Abstract: An object of the present invention is to provide high-quality 1,4BG capable of working out to a raw material of PBT with good color tone, by efficiently removing and refining impurities mixed when producing a biomass-derived 1,4BG on an industrial scale and the present invention relates to a production method of refined 1,4BG, where a crude 1,4BG-containing solution is obtained from refined raw material 1,4BG obtained by removing bacterial cells, salt contents and water from the fermentation culture medium, through a step of removing high-boiling-point components and/or low-boiling-point components by distillation and/or a step of converting an unsaturated compound to a hydride and the target product is obtained as a side stream in a further distillation step.

Abstract: At the time of producing a polyester by using a dicarboxylic acid component and a biomass-resource-derived diol as raw materials, a polyester is efficiently produced with good color tone, as the raw material diol derived from biomass resources, a diol in which the content of a cyclic carbonyl compound having a carbon atom number of 5 or 6 is from 0.01 to 12 ppm by mass, is used, and by controlling the content of a cyclic carbonyl compound having a carbon atom number of 5 or 6 in the raw material diol to fall in a prescribed range, the color tone of the polyester is improved.

Abstract: The present invention aims to provide a method for producing polybutylene terephthalate (PBT) with an excellent color using biomass-derived 1,4-butanediol (BG). The invention relates to a method for producing PBT comprising a step of subjecting a diol component containing raw material 1,4-BG having a nitrogen content of 0.01 to 50 ppm by mass and a dicarboxylic acid component to esterification or ester-exchange reaction, and a polycondensation reaction step for obtaining PBT from the reactant, wherein the content of gamma butyrolactone in the raw material 1,4-BG is 1 to 100 ppm by mass.

Abstract: An object of the present invention is to provide high-quality 1,4BG capable of working out to a raw material of PBT with good color tone, by efficiently removing and refining impurities mixed when producing a biomass-derived 1,4BG on an industrial scale and the present invention relates to a production method of refined 1,4BG, where a crude 1,4BG-containing solution is obtained from refined raw material 1,4BG obtained by removing bacterial cells, salt contents and water from the fermentation culture medium, through a step of removing high-boiling-point components and/or low-boiling-point components by distillation and/or a step of converting an unsaturated compound to a hydride and the target product is obtained as a side stream in a further distillation step.

Abstract: The present invention aims to provide a method for producing polybutylene terephthalate (PBT) with an excellent color using biomass-derived 1,4-butanediol (BG). The invention relates to a method for producing PBT comprising a step of subjecting a diol component containing raw material 1,4-BG having a nitrogen content of 0.01 to 50 ppm by mass and a dicarboxylic acid component to esterification or ester-exchange reaction, and a polycondensation reaction step for obtaining PBT from the reactant, wherein the content of gamma butyrolactone in the raw material 1,4-BG is 1 to 100 ppm by mass.

Abstract: At the time of producing a polyester by using a dicarboxylic acid component and a biomass-resource-derived diol as raw materials, a polyester is efficiently produced with good color tone, as the raw material diol derived from biomass resources, a diol in which the content of a cyclic carbonyl compound having a carbon atom number of 5 or 6 is from 0.01 to 12 ppm by mass, is used, and by controlling the content of a cyclic carbonyl compound having a carbon atom number of 5 or 6 in the raw material diol to fall in a prescribed range, the color tone of the polyester is improved.

Abstract: A method of producing an aliphatic polyester resin by continuously esterifying and melt polycondensing an aliphatic dicarboxylic acid and an aliphatic diol; and at least one aliphatic hydroxycarboxylic acid; and at least one of an aliphatic unsaturated dicarboxylic acid and cis- and trans-isomers of aliphatic unsaturated tricarboxylic acids, wherein the total amount of the at least one aliphatic hydroxycarboxylic acid and the at least one of aliphatic unsaturated dicarboxylic acid and cis- and trans-isomers of aliphatic unsaturated tricarboxylic acids is from 0.0010 to 0.50 mol % of the total amount of the aliphatic polyester resin; and the total amount of the at least one aliphatic hydroxycarboxylic acid is from 1.0 to 7.0 in terms of a molar ratio to the total amount of the at least one of aliphatic unsaturated dicarboxylic acid and cis- and trans-isomers of aliphatic unsaturated tricarboxylic acids.

