RU2807508C1 - Method for obtaining particle-based washing detergent composition - Google Patents

Abstract

FIELD: detergents.

SUBSTANCE: invention is related to a method for producing a particle-based laundry detergent composition. The method includes the following steps: (a) bringing water, starch, acid and flavouring into contact to form a concentrated water-acid mixture, wherein the concentrated acid mixture contains: from 20 to 60 wt.% starch; from 10 to 50 wt.% acid; from 2 to 20 wt.% flavouring; from 10 to less than 45 wt.% water; and wherein the concentrated acid mixture has a pH of less than 4.5; (b) subjecting the concentrated acid mixture to a flavour emulsification step to emulsify the flavour to form an emulsified flavour mixture in fluid form; (c) spraying the emulsified fragrance mixture in fluid form onto the detergent base particles such that the emulsified fragrance mixture at least partially covers the detergent base particles to form a powdered laundry detergent composition wherein the detergent base particles range from 4 to 60 wt.% of the detergent surfactant.

EFFECT: invention provides a particle-based laundry detergent composition that does not discolour after storage.

15 cl, 5 tbl, 1 ex

Description

FIELD OF APPLICATION OF THE INVENTION

The present invention relates to a method for preparing a particulate laundry detergent composition. The method allows starch/flavor mixtures to be injected directly into laundry detergent, providing a convenient and efficient method of producing laundry detergent having a high freshness profile and a high color profile (no discoloration).

PREREQUISITES FOR CREATION OF THE INVENTION

Laundry powders typically contain fragrance to provide a high freshness profile. The freshness profile should provide a distinct odor of freshness to the product (e.g., the odor observed on the product before adding the product to a wash tub (or automatic washing machine), a distinct odor from wet fabric (e.g., odor observed from wet fabric/clothes washed using the product) ) and a noticeable odor of dry fabric (for example, the odor observed from dry fabric after washing with the product).

Fragrances can be incorporated into the laundry detergent in a variety of ways: for example, by spraying onto the base particles (to at least partially coat the base particles). This atomization step can also be performed in the presence of other particles (where the flavor typically also at least partially coats the other particles as well as the base particles).

Fragrances can also be incorporated into laundry detergent by forming fragrance particles and adding these fragrance particles to the detergent base particles (and other particles if they are also present). At one time, such a flavor particle was a starch-encapsulated flavor accord (SEA). These SEAs are typically created by forming a mixture of starch and flavor and spray drying this mixture to form spray dried SEA. The spray-dried SEA is then mixed with detergent base particles to form laundry powder.

The present inventors have attempted to introduce the chemical structure of SEA (starch and aroma) directly into laundry detergent (through a spray process), thereby avoiding the complexity and energy costs associated with the need to produce spray-dried SEA particles. However, attempts to simply spray the starch/fragrance mixture onto the detergent base particles resulted in the laundry detergent becoming discolored after one week (in a typical shelf stability test). The laundry detergent formed yellow spots throughout the laundry detergent.

The present inventors have discovered that incorporating an acid into a starch/flavor mixture (emulsion) and adjusting the pH of that emulsion allows the chemical structure of the starch/flavor to be dispersed onto the detergent base particles to at least partially coat the detergent base particles and so that the resulting detergent composition for particle-based laundry did not discolor after storage.

SUMMARY OF THE INVENTION

The present invention provides a method for preparing a particulate laundry detergent composition, comprising the steps of: (a) contacting water, starch, acid and fragrance to form a concentrated water-acid mixture, wherein the concentrated acid mixture comprises: (i) from 20 wt.% to 60 wt.% starch; (ii) from 10 wt.% to 50 wt.% acid; (iii) from 2 wt.% to 20 wt.% flavoring; (iv) from 10 wt.% to less than 45 wt.% water; and wherein the concentrated acid mixture has a pH of less than 4.5; (b) subjecting the concentrated acid mixture to a flavor emulsification step to emulsify the flavor to form an emulsified flavor mixture in fluid form; and (c) spraying the emulsified fragrance mixture in fluid form onto the detergent base particles such that the emulsified fragrance mixture at least partially covers the detergent base particles to form a powdered laundry detergent composition, wherein the base detergent particles comprise from 4 weight percent .% to 60 wt.% detergent surfactant.

DETAILED DESCRIPTION OF THE INVENTION

Method for preparing a particle-based laundry detergent composition

The method includes the steps of: (a) bringing water, starch, acid and flavoring into contact to form a concentrated water-acid mixture, wherein the concentrated acid mixture contains: (i) from 20 wt.% to 60 wt.% starch; (ii) from 10 wt.% to 50 wt.% acid; (iii) from 2 wt.% to 20 wt.% flavoring; (iv) from 10 wt.% to less than 45 wt.% water; and wherein the concentrated acid mixture has a pH of less than 4.5; (b) subjecting the concentrated acid mixture to a flavor emulsification step to emulsify the flavor to form an emulsified flavor mixture in fluid form; and (c) spraying the emulsified fragrance mixture in fluid form onto the detergent base particles such that the emulsified fragrance mixture at least partially covers the detergent base particles to form a powdered laundry detergent composition, wherein the base detergent particles comprise from 4 weight percent .% to 60 wt.% detergent surfactant.

Stage (a) of obtaining a concentrated water-acid mixture.

In step (a), water, starch, acid and flavor are brought into contact to form a concentrated water-acid mixture.

Typically, in step (a), the starch is in the form of a concentrated aqueous starch mixture when it is contacted with the flavoring material, wherein the concentrated aqueous starch mixture contains more than 50% by weight starch.

Step (b) of obtaining an emulsified flavor mixture.

In step (b), the concentrated acid mixture is subjected to a flavor emulsification step to emulsify the flavor to form an emulsified flavor mixture in fluid form.

Typically, step (b) is performed in a rotor-stator device operating such that the tip speed is greater than 5.0 ms ^-1 , or greater than 6.0 ms ^-1 , or even greater than 7.0 ms ^-1 .

For step (b) any suitable mixing device can be used. The preferred mixing device is a high shear mixer. Suitable high shear mixers may be dynamic or static mixers. A suitable dynamic mixer may be a rotor-stator mixer. The most preferred mixers are rotor-stator mixers, preferably rotor-static mixers, which operate at a final speed greater than 5.0 ms ^-1 , or greater than 6.0 ms ^-1 , or even greater than 7.0 ms ^-1 .

A suitable high shear mixer is a Silverstone fast mixer or an IKA homogenizer. Step (b) may be a batch or continuous process step.

Preferably, step (b) is carried out at a temperature of from 20 °C to 60 °C. The emulsion can have a temperature between 20°C and 60°C. Preferably, the emulsified flavor mixture in fluid form formed in step (b) has a temperature of from 20°C to 60°C.

Step (c) of spraying the emulsified flavor mixture.

In step (c), the emulsified fragrance mixture in fluid form is sprayed onto the detergent base particles such that the emulsified fragrance mixture at least partially covers the detergent base particles to form a particulate laundry detergent composition.

