GB2428247A - Reduced mass detergent tablet and packaging - Google Patents

Abstract

A plurality of cleaning tablets for use in a washing operation, having a mass of 1 to 15g, are arranged in a strip conjoined by wrapping material. The tablets may be used with one or more like tablets. The tablet may be used in a dish-washing operation and may contain detergent, rinse-aid and dishwasher salt. The tablet may have a surface area of 800 mm<2> to 1500 mm<2>. Also disclosed is a packaged product, in which the conjoined tablets are contained with a secondary outer packaging such that a consumer may remove the required number of tablets from the secondary packaging. The secondary packaging may have cutting means to aid detachment, and withdrawal may be aided by the tablets being located around a hub or spool.

Description

11669P4 G82 1

ARTICLE AND METHOD

The present invention relates to cleaning tablets, including dishwashing tablets, laundry cleaning tablets and water softening tablets used in cleaning methods. The invention further relates to cleaning methods using such

tablets.

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 tablet form. These tablets are usually manufactured from the same ingredients as the known powders or granules, with the addition of tabletting aids. The problems with the formation of lumps which are known with powders and granules are avoided by such tablets. The known detergent tablets also have the advantage that they avoid the need to measure out powder 11669P4 G2 2 or granules which can sometimes be somewhat complicated and tiresome.

However, such tablets 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 may comprise a detergent composition together with other cleaning aid compositions.

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

It is typical for such an automatic dishwasher tablet comprising a detergent, dishwasher salt function and rinse aid function to weigh between 20 and 25g. For example, such a tablet may comprise around log of detergent composition, around log 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 11669P4 GB2 3 crockery or extent of the soiling of the crockery which is to be washed in the dishwasher.

US6610643 discloses detergent tablet packaging in which a number of tablets are packaged together but relates to the provision of a detergent composition in separate or separable portions.

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.

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.

11669P4 G52 4 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 product comprising a plurality of cleaning tablets for use in a washing operation, the tablets being arranged in a strip conjoined by wrapping material, characterised in that the tablet has a mass of between ig and 15g such that it can be used singularly or with one or more other like tablets depending upon a required washing performance.

The tablets may be arranged in individual groups (e.g. pairs, groups of three or more) along the strip.

Suitably the product comprises N tablets / groups of tablets in a strip. Suitably N is two, three, four, five, six, ten or twelve.

Suitably, the strip comprises a plurality of substantially identical tablets. Suitably, the strip only comprises substantially identical tablets.

A product or a plurality of products may be disposed within a secondary packaging material. According to the invent ion there may thus be provided a packaged product comprising a product or products as herein described and secondary packaging. For example a secondary packaging (such as a box) may contain a plurality of product (with, f or example, each product comprising 2 or 3 tablets / groups of tablets). Alternatively the product may be much larger / longer such that the secondary package acts as a 11669P4 GB2 5 housing for the product. In this case a consumer may detach as many tablets as are required from the product, leaving the remainder / un-used portion of the product in the secondary packaging. The secondary packaging may comprise a cutting means to aid the detachment of the requisite number of tablets from the remainder of the strip. Such a cutting mean may comprises a blade (e.g. a metal blade or a cardboard blade / serrated edge) For such long products the housing may contain an aid for withdrawal of a portion of the product. Such an aid may comprise a hub around which the product may be spooled.

The housing most preferably comprises an aperture for withdrawal of portions of the product.

Particularly for long products a consumer may need to break the product, detaching the required number of tablets for a washing operation. To aid detachment the product preferably comprises a detachment aid between tablets / groups of tablets. Generally the detachment aid comprises a line of weakness. Usually the line of weakness does not extend fully to the edge of the packaging material. In this way it has been found that whilst an adult can still detach a portion of the strip it is more difficult for a child to do so. By the use of the term line it will be appreciated that this term is not limited to a simple geometric line but encompasses other shapes (curves, zig-zag, etc.) of complete lines / perforations.

It has been found that long products have enhanced child safety features as the length of the product not only makes it more difficult for a child to obtain / ingest a 11669P4 GB2 6 single tablet but also the long products per se are not easily ingested by a child.

Optionally the wrapping material comprises a water soluble I dispersible material (e.g. PVOH) and thus need not be removed from the tablet(s) before use.

