EP1190029A1 - Dish washing process and compositions relating thereto - Google Patents

Dish washing process and compositions relating thereto

Info

Publication number
EP1190029A1
EP1190029A1 EP00925289A EP00925289A EP1190029A1 EP 1190029 A1 EP1190029 A1 EP 1190029A1 EP 00925289 A EP00925289 A EP 00925289A EP 00925289 A EP00925289 A EP 00925289A EP 1190029 A1 EP1190029 A1 EP 1190029A1
Authority
EP
European Patent Office
Prior art keywords
acid
builder
composition
salt
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00925289A
Other languages
German (de)
French (fr)
Inventor
Alan Digby Unilever Res. Vlaardingen Tomlinson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Unilever PLC
Unilever NV
Original Assignee
Unilever PLC
Unilever NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Unilever PLC, Unilever NV filed Critical Unilever PLC
Priority to EP00925289A priority Critical patent/EP1190029A1/en
Publication of EP1190029A1 publication Critical patent/EP1190029A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
    • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
    • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
    • C11D17/0047—Detergents in the form of bars or tablets
    • C11D17/0065—Solid detergents containing builders
    • C11D17/0073—Tablets
    • C11D17/0091—Dishwashing tablets
    • C—CHEMISTRY; METALLURGY
    • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
    • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
    • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
    • C11D3/02—Inorganic compounds ; Elemental compounds
    • C11D3/04—Water-soluble compounds
    • C11D3/06—Phosphates, including polyphosphates
    • C—CHEMISTRY; METALLURGY
    • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
    • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
    • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
    • C11D3/16—Organic compounds
    • C11D3/20—Organic compounds containing oxygen
    • C11D3/2075—Carboxylic acids-salts thereof
    • C11D3/2086—Hydroxy carboxylic acids-salts thereof
    • C11D2111/14—

