Rinse aid composition containing water-soluble metal salt for use in automatic dishwashing for metal corrosion and rust formation protection

• US 20040180807A1
• Filed: 12/17/2003
• Published: 09/16/2004
• Est. Priority Date: 12/30/2002
• Status: Abandoned Application

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Salem, Marie Rose, Song, Brian Xiaoqing
• Application Number:
  US10/738,569
• Publication Number:
  US 20040180807A1
• Time in Patent Office: Days
• US Class Current: 510/521
• CPC Class Codes: C11D 1/66 Non-ionic compounds C11D1/002, C11D1/004, C11D1/008 take precedence
• CPC Class Codes: C11D 2111/16 Metals
• CPC Class Codes: C11D 3/0073 Anticorrosion compositions
• CPC Class Codes: C11D 3/042 Acids
• CPC Class Codes: C11D 3/046 Salts
• CPC Class Codes: C11D 3/048 Nitrates or nitrites
• CPC Class Codes: C11D 3/2075 Carboxylic acids-salts thereof
• CPC Class Codes: C11D 3/2082 Polycarboxylic acids-salts thereof
• CPC Class Codes: C11D 3/2086 Hydroxy carboxylic acids-salts thereof
• CPC Class Codes: C11D 3/33 Amino carboxylic acids
• CPC Class Codes: C11D 3/3757 (Co)polymerised carboxylic acids, -anhydrides, -esters in solid and liquid compositions

Abstract

A rinse aid composition containing a water-soluble metal salt and a non-ionic surfactant for use in automatic dishwashing is disclosed.

Claims

1. A rinse aid composition for reducing metal corrosion and rust formation comprising:

(a) at least one water-soluble metal salt;

(b) a non-ionic surfactant; and

(c) optionally, at least one component selected from the group consisting of acid, hydrotrope, binder, dispersant polymer, perfume, carrier medium, antibacterial active, dye, and mixtures thereof;

wherein said rinse aid composition has a pH of less than about 5 when measured at a 10% concentration in an aqueous solution.

2. A rinse aid composition according to claim 1, wherein said composition is in the form of a liquid, gel, solid, granular, powder, and combinations thereof.

3. A rinse aid composition according to claim 1, wherein said rinse aid composition delivers from about 0.01 mM to about 10 mM of said at least one water-soluble metal salt in the rinse liquor.

4. A rinse aid composition according to claim 3, wherein said rinse aid composition delivers from about 0.02 mM to about 5 mM of said at least one water-soluble metal salt in the rinse liquor.

5. A rinse aid composition according to claim 1, wherein said effective amount of said at least one water-soluble metal salt is from about 0.01% to about 70% by weight of the composition.

6. A rinse aid composition according to claim 1, wherein said at least one water-soluble metal salt comprises a metal selected from the group consisting of aluminum, zinc, magnesium, calcium, lanthanum, tin, gallium, strontium, titanium, and mixtures thereof.

7. A rinse aid composition according to claim 6, wherein said metal in said water-soluble metal salt is zinc.

8. A rinse aid composition according to claim 7, wherein said water-soluble zinc salt is selected from the group consisting of zinc acetate, zinc chloride, zinc gluconate, zinc formate, zinc malate, zinc nitrate, zinc sulfate, and mixtures thereof.

9. A rinse aid composition according to claim 8, wherein said water-soluble zinc salt is zinc chloride.

10. A rinse aid composition according to claim 8, wherein said water-soluble zinc salt is zinc gluconate.

11. A rinse aid composition according to claim 8, wherein said water-soluble zinc salt is zinc nitrate.

12. A rinse aid composition according to claim 8, wherein said water-soluble zinc salt is zinc sulfate.

13. A rinse aid composition according to claim 1, wherein said acid is present from about 0.01% to about 25% by weight of the composition.

14. A rinse aid composition according to claim 1, wherein said acid is selected from the group consisting of organic, inorganic, and mixtures thereof.

15. A rinse aid composition to claim 14, wherein said acid is selected from the group consisting of acetic acid, aspartic acid, benzoic acid, boric acid, bromic acid, citric acid, formic acid, gluconic acid, glutamic acid, hydrochloric acid, lactic acid, malic acid, nitric acid, sulfamic acid, sulfuric acid, tartaric acid, and mixtures thereof.

16. A rinse aid composition according to claim 15, wherein said acid is nitric acid.

17. A rinse aid composition according to claim 15, wherein said acid is hydrochloric acid.

18. A rinse aid composition according to claim 15, wherein said acid is citric acid.

19. A rinse aid composition according to claim 1, wherein said pH is in the range of from about 1 to about 4.

20. A rinse aid composition according to claim 1, wherein said dispersant polymer comprises at least one or more homopolymer, copolymer, terpolymer, and mixtures thereof.

