NL1016803C2 - Use of dishwashing compositions. - Google Patents

Abstract

A machine dishwashing tablet is used in a process for washing dishes in which no rinse aid and no salt is used in the machine. The tablet comprises greater than 45 wt% of a builder and has a distinct defined region (A) which is a maximum of 30 wt% of total weight of the tablet, the separate defined region (A) comprising a material that controls regions (A) dissolution in water.

Description

5

Use of dishwashing compositions.

Description Technical area

The present invention relates to the field of machine dishwashing. More particularly, the invention relates to a method of using automatic dishwashing tablets.

Background of the Invention Dishwashing items in a commercial dishwasher includes use of three types of products. Salt is added to the salt compartment to soften the water, a dishwashing formulation is used to clean the items and a rinse aid is used to ensure that the items are rinsed without streaks or stains.

Users find it difficult to replace the salt and rinse aid in a dishwasher. The present invention relates to a dishwashing method which makes the salt and rinse aid unnecessary in machine dishwashing.

Description of the invention

Accordingly, the present invention provides for the use of a machine dishwashing tablet in a dishwashing method in which no rinse aid and no salt are used in the machine, the tablet comprising more than 45% by weight of forming agent and a distinct defined range ( A) has a maximum of 35 wt% of the total weight of the tablet, the distinct defined area (A) comprising a material that controls the dissolution of the area (A) in water.

1016803 2

In addition, in the present application, a method for washing articles in a mechanical washing machine is defined, which method comprises the steps of: i) treating the articles with a washing liquid to which a tablet is added containing more than 45% by weight of forming agent and has a separately defined area that constitutes up to 30% by weight of the total weight of the tablet, the distinguished defined area comprising a material which retards its dissolution in water and no additional rinse aid and / or salt in the machine is present.

In the context of the present invention, the term "additional rinse aid or salt" refers to a separate rinse aid or salt product that is not part of the tablet.

The invention also relates to a kit of parts comprising a cleaning agent as described above, as well as instructions stating that no rinse aid or salt needs to be added to the dishwasher.

Detailed description of the invention Tablets according to the invention have two areas, the areas A and B.

Area A

As described above, the tablet comprises a defined region (A) which accounts for up to 30% by weight of the total weight of the tablet as well as a material that controls its dissolution in water. Preferably, a material is present which retards the dissolution of region A. For purposes of the invention, the remainder of the tablet will be referred to as region (B). The constituents of the defined area (A) will be delivered to the water in the machine after the constituents in the remainder of the tablet (B) Λ 015 8 01 3. In another aspect of the present invention, the defined region (A) preferably dissolves at a temperature above 50 ° C and preferably above 60 ° C.

The rest of the tablet (B) will begin to dissolve immediately on contact with water. Preferably for region (B), at least 60%, more preferably at least 80%, and most preferably at least 95% of region (B) dissolves in demineralized water at 50 ° C within 12 minutes. It is highly preferred that region A be solid.

Dissolution of region (A) can be delayed by the selection of particulate components encapsulated with a component that is slowly soluble in water or partially soluble. Such encapsulation materials include cellulose acetate phthalate (CAP), hydroxypropylmethyl-15 cellulose (HPMC), carboxymethyl cellulose (CMC) and mixtures thereof. A hydroxypropylmethylcellulose polymer preferably has a number average molecular weight of 50,000 to 200,000 and a viscosity of an aqueous solution of 2% by weight at 25 ° C (ADTMD2363) of 50,000 to 120,000 cps. A particularly preferred hydroxypropylmethylcellulose polymer is Methocel O J75MS-N with a viscosity of an aqueous solution of 2% by weight at 25 ° C of about 75,000 cps. Other preferred encapsulation materials include gelatin with a coating strength in the range of 30 to 200 and preferably 75 to 200.

The thickness of the encapsulating material will determine the rate of dissolution of the encapsulated detergent component and thus determine the rate of release of the detergent component to the wash water.

