GB2346319A - Dishwashing kit comprising packaged amounts of detergent and rinse aid - Google Patents

Abstract

A dishwashing kit comprising a packaged amount of rinse aid and a packaged amount of detergent wherein the amount of rinse aid is proportional to the amount of detergent. The kit may include the same amount of detergent and rinse aid. The packaged rinse aid and detergent may be enclosed within a secondary pack. Preferably the secondary pack comprises a first compartment containing a plurality of tablets wrapped in flow wrap and a second compartment containing a bottle of rinse aid. Alternatively the kit may comprise a two receptacles which engage in a retro fit manner, preferably with the rinse aid receptacle engaging a lid means of the detergent receptacle. The receptacles may engage in a tamper evident manner. Instructions may be provided with the kit.

Description

3 8 9'- 2346319 A MACHINE PISHWASKING KIT

Technical Field

The present invention is in he field of machine dishwashing. More specifical ly, the invention encompasses a machine dishwashing kit.

Background of the Invention

To wash articles in a commerc ally available dish washing machine entails using three poduct types. Salt is added to the salt compartment to softe the water, a dish washing formulation is used to clean the articles and a rinse aid is used to ensure that the arti4es are rinsed with no streaks or smears.

Heretofore, all of the three omponents have been sold separately, with each compone4t being sold in different volumes and having different concentrations of active ingredients and different dos4ge instructions. Thus, when a consumer buys all three compori.ents at the same time, it is inevitable that the different components will need replacing at different times which is an, inconvenience for the consumer. Further, it is not i Mediately apparent when rinse aid needs to be replaced. This.is primarily due to the fact that the bottle of rinse aid i generally emptied completely into a rinse aid reservoir in he machine, from which receiver the rinse aid is autoatically dosed into the machine. Thus, the consumer ca,not use the bottle of rinse aid to gauge how much product temains, and must revert to checkil-g the level of rinse ai' remaining in the reservoir.,As such reservoirs tend to be Within the machine, this is C 3 8 9.C:

2 not an ideal situation. A partial solution to this problem has been provided by some machine manufacturers with the incorporation of a warning light into the machine which lights when the reservoir is nearly empty. However, this solution relies on the consumer noticing and heeding the warning light and acting accordingly, which in many cases simply does not happen. Furthermore, many machines do nor have such warning systems.

It is an object of the invention to overcome at least some of the above problems. It is a particular object of the invention to provide a machine dishwashing kit which is formulated to provide a greater level of convenience for the consumer. 15 Description of the Invention

According to the invention there is provided a machine dishwashing kit comprising equivalent amounts of rinse aid 20 and detergent. Thus the kit may comprise:

- an amount of packaged rinse aid composition sufficient to provide X number of rinse cycles; and - an amount of packaged detergent composition sufficient to provide X/Y number of washes, wherein X is greater than or equal to Y, X and Y are whole numbers, X/Y is equal to a whole number, and Y is between 1 and 3.

In a preferred embodiment of the invention, Y is equal to 1. With this embodiment, the amount is rinse aid in the kit is C38 9 directly proportional to the amount of detergent in the kit, and as such, when the detergent has been used up, a user knows that the rinse aid resorvoir needs to be replenished. Thus a user simply buys the kit of the invention, empties the rinse aid into an empty rinse aid reservoir in the machine, and then uses the detergent according to the dosage instructions until no deterge. nt remains, at which point the rinse aid reservoir will alsobe empty, whereby a user purchases a further kit and repeats the process.

Furthermore, as the rinse aid,and detergent can be formulated to be otherwise cornpatible, use of the kit should result in improved cleaning o dishes as opposed to the combination of products not p rovided in the form of a specifically designed kit.

Generally, the rinse aid and Ietergent are separate components which are ideally packaged separately.

In an alternative embodiment pf the invention, one or both of the rinse aid and detergent composition are formulated to create conditions within the Machine during a washing/rinse cycle that obviate the need fpr a separate ion exchange regenerating salt. Thus, the OH of the rinse aid is lowered ideally by formulating it such that it comprises 20wt% or greater of a water soluble acid builder or salt thereof. Typically, the acid is a carbqxy acid such as, for example, carboxy acid. Thus, the kit a4cording to the invention effectively provides, in addition to the detergent and rinse aid, the effects of a dishwashing salt.

optionally, or in addition, te detergent composition comprises greater than 20wt% f a bicarbonate salt and a silica or silicate material. T ypically, the detergent C38 9 4 composition further comprises a polymer or copolymer of acrylic acid. Ideally, a 1% aqueous solution of the detergent composition, at a temperature of 25oC, has a pH from 8.5 to 10. 5 In one embodiment of the invention, the detergent comprises a plurality of unit doses such as tablets, in which each tablet ideally provides sufficient detergent for a single wash cycle. Alternatively, the detergent composition is in a particulate form, wherein the kit further includes means for dispensing an accurate and consistent dose of the detergent composition, such as for example, a pourspout. The rinse aid is for the most part in the form of a liquid, however other forms are envisaged such as for example gels.