21. A rinse aid composition according to claim 1, wherein said dispersant polymer is a low molecular weight polyacrylate dispersant polymer having a molecular weight of less than about 15,000 and is the non-neutralized form of the polymer comprising about 70% by weight acrylic acid and about 30% by weight methacrylic acid.

22. A rinse aid composition according to claim 21, wherein said molecular weight is from about 500 to about 10,000.

23. A rinse aid composition according to claim 22, wherein said molecular weight is about 3500.

24. A rinse aid composition according to claim 1, wherein said dispersant polymer is a low molecular weight modified polyacrylate copolymer, wherein said copolymer contains as monomer units:

a) from about 90% to about 10% by weight acrylic acid or its salts, and

b) from about 10% to about 90% by weight of a substituted acrylic monomer or its salt and have the general formula;

—

[(C(R²)C(R¹)(C(O)OR³)]—

wherein the incomplete valencies inside the square braces are hydrogen and at least one of the substituents R¹, R² or R³ is a 1 to 4 carbon alkyl or hydroxyalkyl group, and wherein R¹ or R² can be a hydrogen and R³ can be a hydrogen or alkali metal salt.

25. A rinse aid composition according to claim 24, wherein said incomplete valencies inside the square braces are hydrogen and at least one of the substituents R¹ or R² is a 1 to 4 carbon alkyl or hydroxyalkyl group.

26. A rinse aid composition according to claim 24, wherein said dispersant polymer is a substituted acrylic monomer, and wherein R¹ is methyl, R² is hydrogen and R³ is sodium.

27. A rinse aid composition according to claim 2, wherein said composition is a solid;

and wherein said water-soluble metal salt is in the form of a powder, crystal, core particle, aggregate of core particles, prill, agglomerate, and mixtures thereof.

28. A rinse aid composition according to claim 1, wherein said acid enables said metal salt to dissolve quickly in the rinse liquor of an automatic dishwashing appliance so as to minimize formation of insoluble precipitates on hard surfaces.

29. A rinse aid composition according to claim 1, wherein said composition further comprises at least one component selected from the group consisting of acid, hydrotrope, binder, dispersant polymer, perfume, carrier medium, antibacterial active, dye, and mixtures thereof.

30. A method of rinsing cleaned metal surfaces in an automatic dishwashing appliance comprising the step of rinsing said cleaned metal surface with a rinse aid composition comprising:

(a) at least one water-soluble metal salt;

(b) a non-ionic surfactant; and

(c) optionally, at least one component selected from the group consisting of acid, hydrotrope, binder, dispersant polymer, perfume, carrier medium, antibacterial active, dye, and mixtures thereof;

wherein said rinse aid composition has a pH of less than about 5 when measured at a 10% concentration in an aqueous solution.

31. A method according to claim 30, wherein from about 0.01 mM to about 10 mM of said at least one water-soluble metal salt is delivered to the rinse liquor of an automatic dishwashing appliance during operation.

32. A method according to claim 30, wherein said at least one water-soluble metal salt comprises from about 0.01% and about 70% by weight of the composition.

33. A method according to claim 30, wherein said non-ionic surfactant comprises from about 0.01% to about 60% by weight of the composition.

34. A method according to claim 30, further comprising at least one component selected from the group consisting of acid, hydrotrope, binder, dispersant polymer, perfume, carrier medium, antibacterial active, dye, and mixtures thereof.

35. A kit A kit reducing glassware corrosion and film formation in an automatic dishwashing process comprising:

(a) a package, (b) instructions for use, and (c) a rinse aid composition suitable for use in automatic dishwashing comprising (i) a water-soluble metal salt comprising a metal selected from the group consisting of aluminum, zinc, magnesium, calcium, lanthanum, tin, gallium, strontium, titanium, and combinations thereof;

(ii) a non-ionic surfactant; and

(iii) optionally at least one component selected from the group consisting of an acid, hydrotrope, binder, dispersant polymer, perfume, carrier medium, antibacterial active, dye, and mixtures thereof.

36. A method for reducing hard metal surface corrosion and rust formation in an automatic dishwashing process, wherein said method comprises the step of rinsing cleaned hard metal surfaces with a rinse aid composition comprising:

(a) at least one water-soluble metal salt;

(b) a non-ionic surfactant; and

(c) at least one component selected from the group consisting of acid, hydrotrope, binder, dispersant polymer, perfume, carrier medium, antibacterial active, dye, and mixtures thereof; and

wherein said rinse aid composition has a pH of less than about 5 when measured at a 10% concentration in an aqueous solution.