Granted Patent B2

US 10,570,519 · App. 15/958,276 · Granted Feb 25, 2020

Abstract

Claims (52)

1. A method of coating a metal surface with a conversion coating composition, the method comprising:

applying a metal surface conversion coating composition to a metal surface wherein the conversion coating composition comprises:

(i) at least one metal corrosion inhibitor, wherein the at least one metal corrosion inhibitor is zirconium-containing compound selected from the group consisting of ZrF 4 , Zr(NO 3 ) 4 , H 2 ZrF 6 , (NH 4 ) 2 ZrF 6 , Na 2 ZrF 6 , K 2 ZrF 6 , ZrO[NO 3 ] 2 , Zr[SO 4 ] 2 and ZrOSO 4 ;

or is a titanium-containing compound selected from the group consisting of Ti(OCH 2 CH 3 ) 4 , H 2 TiF 6 , (NH 4 ) 2 TiF 6 , Na 2 TiF 6 , K 2 TiF 6 and Ti[SO 4 ] 2 ;

or, mixtures thereof;

(ii) water; and,

(iii) at least one water soluble dye having the structure of formula (I)

wherein:

G 1 is an organic group having from 1 to about 20 carbon atoms and containing at least one oxygen or nitrogen heteroatom;

A is a nitrogen atom or (−) 3 C—R*, where R* is a monovalent group chosen from alkyl, cycloalkyl, alkenyl, aralkyl or aryl group each having up to about 10 carbon atoms;

R 6 is an alkyl, a hydroxylalkyl, an alkoxyalkyl, a cycloalkyl, an aralkyl optionally substituted with a halogen or alkoxy group, an aryl optionally substituted with a halogen or alkoxy group, a cyanoalkyl, a carbamatoalkyl or a carboalkoxyalkyl group each containing up to about 10 carbon atoms, or hydrogen;

R 7 is an alkyl, alkoxy, aryl alkylsulfonyl, or arylsulfonyl group each containing up to about 10 carbon atoms or hydrogen;

R 8 is an alkyl, alkoxy, aryl alkylsulfonyl, arylsulfonyl, or aminosulfonyl group each containing up to about 10 carbon atoms or hydrogen;

R 9 is an alkyl, alkoxy, aryl alkylsulfonyl, or arylsulfonyl group each containing up to about 10 carbon atoms or hydrogen;

R 10 is an alkyl, alkoxy, aryl alkylsulfonyl, or arylsulfonyl group each containing up to about 10 carbon atoms or hydrogen:,

R 11 is an alkyl, a hydroxylalkyl, an alkoxyalkyl, cycloalkyl, an aralkyl optionally substituted with a halogen or alkoxy group, an aryl optionally substituted with a halogen or alkoxy group, a cyanoalkyl, a carbamatoalkyl or an alkoxycarbonyIalkyl group each containing up to about 10 carbon atoms or hydrogen,

R 12 is an alkyl group containing from 1 to about 6 carbon atoms or hydrogen; and n is an integer of from 1 to 3,

such that when the conversion coating composition is applied to a metal surface, the dye is visible to the naked eye and/or its presence is detectable and its intensity is measurable by optical instrumentation and where the metal surface conversion coating composition does not have detrimental precipitates in the amount of greater than 1000 milligrams of precipitate per kilogram of the conversion coating composition after the coating composition has been stored for a period of at least 48 hours at 25° C.

2. The method of claim 1 further comprising:

measuring the intensity of the water-soluble dye within a predetermined area of the applied conversion coating composition by optical instrumentation to provide a measured intensity of the dye; and,

using the measured intensity of the dye to calculate the thickness and/or uniformity of the applied conversion coating.

3. The method of claim 1 , wherein the at least one metal corrosion inhibitor (i) is present in the amount of from about 0.01 to about 80 weight percent, based on the total weight of the metal surface conversion coating composition.

4. The method of claim 3 wherein the at least one metal corrosion inhibitor (i) is H 2 ZrF 6 , or K 2 ZrF 6 .

5. The method of claim 3 wherein the at least one metal corrosion inhibitor (i) is H 2 TiF 6 or K 2 TiF 6 .

6. The method of claim 1 wherein the solubility of the dye (iii) is such that up to 0.0001 grams of the dye will dissolve in 100 grams of distilled of water at 25° C.

