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
  • C11D17/0004—Non aqueous liquid compositions comprising insoluble particles
• • 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
  • C11D1/66—Non-ionic compounds
  • C11D1/825—Mixtures of compounds all of which are non-ionic

Definitions

• This invention relates to liquid compositions containing solid particles suspended in a liquid phase which is essentially non-aqueous and, at least predominantly, is nonionic surfactant.
• compositions of the present invention include at least one hydratable salt in the suspended solid material.
• Non-aqueous compositions containing suspended particulate solids are known, e.g. from GB 1292352 (Unilever). This discloses liquid detergent compositions containing nonionic surfactant as the liquid phase, with particulate water-soluble salts suspended in it. Most of these compositions also contain some organic solvent other than surfactant, usually mostly ethanol, as diluent and thinning agent.
• US-A-4316812 discloses non-aqueous detergent compositions comprising one or more builders and a bleach in a substantially water free nonionic liquid surfactant.
• a list of possible builder materials includes sodium bicarbonate which has no stable hydrate at 20°C and also various hydratable builder salts. The solids are required to have an average particle diameter of less than 10 microns.
• composition should provide stable suspension of the solid without however setting or gelling to an excessively viscous state.
• This invention provides a liquid, non-aqueous composition
• a liquid phase which is at least predominantly nonionic surfactant in an amount of 25 to 75% of nonionic surfactant by weight, having suspended therein 20 to 75% by weight of solid particulate material with a surface weighted mean particle size in the range of 1 to 100 ⁇ , better not over 70 ⁇ , which material comprises
• the suspended solid carrier material having a surface weighted mean particle size in the range 1 to 900m ⁇ is conveniently referred to as a "submicron carrier".
• This material will generally be an oxide.
• compositions in accordance with the invention may serve as various types of cleaning composition.
• One possibility is a liquid detergent composition for use in washing fabrics.
• compositions of this invention may serve as abrasive cleaners, for instance as hard surface cleaners.
• Such a formulation provides a convenient method of delivering surfactant and desired solids to a surface which is to be cleaned.
• Certain forms of the invention are additionally advantageous in that the non-aqueous liquid phase permits use of water-soluble solid abrasive particles which can be readily rinsed from the surface after cleaning.
• a further advantage is that the solids present can include a peroxygen bleach which will be in a stable condition by reason of the non-aqueous environment. Admixture of water at the time of use will then make the bleach active.
• suspended hydratable salt increases the suspending properties of the composition and this effect adds to the suspending properties brought about by submicron carrier material, if any.
• non-hydratable salts do not enhance suspending properties - at least not as much as do hydratable salts - but also do not increase the tendency to gelation and setting. Non-hydratable salts are thus able to function as a solid diluent for hydratable salts.
• a preferred additional constituent of compositions of the present invention is 0.1 to 20% by weight of an organic solvent.
• the presence of such solvent is useful in improving the ability of the compositions to remove a range of soil from a surface. It may be preferred to avoid hydroxylic solvents, or at any rate the lower (C1 to C6 alcohols). These may be oxidised at varying speeds by a bleach system, if such a system is present.
• Organic solvent does tend to cause a reduction in suspending properties which must then be compensated by an enhancement of the amount of carrier or hydratable salt.
• the amount of nonionic surfactant must be in the range 25 to 75% by weight of the composition.
• the amount of nonionic surfactant is not more than 65% better not more than 50% by weight of the composition.
• a particularly preferred range is 35% to 49%.
• the amount of organic solvent, if any, is not more than 8% and that the total amount of liquid phase does not exceed 55% or possibly does not exceed even 49% of the composition (all percentages being by weight based on the whole composition).
• This invention may be utilised in conjunction with other expedients for ameliorating gelation while achieving good suspension of solids.
• other expedients for ameliorating gelation while achieving good suspension of solids.
• polyvinylpyrrolidone or a derivative thereof as taught in our European application EP 359491.