Another example of a way in which the dissolution of the subarea A can be delayed is the premixing of the cleaning agent constituents in a matrix which is slowly dissolved in water or is partially soluble.

Preferred polymers for this include polyethylene glycol with a molecular weight of 1000 to 20,000 and more preferably 1016803-4000 to 10,000 or even 12,000.

Yet another example of how the dissolution of region A can be controlled is to coat region A with a coating layer. The coating layer preferably comprises a material which solidifies in preferably less than 15 minutes, more preferably less than 10 minutes, even more preferably less than 5 minutes and most preferably less than 60 seconds upon contact with the region A. The coating layer is preferably water-soluble. Preferred coating layers 10 include materials selected from the group consisting of fatty acids, alcohols, diols, esters and ethers, adipic acid, carboxylic acids, dicarboxylic acids, polyvinyl acetate (PVA), polyvinyl pyrrolidone (PVP), polyacetic acid (PLA ), polyethylene glycol 15 (PEG) and mixtures thereof. Preferred carboxylic and dicarboxylic acids preferably include an even number of carbon atoms. Preferably, the carboxylic or dicarboxylic acids comprise at least 4, more preferably at least 6, even more preferably at least 8 carbon atoms, and most preferably 8 to 13 carbon atoms. Preferred dicarboxylic acids include adipic acid, suberic acid, azelaic acid, subacinic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid and mixtures thereof. Preference is given to those fatty acids which have a carbon chain length of C12 to C22 and most preferably C18 to C22. The coating layer may also preferably comprise a breaking agent.

Suitable coatings for area A are described in WO 00/06684, JP 61-28440, JP 60-141705, JP 61-28441, JP 61-28596, JP 61-28597 and JP 61-28598.

When present, the coating layer generally comprises a level of at least 0.05%, preferably at least 0.1%, more preferably at least 1%, and most preferably at least 2% or even at least% of the detergent tablet.

The coating can be used to bond area A to area B.

In yet another example, region A is such that it comprises at least one component that reacts with an external stimulus, such as temperature and pH, to start dissolution. An example of an ingredient that initiates dissolution in response to a temperature change is a wax. In particular, it is contemplated that a suitable wax will have a melting temperature above the room temperature, preferably above 40 ° C, more preferably above 50 ° C, and most preferably above 55 ° C.

It is preferable if region A is present in the tablet.

A region A useful for the present invention may further comprise a water-soluble acid-forming agent or salt, preferably organic acids including, for example, carboxylic acids, such as citric acid and succinic acid, polycarboxylic acids, such as polyacrylic acid, as well as acetic acid, boric acid, malonic acid, adipic acid, fumaric, lactic, glycolic, tartaric, tartronic, maleic, derivatives and mixtures thereof.

Suitable water-soluble monomeric or oligomeric carboxylate-forming agents can be selected from a wide range of compounds, but such compounds preferably have a logarithmic acid constant of the first carboxyl group (pKi) less than 9, preferably between 2 and 8, 5 and more preferably between 2.5 and 7.5.

The carboxylate or polycarboxylate forming agent can be of a monomer or oligomer type, although monomeric polycarboxylates are generally preferred for cost and performance. Monomeric and oligomeric forming agents can be selected from acyclic, alicyclic, heterocyclic and aromatic carboxylates.

Suitable carboxylates containing one carboxyl group include water-soluble salts of lactic acid, glycolic acid and ether derivatives thereof. Polycarboxylates containing two carboxyl groups include water-soluble salts of succinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid and fumaric acid, as well as ether carboxylates and sulfinyl carboxylates. Polycarboxylates containing three carboxyl groups include, in particular, water-soluble citrates, acetates and citraconates as well as succinate derivatives such as 5-carboxymethyl oxysuccinates, lactoxysuccinates and amino succinates, and also oxypolycarboxylates such as 20-oxa-1,3-propanantric. The above-described carboxylate or polycarboxylate-forming compounds may also have a dual function as pH control agents.

