| 摘要 |
a method of treating an aqueous system comprising adding to the system a water-soluble tri-copolymer having the formula I: (A)x(B)y(C)z I or a salt thereof, wherein A is a group having the formula: <CHEM> or a hydrolysed (dicarboxylic acid or salt) form of this group; B is a group having the formula: -CH2-C(R1)(CO2R2)- wherein R1 is hydrogen or methyl, and R2 is hydrogen or C1-C8 straight- or branched chain alkyl, preferably methyl or ether, or R2 is C1-C8 straight- or branched chain alkyl substituted by a group -OR3 wherein R3 is hydrogen or a group of formula -[CH2CH(R4)O]nH wherein R4 is hydrogen or methyl and n is an integer from 1 to 10; C is a group having the formula: -CH(R5)-C(R6)(R7)- wherein R5 is hdrogen, phenyl or C1-C18 straight- or branched chain alkyl, preferably hydrogen and R6 and R7, independently, are hydrogen, C1-C18 straight- or branched chain alkyl, phenyl or substituted phenyl, and x, y and z are integers, so chosen that 1) the molar ratio of A in the tri-copolymer ranges from 30 to 80 % by weight; the molar ratio of B in the tri-copolymer ranges from 10 to 40 % by weight; and the molecular ratio of C ranges from 10 to 30 % by weight; and 2) the molar weight of the tri-copolymer is within the range of from 600 to 10,000. |