Typically, step (c) is carried out in a mixer, the weight ratio of the emulsified flavor mixture in fluid form to the detergent base particles dispensed into the mixer being in the range of 0.002:1 to 0.15:1.

A suitable mixer is a rotary mixing drum.

A suitable means of spraying the emulsified fragrance mixture onto the detergent base particles is a spray nozzle. A spray nozzle typically sprays an emulsified flavor mixture into droplets. Suitable spray nozzles can be either pressure or multi-phase nozzles.

A powder mixer can be used to ensure that the emulsified fragrance mixture is sufficiently dispersed onto the detergent base particles. A suitable powder mixer is a paddle mixer.

During step (c), other detergent particles may be present, and typically the emulsified flavor mixture will at least partially coat the other detergent particles as well as at least partially coat the base detergent particles.

Aromatic substance.

Any flavor raw material (PRM) is suitable. Suitable PRMs include those selected from the group consisting of the following: 3-(4-tert-butylphenyl)-2-methylpropanal, 3-(4-tert-butylphenyl)-propanal, 3-(4-isopropylphenyl)-2-methylpropanal, 3 -(3,4-methylenedioxyphenyl)-2-methylpropanal, 2,6-dimethyl-5-heptenal, damascone, 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanone, methyl-7,3-dihydro-2H-1,5-benzodioxepin-3-one, 2-[2-(4-methyl-3-cyclohexenyl-1-yl)propyl]cyclopentan-2-one, 2-sec- butylcyclohexanone, dihydroionone, linalool, ethylinalool, tetrahydrolinalool, dihydromyrcenol and any combination thereof.

Further examples of suitable flavoring raw materials are described in WO 99/55819.

Particularly preferred flavor raw materials include high impact accord (HIA) flavor raw materials, especially those PRMs that have a boiling point determined at normal standard pressure of approximately 760 mm Hg, 275 °C or lower, partition coefficient P octanol/water of approximately 2000 or greater and an odor detection threshold of less than 50 parts per billion (ppb).

Preferred flavor raw materials may have a logP of 2.0 or higher.

Acid. Preferably the acid is an organic acid. The preferred acid is selected from carboxylic acids. The most preferred acid is citric acid.

The preferred acid is C ₁ -C ₁₂ carboxylic acid. The term "C ₁ -C ₁₂ carboxylic acids" refers to carboxylic acids having from 1 to 12 carbon atoms, including the C atom of the carboxyl group. Carboxylic acids may be saturated hydrocarbons. Alternatively, the carboxylic acids may be unsaturated hydrocarbons.

The carboxylic acid may be a cyclic carboxylic acid. Examples of cyclic carboxylic acids are lactones, such as ascorbic acid.

The carboxylic acid may be an aromatic carboxylic acid. An example of an aromatic carboxylic acid is salicylic acid.

Preferably the carboxylic acid is at least a dicarboxylic acid. More preferably, it is at least a tricarboxylic acid. At least tricarboxylic acid means that it bears at least three carboxyl groups.

Preferably the carboxylic acid is a C ₄ -C ₈ carboxylic acid. In a preferred embodiment of the present invention, the carboxylic acid is selected from C ₂ -C ₆ carboxylic acids.

Preferably, the carboxylic acid is selected from the group consisting of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, citric acid, succinic acid, hydroxysuccinic acid, maleic acid, fumaric acid, hydroxylic acid, glyoxylic acid, adipic acid , lactic acid, tartaric acid, salicylic acid, ascorbic acid, potassium, calcium and/or sodium salts of any of the above acids and mixtures of any of them.

The acid, and especially a carboxylic acid such as citric acid, may be in the form of a salt. Preferably the acid salts are potassium and/or sodium salts. More preferably, the acid is a tripotassium and/or trisodium salt of a tricarboxylic acid. Most preferably, the acid is tripotassium and/or trisodium citric acid.

The above acids and their salts are commercially available, and their synthesis or isolation from starting materials is known to those skilled in the art.

Starch. Typically, in step (a), the starch is in the form of a concentrated aqueous starch mixture when it is contacted with the flavoring material, wherein the concentrated aqueous starch mixture contains more than 50% by weight starch.

Preferably the starch is selected from starch octenyl succinates.

Suitable starches can be obtained from raw starch, pregelatinized starch, modified starch derived from tubers, legumes, cereals and grains, for example, corn starch, wheat starch, rice starch, waxy corn starch, oat starch, cassava starch, waxy barley starch, waxy rice starch, sweet rice starch, amioca starch, potato starch, tapioca starch, oat starch, cassava starch and any combination thereof.

Suitable modified starches include hydrolyzed starch, acid-diluted starch, starch esters with short-chain and long-chain hydrocarbons, for example, starch acetates, starch octenyl succinate, starch dodecenyl succinate, and any combination thereof.

The term "hydrolyzed starch" refers to oligosaccharide-type materials that are typically produced by acid and/or enzymatic hydrolysis of starches, preferably corn starch. Suitable hydrolyzed starches include maltodextrins and corn syrup solids.

Suitable hydrolyzed starches typically have a dextrose equivalent (DE) value of 10 to 36 DE. The DE value is a measure of the reduction equivalent of hydrolyzed starch relative to dextrose and is expressed as a percentage (on a dry weight basis). The higher the DE value, the more reducing sugars are present. A method for determining DE values can be found in Standard Analytical Methods of the Member Companies of Corn Industries Research Foundation, ^6th ed. Corn Refineries Association, Inc. Washington, DC 1980, D-52.

Suitable starch esters have degrees of substitution ranging from 0.01% to 10.0%. The hydrocarbon portion of the modifying ester typically has a carbon group ranging from C ₂ to C ₁₆ . Suitable starches include octenyl succinic anhydride (OSA)-substituted waxy corn starches of various types, such as: (i) waxy starch: acid-diluted and OSA-substituted; (ii) a mixture of corn syrup solids: waxy starch, substituted OSA and dextrinized; (iii) waxy starch: substituted by OSA and dextrinized; (iv) a mixture of corn syrup solids or maltodextrins with waxy starch: acid-diluted and substituted with OSA, then heat-treated and spray-dried; (v) waxy starch: diluted with acid and substituted with OSA, then heat treated and spray dried; and (vi) with high and low viscosities of the above modifications (depending on the level of acid treatment).

Suitable modified starches, such as starch octenyl succinates, typically have emulsifying and emulsion stabilizing properties such that they have the ability to trap flavor oil droplets in the emulsion due to the hydrophobic nature of the starch modifying agent. Typically, the flavor oils remain trapped in the modified starch until they are dissolved in the wash solution.

Concentrated aqueous acid mixture. The concentrated acid mixture contains: (i) from 20 wt.% to 60 wt.% starch; (ii) from 10 wt.% to 50 wt.% flavoring; (iii) from 2 wt.% to 20 wt.% acid; (iv) from 10 wt.% to less than 45 wt.% water; and wherein the concentrated acid mixture has a pH of less than 4.5.