Polycarboxylates containing four carboxyl groups include oxydisuccinates, 1,1,2,2-ethane tetracarboxylates, 1,1,3,3-propane tetracarboxylates and 1,1,2,3-propane tetracarboxylates. Sulfo substituents containing polycarboxylates include sulfosuccinate derivatives as well as sulfone-containing pyrolysed citrates.

Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis, cis, cis-tetracarboxylates, cyclo-pentadienide pentacarboxylates, 2,3,4,5-tetrahydrofuran-cis, cis, cis-tetracarboxylates, 2,5-tetrahydrofuran-cis-dicaryl 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 described in British Patent No. 1,425,343.

Of the above, preferred polycarboxylates are hydroxycarboxylates containing up to three carboxyl groups per molecule, more particularly citrates and citric acid.

The stem 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 used as components of Stage A forming systems. according to the present invention.

35 An anti-tarnishing agent may be present in area A. Suitable anti-scaling agents are EDHP (hydroxyethyl-1,1-diphosphonate) and Bayhibit (2-phosphonobutane-1,2,4-1016803-7 tricarboxylic acid) and also suitable polymers such as Alcosperse 240 as in US 5,956,855 and US 5,547 .612 is described. Alternatively, polymers and copolymers of acrylic acid with a molecular weight between 500 and 20,000 can also be used. Anti-scale agents are present in levels such that 1-100 ppm is released with a 5 liter flush.

Preferably, in region A there is a surfactant system comprising a surfactant selected from nonionic, anionic, cationic, ampholytic and zwitterionic surfactants as well as mixtures thereof.

Most preferably, the surfactant system comprises a low foaming non-ionic surfactant selected for the wetting ability and is preferably selected from ethoxy groups and / or propoxy groups containing nonionic surfactants and with more preferred is selected from nonionic ethoxy / propoxy fatty alcohols as surfactants.

The surfactant system is usually present in region A at a minimum level of 0.05 g, and more preferably at a minimum level of 0.1 g. The maximum preferred level is preferably 0.8 g or less, more preferably 0.6 g or less. The most preferred level is 0.2 g to 0.4 g. It is most preferred that the level of surfactant, especially non-ionic surfactant, is 25 wt% to 75 wt% relative to the total weight of the non-ionic surfactant in the tablet.

Hydrotropic agents may be present, usually present at levels from 0.5 wt% to. 20 wt% and preferably 1 wt% to 10 wt%.

Useful hydrotropic agents include sodium, potassium and ammonium xylene sulfonates, sodium, potassium and ammonium toluenesulfonate, sodium, potassium and ammonium cumene sulfonate as well as mixtures thereof.

In a very preferred aspect of the invention, region A will have a pH as 1% solution in distilled water at 20 ° C less than 7, preferably 0.5 to 6.5, and most preferably 0.5 to 1 , Have 0.

Area B

Forming material

A composition according to the invention can contain a forming agent. The forming agent can be a phosphate or non-phosphate containing agent.

Compositions of the invention comprising a water-soluble phosphate-forming agent usually contain this forming agent at a level of 50 to 90% by weight, and preferably 55 to 80% by weight.

Phosphate-forming agents are particularly preferred. Specific examples of water-soluble phosphate-forming agents are alkali metal tripolyphosphates, sodium, potassium and ammonium pyrophosphate, sodium, potassium and ammonium orthophosphate, sodium polymeta / phosphate with the degree of polymerization ranging from 6 to 21, and salts of phytic acid. Most preferred is sodium or potassium tripolyphosphate.

Compositions according to the invention can comprise a water-soluble non-phosphate-forming agent. This is usually present at a level of 1 to 90% by weight, preferably 10 to 80% by weight and most preferably 20 to 70% by weight relative to the weight of the composition. Suitable examples of non-phosphorus-containing inorganic forming agents include water-soluble alkali metal carbonates, hydrogen carbonates, sesquicarbonates, borates, silicates including layered silicates such as SKS-6, e.g. Clarent, metasilicates and crystalline and amorphous alumino silicates. Specific examples include sodium carbonate (with or without calcite seed), potassium carbonate, sodium and potassium hydrogen carbonate, silicates including layered silicates and zeolites.

