Mitsui Toatsu Chemicals, Incorporated

Kuraray Co., Ltd.

Kohei Shizuka

Masahiro Kouno

Masanori Osawa

Kazumi Mizutani

Hiromi Nakano

Akihiro Yamaguchi

Shiro Asano

Junji Mikami

Tadatoshi Honda

Hiroshi Kato

Akio Ohmory

Yoshihiko Kambara

Akio Matsuyama

Akitsugu Akiyama

Shoji Asano

Teruo Hyugaji

Toshimasa Hashimoto

Hirotoshi Katsuoka

Mutsuo Matsumura

Toshihiro Toyoda

Kenichi Hirakawa

Akira Miyamoto

Disclosed is a method for measuring the thermal diffusivity in the thickness direction of a thin sample plate, which has the steps of forming a conductive thin layer on at least one surface of said thin sample plate to allow the thin film to function as an ac heater generating joule heat, applying an ac current modulated with a given modulation frequency to the ac heater (conductive thin layer) so as to produce ac joule-heating, generating an oscillation response corresponding to said ac joule-heating on the opposite surface of the ac heater, and measuring the phase shift between said oscillation response, and the ac joule-heating, thereby obtaining the thermal diffusivity in the thickness direction of said sample plate. Apparatus useful for the method are also disclosed.

Method and apparatus for measuring thermal diffusivity by ac

Aromatic polyamide having good high-temperature resistance and processing ability is obtained by specifying the ratio of storage modulus at the glass transition temperature (Tg).degree.C. to that of (Tg+100).degree.C.

Aromatic polyamide molded article having storage modulus

A polyamide and/or polyimide is prepared by using N,N'-dimethylethyleneurea or N,N'-dimethylpropyleneurea as a solvent upon polycondensation of a polycarboxylic acid and a diisocyanate at a temperature above 100.degree. C. in the presence of an alkali metal carbonate, alkali metal hydrogencarbonate, alkali metal hydroxide or an alkali metal salt of a polycarboxylic acid.

Catalytic preparation of polyamide or polyamide-polymide with

Disclosed herein is a process for preparing heat-resistant polymers by reacting an organic polyisocyanate with one or more compounds selected from the group consisting of organic polycarboxylic acids and organic polycarboxylic acid anhydrides in the presence of an alkali metal fluoride or an alkali metal fluoride combined with a quaternary onium salt as a catalyst.

Preparation process of heat-resistant polymers from polycarboxylic acids

Heat resistant organic fibers comprising a wholly aromatic polymer having amide group and/or imide group, said fibers having properties satisfying the following formulas

Heat resistant organic synthetic fibers and process for producing the

Preparation process of heat-resistant polymers from polycarboxcylic

An aqueous solution of acrylamide obtained by catalytic hydration of acrylonitrile in the presence of a copper-based catalyst is purified by the steps, in sequence, of (a) removal of the unreacted acrylonitrile, (b) removal of copper, (c) treatment under basic conditions, (d) cation exchanging treatment and (e) weakly basic anion exchanging treatment. The acrylamide obtained by this process has good storage stability. An acrylamide polymer produced from this monomer is useful as a flocculant having a reduced content of the unreacted monomer, a high molecular weight and excellent solubility in water.

Process for purifying an aqueous solution of acrylamide

An improved process is disclosed for the purification of an aqueous solution of acrylamide. It comprises bringing a crude aqueous solution of acrylamide into contact with oxygen or an oxygen-containing gas and thereafter subjecting the solution to a dual treatment with a strongly acidic cation exchange resin followed by a weakly basic anion exchange resin. If necessary, the aqueous solution of acrylamide is treated, while maintaining its oxygen content at least at 4ppm and then subjected to the treatment with the ion exchange resins.

Purification of an aqueous solution of acrylamide

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Fujisawa, Japan

Kohei Shizuka