Abstract: A problem of the invention is to provide polyethylene terephthalate, a molded article of which has low acetaldehyde content and oligomer content. The problem of the invention can be solved by a manufacturing method of polyethylene terephthalate including a step of carrying out melt polycondensation by using a compound represented by the following general formula (I) as a polycondensation catalyst to obtain melt polycondensed polyethylene terephthalate having an intrinsic viscosity of from 0.48 to 0.53 dL/g and a terminal carboxyl number of from 14 to 22 mmol/kg; and a step of further solid phase polycondensing the melt polycondensed polyethylene terephthalate to obtain solid phase polycondensed polyethylene terephthalate having an intrinsic viscosity of from 0.70 to 0.86 dL/g. [In the foregoing general formula (I), R1 represents an alkyl group having from 2 to 12 carbon atoms.

Abstract: Processes for making elastomeric polyether esters from polyesters and polyols are provided. The processes can offer a reduction in manufacturing cost, energy use and a lower environmental footprint than conventional processes, particularly when the processes utilize post-consumer polyesters as starting materials.

Abstract: There is now provided a polyester polymer particle having an It.V., a surface, and a center, wherein the It.V. at the surface of the particle is less than 0.25 dL/g higher than the It.V. at the center of the particle. The polyester polymer particle is desirably crystalline to prevent the particles from sticking to each other while drying, and desirably contains less than 10 ppm acetaldehyde. A polyester container, preferably a preform or beverage bottle, is made by feeding crystallized polyester particles having an It.V. of at least 0.70 dL/g to an extrusion zone, melting the particles in the extrusion zone to form a molten polyester polymer composition, and forming a sheet or a molded part from extruded molten polyester polymer, wherein at least a portion of the polyester particles have an It.V. at their surface which does not vary from their It.V. at their center by more than 0.25 dL/g, and the particles have not been solid state polymerized. Such polyester compositions have an It.V.

Abstract: This invention relates to a continuous process for production of poly(trimethylene terephthalate), wherein gaseous 1,3-propanediol by product resulting from the process is condensed in a condenser, and a portion of the condensed by-product is recycled back into the process.

Abstract: A structure containing polyhydroxyalkanoate and a magnetic substance includes an external phase part containing polyhydroxyalkanoate and an internal phase part contained in the external phase part, at least one of the external phase part and the internal phase part containing a magnetic substance. Accordingly, provided is a microcapsule, which can be suitably used for formation of an active ingredient of a sustained release pharmaceutical preparation or an ultrasonic contrast agent.

Abstract: The present invention is a method for efficiently incorporating a nitrogen containing methine light absorber into a polyester resin. The method includes forming a reaction mixture comprising combining a diol component, a diacid component selected from the group consisting of dicarboxylic acids, dicarboxylic acid derivatives, and mixtures thereof, an antimony containing compound, a phosphorus containing compound, a metal containing compound, and a nitrogen containing methine light absorber. The reaction mixture is polymerized in a polycondensation reaction system. In another embodiment the light absorber is added while the reaction products of one reactor are being transferred to the next reactor in the polycondensation reaction system. The present invention is also directed articles made from the polyester resin.

Abstract: This invention relates to a continuous process for production of poly(trimethylene terephthalate), wherein gaseous 1,3-propanediol by-product resulting from the process is condensed in a condenser, the total amount of any trimethylene terephthalate cyclic dimer and poly(trimethylene terephthalate) in the condensed by-product 1,3-propanediol is adjusted, and a portion of the condensed by-product is recycled to the condenser while another portion is recycled back into the process.

Abstract: The invention provides: a polycondensation catalyst for polyester production, which contains titanium atoms, alkaline earth metal atoms and phosphorus atoms, has high reactivity and excellent long-term storage stability, can be easily produced industrially, and has an advantage in cost; a polyester resin obtained with the catalyst; and a molded article. These are: a polymerization catalyst for polyester production containing titanium atoms, alkaline earth metal atoms and phosphorus atoms and having a specific constitution; a polyester resin obtained with the catalyst; and a molded article.

