CLEANING COMPOSITION

The present invention relates to a liquid abrasive cleaner, particularly to an aqueous liquid abrasive cleaner.

Liquid abrasive cleaners containing a dispersed particulate abrasive provide a useful hard surface cleaner suitable for use in for example bathrooms and kitchens. The abrasive is held in suspension and is thus available for action as an abrasive in use. A number of means are known for retaining the abrasive material in suspension within the bulk of the liquid.

The choice of abrasive is determined by a number of factors including both the degree abrasive action and the degree of rinsability required in the product. The degree of abrasive action is primarily determined by the amount of abrasive present, the average size and the spread of sizes of the particles constituting the abrasive and the Moh hardness of the abrasive material used. Selection of an appropriate particle material can be important in order to avoid scratching relatively soft surfaces to be cleaned, such as plastic and aluminium.

A recent proposal to provide a liquid abrasive cleaner having a high degree of rinsability is EP-A-193375 (Unilever PLC, Unilever NV) which describes a pourable homogeneous abrasive aqueous detergent composition suitable for cleaning hard surfaces comprising water, 1.5 to 30wt% detergent active compound, 6 to 45wt% water soluble salt at least 5wt% of which at 20°C comprises a solid phase in the form of undissolved particles having a mean particle diameter of 10 to 500μm, the salt having not more than a single hydrated species when present as a crystalline solid in water at a temperature of from 10 to 40°C in an amount above that required to form a saturated solution and a saturation solubility in water at 40°C which is less than ten times that at 10°C, the composition having- an apparent viscosity at 20°C of at least 6500 Pas at a shear rate of 3 x 10 -5 sec-1 and not more than 10 pas at a shear rate of 21 sec . EP-A-193375 thus describes a shear thinning liquid abrasive cleaner containing a water soluble abrasive in saturated solution. In use any surplus undissolved water-soluble salt abrasive remaining on the cleaned surface can readily be removed by rinsing with clean water in which it dissolves. The composition described in EP-A-193375 thus exhibits good rinsability.

The water soluble abrasives disclosed in EP A-193375 are sodium bicarbonate, sodium tripolyphosphate pentahydrate and sodium tetraborate decahydrate, of which for a variety of reasons sodium bicarbonate is said to be preferred. In each case however the abrasive can only be present to a maximum level of 45wt% with respect to the total composition. This upper limit on the amount of water soluble abrasive present limits the abrasive action of the particulate material and hence the severity of the soil that can be successfully tackled with the cleaning composition.

US-A-4179414 (Mobil Oil Corp) describes a paste containing 50 to 65wt% sodium bicarbonate, 50 to 35wt% water, sodium chloride and diethanola ide. US-A-4264466 (The Procter & Gamble Company) describes liquid mulls having a liquid phase and a dispersed solid phase comprising 30 to 95wt% liquid nonionic surfactant, 1 to 65wt% of a dispersed particulate material which is insoluble in said liquid phase, 1 to 15wt% chain structure type clay and optionally up to 10wt% water. Amongst many examples the particulate material can be a builder such as sodium bicarbonate. US-A-3981826 (The Procter & Gamble Company) describes a water-soluble non-aqueous .liquid pasty or gelatinous detergent compositions comprising 19 to 79wt% of a water miscible liquid polyhydric alcohol or water miscible mixture of liquid polyhydric alcohol and a lower monohydric alcohol, with no more than 5wt% water, and 5 to 60wt% solid particulate water soluble abrasive inorganic salt selected from the group comprising chlorides, sesquicarbonates, sulphates, phosphates, carbonates and borates, and a specified suspending agent to suspend the water soluble inorganic salt.

It is an object of the present invention to provide an aqueous liquid abrasive cleaner containing a high level of water soluble particulate abrasive.

According to the present invention there is provided a shear thinning liquid abrasive cleaner composition comprising:

(i) more than 10% by weight water;

(ii) 1.5 to 30% by weight detergent active compound;

(iii) more than 45% and up to 75% by weight water

soluble salt at least 40% by weight of the total composition of which at 20°C comprises a solid phase in the form of undissolved particles having a volume distribution diameter and span of less than 80 microns and between 1 and 3 respectively.

We have found that amounts of water soluble abrasive of more than 45wt% can be stably suspended so as to provide an aqueous liquid composition provided that the particle size and the particle size distribution of the abrasive comply with the above requirements. The present invention thus provides an aqueous abrasive cleaner in liquid form containing high amounts of water soluble abrasive suspended therein and having good scouring and rinsing properties.

