WO2007007031A1

WO2007007031A1 - Cleaning article and cleaning method

Info

Publication number: WO2007007031A1
Application number: PCT/GB2006/002399
Authority: WO
Inventors: Laurence Geret; Andreas Wegner
Original assignee: Reckitt Benckiser N.V.; Reckitt Benckiser (Uk) Limited
Priority date: 2005-07-08
Filing date: 2006-06-29
Publication date: 2007-01-18
Also published as: GB0613022D0; DE202006010472U1; AT502111A1; GB0514009D0; LU91261B1; DE102006031367A1; GB2428683A

Abstract

The invention provides water soluble / dispersible cleaning sachets for use in a washing operation. The sachets are characterized in that each sachet has a mass of between 1g and 15g such that it can be used singularly or with one or more other like sachets depending upon a required washing performance. Also provided are cleaning methods which use the sachets.

Description

CLEANING ARTICLE AND CLEANING METHOD

The present invention relates to cleaning sachets, including dishwashing sachets, laundry cleaning sachets and wa- ter softening sachets used in cleaning methods. The invention further relates to cleaning methods using such sachets .

It is known to provide cleaning compositions in various forms for use in ware washing machines such as dish and clothes washing machines .

One of the most common forms in which laundry and dish washer detergents are used consists of powder or granules in which the average particle size ranges between 0.1 and 2mm in diameter. In use, such powder or granules are placed in a chamber from which they are washed out during the washing cycle. Because of the hygroscopic nature of the powder or granules lumps occasionally form as a result of which the detergent may not be correctly delivered into the washing chamber of a dishwasher or washing machine. It is known to use additives to alleviate this effect, but these may not always be effective.

Accordingly, as an alternative to powders or granules it is known to use detergents in larger form such as tablets or water soluble sachets. These larger forms are usually manufactured from the same ingredients as the known powders or granules. The problems with the formation of lumps which are known with powders and granules are avoided by such forms. The larger forms also have the advantage that they avoid the need to measure out powder or granules which can sometimes be somewhat complicated and tiresome .

However, such forms have a disadvantage compared to the use of powder or granules which is that they reduce the flexibility in measuring out the required quantity of detergent. Instead, it is usual for the same amount of detergent to be added to every washing cycle, which is determined by the size of the tablet, irrespective of whether the crockery or laundry to be cleaned is heavily or lightly soiled and/or whether the machine being operated has a full or reduced load.

Known detergent tablets / sachets may comprise a detergent composition together with other cleaning aid compositions.

EP-A-414462 discloses sachets comprising detergent for use in a washing machine. The sachets comprise at least 23g of a mixture of a bleaching component and a detergent com- position. Each sachet is used as a half-dose so that a full dose of detergent composition is at least 46g.

For example, known multi-benefit automatic dishwasher tablets /^■ sachets comprise three major components: a deter- gent composition, a water softening ("dishwasher salt function") composition and a rinse aid function. These components may be provided in separate conjoined layers of the product and arranged to dissolve into the wash water during different stages of the washing operation.

It is typical for such an automatic dishwasher product comprising a detergent, dishwasher salt function and rinse aid function to weigh between 20 and 25g. For example, such a tablet may comprise around 1Og of detergent composition, around 1Og of water softening function composition and around Ig to 2g of rinse aid function. In order to clean crockery using a domestic dishwasher a single tablet will be added regardless of the amount of crockery or extent of the soiling of the crockery which is to be washed in the dishwasher.

The provision of dishwasher detergent in the form of smaller tablets is known from EP 0 318 204 Al. However, this document relates to difficulties associated with incompatible components. In this case it is necessary to use a combination of at least two types of tablet with incompatible components being distributed among the tablet types in such a way that substantially only compatible ingredients are formulated in the same tablet type.

The different types can either be offered separately and mixed in the correct proportions by the user or provided as a pre-mixed product. However, both cases have their own difficulties. In the first case, the difficulty arises of maintaining the correct proportions between the various tablet types when measuring out the amount required. In the second case, problems occur if the tablet types become unevenly distributed in the mixture or if they are separated during transport or storage.

GB-A-2 , 305, 931 discloses water soluble containers having a size sufficiently small to allow flexibility of use with regards to dosing for laundry compositions. EP-A-700989 discloses water soluble packages for use in machine dishwashing compositions comprising preferably between 25g and packages containing from preferably about 5g to about 25g of detergent for use in automatic dishwashing.

Accordingly, there remains a need to provide a detergent composition in a form which allows for variable dosage in a simple manner which is convenient for the consumer and/or which avoids wastage of detergent composition.

Accordingly, the present invention aims to address at least one disadvantage associated with the prior art whether discussed herein or otherwise.

According to a first aspect of the present invention there is provided a water soluble / dispersible cleaning sachet for use in a washing operation, characterised in that the sachet has a mass of between Ig and 15g such that it can be used singularly or with one or more other like sachets depending upon a required washing performance .

