Mitsui Toatsu Chemicals, Incorporated

Mitsui Chemicals, Inc.

Chojiro Higuchi

Akihiro Yamaguchi

Ryuichi Mita

Toshio Katoh

Masanobu Ajioka

Takeshi Oura

Toshio Kato

Masatoshi Takagi

Yuji Terado

Takeshi Kashima

Takao Takano

Nobuyuki Kawashima

Hisamichi Murakami

Taiji Kameoka

Ikumi Kitada

Atsuo Otsuji

Akinori Nagatomo

Hiroshi Suizu

Masaharu Ohoka

Shosuke Nagai

Katsuya Sakai

Shousuke Nagai

Kenichi Sugimoto

Koju Okazaki

Tatsuhiro Urakami

Katashi Enomoto

Kouji Suesugi

Mitsuo Nakamura

Nobuhiro Kawashima

Ryohei Ogawa

Motoaki Isokawa

Yasuhiro Nukii

Tetsuya Toida

Narimichi Honda

It is an object of the present invention to provide a resin composition having improved heat resistance (high crystallinity) and transparency without impairing rigidity intrinsic to a polylactic acid based resin, a molded body formed from the resin composition, and a new polylactic acid based resin used in the resin composition. A polylactic acid based resin (A) according to the present invention is characterized by having a specific structural moiety and a weight average molecular weight (Mw) of 5,000 to 1,000,000. A polylactic acid based resin composition according to the present invention is characterized by containing the above-described polylactic acid based resin (A).

Polylactic acid based resin, polylactic acid based resin composition, molded body of polylactic acid based resin or polylactic acid based resin composition, and method for producing polylactic acid based resin

A (meth)acrylic ester compound represented by the general formula (1) and a dental material containing the compound, 

(Meth) acrylic ester compound and use thereof

A poly(thio)ester (co)polymer which comprises a repeating structural unit represented by the formula (1-A) as an essential structural unit:[wherein Ris a divalent aliphatic hydrocarbon group which may contain at least one sulfur atom in a sulfide group; Ris a mono- or poly-cyclic aliphatic or aromatic dicarboxylic acid residue; and Xand Xare each independently an oxygen atom or sulfur atom, and when Xand Xare the oxygen atoms, Ris a divalent aliphatic hydrocarbon group containing at least one sulfur atom in the sulfide group]; and an optical component obtainable by molding the poly(thio)ester (co)polymer. The poly(thio)ester (co)polymer is excellent in transparency and optical characteristics (e.g., a higher refractive index, higher Abbe number, and lower birefringence), and has also good mechanical characteristics and thermal characteristics, and further is excellent in melt fluidity and injection moldability.

Optical component and sulfur-containing poly(thio)ester (co)polymer

A biodegradable aliphatic polyester elastomer which has rubber-like elasticity, hardness of 80 or less in accordance with ASTM D 676-58T, and elastic modulus from 1.times.10.sup.5 Pa to 1.times.10.sup.8 Pa at 25.degree. C., and decomposes with ease in the natural environment, under composting conditions or under hydrolysis conditions. The biodegradable aliphatic elastomer can be obtained by crosslinking aliphatic polyester containing aliphatic unsaturated polybasic acid as a polymer constituting ingredient and having a weight average molecular weight of 15,000 or more.

Biodegradable aliphatic polyester elastomer and preparation process of

A degradable polymer and a process for preparing the degradable polymer which has a structure resulting from combination of a star-shaped polymer comprising a polyfunctional base compound of polycarboxylic acid having three or more carboxyl groups and/or anhydride of the same or aliphatic polyhydric alcohol having three or more hydroxyl groups and a unit of aliphatic hydroxycarboxylic acid, with aliphatic polyhydric alcohol having two or more hydroxyl groups or polycarboxylic acid having two or more carboxyl groups or anhydrides of the same. The degradable polymer leads to remarkably low coloration as compared with a polymer comprising polysaccharide as a polyfunctional base compound, has high melt tension as compared to common aliphatic polyester is excellent in processability on various molding methods, foam molding and blow molding in particular, and high transparency.

Degradable polymer and preparation process of the same

A degradable copolymer obtained by heat-dehydration reaction of aromatic polycarbonate and aliphatic polyester in the presence of a catalyst, has degradability which cannot be exhibited by common aromatic polycarbonate, transparency equal to polycarbonate, thermal resistance which cannot be exhibited by common aliphatic polyester, melt flowability superior to common aromatic polycarbonate and other excellent characteristics, and thus can be widely used for processed articles which require severe properties.

Degradable copolymer and preparation process thereof

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

A preparation process of aliphatic polyester having a weight average molecular weight of 15,000 or more by conducting a direct polycondensation reaction of an aliphatic polyhydric alcohol or a mixed aliphatic polyhydric alcohol and an aliphatic polybasic acid or a mixed aliphatic polybasic acid, or additionally a hydroxycarboxylic acid or a mixed hydroxycarboxylic acid or an oligomer of the hydroxycarboxylic acid in a reaction mixture containing an organic solvent. The aliphatic polyester thus obtained contains an extremely small amount of impurities, has low color and can exhibit satisfactory strength in the form of films, filaments and other shaped articles.

Aliphatic polyester and preparation process thereof

.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

Disclosed is an improved process for the preparation of an N-protected .alpha.-L-aspartyl-L-phenylalanine methyl ester from an N-protected L-aspartic anhydride and L-phenylalanine methyl ester, the improvement which comprises employing the L-phenylalanine methyl ester in the form of a mineral acid salt thereof and conducting the reaction either (a) in an organic solvent and in the presence of a salt of an organic carboxylic acid, or (b) in an organic solvent comprising an organic carboxylic acid and in the presence of at least one member of the group consisting of an alkali metal or an alkaline earth metal inorganic base, an ammonium alkali metal or alkaline earth metal salt of an organic carboxylic acid and ammonium carbonate. The starting N-protected aspartic anhydride, e.g., N-benzyloxycarbonyl-L-aspartic anhydride, can be produced by the reaction of N-protected aspartic acid with phosgene. When the N-protecting group sibenzyloxycarbonyl and the solvent is acetic acid, the desired product can be isolated from the reaction mixture in crystalline form in high purity by adding water thereto.

Preparation of N-protected .alpha.-L-aspartyl-L-phenylalanine methyl

A method for separating .alpha.-L-aspartyl-L-phenylalanine methyl ester (.alpha.-APM) from a solution containing .alpha.-APM and impurities associated with the production thereof which comprises adding a mineral acid or an organic sulfonic acid to the solution in an organic carboxylic acid or in a solvent containing an organic carboxylic acid, and isolating the pure salt of .alpha.-APM which precipitates therefrom.

Separation method of .alpha.-l-aspartyl-l-phenylalanine methyl ester

A method for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester (.alpha.-APM), substantially free from acid ion contamination, is disclosed which comprises the steps of contacting a solution of a mineral acid salt or an organic sulfonic acid salt of .alpha.-APM in an aqueous solvent with an anion exchange resin in free base form, separating the resin from the thus-produced solution of .alpha.-APM; and isolating the .alpha.-APM therefrom, preferably with regeneration and recycling the resin.

Method for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester

A cyclical process for producing and isolating a mineral acid salt of an amino acid methyl ester in high purity and yield from the reaction solution produced by esterifying an amino acid with methanol in methanol in the presence of a mineral acid, by cooling the resulting reaction solution to precipitate crystals of the mineral acid salt; filtering the crystals;

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Kamakura, Japan

Chojiro Higuchi