AU2011260477A1 - Laundry detergent composition - Google Patents

Abstract

The present invention relates to a laundry detergent composition comprising 0.005 to less than 0.5 wt% hydroxamate and 3 to 80 wt% of a surfactant system comprising anionic and non-ionic surfactant in a ratio of from 1:1.1 to 19:1. The composition exhibits enhanced detergency, especially in relation to particulate stains.

Description

WO 2011/151170 PCT/EP2011/057935 1 Laundry Detergent Composition Field of the invention The present invention relates to the use of hydroxamic acid and 5 its corresponding salts in laundry detergent compositions with low levels of zeolite and phosphate builder, leading to improved detergency and stain removal. Background of the invention 10 Improvement of stain removal is one of the constant goals of the detergent industry, as this may lead to savings on the use of chemicals in detergent compositions, or may lead to washing at lower temperatures, and/or for shorter times, and therewith saving energy. Therefore, there is still an interest to improve 15 the detergency effect, especially the primary detergency effect of laundry detergent compositions on textile stains, for example particulate stains, such as stains comprising soils or clay, or plant based stains, such as grass. Especially particulate stains are difficult to remove during the 20 laundering process. Hydroxamic acids are a class of chemical compounds in which a hydroxylamine is inserted into a carboxylic acid. The general structure of a hydroxamic acid is the following: 25 C OH R1 N H Formula 1 WO 2011/151170 PCT/EP2011/057935 2 in which R' is an organic residue, for example alkyl or alkylene groups. The hydroxamic acid may be present as its corresponding alkali metal salt, or hydroxamate. 5 The hydroxamates may conveniently be formed from the corresponding hydroxamic acid by substitution of the acid hydrogen atom by a cation: 0 0 OH LOH 1 e L R C OH R C R N H H (Formula 2) 10 L+ is a monovalent cation such as for example the alkali metals (e.g. potassium, sodium), or ammonium or a substituted ammonium. 15 Hydroxamic acids and hydroxamates are known to be useful as metal chelators. They have also been used in detergent compositions in order to improve bleaching performance, as well as use as a builder substance. 20 EP 388 389 A2 discloses bleach free under built liquid detergent compositions containing hydroxamic acids and their derivatives which assist in the removal of bleachable wine stains from fabrics during laundering. Hydroxamic acids as in formula 1 are disclosed, wherein R' represents an optionally 25 substituted straight- or branched chain C5-C21 alkyl or C5-C21 alkenyl group or an optionally-substituted phenyl group, and R 2 represents hydrogen, or an optionally substituted C1-C6 alkyl group, or an optionally-substituted phenyl group. One of the examples shows an improved bleaching performance when a 30 hydroxamate is used in a detergent composition in hard water WO 2011/151170 PCT/EP2011/057935 3 (200 German hardness, which is about 143 milligram calcium per litre) . The examples use C12 linear, C12 branched, C13 branched and C18 hydroxamates in detergent formulations comprising mixtures of anionic surfactant and nonionic surfactant. In 5 examples I, II and IV there is an excess of nonionic surfactant of at least 1.25 to 1 and in example III there is 100% anionic surfactant. The liquids also contain at least 6 wt% ethanol, which assists in solubilising the long chain hydroxamates. 10 EP 384 912 A2 discloses the use of hydroxamic acids and their derivatives as stabilizers for peroxygen bleach compounds in built, mainly granular, detergent compositions. Fully formulated detergent powder examples with 20 wt% zeolite used C12, C13 and C12 branched hydroxamates. C18 was also used. 15 US 4,874,539 discloses polymeric carboxy hydroxamic acids useful as detergent additives, especially as metal ion chelating agents, and also leading to improved tea stain removal from a test cloth, as compared to a detergent powder 20 without a metal ion chelating agent. US 4,863,636 discloses liquid detergent compositions comprising one or more detersive surfactants and one or more of N hydroxyimide or carboxy hydroxamic acid detergent additives. 25 These compounds serve as active metal ion chelants, leading to improved stain removal. WO 97/48786 discloses a multicomponent system for use with detergent substances, containing an oxidation catalyst, a 30 suitable oxidant, at least one mediator that has been selected from the group of, among others, hydroxamic acids and hydroxamic acid derivatives, a co-mediator, and optionally a low quantity of at least one free amine of each inserted WO 2011/151170 PCT/EP2011/057935 4 mediator. This system leads to improved bleach function of the detergent, and less consumption of a mediator. GB 1317445 discloses detergent compositions comprising an 5 alkali-metal salt of a hydroxamic acid. The function of this salt is to prevent the corrosion of copper and copper alloys that is utilised in the construction of the washing machines. Copending patent application PCT/EP2009/067193 describes 10 laundry detergent formulations comprising 0.5 to 20% by weight hydroxamic acid or its corresponding hydroxamate having a structure as specified therein. It is also shown in this document that the primary detergent effect, especially on red clay particulate soil, can be improved when applying these 15 laundry detergent formulations for treating soiled fabric. It has now surprisingly been found that this beneficial effect can also be obtained when using laundry detergent formulations similar to those of PCT/EP2009/067193 but containing less than 20 0.5% by weight hydroxamic acid or its corresponding hydroxamate. Laundry detergents need to be able to remove everyday dirt and stains that are commonly found in a wash load. Two particular 25 satains that are problematic, especially when children's wear or sport's wear is being washed, are clay soil stains and grass stains. One type of clay that is particularly resistant to removal by surfactants alone is red clay, such as red pottery clay or Red Georgia clay. This is a particulate soil stain. 30 Definition of the invention Accordingly, the present invention provides a laundry detergent composition comprising WO 2011/151170 PCT/EP2011/057935 5 a) 0.005 to less than 0.5 wt% hydroxamic acid or its corresponding hydroxamate of the structure: O /C\ /OH RI N II R2 wherein R1 is 5 a straight or branched C4-C20 alkyl, or a straight or branched substituted C4-C20 alkyl, or a straight or branched C4-C20 alkenyl, or a straight or branched substituted C4-C20 alkenyl, or an alkyl ether group CH3 (CH 2 )n (EO)m wherein n is from 2 to 20 10 and m is from 1 to 12, or a substituted alkyl ether group CH3 (CH 2 )n (EO)m wherein n is from 2 to 20 and m is from 1 to 12, and the types of substitution include one or more of -NH 2 , -OH, C OH -S-, -0-, -COOH, and C - N 15 and R2 is selected from hydrogen and a moiety that forms part of a cyclic structure with a branched R1 group, b) 3 to 80 wt% of detersive surfactant system comprising (i) anionic surfactant; and (ii) nonionic surfactant, 20 wherein the ratio of (i) to (ii) lies in the range 1:1.1 to 19:1, and wherein the weight ratio a) to b) lies in the range 1: 6 to 1:16000, and c) optionally, other ingredients to 100 wt% provided that 25 zeolite and phosphate builders are present at less than 5 wt% and ethanol is present at a level of less than 5 wt%.