Alternatively the wrapping material comprises a water resilient material. In this case preferably the wrapping material adjacent each tablet / group of tablets has an opening means including a first line comprising a line of weakness or one or more cuts extending in a first direction and a second line comprising a line of weakness or one or more cuts extending from the first line towards the boundary line in a second direction.

Suitably, in use, the wrapping material is opened by a user holding the second portion on the side of the first line of weakness or cut(s) opposed to the boundary line (the "outward side") and pulling the first and second portions in generally opposed directions to cause tears to develop at the end of the first line such that a part of the outward side of the second portion tears away from the remainder of the wrapper. Suitably, until said part of the outward side of the second portion is removed it prevents the parts of the second portion lying on opposed sides of the second line of weakness or cut(s) from being moved apart.

Suitably, with said outward part of the second portion removed a user can pull parts of the second portion lying on opposed sides of the second line in generally opposed directions such that a tear in the wrapper is caused to 11669P4 G22 7 develop at the end of the second line lying closest to the boundary line. Suitably, in use, the parts of the second portion lying on opposed sides of the second line are pulled until the tear spreads from the end of the second line across the boundary line such that it breaches the seal closing the first portion of the wrapper. Thus, a tablet enclosed by the wrapper may be accessed.

Thus, opening is suitably a two stage process requiring the packaging to first be pulled in opposed directions extending transverse to the boundary line and secondly to be pulled in opposed directions extending transverse to said directions of the first stage. This operation may be simple for an adult, even with wet hands, but difficult for a child thus decreasing the likelihood of a child accessing and digesting tablets contained in the packaging.

By "boundary line" it is meant any line, which is preferably unbroken, and which may be straight, curved or zig-zagged, which separates the first portion from the second portion.

The boundary line may comprise a seal closing the first portion. Suitably, the second portion comprises a seal closing the first portion and the boundary line comprises an edge of that seal. Suitably, the boundary line forms an edge of the first portion.

By "first line" it is meant any line, which may be broken or unbroken, and which may be straight, curved or zig- zagged.

11669P4 0B2 8 Suitably, the first line comprises a cut, preferably a single cut which may be substantially straight.

By "second line" it is meant any line, which may be broken or unbroken, and which may be straight, curved or zig- zagged.

Suitably, the second line comprises a cut, preferably a single cut, which may be substantially straight.

Suitably, said first direction extends generally parallel to the boundary line.

The first line of weakness or cut(s) may thus extend is generally parallel to the boundary line. Suitably, the first line of weakness or cut(s) lies generally equidistant from the boundary line.

The term "first direction extends generally parallel" as used herein is meant to have a broad meaning and encompasses a first direction which extends at an angle of +1- 30 degrees relative to the direction of the boundary line.

Preferably, the first direction extends at an angle of between +1-15 degrees relative to the direction of the boundary line. Thus, the first line preferably does not form an angle of greater than /- 15 degrees with the boundary line.

By "first direction" it is meant the general end to end direction of the first line rather than the direction of the first line at any particular point thereof.

11669P4 GB2 9 By "direction of the boundary line" it is meant the general end to end direction of the boundary line rather than the direction of the boundary line at any particular point thereof.

Suitably, said second direction extends generally perpendicular to the boundary line.

The second line of weakness or cut(s) may thus extend generally perpendicular to the boundary line. Suitably, the second line of weakness or cut(s) lies generally equidistant from opposed sides of the wrapper.

The term "second direction extends generally perpendicular" as used herein is meant to have a broad meaning and encompasses a second direction which extends at an angle of between 30 and 150 degrees, more preferably and 120 degrees relative to the direction of the boundary line.

Preferably, the second direction extends at an angle of between 75 and 105 degrees relative to the direction of the boundary line.

By "second direction" it is meant the general end to end direction of the second line rather than the direction of the second line at any particular point thereof.

Preferably, the second direction extends at an angle of between 30 and 150 degrees, more preferably 60 and 120 degrees, relative to the first direction, preferably at an angle of between 75 and 105 degrees. The second line may 11669P4 GB2 10 thus extend generally perpendicular relative to the first line.

Suitably, the wrapper comprises a front face, rear face, first and second opposed sides and first and second opposed ends.

Suitably, the second portion of the wrapper comprises one of said ends, preferably said first end.

Suitably, the boundary line extends in a side to side direction of the wrapper.

Suitably, the first line extends in a side to side direction of the wrapper.

Suitably, the second line extends in an end to end direction of the wrapper.

