Compositions – Oxidative bleachant – oxidant containing – or generative – Composition containing a stabilizer or a product in the form...
Patent
1996-03-05
1997-12-30
Anthony, Joseph D.
Compositions
Oxidative bleachant, oxidant containing, or generative
Composition containing a stabilizer or a product in the form...
25218643, 25218638, 510309, 510310, 4234152, C01B 15043, C01B 1510, C01B 3124, C11D 339
Patent
active
057026351
DESCRIPTION:
BRIEF SUMMARY
CROSS REFERENCE TO RELATED APPLICATION
This application is a 371 of PCT/US94/10135 filed on Sep. 13, 1994.
1. Technical Field
The present invention relates to particulate bleaching compositions for laundry. Particulate laundry bleaching compositions are described which comprise percarbonate as the bleaching specie, said compositions being stable upon manufacture and storage.
2. Background of the Invention
The inorganic perhydrate bleach most widely used in the context of laundry bleaching is sodium perborate in the form of either the monohydrate or tetrahydrate. However, concerns about the impact of boron salts on the environment have led to an increasing interest in other perhydrate salts, of which sodium percarbonate is the most readily available.
Detergent compositions containing sodium percarbonate are known in the art, for instance in FR 2,385,837, U.S. Pat. No. 4,428,914 and GB 1,553,505. Percarbonate salts, particularly sodium percarbonate, are attractive perhydrates for use in detergent compositions because they dissolve readily in water, are weight efficient and, after giving up their available oxygen, provide a useful source of carbonate ions for detergency purposes.
However, the inclusion of percarbonate salts in detergent compositions has been restricted hitherto by the relative instability of the bleach both as is and in use. Sodium percarbonate loses its available oxygen at a significant rate in the presence of ions or heavy metals such as iron, copper and manganese and also in the presence of moisture, these effects being accelerated at temperatures in excess of about 30.degree. C.
Moisture and heavy metal ions are unavoidable components of conventional granular laundry treatment compositions. Also percarbonate decomposition due to moisture becomes more of an issue during storage as laundry treatment products are often stored in humid environments when the product picks up moisture. This has resulted in marginally acceptable percarbonate bleach stability under Northern European summer conditions, where the average maximum temperature over the hottest months is from 21.degree. C. to 25.degree. C., and unacceptable stability under temperatures higher than this. Such conditions are found in the Middle East and Southern Asia and also in Southern Europe where average maximum temperatures are in the 27.degree. C. to 33.degree. C. range for the hottest summer month.
Such temperature accelerated percarbonate decomposition also occurs during the manufacture of the finished product. Indeed, as individual ingredients are mixed together the temperature of the mixture increases, accelerating the decomposition of the percarbonate. Furthermore, the temperature increase is greater if the mixing occurs under adiabatic or semi-adiabatic conditions.
Additionally when said percarbonate having a poor thermal stability is used in granular compositions together with common bleach activators (TAED, NOBS, . . . ) the stability becomes even more of a problem. Indeed, said percarbonate and said activators which are capable to react as fast as possible in water during the bleaching operation also tend to violently react in said granular compositions upon the manufacture or the storage, especially if said compositions are subjected to humid environments. In other words, said compositions may lose some activity.
It is therefore an object of the present invention to provide a particulate laundry bleaching composition incorporating an alkali metal percarbonate bleach, said bleach displaying improved stability both upon the manufacture and the storage of said particulate laundry bleaching composition.
It is a further object of the present invention to provide a stable particulate laundry bleaching composition comprising a percarbonate source of hydrogen peroxide together with a bleach activator.
It has now been found that these objects could be met by formulating a particulate bleaching composition comprising particles of percarbonate wherein said particles further comprise a hydrophobic ester of citric acid or mixtures th
REFERENCES:
patent: 3025271 (1962-03-01), Borchert et al.
patent: 3901819 (1975-08-01), Nakagawa et al.
patent: 3936303 (1976-02-01), Shiba et al.
patent: 3979318 (1976-09-01), Tokiwa et al.
patent: 4892967 (1990-01-01), Hull et al.
patent: 4931583 (1990-06-01), Hull et al.
patent: 5244644 (1993-09-01), Doetsch
patent: 5258133 (1993-11-01), Chapple
patent: 5346680 (1994-09-01), Roesler et al.
patent: 5409632 (1995-04-01), Showell et al.
patent: 5496728 (1996-03-01), Hardy et al.
Ricci Carlo
Trani Marina
Anthony Joseph D.
Aylor Robert B.
Reed T. David
The Procter & Gamble & Company
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