WO2023025685A1

WO2023025685A1 - Detergent composition

Info

Publication number: WO2023025685A1
Application number: PCT/EP2022/073210
Authority: WO
Inventors: Sujitkumar Suresh Hibare; Hemendra Dilip JOSHI; Shashank Khare; Rajan Chandrakant MHAMUNKAR; Subhajit MANNA
Original assignee: Unilever Ip Holdings B.V.; Unilever Global Ip Limited; Conopco, Inc., D/B/A Unilever
Priority date: 2021-08-27
Filing date: 2022-08-19
Publication date: 2023-03-02
Also published as: CN117881765A

Abstract

The present invention relates to a detergent composition, particularly to a solid detergent composition which has good dissolution.Thus, there remains a need for a granular laundry detergent composition comprising an anionic detersive surfactant and a carbonate builder having a good fabric-cleaning performance and very good dispensing and dissolution profiles.The present invention provides a solid laundry detergent composition which exhibits good dissolution properties. The good dissolution properties of solid laundry detergent composition being attributed to the presence of carefully and specifically controlled levels of carbonate builder, an anionic surfactant selected from the group consisting of sulphate surfactant, sulphonate surfactant or mixtures thereof in combination with a hydrotrope.

Description

DETERGENT COMPOSITION

Field of the invention

The present invention relates to a detergent composition, particularly to a solid detergent composition which has good dissolution properties.

Background of the invention

Solid laundry detergent compositions need to have good dispensing and dissolution profiles. Dissolution of the solid detergent composition in water, is an important criterion for product acceptability by the consumer, as it indicates to the consumer that the solid laundry detergent composition is available for cleaning.

Certain ingredients in the solid detergent composition which dissolve slowly in the wash liquor, remain as undissolved residues and may deposit on fabrics and are usually manifested in the form of distinct particles which appear as stains, particularly on darkcoloured fabrics.

In the past, few attempts have been made to address dissolution issues.

WO98/44084 (The Procter & Gamble Company) relates to improving the dispensing the detergent composition by incorporating a hydrotrope in a detergent composition having an anionic sulphonate surfactant. This document discloses examples of detergent composition which includes either high levels of zeolite or phosphate builder.

WO 2011/061045 A1 (Unilever NV) discloses a detergent granule which has a surfactant system, habit modified sodium carbonate and CBS-X.

WO 97/30140 A1 (Stephan Company) discloses a hard surface cleaning composition having a detergent surfactant, builder and hydrotrope.

WO 95/23206 A1 (The Procter & Gamble Company) discloses a process for preparing a granular detergent composition having improved solubility in cold temperature. The composition includes primary alkyl sulphate, alkyl ethoxy sulphate surfactant, xylene sulphonate and 39 wt.% zeolite. EP1754781 A1 (The Procter & Gamble Company, 2007) discloses a solid laundry detergent composition having an anionic detersive surfactant, 0 to 5 wt.% zeolite builder, 0 to 5 wt.% phosphate builder and calcium augmented technology.

Although the prior art documents include hydrotrope to improve dispensing of detergent composition but the presence of significant amounts of zeolite in the composition may still form insoluble residue which deposit on the fabric and appear as unsightly spots or stains.

Builders such as zeolite and phosphate are added to the detergent composition to sequester free calcium and magnesium cations and reduce the formation of undesirable complexes between the free cations and anionic detersive surfactant. However, zeolite builders are water-insoluble and their incorporation in laundry detergent compositions leads to poor dissolution of the laundry detergent composition and can also lead to undesirable residues being deposited on the fabric. Phosphate builders on the other hand do not have favourable environmental profiles and their use in laundry detergent compositions is becoming less common, for example, due to phosphate legislation in many countries.

It has also been tried to lower zeolite and phosphate levels in the detergent composition and such composition have been formulated with carbonate builder. However, carbonate builder is found to exhibit poor dissolution kinetics under certain conditions. Poor dissolution occurs usually when cold water is employed for washing and may result in clumping of detergent which remain undissolved and may deposit on washed clothes as unsightly spots.

Thus, there remains a need for a solid laundry detergent composition comprising an anionic detersive surfactant and a carbonate builder having good dispensing and dissolution profiles while maintaining a good fabric-cleaning performance and good free-flowing powder properties.

It is thus an object of the present invention to provide a solid laundry detergent composition which has good dissolution profile.

It is thus also an object of the present invention to provide a solid laundry detergent composition which is free flowing and has good storage properties. It is yet another object of the present invention to provide a solid laundry detergent composition which has good dissolution properties while maintaining desired alkalinity levels.

Summary of the invention

The present invention provides a solid laundry detergent composition which exhibits good dissolution properties. The good dissolution properties of solid laundry detergent composition being attributed to the presence of carefully and specifically controlled levels of sodium carbonate builder, an anionic surfactant selected from the group consisting of sulphate surfactant, sulphonate surfactant or mixtures thereof in combination with a hydrotrope.

The present inventors have found that to improve the dissolution properties of a free-flowing carbonate built solid laundry detergent composition it is necessary to have a combination of anionic surfactant, hydrotrope and sodium carbonate builder preferably at specific levels. They have further surprisingly found that incorporation of insoluble alkaline earth metal carbonate to the formulation improves the powder properties without negatively impacting the dissolution properties.

Detailed description of the invention

The solid detergent composition according to the first aspect of the present invention includes an anionic surfactant, a hydrotrope and a carbonate builder.

Anionic surfactant

According to the first aspect of the present invention disclosed solid detergent composition includes an anionic surfactant selected from sulphate surfactant, sulphonate surfactant or mixtures thereof. Suitable anionic surfactant may be in salt form. Suitable counter-ions include sodium, calcium, magnesium, amino alcohols and any combination thereof. A preferred counterion is sodium.

