Field of the invention

The present invention relates to a detergent composition. More particularly, the invention is directed to a softening in the wash laundry detergent composition.

Background of the invention

Textile fabrics, including clothes, have traditionally been cleaned with laundry detergents. After cleaning, fabrics may often feel harsh. Consumers prefer fabrics to be clean and with a soft feel.

To prevent harshness experienced after multiple wash cycles, technologies have been developed to improve the softness of fabrics. Various materials providing fabric softening benefit to the laundered fabric are known. The commonly used fabric softening compounds includes clay and silicone. Such softening compounds added in rinse-added conditioner compositions or main-wash laundry detergent composition are widely available commercially.

Laundry detergent composition which simultaneously achieves detergency and softness of the fabric during the laundering process by incorporating fabric softening component that impart a fabric softening benefit to the laundered fabric in wash is described in the following references.

WO 2000/66688 A1 (Procter & Gamble, 2000) discloses a laundry detergent composition having compressed clay for providing softness benefits.

More recently, WO 2005/075618 A1 (Procter & Gamble) discloses a solid particulate laundry detergent composition for providing fabric softening having a co-particulate admixture of silicone and clay.

Previously published documents disclose detergent composition containing clay, silicone or combinations thereof for delivering softening benefits on fabric. However, it is seen that in a carbonate-built detergent composition, the softening properties of a fabric softening component on the fabric is undermined over multiple washes and opportunity to further improve the softening benefits on fabric in wash remains. Moreover, there is a need to provide softening detergent compositions while maintaining the cleaning performance. It is further desired to provide such a carbonate- built detergent composition which has low levels of phosphate builder and zeolite component. Although phosphate builders and zeolite builders are preferred for providing good softening benefits and cleaning performance, detergent composition with low levels of phosphate builders are desired as they are environmentally friendly and low levels of zeolite in detergent composition are preferred as zeolites have a tendency to form undesirable cloudy wash liquor upon contact with water and may also form undesirable deposits on fabrics.

It is thus an object of the present invention to provide a detergent composition capable of imparting improved fabric softness and cleaning performance during the wash cycle of a laundering process.

Yet another object of the invention is to provide a carbonate built detergent composition which achieves improved fabric softening performance.

A still further object of the present invention is to provide a detergent composition which achieves improved cleaning and fabric softening performance at lower concentration of fabric softening agent.

Summary of the invention

It is found by the present inventors that the presence of a specific chelating agent and a bicarbonate salt significantly enhances the performance of a fabric softening agent in a carbonate-built powder detergent composition while maintaining the cleaning performance. It is further found that the fabric softening benefit is efficiently delivered despite the use of relatively low levels of fabric softening agent in the composition. It is further found that the fabric softening benefits is efficiently delivered in a carbonate built detergent composition which has low levels of phosphate builder and also low levels of zeolite builder. Without wishing to be bound by theory, it is believed that bicarbonate salt reduces damage to fabric in a carbonate built detergent formulation and enhances benefit of specific fabric softening agent onto the fabric, and further in presence of the specific chelating agent the bicarbonate salt also contributes to reduced calcium carbonate ashing on the fabric thereby contributing to improved performance of fabric softening agent. Thus, surprisingly improved softening is obtained, whilst maintaining a good cleaning performance.

According to a first aspect of the invention, disclosed is a detergent composition comprising: i) a chelating agent selected from the group consisting of amino carboxylates, phosphonates or mixtures thereof; ii) a fabric softening agent selected from the group consisting of clay, silicone or a combination thereof; iii) from 20 wt.% to 35 wt.% carbonate builder; iv) from 0 wt.% to 5 wt.% zeolite builder; v) from 0 wt.% to 4 wt.% phosphate builder; and, vi) a bicarbonate salt.

According to a second aspect of the invention, disclosed is a method for softening fabric comprising, in no particular order, the steps of: i) providing a fabric in a washing machine or in a hand wash container; ii) contacting the fabric during a wash cycle of said washing machine or hand wash process with the composition according to the first aspect; iii) optionally allowing the fabric to dry or mechanically tumble-drying them.

According to a third aspect of the present invention disclosed is use of a chelating agent selected from the group consisting of amino carboxylates, phosphonates or mixtures thereof, specific fabric softening agent selected from the group consisting of clay, silicone or a combination thereof and bicarbonate salt in a detergent composition having from 20 wt.% to 35 wt.% carbonate builder, from 0 wt.% to 5 wt.% zeolite builder and from 0 wt.% to 4 wt.% phosphate builder to provide softening benefit on fabric treated with the composition.

Detailed description of the invention

According to a first aspect of the invention, disclosed is a detergent composition which includes a chelating agent, a fabric softening agent and a bicarbonate salt.

The detergent composition according to the present invention provides a through the wash fabric softening that is convenient for the consumer to dose to the washing machine.

Detergent composition

The detergent composition according to the present invention includes from 0 wt.% to 4 wt.% phosphate builder. Preferably the detergent composition according to the present invention is a non-phosphate laundry detergent formulation, i.e. , preferably contains less than 4 wt.%, still preferably less than 3 wt%., further preferably less than 2 wt.%, more preferably less than 1 wt.% of phosphate builder material. In this art the term 'phosphate' includes diphosphate or triphosphate species.

The detergent composition is predominantly carbonate built, i.e. the weight% of sodium carbonate is greater than the weight % of the sum of other builder material present, preferably the amount of other builder material is less than 30 wt.%, more preferably less than 15 wt.%, still preferably less than 10 wt.%, still further preferably less than 5% of the weight% level of sodium carbonate.

It is preferred that the other builder material is non-phosphate, its highly preferred that the composition is substantially free of a phosphate builder, that is the level of the phosphate builder is less than 1 wt%, more preferably there is no deliberately added phosphate builder in the detergent composition.