Preferably, the first and second lines form a "T" shape with the first line forming the arms of the "T" and the second line forming the stem of the "T".

Suitably, the "T" is orientated such that the stem extends towards the boundary line.

Suitably, the opening means comprises cut lines.

Preferably, the opening means comprises a "T" shaped cut comprising the first and second lines.

Alternatively, the second line may intersect the first line. The, second line may thus extend from the first 11669P4 GB2 11 line both towards the boundary line and the first edge of the wrapper.

The wrapper may have an arrangement as described in GB patent application no. 0408840.7, the subject matter of which is incorporated by reference.

Preferably the tablet has a mass of no more than 14g, more preferably rio more than 13g, more preferably no more than 12g, more preferably no more than hg, still more preferably no more than log. The tablet may have a mass of no more than 9g, for example of no more than 8g, 7g, 6g, or 5g.

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

Suitably, the cleaning tablet comprises a detergent composition. Alternatively or in addition, the cleaning tablet may comprise a watersoftening tablet which comprises a cleaning composition comprising a water- softening composition.

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

Preferably, the cleaning tablet comprises a tablet for use in an automatic dishwashing machine. Suitably, the detergent tablet comprises a detergent composition together with a rinse aid function and/or dishwasher salt function. Alternatively, the detergent tablet may be arranged to be used in combination with a separate supply 11669P4 GB2 12 of dishwasher salt and/or rinse aid. Thus, the tablet may be substantially free from rinse aid and/or dishwasher salt functions. In either case the detergent tablet may comprise a detergent composition suitable for washing crockery.

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 protective care, such as fabric treaters or final rinses.

Included in the term "cleaning composition" are mixtures of ingredients selected from: surfactant, builder, tiller, 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 brighteners.

By use of th 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 11669P4 GB2 13 support a cleaning function. Alternatively, the cleaning composition may consist essentially of a detergent composition.

As used herein the term "detergent composition" is understood 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 tablet 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 tablet comprises detergent composition in an amount of no more than 12g. preferably no more than hg, more preferably no more than lOg, for example no more than 9g, 8g. 7g, 6g, 5g. 4g, 3g or 2g.

Suitably, the tablet 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.

11669P4 GB2 14 The tablet may comprise a "mono-benefit" tablet. The tablet may comprise a single-function tablet for use in an automatic dish washer. Thus, at least 90% by weight of the cleaning composition may comprise detergent composition and the cleaning composition may preferably consist essentially of a detergent composition, which may suitably comprise fillers and/or tabletting aids in addition to the active components.

Suitably the tablet has a mass of between lg and 7g, preferably of between 2g and Gg, more preferably between 3g and 5g, for example around 4g.

Suitably, the tablet comprises a surface area of between 800mm2 and 1500mm2, more preferably between 1000mm2 and 1300mm2.

Alternatively, the tablet may comprise a "multi-function" tablet. The tablet may comprise a multi-function tablet for use in an automatic dish washer. The tablet may comprise a detergent composition in combination with other compositions which perform a function during a washing operation. Suitably, the tablet comprises a water- softening composition. Suitably, the tablet comprises a rinse aid.

A tablet according to the present invention may comprise a multi zone tablet, for example a multilayer tablet, with each zone having a distinct composition.

Suitably, the tablet has a mass of between 5g and 13g, preferably between 7g and Hg, more preferably between Bg and lOg, for example around 9g.

11669P4 GB2 15 Suitably, the tablet comprises a surface area of between 800mm2 and 2500mm2, more preferably between 1800mm2 and 2500mm2.

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 tablets according to the present invention comprising different compositions Difficulties associated with a consumer having to count out a selection of different tablets may thus be avoided.

Preferably, the tablet has a surface area of at least 800mm2, more preferably at least 900mm2, more preferably at least 1000mm2, for example at least 1100mm2, 1200mm2, 1300mm2, 1400rnm22, 1500mm2, 1600mm2, 1700mm2, 1800mm2, 1900mm2, 2000mm2, 2100mm2, 2200mm2, 2300mm2, 2400mm2, 2500mm2.

Suitably, the tablet has a surface area of 2500mm2 or less, for example of 2400mm2, 2300mrri2, 2200mm2, 2100mm2, 2000mm2 1900mm2, 1800mm2, 1700mm2, 1600mm22, 1500mm2, 1400mm2, 1300mm2, 1200mm2, 1100mm2, 1000mm2 or 900mm2 or less.