WO 2011/151170 PCT/EP2011/057935 6 It should be understood that references to a number of carbon atoms include mixed chain length materials provided that some of the hydroxamate material falls within the ranges specified and the ratios and amounts are determined by excluding any 5 material falling outside of the specified range. Soap is not included in the calculation of anionic surfactant amounts and ratios. 10 It is undesirable to have ethanol present at all as it is an explosion hazard during manufacture, and subsequently. If a high level of surfactant is present, it is desirable to seek alternative hydrotrope systems. We prefer a hydrotrope system comprising propylene glycol and glycerol at levels of at least 15 6 wt%, more preferably at least 10 wt%. The preferred hydroxamates are those where R2 is Hydrogen and R is C8 to C14 alkyl, preferably normal alkyl, most preferably saturated. 20 The detergent composition is preferably used in aqueous wash liquor, but may comprise one or more solvents suitable for use for domestic laundry purposes. Preferably, the improved stain removal occurs during the main wash of the laundry process, 25 i.e. preferably the laundry detergent composition in which the hydroxamates are used is a main wash product. The wash liquor is preferably free of formate salts. Furthermore, it is preferably free from bleach, especially peroxygen bleach. 30 The composition may comprise from 1 to 15 wt% soap. The preferred soaps are made from saturated fatty acids.

WO 2011/151170 PCT/EP2011/057935 7 Especially preferred compositions comprise at least 0.5 wt% of soil release polymer. This improves the multiwash performance of the detergent system for the removal of the clay. Inclusion of at least 0.5 wt% anti redeposition polymer is also 5 beneficial due to the very high efficiency of primary detergency soil removal meaning that there is an increased level of soil in the wash liquor, which must then be prevented from redeposition onto the same or a different piece of fabric. 10 The preferred weight ratio of hydroxamate to detersive surfactant system for optimum particulate red clay soil removal lies in the range 1:10 to 1:400. An even more preferred range of weight ratios being 1:20 to 1:100. 15 The preferred ratio of anionic to nonionic surfactant for particulate red clay soil removal is at least 1:1, more preferably at least 3:2. Preferably, it is at most 9:1. So a most preferred range is 1:1 to 9:1, or 3:2 to 9:1. 20 The compositions are particularly suitable for use on particulate stains such as soils and clays, especially red clay, and also surprisingly grass. The invention also extends to the use of 0.005 to less than 0.5 25 wt% hydroxamic acid or its corresponding hydroxamate of the structure: /C\ /OH RI N R2 wherein R is a C8 normal alkyl group, and R2 is a hydrogen atom, in a laundry detergent composition, for improving the WO 2011/151170 PCT/EP2011/057935 8 particulate soils stain removal from a textile substrate, wherein the composition further comprises a detersive surfactant system comprising anionic surfactant and nonionic surfactant at a concentration from 3 to 80 wt%; and optionally 5 other ingredients to 100 wt%. The hydroxamate may be incorporated within the laundry detergent compositions in any suitable fashion within the knowledge of a person of ordinary skill in the art. 10 Detailed Description of the Invention Whenever either the term 'hydroxamic acid' or 'hydroxamate' is used in this specification, this encompasses both hydroxamic acid and the corresponding hydroxamate (salt of hydroxamic 15 acid), unless indicated otherwise. All percentages mentioned herein are by weight calculated on the total composition, unless specified otherwise. The abbreviation 'wt%' is to be understood as % by weight of the 20 total composition. The stained fabric is treated with the laundry detergent composition comprising hydroxamate according to the invention and the primary detergency is the measured stain removal by the 25 laundry composition on the stain. This is a separate process to so-called soil release using a polymer, which is treatment of fabric with a polymer (through a wash or other such treatment), with subsequent staining of the fabric, the soil release polymer having the effect of the easier removal of the stain. 30 The following definitions pertain to chemical structures, molecular segments and substituents: WO 2011/151170 PCT/EP2011/057935 9 Molecular weights of monomers and polymers are expressed as weight average molecular weights, except where otherwise specified. 5 The textile/fabric substrates used can be any typical textile/fabric substrate, such as cotton (woven, knitted & denim), polyester (woven, knitted & micro fibre), nylon, silk, polycotton (polyester/cotton blends), polyester elastane, cotton elastane, viscose rayon, acrylic or wool. Particularly 10 suitable textile/fabric substrates are cotton, polycotton and polyester substrates. Particulate stains are stains comprising for example dirt, soil, clay, mud or soot. They are predominately solid in nature 15 and come into contact with fabrics in the course of their regular use. Hydroxamic acid and derivatives The general structure of a hydroxamic acid in the context of 20 the present invention has been indicated in formula 3, and R', is as defined above. When R1, is an alkyl ether group CH3 (CH 2 )n (EO)m wherein n is from 2 to 20 and m is from 1 to 12 then the alkyl moiety terminates this side group. Preferably, R' is chosen from the group consisting of C4, C5, C6, C7, C8, C9, Cio, 25 C11, or C12 or C14 normal alkyl group, most preferably R1 is at least a C8-14 normal alkyl group. When the C8 material is used this is called octyl hydroxamic acid. The potassium salt is particularly useful.