Definitions

  • the present invention is in the field of machine dishwashing. More specifically, the invention encompasses automatic dishwashing detergents and rinse aids and a process for using them.
  • To wash articles in a commercially available dish washing machine entails using three product types. Salt is added to the salt compartment to soften the water, a dish-washing formulation is used to clean the articles and a rinse aid is used to ensure that the articles are rinsed with no streaks or smears .
  • the salt in the machine does not have to be replaced every wash, however it is inconvenient for consumers replace the salt .
  • the present invention relates to a process of washing dishes that obviates the need for salt in a machine dish-washing formulation. Description of the Invention
  • the present invention provides a process for washing articles m a mechanical washing machine comprising the steps of: (I) treating the articles with a wash liquor comprising a dishwashing composition, when un-diluted said composition comprising 55 wt % or greater of an inorganic poly-valent builder (n) followed by treating the article with a rinsing solution comprising a rmse aid, the rmse aid when undiluted comprising at least 20 wt . % of a water soluble builder or salt thereof; (in) wherein no salt is added to the machine .
  • the detergency builder salt for use with the present invention is a poly-valent inorganic builder.
  • the builder is water-soluble.
  • suitable, inorganic builder salts include the alkali metal, phosphates, polyphosphates, and tripolyphosphates. Specific examples of such salts include the sodium and potassium, tripolyphosphates, orthophosphates and hexametaphosphates .
  • Sodium tripolyphosphate is particularly preferred as a builder.
  • the level of inorganic builder is 55 wt. % or greater. Most preferably the level of builder is from 58 wt.% to 65 wt.%.
  • Particularly suitable for use with the invention is sodium tripolyphosphate, which can be converted to the phase I form by heating to above the transition temperature, at which phase II anhydrous sodium polyphosphate is transformed into the phase I form.
  • a process for the manufacture of particles containing a high proportion of the phase I form of sodium tripolyphosphate by spray drying below 420 °C is given in US-A-4536377. Suitable material is commercially available. Suppliers include Rhodia, Courbevoie, France and Albright & Wilson, Warley, West Midlands, UK.
  • the sodium tripolyphosphate should be partially hydrated, but the phase I anhydrous form should also be present.
  • the sodium tripolyphosphate in the particles may incorporate up to 5% (by weight of the sodium tripolyphosphate in these particles) of water of hydration.
  • the extent of hydration is desirably from 1% to 4% or 5% by weight. This degree of hydration in general means that the sodium tripolyphosphate is partially hydrated.
  • the sodium tripolyphosphate in these particles is preferably hydrated by a process, which leads to a homogeneous distribution of the water of hydration within the tripolyphosphate. This can be accomplished by exposing anhydrous sodium tripolyphosphate to steam or moist air.
  • the particles preferably consist solely of sodium tripolyphosphate with a high content of the phase I form.
  • the phase I content of the sodium tripolyphosphate being measured by X-ray diffraction, or IR.
  • the particles preferably contain sodium tripolyphosphate in a porous form so as to have high surface area.
  • a blowing agent that is a compound such as ammonium carbonate which decomposes to yield a gas during the course of the spray drying. This gives the dried material a porous structure, with higher surface area than hollow beads of tripolyphosphate obtained without blowing agent .
  • the bulk density of the of sodium tripolyphosphate particles is preferably 0.75 Kg/M 3 or less, more preferably from 0.52 to 0.72 Kg/M 3 .
  • the particles which contain or consist of sodium tripolyphosphate preferably have a small mean particle size, such as not over 300 ⁇ m, better not over 250 ⁇ m. Small particle size can if necessary be achieved by grinding.
  • Rhodiaphos HPA 3.5 is a grade of sodium tripolyphosphate from Rhodia which has been found to be particularly suitable. It consists of porous particles of small particle size (mean size below 250 ⁇ m) with 70% phase I and prehydrated with 3.5% water of hydration. Preferably the said particles containing sodium tripolyphosphate with more than 50% of phase I material provide this phase I tripolyphosphate as at least 3% by weight of the tablet or region thereof . More preferably they provide sodium tripolyphosphate, including the phase I tripolyphosphate, in a quantity which is from 30% up to 40% or 60% by weight of the tablet or region thereof.
  • the detergency builder system may additionally comprise a bicarbonate salt, preferably sodium or potassium bicarbonate most especially sodium bicarbonate.
  • Bicarbonate salts are particularly preferred as builders as they also have a buffering capacity.
  • the builder may further comprise a carboxylate or polycarboxylate builder containing from one to four carboxy groups, particularly selected from monomeric polycarboxylates or their acid forms, homo or copolymeric polycarboxylic acids or there salts in which the polycarboxylate comprises at least two carboxylic radicals selected from each other by not more than two carbon atoms .
  • Preferred carboxylates include the polycarboxylate materials described in US-A-2 , 264 , 103 , including the water-soluble alkali metal salts of mellitic acid and citric acid, dipicolinic acid, oxydisuccinic acid and alkenyl succinates .
  • polycarboxylate polymers and copolymers such as are described in US-A-3 , 308 , 067 are also be suitable for use with the invention.
  • the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecule, especially citric acid or its salt, particularly sodium citrate.
  • detergency builders organic alkaline compounds such as water-soluble amino polyacetates, e.g. sodium and potassium ethylenediamine tetraacetates, nitrilotriacetates and N- (2-hydroxyethyl) nitrilodiacetates ; water-soluble salts of phytic acid, e.g. sodium and potassium phytates; water-soluble polyphosphonates , including sodium, potassium and lithium salts of ethane- 1- hydroxy-1 , 1-diphosphonic acid; sodium, potassium and lithium salts of methylenediphosphonic acid and the like.
  • water-soluble amino polyacetates e.g. sodium and potassium ethylenediamine tetraacetates, nitrilotriacetates and N- (2-hydroxyethyl) nitrilodiacetates
  • water-soluble salts of phytic acid e.g. sodium and potassium phytates
  • water-soluble polyphosphonates including sodium, potassium and lithium salts of
  • 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) .
  • 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 ⁇ m, more preferably at most 30 ⁇ m, most preferably at most 20 ⁇ m provides better results in the wash.
  • the particle size of the silica material is at least l ⁇ m, more preferably at least 2 ⁇ m, most preferably at least 5 ⁇ m.
  • the primarily particle size of the silica is in general less than about 30nm, in particular less than about 25nm.
  • elementary particles sizes are less than 20nm or even lOnm. There is no critical lower limit of the elementary particle size; the lower limit is governed by other factors such as the manner of manufacture, etc. In general commercial available silicas have elementary particle sizes of 1 nm or more.
  • the silica material is present in the wash liquor at a level of at least 2.5xl0 ⁇ 4 %, more preferably at least 12.5xl0 "4 %, most preferably at least 2.5xl0 "3 % by weight of the wash liquor and preferably at most lxl0 _1 %, more preferably at most 8xl0 "2 %, most preferably at most 5xl0 "2 % by weight of the wash liquor.
  • the level of dissolved silica material in the wash liquor is at least 80-ppm, more preferably at least 100 ppm, most preferably at least 120 ppm and preferably at most 1,000 ppm.
