The present invention is in the field of hard surface cleaning compositions; in particular antifoaming composition for use in detergent compositions having foaming and cleaning characteristics in the main wash, yet significant foam reduction during rinse.

Background of the invention

Water is becoming a more and more scarcely available commodity, especially in developing countries, where it is not unusual that people have to walk many kilometres to arrive at a water source. As a result of which, there is an increasing need to save water.

One way of saving water is to reuse the water and another way is to reduce the amount of water being used.

Washing processes, including laundry, dishwashing and other household cleaning processes, require large amounts of water throughout the world. These are daily chores in which the use of water and a detergent cannot be avoided. Consumers usually like to see a lot of foam while washing as they associate foaming with detergent efficiency. However, it's rinsing that often takes a lot of effort and uses excess of water. This is predominantly caused by the consumer perception that they need to continue rinsing until the rinse water is no longer foaming. Thus, it has been a challenge to provide consumers with a cleaning composition that maintains the foam in the main wash while exhibiting an antifoaming effect during rinse.

US 4,869,842 discloses a liquid cleaning composition for use as a hard surface cleaner, comprising a base liquid composition comprising a base composition of an anionic surfactant, a non-ionic surfactant, a non-polar grease removal solvent, a water soluble detergent builder salt, optionally a perfume and a dye and water; and an abrasive. This document further discloses that the inorganic abrasives may be coated with synthetic resins or a fatty acid to make them soft. However, there is no disclosure of a fatty acid as a separate component in a concentration similar to the present invention.

US 5,076,955 discloses a composition and a method for producing a composition that is acidic, viscous, stable cleaning agent with a scouring action for cleaning acid resistant hard surfaces in household, especially glass ceramics. The composition comprises linear alkylbenzene sulphonate or alkane sulphonate, fatty alcohol oxyethylate, fatty acids with a carbon chain length of C12 to C18, mono or

sesquiterpenes, silicones, scouring agents in the form of alumina mixtures, acid for pH adjustment, water, perfume oil and colouring material. However, this document does not disclose an inorganic abrasive coated with a fatty acid for an antifoaming effect during rinse.

WO01/77273 discloses a solid composition containing abrasive and suitable to be dispersed in water to obtain a liquid abrasive composition for cleaning hard surfaces. In one embodiment, the solid composition comprises powdered abrasive, anioninc sulphate or sulphonate surfactant, ethoxylated alcohol non-ionic surfactant, alkaline pH regulator and fatty acid. However, this document does not disclose an inorganic abrasive coated with a fatty acid for an antifoaming effect during rinse.

JP2006193733 discloses an inorganic abrasive-containing liquid detergent composition having thixotropic properties, excellent in detergency, by uniformly and stably dispersing an inorganic abrasive in a liquid, and having good storage stability and a good appearance. This inorganic abrasive-containing liquid detergent composition contains a non-soap based anionic surfactant, a semi-polar surfactant having a specific structural formula, for example, represented by a 10-14C alkyldimethylamine oxide, at least one kind of an 8-24C straight-chain/branched higher alcohol and/or fatty acid and an inorganic abrasive, a viscosity at 60 rpm of the composition is 1 ,000-5,000 mPa/s, when measured by a Brookfield viscometer at 25 degrees centigrade, and a ratio of viscosity at 6 rpm to viscosity at 60 rpm is 5 or more. This document again has no disclosure of an inorganic abrasive coated with a fatty acid for an antifoaming effect during rinse. It is therefore an object of the present invention to provide water saving in household process, especially hand dish wash processes.

It is another object of the present invention to provide an anti foaming composition that has an antifoaming effect only during rinse while maintaining foaming characteristics in the mainwash.

It is a further object of the present invention to provide a detergent composition that uses less water during rinsing in hand dish wash processes.

Surprisingly, it has been found that an antifoaming effect may be obtained only during rinse in hard surface cleaning processes by an antifoaming composition essentially comprising a non-ionic surfactant, a fatty acid and a hydrophobic particle wherein the hydrophobic particle is an inorganic abrasive coated with a fatty acid.

Summary of the invention

Accordingly, in a first aspect the invention provides an antifoaming composition for use in a detergent composition comprising 1 to 35% by weight of a non-ionic surfactant; 5 to 65% by weight of a hydrophobic particle; 0.05 to less than 1 % by weight of a fatty acid; and 0 to 94% by weight of a filler; wherein the hydrophobic particle is an inorganic abrasive coated with a fatty acid, where the amount of fatty acid in the antifoaming composition excludes the fatty acid introduced in the antifoaming composition as part of the hydrophobic particles. In a second aspect, the invention provides use of an antifoaming composition according to the invention for providing anti-foaming activity upon rinse.

In the context of the present invention, the reference to "hard surface" typically means utensils or kitchenware, kitchen tops, kitchen floors, sinks 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 an antifoaming composition for use in a detergent composition comprising a non-ionic surfactant, a hydrophobic particle, a fatty acid and filler.

Antifoaming composition

Non-ionic surfactant

The antifoaming composition of the present invention comprises a non-ionic surfactant.