Preferably, the concentrated acid mixture has a pH of less than 4.0.

Typically, a concentrated water-acid mixture has a viscosity in the range of 0.1 to 3.0 Pa s when measured at a shear rate of 10 s ^-1 and a temperature of 40 °C. The method for measuring the viscosity of a concentrated water-acid mixture is described in more detail below.

Emulsified flavor mixture. The emulsified flavor mixture is in fluid form. Typically, the emulsified flavor mixture is in the form of a liquid suspension.

Preferably, the emulsified flavor mixture contains flavor oil droplets of less than 20 microns, preferably less than 15 microns, more preferably less than 5.0 microns, and most preferably less than 2.5 microns, preferably from 0.5 microns to 5.0 microns. A method for measuring the size of flavor oil droplets in an emulsified flavor mixture is described in more detail below.

Preferably, the emulsified flavor mixture contains more than 10 wt%, preferably more than 30 wt%, more preferably more than 40 wt%, and most preferably more than 50 wt% flavor.

Typically, the emulsified flavor mixture is not subjected to a spray drying step.

Detergent base particles. The detergent base particles contain from 4 wt.% to 60 wt.% detergent surfactant.

Typically, the detergent base particles contain: (a) from 4 to 35 wt.% detergent surfactant; and (b) from 5 wt.% to 91 wt.% of the carrier material.

Generally, detergent base particles are alkaline. Typically, detergent base particles, when dissolved in deionized water at 20°C to a concentration of 1 g/L, have a pH greater than 7.5, or greater than 8.0, or greater than 9.0, or greater than 10.0.

The detergent base particles may be in the form of agglomerates, extrudates, peas, granules or spray-dried particles. The detergent base particles may be in the form of agglomerates. The detergent base particles may be in the form of spray-dried particles.

Preferably, the detergent surfactant is an anionic detergent surfactant. Suitable detergent surfactants and anionic detergent surfactants are described in more detail below.

Particle-based laundry detergent composition. Typically, a particulate laundry detergent composition is a complete laundry detergent composition and not a portion thereof, such as spray-dried, extruded or agglomerated particles that form only a portion of the laundry detergent composition. Typically, the solid composition contains a plurality of chemically distinct particles, such as spray-dried detergent base particles, and/or agglomerated detergent base particles, and/or extruded detergent base particles, in combination with one or more typically , two or more, or five or more, or even ten or more kinds of particles selected from surfactant particles, including surfactant agglomerates, surfactant extrudates, surfactant needles, surfactant filaments , surfactant flakes; phosphate particles; zeolite particles; silicate salt particles, in particular sodium silicate particles; carbonate salt particles, in particular sodium carbonate particles; polymer particles such as carboxylate polymer particles, cellulose polymer particles, starch particles, polyester particles, polyamine particles, terephthalate polymer particles, polyethylene glycol particles; aesthetically pleasing particles such as dyed threads, needles, lamellar particles and ring particles; enzyme particles such as protease granules, amylase granules, lipase granules, cellulase granules, mannanase granules, pectate lyase granules, xyloglucanase granulates, bleaching enzyme granules and mixed granules of any of these enzymes, such enzyme granules preferably containing sodium sulfate; bleach particles such as percarbonate particles, in particular coated percarbonate particles such as percarbonate coated with a carbonate salt, sulfate salt, silicate salt, borosilicate salt or any combination thereof, perborate particles, bleach activator particles such as tetraacetylethylenediamine particles and/or alkyloxybenzenesulfonate particles, bleach catalyst particles such as transition metal catalyst particles and/or isoquinoline bleach catalyst particles, preformed peracid particles, in particular preformed coated peracid particles; filler particles such as sulfate salt particles and chloride particles; clay particles such as montmorillonite particles and clay and silicone particles; coagulant particles such as polyethylene oxide particles; wax particles such as wax agglomerates; silicone particles, clarifier particles; dye transfer inhibitor particles; dye fixative particles; flavor particles such as flavor microcapsules and flavor combination particles encapsulated in starch or flavor precursor particles such as Schiff base reaction product particles; particles of coloring pigment; chelating agent particles such as chelating agent agglomerates; and any combination thereof.

Suitable laundry detergent compositions contain a detergent component selected from a detergent surfactant, such as anionic detergent surfactants, nonionic detergent surfactants, cationic detergent surfactants, zwitterionic detergent surfactants, and amphoteric detergent surfactants; polymers, such as carboxylate polymers, dirt-releasing polymers, anti-redeposition polymers, cellulosic polymers and protective polymers; bleach, such as hydrogen peroxide sources, bleach activators, bleach catalysts and prepared peracids; photobleach, for example sulfonated zinc and/or aluminum phthalocyanines; enzymes, for example proteases, amylases, cellulases, lipases; zeolite detergent component; phosphate detergent component; auxiliary detergent components, such as citric acid and citrate; carbonate, such as sodium carbonate and sodium bicarbonate; sulfate salt, for example sodium sulfate; silicate salt, for example sodium silicate; a chloride salt, for example sodium chloride; clarifiers; chelating agents; coloring agents; dye transfer inhibitors; dye fixatives; aromatic substance; silicone; fabric softeners such as clay; coagulants, for example polyethylene oxide; foam suppressants; and any combination thereof.

Suitable laundry detergent compositions may have low buffer capacity. Such laundry detergent compositions typically have an alkalinity reserve to pH = 9.5 of less than 5.0 g NaOH/100 g. Such low buffer laundry detergent compositions typically contain low levels of carbonate salt.

Detergent surfactant. Suitable detergent surfactants include anionic detergent surfactants, nonionic detergent surfactants, cationic detergent surfactants, zwitterionic detergent surfactants, and amphoteric detergent surfactants. Suitable detergent surfactants may be linear or branched, substituted or unsubstituted, and may be derived from petrochemical feedstocks or biomaterials.

Anionic detergent surfactant. Suitable anionic detergent surfactants include sulfonate and sulfate detergent surfactants.

Suitable sulfonate detergent surfactants include methyl ester sulfonates, alpha olefin sulfonates, alkyl benzene sulfonate, preferably C _10-13 alkyl benzene sulfonate. A suitable alkyl benzene sulfonate (LAS) can be prepared, preferably obtained, by sulfonation of commercially available linear alkyl benzene (LAB); a suitable LAB includes a short 2-phenyl LAB, another suitable LAB includes a long 2-phenyl LAB, for example available from Sasol under the trade name Hyblene®.

Suitable sulfate detergent surfactants include alkyl sulfate, preferably C _8-18 alkyl sulfate or preferably C ₁₂ alkyl sulfate.