The composition of the present invention can be made via a variety of conventional methods known in the art. These methods include but is not limited to homogenous mixing of ingredients, including dry-mixing; compaction techniques such as agglomerating, extrusion, tableting; spray-drying a slurry of the ingredients, or a mixture of one or more of these techniques. The various components added to the detergent composition of the present invention may also be made by for various conventional methods for example compaction, including extrusion and agglomerating, or spray-drying. The detergent composition is preferably prepared by the technique of slurry making and spray drying.

Preferably the composition is in the form of a solid detergent composition. Preferably they are main wash detergent composition. It can take the form of a detergent composition for the main wash, which may be dilutable or non-dilutable.

The detergent composition herein can take a variety of physical solid forms which includes forms such as powder, particulate, granule, ribbon, noodle, paste, tablet, flake, pastille and bar, and preferably the composition is in the form of powder, particulate, granules or a tablet, still preferably the detergent composition is in the form of a powder or particulate. Further preferably the composition is in the form of a spray-dried powder or particulate. The composition of the present invention preferably has a density of more than 350 grams/litre, more preferably more than 450 grams/litre or even more than 570 grams/litre.

The detergent composition according to the present invention usually has an alkaline pH, generally in the region of pH 9 to 12.5 when measured with a 1wt% dilution in de ionised water at 25°C, which is achieved by the presence of sodium carbonate and other alkaline salts especially sodium silicates such as the meta-, neutral or alkaline silicates, preferably at levels up to about 35 wt.% of the composition. More preferably the detergent composition has a pH from 9 to 11, still preferably from 9 to 10.5. Most preferably the pH is from 10.3 to 10.8. Chelating agent:

According to the first aspect of the present invention disclosed detergent composition includes a chelating agent selected from the group consisting of amino carboxylates, phosphonates or mixtures thereof.

Chelating agent as used herein includes those chemicals which interact with divalent ions, cations and anions, having tendency to precipitate in their saturated aqueous solutions. Chelating agents through threshold inhibition act as catalyst to delay the precipitation reaction of these ions in their saturated aqueous solutions. In the present context the term "chelating agent" comprises the catalyst, a cation of calcium and / or magnesium ions and carbonate anions. Throughout this document chelating agent and crystal growth inhibitor is used interchangeably.

Useful amino carboxylate chelating agents includes, but are not limited to, the following: N-(1 ,2-dicarboxy- ethyl)-D,L-aspartic acid (IDS), N-(2- hydroxyethyl)iminodiacetic acid (EDG), aspartic acid-N- monoacetic acid (ASMA), aspartic acid- N,N-diacetic acid (ASDA), aspartic acid-N- mono- propionic acid (ASMP), iminodisuccinic acid (IDA), N- (2-sulfomethyl) aspartic acid (SMAS), N- (2-sulfoethyl) aspartic acid (SEAS), N- (2- sulfomethyl) glutamic acid (SMGL), N- (2- sulfoethyl) glutamic acid (SEGL), N- methyliminodiacetic acid (MIDA), a- alanine-N,N- diacetic acid (a - ALDA) , serine-N,N-diacetic acid (SEDA), isoserine-N,N-diacetic acid (ISDA), phenylalanine-N,N-diacetic acid (PHDA) , anthranilic acid- N ,N - diacetic acid (AND A), sulfanilic acid-N, N-diacetic acid (SLDA) , taurine-N, N-diacetic acid (TUDA), sulfomethyl- N, N-diacetic acid (SMDA), N-(hydroxyethyl)-ethylidenediaminetriacetate (HEDTA), diethanolglycine (DEG), aminotris(methylenephosphonic acid) (ATMP).

The chelating agent may contain an amino group and may be, e.g., an amino- polycarboxylate or a phosphonate. It may be a monomeric molecule comprising one, two or three amino groups (typically secondary or tertiary amino groups), and it may contain two, three, four or five carboxyl groups or even more carboxyl groups. The chelating agents may be phosphorus containing or without phosphorus. Suitable chelating agents includes those based on carboxylate groups includes EDTA (ethylene diamine tetraacetate), NTA (2,2',2"-nitrilotriacetate), citrate, 2-hydroxypropan- 1,2,3-tricarboxylate, DTPA (diethylenetriaminepentaacetic acid), MGDA (methylglycinediacetic acid OT N,N'-bis(carboxymethyl)alanine), EGTA (ethylene glycol tetraacetic acid), EDDS (ethylenediamine- N,W-disuccinic acid),, GLDA (L-Glutamic acid, N,N-diacetic acid). The composition preferably also includes otherpolycarboxylates such as PAA [poly(acrylic acid)], PAA/PMA [copoly(acrylic acid/maleic acid)], or mixtures thereof. The chelating agents may be phosphonates. Aminoalkane and/or hydroxyalkane phosphonates are preferably used as phosphonates. Suitable examples of these phosphonate chelating agent includes, HEDP (1-hydroxyethylidene-1,1-diphosphonic acid), EDTMP [ethylenediamine tetra(methylene phosphonic acid], EDTMPA (ethylenediaminetetramethylene- tetraphosphonic acid), DTPMP (diethylenetriamine penta (methylene phosphonic acid), DTMPA

(diethylenetriaminepenta(methylenephosphonic acid)) nitrilotris(methylenephosphonic acid) (NTMP), 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), ethylenediamine tetramethylene phosphonate (EDTMP), and the higher homologs thereof. Among the hydroxyalkane phosphonates, 1-hydroxyethane-1,1-diphosphonate (HEDP) is of particular importance.

Still preferably the chelating agents selected from carboxylate chelating agent and/or phosphonate chelating agent which may contain nitrogen such as in EDTA, NTA,

DTPA, PDTA, GLDA, MGDA, EDDS, EDTMP, EDTMPA, and DTPMP or ASMA, ASDA, ASMP, IDA, SMAS, SEAS, SMGL, SEGL, MIDA, a-ALDA, SEDA, ISDA, PHDA, ANDA, SLDA, TUDA, SMDA, HEDTA, DEG, ATMP, or mixtures thereof.