  • 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.
  • 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 cleaning composition and preferably at most 10%, more preferably at most 8%, most preferably at most 5% by weight of the cleaning composition.
  • 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.
  • the Si0 2 level should be from 1% to 25%, preferably from 2% to 20%, more preferably from 3% to 10%, based on the weight of the ADD.
  • 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 Si0 2 :M 2 0 ratio of from 2.0 to 2.4 are, as noted, greatly preferred.
  • Anhydrous forms of the alkali metal silicates with a Si0 2 :M 2 0 ratio of 2.0 or more are also less preferred because they tend to be signi icantly less soluble than the hydrous alkali metal silicates having the same ratio .
  • a particularly preferred alkali metal silicate is a granular hydrous sodium silicate having a Si0 2 :Na0 ratio of from 2.0 to 2.4 available from PQ Corporation, named Britesil H20 and Britesil H24. Most preferred is a granular hydrous sodium silicate having a Si0 2 :Na 2 0 ratio of 2.0. While typical forms, i.e. powder and granular, of hydrous silicate particles are suitable, preferred silicate particles having a mean particle size between 300 and 900 microns and less than 40% smaller than 150 microns and less than 5% larger than 1700 microns.
  • compositions of the present invention having a pH of 9 or less preferably will be substantially free of alkali metal silicate.
  • Enzymes may be present in the compositions of the invention.
  • Examples of enzymes suitable for use in the cleaning compositions of this invention include lipases, peptidases, amylases (amylolytic enzymes) and others which degrade, alter or facilitate the degradation or alteration of biochemical soils and stains encountered in cleansing situations so as to remove more easily the soil or stain from the object being washed to make the soil or stain more removable in a subsequent cleansing step. Both degradation and alteration can improve soil removal.
  • the enzymes most commonly used in machine dishwashing compositions are amylolytic enzymes.
  • the composition of the invention also contains a proteolytic enzyme. Enzymes may be present in a weight percentage amount of from 0.2 to 5% by weight.
  • amylolytic enzymes the final composition will have amylolytic activity of from 10 2 to 10 6 Maltose units/kg.
  • proteolytic enzymes the final composition will have proteolytic enzyme activity of from 10 6 to 10 9 Glycine Units/kg .
  • 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.
  • peroxyacids usable in the present invention are solid and, preferably, substantially water- insoluble compounds.
  • substantially water-insoluble is meant herein a water-solubility of less than about 1% by weight at ambient temperature.
  • 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.
  • these materials are salts of onopersulphate, perborate monohydrate, perborate tetrahydrate, and percarbonate .
  • Monoperoxy acids useful herein include alkyl peroxy acids and aryl peroxyacids such as peroxybenzoic acid and ring-substituted peroxybenzoic acids (e.g. peroxy-alpha- naphthoic acid) ; aliphatic and substituted aliphatic monoperoxy acids (e.g. peroxylauric acid and peroxystearic acid) ,- and phthaloyl amido peroxy caproic acid (PAP) .
  • alkyl peroxy acids and aryl peroxyacids such as peroxybenzoic acid and ring-substituted peroxybenzoic acids (e.g. peroxy-alpha- naphthoic acid) ; aliphatic and substituted aliphatic monoperoxy acids (e.g. peroxylauric acid and peroxystearic acid) ,- and phthaloyl amido peroxy caproic acid (PAP) .
  • PAP phthaloyl amido peroxy ca
  • diperoxy acids useful herein include alkyl diperoxy acids and aryldiperoxy acids, such as 1 , 12 -di-peroxy- dodecanedioic acid (DPDA) ; 1 , 9-diperoxyazelaic acid, diperoxybrassylic acid, diperoxysebacic acid and diperoxy- isophthalic acid; and 2-decyldiperoxybutane-l , 4-dioic acid.
  • DPDA dodecanedioic 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) , sodium nonanoyloxybenzene sulphonate (SNOBS) , sodium benzoyloxybenzene sulphonate (SBOBS) and the cationic peroxyacid precursor (SPCC) as described in US-A-4 , 751 , 015.
  • TAED sodium nonanoyloxybenzene sulphonate
  • SBOBS sodium benzoyloxybenzene sulphonate
  • SPCC cationic peroxyacid precursor
  • 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 , this may be presented in the form of a second encapsulate separately from the bleach capsule or granule. Cobalt catalysts can also be used.
  • suitable reactive chlorine- or bromine-oxidizing materials are heterocyclic N-bromo and N-chloro imides such as trichloroisocyanuric, tribromoisocyanuric, dibromoisocyanuric and dichloroisocyanuric acids, and salts thereof with water-solubilizing cations such as potassium and sodium.
  • Hydantoin compounds such as 1 , 3-dichloro-5 , 5- dimethyl -hydantoin are also quite suitable.
  • 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 bleaching materials.
  • Encapsulation techniques are known for both peroxygen and chlorine bleaches, e.g. as described in US-A-4 , 126 , 573 , US- A-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.
  • encapsulation techniques are particularly useful when using halogen based bleaching systems .
  • compositions of the invention may comprise from about 0.5% to about 3% avCl (available
  • a suitable range are also from 0.5% to 3% avO (available Oxygen) .
  • the amount of bleach material in the wash liquor is at least 12.5xl0 ⁇ 4 % and at most 0.03% avO by weight of the liquor.
  • a surfactant system comprising a surfactant selected from nonionic, anionic, cationic, ampholytic and zwitterionic surfactants and mixtures thereof is preferably present in the composition.
  • 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.
  • an excessive proportion of nonionic surfactant should be avoided.
  • 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, more preferably 0.5% by weight or higher is quite sufficient, although higher level may be used.
  • nonionic surfactants for use in the invention are the low- to non-foaming ethoxylated straight - chain alcohols of the Plurafac ® RA series, supplied by the Eurane Company; of the Lutensol ® LF series, supplied by the BasF Company and of the Triton ® DF series, supplied by the Rohm & Haas Company.
  • anionic surfactant may be used but may require the additional presence of an antifoam to surpress foaming. If an anionic surfactant is used it is advantageously present at levels of 2 wt% or below.
  • a water-soluble polymeric polycarboxylic compound is advantageously present in the dish wash composition.
  • these compounds are homo- or co-polymers of polycarboxylic compounds, especially co-polymeric compounds in which the acid monomer comprises two or more carboxyl groups separated by not more than two carbon atoms. Salts of these materials can also be used.
  • Particularly preferred polymeric polycarboxylates are co- polymers derived from monomers of acrylic acid and maleic 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 m the composition of the invention are homo- polymeric polycarboxylic acid compounds with acrylic acid as the monome ⁇ c unit.
  • the average weight of such homo- polymers m the acid form preferably ranges from 1,000 to 100,000 particularly from 3,000 to 10,000.
  • Acrylic sulphonated polymers as described m EP 851 022 (Unilever) are also suitable.
  • 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.
  • a chelatmg agent may be present the composition. If present it is preferable if the level of chelatmg agent is from 0.5 to 3 wt.% of the total composition.
  • Preferred chelatmg agents include organic phosphonates, ammo carboxylates, polyfunctionally-substituted compounds, and mixtures thereof .
  • Particularly preferred chelatmg agents are organic phosphonates such as ⁇ -hydroxy-2 phenyl ethyl diphosphonate, ethylene diphosphonate, hydroxy 1 , 1-hexyl ⁇ dene, v ylidene 1,1 diphosphonate, 1,2 dihydroxyethane 1,1 diphosphonate and hydroxy-ethylene 1,1 diphosphonate. Most preferred is hydroxy-ethylene 1,1 diphosphonate.
