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
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/38—Cationic compounds
  • C11D1/62—Quaternary ammonium compounds
• • 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
  • C11D11/00—Special methods for preparing compositions containing mixtures of detergents ; Methods for using cleaning compositions
  • C11D11/02—Preparation in the form of powder by spray drying
• • 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
  • C11D3/04—Water-soluble compounds
  • C11D3/08—Silicates

Definitions

• the present invention provides a process for the preparation of granular detergent composition or component comprising a water-soluble cationic surfactant, and also provides granular detergent composition or component obtainable by the process.
• Cationic surfactants are well-known detergent ingredients which are used, in particular, for imparting a soft feel to fabrics after they have been washed.
• the most commonly used cationic surfactants are commercially available as aqueous solutions, typically with a surfactant activity of about 35% or 40%.
• Various techniques are known to dry the aqueous solutions to form powders, however these techniques have a number of disadvantages. Expensive equipment may be required, and the process may require temperatures which cause the cationic surfactant to degrade. The products prepared in this way tend to be sticky which makes subsequent handling and processing difficult.
• simply adding cationic surfactant in the form a fine powder to a granular detergent matrix significantly impairs the dispensing properties of the product for example by forming sticky, viscous gels upon contact with water.
• EP-A-0 714 976 published on 5th June 1996, describes a process for spray drying cationic surfactant in the presence of low levels of anionic surfactants.
• the counter-current spray drying process described requires high temperatures which can cause some cationic surfactants to degrade.
• the object of the invention is to provide a process for incorporating aqueous solutions of cationic surfactants into free-flowing, high bulk density, high active detergent granules and to avoid any degredation of the cationic surfactants, especially those with alkyl chains of C10 or less, due to high temperatures.
• a further object of the invention is to provide detergent granule composition which comprise cationic surfactants and which provide good dispensing properties when used as a component of a laundry product.
• drying step is carried out in a co-current spray dryer and the drying gas is air.
• the aqueous solution or dispersion also comprises water-soluble silicate.
• a suitable water-soluble silicate is sodium silicate having a ratio of SiO2 to Na2O is from 0.5 to 3.3, preferably from 1.0 to 2.4.
• the water-soluble cationic surfactant is a quaternary ammonium salt having the general formula R1R2R3R4 N + and wherein R1 is a C6 to C10 alkyl chain and R2, R3, and R4 are C1 to C7 alkyl or hydroxy alkyl chains
• the invention also relates to a granular detergent composition or component comprising:
• the aqueous solution or dispersion of cationic surfactant is dried to remove water and form a free-flowing granular product.
• the drying step is carried out with a drying gas having a temperature of less than 250°C, preferably in a concurrent spray dryer.
• a drying gas having a temperature of less than 250°C, preferably in a concurrent spray dryer.
• the aqueous solution or dispersion is atomised to form droplets, and the droplets are directed into a hot gas entering the drying chamber.
• spray evaporation is rapid, the hot drying gas cools accordingly, and evaporation times are short.
• the cationic surfactant is not subject to heat degradation.
• Both rotary and nozzle-type atomisers can be used in co-current spray dryers. Most commonly the hot drying gas is air.
• An alternative arrangement is a counter-current spray dryer in which the droplets and the hot gas pass through the drying chamber in generally opposite directions.
• this arrangement often results in temperatures greater than 250°C which falls outside of the scope of the present invention.
• Cationic surfactants useful in the present invention include water-soluble quaternary ammonium compounds of the form R 1 R 2 R 3 R 4 N + X - , in which R 1 is a hydroxyalkyl group having no greater than 6 carbon atoms; each of R 2 and R 3 is independently selected from C 1-4 alkyl or alkenyl; R 4 is a C 5-11 alkyl or alkenyl; and X - is a counterion.
