Scale inhibiting copolymer

Claim 1

A composition for treating a predominantly aqueous stream to inhibit the deposition of precipitates selected from the group consisting of calcium phosphate, magnesium phosphate, zinc phosphate, calcium silicate, magnesium silicate, magnesium hydroxide, zinc hydroxide, iron oxide and mixtures thereof, said composition comprising an effective amount for the purpose, of a water-soluble essentially non-crosslinked random copolymer consisting essentially of a copolymer of acrylic acid or methacrylic acid, acrylamide or methacrylamide, and an alkoxylated primary alcohol ester of (meth)acrylic acid, the copolymer having the structural formula ##STR2## wherein X represents H, or NH 4 , or an alkali metal selected from the group consisting of sodium and potassium; R 1 represents H, or methyl; R 2 represents alkyl having from 2 to about 4 carbon atoms; R 3 represents alkyl having from 1 to about 10 carbon atoms; n is an integer in the range from 2 to about 6; m is an integer in the range from about 3 to about 70; and, for each y (that is, y=1) x is an integer in the range from about 1 to about 8, and z is a number in the range from 1 to about 0.075; and x, y and z are present in relative heterogeneous order.