| 摘要 |
PROBLEM TO BE SOLVED: To improve water-absorbent capacity, liquid-absorbent capacity, retention of water-absorbent resin after water-absorption, and moldability to a plate, particularly to a thick plate, by crosslinking/expanding a water-absorbent resin composition comprising a thermoplastic polyolefin, a crosslinking product of an N-vinylcarboxylic acid amide polymer, an expanding agent and a crosslinking agent. SOLUTION: The crosslinked product of an N-vinylcarboxylic acid amide polymer can be prepared by adding, to an N-vinylcarboxylic acid amide monomer represented by the formula: CH2-CH-NR1-CO-R2 wherein R1 and R2 are independently a hydrogen atom or a 1-3C alkyl group or to a monomer mixture containing 50 wt.% or more of the monomer, a crosslinkable compound having at least two polymerizable unsaturated bonds in the molecule, and using a radical polymerization initiator in the substantial absence of oxygen. The blending proportions of the water-absorbent resin composition are, by weight, 100 pts. of a thermoplastic polyolefin, 5-400 pts. of crosslinked product of an N- vinylcarboxylic acid amide polymer, 0.1-30 pts. of an expanding agent and 0.1-5 pts. of a crosslinking agent.
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