By "volume distribution diameter" we mean the distribution weighted according to the volume of the particles from which is obtained the average volume weighted diameter. By "span" we mean the difference between the upper decile and the lower decile divided by the Median. Span is thus a measure of the width of the distribution.

In order to achieve a liquid, i.e. pourable, composition, as required by the present invention, a small amount of trial and error may be required in order to achieve an appropriate combination of quantity of abrasive water soluble salt and particle size. We have for example found that at least in the case of sodium bicarbonate as the soluble abrasive salt it is preferable when employing very large amounts to select a type of bicarbonate having a volume distribution diameter of less than about 40 microns in order to achieve a product in liquid form.

Preferably the volume distribution diameter of the water soluble abrasive is less than 70, more preferably than 60 microns and preferably more than 20 microns. Suitably the water soluble abrasive comprises particles having a volume distribution diameter span between 1.5 and 2.5.

Preferably the water soluble abrasive comprises particles having a number distribution diameter and span of less than 20 microns and between 1 and 3 respectively. More preferably the number distribution diameter is less than 15 microns and more than 1 micron and has a span between 1.5 and 2.5.

Statistical definitions of "volume distribution diameter" and "number distribution diameter" are given in "Small Particle Statistics" by G Herdan Butterworth 1960.

Preferably the composition comprises 50 to 65wt% of the said water soluble salt, more preferably from 50 to 60wt%. As is noted above the higher levels of water soluble salt may only be achievable in combination with lower ranges of volume distribution diameter for the particle size of the abrasive water soluble salt in order to provide a product in liquid form.

The water soluble salt is preferably selected from the group comprising sodium bicarbonate, sodium tripolyphosphate hexahydrate, sodium tetraborate decahydrate and m±xturεs thereof. Sodium bicarbonate is preferred.

DISCLOSURE OF THE INVENTION

Deterσent Active Comcound

The composition according to the invention will comprise detergent actives chosen from both synthetic anionic and nonionic detergent actives.

Suitable synthetic anionic detergent active compounds are water-soluble salts of organic sulphuric reaction products having in the molecular structure an alkyl radical containing from 8 to 22 carbon atoms, and a radical chosen form sulphonic acid or sulphur acid ester radicals and mixtures thereof. Examples of synthetic anionic detergents are sodium and potassium alkyl sulphates, especially those obtained by sulphating the higher alcohols produced by reducing the glycerides of tallow or coconut oil; sodium and potassium alkyl benzene sulphates such as those in which the alkyl group contains from 9 to 15 carbon atoms; sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulphates; sodium and potassium salts of sulphuric acid esters of the reaction product of one mole of a higher fatty alcohol and from 1 to 6 moles of ethylene oxide ether sulphate with from 1 to 8 units of ethylene oxide molecule and in which the alkyl radicals contain from 4 to 14 carbon atoms; the reaction product of fatty acids esterified with i≤ethionic acid and neutralised with sodium hydroxide where, for example, the fatty acids are derived from coconut oil and mixtures thereof.

The preferred water-soluble synthetic anionic detergent active compounds are the ammonium and substituted ammonium (such as.mono, di and triethanola ine) , alkaline, metal (such as sodium and

potassium) and alkaline earth metal (such as calcium and magnesium) salts of higher alkyl benzene sulphates and mixtures with olefinsulphonates and higher alkyl sulphates, and the higher fatty acid monoglyceride sulphates. The most preferred anionic detergent active compounds are higher alkyl aromatic sulphonates such as higher alkyl benzene sulphonates containing from 6 to 20 carbon atoms in the alkyl group in a straight or branched chain, particular examples of which are sodium salts of higher alkyl benzene sulphonates or of higher-alkyl toluene, xylene or phenol sulphonates, alkyl naphthalene sulphonates, ammonium diamyl naphthalene sulphonate, and sodium dinonyl naphthalene sulphonate.

The amount of synthetic anionic detergent active to be employed in the detergent composition of this invention will generally be from 1 to 25%, preferably from 2 to 20%, and most preferably from 2 to 15% by weight.

