Process for preparing vinylpyrrolidone polymer
AssigneeDai-Ichi Kogyo Seiyaku Co., Ltd.
InventorsAkira Kitada, Keiichi Fujise, Itsuko Hamaguchi
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Abstract
A vinylpyrrolidone polymer which is little colored, gives off a bad smell little, and contains extremely little impurities is provided. The polymerization is performed by adding a water-soluble organic peroxide and a sulfite to a vinylpyrrolidone aqueous solution.
Claims14
A process for preparing a vinylpyrrolidone polymer, wherein a water-soluble organic peroxide and a sulfite are added to a vinylpyrrolidone aqueous solution to polymerize vinylpyrrolidone, and to obtain a vinylpyrrolidone polymer.
A vinylpyrrolidone polymer containing a little amounts of vinylpyrrolidone, which is obtained by adding a water-soluble organic peroxide and a sulfite to a vinylpyrrolidone aqueous solution to polymerize vinylpyrrolidone.
A vinylpyrrolidone polymer which has a K value evaluated according to Fikentscher method of 10 to 40, and Hazen No. (APHA) value in a 10% aqueous solution according to JIS K3331 of at most 10, and which contains at most 10 ppm of remaining vinylpyrrolidone based on the vinylpyrrolidone polymer.
Dependencies are inferred from the claim text.