Encapsulated bleaches

• US 4,830,773 A
• Filed: 07/10/1987
• Issued: 05/16/1989
• Est. Priority Date: 07/10/1987
• Status: Expired due to Term

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab, Inc.
• Inventors: Olson, Keith E.
• Primary Examiner(s): Lieberman, Paul
• Assistant Examiner(s): McNally, John F.
• Application Number:
  US07/071,788
• Time in Patent Office: 676 Days
• Field of Search: 252/99, 252/186.25, 252/186.35
• US Class Current: 252/186.35
• CPC Class Codes: C11D 17/0039 Coated compositions or coated components in the compositions, (micro)capsules
• CPC Class Codes: C11D 3/3953 Inorganic bleaching agents C11D3/3951 takes precedence

Abstract

Stable encapsulated bleach comprising a core of bleaching agent such as an alkaline metal salt of chloroisocyanurate, an inner coating of a chemically compatable separating compound such as sodium sulfate, sodium tripolyphosphate and mixtures thereof, and an outer coating of a water soluble cellulose ether such as hydroxyethyl and hydroxypropyl celluloses.

Claims

1. An encapsulated bleach particle, comprising:

(a) a bleaching agent core;

(b) an inner coating of a separating compound in an amount sufficient to retard any chemical interaction between the bleaching agent core and an outer coating compound; and

(c) an outer coating of encapsulating amount of a water soluble cellulose ether compound selected from the group consisting of (C_1-4) alkyl cellulose, carboxy (C_1-4) alkyl cellulose, hydroxy (C_1-4) alkyl cellulose, carboxy (C_1-4) alkyl hydroxy (C_1-4) alkyl cellulose, C_1-4) alkyl hydroxy (C_1-4) alkyl cellulose, and mixtures thereof.

2. The encapsulated particle of claim 1 wherein the bleaching agent is a source of active halogen.

3. The encapsulated particle of claim 2 wherein the bleaching agent is a source of active chlorine.

4. The encapsulated particle of claim 3 wherein the bleaching agent is an alkali metal dichloroisocyanurate, and hydrates thereof.

5. The encapsulated particle of claim 1 wherein the separating compound is a water soluble detergent builder or filler.

6. The encapsulated particle of claim 5 wherein the detergent builder or filler is sodium sulfate, sodium chloride, a condensed phosphate or a combination thereof.

7. The encapsulated particle of claim 5 wherein the water soluble cellulose ether is a hydroxy (C_1-4) alkyl cellulose.

8. The encapsulated particle of claim 7 wherein the hydroxy (C_1-4) alkyl cellulose is hydroxypropylcellulose.

9. The encapsulated particle of claim 7 wherein the hydroxy (C_1-4) alkyl cellulose is hydroxyethylcellulose.

10. The encapsulated particle of claim 7 wherein the hydroxy (C_1-4) alkyl cellulose has a DS of about 0.7 to 3.0.

11. The encapsulated particle of claim 8 wherein the hydroxypropylcellulose has aDDS of about 1.4 to 3.0.

12. The encapsulated particle of claim 9 wherein the hydroxyethylcellulose has a DS of about 1.2 to 3.0.

13. The encapsulated particle of claim 1 wherein the encapsulated particle comprises about 20-90 wt-% core, about 50-60 wt-% inner coating and about 1-25 wt-% outer coating.

14. The encapsulated particle of claim 1 wherein the encapsulated particle comprises about 40-70 wt-% core, about 10-50 wt-% inner coating compound and about 2-10 wt-% outer coating compound.

16. The particle of claim 13 wherein the particle comprises:

(a) about 40-70 wt-% core;

(b) about 10-50 wt-% inner coating of sodium sulfate, sodium chloride, a condensed phosphate or a combination thereof; and

(c) about 2-10 wt-% outer coating of hydroxypropylcellulose.

17. The particle of claim 13 wherein the particle comprises:

(a) about 40-70 wt-% core;

(b) about 10-50 wt-% inner coating of sodium sulfate, sodium chloride, a condensed phosphate or a combination thereof; and

(c) about 2-10 wt-% outer coating of hydroxyethylcellulose.

15. An encapsulated bleach particle, comprising:

(a) about 20-90 wt-% core of an active chlorine source;

(b) about 5-60 wt-% inner coating of a detergent builder or filler surrounding and in physical contact with the core; and

(c) about 1-25 wt-% outer encapsulating coating of a hydroxy (C_1-4) alkyl cellulose which is physically separated from the core of active chlorine source by the inner coating.