Suitable nonionic detergent active compounds can be broadly described as compounds produced by the condensation of alkylene oxide groups, which are hydrophilic in nature, with an organic hydrophobic compound which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particlar hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements. Particular examples 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; 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; 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; tertiary amine oxides of structure R ₃ N0, 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; teritary phosphine oxides of structure R_P0, where one group R is an alkyl group of from 10 to 18 carbon atoms, and the others are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, for instance dimethyldodecylphosphine oxide; and dialkyl sulphoxides of structure ₂ S0 where the group R is an alkyl group of from 10 to 18 carbon atoms and the other is methyl or ethyl, for instance methyltetradecyl sulphoxide; fatty acid alkylolamides; alkylene oxide condensates of fatty acid alkylolamides and alkyl mercaptans.

The amount of nonionic detergent active to be employed in the detergent composition of the invention will generally be from 0.5 to 15%, preferably from 1 to 10%, and most preferably from 1 to 8% by weight.

The weight ratio of anionic detergent to nonionic detergent active may vary but is preferably in the range of from 1:1 to 9:1, ideally from 2:1 to 4:1.

Preferably, the compositions contain an amount of both the anionic and the nonionic detergent active which is chosen so as to provide a structured liquid detergent composition, i.e. one which is 'self thickened without necessarily employing any thickening agent per se.

According to a preferred embodiment illustrating this aspect of the invention, the detergent compositions will comprise from 2 to 8% by weight of a water-soluble, synthetic anionic sulphated or sulponated detergent salt containing an alkyl radical having from 8 to 22 carbon atoms in the molecule, and from 0.5 to 4% by weight of an alkyleneoxylated nonionic detergent derived from the condensation of an aliphatic alcohol having from 8 to 22 carbon atoms in the molecule with ethylene oxide, such that the condensate has from 2 to 15 moles of ethylene oxide per mole of aliphatic alcohol.

It is also possible optionally to include amphoteric, cationic or zwitterionic detergent actives in the compositions according to the invention.

Suitable amphoteric detergent-active compounds that optionally can be employed are derivatives of aliphatic secondary and tertiary amines containing an alkyl group of 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance sodium 3-dodecylamino-propionate, sodium 3-dodecylaminopropane sulphonate and sodium N-2-hydroxydodecyl-N-methyltaurate.

Suitable cationic detergent-active compounds are quaternary ammonium salts having an aliphatic radical of from 8 to 18 carbon atoms, for instance cetyltrimethyl ammonium bromide.

Suitable zwitterionic detergent-active compounds that optionally can be employed are derivatives of aliphatic quaternary ammonium, sulphonium and phosphonium compounds having an aliphatic radical of from 8 to 18 carbon atoms and an aliphatic radical substituted by an

anionic water-solubilising group, for instance 3-(N,N-dimethyl-N-hexadecylammonium) propane-l-sulphonate betaine, 3-(dodecylmethyl sulphonium) propane-l-sulphonate betaine and 3-(cetylmethylphosphonium) ethane sulphonate betaine.

Further examples of suitable detergent-active compounds are compounds commonly used as surface-active agents given in the well-known textbooks "Surface Active Agents", Volume I by Schwartz and Perry and "Surface Active Agents and Detergents", Volume II by Schwartz, Perry and Berch.

The total amount of detergent active compound to be employed in the detergent composition of the invention will generally be from 1.5 to 30%, preferably from 2 t 10% by weight.

The Water-soluble Salt

The composition according to the invention will also comprise at least one water-soluble salt which can function both as an abrasive and as a detergency builder. This salt will be present in the composition in an amount in excess of its saturation solubility, and will accordingly be present in both a dissolved and an undissolved state. The composition will therefore comprise a saturated aqueous solution of the salt, together "with at least 40% by -weight of the composition at 20°C in the form of a solid phase comprising particles of the salt having the above stated particle size distribution.

The water-soluble salt is preferably an inorganic salt, normally possessing not more than a single hydrated species when present as a crystalline solid in water at a temperature of from 10° to 40°C in an amount in excess of that required to form a saturated solution. The saturation solubility of the salt in water at 40°C will be less than ten times, preferably less than eight times, and most preferably less than twice that at 10°C. This is to ensure that the characteristics of the product, in particular the size, shape and amount of crystalline abrasive particles, do not change significantly over the normal temperature range of use. Uniformity of performance is accordingly ensured. It is also apparent that the choice of a salt having the properties as defined herein will ensure that when the composition is self structured, that is the structure which provides the desired viscosity characteristics is derived from an appropriate choice of anionic and nonionic detergent actives, it will remain stable without substantial change in viscosity.

