Process for coating detergent granules in a fluidized bed

• US 20040235704A1
• Filed: 06/30/2004
• Published: 11/25/2004
• Est. Priority Date: 06/21/1999
• Status: Active Grant

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Mort, Paul R. III, Ridyard, Mark William, Beimesch, Wayne Edward, Capeci, Scott William, Wasserman, Matthew Israel
• Granted Patent: US 6,900,169 B2
• Time in Patent Office: Days
• US Class Current: 510/447
• CPC Class Codes: B01J 2/006 Coating of the granules without description of the process or the device by which the granules are obtained to prevent the granules sticking together B01J2/30
• CPC Class Codes: B01J 2/16 by suspending the powder material in a gas, e.g. in fluidised beds or as a falling curtain
• CPC Class Codes: C11D 11/0088 the liquefied ingredients being sprayed or adsorbed onto solid particles
• CPC Class Codes: C11D 17/0039 Coated compositions or coated components in the compositions, (micro)capsules
• CPC Class Codes: Y10T 428/12625 Free carbon containing component

Abstract

A process for preparing coated detergent granules in a fluidized bed is provided. The fluidized bed is operated at a flux number of at least about 3.5 and/or a Stokes Number of greater than 1.0. Upon drying, the resultant detergent particles have improved appearance and flow properties and may be packaged and sold as a detergent material or mixed with various other detergent ingredients to provide a fully formulated detergent composition.

Claims

1. A process for coating a detergent particle comprising the steps of coating a detergent granule having at least one detergent active material in a fluidized bed with a water-soluble coating material to form coated detergent granules wherein said fluidized bed is operated at a flux number FN of at least about 3.5.

2. The process as claimed in claim 1, wherein said fluidized bed is operated at a flux number FN of from about 3.5 to about 7.0.

3. The process as claimed in claim 2 wherein said fluidized bed is operated at a flux number of from about 3.5 to about 5.0.

4. The process as claimed in claim 1 wherein said fluidized bed is operated at a Stokes number of greater than one.

5. The process as claimed in claim 1, wherein said detergent granules are selected from spray-dried granules, dry agglomerates, wet agglomerates, detergent adjuncts, mixed agglomerates and mixtures thereof.

6. The process as claimed in claim 1, wherein said water soluble coating material is selected from detersive surfactants, hydrotropes, inorganic salts, organic salts, and mixtures thereof.

7. The process as claimed in claim 6 wherein said coating material is comprises an anionic surfactant or precursor thereof.

8. The process as claimed in claim 1 wherein said coating material further includes a detergent adjunct ingredients such as brighteners, chelants, nonionic surfactants, co-builders and mixtures thereof.

9. The process as claimed in claim 1 further comprising the steps of mixing said coated detergent granules with a flow control aid to adhere said flow control aid to the surface of said granules.

10. The process as claimed in claim 9 wherein the flow control aid is an inorganic powder material with a mean particle size of less than about 5 microns and is selected from the group consisting of crystalline layered silicate, carbonate, sodium sulfate, aluminosilicate, magnesium silicate, calcium silicate, clay, and mixtures thereof.

11. A process for coating a detergent particle comprising the steps of coating a detergent granule having at least one detergent active material in a fluidized bed with a water-soluble coating material to form coated detergent granules wherein said fluidized bed is operated at a Stokes number greater than 1.0.

12. A process for producing a detergent composition comprising:

a) mixing detergent granules selected from the group consisting of wet agglomerates, dry agglomerates, spray-dried granules, detergent adjunct ingredients and mixtures thereof in a moderate speed mixer to form a mixed agglomerate; and

b) passing said mixed agglomerate to a fluid bed coating and coating said mixed agglomerate with a water-soluble coating material to form coated detergent granules wherein said fluidized bed is operated at a flux number FN of at least about 3.5.

13. The process as claimed in claim 12 further comprising the step of passing said mixed agglomerate to a fluid bed granulator and further agglomerating said mixed agglomerate prior to said coating step.

14. The process as claimed in claim 12 further comprising the steps of passing said granules through a high speed mixer prior to passing through said moderate speed mixer.