1 016 8 0 3 9

Organic detergent-forming agents can also be used as non-phosphate-containing forming agents of the present invention. Examples of organic forming agents include alkali metal citrates, 5-succinates, malonates, fatty acid sulfonates, fatty acid carboxylates, nitrilotriacetates, oxydisuccinates, alkyl and alkenyl disuccinates, oxydiacetates, carboxymethyl-oxysuccinates, acetyl-oxysuccinates tartrate monosuccinates, tartrate disuccinates, tartrate monoacetates, tartrate diacetates, oxidized starch, oxidized heteropolymeric polysaccharides, polyhydroxysulfonates such as polyacrylate / polyacrylate / polyacrylate / polyacrylates, polyhydric acrylates, polyhydric acrylates polymethacrylate copolymers, acrylate / maleate / vinyl alcohol terpolymers, aminopolycarboxylates and polyacetal carboxylates, as well as polyaspartates and mixtures thereof. Such carboxylates are described in U.S. Pat. Nos. 4,144,226, 4,146,495 and 4,686,062. Alkali language citrates, nitrilotriacetates, oxydisuccinates, acrylate / maleate copolymers, and acrylate / maleate / vinyl alcohol tert polymers are particularly preferred nonphosphate-forming agents.

Silicon oxide material Suitable forms of silicon oxide include amorphous silicon oxide, such as precipitated silica, pyrogenic silica and silica gels, such as -hydrogels, xerogels and aerogels, or the pure crystal forms of quartz, tridymite and cryobalite, but the amorphous forms of silicon oxide are preferred. Suitable silicon oxides are readily available commercially. For example, they are sold under the registered trade name Gasil 200 (e.g. Crosfield, GB).

Preferably, the silicon oxide in the product is present in such a form that it can dissolve when added to the washing liquid. Therefore, the addition of silicon oxide as the addition of anti-foam 1016803 silicon oxide particles and silicone oil is not preferred.

The particle size of the silica material of the present invention may be of interest, especially since it is believed that any silica material that remains undissolved in the washing procedure can deposit on the glass at a later stage.

Therefore, it is preferred that a silicon oxide material be used with a particle size (as determined by a Malvern laser, ie, the "aggregated" particle size) of up to 40 µm and most preferably up to 20 µm, with better washing results are obtained. In view of addition to a cleaning composition, it is preferred that the particle size of the silica material is at least 1 µm, more preferably at least 2 µm, and most preferably at least 5 µm.

Preferably, the primary particle size of the silicon oxide is generally less than about 30 nm and in particular less than about 25 nm. Preferably, the elementary particle size is less than 20 nm or even 10 nm. There is no critical lower limit for the elementary particle size: the lower limit is determined by other factors such as the method of preparation, etc. Generally, commercially available silicon oxides have an elementary particle size of 1 nm or more.

Preferably, the silica material is present in the washing liquid at a level of at least 2.5x10-4 wt%, more preferably at least 12.5x10 4 wt%, and most preferably at least 2.5x10 4 wt%. 3% by weight relative to the weight of the washing liquid and preferably maximum 1x10-1% by weight, more preferably maximum 8x10-10% by weight and most preferably maximum 5x10-10% by weight the weight of the washing liquid.

Preferably, the level of dissolved silica-material in the washing liquid is at least 80 ppm, more preferably at least 100 ppm, and most preferably at least 120 ppm, and preferably at most 1000 ppm. It is noted that in order for the silica material to be effective, the lowest level of the dissolved silica material depends on the pH value, ie that at pH = 6.5 the level is preferably at least 100 ppm, at pH = 7 , 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 and at pH = 10 Is preferably at least 400 ppm.

Preferably, the silicon oxide material in the cleaning composition is present at a level of at least 0.1 wt%, more preferably at least 0.5 wt%, and most preferably at least 1 wt%, relative to the weight of the cleaning composition and preferably a maximum of 10% by weight, more preferably a maximum of 8% by weight and most preferably a maximum of 5% by weight, relative to the weight of the cleaning composition.