Preferably, the water-soluble salt will have a Mohs hardness of at least 2 and less than 3, and a saturation solubility in water which at 10°C does not exceed 15% by weight.

The salt will also have a solubility in water of at least 5g/l at 10°C, to ensure that any surplus salt can readily be rinsed from a hard surface after cleaning with the composition. In this way, the surface can be free from residual spots or streaks.

The preferred salts chosen for this dual role of both builder and abrasive are given below together with data relevant to their saturation solubility in water and their hydrated species.

Salt Solubility (% w/v) at Hydrated 10 ^β C 40 ^β C ^• species

(10"C-40 ^β C)

sodium bicarbonate

(NaHC0„) 13 None sodium- tripoly- phosphate hexa- hydrate sodium tetraborate decahydrate

(Na>B,O„.10H„O) 9.5 10H. ___O

The ideal salt is sodium bicarbonate.

Mixtures of these salts can be employed.

The advantaσes cf επciovinσ sodium bicarbonate are that:

(i) it is cheap and readily available;

(ϋ) it is non-toxic and does not harm the

(iii) its solubility in water does not vary much over the normal product storage temperature range of from 0° to 40°C, its solubility in g per lOOml at 10•C being 8 and at 40°c being 13;

(iv) its saturation solubility in water at 10°C being about 3% by weight ancm-i*'- that an excess cf it will remain undissolved in the detergent ^" caposition to provide abrasive properties, whereas it is

sufficiently soluble in water to dissolve when finally rinsing with water a hard surface that has been cleaned with the detergent composition;

5

(v) it exists only in one crystalline form between 10° and 40°C and does not exist as an hydrated form (i.e. it does not contain

10 water of crystallisation) ; its crystalline structure will therefore remain unchanged in the detergent composition during storage at normal temperatures;

₁ 5 (vi) the crystalline form is sufficiently hard to exhibit good cleaning qualities, but since its hardness is a little less than that of calcite (ie it has a hardness of less than 3 on the Moh scale) , it is less likely to scratch a hard surface to the

<_.J degree that can occur when using similar products containing a water-insoluble abrasive such as calcite, which has a Mohs hardness of 3.

25 No other abrasive material exhibits all these qualities.

The total amount of the water-soluble salt present in the detergent composition, both in dissolved and

3° undissolved form, is from more than 45 to 75% by weight preferably from 45 to 65wt%, more prererably from 50 to 60wt%. The amount of the total composition comprising particulate undissolved salt is preferably from 40 to 70%, and ideally 40 to 55% by weight at normal storage or

35 use temperatures of from 10° to 40°C

In addition to sodium bicarbonate, sodium tripolyphosphate hexahydrate and sodium tetraborate decahydrate, the composition according to the invention can also optionally comprise other water-soluble inorganic salts or organic salts of lithium, magnesium, sodium, potassium and calcium, which salts can also function as builders and abrasives. Specific examples are sodium oxalate, sodium succinate, sodium adipate and sodium glutarate. Each of these optional salts can be present in the composition in an amount below or above its relevant saturation solubility. Mixtures of such salts can be employed.

Water

The composition according to the invention will also comprise water which will comprise more than 10wt% of the composition and up to the balance needed to complete the composition having regard to the other ingredients present. Preferably water will comprise from 20 to 50%, and ideally 30 to 40% by weight of the composition.

Optional Ingredients

The composition according to the invention can contain other ingredients which aid in the cleaning performance. For example, the composition can contain detergent builders other than the special water-soluble salts, as defined herein, such as nitrilotriacetates, polycarboxylates, citrates, dicarboxylic acids, water-soluble phosphates especially polyphosphates, mixtures of ortho- and pyrophosphate, zeolites and mixtures thereof. Such builders can additionally function as abrasives if present in an amount in excess of their solubility in water as explained herein. In general, the builder, other than the special water-soluble salts when employed, preferably will form from 0.1 to 25% by weight of the composition.

Metal ion sequestrants such as ethylenedia inetetraacetates, amino-polyphosphonates (DEQUEST) and phosphates and a wide variety of other poly-functional organic acids and salts, can also optionally be employed.

