THICKENER FOR EXCAVATION STABILIZATION LIQUID, EXCAVATION STABILIZATION LIQUID AND EXCAVATION METHOD USING SAME, AND ITS TREATMENT METHOD

摘要

PROBLEM TO BE SOLVED: To provide a thickener which hardly forms undispersed lumps of powder when mixed into an aqueous medium and is easily mixed to increase the viscosity by incorporating, into the same, a polymer powder which is obtained by the polymeriza tion of a monomer component having a group of which the hydrophilicity is enhanced when brought into contact with an alkaline substance in the presence of an aqueous medium. SOLUTION: This thickener contains a thickening polymer which has a particle size of 500 m or lower and is prepared by polymerizing a monomer component containing a polymerizable monomer having a group, such as a carboxyl or sulfo group, of which the hydrophilicity is enhanced when brought into contact with an alkaline substance in the presence of an aqueous medium. An excavation stabilization liquid having a pH of 6-13 is prepared by mixing 0.01-20 pts.wt. thickening polymer, 0.1-20 pts.wt. clay mineral (e.g. zeolite), 0.001-3 pts.wt. antifoaming agent (e.g. a silicone) and an alkaline substance into 80-99.9 pts.wt. water. The polymerizable monomer is (meth)acrylic acid, maleic acid, styrenesulfonic acid, vinylphenol, methyl acrylate, hydroxyethyl acrylate or the like.