WO 2011/151170 PCT/EP2011/057935 10 H NOH octanohydroxamic acid K salt However, other hydroxamic acids, whilst less preferred, are suitable for use in the present invention. Such suitable compounds include, but are not limited to, the following 5 compounds:

NH

2 N OH 2 0 NH 0 OH Lysine Hydroxamate*HCI NH 2 H N H2 SH NH2 H N >D H Methionine Hydroxamate Norvaline Hydroxamate 0 0 Such hydroxamic acids are commercially available. 25 Without wishing to be bound by theory, we believe that the hydroxamate acts by binding to metal ions that are present in the soil on the fabric. This binding action, which is, in effect, the known sequestrant property of the hydroxamate is 30 not, in itself, of any use to remove the soil from the fabric. The key is the "tail" of the hydroxamate i.e. the group R minus any branching that folds back onto the amate Nitrogen via group R 2. The tail is selected to have an affinity for the WO 2011/151170 PCT/EP2011/057935 11 surfactant system. This means that the soil removal ability of an already optimised surfactant system is further enhanced by the use of the hydroxamate as it, in effect, labels the difficult to remove particulate material (clay) as "soil" for 5 removal by the surfactant system acting on the hydroxamate molecules now fixed to the particulates via their binding to the metal ions embedded in the clay type particulates. The detersive surfactants will adhere to the hydroxamate, leading overall to more surfactants interacting with the fabric, 10 leading to better soil release. Therewith the hydroxamic acids act as a linker molecule facilitating the removal and suspension of the particulate soil from the fabric into a wash liquor and thus boosting the primary detergency. 15 This enhancing of the primary detergency of surfactant systems is especially relevant when using concentrated liquid detergent compositions, as the pH during the laundering process is relatively low (pH 7.5-8) as compared to traditional laundering processes with particulate detergent compositions (pH 9-10.5). 20 The lower pH during the laundering process with liquid detergent compositions may lead to reduced soil release, as the surface charges of the soils are less negative as compared to the higher pH during the conventional well built and buffered laundering processes, achieved with conventional zeolite or 25 phosphate built powder products. This surface charge of the soil may lead to increased repellence of the surfactants by the soil, possibly leading to reduced release of the soil. Hence, in a preferred embodiment, the hydroxamates are used in liquid detergent compositions, and more preferred the detersive 30 surfactant concentration in said liquid detergent compositions is from 20 to 80 wt%.

WO 2011/151170 PCT/EP2011/057935 12 The hydroxamates have a higher affinity for transition metals, like iron, than for alkaline earth metals like calcium and magnesium, therefore the hydroxamic acid primarily acts to improve the removal of soil on fabric, especially particulate 5 soils, and not additionally as a builder for calcium and magnesium. This selectively is especially beneficial if the laundering composition is underbuilt; especially when it comprises less than 5 wt% zeolite or phosphate builder. 10 Surfactants The laundry detergent composition in which the hydroxamate is used comprises a detersive surfactant system at a concentration from 3 to 80 wt%. By a detersive surfactant system, we mean that the surfactants therein provide a detersive, i.e. cleaning 15 effect to textile fabrics treated as part of a laundering process. Other surfactants, which are not detersive surfactants, can be used as part of the composition. Preferably, the detersive surfactant is present at a level of 20 from 5 to 60 wt%, more preferably from 10 to 50 wt%. Even more preferably, the detersive surfactant system comprises at least 20, or 30 or even 40 wt% of the composition. In general, any surfactant may be used as detersive 25 surfactants, including anionic, nonionic, cationic, and amphoteric or zwitterionic surfactants, or combinations of these, provided that there is anionic and nonionic surfactant present in the range of ratios specified above. 30 Cationic surfactant may optionally be present as part of the detersive surfactant.

