PURPOSE: In polymerizing an aqueous solution of a water-soluble ethylenic unsaturated monomer, to obtain a water-absorbing material useful as a water- retaining agent for agriculture, sanitary material, etc., having improved water- absorbing rate for a salt solution or the blood, by adding a surface active agent to the polymerization system during polymerization or after polymerization.
CONSTITUTION: An aqueous solution of a water-soluble ethylenic unsaturated monomer (e.g., acrylic acid, etc.) is dispersed or suspended in a hydrocarbon or a halogenated hydrocarbon in the presence of an oil-soluble cellulose or cellulose ester, and polymerized with a water-soluble radical polymerization initiator. In the polymerization, an aqueous and/or water-dispersed surface active agent (preferably nonionic surface active agent and anionic surface active agent having ≥7; HLB polyoxyethylene alkyl ether, sodium oleate, etc.) is added to the polymerization system during polymerization or after polymerization, to give a water-absorbing material having improved water absorption properties.
TSUNODA YUUZOU
HARADA SHIYOUICHIROU
| JPS56143205A | 1981-11-07 |