METHOD OF LAUNDERING FABRIC

Abstract
The present invention relates to a method of laundering fabric. The fabric to be laundered is subjected to a first acidic soaking step, followed by an alkaline washing step.
Description
FIELD OF THE INVENTION

The present invention relates to a method of laundering fabric. The method involves a first acidic soaking step followed by an alkaline washing step. The method provides good cleaning performance as well as good care performance, such as a good tensile strength loss profile.


BACKGROUND OF THE INVENTION

Detergent manufacturers develop laundry detergent products to clean fabric. In addition to good cleaning performance, consumers of these products also require good fabric care performance. An especially desired need is to preserve the integrity of the fabric being laundered, this is known as tensile strength loss. Often detergent manufacturers develop in isolation products to be used in part of the laundering process: such as a laundry detergent composition, or a fabric enhancer composition.


The present invention addresses the need to provide a laundering process that provides both good cleaning performance, and good fabric care performance, such as a good tensile strength loss profile.


The present invention provides a very specific process whereby an acidic soak at very controlled dose, volume and pH is then followed by an alkaline wash also at very controlled dose, volume and pH.


SUMMARY OF THE INVENTION

The present invention provides a method of laundering fabric wherein the method comprises the steps:

    • (a) contacting from 10 g to 100 g of an acidic solid laundry detergent composition to from 1.0 L to 10.0 L of water to form an acidic aqueous wash bath having a pH in the range of from 2.0 to 3.0, wherein the acidic solid laundry detergent composition has 10 wt % to 70 wt % acidic component and from 1.0 wt % to 20 wt % detersive surfactant;
    • (b) contacting soiled fabric to the acidic aqueous wash bath, and soaking the soiled fabric in the acidic aqueous wash bath for from 1 hour to 24 hours;
    • (c) removing the soaked fabric from the acidic aqueous wash bath;
    • (d) contacting from 10 g to 200 g of an alkaline solid laundry detergent composition to from 1.0 L to 70 L of water to form an alkaline aqueous wash bath having a pH in the range of from 8.0 to 12.0;
    • wherein the alkaline solid laundry detergent composition comprises from 3.0 wt % to 50 wt % alkaline component and from 1.0 wt % to 30 wt % detersive surfactant;
    • (e) contacting the soaked fabric from step (c) to the alkaline aqueous wash bath, and washing the soaked fabric in the alkaline aqueous wash bath for from 10 mins to 4 hours;
    • (f) removing the washed fabric from the alkaline aqueous wash bath;
    • (g) rinsing the washed fabric from step (f) with water.







DETAILED DESCRIPTION OF THE INVENTION
Method of Laundering Fabric

The method of laundering fabric comprises the steps:

    • (a) contacting from 10 g to 100 g of an acidic solid laundry detergent composition to from 1.0 L to 10.0 L of water to form an acidic aqueous wash bath having a pH in the range of from 2.0 to 3.0, wherein the acidic solid laundry detergent composition comprises from 10 wt % to 70 wt % acidic component, and from 1.0 wt % to 20 wt % detersive surfactant;
    • (b) contacting soiled fabric to the acidic aqueous wash bath, and soaking the soiled fabric in the acidic aqueous wash bath for from 1 hour to 24 hours;
    • (c) removing the soaked fabric from the acidic aqueous wash bath;
    • (d) contacting from 10 g to 200 g of an alkaline solid laundry detergent composition to from 1.0 L to 70 L of water to form an alkaline aqueous wash bath having a pH in the range of from 8.0 to 12.0;
    • wherein the alkaline solid laundry detergent composition comprises from 3.0 wt % to 50 wt % alkaline component and from 1.0 wt % to 30 wt % detersive surfactant;
    • (e) contacting the soaked fabric from step (c) to the alkaline aqueous wash bath, and washing the soaked fabric in the alkaline aqueous wash bath for from 10 mins to 4 hours;
    • (f) removing the washed fabric from the alkaline aqueous wash bath;
    • (g) rinsing the washed fabric from step (f) with water.


Preferably, the ratio of (i) the concentration in ppm of surfactant present in the acidic aqueous wash bath to (ii) the concentration in ppm of surfactant present in the alkaline aqueous wash bath is in the range of from above 2:1 to 20:1.


Step (a) Forming an Acidic Aqueous Wash Bath

Step (a) contacts from 10 g to 100 g of an acidic solid laundry detergent composition to from 1.0 L to 10.0 L of water to form an acidic aqueous wash bath having a pH in the range of from 2.0 to 3.0. The acidic solid laundry detergent composition has 10 wt % to 70 wt % acidic component and from 1.0 wt % to 20 wt % detersive surfactant.


Step (b) Acidic Soaking Step

Step (b) contacts soiled fabric to the acidic aqueous wash bath, and soaks the soiled fabric in the acidic aqueous wash bath for from 1 hour to 24 hours.


Preferably, the acidic soaking step (b) is carried out under a mechanical agitation of less than 10%.


Preferably, during step (b) the soiled fabric is soaked in the acidic aqueous wash bath for from 1 hour to 4 hours.


Step (c) Removing the Soaked Fabric

Step (c) removes the soaked fabric from the acidic aqueous wash bath.