Particularly preferred chelating agents includes but are not limited to the following: ethylene- diamine- tetra- acetic acid (EDTA), diethylene triamine penta methylene phosphonic acid (DTMPA, DTPMP), hydroxy-ethane diphosphonic acid (HEDP), ethylenediamine N,N- disuccinic acid (EDDS), methyl glycine di-acetic acid (MGDA), diethylene triamine penta acetic acid (DTPA), propylene diamine tetraacetic acid (PDTA), 2-hydroxypyridine-N-oxide (HPNO), methyl glycine diacetic acid (MGDA), glutamic acid N,N-diacetic acid (N,N-dicarboxymethyl glutamic acid tetrasodium salt (GLDA) and nitrilotriacetic acid (NTA) or mixtures thereof. The chelating agent may be present in their acid form or a salt, preferably the chelating agents may be present as a sodium, ammonium or potassium salt.

Especially preferred chelating agent includes diethylenetriamine pentacetic acid (DTPA), ethylenediamine-N, N’-disuccinic acid (EDDS) and 1,1 hydroxyethane diphosphonic acid (HEDP) or the alkali metal, potassium, alkaline earth metal, ammonium or substituted ammonium salts thereof, or mixtures thereof. Preferably the chelating agent is a phosphonate. HEDP in its acid form or salt form with alkali metal, potassium, alkaline earth metal, ammonium or substituted ammonium is a highly preferred phosphonate chelating agent.

In the detergent composition according to the present invention, the chelating agent is preferably present in an amount from 0.1 to 10 wt.%, still preferably from 0.1 wt.% to 5 wt.%, preferably from 0.1 wt.% to 3 wt.%, more preferably from 0.1 wt.% to 1 wt.%.

Preferably the detergent composition comprises at least 0.2 wt.% chelating agent based on the weight of the detergent composition, still preferably at least 0.3 wt.%, still preferably at least 0.5 wt.%, most preferably at least 0.6 wt.%, but typically not more than 3 wt.%, still preferably not more than 2 wt.%, most preferably not more than 1 wt.% of the chelating agent according to the present invention.

Fabric softening agent Disclosed detergent composition includes a fabric softening agent selected from the group consisting of clay, silicone or mixtures thereof. A fabric softening agent is a compound that delivers softness to the touch, reduces tangling, knotting or wrinkling, or gives ease of ironing or static control to a fabric that is treated with a fabric softening agent during the laundering process.

Clay:

The detergent composition according to the present invention includes a fabric softening agent which may be a clay. Typically, the clay is a fabric-softening clay. The clay may be selected from the group consisting of allophane clays; chlorite clays, preferred chlorite clays are amesite clays, baileychlore clays, chamosite clays, clinochlore clays, cookeite clays, corundophite clays, daphnite clays, delessite clays, gonyerite clays, nimite clays, odinite clays, orthochamosite clays, pannantite clays, penninite clays, rhipidolite clays, sudoite clays and thuringite clays; illite clays; inter- stratified clays; iron oxyhydroxide clays, preferred iron oxyhydroxide clays are hematite clays, goethite clays, lepidocrite clays and ferrihydrite clays; kaolin clays, preferred kaolin clays are kaolinite clays, halloysite clays, dickite clays, nacrite clays and hisingerite clays; smectite clays; vermiculite clays; and mixtures thereof.

Preferably the clay is a smectite clay. The term smectite clays herein includes both the clays in which aluminium oxide is present in a silicate lattice and the clays in which magnesium oxide is present in a silicate lattice. Typical smectite clay compounds include the compounds having the general formula AhiShOsMOH^.nhbO and the compounds having the general formula Mg ₃ (Si ₂ O ₅ ) ₂ (OH) ₂ .nH ₂ 0. Smectite clays tend to adopt an expandable three-layer structure. Preferred may be three-layer, expandable alumino-silicates which having a dioctahedral crystal lattice, while the expandable three-layer magnesium silicates have a trioctahedral crystal lattice. Preferred smectite clay are beidellite clays, hectorite clays, laponite clays, montmorillonite clays, volchonskoite clays, nontonite clays, saponite clays, sauconite clays and mixtures thereof.

Preferably the smectite clay is a dioctahedral smectite clay, more preferably a montmorillonite clay. Dioctrahedral smectite clays typically have one of the following two general formulae:

Na _x Al2-xMg _x Si40io(OH)2 . Formula (I)

Ca _x AI _2-x Mg _x Si40io(OH)2. Formula (II) where x is a number from 0.1 to 0.5, preferably from 0.2 to 0.4.

Preferred clays are low charge montmorillonite clays (also known as a sodium montmorillonite clay or Wyoming-type montmorillonite clay) which have a general formula corresponding to formula (I) above. Preferred clays are also high charge montmorillonite clays (also known as a calcium montmorillonite clay or cheto-type montmorillonite clay) which have a general formula corresponding to formula (II) above.

Smectite clays, and more specifically montmorillonite clays, are preferred because of their desirable swelling and dispersing properties, which leads to a good fabric softening profile.