• the cationic surfactant comprises a mixture of cationic surfactants of formula I: R 1 R 2 R 3 R 4 N + X - in which R 1 is a hydroxyalkyl group having no greater than 6 carbon atoms; each of R 2 and R 3 is independently selected from C 1-4 alkyl or alkenyl; R 4 is a C 5-11 alkyl or alkenyl; and X - is a counterion which does not substantially exchange with a hydroxide ion in a 0.5% by weight aqueous solution of the detergent composition at 20°C and wherein, in the mixture of cationic surfactants of formula I, at least 10%, preferably at least 20 % or event at least 50% by weight of the cationic surfactant has R 4 which is C 5-9 alkyl or alkenyl.
• the cationic surfactant comprises a mixture of surfactants of formula I wherein there is a longer alkyl chain surfactant having R 4 with n carbon atoms where n is from 8 to 11 and a shorter alkyl chain surfactant having (n-2) carbon atoms.
• alkyl or alkenyl as used herein may be branched, linear or substituted.
• Substituents may be for example, aromatic groups, heterocyclic groups containing one or more N, S or O atoms, or halo substituents.
• Silicates are well-known detergent components, and are optional components of the present invention.
• sodium silicate is often added to detergent compositions in order to act as a corrosion inhibitor.
• Water-soluble silicates which are suitable for use in the present invention may be amorphous or layered.
• Such silicates may be characterised by the ratio of SiO 2 to Na 2 O in their structure. In the present invention, this ratio may typically be less than 3.3:1, preferably less than 2.8:1, more preferably less than 2.4:1, most preferably about 2.0:1.
• amorphous silicates are preferred to crystalline silicates.
• crystalline silicates may be included in the paste compositions of the invention.
• Crystalline layered sodium silicates have the general formula NaMSi x O 2x+1 . yH 2 O wherein m is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20.
• 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. More preferably M is sodium.
• Preferred examples of this formula comprise the ⁇ -, ⁇ -, ⁇ -, ⁇ - forms of Na 2 Si 2 O 5 . These materials are available from Hoechst AG, Germany, as, respectively, NaSKS-5, NaSKS-7, NaSKS-11 and NaSKS-6. The most preferred material is ⁇ - Na 2 Si 2 O 5 , NaSKS-6.
• aqueous solution or dispersion of the water-soluble cationic surfactant and the silicate, where present, in the process of the present invention may be carried out using any suitable mixing equipment.
• One particularly suitable piece of mixing equipment is known in the industry as a "crutcher”.
• Other materials may be added to the crutcher at this stage, especially inorganic materials such as aluminosilicate, sulphate etc.
• the free-flowing granular product may be dry mixed or otherwise blended with other detergent components to form a finished detergent composition.
• Typical components of a finished detergent composition include surfactants, soluble and insoluble builders, cheating agents, anti-redeposition and soil suspension agents, bleach and bleach activators, optical brighteners, soil release agents, suds suppressors, enzymes, fabric softening agents including clays, perfumes and colours, as well as other ingredients known to be useful in laundry detergents.
• composition of Examples 1 to 3 were made by mixing aqueous solution of the quaternary ammonium salt (50% active) with an aqueous solution of the sodium silicate (45% active), and forming a homogeneous single phase mixture. The mixture was then passed through an atomising nozzle within a co-current spray-drying tower having an inlet air temperature of about 200°C. The hot granular compositions were collected at the bottom of the spray-drying tower and allowed to cool to ambient temperature. The resulting granular compositions were found to be free-flowing.

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• 1997
  • 1997-05-21 EP EP97201517A patent/EP0879876A1/de not_active Withdrawn
• 1998
  • 1998-05-13 WO PCT/IB1998/000712 patent/WO1998053037A1/en active Search and Examination
  • 1998-05-20 MA MA25083A patent/MA24550A1/fr unknown
  • 1998-05-21 AR ARP980102359 patent/AR015327A1/es unknown

Patent Citations (7)

Non-Patent Citations (2)

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