Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/395—Bleaching agents
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/12—Water-insoluble compounds
  • C11D3/124—Silicon containing, e.g. silica, silex, quartz or glass beads
  • C11D3/1246—Silicates, e.g. diatomaceous earth
  • C11D3/1253—Layer silicates, e.g. talcum, kaolin, clay, bentonite, smectite, montmorillonite, hectorite or attapulgite
  • C11D3/1273—Crystalline layered silicates of type NaMeSixO2x+1YH2O
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/16—Organic compounds
  • C11D3/20—Organic compounds containing oxygen
  • C11D3/2075—Carboxylic acids-salts thereof
  • C11D3/2086—Hydroxy carboxylic acids-salts thereof
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3942—Inorganic per-compounds

Definitions

• the present invention relates to bleaching compositions for laundry.
• Granular laundry bleaching compositions are described which comprise percarbonate as the bleaching specie, said compositions being stable upon storage.
• 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.
• 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.
• Percarbonate salts particularly sodium percarbonate
• detergent compositions containing sodium percarbonate are known in the art.
• 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.
• percarbonate salts have 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 of 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°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°C to 25°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°C to 33°C range for the hottest summer month.
• composition comprising an alkali metal salt of percarbonate together with a crystalline layered silicate or mixtures thereof.
• Granular bleaching compositions comprising percarbonate have been described for instance in FR 2,385,837, US 4,428,914 and GB 1,553,505.
• Crystalline layered silicate and their methods of preparation have been described for instance in EP-A-164 514, DE-A-34 17 649 and DE-A-37 42 043 and their application to the field of laundry treatment has been described in applicant's copending British applications GB 90 21 761.3, GB 90 18157.9 and GB 91 08639.7.
• compositions according to the present invention also allow adequate control of the pH in the bleaching liquor, giving appropriate balance between bleaching performance and fabric safety.
• compositions according to the present invention are granular bleaching compositions comprising more than 20% and up to 80% by weight of the total composition of an alkali metal salt of percarbonate bleach and from 5% to 80% by weight of the total composition of a crystalline layered silicate of formula NaMSi x O 2x+1 .yH2O wherein M is sodium or hydrogen, x is a number of from 1.9 to 4 and y is a number of from 0 to 20, or mixtures thereof.
• Preferred compositions herein further comprise an anhydrous acidifying agent, preferably citric acid.
• the compositions according to the present invention comprise an alkali metal salt of percarbonate, preferably sodium percarbonate.
• Sodium percarbonate is available commercially as a crystalline solid. Most commercially available material includes a low level of a heavy metal sequestrant such as EDTA, 1-hydroxyethylidene 1, 1-diphosphonic acid (HEDP) or an amino-phosphonate, that is incorporated during the manufacturing process.
• EDTA 1-hydroxyethylidene 1, 1-diphosphonic acid
• HEDP 1-diphosphonic acid
• the percarbonate can be incorporated into detergent compositions without additional protection.
• the percarbonate Whilst heavy metals present in the sodium carbonate used to manufacture the percarbonate can be controlled by the inclusion of sequestrants in the reaction mixture, it is preferred that the percarbonate be protected from heavy metals present as impurities in other ingredients of the product. It has been found that the total level of Iron, Copper and Manganese ions in the product should not exceed 25 ppm and preferably should be less than 20 ppm in order to avoid an unacceptably adverse effect on percarbonate stability.
• compositions according to the present invention comprise more than 20% by weight of the total composition of percarbonate, up to 80% by weight of the total composition, preferably from 40% to 50%.
• the second essential component of the invention is a crystalline layered silicate.
• the crystalline layered silicates suitable for use herein are of the granular formula NaMSi x O 2x+1 .yH2O wherein M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20, or mixtures thereof.
• Crystalline layered sodium silicates of this type are disclosed in EP-A-164 514 and methods for their preparation are disclosed in DE-A-34 17 649 and DE-A-37 42 043.
• x in the general formula above has a value of 2, 3 or 4 and is preferably 2.
• M is sodium and y is 0 and preferred examples of this formula comprise the ⁇ , ⁇ , ⁇ and ⁇ forms of Na2Si2O5
• These materials are available from Hoechst AG FRG as respectively NaSKS-5, NaSKS-7, NaSKS-11 and NaSKS-6.
• the most preferred material is ⁇ - Na2Si2O5 , NaSKS-6.
• Crystalline layered silicates are incorporated either as dry mixed solids, or as solid components of agglomerates with other components.
• compositions according to the present invention comprise from 5% to 80% by weight of the total composition of said crystalline layered silicates or mixtures thereof, preferably from 15% to 25%.
• compositions according to the present invention further comprise an anhydrous acidifying agent or mixtures thereof.
• the purpose of said acidifying agent is to control the alkalinity generated by the percarbonate in the bleaching liquor. Said agent need to be incorporated in the product in an anhydrous form, and to have a good stability in oxidizing environment.