Abstract: An object of the present invention is to provide an environmentally friendly polymerization catalyst of polyalkylene terephthalate which does not use a heavy metal such as antimony. Another object of the present invention is to provide the method of producing polyalkylene terephthalate using the catalyst. The inventive titanium oxide sol for a catalyst for polymerizing a polyalkylene terephthalate is a titanium oxide sol containing an organic solvent as a dispersion medium, wherein the titanium oxide in the sol has a concentration of 0.7 g/L, the sol has a light transmittance of not less than 50%, the light transmittance being measured by setting an optical path length to 1 cm in a wavelength range of 400 to 800 nm, and the amount of hydroxyl groups per 1 g of titanium oxide is not less than 1.8 mmol.

Abstract: A polyester for a toner, obtainable by polycondensing an alcohol component and a carboxylic acid component containing a (meth)acrylic acid-modified rosin; and a toner containing the polyester for a toner. The polyester for a toner of the present invention is usable as a resin binder for a toner usable in, for example, developing electrostatic latent images formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Abstract: A promoter for a polycondensation reaction used together with a catalyst in a polycondensation reaction, the promoter for a polycondensation reaction comprising a pyrogallol compound having a benzene ring of which three hydrogen atoms adjacent to each other are substituted by hydroxyl groups; and a polycondensation resin obtained by polycondensing raw material monomers using the promoter as defined above and the catalyst. A polycondensation resin can be produced using the promoter of the present invention together with a catalyst in a polycondensation reaction, and the polycondensation resin can be used in various applications including, for example, films, sheets, fibers, toner materials for electrophotography, and the like.

Abstract: A problem of the invention is to provide a process for producing a polyester with high molecular weight and high quality and having practicality as a container material, etc., which is able to achieve the production for a relatively short period of time of solid phase polycondensation without using a complicated melt polycondensation reaction device and consequently at a low cost and with good efficiency. The invention is concerned with a continuous production process for continuously producing a polyester including an esterification step, a melt polycondensation step, a granulation step and a solid phase polycondensation step, wherein at least two kinds of a catalyst 1 and a catalyst 2 which are satisfied with the following requirements (1) to (3) are successively added as catalysts in two arbitrary different places prior to the granulation step; an intrinsic viscosity of the polyester prepolymer granule obtained in the granulation step is 0.18 dL/g or more and not more than 0.

Abstract: Disclosed is a method for increasing the solid state polymerization (SSP) rates of organic titanate catalyzed polyester. The method comprises in a first step, reacting a dicarboxylic acid or a C1-C4 dicarboxylic diester with a diol at a suitable temperature and pressure to effect esterification or transesterification to prepare a precondensate and in a second step, reacting the precondensate to effect polycondensation at a suitable temperature and pressure to prepare a high molecular weight polyester and in a third step, further increasing the molecular weight and viscosity of the polyester under SSP conditions of a suitable temperature and pressure, where an organic titanate is added in the first step or in the second step as a reaction catalyst, and where a phosphinic acid compound is added in the first step, in the second step or just prior to the third step. The phosphinic acid compound is for example diisooctyl phosphinic acid.

Abstract: A tinted polyester resin composition having good color and useful for many uses (fibers, films and other formed articles) contains an aromatic polyester polymer and a tinting agent; the tinting agent is contained in a content of 0.1 to 10 ppm by mass in the composition, and has a maximum absorption wavelength in the range of from 540 to 600 nm in the absorption spectrum in the wavelength band of from 380 to 780 nm, determined in a solution of the tinting agent in a concentration of 20 mg/liter in chloroform in an optical path having a length of 1 cm; and ratios of optical absorbances A400, A500, A600 and A700 of visible light spectra at wavelengths of 400 nm, 500 nm, 600 nm and 700 nm respectively to an optical absorbance Amax in the visible light spectrum at the maximum absorption wavelength, determined in the above-mentioned chloroform solution at a optical path having a length of 1 cm, satisfy the requirements of 0.00?A400/Amax?0.20, 0.10?A500/Amax?0.70, 0.55?A600/Amax?1.00 and 0.00?A700/Amax?0.05.

Abstract: A polycarbonate-polyester block copolymer includes a polycarbonate block and a polyester block, each having specific structures. The block copolymer can be prepared, at least in part, from renewable feedstocks. In some forms, the block copolymer includes biodegradable segments that facilitate structural breakdown of objects molded from the block copolymer. Methods of preparing the block copolymer are described as are- compositions that include it and articles prepared from it.

