Abstract: A process for producing an organic acid ester-type liquid is disclosed which is a process for removing an organic peroxide contained in an organic acid ester-type liquid which is a solvent of a resist for producing electronic parts or an organic acid ester-type liquid which is a rinsing liquid for producing electronic parts, which comprises contacting the organic acid ester-type liquid with a platinum group metal catalyst to remove the organic peroxide in the organic acid ester-type liquid, and a resist solvent for producing electronic parts or a rinsing liquid for producing electronic parts which comprises an organic acid ester-type liquid in which an organic peroxide contained therein has been removed by using the producing process and a peroxide value (POV) thereof is 2 mmoL/kg or less.

Abstract: A process for producing an organic acid ester-type liquid is disclosed which is a process for removing an organic peroxide contained in an organic acid ester-type liquid which is a solvent of a resist for producing electronic parts or an organic acid ester-type liquid which is a rinsing liquid for producing electronic parts, which comprises contacting the organic acid ester-type liquid with a platinum group metal catalyst to remove the organic peroxide in the organic acid ester-type liquid, and a resist solvent for producing electronic parts or a rinsing liquid for producing electronic parts which comprises an organic acid ester-type liquid in which an organic peroxide contained therein has been removed by using the producing process and a peroxide value (POV) thereof is 2 mmoL/kg or less.

Abstract: Provided is a method for purifying an aliphatic polyester which reduces coloring of the aliphatic polyester, reduces the amount of residual monomer and residual catalyst, and improves stability and appearance. This method for purifying an aliphatic polyester subjects an aliphatic polyester containing a monomer to heat treatment under dry air containing oxygen at a temperature at or above the melting point of the monomer and at or below the melting point of the aliphatic polyester.

Abstract: A composition which comprises polylactide and has excellent heat stability, color and hydrolytic resistance. The composition comprises (i) polylactide, (ii) a metal catalyst and (iii) a hypophosphorous acid-based deactivator or a metaphosphoric acid-based deactivator.

Abstract: It is an object of the present invention to provide polylactic acid containing a stereocomplex crystal and having excellent moldability, a high molecular weight, high crystallinity and a high melting point and a process for manufacturing the same. It is another object of the present invention to provide a composition comprising the polylactic acid and a molded product of the polylactic acid. The present invention is characterized from polylactic acid having a weight average molecular weight of 80,000 to 500,000 and a melting peak at 195° C. or higher which accounts for 80% or more of the total of melting peaks in the temperature elevation step when measured by a differential scanning calorimeter (DSC) and a process for manufacturing the same.

Abstract: An object of the present invention is to provide a fiber made of polylactic acid and having excellent strength, heat resistance and heat shrinkage resistance and a manufacturing method thereof. The present invention relates to the fiber is made of a composition which includes (i) poly(L-lactic acid) having a weight average molecular weight of 50,000 to 300,000 (component A), (ii) poly(D-lactic acid) having a weight average molecular weight of 50,000 to 300,000 (component B) and (iii) 0.01 to 5 parts by weight of a phosphate metal salt (component C) based on 100 parts by weight of the total of the components A and B and has a strength of 2.5 to 10 cN/dTex and a manufacturing method thereof.

Abstract: It is an object of the present invention to provide a composition which contains polylactic acid and has excellent heat stability, mechanical strength and color. The composition contains 0.001 to 0.1 part by weight of a metal catalyst and 0.001 to 0.5 part by weight of a phosphono-fatty acid ester based on 100 parts by weight of polylactic acid.

Abstract: It is an object of the present invention to provide a method for producing a polylactic acid block copolymer having high molecular weight, and in lower cost, wherein only a stereo-complex crystal is capable of growing, even when heat melting process is repeated. The present invention relates to a method for producing a polylactic acid block copolymer characterized in that (i) ring-opening polymerization of D-lactide (D component) is carried out in the presence of poly-L-lactic acid (L component), or (ii) ring-opening polymerization of L-lactide (L component) is carried out in the presence of poly-D-lactic acid (D component), and mass ratio of the D component and the L component is the D component/the L component=60/40 to 91/9, or the L component/the D component=60/40 to 91/9.

Abstract: It is an object of the present invention to provide a polylactic acid composition having excellent crystallinity, wet heat stability and melt stability. It is another object of the present invention to provide a molded article which is obtained from the polylactic acid composition and excellent in appearance and color. The present invention is a composition and molded article thereof which comprises a polylactic acid (component A), a carbodiimide compound (component B) and a phosphoric acid ester metal salt (component C).