Arranging the tablet dimensions such that the volume (mm3) :surface area(nlrn2) ratio falls within the above selected ranges may provide a tablet having improved cleaning properties compared to one falling outside the given ranges. In particular, a detergent comprising tablet having a volume (mm3) :surf ace area(mm2) ratio in the 1].669p4 GB2 16 range of 1.5:1 to 2.0:1 or 2.7:1 to 3.2:1 may have surprisingly advantageous cleaning performance.

Preferably, the tablet has a volume(mm3) :surface area(mm2) ratio of 3. 1:1 or less, more preferably of 3:1 or less, for example of 2.9:1, 2.8:1, 2.7:1, 2.6:1, 2.5:1, 2.4:1, 2.3:1, 2.2:1, 2.1:1, 2:1, 1.9:1, 1.7:1 or 1.6:1 or less.

Suitably, the tablet has a volume(rnm3) :surface area(mm2) ratio of at least 1.5:1, for example of at least 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1; 2.7:1, 2.8:1, 2.9:1, or 3.0:1.

Suitably, the tablet is free from Phosphorus-containing compounds.

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

As the tablet is smaller than known tablets it comprises less detergent and thus if a single tablet 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 tablet 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 tablets accordingly to the present invention may provide significant environmental benefits.

Tablets according to the present invention may also be "multi-dosed". For example, for a small load one tablet could be used with the environmental advantage as described above. For a larger load then two tablets may 11669P4 GB2 17 be used. For a particularly heavily soiled load three tablets 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 tablets of the present invention may be more effective than the use of a known tablet having the same formulation as the tablets of the present invention and a weight equal to the combined weight of said two tablets of the present invention.

Accordingly, it may for example be possible to achieve the same cleaning effect provided by a known 21g tablet by using two 9g tablets, each having the same composition as the known tablet. 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 tablets accordingly to the present invention will thus be readily apparent.

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

As tablets according to the present invention may have a larger surface area per unit volume than known tablets, it may be possible to spray on more material or to apply it by means of other coating methods. Tablets according to the present invention suitably have a high surface-to11669P4 GB2 18 volume ratio they may be more rapidly soluble than known cleaning tablets. The tablets may thus comprise more poorly soluble substances (especially such as surfactants), optionally employing an effervescent system in order to enhance solubility still further.

Tablets according to the present invention may be less susceptible to breakage and may be more easily removed from a machine chamber and distributed in a dish washing machine than known tablets. A problem which occasionally occurs with known dishwasher detergent tablets, namely that the tablets become stuck between pieces of crockery and do not dissolved correctly as a result, may also be substantially avoided.

Suitably, the tablet is such that it need not be used in combination with other tablets of differing type.

The starting material for the cleaning tablets of the invention may be formulated in the same way as conventional powders, granules or tablets. A suitable formulation for a tablet 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, hydrotropic agents, etc. 11669P4 GB2 19 In addition, the tablet composition may contain suitable fillers, such as suiphates and chlorides, and tabletting aids, such as polyethylene glycol, starch or starch derivatives, etc. The tablet may be provided with a water soluble coating, the nature of that coating being determined by the purpose for which it is intended. Any water-soluble polymer may be provided for a coating, for example, if the purpose of the coating is to provide greater stability during storage and handling and/or a certain delay in dissolution in the wash liquor. If the aim of the delay is, for example, for the ingredients to be released in a certain phase of the washing cycle, as is the case with formulations for the final rinse for machine rinsing in the form of the invention, PH- dependent coating materials can be used.

The tablets 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 dissolution of the tablets, especially when poorly soluble ingredients are included.

If the tablet is for use in laundry washing, it may typically comprise, for example, a bleach, stain remover, water-softener, enzyme or fabric conditioner, in addition to the cleaning composition. The tablet may be designed to release components at different times during the laundry wash. For example, a bleach or fabric conditioner is generally 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.

11669P4 GB2 20 If the tablet is for use in dishwashing it may comprise, for example, a water-softener salt, enzyme, rinse aid, bleach or bleach activator. The tablet 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 water-softener salt or enzyme is generally released at the start of a wash.

Examples of water-softening particulates which may be used in tablets according to the present invention include: A) homo or co polymers of the following monomeric units or salts thereof - acrylic acids, maleic acids, sulfonjc 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 composition 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 11669P4 GB2 21 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/rnalejc copolymers, and acrylic phosphonates, and sulfonates.

