Protective coatings for detersive agents and methods of forming and detecting the same
First Claim
1. A method of creating a protective coating on an alkali metal hydroxide-containing solid block, comprising:
- preparing a detergent composition mixture comprising at least 15 wt-% alkali metal hydroxide selected from sodium hydroxide, potassium hydroxide, or a combination thereof;
forming the detergent composition mixture into a solid block having an exterior surface and a weight of at least 1 kilogram;
applying a carbon dioxide atmosphere comprising at least 60% carbon dioxide to the exterior surface of the solid block and allowing an outermost layer of the alkali metal hydroxide and carbon dioxide to react until up to 20% of the alkali metal hydroxide has reacted; and
rotating the solid block at least once to allow the carbon dioxide to react with the alkali metal hydroxide until a water-soluble carbonate-containing layer forms on all sides of the exterior surface of the solid block.
1 Assignment
0 Petitions
Accused Products
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.
-
Citations
11 Claims
-
1. A method of creating a protective coating on an alkali metal hydroxide-containing solid block, comprising:
-
preparing a detergent composition mixture comprising at least 15 wt-% alkali metal hydroxide selected from sodium hydroxide, potassium hydroxide, or a combination thereof; forming the detergent composition mixture into a solid block having an exterior surface and a weight of at least 1 kilogram; applying a carbon dioxide atmosphere comprising at least 60% carbon dioxide to the exterior surface of the solid block and allowing an outermost layer of the alkali metal hydroxide and carbon dioxide to react until up to 20% of the alkali metal hydroxide has reacted; and rotating the solid block at least once to allow the carbon dioxide to react with the alkali metal hydroxide until a water-soluble carbonate-containing layer forms on all sides of the exterior surface of the solid block. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method of making a solid detergent composition, comprising:
-
(a) combining from 5 to 65 wt-% alkali metal hydroxide, surfactant, sequestrant, and solidification agent to form a combination, wherein the combination is substantially free of carbonates and bicarbonates; (b) allowing the combination to solidify to form a solid having a weight of at least 1 kilogram and comprising a core and an exterior portion completely encasing the core; and (c) treating the solid with gaseous or solid carbon dioxide and rotating the solid at least once such that a carbonate-containing coating or bicarbonate-containing coating forms on the exterior portion of the solid containing the alkali metal hydroxide, wherein the coating and any remaining alkali metal hydroxide are at a weight ratio of 1part of coating to every 5 to 20 parts of alkali metal hydroxide. - View Dependent Claims (8, 9, 10)
-
-
11. A method of determining the quality of the carbonate coating, comprising:
-
providing a carbonate-coated solid prepared by 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; 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.
-
Specification