The sachet may, for example, be formed of a film. The film may be a single film, or a laminated film as disclosed in GB-A-2,244,258.

The thickness of the film may be up to 2mm, more prefera- bly up to 1mm, more preferably 40 to 300μm, more preferably 60 to 200μm, especially 60 to 160μm, more especially 60 to 150μm and most especially 60 to 150μm.

The film may be produced by any process, for example by extrusion and blowing or by casting. The film may be un- oriented, monoaxially oriented or biaxially oriented. If the layers in the film are oriented, they usually have the same orientation, although their planes of orientation may^¬ be different if desired.

The layers in a laminate may be the same or different. Thus they may each comprise the same polymer or a different polymer .

Examples of water-soluble polymers which may be used in a single layer film or in one or more layers of a laminate or which may be used for injection moulding or blow moulding are poly (vinyl alcohol) (PVOH), cellulose derivatives such as hydroxypropyl methyl cellulose (HPMC) and gelatin. An example of a preferred PVOH is ethoxylated PVOH. The PVOH may be partially or fully alcoholised or hydrolysed. For example it may be from 40 to 100%, preferably from 70 to 92%, more preferably about 88% or about 92%, alcoholised or hydrolysed. The degree of hydrolysis is known to influence the temperature at which the PVOH starts to dissolve in water. 88% hydrolysis corresponds to a film soluble in cold (i.e. room temperature) water, whereas 92% hydrolysis corresponds to a film soluble in warm water.

The sachet may be formed by, for example, vacuum forming or thermoforming . For example, in a thermoforming process the film may be drawn down or blown down into a mould. Thus, for example, the film is heated to the thermoforming temperature using a thermoforming heater plate assembly, and then drawn down under vacuum or blown down under pressure into the mould. Plug-assisted thermoforming and pre- stretching the film, for example by blowing the film away from the mould before thermoforming, may, if desired, be used. One skilled in the art can choose an appropriate temperature, pressure or vacuum and dwell time to achieve an appropriate sachet . The amount of vacuum or pressure and the thermoforming temperature used depend on the thickness and porosity of the film and on the polymer or mixture of polymers being used. Thermoforming of PVOH films is known and described in, for example, WO 00/55045.

A suitable forming temperature for PVOH or ethoxylated PVOH is, for example, from 90 to 130⁰C, especially 90 to 120⁰C. A suitable forming pressure is, for example, 69 to 138kPa (10 to 20 p.s.i.), especially 83 to 117 kPa (12 to 17 p.s.i.) . A suitable forming vacuum is 0 to 4 kPa (0 to 40 mbar) , especially 0 to 2 kPa (0 to 20 mbar) . A suitable dwell time is, for example, 0.4 to 2.5 seconds, especially 2 to 2.5 seconds.

While desirably conditions chosen within the above ranges, it is possible to use one or more of these parameters outside the above ranges, although it may be necessary to compensate by changing the values of the other two parame- ters.

The sachet may be in the form of a solid body. That is to say the sachet is not in the form of a walled container but instead a shape, which is substantially solid (option- ally with pores / apertures) . The solid preferably comprises a matrix. The matrix may be formed of the material used for the film of the sachet or alternatively the matrix may comprise a second material . Preferred matrix forming materials include gelatin, especially in an admix- ture with glycerine, optionally with water. A further preferred matrix forming material is polyethylene glycol (PEG) having a molecular mass of 3000 or above, e.g. such as 6000, 8000, 20000, 35000 or 8 million. Generally the sachet has the dimensions of between 5 and 50mm.

Preferably the sachet has a mass of no more than 14g, more preferably no more than 13g, more preferably no more than 12g, more preferably no more than Hg, still more preferably no more than 1Og. The sachet may have a mass of no more than 9g, for example of no more than 8g, 7g, 6g, or 5g.

Preferably, the sachet has a mass of at least 2g, more preferably at least 3g. The sachet may have a mass of at least 4g, for example at least 5g, 6g, 7g or 8g.

Suitably, the cleaning sachet comprises a cleaning composition. Alternatively or in addition, the cleaning sachet may comprise a water-softening sachet which comprises a cleaning composition comprising a water-softening composi- tion.

The cleaning composition may be in the form of a solid (powders, granulates, tablets) or a liquid (including gels) or an admixture of both. The cleaning composition may be made up of two or more separate compositions. In this case the sachet generally has separate compartments, with each compartment containing a composition.

Suitably, the cleaning sachet comprises a sachet for use in an automatic ware washing machine.

Preferably, the cleaning sachet comprises a sachet for use in an automatic dishwashing machine. Suitably, the deter- gent sachet may be arranged to be used in combination with a separate supply of dishwasher salt and/or rinse aid. Thus, the sachet may be substantially free from rinse aid function and/or dishwasher salt function.