Preferred light coloured crystalline clay minerals are china clays, halloysite clays, dioctahedral clays such as kaolinite, trioctahedral clays such as antigorite and amesite, smectite and honnite clays such as bentonite (montmorillonite), beidilite, nontronite, hectorite, attapulgite, pimelite, mica, muscovite and venniculite clays, as well as pyrophyllite/talc, willemseite and minnesotaite clays. Preferred light coloured crystalline clay minerals are described in GB2357523A and WO01/44425. Substitution of small cations, such as protons, sodium ions, potassium ions, magnesium ions and calcium ions, and of certain organic molecules including those having positively charged functional groups can typically take place within the crystal lattice structure of the smectite clays. A clay may be chosen for its ability to preferentially absorb one cation type, such ability being assessed by measurements of relative ion exchange capacity. Preferred clays have a cationic exchange capacity of at least 50meq/100 grams, still preferably at least 70meq/100g. The cationic exchange capacity of clays can be measured using the method described in Grimshaw, The Chemistry and Physics of Clays, Interscience Publishers, Inc., pp. 264-265 (1971). The clay preferably has a weight average particle size ranging from 180 micrometers to 1400 micrometres. Preferably, the clay has a weight average primary particle size, typically of greater than 20 micrometers, preferably more than 23 micrometers, preferably more than 25 micrometers, or preferably from 21 micrometers to 60 micrometers, more preferably from 22 micrometers to 50 micrometers, more preferably from 23 micrometers to 40 micrometers, more preferably from 24 micrometers to 30 micrometers, more preferably from 25 micrometers to 28 micrometers. However, it may also be preferred for the clay to have a weight average particle size of from 10 to 50 micrometers, more preferably from 20 to 40 micrometers. The crystal lattice structure of the clay mineral compounds may have, in a preferred execution, a cationic fabric softening agent substituted therein. Such substituted clays have been termed "hydrophobically activated' clays. The cationic fabric softening agents are typically present at a weight ratio, cationic fabric softening agent to clay, of from 1 :200 to 1 : 10, preferably from 1 : 100 to 1 :20. Suitable cationic fabric softening agents include the water insoluble tertiary amines or di-long chain amide materials as disclosed in GB-A-1 514276 and EP-B-0011 340. A preferred commercially available "hydrophobically activated" clay is a bentonite clay containing approximately 40% by weight of a dimethyl ditallow quaternary ammonium salt sold under the tradename Claytone EM by English China Clays International.

Preferably in the fabric softening clay at least 30% or even at least 40% or preferably at least 50% or even at least 60% of the exchangeable cations may be replaced by a long-chain organic cation. Such clay will herein be referred to as organophilic or hydrophobic clay. The long-chain organic cations herein comprise at least one chain of at least 10 or even at least 12 or even at least 14 or even at least 16 or even at least 18 carbon atoms. It may be preferred that at least two of such long-chains are present in the cation. Highly preferred cations are quaternary ammonium cations having two Cie to C28 or even Cie to C24 alkyl chains. Highly preferred are one or more organic cations which have one or preferably two alkyl groups derived from natural fatty alcohols, the cations preferably being selected from dicocoyl methyl benzyl ammonium, dicocoyl ethyl benzyl ammonium, dicocoyl dimethyl ammonium, dicocoyl diethyl ammonium; more preferably ditallow diethyl ammonium, ditallow ethyl benzyl ammonium; more preferably ditallow dimethyl ammonium and/or ditallow methyl benzyl ammonium.

In the detergent composition according to the present invention, the clay is preferably present in an amount from 2 wt.% to 20 wt.%, preferably from 2 wt.% to 10 wt.%, more preferably from 2 wt.% to 5 wt.%. Preferably the detergent composition comprises at least 2 wt.% clay based on the weight of the detergent composition, still preferably at least 2.5 wt.%, still preferably at least 3 wt.%, most preferably at least 4 wt.%, but typically not more than 15 wt.%, still preferably not more than 10 wt.%, most preferably not more than 8 wt.% of the clay. Silicone:

The fabric softening agent may be a silicone which imparts a softening benefit on the fabric during the wash.

Fabric softening silicone and their chemistry are described in, for example in The Encyclopaedia of Polymer Science, volume 11 , p765. The silicone includes but is not limited to 1) non-functionalized silicones such as polydimethylsiloxane (PDMS) or alkyl (or alkoxy) functional silicones 2) functionalized silicones or copolymers with one or more different types of functional groups such as amino, phenyl, polyether, acrylate, silicon hydride, carboxylic acid, quaternized nitrogen, etc. Suitable fabric softening silicone are described in W018145898 A1 and WO 2010/039575 A1 which are incorporated herein by reference.

Preferably the silicone is a functionalized silicone. The molecular weight of the silicone is preferably from 1,000 to 500,000, more preferably 25 from 2,000 to 250,000 even more preferably from 5,000 to 100,000. Preferably the silicone is an anionic functionalized silicone. Examples of fabric softening anionic silicones suitable for the current invention include silicones containing the following functionalities; carboxylic, sulphate, sulphonic, phosphate and/or phosphonate functionality. More preferably the anionic silicone of the present invention comprises carboxyl functionalised silicones. Most preferably the anionic silicone of the current invention is a carboxyl silicone.

When the silicone is in the form of a silicone emulsion, then preferably the particle size is in the range from about 1 nm to 100 microns and preferably from about 10 nm to about 10 microns including microemulsions (< 150 nm), standard emulsions (about 200 nm to about 500 nm) and macroemulsions (about 1 micron to about 20 microns).

Preferred silicone are selected from polydialkylsiloxanes, especially polydimethylsiloxane; amino functionalised silicone; and anionic silicones, especially carboxyl functionalised silicone. Preferably the silicone is a polydimethylsiloxane. Most preferably the fabric softening silicone is a functionalised silicone selected from amino functionalized silicone, anionic functionalized silicone preferably carboxyl functionalised silicone. Preferably the amino functionalized silicone is an aminopolydimethylsiloxanes having a viscosity from 100 to 100, 000 mPas. The polydimethylsiloxane has the general formula: Formula I wherein, each Ri and R2are methyl; and x is a number, typically a number greater than 50.

The polydimethylsiloxane typically has a viscosity of from 5,000cP to 1,000,000cP, or from 10,000cP to 1 ,000,000cP, or from 10,000cP to 600,000cP, more preferably from 50,000cP to 400,000cP when measured at a shear rate of 20s ¹ and at ambient conditions (20°C and 1 atmosphere). Polydimethylsiloxanes having these preferred viscosities have an optimum deposition on fabric to provide a good fabric-softening benefit. The viscosity is typically measured using a Brookfield Viscositmeter at 25°C according to the method ASTM D 2983. A preferred form of the polydimethylsiloxane is in a pre-emulsified form. Typically, the emulsion has a volume average primary droplet size of from 0.1 micrometers to 5,000 micrometers, preferably from 0.1 micrometers to 50 micrometers, and most preferably from 0.1 micrometers to 5 micrometers. The volume average primary particle size is typically measured using a Coulter Multisizer™ or by the method described in more detail below. The emulsion typically has a viscosity of from 1 ,500cP to 50,000cP, preferably from 2,000cP to 15,000cP. The emulsion may comprise water and/or other solvents in an effective amount to aid the emulsification of polydimethylsiloxane/solvent mixture. Typically, the polydimethylsiloxane has a weight average molecular weight of greater than 3,700Da.