In one embodiment of the invention, the packaged detergent and rinse aid compositions are enclosed within a secondary pack. In one particularly preferred embodiment of the invention, the kit may comprise a plurality of detergent tablets, each tablet packed in an individual pack such as a flow wrap, and a liquid rinse aid composition in a bottle, the kit further including a secondary pack having a first compartment for the wrapped tablets and a second compartment for the bottle of rinse aid.

In a further arrangement, the detergent composition is packaged within a first receptacle, and the rinse aid is packaged within a second receptacle, wherein the first and second receptacles engage in a retro 'Lit manner, and ideally also in a tamper evident manner. Typically, the rinse aid receptacle engages a lid means of the detergent receptacle.

C38 95-.

The invention also describes the use of a machine dishwashing kit according to the invention, wherein the rinse aid reservoir of a was4ng machine is drained of any dual -'nse aid before thei-inse aid of the kit is added res-L..L to the reservoir. Preferably,'the rinse aid reservoir is set such that it delivers an appr(priate dose of rinse aid. Ideally the dosage of rinse aid is 3mls.

Detailed Descril2tion of the I!jvention Dish Washing Composition Builder material The detergency builder system is preferably water soluble and more preferably comprises a bicarbonate salt, preferably sodium or potassium bicarbonat.e most especially sodium bicarbonate. Bicarbonate salts' are particularly preferred as builders as they also have a buffering capacity. It is preferable if the bicarbonate Is present at a level greater than 20 wt% of the total compo"sition, more particularly at least 24 wt% of the total comp bsition.

It is preferable if the buildei further comprises a ca-rboxylate or polycarboxylateibuilder containing from one to four carboxy groups, particPlarly selected from monomeric polycarboxylates or their acid'forms, homo or copolymeric polycarboxylic acids or there alts in which the polycarboxylate comprises at 1(ipast two carboxylic radicals selected from each other by no'- more than two carbon atoms. Preferred carboxylates include,the polycarboxylate materials bed in US-A-2,264,103, icluding the water-soluble descri alkali metal salts of mellitic acid and citric a-cid, C 3 8 9 5 - 6 dipicolinic acid, oxydisuccinic acid and alkenyl succinates. The water- soluble salts of polycarboxylate polymers and copolymers, such as are described in US-A-3,308,067 are also be suitable for use with the invention. of the builder 5 materials listed in the above paragraph, the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecule, especially citric acid or its salt, particularly sodium citrate. It is preferable if the carboxylate builder is present at a level of at least 20 wt% of the total formulation, more preferably at a level greater than 30 wt%.

It is preferred if the weight ratio of polycarboxylate builder to bicarbonate builder is at least 1:1, preferably greater than 3:2 Furt.her soluble detergency builder salts which can be used with the present invention are poly-valent inorganic and poly-valent organic builders, or mixtures thereof. Non- limiting examples of suitable water-soluble, inorganic alkaline detergency builder salts include the alkali metal carbonates, borates, phosphates, polyphosphates, tripolyphosphates, phosphono carboxylates. Specific examples of such salts include the sodium and potassium tetraborates, carbonates, tripolyphosphates, orthophosphates and hexametaphosphates. However it is preferable if the detergent formulation is free or only has low levels (5% or less) of builder salts which precipitate during the wash in the presence of calcium, an example of such a salt is sodium tripolyphosphate.

In preferred builder systems the weight ratio of alkali metal b'Lcarbonate to alkali metal carbonate is greater than C 3 8 9 5- 1:1, preferably greater than.2:1 in particularly preferred systems the builder does not comprises a alkali metal carbonate.

Other suitable detergency buiders organic alkaline compounds such as water-solubIle amino polyacetates, e.g. sodium and potassium ethyleneoiamine tellraacetates, nitrilotriacetates and N-(2-hyd-oxyethyl)nitrilodiacetates; water-soluble salts of phytic acid, e.g. sodium and potassium phytates; water-solvible polyphosphonates, including sodium, potassium atd lithium salts of ethane-lhydroxy-1,1-diphosphonic acidf sodium, potassium and lithium salts of methylenediphosphoni acid and the like.