WO 2011/151170 PCT/EP2011/057935 13 Anionic surfactant may be present at a level of from 0.1 to 50 wt%, preferably from 1 to 40 wt%, more preferably from 1.5 to 25 wt%. Nonionic surfactant may be incorporated at a level of from 0.1 to 50 wt%, preferably from 1 to 40 wt%, more 5 preferably from 1.5 to 25 wt%. The ratio of anionic surfactant to nonionic surfactant is from 19:1 to 1:1.1, more preferably from 9:1 to 1:1. In general, the nonionic and anionic surfactants of the 10 surfactant system may be chosen from the surfactants described in 'Surface Active Agents' Vol. 1, by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz, Perry & Berch, Interscience 1958, in the current edition of 'McCutcheon's Emulsifiers and Detergents' published by Manufacturing 15 Confectioners Company or in 'Tenside-Taschenbuch', H. Stache, 2nd Edn., Carl Hauser Verlag, 1981. Nonionic surfactant For the purposes of this disclosure, 'nonionic surfactant' 20 shall be defined as amphiphilic molecules with a molecular weight of less than about 10,000, unless otherwise noted, which are substantially free of any functional groups that exhibit a net charge at the normal wash pH of 6-11. 25 Any type of nonionic surfactant may be used, although preferred materials are further discussed below. Highly preferred are fatty acid alkoxylates, especially ethoxylates, having an alkyl chain of from C 8

-C

3 5 , preferably C 8 -C30, more preferably C 1 0

-C

2 4 , especially C 10

-C

18 carbon atoms, for example, the Neodol range 30 from Shell (The Hague, The Netherlands); ethylene WO 2011/151170 PCT/EP2011/057935 14 oxide/propylene oxide block polymers which may have molecular weight from 1,000 to 30,000, for example, Pluronic (trademark) from BASF (Ludwigshafen, Germany); and alkylphenol ethoxylates, for example Triton X-100, available from Dow Chemical (Midland, 5 Mich., USA). Other nonionic surfactants should also be considered within the scope of this invention. These include condensates of alkanolamines with fatty acids, such as cocamide DEA, polyol 10 fatty acid esters, such as the Span series available from Uniqema (Gouda, The Netherlands), ethoxylated polyol-fatty acid esters, such as the Tween series available from Uniqema (Gouda, The Netherlands), alkylpolyglucosides, such as the APG line available from Cognis (Dtisseldorf, Germany) and n 15 alkylpyrrolidones, such as the Surfadone series of products marketed by ISP (Wayne, N.J., USA). Furthermore, nonionic surfactants not specifically mentioned above, but within the definition, may also be used. 20 The more preferred nonionic surfactants are the fatty acid ethoxylates with an average degree of ethoxylation of 7, alkoxylates with one propylene oxide and multiple ethylene oxide units, seed oil based surfactant, such as Ecosurf SA7 or SA9 available from Dow Chemical, APGs, and branched alcohol 25 Guerbet nonionics. Anionic surfactant 'Anionic surfactants' are defined herein as amphiphilic molecules comprising one or more functional groups that exhibit 30 a net anionic charge when in aqueous solution at the normal wash pH of between 6 and 11.

WO 2011/151170 PCT/EP2011/057935 15 Preferred anionic surfactants are the alkali metal salts of organic sulphur reaction products having in their molecular structure an alkyl radical containing from about 6 to 24 carbon atoms and a radical selected from the group consisting of 5 sulphonic and sulphuric acid ester radicals. Although any anionic surfactant hereinafter described can be used, such as alkyl ether sulphates, soaps, fatty acid ester sulphonates, alkyl benzene sulphonates, sulphosuccinate esters, 10 primary alkyl sulphates, olefin sulphonates, paraffin sulphonates and organic phosphate; preferred anionic surfactants are the alkali and alkaline earth metal salts of fatty acid carboxylates, fatty alcohol sulphates, preferably primary alkyl sulfates, more preferably they are ethoxylated, 15 for example alkyl ether sulphates; alkylbenzene sulphonates, alkyl ester fatty acid sulphonates, especially methyl ester fatty acid sulphonates and mixtures thereof. Cationic, amphoteric surfactants and/or zwitterionic 20 surfactants Also cationic, amphoteric surfactants and/or zwitterionic surfactants may be present in the laundry detergent compositions in which the hydroxamate is used as cosurfactant according to the invention. 25 Preferred cationic surfactants are quaternary ammonium salts of the general formula RiR 2 R3R 4 NV X-, for example where Ri is a C12 C14 alkyl group, R 2 and R 3 are methyl groups, R 4 is a 2-hydroxyethyl group, and X is a chloride ion. This material 30 is available commercially as Praepagen (Trade Mark) HY from Clariant GmbH, in the form of a 40% by weight aqueous solution.

WO 2011/151170 PCT/EP2011/057935 16 In a preferred embodiment the laundry detergent composition in which the hydroxamate is used according to the invention further comprises an amphoteric or zwitterionic surfactant. Amphoteric surfactants are molecules that contain both acidic 5 and basic groups and will exist as zwitterions at the normal wash pH of between 6 and 11. Preferably an amphoteric or zwitterionic surfactant is present at a level of from 0.1 to 20% by weight, more preferably from 0.25 to 15% by weight, even more preferably from 0.5 to 10% by weight. 10 Suitable zwitterionic surfactants are exemplified as those which can be broadly described as derivatives of aliphatic quaternary ammonium, sulfonium and phosphonium compounds with one long chain group having about 8 to about 18 carbon atoms 15 and at least one water solubilizing radical selected from the group consisting of sulfate, sulfonate, carboxylate, phosphate or phosphonate. A general formula for these compounds is: Ri(R 2 )xYVR3Z 20 wherein R, contains an alkyl, alkenyl or hydroxyalkyl group with 8 to 18 carbon atoms, from 0 to 10 ethylene-oxy groups or from 0 to 2 glyceryl units; Y is a nitrogen, sulphur or phosphorous atom; R 2 is an alkyl or hydroxyalkyl group with 1 25 to 3 carbon atoms; x is 1 when Y is a sulphur atom and 2 when Y is a nitrogen or phosphorous atom; R3 is an alkyl or hydroxyalkyl group with 1 to 5 carbon atoms and Z is radical selected from the group consisting of sulfate, sulfonate, carboxylate, phosphate or phosphonate. 30 Preferred amphoteric surfactants are amine oxides, for example coco dimethyl amine oxide.

