Patent EA-001548-B1 (EA)
Title: Production of anionic detergent particles
Inventor: EMEERY WILLIAM DEREK
IPC: C11D11/00
Filed: 1997-02-08
Abstract: 1. A process for producing detergent particles comprising an anionic surfactant, the process comprising the steps of feeding a paste material comprising water and an anionic surfactant into a drying zone, heating the paste material in the drying zone to reduce the water content thereof, average time of the paste material to be in the drying zone is less than 5 minutes and subsequently cooling the paste material in a cooling zone at a temperature not exceeding 50 degree C to form detergent particles, characterised by introducing a layering agent into the cooling zone during the cooling step. 2. A process for producing detergent particles comprising an anionic surfactant, the process comprising the steps of feeding a paste material comprising water and an anionic surfactant into a drying zone, heating the paste material in the drying zone to reduce the water content thereof average time of the paste material to be in the drying zone is less than 5 minutes and subsequently cooling the paste material in a cooling zone at a temperature not exceeding 50 degree C to form detergent particles, characterised by treating the paste material in the cooling zone with a stream of cooling gas. 3. A process according to claim 1 or claim 2, wherein the anionic surfactant comprises a linear alkylbenzene sulphonate. 4. A process according to claim 3, wherein the linear alkylbenzene sulphonate comprises from 10% to 100% by weight of the total anionic surfactant. 5. A process according to any preceding claim, wherein the paste material comprises no more than 50% by weight of water. 6. A process according to any preceding claim, wherein the layering agent comprises an aluminosilicate, a silica or a mixture thereof. 7. A process according to claim 1, wherein the layering agent is dosed into the cooling zone at a weight ratio of from 1:5 to 1:20 relative to the finished particles. 8. A process according to any preceding claim, wherein the anionic surfactant is formed by admixture of the free acid form of the anionic surfactant and a neutralising agent. 9. A process according to any preceding claim, wherein the resultant particles comprise at least 75% by weight of the anionic surfactant and no more than 10% by weight of water. 10. A process according to any preceding claim, wherein the resultant particles have a D(4,3) average particle diameter of from 180 to 1500 microns. 11. Detergent particles produced according to any preceding claim. 12. Detergent particles according to claim 11 comprising at least 60% by weight of the particle of an anionic surfactant, and not more than 5% by weight of water, the particles being coated with a layering agent. 13. Detergent particles according to claim 11 comprising an anionic surfactant, in an amount of at least 60% by weight of the particle, wherein the particles are coated with a layering agent and have a porosity of from 0% to 25% by volume of the particle and a particle size distribution such that at least 80% of the particles have a particle size of 180 to 1500 microns. 14. Detergent particles according to any of claims 11-13, wherein the anionic surfactant comprises a linear alkylbenzene sulphonate. 15. A detergent composition comprising detergent particles according to any of claims 11-14 and a base powder.