• Another possible expedient is the incorporation of an organic acid, such as alkyl benzene sulphonic acid.
• the submicron carrier will have a mean particle size which is well below 1 micron regardless of the mean size definition which is used, and the other suspended solid will have a mean particle size of at least 1 micron with most definitions of mean size.
• the surfactant is a compound or mixture of compounds produced by the condensation of alkylene oxide groups, which are hydrophilic in nature, with an organic hydrophobic compound which may be aliphatic, notably with a C8 to C22 alkyl chain or alkyl aromatic, notably with a C6 to C14 alkyl chain.
• the length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
• nonionic surfactants include the condensation product of aliphatic alcohols having from 8 to 22 carbon atoms in either straight or branched chain configuration with ethylene oxide, such as a coconut oil ethylene oxide condensate having from 2 to 15 moles of ethylene oxide per mole of coconut alcohol, and condensates of synthetic primary or secondary alcohols having 8 to 15 carbon atoms with 3 to 12 moles of ethylene oxide per mole of the synthetic alcohol, and condensates of alkylphenols whose alkyl group contains from 6 to 12 carbon atoms with 5 to 25 moles of ethylene oxide per mole of alkylphenol.
• ethylene oxide such as a coconut oil ethylene oxide condensate having from 2 to 15 moles of ethylene oxide per mole of coconut alcohol
• condensates of synthetic primary or secondary alcohols having 8 to 15 carbon atoms with 3 to 12 moles of ethylene oxide per mole of the synthetic alcohol
• nonionic surfactants are condensates of the reaction product of ethylenediamine and propylene oxide with ethylene oxide, the condensates containing from 40 to 80% of polyoxyethylene radicals by weight and having a molecular weight of from 5,000 to 11,000; block copolymers of ethylene oxide and propylene oxide; tertiary amine oxides of structure R3NO, where one group R is an alkyl group of 8 to 18 carbon atoms and the others are each methyl, ethyl or hydroxyethyl groups, for instance dimethyldodecylamine oxide; glycosides or polyglycosides etherified with at least one C8-C22 alkyl group or esterified with at least one C8-C22 fatty acyl group; fatty acid alkylolamides; and alkylene oxide condensates of fatty acid alkylolamides.
• Mixtures of nonionic surfactant actives can be employed.
• nonionic surfactants are ethoxylated alcohols. These may in particular be derived from alcohols containing from 5 to 15 carbon atoms and ethoxylated with an average of 5 to 10 ethylene oxide residues. Especially preferred is nonionic surfactant derived from a mixture of alcohols mostly containing 9 to 11 carbon atoms and having an average of 6 ethylene oxide residues.
• nonionic surfactant is "topped” or “peaked”, that is to say partially fractionated in order to free it from unethoxylated alcohol which tends to have an unpleasant odour.
• This material is a finely divided solid having a mean primary particle size of less than one micron, for instance in the range 1 to 900 m ⁇ and preferably well below 900 m ⁇ . Typically such solids will have an average surface area of 50 to 500m2/g and a bulk density of 10 to 180 g/litre.
• Suitable inorganic carrier materials are light, highly voluminous metal and metalloid oxides including, for example, silica, alumina, magnesia and ferric oxide and mixtures thereof. These materials, particularly silicas, may readily be obtained commercially. Suitable silicas are sold by Degussa under the Registered Trade Mark Aerosil and by Cabot Corporation under the Registered Trade Mark Cab-O-Sil.
• the carrier material should have a bulk density within the range of from 20 to 150g/l, more particularly from 30 to 100g/l, and an average surface area lying within the range of from 150 to 400m2/g.
• the average surface area is indicative of particle size and is defined as that measured by the Brenauer, Emmet and Teller method.
• the preferred particle size and size distribution of the inorganic carrier material is such that substantially all of the particles of the carrier material lie within a size range of 1 to 100 m ⁇ .