The term "cleaning composition" is understood in the broad sense in the present application, namely as comprising all those substances and mixtures of substances which can be used in connection with cleaning processes. These include not only the compositions which are actually active in cleaning, such as detergents, for example dishwasher detergents, and washing substances, but all compositions which support cleaning functions concerned, such as water softeners, or which have the effect of providing protec- tive care, such as fabric treaters or final rinses.

Included in the term "cleaning composition" are mixtures of ingredients selected from: surfactant, builder, filler, bleach (optionally containing also bleach activator and/or a bleach catalyst) , water-softening composition and enzymes. The cleaning composition may contain other minor ingredients such as dye, fragrance and optical bright- eners .

By use of the term "water-softening composition" we mean a mixture of a water-softening active (s) with other compounds selected from those mentioned in the previous paragraph, or elsewhere in this specification.

Suitably, the cleaning composition comprises a detergent composition. The cleaning composition may comprise a detergent composition together with other components which support a cleaning function. Alternatively, the cleaning composition may consist essentially of a detergent composition.

As used herein the term "detergent composition" is under- stood to comprise all those substances and mixtures of substances which are active in cleaning, such as detergents and washing substances.

Included in the term "detergent composition" are mixtures of ingredients selected from: surfactant, builder, filler, bleach (optionally containing also bleach activator and/or a bleach catalyst) and enzymes.

The detergent composition may be substantially free of components which support cleaning functions, such as water-softeners, or which have the effect of providing protective care, such as fabric softeners or final rinses (rinse aids) .

Suitably, the sachet comprises a detergent composition in an amount of from Ig to 12g, preferably an amount of from 2g to 8g, for example an amount of from 3g to 6g.

Suitably, the sachet comprises detergent composition in an amount of no more than 12g, preferably no more than Hg, more preferably no more than 1Og, for example no more than 9g, 8g, 7g, 6g, 5g, 4g, 3g or 2g.

Suitably, the sachet comprises a detergent composition in an amount of at least Ig, preferably at least 2g, for example at least 3g, 4g, 5g, 6g, 7g or 8g. The sachet may comprise a "mono-benefit" sachet. The sachet may comprise a single-function sachet for use in an automatic dish washer. Thus, at least 90% by weight of the cleaning composition may comprise detergent composi- tion and the cleaning composition may preferably consist essentially of a detergent composition, which may suitably comprise fillers in addition to the active components.

Suitably the sachet has a mass of between Ig and 7g, pref- erably of between 2g and 6g, more preferably between 3g and 5g, for example around 4g.

Suitably, the sachet has a mass of between 5g and 13g, preferably between 7g and Hg, more preferably between 8g and 1Og, for example around 9g.

Suitably, the cleaning composition comprises detergent composition which comprises a substantially complete formulation for its respective use. Accordingly, it is suitably not necessary to employ a number of sachets according to the present invention comprising different compositions. Difficulties associated with a consumer having to count out a selection of different sachets may thus be avoided.

Suitably, the sachet is free from phosphorus-containing compounds .

The cleaning sachets of the present invention may have a number of advantages compared to known larger sachets.

As the sachet is smaller than known sachets it comprises less detergent and thus if a single sachet is used in a wash cycle of an automatic dishwashing machine there will be less release of detergent composition into the waterways. The use of a single sachet in a ware washing machine of the floor standing type may be appropriate to wash a small load or if the load is lightly soiled and thus the use of sachets accordingly to the present invention may provide significant environmental benefits.

Sachets according to the present invention may also be "multi-dosed" . For example, for a small load one sachet could be used with the environmental advantage as described above. For a larger load then two sachets may be used. For a particularly heavily soiled load three sachets may be used. Thus, a consumer may be provided with the flexibility to vary the amount of detergent used in an automatic dishwashing machine, particularly in a machine of the floor standing type, without having to expend the time and energy associated with using powder or granular detergents .

The use of two like sachets of the present invention may be more effective than the use of a known sachet having the same formulation as the sachets of the present invention and a weight equal to the combined weight of said two sachets of the present invention.

Accordingly, it may for example be possible to achieve the same cleaning effect provided by a known 20g sachet by using two 9g sachets, each having the same composition as the known sachet. Accordingly, it may be possible to use around 10% less detergent to achieve the same cleaning effect. The environmental benefits associated with the use of sachets accordingly to the present invention will thus be readily apparent .

Whilst having advantages over known sachets, the sachets according to the present invention may also retain the benefits that those known sachets have over powder or granular detergent compositions.

Sachets according to the present invention may be less susceptible to breakage / rupture and may be more easily removed from a machine chamber and distributed in a dish washing machine than known sachets.

The starting material for the cleaning sachets of the in- vention may be formulated in the same way as conventional powders, granules or sachets. A suitable formulation for a sachet composition may therefore comprise a large number of different ingredients, which may include any of the following: builders, surfactants, enzymes, bleaches, bleach activators, sources of alkalinity, dyes, perfumes, disintegrants, dispersants for lime soaps, organic polymers, including polymers to inhibit colour transfer, crystal growth inhibitors, complexing agents for heavy metal ions, salts, enzyme stabilisers, corrosion inhibitors, solvents, fabric softeners, optical brighteners, hydro- tropic agents, etc.

