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
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/06—Powder; Flakes; Free-flowing mixtures; Sheets
• • 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
  • C11D11/04—Special methods for preparing compositions containing mixtures of detergents by chemical means, e.g. by sulfonating in the presence of other compounding ingredients followed by neutralising

Definitions

• the present invention relates to a detergent composition having a low bulk density (BD) and a process for its production by dry neutralisation and further envisages the use of a fluidised bed for manufacture of such detergent compositions.
• BD bulk density
• Henkel 4304062 describes the production of a cleaning active surfactant granulate in which an anionic surfactant in acid form is neutralized with an aqueous alkali solution under high gas pressure in a granulation and drying chamber. In this process the drying of a non-surfactant liquid component by using hot air is an essential step.
• East German Patent No. 140 987 discloses a continuous process for the production of granular washing and cleaning compositions, wherein liquid components such as nonionic surfactants or the acid precursors of anionic surfactants are sprayed onto a powdered builder material, especially sodium tripolphosphate (STPP) having a high phase II content to obtain a product with bulk density ranging from 530 - 580 g/L.
• STPP sodium tripolphosphate
• the process according to the said East German Patent is restricted to the use of STPP having a high phase II content.
• GB1404317 discloses the preparation of a detergent powder of low or moderate bulk density by a dry neutralization process. Sulphonic acid is mixed with an excess of soda ash in the presence of sufficient water to initiate the neutralization reaction but not enough to wet the resulted product which is in the form of a free-flowing powder.
• the process is carried out in a mixing apparatus, for example a ribbon blender, planetary mixer or air transfer mixer.
• a mixing apparatus the particulate detergent material is subjected to compressive forces which may lead to an increase in bulk density.
• a process for the production of a " detergent composition having a low bulk density which comprises contacting an acid precursor of an anionic surfactant with a neutralizing agent in a fluidised bed to effect- neutralisation of the precursor whereby the detergent composition is obtained.
• the invention provides in a second aspect, a process for the production of a particulate detergent composition having a low bulk density which comprises feeding a particulate material comprising a neutralising agent and optionally a detergency builder in a fluidisation zone, fluidising the material, contacting a liquid precursor of an anionic surfactant with the fluidised material to effect at least partial, and preferably substantially complete, neutralisation of the acid precursor and to effect the formation of detergent particles comprising the neutralised precursor acid.
• the fluidisation zone is provided by means of a fluid bed.
• a process for the production of a particulate detergent composition having a low bulk density which comprises:-
• introducing a particulate material comprising a builder and a neutralizing agent into a fluidised bed ii. introducing linear alkyl benzene sulphonate (LAS) acid into the said bed over a sufficient time to effect at least partial neutralization of the acid and to attain the required properties of the powder.
• LAS linear alkyl benzene sulphonate
• the invention also provides a detergent composition obtainable by a process as defined in the claims.
• the process may be carried out in either batch or continuous mode of operation as desired.
• the term "detergent composition” as used herein includes a detergent material which may be mixed with other conventional materials for example bleaches and enzymes to produce a fully formulated product and also a detergent component, often referred to as an adjunct, which may be treated further to produce a detergent material which may then be mixed with other materials as desired.
• the process envisages dry neutralization of the acid precursor of an anionic surfactant with a neutralising agent by fluidisation of the neutralising agent; preferably the process is carried out in a fluidised bed.
• the process of dry neutralisation refers to at least partial and preferably substantially complete neutralisation of the acid precursor while the mixture remains in particulate form.
• addition of the acid precursor is controlled so that it does not accumulate in the unneutralised form in the detergent composition.
• the neutralising agent is suitably particulate and comprises an alkaline inorganic material, preferably an alkaline salt.
• Suitable materials include alkali metal carbonates and bicarbonates for example sodium salts thereof.
• the neutralising agent is suitably present at a level sufficient to neutralise fully the acid precursor. If desired a stoichiometric excess of neutralising agent may be employed to ensure complete neutralisation or to provide an alternative function, for example building, in the case of sodium carbonate.
• anionic surfactants or nonionic, cationic, zwitterionic, amphoteric or semipolar surfactants and mixtures thereof may be added at a suitable time.
• Suitable surfactants include those generally described in "Surface active agents and detgents " Vol I by Schwartz and Perry.
• soap derived from saturated or unsaturated fatty acids having C 12 to C 15 carbon atoms may also be present as an anionic surfactant.
• the detergent active is suitably present at a level of 5 to 40%, preferably 12 to 30% by weight of the detergent composition.
• the detergent composition suitably contains a detergency builder.
• the builder may be introduced with the neutralising agent and/or added subsequently as desired.
• the builder is introduced with the neutralising agent .
• Any conventional builder may be employed; suitable builders include sodium carbonate, zeolite, sodium tripolphosphate (STPP) sodium citrate and/or high surface area calcite.
• suitable builders include sodium carbonate, zeolite, sodium tripolphosphate (STPP) sodium citrate and/or high surface area calcite.
• STPP sodium tripolphosphate
• the builder can also consist of one of the above singularly or in combination with other builders.
• the builder and neutralising agent may be the same material, for example sodium carbonate, in which case sufficient material will be employed for both functions.
• the builder is suitably present at a level of 15 to 65% and preferably 15 to 50% by weight of the detergent composition.
• Detergent powder obtained by the present invention suitably has a low bulk density in the range 350 to 650 g/1, or 450 to 650g/l, for example, in the proximity of 500 g/L and is thus comparable to a bulk density obtained by the method of spray drying.
• a flow aid is incorporated into the composition.
• the flow aid may be mixed with the neutralising agent and, if present, builder prior to or subsequent to partial or complete addition of the acid precursor. It is especially preferred that the flow aid be added prior to or after partial introduction of the acid precursor as a significant reduction in the bulk density of the final powder may be achieved.
• the flow aid is suitably present in an amount of 0.1 to 15% by weight of the detergent composition and more preferably in an amount of 0.5 to 5%.
• Suitable flow aids include crystaline or amorphous alkali metal silicate, calcite, diatomaceous earth, silica, for example precipitated silica, magnesium sulphate, and calcium carbonate, for example precipitated calcium carbonate. Mixtures of these materials may be employed as desired.
• the flow aid is Dicamol.
• the composition may also comprise a particulate filler which suitably comprises an inorganic salt, for example sodium sulphate and sodium chloride.
• the filler may be present at a level of 5 to 50% by weight of the composition.
• the detergent composition produced according to the invention suitably comprises the detergent active and builder and optionally one or more of a flow aid, a filler and other minor ingredients such as colour, perfum, fluorescers, bleaches, enzymes.
• the particulate material (s) have a particle size distribution such that not more than 5% by weight of the particles have a particle size greater than 250 ⁇ . It is also preferred that at least 30% by weight of the particles have a particle size below 75 ⁇ .
• the particulate material (s) has an average particle size below 200 ⁇ to provide detergent powders having a particularly desired low bulk density.
• a controlled amount of water may be added to facilitate neutralisation.
• the water may be added in amounts of 0.5 to 2% by weight of the final detergents composition. Any such water is suitably prior to or together or alternating with the addition of the acid precursor.
• the particulate material is introduced into a fluidised bed and the required amount of LAS acid is then introduced preferably by spraying onto the said material and preferably from the top.
• the flow aid maybe introduced with the starting material. However, it is preferred that the flow aid be added after part introduction of part of the LAS acid to obtain a lower bulk density.
• the fluid bed is suitably operated at a temperature of ambient to 60°C.
• the air flow is sufficient to cause fluidisation and is preferably in the range 0.6 to 1 ins "1 .
• Fluidisation of the solid material is an essential feature of the present invention as this facilitates neutralisation and granulation whilst keeping the particles apart. This is to be contrasted with mixing processes in which the particles, are intentionally contacted and compressed, which may lead to higher bulk density powder and poorer powder properties.
• EXAMPLES 1 to 19 A powdered builder/inorganic alkaline material (in Examples 1 to 4, sodium carbonate performed both functions) and a filler was introduced into a fluid bed and was fluidised by operating at a superficial air velocity above the minimum fluidisation velocity. The temperature in the fluid bed was from ambient to 60°C. Linear alkyl benzene sulphonic acid (LAS acid) was sprayed onto the powdered mix in the fluid bed.
• LAS acid Linear alkyl benzene sulphonic acid
• Examples 1 to 3 illustrate the effect of incorporation a flow aid (in this case Dicamol) to the composition at different points in the process.
• a flow aid in this case Dicamol
• Example 1 the flow aid was not added to the material.
• Example 2 the flow aid was added to the starting material prior to the introduction of LAS acid.
• Example 3 the flow aid was added after introduction of 50% of the LAS acid.
• Example 4 illustrates the benefits obtained in employing a fine grade of particulate material. The results are shown below in Table 1.
• Examples 2 and 3 illustrate that a significant reduction in bulk density may be achieved by addition of the flow aid either prior to or subsequent to introduction of part of the LAS acid.
• Examples 5 to 19, as detailed below in Tables 3 to 5 were prepared according to the process described for Examples 1 to 4 and various raw materials having a different particle size distribution were employed. Table 2 summarises the size distribution of the various materials.
• Soda ash % 22.0 20.0 22.0 22.0 20.0 20.0
• Fine salt % - 30.0 - - 16.0 15.0
• Tables 3 and 4 show the results for STPP built powders containing active in the range of 17 to 31%.
• the soda ash and STPP had a similar particle size distribution as shown in Table 2 and formulations based on such builder systems resulted in products with bulk density close to 500 g/L.
• Table 5 shows powders based on various builder systems, i.e. STPP, soda ash and HSA calcite. Both the soda ash and STPP built formulations resulted in powders with BD of about 500 g/1 whereas formulations based on HSA calcites resulted in powders with bulk density lower than 500 g/L.
• Example 19 relates to a mixed active system containing 13% LAS AD and 4% soap and resulted in powder with bulk density of 500 g/L.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Detergent Compositions (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (13)