• Suitable anhydrous acidifying agents for use herein are carboxylic acids such as citric acid, succinic acid, adipic acid, glutaric acid, 3 chetoglutaric acid, citramalic acid, tartaric acid and maleic acid.
• Other suitable acidifying agents include sodium bicarbonate, sodium sesquicarbonate and silicic acid. Highly preferred for use herein is citric acid.
• citric acid is commercially available in anhydrous form, it additionally acts as a builder and a chelant, and it is biodegradable.
• the compositions according to the present invention comprise from up to 15% by weight of the total composition of anhydrous citric acid, preferably from 2% to 8%, most preferably about 5%.
• compositions in accordance with the invention can also comprise optional ingredients such as optical brighteners, anti dusting agents such as olefines and waxes, enzymes, chelants, dispersants, surfactants, soil release agents, photoactivated bleaches such as Zn phthalocyanine sulphonate, dyes, pigments and perfumes are examples of such optional ingredients and can be added in varying amounts as desired.
• optional ingredients such as optical brighteners, anti dusting agents such as olefines and waxes, enzymes, chelants, dispersants, surfactants, soil release agents, photoactivated bleaches such as Zn phthalocyanine sulphonate, dyes, pigments and perfumes are examples of such optional ingredients and can be added in varying amounts as desired.
• Optional but highly preferred ingredients are peroxy carboxylic acids bleach or precursors thereof, commonly referred to as bleach activators, which are preferably added in a prilled or agglomerated form.
• bleach activators peroxy carboxylic acids bleach or precursors thereof, commonly referred to as bleach activators, which are preferably added in a prilled or agglomerated form.
• suitable compounds of this type are disclosed in British Patent GB 1 586 769 and GB 2 143 231 and a method for their formation into a prilled form is described in European Published Patent Application EP-A-62 523.
• TAED tetracetyl ethylene diamine
• NOBS n-nonanoyloxybenzenesulphonate
• ATC acetyl triethyl citrate
• compositions according to the present invention naturally comprise inorganic filler salts such as alkali metal carbonates bicarbonates and sulphates.
• inorganic filler salts such as alkali metal carbonates bicarbonates and sulphates.
• Such fillers for instance sodium bicarbonate, may also act as acidifying agent as described herein above. Accordingly, sodium percarbonate is a preferred filler material for use herein.
• compositions according to the present invention can be made by a variety of methods well known in the art, including dry-mixing, spray drying, agglomeration and granulation and combinations thereof.
• compositions according to the present invention can be prepared with different bulk densities, from conventional granular products to so-called “concentrated” products (i.e. with a bulk density above 600g/l).
• compositions 1 2 3 4 5 6 Sodium percarbonate 40.0 35.0 54.0 55.0 46.0 47.0 TAED 8.7 7.6 11.7 - 9.5 - Silicate layered SKS-6 25.0 30.0 20.0 10.0 18.0 20.0 Anhydrous citric acid 10.0 12.0 12.0 5.0 5.0 5.0 Sodium sulphate 15.3 14.3 1.0 20.0 0.5 15.0 Sodium bicarbonate - - - 5.0 18.0 - NOBS - - - - - 10.3 minors up to 100%
• compositions were made by mixing the listed ingredients in the listed proportions.
• the self heating rates of the products were monitored as follows.
• the product is made and put in a bottle.
• the bottle is then put in an oven which is heated up to 70°c.
• a probe in the product allows to monitor the temperature of the product.
• the bottle is covered and the system is isolated in an adiabatic/thermo bell which maintains the temperature of the oven constant at 70°c as above. This places the product in adiabatic conditions and from thereon, the temperature of the product is monitored.
• the temperature increase thus measured is due to the self-heating of the product (runaway reaction).
• SHR1 is the average temperature increase measured during the first two hours of adiabatic conditions
• SHR2 is the average temperature increase measured during the three following hours
• SHR3 is the average temperature increase measured beyond 5 hours.
• the table below lists the results obtained for various compositions, with and without crystalline layered silicate. In some cases the runaway reaction was out of control and experiments had to be interrupted for safety reasons. Such experiments are marked "ooc" (out of control).
• compositions 7-12 show good thermal stability, and no temperature increase is reported after 5 hours storage and beyond. In the absence of crystalline layered silicate i.e. in compositions 7a-12a, self-heating rates measured were so high that experiments had to be stopped for safety purposes.

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Cited By (15)

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Citations (3)

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• 1992
  • 1992-01-03 EP EP92200005A patent/EP0550077A1/de not_active Ceased
  • 1992-12-24 CA CA002126847A patent/CA2126847A1/en not_active Abandoned
  • 1992-12-24 RU RU94035995/04A patent/RU94035995A/ru unknown
  • 1992-12-24 JP JP5511910A patent/JPH07502770A/ja active Pending
  • 1992-12-24 BR BR9207019A patent/BR9207019A/pt not_active Application Discontinuation
  • 1992-12-24 AU AU34224/93A patent/AU666918B2/en not_active Ceased
  • 1992-12-24 WO PCT/US1992/011222 patent/WO1993012843A1/en active Application Filing
  • 1992-12-24 KR KR1019940702293A patent/KR940703911A/ko active IP Right Grant
  • 1992-12-30 MX MX9207671A patent/MX9207671A/es not_active Application Discontinuation
  • 1992-12-30 MA MA23046A patent/MA22754A1/fr unknown
• 1993
  • 1993-01-02 CN CN93101189A patent/CN1075749A/zh active Pending

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