In addition, the sachet composition may contain suitable fillers, such as sulphates and chlorides.

The sachets may also contain a scattering agent or effervescent system, such as a combination of bicarbonate of soda and citric acid, in order to support the rapid disso- lution of the sachets, especially when poorly soluble ingredients are included.

If the sachet is for use in laundry washing, it may typi- cally comprise, for example, a bleach, stain remover, water-softener, enzyme or fabric conditioner, in addition to the cleaning composition. The sachet may be designed to release components at different times during the laundry wash. For example, a bleach or fabric conditioner is gen- erally released at the end of a wash, and a water-softener is generally released at the start of a wash. An enzyme may be released at the start or the end of a wash.

If the sachet is for use in dishwashing it may comprise, for example, a water-softener, salt, enzyme, rinse aid, bleach or bleach activator. The sachet may be designed to release the components at different times during the wash cycle. For example, a rinse aid, bleach or bleach activator is generally released at the end of a wash, and a wa- ter-softener, salt or enzyme is generally released at the start of a wash.

Examples of water-softening particulates which may be used in sachets according to the present invention include:

A) homo or co polymers of the following monomeric units or salts thereof - acrylic acids, maleic acids, sulfonic acids or phosphonics acid; and/or

B) citrate salts, for example alkali metal citrates, and especially sodium citrate. Preferably a compound of class A) and a compound of class B) are both present in a water-softening composition.

Additional beneficial compounds in a water-softening com- position include one or more of:

(1) ion exchange agents, including alkali metal (preferably sodium) aluminosilicates, either crystalline, amorphous or a mixture of the two;

(2) ion capture agents - agents which prevent metal ions from forming insoluble salts or reacting with surfactants, such as polyphosphate, monomeric polycarbonates, such as citric acid or salts thereof, EDTA, algins, alginates; and

(3) anti-nucleating agents - agents which prevent seed crystal growth, such as polycarbonate polymers, such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphonates, and sulfonates.

The components of a cleaning sachet depend on its intended use. Generally, the sachet may contain surface active agents such as an anionic, non-ionic, cationic, amphoteric or zwitterionic surface active agents or mixtures thereof.

Examples of anionic surfactants are straight-chained or branched alkyl sulfates and alkyl polyalkoxylated sulfates, also known as alkyl ether sulfates. Such surfac- tants may be produced by the reaction of sulfates with higher (e.g. C₈-C_2O) fatty alcohols. Examples of primary alkyl sulfate surfactants are those of formula:

ROS(VM⁺

wherein R is a linear C₈-C₂O hydrocarbyl group and M is a water-solubilising cation. Preferably R is Ci₀-Ci₆ alkyl, for example Ci₂-Ci₄, and M is alkali metal such as lithium, sodium or potassium.

Examples of secondary alkyl sulfate surfactants are those which have the sulfate moiety on a "backbone" of the molecule, for example those of formula:

CH₂ (CH₂) _n (CHOSO₃-M⁺) (CH₂) _mCH₃

wherein m and n are independently 2 or more, the sum of m+n typically being 6 to 20, for example 9 to 15, and M is a water-solubilising cation such as lithium, sodium or po- tassium.

Especially preferred secondary alkyl sulfates are the (2,3) alkyl sulfate surfactants of formulae:

CH₂ (CH₂) _x (CHOSO₃ ^"M⁺) CH₃ and

CH₃ (CH₂) _x (CHOSO₃-M⁺) CH₂CH₃

for the 2-sulfate and 3-sulfate, respectively. In these formulae x is at least 4, for example 6 to 20, preferably 10 to 16. M is cation, such as an alkali metal, for example lithium, sodium or potassium. Examples of alkoxylated alkyl sulfates are ethoxylated al- kyl sulfates of the formula:

RO(C₂H₄O)_nSO₃-M⁺

wherein R is a C₈-C_2O alkyl group, preferably C₁₀-Ci₈ such as a Ci₂-Ci₆, n is at least 1, for example from 1 to 20, preferably 1 to 15, especially 1 to 6, and M is a salt- forming cation such as lithium, sodium, potassium, ammo- nium, alkylammonium or alkanolammonium. These compounds can provide especially desirable fabric cleaning performance benefits when used in combination with alkyl sulfates.

The alkyl sulfates and alkyl ether sulfates will generally be used in the form of mixtures comprising varying alkyl chain lengths and, if present, varying degrees of alkoxy- lation.

Other anionic surfactants which may be employed are salts of fatty acids, for example C₈-Ci₈ fatty acids, especially the sodium or potassium salts, and alkyl, for example C₈- Ciβ, benzene sulfonates.

