Westerman, Hattori, Daniels & Adrian, LLP
Saponification product of vinyl ester/ethylenically unsaturated carboxylic acid ester copolymer and process for producing the same
The present invention provides a saponification product of a vinyl ester/ethylenically unsaturated carboxylic acid ester copolymer having superior tolerance of the aqueous thickening liquid against mechanical shear. More specifically, the present invention provides a saponification product of a vinyl ester/ethylenically unsaturated carboxylic acid ester copolymer having the superior tolerance, by polymerizing a mixture where the molar ratio of the vinyl ester/ethylenically unsaturated carboxylic acid ester is from 8/2 to 3/7, and saponifying the obtained copolymer in a mixed solvent where the mass composition ratio of an aqueous organic solvent/water mixture solvent is from 3/7 to 8/2.
SUMITOMO SEIKA CHEMICALS CO., LTD.
Y C C C C
Y10T C08F C08F C08J C08J
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Tomoaki Yuji Shigeki
Yamasaki Kinpara Hamamoto