Step (d) Forming an Alkaline Aqueous Wash Bath

Step (d) contacts from 10 g to 200 g of an alkaline solid laundry detergent composition to from 1.0 L to 70 L of water to form an alkaline aqueous wash bath having a pH in the range of from 8.0 to 12.0. The alkaline solid laundry detergent composition comprises from 3.0 wt % to 50 wt % alkaline component and from 1.0 wt % to 30 wt % detersive surfactant.


Step (e) Alkaline Washing Step

Step (e) contacts the soaked fabric from step (c) to the alkaline aqueous wash bath, and washes the soaked fabric in the alkaline aqueous wash bath for from 10 mins to 4 hours.


Preferably, the alkaline washing step (e) is carried out under a mechanical agitation of 10% or greater.


Step (f) Removing the Washed Fabric

Step (f) removes the washed fabric from the alkaline aqueous wash bath.


Step (g) Rinsing the Washed Fabric

Step (g) rinses the washed fabric from step (f) with water.


Acidic Solid Laundry Detergent Composition

The acidic solid laundry detergent composition comprises from 10 wt % to 70 wt % acidic component, and from 1.0 wt % to 20 wt % detersive surfactant.


The acidic solid laundry detergent composition preferably comprises from 30 wt % to 70 wt % acidic component, and from 3.0 wt % to 10 wt % detersive surfactant.


Alkaline Solid Laundry Detergent Composition

The alkaline solid laundry detergent composition preferably comprises from 3.0 wt % to 30 wt % alkaline component, and from 5.0 wt % to 20 wt % detersive surfactant.


Acidic Component

Any suitable acidic component can be used.


A suitable acidic component is a polycarboxylic acid.


A preferred acidic component is citric acid.


Alkaline Component

Any suitable alkaline component can be used.


A preferred alkaline component is sodium carbonate and/or sodium silicate.


Detersive Surfactant

Any suitable detersive surfactant can be used.


A suitable detersive surfactant is selected from: alkyl benzene sulphonate, alkyl sulphate, alkoxylated alkyl sulphate, alkoxylated alcohol and any combination thereof.


Alkaline solid laundry detergent composition: Typically, the laundry detergent composition is a fully formulated laundry detergent composition, not a portion thereof such as a spray-dried, extruded or agglomerate particle that only forms part of the laundry detergent composition. Typically, the solid composition comprises a plurality of chemically different particles, such as spray-dried base detergent particles and/or agglomerated base detergent particles and/or extruded base detergent particles, in combination with one or more, typically two or more, or five or more, or even ten or more particles selected from: surfactant particles, including surfactant agglomerates, surfactant extrudates, surfactant needles, surfactant noodles, surfactant flakes; phosphate particles; zeolite particles; silicate salt particles, especially sodium silicate particles; carbonate salt particles, especially sodium carbonate particles; polymer particles such as carboxylate polymer particles, cellulosic polymer particles, starch particles, polyester particles, polyamine particles, terephthalate polymer particles, polyethylene glycol particles; aesthetic particles such as coloured noodles, needles, lamellae particles and ring particles; enzyme particles such as protease granulates, amylase granulates, lipase granulates, cellulase granulates, mannanase granulates, pectate lyase granulates, xyloglucanase granulates, bleaching enzyme granulates and co-granulates of any of these enzymes, preferably these enzyme granulates comprise sodium sulphate; bleach particles, such as percarbonate particles, especially coated percarbonate particles, such as percarbonate coated with carbonate salt, sulphate salt, silicate salt, borosilicate salt, or any combination thereof, perborate particles, bleach activator particles such as tetra acetyl ethylene diamine particles and/or alkyl oxybenzene sulphonate particles, bleach catalyst particles such as transition metal catalyst particles, and/or isoquinolinium bleach catalyst particles, pre-formed peracid particles, especially coated pre-formed peracid particles; filler particles such as sulphate salt particles and chloride particles; clay particles such as montmorillonite particles and particles of clay and silicone; flocculant particles such as polyethylene oxide particles; wax particles such as wax agglomerates; silicone particles, brightener particles; dye transfer inhibition particles; dye fixative particles; perfume particles such as perfume microcapsules and starch encapsulated perfume accord particles, or pro-perfume particles such as Schiff base reaction product particles; hueing dye particles; chelant particles such as chelant agglomerates; and any combination thereof.


Suitable laundry detergent compositions comprise a detergent ingredient selected from: detersive surfactant, such as anionic detersive surfactants, non-ionic detersive surfactants, cationic detersive surfactants, zwitterionic detersive surfactants and amphoteric detersive surfactants; polymers, such as carboxylate polymers, soil release polymer, anti-redeposition polymers, cellulosic polymers and care polymers; bleach, such as sources of hydrogen peroxide, bleach activators, bleach catalysts and pre-formed peracids; photobleach, such as such as zinc and/or aluminium sulphonated phthalocyanine; enzymes, such as proteases, amylases, cellulases, lipases; zeolite builder; phosphate builder; co-builders, such as citric acid and citrate; carbonate, such as sodium carbonate and sodium bicarbonate; sulphate salt, such as sodium sulphate; silicate salt such as sodium silicate; chloride salt, such as sodium chloride; brighteners; chelants; hueing agents; dye transfer inhibitors; dye fixative agents; perfume; silicone; fabric softening agents, such as clay; flocculants, such as polyethyleneoxide; suds supressors; and any combination thereof.