A preferred sulfate detergent surfactant is an alkyl alkoxylated sulfate, preferably an alkyl ethoxylated sulfate, preferably a C _8-18 alkyl alkoxylated sulfate, preferably a C _8-18 alkyl ethoxylated sulfate; preferably the alkyl alkoxy sulfate has an average degree of alkoxylation of from 0.5 to 20, preferably from 0.5 to 10; preferably the alkyl alkoxylated sulfate is a C _8-18 alkyl ethoxylated sulfate having an average degree of ethoxylation of 0.5 to 10, preferably 0.5 to 5, more preferably 0.5 to 3, and most preferably 0.5 to 1, 5.

Alkyl sulfate, alkyl alkoxy sulfate and alkyl benzene sulfonates may be linear or branched, substituted or unsubstituted, and may be derived from petrochemical feedstocks or biomaterials.

Other suitable anionic detergent surfactants include alkyl ether carboxylates.

Suitable anionic detergent surfactants may be in salt form; suitable counterions include sodium, calcium, magnesium, amino alcohols, and any combination thereof. The preferred counterion is sodium.

Nonionic detergent surfactant. Suitable nonionic detergent surfactants are selected from the group consisting of: C ₈ -C ₁₈ alkyl ethoxylates, such as NEODOL® series nonionic surfactants from Shell; C ₆ -C ₁₂ alkylphenol alkoxylates, wherein preferably the alkoxylate units are ethyleneoxy units, propyleneoxy units or a mixture thereof; C ₁₂ –C ₁₈ alcohol and C ₆ –C ₁₂ alkylphenol condensation products with ethylene oxide/propylene oxide block polymers such as Pluronic® from BASF; alkyl polysaccharides, preferably alkyl polyglycosides; methyl ester ethoxylates; polyhydroxy fatty acid amides; surfactants based on polyoxyalkylated alcohol with ether end groups; and mixtures thereof.

Suitable nonionic detergent surfactants are an alkyl polyglucoside and/or an alkyl alkoxylated alcohol.

Suitable nonionic detergent surfactants include alkyl alkoxylated alcohols, preferably C _8-18 alkyl alkoxylated alcohols, preferably C _8-18 alkyl ethoxylated alcohols; preferably the alkylalkoxylated alcohol has an average degree of alkoxylation of 1 to 50, preferably 1 to 30, or 1 to 20, or 1 to 10; preferably the alkyl alkoxylated alcohol is a C _8-18 alkyl ethoxylated alcohol having an average degree of ethoxylation of 1 to 10, preferably 1 to 7, more preferably 1 to 5, and most preferably 3 to 7. The alkyl alkoxylated alcohol may be linear or branched and substituted or unsubstituted.

Suitable nonionic detergent surfactants include secondary alcohol detergent surfactants.

Cationic detergent surfactant. Suitable cationic detergent surfactants include alkyl pyridinium compounds, alkyl quaternary ammonium compounds, alkyl quaternary phosphonium compounds, alkyl tertiary sulfonium compounds, and mixtures thereof.

Preferred cationic detergent surfactants are quaternary ammonium compounds having the general formula:

(R)(R ₁ )(R ₂ )(R ₃ )N ⁺ X ^-

where R is a linear or branched, substituted or unsubstituted C _6-18 alkyl or alkenyl functional group, R ₁ and R ₂ are independently selected from methyl or ethyl functional groups, R ₃ is hydroxyl, hydroxymethyl or hydroxyethyl functional group, X is an anion that provides charge neutrality, preferred anions include halides, preferably chloride; sulfate; and sulfonate.

Zwitterionic detergent surfactant. Suitable zwitterionic detergent surfactants include amine oxides and/or betaines.

Polymer. Suitable polymers include carboxylate polymers, dirt-releasing polymers, anti-redeposition polymers, cellulosic polymers, barrier polymers, and any combination thereof.

Carboxylate polymer. The composition may contain a carboxylate polymer, for example a maleate/acrylate random copolymer or a polyacrylate homopolymer. Suitable carboxylate polymers include polyacrylate homopolymers with a molecular weight of 4000 Da to 9000 Da; maleate/acrylate random copolymers with a molecular weight of 50,000 Da to 100,000 Da or 60,000 Da to 80,000 Da.

Another suitable carboxylate polymer is a copolymer that contains: (i) from 50 to less than 98 wt.% structural units derived from one or more monomers containing carboxyl groups; (ii) from 1 to less than 49% by weight of structural units derived from one or more monomers containing sulfonate functional groups; and (iii) from 1 to 49% by weight of structural units derived from one or more types of monomers selected from the ether linkage-containing monomers represented by formulas (I) and (II):

formula (I):

wherein in formula (I), R ₀ represents a hydrogen atom or a CH ₃ group, R represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, X represents a number in the range 0–5, provided that X is a number in the range 1–5 if R is a single bond and _R1 is a hydrogen atom or a _C1 – _C20 organic group;

formula (II):

wherein in formula (II), R ₀ represents a hydrogen atom or a CH ₃ group, R represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, X represents a number in the range 0–5, and R ₁ represents is a hydrogen atom or an organic group C ₁ –C ₂₀ .

It may be preferable that the polymer has a weight average molecular weight of at least 50 kDa or even at least 70 kDa.

Dirt-repellent polymer. The composition may contain a dirt-releasing polymer. A suitable dirt-releasing polymer has a structure corresponding to one of the following structures (I), (II) or (III):

(I) –[(OCHR ¹ –CHR ² ) _a –O–OC–Ar–CO–] _d

(II) –[(OCHR ³ –CHR ⁴ ) _b –O–OC–sAr–CO–] _e

(III) –[(OCHR ⁵ –CHR ⁶ ) _c –OR ⁷ ] _f ,

Where:

a, b and c are numbers from 1 to 200;

d, e and f range from 1 to 50;

Ar is 1,4-substituted phenylene;

sAr is 1,3-substituted phenylene substituted at position 5 with SO ₃ Me;

Me represents Li, K, Mg/2, Ca/2, Al/3, ammonium, mono-, di-, tri- or tetraalkylammonium, the alkyl groups being _C1 - _C18 alkyl or _{C2- C10} hydroxyalkyl or mixtures thereof;

R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are independently selected from H or C ₁ –C ₁₈ n- or isoalkyl; And

R ⁷ represents a linear or branched C ₁ -C ₁₈ alkyl, or a linear or branched C ₂ -C ₃₀ alkenyl, or a cycloalkyl group with 5-9 carbon atoms, or a C ₈ -C ₃₀ aryl group, or a C ₆ -C ₃₀ arylalkyl group.

Suitable dirt-releasing polymers are sold by Clariant as a series of polymers under the trade name TexCare®, for example TexCare® SRN240 and TexCare® SRA300. Other suitable dirt-releasing polymers are sold by Solvay as a series of polymers under the trade name Repel-o-Tex®, for example Repel-o-Tex® SF2 and Repel-o-Tex® Crystal.

Polymer that prevents redeposition. Suitable anti-redeposition polymers include polyethylene glycol polymers and/or polyethyleneimine polymers.

