Detergent composition for dishwashing, preferably detergent composition for automatic dishwashing

Abstract

The present invention relates to a detergent composition for dishwashing, preferably automatic dishwashing, wherein the detergent composition comprises at least one reducing monosaccharide and / or at least one reducing disaccharide. The invention also relates to the use of this inventive detergent composition for dishwashing, preferably for automatic dishwashing, in a dishwashing process, preferably in an automatic dishwashing process, for silver corrosion protection of silver dishwashing. Furthermore, the present invention relates to the use of a detergent composition for dishwashing, preferably automatic dishwashing, comprising a tamarind extract comprising a mixture of reducing monosaccharides and reducing disaccharides for silver corrosion protection of silver dishware during dishwashing, preferably during automatic dishwashing.

Description

Technical Field

[0001] The present invention relates to a detergent composition for dishwashing, preferably automatic dishwashing.

[0002] The invention also relates to the use of the inventive dishwashing, preferably automatic dishwashing, detergent composition for protecting silver cutlery against silver corrosion in a dishwashing process, preferably in an automatic dishwashing process.

[0003] Furthermore, the present invention relates to the use of a dishwashing, preferably automatic dishwashing, detergent composition comprising a tamarind extract comprising a mixture of reducing monosaccharides and reducing disaccharides for protecting silver cutlery from silver corrosion in a dishwashing process, preferably in an automatic dishwashing process. Background Art

[0004] Consumers have long used silver / copper corrosion inhibitors to protect their silver / copper dishwashing products in automatic dishwashing detergent compositions.

[0005] A wide variety of compositions designed for use in automatic dishwasher machines are well known, and detergent manufacturers have been continually striving to reduce tarnishing of silver and copper articles and surfaces in dishwashers. The problem becomes apparent when using bleach-containing compositions, especially those containing oxygen bleaching species. The degree of tarnish observed can range from a slight discoloration to the formation of a dense black coating on the surface of the silver or copper, depending on the formulation and the bleach. Therefore, the dual challenge of formulating a product is to optimize the cleaning of bleachable soils while minimizing the occurrence of silver article tarnishing.

[0006] Existing formulations achieve this by including BTA (1H-benzotriazole) and / or TTA (a mixture of 4-methyl-1H-benzotriazole and 5-methyl-1H-benzotriazole). Both BTA and TTA are effective in reducing the tarnishing of silverware parts in the presence of bleach. However, BTA has been found to be toxic to aquatic organisms and is also a potential endocrine disruptor (Seeland et al., J. Environ. Sci. Pollut. Res. Int, 2012, 19(5), 1781-1790).

[0007] Although alternatives to BTA, such as tellurium and selenium dioxide, were initially identified, they have been ruled out due to concerns about toxicity. In addition, reformulation efforts focused on increasing disilicate content have not produced viable formulations with improved corrosion protection without exceeding regulatory limits. In the following years, as evidence of BTA's adverse effects increased, BTA in the formulation was replaced by TTA. However, in recent years, multiple studies have found that TTA (particularly the 4-methyl isomer) is harmful to the aquatic environment (see Brauch et al., Water Research and Management, 2011, Vol. 1, No. 1, 17-28 and Huntscha et al., J. Environ. Sci. Technol., 2014, 48, 4435-4443). Because TTA contains a large amount of 4-methyl-1H-benzotriazole, existing bleach-containing automatic dishwashing compositions that are effective in minimizing silver and copper tarnish can also harm the aquatic environment.

[0008] Therefore, since the currently used BTA / TTA are less sustainable and regulations will soon prohibit their use in detergent compositions, there remains a growing need to replace them as raw materials for preventing silver corrosion in automatic dishwashing (ADW) compositions.

[0009] Along these lines, explored avenues to address this problem have so far been limited to imidazole-based small molecules, sulfur- or thiol-containing amino acids (such as cystine and cysteine), and specific redox-active species.

[0010] Purpose of the invention

[0011] In view of the prior art, it was therefore an object of the present invention to provide a novel alternative composition for silver protection in dishwashing processes which should not exhibit the above-mentioned disadvantages of the known prior art dishwashing compositions.

