METHOD FOR RESTORING COOLING CHARACTERISTICS OF WATER-SOLUBLE HARDENING AGENT AND WATER-SOLUBLE HARDENING AGENT HAVING RESTORED COOLING CHARACTERISTICS

摘要

PROBLEM TO BE SOLVED: To restore the cooling characteristics of a water-soluble hardening agent deteriorated by use to the state close to the state of the fresh liquid by adding an aq. soln. contg. a water-soluble polymer having a specific weight average mol.wt. into the water-soluble hardening agent under use. ;SOLUTION: The aq. soln. contg. the water-soluble polymer (B) having the weight average mol.wt. larger than the weight average mol.wt. of the water-soluble polymer (A) in the water-soluble hardening agent before use is added to the water-soluble hardening agent under use. More adequately, the weight average mol.wt. of the water-soluble polymer B is specified to 1.2 to 20 times the weight average mol.wt. of the water-soluble polymer A. The water-soluble polymers are not particularly limited, insofar as these polymers are usable as the hardening agent. Such polymers adequately include PVA, polyvinyl pyrrolidone, alkaline salts (Na, K, etc.) of polyisobutyrene maleic acid, alkaline salts of polyacrylic acid, polyamide, etc. The weight average mol.wt. of the water-soluble polymers of the fresh liquid before use is preferably 10,000 to 100,000 and further preferably 30,000 to 60,000.;COPYRIGHT: (C)1997,JPO