It is to be understood that, while the alkali metal salts of the foregoing inorganic and organic poly-valent anionic builder salts are preferred fqr use herein from an economic standpoint, the ammonium, alk$nolammonium, e.g. triethanolammonium, diethanol ammonium, 4nd the like, water-soluble salts of any of the foregoing 'builder anions are useful herein.

Mixtures of organic and/or inorganic builder salts can be used herein.

While any of the poly-valent builder materials are useful herein, the compositions of the invention are preferably free of phosphate builders for. environmental and ecological reasons.

Preferred builders for use in the invention are sodium citrate and sodium bicarbonate and mixtures thereof.

C389'- 8 Alternatively the potassium salts of these acids may be used.

Preferably, the amount of builders in the composition is from about 30 to 80% by weight, more preferably from 40 to about 70% by weight.

Silica material Suitable forms of silica include amorphous silica, such as precipitated silica, pyrogenic silica and silica gels, such as hydrogels, xerogels and aerogels, or the pure crystal forms quartz, tridymite or crystobalite, but the amorphous forms of silica are preferred. Suitable silicas may readily be obtained commercially. They are sold, for example under the Registered Trade Name Gasil 200 (ex Crosfield, UK).

Preferably, the silica is in the product in such a form that it can dissolve when added to the wash liquor. Therefore, addition of silica by way of addition anti-foam particles of silica and silicone oil is not preferred.

The particle size of the silica material of the present invention may be of importance, especially as it is believed that any silica material that remains undissolved during the washing process, may deposit on the glass at a later stage. Therefore, it is preferred that silica material are used that have a particle size (as determined with a Malvern Laser, i.e. "aggregated" particles size) of at most 40 mm, more preferably at most 30mm, most preferably at most 20mm provides better results in the wash. In view of incorporation in a cleaning composition, it is preferred that the particle size of the silica material is at least C38 95- 9 irrLm, more preferably at least 2mm, most preferably at least Srr,m.

Preferably the primarily particle size of the silica is in general less than about 30nm, in particular less than about 25nm. Preferably, elementary particles size are less than 20nm or even 10nm. There is no critical lower limit of the elementary particle size; thq lower limit is governed by other factors such as the malner of manufacture, etc. In general commercial available silicas have elementary particle sizes of 1 nm or mote.

Preferably, the silica material is present in the wash liquor at a level of at least.2. SX10-4%, more preferably at -5 least 12.5X10-4%, most prefer4bly at least 2.5X10-3% by weight of the wash liquor and preferably at most lxlO-'%, more preferably at most SX10-2%. most preferably at most 5xl 0-2 % by weight of the wash liquor.

Preferably, the level of dissolved silica material in the wash liquor is at least 80 ppih, more preferably at least 100 ppm, most preferably at least.120 ppm and preferably at most 1,000 ppm. It is noted that f)r the silica material to be effective, the lower level of dissolved silica material depends on the pH value, i.e.,thus at pH 6.5, the level is preferably at least 100 ppm; at pH 7.0 preferably at least 110 ppm; at pH 7.5 preferably at least 120 ppm; at pH 9.5 preferably at least 200 ppm; at pH 10 preferably at least 300 ppm; at pH 10.5 preferably at least 400ppm.

Preferably, the silica material is present in the cleaning composition at a level of at least 0.1%, more preferably at least 0.5%, most preferably at least 1% by weight of the C31 8 9 - cleaning composition and preferably at most 10%, more preferably at most 8%, most preferably at most 5% by weigh-, of the cleaning composition.

S Silicates The composition optionally comprises alkali metal silicates. The alkali metal may provide pH adjusting capability and protection against corrosion of metals and against attack on dishware, including fine china and glassware benefits. When silicates are present, the SiO2 level should be from 1% to 2S%, preferably from 2% to 20%, more preferably from 3% to 10%, based on the weight of the ADD. The ratio of Si02 to the alkali metal oxide (M20, where M=alkali metal) is typically from 1 to 3.5, preferably from 1.6 to 3, more preferably from 2 to 2.8. Preferably, the alkali metal silicate is hydrous, having from 15% to 25% water, more preferably, from 17% to 20%.

The highly alkali metasilicates can in general be employed, although the less alkaline hydrous alkali metal silicates having a Si02:M20 ratio of from 2.0 to 2.4 are, as noted, greatly preferred. Anhydrous forms of the alkali metal silicates with a Si02:M20 ratio of 2.0 or more are also less preferred because they tend to be significantly less soluble than the hydrous alkali metal silicates having the same ratio.

