EP3519542B1

EP3519542B1 - Domestic laundering method

Info

Publication number: EP3519542B1
Application number: EP17776999.9A
Authority: EP
Inventors: Stephen Norman Batchelor; Jayne Michelle Bird; David Stephen Grainger
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Priority date: 2016-09-27
Filing date: 2017-09-25
Publication date: 2020-02-19
Anticipated expiration: 2037-09-25
Also published as: AR109557A1; CN109790491B; PH12019500526B1; BR112019006017A2; EP3519542A1; PH12019500526A1; WO2018060139A1; ZA201901996B; CN109790491A

Description

Field of Invention

The present invention provides a method for cleaning clothes in domestic laundry.

Background of Invention

Main wash detergent formulations containing anionic surfactant for cleaning clothes surfactant are ubiquitous.
Rinse formulations containing quaternary ammonium compounds having at least one C12 to C22 alkyl chain for softening clothes are ubiquitous.
WO2013/087286 (Unilever) discloses liquids formulations containing alkyl ether carboxylic acids, betaines, anionic surfactant, non-ionic surfactant for providing softening benefits. US5269960 (Clorox) discloses liquid aqueous enzyme detergent containing enzymes, non-ionic surfactant, fatty acid and alkyl ether carboxylic acids that have enhanced physical and enzyme stability.
EP0154380 discloses a laundering agent which contains active detergent, builders, a combination of polyphosphate with zeolite as sequestering agent and, if desired, further usual additives, wherein the sequestering effect of the polyphosphate-zeolite combination is enhanced by an ethercarboxylic acid of the formula RO-(C2H4O)x-CH2COOM or R-CO-NH-(C2H4O)x-CH2COOM, wherein R is the residue of an aliphatic or alkyl aromatic hydrocarbon having at least 8 carbon atoms, x is a number having an average value of 0.5-20 and M is hydrogen or a cation permissible in laundering agents, said polyether carboxylic acid being present in an amount of 0.3 to 10 percent, preferably 0.3 to 5 percent, based on the entire composition.
US3741911 discloses a detergent composition, preferably phosphate-free, built using conventional builders, optionally including an organic sequestering agent, and contains as the active 15 system a coacervate system containing an alkyl or alkyl-aryl polyoxyalkylene carboxylic acid and a non-ionic detergent. The coacervate system is suitable for washing fabrics and for use in automatic dish washing machines.
Further wash methods for textiles are disclosed in GB 2 338 242 , WO 2013/087286 , GB 2 309 706 .

Summary of the Invention

There is a need to increase cleaning in wash methods that combine main wash detergent formulations containing anionic surfactant and rinse conditioners containing quaternary ammonium compound.
We have found that the use of a rinse conditioner containing quaternary ammonium compounds in combination with a main wash detergent containing an alkyl ether carboxylate provides enhanced cleaning benefits.
In one aspect the present invention provides a wash method, the wash method comprising the sequential steps of:

(i) agitating a textile garment in an aqueous solution of from 0.5 to 10g/L of a rinse conditioner, wherein the rinse conditioner comprises from 1 to 25 wt%, preferably 3 to 15 wt%, of a quaternary ammonium compound wherein in step (i) the quaternary ammonium compound has the general formula (I):

[W(R₁)(R₂)(R₃)(R₄)]_y X^- (I),

wherein:
- R₁, R₂, R₃ and R₄, are independently selected from a C1-C30 hydrocarbon group, optionally containing a heteroatom or an ester or amide group; wherein at least 1 one of R₁, R₂, R₃ and R₄ are selected from C10 to C20 hydrocarbons group;
- X is an anion; and,
- y is the valence of X;
(ii) drying the textile garment;
(iii) agitating the textile garment in an aqueous solution of from 0.5 to 10g/L of a main wash detergent formulation comprising from 5 to 40 wt%, preferably 10 to 20 wt%, of an anionic surfactant, the anionic surfactant providing from 0.02 to 1g/L, preferably 0.04 to 0.4g/L, of an alkyl ether carboxylic acid or carboxylate salt thereof of the following structure:

R-(OCH₂CH₂)_n-OCH₂-COOH,

wherein R is a saturated or mono-unsaturated C10 to C18 alkyl chain, preferably R is selected from the group consisting of: lauryl; stearyl; and;, oleyl alkyl chain, and n is greater than 4, more preferably from 5 to 20, most preferably from 10 to 20; and,
(iv) optionally treating again with the rinse conditioner and drying the fabric; wherein in step (iii) the main wash detergent formulation has a weight fraction of non-ionic surfactant/anionic surfactant of from 0 to 0.3.

The treatment steps (i) and (iii) preferably take from 5 to 120 minutes each.
The wt% of anionic surfactants are calculated as the sodium salt.

Detailed Description of the Invention

Where 'a' or 'an' is used in reference to a class of ingredients, this can refer equally to one or one or more of the ingredient (i.e. to a single ingredient, or to a mixture of two or more of the ingredients). For example 5 to 40 wt.% of an anionic surfactant can mean a single anionic surfactant or a mixture of anionic surfactants.

Rinse conditioner

In step (i) the quaternary ammonium compound has the general formula (I):

[W(R₁)(R₂)(R₃)(R₄)]_y X^- (I),

wherein:

R₁, R₂, R₃ and R₄, are independently selected from a C1-C30 hydrocarbon group, optionally containing a heteroatom or an ester or amide group; wherein at least 1 one of R₁, R₂, R₃ and
R₄ are selected from C10 to C20 hydrocarbons group;
X is an anion; and,
y is the valence of X

The quaternary ammonium compound preferably has the general formula (I):

[W(R₁)(R₂)(R₃)(R₄)]_y X^- (I)

wherein:

R₁, R₂, R₃ and R₄, are independently selected from a C1-C30 hydrocarbon group, optionally containing a heteroatom or an ester or amide group; wherein at least 1 one of R₁, R₂, R₃ and
R₄, preferably at least 2 of R₁, R₂, R₃ and R₄, are selected from C10 to C20 hydrocarbons group, preferably C12 to C18. Preferably the hydrocarbon groups are linear alkyl chains that are saturated or mono-unsaturated.
X is an anion; or example halide, such as Cl or Br, sulphate, alkyl sulphate, nitrate or acetate;
y is the valence of X.

Preferred examples of quaternary ammonium compounds are:

TET : Di(tallowcarboxyethyl)hydroxyethyl methyl ammonium methylsulfate;
TEO : Di(oleocarboxyethyl)hydroxyethyl methyl ammonium methylsulfate;
TES : Distearyl hydroxyethyl methyl ammonium methylsulfate;
TEHT : Di(hydrogenated tallow-carboxyethyl)hydroxyethyl methyl ammonium methylsulfate;
TEP : Di(palmiticcarboxyethyl)hydroxyethyl methyl ammonium methylsulfate;
DEEDMAC : Dimethylbis[2-[(1-oxooctadecyl)oxy]ethyl]ammonium chloride; and
DHT : Dihydrogenated tallowdimethylammonium chloride.
TEAQ : methyl bis-[ethyl (tallowoyl)]- 2-hydroxyethyl ammonium methyl sulphate.

Preferably the rinse conditioner has a pH of less than 7.More preferably the rinse conditioner has a pH of from 3 to 6.5.
Preferably the pH of the aqueous solution of step (i) is less than 7, more preferably from pH 3 to 6.5. This in use pH is provided by the rinse conditioner formulation. The in use pH can be measured for example by measuring an aqueous solution of the rinse conditioner dosed at 1g/L.
Preferably the rinse conditioner used in step (i) comprises at most 1% anionic surfactant. More preferably the rinse conditioner is free from anionic surfactant.
Preferably the rinse conditioner used in step (i) comprises at most 1% nonionic surfactant. More preferably the rinse conditioner is free from nonionic surfactant.