The nonionic surfactant of the present invention includes the condensation products of a higher alcohol (e.g., an alkanol containing about 8 to 18 carbon atoms in a straight or branched chain configuration) condensed with about 5 to 30 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 16 moles of ethylene oxide (EO), tridecanol condensed with about 6 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. Particularly preferred is lauryl alcohol condensed with 5, 7, 9 and 23 moles of ethylene oxide (Laureth 5, Laureth 7, Laureth 9, Laureth 23). Condensates of 2 to 30 moles of ethylene oxide with sorbitan mono- and tri-Cio-C2o alkanoic acid esters having a HLB of 8 to 15 also may be employed as the nonionic surfactant. These surfactants are well known and are available from Imperial Chemical Industries under the Tween trade name. Suitable surfactants include polyoxyethylene (4) sorbitan monolaurate, polyoxyethylene (4) sorbitan monostearate, polyoxyethylene (20) sorbitan trioleate and polyoxyethylene (20) sorbitan tristearate.

Preferred non-ionic surfactants of the present invention are Laureth 5, Laureth 7 and Laureth 9, most preferred being Laureth 7. The non-ionic surfactant is present in the composition in a concentration of 1 to 35%, preferably not less than 5%, more preferably not less than 10%, still more preferably not less than 15% but typically not more than 30%, preferably not more than 25% or even not more than 20% by weight of the antifoaming composition. Hydrophobic particle

The antifoaming composition of the present invention comprises a hydrophobic particle. The hydrophobic particle of the present invention is an inorganic abrasive coated with a fatty acid. Suitable inorganic abrasives are water-insoluble and non-gritty including calcium carbonate (calcite), calcium sulphate, limestone, dolomite, diatomaceous earth, Fuller's earth, magnesium carbonate, china clay, bentonite clays, feldspar, attapulgite, calcium hydroxyapatite, calcium orthophosphate or the like, or any other mineral salt. Preferred inorganic abrasives are calcite, dolomite, feldspar and china clay.

Suitable fatty acids to coat the inorganic abrasive include fatty acids having a carbon chain length of C8 to C18, preferably C12 to C18. Most preferred fatty acid to coat the inorganic abrasive is stearic acid.

The hydrophobic particle is present in the composition in a concentration of 5 to 65%, preferably not less than 10%, more preferably not less than 20%, still more preferably not less than 25% but typically not more than 60%, preferably not more than 50% or even not more than 40% by weight of the antifoaming composition.

Fatty acid

The antifoaming composition of the present invention comprises a fatty acid.

Suitable fatty acids include a fatty acid or mixture of fatty acids comprising aliphatic chains with 6 to 22 carbon atoms, preferably 8 to 20 carbon atoms, more preferably 10 to 18 or even more preferably 12 to 16 carbon atoms. Fatty acids used herein are saturated fatty acids.

Examples of suitable fatty acids include, but are not limited to caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated topped palm kernel fatty acids, hydrogenated coconut fatty acids, coconut fatty acids, palm kernel fatty acids or a mixture thereof.

The most preferred fatty acids are hydrogenated topped palm kernel fatty acids, lauric acid, stearic acid or a mixture thereof.

The fatty acid is present in the composition in a concentration of 0.05 to less than 1 %, preferably at least 0.1 %, more preferably at least 0.3% but typically not more than 0.8%, preferably not more than 0.5% by weight of the antifoaming composition.

The amount of fatty acid in the antifoaming composition excludes the fatty acid introduced in the antifoaming composition as part of the hydrophobic particles.

Filler

The antifoaming composition of the present invention may optionally comprise fillers. Suitable fillers are water-insoluble including calcium carbonate (e. g. calcite), dolomite, china clay, feldspar, or the like, or any other mineral salt.

Preferred fillers are calcite, china clay and dolomite, the most preferred being calcite and china clay.

When present, the filler is present in the composition in a concentration of 1 to 94%, preferably at least 10%, more preferably at least 20%, still more preferably at least 35%, even more preferably at least 45% but typically not more than 90%, preferably not more than 80%, more preferably not more than 70%, still more preferably not more than 60% by weight of the antifoaming composition.

In a second aspect, the invention relates to use of an antifoaming composition according to the invention for providing anti-foaming activity upon rinse.

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

Materials: Table 1

Name Chemical /Material Grade Manufacturer/

Supplier

Anionic LABSA (Linear alkyl benzene Industrial Galaxy surfactant sulfonic acid) grade surfactants

Non-ionic Laureth 7 (Lauryl alcohol Industrial Galaxy surfactants ethoxylates-E07) grade surfactants

Laureth 23 (Lauryl alcohol Industrial Galaxy ethoxylates-E023) grade surfactants

Hydrophobic Activated calcium carbonate Industrial Indocal limited particle (Coated calcite) grade

Fatty acid Prifac 5908 (Hydrogenated palm Industrial Croda

kernel fatty acid) grade

Stearic acid (Octadecanoic acid) Lab grade SD Fine Chem

Ltd.

