Fabric washing process and detergent composition for use therein
US4428749A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 12, 1982 |
| Grant date | Jan 31, 1984 |
| Priority date | — |
| Expiry date | Jan 12, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC11D3/062
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for washing fabrics includes contacting the fabrics with a liquor containing an orthophosphate material and, at least one minute thereafter, contacting the fabrics with a liquor containing a pyrophosphate material free of polymer phosphate. Each liquor contains a detergent active material and has a pH between about 8 and about 12. The delayed contact with the pyrophosphate reduces the level of deposition on the fabrics and the use of a combination of orthophophate and pyrophosphate enables compositions for use in the process to contain lower than conventional total levels of phosphorus. The pyrophosphate containing liquor may be separate from the orthophosphate containing liquor, or it may be the same liquor to which the pyrophosphate is added with a suitable delay. This delay may be achieved by the separate addition of the pyrophosphate material, by the use of a two compartment sachet, by coating, encapsulation or co-granulating the pyrophosphate, or by selecting a particle size for the pyrophosphate which will sufficiently reduce its rate of dissolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.