WO2015078679A1

WO2015078679A1 - Hard surface cleaning composition

Info

Publication number: WO2015078679A1
Application number: PCT/EP2014/073963
Authority: WO
Inventors: Sumanth Kumar ARNIPALLY; Punam Bandyopadhyay; Manoj Vilas DAGAONKAR; Suresh Murigeppa NADAKATTI; Megha Pratap VARMA
Original assignee: Unilever N.V.; Unilever Plc; Conopco, Inc., D/B/A Unilever
Priority date: 2013-11-28
Filing date: 2014-11-06
Publication date: 2015-06-04
Also published as: AR098553A1

Abstract

Disclosed invention is in the field of hard surface cleaning compositions for tough soil removal providing effective action against tough stains and grease with less effort and time. Disclosed composition includes combination of an inorganic alkaline material having a pH of more than 11 and reserve alkalinity of more than 45 in 1 % solution; and an abrasive having a Mohs' index of more than 3.5 in an anionic detergent composition wherein the composition further comprises water and wherein water is in a concentration of 20 - 40% by weight of the composition.

Description

HARD SURFACE CLEANING COMPOSITION

Field of the invention The present invention is in the field of cleaning compositions; and in particular relates to hard surface cleaning compositions for tough soil removal.

Background of the invention Washing processes, including laundry, dishwashing and other household cleaning processes, require large amounts of water throughout the world. These are exhaustive daily chores in which the use of water and a detergent cannot be avoided and the use increases as the target soil for removal gets tougher. Hard surface cleaning involves the removal of all kinds of soils. The commonly encountered soils include soft/mobile grease, particulate food, burnt-on food, burnt-on milk, burnt-on grease and scorch marks.

Hard surface cleaning also involves removal of burnt-on soot from the exterior of a cooking utensil which is due to heating with fuel sources like wood, charcoal, waste papers, dried leaves, etc. This soil is typically charred carbonized material that is tenaciously bound to the outside of cooking utensils. They get accumulated over a time period and due to repeated heating cycles and aging, they become difficult to clean. It therefore becomes a challenge to remove this soil.

Chemically unsaturated oily soils, once they have aged, are among the most difficult to clean from utensils. Ageing allows oxidative changes to occur in the oil, resulting in polymerization, cross-linking and toughening. Free radical oxidation chemistry can convert an easily-removable, mobile, liquid oil to a sticky, viscous material and ultimately to a rubbery solid. In these forms the soil requires far more physical effort from the consumer to clean. There is a long felt need for hard surface cleaning products which aim at (i) the removal of tough stains like burnt-on soot and/or burnt-on food from surfaces like cooking utensils, (ii) the removal of grease from surfaces, (iii) perceptibly less effort and time in cleaning as compared to current products in use.

WO 2004/013268 (Unilever) discloses a synergistic cleaning composition comprising 0.1 to 40% by weight of a detergent active and 0.1 to 40% by weight of a shape selective particulate abrasive, said shape selective particulate of the abrasive having 0.6 to 1.0 roundness factor and optionally other abrasives such that the total amount of abrasives is from 0.1 to 98% by weight of the total composition. The abrasives preferred in this composition have a roundness factor of 0.6 to 1 .0 to ensure that no damage is caused to the surface.

JP 7034062 (Yoda Shigeo) discloses an abrasive consisting of 100 pts wt of abradant, 0.1 - 10 pts wt of surfactant or degreasing agent and optionally 0.1 - 500 pts wt of fibrous ingredient. The abrasive is suitable for lapping like buffing and barrel polishing.

However, a hard surface cleaning composition which aims at (i) removal of tough stains like burnt-on soot and/or burnt-on food from surfaces like cooking utensils, (ii) removal of grease from surfaces, (iii) perceptibly less effort and time in cleaning as compared to current products in use still remains to be desired.

WO00/42143 Al (Unilever) discloses a detergent bar for cleaning dishes. The bar contains surfactant, a gum called Gum Ghatti and other usual ingredients. The water content of exemplified compositions is about 15%. Gum Ghatti is very likely to separate out under high alkaline pH (>1 1 ) and electrolyte concentration. As it is an acidic ingredient, it may lead to drop in pH and may not give pH greater than 1 1.

GB1454895 A (Unilever) discloses scouring powders, pastes or liquids with neutral silicates.

