초록

Water supplies are treated to inhibit the formation of scale deposits of alkaline earth phosphates, phosphonates, sulphates and carbonates using various hydrocarbon polymers which contain an amido functionality and which have been prepared by post-polymerization derivatization.

대표청구항 ▼

A method of controlling scale deposits by adding to waters having a tendency to form scale, a scale-inhibitorily effective amount of a derivatized maleic anhydride polymer having N-substituted maleamic units, N-substituted maleimide units and maleic acid (and salts) units, said units having respecti

A method of controlling scale deposits by adding to waters having a tendency to form scale, a scale-inhibitorily effective amount of a derivatized maleic anhydride polymer having N-substituted maleamic units, N-substituted maleimide units and maleic acid (and salts) units, said units having respectively structures as follows: [Figure] wherein R1, R2 and R3 are each independently chosen from the group consisting of hydrogen, sulfonic acid substituted phenyl, and linear or branched sulfonic acid substituted alkyl of from one to ten carbon atoms and combinations thereof, wherein at least one of R1, R2 and R3 is sulfophenyl or sulfoalkyl, and wherein M+is H+, alkali metal ion, alkaline earth metal ion, ammonium ion or zinc ion, and wherein the total moles of N-substituted maleamic units, N-substituted maleimide units and maleic acid (and salts) units in said derivatized maleic anhydride polymer is n, wherein n is a number in the range of from 10 to about 1200, wherein the total moles of said N-substituted maleamic units in said derivatized maleic anhydrided polymer is xn, wherein x is a number from about 0.5 to about 0.95 and n is as defined above; wherein the total moles of said N-substituted maleimide units in said derivatized maleic anhydride polymer is yn, wherein y is a number from about 0.05 to about 0.95, and n is as defined above; wherein the total moles of said maleic acid and salts units in said derivatized maleic anhydride polymer is zn, wherein z is a number from about 0.05 to about 0.95 and n is as defined above; and wherein x+y+z=1.