Preferably the detergent composition according to the present invention includes the fabric softening silicone at a level of from 0.1 wt.% to 10 wt.%, preferably from 0.2 wt.% to 5 wt.%, more preferably from 0.5 wt.% to 3 wt.%. In the detergent composition according to the present invention, the fabric softening silicone is preferably present in an amount from 0.1 wt.% to 10 wt.%, preferably from 0.2 wt.% to 10 wt.%, more preferably from 1 wt.% to 5 wt.%. Preferably the detergent composition comprises at least 0.2 wt.% fabric softening silicone based on the weight of the detergent composition, still preferably at least 0.5 wt.%, still preferably at least 1 wt.%, most preferably at least 1.5 wt.%, but typically not more than 8 wt.%, still preferably not more than 6 wt.%, most preferably not more than 5 wt.% of the fabric softening silicone.

Bicarbonate salt

Disclosed detergent composition includes a bicarbonate salt. The bicarbonate salt is preferably a water-soluble alkali metal salt of bicarbonate, preferably sodium bicarbonate or potassium bicarbonate. Most preferably the bicarbonate salt is sodium bicarbonate.

In the detergent composition according to the present invention, the bicarbonate salt is preferably present in an amount from 5 wt.% to 20 wt.%, preferably from 5 wt.% to 15 wt.%, more preferably from 5 wt.% to 12 wt.% and still more preferably from 5 wt.% to 10 wt.%.

Preferably the detergent composition comprises at least 5 wt.% bicarbonate salt based on the weight of the detergent composition, still preferably at least 6 wt.%, still preferably at least 7 wt.%, most preferably at least 8 wt.%, but typically not more than 18 wt.%, still preferably not more than 15 wt.%, most preferably not more than 12 wt.% of the bicarbonate salt.

Further ingredients Surfactants:

In the case of a detergent composition for laundering fabrics, the composition typically comprises one or more detersive synthetic non-soap surfactants. In the detergent composition of the present invention, suitable detersive surfactant is chosen from anionic surfactant, nonionic surfactant, cationic surfactant, zwitterionic surfactant, amphoteric surfactant and mixtures thereof. Soap may also be included in the composition. Many suitable surface-active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch. Suitable detersive surfactants may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial.

Suitable anionic surfactant includes sulphonate and sulphate detersive surfactants. Examples of such sulphonate detersive surfactants include methyl ester sulphonate, alpha olefin sulphonates, alkyl benzene sulphonates, especially alkyl benzene sulphonates, preferably Cio to C alkyl benzene sulphonate. Suitable alkyl benzene sulphonate (LAS) is obtainable, preferably obtained, by sulphonating commercially available linear alkyl benzene (LAB); suitable LAB includes low 2-phenyl LAB, other suitable LAB includes high 2-phenyl LAB, such as those supplied by Sasol under the tradename Hyblene®. The alkyl benzene sulphonates may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial. Examples of sulphate detersive surfactants include alkenyl sulfate, alkyl ether sulfate, alkyl ethoxy sulfate, sodium lauryl ether sulfate (SLES), primary alcohol sulphate, alkenyl sulfate, alkyl sulphate, preferably Cs to Cie alkyl sulphate, or predominantly C12 alkyl sulphate. The alkyl sulphate may be linear or branched, substituted or un- substituted, and may be derived from petrochemical material or biomaterial.

Preferably the sulphate detersive surfactant is alkyl alkoxylated sulphate, preferably alkyl ethoxylated sulphate, preferably a Cs to Cis alkyl alkoxylated sulphate, preferably a Cs to Cis alkyl ethoxylated sulphate, preferably the alkyl alkoxylated sulphate has an average degree of alkoxylation of from 0.5 to 20. preferably from 0.5 to 10, preferably the alkyl alkoxylated sulphate is a Cs to Cis alkyl ethoxylated sulphate having an average degree of ethoxylation of from 0.5 to 10, preferably from 0.5 to 5. more preferably from 0.5 to 3 and most preferably from 0.5 to 1.5. The alkyl alkoxylated sulphate may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial. Other suitable anionic detersive surfactants include alkyl ether carboxylates. Suitable anionic detersive surfactants may be in salt form, suitable counter-ions include sodium, calcium, magnesium, amino alcohols, and any combination thereof. A preferred counterion is sodium.

Suitable anionic surfactants comprising one or more anionic groups selected from sulfonate and sulfate. Examples of such anionic surfactants include and combinations thereof. More preferably, anionic surfactants selected from sodium dodecyl benzene sulfonate (Na-LAS), sodium dodecyl sulfate (SDS), sodium lauryl ether sulfate (SLES), methyl ester sulfate (MES), primary alcohol sulfate (PAS), alpha olefin sulfonate and combinations thereof. The compositions of the invention may for example contain linear alkylbenzene sulphonate, particularly linear alkylbenzene sulphonates having an alkyl chain length of Cs to C15. It is preferred if the level of linear alkylbenzene sulphonate is from 0 wt% to 30 wt%, more preferably 1 wt% to 25 wt%, most preferably from 2 wt% to 15 wt%.

The compositions of the invention may also contain non-ionic surfactant. Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the Cs to C20 aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C10 to C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides, glycerol monoethers, and polyhydroxyamides (glucamide). It is preferred if the level of non-ionic surfactant is from 0 wt% to 30 wt%, preferably from 1 wt% to 25 wt%, most preferably from 2 wt% to 15 wt%.