WO 2011/151170 PCT/EP2011/057935 17 Preferred zwitterionic surfactants are betaines, and especially amidobetaines. Preferred betaines are C8 to C18 alkyl amidoalkyl betaines, for example coco amido betaine. These may be included as co-surfactants, preferably present in an amount 5 of from 0 to 10 wt %, more preferably 1 to 5 wt %, based on the weight of the total composition. Other betaines that may be employed are sulfatobetaines, such as 3 (dodecyldimethylammonium)-1-propane sulfate; and 2 (cocodimethylammonium)-1-ethane sulfate. Sulfobetaines, such 10 as: 3-(dodecyldimethyl-ammonium)-2-hydroxy-1-propane sulfonate; 3-(tetradecyl-dimethylammonium)-1-propane sulfonate; 3-(C12-C14 alkyl-amidopropyldimethylammonium)-2-hydroxy-1-propane sulfonate; and 3-(cocodimethylammonium)-1-propane sulfonate. Carboxybetaines, such as (dodecyldimethylammonium) acetate 15 (also known as lauryl betaine); (tetradecyldimethylammonium) acetate (also known as myristyl betaine); (cocodimethylammonium) acetate (also known as coconut betaine); (oleyldimethylammonium) acetate (also known as oleyl betaine); (dodecyloxymethyldimethylammonium) acetate; and (cocoamido 20 propyldimethylammonium) acetate (also known as cocoamido-propyl betaine or CAPB). The sulfoniumbetaines, such as: (dodecyldimethylsulfonium) acetate; and 3-(cocodimethyl-sulfonium)-1-propane sulfonate. 25 The phosphoniumbetaines, such as 4-(trimethylphosphonium)-1 hexadecane sulfonate; 3-(dodecyldimethylphosphonium)-1 propanesulfonate; and 2-(dodecyldimethylphosphonium)-1-ethane sulfate. The laundry detergent compositions preferably comprise 30 carboxybetaines or sulphobetaines as amphoteric or zwitterionic surfactants, or mixtures thereof. Especially preferred is lauryl betaine. The betaines and hydroxamates may provide even WO 2011/151170 PCT/EP2011/057935 18 further enhanced particulate soil removal when used together in the compositions according to the invention. Detergency builders 5 The laundry detergent compositions in which the hydroxamate is used preferably comprise low levels of detergency builder, based on the weight of the total composition. The amounts of the inorganic builders zeolite and phosphate are less than 5 wt%. These builders are considered to be harmful to the 10 environment when used in large quantities. Furthermore they need to be used at high levels to have a significant building effect and this is inconsistent with the modern concentrated highly weight efficient laundry detergent formulations. 15 Preferably the builder is selected from the group of alkali and alkaline earth metal carbonates (e.g. sodium carbonate), silicates (e.g. layered silicate), and organic builders such as citrates (e.g. sodium citrate), succinates, sulphamates and malonates, and any combination of these. The organic builders 20 are preferred. They may be used at levels of 1 wt% or more, up to, say, 50 wt%. Organic builders that may be present include polycarboxylate polymers such as polyacrylates and acrylic/maleic copolymers; 25 polyaspartates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-di- and trisuccinates, carboxymethyloxysuccinates, carboxy methyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates; and sulphonated 30 fatty acid salts. Organic builders may be used in minor amounts Especially preferred organic builders are citrates, suitably used in WO 2011/151170 PCT/EP2011/057935 19 amounts of from 1 to 30 wt%, preferably from 1.5 to 10 wt%; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 to 15 wt%, preferably from 1 to 10 wt%. 5 Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form. Other optional Ingredients 10 In addition to the essential components detailed in the claims, the formulation may include one or more optional ingredients to enhance performance and properties. While it is not necessary for these elements to be present in order to practice this invention, the use of such materials is often very helpful in 15 rendering the formulation acceptable for consumer use. Examples of optional components include, but are not limited to: hydrotropes, fluorescent whitening agents, photobleaches, fibre lubricants, reducing agents, enzymes, enzyme stabilising 20 agents (such as borates and polyols), powder finishing agents, defoamers, bleaches, bleach catalysts, soil release agents, especially soil release polymers for cotton or polyester or both, antiredeposition agents, especially antiredeposition polymers, dye transfer inhibitors, buffers, colorants, 25 fragrances, pro-fragrances, rheology modifiers, anti-ashing polymers, preservatives, insect repellents, soil repellents, water-resistance agents, suspending agents, aesthetic agents, structuring agents, sanitisers, solvents, including aqueous and non-aqueous solvents, fabric finishing agents, dye fixatives, 30 wrinkle-reducing agents, fabric conditioning agents and deodorizers.