[0012] In particular, it is an object of the present invention to provide a novel alternative composition for silver protection in dishwashing processes which should reduce the release of harmful and poorly biodegradable benzotriazoles into the environment.

[0013] Furthermore, it was an object to provide a novel alternative composition for silver protection in dishwashing processes which has comparable efficacy in inhibiting silver corrosion compared to the use of compositions comprising BTA and / or TTA. Summary of the invention

[0014] These objects as well as other objects which are not explicitly stated but which can be immediately derived or discerned from the connections discussed herein by way of introduction are achieved by a dishwashing, preferably automatic dishwashing, detergent composition having all the features of claim 1. Suitable modifications of the dishwashing, preferably automatic dishwashing, detergent composition of the invention are protected in the dependent claims 2 to 13. Claim 14 relates to the use of this inventive dishwashing, preferably automatic dishwashing, detergent composition for protecting silver tableware from silver corrosion in a dishwashing process, preferably in an automatic dishwashing process; and claim 15 relates to the use of a dishwashing, preferably automatic dishwashing, detergent composition comprising a tamarind extract comprising a mixture of reducing monosaccharides and reducing disaccharides in a dishwashing process, preferably in an automatic dishwashing process, for protecting silver tableware from silver corrosion.

[0015] Therefore, the present invention provides a detergent composition for dishwashing, preferably automatic dishwashing, wherein the detergent composition comprises at least one reducing monosaccharide and / or at least one reducing disaccharide.

[0016] Thus, in an unforeseeable manner, it was possible to provide a novel alternative composition for silver protection in dishwashing processes which does not exhibit the above-mentioned disadvantages of known prior art dishwashing compositions.

[0017] Additionally, novel alternative compositions for silver protection during dishwashing reduce the release of harmful and poorly biodegradable benzotriazoles into the environment.

[0018] Furthermore, the novel alternative composition for silver protection in dishwashing processes has comparable efficacy in inhibiting silver corrosion compared to the use of compositions comprising BTA and / or TTA.

[0019] Brief description of the form

[0020] The objects, features and advantages of the present invention will also become apparent from the following description read in conjunction with the tables, in which:

[0021] Table 1 shows a comparison of the comparative formulation and the formulation of the invention.

[0022] Table 2 shows a comparison of additional comparative formulations and the formulations of the present invention.

[0023] Table 3 shows information about the individual silver corrosion protection compounds used in the comparative formulations of Tables 1 and 2 and the formulations of the present invention.

[0024] Table 4 shows information regarding the comparative formulations of Tables 1 and 2 and mixtures of individual silver corrosion protection compounds used in the formulations of the present invention. DETAILED DESCRIPTION

[0025] As used herein, the term "reducing monosaccharide" or "reducing disaccharide" refers to a monosaccharide or disaccharide that can be used as a reducing agent according to the present invention.

[0026] If such a "reducing monosaccharide" or "reducing disaccharide" is present, it can be readily determined by standard procedures (eg, by Benedict's reagent).

[0027] Benedict's reagent is a chemical reagent, which is a complex mixture of sodium carbonate, sodium citrate and copper (II) sulfate pentahydrate. It is often used instead of Fehling's reagent to detect the presence of reducing sugars. A positive test with Benedict's reagent shows a color change from clear blue to brick red, accompanied by a precipitate.

[0028] In one embodiment, the detergent composition is substantially free, preferably completely free, of any triazoles, especially BTA and TTA.

[0029] In the context of the present invention, the expression "substantially free" means a concentration of less than 5% by weight, preferably less than 3% by weight, more preferably less than 0.5% by weight.

[0030] In one embodiment, the at least one reducing monosaccharide is selected from the group consisting of glucose, fructose, galactose, deoxyribose, ribose, xylose, arabinose, lyxose, allose, altrose, mannose, gulose, iodose and talose.

[0031] In one embodiment, the at least one reducing disaccharide is selected from the group consisting of maltose, lactose, cellobiose, melibiose, chitobiose, kojibiose, nigerobiose, isomaltose, sophorose, laminaribiose, gentiobiose, trehalulose, turanose, maltulose, leucrose, isomaltulose, gentiodiulose, mannobiose, plantagobiose, rutinose, rutinulose and xylobiose.