  • Anti -tarnishing agents such as benzotriazole and those described in EP 723 577 (Unilever) may also be included.
  • Optional ingredients are, for example, buffering agents, reducing agents, e.g., borates, alkali metal hydroxide and the well-known enzyme stabilisers such as the polyalcohols, e.g. glycerol and borax; anti-scaling agents; crystal -growth inhibitors, threshold agents; thickening agents; perfumes and dyestuffs and the like.
  • buffering agents reducing agents, e.g., borates, alkali metal hydroxide and the well-known enzyme stabilisers such as the polyalcohols, e.g. glycerol and borax; anti-scaling agents; crystal -growth inhibitors, threshold agents; thickening agents; perfumes and dyestuffs and the like.
  • reducing agents e.g., borates, alkali metal hydroxide
  • the well-known enzyme stabilisers such as the polyalcohols, e.g. glycerol and borax
  • anti-scaling agents
  • Reducing agents may e.g. be used to prevent the appearance of an enzyme-deactivating concentration of oxidant bleach compound.
  • Suitable agents include reducing sulphur-oxy acids and salts thereof.
  • Most preferred for reasons of availability, low cost, and high performance are the alkali metal and ammonium salts of sulphuroxy acids including ammonium sulphite ((NH ) 2 S0 3 ), sodium sulphite (Na 2 S0 3 ) , sodium bisulphite (NaHS0 3 ) , sodium metabisulphite (NaS 2 0 3 ) , potassium metabisulphite (K 2 S 2 0 5 ) , lithium hydrosulphite (Li 2 S 2 0 4 ) , etc., sodium sulphite being particularly preferred.
  • Another useful reducing agent 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.
  • the invention relates to washing processes m mechanical dish washing machines wherein the wash liquor has a low pH.
  • 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.
  • the pH is lower than about 10.5, more preferably lower than about 10, more preferably lower than about 9.5.
  • the most advantageous pH range is from 8.5 to 10.
  • the present invention preferably relates to processes of mechanically washing soiled articles with a wash liquor at a temperature of at least 40°C, more preferably at least 50°C, most preferably at least 55°C.
  • the rmse aid for use m the invention comprises a water soluble acid builder or salt, preferably organic acids including, for example, carboxylic acids, such as citric and succimc acids, polycarboxylic acids, such as polyacrylic acid, and also acetic acid, boric acid, malomc acid, adipic acid, fuma ⁇ c acid, lactic acid, glycolic acid, tarta ⁇ c acid, tartronic acid, maloic acid, their derivatives and any mixtures of the foregoing.
  • carboxylic acids such as citric and succimc acids
  • polycarboxylic acids such as polyacrylic acid
  • acetic acid boric acid, malomc acid, adipic acid, fuma ⁇ c acid, lactic acid, glycolic acid, tarta ⁇ c acid, tartronic acid, maloic acid, their derivatives and any mixtures of the foregoing.
  • the level of water soluble builder salt in the composition is at least 20wt% of the total composition, preferably at least 25 wt.%, more preferably at least 30 wt.%, most preferably at least 35 wt.%
  • 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 acidity/constant (pKi) of less than 9, preferably of between 2 and 8.5, more preferably of between 2.5 and 7.5.
  • pKi carboxyl logarithmic acidity/constant
  • the carboxylate or polycarboxylate builder can be monomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance.
  • Monomeric and oligomeric builders can be selected from acyclic, alicyclic, heterocyclic and aromatic carboxylates .
  • Suitable carboxylates containing one carboxy group include the water-soluble salts of lactic acid, glycolic acid and ether derivatives thereof.
  • Polycarboxylates containing two carboxy groups include the 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 the ether carboxylates and the sulfinyl carboxylates.
  • Polycarboxylates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citraconates as well as succinate derivatives such as the carboxymethyloxysuccinates , lactoxysuccinates , and aminosuccinates , and the oxypolycarboxylate materials such as 2-oxa-l , 1 , 3-propane tricarboxylates.
  • the carboxylate or polycarboxylate builder compounds described above can also have a dual function as pH controlling agents.
  • Polycarboxylates containing four carboxy groups include oxydisuccinates , 1 , 1 , 2 , 2 -ethane tetracarboxylates, 1,1,3,3- propane tetracarboxylates and 1 , 1 , 2 , 3-propane tetracarboxylates.
  • Polycarboxylates containing sulfo substituents include the sulfosuccinate derivatives, and the sulfonated pyrolysed citrates.
  • Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis , cis , cis-tetracarboxylates , cyclopen- tadienide pentacarboxylates, 2 , 3 , 4 , 5-tetrahydroturan - cis, cis, cis-tetracarboxylates, 2 , 5-tetrahydrofuran - cis - dicarboxylates , 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
  • the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecules, more particularly citrates or citric acid.
  • 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 nonionic, 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 nonionic surfactants, more preferably selected from nonionic ethoxylated/propoxylated fatty alcohol surfactants.
  • the surfactant system is typically present at a level of from 1% to 40% by weight, more preferably 1.5 % to 30% by weight, most preferably from 5% to 20% by weight of the compositions. If an anionic surfactant is used it is advantageously present at levels of 1 wt% or below.
  • compositions of the invention may contain organic solvents, particularly when formulated as liquids or gels.
  • compositions in accord with the invention preferably contain a solvent system present at levels of from 1% to
  • the solvent system may be a mono or mixed solvent system.
  • Suitable organic solvent for use herein has the general formula RO (CH 2 C (Me) HO) n H, wherein R is an alkyl, alkenyl, or alkyl aryl group having from 1 to 8 carbon atoms, and n is an integer from 1 to 4.
  • R is an alkyl group containing 1 to 4 carbon atoms, and n is 1 or 2.
  • Especially preferred R groups are n-butyl or isobutyl .
  • Water-soluble CARBITOL 7 solvents are compounds of the 2- (2 alkoxyethoxy) ethanol class wherein the alkoxy group is derived from ethyl, propyl or butyl; a preferred water- soluble 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 2- butoxyethoxyethanol being preferred.
  • Suitable solvents are benzyl alcohol, and diols such as 2 -ethyl -1 , 3 -hexanediol and 2 , 2 , 4-trimethyl-l , 3- pentanediol .
  • 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 .
  • the compositions have a pH as a 1% solution in distilled water at 20°C of less than 7, preferably from 0.5 to 6.5, most preferably from 0.5 to 1.0.
  • the dish washing composition for use in the invention may be in any product form, however it is preferred if it granular.
  • Granular in the context of the present invention includes both powdered material and tablets. Tablets are particularly preferred.
  • the rinse aid is preferably a liquid.
  • Dishwash compositions according to the present invention may be dosed in the wash liquor at levels of from 10 g/1 to 2.5 g/i.
  • Rinse aid composition according to the present invention may be dosed in the final rinse liquor at levels 1 g/1 or less.
  • compositions were tested in a robotised Miele G5953C (total water hardness 28°FH, including temporary hardness of 18°FH) .
  • the compositions were dosed at a level of 20 g/wash; the main wash time was 20 minutes; the drying time with open door was 10-20 minutes; the washing temperature was up to 65°C;
  • Rinse aid was added to the rinse via the rinse and dispenser.
  • the rinse aid had the following formulation:
  • Nonionic surfactant LF400s (ex BASF) 14.55%; sodium Xylene sulphonate 5%; citric acid 40% and water to 100%.

