| abstract |
PURPOSE: To obtain a resin having properties suitable as a water absorbing agent in a sanitary material field and improved safety, by polymerizing an α,β-unsaturated carboxylic acid by the use of a specific polyglycerin fatty acid ester as a surface active agent. n CONSTITUTION: In polymerizing ≥25wt% aqueous solution of an α,β-unsaturated carboxylic acid (e.g., acrylic acid, etc.,) and an alkali metallic salt thereof by the use of a radical polymerization initiator (e.g., potassium persulfate, etc.,) in a petroleum hydrocarbon solvent (e.g., n-heptane, benzene, xylene, etc.,) optionally in the presence of a crosslinking agent (e.g., N,N-methylene bisacrylamide, etc.,), a polyglycerin fatty acid ester (e.g., diglyceryl monobehenilate, etc.,) shown by the formula (R is acyl or H; n is 0W8) having 2W16 HLB is used as a surface active agent. The amount of the surface active agent used is 0.05W15wt%, preferably 0.1W10wt% based on the monomer. n COPYRIGHT: (C)1987,JPO&Japio |