Silicates The composition optionally includes alkali metal silicates. The alkali metal can provide a pH adjusting ability, protection against corrosion of metals and deterioration of the dishes, including benefits for porcelain and glassware. When silicates are present, the SiC> 2 content should be 1 wt% to 25 wt%, preferably 2 wt% to 20 wt%, and more preferably 3 wt% to 10 wt% based on the weight of the ADD. The ratio of S1O2 to the alkali metal oxide (M20, where M = alkali metal) is usually 1: 3.5, preferably 1.6: 3, and more preferably 2: 2.8. Preferably, the alkali metal silicate is water-containing, from 15% to 25%, and more preferably 17% to 20%, water.

Generally, highly alkaline alkali metal silicates can be used, although less alkaline aqueous alkali metal silicates with an SiO 2 / M 2 O ratio of 2.0 to 2.4 as mentioned are particularly preferred. Anhydrous forms of alkali metal silicates with an SiO 2 / M 2 O ratio of 2.0 or more are also less preferred because they tend to be considerably less soluble than aqueous alkali metal silicates at the same ratio.

Sodium and potassium and in particular sodium silicates are preferred. A particularly preferred alkali metal silicate is a granular hydrous sodium silicate with a SiC> 2 / Na 2 O ratio of 2.0 to 2.4, which is available from PQ under the name of Britesil H20 and Britesil H24. Most preferred is a granular aqueous sodium silicate with an SiO 2 / Na 2 O ratio of 2.0. While conventional forms, ie, powder and granules, of hydrous silicate particles are suitable, preferred silicate particles have an average particle size between 300 and 900 µm and are less than 40% less than 150 µm and less than 5% larger than 1700 µm . Particular preference is given to a silicate particle with an average particle size between 400 and 700 µm and is less than 20% less than 150 µm and less than 20% larger than 1700 µm. Preferably, compositions of the present invention having a pH of 9 or less will essentially contain no alkali metal silicate.

Enzymes Enzymes may be present in compositions of the invention. Examples of enzymes suitable for use in cleaning compositions of the present invention include lipases, peptidases, amylases (amilolytic enzymes) and other enzymes that break down, modify or degrade biochemical contaminants and stains found in cleaning situations or facilitate modification so that the contaminants and stains are more easily removed from the object being washed and the contaminants and stains are more easily removed in a subsequent cleaning step. The removal of contamination can be improved by both degradation and modification.

Well-known and preferred examples of these enzymes are lipases, amylases and proteases. The most commonly used enzymes in dishwasher compositions are amylolytic enzymes. Preferably, a composition according to the invention also contains a proteolytic enzyme.

The enzymes can be present in an amount in weight percent from 0.2 to 7 weight percent. For amylolytic enzymes, the final composition will have an amylolytic activity of 102 to 106 maltose units / kg. For proteolytic enzymes, the final composition will have a proteolytic enzyme activity of 106 to 109 glycine units / kg.

Bleaching Material Optionally and preferably bleaching materials can be added to a composition for use in methods of the present invention. These materials can be added in the solid form or in the form of encapsulated materials and less preferably in dissolved form.

The bleaching material can be a chlorine or bromine releasing agent or a peroxygen compound. However, bleaching materials based on peroxygen compounds are preferred.

Organic peroxyacids or precursor products thereof are usually used as the bleaching material. Peroxyacids useful in the present invention are solid and preferably substantially water-insoluble compounds. By "preferably substantially water-insoluble" in the present specification is meant water solubility of less than about 1% by weight at ambient temperature. In general, at least 7 carbon atoms containing peroxyacids are sufficiently insoluble in water for use in the present invention.

Also, conventional inorganic peroxygen-forming compounds are used as the bleaching material of the present invention. Examples of these materials are 101680314 monopersulfate, perborate monohydrate, perborate tetrahydrate and percarbonate salts.