It is also possible to include certain mono-alkyl cationic surfactants which can be used in main-wash compositions for fabrics. Cationic surfactants that may be used include quaternary ammonium salts of the general formula R _I R ₂ R _S R ₄ N ⁺ X wherein the R groups are long or short hydrocarbon chains, typically alkyl, hydroxyalkyl or ethoxylated alkyl groups, and X is a counter-ion (for example, compounds in which Ri is a CstoC ₂₂ alkyl group, preferably a Cs to C1 ₀ or C12 to C _M alkyl group, R _{2 IS} a methyl group, and R ₃ and R4, which may be the same or different, are methyl or hydroxyethyl groups); and cationic esters (for example, choline esters).

The choice of surface-active compound (surfactant), and the amount present, will depend on the intended use of the detergent composition. In fabric washing compositions, different surfactant systems may be chosen, as is well known to the skilled formulator, for handwashing products and for products intended for use in different types of washing machine. The total amount of surfactant present will also depend on the intended end use and may be as high as 60 wt.%, for example, in a composition for washing fabrics by hand. Detergent compositions suitable for use in most automatic fabric washing machines generally contain anionic non-soap surfactant, or non-ionic surfactant, or combinations of the two in any suitable ratio, optionally together with soap.

In compositions for machine washing of fabrics, an amount of from 5 wt.% to 40 wt.% is generally appropriate. Typically, the compositions will comprise at least 2 wt.% surfactant e.g. 2 wt.% to 60 wt.%, preferably 15 wt.% to 40 wt.% most preferably 25 wt.% to 35 wt.%.

Builders:

The composition according to the present invention may also contain one or detergency builders in addition to carbonate based builders. Inorganic builders that may be present include crystalline and amorphous aluminosilicates, for example, zeolites as disclosed in GB 1473201 (Henkel), amorphous aluminosilicates as disclosed in GB 1473202 (Henkel) and mixed crystalline/amorphous aluminosilicates as disclosed in GB 1470250 (Procter &

Gamble); and layered silicates as disclosed in EP 164514B (Hoechst).

The compositions of the invention preferably contain an alkali metal, preferably sodium, aluminosilicate builder. The alkali metal aluminosilicate may be either crystalline or amorphous or mixtures thereof, having the general formula: 0.8 to 1.5 Na ₂ 0.AI ₂ 0 ₃ . 0.8 to 6 Si0 ₂ .

These materials contain some bound water and are required to have a calcium ion exchange capacity of at least 50 mg CaO/g. The preferred sodium aluminosilicates contain 1.5 to 3.5 Si0 ₂ units (in the formula above). Both the amorphous and the crystalline materials can be prepared readily by reaction between sodium silicate and sodium aluminate, as amply described in the literature. Suitable crystalline sodium aluminosilicate ion-exchange detergency builders are described, for example, in GB 1429143 (Procter & Gamble). The preferred sodium aluminosilicates of this type are the well-known commercially available zeolites A and X, and mixtures thereof.

The zeolite may be the commercially available zeolite 4A now widely used in laundry detergent powders. However, according to a preferred embodiment of the invention, the zeolite builder incorporated in the compositions of the invention is maximum aluminium zeolite P (zeolite MAP) as described and claimed in EP 384070A (Unilever). Zeolite MAP is defined as an alkali metal aluminosilicate of the zeolite P type having a silicon to aluminium ratio not exceeding 1.33, preferably within the range of from 0.90 to 1.33, and more preferably within the range of from 0.90 to 1.20.

Especially preferred is zeolite MAP having a silicon to aluminium ratio not exceeding 1.07, more preferably about 1.00. The calcium binding capacity of zeolite MAP is generally at least 150 mg CaO per g of anhydrous material. Zeolites are present in the composition in an amount ranging from 0 wt.% to 5 wt.% in the composition. Preferably the detergent composition has less than 4 wt.%, still preferably less than 3 wt.%, further preferably less than 2 wt.%, still further preferably less than 1 wt.% of zeolite in the composition. The composition may even be substantially free of zeolite builder; substantially free means "no deliberately added".

Optionally, organic builders such as citrates, suitable used in amounts of from 1wt.% to 30 wt.%, preferably 5 wt.% to 30 wt%, preferably from 5 wt.% to 15 wt.%, still preferably from 5 wt.% to 10 wt.% are used. Preferably the amount of citric acid and citrates in the composition is from 1 wt.% to 5 wt.%. Water-soluble, non-phosphorus organic builders useful herein include the various alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxy sulfonates. Suitable non-phosphorus, inorganic builders include the borates such as tetraborate decahydrate, and carbonates, such as sodium and potassium sesquicarbonate, and silicates preferably having a weight ratio of S1O2 to alkali metal oxide of from about 0.5 to about 4.0, or from about 1.0 to about 2.4.

Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form.

Enzymes

The compositions preferably include one or more detergent enzymes which provide cleaning performance and/or fabric care benefits. Examples of suitable enzymes include hemicellulases, peroxidases, proteases, cellulases, xylanases, lipases, phospholipases, esterases, cutinases, pectinases, keratanases, reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, 11-glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase, and amylases, or mixtures thereof. A typical combination may be a cocktail of conventional applicable enzymes like mannanase, protease, lipase, cutinase and/or cellulase in conjunction with amylase. Enzymes can be used at their recommended levels, for example at levels recommended by suppliers such as Novozymes and Genencor. Typical levels in the compositions are from about 0.0001 wt.% to about 5 wt.%. When enzymes are present, they can be used at very low levels, e.g., from about 0.001% or lower; or they can be used in heavy-duty laundry detergent formulations at higher levels, e.g., about 0.1% and higher. The detergent composition according to the present may be enzyme-free. By the term “enzyme-free” it means that there is no deliberately added enzyme in the composition.

