| 摘要 |
<p>PURPOSE:To improve an absorbing capacity for a concd. aq. soln. of inrog. salts by consisting the adosrbent essentially of a copolymer of 50-99.8mol% vinyl acetate of which >=70mol% is saponified and 50-0.2mol% unsatd. dicarboxylic acid monomer. CONSTITUTION:A copolymer is obtained by ordinary soln. polymn. of 50- 99.8mol% vinyl acetate and 50-0.2mol% unsatd. discarboxylic acid monomer such as maleic acid, fumaric acid or the like. The copolymer is saponified by using an alkali catalyst such as caustic soda, caustic potash or the like to prepare the copolymer wherein >=70mol% is saponified. The saponified matter contains the solvent in the stage of the soln. polymn. and the acetate by-produced by saponification, etc.; therefore, these are removed by heating at 50- 110 deg.C, whereafter said matter is dried by heating. The resulted powder is subjected to a heat treatment, whereby the adsorbent for a concd. aq. soln. of inorg. salts is obtained.</p> |