Abstract

A process for washing articles in a mechanical washing machine in which no salt is added to the machine. The process involves treating the articles with a wash liquor comprising a dishwashing composition when undiluted said composition comprising 55 wt. % or greater of an inorganic poly-valent builder; followed by treating the article with a rinsing solution comprising a rinse aid, the rinse aid when undiluted comprising at least 20 wt. % of a water soluble builder or salt thereof; wherein no salt is added to the machine.

Description

DISH WASHING PROCESS AND COMPOSITIONS RELATING THERETO
Technical Field
The present invention is in the field of machine dishwashing. More specifically, the invention encompasses automatic dishwashing detergents and rinse aids and a process for using them.
Background of the Invention
To wash articles in a commercially available dish washing machine entails using three product types. Salt is added to the salt compartment to soften the water, a dish-washing formulation is used to clean the articles and a rinse aid is used to ensure that the articles are rinsed with no streaks or smears .
The salt in the machine does not have to be replaced every wash, however it is inconvenient for consumers replace the salt .
The present invention relates to a process of washing dishes that obviates the need for salt in a machine dish-washing formulation. Description of the Invention
Accordingly, the present invention provides a process for washing articles m a mechanical washing machine comprising the steps of: (I) treating the articles with a wash liquor comprising a dishwashing composition, when un-diluted said composition comprising 55 wt % or greater of an inorganic poly-valent builder (n) followed by treating the article with a rinsing solution comprising a rmse aid, the rmse aid when undiluted comprising at least 20 wt . % of a water soluble builder or salt thereof; (in) wherein no salt is added to the machine .
Detailed Description of the Invention
Dish Washing Composition
Builder material
The detergency builder salt for use with the present invention is a poly-valent inorganic builder. Preferably the builder is water-soluble. Non-limitmg examples of suitable, inorganic builder salts include the alkali metal, phosphates, polyphosphates, and tripolyphosphates. Specific examples of such salts include the sodium and potassium, tripolyphosphates, orthophosphates and hexametaphosphates . Sodium tripolyphosphate is particularly preferred as a builder. The level of inorganic builder is 55 wt. % or greater. Most preferably the level of builder is from 58 wt.% to 65 wt.%. Particularly suitable for use with the invention is sodium tripolyphosphate, which can be converted to the phase I form by heating to above the transition temperature, at which phase II anhydrous sodium polyphosphate is transformed into the phase I form. A process for the manufacture of particles containing a high proportion of the phase I form of sodium tripolyphosphate by spray drying below 420 °C is given in US-A-4536377. Suitable material is commercially available. Suppliers include Rhodia, Courbevoie, France and Albright & Wilson, Warley, West Midlands, UK. The sodium tripolyphosphate should be partially hydrated, but the phase I anhydrous form should also be present. Thus, the sodium tripolyphosphate in the particles may incorporate up to 5% (by weight of the sodium tripolyphosphate in these particles) of water of hydration. The extent of hydration is desirably from 1% to 4% or 5% by weight. This degree of hydration in general means that the sodium tripolyphosphate is partially hydrated.
The sodium tripolyphosphate in these particles is preferably hydrated by a process, which leads to a homogeneous distribution of the water of hydration within the tripolyphosphate. This can be accomplished by exposing anhydrous sodium tripolyphosphate to steam or moist air. The particles preferably consist solely of sodium tripolyphosphate with a high content of the phase I form. The phase I content of the sodium tripolyphosphate being measured by X-ray diffraction, or IR.
The particles preferably contain sodium tripolyphosphate in a porous form so as to have high surface area. This can be achieved by spray drying the tripolyphosphate as a mixture with a blowing agent, that is a compound such as ammonium carbonate which decomposes to yield a gas during the course of the spray drying. This gives the dried material a porous structure, with higher surface area than hollow beads of tripolyphosphate obtained without blowing agent .
The bulk density of the of sodium tripolyphosphate particles is preferably 0.75 Kg/M3 or less, more preferably from 0.52 to 0.72 Kg/M3.
The particles which contain or consist of sodium tripolyphosphate preferably have a small mean particle size, such as not over 300μm, better not over 250μm. Small particle size can if necessary be achieved by grinding.
Uniform prehydration, high phase I content, porosity and small particle size all promote rapid hydration when the tripolyphosphate comes into contact with water. A standard test for the rapidity of hydration is the Olten test. It is desirable that in such a test the tripolyphosphate reaches 90% of the final value (i.e. 90% of complete hydration when exposed to water at 80°C) within 60 seconds.
"Rhodiaphos HPA 3.5" is a grade of sodium tripolyphosphate from Rhodia which has been found to be particularly suitable. It consists of porous particles of small particle size (mean size below 250μm) with 70% phase I and prehydrated with 3.5% water of hydration. Preferably the said particles containing sodium tripolyphosphate with more than 50% of phase I material provide this phase I tripolyphosphate as at least 3% by weight of the tablet or region thereof . More preferably they provide sodium tripolyphosphate, including the phase I tripolyphosphate, in a quantity which is from 30% up to 40% or 60% by weight of the tablet or region thereof.
The detergency builder system may additionally comprise a bicarbonate salt, preferably sodium or potassium bicarbonate most especially sodium bicarbonate. Bicarbonate salts are particularly preferred as builders as they also have a buffering capacity.
The builder may further comprise a carboxylate or polycarboxylate builder containing from one to four carboxy groups, particularly selected from monomeric polycarboxylates or their acid forms, homo or copolymeric polycarboxylic acids or there salts in which the polycarboxylate comprises at least two carboxylic radicals selected from each other by not more than two carbon atoms . Preferred carboxylates include the polycarboxylate materials described in US-A-2 , 264 , 103 , including the water-soluble alkali metal salts of mellitic acid and citric acid, 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 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.
Other suitable detergency builders organic alkaline compounds such as water-soluble amino polyacetates, e.g. sodium and potassium ethylenediamine tetraacetates, nitrilotriacetates and N- (2-hydroxyethyl) nitrilodiacetates ; water-soluble salts of phytic acid, e.g. sodium and potassium phytates; water-soluble polyphosphonates , including sodium, potassium and lithium salts of ethane- 1- hydroxy-1 , 1-diphosphonic acid; sodium, potassium and lithium salts of methylenediphosphonic acid and the like.
