Toray Industries, Inc.

Tsuyoshi Tanaka

Hiroyuki Ome

Hideyuki Umetsu

Sadanori Kumazawa

Makito Yokoe

Yusuke Tojo

Koya Kato

Tatsuya Nagano

Takuro Okubo

A terminal modified polybutylene terephthalate resin has a weight average molecular weight Mw of 10,000 to 100,000, a melting point of 210&#xb0; C. to 235&#xb0; C., and a melt viscosity &#x3bc; at 250&#xb0; C. of not more than 10 Pa&#xb7;s, and includes 90 to 300 mol/ton of a compound having a (poly)oxyalkylene structure, the compound being terminally bound in the resin, wherein the weight average molecular weight Mw represents a relative weight average molecular weight with respect to the molecular weight of a standard poly(methyl methacrylate) as determined by gel permeation chromatography using hexafluoroisopropanol (supplemented with 0.005 N sodium trifluoroacetate) as a mobile phase.

Terminally modified polybutylene terephthalate resin, thermoplastic resin composition including same, and molded article

The present invention is directed to a method for producing a polylactic acid resin, including the step of subjecting a crystallized prepolymer, which is a prepolymer including a lactic acid unit as a main component, and has an optical purity (Ea) of 60 to 94%, a weight average molecular weight of 5,000 to 100,000, and a crystal melting enthalpy (&#x394;Hma) of 4 to 50 J/g, to solid phase polymerization. According to the present invention, it is possible to obtain a polylactic acid resin which is excellent in moldability upon melt processing and drawdown resistance upon melt processing, and is also excellent in hydrolysis resistance.

Polylactic acid resin and method for producing same

A method of producing a poly(lactic acid) resin includes carrying out direct polycondensation using lactic acid as a main raw material to prepare a crystallized prepolymer having a weight average molecular weight of 5,000 to 25,000, an enthalpy of fusion &#x394;Hm of 50 to 65 J/g and an acid value A mol/ton satisfying (1) below:450/(Mw/10,000&#x2212;0.14)&#x3c;&#x3c;950/(Mw/10,000&#x2212;0.14)&#x2003;&#x2003;(1)(wherein Mw represents weight average molecular weight of the crystallized prepolymer); and subjecting the crystallized prepolymer to solid-phase polymerization.

Process for production of poly(lactic acid)-type resin, and poly(lactic acid)-type prepolymer

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Nagoya, Japan

Tsuyoshi Tanaka