Stable compositions for use as corrosion inhibitors

Claim 2

A composition comprising in combination: (i) water-soluble zinc compound, (ii) water-soluble chromate compound, and (iii) water-soluble polymer comprising moieties derived from acrylic acid or water-soluble salt thereof and moieties of hydroxylated lower alkyl acrylate, wherein the moieties of said polymer have the following formulas: ##STR4## where R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, NH 2 or OM where M is a water-soluble cation; R 2 is a lower alkyl of about 2 to 6 carbon atoms, R 3 is H or lower alkyl of from 1 to 3 carbon atoms and the mole ratio of x:y is 1:4 to 36:1, said polymer being capable of retaining a corrosion inhibiting amount of said zinc compound in soluble form in said aqueous medium.

Claim 3

The composition of claim 1, wherein on a weight basis said zinc compound comprises about 1 to 95%, said chromate compound comprises about 1 to 98%, and said polymer comprises about 1 to 95% of the total amount of water-soluble zinc compound, water-soluble chromate compound and water-soluble polymer.

Claim 4

The composition of claim 2, wherein said polymer has a molecular weight of about 1,000 to 50,000.

Claim 5

The composition of claim 3, wherein the pH of said aqueous solution is about 6.5 to 9.5.

Claim 6

The composition of claim 1, comprising a stable aqueous solution of said components (i)-(iii).

Claim 7

The composition of claim 5, wherein said polymer has a molecular weight of about 1,000 to 50,000.

Claim 8

The composition of claim 6, wherein the pH of said aqueous solution is about 6.5 to 9.5.

Claim 9

The composition of claim 1, 3 or 6 wherein the mole ratio of x:y is about 1:1 to 11:1.

Claim 10

The composition of claim 8, wherein said polymer has a molecular weight of about 2,000 to 6,000.

Claim 11

The composition of claim 9, wherein the pH of said aqueous solution is about 6.5 to 9.5.

Claim 12

The composition of claim 7, wherein said polymer is acrylic acid/hydroxypropylacrylate.

Claim 13

The composition of claim 11, wherein the mole ratio of x:y is about 1:1 to 5:1.

Claim 14

A composition comprising in combination: (i) water-soluble zinc compound, (ii) water-soluble chromate compound, (iii) water-soluble orthophosphate or precursor thereof, and (iiii) water-soluble polymer comprising moieties derived from acrylic acid or water-soluble salt thereof and moieties of hydroxylated lower alkyl acrylate, wherein the moieties of said polymer have the following formulas: ##STR5## where R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, NH 2 or OM where M is a water-soluble cation; R 2 is a lower alkyl of about 2 to 6 carbon atoms, R 3 is H or lower alkyl of from 1 to 3 carbon atoms and the mole ratio of x:y is 1:4 to 36:1, said polymer being capable of retaining a corrosion inhibiting amount of said zinc compound in soluble form in said aqueous medium.

Claim 15

A composition comprising in combination: (i) water-soluble zinc compound, (ii) water-soluble chromate compound, (iii) water-soluble orthophosphate or precursor thereof, and (iiii) water-soluble polymer comprising moieties derived from acrylic acid or water-soluble salt thereof and moieties of hydroxylated lower alkyl acrylate, wherein the moieties of said polymer have the following formulas: ##STR5## where R is hydrogen or a lower alkyl of from 1 to 3 carbon atoms; R 1 is OH, NH 2 or OM where M is a water-soluble cation; R 2 is a lower alkyl of about 2 to 6 carbon atoms, R 3 is H or lower alkyl of from 1 to 3 carbon atoms and the mole ratio of x:y is 1:4 to 36:1, said polymer being capable of retaining a corrosion inhibiting amount of said zinc compound in soluble form in said aqueous medium.

Claim 16

The composition of claim 13, wherein on a weight basis, said zinc compound comprises about 1 to 95%, said orthophosphate comprises about 1 to 95%, said chromate compound comprises about 1 to 97%, and said polymer comprises about 1 to 97% of the total amount of water-soluble zinc compound, water-soluble orthophosphate or precursor, water-soluble chromate and water-soluble polymer.

Claim 17

The composition of claim 14, wherein said polymer has a molecular weight of about 1,000 to 50,000.

Claim 18

The composition of claim 15, wherein the pH of said aqueous solution is about 6.5 to 9.5.

Claim 19

The composition of claim 13, 15 or 16, comprising a stable aqueous solution of said components (i)-(iiii).

Claim 20

The composition of claim 17, wherein the mole ratio of x:y is about 1:1 to 11:1.

Claim 21

The composition of claim 18, wherein said polymer has a molecular weight of about 2,000 to 6,000.

Claim 22

The composition of claim 19, wherein said polymer is acrylic acid/hydroxypropylacrylate.