PURPOSE: To provide the titled compsn. which has a high capacity of absorbing solutions contg. salts. and a high initial water absorption rate and does not form undissolved lump, consisting of a specified water-absorbing polymer and crystalline cellulose.
CONSTITUTION: An α,β-unsaturated carboxylic acid or its metal salt [e.g., sodium (meth)acrylate] is subjected to reversed phase suspension polymerization with not more than 20wt% other copolymerizable monomer (e.g., acrylamide) in an high, petroleum hydrocarbon solvent having a b.p. of 30W200°C (e.g., n-butane) in the presence of a surfactant having an HLB of 0.8 or above (e.g., polyoxyethylene alkyl ether), a polymn. initiator (e.g., ammonium persulfate), a crosslinking agent (e.g., N,N-methylenebisamide), etc., to obtain a water- absorbing polymer (A) having carboxyl groups and/or carboxylate groups in the molecule. 0.3W80pts.wt. crystalline cellulose (B) having an average particle size of 40W120μ, represented by the formula, is sprinkled over 100pts.wt. component A.
SASAKI MASAJI
MIYAWAKI YOZO