Abstract: It is an object of the present invention to provide a method for producing a polylactic acid block copolymer having high molecular weight, and in lower cost, wherein only a stereo-complex crystal is capable of growing, even when heat melting process is repeated. The present invention relates to a method for producing a polylactic acid block copolymer characterized in that (i) ring-opening polymerization of D-lactide (D component) is carried out in the presence of poly-L-lactic acid (L component), or (ii) ring-opening polymerization of L-lactide (L component) is carried out in the presence of poly-D-lactic acid (D component), and mass ratio of the D component and the L component is the D component/the L component=60/40 to 91/9, or the L component/the D component=60/40 to 91/9.

Abstract: It is an object of the present invention to provide a polylactic acid composition having excellent crystallinity, wet heat stability and melt stability. It is another object of the present invention to provide a molded article which is obtained from the polylactic acid composition and excellent in appearance and color. The present invention is a composition and molded article thereof which comprises a polylactic acid (component A), a carbodiimide compound (component B) and a phosphoric acid ester metal salt (component C).

Abstract: An object of the present invention is to provide a composition containing polylactic acid and having improved blow moldability and a blow molded product thereof. The polylactic acid composition meets the following requirements (a) to (g) at the same time: (a) the weight average molecular weight must be 70,000 to 700,000; (b) the total content (metal content) of Sn atom, Ti atom, Al atom and Ca atom must be 3 to 20 ppm; (c) the content of P atom must be 3 to 3,000 ppm; (d) the (total number of gram-atoms of Sn, Ti, Al and Ca)/(number of gram-atoms of P) value must be 0.01 to 5; (e) the content of a compound having a molecular weight of 150 or less must be not more than 0.2 wt %; (f) the COOH terminal group concentration must be not more than 30 equivalents/ton; and (g) the following expressions (1) and (2) must be satisfied: 10 Pa·s<P<100 Pa·s??(1) 10 MPa<S??(2) (P is a melt viscosity at 230° C. and S is a stress at 150° C.).

Abstract: An object of the present invention is to provide a fiber made of polylactic acid and having excellent strength, heat resistance and heat shrinkage resistance and a manufacturing method thereof. The present invention relates to the fiber is made of a composition which comprises (i) poly(L-lactic acid) having a weight average molecular weight of 50,000 to 300,000 (component A), (ii) poly(D-lactic acid) having a weight average molecular weight of 50,000 to 300,000 (component B) and (iii) 0.01 to 5 parts by weight of a phosphate metal salt (component C) based on 100 parts by weight of the total of the components A and B and has a strength of 2.5 to 10 cN/dTex and a manufacturing method thereof.

Abstract: A method of manufacturing polylactic acid having excellent heat resistance and strength without using a harmful solvent and a method of manufacturing a film thereof. An aqueous emulsion of polylactic acid which is suitable for the manufacture of polylactic acid and does not contain a harmful solvent, and a coating agent containing the same. The method of manufacturing polylactic acid includes the steps of: (1) preparing an aqueous emulsion of poly-L-lactic acid and an aqueous emulsion of poly-D-lactic acid; (2) mixing them together to prepare a mixed emulsion; and (3) drying the mixed emulsion.

Abstract: It is an object of the present invention to provide polylactic acid containing a stereocomplex crystal and having excellent moldability, a high molecular weight, high crystallinity and a high melting point and a process for manufacturing the same. It is another object of the present invention to provide a composition comprising the polylactic acid and a molded product of the polylactic acid. The present invention is characterized from polylactic acid having a weight average molecular weight of 80,000 to 500,000 and a melting peak at 195° C. or higher which accounts for 80% or more of the total of melting peaks in the temperature elevation step when measured by a differential scanning calorimeter (DSC) and a process for manufacturing the same.

Abstract: A method for the purification of lactide is provided which permits lactide of high optical purity or DL-lactide of high purity to be produced from crude lactide by the removal of meso-lactide from the crude lactide. This method for the purification of lactide is characterized by causing a mixture containing L-lactide and/or D-lactide together with meso-lactide to contact with water thereby effecting hydrolysis of meso-lactide. This method can remove meso-lactide from crude lactide and produce DL-lactide and/or optically active lactide of high optical purity in high yield and, in the production of optically active lactide, can eliminate the restrictions otherwise imposed on the formation of meso-lactide. Thus, it lends itself to the simplification of the procedure for the synthesis of lactide.