Sodium and potassium, and especially sodium, silicates are preferred. A particularly preferred alkali metal silicate is a granular hydrous sodium silicate having a Si02:Na2O ratio of from 2.0 to 2.4 available from PQ Corporation, named Britesil H20 and Britesil H24. Most preferred is a C3895 granular hydrous sodium silicpte having a Si02:Na2O ratio of 2.0. While typical forms, i.b. powder and granular, of hydrous silicate particles ar6 suitable, preferred silicate particles having a mean partii--le size between 300 and 900 microns and less than 40% smaller than 150 microns and less than 5% larger than 1700 micrpns. Particularly preferred is a silicate particle with a me;n particle size between 400 and 700 microns with less that 20% smaller than 150 microns and less than 1% larger then 1700 microns. Compositions of the present invention having pH of 9 or less preferably will be substantially free ofalkali metal silicate.

Enzymes Enzymes may be present in thecompositions of the invention. Examples of enzymes suitable for use in the cleaning compositions of this inventio include lipases, peptidases, amylases (amylolytic enzymes),and others which degrade, alter or facilitate the degra4ation or alteration of biochemical soils and stains Oncountered in cleansing situations so as to remove mo4e easily the soil or stain from the object being washed o make the soil or stain more removable in a subsequent clensing step. Both degradation and alteration can improve sol removal.

Well-known and preferred examples of these enzymes are lipases, amylases and proteas( s. The enzymes most commonly used in machine dishwashing compositions are amylolytic enzymes. Preferably, the comp6sition of the invention also contains a proteolytic enzyme. Enzymes may be present in a weight percentage amount of fr.om 0.2 to 5% by weight. For amylolytic enzymes, the final.!composition will have to 106 Ma'tose units/kg. For amy'Lolytic activity o4f from 10' _L C3895 - proteolytic enzymes the final composition will have proteolytic enzyme activity of from 106 to 109 Glycine Units/kg.

Bleach Material Bleach material may optionally and preferably be incorporated in composition for use in processes according to the present invention. These materials may be incorporated in solid form or in the form of encapsulates and less preferably in dissolved form.

The bleach material may be a chlorine- or bromine-releasing agent or a peroxygen compound. Peroxygen based bleach materials are however preferred.

organic peroxy acids or the precursors therefor are typically utilized as the bleach material. The peroxyacids usable in the present invention are solid and, preferably, substantially water-insoluble compounds. By "substantially water- insoluble" is meant herein a water-solubility of less than about 1% by weight at ambient temperature. In general, peroxyacids containing at least about 7 carbon atoms are sufficiently insoluble in water for use herein.

Inorganic peroxygen-generating compounds are also typically used as the bleaching material of the present invention. Examples of these materials are salts of monopersulphate, perborate monohydrate, perborate tetrahydrate, and percarbonate.

Monoperoxy acids useful herein include alkyl peroxy acids and aryl peroxyacids such as peroxybenzoic acid and C3895 ring-substituted peroxybenzoic acids (e.g. peroxy-alphanaphthoic acid); aliphatic and substituted aliphatic monoperoxy acids (e.g. peroxylauric acid and peroxystearic acid); and phthaloyl amido p(roxy caproic acid (PAP). 5 Typical diperoxy acids useful herein include alkyl diperoxy acids and aryidineroxy acidsi such as 1,12-di-peroxydodecanedioic acid (DPDA); 1,9-diperoxyazelaic acid, diperoxybrassylic acid, ddLperoxysebacic acid and diperoxy- isophthalic acid; and 2-decydiperoxybutane-1,4-dioic acid.

Peroxyacid bleach precursors are well known in the art. As non-limiting examples can be named N,N,N',N'-tetraacetyl ethylene diamine (TAED), sodiim nonanoyloxybenzene sulphonate (SNOBS), sodium berzoyloxybenzene sulphonate (SBOBS) and the cationic peroXyacid precursor (SPCC) as described in US-A-4,751,015.

If desirably a bleach catalyst, such as the manganese complex, e.g. Mn-Me TACN, as described in EP-A-0458397, or the sulphonimines of US-A-5,041,232 and US-A-5,047,163, is to be incorporated, this may e presented in the form of a second encapsulate separately from the bleach capsule or granule. Cobalt catalysts cal also be used.

Among suitable reactive chlorne- or brom-ine-oxidizing materials are heterocyclic N-bromo and N-chloro imides such as trichloroisocyanuric, tribromoisocyanuric, d-'Lbromoisocyanuric and dichlor: oisocyanuric acids, and salts thereof with water-solubilizinq cations such as potassium and sodium. Hydantoin compoundp such as 1,3-dichloro-5,5dimethyl-hydantoin are also qu te suitable.

C38 95 Particulate, water-soluble anhydrous inorganic salts are likewise suitable for use herein such as lithium, sodium or calcium hypochlorite and hypobromite. Chlorinated trisodium phosphate and chloroisocyanurates are also suitable 5 bleaching materials.