WO 2011/151170 PCT/EP2011/057935 20 These optional ingredients may include, but are not limited to, any one or more of the following: soap, peroxyacid and persalt bleaches, bleach activators, sequestrants, cellulose ethers and esters, other antiredeposition agents, sodium sulphate, sodium 5 silicate, sodium chloride, calcium chloride, sodium bicarbonate, other inorganic salts, fluorescers, photobleaches, polyvinyl pyrrolidone, other dye transfer inhibiting polymers, foam controllers, foam boosters, acrylic and acrylic/maleic polymers, proteases, lipases, cellulases, amylases, other 10 detergent enzymes, citric acid, soil release polymers, fabric conditioning compounds, coloured speckles, and perfume. The laundry detergent composition may suitably contain a bleach system based on peroxy bleach compounds, for example, inorganic 15 persalts or organic peroxyacids, capable of yielding hydrogen peroxide in aqueous solution. Suitable peroxy bleach compounds include organic peroxides such as urea peroxide, and inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates, persilicates and persulphates. Preferred 20 inorganic persalts are sodium perborate monohydrate and tetrahydrate, and sodium percarbonate. Especially preferred is sodium percarbonate having a protective coating against destabilisation by moisture. Sodium percarbonate having a protective coating comprising sodium metaborate and sodium 25 silicate is disclosed in GB 2 123 044B (Kao). The peroxy bleach compound is suitably present in an amount of from 5 to 35% by weight, preferably from 10 to 25% by weight. 30 The peroxy bleach compound may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. The bleach precursor is suitably WO 2011/151170 PCT/EP2011/057935 21 present in an amount of from 1 to 8% by weight, preferably from 2 to 5% by weight. Preferred bleach precursors are peroxycarboxylic acid 5 precursors, more especially peracetic acid precursors and peroxybenzoic acid precursors; and peroxycarbonic acid precursors. An especially preferred bleach precursor suitable for use in the present invention is N,N,N',N'-tetracetyl ethylenediamine (TAED). Also of interest are peroxybenzoic acid 10 precursors, in particular, N,N,N-trimethylammonium toluoyloxy benzene sulphonate. A bleach stabiliser (heavy metal sequestrant) may also be present. Suitable bleach stabilisers include ethylenediamine 15 tetraacetate (EDTA) and the polyphosphonates such as Dequest (Trade Mark), EDTMP. However, notwithstanding the above it is preferred for the composition to contain no bleach and to rely on the improved clay stain removal derived from the novel hydroxamate and 20 surfactant combination. This is particularly the case for liquid compositions. The detergent compositions may also contain one or more enzymes. Suitable enzymes include the proteases, amylases, 25 cellulases, oxidases, peroxidases and lipases usable for incorporation in detergent compositions. In particulate detergent compositions, detergency enzymes are commonly employed in granular form in amounts of from about 0.1 30 to about 3.0 wt%. However, any suitable physical form of enzyme may be used in any effective amount.

WO 2011/151170 PCT/EP2011/057935 22 Antiredeposition agents, for example cellulose esters and ethers, for example sodium carboxymethyl cellulose, may also be present. 5 The compositions may also contain soil release polymers, for example sulphonated and unsulphonated PET/POET polymers, both end-capped and non-end-capped, and polyethylene glycol/polyvinyl alcohol graft copolymers such as Sokolan (Trade Mark) HP22. Especially preferred soil release polymers 10 are the sulphonated non-end-capped polyesters described and claimed in WO 95 32997A (Rhodia Chimie). Product form and preparation A product according to the invention may take any suitable 15 form, such as a solid, liquid or paste composition, for example as particulates (powders, granules), tablets or bars. Preferably, the product is in a concentrated liquid with a surfactant concentration of at least 30wt%. Such compositions require the presence of hydrotropes to solubilise the 20 ingredients. Ethanol is preferably avoided. Preferred hydrotropes are propylene glycol and glycerol. Based on this teaching the skilled person will be able to select other hydrotropes that avoid the use of highly volatile solvents like ethanol without the need for inventive activity. 25 According to a second embodiment of the invention, the detergent composition is in particulate form. The ratio of anionic to nonionic surfactant in the detersive surfactant system is then preferably at least 3:2, preferably at least 7:2. 30 Powders of low to moderate bulk density may be prepared by spray-drying slurry, and optionally post dosing (dry-mixing) further ingredients. Routes available for powder manufacture WO 2011/151170 PCT/EP2011/057935 23 include spray drying, drum drying, fluid bed drying, and scraped film drying devices such as the wiped film evaporator. A preferred form of scraped film device is a wiped film evaporator. One such suitable wiped film evaporator is the 5 'Dryex system' based on a wiped film evaporator available from Ballestra S.p.A. Alternative equipment would be the Chemithon the 'Turbo Tube' dryer system wherein a high active surfactant paste is heated and metering to a multi tube, steam-jacketed drying vessel. 10 'Concentrated' or 'compact' powders may be prepared by mixing and granulating processes, for example, using a high-speed mixer/granulator, or other non-tower processes. 15 Tablets may be prepared by compacting powders, especially 'concentrated' powders. The invention will now be further described with reference to the following non-limiting examples. 20 EXAMPLES Measurement of Soil Release Index (SRI) SRI is a measure of how much of a stain on textile is removed during a washing process. The intensity of any stain can be 25 measured by means of a reflectometer in terms of the difference between the stain and a clean cloth giving AE* for each stain. It is defined as AE* and is calculated as: AE* = (L*,tainbefore - Lclean ,cloth) + (a ,tainbefore - clean cloth) + b -,inbefore - beanclot 30 L*, a*, and b* are the coordinates of the CIE 1976 (L*, a*, b*) colour space, determined using a standard reflectometer. AE* can be measured before and after the stain is washed, to give WO 2011/151170 PCT/EP2011/057935 24 AE*bw (before wash) and AE*, (after wash). SRI is then defined as: SRI =100- AEW 5 A SRI of 100 means complete removal of a stain. AE after wash is the difference in L a b colour space between the clean (unwashed) fabric and the stain after wash. So a AE 10 after wash of zero means a stain that is completely removed. Therefore, a SRIaw (aw: after wash) of 100 is a completely removed stain. The clean (or virgin) fabric is an "absolute standard" which is not washed. For each experiment, it refers to an identical piece of fabric to that which the stain is 15 applied. Therefore, its point in L a b colour space stays constant. Determination of SRI-values For the determination of the SRI-values, a standard protocol 20 was used, called the Tergometer wash protocol. Said Tergometer wash protocol is as follows: 1. Measurement of the colour of the stain on the textile cloth (before washing). 2. Switch on the Tergometer and set to a temperature of 300C. 25 3. Add water of required hardness, leave to heat to 300C for 10 minutes. 4. Add formulation to each pot and then agitate at 100 rpm for 1 minute 5. Add the stained swatches and ballast into each pot. 30 6. Start the wash, agitate at 100 rpm and leave to wash for 12 minutes. 7. Rinse with fresh water (26 0 FH) for 2 minutes.

