Water soluble polymers and methods of use thereof

Claim 1

A method of controlling the deposition of calcium phosphate or phosphonate on the structural parts of a system exposed to an aqueous medium, which comprises adding to said aqueous medium an effective amount for the purpose of a water soluble polymer comprising repeat unit moieties (a) and (b), wherein said repeat unit (a) comprises and wherein-said repeat unit-(b) comprises the structure wherein Rl is H or lower alkyl (C 1 -C 3 ), R 2 is OH, OM, or NH 2 , M is a water soluble cation, R 3 is a hydroxy substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms or a non-substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms, X is an anionic radical, Z is H or hydrogens or a water soluble cation or cations which together counterbalance the valence of X, and a is 0 or 1.

Claim 2

A method of controlling the deposition of calcium phosphate or phosphonate on the structural parts of a system exposed to an aqueous medium, which comprises adding to said aqueous medium an effective amount for the purpose of a water soluble polymer comprising repeat unit moieties (a) and (b), wherein said repeat unit (a) comprises and wherein-said repeat unit-(b) comprises the structure wherein Rl is H or lower alkyl (C 1 -C 3 ), R 2 is OH, OM, or NH 2 , M is a water soluble cation, R 3 is a hydroxy substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms or a non-substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms, X is an anionic radical, Z is H or hydrogens or a water soluble cation or cations which together counterbalance the valence of X, and a is 0 or 1.

Claim 3

A method as claimed in claim I for controlling the deposition of calcium phosphate on the structural parts of a system exposed to an aqueous medium containing calcium cations and phosphate anions under deposit forming conditions.

Claim 5

A method as claimed in any of claims 1 to 3, in which the water soluble polymer comprises a third repeat unit moiety (c), said repeat unit (c) comprising a monomeric repeat unit selected from acrylic acid, alkyl acrylate, hydroxylated lower alkyl (C 1 - C 6 ) acrylate, methacrylic acid, and acrylamide and water soluble salt forms thereof, with the proviso that repeat unit (a) and repeat unit (c) are different.

Claim 6

A method as claimed in any of claims 1 to 4, in which R i is hydrogen, R 2 is OH or OM, R 3 is 2-hydroxypropylidene, X is S0 3 , and Z is a member or members selected from H, Na, NH + 4 , Ca and K and wherein a is one.

Claim 7

A method as claimed in any of claims 1 to 5, in which the number average molecular weight of said water soluble polymer is between about 1,000 to 1,000,000 and wherein the molar ratio x:y is between 10:1 and 1:5 and wherein said system is a cooling water system.

Claim 8

A method of inhibiting the corrosion of ferrous metal parts in contact with an aqueous solution with little or no attendant deposition of scale on said ferrous parts, which corrosion inhibition is obtained by providing for the formation of a protective passive oxide film on the metal surface in contact with said aqueous medium, which method comprises adding to said aqueous medium (A) a water soluble polymer comprising repeat unit moieties (a) and (b) wherein said repeat unit (a) comprises the structure and wherein said repeat unit (b) comprises the structure wherein R 1 is H or lower alkyl (C i -C 3 ), R 2 is OH, OM, or NH 2 , M is a water soluble cation, R 3 is a hydroxy substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms or a non-substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms, X is an anionic radical, Z is H or hydrogens or a water soluble cation or cations which together counterbalance the valence of X, and a is 0 or 1, and (B) a water soluble orthophosphate compound, said polymer and the orthophosphate compound being sufficient to provide a substantially scale-free protective passive oxide film on the metallic surface.

Claim 9

A method of inhibiting the corrosion of ferrous metal parts in contact with an aqueous solution with little or no attendant deposition of scale on said ferrous parts, which corrosion inhibition is obtained by providing for the formation of a protective passive oxide film on the metal surface in contact with said aqueous medium, which method comprises adding to said aqueous medium (A) a water soluble polymer comprising repeat unit moieties (a) and (b) wherein said repeat unit (a) comprises the structure and wherein said repeat unit (b) comprises the structure wherein R 1 is H or lower alkyl (C i -C 3 ), R 2 is OH, OM, or NH 2 , M is a water soluble cation, R 3 is a hydroxy substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms or a non-substituted alkyl or alkylene radical having from 1 to about 6 carbon atoms, X is an anionic radical, Z is H or hydrogens or a water soluble cation or cations which together counterbalance the valence of X, and a is 0 or 1, and (B) a water soluble orthophosphate compound, said polymer and the orthophosphate compound being sufficient to provide a substantially scale-free protective passive oxide film on the metallic surface.

Claim 12

A method as claimed in any of claims 7 to 9, in which the number average molecular weight of said water soluble polymer is between about 1,000 to 1,000,000 and wherein the molar ratio x:y is between 10:1 to 1:5 and wherein said aqueous medium comprises a cooling water system.