[0032] In one embodiment, the at least one reducing monosaccharide is selected from the group consisting of glucose, fructose, galactose and arabinose; and the at least one reducing disaccharide is selected from the group consisting of maltose, lactose, cellobiose and melibiose.

[0033] In one embodiment, the detergent composition further comprises at least one non-reducing monosaccharide and / or at least one non-reducing disaccharide.

[0034] In a preferred embodiment thereof, the detergent composition further comprises at least sucrose and / or trehalose.

[0035] In another embodiment, the detergent composition is substantially free, preferably completely free, of any non-reducing monosaccharides and non-reducing disaccharides.

[0036] In one embodiment, the detergent composition comprises at least two different reducing disaccharides.

[0037] In a preferred embodiment thereof, the detergent composition comprises two different reducing disaccharides, with the proviso that no other reducing monosaccharides or reducing disaccharides are contained.

[0038] In a more preferred embodiment thereof, the two different reducing disaccharides are cellobiose and melibiose.

[0039] In one embodiment, the detergent composition is substantially free, preferably completely free, of any other reducing agents other than reducing monosaccharides and / or reducing disaccharides.

[0040] In one embodiment, the detergent composition comprises 0.1 to 5 wt %, preferably 0.25 to 3 wt %, more preferably 0.4 to 1.2 wt % of the reducing monosaccharides and reducing disaccharides in total.

[0041] As used herein, the terms "wt %", "% wt.", "weight %" and "% weight" are synonymous with each other. All of these expressions refer to the weight percentage of the corresponding component.

[0042] The dishwashing, preferably automatic dishwashing, detergent compositions of the present invention may contain a builder.

[0043] The builder can be a phosphate-free builder. In many countries including the United States and the European Union, phosphate builders are restricted, or the amount of phosphate allowed in the detergent composition is strictly limited. Therefore, in a preferred embodiment, the detergent composition is substantially free of phosphate.

[0044] The builder comprises one or more small molecule builders selected from hydroxycarboxylates (e.g. citrates, such as trisodium citrate, which may be anhydrous), aminocarboxylates (e.g. methylglycine diacetic acid (MGDA) or N,N-dicarboxymethylglutamic acid (GLDA)), dicarboxylic acid amines (e.g. iminodisuccinic acid (IDS)) and / or phosphates (e.g. tripolyphosphates), or salts thereof.

[0045] The builder can be present in an amount greater than 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt% or greater than 50 wt%. The builder can be present in an amount of 31 to 49 wt%, 32 to 41 wt%, or 33 to 39 wt%.

[0046] The builder may be present in an amount of up to 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.5 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt% or up to 10 wt%.

[0047] The actual amount employed in the detergent compositions may depend upon the nature of the builder employed.

[0048] The builder may be an organic builder.

[0049] The detergent composition may contain a secondary builder (co-builder), for example a phosphonate, such as tetrasodium-HEDP.

[0050] The dishwashing, preferably automatic dishwashing detergent composition of the present invention may comprise at least one polymer, preferably at least one polycarboxylate. The term "polycarboxylate" refers to any polymeric material containing carboxylic acid or carboxylate groups which can be used for chelation. The polycarboxylate polymer may be a homopolymer and / or a copolymer and / or a terpolymer.

[0051] The one or more polymers may be present in an amount from 3 to 25 weight percent, from 5 to 20 weight percent, from 6 to 18 weight percent, from 7 to 16 weight percent, from 8 to 15 weight percent, or from 9 to 13 weight percent.

[0052] The polymer may be a polycarboxylate polymer comprising an itaconic acid copolymer.

[0053] The polymer may be a polycarboxylate polymer comprising acrylic acid monomers.

[0054] The polymer may be a polycarboxylate polymer comprising an acrylic acid homopolymer. The number average molecular weight of the homopolymer may be from 2,000 to 10,000, from 3,000 to 9,000, or from 4,000 to 8,000. The homopolymer may be present in an amount of 0.1 to 5 weight percent, 0.2 to 4.5 weight percent, 0.3 to 4 weight percent, 0.3 to 3.5 weight percent, 0.4 to 3 weight percent, 0.5 to 2.5 weight percent, 0.6 to 2 weight percent, or 0.7 to 1.5 weight percent.

