Shaped solid comprising oxidant bleach with encapsulate source of bleach

• US 6,589,443 B1
• Filed: 08/07/1996
• Issued: 07/08/2003
• Est. Priority Date: 02/26/1993
• Status: Expired due to Fees

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab, Inc.
• Inventors: Man, Victor F., Olson, Keith E.
• Primary Examiner(s): ANTHONY, JOSEPH DAVID
• Application Number:
  US08/692,987
• Time in Patent Office: 2,526 Days
• Field of Search: 252/186.2, 252/186.25, 252/186.34, 252/186.35, 252/186.36, 427/213.31, 428/402.24, 510/302, 510/319, 510/367, 510/382
• US Class Current: 252/186.2
• CPC Class Codes: C11D 17/0065 Solid detergents containing builders C11D17/06 takes precedence
• CPC Class Codes: C11D 3/3953 Inorganic bleaching agents C11D3/3951 takes precedence
• CPC Class Codes: C11D 3/3955 Organic bleaching agents C11D3/3951 takes precedence
• CPC Class Codes: Y10T 428/2989 Microcapsule with solid core [includes liposome]

Abstract

Aqueous bleach solutions can be made by directing a spray of water onto a bulk or shaped solid (brick, tablet, block, etc.) comprising a continuous solid phase of an encapsulated source of an active halogen bleach or a solid comprising a source of an oxidizing active halogen bleach, and an encapsulated oxidizing halogen bleach source. Such shaped solids can be used to dispense uniform quantities of an aqueous bleach concentrate to bleaching locus such as a washing machine. The tablets can be made from the encapsulated bleach or from a powder mixture of a particulate, granulated or powdered unencapsulated source of active oxidizing bleach and an encapsulated source of active oxidizing bleach by forming the powder mixture into a desired shape. Such a shaped solid bleach can be packaged in a container and can then be contacted with an aqueous spray in a dispenser to create a solution of active bleach for cleaning bleaching processes. The presence of the encapsulate in the solid with the powder reduces the tendency of the solid to absorb water which can be wicked through the solid to pass water through the solid into adjacent solids. Substantial proportions of absorbed water can cause the tablets to crack, crumble and to periodically dispense uneven, substantially large and undesirable concentrations of active bleach into a wash or bleach cycle. Such large amounts of halogen can cause corrosion of metal machine or dispenser parts, clothing damage, can cause pinholing or other fabric damage, can result in color loss or change, or can result in other undesirable effects in either the dispenser, washing machine or the cleaned item.

Claims

1. A shaped solid oxidant bleach composition consisting of at least 100 grams of a plurality of encapsulated active halogen bleach sources, wherein each of said active halogen bleach sources is encapsulated with at least one encapsulating layer and said plurality of encapsulated active halogen bleach sources being the only oxidant bleach in the composition.

2. The solid of claim 1 wherein the mass of the solid is at least 1 gram and each of the plurality of encapsulated active halogen bleach sources is in a particulate form and has a diameter no greater than about 5 millimeters.

3. The solid of claim 1 wherein the encapsulate comprises a core of an active halogen source and at least one organic encapsulating layer.

4. The solid of claim 1 wherein the encapsulate comprises a core comprising an active halogen source and at least one inorganic encapsulating layer.

5. The solid of claim 1 wherein the encapsulate comprises a core of an active halogen source, a first inorganic inner layer and a second organic outer layer.

6. The solid of claim 1 wherein the solid is a compressed solid.

7. The solid of claim 1 wherein the shaped solid is a cylindrical solid with a thickness of about 20 to 80 millimeters and a diameter of about 50 to 150 millimeters.

8. The solid of claim 7 wherein the plurality of active halogen bleach sources comprise chlorinated trisodium phosphate or chlorinated sodium tripolyphosphate.

9. A shaped solid oxidant bleach composition consisting of at least 100 grams of a plurality of active halogen bleach sources selected from the group consisting of a sodium salt of a chlorinated isocyanurate, a potassium salt of a chlorinated isocyanurate, and a mixture thereof, wherein said active halogen bleach source is encapsulated with at least one encapsulating layer and said active halogen bleach source being the only oxidant bleach in the composition.

10. A shaped solid oxidant bleach composition consisting of a plurality of active halogen bleach sources and a sequestrant, wherein said active halogen bleach sources are encapsulated with at least one encapsulating layer and said active halogen bleach sources being the only oxidant bleach in the composition.