Encapsulation techniques are known for both peroxygen and chlorine bleaches, e.g. as described in US-A-4,126,573, USA-4,327,151, US-A-3,983, 254, US-A-4,279,764, US-A-3,036,013 and EP-A-0,436,971 and EP-A-0,510,761. However, encapsulation techniques are particularly useful when using halogen based bleaching systems.

Chlorine bleaches, the compositions of the invention may comprise from about 0.5% to about 3% avCl (available Chlorine). For peroxygen bleaching agents a suitable range are also from 0.5% to 3% avO (available Oxygen). Preferably, the amount of bleach material in the wash liquor is at least 12.5x'. 0-4 % and at most 0.03% avO by weight of the liquor.

Sur"Eactant material A surfactant system comprising a surfactant selected from nonionic, anionic, cationic, ampholytic and zwitterionic surfactants and mixtures thereof is preferably present in the composition.

Typically the surfactant is a low to non foaming nonionic surfactant, which includes any alkoxylated nonionic surface- active agent wherein the alkoxy moiety is selected from the group consisting of ethylene oxide, propylene oxide and mixtures thereof, is preferably used to improve the detergency without excessive foaming. However, an excessive C3895 proportion of nonionic surfactant should be avoided. Normally, an amount of 15% by weight or lower, preferably 10% by weight or lower, more preferably 7% by weight or lower, most preferably 5% by weight or lower and preferably 0.1% by weight or higher, mote preferably 0.5% by weight or higher is quite sufficient, 41though higher level may be used.

Examples of suitable nonionid surfactants for use in the invention are the low- to non.-foaming ethoxylated straightchain alcohols of the Plurafa:c(D RA series, supplied by the Eurane Company; of the Lutens'ol@ LF series, supplied by the BasF Company and of the TritoTi(D DF series, supplied by the Rohm & Haas Company.

Other surfactants such as anipnic surfactant may be used but may require the additional presence of an antifoam. to surpress foaming. If an anionjc surfactant is used it is advantageously present at lev(ls of 2 wt% or below.

Water Soluble Polymeric Polycrboxylic Com2ounds I A water soluble polymeric polycarboxylic compound is advantageously present in the dish wash composition.

Preferably these compounds are homo- or co-polymers of polycarboxylic compounds, espEkcially co-polymeric compounds in which the acid monomer comprises two or more carboxyll groups separated by not more than two carbon atoms. Salts of these materials can also be:used.

Particularly preferred polymerc polycarboxylates are copolymers derived from monomers,of acrylic acid and maleic C 3 8 9 16 - acid. the average molecular weight of these polymers in the acid form preferably ranges from 4,000 to 70,000.

Another type of polymeric polycarboxylic compounds suitable for use in the composition of the invention are homopolymeric polycarboxylic acid compounds with acrylic acid as the monomeric unit. The average weight of such homopolymers in the acid form preferably ranges from 1,000 to 100,000 particularly from 3,000 to 10,000.

Acrylic sulphonated polymers as described in EP 851 022 (Unilever) are also suitable.

Preferably, this polymeric material is present at a level of at least 0.1%, more preferably at levels from 1 wt% to 7 wt% of the total composition.

Chelating Agent A chelating agent may be present in the composition. If present it is preferable if the level of chelating agent is 4C from 0.5 to 3 wt% of the total composition.

Preferred chelating agents include organic phosphonates, 2S amino carboxylates, polyfunctionally-substituted compounds, and mixtures thereof.

Particularly preferred chelating agents are organic phosphonates such as a-hydroxy-2 phenyl ethyl diphosphonate, ethylene diphosphonate, hydroxy 1,1-hexylidene, vinylidene 1,1 diphosphonate, 1,2 dihydroxyethane 1,1 diphosphonate and hydroxy-ethylene 1,1 diphosphonate. Most preferred is hydroxy-ethylene 1,1 diphosphonate.

C38 95_ Inti-tarnishing Agents Anti-tarnishing agents such as benzutriazole and those described in EP 723 577 (Unil I Pver) may also be included.

Optional Ingredients Optional ingredients are, forlexample, buffering agents, reducing agents, e.g., borate!, alkali metal hydroxide and the well-known enzyme stabiliers such as the polyalcohols, e.g. glycerol and borax; anti7scaling agents; crystal-growth inhibitors, threshold agents; thickening agents; perfumes and dyestuffs and the like.