It is therefore an object of the present invention to provide a hard surface cleaning composition that easily removes tough stains and soils from surfaces. It is another object of the present invention to provide water saving in household process, especially hard surface cleaning processes.

It is yet another object of the present invention to provide a hard surface cleaning composition that requires less effort and time in cleaning.

It is yet another object of the present invention to provide a hard surface cleaning composition with high reserve alkalinity. Surprisingly, it has been found that easy and better removal of tough soils and stains from surfaces may be obtained by the combination of an inorganic alkaline material having a pH of more than 1 1 and reserve alkalinity of more than 45 in 1 % solution; and an abrasive having a Mohs' index of more than 3.5 in a hard surface cleaning composition wherein the composition further comprises water and wherein water is in a concentration of 20 - 40% by weight of the composition..

Summary of the invention

Accordingly, in a first aspect, the present invention provides a hard surface cleaning composition comprising 5-50% by weight of an anionic surfactant, 0.5-45% by weight of an inorganic alkaline builder having a pH of more than 1 1 and reserve alkalinity of more than 45 in 1 % solution; and 20-60% by weight of an abrasive having a Mohs' index of more than 3.5 wherein the composition further comprises water and wherein water is in a concentration of 20 - 40% by weight of the composition..

In a second aspect, the invention provides a use of the composition according to the invention for hard surface cleaning.

In a third aspect, the invention provides a process for cleaning a hard surface comprising the steps of applying onto the surface 0.3 to 5g of the composition according to the invention, scrubbing the surface for not more than 30 times, and rinsing the surface. In the context of the present invention, the reference to "hard surface" typically means utensils or kitchenware, kitchen tiles, sink and platforms, floors and bathrooms.

These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about".

Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

Detailed description of the invention

In a first aspect, the invention relates to a hard surface cleaning composition comprising an anionic surfactant, an inorganic alkaline material and an abrasive wherein the composition further comprises water and wherein water is in a concentration of 20 - 40% by weight of the composition..

Surfactant One of the key ingredients in a hard surface cleaning composition is the surfactant.

The hard surface cleaning composition of the invention comprises an anionic surfactant or a mixture of anionic surfactants. Anionic surfactants are included in the composition for primary cleaning action by emulsifying the oil attached to the substrate. Any non- soap anionic surfactant known in the art for use in hand dish wash detergents may be used herein. In general, these surfactants are described in well known textbooks like "Surface Active Agents" Vol. 1 , by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz, Perry & Berch, Interscience 1958, and/or the current edition of "McCutcheon's Emulsifiers and Detergents" published by Manufacturing Confectioners Company or in

"Tenside-Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981 .

A suitable class of anionic surfactants are water-soluble salts, particularly alkali metal (eg. sodium or potassium), ammonium and alkylolammonium salts of organic sulphuric acid mono-esters and sulphonic acids having in the molecular structure a branched or straight chain alkyl group and condensations products thereof containing 8 to 22 carbon atoms or an alkylaryl group containing 6 to 20 carbon atoms in the alkyl part.

Preferred anionic surfactants include 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 higher alkyl benzene sulphonates or of higher-alkyl toluene, xylene or phenol sulphonates, alkyl naphthalene sulphonates, diamyl naphthalene sulphonate, and dinonyl naphthalene sulphonate; alkyl sulphates containing 8 to 22 carbon atoms and alkyl ether sulphates containing from 1 to 10 ethylene oxide or propylene oxide, preferably 2 to 3 ethylene oxide units per molecule.

Non-limiting examples of the anionic surfactants include any of the common anionic surfactants such as linear or modified, e. g., branched alkylbenzene sulphonates, alkylpoly(ethoxylates), sodium lauryl ether sulphates, methyl ester sulphonates, primary alkyl sulphates or mixtures thereof.

The non-soap anionic surfactant is present in the composition in a concentration of 5 - 50%, preferably not less than 10%, more preferably not less than 12%, still more preferably not less than 15% but typically not more than 40%, preferably not more than 35% or even not more than 30% by weight of the total composition.

Anionic surfactant of the present invention may be combined with another surfactant generally chosen from non-ionic, cationic, amphoteric or zwitterionic surfactants.