[0055] At least one polycarboxylate may include sulfonic acid monomers. The sulfonic acid monomers may be present in an amount of 4 to 14 weight percent, 5 to 13 weight percent, 6 to 12 weight percent, or 7 to 11 weight percent.

[0056] Preferred monomers containing sulfonic acid groups are those of the formula:

[0057] R 1 (R 2 )C=C(R 3)-X-SO3H

[0058] Where R 1 To R 3 independently of one another -CH3, a linear or branched saturated alkyl residue having 2 to 12 carbon atoms, a linear or branched monounsaturated or polyunsaturated alkenyl residue having 2 to 12 carbon atoms, an alkyl or alkenyl residue substituted with -NH2, -OH or -COOH, or -COOH or -COOR 4 , R 4 is a saturated or unsaturated, linear or branched hydrocarbon residue having 1 to 12 carbon atoms, and X represents an optionally present spacer group selected from -(CH2)n- (wherein n = 0 to 4), -COO-(CH2)k- (wherein k = 1 to 6), -C(O)-NH-C(CH3)2- and CH(CH2CH3)-.

[0059] Preferred monomers of the above formula include, for example, those of the following formula:

[0060] H2C=CH-X-SO3H

[0061] H2C=C(CH3)-X-SO3H

[0062] HO3S-X-(R 5 )C=C(R 6 )-X-SO3H

[0063] Where R 5 and R 6 are independently selected from -H, -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, and X represents an optionally present spacer group selected from -(CH2)n- (wherein n=0 to 4), -COO-(CH2)k (wherein k=1 to 6), -C(O)-NH-C(CH3)2- and -C(O)-NH-CH(CH2CH3)-.

[0064] Preferred monomers containing sulfonic acid groups are 1-acrylamido-1-propanesulfonic acid, 2-acrylamido-2-propanesulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, 2-methacrylamido-2-methyl-1-propanesulfonic acid, 3-methacrylamido-2-hydroxypropanesulfonic acid, allylsulfonic acid, methallylsulfonic acid, allyloxybenzenesulfonic acid, methallyloxybenzenesulfonic acid, 2-hydroxy-3-(2-propenyloxy)propanesulfonic acid, 2-methyl-2-propene-1-sulfonic acid, styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, sulfomethacrylamide, sulfomethylmethacrylamide and mixtures of the acids or their water-soluble salts. Particularly preferred is 2-acrylamido-2-methyl-1-propanesulfonic acid.

[0065] The sulfonic acid groups may be present in the polymer in all or partly neutralized form, i.e. the acidic hydrogen atoms of the sulfonic acid groups may be replaced in some or all of the sulfonic acid groups by metal ions, preferably alkali metal ions, in particular sodium ions. According to the invention, preference is given to using copolymers containing partially or completely neutralized sulfonic acid groups.

[0066] The molar mass of the sulfonic acid polymer can be varied to tailor the properties of the polymer to the desired intended application. The number average molecular weight of the copolymer can be from 2000 to 200,000 g mol -1 , 4000 to 25,000 g mol -1 , or 5000 to 15,000 gmol -1 The polymer preferably has a pH of from 3 to 5, such as from 3.5 to 4.5.

[0067] The polycarboxylates may be copolymers comprising sulfonic acid monomers and acrylic acid monomers.

[0068] At least one polycarboxylate comprises maleic acid monomers. Such polymers are preferably present in an amount of 0.1 to 5 weight percent, 0.2 to 4.5 weight percent, 0.3 to 4 weight percent, 0.3 to 3.5 weight percent, 0.4 to 3 weight percent, 0.5 to 2.5 weight percent, 0.6 to 2 weight percent, or 0.7 to 1.5 weight percent.