Abstract: Polyester compositions, especially polyethylene terephthalate homopolymer and copolymers, are disclosed containing titanium catalysts and catalyst deactivator added late in the manufacturing processing having reduced acetaldehyde generation rates. The polyester compositions are low in free acetaldehyde, making them suitable for fabrication into beverage containers for relatively tasteless beverages such as bottle water. Furthermore, the polyesters are polymerized to a high inherent viscosity in reduced processing time, without the necessity of further polymerization in the solid state, and in the absence of acetaldehyde scavengers leading to polyester polymers having reduced color.

Abstract: An amorphous polyester chip having superior processing ability is characterized by a moisture content of not more than 300 ppm and a fine particle content of not more than 500 ppm. A preferred embodiment is a copolymerized polyester chip comprising a main repeating unit consisting of ethylene terephthalate, and 1,4-dimethylene-cyclohexane terephthalate or neopentyl terephthalate, wherein the glycol component of the copolymerized polyester has a specific composition of 50 to 85 mol % of ethylene glycol, 12 to 45 mol % of 1,4-cyclohexanedimethanol or neopentyl glycol and 1.5 to 7.0 mol % of diethylene glycol. Such amorphous polyester chip can be obtained by cooling an amorphous polyester obtained by melt polymerization, cutting the polyester to give a chip, feeding the chip in a treatment tank, drying the chip and removing fine particles.

Abstract: A polyester polymer comprising alkylene arylate units, said polymer having an It.V. of at least 0.72 dl/g, a vinyl ends concentration of at least 0.8 microequivalents per gram, an AA generation rate of less than 20 ppm are prepared by addition of a catalyst deactivator either late in the polycondensation or upon remelting of a solid polyester polymer.

Abstract: A composition and a process for producing an ester or polyester are provided. The composition comprises a titanium compound and clay or a dispersion of clay. The process comprises contacting a carbonyl compound, in the presence of a catalyst, with a glycol in which the catalyst comprises a titanium compound and clay or a dispersion of clay.

Abstract: Polyester compositions are disclosed that include polyester polymers or copolymers having incorporated therein titanium nitride particles that provide one or more of the following advantages: improving the reheat properties of the compositions, improving the color of the compositions through reduced yellowness, and improving the UV-blocking properties of the compositions. Processes for making such compositions are also disclosed. The titanium nitride particles may be incorporated in the polyester by melt compounding, or may be added at any stage of the polymerization, such as during the melt-phase of the polymerization. A range of particle sizes may be used, as well as a range of particle size distributions. The polyester compositions are suitable for use in packaging made from processes in which a reheat step is desirable, or decreased yellowness is desired, or increased resistance to the effects of ultraviolet light is desired, or any combination of the foregoing.

Abstract: A photosensitive resin which exhibits excellent storage stability, affinity, miscibility, or solubility with respect to a variety of compounds, and high sensitivity can be solidified even under hydrous conditions as well as exhibiting high cure-related sensitivity and high flexibility and being uniformly solidified even under highly hydrous conditions, a photosensitive resin composition containing the resin, and a novel compound. The photosensitive resin is a saponified poly(vinyl acetate)-based photosensitive resin having a structural unit represented by formula (1): (wherein R1 represents H or Me; R2 represents a linear or branched C2-C10 alkylene group; n is an integer of 1 to 3; X represents m is an integer of 0 to 6; and Y represents an aromatic ring or a single bond).

Abstract: A polyester based on poly(trimethylene terephthalate) consisting essentially of trimethylene terephthalate repeating units, comprising at least one kind of compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds and manganese compounds in an amount of 10 to 150 ppm expressed in terms of the metal element in a molar ratio of the total amount of elements of the contained alkali metal elements, alkaline earth metal elements and manganese element to the amount of the contained phosphorus element within the range of the following formula (I): 0?P/M?1??(I) wherein, P is the molar amount of the phosphorus element in the polyester; M is the total amount of the alkali metal elements, alkaline earth metal elements and manganese element.

Abstract: The present invention relates to a biodegradable copolyester of high molecular weight and narrow molecular weight distribution. The copolyester has a Mw of 100,000-600,000 g/mol, and a molecular weight distribution of 1.2-3.

Abstract: The object of the present invention is to provide a high quality polyester resin having high productivity, stability and safety, a catalyst for polyester production with high catalytic activity, a method for producing the polyester resin with the catalyst, a polyester resin obtained with the catalyst, and a hollow molded container having the polyester resin. The polyester resin of the present invention satisfies specific parameters regarding polymerizability, stability, and metal content. The catalyst for polyester production satisfies specific parameters. The catalyst particularly preferably has: (a) a solid titanium-containing compound which has a maximum solubility in ethylene glycol of 1,000 ppm or more in terms of converted titanium amount when dissolved in ethylene glycol with heating at 150° C.