Sulphate surfactant

Suitable sulphate surfactant includes Cs to C20 alkyl sulphate, preferably Cs to C18 alkyl sulphate, still preferably C12 to C14 alkyl sulphate, more preferably it is predominantly C12 alkyl sulphate. The alkyl sulphate surfactant may be linear or branched, substituted or unsubstituted, and may be derived from petrochemical material or biomaterial. Preferably the alkyl sulphate surfactant is linear. Still preferably it is preferred that the alkyl sulphate surfactant is a C10 to C14 alkyl sulphate surfactant, most preferably a lauryl sulphate surfactant.

Conventional primary alkyl sulfate surfactant has the general formula: R"OSOs'M⁺ wherein R" is typically a Cs to C20 alkyl group, which may be straight chain or branched chain, and M is a water-solubilizing cation. In specific embodiments, R" is a C10 to C15 alkyl group, and M is alkali metal, more specifically R" is C12 to C14 alkyl and M is sodium. Specific, non-limiting examples of anionic alkyl sulphate surfactant useful herein include: C10 to C20 primary, branched-chain and random alkyl sulfates (AS); or C to Cis secondary (2,3)-alkyl sulfates having following formulae:

wherein M is hydrogen or a cation which provides charge neutrality, and all M units, can either be a hydrogen atom or a cation depending upon the form isolated or the relative pH of the system wherein the surfactant is used, with non-limiting examples of preferred cations including sodium, potassium, ammonium, and mixtures thereof, and x is an integer of at least about 7, preferably at least about 9, and y is an integer of at least 8, preferably at least about 9.

A preferred sulphate surfactant is alkyl alkoxylated sulphate, preferably alkyl ethoxylated sulphate, preferably a Cs to Cis is 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 surfactant may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial. Preferably the sulphate surfactant is a linear or branched, substituted or unsubstituted Cs to Cis alkyl sulphate surfactant, Cs to Cis alkyl ether sulphate surfactant or mixtures thereof. Sulphonate surfactant

Suitable sulphonate detersive surfactant include methyl ester sulphonate, alpha olefin sulphonates, alkyl benzene sulphonate, especially alkyl benzene sulphonate, preferably C to C14 alkyl benzene sulphonate or mixtures thereof. 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 include high 2- phenyl LAB, such as those supplied by Sasol under the tradename Hyblene®. The sulphonate surfactant may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial. The sulphonate surfactant is preferably a linear or branched, substituted or unsubstituted C10 to C14 alkyl benzene sulphonate. The sulphonate surfactant may also be selected from the modified alkylbenzene sulfonate (MLAS) as discussed in WO 99/05243, WO 99/05242 and WO 99/05244; methyl ester sulfonate (MES); and alpha-olefin sulfonate (AOS).

The detergent composition of the present invention includes from 2 wt.% to 50 wt.% of anionic detersive surfactant, most preferably from 2 wt.% to 25 wt.% anionic surfactant. Preferably the detergent composition comprises at least 4 wt.%, still preferably at least 5 wt.%, still preferably at least 8 wt.%, still preferably at least 10 wt.%, still more preferably at least 12 wt.% of the anionic surfactant, most preferably at least 15 wt.% of the anionic surfactant, but typically not more than 45 wt.%, still preferably not more than 40 wt.%, still further preferably not more than 35 wt.%, still more preferably not more than 30 wt.% and most preferably not more than 25 wt.%, still more preferably not more than 20 wt.% of an anionic surfactant based on the weight of the detergent composition.

Preferably the anionic surfactant includes 0 wt.% to 25 wt.% alkyl sulfate surfactant, preferably 0 wt.% to 10 wt.% alkyl sulfate surfactant, preferably primary alkyl sulphate surfactant (PAS). The anionic surfactant may also preferably include from 0 wt.% to 10 wt.% MES, more preferably 0 wt.% to 5 wt.% MES. The anionic surfactant may include an alkyl alkoxylate sulphate surfactant, preferably an alkyl ethoxylate sulphate surfactant with 1 to 7EO group, still preferably a sodium lauryl ether sulphate with 1 to 7 EO, still preferably SLES 1 to 3 EO, preferably included in the composition in an amount from 0 wt.% to 15 wt.%, preferably 0 wt.% to 8 wt.% SLES, still preferably 0 wt.% to 8 wt.% SLES. Preferably the detergent composition includes alkyl benzene sulphonate surfactant or primary alkyl sulphate surfactant (PAS) as the sole anionic detersive surfactant. In still other embodiments the alkyl benzene sulphonate surfactant and/or primary alkyl sulphate surfactant (PAS) is present in combination with other sulphonate surfactant, sulphate surfactant or alkyl alkoxylate sulphate surfactant.

Preferably the anionic detersive surfactant includes a combination of alkyl benzene sulphonate and alkoxylated alkyl sulphate surfactant wherein the ratio of the alkoxylated alkyl sulphate surfactant to alkyl benzene sulphonate is from 30:70 to 40:60.

Hydrotrope

According to the first aspect of the present invention disclosed solid detergent composition includes a hydrotrope. The hydrotrope is an aryl sulphonate which is substituted with Ci to C4 alkyl group. Suitable example of unsubstituted aryl sulphonate includes benzene sulphonate, preferably sodium benzene sulphonate which may be present in addition to the substituted aryl sulphonate in the composition. The term sulphonate include sulphonic acid. The hydrotrope is preferably present in the salt form which includes alkali metal, alkaline earth metal, alkyl amine or ammonium salt of the sulphonic acid. More preferably sodium salt.

More preferably the substituted hydrotrope is selected from cumene sulphonate, xylene sulphonate, toluene sulphonate or mixtures thereof. The preferred hydrotrope according to the present invention is cumene sulphonate, preferably sodium cumene sulphonate.