The components of a cleaning tablet depend on its intended use. Generally, the tablet may contain surface active agents such as an anionic, nonionIc, 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 surfactants may be produced by the reaction of sulfates with higher (e.g.C8-c20) fatty alcohols.

Examples of primary alkyl sulfate surfactants are those of formula: ROSO3 M wherein R is a linear C8-C0 hydrocarby]. group and M is a watersolubilising cation. Preferably R is C0-C1 alkyl, for example c12-c14, 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: 11669P4 GB2 22 CH2(CH2)(CHQSQ3i) (CH)CH 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-soi.ubilising cation such as lithium, sodium or potassium.

Especially preferred secondary alkyl sulfates are the (2,3) alkyl sulfate surfactants of formulae: CR2 (CH2) (CHOSO3M) CH3 and CR3 (CH2) (CHOSO3M) CH2CH3 for the 2-sulfate and 3-sulfate, respectively. In these formulae x is at least 4, for example 6 to 20, preferably to 16. M is cation, such as an alkali metal, for example lithium, sodium or potassium.

Examples of alkoxylated alkyl sulfates are ethoxylated alkyl sulfates of the formula: RO (C2H40) SO3M wherein R is a C8-C20 alkyl group, preferably C10-C18 such as a C12-C16, n is at least 1, for example from 3. to 20, preferably 1 to 15, especially 1 to 6, and M is a salt- forming cation such as lithium, sodium, potassium, ammonium, alkylamrnonium or alkanolarrtmonium. These compounds can provide especially desirable fabric cleaning performance benefits when used in combination with alkyl sulfates.

11669P4 GB2 23 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 alkoxylat ion.

Other anionic surfactants which may be employed are salts of fatty acids, for example C8-C18 fatty acids, especially the sodium or potassium salts, and alkyl, for example C8- C18, benzene sulfonates.

Examples of non-ionic surf actants are fatty acid alkoxylates, such as fatty acid ethoxylates, especially those of formula: R(C2H4O)OH wherein R is a straight or branched C8-C16 alkyl group, preferably a C9-C15, for example C10-C14, 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 hydrophilic-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 11669P4 GB2 24 with about 5 moles of ethylene oxide; NEQDOL 23-9, an ethoxylated primary c12-c13 alcohol having about 9 moles of ethylene oxide; and NEODOL 91-10, an ethoxylated C9-C11 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-C11 fatty alcohol with an average of 5 moles ethylene oxide and DOBANOL 25-7 is an ethoxylated C12-c15 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 C11-C15 linear secondary 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 nunther of ethylene oxide groups per mole being about ii. Such products are also available from Shell Chemical Company.

Further non-ionic surfactants are, for example, C10-C18 alkyl polyglycosides, such as C12-C16 alkyl polyglycosides.

These are especially useful when high foaming compositions are desired. Further surfactants are polyhydroxy fatty acid amides, such as C10-C18 N(3-methoxypropyl) glycamides 11669P4 GB2 25 and ethylene oxide-propylene oxide block polymers of the Pluronic type.

Examples of cationic surf actants are those of the quaternary ammonium type.

The total content of surfactants in the tablet 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

tablet.

The tablets, Particularly when used as laundry washing or dishwashing tablets, 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 tablets in an amount of from 0.5 to 3 wt%, especially i 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.

Tablets used in dishwashjng independently usually comprise a detergency builder. The builders counteract the effects of calcium, or other ion, water hardness. Examples of such materials are citrate, succiriate, malonate, 11669P4 GB2 26 carboxymethyl succinate, carboxylate, polycarboxylate and polyacetyl 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, mellitjc acid, benzene polycarboxylic acids, C10-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 alkyihydroxy phosphonates. Citrate salts and C12-C18 fatty acid soaps are preferred. Further builders are: phosphates such as sodium, potassium or ammonium salts of mono-, di- or tn- poly or oligo-phosphates; zeolites; 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/polyrnaleic and copolymers and their salts, such as those sold by BASF under the trade mark SOKkLLAN.

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 tablet. Further details of suitable components are given in, for example, EP-A-694,059, EP-A-518,720 and WO 99/06522.

The tablets 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 11669P4 GB2 27 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 srnectite 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

tablets.

Tablets which comprise an enzyme may optionally contain materials which maintain the stability of the enzyme.

Such enzyme stabilizers include, for example, polyols such is 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 tablets.