7. The method of claim 1 wherein the dye (iii) is in an amount of from about 0.0001 to about 5 weight, based on the total weight of the metal surface conversion coating composition.

8. The method of claim 1 wherein the dye (iii) is fluorescent brightener 363 CAS: 95078-19-6.

9. The method of claim 1 wherein the conversion coating composition is a chrome-free conversion coating.

10. The method of claim 1 wherein following the step of applying a conversion coating composition to the metal surface, the metal surface is washed with water.

11. A conversion coating composition comprising:

(i) at least one metal corrosion inhibitor compound selected from the group consisting of ZrF 4 , Zr(NO 3 ) 4 , H 2 ZrF 6 , (NH 4 ) 2 ZrF 6 , Na 2 ZrF 6 , K 2 ZrF 6 , ZrO[NO 3 ] 2 , Zr[SO 4 ] 2 and ZrOSO 4 ;

or is at least one titanium-containing compound selected from the Group consisting of Ti(OCH 2 CH 3 ) 4 , H 2 TiF 6 , (NH 4 ) 2 TiF 6 , Na 2 TiF 6 , K 2 TiF 6 and Ti[SO 4 ] 2 ;

or, mixtures thereof;

(ii) water; and,

(iii) at least one water soluble dye having the structure of formula (I)

wherein;

G 1 is an organic group having from 1 to about 20 carbon atoms and containing at least one oxygen or nitrogen heteroatom;

A is a nitrogen atom or (−) 3 C—R*, where R* is a monovalent group chosen from alkyl, cycloalkyl, alkenyl, aralkyl or aryl group each having up to about 10 carbon atoms;

R 6 is an alkyl, a hydroxylalkyl, an alkoxyallcyl, a cycloalkyl, an aralkyl optionally substituted with a halogen or alkoxy group, an aryl optionally substituted with a halogen or alkoxy group, a cyanoalkyl, a carbamatoalkyl or a carboalkoxyalkyl group each containing up to about 10 carbon atoms, or hydrogen:,

R 7 is an alkyl, alkoxy, aryl alkylsulfonyl, or arylsulfonyl group each containing up to about 10 carbon atoms or hydrogen;

R 8 is an alkyl, alkoxy, aryl alkylsulfonyl, arylsulfonyl, or aminosulfonyl group each containing up to about 10 carbon atoms or hydrogen;

R 9 is an alkyl, alkoxy, aryl alkylsulfonyl, or arylsulfonyl group each containing up to about 10 carbon atoms or hydrogen;

R 10 is an alkyl, alkoxy, aryl alkylsulfonyl, or arylsulfonyl group each containing up to about 10 carbon atoms or hydrogen;

R 11 is an alkyl, a hydroxylalkyl, an alkoxyalkyl, cycloalkyl, an aralkyl optionally substituted with a halogen or alkoxy group, an aryl optionally substituted with a halogen or alkoxy group, a cyanoalkyl, a carbamatoalkyl or an alkoxycarbonylalkyl group each containing up to about 10 carbon atoms or hydrogen

R 12 is an alkyl group containing from 1 to about 6 carbon atoms or hydrogen; and n is an integer of from 1 to 3,

such that when the conversion coating composition is applied to a metal surface, the dye is visible to the naked eye and/or its presence is detectable and its intensity is measurable by optical instrumentation and where the metal surface conversion coating composition does not have detrimental precipitates in the amount of greater than 1000 milligrams of precipitate per kilogram of the conversion coating composition after the coating composition has been stored for a period of at least 48 hours at 25° C.

12. The conversion coating composition of claim 11 wherein the at least one metal corrosion inhibitor (i) is present in the amount of from about 0.01 to about 80 weight percent, based on the total weight of the metal surface conversion coating composition.

13. The conversion coating composition of claim 12 wherein the at least one metal corrosion inhibitor (i) is H 2 ZrF 6 or K 2 ZrF 6 .

14. The conversion coating composition of claim 12 wherein the at least one metal corrosion inhibitor (i) is H 2 TiF 6 or K 2 TiF 6 .

15. The conversion coating composition of claim 12 wherein the dye (iii) is in an amount of from about 0.0001 to about 5 weight percent, based on the total weight of the metal surface conversion coating composition.

16. The conversion coating composition of claim 11 , wherein the conversion coating composition is a chrome-free conversion coating.

17. A metal surface coated with the conversion coating of claim 11 .

Assignments (10)