Suitable polyethylene glycol polymers include random graft copolymers containing: (i) a hydrophilic backbone containing polyethylene glycol; and (ii) hydrophobic side chain(s) selected from the group consisting of: C ₄ -C ₂₅ alkyl group, polypropylene, polybutylene, C ₁ -saturated vinyl ester C ₆ monocarboxylic acid, C ₁ –C ₆ alkyl ester of acrylic or methacrylic acid and mixtures thereof. Suitable polyethylene glycol polymers have a polyethylene glycol backbone with randomly grafted polyvinyl acetate side chains. The average molecular weight of the polyethylene glycol backbone may range from 2000 Da to 20,000 Da or from 4000 Da to 8000 Da. The molecular weight ratio of polyethylene glycol backbone to polyvinyl acetate side chains may range from 1:1 to 1:5 or from 1:1.2 to 1:2. The average number of grafting points per ethylene oxide unit may be less than 0.02 or less than 0.016, the average number of grafting points per ethylene oxide unit may be in the range of 0.010 to 0.018, or the average number of grafting points per ethylene oxide unit may be less than 0.010 or in the range of 0.004 up to 0.008.

Suitable polyethylene glycol polymers are described in WO08/007320.

A suitable polyethylene glycol polymer is Sokalan HP22.

Cellulose polymer. Suitable cellulose polymers are selected from alkylcellulose, alkylalkoxycellulose, carboxyalkylcellulose, alkylcarboxyalkylcellulose, sulfoalkylcellulose, more preferably selected from carboxymethylcellulose, methylcellulose, methylhydroxyethylcellulose, methylcarboxymethylcellulose and mixtures thereof.

Suitable carboxymethylcelluloses have a degree of carboxymethyl substitution from 0.5 to 0.9 and a molecular weight from 100,000 Da to 300,000 Da.

Suitable carboxymethylcelluloses have a degree of substitution greater than 0.65 and a blockiness greater than 0.45, for example as described in WO09/154933.

Protective polymers. Suitable security polymers include cellulose polymers with cationic modification or hydrophobic modification. Such modified cellulose polymers can provide abrasion resistance and pigment fixation to fabrics during the wash cycle. Suitable cellulose polymers include cationically modified hydroxyethylcellulose.

Other suitable barrier polymers include pigment fixation polymers, for example a condensation oligomer obtained by condensation of imidazole and epichlorohydrin, preferably in a ratio of 1:4:1. A suitable commercially available pigment fixation polymer is Polyquart® FDI (Cognis).

Other suitable protective polymers include aminosilicone, which can improve the feel of the fabric and impart dimensional stability to the fabric.

Bleach. Suitable bleaches include sources of hydrogen peroxide, bleach activators, bleach catalysts and prepared peracids, and any combination thereof. A particularly suitable bleach includes a combination of a source of hydrogen peroxide with a bleach activator and/or a bleach catalyst.

Source of hydrogen peroxide. Suitable sources of hydrogen peroxide include sodium perborate and/or sodium percarbonate.

Bleach activator. Suitable bleach activators include tetraacetylethylenediamine and/or alkyloxybenzenesulfonate.

Bleach catalyst. The composition may contain a bleach catalyst. Suitable bleach catalysts include oxaziridinium bleach catalysts, transition metal bleach catalysts, especially manganese and iron bleach catalysts. A suitable bleach catalyst has a structure corresponding to the general formula below:

where R ¹³ is selected from the group consisting of 2-ethylhexyl, 2-propylheptyl, 2-butyloctyl, 2-pentylnonyl, 2-hexidecyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, isononyl, isodecyl, isotridecyl and isopentadecyl.

Ready peracid. Suitable prepared peracids include phthalimidoperoxycaproic acid.

Enzymes. Suitable enzymes include lipases, proteases, cellulases, amylases, and any combination thereof.

Protease. Suitable proteases include metalloproteases and/or serine proteases. Examples of suitable neutral or alkaline proteases include: subtilisins (EC 3.4.21.62); trypsin or chymotrypsin proteases; and metalloproteases. Suitable proteases include chemically or genetically modified mutants of the suitable proteases listed above.

Suitable commercially available protease enzymes include those offered under the trade names Alcalase®, Savinase®, Primase®, Durazym®, Polarzyme®, Kannase®, Liquanase®, Liquanase Ultra®, Savinase Ultra®, Ovozyme®, Neutrase®, Everlase® and Esperase® manufactured by Novozymes A/S (Denmark), offered under the trade name Maxatase®, Maxacal®, Maxapem®, a series of Preferenz P® proteases, including Preferenz® P280, Preferenz® P281, Preferenz® P2018-C, Preferenz® P2081-WE , Preferenz® P2082-EE and Preferenz® P2083-A/J, Properase®, Purafect®, Purafect Prime®, Purafect Ox®, FN3®, FN4®, Excellase® and Purafect OXP® from DuPont, marketed under the Opticlean® trade name and Optimase® manufactured by Solvay Enzymes, offered by Henkel/Kemira, namely BLAP (sequence shown in Fig. 29 of US patent 5,352,604 with the following mutations S99D + S101 R + S103A + V104I + G159S, hereinafter referred to as BLAP), BLAP R (BLAP with S3T + V4I + V199M + V205I + L217D), BLAP X (BLAP with S3T + V4I + V205I) and BLAP F49 (BLAP with S3T + V4I + A194P + V199M + V205I + L217D) - all made by Henkel/Kemira; and KAP ( Bacillus alkalophilus subtilisin with mutations A230V + S256G + S259N) from Kao.

Suitable protease is described in WO11/140316 and WO11/072117.

Amylase. Suitable amylases are obtained from alpha-amylase AA560, endogenous to Bacillus sp. DSM 12649, preferably with the following mutations: R118K, D183*, G184*, N195F, R320K and/or R458K. Suitable commercially available amylases include Stainzyme®, Stainzyme® Plus, Natalase, Termamyl®, Termamyl® Ultra, Liquezyme® SZ, Duramyl®, Everest® (all from Novozymes) and Spezyme® AA, Preferenz S® series of amylases, Purastar® and Purastar ® Ox Am, Optisize® HT Plus (all manufactured by Du Pont).

A suitable amylase is described in WO06/002643.

Cellulase. Suitable cellulases include enzymes of bacterial or fungal origin. In addition, chemically modified or protein engineered mutants are acceptable options. Suitable cellulases include cellulases from the genera Bacillus, Pseudomonas, Humicola, Fusarium, Thielavia, Acremonium , for example fungal cellulases derived from Humicola insolens, Myceliophthora thermophila and Fusarium oxysporum .

Commercially available cellulases include Celluzyme®, Carezyme® and Carezyme® Premium, Celluclean® and Whitezyme® (Novozymes A/S), the Revitalenz® enzyme series (Du Pont) and the Biotouch® enzyme series (AB Enzymes). Suitable commercially available cellulases include Carezyme® Premium, Celluclean® Classic. Suitable cellulases are described in WO07/144857 and WO10/056652.