[0069] The viscosity of the polymer may be 500 to 3000 mPa.s, 750 to 2500 mPa.s, 1000 to 2000 mPa.s. The weight average molecular weight of such copolymer may be 10,000 to 100,000 g mol -1 , 20,000 to 80,000 g mol -1 , 30,000 to 70,000 g mol -1 , or 45,000 to 55,000 g mol -1 .

[0070] The polycarboxylate may be a copolymer comprising maleic acid monomers and acrylic acid monomers.

[0071] The acrylic acid-maleic acid copolymer may be formed from 2-acrylic acid and 2,5-furandione. The pH of the acrylic acid-maleic acid copolymer evaluated by DIN 19268 may be 7 to 9, for example 7.5 to 8.5.

[0072] The polymer may be an acrylic acid homopolymer, an acrylic acid-sulfonic acid, and / or an acrylic acid-maleic acid copolymer.

[0073] The polymer may comprise one or more polycarboxylate homopolymers and one or more polycarboxylate copolymers. The homopolymers and copolymers may be present in a ratio of 1:20 to 1:2, preferably 1:15 to 1:5.

[0074] The polymer may include polyepoxysuccinic acid (PESA) or a derivative thereof. Polyepoxysuccinic acid is also known as epoxysuccinic acid homopolymer, polyoxirane-2,3-dicarboxylic acid, 2,3-oxirane dicarboxylic acid homopolymer, or poly (1-oxirane-2,3-dicarboxylic acid); and has the following general structure:

[0075]

[0076] And its derivatives have the following general structure:

[0077]

[0078] Where R can be hydrogen or any organic chain (but preferably an ester, such as C 1-4 alkyl), and wherein M can be any cation (preferably Na + , H + , K + and / or NH4 + ).

[0079] Unless otherwise stated, all references to PESA hereinafter should be construed to refer to polyepoxysuccinic acid or its derivatives.

[0080] The weight average molecular weight of PESA can range from 100 to 10,000 g mol -1 , 400 to 2000 g mol -1 , 1000 to 1800 gmol -1 The PESA may have 2 to 100 repeating monomer units, such as 2 to 50, 2 to 45, 2 to 20 or 2 to 10 repeating monomer units.

[0081] The polymer may comprise PESA in an amount of 0.1 to 5 wt%, 0.1 to 4 wt%, 0.15 to 3 wt%, 0.2 to 1.9 wt%, 0.25 to 1.5 wt%, or 0.6 to 1.1 wt%. PESA is preferably present in an amount of 5 to 20 wt%, 8 to 19 wt%, or 9 to 15 wt%, relative to the total amount of polymer present.

[0082] The polymer may include any biodegradable polymer.

[0083] Biodegradable polymers may include, for example, Alcoguard (RTM) H 5941.

[0084] Biodegradable polymers may comprise a bio-based carbohydrate backbone, such as starch, cellulose or inulin. The polymer may comprise one or more synthetic, fossil-based grafting groups.

[0085] The polymer may be cationic, anionic or amphoteric.

[0086] The dishwashing, preferably automatic dishwashing detergent compositions of the present invention may comprise one or more surfactants. Any nonionic, anionic, cationic, amphoteric or zwitterionic surfactant or a suitable mixture thereof may be used. Many such suitable surfactants are described in "Surfactants and Detersive Systems" by Kirk Othmer (Encyclopedia of Chemical Technology, 3rd edition, volume 22, pages 360-379), which is incorporated herein by reference. Preferably, a bleach-stable surfactant may be used.

[0087] In the case of automatic dishwashing compositions, it is preferred to minimize the amount of anionic surfactants. Thus, preferably, the composition comprises no more than 15 wt%, no more than 10 wt%, no more than 5 wt%, no more than 2 wt%, no more than 1 wt% anionic surfactants, or is free of anionic surfactants. Preferably, the composition comprises no more than 15 wt%, no more than 10 wt%, no more than 5 wt%, no more than 2 wt%, no more than 1 wt% ionic surfactants, or is free of any type of ionic surfactants.

[0088] Nonionic surfactants are preferred for use in automatic dishwashing products. The composition may comprise 5 to 25 wt%, 10 to 20 wt%, 11 to 19 wt%, 12 to 18 wt%, 13 to 17 wt%, 14 to 16 wt%, or 15 wt% of one or more nonionic surfactants.

