Preparation of laundry detergent tablets

• US 5,916,866 A
• Filed: 06/25/1997
• Issued: 06/29/1999
• Est. Priority Date: 11/14/1994
• Status: Expired due to Fees

• Current Assignee: Lever Brothers Company, Division Of Conopco, Inc.
• Original Assignee: Lever Brothers Company, Division Of Conopco, Inc.
• Inventors: Edwards, Sara Jane, Davies, Alan Phillip, Wraige, Douglas
• Primary Examiner(s): DOUYON, LORNA M
• Application Number:
  US08/882,656
• Time in Patent Office: 734 Days
• Field of Search: 510/441, 510/446, 510/475, 510/476, 510/294, 510/298, 510/507
• US Class Current: 510/441
• CPC Class Codes: C11D 17/0078 Multilayered tablets
• CPC Class Codes: C11D 17/0082 Coated tablets
• CPC Class Codes: C11D 17/0086 Laundry tablets
• CPC Class Codes: C11D 3/3707 Polyethers, e.g. polyalkyleneoxides
• CPC Class Codes: C11D 3/3776 Heterocyclic compounds, e.g. lactam

Abstract

In a process for making detergent tablets comprising spraying a coating of a water-soluble organic polymeric binder onto the exterior of particles of detergent composition containing detergent active and detergency builder and compacting the composition, the improvement comprises spraying an external coating of a film-forming water-soluble organic polymer onto the tablets. The coating on the tablet exterior reduces friability and abrasion and provides extra enhancement of strength while permitting disintegration/dissolution in a wash liquor.

Claims

1. In a process for making tablets of compacted particulate laundry detergent composition for fabric washing comprising the steps of:

spraying a coating of polyethylene glycol which is a water-soluble organic polymeric binder which melts at a temperature in the range from 35°

C. to 80°

C. onto the exterior of particles of a particulate detergent composition which particles contain from 2% to 50% by weight of a detergent active selected from the group consisting of anionic, cationic, nonionic, zwitterionic and amphoteric detergent active compounds and mixtures thereof and from 15% to 60% by weight of aluminosilicate detergency builder, said particles having a particle size in the range from 250 to 1400 μ

, and

thereafter compacting said composition with said binder on the exterior of said particles into tablets in which said particles and binder thereon are distributed within at least a region of the tablet;

the improvement which comprises

spraying onto said tablets an external coating of a film-forming water-soluble organic polymer selected from the group consisting of polyethylene glycol, copolymer of vinylpyrrolidone and vinyl acetate, and copolymer of maleate and acrylate;

wherein said external coating provides between 1 and 10% of overall weight of the tablet.

2. A process according to claim 1 wherein said tablet comprises:

from 5% to 40% by weight of said detergent-active, at least 20% by weight of said aluminosilacate detergency builder, and from 1% to 8% by weight of said water-soluble organic polymeric binder.

3. A process according to claim 2 wherein the tablet contains at least 9% by weight of detergent active.

4. A process according to claim 1 wherein the binder is present in an amount from 3% to 6% by weight of the tablet.