Lipase. Suitable lipases include lipases of bacterial, fungal or synthetic origin and variants thereof. In addition, chemically modified or protein engineered mutants are acceptable options. Examples of lipases include those from Humicola (synonym Thermomyces ), such as from H. lanuginosa ( T. lanuginosus ).

The lipase may be a "first cycle lipase" such as those described in WO06/090335 and WO13/116261. In one aspect, the lipase is a first wash lipase, preferably a wild-type variant of the lipase from Thermomyces lanuginosus containing the T231R and/or N233R mutations. Preferred lipases include those sold under the trade names Lipex®, Lipolex® and Lipoclean® from Novozymes, Bagsvaerd, Denmark.

Other suitable lipases include: Liprl 139, for example as described in WO2013/171241; and TfuLip2, for example, as described in WO2011/084412 and WO2013/033318.

Other enzymes. Other suitable enzymes include bleaching enzymes such as peroxidases/oxidases, which include enzymes of plant, bacterial or fungal origin and variants thereof. Commercially available peroxidases include Guardzyme® (Novozymes A/S). Other suitable enzymes include choline oxidases and perhydrolases, such as those used in Gentle Power Bleach™.

Other suitable enzymes include pectate lyases sold under the trade names X-Pect®, Pectaway® (manufactured by Novozymes A/S, Bagsvaerd, Denmark) and PrimaGreen® (DuPont), and mannanases sold under the trade names Mannaway® (Novozymes A/ S, Bagsvaerd, Denmark) and Mannastar® (Du Pont).

Zeolite component. The composition may contain a zeolite detergent component. The composition may contain from 0 to 5 wt.% zeolite detergent component or 3 wt.% zeolite detergent component. The composition may even be substantially free of zeolite detergent component; “substantially not contain” means that it is not specifically added. Typical zeolite detergent components include zeolite A, zeolite P and zeolite MAP.

Phosphate component. The composition may contain a phosphate detergent component. The composition may contain from 0 to 5 wt.% phosphate detergent component or up to 3 wt.% phosphate detergent component. The composition may even be substantially free of phosphate detergent component; “substantially not contain” means that it is not specifically added. A common phosphate detergent ingredient is sodium tripolyphosphate.

Carbonate salt. The composition may contain a carbonate salt. The composition may contain from 0 wt. % up to 10 wt. % carbonate salt or up to 5 wt. % carbonate salt. The composition may even be substantially free of carbonate salt; “substantially not contain” means that it is not specifically added. Suitable carbonate salts include sodium carbonate and sodium bicarbonate.

Silicate salt. The composition may contain a silicate salt. The composition may contain from 0 wt. % up to 10 wt. % silicate salt or up to 5 wt. % silicate salt. The preferred silicate salt is sodium silicate, particularly preferred are sodium silicates with a Na ₂ O : SiO ₂ ratio of 1.0 to 2.8, preferably 1.6 to 2.0.

Sulfate salt. A suitable sulfate salt is sodium sulfate.

Clarifier. Suitable fluorescent brighteners include distyrylbiphenyl compounds, for example Tinopal® CBS-X, diaminostilbene disulfonic acid compounds, for example Tinopal® DMS pure Xtra and Blankophor® HRH, and pyrazoline compounds, for example Blankophor® SN, and coumarin compounds, for example Tinopal® SWN.

Preferred brighteners are: sodium 2-(4-styryl-3-sulfophenyl)-2H-naphthol[1,2-d]triazole, disodium-4,4'-bis{[(4-anilino-6-(N -methyl-N-2-hydroxyethyl)amino 1,3,5-triazin-2-yl)];amino}stilbene-2-2'-disulfonate, disodium-4,4'-bis{[(4-anilino- 6-morpholino-1,3,5-triazin-2-yl)]amino}stilbene-2-2'-disulfonate and disodium-4,4'-bis(2-sulfostyryl)biphenyl. A suitable fluorescent brightener is a C.I. fluorescent brightener. 260, which can be used in its beta or alpha crystalline forms or a mixture of such forms.

Chelating agent. The composition may also contain a chelating agent selected from diethylenetriamine pentaacetate, diethylenetriamine penta(methylphosphonic acid), ethylenediamine-N'N'-disuccinic acid, ethylenediaminetetraacetate, ethylenediaminetetra(methylenephosphonic acid) and hydroxyethanedi(methylenephosphonic acid). The preferred chelating agent is ethylenediamine-N'N'-disuccinic acid (EDDS) and/or hydroxyethane diphosphonic acid (HEDP). The composition preferably contains ethylenediamine-N'N'-disuccinic acid or a salt thereof. Ethylenediamine-N'N'-disuccinic acid is preferably in its S,S enantiomeric form. The composition preferably contains the disodium salt of 4,5-dihydroxy-m-benzenedisulfonic acid. Preferred chelating agents may also function as calcium carbonate crystal growth inhibitors, for example: 1-hydroxyethanediphosphonic acid (HEDP) and its salt; N,N-dicarboxymethyl-2-aminopentane-1,5-dicarboxylic acid and its salt; 2-phosphonobutane-1,2,4-tricarboxylic acid and its salt; and their combination.

Coloring agent. Suitable colorants include low molecular weight dyes, which generally correspond to the color index (CI) classification of acidic, direct, basic, mordant (including hydrolyzed forms thereof), or soluble or dispersed dyes, for example those categorized as blue, violet, red, green or black, and provide the desired shade individually or in combination. Such colorants preferably include Acid Violet 50, Direct Violet 9, 66 and 99, Solvent Violet 13 and any combination thereof.

Many coloring agents are known and described in the art that may be suitable for use in the present invention, for example the coloring agents described in WO2014/089386.

Suitable coloring agents include phthalocyanine-azo dye conjugates such as those described in WO2009/069077.

Suitable coloring agents may be alkoxylated. Such alkoxylated compounds can be prepared by organic synthesis, during which a mixture of molecules with varying degrees of alkoxylation can be obtained. Such mixtures can be used directly to obtain a coloring agent, or they can undergo a purification step to increase the proportion of the desired molecule. Suitable coloring agents include alkoxylated bis-azo dyes such as those described in WO2012/054835 and/or alkoxylated thiophene azo dyes such as those described in WO2008/087497 and WO2012/166768.

The colorant may be included in the detergent composition as part of a reaction mixture that results from the organic synthesis of the colorant molecule, with optional purification step(s). Such reaction mixtures typically contain the dye molecule itself and may also contain unreacted starting materials and/or by-products from the organic synthesis route. Suitable coloring agents can be included in the color pigment particles, for example as described in WO2009/069077.

Dye transfer inhibitors. Suitable dye transfer inhibitors include polyamine N-oxide polymers, N-vinylpyrrolidone-N-vinylimidazole copolymers, polyvinylpyrrolidone, polyvinyloxazolidone, polyvinylimidazole, and mixtures thereof. Preferred are poly(vinylpyrrolidone), poly(vinylpyridine betaine), poly(vinylpyridine-N-oxide), poly(vinylpyrrolidone-vinylimidazole) and mixtures thereof. Suitable commercially available dye transfer inhibitors include PVP-K15 and K30 (Ashland), Sokalan® HP165, HP50, HP53, HP59, HP56K, HP56, HP66 (BASF), Chromabond® S-400, S403E and S-100 (Ashland).