Cited By (28)

Families Citing this family (1)

Citations (8)

• 1994
  • 1994-08-05 GB GB9415904A patent/GB9415904D0/en active Pending
• 1995
  • 1995-07-24 CA CA002195313A patent/CA2195313A1/en not_active Abandoned
  • 1995-07-24 CN CN95194514A patent/CN1115403C/zh not_active Expired - Fee Related
  • 1995-07-24 EP EP95927721A patent/EP0775193A1/en not_active Withdrawn
  • 1995-07-24 WO PCT/EP1995/002935 patent/WO1996004359A1/en active IP Right Grant
  • 1995-07-24 AU AU31656/95A patent/AU702808B2/en not_active Ceased
  • 1995-07-24 CZ CZ1997305A patent/CZ289884B6/cs not_active IP Right Cessation
  • 1995-07-24 SK SK145-97A patent/SK282576B6/sk unknown
  • 1995-07-24 PL PL95318548A patent/PL181161B1/pl not_active IP Right Cessation
  • 1995-07-24 BR BR9508505A patent/BR9508505A/pt not_active IP Right Cessation
  • 1995-07-24 HU HU9700357A patent/HU222907B1/hu not_active IP Right Cessation
  • 1995-08-01 ZA ZA9506415A patent/ZA956415B/xx unknown
  • 1995-08-09 TW TW084108296A patent/TW380161B/zh not_active IP Right Cessation

Patent Citations (8)

Non-Patent Citations (1)

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