In view of the anionic character of the anionic surfactant, cationic, amphoteric or zwitterionic surfactants when added are added at concentrations that do not hinder the performance of the composition. Suitable non-ionic surfactants include water soluble aliphatic ethoxylated nonionic surfactants commercially known, including the primary aliphatic alcohol ethoxylates and secondary aliphatic alcohol ethoxylates. This includes the condensation products of a higher alcohol (e.g., an alkanol containing about 8 to 16 carbon atoms in a straight or branched chain configuration) condensed with about 4 to 20 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 10 moles of ethylene oxide (EO), tridecanol condensed with about 6 to 15 moles of EO, myristyl alcohol condensed with about 10 moles of EO per mole of myristyl alcohol, the condensation product of EO with a cut of coconut fatty alcohol containing a mixture of fatty alcohols with alkyl chains varying from 10 to about 14 carbon atoms in length and wherein the condensate contains either about 6 moles of EO per mole of total alcohol or about 9 moles of EO per mole of alcohol and tallow alcohol ethoxylates containing 6 EO to 1 1 EO per mole of alcohol.

Examples of the foregoing nonionic surfactants include, but are not limited to, the Neodol (trade mark, ex Shell) ethoxylates, which are higher aliphatic, primary alcohol containing about 9-15 carbon atoms, such as C9-C1 1 alkanol condensed with 4 to l Omoles of ethylene oxide (Neodol 91-8 or Neodol 91 -5), C12-13 alkanol condensed with 6.5 moles ethylene oxide (Neodol 23-6.5), C12-15 alkanol condensed with 12 moles ethylene oxide (Neodol 25-12), C14-15 alkanol condensed with 13 moles ethylene oxide (Neodol 45-13), and the like. Such ethoxamers have an HLB

(hydrophobic lipophilic balance) value of about 8 to 15 and give good O/W

emulsification, whereas ethoxamers with HLB values below 7 contain less than 4 ethyleneoxide groups and tend to be poor emulsifiers and poor detergents. Suitable amphoteric surfactants include 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-solubilizing group, such as sodium 3-dodecylamino- propionate, sodium 3-dodecylaminopropane sulphonate and sodium N-2- hydroxydodecyl-N-methyltaurate.

Suitable cationic surfactants are quaternary ammonium salts according to the present invention are quaternary ammonium salts characterised in that the ammonium salt has the general formula: R₁R₂R₃R₄N⁺ X^", wherein R-i is a C₁₂-C₁₈ alkyl group, each of R₂, R3 and R₄ independently is a C-|-C₃ alkyl group and X is an inorganic anion. R-i is preferably a C₁₄-C₁₆ straight chain alkyl group, more preferably C₁₆. R₂-R₄ are preferably methyl groups. The inorganic anion is preferably chosen from halide, sulphate, bisulphate or OH^". Thus, for the purposes of this invention, a quaternary ammonium hydroxide is considered to be a quaternary ammonium salt. More preferably the anion is a halide ion or sulphate, most preferably a chloride or sulphate. Cetyl-trimethylammonium chloride is a specific example of a suitable compound and commercially abundantly available.

Another type of quaternary ammonium cationic surfactant is the class of benzalkonium halides, also known as alkyldimethylbenzylammonium halides. The most common type being benzalkonium chloride, also known as alkyldimethylbenzylammonium chloride (or ADBAC). A preferred class of bezalkonium chlorides is given in the formula below.

Suitable zwitterionic surfactants include 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-1 -sulphonate betaine, 3-(dodecylmethyl sulphonium) propane-1 -sulphonate betaine and 3- (cetylmethylphosphonium) ethane sulphonate betaine.

When present in the composition, the additional surfactant replaces 0.5 -15% by weight, preferably 5 to 10% by weight of the anionic surfactant.

Inorganic alkaline material

The inorganic alkaline material according to the present invention includes one or more alkaline builders having a pH of more than 1 1 and reserve alkalinity of more than 45 in 1 % solution.

Alkaline builders are water soluble bases added to detergent compositions to raise the pH of the cleaning solution.

It is known that alkaline pH favors removal of tough soil, however, the pH of main wash may decrease during washing. Hence, for better oily soil removal, there is a need to maintain alkaline pH (more than 10.5) during the wash. Product with higher reserve alkalinity will decrease the drop in pH and hence are expected to clean better. When builders are added to water, they result in the formation of alkaline solutions due to the following hydrolysis reactions:

Substance water + salt ^ conjugate weak acid + OH- (1 ) STPP H₂0 + P3O105-≠ HP3O104- + OH- (2)

Alkaline silicate H₂0 + SiO(OH)3-≠ Si(OH)4 + OH- (3)

Meta-silicate H₂0 + Si02(OH)22-≠ SiO(OH)3- + OH- (4)

Carbonate H₂0 + C032-≠ HC03- + OH- (5)

Meta-borate H₂0 + B(OH)4-≠ B(OH)3 + OH- (6)

These hydroxyl ions are responsible for maintaining pH and react with acidic impurities present in the soil/product/water and hence are not available to maintain alkaline pH for longer duration. Preferred inorganic alkaline builders are sodium aluminate, sodium silicate and sodium disilicate.