[0089] The nonionic surfactant can be an alkyl alkoxylate that is optionally end-capped. A preferred class of nonionic surfactants is ethoxylated nonionic surfactants, which are prepared by the reaction of monohydroxy alkanols or alkylphenols having 6 to 20 carbon atoms. Preferably, the surfactant has at least 12 moles per mole of alcohol or alkylphenol. Particularly preferred nonionic surfactants are nonionic, which come from straight-chain fatty alcohols having 10 to 20 carbon atoms and at least 5 moles of ethylene oxide per mole of alcohol. The nonionic surfactant can contain propylene oxide (PO) units in the molecule. The PO unit can account for up to 40 weight %, 35 weight %, 30 weight %, 25 weight %, 20 weight % or up to 15 weight % of the total molecular weight of the nonionic surfactant.

[0090] Mixtures of any of the above nonionic surfactants are suitable for use in the compositions of the present invention.

[0091] The dishwashing, preferably automatic dishwashing detergent compositions of the present invention may comprise one or more enzymes. Preferably, the one or more enzymes are selected from proteases, lipases, amylases, cellulases and peroxidases, with proteases and amylases being most preferred. Most preferably, proteases and / or amylases are included in the compositions according to the present invention, as such enzymes are particularly effective in dishwashing detergent compositions.

[0092] The one or more enzymes may be present in an amount of 1 to 40 wt %, 2 to 38 wt %, 4 to 36 wt %, 6 to 34 wt %, 8 to 32 wt %, 10 to 30 wt %, 12 to 28 wt %, 14 to 26 wt %, 16 to 24 wt %, 18 to 24 wt %, 20 to 24 wt %, 22 to 24 wt %, or 23 wt %, based on the weight of the detergent composition.

[0093] The dishwashing, preferably automatic dishwashing detergent compositions of the present invention may contain one or more bleaching agents, preferably in combination with one or more bleach activators and / or one or more bleach catalysts. The one or more bleaching agents are preferably selected from the group consisting of oxygen-releasing bleaches, chlorine-releasing bleaches and mixtures thereof.

[0094] The bleaching agent may comprise the active bleaching substance itself or a precursor of such a substance. The bleaching agent may be selected from the group consisting of inorganic peroxides, organic peracids and mixtures thereof. The terms "inorganic peroxide" and "organic peracid" include salts and derivatives thereof. Inorganic peroxides include percarbonates, perborates, persulfates, hydrogen peroxide and derivatives and salts thereof. Sodium and potassium salts of these inorganic peroxides are suitable, particularly the sodium salt. Sodium percarbonate is particularly preferred.

[0095] The active bleach is preferably present in an amount of 5 to 25 wt%, 7 to 23 wt%, 9 to 19 wt%, or 11 to 17 wt%.

[0096] The detergent composition may also contain one or more bleach activators and / or bleach catalysts. If activation of the bleach is desired, any suitable bleach activator may be included, such as tetraacetylethylenediamine (TAED). Any suitable bleach catalyst may be used, such as manganese acetate or binuclear manganese complexes, such as those described in EP 1741774 A1, the contents of which are incorporated herein by reference. Organic peracids such as perbenzoic acid and peroxycarboxylic acids such as phthalimidoperoxycaproic acid (PAP) do not require the use of bleach activators or catalysts because these bleaches are active at relatively low temperatures such as 30°C.

[0097] The bleach catalyst may be a manganese complex comprising 1,4,7-triazacyclononane (TACN) or any derivative of the TACN ligand such as 1,4,7-trimethyl-TACN, manganese oxalate, manganese acetate, or a binuclear manganese complex, for example a binuclear manganese complex comprising TACN or any derivative of the TACN ligand such as 1,4,7-trimethyl-TACN.

[0098] Furthermore, the object of the present invention is also solved by using the inventive dishwashing, preferably automatic dishwashing detergent composition for protecting silver cutlery from silver corrosion during dishwashing, preferably in automatic dishwashing.