The detergent composition of the present invention includes from 0.2 wt.% to 10 wt.% hydrotrope, more preferably 0.5 wt.% to 5 wt.%. Preferably the detergent composition comprises at least 0.3 wt.%, still preferably at least 0.35 wt.%, still preferably at least 0.45 wt.%, most preferably at least 0.5 wt.% of the hydrotrope, but typically not more than 8 wt.%, still preferably not more than 7.5 wt.%, still further preferably not more than 6 wt.%, still more preferably not more than 4 wt.% and most preferably not more than 2 wt.%, hydrotrope by weight of the detergent composition. Preferred level of inclusion is in the range of 0.5 wt.% to 2 wt.%. Sodium carbonate builder

The detergent composition of the present invention includes a sodium carbonate builder. In addition to the sodium carbonate builder the composition may also include sodium bicarbonate, potassium carbonate, sodium sesquicarbonate or mixtures thereof.

The detergent composition of the present invention includes from 5 wt.% to 40 wt.% sodium carbonate builder. Preferably the detergent composition comprises at least 6 wt.%, still preferably at least 8 wt.%, still preferably at least 10 wt.%, most preferably at least 12 wt.% of the carbonate builder, most preferably at least 15 wt.% of the carbonate builder but typically not more than 38 wt.%, still preferably not more than 35 wt.%, most preferably not more than 30 wt.%, most preferably not more than 25 wt.% of sodium carbonate builder based on the weight of the laundry detergent composition.

Co-particle

The anionic surfactant and the hydrotrope is preferably present in intimate contact with each other. The anionic surfactant and the hydrotrope is preferably in the form of a co-particle. As used herein, the term "co-particle" means particle having more than one compound or component present in the solid detergent composition. The term "particle" is to be interpreted broadly and is intended to embrace various particulate forms such as but not limited to granulate, noodles, coarse powder, agglomerate, needles, and tablets. Still preferably the coparticle includes sodium carbonate. Preferably the co-particle is formed by agglomeration or spray-dried process.

The anionic detersive surfactant is preferably present in an amount ranging from 2 wt.% to 40 wt.% by weight of the co-particle, more preferably 5 wt.% to 30 wt.%, still preferably 5 wt.% to 25 wt.% by weight of the co-particle.

The hydrotrope is preferably present in an amount ranging from 0.2 wt.% to 10 wt.% by weight of the co-particle, more preferably 0.2 wt.% to 5 wt.%, still preferably from 0.2 wt.% to 2 wt.% by weight of the co-particle. The sodium carbonate is preferably present in an amount ranging from 0 wt.% to 50 wt.% by weight of the co-particle, more preferably 5 wt.% to 40 wt.%, still preferably from 5 wt.% to 30 wt.% by weight of the co-particle.

The process of forming the co-particle involves agglomeration wherein preferably anionic detersive surfactant and hydrotrope are intimately mixed together. More preferably anionic detersive surfactant, sodium carbonate builder and hydrotrope are intimately and homogenously mixed to form the co-particle.

In one preferred process for forming the co-particle, the co-particle is formed preferably by spraying the anionic detersive surfactant in the acid or salt form onto a filler, or preferably the sodium carbonate builder along with continuous mixing. The hydrotrope is added to the mixture either before or after spraying the anionic detersive surfactant. Preferably the hydrotrope and the salt or acid form of the anionic surfactant are added in separate step during the process.

Still preferably the co-particle has less than 4 wt.% zeolite. The solid laundry detergent composition preferably has 0 wt.% zeolite in the co-particle and/or detergent composition of the invention. Still preferably the co-particle has less than 4 wt.% phosphate builder.

Phosphate salts may even be completely absent from the co-particle and/or detergent composition of the invention.

Without wishing to be bound by theory, the inventors surprisingly found that preferably when the anionic surfactant and the hydrotrope are in the co-particle it allowed good dissolution of the overall solid laundry detergent composition having the sodium carbonate. More preferably the co-particle has sodium carbonate, LAS and hydrotrope wherein the hydrotrope is an aryl sulphonate which is substituted with a Ci to C4 aryl group.

Alkaline earth metal salt of carbonate

The solid detergent composition according to the present invention may preferably include an alkaline earth metal salt of carbonate. Preferably the alkaline earth metal salt of carbonate includes calcium carbonate, magnesium carbonate or mixtures thereof. The detergent composition preferably includes a flow aid selected from the group consisting of calcium carbonate, magnesium carbonate, double salt of calcium and magnesium carbonate, dolomite, calcite or mixture thereof. Without being bound by theory it is believed that alkaline earth metal salt of carbonate provides as a flow aid and ensures free flowing characteristics of the solid laundry detergent composition. It was further found that the addition of the alkaline earth metal salt of carbonate does not negatively impact the dissolution properties of the composition.

Preferably the calcium carbonate is selected from ground natural calcium carbonate (GNCC) or precipitated calcium carbonate (PCC). Preferably the calcium carbonate is finely divided. The calcium carbonate may preferably be surface treated. The calcium carbonate may preferably have a specific surface area ranging from 5 to 200 m²/g measured using nitrogen and the BET method according to ISO 9277:2010. Preferably the calcium carbonate has specific pore volume in the range from 0.1 to 2.3 cm³/g calculated from mercury porosimetry measurement.