• the amount of the submicron carrier material which is used is preferably of the order of from 0.7 to 3% by weight of the composition.
• This comprises the mixture of hydratable and non-hydratable salts. These will preferably have an average particle size in the range of 1 ⁇ to 100 ⁇ . Desirably though they should have an average particle size smaller than 70 ⁇ to avoid palpable grittiness. It is preferred that at least 99% by weight of the particles should pass a 53 ⁇ sieve, with the average particle size being less than 50 ⁇ .
• composition is intended to be abrasive, it is preferred that at least the water-soluble salts should have a relatively larger particle size than is preferred for a composition intended for some other application such as adding to water to make a fabric washing liquor.
• composition is not intended to be abrasive it will be desirable, as with known fabric washing liquids, to comminute the suspended particles to an average particle size not exceeding 10 ⁇ better not exceeding 5 ⁇ .
• the water-soluble salts should have an average particle size exceeding 5 ⁇ .
• the hydratable and the non-hydratable salts may both satisfy this requirement.
• the surface weighted mean particle size of the water-soluble salt(s) present is between 10 and 25 ⁇ while the particle size distribution satisfies the relationship: where D(v,0.5) is the median particle diameter, D(v,0.9) is the upper decile diameter (i.e. 10% of particles are larger, 90% are smaller) and D(v,0.1) is the lower decile diameter.
• the suspended solid can function as an abrasive. As explained below, it may serve other functions.
• the size range mentioned above is smaller than is customary in liquid abrasive cleaners. It is advantageous in giving less tendency to scratch and easier rinsing.
• the suspended solid should preferably constitute between 20 or 25% and 60% by weight of the composition. More preferably it constitutes between 35 and 58% by weight of the composition. In particularly preferred compositions the total amount of suspended solid other than the submicron carrier is at least 51% by weight of the composition.
• a wide range of salts have hydrates at 20°C and can be used.
• Organic salts such as citrates may possibly be used, but inorganic salts will generally be used.
• inorganic salts which have hydrates are sodium carbonate, sodium tripolyphosphate, sodium sulphate, sodium silicate in various forms, and the double salt sodium sesquicarbonate.
• Sodium citrate and the organic builder sodium nitrilotriacetate are both hydratable. It will be appreciated that a number of these salts are known detergency builders and can function as such when the composition is eventually diluted with water during use.
• the hydratable salt can be a peroxygen bleach.
• Sodium perborate and sodium percarbonate are both hydratable salts.
• Sodium percarbonate is a perhydrate of sodium carbonate and is further hydratable, analogously to sodium carbonate itself.
• the amount of hydratable salt is desirably sufficient, in relation to the amount of voluminous submicron inorganic carrier, to reduce sedimentation to a very low level. Sedimentation can be observed as the volume of clear liquid which separates at the top of a column of the composition in a measuring cylinder. Preferred compositions have not more than 1% separation after standing for 10 days.
• the amount of hydratable salt should not cause gelling of the composition, or at any rate should allow a reasonable storage time before serious gelling.
• the effect of hydratable salts varies from one to another. Thus sodium perborate and sodium carbonate both cause a greater enhancement of suspending properties than an equal amount of sodium tripolyphosphate, but the amount of them which can be tolerated without gelling is also less.
• the amount of hydratable salt is 5 to 45% by weight of the composition.
• the amount will generally be 5 to 25% by weight of the composition and preferably is 8 to 20% by weight of the composition.
• a water-soluble but non-hydratable salt can be used. This is advantageous in that the entire composition can be water-soluble, and hence can be rinsed away with water without leaving any insoluble residue. Such complete solution on rinsing helps to avoid leaving any undesired residue on cleaned surfaces. Salts which are water-soluble but non-hydratable appear to be uncommon.
• the salt envisaged for this use is sodium bicarbonate (whose water-solubility is rather low).