Abstract: The present invention is aimed to provide a method for producing a polyester with reduced CD content and elution amount, in which even after the production method, a reduction in physical properties of the polyester is small, and furthermore, a polyester having good moldability can be produced, and the present invention is concerned with a method for producing a polyester including an esterification reaction step of allowing an aliphatic diol and an aliphatic dicarboxylic acid to react with each other; a step of pelletizing a polyester obtained through the esterification reaction step; and a contact treatment step of bringing the obtained polyester pellets into contact with a mixed solution containing ethanol and water, wherein the mixed solution contains water in an amount of 10% by mass or more and not more than 99% by mass relative to the whole of the mixed solution.

Abstract: An aliphatic polyester resin having excellent moldability and its production method are provided. When the amount of specific structural units contained in an aliphatic polyester resin is adjusted to an optimum amount, an aliphatic polyester resin having sufficient melt tension at the time of molding and excellent moldability than in the past and its production method is provided.

Abstract: An object of the present invention is to provide a method for efficient continuous production of aliphatic polyester having good quality. The invention relates to a continuous production method of aliphatic polyester, wherein the polyester is obtained through a preparation step of slurry containing aliphatic dicarboxylic acid and aliphatic diol, an esterification reaction step and a polycondensation reaction step, wherein temperature range of the slurry during the preparation step thereof is from the coagulation point of the aliphatic diol to 80° C., and moisture content in the slurry is from 0.01 to 10% by weight.

Abstract: An aliphatic polyester resin having excellent moldability and its production method are provided. When the amount of specific structural units contained in an aliphatic polyester resin is adjusted to an optimum amount, an aliphatic polyester resin having sufficient melt tension at the time of molding and excellent moldability than in the past and its production method is provided.

Abstract: An object of the present invention is to provide a method for efficient continuous production of aliphatic polyester having good quality. The invention relates to a continuous production method of aliphatic polyester, wherein the polyester is obtained through a preparation step of slurry containing aliphatic dicarboxylic acid and aliphatic diol, an esterification reaction step and a polycondensation reaction step, wherein temperature range of the slurry during the preparation step thereof is from the coagulation point of the aliphatic diol to 80° C., and moisture content in the slurry is from 0.01 to 10% by weight.

Abstract: An aliphatic polyester resin having excellent moldability and its production method are provided. When the amount of specific structural units contained in an aliphatic polyester resin is adjusted to an optimum amount, an aliphatic polyester resin having sufficient melt tension at the time of molding and excellent moldability than in the past and its production method is provided.

Abstract: Polybutylene terephthalate has an intrinsic viscosity of 0.7 to 1.0 dL/g and an end carboxyl group concentration of 0.1 to 18 ?eq/g, which is produced in a presence of a catalyst comprising a titanium compound and a metal compound containing a metal of Group 2A of the Periodic Table. In the preferable embodiment of the present invention, the polybutylene terephthalate has a crystallization temperature of 170 to 195° C. as measured at a temperature drop rate of 20° C./min using a differential scanning calorimeter, an end vinyl group concentration of not more than 10 ?eq/g, and not more than 10% of a solution haze of a solution prepared by dissolving 2.7 g of said polybutylene terephthalate in 20 mL of a mixed solvent containing phenol and tetrachloroethane at a weight ratio of 3:2.

Abstract: Polybutylene terephthalate is produced by continuously subjecting terephthalic acid and 1,4-butanediol to an esterification reaction in the presence of a titanium compound catalyst using one-stage or plural-stage esterification reaction vessel(s) and then subjecting the resultant reaction product to a polycondensation reaction, wherein the esterification reaction between terephthalic acid and 1,4-butanediol is conducted in the presence of a titanium compound having a specific concentration under a specific pressure at a specific molar ratio between the raw materials. The process avoids undesirable side reactions by continuously conducting esterification reaction using terephthalic acid as a raw material, and can minimize loss of raw materials.

Abstract: An object of the present invention is to provide polybutylene terephthalate which has excellent color tone, hydrolysis resistance, heat stability, transparency and moldability as well as a less content of impurities, can be produced with maintaining its productivity while preventing from generation of tetrahydrofuran as a by-product, and can be suitably applied to films, monofilaments, fibers, electric and electronic parts, automobile parts, etc.

Abstract: A process for producing polybutylene terephthalate comprising the steps of continuously subjecting terephthalic acid and 1,4-butanediol to esterification reaction in the presence of a titanium compound catalyst using one-stage or plural-stage esterification reaction vessel(s) and then subjecting the resultant reaction product to polycondensation reaction, wherein the esterification reaction between terephthalic acid and 1,4-butanediol is conducted in the presence of a titanium compound having a specific concentration under a specific pressure at a specific molar ratio between the raw materials. The process of the present invention can be prevented from undergoing undesirable side reactions upon continuously conducting esterification reaction using terephthalic acid as a raw material, and can minimize loss of raw materials.