Any crystalline form of calcium carbonate may be used or a mixture thereof, these includes calcite, aragonite, vaterite, but calcite is preferred because aragonite and vaterite appear to be more difficult to prepare with high surface areas. Calcium carbonate can be prepared conveniently by precipitation processes, for example by passing carbon dioxide into a suspension of calcium hydroxide, or by reaction between any fairly soluble calcium salt and a soluble carbonate salt, for example calcium sulphate or calcium hydroxide with sodium carbonate, after which the calcium carbonate needs to be filtered from the reaction medium and then dried. Suitable forms of calcium carbonate, especially calcite, are commercially available. The calcium carbonate is preferably in substantially pure form, but this is not essential, and the calcium carbonate used may contain minor amounts of other cations with or without other anions.

The detergent composition of the present invention includes from 0.1 wt.% to 40 wt.% alkaline earth metal carbonate, preferably calcium carbonate. Preferably the detergent composition comprises at least 0.8 wt.%, still preferably at least 1 wt.%, still preferably at least 2 wt.%, most preferably at least 5 wt.% of the alkaline earth metal carbonate salt, but typically not more than 38 wt.%, still preferably not more than 35 wt.%, most preferably not more than 30 wt.% of alkaline earth metal carbonate based on the weight of the solid laundry detergent composition. More preferably the amount of alkaline earth metal carbonate present in the solid laundry detergent composition ranges from 0.1 to 10 wt.%

The alkaline earth metal carbonate may also preferably be magnesium carbonate or a double salt of calcium and magnesium carbonate. Preferably the detergent composition includes dolomite at levels ranging from 1 wt.% to 20 wt.%.

Preferred ingredients

Preferably the detergent composition of the present invention may include builders selected from the group consisting of silicates, silica, zeolites, phosphates or mixtures thereof. Yet other which may be present includes organic builders which are not limited to as succinates, carboxylates, malonates, polycarboxylates, citric acid or a salt thereof.

Suitable silicates include the water-soluble sodium silicates with an SiO2:Na2O ratio of from 1.0 to 2.8, with ratios of from 1.6 to 2.4 being preferred, and 2.0 ratio being most preferred. The silicates may be in the form of either the anhydrous salt or a hydrated salt. Sodium silicate with an SiCh: Na2O ratio of 2.0 is the most preferred silicate.

Silicates are preferably present in the detergent compositions in accordance with the invention at a level of from 2% to 50% by weight of the composition, more preferably from 5% to 40% by weight, still preferably from 7 wt.% to 40 wt.%, even more preferably 7% to 20%.

The detergent composition according to the present invention includes from 0 wt.% to 4 wt.% zeolite. Preferably the detergent composition is substantially free of zeolite builder. By substantially free it is meant that the composition does not include deliberately added zeolite. Most preferably the composition includes 0 wt.% zeolite.

The detergent composition according to the present invention includes from 0 wt.% to 4 wt.% phosphate builder. Preferably the detergent composition is substantially free of phosphate builder. By substantially free it is meant that the composition does not include deliberately added phosphate. Most preferably the composition includes 0 wt.% phosphate. Form of the composition

The composition of the present invention is in the solid form. The composition according to the present invention may be made via a variety of conventional methods known in the art and those which includes but is not limited to the mixing of ingredients, including dry-mixing, compaction such as agglomerating, extrusion, tabletting, or spray-drying of the various compounds comprised in the detergent component, or mixtures of these techniques, whereby the components herein also can be made by for example compaction, including extrusion and agglomerating, or spray-drying. The detergent composition may be made by any of the conventional processes, especially preferred is the technique of slurry making and spray drying.

The compositions herein can take a variety of physical solid forms including forms such as powder, granule, ribbon, noodle, needle, paste, tablet, flake, pastille and bar, and preferably the composition is in the form of powder, granules or a tablet, still preferably the composition is in the form of a powder. The composition may be in the form of a unit dose formulation, delayed delivery formulation, detergent contained on or in a porous substrate or nonwoven sheet, and other suitable forms that may be apparent to one skilled in the art in view of the teachings herein. The composition according to the present invention may preferably be in a form selected from powder, unit dose or pouch form, tablet, gel, paste, bar, or flake. Preferably the composition is for manual-washing. Preferably, the composition of the present invention is a solid laundry detergent composition. Preferably the composition is in the form of a spray -dried powder.

The compositions preferably have a bulk density of more than 350 grams/litre, more preferably more than 450 grams/litre or even more than 570 grams/litre.

The composition according to the present invention has a pH of from 8 to 13, preferably from 8.5 to 12, when measured at 1 wt.% dilution in de-ionised water at 25°C. The composition of the present invention preferably also includes further alkaline source which is selected from bicarbonates and semi-bicarbonates. The composition may preferably include a buffer. Optional ingredients

The detergent composition of the present invention may preferably include one or more of the optional ingredients selected from the group consisting of cleaning and care ingredients. The optional ingredients include one or more adjunct cleaning additives selected from polymers, enzymes, enzyme stabilizer, brightening agents, hueing agent, bleach, chelating agent, humectant, perfume, filler or carrier, an alkalinity system, a buffer or combinations thereof.

Polymers:

The composition of the present invention may preferably include polymers which provide cleaning or care benefits. The cleaning polymer includes but is not limited to soil release polymer, carboxylate polymers, antiredeposition polymers, cellulosic polymers, care polymers, dye-transfer inhibiting polymer, amphiphilic alkoxylated grease cleaning polymers, clay soil cleaning polymers, soil suspending polymers or mixtures thereof.

Suitable carboxylate polymer includes polymers such as a maleate/acrylate random copolymer or polyacrylate homopolymer. Suitable carboxylate polymers homopolymeric or copolymeric carboxylic acids, such as polyacrylic acid, polymethacrylic acid, polymaleic acid, copolymers of acrylic acid or methacrylic acid with maleic acid. Preferred representatives of this group are sodium polyacrylate and sodium salts of acrylic acid-maleic acid copolymers.