Mixtures of organic and/or inorganic builder salts can be used herein.
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 μm, more preferably at most 30μm, most preferably at most 20μm 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 lμm, more preferably at least 2μm, most preferably at least 5μm.
Preferably the primarily particle size of the silica is in general less than about 30nm, in particular less than about 25nm. Preferably, elementary particles sizes are less than 20nm or even lOnm. There is no critical lower limit of the elementary particle size; the lower limit is governed by other factors such as the manner of manufacture, etc. In general commercial available silicas have elementary particle sizes of 1 nm or more.
Preferably, the silica material is present in the wash liquor at a level of at least 2.5xl0~4%, more preferably at least 12.5xl0"4%, most preferably at least 2.5xl0"3% by weight of the wash liquor and preferably at most lxl0_1%, more preferably at most 8xl0"2%, most preferably at most 5xl0"2% by weight of the wash liquor. Preferably, the level of dissolved silica material in the wash liquor is at least 80-ppm, more preferably at least 100 ppm, most preferably at least 120 ppm and preferably at most 1,000 ppm. It is noted that for 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 cleaning composition and preferably at most 10%, more preferably at most 8%, most preferably at most 5% by weight of the cleaning composition.
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 Si02 level should be from 1% to 25%, 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 signi icantly 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:Na0 ratio of from 2.0 to 2.4 available from PQ Corporation, named Britesil H20 and Britesil H24. Most preferred is a granular hydrous sodium silicate having a Si02:Na20 ratio of 2.0. While typical forms, i.e. powder and granular, of hydrous silicate particles are suitable, preferred silicate particles having a mean particle size between 300 and 900 microns and less than 40% smaller than 150 microns and less than 5% larger than 1700 microns. Particularly preferred is a silicate particle with a mean particle size between 400 and 700 microns with less than 20% smaller than 150 microns and less than 1% larger then 1700 microns. Compositions of the present invention having a pH of 9 or less preferably will be substantially free of alkali metal silicate. Enzymes
Enzymes may be present in the compositions of the invention. Examples of enzymes suitable for use in the cleaning compositions of this invention include lipases, peptidases, amylases (amylolytic enzymes) and others which degrade, alter or facilitate the degradation or alteration of biochemical soils and stains encountered in cleansing situations so as to remove more easily the soil or stain from the object being washed to make the soil or stain more removable in a subsequent cleansing step. Both degradation and alteration can improve soil removal.
Well-known and preferred examples of these enzymes are lipases, amylases and proteases. The enzymes most commonly used in machine dishwashing compositions are amylolytic enzymes. Preferably, the composition of the invention also contains a proteolytic enzyme. Enzymes may be present in a weight percentage amount of from 0.2 to 5% by weight. For amylolytic enzymes, the final composition will have amylolytic activity of from 102 to 106 Maltose units/kg. For 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 onopersulphate, perborate monohydrate, perborate tetrahydrate, and percarbonate .
Monoperoxy acids useful herein include alkyl peroxy acids and aryl peroxyacids such as peroxybenzoic acid and ring-substituted peroxybenzoic acids (e.g. peroxy-alpha- naphthoic acid) ; aliphatic and substituted aliphatic monoperoxy acids (e.g. peroxylauric acid and peroxystearic acid) ,- and phthaloyl amido peroxy caproic acid (PAP) .
Typical diperoxy acids useful herein include alkyl diperoxy acids and aryldiperoxy acids, such as 1 , 12 -di-peroxy- dodecanedioic acid (DPDA) ; 1 , 9-diperoxyazelaic acid, diperoxybrassylic acid, diperoxysebacic acid and diperoxy- isophthalic acid; and 2-decyldiperoxybutane-l , 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) , sodium nonanoyloxybenzene sulphonate (SNOBS) , sodium benzoyloxybenzene 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 be presented in the form of a second encapsulate separately from the bleach capsule or granule. Cobalt catalysts can also be used.
Among suitable reactive chlorine- or bromine-oxidizing materials are heterocyclic N-bromo and N-chloro imides such as trichloroisocyanuric, tribromoisocyanuric, dibromoisocyanuric and dichloroisocyanuric acids, and salts thereof with water-solubilizing cations such as potassium and sodium. Hydantoin compounds such as 1 , 3-dichloro-5 , 5- dimethyl -hydantoin are also quite suitable.
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 bleaching materials. Encapsulation techniques are known for both peroxygen and chlorine bleaches, e.g. as described in US-A-4 , 126 , 573 , US- A-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 12.5xl0~4% and at most 0.03% avO by weight of the liquor.
Surfactant 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 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, more preferably 0.5% by weight or higher is quite sufficient, although higher level may be used.
Examples of suitable nonionic surfactants for use in the invention are the low- to non-foaming ethoxylated straight - chain alcohols of the Plurafac® RA series, supplied by the Eurane Company; of the Lutensol® LF series, supplied by the BasF Company and of the Triton® DF series, supplied by the Rohm & Haas Company.
Other surfactants such as anionic surfactant may be used but may require the additional presence of an antifoam to surpress foaming. If an anionic surfactant is used it is advantageously present at levels of 2 wt% or below.
Water Soluble Polymeric Polycarboxylic Compounds
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, especially co-polymeric compounds in which the acid monomer comprises two or more carboxyl groups separated by not more than two carbon atoms. Salts of these materials can also be used.
Particularly preferred polymeric polycarboxylates are co- polymers derived from monomers of acrylic acid and maleic 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 m the composition of the invention are homo- polymeric polycarboxylic acid compounds with acrylic acid as the monomeπc unit. The average weight of such homo- polymers m the acid form preferably ranges from 1,000 to 100,000 particularly from 3,000 to 10,000.
Acrylic sulphonated polymers as described m 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.
Chelatmg Agent
A chelatmg agent may be present the composition. If present it is preferable if the level of chelatmg agent is from 0.5 to 3 wt.% of the total composition.
Preferred chelatmg agents include organic phosphonates, ammo carboxylates, polyfunctionally-substituted compounds, and mixtures thereof .
Particularly preferred chelatmg agents are organic phosphonates such as α-hydroxy-2 phenyl ethyl diphosphonate, ethylene diphosphonate, hydroxy 1 , 1-hexylιdene, v ylidene 1,1 diphosphonate, 1,2 dihydroxyethane 1,1 diphosphonate and hydroxy-ethylene 1,1 diphosphonate. Most preferred is hydroxy-ethylene 1,1 diphosphonate. Anti-tarnishing Agents
