Mitsui Toatsu Chemicals, Incorporated

Mitsui Chemicals, Inc.

Ikumi Kitada

Akihiro Yamaguchi

Masanobu Ajioka

Chojiro Higuchi

Masatoshi Takagi

Katashi Enomoto

Akinori Nagatomo

Hiroshi Suizu

Yuji Terado

Taiji Kameoka

Takeshi Kashima

A preparation process of a degradable copolymer comprising carrying out dehydration polycondensation of polysaccharide (A) with one or more compounds (B) selected from the group consisting of:

Preparation of degradable copolymers

A process for preparing a degradable copolymer of aliphatic polyester comprising the steps of reacting two or more kinds of aliphatic polyester homopolymer in the presence of a catalyst in a reaction mixture containing an organic solvent, and a degradable copolymer of aliphatic polyester obtained by said preparation process. The copolymers exhibits high transparency in addition to excellent strength and elongation, can be processed into various molded articles and formed items such as films and filaments, and can provide heat resistance by heat treatment of said molded articles and formed items. The copolymer can be suitably utilized for processed articles such as a film, breathable film, sheet, textile, monofilament, multifilament, yarn, non-woven fabric, flat yarn, staple, crimped fiber, ribbed tape, split yarn, conjugate fiber, laminate, blow-bottle, sheet, stretched sheet, foam and net.

Preparation process of degradable polymer

.alpha.-L-Aspartyl-L-phenylalanine methyl ester (.alpha.-APM) is prepared by catalytic hydrogenation of N-benzyloxycarbonyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester (Z-.alpha.-APM). The catalytic hydrogenation is conducted in an aqueous suspension containing the Z-.alpha.-APM in the form of particles whose average particle size is not greater than 800 .mu.m. The starting Z-.alpha.-APM may contain up to 30 wt. % of its .beta.-isomer provided that the process additionally includes recrystallization of the .alpha.-APM, collection of the .alpha.-APM by filtration and recycling of the filtrate for use in the aqueous suspension of Z-.alpha.-APM.

Preparation process of .alpha.-aspartyl-L-phenylalanine methyl ester

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Kanagawa-ken, Japan

Ikumi Kitada