Dye-transfer inhibiting agents: The composition according to the present invention may also include from 0.0001 to 10 wt.%, preferably at least 0.01 wt.%, still preferably at least 0.05 wt.% by weight of the composition of a dye-transfer inhibiting agent. But typically, not more than 2 wt.%, preferably not more than 1wt.% of one or more dye transfer inhibiting agents such as polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of Nvinylpyrrolidone and N-vinylimidazole, polyvinyloxazolidones and polyvinylimidazoles or mixtures thereof. Brighteners:

The detergent composition according to the present invention may preferably include an optical brightener also known as Non-limiting examples of useful brighteners include: derivatives of stilbene or 4,4'-diaminostilbene, biphenyl, five membered heterocycles such as triazoles, pyrazolines. oxazoles, imidiazoles, etc., or six membered heterocycles (coumarins, naphthalamide, s-triazine, etc.). Cationic, anionic, nonionic, amphoteric and zwitterionic brighteners can be used. Suitable brighteners include those commercially marketed under the trade name Tinopal-UNPA-GX by Ciba Specialty Chemicals Corporation (High Point, NC). Perfume:

Preferred compositions include a perfume. In such a case, the detergent composition may deliver high-quality and long-lasting perfume impact on clothes.

As used herein the term "perfume" is used to indicate any odoriferous material that is subsequently released into the aqueous wash solution and/or onto fabrics contacted therewith.

The perfume will most often be liquid at ambient temperatures. A wide variety of chemicals are known for perfume uses, including materials such as aldehydes, ketones, and esters. The perfumes herein can be relatively simple in their compositions or can comprise highly sophisticated complex mixtures of chemical components, all chosen to provide any desired odour. Likewise, the perfume may be of the encapsulated type, such as, shear sensitive encapsulates which deposit on fabrics during the rinse process and are capable of undergoing rupture, later, to release the perfume. The perfume may be a perfume microcapsule, or a moisture-activated perfume microcapsule, comprising a perfume carrier and an encapsulated perfume composition, wherein said perfume carrier may be selected from the group consisting of cyclodextrins, starch microcapsules, porous carrier microcapsules, and mixtures thereof; and wherein said encapsulated perfume composition may comprise low volatile perfume ingredients, high volatile perfume ingredients, and mixtures thereof. The perfume may additionally include a pro-perfume. Pro-perfumes may comprise nonvolatile materials that release or convert to a perfume material as a result of, e.g., simple hydrolysis, or may be pH-change-triggered pro-perfumes (e.g. triggered by a pH drop) or may be enzymatically releasable pro-perfumes or light-triggered pro-perfumes. The pro-perfumes may exhibit varying release rates depending upon the pro-perfume chosen. Fabric Hueing agent:

The composition may preferably include a fabric hueing agent (sometimes referred to as shading, bluing or whitening agents). Typically, the hueing agent provides a blue or violet shade to fabric. Hueing agents can be used either alone or in combination to create a specific shade of hueing and/or to shade different fabric types. This may be provided for example by mixing a red and green-blue dye to yield a blue or violet shade. Hueing agents may be selected from any known chemical class of dye, including but not limited to acridine, anthraquinone (including polycyclic quinones), azine, azo (e.g., monoazo, disazo, trisazo, tetrakisazo, polyazo), including premetallized azo, benzodifurane and benzodifuranone, carotenoid, coumarin, cyanine, diazahemicyanine, diphenylmethane, fonnazan, hemicyanine, indigoids, methane, naphthalimides, naphthoquinone, nitro and nitroso, oxazine, phthalocyanine, pyrazoles, stilbene, styryl, triarylmethane, triphenylmethane, xanthenes and mixtures thereof.

Suitable fabric hueing agents include dyes, dye-clay conjugates, and organic and inorganic pigments. Suitable dyes include small molecule dyes and polymeric dyes. Suitable small molecule dyes include small molecule dyes selected from the group consisting dyes falling into the Colour Index (C.l.) classifications of Acid, Direct, Basic, Reactive or hydrolysed Reactive, Solvent or Disperse dyes for example that are classified as Blue, Violet, Red, Green or Black, and provide the desired shade either alone or in combination. In another aspect, suitable small molecule dyes include small molecule dyes selected from the group consisting of Colour Index (Society of Dyers and Colourists, Bradford, UK) numbers Direct Violet dyes such as 9, 35, 48, 51, 66, and 99, Direct Blue dyes such as 1, 71, 80 and 279, Acid Red dyes such as 17, 73, 52, 88 and 150, Acid Violet dyes such as 15, 17, 24, 43, 49 and 50, Acid Blue dyes such as 15, 17, 25, 29, 40, 45, 75, 80, 83, 90 and 113, Acid Black dyes such as 1, Basic Violet dyes such as 1, 3, 4, 10 19, 35, 38, and 48, Basic Blue dyes such as 3, 16, 22, 47, 65, 66, 67, 71, 75 and 159, Disperse or Solvent dyes, and mixtures thereof. In another aspect, suitable small molecule dyes include small molecule dyes selected from the group consisting of C. I. numbers Acid Violet 17, Acid Blue 80, Acid Violet 50, Direct Blue 71, Direct Violet 51, Direct Blue 1, Acid Red 88, Acid Red 150, Acid Blue 29, Acid Blue 113 or mixtures thereof. Process for treating the fabric:

The detergent composition disclosed herein enable consumers to achieve softening through the wash, in particular the wash sub-cycle of a washing machine. By providing softening through the wash sub-cycle, consumers only need to dose the detergent composition, for example in the wash basin, prior to or shortly after the start of the washing machine. This can be more convenient to consumers than using a liquid fabric care composition that is separately dispensed into the wash basin after the wash sub cycle is completed, for example prior to, during, or in between rinse cycles. For instance, it can be inconvenient for the consumer to manually dispense fabric softening composition after completion of the wash sub-cycle since the consumer must monitor the progress of the sub-cycles of the washing machine, interrupt progress of the cycles of the washing machine, open the washing machine, and dispensing fabric softening composition into the wash basin. It can further be inconvenient to use auto-dispensing feature of modern upright and high efficiency machines since that requires loading the fabric softening composition to a location other than where detergent composition is dispensed. In addition, use of two different compositions one for cleaning and another for softening the fabric is perceived as an inconvenience for the consumer as they must store them separately and each time dispense them separately.

