| 摘要 |
PROBLEM TO BE SOLVED: To provide a muddy water stabilizer for drilling excellent in dispersion stability of clay, having sufficient freeness even if the contents of the clay is small, and little deteriorate of the filtrability with time and by mixing of earth or sand. SOLUTION: This muddy water stabilizer comprises a urethane compound represented by the general formulae: X-(A<1> -O)a-(C=O)-NH-R<1> -[-NH-(C=O)-(O-A<1> ) a-X]m (1), R<2> - -O-(A<2> -O)b-[-(C=O)-NH-R<3> -NH-(C=O)-(O-A<3> )c]p -O-(C=O)-NH-R<4> }n (2), and R<2> - -O-(A<2> -O)b-(C=O)-NH-R<3> -NH-(C=O)-[(O-A<3> )c-O-(C=O)-NH-R<3> -NH-(C =O)-]q -(O-A<4> )d-X}n (3), and its 0.5% aqueous solution has a cloud point of not lower than 50 deg.C. |