Soil release polymers are designed to modify the surface of the fabric to facilitate the ease of removal of soil. Suitable soil release polymers are sold by Clariant under the TexCare® series of polymers, e.g. TexCare® SRN240. Other suitable soil release polymers are sold by Rhodia under the Repel-o-Tex® series of polymers, e.g. Repel-o-Tex® SF2. A preferred polymer is selected from the group consisting of polyester soil release polymer, both endcapped and non-end-capped sulphonated or unsulphonated PET/POET polymers. Preferably the levels of these soil release polymer in the adjunct particle is from 3 wt.% to 15wt.%.

Anti-redeposition polymers are designed to suspend or disperse soil. Typically, antiredeposition polymers are polyethylene glycol polymers, polycarboxylate polymers, polyethyleneimine polymers or mixtures thereof. Such polymers are available from BASF under the trade name Sokalan®CP5 (neutralised form) and Sokalan®CP45 (acidic form). Suitable antiredeposition polymers are ethoxylated and or propoxylated polyethylene imine or polycarboxylate materials, for example, acrylic acid-based homo or copolymers available under the trademark ACLISOL from Dow Chemical, Alcosperse from Akzonobel or Sokolan from BASF.

Suitable care polymers include cellulosic polymers that are cationically modified or hydrophobically modified. Such modified cellulosic polymers can provide anti- abrasion benefits and dye lock benefits to fabric during the laundering cycle. Suitable cellulosic polymers include cationically modified hydroxyethyl cellulose.

Examples of suitable sequestering polymers are DEQUEST™, organic phosphonate type sequestering polymers sold by Monsanto and alkanehydroxy phosphonates.

The cleaning composition is preferably substantially free of phosphate based sequestering polymers. By substantially free, it is meant herein that no phosphate based sequestering polymers is deliberately added.

Enzymes:

The composition of the present invention preferably includes one or more enzymes. Preferred examples of the enzymes include those which provide cleaning performance and/or fabric care benefits.

Examples of suitable enzymes include, but are not limited to, hemicellulases, peroxidases, proteases, cellulases, xylanases, lipases, xyloglucanase, phospholipases, esterases, cutinases, pectinases, mannanases, pectate lyases, keratinases, reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, G-glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase, and amylases, or mixtures thereof. A typical combination is an enzyme cocktail that may comprise, for example, a protease and lipase in conjunction with one or more of amylase, mannanase and cellulase. When present in a detergent composition, the aforementioned additional enzymes may be present at levels from about 0.00001% to about 2%, from about 0.0001% to about 1% or from 0.001% to about 0.5% enzyme protein by weight of the detergent composition. Suitable commercially available protease enzymes include those sold under the trade names Alcalase®, Savinase®, Primase®, Durazym®, Polarzyme®, Kannase®, Liquanase®, Liquanase Ultra®, Savinase Ultra®, Ovozyme®, Neutrase®, Everlase® and Esperase® by Novozymes A/S (Denmark), those sold under the tradename Maxatase®, Maxaca®l, Maxapem®, Properase®, Purafect®, Purafect Prime®, Purafect Ox®, FN3®, FN4®, 10 Excellase® and Purafect OXP® by Genencor International, those sold under the tradename Opticlean® and Optimase by Solvay Enzymes. Suitable commercially available alpha-amylases include DURAMYL®, LIQUEZYME®, TERMAMYL®, TERMAMYL ULTRA®, NATALASE®, SUPRAMYL®, STAINZYME®, STAINZYME PLUS®, FUNGAMYL® and BAN® (Novozymes A/S, Bagsvaerd, Denmark), 15 KEMZYM® AT 9000 Biozym Biotech Trading GmbH Wehlistrasse 27b A-1200 Wien Austria, RAPIDASE®, PURASTAR®, ENZYSIZE®, OPTISIZE HT PLUS®, POWERASE® and PURASTAR OXAM® (Genencor International Inc., Palo Alto, California) and KAM® (Kao, 14-10 Nihonbashi Kayabacho, 1-chome, Chuo-ku Tokyo 103-8210, Japan). In one aspect, suitable amylases include NATALASE®, STAINZYME and STAINZYME PLUS® and mixtures thereof. Preferred lipases would include those sold under the tradenames Lipex® and Lipolex®. Suitable endoglucanases are sold under the tradenames Celluclean® and Whitezyme® (Novozymes A/S, Bagsvaerd, Denmark). Other preferred enzymes include pectate lyases sold under the tradenames Pectawash®, Pectaway®, Xpect® and mannanases sold under the tradenames Mannaway® (all from Novozymes A/S, Bagsvaerd, Denmark), and Purabrite® (Genencor International Inc., Palo Alto, California).

Enzyme stabilizing system:

The enzyme-containing compositions described herein may optionally comprise from 0.001% to 10%, by weight of the composition, of an enzyme stabilizing system. The enzyme stabilizing system can be any stabilizing system which is compatible with the detersive enzyme. Such stabilizing systems can, for example, comprise calcium ion, boric acid, propylene glycol, short chain carboxylic acids, boronic acids, chlorine bleach scavengers and mixtures thereof, and are designed to address different stabilization problems depending on the type and physical form of the cleaning composition. In the case of detergent compositions comprising protease, a reversible protease inhibitor, such as a boron compound, including borate, 4-formyl phenylboronic acid, phenylboronic acid and derivatives thereof, or compounds such as calcium formate, sodium formate and 1 ,2-propane diol may be added to further improve stability. Brightening agents:

Optical brighteners or other brightening or whitening agents may be incorporated at levels from 0.01 % to 1 .2%, by weight of the composition. Commercial brighteners suitable for the present invention can be classified into subgroups, including but not limited to: derivatives of stilbene, pyrazoline, coumarin, benzoxazoles, carboxylic acid, methinecyanines, dibenzothiophene-5, 5- dioxide, azoles, 5- and 6-membered-ring heterocycles, and other miscellaneous agents. Preferred commercially available Brighteners includes Tinopal AMS- GX by Ciba Geigy Corporation, Tinopal UNPA-GX by Ciba-Geigy Corporation, Tinopal 5BM- GX by Ciba-Geigy Corporation. The brighteners may be added in particulate form or as a premix with a suitable solvent, for example nonionic surfactant, monoethanolamine, propane diol.