• the amount of non-hydratable salt is a balancing quantity as required to increase the total amount of suspended solid to the desired level but in accordance with this invention it is at least 10% of the composition, specifically in the range 10 to 55% of the composition, with amounts at the higher end of this range being appropriate for abrasive compositions where the non-hydratable salt can serve as abrasive material.
• organic solvent is desirably included, but this does tend to cause a reduction in suspending properties which must then be compensated by an enhancement of the amount of carrier or hydratable salt.
• a bleach activator may be included in the composition.
• the preferred material is tetraacetylethylenediamine (TAED). It is a fairly soft organic solid and may dissolve, at least partially, in organic solvent (if present) and nonionic surfactant. Its density is about 1g/ml and so is similar to that of the surfactant and it appears to have little or no effect on the properties of the composition.
• the composition should not contain sufficient moisture to destroy its non-aqueous character. Depending on the nature of the suspended solids some moisture content may be acceptable.
• the quantity of moisture in the composition should not exceed 5% of the composition by weight. If a bleach is present this free moisture content should preferably not exceed 1%, better 0.1% of the composition by weight.
• compositions were prepared using a standard preparative procedure.
• nonionic surfactant was C9-C11 alcohol ethoxylated with average 6EO and topped to remove residual unethoxylated alcohol.
• Organic solvent was a paraffinic/alcohol solvent mixture. The carbon chains in both solvents contain more than six carbon atoms.
• Inorganic carrier was Aerosil 380, a fumed silica available from Degussa AG and which has a primary particle size of less than 50m ⁇ (the manufacturers quote 7 to 40m ⁇ ).
• Sodium carbonate and tripolyphosphate were used in forms which are almost anhydrous.
• Sodium perborate was used as the so-called monohydrate which is actually an anhydrous dimer of sodium borate and hydrogen peroxide.
• the liquid base was prepared by stirring together in a beaker the requisite amounts of nonionic surfactant, organic solvent and perfume using a Heidolph RZR50 paddle stirrer and then adding the fumed silica (Aerosil 380).
• stirring was continued for 10 minutes using a Silverson laboratory mixer equipped with a special shaft with a hard coating on the journal area, a medium emulsor screen and axial flow head.
• the requisite quantities of the other solids were stirred into the liquid base, using the paddle stirrer once again.
• the extent of gelation (setting) of a composition was assessed in either or both of two ways.
• One assessment procedure consisted of decanting off the clear supernatant, if any, and then rating the firmness of the residual sediment as a setting index on a scale from 1 to 6.
• the lowest number, 1, denotes a sediment which is pourable without preliminary agitation.
• the numbers 2 to 6 were assigned according to the number of strokes of a glass tube needed to liquify the sediment to the point of being just pourable.
• a setting index of 6 denotes a firmly set composition.
• Trial compositions were prepared by the above procedure, omitting the step of adding silica.
• the ingredients of each composition are tabulated below. Also set out below is the separation after varying periods of time.
• the densities and particle sizes of the suspended solids were not identical.
• the densities, mean particle diameters, and theoretical initial sedimentation rates were:
• Trial compositions were prepared by the procedure mentioned above. Some contained 46% liquid, others 60% liquid. The formulations and the extent of separation after varying periods of time are set out in the following Tables. If it was noted that a composition had obviously gelled to a set state, this was noted with the abbreviation "gld”.
• compositions were prepared with ingredients as set out in the following Table, in which separations after periods of time are also quoted.
• compositions A, B, D and E show that increasing silica enhances suspending properties.
• compositions C and D show that solvent slightly reduces suspending properties.
• compositions E and F or D and H show that sodium tripolyphosphate enhances suspending properties.
• composition H Comparison of composition H with composition G shows that perborate enhances suspending properties (but this is partly offset by the presence of solvent in composition H).
• a composition was prepared using a fine calcite as the non-hydratable salt. This abrasive is the same as the calcite referred to in Example 1; it was Durcal 2 available from Omya.
