MODIFIER FOR EXCAVATION SLURRY AND EXCAVATION SLURRY COMPOSITION CONTAINING SAME

摘要

PROBLEM TO BE SOLVED: To obtain a modifier which provides a high viscosity at a low level of addition and gives an aq. soln. having excellent resistances to heat and salts and a stable viscosity by incorporating a polysaccharide produced by bacteria of the genus Alcaligenes into the same. ;SOLUTION: A polysaccharide produced by Alcaligenes latus B16 strain (FERM BP-2015) is esp. pref. This bacteria are cultured by using a culture medium contg. a carbon source such as a monosaccharide (e.g. fructose or glucose), a disaccharide (e.g. sucrose), a natural polymer (e.g. starch or corn starch), or an oil (e.g. olive oil); an inorg. nitrogen source such as urea, ammonium chloride, ammonium nitrate, or ammonium sulfate; tryptone, an yeast extract, a meat extract, peptone malt extract, or the like; and an inorg. phosphate or the like at a pH of 4-10 at 15-40°C usually under stirring with air flow. The modifier is pref. added to an excavation slurry contg. bentonite usually in an amt. of 0.001-0.5 wt.%.;COPYRIGHT: (C)1999,JPO