Uncoated calcite Calcite (Calcium carbonate) Industrial Saurashtra

grade chemicals Preparing the compositions:

2.5 grams of anionic surfactant was taken in a 50ml_ Tarson® tube (the concentrations of the surfactant in the examples have been calculated taking into account the purity of the material). 25ml_ of de-mineralized water was added to the surfactant and vortexed till the surfactant had dissolved completely. The fatty acid(s) was then added to the mixture and heated to a temperature of 60°C in a water bath (maintained at 65°C). The mixture was stirred in between to ensure homogenous mixing. After complete solubilization of the fatty acid, the mixture was cooled to a temperature of 25 to 30°C, to which the non-ionic surfactant, hydrophobic particles and the filler were added and stirred for about 2 to 3 minutes by vortexing. A total of 0.63 grams of antifoaming composition was used in all the examples. 475ml_ of de-mineralized water was then added to the mixture and stirred again for about 2 to 3 minutes. The final mixture was allowed to cool before being used for foam volume studies.

Procedure for measurement of foam volume:

For the measurement of foam volume, standard cylinder shake method was used. 6.25 g/l of the test solution was prepared in 24 F.H. water. 50 ml of the test solution was taken in a 250 ml graduated glass cylinder. The solution was shook by covering the opening of the cylinder and inverting it 10 times. Then the cylinder was placed on a flat surface of a table for one minute for the aqueous layer to separate and it was shook once again to even out the foam level. The volume of foam (excluding aliquot water), in ml was measured and recorded as the initial foam volume.

To measure the foam in the first and further rinse cycles, the aliquot water was decanted along the sides of the cylinder retaining foam in the cylinder. 50 ml of fresh 24 F.H. water was added along the sides of the cylinder and the solution was shook and the foam volume measured as mentioned for initial foam measurement above. The cycles were repeated till the foam volume was <10 ml. Initial foam volume equal to the control or upto 10 ml lesser than the control is considered to be good. Foam volume reduction of <10 ml in the fifth or lower cycles are considered to be good. Example 1 : Effect of each component of the composition on foam volume

In this example, the volume of foam generated in the initial wash and the antifoaming effect during rinse by the composition according to the invention (Ex1 ) is compared to comparative compositions (C1 to C7) comprising only one component of the

composition.

Table 2

The above table shows that the composition according to the invention performs better with respect to the number of rinse cycles than any of the comparative examples, whilst maintaining a high foam value during the main wash.

Example 2: Effect of concentration of fatty acid on foam volume

This example demonstrates the effect of concentration of fatty acid on initial foam and the antifoaming effect during rinse. The example compositions Ex 2 and Ex 3 are compared with comparative examples C8 and C9 comprising fatty acid in a

concentration outside the scope of the invention. Table 3

The table above shows that best results for antifoaming effect during rinse are obtained at a fatty acid concentration within the scope of the present invention. The table also indicates that at higher fatty acid concentrations, the initial foam is considerably compromised (C8 and C9).

Example 3: Effect of concentration of non-ionic surfactant on foam volume

In this example, compositions according to the invention comprising different concentrations of non-ionic surfactant (Ex 4 to Ex 6) are compared with comparative compositions having non-ionic surfactant in a concentration outside the scope of the present invention (C10 and C10a).

Table 4

It is inferred from the results of the above table that a good antifoaming effect during rinse is obtained at a non-ionic surfactant concentration according to the invention. It is particularly noted that use of non-ionic concentrations above the range according to the invention (C10a) deteriorates the initial foam. Example 4: Effect of concentration of hydrophobic particles on foam volume

This example demonstrates the effect of concentration of hydrophobic particles on initial foam and the antifoaming effect during rinse. The example compositions Ex 7, Ex 7a, Ex 7b and Ex 8 are compared with comparative examples C1 1 , C12 and C12a comprising hydrophobic particles in a concentration outside the scope of the invention.

Table 5

The table above shows that best results for antifoaming effect during rinse are obtained at a hydrophobic particle concentration within the scope of the present invention. It is particularly noted that use of hydrophobic particle concentrations above the range according to the invention (C12a) deteriorates the initial foam.

Example 5: Effect of a different fatty acid on foam volume

This example demonstrates the effect of a different fatty acid according to the invention on initial foam and the antifoaming effect during rinse (Ex 9).

Table 6

Set wt% Foam volume per rinse cycle, ml

Filler Laureth7 Acid Coated Initial 1 2 3 4 5 6 calcite foam

Ex1 0 35 Prifac® 0.5 64.5 170 180 150 130 30 <10 -

Ex9 0 35 Stearic 0.5 64.5 160 120 90 50 30 <10 - acid The table above shows that the desired initial foam and the antifoaming effect during rinse is obtained by any fatty acid according to the invention.

Example 6: Effect of a different non-ionic surfactant on foam volume

This example demonstrates the effect of a different non-ionic surfactant according to the invention on initial foam and the antifoaming effect during rinse (Ex 10).

Table 7

The table above shows that the desired initial foam and the antifoaming effect during rinse is obtained by any non-ionic surfactant according to the invention.