Reducing agents may e.g. be ued to prevent the appearance of an enzymedeactivating concentration of oxidant bleach compound. Suitable agents inc;ude reducing sulphur-oxy acids and salts thereof. Most prefetred for reasons of availability, low cost, and high performance are the alkali metal and ammonium salts of sqlphuroxy acids including ammonium sulphite ( (NH4) 2SO3).:sodium sulphite (Na2SO3) I sodium bisulphite (NaHS03), sooium metabisulphite (Na2S2()3), iDotassium metabisulphite (K2S205), lithium hydrosulphite (Li2S204), etc., sodium sulphit,e being particularly preferred. Another useful redu.cing agent, though not particularly preferred for rearsons of cost, is ascorbic acid. The amount of reducing agents to be used may vary from case to case depending on the type of bleach and the form it is in, but normally a range of!about 0.01% to about 1.0% by weight, preferably from about 0.02% to about 0.5% by weight, will be sufficient.

C3895 18 pH of wash liquor The invention relates to washing processes in mechanical dish washing machines wherein the wash liquor has a low pH.

By "low pH" is meant here that the pH of the wash liquor is preferably higher than about 6.5, more preferably 7.5 or higher, most preferably 8.5 or higher. Preferably the pH is lower than about 10.5, more r)referably lower than about 10, more preferably lower than about 9.5. The most advantageous pH range is from 8.5 to 10.

Temperature of washing process The present invention preferably relates to processes of mechanically washing soiled articles with a wash liquor at a temperature of at least 40C, more preferably at least 50'C, most preferably at least 55'C.

Rinse Aid The rinse aid for use in the invention comprises a water soluble acid builder or salt, preferably organic acids including, for example, carboxylic acids, such as citric and succinic acids, polycarboxylic acids, such as polyacrylic acid, and also acetic acid, boric acid, malonic acid, adipic acid, fumaric acid, lactic acid, glycolic acid, tartaric acid, tartronic acid, maloic acid, the4r derivatives and any mixtures of the foregoing.

Suitable water-soluble monomeric or oligomeric carboxylate builders can be selected from a wide range of compounds but such compounds preferably have a first carboxyl logarithmic C3895 acidity/ constant (pKj) o"f les than 9, preferably of between 2 and 8.5, more preferably of1between 2.5 and 7.5.

1 The carboxylate or polycarboxylate builder can be monomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for rasons of cost and performance. Monomeric and oligomeric builoers can be selected from acyclic, alicyclic, hete--ocyc'ic and aromatic carboxylates.

rL Suitable carboxylates containng one carboxy group include the water soluble salts of latic acid, glycolic acid and ether derivatives thereof. Pplycarboxylates containing two carboxy groups include the water-soluble salts of succinic acid, malonic acid, (ethyleneioxy) diacetic acid, maleic acid, diglycolic acid, tartartc acid, tartronic acid and fumaric acid, as well as the Other carboxylates and the sulfinyl carboxylates. Polycrboxylates containing three carboxy groups include, in paticular, water-soluble citrates, aconitrates and cittaconates as well as succinate derivatives such as the carboxymethyloxysuccinates, lactoxysuccinates, and aminosqccinates, and the oxypolycarboxylate materials 4uch as 2-oxa-1, 1,3-propane tricarboxylates. The carboxylqte or polycarboxylate builder compounds described above canalso have a dual function as pH controlling agents.

Polycarboxylates containing faur carboxy groups include oxydisuccinates, 1,1,2,2-ethane tetracarboxylates, 1,1,3,3pror-)ane "-- etracarboxylatesand,'L,1,2,3-propane tetracar- boxylates. Polycarboxyla-Les d ontaining sulfo substituents include the sulfosuccinate dei.i4vatives, and the sulfonated pyrolysed citrates.

C3895 Alicyclic and heterocyclic polycarboxylates include cyc'Lopentane-ci-s, cis,cis-tetracarboxylates, cyclopentadienide pentacarboxy'Lates, 2,3,4,5- tetrahydroturan cis, cis, cis-tetracarboxy-lates, 2,5-tetrahydrofuran - cis dica--boxylates, 2,2,5,5-tetrahydrofuran - tetracarboxylates, 1,2,3,4,5,6- hexane hexacarboxylates and carboxymethyl derivatives of polyhydric alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in British Patent No. 1,425,343.

Of the above, the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecules, more particularly citrates or citric acid.

As an alternative to the above phosphonates may be used.

The parent acids of the monomeric or oligomeric polycarboxylate chelating agents or mixtures thereof with their salts, e.g. citric acid or citrate/citric acid mixtures are also contemplated as components of builder systems of rinse compositions in accordance with the present invention.

A surfactant system comprising a surfactant selected from non'Lonic, anionic, cationic, ampholytic and zwitterionic surfactants and mixtures thereof is preferably present in the composition.

