Mitsui Chemicals, Inc.

Mitsui Toatsu Chemicals, Incorporated

Yoshihiro Irizato

Toshio Katoh

Makoto Sukegawa

Teruyuki Nagata

Masaru Wada

Hiroaki Tamatani

Yoshinobu Kanemura

Akinori Nagatomo

Shinichi Umeda

Keisuke Takuma

Koju Okazaki

Masayuki Furuya

Mamoru Tanaka

Shinji Ogawa

Chitoshi Shimakawa

Chiyuki Kusuda

Hiroshi Naruse

Kimitoshi Katho

Susumu Fukawa

Katsuhiko Machida

A production process of high molecular weight polysuccinimide having a weight average molecular weight of 40,000 or higher is disclosed, which comprises the following steps: 1) mixing and heating aspartic acid and an acidic catalyst to produce a liquid, low molecular weight polymer mixture, 2) separating the acidic catalyst to appropriate extent from the liquid, low molecular weight polymer mixture, thereby directly changing a polymer-containing phase from a liquid phase into a solid phase to produce a solid, low molecular weight polymer mixture, and 3) conducting solid-state polymerization on the thus-obtained solid, low molecular weight polymer mixture. This process can be practiced in a simple apparatus, and is free of problems such as formation of a highly viscous phase, excessive formation of foam, and formation of a reaction mixture into coherent mass.

Production process of polysuccinimide

A process is disclosed for producing with good productivity a cross-linked polyaspartic acid resin having biodegradability and high water absorbency. The process features inclusion of one of the following steps: (a) a polysuccinimide, which has been brought into a dispersed state by a dispersant, and a cross-linking agent are reacted to produce the cross-linked polyaspartic acid resin; (b) imide rings of a cross-linked polysuccinimide are subjected to a hydrolysis reaction while controlling a swelling degree of a resulting gel, whereby the cross-linked polyaspartic acid resin is produced; and (c) a gel of a cross-linked polysuccinimide, which has been obtained by reacting a cross-linking agent to a solution of a polysuccinimide in an organic solvent, is disintegrated to subject imide rings of the cross-linked polysuccinimide to a hydrolysis reaction, so that the cross-linked polyaspartic acid resin is produced. The process may also include one or both of the following steps as needed: (d) a gel of the cross-linked polyaspartic acid resin is washed with water and/or a water-miscible organic solvent; and (e) the polysuccinimide is produced using a basic amino acid as a cross-linking agent.

Production process of cross-linked polysuccinimide resin

Production process of cross-linked polyaspartic acid resin

A cross-linked polymer containing, in its molecule, recurring units represented by the following formula (1), and having biodegradability and high water-absorbency: ##STR1## wherein R.sub.1 is a pendant group having at least one functional group selected from the group consisting of acidic groups and salts thereof, a glycino group and salts thereof, cationic groups and betaine groups; X.sub.1 is NH, NR.sub.1 ', R.sub.1 ' being an alkyl, aralkyl or aryl group, O or S; and n.sub.1 is 1 or 2.

Cross-linked polymer

A composition for polysulfide-based resin comprising a polythiol having 4 or more functional groups and a compound having a reactive unsaturated bond(s) and/or b epoxy group(s) and/or c iso(thio)cyanato group(s) in one molecule (however, a+b+c.gtoreq.2, and a and b are not simultaneously 0). A polysulfide-based resin obtained by curing the composition, an optical material comprising the resin, a lens consisting of the optical material and a method for producing the polysulfide-based resin are also set forth.

Polysulfide-based resin composition, polysulfide-based resin, and

The present invention discloses a sulfur-containing urethane-based resin composition of the present invention is directed to a sulfur-containing urethane-based resin composition which comprises a polythiol compound represented by formula (1): ##STR1## wherein X.sub.1, X.sub.2 and X.sub.3 each is a hydrogen atom or a mercapto group; x, y and z each is an integer of 0 to 8; and in their combinations, formula (1) has at least two mercapto groups, a polyiso(thio)cyanate compound, and a compound having two or more reactive unsaturated groups in an amount of 30 to 70% by weight based on the total weight of the composition, or a sulfur-containing urethane-based resin composition which comprises the polythiol compound represented by formula (1), the polyiso(thio)cyanate compound, the compound having two or more reactive unsaturated groups in an amount of 10 to 70% by weight based on the total weight, and a photopolymerization catalyst.

Sulfur-containing urethane-based resin composition, its resin, and

A process for the preparation of 4-methoxy-2,2',6-trimethyldiphenylamine, which comprises heating and reacting 2,6-dimethylcyclohexanone and 2-methyl-4-methoxyaniline in the presence of a dehydrogenation catalyst while removing the resultant hydrogen and water from the reaction system.

Process for the preparation of 4-methoxy-2,2',6'-Trimethyldiphenylamine

Preparation process of

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Kanagawa, Japan

Yoshihiro Irizato