WO 2011/151170 PCT/EP2011/057935 25 8. Repeat rinse. 9. Dry overnight in the dark. 10. Read stains after wash. 5 Example 1: Removal of a range of red mud on knitted polyester and woven cotton Six liquid formulations were formulated. The surfactants were sodium alkyl benzene sulphonate (Na LAS anionic), alcohol ethoxylate (non-ionic C12 -7EO, Neodol 25-7 ex 10 Shell) and a neutralised saturated soap (coco fatty acid Prifac-5908 ex Uniqema), as shown in Table 1 at the indicated concentrations. Also used were standard compounds of a laundry liquid builder (sodium citrate), buffer and sequestrant (Dequest 2066 phosphonate) and enzyme (Savinase Ultra 16L 15 protease), The pH of these formulations was buffered to between 7 and 8. The formulations were made using demineralised water.

WO 2011/151170 PCT/EP2011/057935 26 Table 1: Formulations used Formulations Ingredient 1 2 3 4 5 6 (comparative) % Weight in Product Na LAS 3.1 3.1 3.1 3.1 3.1 3.1 alcohol 1.4 1.4 1.4 1.4 1.4 1.4 ethoxylate (C12 7EO) Na soap 0.8 0.8 0.8 0.8 0.8 0.8 decyl 0.08 0.4 hydroxamate (potassium salt) dodecyl 0.08 hydroxamate (potassium salt) tetradecyl 0.08 0.14 hydroxamate (potassium salt) Dequest 2066 0.05 0.05 0.05 0.05 0.05 0.05 sodium citrate 0.22 0.22 0.22 0.22 0.22 0.22 triethanol 0.36 0.36 0.36 0.36 0.36 0.36 amine hydrotropes, 1.5 1.5 1.5 1.5 1.5 1.5 enzymes & minors water 92.6 92.5 92.5 92.5 92.5 92.5 5 The liquid formulations shown in Table 1 were used to remove red mud stains on knitted polyester and woven cotton in a Tergometer wash protocol as described hereinabove. In all cases the product dose was 12 grams/litre. The level of surfactants and hydroxamates in the Tergometer 10 protocol are shown in Table 2.

WO 2011/151170 PCT/EP2011/057935 27 Table 2: Surfactant and Hydroxamate levels in the Tergometer protocol 5 Formulations Ingredient 1 2 3 4 5 6 (comparative) In wash concentration (g/L) Na LAS 0.37 0.37 0.37 0.37 0.37 0.37 alcohol 0.17 0.17 0.17 0.17 0.17 0.17 ethoxylate

(C

12 7EO) Na soap 0.1 0.1 0.1 0.1 0.1 0.1 decyl 0.0096 hydroxamate (potassium salt) dodecyl 0.0096 0.048 hydroxamate (potassium salt) tetradecyl 0.0096 0.017 hydroxamate (potassium salt) The results obtained for the removal of red mud stains on knitted polyester and woven cotton are shown in Table 3.

WO 2011/151170 PCT/EP2011/057935 28 Table 3: Stain removal index (SRI) for Red mud stains on knitted polyester and woven cotton (Tergometer wash protocol) Formulation SRI aw SRI aw Red Mud on Knitted Red Mud on woven Polyester cotton 1 (comparative) 70.1 64.8 2 with decyl 77.2 69.9 hydroxamate at 0.08% bwt in product 3 with dodecyl 76.1 69.5 hydroxamate at 0.08% by weight in product 4 with tetradecyl 81.2 70.5 hydroxamate at 0.08% by weight in product 5. with decyl 77.2 70.8 hydroxamate at 0.4% by weight in product 6. with tetradecyl 75.1 69.4 hydroxamate at 0.14% by weight in product 5 These results show that the use of the hydroxamate salts included in formulations 2-6 leads to better removal of red mud from both knitted polyester and woven cotton. 10 Example 2: Removal of a range of red mud on knitted polyester (Hydroxamate level less than or equal to 0.05% in product) Three liquid formulations were formulated. 15 The surfactants were sodium alkyl benzene sulphonate (Na LAS anionic) , alcohol ethoxylate (non-ionic C12 -7EO, Neodol 25-7 ex Shell) and a neutralised saturated soap (coco fatty acid - WO 2011/151170 PCT/EP2011/057935 29 Prifac-5908 ex Uniqema), as shown in Table 4 at the indicated concentrations.. Also used were standard compounds of a laundry liquid builder (sodium citrate), , buffer and sequestrant (Dequest 2066 phosphonate) and enzyme (Savinase Ultra 16L 5 protease), The pH of these formulations was buffered to between 7 and 8. The formulations were made using demineralised water. Table 4: Formulations used Ingredient Formulation 7 Formulation Formulation (comparative) 8 9 %weight in Product Na LAS 11.2 11.2 11.2 alcohol 5.0 5.0 5.0 ethoxylate