Suitable laundry detergent compositions may have a low buffering capacity. Such laundry detergent compositions typically have a reserve alkalinity to pH 9.5 of less than 5.0 g NaOH/100 g. These low buffered laundry detergent compositions typically comprise low levels of carbonate salt.


Detersive Surfactant: Suitable detersive surfactants include anionic detersive surfactants, non-ionic detersive surfactant, cationic detersive surfactants, zwitterionic detersive surfactants and amphoteric detersive surfactants. Suitable detersive surfactants may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial.


Anionic detersive surfactant: Suitable anionic detersive surfactants include sulphonate and sulphate detersive surfactants.


Suitable sulphonate detersive surfactants include methyl ester sulphonates, alpha olefin sulphonates, alkyl benzene sulphonates, especially alkyl benzene sulphonates, preferably C10-13 alkyl benzene sulphonate. Suitable alkyl benzene sulphonate (LAS) is obtainable, preferably obtained, by sulphonating commercially available linear alkyl benzene (LAB); suitable LAB includes low 2-phenyl LAB, other suitable LAB include high 2-phenyl LAB, such as those supplied by Sasol under the tradename Hyblene®.


Suitable sulphate detersive surfactants include alkyl sulphate, preferably C8-C18 alkyl sulphate, or predominantly C12 alkyl sulphate.


A preferred sulphate detersive surfactant is alkyl alkoxylated sulphate, preferably alkyl ethoxylated sulphate, preferably a C8-C18 alkyl alkoxylated sulphate, preferably a C8-C18 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 C8-C18 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 sulphate, alkyl alkoxylated sulphate and alkyl benzene sulphonates may be linear or branched, substituted or un-substituted, and may be derived from petrochemical material or biomaterial.


Other suitable anionic detersive surfactants include alkyl ether carboxylates.


Suitable anionic detersive surfactants may be in salt form, suitable counter-ions include sodium, calcium, magnesium, amino alcohols, and any combination thereof. A preferred counter-ion is sodium.


Non-ionic detersive surfactant: Suitable non-ionic detersive surfactants are selected from the group consisting of: C8-C18 alkyl ethoxylates, such as, NEODOL® non-ionic surfactants from Shell; C6-C12 alkyl phenol alkoxylates wherein preferably the alkoxylate units are ethyleneoxy units, propyleneoxy units or a mixture thereof; C12-C18 alcohol and C6-C12 alkyl phenol condensates with ethylene oxide/propylene oxide block polymers such as Pluronic® from BASF; alkylpolysaccharides, preferably alkylpolyglycosides; methyl ester ethoxylates; polyhydroxy fatty acid amides; ether capped poly(oxyalkylated) alcohol surfactants; and mixtures thereof.


Suitable non-ionic detersive surfactants are alkylpolyglucoside and/or an alkyl alkoxylated alcohol.


Suitable non-ionic detersive surfactants include alkyl alkoxylated alcohols, preferably C8-C18 alkyl alkoxylated alcohol, preferably a C8-C18 alkyl ethoxylated alcohol, preferably the alkyl alkoxylated alcohol has an average degree of alkoxylation of from 1 to 50, preferably from 1 to 30, or from 1 to 20, or from 1 to 10, preferably the alkyl alkoxylated alcohol is a C8-C18 alkyl ethoxylated alcohol having an average degree of ethoxylation of from 1 to 10, preferably from 1 to 7, more preferably from 1 to 5 and most preferably from 3 to 7. The alkyl alkoxylated alcohol can be linear or branched, and substituted or un-substituted.


Suitable nonionic detersive surfactants include secondary alcohol-based detersive surfactants.


Cationic detersive surfactant: Suitable cationic detersive surfactants include alkyl pyridinium compounds, alkyl quaternary ammonium compounds, alkyl quaternary phosphonium compounds, alkyl ternary sulphonium compounds, and mixtures thereof.


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





(R)(R1)(R2)(R3)N+X

    • wherein, R is a linear or branched, substituted or unsubstituted C6-18 alkyl or alkenyl moiety, R1 and R2 are independently selected from methyl or ethyl moieties, R3 is a hydroxyl, hydroxymethyl or a hydroxyethyl moiety, X is an anion which provides charge neutrality, preferred anions include: halides, preferably chloride; sulphate; and sulphonate.


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


Polymer: Suitable polymers include carboxylate polymers, soil release polymers, anti-redeposition polymers, cellulosic polymers, care polymers and any combination thereof.


Carboxylate polymer: The composition may comprise a carboxylate polymer, such as a maleate/acrylate random copolymer or polyacrylate homopolymer. Suitable carboxylate polymers include: polyacrylate homopolymers having a molecular weight of from 4,000 Da to 9,000 Da; maleate/acrylate random copolymers having a molecular weight of from 50,000 Da to 100,000 Da, or from 60,000 Da to 80,000 Da.