Anti -tarnishing agents such as benzotriazole and those described in EP 723 577 (Unilever) may also be included.
Optional Ingredients
Optional ingredients are, for example, buffering agents, reducing agents, e.g., borates, alkali metal hydroxide and the well-known enzyme stabilisers such as the polyalcohols, e.g. glycerol and borax; anti-scaling agents; crystal -growth inhibitors, threshold agents; thickening agents; perfumes and dyestuffs and the like.
Reducing agents may e.g. be used to prevent the appearance of an enzyme-deactivating concentration of oxidant bleach compound. Suitable agents include reducing sulphur-oxy acids and salts thereof. Most preferred for reasons of availability, low cost, and high performance are the alkali metal and ammonium salts of sulphuroxy acids including ammonium sulphite ((NH )2S03), sodium sulphite (Na2S03) , sodium bisulphite (NaHS03) , sodium metabisulphite (NaS203) , potassium metabisulphite (K2S205) , lithium hydrosulphite (Li2S204) , etc., sodium sulphite being particularly preferred. Another useful reducing agent, though not particularly preferred for reasons 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.
pH of wash liquor
The invention relates to washing processes m 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 preferably 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 40°C, more preferably at least 50°C, most preferably at least 55°C.
Rmse Aid
The rmse aid for use m the invention comprises a water soluble acid builder or salt, preferably organic acids including, for example, carboxylic acids, such as citric and succimc acids, polycarboxylic acids, such as polyacrylic acid, and also acetic acid, boric acid, malomc acid, adipic acid, fumaπc acid, lactic acid, glycolic acid, tartaπc acid, tartronic acid, maloic acid, their derivatives and any mixtures of the foregoing. - I S
The level of water soluble builder salt in the composition is at least 20wt% of the total composition, preferably at least 25 wt.%, more preferably at least 30 wt.%, most preferably at least 35 wt.%
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 acidity/constant (pKi) of less than 9, preferably of between 2 and 8.5, more preferably of between 2.5 and 7.5.
The carboxylate or polycarboxylate builder can be monomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance. Monomeric and oligomeric builders can be selected from acyclic, alicyclic, heterocyclic and aromatic carboxylates .
Suitable carboxylates containing one carboxy group include the water-soluble salts of lactic acid, glycolic acid and ether derivatives thereof. Polycarboxylates containing two carboxy groups include the 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 the ether carboxylates and the sulfinyl carboxylates. Polycarboxylates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citraconates as well as succinate derivatives such as the carboxymethyloxysuccinates , lactoxysuccinates , and aminosuccinates , and the oxypolycarboxylate materials such as 2-oxa-l , 1 , 3-propane tricarboxylates. The carboxylate or polycarboxylate builder compounds described above can also have a dual function as pH controlling agents.
Polycarboxylates containing four carboxy groups include oxydisuccinates , 1 , 1 , 2 , 2 -ethane tetracarboxylates, 1,1,3,3- propane tetracarboxylates and 1 , 1 , 2 , 3-propane tetracarboxylates. Polycarboxylates containing sulfo substituents include the sulfosuccinate derivatives, and the sulfonated pyrolysed citrates.
Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis , cis , cis-tetracarboxylates , cyclopen- tadienide pentacarboxylates, 2 , 3 , 4 , 5-tetrahydroturan - cis, cis, cis-tetracarboxylates, 2 , 5-tetrahydrofuran - cis - dicarboxylates , 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 nonionic, 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 nonionic surfactants, more preferably selected from nonionic ethoxylated/propoxylated fatty alcohol surfactants.
The surfactant system is typically present at a level of from 1% to 40% by weight, more preferably 1.5 % to 30% by weight, most preferably from 5% to 20% by weight of the compositions. If an anionic surfactant 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 from 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 major component of the solvent system is of low volatility. Suitable organic solvent for use herein has the general formula RO (CH2C (Me) HO) nH, wherein R is an alkyl, alkenyl, or alkyl aryl group having from 1 to 8 carbon atoms, and n is an integer from 1 to 4. Preferably, R is an alkyl group containing 1 to 4 carbon atoms, and n is 1 or 2. Especially preferred R groups are n-butyl or isobutyl . Preferred solvents of this type are 1 -n-butoxypropane-2-ol (n = 1) : and 1 (2-n-butoxy-l -methylethoxy) propane-2 -ol (n = 2), and mixtures thereof .
Other solvents useful herein include the water-soluble CARBITOL7 solvents or water-soluble CELLOSOLVE7 solvents. Water-soluble CARBITOL7 solvents are compounds of the 2- (2 alkoxyethoxy) ethanol class wherein the alkoxy group is derived from ethyl, propyl or butyl; a preferred water- soluble carbitol is 2 (2-butoxyethoxy) ethanol also known as butyl carbitol. Water-soluble CELLOSOLVE7 solvents are compounds of the 2 -alkoxyethoxy ethanol class, with 2- butoxyethoxyethanol being preferred.
Other suitable solvents are benzyl alcohol, and diols such as 2 -ethyl -1 , 3 -hexanediol and 2 , 2 , 4-trimethyl-l , 3- pentanediol .
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 20°C of less than 7, preferably from 0.5 to 6.5, most preferably from 0.5 to 1.0.
Product Form
The dish washing composition for use in the invention may be in any product form, however it is preferred if it granular. Granular in the context of the present invention includes both powdered material and tablets. Tablets are particularly preferred.
The rinse aid is preferably a liquid.
Dishwash compositions according to the present invention may be dosed in the wash liquor at levels of from 10 g/1 to 2.5 g/i.
Rinse aid composition according to the present invention may be dosed in the final rinse liquor at levels 1 g/1 or less.
The invention will now be illustrated by the following non- limiting Examples. Examples of the invention are illustrated by a number, comparative Examples are illustrated by a letter. All percentages are on a weight basis
EXAMPLE I
Table 1
The compositions were tested in a robotised Miele G5953C (total water hardness 28°FH, including temporary hardness of 18°FH) . The compositions were dosed at a level of 20 g/wash; the main wash time was 20 minutes; the drying time with open door was 10-20 minutes; the washing temperature was up to 65°C;
30 washes were carried out by loading the machine with glass, and plastics,
Rinse aid was added to the rinse via the rinse and dispenser. The rinse aid had the following formulation:
Nonionic surfactant LF400s (ex BASF) 14.55%; sodium Xylene sulphonate 5%; citric acid 40% and water to 100%.
Overall appearance
Overall appearance was measured by placing the tested articles on a black cloth under a reflected artificial daylight source (Kelvin temperature 2300°K) ; placed 2 metres above the articles. A subjective scoring system on a 1-9 scale was used
1 as new - 9 extremely poor.
The overall appearance was a combination of white filming due to calcium salt deposits, spots, streaks and glass corrosion. The results are given in table 3
TABLE 3