The inorganic alkaline builder is present in the composition in a concentration of 0.5- 45%, preferably not less than 1 %, more preferably not less than 3% but typically not more than 40%, preferably not more than 35%, more preferably not more than 30%, still more preferably not more than 20%, even more preferably not more than 15% by weight of the total composition. Abrasive

The hard surface cleaning composition according to the present invention comprises a particulate abrasive. The particulate abrasive may be soluble or insoluble in water. Water soluble abrasives when used may be present in such excess to any water present in the composition so that the solubility of the abrasive in the aqueous phase is exceeded and consequently the abrasive exists in the composition.

The abrasive according to the present invention has a Mohs' index of more than 3.5. The volume average particle size of the abrasive is between 0.5 and 400 μηη, preferably between 10 and 200 μηη. Preferably the span is between 2 and 5; and wherein the span is defined as the broadness or width in particle distribution between a 10% limit (D10) and a 90% limit (D90) divided by the mean particle diameter (D50), whereby 10% by volume of the particles have a diameter below the 10% limit and 10% by volume of the particles have a diameter above the 90% limit.

Preferred abrasives having a Mohs' index of more than 3.5 include feldspar, silica, aluminium oxide, amalgam, anatase, apatite, boron carbide, corundum (natural aluminium oxide), crystolon, cuttlebone, diamond, diopside, emery, enamel, enstatite, fluorite, garnet, glass bead, glass, hematite, kyanite, magnetite, olivine, orthoclase, petalite, porcelain, feldspathic , pyrite, pumice, quartz, silica sand, silicon carbide, spinel, spodumene, staurolite, topaz, titanium dioxide, tungsten carbide, zirconium silicate ,zirconia, particulate zeolites, silicates, other carbonates, bicarbonates, borates, sulphates and polymeric materials such as polyethylene. Examples of the most preferred abrasives include feldspar, alumina and silica.

The abrasive is present in the composition in a concentration of 20-60%, preferably not more than 50%, more preferably not more than 45%, still more preferably not more than 40% but typically not less than 25%, preferably not less than 30%by weight of the total composition.

Water Water is present in a concentration of 20 -40% by weight of the composition. pH of the composition

It is known that alkaline pH favours removal of tough soil. However, the pH in main wash may decrease during washing, thereby affecting the cleaning performance.

Hence, for better soil removal, there is a need to maintain alkaline pH during the main wash. To achieve this, a buffer system (Reserve alkalinity) is required which

normalizes effect of these acidic materials. In the present invention, surprisingly the combination of an inorganic alkaline material having a pH of more than 1 1 and reserve alkalinity of more than 45 in 1 % solution; and an abrasive having a Mohs' index of more than 3.5 have been found to work well on tough soil. Therefore, the pH of 1 % solution of the hard surface cleaning composition of the present invention is preferably between 1 1 and 13.

Reserve alkalinity of the composition

The reserve alkalinity of 1 % solution of the hard surface cleaning composition is preferably more than 2. Other ingredients

The hard surface cleaning composition according to the invention may further comprise conventional ingredients like perfume, colour, electrolytes, structuring agent and filler.

Use of the composition

In a second aspect, the invention relates to the use of the composition according to the invention for hard surface cleaning.

Product format

The composition according to the invention may be in the form of a liquid, paste or gel. The composition may be packaged in the form of any commercially available bottle or pouch for storing the liquid or in the form of a jar, box, tray or pouch for storing the paste or gel.

The bottle, jar and the pouch containing the product can be of different sizes and shapes to accommodate different volumes of the product; preferably between 0.1 and 2 L, more preferably between 0.25 and 1 .5 L or even between 0.25 and 1 L. The bottle, jar and the pouch are preferably provided with a dispenser with or without a closure, which enables the consumer an easier mode of dispersion and storage of the liquid, paste or gel. Dispensers with a push-pull closure or a flip-top closure may be used. Spray or pump-dispensers may also be used.