Abstract: The present invention is a method for efficiently incorporating a nitrogen containing methine light absorber into a polyester resin. The method includes forming a reaction mixture comprising combining a diol component, a diacid component selected from the group consisting of dicarboxylic acids, dicarboxylic acid derivatives, and mixtures thereof, an antimony containing compound, a phosphorus containing compound, a metal containing compound, and a nitrogen containing methine light absorber. The reaction mixture is polymerized in a polycondensation reaction system. In another embodiment the light absorber is added while the reaction products of one reactor are being transferred to the next reactor in the polycondensation reaction system. The present invention is also directed articles made from the polyester resin.

Abstract: A method for reducing organic carbon emissions from PBT-block-containing resins is disclosed. The method involves adding a titanium-catalyst deactivating compound to the resin after polymerisation.

Abstract: A process is provided for producing an enriched carboxylic acid compositions produced by contacting composition comprising a carboxylic acid with an enrichment feed in an enrichment zone to form an enriched carboxylic acid composition. This invention also relates to a process and the resulting compositions for removing catalyst from a carboxylic acid composition to produce a post catalyst removal composition.

Abstract: The invention relates to a method for producing high-molecular weight polyesters, such as e.g. polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polynaphthalene terephthalate (PEN), polytrimethylene terephthalate (PTT) and/or polyesters of other dicarboxylic acids and diols including copolymers thereof. The invention relates likewise to a device for implementing this method. The latter concerns a single-stage tower reactor with which a method, comprising only two reactors, is made available for the total process.

Abstract: In the continuous production of polyesters, the esterification/transesterification of dicarboxylic acids or esters of the dicarboxylic acids with diols is performed in at least one reaction stage, the prepolycondensation of the esterification/transesterification product is performed under a vacuum in a reaction stage consisting of a vertical tube, and the polycondensation of the prepolycondensation product is performed in at least one reaction stage.

Abstract: A method is described for the manufacture of polyesters of aromatic dicarboxylic acids with aliphatic and/or cycloaliphatic dials, in which an aromatic dicarboxylic acid in the presence of a monocarboxylic acid or a mixture of a monocarboxylic acid present in a saturated solution with water or another suitable solvent is converted with an aliphatic or cycloaliphatic dial to a dicarboxylic acid alkanediolestercarboxylate and/or its oligomers, which are polycondensed in further process steps to the polyester.

Abstract: A composition and a process for using the composition are disclosed. The composition comprises, or is produced from, a titanium chelate and an aluminum hydroxyhalide, in a solvent. A process comprises contacting a carbonyl compound, in the presence of a composition, with a glycol in which the composition comprises or is produced from a titanium chelate and an aluminum hydroxyhalide. The composite can be produced in the order of adding the aluminum hydroxyhalide to the titanium chelate in the solvent.

Abstract: A polyester resin composition for a toner comprising a titanium compound in an amount of from 0.005 to 4% by weight, and an inorganic phosphorus compound in an amount of from 0.001 to 5% by weight; a toner comprising the polyester resin composition as defined above; and a process for preparing the polyester resin composition for a toner as defined above, comprising the step of polycondensing the raw material monomers for the polyester in the presence of a titanium compound and an inorganic phosphorus compound. The polyester resin composition for a toner is suitably used as a resin binder for a toner for developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like, a process for preparing the same, and a toner comprising the polyester resin composition.

Abstract: A knitted/woven fabric of polyester fibers is produced from a polyester polymer obtained by condensation-polymerizing an aromatic dicarboxylate in the presence of a catalyst which comprises a mixture of a titanium compound ingredient (A) comprising a titanium alkoxide and at least one product of the reaction of the titanium alkoxide with a specific carboxylic acid or anhydride thereof and a specific phosphorus compound ingredient (B) and/or comprises a product of the reaction of a titanium compound ingredient (C) with a specific phosphorus compound ingredient (D). The knitted/woven fabric obtained has a satisfactory color tone (low value of b*) and is excellent in suitability for knitting/weaving and dyeability.