Examples of non-ionic surfactants are fatty acid alkoxy- lates, such as fatty acid ethoxylates, especially those of formula :

R(C₂H₄O)_nOH

wherein R is a straight or branched C₈-Ci₆ alkyl group, preferably a Cg-Ci₅, for example Ci₀-Ci₄, alkyl group and n is at least 1, for example from 1 to 16, preferably 2 to 12, more preferably 3 to 10.

The alkoxylated fatty alcohol non-ionic surfactant will frequently have a hydrophilie-lipophilic balance (HLB) which ranges from 3 to 17, more preferably from 6 to 15, most preferably from 10 to 15.

Examples of fatty alcohol ethoxylates are those made from alcohols of 12 to 15 carbon atoms and which contain about 7 moles of ethylene oxide. Such materials are commercially marketed under the trademarks NEODOL 25-7 and NEODOL 23-6.5 by Shell Chemical Company. Other useful compounds of this type include NEODOL 1-5, an ethoxylated fatty alcohol averaging 11 carbon atoms in its alkyl chain with about 5 moles of ethylene oxide; NEODOL 23-9, an ethoxylated primary C₁₂-Ci₃ alcohol having about 9 moles of ethylene oxide; and NEODOL 91-10, an ethoxylated C₉-Cn primary alcohol having about 10 moles of ethylene oxide.

Alcohol ethoxylates of this type have also been marketed by Shell Chemical Company under the DOBANOL trademark. DOBANOL 91-5 is an ethoxylated C₉-Cn fatty alcohol with an average of 5 moles ethylene oxide and DOBANOL 25-7 is an ethoxylated Ci₂-Ci₅ fatty alcohol with an average of 7 moles of ethylene oxide per mole of fatty alcohol.

Other examples of suitable ethoxylated alcohol non-ionic surfactants include TERGITOL 15-S-7 and TERGITOL 15-S-9, both of which are linear secondary alcohol ethoxylates available from Union Carbide Corporation. TERGITOL 15-S-7 is a mixed ethoxylated product of a Cn-Ci₅ linear secon- dary alkanol with 7 moles of ethylene oxide and TERGITOL 15-S-9 is the same but with 9 moles of ethylene oxide.

Other suitable alcohol ethoxylated non-ionic surfactants are NEODOL 45-11, which is a similar ethylene oxide condensation products of a fatty alcohol having 14-15 carbon atoms and the number of ethylene oxide groups per mole being about 11. Such products are also available from Shell Chemical Company.

Further non-ionic surfactants are, for example, Ci₀-Ci₈ al- kyl polyglycosides, such as Ci₂-Ci₆ alkyl polyglycosides . These are especially useful when high foaming compositions are desired. Further surfactants are polyhydroxy fatty acid amides, such as Ci₀-Ci₈ N- (3-methoxypropyl) glycamides and ethylene oxide-propylene oxide block polymers of the Pluronic type.

Examples of cationic surfactants are those of the quater- nary ammonium type.

The total content of surfactants in the sachet is desirably 60 to 95 wt%, especially 75 to 90 wt%. Desirably an anionic surfactant is present in an amount of 50 to 75 wt%, the nonionic surfactant is present in an amount of 5 to 50 wt%, and/or the cationic surfactant is present in an amount of from 0 to 20 wt%, by weight of sachet.

The sachets, particularly when used as laundry washing or dishwashing sachets, may also independently comprise enzymes, such as protease, lipase, amylase, cellulase and peroxidase enzymes. Such enzymes are commercially available and sold, for example, under the registered trade marks ESPERASE, ALCALASE and SAVINASE by Nova Industries A/S and MAXATASE by International Biosynthetics, Inc. Desirably the enzymes are independently present in the sachets in an amount of from 0.5 to 3 wt%, especially 1 to 2 wt%, when added as commercial preparations they are not pure and this represents an equivalent amount of 0.005 to 0.5 wt% of pure enzyme. As mentioned above they can be incorporated after extrusion if wished.

The sachets may, if desired, comprise a thickening agent or gelling agent. Suitable thickeners are polyacrylate polymers such as those sold under the trade mark CARBOPOL, or the trade mark ACUSOL by Rohm and Haas Company. Other suitable thickeners are xanthan gums. The thickener, if present, is generally present in an amount of from 0.2 to 4 wt%, especially 0.5 to 2 wt%.

Sachets used in dishwashing independently usually comprise a detergency builder. The builders counteract the effects of calcium, or other ion, water hardness. Examples of such materials are citrate, succinate, malonate, carboxy- methyl succinate, carboxylate, polycarboxylate and polya- cetyl carboxylate salts, for example with alkali metal or alkaline earth metal cations, or the corresponding free acids. Specific examples are sodium, potassium and lithium salts of oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, Ci₀-C₂₂ fatty acids and citric acid. Other examples are organic phosphonate type sequestering agents such as those sold by Monsanto under the trade mark DEQUEST and alkylhydroxy phosphonates . Citrate salts and Ci₂-Ci₈ fatty acid soaps are preferred. Further builders are: phosphates such as sodium, potassium or ammonium salts of mono-, di- or tri-poly or oligo-phosphates; zeo- lites; silicates, amorphous or structured, such as sodium, potassium or ammonium salts .