Main wash detergent

The main wash detergent formulation may be a powder, liquid or gel.
The main wash detergent formulation is preferably a non-phosphate laundry detergent formulation, i.e., contains less than 1 wt% of phosphate. In this art the term 'phosphate' embraces diphosphate, triphosphate, and phosphonate species.
Preferably the pH of the aqueous solution of step (iii) is from pH 7 to 11. This in use pH is provided by the main wash detergent formulation. The in use pH can be measured for example by measuring an aqueous solution of the main wash detergent dosed at 1g/L. Powder laundry detergent formulations are predominantly carbonate built, i.e. the weight% of sodium carbonate is greater than the weight % sum of other builder ingredient present, preferably the weight% level of other builder materials is less than 30%, more preferably less than 15 wt% of the weight% level of sodium carbonate. Powders, should preferably give an in use pH of from 9.5 to 11. Liquid detergent formulations should preferably give an in use pH of from 7 to 9.
Preferably the main wash detergent formulation are powder laundry detergent formulations. Preferably the main wash detergent formulations used in step (iii) comprises at most 1% quaternary ammonium compounds. More preferably the main wash detergent is free from quaternary ammonium compounds.
The main wash detergent formulation may be present in a polvyinylalcohol pouch for ease of dispensing.
The main wash detergent formulation may contain non-ionic surfactant wherein the weight fraction of non-ionic surfactant/anionic surfactant is from 0 to 0.3, preferably 0 to 0.15, most preferably 0 to 0.12;
Preferably the main wash detergent formulation contains from 0.002 to 0.2wt% of a subtilisin protease enzyme, preferably from 0.005 to 0.05 wt%;

Alkyl Ether Carboxylic acid

Alkyl Ether Carboxylic acid have the form: R-(OCH₂CH₂)_n-OCH₂-COOH, wherein R is saturated or mono-unsaturated C10 to C18 alkyl chain and n is greater than 4, preferably selected from 5 to 20, most preferably 10 to 20, even more preferably from 15 to 20.
Alkyl Ether Carboxylic acid may be used as salt version for example sodium salt, or amine salt. So for the avoidance of doubt, where the acid form of the alkyl ether carboxylic acid is stated, or depicted, it is also intended to include carboxylate salts of the acid form.
The alkyl chain is preferably selected from: oleyl, Palmitoleyl, CH₃(CH₂)₉-; CH₃(CH₂)₁₀-; CH₃(CH₂)_n-; CH₃(CH₂)₁₂-; CH₃(CH₂)₁₃-; CH₃(CH₂)₁₄-; CH₃(CH₂)₁₅-; CH₃(CH₂)₁₆-; and, CH₃(CH₂)₁₇-. More preferably CH₃(CH₂)₁₁-; CH₃(CH₂)₁7- and oleyl ; most preferably CH₃(CH₂)₁₇- and oleyl.
Alkyl ether carboxylic acid are available from Kao (Akypo ®), Huntsman (Empicol®) and Clariant (Emulsogen ®).
Alkyl ether carboxylic acids may be prepared by the modified Williamson synthesis:

R-(OCH₂CH₂)_n-OH+ NaOH +ClCH₂COONa → R-(OCH₂CH₂)_n-OCH₂COONa + NaCl + H₂O
An alternative is via on oxidation reaction with a Pt or Pd catalyst as described in DE3135946 ; DE2816127 and EP0304763 .
For powders the alkyl ether carboxylic acid dispersants is preferably added to the slurry before granulation of the detergent powder. Alternatively, it may be separately granulated and post-dosed or sprayed onto the finished powder.