[0099] Furthermore, the object of the present invention is also solved by protecting silver cutlery from silver corrosion in a dishwashing process, preferably in an automatic dishwashing process, using a dishwashing, preferably automatic dishwashing detergent composition comprising a tamarind extract comprising a mixture of reducing monosaccharides and reducing disaccharides.

[0100] Furthermore, the object of the present invention is solved by a method for protecting silverware from corrosion during dishwashing, which method comprises adding at least one reducing monosaccharide and / or at least one reducing disaccharide to a detergent composition for automatic dishwashing.

[0101] Furthermore, the object of the present invention is also solved by a method for protecting silverware from corrosion during dishwashing, the method comprising adding a tamarind extract comprising a mixture of reducing monosaccharides and reducing disaccharides to an automatic dishwashing detergent composition.

[0102] The following non-limiting examples are provided to illustrate embodiments of the present invention and to aid in the understanding of the present invention, but are not intended to limit the scope of the present invention, which is defined by the appended claims.

[0103] Experimental part:

[0104] The natural food referred to in the present invention is "Tamarindus Indica L." The whole extract of Tamarindus Indica L. as well as selected components and mixtures thereof have been shown to prevent silver corrosion in ADW compositions lacking BTA and / or TTA currently used. In particular, the known reducing sugars in Tamarindus Indica L., i.e., a mixture of specific monosaccharides and disaccharides such as glucose, galactose, fructose, arabinose, lactose, melibiose, cellobiose and maltose, have been shown to be potential natural alternatives for silver corrosion resistance in ADW formulations for superior material care.

[0105] In the first case, an extract of tamarind pulp from the common brown Indian variety was used. The tamarind fruit was extracted in warm water and the contents were directly tested for silver corrosion protection with a baseline formulation that did not contain BTA / TTA in the composition.

[0106] Subsequently, a range of reducing sugars in tamarind pulp extracts were obtained from commercial sources and used as a silver corrosion protectant in the form of a mixture. Studies have shown that the common brown Indian variety of tamarind contains 25-45% reducing sugars. In particular, depending on the growing region, the fruit may contain a mixture of reducing mono- and disaccharides such as glucose, fructose, galactose, lactose, arabinose, and non-reducing sugars such as sucrose. A range of reducing mono- and disaccharides, namely cellobiose, melibiose, maltose, lactose, glucose, fructose, arabinose and galactose in a specific mixture were tested.

[0107] The performance of the natural extracts as well as the reducing sugar components were tested in a beaker test and scored by visual assessment based on the degree of tarnish.

[0108] Experimental conditions:

[0109] Bench tests were conducted to evaluate the extent of silver tarnishing in the presence of various silver corrosion protectants. The test procedure used was as follows:

[0110] In a 5L beaker, 3L of water was heated to 50°C over 2 hours and stirred to evenly heat. The reference formulation was dissolved in the water over 30 minutes to dissolve completely. Subsequently, as described in Tables 1 and 2, a silver corrosion protection agent (B1, T1, S1-S6, or 1a-8a) was added in appropriate amounts. After 10 minutes, the handle of a silver fork / spoon / butter knife was suspended in the solution without causing any interference to the magnetic stirring bar, and the solution was stirred continuously. After 24 hours, the silverware was removed from the beaker and dried under ambient conditions.

[0111] The silver was then visually evaluated and rated as an average of luster and brightness from 1.0 (complete tarnish to black), 2.0 (significant tarnish), 3.0 (acceptable tarnish), 4.0 (slight discoloration or luster loss) to 5.0 (no tarnish at all, almost complete retention of luster and brightness).

[0112] Experimental results:

[0113]

[0114] Table 1: Comparative formulations and formulations of the invention.

[0115]

[0116] Table 2: Additional comparative formulations and formulations of the invention.

[0117] Silver corrosion protection agent (1.0 wt%) T1 B1 S1 S2 S3 S4 S5 S6 BTA - + - - - - - - Tamarind Extract + - - - - - - - glucose - - + - - - - - sucrose - - - + - - - - lactose - - - - + - - - maltose - - - - - + - - Cellobiose - - - - - - + - Melibiose - - - - - - - +

[0118] Table 3: Individual silver corrosion protection compounds used in the examples

[0119] Silver Corrosion Protectant 1a 2a 3a 4a 5a 6a 7a 8a glucose + + + + - + - - sucrose - + - - - - - - lactose + + + + - - + - maltose + + + + - + + - Cellobiose + + - + + + + + Melibiose + + - + + + + + fructose + - - - - - - - Arabinose + - - - - - - - Galactose + - - - - - - -

[0120] Table 4: Mixtures of individual silver corrosion protection compounds used in the examples.