Another suitable carboxylate polymer is a co-polymer that comprises: (i) from 50 to less than 98 wt % structural units derived from one or more monomers comprising carboxyl groups; (ii) from 1 to less than 49 wt % structural units derived from one or more monomers comprising sulfonate moieties; and (iii) from 1 to 49 wt % structural units derived from one or more types of monomers selected from ether bond-containing monomers represented by formulas (I) and (II):




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    • wherein in formula (I), R0 represents a hydrogen atom or CH3 group, R represents a CH2 group, CH2CH2 group or single bond, X represents a number 0-5 provided X represents a number 1-5 when R is a single bond, and R1 is a hydrogen atom or C1 to C20 organic group;







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    • wherein in formula (II), R0 represents a hydrogen atom or CH3 group, R represents a CH2 group, CH2CH2 group or single bond, X represents a number 0-5, and R1 is a hydrogen atom or C1 to C20 organic group.





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


Soil release polymer: The composition may comprise a soil release polymer. A suitable soil release polymer has a structure as defined by one of the following structures (I), (II) or (III):





—[(OCHR1—CHR2)a—O—OC—Ar—CO-]d  (I)





—[(OCHR3—CHR4)b—O—OC-sAr-CO-]e  (II)





[(OCHR5—CHR6)c—OR7]f  (III)


wherein:

    • a, b and c are from 1 to 200;
    • d, e and f are from 1 to 50;
    • Ar is a 1,4-substituted phenylene;
    • sAr is 1,3-substituted phenylene substituted in position 5 with SO3Me;
    • Me is Li, K, Mg/2, Ca/2, Al/3, ammonium, mono-, di-, tri-, or tetraalkylammonium wherein
    • the alkyl groups are C1-C18 alkyl or C2-C10 hydroxyalkyl, or mixtures thereof;
    • R1, R2, R3, R4, R5 and R6 are independently selected from H or C1-C18 n- or iso-alkyl; and
    • R7 is a linear or branched C1-C18 alkyl, or a linear or branched C2-C30 alkenyl, or a cycloalkyl group with 5 to 9 carbon atoms, or a C8-C30 aryl group, or a C6-C30 arylalkyl group.


Suitable soil release polymers are sold by Clariant under the TexCare® series of polymers, e.g. TexCare® SRN240 and TexCare® SRA300. Other suitable soil release polymers are sold by Solvay under the Repel-o-Tex® series of polymers, e.g. Repel-o-Tex® SF2 and Repel-o-Tex® Crystal.


Anti-redeposition polymer: Suitable anti-redeposition polymers include polyethylene glycol polymers and/or polyethyleneimine polymers.


Suitable polyethylene glycol polymers include random graft co-polymers comprising: (i) hydrophilic backbone comprising polyethylene glycol; and (ii) hydrophobic side chain(s) selected from the group consisting of: C4-C25 alkyl group, polypropylene, polybutylene, vinyl ester of a saturated C1-C6 mono-carboxylic acid, C1-C6 alkyl ester of acrylic or methacrylic acid, and mixtures thereof. Suitable polyethylene glycol polymers have a polyethylene glycol backbone with random grafted polyvinyl acetate side chains. The average molecular weight of the polyethylene glycol backbone can be in the range of from 2,000 Da to 20,000 Da, or from 4,000 Da to 8,000 Da.


The molecular weight ratio of the polyethylene glycol baackbone to the polyvinyl acetate side chains can be in the range of from 1:1 to 1:5, or from 1:1.2 to 1:2. The average number of graft sites per ethylene oxide unit can be less than 0.02, or less than 0.016, the average number of graft sites per ethylene oxide unit can be in the range of from 0.010 to 0.018, or the average number of graft sites per ethylene oxide unit can be less than 0.010, or in the range of from 0.004 to 0.008.


Suitable polyethylene glycol polymers are described in WO08/007320.


A suitable polyethylene glycol polymer is Sokalan HP22.


Cellulosic polymer: Suitable cellulosic polymers are selected from alkyl cellulose, alkyl alkoxyalkyl cellulose, carboxyalkyl cellulose, alkyl carboxyalkyl cellulose, sulphoalkyl cellulose, more preferably selected from carboxymethyl cellulose, methyl cellulose, methyl hydroxyethyl cellulose, methyl carboxymethyl cellulose, and mixures thereof.


Suitable carboxymethyl celluloses 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 carboxymethyl celluloses have a degree of substitution greater than 0.65 and a degree of blockiness greater than 0.45, e.g. as described in WO09/154933.


Care polymers: 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.


Other suitable care polymers include dye lock polymers, for example the condensation oligomer produced by the condensation of imidazole and epichlorhydrin, preferably in ratio of 1:4:1. A suitable commercially available dye lock polymer is Polyquart® FDI (Cognis).


Other suitable care polymers include amino-silicone, which can provide fabric feel benefits and fabric shape retention benefits.


Bleach: Suitable bleach includes sources of hydrogen peroxide, bleach activators, bleach catalysts, pre-formed 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 tetra acetyl ethylene diamine and/or alkyl oxybenzene sulphonate.


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




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    • wherein R13 is selected from the group consisting of 2-ethylhexyl, 2-propylheptyl, 2-butyloctyl, 2-pentylnonyl, 2-hexyldecyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, iso-nonyl, iso-decyl, iso-tridecyl and iso-pentadecyl.