Surfactants

The main wash detergent formulation comprises anionic charged surfactant (which includes a mixture of the same). Alkyl ether carboxylate are included as anionic charged surfactant.
Suitable anionic detergent compounds which may be used are usually water-soluble alkali metal or amine salts of fatty acids (soaps), organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher alkyl radicals.
Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher C₈ to C₁₈ alcohols, produced for example from tallow or coconut oil, sodium and potassium alkyl C₉ to C₂₀ benzene sulphonates, particularly sodium linear secondary alkyl C₁₀ to C₁₅ benzene sulphonates; and sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum.
The anionic surfactant is preferably selected from: linear alkyl benzene sulphonate; alkyl sulphates; alkyl ether sulphates; soaps; alkyl (preferably methyl) ester sulphonates, and mixtures thereof.
The most preferred anionic surfactants are selected from: linear alkyl benzene sulphonates; alkyl sulphates; soaps; alkyl ether sulphates and mixtures thereof. Preferably the alkyl ether sulphate is a C₁₂-C₁₄ n-alkyl ether sulphate with an average of 1 to 3EO (ethoxylate) units. Sodium lauryl ether sulphate is particularly preferred (SLES). Preferably the linear alkyl benzene sulphonate is a sodium C₁₁ to C₁₅ alkyl benzene sulphonates (LAS). Preferably the alkyl sulphates is a linear or branched sodium C₁₂ to C₁₈ alkyl sulphates. Sodium dodecyl sulphate is particularly preferred, (SDS, also known as primary alkyl sulphate). Soaps are preferably C₁₂ to C₁₈ saturated fatty acids, preferably they are present at levels of less than 3wt% of the formulation.
In carbonate built powder detergent, it is preferable in the composition that LAS is the dominant anionic surfactant present. It is preferably that >80wt% of the anionic surfactant present is LAS.
In liquid detergents, it is preferably that >70wt% of the anionic surfactant are selected from LAS and SLES.
Non-ionic surfactant may be present in the surfactant mix.
Suitable nonionic detergent compounds which may be used include, in particular, the reaction products of compounds having an aliphatic hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids or amides, especially ethylene oxide either alone or with propylene oxide. Preferred nonionic detergent compounds are the condensation products of aliphatic C₈ to C₁₈ primary or secondary linear or branched alcohols with ethylene oxide.
Preferably the non-ionic surfactant is an alkyl ethoxylated non-ionic surfactant and is a C₈ to C₁₈ primary alcohol, most preferably a C₁₂-C₁₆ primary alcohol, with an average ethoxylation of 7EO to 9EO units.

Protease

Subtilisin protease enzymes (EC 3.4.21.62) hydrolyse bonds within peptides and proteins, in the laundry context this leads to enhanced removal of protein or peptide containing stains. Subtilisin protease enzymes are members of the subtilase type serine proteases family.
The Serine protease families are described in the MEROPS peptidase database (http://merops.sanger.ac.uk/). The term "subtilases" refers to a sub-group of serine protease according to Siezen et al., Protein Engng. 4 (1991) 719-737 and Siezen et al. Protein Science 6 (1997) 501 -523. Serine proteases are a subgroup of proteases characterized by having a serine in the active site, which forms a covalent adduct with the substrate. The subtilases may be divided into 6 sub-divisions, of which the Subtilisin family is one.
Examples of subtilases are those derived from Bacillus such as Bacillus lentus, B. alkalophilus, B. subtilis, B. amyloliquefaciens, Bacillus pumilus and Bacillus gibsonii described in; US7262042 and WO09/021867 , and subtilisin lentus, subtilisin Novo, subtilisin Carlsberg, Bacillus licheniformis, subtilisin BPN', subtilisin 309, subtilisin 147 and subtilisin 168 described in WO89/06279 and protease PD138 described in ( WO93/18140 ). Further proteases are described in: WO92/19729 , WO96/034946 , WO98/201 15 , WO98/201 16 , WO99/01 1768 , WO01/44452 , WO03/006602 , WO04/03186 , WO04/041979 , WO07/006305 , WO1 1/036263 , WO1 1/036264 , especially the variants with substitutions in one or more of the following positions: 3, 4, 9, 15, 27, 36, 57, 68, 76, 87, 95, 96, 97, 98, 99, 100, 101 , 102, 103, 104, 106, 1 18, 120, 123, 128, 129, 130, 160, 167, 170, 194, 195, 199, 205, 206, 217, 218, 222, 224, 232, 235, 236, 245, 248, 252 and 274 using the BPN' numbering. More preferred the subtilase variants may comprise the mutations: S3T, V4I, S9R, A15T, K27R, *36D, V68A, N76D, N87S,R, *97E, A98S, S99G,D,A, S99AD, S101 G,M,R S103A, V104I,Y,N, S106A, G1 18V,R, H120D,N, N123S, S128L, P129Q, S130A, G160D, Y167A, R170S, A194P, G195E, V199M, V205I, L217D, N218D, M222S, A232V, K235L, Q236H, Q245R, N252K, T274A (using BPN' numbering).
Most preferably the subtilisin is derived from Bacillus gibsonii or Bacillus Lentus.
The use of protease provides enhances cleaning in combination with the method.
For powder inclusion the protease enzyme is preferably granulated and post-dosed into the powder. Preferably the enzyme granules have a particle size smaller than 2 mm, as determined using graded sieves. Most preferably the enzyme granules have a particle size from 0.2 to 1.5mm as determined using graded sieves.
Subtilisin are commercially available, for example, from Novozymes™ and Genencor™
For powders the alkyl ether carboxylic acid dispersants is preferably added to the slurry before granulation of the detergent powder. Alternatively, it may be separately granulated and post-dosed or sprayed onto the finished powder.