Aromatic substance. Suitable aromatics comprise aromatics selected from the group of: (a) aromatics with a ClogP of less than 3.0 and a boiling point below 250 °C (quadrant 1 aromatics); (b) aromatics with a ClogP of less than 3.0 and a boiling point of 250 °C or higher (quadrant 2 aromatics); (c) aromatics with a ClogP of 3.0 or higher and a boiling point below 250 °C (quadrant 3 aromatics); (d) aromatics with a ClogP of 3.0 or higher and a boiling point of 250 °C or higher (quadrant 4 aromatics); and (e) mixtures thereof.

It may be preferable that the flavoring agent be in a form consistent with the flavoring delivery technology. Such delivery technologies further stabilize and enhance the application and release of fragrances from fabrics after washing. Such fragrance delivery technologies can also be used to further increase the release time of fragrance from fabrics after washing. Suitable aroma delivery technologies include aroma microcapsules, aroma precursors, polymer delivery, other molecule delivery, fiber delivery, amine delivery, cyclodextrin, starch-encapsulated combinations, zeolite and other inorganic carriers, and any of these. mixture. Suitable microcapsules of aromatic substances are described in WO2009/101593.

Silicone. Suitable silicones include polydimethylsiloxane and aminosilicones. Suitable silicones are described in WO05075616.

Method for preparing detergent particles: In general, the composition particles can be prepared using any suitable method. Examples include spray drying, agglomeration, extrusion, and any combination thereof.

Typically, a suitable spray drying process includes the step of forming an aqueous slurry and feeding it through at least one pump, preferably two pumps, to a high pressure nozzle. Spraying the aqueous slurry into a spray drying tower and drying the aqueous slurry to form spray drying particles. Preferably, the spray drying tower is a countercurrent spray drying tower, although a parallel flow spray drying tower can also be used.

The powder obtained by spray drying usually goes through a cooling stage, for example, in a stream of air. Spray-dried powder is typically subjected to particle size separation, such as a sieve, to obtain the desired particle size distribution. Preferably, the spray-dried powder has a particle size distribution such that the weight average particle size is in the range of 300 to 500 µm and less than 10 wt.% of the spray-dried particles are larger than 2360 µm.

It may be preferable to heat the aqueous suspension to elevated temperatures before spraying in a spray drying tower, for example as described in WO2009/158162.

It may be preferable that an anionic surfactant, such as an alkyl benzene sulfonate, be introduced into the spray drying process after the aqueous suspension formation step: for example, introducing an acid precursor into the aqueous suspension after a pump, as described in WO 09/158449.

It may be preferable that a gas, such as air, is introduced into the spray drying process after the aqueous suspension formation step as described in WO2013/181205.

It may be preferable that any inorganic components, for example sodium sulfate and sodium carbonate, if present in the aqueous suspension, are micronized to small particle sizes, as described in WO2012/134969.

Typically, a suitable agglomeration process includes the step of mixing a detergent component, such as a detergent surfactant, such as linear alkyl benzene sulfonate (LAS) and/or alkyl alkoxy sulfate, with an inorganic material, such as sodium carbonate and/or silica, in a mixer. The agglomeration process may also be an in-situ mixing neutralization agglomeration process, in which an acidic detergent surfactant precursor, such as LAS, is reacted with an alkaline compound, such as sodium carbonate and/or sodium hydroxide, in a mixer, whereby the acidic detergent surfactant precursor is neutralized by an alkaline compound to form the detergent surfactant through an agglomeration process.

Other suitable detergent components that may undergo agglomeration include polymers, chelating agents, bleach activators, silicones, and any combination thereof.

The agglomeration process may be a high, medium and low shear agglomeration process using a high, medium and low shear mixer, respectively. The agglomeration process may be a multi-stage agglomeration process that uses two or more mixers, for example a high shear mixer in combination with a medium or low shear mixer. The agglomeration process may be a continuous process or a batch process.

It may be preferable that the agglomerates undergo a drying step, for example a fluidized bed drying step. It may also be preferable that the agglomerates undergo a cooling step, for example a fluidized bed cooling step.

Typically, the agglomerates are subjected to particle size separation, such as fluid bed and/or sieve elutriation, to obtain the desired particle size distribution. Preferably, the agglomerates have a particle size distribution such that the weighted average particle size is in the range from 300 to 800 μm, and less than 10 wt.% of the agglomerates have a particle size less than 150 μm and less than 10 wt.% of the agglomerates have a particle size greater than 1200 μm.

It may be preferable for small agglomerates and oversized agglomerates to be returned to the agglomeration process. Oversized particles typically undergo a size reduction step, such as grinding, and are returned to an appropriate step in the agglomeration process, such as a mixer. The fine particles are usually returned to an appropriate stage of the agglomeration process, such as a mixer.

It may be preferable that components such as a polymer and/or a nonionic surfactant and/or a fragrance are sprayed onto detergent base particles, such as spray-dried detergent base particles and/or agglomerated detergent base particles. detergent particles. This atomization step is usually carried out in a drum mixer.

Method of washing fabric. A method for washing fabric includes the step of mixing a solid composition with water to form a washing solution, followed by washing the fabric in said washing solution. Typically, the cleaning solution has a temperature above 0 to 90 °C, or up to 60 °C, or up to 40 °C, or up to 30 °C, or up to 20 °C. The fabric may be contacted with water before, after, or simultaneously with contacting the solid composition with water. Typically, the detergent solution is formed by mixing laundry detergent with water in such quantities that the concentration of the laundry detergent composition in the detergent solution is from 0.2 to 20 g/L, or from 0.5 to 10 g/L, or up to 5.0 g/l. The method of washing the fabric can be carried out in an automatic front-loading washing machine, in an automatic top-loading washing machine, including automatic high-efficiency washing machines, or in suitable hand wash containers. Typically, the cleaning solution contains 90 liters or less, or 60 liters or less, or 15 liters or less, or 10 liters or less of water. To obtain a washing solution, 200 g or less, 150 g or less, 100 g or less, or 50 g or less of a laundry detergent composition are usually added to water.

A method for measuring the viscosity of a concentrated aqueous acid mixture. The shear viscosity of the concentrated aqueous mixture of the present invention is measured using a TA AR2000 rheometer using a cup and a float. Measurements are made using a continuous shear rate ramp from 2000 s ^-1 to 0.1 s ^-1 over 390 seconds. The rheometer cup is preheated to 40 °C and the sample is allowed to thermally equilibrate for at least 30 minutes before starting the rheological test. Shear viscosity is noted at a shear rate of 10 s ^-1 .