• a similar composition was prepared using sodium carbonate and bicarbonate. The two formulations were as follows: Ingredient A B % by weight Nonionic surfactant 38.5 38.8 Organic solvent 5.0 5.0 Perfume 0.5 0.5 Fumed silica 2.0 2.2 Abrasive Calcite (Durcal 2) 39.0 - Abrasive Sodium carbonate - 21.0 Abrasive Sodium bicarbonate - 21.0 Builder Sodium tripolyphosphate 3.5 - Bleach Sodium perborate 10.0 10.0 TAED 1.5 1.5 100.0 100.0
• Both formulations A and B were tested for physical cleaning efficiency in comparison with a current commercial product having an aqueous liquid phase. The efficiency was tested on the following soiled substrates.
• a solution of stearic acid in chloroform was sprayed onto Perspex sheet as above (following the established code of practice for safe handling of chloroform).
• the plate was then repeatedly immersed in a solution of calcium chloride and left to dry in an oven at 50°C.
• a damp tissue was used to wipe non-adherent salts from the surface, leaving behind a thin hard layer of calcium stearate.
• Calcium stearate (75g), carbon black (0.5g Elftex 125) and isopropanol (250ml) were mixed together thoroughly and dispersed by application of ultrasound.
• the dispersion was diluted as necessary with isopropanol and sprayed in a band down the centre of a white enamelled steel plate. The plate was then placed in an oven preheated to 180°C for 20 minutes.
• Shoe polish was applied with a tissue in a band in the middle of a white vinyl tile. The tile was aged overnight before use.
• Rubber was cut from the sole of a discarded shoe and applied in close straight lines on a white vinyl tile to give a band of rubber-marked tile.
• Soil removal was determined using a Sheen Instruments in-line scrubber equipped with a cellulose sponge and operating at a relatively low surface pressure (28g cm ⁇ 2) equivalent to light rubbing. Tests were carried out by pre-moistening a clean sponge and applying a fixed amount of formulation (1ml). The number of strokes required to completely remove the soil from a variety of soil/substrate combinations was determined. Results are presented in the Table below as:
• non-aqueous formulations clearly perform very well on oily and waxy soils and exceptionally well on rubber-marked vinyl. Performance was similar on both artificial bath scum soils consisting mainly of calcium stearate on Perspex and enamel.
• a Sheen in-line scrubber was used with pre-moistened terry toweling operating over a range of surface pressures (28-149g cm ⁇ 2).
• the change in reflectance at 60° from normal incidence was measured after 100 strokes (10ml formulation) using a BYK Chemie 'Color Gloss' gloss meter equipped with a multi-angle gloss sensing head.
• the formulations were also compared on painted wooden tiles using a Wool Industries Research Association abrasion tester with pre-moistened terry toweling covered heads operating at a surface pressure of 422g cm ⁇ 2 (500 rubs, 20ml formulation).
• formulation B was superior to formulation A.

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• 1990
  • 1990-02-26 GB GB909004289A patent/GB9004289D0/en active Pending
• 1991
  • 1991-02-19 CA CA002036593A patent/CA2036593C/en not_active Expired - Fee Related
  • 1991-02-25 WO PCT/GB1991/000294 patent/WO1991013139A1/en unknown
  • 1991-02-25 BR BR919106051A patent/BR9106051A/pt not_active IP Right Cessation
  • 1991-02-25 JP JP3505201A patent/JPH05503548A/ja active Pending
  • 1991-02-25 AU AU73441/91A patent/AU660605B2/en not_active Ceased
  • 1991-02-26 EP EP91301509A patent/EP0444858B1/en not_active Revoked
  • 1991-02-26 ZA ZA911395A patent/ZA911395B/xx unknown
  • 1991-02-26 ES ES91301509T patent/ES2078435T3/es not_active Expired - Lifetime
  • 1991-02-26 DE DE69112671T patent/DE69112671T2/de not_active Expired - Fee Related

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