Abstract: A process for the production of polytrimethylene terephthalate (PTT), wherein the process comprises: (i) one or more esterification steps, wherein terephthalic acid (TPA) or an alkyl diester of terephthalic acid is reacted with 1,3-propanediol (PDO); and (ii) one or more subsequent polycondensation steps, wherein the process further comprises the addition of a protic acid, other than terephthalic or isophthalic acid, before and/or during the one or more esterification steps, wherein the protic acid has a dissociation constant of at most 4 (pKa measured in water at 25° C.), and wherein the total amount of protic acid added before and/or during the one or more esterification steps is in the range of from 0.001 to 10 millimole of acid per kilogram of polytrimethylene terephthalate produced.

Abstract: A poly(ethylene aromatic dicarboxylate ester) resin usable for the production of fibers, films and bottle-formed articles, is produced by polycondensing a diester of an aromatic dicarboxylic acid with ethylene glycol by using a catalyst including a non-reacted mixture or reaction product of a titanium compound component including at least one member selected from titanium alkoxides and reaction products of the titanium alkoxides with aromatic polyvalent carboxylic acids or anhydrides thereof, with a specific phosphorus compound, in which catalyst the contents of titanium and phosphorus elements are controlled.

Abstract: A toner for forming a full color image, which includes a colorant and a binder resin including a polyester resin which is prepared by a polycondensation ester reaction in the presence of a titanium-containing catalyst selected from the group consisting of halogenated titanium, titanium diketone enolates, titanium carboxylates, titanyl carboxylates, and salts of titanyl carboxylates. A toner kit including a yellow toner, a magenta toner, a cyan toner and a black toner, wherein each of the toners is the toner mentioned above. An image forming apparatus including an image bearing member; a charger; a light irradiator; a developing device configured to develop an electrostatic latent image with a developer including the toner mentioned above; a transfer device; and a fixing device.

Abstract: In the invention, a polyester resin having dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process including an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a titanium compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.

Abstract: Optically transparent, relatively high refractive index polymeric compositions and ophthalmic devices such as intraocular lenses, contact lenses and corneal inlays made therefrom are described herein. The preferred polymeric compositions are produced through the polymerization of one or more siloxysilane monomers or the copolymerization of one or more siloxysilane monomers with one or more aromatic or non-aromatic non-siloxy monomers, hydrophobic monomers or hydrophilic monomers.

Abstract: In a polyester production method, a titanium compound having a radical selected from a carbonyl group, a carboxyl group, or an ester group, and a phosphorous compound having a structure illustrated in Formula (I), are added This yields a polyester composition which does not exhibit increased filter pressure when forming, which has excellent filament and film forming properties, and which has a polymer color tone superb to that of conventional products.

Abstract: A method for preparing a biodegradable copolyester includes: (a) optionally preparing an aromatic prepolymer by reacting a first aromatic dicarboxylic compound with a first aliphatic glycol; (b) reacting the aromatic prepolymer with a second aromatic dicarboxylic compound and a second aliphatic glycol so as to form a first reaction product; (c) reacting the first reaction product with an aliphatic dicarboxylic compound so as to form a second reaction product; and (d) performing polycondensation of the second reaction product.

Abstract: Optically transparent, relatively high refractive index polymeric compositions and ophthalmic devices such as intraocular lenses, contact lenses and corneal inlays made therefrom are described herein. The preferred polymeric compositions are produced through the polymerization of one or more siloxysilane monomers or the copolymerization of one or more siloxysilane monomers with one or more aromatic or non-aromatic non-siloxy monomers, hydrophobic monomers or hydrophilic monomers.

Abstract: A composition that can be used as catalyst in esterification, transesterification or polycondensation is disclosed, which comprises a stable solution comprising (a) titanium in the form of a titanium ?-hydroxycarboxylic acid or its salt, (b) a C1–C6 carboxylic acid, and (c) zinc in the form of a water-soluble zinc salt, and (d) water; and substantially free of an alkanolamine, an aminocarboxylic acid, or combinations two or more thereof. Also disclosed is an esterification, transesterification or polycondensation process, which comprises contacting, in the presence of the solution composition, an organic acid or its ester or its salt with an alcohol, optionally in the presence of a phosphorus compound, an organic or inorganic toning agent such as cobalt acetate, or combinations thereof.

Abstract: A shaped article comprising poly[(trimethylene-co-dianhydrosugar ester) dicarboxylate] or poly(trimethylene-co-dianhydro-dicarboxylate having improved stability in the form of less change of Tg and reduced shrinkage upon storage at elevated temperature is disclosed.