The surfactant system most preferably comprises low foaming nonionic surfactant, selected for its wetting ability, preferably selected from ethoxylated and/or propoxylated C3895 nonionic surfactants, more preferably selected from nonionic ethoxylated/propoxylated fatty alcohol surfactants.

I The surfactant system is typically present at a level of from 1% to 40% by weight, moie preferably 1.5 % to 30% by weight, most preferably from 5% to 20% by weight of the compositions. If an anionicsurfactant is used it is advantageously present at levels of 1 wt% or below.

The compositions of the invention may contain organic solvents, particularly when formulated as liquids or gels. The compositions in accord with the invention preferably contain a solvent system present at levels of from 1% to 30% by weight, preferably frop 3% to 25% by weight, more preferably form 5% to 20% by weight of the composition. The solvent system may be a mono or mixed solvent system. Preferably, at least the majo. component of the solvent system is of low volatility.

Suitable organic solvent for 43e herein has the general formula RO(CH2C(Me)HO)nH, wherein R is an alkyl, alkenyl, or alkyl aryl group having from to 8 carbon atoms, and n is an integer from 1 to 4. Prefe4ably, R is an alkyl group containing 1 to 4 carbon atoms, and n is I or 2. Especially preferred R groups are n-butyl. or isobutyl. Preferred solvents of this type are 1 -R-butoxypropane-2-ol (n = 1): and 1(2-n-butoxy-1 -methyletho. xy)propane-2-ol (n = 2), and mixtures thereof.

Other solvents useful herein ipclude the water soluble 7 CARBITOL solvents or wat-er-soluble CELLOSOLVE7 solvents. Water-soluble CARBITOL7 solvents are compounds of the 2-(2 alkoxyethoxy)ethanol class wherein the alkoxy group is C3895 derived from ethyl, propyl or butyl; a preferred watersoluble carbitol is 2 (2-butoxyethoxy) ethanol also known as butyl carbitol. Water-soluble CELLOSOLVE 7 solvents are compounds of the 2-alkoxyethoxy ethanol class, with 25 butoxyethoxyethanol being preferred.

Other suitable solvents are benzyl alcohol, and diols such as 2-ethyl-1,3hexanediol and 2,2,4-trimethyl-1,3pentanediol. 10 Hydrotropes may be present and are typically present at levels of from 0.5% to 20%, preferably from 1% to 10%, by weight.

Useful hydrotropes include sodium, potassium, and ammonium xylene sulfonates, sodium, potassium, and ammonium toluene sulfonate, sodium potassium and ammonium cumene sulfonate, and mixtures thereof.

In a highly preferred aspect of the invention, the compositions have a pH as a 1% solution in distilled water at 200C of less than 7, preferably from 0.5 to 6.5, most preferably from 0.5 to 1.0.

C3895 Product Form The dish washing composition for use in the invention may be in any product form, however t is preferred if it granular.

Granular in the context of th4 present invention includes both powdered material and tallets.

The rinse aid is preferably a liquid.

Dishwash compositions accordijg to the present invention may be dosed in the wash liquor at levels of from 10 g/l to 2.5 g/l.

Rinse aid composition accordirig to the present invention may 15 be dosed in the final rinse l4quor at levels I g/l or 'Less.

The invention will now be illq 1 strated by the following non limiting Examples. Examples qf the invention are I illustrated by a number, compa,rative Examples are illustrated by a letter.

All percentages are on a weight basis.

C 3 8 9 S EXAMPLE I

Table 1

WT/% DW 1 DW2 Ga S4 1 200 TP' 0 3.0 L Na-citrate 2aq 39.4 40.0 Na-bicarbonate 0 25.7 Na-carbonate 5.5 Na-perborate 18.0 16.0 Enzyme 4.0 3.5 Sokalan PC 5251- 6.0 6.0 EHDP 1.0 1.5 Bleach catalyst 2.8 2.8 Perfume 0.2 0.2 Nonionic surfactant' 1.5 1.4 Na disilicate 21.7 0 1) maleic and acrylic acid copolymer MWT 50,000, acrylic acid polymer mwt 4,000.