Pre-formed peracid: Suitable pre-form peracids include phthalimido-peroxycaproic 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-type or chymotrypsin-type proteases; and metalloproteases. The suitable proteases include chemically or genetically modified mutants of the aforementioned suitable proteases.


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®, Maxacal®, Maxapem®, Preferenz P® series of 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® by DuPont, those sold under the tradename Opticlean® and Optimase® by Solvay Enzymes, those available from Henkel/Kemira, namely BLAP (sequence shown in FIG. 29 of U.S. Pat. No. 5,352,604 with the folowing 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 from Henkel/Kemira; and KAP (Bacillus alkalophilus subtilisin with mutations A230V+S256G+S259N) from Kao.


A suitable protease is described in WO11/140316 and WO11/072117.


Amylase: Suitable amylases are derived from AA560 alpha amylase endogenous to Bacillus sp. DSM 12649, preferably having 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 Novozymes) and Spezyme® AA, Preferenz S® series of amylases, Purastar® and Purastar® Ox Am, Optisize® HT Plus (all Du Pont).


A suitable amylase is described in WO06/002643.


Cellulase: Suitable cellulases include those of bacterial or fungal origin. Chemically modified or protein engineered mutants are also suitable. Suitable cellulases include cellulases from the genera Bacillus, Pseudomonas, Humicola, Fusarium, Thielavia, Acremonium, e.g., the fungal cellulases produced from Humicola insolens, Myceliophthora thermophila and Fusarium oxysporum.


Commercially available cellulases include Celluzyme®, Carezyme®, and Carezyme® Premium, Celluclean® and Whitezyme® (Novozymes A/S), Revitalenz® series of enzymes (Du Pont), and Biotouch® series of enzymes (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 those of bacterial, fungal or synthetic origin, and variants thereof. Chemically modified or protein engineered mutants are also suitable. Examples of suitable lipases include lipases from Humicola (synonym Thermomyces), e.g., from H. lanuginosa (T. lanuginosus).


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


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


Other enzymes: Other suitable enzymes are bleaching enzymes, such as peroxidases/oxidases, which include those 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 tradenames X-Pect®, Pectaway® (from Novozymes A/S, Bagsvaerd, Denmark) and PrimaGreen® (DuPont) and mannanases sold under the tradenames Mannaway® (Novozymes A/S, Bagsvaerd, Denmark), and Mannastar® (Du Pont).


Zeolite builder: The composition may comprise zeolite builder. The composition may comprise from 0 wt % to 5 wt % zeolite builder, or 3 wt % zeolite builder. The composition may even be substantially free of zeolite builder; substantially free means “no deliberately added”. Typical zeolite builders include zeolite A, zeolite P and zeolite MAP.


Phosphate builder: The composition may comprise phosphate builder. The composition may comprise from 0 wt % to 5 wt % phosphate builder, or to 3 wt %, phosphate builder. The composition may even be substantially free of phosphate builder; substantially free means “no deliberately added”. A typical phosphate builder is sodium tri-polyphosphate.


Carbonate salt: The composition may comprise carbonate salt. The composition may comprise from 0 wt % to 10 wt % carbonate salt, or to 5 wt % carbonate salt. The composition may even be substantially free of carbonate salt; substantially free means “no deliberately added”. Suitable carbonate salts include sodium carbonate and sodium bicarbonate.


Silicate salt: The composition may comprise silicate salt. The composition may comprise from 0 wt % to 10 wt % silicate salt, or to 5 wt % silicate salt. A preferred silicate salt is sodium silicate, especially preferred are sodium silicates having a Na2O:SiO2 ratio of from 1.0 to 2.8, preferably from 1.6 to 2.0.


Sulphate salt: A suitable sulphate salt is sodium sulphate.


Brightener: Suitable fluorescent brighteners include: di-styryl biphenyl compounds, e.g. Tinopal® CBS-X, di-amino stilbene di-sulfonic acid compounds, e.g. Tinopal® DMS pure Xtra and Blankophor® HRH, and Pyrazoline compounds, e.g. Blankophor® SN, and coumarin compounds, e.g. Tinopal® SWN.


Preferred brighteners are: sodium 2 (4-styryl-3-sulfophenyl)-2H-napthol[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 C.I. Fluorescent Brightener 260, which may be used in its beta or alpha crystalline forms, or a mixture of these forms.


Chelant: The composition may also comprise a chelant selected from: diethylene triamine pentaacetate, diethylene triamine penta(methyl phosphonic acid), ethylene diamine-N′N′-disuccinic acid, ethylene diamine tetraacetate, ethylene diamine tetra(methylene phosphonic acid) and hydroxyethane di(methylene phosphonic acid). A preferred chelant is ethylene diamine-N′N′-disuccinic acid (EDDS) and/or hydroxyethane diphosphonic acid (HEDP). The composition preferably comprises ethylene diamine-N′N′-disuccinic acid or salt thereof. Preferably the ethylene diamine-N′N′-disuccinic acid is in S,S enantiomeric form. Preferably the composition comprises 4,5-dihydroxy-m-benzenedisulfonic acid disodium salt. Preferred chelants may also function as calcium carbonate crystal growth inhibitors such as: 1-hydroxyethanediphosphonic acid (HEDP) and salt thereof; N,N-dicarboxymethyl-2-aminopentane-1,5-dioic acid and salt thereof; 2-phosphonobutane-1,2,4-tricarboxylic acid and salt thereof; and combination thereof.