Fabric hueing agents:

The composition may comprise 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 30 premetallized azo, benzodifurane and benzodifuranone, carotenoid, coumarin, cyanine, diazahemicyanine, diphenylmethane, formazan, 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.

Foam boosting agent:

The solid detergent composition according to the present invention preferably includes a foam boosting agent. The foam boosting agent used herein means an agent which can increase the level of foam produced in the aqueous solution of the detergent composition and/or increase the duration that the foam lasts by stabilizing the bubbles in the foam; compared to the foam of a composition that does not contain the foam boosting agent. Non-limiting examples of the foam boosting ingredient includes isethionate surfactant, siloxane with polyoxyalkylene group, sulphated ethoxylated Cs to C10 Guerbet alcohol surfactant or mixtures thereof.

The isethionate surfactant is preferably a Cs to Cis isethionate surfactant. Still preferably an isethionate surfactant of the formula (I)

wherein R¹ represents a C4 to 36 substituted or unsubstituted hydrocarbyl group; each of R², R³, R⁴ and R⁵ independently represents a hydrogen atom or a Ci to 4 alkyl group and M⁺ represents a cation.

Preferably R¹ is selected from a substituted or unsubstituted alkyl, alkenyl, aryl or alkylaryl group. More preferably R¹ is selected from a substituted or unsubstituted alkyl or alkenyl group. Preferably R¹ is an alkyl group. Most preferably R¹ is an unsubstituted alkyl or alkenyl group, especially an unsubstituted alkyl group. Preferably R¹ represents a C5 to 30 alkyl group, preferably a C7 to 24 alkyl group, more preferably a C?to2i alkyl group, most preferably a Csto is alkyl group. Most preferably the isethionate surfactant is a Csto is isethionate surfactant.

In some embodiments R² represents a Ci to 4 alkyl group, suitably a Ci to 4 alkyl group in which a propyl or butyl group, when present, is straight-chained. Suitably R² may represent an n- propyl, ethyl or preferably, a methyl group. However, in preferred embodiments R² is hydrogen. Preferably R³ represents a hydrogen atom. In some embodiments R⁴ and R⁵ represents a hydrogen atom and the other represents a hydrogen atom or a Ci to 4 alkyl group. Suitable one of R⁴ and R⁵ represents a hydrogen atom or a Ci to 4 alkyl group in which a propyl or butyl group is straight-chain. Preferably one of R⁴ and R⁵ represents an n-propyl, ethyl or methyl group or, most preferably, a hydrogen atom. Most preferably both R⁴ and R⁵ represent hydrogen atoms. In especially preferred embodiments each of the R², R³, R⁴ and R⁵ is hydrogen and the isethionate compound is of formula R¹CO2CH2CH2SO3M. Preferably M⁺ represents a metal cation or an ammonium cation. Suitable metal cations include alkali metal cations, for example sodium, lithium and potassium cations, and alkaline earth metal cations, for example calcium and magnesium cations. Preferably M⁺ represents a potassium cation, or, especially, a sodium cation.

Examples of the isethionate surfactant includes but is not limited to the group consisting of sodium lauroyl methyl isethionate, ammonium cocoyl isethionate, sodium cocoyl isethionate, sodium hydrogenated cocoyl methyl isethionate, sodium lauroyl isethionate, sodium myristoyl isethionate, sodium oleoyl isethionate, sodium oleoyl methyl isethionate, sodium palm kerneloyl isethionate, sodium stearoyl methyl isethionate, sodium isethionate, dibromopropamidine diisethionate, hexamidine diisethionate, sodium methyl isethionate, and combinations thereof. Most preferably the composition of the present invention comprises sodium lauroyl isethionate and/or sodium cocoyl isethionate. The isethionate surfactant may further comprise one or more of sodium lauroyl methyl isethionate, sodium cocoyl methyl isethionate and sodium oleoyl methyl isethionate. Sodium cocoyl isethionate is especially preferred.

Suitable examples of the commercially available isethionate surfactants include sodium cocyl isethionate available under the tradename Pureact SNDT-LO, Pureact I-78/80, Pureact I- 85EC, Pureact I-85E Flakes and Pureact I-85C from Innospec, Inc.

Another preferred foam boosting agent is the siloxane with a polyoxyalkylene group represented by the following general formula (I):

(R¹3-aYaSiOl/₂)j(R³2-bY_bSiO₂/2)k(R²2SiO₂/2)_P, (I) wherein:

R¹ is same or different and is selected from an alkyl, alkenyl or aryl alkyl group having from 1 to 20 carbon atoms; or alkyl, alkenyl or aryl alkyl group having from 1 to 20 carbon atoms comprising a functional group, or mixtures thereof;

Y is a polyoxyalkylene group having 19 to 30 oxyalkylene group,

R² and R³ are same or different and is selected from an alkyl, alkenyl or aryl alkyl group having from 1 to 20 carbon atoms; or alkyl, alkenyl or aryl alkyl group having from 1 to 20 carbon atoms comprising a functional group, wherein, a is 0, 1 or 2, b is 1 or 2, where if a is 0 then p is 0 or an integer from 1 to 3, and if a is 1 or 2 then p is 0 or an integer from 1 to 50, j, k, are independent of each other and is 0 or an integer from 1 to 50, where either j or k or both is at least 1 , with the proviso that the siloxane comprises at least one Y radical per molecule.