Preferred dishwashing tablets 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 tablets 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%, 11669P4 GB2 28 preferably 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) tablets 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 tablet comprises at least one non-ionic surfactant. One class of non-lonics are ethoxylated non- ionic surfactants prepared by the reaction of a monohydroxy 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.

11669P4 GB2 29 The flOn-IOnjc surfactant may additionally comprise propylene oxide (P0) units in the molecule. Preferably the P0 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 block copolymer units. The alcohol or alkyiphenol 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 surf actants includes reverse block copolyrners of polyoxyethylene and polyoxypropy].ene and block copolyrners of polyoxyethylene and polyoxypropylene initiated with trimethyloipropane.

Another preferred non-ionic surfactant can be described by the formula: R10 [CH2CH (CH3) OJ [CH2CH2Q] [CH2CH (OH) R2] wherein R1 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 flOflionic surfactants are the end-capped polyoxyalkylated flon-loflics of formula: 11669P4 GB2 30 R'O [CH2CI-I CR3) OJ x [CH2] kCH (OH) [CH2J)0R2 wherein R' and R2 represent linear or branched chain, saturated or unsaturated, aliphatic or aromatic hydrocarbon 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 (P0) (EO) (EQ), (EO) (P0) CEO), (ED) (EO) (P0), (EO) (EO) (EQ), (P0) (EO) (P0), (P0) (P0) (E0) and (P0) (P0) (P0).

The value 3 for x is only an example and bigger values can be chosen whereby a higher number of variations of (ED) or (P0) units would arise.

Particularly preferred end- capped polyoxyalkylated alcohols of the above formula are those where k=1 and j=1 originating molecules of simplified formula: R'O [CH2CH (R3) 0] xCH2CH (OH) CH2OR2 1].669P4 GB2 31 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 tablet disintegrant could be present in the tablets, for example a water-swellable cellulosic compound.

The cleaning tablets of the present invention can suitably be manufactured using a variety of processes; for example by pressing under pressure. Depending on the demands placed on the dissolution behaviour and stability in storage and transport, and depending on the nature of the ingredients, the appropriate pressing pressure can be set accordingly.

A further preferred manufacturing process is compacting, which is understood in this application to mean pressing agglomeration without the use of binders, which is usually performed by rollers rotating in opposite directions and possessing grooves of the appropriate dimensions. With this production process, it is also possible to use other ingredients, which are usually not suitable for pressing, because the pressures during compacting are considerably lower.

Tablets accordingly to the invention may be manufactured using procedures other than compacting (e.g. extrusion / injection-moulding), and noncompacting methods may provide greater flexibility with regard to the manufacturing process.

11669P4 GB2 32 A cleaning tablet of the invention may be used in a variety 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 machine, 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 tablet is arranged such that N tablets 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 tablet is arranged such that the number of tablets 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 packaged product comprising one or more products according to the first aspect and a secondary packaging.

The secondary packaging may contain a plurality of products according to the first aspect. Alternatively, the secondary packaging may comprise a single product according to the first aspect. The product may comprise a single strip holding sufficient tablets for a plurality of washing operations, suitably 5 or more, for example 10 or more, washing operations.

11669P4 GB2 33 Suitably, the secondary packaging comprises an outer housing. Suitably, the secondary packaging comprises an outer housing such that a consumer may detach as many tablets as are required from the product, leaving the remainder I un-used portion of the product in the secondary packaging.

Suitably, the secondary packaging comprises a cutting means to aid the detachment of the requisite number of tablets from the remainder of the strip.

Suitably the housing contains an aid for withdrawal of a portion of the product and which aid comprises a hub around which the product may be spooled.

Suitably, to aid detachment the product comprises a detachment aid between tablets / groups of tablets.

Suitably, the packaged product comprises any feature as described in relation to the first aspect.

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

Suitably, the method only employs substantially identical tablets according to the first aspect. It may thus not be necessary to use a combination of tablets having distinct formulations.

Suitably, the tablets comprise a detergent composition.

11669P4 GB2 34 Suitably, where the method employs a plurality of tablets the tablets 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.

The ware washing machine may comprise a table-top ware washing machine or a floor standing type of ware washing machine.

Preferably, the method comprises the step of determining whether one or more tablets 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 tablets.

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 tablets.

Suitably, A = 0 to 2. Suitably, A is > 0 and = (N - 1).

