Aqueous coating compositions and process for treating metal plated substrates

1 . An aqueous composition comprising

(A) an alkanol amine salt of an aliphatic dicarboxylic acid containing at least about six carbon atoms in the aliphatic group,

(B) at least one alkanol amine,

(C) at least one chelating agent, and

(D) water, wherein the composition is free of aliphatic monocarboxylic acids.

2 . The composition of claim 1 also comprising at least one surfactant.

3 . The composition of claim 1 wherein the aliphatic dicarboxylic acid of (A) contains from about 6 to about 22 carbon atoms in the aliphatic group.

4 . The composition of claim 1 wherein the alkanol amine of the salt (A) and the alkanol amine (B) are each independently represented by the formula

R—N—(X)Y

wherein R is a hydroxyalkyl group, and X and Y are each independently hydrogen, an alkyl group or a hydroxyalkyl group.

5 . The composition of claim 1 wherein the alkanol amine of the salt (A) and the alkanol amine (B) are each independently selected from monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, N-diethylethanolamine, N-dimethyl isopropanolamine, N-methyldiethanolamine, and N-ethyldiethanolamine.

6 . The composition of claim 2 wherein the surfactant is a nonionic surfactant.

7 . The composition of claim 1 wherein the composition is free of mineral oil.

8 . The composition of claim 1 which is free of boron compounds capable of reacting with the alkanol amine.

9 . An aqueous composition comprising

(A) an alkanol amine salt of an aliphatic dicarboxylic acid containing at least about six carbon atoms,

(B) at least one alkanol amine, and

(C) at least one metal chelating agent, and

(D) at least one surfactant, and

(E) water, wherein the composition is free of aliphatic monocarboxylic acids.

10 . The composition of claim 9 wherein the alkanol amine of the salt (A) and the alkanol amine (B) are each independently represented by the formula

R—N—(X)Y

wherein R is a hydroxyalkyl group, and X and Y are each independently hydrogen, an alkyl group or a hydroxyalkyl group.

11 . The composition of claim 9 wherein the aliphatic dicarboxylic acid of (A) contains from about 6 to about 22 carbon atoms in the aliphatic group.

12 . The composition of claim 11 which is free of mineral oil.

13 . The composition of claim 9 comprising

(A) from about 0.05 to about 50% by weight of the alkanol amine salt,

(B) from about 0.01 to about 25% by weight of the alkanol amine,

(C) from about 0.005 to about 15% by weight of the chelating agent,

(D) from about 0.0001 to about 5% by weight of the surfactant, and

(E) water.

14 . The composition of claim 9 comprising

(A) from about 0.5 to about 4.5% by weight of the alkanol amine salt,

(B) from about 0.15 to about 2.25% by weight of the alkanol amine,

(C) from about 0.05 to about 1.5% by weight of the chelating agent,

(D) from about 0.002 to about 0.30% by weight of the surfactant, and

(E) water.

15 . The composition of claim 9 which is free of boron compounds capable of reacting with the alkanol amine.

16 . A process for treating a metal plated substrate to improve corrosion resistance and resistance to staining comprising

(A) providing a substrate,

(B) plating the substrate with at least one layer of metal or metal alloy, and

(C) treating the metal plated substrate with an aqueous composition of claim 1 .

17 . The process of claim 16 wherein the substrate is a polymer or metal.

18 . The process of claim 16 wherein the substrate is a non-conductive substrate.

19 . The process of claim 16 wherein a chromate coating is applied to the metal plated substrate before the metal plated substrate is treated with an aqueous composition of claim 1 .

20 . The process of claim 16 wherein the substrate is plated with at least one layer of metal or metal alloy utilizing electroless or electrolytic plating processes.

21 . The process of claim 16 wherein the metal is selected from tin, silver, chromium, bismuth, copper, nickel, manganese, lead, zinc, indium, palladium, platinum, gold, cadmium, ruthenium, cobalt, gallium and germanium, and alloys thereof.

22 . The process of claim 16 wherein the substrate is cleaned and etched prior to plating.

23 . The process of claim 16 wherein the substrate is a polymer substrate, and the polymer substrate is plated with at least one layer of electroless nickel or copper, then plated with electrolytic copper, and thereafter plated with one or more layers of nickel prior to treatment with an aqueous composition of claim 1 .

24 . The process of claim 23 wherein the copper plated and nickel plated polymer substrate is provided with a chromium coating from a trivalent chromium electroplating bath before the plated substrate is treated with the aqueous composition of claim 1 .

25 . The process of claim 24 wherein the chromium coating on the plated polymer substrate is provided with a chromate coating before the plated substrate is treated with an aqueous composition of claim 1 .

26 . The process of claim 16 wherein the substrate is a metal substrate, and the metal substrate is plated with chromium.

27 . The process of claim 26 wherein the chromium is deposited from a hexavalent hard chromium electroplating bath.

28 . The process of claim 16 wherein the treated metal plated substrate obtained in (C) is dried, rinsed with water and again dried.

29 . A process for treating a substrate comprising

(A) providing a substrate,

(B) plating the substrate with at least one layer of metal or metal alloy,

(C) treating the metal plated substrate with an aqueous composition of claim 9 .

30 . The process of claim 29 wherein the treated metal plated substrate obtained in (C) is rinsed with water and dried.

31 . The process of claim 29 wherein the treated metal plated substrate obtained in (C) is dried, rinsed with water and again dried.

32 . The process of claim 16 wherein the substrate is a metal substrate, and the metal substrate is plated with at least one layer of electroless nickel in (B).