Hueing agent: Suitable hueing agents include small molecule dyes, typically falling into the Colour Index (C.I.) classifications of Acid, Direct, Basic, Reactive (including hydrolysed forms thereof) or Solvent or Disperse dyes, for example classified as Blue, Violet, Red, Green or Black, and provide the desired shade either alone or in combination. Preferred such hueing agents include Acid Violet 50, Direct Violet 9, 66 and 99, Solvent Violet 13 and any combination thereof.


Many hueing agents are known and described in the art which may be suitable for the present invention, such as hueing agents described in WO2014/089386.


Suitable hueing agents include phthalocyanine and azo dye conjugates, such as described in WO2009/069077.


Suitable hueing agents may be alkoxylated. Such alkoxylated compounds may be produced by organic synthesis that may produce a mixture of molecules having different degrees of alkoxylation. Such mixtures may be used directly to provide the hueing agent, or may undergo a purification step to increase the proportion of the target molecule. Suitable hueing agents include alkoxylated bis-azo dyes, such as described in WO2012/054835, and/or alkoxylated thiophene azo dyes, such as described in WO2008/087497 and WO2012/166768.


The hueing agent may be incorporated into the detergent composition as part of a reaction mixture which is the result of the organic synthesis for a dye molecule, with optional purification step(s). Such reaction mixtures generally comprise the dye molecule itself and in addition may comprise un-reacted starting materials and/or by-products of the organic synthesis route. Suitable hueing agents can be incorporated into hueing dye particles, such as described in WO 2009/069077.


Dye transfer inhibitors: Suitable dye transfer inhibitors include polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidone, polyvinyloxazolidone, polyvinylimidazole and mixtures thereof. Preferred are poly(vinyl pyrrolidone), poly(vinylpyridine betaine), poly(vinylpyridine N-oxide), poly(vinyl pyrrolidone-vinyl imidazole) 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).


Perfume: Suitable perfumes comprise perfume materials selected from the group: (a) perfume materials having a ClogP of less than 3.0 and a boiling point of less than 250° C. (quadrant 1 perfume materials); (b) perfume materials having a ClogP of less than 3.0 and a boiling point of 250° C. or greater (quadrant 2 perfume materials); (c) perfume materials having a ClogP of 3.0 or greater and a boiling point of less than 250° C. (quadrant 3 perfume materials); (d) perfume materials having a ClogP of 3.0 or greater and a boiling point of 250° C. or greater (quadrant 4 perfume materials); and (e) mixtures thereof.


It may be preferred for the perfume to be in the form of a perfume delivery technology. Such delivery technologies further stabilize and enhance the deposition and release of perfume materials from the laundered fabric. Such perfume delivery technologies can also be used to further increase the longevity of perfume release from the laundered fabric. Suitable perfume delivery technologies include: perfume microcapsules, pro-perfumes, polymer assisted deliveries, molecule assisted deliveries, fiber assisted deliveries, amine assisted deliveries, cyclodextrin, starch encapsulated accord, zeolite and other inorganic carriers, and any mixture thereof. A suitable perfume microcapsule is described in WO2009/101593.


Silicone: Suitable silicones include polydimethylsiloxane and amino-silicones. Suitable silicones are described in WO05075616.


Process for making the solid composition: Typically, the particles of the composition can be prepared by any suitable method. For example: spray-drying, agglomeration, extrusion and any combination thereof.


Typically, a suitable spray-drying process comprises the step of forming an aqueous slurry mixture, transferring it through at least one pump, preferably two pumps, to a pressure nozzle. Atomizing the aqueous slurry mixture into a spray-drying tower and drying the aqueous slurry mixture to form spray-dried particles. Preferably, the spray-drying tower is a counter-current spray-drying tower, although a co-current spray-drying tower may also be suitable.


Typically, the spray-dried powder is subjected to cooling, for example an air lift. Typically, the spray-drying powder is subjected to particle size classification, for example a sieve, to obtain the desired particle size distribution. Preferably, the spray-dried powder has a particle size distribution such that weight average particle size is in the range of from 300 micrometers to 500 micrometers, and less than 10 wt % of the spray-dried particles have a particle size greater than 2360 micrometers.


It may be preferred to heat the aqueous slurry mixture to elevated temperatures prior to atomization into the spray-drying tower, such as described in WO2009/158162.


It may be preferred for anionic surfactant, such as linear alkyl benzene sulphonate, to be introduced into the spray-drying process after the step of forming the aqueous slurry mixture: for example, introducing an acid precursor to the aqueous slurry mixture after the pump, such as described in WO 09/158449.


It may be preferred for a gas, such as air, to be introduced into the spray-drying process after the step of forming the aqueous slurry, such as described in WO2013/181205.


It may be preferred for any inorganic ingredients, such as sodium sulphate and sodium carbonate, if present in the aqueous slurry mixture, to be micronized to a small particle size such as described in WO2012/134969.