Suitably, for a domestic dish washer of the floor standing type A = 1 or 2, preferably 1.

11669P4 GB2 35 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 tablets.

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 tablets.

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

Suitably, for a given ware washing machine and tablet 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 "dose" of tablets 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 11669P4 GB2 36 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 tablets 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 tablets should be used or if an adjustment needs to be made. Suitably, a value for N will be provided with the tablets. Suitably, if an adjustment is required a user will use a value for A, B or C provided with the

tablets.

Claims (29)

11669P4 GB2 37 Cia i ms 1. A product comprising a plurality of cleaning

tablets for use in a washing operation, the tablets being arranged in a strip conjoined by wrapping material, characterjsed in that the tablet has a mass of between ig and 15g such that it can be used singularly or with one or more other like tablets depending upon a required washing performance.

2. A product according to Claim 1, wherein tablets are arranged in individual groups along the strip.

3. A product according to Claim 1 or 2, wherein the product comprises N tablets / groups of tablets in a strip and where N is two, three, four, five, six, ten or twelve.

4. A product according to any of Claims 1 to 3, wherein the strip only comprises substantially

identical tablets.

5. A product according to any preceeding Claim, comprising a detergent composition.

6. product according to any preceeding Claim, comprising a watersoftening composition.

7. A product according to any preceding Claim, wherein the tablet is for a ware washing machine.

8. A product according to Claim 7, wherein the tablet is for an automatic dish washing machine.

11669P4 GB2 38

9. A product according to Claim 8, except when dependent on Claim 6, wherein the tablet comprises a single function detergent tablet which comprises a detergent composition and is substantially free from dishwasher salt. or rinse aid.

10. A product according to Claim 9, wherein the tablet has a mass of between ig and 7g.

11. A product according to Claim 9 or 10, wherein the tablet has a surface area of between 800mm2 and 1500mm2.

12. A product according to Claim 8, wherein the tablet comprises a multifunction detergent tablet which comprises a detergent composition and dishwasher salt function and/or rinse aid function.

13. A product according to Claim 12, wherein the tablet has a mass of between 5g and 13g.

14. A product according to Claim 12 or 13, wherein the tablet has a surface area of between 1500mm2 and 2500mm2.

15. A product according to any preceding claim, wherein the tablet has a volume(mm3):surface area(mm2) ratio of between 1.5:1 and 3.0:1.

16. A packaged product comprising one or more products according to any preceding claim and a secondary packaging.

11669P4 GB2 39

17. A packaged product according to Claim 16, wherein the secondary packaging contains a plurality of products according to any of Claims 1 to 15.

18. A packaged product according to Claim 16, wherein the secondary packaging comprises an outer housing such that a consumer may detach as many tablets as are required from the product, leaving the remainder I unused portion of the product in the secondary packaging.

19. A packaged product according to Claim 17, wherein the secondary packaging comprises a cutting means to aid the detachment of the requisite number of tablets from the remainder of the strip.

20. A packaged product according to Claim 17 or 18, wherein the housing contains an aid for withdrawal of a portion of the product and which aid comprises a hub around which the product is spooled.

21. A packaged product according to any of Claims 16 to 20, wherein to aid detachment the product comprises a detachment aid between tablets I groups of

tablets.

22. A method of performing a washing operation characterjsed in that the method employs one or more tablets from a product or packaged product according to any of the preceding claims and a quantity of water.

11669P4 GB2 40

23. A method according to Claim 22, wherein the method comprises the step of determining whether one or more tablets are required depending on the level of soiling and the quantity of articles to be washed.

24. A method according to Claim 22 or 23, wherein the method comprises washing articles in an automatic ware washing machine.

25. A method according to Claim 24, wherein the tablets comprise detergent composition and the method comprises washing articles in an automatic dishwashing machine.

26. A method according to Claim 25, 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 dishwashing machine the method uses N tablets where N = 2, 3, or 4.

27. A method according to Claim 25 or 26, 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 tablets where N = 2, 3, or 4 and A is > 0 and = (N - 1).

28. A method according to any of Claims 25 to 27, wherein the dishwashing machine comprises a domestic dishwasher of the floor standing type, and 11669P4 GB2 41 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 tablets where N 2, 3, or 4 and is > 0 and = (N - 1).

29. A method according to any of Claims 25 to 28, 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 tablets where N = 2, 3, or 4 and C is > 0 and = (N - 1)