.

Abstract: Disclosed is a radiation crosslinkable water-dispersible adhesive composition that is useful in forming paper and plastic articles and other products that can be recycled through a process which includes washing or repulping in aqueous media. The cross-linkable water-dispersible adhesive composition is preferably used as a hot melt adhesive. The cross-linkable water-dispersible adhesive composition is a low molecular weight, branched copolyester containing a sulfomonomer and unsaturated moieties. The radiation crosslinked adhesive composition has more cohesive strength and viscosity than its corresponding uncross-linked adhesive, yet is still water-dispersible during product recycling.

Abstract: A process to prepare a high molecular weight aliphatic polyester is disclosed, where a catalyst is portionwise added, and a radical scavenger is also added. The aliphatic polyester obtained has a number average molecular weight larger than 70,000.

Abstract: Oxysulfonylated polyesters, well suited for conversion into oriented composite polyester films, are prepared by polycondensing a lower alkyl diester of at least one aliphatic dicarboxylic acid and a lower alkyl diester of at least one aromatic dicarboxylic acid bearing an oxysulfonyl substituent, and optionally a lower alkyl diester of at least one aromatic dicarboxylic acid, with at least one diol, in the presence of a catalytically effective amount of at least one titanium compound and at least one manganese carboxylate.

Abstract: A method for preparing polyester by use of a catalyst. The method comprises the steps of: esterifying either a terephthalic acid, a dicarboxylic acid containing terephthalic acid or derivatives thereof with either ethylene glycol or a glycol containing ethylene glycol, or derivatives thereof to produce an esterification product containing either bis(.beta.-hydroxyethyl) terephthalate, its low molecular weight polymer, or a combination of .beta.-hydroxyethyl terephthalate and its low molecular weight polymer; and continuously polycondensing the obtained esterification product to prepare a polyester, wherein in the said polycondensing step, a composite polymerization catalyst dissolved in an ethylene glycol or an ethylene glycol-containing solution, consisting of a compound of antimony, a compound of titanium, and a compound of tin is used.

Abstract: An improved clarity copolyester of a diethylene glycol modified poly(ethylene terephthalate) has a b* value of less than 15, preferably less than 10. The copolyester composition has an inherent viscosity of about 0.4 to 1.0 dL/g and comprises (A) 100 mol percent dicarboxylic acid residue component, (B) 100 mol percent diol residue component, (C) catalyst residues and (D) color control agent residues. The dicarboxylic acid residue component comprises at least 75 mol percent of terephthalic acid residues. The diol residue component comprises 10 to 50 mol percent diethylene glycol residue and 50 to 90 mol percent ethylene glycol residue. The catalyst residues comprise 20 to 100 ppm manganese, 50 to 300 ppm antimony, 0 to 100 ppm titanium and 40 to 150 ppm phosphorus, based on the weight of the copolyester.

Abstract: This invention relates to a three step process for preparing copolyesters exhibiting a neutral hue, high clarity and increased brightness. The process involves reacting terephthalic acid, ethylene glycol, and 1,4-cyclohexanedimethanol in a feed mole ratio of total glycols to dicarboxylic acid of 1.7:1 to 6.0:1, at a temperature of 240.degree. C. to 280.degree. C., and a pressure of 15 psig to 80 psig to form an esterification product; adding a polycondensation catalyst and a toner; and polycondensing the product at a temperature of 260.degree. C. to 290.degree. C. and a reduced pressure to form a high molecular weight copolyester.

Abstract: A method for preparing rapidly crystallized polyesters from macrocyclic polyester oligomers comprising the step of contacting macrocyclic polyester oligomers, polymerization catalysts and nucleating agents.

Abstract: Macrocyclic polyester oligomer compositions are polymerized to high molecular weight polyesters by heating with a titanate ester composition comprising moieties having oxygen or nitrogen chelated with a titanium atom or having two titanium atom connected by alkylene ester units. Depending on the chemical nature of the initiator, the polymerization reaction may be extremely rapid as desired for structural reaction injection molding, or may have an induction period as desired for resin transfer molding.

Abstract: The present invention comprises a new catalyst for the production of polyesters consisting essentially of a finely dispersed, large surface area titanium compound selected from hydrated TiO.sub.2 obtained by hydrolysis and having the composition yTiO.sub.2.zH.sub.2 O and from titanates having the composition (Me.sub.n O).sub.x.(TiO.sub.2).sub.y.(H.sub.2 O).sub.z, wherein Me is an alkaline earth metal or alkali metal. In addition, the present method comprises a process for the production of polyesters using this catalyst as an esterification or transesterification catalyst and as a polycondensation catalyst, whereby a phosphorous-oxygen-compound is added immediately before, during, or after the polycondensation.

Abstract: Provided are an aliphatic polyester carbonate having biodegradability and having a content of carbonate unit of at least 5 mol %, a weight-average molecular weight of at least 100,000, a melt viscosity of 2,000-50,000 poises at 190.degree. C. and under a load of 60 kg and a melting point of 70.degree.-180.degree. C., and a process for producing said aliphatic polyester carbonate which comprises reacting an aliphatic dihydroxy compound with an aliphatic dibasic acid in the presence of an ester exchange catalyst to obtain an oligomer and then reacting the oligomer with a diaryl carbonate in the presence of the ester exchange catalyst. A phosphorus compound may be added to the aliphatic polyester carbonate for the purpose of stabilization.