According to a second aspect of the invention, disclosed is a method for softening fabric comprising, (i) providing a fabric in a washing machine or in a hand wash container; (ii) contacting the fabric during a wash cycle of said washing machine or hand wash process with the composition according to the first aspect; (iii) optionally allowing the fabric to dry or mechanically tumble-drying them. The process for treating a fabric involves the steps of providing the fabric in a washing machine or a wash container during hand wash. The fabric is contacted during the wash sub-cycle of the washing machine with a composition according to the first aspect of the present invention.

Typically, a fabric laundering process includes a washing step, a rinsing step and a drying step. The washing step employs water and detergent composition comprising anionic surfactant along with other active ingredients to form a wash liquor. After washing, the fabric is rinsed one or more times as part of the rinsing step.

In a washing machine a typical cycle of operation involves a wash cycle and a rinse cycle. In the wash cycle of the washing machine, water fills the wash basin either fully or partially. The wash cycle removes or loosens soil from the fabric and suspends that soil in the wash liquor. Typically, the wash liquor is drained at the end of the wash cycle. The rinse cycle of a washing machine follows the wash cycle and has a main purpose of rinsing soil, and optionally some benefit agents provided to the wash cycle from the fabric.

Use of the detergent composition According to a third aspect of the present invention disclosed is the use of chelating agent selected from the group consisting of amino carboxylates, phosphonates or mixtures thereof, fabric softening agent selected from clay, silicone or mixtures thereof and a bicarbonate salt in a detergent composition having from 20 wt.% to 35 wt.% carbonate builder, from 0 wt.% to 5 wt.% zeolite builder and from 0 wt.% to 4 wt.% phosphate builder to provide softening benefit on fabric treated with the composition.

The invention will now be described by way of example only and with reference to the following non-limiting examples. In the examples and throughout this specification all percentages are percentages by weight unless indicated otherwise.

Examples Example 1 :

Two different spray-dried solid detergent compositions were prepared according to the formulations given in Table 1. The compositions were prepared by the slurry route where a solution of the anionic surfactant, sodium carbonate builder and filler were prepared and then dried into a solid form in a spray drier. The remaining ingredients were post dosed to obtain the composition as shown in Table 1.

Softness evaluation:

The above prepared compositions were evaluated as follows. Each of the solid detergent composition shown in Table 1 was poured in the powder dispensing drawer of a separate Samsung automatic top loading machine at a dosage of 3 grams per litre in the wash stage.

Approximately 2.7 Kgs of a fabric ballast was added into the washing machine. The fabric consisted of 100% clean polyester. 35 litres water was filled in the washing machine and the ballast was washed by selecting the fuzzy cycle of the washing machine at a wash water temperature of 28°C. The water has a hardness of 24°FH with a Ca:Mg ratio of 2:1. The main wash was followed by 2 rinse cycles. The washed fabric was line dried after each wash.

This process was repeated for 20 washes and the softness of the fabric was evaluated after 5,10,15 and 20 washes.

The above washing process was similarly conducted for the control and the second detergent composition according to the present invention, as given in table 1. The control composition used for the present study was prepared by adding 1.1 wt% silicone (30% active content) and 0.166 wt% cationic polymer (90% active content) to commercially available Surf Excel Top Load matic liquid. The washed fabric was evaluated by 15 trained sensory panellists for their softness intensity on a scale from 1 to 10. Where 1 denotes lowest softness score and 10 denotes highest level of softness score. The results were recorded and provided in Table 2 below. Table 1

* HEDP

^% Bentonite clay “PDMS Table 2

The results of the softness score showed a preference for composition of Ex 1 over control composition ie. the composition according to the present invention, having the HEDP (chelating agent), clay (fabric softening agent), and sodium bicarbonate gave better softening. The same result was obtained when composition of Ex 2 was compared with control. It was also observed that the improved softness was maintained in the fabric over multiple washes.

Example 2: Different spray-dried solid detergent compositions were prepared according to the formulations given in Table 3 (clay as the fabric softening agent). The compositions were prepared by the slurry route where a solution of the anionic surfactant, sodium carbonate builder and filler were prepared and then dried into a solid form in a spray drier. The remaining ingredients were post dosed to obtain the composition as shown in Table 3.

Softness evaluation:

The above prepared compositions were evaluated as follows.

Each of the solid free flowing spray-dried detergent composition shown in Table 3 was poured in the powder-dispensing drawer of a separate Samsung automatic top loading machine at a dosage of 3 grams per litre in the wash stage.

Approximately 2.7 Kgs of a fabric ballast was added into the washing machine. The fabric consisted of 100% clean polyester. 35 litres water was filled in the washing machine and the ballast was washed by selecting the fuzzy cycle of the washing machine at a wash water temperature of 28°C. The water has a hardness of 24° FH with a Ca:Mg ratio of 2:1. The main wash was followed by 2 rinse cycles. The washed fabric was line dried after each wash.

This process was repeated for 20 washes and the softness of the fabric was evaluated after 10,15 and 20 washes.

The above washing process was similarly conducted for the all the six different comparative detergent composition and the two detergent composition according to the present invention, as given in table 3.

The washed fabric was evaluated by 15 trained sensory panellists for their softness intensity on a scale from 1 to 10. where 1 denotes lowest softness score and 10 denotes highest level of softness score. The results were recorded and provided in Table 3 below.

Table 3

* HEDP

^% Bentonite clay

“PDMS, amino functionalized softening silicone The results of fabric softness clearly shows that the presence of a combination of

HEDP (chelating agent), clay/silicone (fabric softening agent), and sodium bicarbonate according to the present invention gave better softening (Ex 3, Ex 4). In a carbonate built detergent composition, the composition according to the present invention (Ex 3) gave better softness over multiple washes in comparison to the comparative examples (Comp A, Comp B, Comp C) which included only clay or clay in combination with either chelating agent or a bicarbonate. These compositions were prepared with no zeolite or phosphate builders (STPP). It was also observed that in comparison to the comparative examples (Comp A, Comp B, Comp C), the improved softness in the composition according to the present invention was maintained in the fabric over multiple washes.