Typically, a suitable agglomeration process comprises the step of contacting a detersive ingredient, such as a detersive surfactant, e.g. linear alkyl benzene sulphonate (LAS) and/or alkyl alkoxylated sulphate, with an inorganic material, such as sodium carbonate and/or silica, in a mixer. The agglomeration process may also be an in-situ neutralization agglomeration process wherein an acid precursor of a detersive surfactant, such as LAS, is contacted with an alkaline material, such as carbonate and/or sodium hydroxide, in a mixer, and wherein the acid precursor of a detersive surfactant is neutralized by the alkaline material to form a detersive surfactant during the agglomeration process.


Other suitable detergent ingredients that may be agglomerated include polymers, chelants, bleach activators, silicones and any combination thereof.


The agglomeration process may be a high, medium or low shear agglomeration process, wherein a high shear, medium shear or low shear mixer is used accordingly. The agglomeration process may be a multi-step agglomeration process wherein two or more mixers are used, such as a high shear mixer in combination with a medium or low shear mixer. The agglomeration process can be a continuous process or a batch process.


It may be preferred for the agglomerates to be subjected to a drying step, for example to a fluid bed drying step. It may also be preferred for the agglomerates to be subjected to a cooling step, for example a fluid bed cooling step.


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


It may be preferred for fines and over-sized agglomerates to be recycled back into the agglomeration process. Typically, over-sized particles are subjected to a size reduction step, such as grinding, and recycled back into an appropriate place in the agglomeration process, such as the mixer. Typically, fines are recycled back into an appropriate place in the agglomeration process, such as the mixer.


It may be preferred for ingredients such as polymer and/or non-ionic detersive surfactant and/or perfume to be sprayed onto base detergent particles, such as spray-dried base detergent particles and/or agglomerated base detergent particles. Typically, this spray-on step is carried out in a tumbling drum mixer.


Method of laundering fabric: The method of laundering fabric comprises the step of contacting the solid composition to water to form a wash liquor, and laundering fabric in said wash liquor. Typically, the wash liquor has a temperature of above 0° C. to 90° C., or to 60° C., or to 40° C., or to 30° C., or to 20° C. The fabric may be contacted to the water prior to, or after, or simultaneous with, contacting the solid composition with water. Typically, the wash liquor is formed by contacting the laundry detergent to water in such an amount so that the concentration of laundry detergent composition in the wash liquor is from 0.2 g/l to 20 g/l, or from 0.5 g/l to 10 g/l, or to 5.0 g/l. The method of laundering fabric can be carried out in a front-loading automatic washing machine, top loading automatic washing machines, including high efficiency automatic washing machines, or suitable hand-wash vessels. Typically, the wash liquor comprises 90 litres or less, or 60 litres or less, or 15 litres or less, or 10 litres or less of water. Typically, 200 g or less, or 150 g or less, or 100 g or less, or 50 g or less of laundry detergent composition is contacted to water to form the wash liquor.


EXAMPLES

Two laundry detergent compositions (Compositions 1 and 2) were made and tested as detailed herein below.


Test Method
I. Preparation of Test Compositions

Tests were carried out using the following detergent compositions: Material additions shown at active material level in finished product (FP).
















Level (% active FP)




Composition









Ingredient
Composition 1
Composition 2












LAS
13.5253
0.0000


AES
0.2700
0.0000


MCAS
0.0000
5.9248


Nonionic
0.5032
1.2644


Citric Acid
0.0057
60.0057


Sodium Silicate
8.5757
0.0000


Zeolite
0.0000
4.0000


Sodium Carbonate
12.1400
0.0000


Lipase
0.2557
0.0000


Mananase
0.0585
0.0000


Natalase
0.1142
0.0000


Protease
0.2568
0.0000


CMC
0.3250
0.0000


LB-Base
1.8463
0.0000


Hue dye (E42-10)
0.0269
0.0000


Brightener 15
0.0872
0.0000


Brightener 49
0.0388
0.0000


Sodium Sulphate
58.30505
26.1847


Sodium Chloride
0.0000
0.2626


HEDP
0.0000
0.6368


Perfume
0.4050
0.4564


Process aids, water and misc
3.2607
1.2646









II. Test Procedure















Wash Equipment
Washing machine
Kenmore Top Loader


Wash Equipment
Plastic 5 L bucket


Soak Volume
3 L


Wash Volume
60 L


Water Hardness
12 gpg
Soft plus spike 12 gpg 2:1 ratio Ca:Mg


Water Temperature
25° C.
Soak & wash & rinse


Detergent addition
Recco dose See below
Wash liquor formed from




Composition 1 pH = 10




Wash liquor formed from




Composition 2 pH = 2.7


Drying
30 mins <60 C.
Tumble drier medium heat


Krefeld
900N cotton fabric


Ballast load
2 Kg
Cotton/ PE mix


Drying equipment
Tumble drier
30 Min medium heat ~60 C.


Lloyd tensiometer
Fabric destruction



force analyzer










Preparation of Fabric for Fabric Strength Analysis Determination of formulation impact on fabric strength was completed using the following procedure.


Standard Hohenstein Krefeld fabric 900N strength was sourced for all test products. The standard cotton was cut into 40 cm pieces. Each of these pieces at the end of testing will generate 11 replicates for TSL testing. One 40 cm piece of fabric was used for each test leg.


