PROTECTIVE COATINGS FOR DETERSIVE AGENTS AND METHODS OF FORMING AND DETECTING THE SAME

• US 20140227790A1
• Filed: 02/08/2013
• Published: 08/14/2014
• Est. Priority Date: 02/08/2013
• Status: Active Grant

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Inventors: Smith, Kim R., Olson, Keith E., Peterson, Mark P.
• Granted Patent: US 10,184,097 B2
• Time in Patent Office: Days
• US Class Current: 436/6
• CPC Class Codes: C11D 17/0039 Coated compositions or coated components in the compositions, (micro)capsules
• CPC Class Codes: C11D 3/02 Inorganic compounds ; Elemental compounds
• CPC Class Codes: C11D 3/044 Hydroxides or bases
• CPC Class Codes: C11D 7/02 Inorganic compounds
• CPC Class Codes: C11D 7/06 Hydroxides

Abstract

A method of creating a protective coating on an alkali metal hydroxide-containing solid is provided. The method includes providing carbon dioxide to an alkali metal hydroxide-containing solid and allowing the alkali metal hydroxide and carbon dioxide to react thereby forming a carbonate or bicarbonate-containing layer on the exterior of the solid wherein the carbonate or bicarbonate-containing layer is non-hygroscopic and water soluble, and wherein greater than 80% of the hydroxide in the hydroxide-containing solid does not react with the carbon dioxide, and further wherein the alkali metal hydroxide-containing solid is substantially free of lithium hydroxide. A method of testing for the presence of carbonate-containing coating on an alkali metal hydroxide containing solid is also provided. The method includes exposing the coated solid to 95 weight percent ethanol, collecting the ethanol effluent and testing the effluent for alkali metal hydroxide. A suitably coated solid does not have dissolved alkali metal hydroxide in the ethanol effluent or is substantially free of alkali metal hydroxide.

Claims

1. A method of creating a protective coating on an alkali metal hydroxide-containing solid, comprising:

providing carbon dioxide to an alkali metal hydroxide-containing solid and allowing the alkali metal hydroxide and carbon dioxide to react thereby forming a carbonate-containing layer on the exterior of the solid wherein the carbonate-containing layer is non-hygroscopic and water soluble, and wherein greater than 80% of the hydroxide in the hydroxide-containing solid does not react with the carbon dioxide, and further wherein the alkali metal hydroxide-containing solid is substantially free of lithium hydroxide.

2. The method of claim 1 wherein the alkali metal hydroxide is comprised of sodium hydroxide or potassium hydroxide or a combination thereof.

3. The method of claim 1 wherein the carbon dioxide is gaseous or solid.

4. The method of claim 1 wherein the solid is comprised of a multiuse block having a weight of at least 1 kilogram.

19. A method of determining the quality of the carbonate coating prepared according to the method of claim 1, comprising:

providing the carbonate-coated solid;

exposing the carbonate-coated solid to 95 weight percent ethanol;

collecting the ethanol exposed to the carbonate-coated solid and testing for alkali metal hydroxide concentration.

5. A method of creating a protective coating on a solid, comprising:

providing a solid comprising alkali metal hydroxide;

treating the solid with carbon dioxide whereby a protective coating is created on the exterior of the solid, and the protective coating is non-hygroscopic and water soluble, and wherein less than 20 wt-% of the hydroxide in the hydroxide-containing solid reacts with the carbon dioxide.

6. The method of claim 5 wherein the carbon dioxide is gaseous or solid.

7. The method of claim 5 wherein the solid is comprised of a single use dosage comprising the shape of particulates, a pellet, or a tablet.

8. The method of claim 5 wherein the solid is comprised of a multi-use dosage comprising the shape of a block, pellet, or a tablet.

9. The method of claim 5 wherein the alkali metal hydroxide is comprised of sodium hydroxide or potassium hydroxide or a combination thereof.

10. A solid composition comprising an exterior laminate of a water-soluble, non-hygroscopic protective coating selected from the group consisting of alkali metal bicarbonate or alkali metal carbonate or a combination thereof;

the laminate surrounding an inner solid core comprising hygroscopic alkali metal hydroxide or alkali metal carbonate or a combination thereof.

11. The composition of claim 10 wherein the weight ratio of alkali metal hydroxide in the inner core to the alkali metal bicarbonate or alkali metal carbonate in the laminate is at least 4 parts hydroxide-containing compound:

5 parts carbonate or bicarbonate compound.

12. The composition of claim 10 wherein the alkali metal hydroxide is comprised of sodium hydroxide or potassium hydroxide or a combination thereof.

13. A method of making a solid detergent composition, comprising the steps of:

(a) combining an alkali metal hydroxide or alkali, surfactant, sequestrant, and solidification agent to form a combination;

(b) allowing the combination to solidify;

(c) treating the solid combination with gaseous or solid carbon dioxide such that a carbonate-containing coating or bicarbonate-containing coating forms on the portion of the solid surface solid containing the alkali metal hydroxide.

14. The method of claim 13 wherein the combination further comprises at least one of a rinse aid, bleaching agent, anti-microbial agent, bleaching agent activator;

detergent builder or filler;

defoaming agent, anti-redeposition agent, optical brightener, dye, or fragrance or any combination thereof.

15. The method of claim 13 wherein said combining step is accomplished in an extruder.

16. The method of claim 15 wherein the after forming the combination it is poured into a mold before being allowed to solidify.

17. The method of claim 16 further comprising removing the solid combination from the mold before carbon dioxide treatment.

18. A method of preparing a cleaning composition, comprising:

a) combining alkali metal hydroxide with any combination of surfactant, defoaming agent, sequestrant, dye, perfume, bleaching agent, solvent;

b) pressing the combination to prepare a solid tablet; and

c) treating the solid tablet with gaseous or solid carbon dioxide such that a carbonate-containing coating or bicarbonate-containing coating forms on a portion of the surface of the tablet.