Abstract: The present invention provides a toner binder for developing electrostatic charge images, which binder comprises a polycondensate polyester resin, said polyester resin being a product formed in the presence of at least one titanium-containing catalyst (A) selected from the group consisting of a titanium halides (A1), a titanium diketone enolate (A2), a titanium carboxylate (A3), a titanyl carboxylate (A4), and a titanyl carboxylate salt (A5). Furthermore, the present invention provides a toner binder for developing electrostatic charge images, which binder comprises a polycondensate polyester resin, said polyester resin being a product formed in the presence of at least one tin-containing catalyst (B) selected from the group consisting of dioctyltin oxide (B1), monobutyltin oxide (B2), and dibutyltin oxide (B3), with the content of tributyltin compounds in (B3) being not more than 250 ppm.

Abstract: A melt polymerization process for the preparation of poly(1,3-propylene-co-isosorbide) terephthalate (3GIT), new 3GITs and products made from the 3GITs. The process comprises (a) providing a mixture comprising terephthalic acid or its alkyl ester, 1,3-propanediol and isosorbide in a molar ratio of diols to terephthalic acid or its alkyl ester of from about 1.1:1 to about 1.6:1 and a molar ratio of 1,3-propanediol to isosorbide of from about 2:1 to about 10:1; (b) reacting the mixture in an inert atmosphere at a temperature of about 180 to about 245° C., with concurrent removal of a distillate comprising at least 80% of the water or alkanol volatile reaction product, wherein the distillate contains less than about 5 weight % 1,3-propanediol and less than 1 weight % isosorbide; and (c) continuing the reaction in the presence of a polycondensation catalyst at a pressure of about 0.25 to about 2 mm Hg and about 245 to about 260° C.

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 ?g per 1 g of the polyester resin, as antimony atoms (Sb).

Abstract: This invention relates to an activated titanium catalyst used in an esterification reaction and/or a transesterification reaction, and a method of manufacturing esters having a low acid value and narrow molecular weight distribution by making effective use of the excellent dehydration esterification reaction properties and transesterification ability of this catalyst.

Abstract: There is provided a laminated film for optical use comprising a polyester film which has a lubricity layer containing globular particles in at least one side thereof, wherein the laminated film has a thickness irregularity of 0.5 to 7.0%, and wherein the polyester film contains inert particles derived from catalysts and the amount of the inert particles determined by a dark-field microscopy satisfies the following conditions: the number of inert particles having a particle size of from 1 to 10 ?m is 200 to 20,000/mm2; and the number of inert particles having a particle size of greater than 10 ?m is 10/mm2 or less. The laminated film for optical use which is improved in uniformity, transparency, lubricity, color tone and scratch resistance, which deposits only a reduced amount of low molecular materials, and which is excellent in the adhesion to a layer adopted for various optical purposes.

Abstract: A catalyst composition is disclosed. The composition comprises a titanium compound, a complexing agent, hypophosphorous acid or its metal salt, water and optionally a solvent. The complexing agent can be hydroxycarboxylic acid, alkanolamines, aminocarboxylic acids, or combinations of two or more thereof. The solvent can be water, ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, isopropylene glycol, butylene glycol, 1-methyl propylene glycol, pentylene glycol, or combinations of two or more thereof. The titanium compound can be combined with a zirconium compound. Also disclosed is a process for using the composition for producing an ester or a polyester. The process comprises contacting a carbonyl compound, in the presence of the compositions, with an alcohol under a condition suitable for esterification, transesterification, polymerization, or combinations of two or more thereof.

Abstract: The present invention provides a catalyst for polyester production capable of producing a polyester with high catalytic activity, a process for producing a polyester using the catalyst and a polyester produced thereby. The catalyst comprises a solid titanium compound obtained by dehydro-drying a hydrolyzate obtained by hydrolysis of a titanium halide and which has a molar ratio (OH/Ti) of a hydroxyl group (OH) to titanium (Ti) exceeding 0.09 and less than 4. In the process, the polyester is obtained by polycondensing an aromatic dicarboxylic acid, or an ester-forming derivative thereof, and an aliphatic diol, or ester-forming derivative thereof, in the presence of the catalyst. The resulting polyester has excellent transparency and tint, a titanium content of 1 to 100 ppm, a magnesium content of 1 to 200 ppm and a magnesium to titanium weight ratio of not less than 0.01.