Aqueous system containing a synergistic combination including polyether polyamino methylene phosphates for controlling calcium carbonate and calcium phosphate scale
First Claim
1. An aqueous system containing scale forming salts and wherein the pH of said system is at least 8.5 and the calcite saturation level of said system is at least 100 times the solubility limit of calcium as calcite, which further contains a synergistic effective amount of a combination comprising:
- (A) a polyether polyamino methylene phosphonate of the formula;
##STR11## where n is, or on average is, from about 2 to about 12, inclusive;
M is hydrogen or a cation of an alkali metal salt; and
each R may be the same or different and is independently selected from hydrogen and methyl; and
(B) a terpolymer comprising the monomers of acrylic acid, sulfophenomethallyl ether and maleic acid, wherein the weight average molecular weight for said terpolymer is in the range from about 4,000 to 10,000.
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Abstract
An aqueous system containing scale forming salts including both calcium carbonate and calcium phosphate and characterized by high pH and high calcite concentrations which further contains a synergistic effective amount of a combination comprising (A) a polyether polyamino methylene phosphonate, and (B) a terpolymer comprising the monomers of acrylic acid, sulfophenomethallyl ether and maleic acid, is disclosed. A method for inhibiting the formation, deposition and adherence of such scale forming salts in the aqueous system employing the synergistic combination is also provided.
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16 Claims
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1. An aqueous system containing scale forming salts and wherein the pH of said system is at least 8.5 and the calcite saturation level of said system is at least 100 times the solubility limit of calcium as calcite, which further contains a synergistic effective amount of a combination comprising:
- (A) a polyether polyamino methylene phosphonate of the formula;
##STR11## where n is, or on average is, from about 2 to about 12, inclusive;
M is hydrogen or a cation of an alkali metal salt; and
each R may be the same or different and is independently selected from hydrogen and methyl; and
(B) a terpolymer comprising the monomers of acrylic acid, sulfophenomethallyl ether and maleic acid, wherein the weight average molecular weight for said terpolymer is in the range from about 4,000 to 10,000. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
- (A) a polyether polyamino methylene phosphonate of the formula;
Specification