Other suitable builders are polymers and copolymers known to have builder properties. For example, such materials include appropriate polyacrylic acid, polymaleic acid, and polyacrylic/polymaleic and copolymers and their salts, such as those sold by BASF under the trade mark SOKALAN. The builder is desirably present in an amount of up to 90 wt%, preferably 15 to 90 wt%, more preferably 15 to 75 wt%, relative to the total weight of the sachet. Further details of suitable components are given in, for example, EP-A-694,059, EP-A-518,720 and WO 99/06522.

The sachets can also optionally comprise one or more additional ingredients. These include conventional cleaning composition components such as further surfactants, bleaches, bleach enhancing agents, builders, suds boosters or suds suppressors, anti-tarnish and anti-corrosion agents, organic solvents, co-solvents, phase stabilisers, emulsifying agents, preservatives, soil suspending agents, soil release agents, germicides, pH adjusting agents or buffers, non-builder alkalinity sources, chelating agents, clays such as smectite clays, enzyme stabilizers, anti- limescale agents, colourants, dyes, hydrotropes, dye transfer inhibiting agents, brighteners, and perfumes. If used, such optional ingredients will generally constitute no more than 10 wt%, for example from 1 to 6 wt%, of the total weight of the sachets.

Sachets which comprise an enzyme may optionally contain materials which maintain the stability of the enzyme. Such enzyme stabilizers include, for example, polyols such as propylene glycol, boric acid and borax. Combinations of these enzyme stabilizers may also be employed. If utilized, the enzyme stabilizers generally constitute from 0.1 to 1 wt% of the sachets.

Preferred dishwashing sachets are adapted to be used in automatic dish washing machines. Due to their specific requirements specialised formulation is required and these are illustrated below.

Amounts of the ingredients can vary within wide ranges, however preferred automatic dishwashing cleaning composition sachets herein (which typically have a 1% aqueous solution pH of above 8, more preferably from 9.5 to 12, most preferably from 9.5 to 10.5) are those wherein there is present: from 5% to 90%, preferably from 5% to 75%, of builder; from 0.1% to 40%, preferably from 0.5% to 30%, of bleaching agent; from 0.1% to 15%, preferably from 0.2% to 10%, of the surfactant system; from 0.0001% to 1%, pref- erably from 0.001% to 0.05%, of a metal-containing bleach catalyst; and from 0.1% to 40%, preferably from 0.1% to 20% of a water-soluble silicate. Such fully-formulated embodiments typically further comprise from 0.1% to 15% of a polymeric dispersant, from 0.01% to 10% of a chelant, and from 0.00001% to 10% of a detersive enzyme, though further additional or adjunct ingredients may be present.

Non-ionic surfactants useful in ADW (Automatic Dish Washing) sachets of the present invention desirably include surfactant (s) at levels of from 1% to 10% of the composition. In general, bleach-stable surfactants are preferred. Non-ionic surfactants generally are well known, being described in more detail in Kirk Othmer ^■ s Encyclopedia of Chemical Technology, 3rd Ed., Vol. 22, pp. 360-379, "Surfactants and Detersive Systems", incorporated by reference herein.

Preferably an ADW sachet comprises at least one non-ionic surfactant. One class of non-ionics are ethoxylated non- ionic surfactants prepared by the reaction of a monohy- droxy alkanol or alkylphenol with 6 to 20 carbon atoms with preferably at least 12 moles, particularly preferably at least 16 moles, and still more preferably at least 20 moles of ethylene oxide per mole of alcohol or alkylphenol .

Particularly preferred non-ionic surfactants are formed from a linear chain fatty alcohol with 16-20 carbon atoms and at least 12 moles, particularly preferably at least 16 moles, and still more preferably at least 20 moles, of ethylene oxide, per mole of alcohol.

The non-ionic surfactant may additionally comprise propylene oxide (PO) units in the molecule. Preferably the PO units constitute up to 25% by weight, preferably up to 20% by weight and still more preferably up to 15% by weight of the overall molecular weight of the non-ionic surfactant. Particularly preferred surfactants are ethoxylated mono- hydroxy alkanols or alkylphenols, which additionally comprises polyoxyethylene-polyoxypropylene block copolymer units. The alcohol or alkylphenol portion of such surfactants constitutes more than 30%, preferably more than 50%, more preferably more than 70% by weight of the overall molecular weight of the non-ionic surfactant. Another class of non-ionic surfactants includes reverse block copolymers of polyoxyethylene and polyoxypropylene and block copolymers of polyoxyethylene and polyoxypropylene initiated with trimethylolpropane .