2) Nonionic surfactant, ex BASF (LF 403) 3) Silica material with an average particle size d5O (by 10 Malvern Laser) of 7-11 mm, ex Crosfield

The compositions were tested in a robotised Miele G5953C (total water hardness 280FH, including temporary hardness of 180FH). 15 The comoositions were dosed at a level of 20 g/wash; the main wash time was 20 minutes; the drying time with open C3895 door was 10-20 minutes; the w4shing temperature was up to 65"C; washes were carried out by loading the machine with on- glaze decorated porcelain, glass, plates plus cutlery, stainless steel articles and plastics, Rinse aid was added to the rinse via the rinse and dispenser. The rinse aid had the following formulations. 10 TAB,E 2 wt% RA 3 RA 4 Nonionic LF400S 14.5 14.5 Sodium Xylene Sulphonate 5.0 5.0 Citric Acid 9.5 40 Water to 10c)-6 ex BASF is overall appearance overall appearance was measure by placing the tested articles on a black cloth under a reflected artificial daylight source (Kelvin temperature 2300'K); placed 2 met-res above the articles. A subjectlive scoring system on a 1-9 scale was used 1 as new --> 9 extremely popr.

C - 3 8 9 5- The overall appearance was a combination of white filming due to calcium salt deposits, spots, streaks and glass corrosion.

C38 95 27 - The results are given in table 3.

TABE 3 Core Glass Pastic Metal DW1 and RA4 9.0 1 6.6 8.5 DW2 and RA3 5.5 5.4 7.3 DW2 and RA4 4.0 4.9 4.2 Composition of Kit A kit according to the invention comprises twenty five 18g tablets of detergent composition formulated according to table 1, each tablet being flow;wrapped in a plastic wrapper.

C mls of rinse aid is providel in a bottle with a directing spout to enable the liquid be poured into a rinse aid reservoir accurately. An outer packaging for the tablets and bottle comprises a cardboard boc having an internal partition dividing the box into two compartments, a first for the wrapped tablets, and a pecond for the bottle.

The invention is not limited to the embodiments hereinbefore described which may be varied ir, construction and detail.

C3895 28 -

Claims (20)

1. A machine dishwashing kit comprising:

- an amount of packaged rinse aid composition sufficient to provide X number of rinse cycles:

- an amount of packaged detergent composition sufficient to provide X/Y number of washes, wherein X is greater than or equal to Y, X and Y are whole numbers, X/Y is equal to a whole number, and Y is between 1 and 3.

2. A kit as claimed in claim 1 in which Y is 1.

3.A kit as claimed in claims 1 or 2 wherein one or both of the rinse aid and detergent composition are formulated to create conditions within the machine during a washing/rinse cycle that obviate the need for a separate ion exchange regenerating salt.

4. A kit as claimed in any preceding claim in which the detergent composition comprises a plurality of unit doses such as tablets.

5. A kit as claimed in claim 4 in which each tablet prov--'-des sufficient detergent for a single wash cycle.

6. A kit as claimed in any of claims 1 to 3 in which the detergent composition is in a particulate form, wherein the kit further includes means for dispensing an accurate and consistent dose of the detergent composition.

C3895 - 29

7. A kit as claimed in claim 6 in which the dispensing means comprises a pourspout.

8. A kit as claimed in any precoding claim in which the rinse aid is a liquid.

9. A kit as claimed in any precpding claim in which the packaged detergent and rinse ai compositions are enclosed within a secondary pack.

10. A kit as claimed in any of ',laims 5, 7, 8 or 9 comprising a plurality of deter'ent tablets, each tablet packed in an individual pack su-,h as a flow wrap, and a liquid rinse aid composition in'a bottle, the kit further including a secondary pack having a first compartment for the wrapped tablets and a seconj compartment for the bottle of rinse aid.

11. A kit as claimed in any of qlai4ms 1 to 8 in which the detergent composition is packaged within a first receptacle, and the rinse aid is packaged w;'-Lhin a second receptacle, wherein the first and second reqeptacles engage in a retro fit manner. 25

12. A kit as claimed in claim 8 in which the receptacles engage in a tamper evident mannEIr.

13. A kit as claimed in either qf claims 1.1 or 12 in which the rinse aid receptacle engage$ a lid means of the detergent receptacle.

C -38 95 -

14. A kit as claimed in any preceding claim in which the detergent composition comprises greater than 20wt% of a bicarbonate salt and a silica or silicate material.

15. A kit as claimed in claim 14 wherein the detergent composition further comprises a polymer or copolymer of acrylic acid.

16. A kit as claimed in claims 14 or 15 in which a 1% aqueous solution of the detergent composition, at a temperature of 25oC, has a pH from 8.5 to 10.

17. A kit as claimed in any preceding claim in which the rinse aid comprises 20wt% or greater of a water soluble acid builder or salt thereof.

18. A kit as claimed in claim 17 in which the acid is a carboxy acid.

19. A kit as claimed in either of claims 17 or 18 in which the acid is citric acid.

20. A kit as claimed in any preceding claim including instructions concerning the dosage of rinse aid required per rinse cycle.