Monoperoxy acids useful in the present invention include alkyl peroxyacids and arylperoxyacids such as peroxybenzoic acid and ring-substituted peroxybenzoic acids (eg peroxy-a-naphthoic acid), aliphatic and substituted aliphatic monoperoxy acids (eg peroxylauric acid and peroxystearic acid) (as well as phthaloyloic acid) ).

Common diperoxy acids useful in the present invention include alkyl diperoxy acids and aryldiperoxy acids, such as 1,12-diperoxydodecanedioic acid (DPDA), 1,9-diperoxyazelaic acid, diperoxybrassylineic acid, diperoxysebicic acid and diperoxyisophthalic acid, as well as 2-decyldiperoxybutan-15-tane-15-tane-15 diacid.

Peroxyacid bleach precursor products are well known in the art. As non-limiting examples, N, N, N ', N'-tetraacetylethylenediamine (TAED), sodium nonanoyloxybenzene sulfonate (SNOBS), sodium benzoyloxybenzene sulfonate (SBOBS) and the one described in US-A-4,751,015 cationic peroxyacid precursor product (SPCC).

If desired, a bleaching catalyst such as the manganese complex, e.g. Mn-Me TACN, which is described in EP-A-0.458.397 whether the sulfonimines according to US-A-5.041.232 and US-A-5.047.163 should be added, this can be added in the form of a second encapsulated material separately from the bleach capsule or granule. Cobalt catalysts can also be used.

Among the suitable reactive oxidation materials based on chlorine or bromine are heterocyclic N-bromine and N-chlorimides such as trichloroisocyanuric acid, tribromoisocyanuric acid, dibromoisocyanuric acid and dichloroisocyanuric acid as well as salts thereof with cations dissolving these compounds in water, such as potassium and sodium cations.

Hydantoin compounds such as 1,3-dichloro-5,5-dimethylhydantoin are also very suitable.

10 75 S 03 15

Also suitable for use in the present invention are particulate, water-soluble anhydrous inorganic salts such as lithium, sodium and calcium hypochlorite and hypobromite. Also suitable bleaching materials are chlorine-containing trisodium phosphate and chloroisocyanurates.

Encapsulation techniques are known for both peroxygen and chlorine bleaches, eg, as described in US-A-4,126,573, US-A-4,327,151, US-A-3,983,254, US-A-10 4,279,764, US -A-3.036.013, EP-A-0.436.971 and EP-A-0.510.761.

Encapsulation techniques, however, are particularly applicable when using halogen-based bleach systems.

Compositions of the invention may comprise from about 0.5% to about 3% avCl (available chlorine) of chlorine bleaches. For peroxygen bleaches, a suitable range is also 0.5% to 3% avO (available oxygen). Preferably the amount of bleaching material in the washing liquid is at least 12.5 x 10-4% and at most 0.03 wt% avO relative to the liquid.

Surfactant material

Preferably present in the composition is a surfactant system comprising a surfactant selected from nonionic, anionic, cationic, ampholytic and zwitterionic surfactants as well as mixtures thereof.

Usually the surfactant is a low to non-foaming non-ionic surfactant comprising a nonionic alkoxy surfactant in which the alkoxy unit is selected from the group consisting of ethylene oxide, propylene oxide and mixtures thereof and the surfactant is preferably used to improve cleaning performance without excessive foaming.

Examples of suitable nonionic surfactants for use in the invention are low 1016803 16 to straight chain non-foaming ethoxy alcohols of the Plurafac® LF series sold by BSF, those of the Synperonic RA series, manufactured by ICI and those from the Triton® DF series, which are sold by 5 Rohm & Haas.

Other surfactants such as anionic surfactants can be used but may require the additional presence of an anti-foaming agent to suppress foaming. When an anionic surfactant is used, it is advantageously present at a level of 2 wt% or less.