Process for cleaning a hard surface

In a third aspect, the invention relates to a process for cleaning a hard surface comprising the steps of applying onto the surface 0.3 to 5g of the composition according to the invention, scrubbing the surface for not more than 30 times, preferably not more than 25 times, more preferably not more than 20 times, still more preferably not more than 15 times, even more preferably more than 10 times or even 5 times and thereafter rinsing the surface.

The composition may be applied by any known ways such as by using a cloth, paper, mop, wipes, sponge, scrubs, spray, including spray guns, atomizers, or other direct application.

The invention will now be illustrated by means of the following non-limiting examples Examples

Table 1 : Materials

Preparing the compositions:

For preparation of 1000g of the sample, 160-670g de-mineralized water [as needed] was charged into the sigma mixer and was mixed at 50 rpm. 44g sodium carbonate (as a structurant precursor), 80g of kaolin and (a stochiometric amount) sodium hydroxide were then added to the mixer and mixed for 5 minutes. To this mixture, anionic surfactant precursor/an ionic surfactant and the abrasive were added and mixed for 5 minutes, followed by the addition of inorganic alkaline builder and mixing again for 5 minutes. The optional ingredients e.g. Aluminum sulphate (29g) and Sodium silicate 26g), were finally added and mixed for 5 minutes.

In the examples with sodium LAS and SLES as the surfactants, 1 1 .25%w of sodium LAS and 2%w of SLES were used. Procedure for tough soil generation:

Oil polymerised by heating at high temperature is known as tough soil. Vegetable oil and wheat flour was mixed in the ratio of 90:10 (wt/wt). A fixed amount of this mix was spread uniformly on 5 cm x 5 cm area of a 10 cm x 10 cm stainless steel plate and was heated at 35°C degrees for 5 minutes to get a polymerised oil film on the plate.

Procedure for tough soil cleaning:

The soiled plate was inserted in an effort testing machine. The composition was diluted with equal weight of water and was uniformly spread on the soiled plate. A load of 3 kg was applied on the implement holder. Nylon scrubber was used as an implement. The number of rotations was fixed to 150. Finally plate was washed with distilled water, dried at room temperature and weighed for estimating tough soil removal. The performance was assessed by gravimetric analysis. % soil removal was calculated as follows:

% Tough soil removal = (Weight of soil removed/Weight of soil deposited) x 100 Tough soil removal of more than 95% is considered to be good. However, the present invention targets at a tough soil removal of more than or equal to 99%. Measurement of reserve alkalinity of an inorganic alkaline builder or composition:

1 g of sample was weighed in a 250 ml beaker. 100 ml of distilled water was added to dissolve the sample. This solution was filtered through what-man filter paper no. 42 and the filtrate was collected. 50 ml of the filtrate was pipetted out in a 100ml beaker and mixed thoroughly using a magnetic stirrer. pH of the solution was noted using pH meter. 0.1 N hydrochloric acid was added drop by drop keeping the pH meter on, until the pH of the solution was dropped to the value 8.0. While hydrochloric acid was added, the solution was stirred continuously. The amount of acid required to bring down the pH to 8.0 was noted down, which was a measure of reserve alkalinity of the test sample.

Example 1 : Reserve Alkalinity In this example the reserve alkalinity of some of the commonly used builders and the alkaline builders according to the invention are determined by the method as described above.

Table 2

have a higher reserve alkalinity as required by the invention as compared to the other commonly used builders. Example 2: Effect of the inorganic alkaline builder on tough soil removal

In this example, tough soil removal with compositions without an inorganic alkaline builder and comprising only an abrasive at different concentrations are compared (Comp A to Comp F). The comparative study was done with two abrasives, calcite (an abrasive outside the scope of the invention) and feldspar (an abrasive according to the invention).

Table 3

The above table shows that better removal of tough soil is obtained with compositions comprising feldspar as the abrasive (Comp D to Comp E) as compared to compositions comprising calcite as the abrasive (Comp A to Comp C). However, it is to be noted that superior tough soil removal of more than 95% is not achieved in the absence of an inorganic alkaline material. Example 3: Effect of concentc2238eration of the inorganic alkaline builder on tough soil removal.

This example demonstrates the effect of concentration of the inorganic alkaline builder over the claimed range on tough soil removal. The example compositions (Ex 1 to Ex 3) comprising the inorganic alkaline builder in different concentrations are compared.