A further optional ingredient for compositions according to the invention is a suds regulating material, which can be employed in compositions according to the invention which have a tendency to produce excessive suds in use. One example of a suds regulating material is soap. Soaps are salts of fatty acids and include alkali metal soaps such as the sodium, potassium, ammonium and alkanol ammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms, and preferably from about 10 to about 20 carbon atoms. Particularly useful are the sodium and potassium and mono-, di- and triethanolamine salts of the mixtures of fatty acids derived from coconut oil and ground nut oil. When

employed, the amount of soap can form at least 0.005%, preferably 0.5% to 2% by weight of the composition. A further example of a suds regulating material is an organic solvent, hydrophobic silica and a silicone oil or hydrocarbons.

The compositions according to the invention may optionally contain structuring agents to aid in providing appropriate rheological properties to maintain the undissolved salt or salts uniformly distributed in the composition and in enhancing their distribution and adherence of the composition to the hard surface to be cleaned. Preferred structuring agents include polysaccharides, such as sodium carboxy ethyl cellulose and other chemically modified cellulose materials, xanthan gum and other non-flocculating structuring agents such as Biopolymer PS87 referred to in US Patent No. 329 448. Certain polymers such as a polymer of acrylic acid cross-linked with a poly functional agent, for example CARBOPOL, can also be used as structuring agents. The amount of such structuring agents, when employed, to be used in compositions according to the invention can be as little as 0.001%, preferably at least 0.01% by weight of the composition.

The compositions according to the invention can also comprise at least partially esterified resin such as an at least partially esterified adduct of rosin and an unsaturated dicarboxylic acid or anhydride, or an at least partially esterified derivatives of co-polymerisation products of mono-unsaturated aliphatic, cycloaliphatic or aromatic monomers having no carboxy groups and unsaturated dicarboxylic acids or anhydrides thereof.

Typical examples of suitable copolymers of the latter type are copolymers of ethylene, styrene, and vinylmethylether with maleic acid, fumaric acid, itaconic acid, citraconic acid and the like and the anhydrides thereof. Preferred are the styrene/maleic anhydride -copolymers.

In general, the compositions of the invention can optionally comprise from 0.005 to 20%, usually from o.l to 15% and preferably from 0.5 to 10% by weight of the at least partially esterified resin.

Compositions according to the invention can also contain, in addition to the ingredients already mentioned, various other optional ingredients such as pH regulants, perfumes, colourants, optical brighteners, soil suspending agents, detersive enzymes, compatible bleaching agents, gel-control agents, freeze-thaw stabilisers, bactericides, preservatives, detergent hy rotropes, opacifiers and solvents.

The compositions according to the invention will not contain more than 10%, preferably not more than 5% by weight of a water-insoluble abrasive, such as calcite, in view of the tendency of such abrasives to leave a deposit on hard surfaces after cleaning, even when rinsed with water.

Ideally, compositions according to the invention are substantially free from water-insoluble abrasives.

Generally, the water and optional ingredients comprising other detergent adjuncts will form the balance of the composition, after accounting for the detergent active compound and the water soluble salt ingredients.

ES

Compositions according to the invention are usually formulated in the alkaline pH range, and will generally have a pH of from 7 to 13, preferably about 7 to 11. Alkalisi g agents such as sodium hydroxide and sodium carbonate can be used to adjust and buffer the pH as desired.

Suspending Properties

It is an important feature of the invention that the composition will be capable of suspending the undissolved particles of salt abrasive, so that the consumer does not need to agitate the composition, for example by shaking it, in order to re-suspend and re-distribute sedimented particles prior to use. For this purpose, the composition should preferably have an apparent viscosity at 20°C of at least 4000 preferably at least 6500 Pas at a shear rate of 3 x 10 -5 sec.-1 to ensure that the particles of salt abrasive do not sediment on standing at

20°C by more than 1 cm in one month. Ideally, the apparent viscosity at 20°C is at least 25,000 Pas at a shear rate of 3 x 10 -5 sec-1

This viscosity value can be determined by application of Stokes Law, with the assumption that the particles of salt abrasive are spherical, and that the above sedimentation rate applies.