Water-soluble polymeric polycarboxyl compounds. A water-soluble polymeric polycarboxyl compound is advantageously present in the dishwashing composition. Preferably these compounds are homo- or copolymers of polycarboxyl compounds, especially copolymeric compounds in which the acid monomer comprises two or more carboxyl groups separated by no more than two carbon atoms. Salts of these substances can also be used.

Particularly preferred polymeric polycarboxylates are copolymers derived from monomers of acrylic acids and maleic acid. The average molecular weight of these polymers in the acid form is preferably in the range of 4,000 to 70,000.

Another type of polymeric polycarboxyl compounds suitable for use in a composition according to the invention are homopolymeric polycarboxylic compounds with acrylic acid as the monomer unit. The average molecular weight of such homopolymers in the acid form is preferably in the range of from 1000 to 100,000 and in particular from 3,000 to 10,000.

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

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

5 Chelating agent

A chelating agent may be present in the composition. If present, it is preferable that the level of the chelating agent is 0.5 to 3% by weight relative to the total weight of the composition.

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

Particularly preferred chelating agents are organic phosphonates such as α-hydroxy-2-phenylethyl diphosphonate, ethylene diphosphonate, hydroxy-1,1-hexylidene-vinylidene-1,1-diphosphonate, 1,2-dihydroxyethane-1,1-diphosphonate and hydroxyethylene-1,1-diphosphonate. Most preferred are hydroxyethylene-1,1-diphosphonate and 2-phosphonobutane-1,2,4-tricarboxylic acid.

20

Anti-shine agents

Also, gloss loss agents such as benzotrizole and the agents described in EP 723,577 (Unilever) can be added.

Optional components

Optional components are, for example, buffering agents, reducing agents, e.g. borates, alkali metal hydroxide and the well-known enzyme stabilizers such as polyalcohols, e.g. glycerol and borax; anti-scale agents, crystal growth inhibitors, threshold agents, thickeners, fragrances and dyes and the like.

For example, reducing agents can be used to prevent the appearance of an enzyme-deactivating concentration of an oxidative bleaching compound. Suitable agents include reductive sulfur oxyacids and 18 salts thereof. Due to its availability, low cost and high performance, alkali metal and ammonium salts enjoy sulfur oxyacids including ammonium sulfite ((NH4) 2S03), sodium sulfite (Na2SC> 3), sodium hydrogen sulfite 5 (NaHSCb), sodium metabisulfite (Na2S205), potassium metabisulfite ( K2S205), lithium hydrosulfite (Li2S204), etc., with sodium sulfite being particularly preferred. Another useful reducing agent is ascorbic acid, although it is not particularly preferred because of the cost. The amount of reducing agents to be used may vary from case to case depending on the type of bleach and the form it has, but usually will range from about 0.01 wt% to about 1.0 wt% and preferably about 0.02 wt% to about 0.5 wt% are sufficient.

15 pH of the washing liquid

The invention relates to methods for washing in mechanical dishwashers in which the washing liquid has a low pH. By "low pH" in the present description is meant that the pH of the washing liquid is preferably higher than about 6.5, more preferably 7.5 or higher and most preferably 8.5 or higher. Preferably, the pH is less than about 11, more preferably less than about 10, more preferably less than about 9.5. The most advantageous pH range is 8.5 to 10.5.

Temperature of the washing process

The present invention preferably relates to methods for mechanical washing of dirty articles with a washing liquid at a temperature below 55 ° C.

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

All percentages (wt%) are based on weight.

1016803 19

Product 1 parts by weight

Area A

Citric Acid 5 15% Nonionic LF 400 S v. BSAF 2,2 ^ EHDP or Bayhibit AM 1

Hydrocarbon wax - mp. 58 ° C 6.8

Area B

Sodium tripolyphosphate 55.54

Sodium Disilicate 10.41 - Sokalan PA 25CL (Low Molecular Weight 3.1 Polyacrylate) 85% TAED 2.4 EHDP or Bayhibit AM 0.4 15 Sodium Perborate 9

Nonionic LF 403 v. BASF 1

Enzymes (Savinade / Amylase 1: 1 - 3.1 wt. Mixture) BTA (Benzotriazole) 0.05 20 Test Regimen Product 1 above (Area A & B) in a total dose of 25 g.