A method for measuring the size of droplets of fragrance oil in an emulsified fragrance mixture. The morphology and particle size distribution of the emulsions were examined using confocal laser scanning microscopy (CLSM) with a 60× oil immersion objective (Leica SP8, Leica, Germany). Two different fluorescent dyes are used to separately visualize the oil inside the capsule and the thickness of the capsule wall. The oil inside the capsule is visualized using Nile red dye, while the starch wall is visualized using calcofluor white (CFW). (X. Jia et al., Food Hydrocolloids 43 (2015) 275-282. Wei Liu, et al., J. Agricultural Food Chemistry 2018 66 (35), 9301-9308. L. Bai et al., Biomacromolecules 2018, 19, 1674−1685).

To image the emulsion, 10 μL of 0.1% w/v is added to 0.5 mL of emulsion. Nile red in ethanol and 100 µl 1% w/v. calcofluor white in water. After mixing uniformly with a small spatula and equilibrating for at least 10 minutes at ambient temperature, 6 μl of stained samples are placed on a microscope slide and covered with a coverslip. Images are acquired confocally. The diameters (d32) of the emulsions were measured using Image J software (FIJI), taking the average of at least 100 drops.

EXAMPLES

A comparison was made between a particulate laundry detergent composition prepared in accordance with the method of the present invention and a comparable particulate laundry detergent composition prepared in accordance with a comparative method (without acid and at a higher pH).

Two fluids were prepared based on the different compositions shown in Table 1 below (parts by weight). All fluids were homogenized using a Silverstone type rapid mixer. For fluid A, citric acid was added and dispersed in an aqueous starch solution at 50 °C before adding the flavor oil. Only fluid A has a pH less than 4 when measured directly in the fluid.

TABLE 1 Fluid Composition Solid active substance (wt.%) A B ¹ Starch Ecoseneur LNP 2115 60.0 65.3 70.0 Anhydrous citric acid 100.0 4.7 0.0 Fragrance oil n/a 30.0 30.0 Measured pH value 3.4 5.6

¹ Starch supplied by Ingredon UK Limited, Manchester M22 5LW, England

The spray-dried laundry detergent was prepared using standard methods according to the composition given in Table 2 (parts by weight).

TABLE 2 Sodium linear alkylbenzenesulfonate 19.6 wt.% Polyacrylate polymer 3.5 wt.% Sodium carbonate 17.3 wt.% Sodium sulfate 44.4 wt.% Sodium silicate 11.6 wt.% Water 1.5 wt.% Other Additive up to 100 wt.%

The particulate laundry detergent according to Table 3, in parts by weight, was prepared by dry mixing in a rotary batch mixer, spraying the nonionic surfactant and dispersing it into a powder.

TABLE 3 % Spray dried base particles according to Table 2 49.4 Aluminosilicate 5.0 Lemon acid 1.0 Clarifiers 0.2 Foam suppressants 0.4 Agglomerate LAS 11.6 Agglomerate AES 2.9 Carbonate 5.1 Percarbonate 14.5 Bleach activator 3.9 Nonionic surfactant 1.3 Other The rest

Table 4 (parts by weight) complements particulate laundry detergent formulations containing several starch-based fluid compositions. Starch-based fluids were sprayed onto the powder and dispersed homogeneously throughout the product to at least partially coat the base particles using a Kenwood kitchen mixer.

TABLE 4 Powder A Powder B Fluid used according to Table 1 C D Final product used according to Table 3 98 98 Fluid 2 2

Discoloration of the powder under storage conditions.

Samples of the granular laundry detergent composition were taken in accordance with Table 4 and placed in Petri dishes. Petri dish samples are placed and stored at 40 °C/30% RH. ow. within 1 week. The results (discoloration scores) are presented in Table 5.

TABLE 5 Product A Product B 40 °C, 1 week No clear discoloration Yellow spots distributed throughout the detergent product.

Powder A (inventive) exhibits minimal discoloration, while Powder B (comparable) exhibits significant discoloration.

The dimensions and quantities described herein are not to be understood as strictly limited to the exact numerical values listed. On the contrary, unless otherwise indicated, each such size assumes both a specified value and a functionally equivalent range within which that value falls. For example, a size described as "40mm" implies "about 40mm".

Claims (25)

1. A method for producing a particle-based laundry detergent composition, comprising the following steps: (a) bringing water, starch, acid and flavoring into contact to form a concentrated water-acid mixture, wherein the concentrated acid mixture contains: (i) from 20 to 60 wt.% starch; (ii) from 10 to 50 wt.% flavoring; (iii) from 2 to 20 wt.% acid; (iv) from 10 to less than 45 wt.% water; And wherein the concentrated acid mixture has a pH less than 4.5; (b) subjecting the concentrated acid mixture to a flavor emulsification step to emulsify the flavor to form an emulsified flavor mixture in fluid form; And (c) spraying the emulsified fragrance mixture in fluid form onto the detergent base particles such that the emulsified fragrance mixture at least partially covers the detergent base particles to form a powdered laundry detergent composition wherein the detergent base particles range from 4 to 60 wt.% detergent surfactant. 2. The method according to claim 1, wherein said emulsified flavor mixture in fluid form is in the form of a liquid suspension. 3. The method according to any of the preceding claims, wherein said emulsified flavor mixture is not subjected to a spray drying step. 4. The method according to any of the preceding claims, wherein in step (a) the starch is in the form of a concentrated aqueous starch mixture when it is in contact with the aromatic substance, wherein the concentrated aqueous starch mixture contains more than 50 wt.% starch. 5. The method according to any of the previous paragraphs, wherein said step (b) is carried out in a rotor-stator device operating such that the tip speed exceeds 5 ms ^-1 . 6. The method according to any of the preceding claims, wherein said step (c) is carried out in a mixer and wherein the weight ratio of the emulsified flavor mixture in fluid form to the detergent base particles dispensed into the mixer is in the range of 0.002:1 to 0.15 :1. 7. A method according to any of the preceding claims, wherein said detergent base particles are in the form of agglomerates. 8. Method according to any one of paragraphs. 1-6, wherein the detergent base particles are in the form of spray-dried particles. 9. A method according to any of the previous paragraphs, wherein said detergent base particles comprise: (a) from 4 to 35 wt.% detergent surfactant; And (b) from 5 to 91 wt.% of the carrier material. 10. The method according to any of the previous paragraphs, and the specified concentrated water-acid mixture has a viscosity in the range from 0.1 to 3.0 Pa⋅s when measured at a shear rate of 10 s ^-1 and a temperature of 40°C. 11. A method according to any of the preceding claims, wherein during step (c) other detergent particles may be present and the emulsified flavor mixture at least partially coats the other detergent particles and also at least partially coats the base detergent particles. 12. Method according to any of the previous paragraphs, wherein said acid is selected from carboxylic acids. 13. A method according to any of the preceding claims, wherein said detergent surfactant is an anionic detergent surfactant. 14. The method according to any of the previous paragraphs, wherein said starch is selected from starch octenyl succinates. 15. The method according to any of the previous paragraphs, wherein said concentrated acid mixture has a pH of less than 4.0.