Another preferred non-ionic surfactant can be described by the formula:

R¹O [CH₂CH (CH₃) 0] x [CH₂CH₂O] _γ [CH₂CH (OH) R²]

wherein JR¹ represents a linear or branched chain aliphatic hydrocarbon group with 4-18 carbon atoms or mixtures thereof, R² represents a linear or branched chain aliphatic hydrocarbon rest with 2-26 carbon atoms or mixtures thereof, x has a value between 0.5 and 1.5 and y has a value of at least 15.

Another group of preferred nonionic surfactants are the end-capped polyoxyalkylated non-ionics of formula:

R¹O [CH₂CH (R³) 0] x [CH₂] _kCH (OH) [CH₂] _jOR²

wherein R¹ and R² represent linear or branched chain, saturated or unsaturated, aliphatic or aromatic hydrocar- bon groups with 1-30 carbon atoms, R³ represents a hydrogen atom or a methyl, ethyl, n-propyl, iso-propyl, n- butyl, 2 -butyl or 2 -methyl -2 -butyl group, x has a value between 1 and 30 and, k and j have values between 1 and 12, preferably between 1 and 5. When the value of x is >2 each R³ in the formula above can be different. R¹ and R² are preferably linear or branched chain, saturated or unsaturated, aliphatic or aromatic hydrocarbon groups with 6-22 carbon atoms, where groups with 8 to 18 carbon atoms are particularly preferred. For the group R³ H, methyl or ethyl are particularly preferred. Particularly preferred values for x are from 1 and 20, preferably from 6 to 15.

As described above, when x >2 , each R³ in the formula can be different. For example, when x=3 , the group R³ could be chosen to build ethylene oxide (R³=H) or propylene oxide (R³=methyl) units which can be used in every single order for example (PO) (EO) (EO) , (EO) (PO) (EO) , (EO) (EO) (PO) , (EO) (EO) (EO) , (PO) (EO) (PO) , (PO) (PO) (EO) and (PO) (PO) (PO) . The value 3 for x is only an example and bigger values can be chosen whereby a higher number of variations of (EO) or (PO) units would arise.

Particularly preferred end-capped polyoxyalkylated alcohols of the above formula are those where k=l and j=l originating molecules of simplified formula:

R¹O [CH₂CH (R³) 0] _XCH₂CH (OH) CH₂OR²

The use of mixtures of different non-ionic surfactants is particularly preferred in ADW formulations for example mixtures of alkoxylated alcohols and hydroxy group containing alkoxylated alcohols.

A sachet disintegrant could be present in the sachets, for example a water-swellable cellulosic compound.

A cleaning sachet of the invention may be used in a vari- ety of ways. By way of example, we may refer to use as a dishwasher detergent, as a final rinse in dishwashers, as a detergent in a washing machine or for a hand wash, as a water softener or fabric softening rinse in a washing ma- chine, or as a descaling agent. Other fields of use in the detergent sector are conceivable and possible, such as use as a detergent composition for dissolution in water, for cleaning hard surfaces, such as floors.

Suitably, the sachet is arranged such that N sachets can be employed in a washing method to wash a load which substantially corresponds to a full load of a ware washing machine, and which load has a normal level of soiling, wherein N is 1, 2, 3 or 4. Preferably N is 2 for an automatic dishwasher of the floor standing type. Suitably the sachet is arranged such that the number of sachets employed in the washing method can be adjusted as detailed in the second aspect which follows.

According to a second aspect of the present invention there is provided a method of performing a washing operation characterised in that the method employs one or more sachets according to the first aspect and a quantity of water.

Here it has been found that as the sachets of the present invention are much smaller than conventional commercial detergent sachets they can be accommodated much more eas- ily in a sachet dispenser. This has been found to be of particular significance when a high amount of cleaning agent (i.e. a high number of cleaning sachets is required) . A suggested reason for this effect is that a large number of small sachet may be accommodated much more easily in a sachet dispenser than one larger sachet due to flexibility in positioning. For example it has been found to be easier to accommodate three sachets of weight 9g than one large sachet of weight 27g. This benefit may seem insignificant as the larger sachet could simply be placed in side the operating part of the machine. However, some automatic washing machines (such as dishwashers) operate a pre-wash cycle in which it is not advantageous to dispense any cleaning formulation. The accommodation of the sachets in the dispenser (which typically does not operate until a main wash cycle) overcomes this disadvantage.

Suitably, the sachets comprise a detergent composition.

Suitably, where the method employs a plurality of sachets the sachets are substantially identical .

Preferably, the method comprises washing articles in an automatic ware washing machine. More preferably the method comprises washing articles, for example crockery, within an automatic dishwashing machine.

Preferably, the method comprises the step of determining whether one or more sachets are required depending on the level of soiling and the quantity of articles to be washed.

Suitably, for a load having a normal level of soiling and which load substantially corresponds to a full load of a ware washing machine, the method will use N sachets.

