Process for producing a water-soluble vinyl polymer
AssigneesJapan Atomic Energy Research Institute, Taki Chemical Co., Ltd.
InventorsJiro Okamoto, Isao Ishigaki, Hironobu Fukuzaki, Shozo Shimbo, Kiyoaki Yoshikawa
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Abstract
A water-soluble vinyl polymer is produced by polymerizing a water-soluble vinyl monomer in the presence of a catalyst or under the action of ultraviolet rays to prepare a polymer having a degree of polymerization of at least 95%, adjusting the water content of the system containing said polymer to be within the range of from 15 to 30%, and irradiating said system with ionizing radiation.
Claims4
A process for producing a water-soluble vinyl polymer which comprises
- polymerizing a water-soluble vinyl monomer selected from the group consisting of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate;
- a tertiary amine salt thereof;
- a quaternary ammonium salt thereof;
- acrylic acid, methacrylic acid and an ester thereof;
- acrylamide and methacrylamide;
- in the presence of a catalyst or under the action of ultraviolet rays to prepare a water-soluble polymer having a degree of polymerization of at least 95%,
- adjusting the water content of the system containing said polymer to be within the range of from 15 to 30%, and
- then irradiating said system with ionizing radiation at a dose rate of 500 to 200,000 rad/m. to substantially reduce the residual monomer content without insolubilizing the polymer.
A process according to any of the preceding claims wherein the system is irradiated with ionizing radiation in a nitrogen atmosphere.
A process according to any one of the preceding claims wherein the ionizing radiation is gamma-rays.
Dependencies are inferred from the claim text.