[0121] The present invention therefore solves the problem of providing a novel alternative composition for silver protection in dishwashing processes which, on the one hand, reduces the release of harmful and poorly biodegradable benzotriazoles into the environment and, on the other hand, has comparable efficacy in inhibiting silver corrosion compared to the use of compositions comprising BTA and / or TTA.

[0122] Although the principles of the present invention have been explained with respect to certain specific embodiments and are provided for illustrative purposes, it should be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it should be understood that the invention disclosed herein is intended to cover such modifications that fall within the scope of the appended claims. The scope of the present invention is limited only by the scope of the appended claims.

Claims

1. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, characterized in that The detergent composition comprises at least one reducing monosaccharide and / or at least one reducing disaccharide.

2. The dishwashing detergent composition, preferably automatic dishwashing detergent composition, according to claim 1, characterized in that The detergent composition is substantially free, preferably completely free, of any triazoles, especially BTA and TTA.

3. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to claim 1 or 2, characterized in that The at least one reducing monosaccharide is selected from the group consisting of glucose, fructose, galactose, deoxyribose, ribose, xylose, arabinose, lyxose, allose, altrose, mannose, gulose, idose and talose.

4. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to any one of the preceding claims, characterised in that The at least one reducing disaccharide is selected from the group consisting of maltose, lactose, cellobiose, melibiose, chitobiose, kojibiose, nigerobiose, isomaltose, sophorose, laminaribiose, gentiobiose, trehalulose, turanose, maltulose, leucrose, isomaltulose, gentiodiulose, mannobiose, plantagobiose, rutinose, rutinulose and xylobiose.

5. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to any one of the preceding claims, characterised in that The at least one reducing monosaccharide is selected from the group consisting of glucose, fructose, galactose and arabinose; and the at least one reducing disaccharide is selected from the group consisting of maltose, lactose, cellobiose and melibiose.

6. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to any one of the preceding claims, characterised in that The detergent composition further comprises at least one non-reducing monosaccharide and / or at least one non-reducing disaccharide.

7. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to claim 6, characterized in that The detergent composition further comprises at least sucrose and / or trehalose.

8. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to any one of the preceding claims 1 to 5, characterized in that The detergent composition is substantially free, preferably completely free, of any non-reducing monosaccharides and non-reducing disaccharides.

9. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to any one of the preceding claims, characterised in that The detergent composition comprises at least two different reducing disaccharides.

10. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to claim 9, characterized in that The detergent composition comprises two different reducing disaccharides, with the proviso that no other reducing monosaccharides or reducing disaccharides are included.

11. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to claim 10, characterized in that The two different reducing disaccharides are cellobiose and melibiose.

12. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to any one of the preceding claims, characterised in that The detergent composition is substantially free, preferably completely free, of any other reducing agents other than reducing monosaccharides and / or reducing disaccharides.

13. A dishwashing detergent composition, preferably an automatic dishwashing detergent composition, according to any one of the preceding claims, characterised in that The detergent composition comprises in total 0.1 to 5 wt%, preferably 0.25 to 3 wt%, more preferably 0.4 to 1.2 wt% of the reducing monosaccharides and reducing disaccharides.

14. Use of a dishwashing detergent composition, preferably an automatic dishwashing detergent composition, as claimed in any one of the preceding claims 1 to 13 for protecting silver cutlery from silver corrosion in a dishwashing process, preferably in an automatic dishwashing process.

15. Use of a dishwashing detergent composition, preferably an automatic dishwashing detergent composition, comprising a tamarind extract comprising a mixture of reducing monosaccharides and reducing disaccharides for protecting silver cutlery from silver corrosion in a dishwashing process, preferably an automatic dishwashing process.

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