Yet another preferred foam boosting agent is the sulphated ethoxylated Cs to C Guerbet alcohol surfactant with a number average degree of ethoxylation in the range of 2.5 to 10, still preferably from 2.5 to 6, still preferably from 3 to 6, further preferably from 3 to 5, more preferably from 3 to 4.5. Most preferably the number average degree of ethoxylation is 4 or 5. Preferably the foam boosting agent is a sulphated ethoxylated C Guerbet alcohol surfactant with a number average degree of ethoxylation in the range from 3 to 6.

Preferably the solid detergent composition according to the present invention comprises from 0.01 wt.% to 5 wt.% foam boosting agent. Preferably the solid detergent composition comprises at least 0.05 wt.%, preferably at least 0.1 wt.%, still preferably at least 0.15 wt.% and most preferably at least 0.2 wt.%, but typically not more than 4 w.t%, still preferably not more than 3 wt.%, still further preferably not more than 2 wt.% and most preferably not more than 1.5 wt.% foam boosting agent.

Bleach:

The solid detergent composition of the present invention may include a bleach. The bleach is preferably selected from percarbonate bleach. More preferably a bleach activator is present. An example of bleach activator includes TAED.

Visual cues:

The solid detergent composition of the present invention may include visual cues. These are preferably coloured particles, more preferably coloured particles which have a colour contrasting with the remaining detergent composition. The visual cue may be of any shape. These includes spherical, rod shaped, square or triangle. Clay:

The solid detergent composition according to the present invention may include a clay. Preferably the clay is a smectite clay, still preferably bentonite. Preferably the clay is present in an amount ranging from 0.5 to 5, still preferably 0.5 to 3, further preferably from 1 to 2.

Sequestrant:

The solid detergent composition according to the present invention may include a sequestrant. Preferably the sequestrant is HEDP, GDA, gluconate, GLDA or mixtures thereof. Preferably the sequestrant is present in an amount ranging from 0.05 to 3 wt.%, still preferably 0.1 to 3 wt.%, further preferably from 0.5 to 2 wt.% of the solid laundry detergent composition.

Additional surfactants:

In addition to the anionic detersive surfactant selected from sulphonate surfactant, sulphate surfactant or mixtures thereof, the detergent composition according to the present invention may include additional surfactants selected from but not limited to non-ionic surfactant, amphoteric surfactant cationic surfactant, zwitterionic surfactant, or mixtures thereof.

Non-ionic surfactant

Non-limiting examples of nonionic surfactants include: C12 to C18 alkyl ethoxylates, Ge to C12 alkyl phenol alkoxylates wherein the alkoxylate units are a mixture of ethyleneoxy and propyleneoxy units; C12 to C18 alcohol and Ce to C12 alkyl phenol condensates with ethylene oxide/propylene oxide block alkyl polyamine ethoxylates alkylpolysaccharides and ether capped poly(oxyalkylated) alcohol surfactants.

Cationic surfactant

Non-limiting examples of cationic surfactants include: the quaternary ammonium surfactants, which can have up to 26 carbon atoms include: alkoxylate quaternary ammonium (AQA) surfactants, dimethyl hydroxyethyl quaternary ammonium, dimethyl hydroxyethyl lauryl ammonium chloride; polyamine cationic surfactants and cationic ester surfactants. Zwitterionic surfactant

Non-limiting examples of zwitterionic or ampholytic surfactants include: derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. Examples of zwitterionic surfactants includes betaines, including alkyl dimethyl betaine and cocodimethyl amidopropyl betaine, Cs to Cis (for example from C12 to Cis) amine oxides and sulfo and hydroxy betaines, such as N-alkyl-N, N-dimethylammino-1-propane sulfonate where the alkyl group can be Cs to Cis and in certain embodiments from C10 to C14.

Moisture content:

The solid detergent composition includes from 1 to 3.5 wt.%, still preferably 1 to 3 wt.% water. Preferably the solid detergent composition is either agglomerated or spray-dried.

Methods of laundering:

According to a second aspect of the present invention, disclosed is a method for laundering a textile surface with the detergent composition according to the first aspect of the present invention comprising the steps of: i) preparing an aqueous wash liquor by contacting the detergent composition according to the first aspect with a liquid; ii) soaking said textile surface in the wash liquor for a predetermined period of time; and, iii) optionally rinsing the textile surface.

The compositions are preferably employed at concentrations of from about 200 ppm to about 15,000 ppm in solution. The water temperatures preferably range from about 5°C to about 100°C.

Machine laundry methods herein typically comprise treating soiled laundry with an aqueous wash solution in a washing machine having dissolved or dispensed therein an effective amount of the detergent composition in accordance with the invention. By an effective amount of the detergent composition it is meant from 20 g to 300 g of product dissolved or dispersed in a wash solution of volume from 5 to 65 liters, as are typical product dosages and wash solution volumes commonly employed in conventional machine laundry methods. Hand-washing methods, and combined handwashing with semiautomatic washing machines are also included.

According to a third aspect of the present invention disclosed is the use of an anionic detersive surfactant selected from sulphate surfactant, sulphonate surfactant or mixtures thereof, sodium carbonate and a hydrotrope wherein the hydrotrope is an aryl sulphonate which is substituted with a Ci to C4 alkyl group in a detergent composition to provide improved dissolution of the composition in wash liquor. More preferably the improved dissolution in cold water having a temperature ranging from 6°C to 25°C.