No additional salt or rinse aid added to the machine.

Product 2 area B is 21.25 g + 3 ml separate rinse aid, regenerated ion exchanger.

Product 3: Reference product using a regenerated ion exchanger and standard products (a Sun tablet and rinse aid as sold in France).

1016803 f 20

Dishwasher: Miele G685 55 ° universal program, 10 consecutive washes. Stain and film formation subjectively determined after 10 washes. Low results are the best.

5

Film formation Spot formation

Results: Product 1 2 2.1

Product 2 1.8 2.3

Product 3 1.9 2.4 10 No significant differences were found.

Product 4 parts by weight

15 Area A

Citric acid 5 15% Non-ionic LF 400 S v. BSAF 2.2 EHDP or Bayhibit AM 0.2 PEG 6000 5.6 20 Acumer 3100 v. Rohm & Haas 1.0

Upholstery * 1.0

Area B

Sodium tripolyphosphate 55.54

Sodium Disilicate 10.41 25 Sokalan PA 25CL (Low Molecular Weight 3.1 Polyacrylate) 85% TAED 2.4 EHDP or Bayhibit AM 0.4 1016803 * 1 21

Sodium perborate 9

Nonionic LF 403 v. BASF 1

Enzymes (Savinade / Amylase 1: 1 - 3.1 wt. Mixture) 5 BTA (Benzotriazole) 0.05

The coating is sprayed on area A. This includes a 2: 1 ratio of polymer AEA (v. Sankyo) and Mawiol 5088 (v. Clariant) 10 Test Regimen Product 4 above (area A & B) in a total dose of 25 g. No additional salt or rinse aid added to the machine.

Product 5 area B only at 21.25 g + 3 ml separate flushing aid (Sun from France), regenerated ion-15 exchanger.

Product 6: reference product using a regenerated ion exchanger and standard products (a Sun tablet and rinse aid from France).

Dishwasher: Miele G685 55 ° universal program, 10 to 20 consecutive washes. Stain and film formation determined subjectively after 10 washes. Low results are the best.

Film formation Spot formation 25 Results: Product 4 2 2.3

Product 5 1.8 2.3

Product 6 1.9 2.4

No significant differences were found.

1016803

Claims (10)

1. Use of a tablet for dishwashing in a dishwashing method in which no rinse aid and no salt are used in the machine, the tablet containing more than 45% by weight of forming agent and having a separately defined area (A) having a maximum of 30 wt% of the total weight of the tablet, wherein the distinct defined area (A) contains a material that controls the dissolution of the area (A) in water. Use according to claim 1, wherein the area A of the tablet contains a material which retards the dissolution of area A in water. 15 The use according to claim 1 or 2, wherein the tablet contains more than 50% by weight of forming agent. Use according to any of the preceding claims, wherein the forming agent is based on phosphate. Use according to any of the preceding claims, wherein the separately defined region (A) further comprises a non-ionic surfactant. 25 6. Use according to any of the preceding claims, wherein the level of the non-ionic surfactant in the separately defined region (A) is 25 wt% to 75 wt% of the total weight of the non-ionic surface active agent in the tablet. Use according to any one of the preceding claims, wherein the area A additionally contains an anti-scale agent. 35 Use according to any of the preceding claims, wherein the separately defined region (A) is contained in the tablet. 9. Method for washing items in a mechanical dishwashing machine, the method comprising the steps of: i) treating the items with a washing liquid to which a tablet has been added containing more than 45% by weight of forming agent and a different defined area having a maximum of 30% by weight of the total weight of the tablet, the distinct defined area containing a material that retards its dissolution in water and no additional rinse aid and salt are present in the machine. 15 A kit of parts containing (i) a detergent tablet according to claim 1 and (ii) instructions stating that no rinse aid or salt needs to be added to the dishwasher. 1016803