Claims
- 1. An automatic dishwashing detergent composition which substantially inhibits lead corrosion of fine tableware comprising:
- a) an effective amount of an aluminum-sequestrant complex;
- b) 1 to 20 wt. % of a bleaching agent selected from a group consisting of a peroxygen agent, a hypohalite agent, corresponding salts and its mixtures thereof;
- c) 1 to 75 wt. % of a builder;
- d) 0 to 40 wt. % of a surfactant; and
- e) 0 to less than 5 wt. % of a silicate,
- wherein the composition is prepared by forming the aluminum-sequestrant complex premix by:
- i) dissolving an effective amount of a sequestrant in water to form a sequestrant solution having a pH not less than one pH unit greater than the pKa of at least one of the ionizable groups on the sequestrant,
- ii) adding the aluminum salt to the sequestrant solution to form an aluminum and sequestrant solution,
- iii) adjusting the pH of the aluminum and sequestrant solution to the same pH as the sequestrant solution in (i) above to form the aluminum-sequestrant complex premix, and
- iv) adding remaining components of the composition to the aluminum-sequestrant complex premix to form an automatic dishwashing composition wherein an aqueous solution of the composition has a pH of 5 to less than 9.
- 2. A composition according to claim 1 wherein the sequestrant solution is maintained at its pH value during dissolution of an entire amount of the sequestrant by adding an inorganic acid or an inorganic base to adjust alkalinity of the sequestrant solution.
- 3. A composition according to claim 2 wherein the inorganic acid is H.sub.2 SO.sub.4 and the inorganic base is NaOH.
- 4. A composition according to claim 1 wherein the aluminum salt is selected from a group consisting of aluminum sulfate, sodium aluminate, aluminum acetate, aluminum acetylacetonate, aluminum formate, aluminum borate, aluminum octoate, aluminum oleate, aluminum palmitate, aluminum tartrate, aluminum acetotartrate, and mixtures thereof.
- 5. A composition according to claim 4 wherein the aluminum salt is selected from a group consisting of aluminum sulfate, sodium aluminate, aluminum acetate, aluminum acetylacetonate, aluminum borate and mixtures thereof.
- 6. A composition according to claim 1 wherein the sequestrant is selected from a group consisting of EDTA, oxalic acid, citric acid, cyanuric acid, NTA, sodium orthophosphate, malonic acid, succinic acid, tartaric acid, aspartic acid, glutamic acid, phosphonate, polyphosphate and alkali metal salts thereof.
- 7. A composition according to claim 6 wherein the sequestrant is selected from a group consisting of EDTA, oxalic acid, citric acid, cyanuric acid and alkali metal salts thereof.
- 8. A composition according to claim 1 wherein the builder is selected from the group consisting of inorganic water soluble builder salts, organic water soluble builder salts and mixtures thereof.
- 9. A composition according to claim 8 wherein the organic builder salt is selected from the group consisting of alkali metal citrates, succinates, aluminosilicates, polycarboxylates, tartrate disuccinates and mixtures thereof.
- 10. A composition according to claim 1 wherein the peroxygen agent is an organic agent or an inorganic agent.
- 11. A composition according to claim 10 wherein the organic agent is selected from the group consisting of epsilon-phthalimido peroxyhexanoic acid, o-carboxybenz amidoperoxyhexanoic acid, N,N-terephthaloyldi(6-amino percaproic acid) and mixtures thereof.
- 12. A composition according to claim 1 further comprising a peroxygen peracid precursor.
- 13. A composition according to claim 1 further comprising 1 to 5 wt. % of an enzyme selected from the group consisting of a protease, an amylase, a lipase and mixtures thereof.
- 14. A process for preparing an automatic dishwashing detergent composition which substantially inhibits lead corrosion of fine tableware comprising:
- a) selecting an effective amount of a sequestrant;
- b) dissolving the sequestrant in water to form a sequestrant solution having a pH not less than one pH unit greater than the pKa of at least one of the ionizable groups on the sequestrant;
- c) selecting an effective amount of an aluminum salt;
- d) adding the aluminum salt to the sequestrant solution to form an aluminum and sequestrant solution;
- e) adjusting the pH of the solution of step (d) to the same pH as the sequestrant solution to form an aluminum-sequestrant complex premix;
- f) adding the premix to an aqueous solution comprising 1 to 20 wt. % of a bleaching agent, 1 to 75 wt. % of a builder and 0 to 40 wt. % of a surfactant to form a detergent composition which is substantially free of added silicates and a 1 % aqueous solution of the composition has a pH of 5 to less than 9.
- 15. A process according to claim 14 wherein the pH of the sequestrant solution is adjusted by adding an effective amount of an inorganic acid or inorganic base.
- 16. A process according to claim 14 wherein the aluminum salt of step (c) is selected from the group consisting of aluminum sulfate, sodium aluminate, aluminum acetate, aluminum acetylacetonate, aluminum formate, aluminum borate, aluminum octoate, aluminum oleate, aluminum palmitate, aluminum tartrate, aluminum acetotartrate, and mixtures thereof.
- 17. A process according to claim 14 wherein the sequestrant of step (a) is selected from the group consisting of EDTA, oxalic acid, citric acid, cyanuric acid, NTA, orthophosphoric acid, malonic acid, succinic acid, tartaric acid, aspartic acid, glutamic acid, phosphonic acid, polyphosphoric acid and alkali metal salts thereof.
- 18. A process according to claim 14 wherein the builder of step (f) is selected from the group consisting of inorganic water soluble builder salts, organic water soluble builder salts and mixtures thereof.
- 19. A process according to claim 18 wherein the organic builder salt is selected from the group consisting of alkali metal citrates, succinates, aluminosilicates, polycarboxylates, tartrate disuccinates and mixtures thereof.
- 20. A process according to claim 14 further comprising adding an effective amount of an enzyme to step (f) selected from the group consisting of a protease, an amylase, a lipase and mixtures thereof.
RELATED APPLICATION
This application is a continuation-in-part application of U.S. Ser. No. 08/444,503, filed May 19, 1995, now U.S. Pat. No. 5,624,892.
US Referenced Citations (5)
Continuation in Parts (1)
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Number |
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444503 |
May 1995 |
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