Table 4

The above table shows that a superior tough soil removal is achieved all through the claimed range of the inorganic alkaline builder.

Example 4: Effect of concentration of the abrasive on tough soil removal

In this example, different concentrations of the abrasive according to the invention (Ex Ex 5) is compared to a comparative composition having the abrasive in a concentration outside the scope of the present invention (Comp G). Table 5

Variation in the concentrations of the abrasive in the compositions show that superior tough soil removal is obtained at an abrasive concentration according to the invention.

Example 5: Effect of the type of abrasive on tough soil removal

In this example, the effect of the type of abrasive according to the invention (Ex 7 and Ex 8) on tough soil removal is compared to comparative compositions comprising an abrasive type outside the scope of the invention (Comp H and Comp I).

Table 6

Set Surf acta Inorgani Wate Abrasive pH in Reserve Tough nt c r 1% alkalinity soil

(NaLAS+ alkaline (wt% solutio of the remov

SLES) builder ) n compositi al (%) wt% (Sodium Type wt on (ml)

aluminat %

e) wt%

Com 13.25 3 34 Calcite 30 1 1 .7 3 42 p H

Com 13.25 6 31 Calcite 30 12.02 5 49 P l

Ex 7 13.25 3 34 Feldsp 30 1 1 .7 3 >99 ar

Ex 8 13.25 6 31 Feldsp 30 12.02 5 >99 ar The above example illustrates that at similar concentrations, comparative compositions with abrasive type outside the scope of the present invention provides only half the cleaning achieved by compositions with the abrasive according to the present invention. It is also noted that a tough soil removal of more than 99% is achieved when the abrasive according to the present invention is present in combination with an inorganic alkaline builder even at a builder concentration as less as 3% (Ex 7).

Example 6: Effect of each component of the composition on tough soil removal

In this example, tough soil removal by the composition according to the invention (Ex 9) is compared to different combinations of the components in comparative examples (Comp J to Comp L), where the comparative example compositions are devoid of at least one component of the composition.

Table 7

The table shows that the composition according to the invention performs better than any of the combinations with one of the components missing.

Example 7: Effect of a different inorganic alkaline builder and an abrasive according to the invention on tough soil removal In this example, a different builder and a different abrasive according to the invention are compared for their efficiency on tough soil removal.

Table 8

The above table illustrates that the composition according to the invention as claimed exhibit a superior tough soil removal of more than 95%.

Claims

1. A hard surface cleaning composition comprising

(a) 5-50% by weight of an anionic surfactant;

(b) 0.5-45% by weight of an inorganic alkaline builder having a pH of more than 1 1 and reserve alkalinity of more than 45 in 1 % solution; and

(c) 20-60% by weight of an abrasive having a Mohs' index of more than 3.5, wherein the composition further comprises water and wherein water is in a concentration of 20 - 40% by weight of the composition.

2. A cleaning composition according to claim 1 , wherein the pH of the composition in 1 % solution is between 1 1 and 13.

3. A cleaning composition according to claim 1 , wherein the reserve alkalinity of the composition in 1 % solution is more than 2.

4. A cleaning composition according to any of the preceding claims 1 to 3, wherein the inorganic alkaline builder is sodium aluminate, sodium silicate or sodium disilicate.

5. A cleaning composition according to anyone of the preceding claims 1 to 4, wherein the anionic surfactant is a mixture of anionic surfactants selected from higher alkyi benzene sulphonates containing from 6 to 20 carbon atoms in the alkyi group and alkyi ether sulphates containing from 1 to 10 ethylene oxide or propylene oxide units per molecule.

6. A cleaning composition according to any one of the preceding claims 1 to 65 wherein the inorganic alkaline builder is in a concentration of 0.5 to 15% by weight of the composition.

7. A cleaning composition according to any one of the preceding claims 1 to 6, further comprising a surfactant selected from non-ionic, amphoteric, zwitterionic, cationic surfactants or their mixtures thereof.

8. A cleaning composition according to any of the preceding claims 1 to 7, wherein the composition is in the form of a paste.

9. Use of the composition according to claim 1 for hard surface cleaning.

10. A process for cleaning a hard surface comprising the steps of:

(a) spplying onto the surface 0.3 to 5g of the composition according to anyone of claims 1 to 8;

(b) scrubbing the surface for not more than 30 times; and

(c) rinsing the surface.