Mitsubishi Rayon Company, Limited

Nitto Chemical Industry Co., Ltd.

Diafloc Co., Ltd.

Nitto Kagaku Kogyo Kabushiki Kaisha

Nobuo Kurashige

Ryoji Handa

Jun Hosoda

Akihisa Furuno

Yasuo Ogawa

Norimasa Yoshida

Kenzo Ariyama

Susumu Seki

Osamu Okushima

Acrylamide polymers having remarkably high molecular weights can be obtained by polymerizing acrylamide or a monomer mixture comprising a preponderant quantity of acrylamide in an aqueous medium with the use of a specific redox initiator and a specific azo compound initiator. The polymerization initiator used in this porcess comprises a combination of a persulfate, formaldehyde sodium sufoxylate and 2,2'-azobis-2-amidinopropane.

Process for preparing acrylamide polymers

In the production of a dried acrylamide polymer by polymerizing, in an aqueous medium, acrylamide alone or a monomer mixture comprising 50 mole % or more of acrylamide and at least one monomer copolymerizable therewith with a radical initiator, and then drying the resulting hydrous acrylamide polymer, the allowing of at least one of the following compounds [I], [II] and [III] to be present in the drying step or a step prior thereto enables the dried acrylamide polymer having a high molecular weight and a good dissolvability in water to be obtained:

Method for preparing acrylamide polymers

In the production of a dried acrylamide polymer by polymerizing, in an aqueous medium, acrylamide alone or a monomer mixture comprising 50 mole % or more of acrylamide and at least one monomer copolymerizable therewith with a radical initiator, and then drying the resulting hydrous acrylamide polymer, the allowing of 2-mercaptobenzimidazole to be present in the drying step or a step prior thereto enables the dried acrylamide polymer having a high molecular weight and a good dissolvability in water to be obtained.

Process for producing acrylamide polymers

Growing community of inventors

Yokohama, Japan

Nobuo Kurashige