The invention will now be illustrated more fully with the aid of the following non-limiting examples. It will be appreciated that other modifications of the present invention within the skill of those in the art can be undertaken without departing from the spirit and scope of this invention. All of the formulations exemplified hereinafter are prepared via conventional formulation and mixing methods unless specific methods are given. All parts, percentages, and ratios herein are by weight unless otherwise specified.

Examples

Example 1

A laundry detergent composition according to the present invention and comparative detergent as shown in table 1 was evaluated for residue deposited on fabric.

The detergent composition according to the present invention (Ex 1) was prepared by adding sodium carbonate and a filler to the sigma mixer and then mixing them homogeneously. While the mixing was in progress, alkyl benzene sulphonic acid and sodium cumene sulphonate (hydrotrope) was added to the mixer and required amount of water was added. After the neutralization of alkyl benzene sulphonic acid to form Na linear alkyl benzene sulphonate (NaLAS), remaining filler and other ingredients as provided in table 1 were added to form the solid detergent composition. Similarly, the other comparative compositions were also prepared. Residue test: Each of the detergent composition provided in table 1 was evaluated to determine the residue content left behind by the composition by performing the residue test. In the residue test, 3 litre water having a hardness of 0 FH when measured at 25°C was taken and 15 grams of the solid detergent composition was added

(concentration 5gpl). Next the above solution was agitated by manually rotating the contents 10 times in clockwise direction. This was further followed by manually whisking the wash liquor for 5 seconds. Next the wash liquor was filtered through a polyester fabric. This allows any improperly dissolved particle in the wash liquor to be retained on the fabric. Next this polyester fabric was air dried. The initial weight of the dry polyester fabric before filtering the wash liquor was measured and the weight of the fabric post air drying was measured and noted. The difference in the weight of the fabric post air drying and the weight of the fabric before filtering was calculated and is provided in table 1 below as the measured residue content in wt.%.

Table 1

As shown in the table 1 above, the results shows that the composition according to the present invention having a combination of anionic surfactant, carbonate builder and a hydrotrope gives good dissolution.

Example 2

Two solid laundry detergent composition having carbonate builder were prepared as shown in table 2. The composition were then evaluated for the amount of residue deposited on the fabric using the method described in Example 1. The residue data was recorded and is provided in the table 2 below. Table 2

As shown in the table 2 above, the solid laundry detergent composition having sodium carbonate builder and with no zeolite and no phosphate builder shows a residue of 5.26 wt.% as compared to the solid laundry detergent composition according to the present invention

(Ex 2) where the composition comprises a hydrotrope (SCS,) according to the present invention which showed lowered residue levels and provides good dissolution properties.

Claims

24

Claims

1 A solid laundry detergent composition comprising: i) an anionic surfactant selected from sulphonate surfactant, sulphate surfactant or mixture thereof; ii) a hydrotrope; iii) a sodium carbonate builder; iv) 0 to 4 wt.% zeolite; and, v) 0 to 4 wt.% phosphate builder; wherein the hydrotrope is an aryl sulphonate which is substituted with a Ci to C4 alkyl group.

2 A composition according to claim 1 wherein the hydrotrope is selected from the group consisting of a salt of benzene sulphonate, toluene sulphonate, xylene sulphonate, cumene sulphonate or mixtures thereof.

3 A composition according to claim 2 wherein the hydrotrope is a sodium cumene sulphonate, sodium toluene sulphonate, sodium xylene sulphonate or mixtures thereof.

4 A composition according to any one of the preceding claims wherein the anionic surfactant and the hydrotrope is in the form of a co-particle.

5 A composition according to claim 4 wherein the co-particle comprises the sodium carbonate builder.

6 A composition according to any one of the preceding claims wherein the sulphonate surfactant is selected from the group consisting of methyl ester sulphonate, alpha olefin sulphonate, alkyl benzene sulphonate or mixtures thereof.

7 A composition according to claim 6 wherein the alkyl benzene sulphonate is a linear or branched, substituted or unsubstituted C10 to C14 alkyl benzene sulphonate. A composition according to any one of the preceding claims wherein the sulphate surfactant is a linear or branched, substituted or unsubstituted Cs to Cis alkyl sulphate surfactant, Cs to Cis alkyl ether sulphate surfactant or mixtures thereof. A composition according to any one of the preceding claims wherein the composition comprises a flow aid selected from the group consisting of calcium carbonate, magnesium carbonate, double salt of calcium and magnesium carbonate, dolomite or mixtures thereof. A composition according to any one of the preceding claims wherein the composition comprises a foam boosting agent, preferably selected from the group consisting of siloxane with polyoxyalkylene group, a sulphated ethoxylated Cs to C Guerbet alcohol cosurfactant, isethionate cosurfactant or mixtures thereof. A composition according to any one of the preceding claims wherein the amount of the anionic surfactant present is in an amount ranging from 2 wt.% to 25 wt.% in the detergent composition. A composition according to any one of the one of the preceding claims wherein the amount of the hydrotrope present is in an amount ranging from 0.5 wt.% to 5 wt.% in the detergent composition. A composition according to any one of the preceding claims wherein the sodium carbonate present is in an amount ranging from 5 wt.% to 40 wt.% in the detergent composition. A method for laundering a textile surface comprising the steps of: i) preparing an aqueous wash liquor by contacting the detergent composition according to claim 1 to 13 with a liquid; ii) soaking said textile surface in the wash liquor for a predetermined period of time; and, iii) optionally rinsing the textile surface. Use of a combination of hydrotrope wherein the hydrotrope is an aryl sulphonate which is substituted with a Ci to C4 alkyl group, sodium carbonate builder, an anionic surfactant selected from sulphate surfactant, sulphonate surfactant or mixtures thereof in a solid laundry detergent composition having 0 to 4 wt.% zeolite builder and 0 to 4 wt.% phosphate builder for providing improved dissolution of the detergent composition.