At the start of the test the Krefeld fabric piece was subjected to soak conditions with the appropriate product, before being added to the 2 Kg ballast load in the drum of the washing machine for the wash step. Each strip of fabric was soaked, washed, and dried for 20 repeat cycles in the conditions described above. Detergent was added to the soak and wash steps as described above.


After washing and drying the pieces of standard cotton (the multiple washed ones) need to be prepared before Place the fabric strips in deionised water for 1 hour before measurement. One set of eleven replicates are soaked together in a 1 litre beaker taking care not to cause creasing in the strips.


Fabric Strength Analysis

Check the jaws of the tensiometer are 20 cm apart (±1 mm).


Remove excess water from each strip by squeezing by hand. Immediately mount test fabric.


Clamp the fabric between upper and lower jaws. & Activate the test.


Record the value of breaking point i.e. the amount of load which was required to break the fabric.


Repeat for all 11 replicates of this fabric and for all fabric samples.


All products from one test cycle should be tested at the same time.


Results below show the measured fabric strength for all replicates for each product measured in Force (N) required to snap the 900N Krefeld fabric and the average Force (N) required to snap the 900N Krefeld fabric for each product calculated as:


Average Force (N): sum of Replicates Force (N)/number of replicates (11).


20 Cycle Test Design:















Test A
Test B


















SOAK (2 hours)
24 g Composition 1
50 g Composition 2


WASH (15 mins)
120 g Composition 1
120 g Composition 1









20 Cycle Results:














Force (N) required to snap 900N Krefeld fabric









Rep/Composition
Test Leg A
Test Leg B












1
852.5
868.9


2
847.6
837.4


3
777.3
852.6


4
794.1
881.6


5
879.1
813.7


6
808.9
875.3


7
790.1
840.7


8
768.6
826.3


9
720.4
808.0


10
804.1
804.7


11
796.2
867.8


Average
804
843


T test vs A

7.51E−01


% conf difference vs A

24.89









The example demonstrates the efficacy of a composition 2 soak followed by a composition 1 wash, to deliver more fabric strength after 20 repeat cycles vs a composition 1 soak followed by a composition 1 wash.


The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.


Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.


While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims
  • 1. A method of laundering fabric wherein the method comprises the steps: (a) contacting from about 10 g to about 100 g of an acidic solid laundry detergent composition to from about 1.0 L to about 10.0 L of water to form an acidic aqueous wash bath having a pH in the range of from about 2.0 to about 3.0,wherein the acidic solid laundry detergent composition comprises from about 10 wt % to about 70 wt % acidic component, and from about 1.0 wt % to about 20 wt % detersive surfactant;(b) contacting soiled fabric to the acidic aqueous wash bath, and soaking the soiled fabric in the acidic aqueous wash bath for from about 1 hour to about 24 hours;(c) removing the soaked fabric from the acidic aqueous wash bath;(d) contacting from about 10 g to about 200 g of an alkaline solid laundry detergent composition to from about 1.0 L to about 70 L of water to form an alkaline aqueous wash bath having a pH in the range of from about 8.0 to about 12.0;wherein the alkaline solid laundry detergent composition comprises from about 3.0 wt % to about 50 wt % alkaline component and from about 1.0 wt % to about 30 wt % detersive surfactant;(e) contacting the soaked fabric from step (c) to the alkaline aqueous wash bath, and washing the soaked fabric in the alkaline aqueous wash bath for from about 10 mins to about 4 hours;(f) removing the washed fabric from the alkaline aqueous wash bath;(g) rinsing the washed fabric from step (f) with water.
  • 2. A method according to claim 1, wherein the acidic soaking step (b) is carried out under a mechanical agitation of less than about 10%.
  • 3. A method according to claim 1, wherein the alkaline washing step (e) is carried out under a mechanical agitation of about 10% or greater.
  • 4. A method according to claim 1, wherein during step (b) the soiled fabric is soaked in the acidic aqueous wash bath for from about 1 hour to about 4 hours.
  • 5. A method according to claim 1, wherein the acidic solid laundry detergent composition has about 30 wt % to about 70 wt % acidic component and from about 3.0 wt % to about 10 wt % detersive surfactant.
  • 6. A method according to claim 1, wherein the alkaline solid laundry detergent composition has about 3.0 wt % to about 30 wt % alkaline component and from about 5.0 wt % to about 20 wt % detersive surfactant.
  • 7. A method according to claim 1, wherein the ratio of (i) the concentration in ppm of surfactant present in the acidic aqueous wash bath to (ii) the concentration in ppm of surfactant present in the alkaline aqueous wash bath is in the range of from above about 2:1 to about 20:1.
  • 8. A method according to claim 1, wherein the acidic component is a polycarboxylic acid.
  • 9. A method according to claim 1, wherein the acidic component is citric acid.
  • 10. A method according to claim 1, wherein the alkaline component is sodium carbonate and/or sodium silicate.
  • 11. A method according to claim 1, wherein the detersive surfactant is selected from: alkyl benzene sulphonate, alkyl sulphate, alkoxylated alkyl sulphate, alkoxylated alcohol and any combination thereof.
Priority Claims (1)
Number Date Country Kind
23182160.4 Jun 2023 EP regional