While it is necessary to ensure that the composition according to the invention has an apparent viscosity which is high enough to prevent any substantial settlement of the undissolved particles of salt abrasive during storage, it should remain fluid, so that it can readily be poured from a bottle or other container when

required for use. For this purpose, the composition should have an apparent viscosity at 20°C, measured using a rotational viscometer which does not exceed 10 Pas at a shear rate of 21 sec . Preferably, the apparent viscosity at 20°C is no greater than 5 Pas at a shear rate of 21 sec

Suitable rheological conditions to suit these critera can be provided by judicial choice of anionic and nonionic detergent to provide a structured liquid having the requisite suspending properties, and/or by use of an appropriate amount of an alternative structuring agent such as is described herein.

Process for Preparation of Compositions

Since the compositions according to the invention are in liquid form, they can be prepared simply by blending the essential and optional ingredients in water.

Packaging and Use of the Compositions

The compositions according to the invention are pourable liquids that are preferably contained in a closable container for convenience of storage, transport and sale, without spillage.

The compositions are particularly suited to the cleaning of soiled hard surfaces, such as those to be found in the domestic kitchen and bathroom. The compositions can be used neat, that is without dilution, or they can first be diluted as required with water before application to a soiled surface using, for example, a cloth, brush or sponge for ease of application. Following use, any surplus undissolved

water-soluble salt abrasive remaining on the surface can readily be removed by rinsing with clean water in which it dissolves.

Surfaces cleaned in this way with compositions of the invention show less of a tendency to residual streaking or spotting than surfaces cleaned with corresponding products containing water-insolube abrasives such as calcite.

EXAMPLES

The invention is illustrated by ^' the following Examples.

Example 1

This example illustrates the formulation of a concentrated detergent composition according to the invention containing sodium bicarbonate as the ater-soluble abrasive salt, which is suitable for cleaning hard surfaces such as sinks, worktops, baths and floors.

The following components were mixed together using a Heidolph RZR50 overhead stirrer equipped with a paddle.

wt% Linear alkyl benzene sulphonate (Dobs 102) 4.875

Alcohol ethoxylate (Dobanol 91-8) 1.625

Perfume 0.07

Sodium Bicarbonate 55.00

Water to 100.00

The sodium bicarbonate employed had the following particle size distributions:

Volume distribution diameters (microns)

Median 59.5

Upper decile 121.3

Lower decile 25.4

Span 1.6

Number distribution diameters (microns)

Median 10.8

Upper decile 32.6

Lower decile 5.6

Span 2.5

The measurements were obtained using a Malvern Mastersizer.

The composition was stable over several months,

Examples 2 to 10

A set of nine examples was prepared from three types of sodium bicarbonate at three levels of abrasive by mixing together the respective solid sodium bicarbonate ingredients with a liquid base having the following formulation:

(wt%)

Sodium bicarbonate (in solution) 7.2

Linear alkyl benzene sulphonate

(Dobs 102) 10.4

Alcohol ethoxylate (Dobanol 91-8) 3.0

Perfume 1.0

Water 78.4

. The sodium bicarbonate was employed at total levels =f 40,55 and 70wt% with respect to the whole composition. The three different types of sodium bicarbonate differed in their volume distribution. The volume distributions and the appearance of the resulting products for each level of sodium bicarbonate present are given in the following table.

Table

Volume weighted distribution wt%

Average diameter Span 40 55 70 (microns) ^'

ex BDH 87 1.7 coarse coarse coarse pasty pasty pasty liquid liquid liquid

ex ICI 66 2.5 smooth smooth smooth (extra fine) creamy creamy thick liquid thick paste liquid

Milled 29 1.7 smooth smooth smooth creamy creamy thick liquid thick creamy liquid liquid

Example 11

This example illustrates the formulation of another concentrated detergent composition according to the invention containing sodium bicarbonate as the water-soluble .abrasive salt. The formulation includes sodium soap obtained by neutralization of a fatty acid mixture which is predominantly C ₁₂ and C ₁₄ fatty acids (Prifac 7901 from Unichema). This acts to regulate the amount of foam produced by the product during use. The composition is suitable for cleaning hard surfaces such as sinks, worktops, baths and floors.

The following components were mixed together using a Heidolph RZR50 overhead stirrer equipped with a paddle. (Wt%)

Linear alkyl benzene sulphonate (DOBS 102) 3.45

Alcohol ethoxylate (Dobanol 23-6.5E0) 1.73 Sodium soap (Prifac 7901) 0.58

Perf me 0.50

Sodium bicarbonate 55.00

Water to 100.00

The sodium bicarbonate employed had the same particle size distribution as that given in Example 1. The composition was stable over several months.