Claims

1. A process for washing articles in a mechanical washing machine comprising the steps of:
i) treating the articles with a wash liquor comprising a dishwashing composition when undiluted said composition comprising 55 wt. % or greater of an inorganic poly-valent builder;
ii) followed by treating the article with a rinsing solution comprising a rinse aid, the rinse aid when undiluted comprising at least 20 wt. % of a water soluble builder or salt thereof;
iii) wherein no salt is added to the machine.
2. A process according to claim 1 in which the water poly- valent builder is sodium tripolyphosphate.
3. A process according to claim 1 or 2 in which the water soluble acid builder is citric acid or citrate.
. A process according to claim any preceding claim in which the rinse aid comprises 30 wt% or greater of water soluble acid builder or salt thereof.
5. A process according to any preceding claim in which the dish washing composition comprises a silica or silicate material . A process according to any preceding claims wherein the temperature of the wash liquor is at least 40°C.
Machine dishwash compositions for use in any of the above claimed processes, said dish washing composition being in tablet form and rinsing composition being in liquid form.
EP00925289A 1999-06-25 2000-05-15 Dish washing process and compositions relating thereto Withdrawn EP1190029A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP00925289A EP1190029A1 (en) 1999-06-25 2000-05-15 Dish washing process and compositions relating thereto

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP99305021 1999-06-25
EP99305021 1999-06-25
PCT/EP2000/004427 WO2001000766A1 (en) 1999-06-25 2000-05-15 Dish washing process and compositions relating thereto
EP00925289A EP1190029A1 (en) 1999-06-25 2000-05-15 Dish washing process and compositions relating thereto

Publications (1)

Publication Number Publication Date
EP1190029A1 true EP1190029A1 (en) 2002-03-27

Family

ID=8241476

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00925289A Withdrawn EP1190029A1 (en) 1999-06-25 2000-05-15 Dish washing process and compositions relating thereto

Country Status (6)

Country Link
EP (1) EP1190029A1 (en)
AR (1) AR024455A1 (en)
AU (1) AU4405600A (en)
BR (1) BR0011929A (en)
WO (1) WO2001000766A1 (en)
ZA (1) ZA200109843B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004511277A (en) * 2000-10-10 2004-04-15 ジョンソンディバーシー・インコーポレーテッド Detergent composition and container cleaning method
DE10105801B4 (en) * 2001-02-07 2004-07-08 Henkel Kgaa Detergents and cleaning agents comprising fine microparticles with detergent components

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2213007A1 (en) * 1972-03-17 1973-09-20 Henkel & Cie Gmbh RINSE AGENT FOR MACHINE DISH WASHING
GB1441588A (en) * 1972-10-04 1976-07-07 Unilever Ltd Rinse composition
DE2259830B2 (en) * 1972-12-07 1981-01-29 Hoechst Ag, 6000 Frankfurt Process for machine washing of dishes, cutlery or glasses
DE2501529A1 (en) * 1975-01-16 1976-07-22 Hoechst Ag Powdered dish-washer cleaning matl - contains poly-(alpha-hydroxyacrylic acid) salt and corrodes porcelain etc. less (NL200776)
GB1586067A (en) * 1976-10-28 1981-03-18 Procter & Gamble Detergent composition
DE3315950A1 (en) * 1983-05-02 1984-11-15 Henkel KGaA, 4000 Düsseldorf METHOD FOR PRODUCING DETERGENT TABLETS
DE3805881A1 (en) * 1988-02-25 1989-09-07 Benckiser Gmbh Joh A Method for the mechanical cleaning of dishes
AU654184B2 (en) * 1991-05-31 1994-10-27 Colgate-Palmolive Company, The Improved phosphate-containing powder automatic dishwashing composition with enzymes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0100766A1 *

Also Published As

Publication number Publication date
AU4405600A (en) 2001-01-31
ZA200109843B (en) 2003-02-26
AR024455A1 (en) 2002-10-02
BR0011929A (en) 2002-03-19
WO2001000766A1 (en) 2001-01-04

Similar Documents

Publication Publication Date Title
EP2245129B1 (en) Machine dishwash detergent compositions
US3701735A (en) Automatic dishwashing compositions
US5898025A (en) Mildly alkaline dishwashing detergents
US5650017A (en) Washing process and composition
CA2145663A1 (en) Mildly alkaline dishwashing detergents
WO2000046341A1 (en) A machine dishwashing kit
JPH0812997A (en) Detergent composition
US6463939B1 (en) Dish washing process
CA2389975A1 (en) Detergent compositions
WO2001000766A1 (en) Dish washing process and compositions relating thereto
EP1111037B1 (en) Use of dish-washing compositions
GB2311536A (en) Dishwashing and laundry detergents
DE4437486A1 (en) Crystalline layered silicates in automatic dishwashing detergents
EP1328613B1 (en) Dish-washing compositions
US6310023B1 (en) Machine dish wash compositions
EP1239026B1 (en) Detergent tablets
EP1159391B1 (en) Detergent tablets
EP1328611B1 (en) Dish-washing compositions
MXPA02000264A (en) Transparent or translucent, liquid or gel type automatic dishwashing detergent product.
CZ342395A3 (en) Preparation for washing dishes in dish washing machines
EP1287107B1 (en) Dish washing compositions
BE1013471A3 (en) USE OF dishwashing.
WO2001002524A1 (en) Dish washing compositions
EP1239028A1 (en) Detergent tablets
ZA200105695B (en) Dish washing process and compolsitions relating thereto.

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20011114

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17Q First examination report despatched

Effective date: 20030811

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20050629