(C

12 7EO) Na soap 2.9 2.9 2.9 tetradecyl 0.05 0.01 hydroxamate (potassium salt) Dequest 2066 0.18 0.18 0.18 sodium 0.8 0.8 0.8 citrate triethanol 1.3 1.3 1.3 amine hydrotropes, 5.4 5.4 5.4 enzymes & minors water 73.2 73.2 73.2 10 The liquid formulations shown in Table 4 were used to remove red mud stains on knitted polyester in a Tergometer wash protocol as described hereinabove. In all cases the product dose was 5.6 grams/litre. 15 The level of surfactants and hydroxamates in the Tergometer protocol are shown in Table 5.

WO 2011/151170 PCT/EP2011/057935 30 Table 5: Surfactant and Hydroxamate levels in the Tergometer protocol Ingredient Formulation Formulation Formulation 7(comparative) 8 9 Na LAS 0.62 0.62 0.62 alcohol ethoxylate (C 12 0.28 0.28 0.28 7EO) Na soap 0.17 0.17 0.17 tetradecyl hydroxamate 0.003 0.0008 (potassium salt) 5 Table 6: Stain removal index (SRI) for Red mud stains on knitted polyester and woven cotton (Tergometer wash protocol) Formulation SRI aw Red Mud on Knitted Polyester 7 (comparative) 69.0 8. with tetradecyl 71.0 hydroxamate at 0.05% by weight in product 9 with tetradecyl 71.9 hydroxamate at 0.008% by weight in product 10 These results show that the use of the hydroxymate salts included in formulations 8&9 leads to better removal of red mud from knitted polyester.

Claims (1)

1. Claims

   1) A laundry detergent composition comprising

   a) 0.005 to less than 0.5 wt% hydroxamic acid or its

   corresponding hydroxamate of the structure:

   R¹

   wherein R¹ is

   a straight or branched C4- C20 alkyl, or

   a straight or branched substituted C4- C20 alkyl, or

   a straight or branched C4- C20 alkenyl, or

   a straight or branched substituted C4- C20 alkenyl, or

   an alkyl ether group C¾ ( CH2 ) _n (EO)_m wherein n is from 2 to 20 and m is from 1 to 12, or

   a substituted alkyl ether group CH₃ (CH₂)_n (EO)_m wherein n is from 2 to 20 and m is from 1 to 12, and

   the types of substitution include one or more of -N¾, -OH,

   C OH II I

   - C - N

   -S-, -0-, -COOH, and

   and R² is selected from hydrogen and a moiety that forms part of a cyclic structure with a branched R¹ group,

   b) 3 to 80 wt% of detersive surfactant system comprising

   (i) anionic surfactant; and

   (ii) nonionic surfactant,

   wherein the ratio of (i) to (ii) lies in the range 1:1.1 to 19:1, and

   wherein the weight ratio a) to b) lies in the range 1: 6 to 1:16000, preferably 1:10 to 1:400, more preferably 1:20 to 1:100, and c) optionally, other ingredients to 100 wt% provided that zeolite and phosphate builders are present at less than 5 wt% and ethanol is present at a level of less than 5 wt%.

   2) Composition according to claim 1, wherein R¹ is chosen from the group consisting of C₄, C₅, e, C₇, Cs, Cg, Cio, Cn, C₁2 or Ci₄ normal alkyl group and R² is hydrogen.

   3) Composition according to claim 1 or 2, wherein R¹ is a Cs-i4 normal alkyl group.

   4) A composition according to any of claims 1 to 3, wherein the composition comprises detergency builder at a concentration from 1 to 50 wt%.

   5) A composition according to any preceding claim which

   comprises at least 20 wt% of the detersive surfactant system, preferably at least 30 wt% and more preferably over 40 wt%.

   6) A composition according to any preceding claim which

   comprises from 1 to 15 wt% soap, preferably made from saturated fatty acids.

   7) A composition according to any preceding claim comprising at least 0.5 wt% of soil release polymer.

   8) A composition according to any preceding claim comprising at least 0.5 wt% anti redeposition polymer.

   9) A composition according to any preceding claim wherein the weight ratio of hydroxamate to detersive surfactant system lies in the range 1:10 to 1:400, preferably 1:10 to 1:100. 10) A composition according to any preceding claim, in which the ratio of anionic to non-ionic surfactant is 1:1 to 9:1, preferably 3:2 to 9:1.

   11) A composition according to any preceding claim in which the composition is a liquid composition.

   12) A composition according to claim 11, comprising a

   hydrotrope system comprising propylene glycol and glycerol at levels of at least 6 wt%.

   13) A composition according to claim 11 or 12, which is a

   liquid composition, comprising detersive surfactant at a concentration from 20 to 80% by weight of the total

   composition .

   14) Use of a composition according to any preceding claim for removal of particulate soils, preferably red clay, most preferably Georgia clay, from polyester and cotton fabrics.

   15) Use of 0.005 to less than 5 wt% hydroxamic acid or its

   corresponding hydroxamate of the structure:

   o

   wherein R¹ is a Cs normal alkyl group, and R² is a hydrogen atom, in a laundry detergent composition, for improving the particulate soils stain removal from a textile substrate, wherein the composition further comprises a detersive surfactant system comprising anionic surfactant and nonionic surfactant at a concentration from 3 to 80 wt%; and optionally other ingredients to 100 wt%.