Mitsui Toatsu Chemicals, Incorporated

Shiro Asano

Kiyotaka Yoshimura

Tadatoshi Honda

Yoshihiko Kambara

Masao Hashimoto

Kohei Shizuka

Junji Mikami

Hiroshi Kato

Nobuyoshi Hashimoto

Mutsuo Matsumura

Mareo Tokunaga

Wataru Isozaki

Syoji Kitado

Ryozi Tsuchiya

Ryoji Tsuchiya

Kenichi Hirakawa

Masao Yamaguchi

A catalyst useful in the practice of a process, in which (meth)acrylamide is prepared through the hydration reaction between (meth)acrylonitrile and water in a suspended liquid-phase bed of a Raney copper catalyst, has been obtained by leaching a Raney copper alloy in the presence of the Raney copper catalyst which has been deteriorated. The above useful catalyst has higher performances, compared with a catalyst obtained by conventionally leaching the Raney copper alloy alone, has satisfactory handling properties in settling and filtering, and can significantly reduced the amount of catalyst to be discarded.

Preparation process of (meth)acrylamide

Acrylamide crystals are prepared from an aqueous solution of acrylamide by causing the aqueous solution and a coolant to flow inside each electrolytically-polished cooling tube of a double-walled or shell-and-tube heat exchanger and outside the cooling tube, respectively, instead of relying upon vacuum crystallization.

Preparation process of acrylamide crystals

In a process for producing acrylamide by hydrating acrylonitrile in the presence of a copper-based catalyst, the reaction is carried out in the presence of 30 to 10,000 ppm of acetone in the reaction solution. According to this process, the activity of the copper-based catalyst is maintained and the economic advantage of acrylamide production is enhanced.

Process for production of acrylamide

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 for converting acrylonitrile to the corresponding amide by hydrating said nitrile in the presence of a metallic copper catalyst and aluminum nitrate as promoter for said catalyst.

Process for manufacturing an amide compound using aluminum nitrate

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

A method for economically concentrating an acrylamide aqueous solution by catalytic hydration without substantial deterioration in the product. According to the method, an acrylamide aqueous solution obtained from catalytic hydration, is concentrated by distillation while maintaining the solution in good contact with at least 0.1 mole. or more of air per mole of water distilled from the acrylamide aqueous solution.

Method for concentrating an acrylamide aqueous solution

A process for continuously manufacturing acrylamide by hydrating acrylonitrile in the presence of a free metallic copper catalyst, characterized in that a reactor is employed, which is internally partitioned into a catalyst slurry circulating section and a catalyst precipitating section, and that raw materials and supplementary catalyst are supplied continuously into the reactor and at the same time the clear reaction liquid and a portion of the catalyst are continuously taken out of the reactor so that the properties of the catalyst are maintained constant.

Process for continuously manufacturing acrylamide

An improved process for preparing acrylamide or methacrylamide which process comprises the step of reacting acrylonitrile or methacrylonitrile with water in the presence of a catalyst system consisting of a metallic copper containing catalyst and a copper salt promoter, said copper salt being copper sulfate, copper nitrate, copper halide, or a copper salt of a lower fatty acid.

Process for the production of acrylamide and methacrylamide

A method of purifying an aqueous solution of acrylamide, which has been formed by reacting acrylonitrile with water in the presences of the metallic copper catalyst, and which contains cuprous ions, comprising treating said aqueous solution in a reaction zone which is substantially free of an oxygen containing gas or liquid.

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Takaishi, Japan

Shiro Asano