Suitably, N = 1 to 4. Suitably for a domestic dish washer of the floor standing type, N = 2, 3 or 4 , preferably 2. Suitably, for a load having a heavy level of soiling and which load substantially corresponds to a full load of the ware washing machine the method will use N + A sachets.

Suitably, A = 0 to 2. Suitably, A is > 0 and < (N - 1) . Suitably, for a domestic dish washer of the floor standing type A = I or 2, preferably 1.

Suitably, for a load having a light level of soiling and which load substantially corresponds to a full load of the ware washing machine the method will use N - B sachets.

Suitably, B = 0 to 2. Suitably, B is > 0 and ≤ (N - 1) . Suitably, for a domestic dishwasher of the floor standing type B = 1 or 2, preferably 1.

Suitably, for a load having a normal level of soiling and which load substantially corresponds to a half load of the ware washing machine the method will use N - C sachets.

Suitably, C = 0 to 2. Suitably, C is > 0 and < (N - 1) . Suitably, for a domestic dishwasher of the floor standing type C = I or 2 , preferably 1.

Suitably, for a given ware washing machine and sachet combination N, A, B and C have fixed values. Suitably, for a domestic dishwasher of the floor standing type A, B and C have the same value. Thus variation of the ^udose" of sachets may thus be simple for a user to perform.

For a domestic dish washer of the table top type N may be 1 or 2, suitably 1. In this case suitably B and C are 0. In this case A may also be 0. Whilst it may thus not be possible to vary the "dose" in the same manner this may not be problematic since such a dishwasher is, for example, less likely to be operated part loaded.

The terms "normal level of soiling", "heavy level of soiling" and "light level of soiling" as well as "full load" and "half load" are somewhat subjective and will, to a degree, be a matter of judgement for a user. Their judgement may depend in part on the efficiency of their machine and on the water characteristics. However, it will be apparent to a user which situation is most likely to apply in any given case and a user can thus make the determination outlined above and calculate the number of sachets to use according to the basic criteria given above.

Suitably, the determination step comprises a user noting the extent of soiling of the articles to be washed, noting the extent to which a machine is loaded and determining whether N sachets should be used or if an adjustment needs to be made. Suitably, a value for N will be provided with the sachets. Suitably, if an adjustment is required a user will use a value for A, B or C provided with the sachets.

Claims

1. A water soluble / dispersible cleaning sachet for use in a washing operation, characterised in . that the sachet has a mass of between Ig and 15g such that it can be used singularly or with one or more other like sachets depending upon a required washing performance .

2. A sachet according to claim 1, comprising a detergent composition.

3. A sachet according to Claim 1 or 2, comprising a water-softening composition.

4. A sachet according to any preceding claim, wherein the sachet is for a ware washing machine.

5. A sachet according to claim 4, wherein the sachet is for an automatic dish washing machine.

6. A sachet according to claim 5, except when dependent on claim 3, wherein the sachet comprises a single function detergent sachet which comprises a de- tergent composition and is substantially free from dishwasher salt or rinse aid.

7. A sachet according to Claim 6, wherein the sachet has a mass of between Ig and no more than 14g.

8. A sachet according to claim 7, wherein the sachet has a mass of between 5g and 13g.

9. A method of performing a washing operation characterised in that the method employs one or more sachets according to any of the preceding claims and a quantity of water.

10. A method according to Claim 9, wherein the method comprises the step of determining whether one or more sachets are required depending on the level of soiling and the quantity of articles to be washed.

11. A method according to Claim 9, wherein the method comprises the step of determining whether one or more sachets are required depending on the level of water hardness.

12. A method according to Claim 9, 10 or 11, wherein the method comprises washing articles in an automatic ware washing machine.

13. A method according to Claim 12, wherein the sachets comprise detergent composition and the method comprises washing articles in an automatic dishwashing machine .

14. A method according to Claim 13, wherein the dishwashing machine comprises a domestic dishwasher of the floor standing type, and for a load having a normal level of soiling and which load substantially corresponds to a full load of the dishwash- ing machine the method uses N sachets where N = 2, 3 , or 4.

15. A method according to Claim 14, wherein the dishwashing machine comprises a domestic dishwasher of the floor standing type, and for a load having a heavy level of soiling and which load substantially corresponds to a full load of the dishwashing machine the method uses N + A sachets where N = 2, 3, or 4 and A is > 0 and ≤ (N - 1) .

16. A method according to Claim 11 or 12, wherein the dishwashing machine comprises a domestic dishwasher of the floor standing type, and for a load having a light level of soiling and which load substantially corresponds to a full load of the dishwashing machine the method uses N - B sachets where N = 2, 3, or 4 and B is > 0 and ≤ (N - 1) .

17. A method according to Claim 11 or 12, wherein the dishwashing machine comprises a domestic dishwasher of the floor standing type, and for a load having a normal level of soiling and which load substantially corresponds to a half load of the dishwashing machine the method uses N - C sachets where N = 2, 3, or 4 and C is > 0 and ≤ (N - 1) .