Builders or Complexing Agents

The main wash formulation preferably contains a builder or complexing agent. Builder materials may be selected from 1) calcium sequestrant materials, 2) precipitating materials, 3) calcium ion-exchange materials and 4) mixtures thereof.
Examples of calcium sequestrant builder materials include alkali metal polyphosphates, such as sodium tripolyphosphate and organic sequestrants, such as ethylene diamine tetra-acetic acid.
Examples of precipitating builder materials include sodium orthophosphate and sodium carbonate.
Examples of calcium ion-exchange builder materials include the various types of water-insoluble crystalline or amorphous aluminosilicates, of which zeolites are the best known representatives, e.g. zeolite A, zeolite B (also known as zeolite P), zeolite C, zeolite X, zeolite Y and also the zeolite P-type as described in EP-A-0,384,070 .
The main wash formulation may also contain 0-65 % of a builder or complexing agent such as ethylenediaminetetraacetic acid, diethylenetriamine-pentaacetic acid, alkyl- or alkenylsuccinic acid, nitrilotriacetic acid or the other builders mentioned below. Many builders are also bleach-stabilising agents by virtue of their ability to complex metal ions.
Zeolite and carbonate (including bicarbonate and sesquicarbonate) are preferred builders for powder detergents.
The main wash formulation may contain as builder a crystalline aluminosilicate, preferably an alkali metal aluminosilicate, more preferably a sodium aluminosilicate. This is typically present at a level of less than 5%wt. Aluminosilicates are materials having the general formula:

0.8-1.5 M₂O. Al₂O₃. 0.8-6 SiO2

where M is a monovalent cation, preferably sodium. These materials contain some bound water and are required to have a calcium ion exchange capacity of at least 50 mg CaO/g. The preferred sodium aluminosilicates contain 1.5-3.5 SiO₂ units in the formula above. They can be prepared readily by reaction between sodium silicate and sodium aluminate, as amply described in the literature.
Alternatively, or additionally to the aluminosilicate builders, other forms of builder include silicates, such as soluble silicates, metasilicates, layered silicates (e.g. SKS-6 from Hoechst) may be present.
Spray drying of the powder detergent is preferred.

Fluorescent Agent

The main wash formulation preferably comprises a fluorescent agent (optical brightener). Fluorescent agents are well known and many such fluorescent agents are available commercially. Usually, these fluorescent agents are supplied and used in the form of their alkali metal salts, for example, the sodium salts. The total amount of the fluorescent agent or agents used in the composition is generally from 0.005 to 2 wt %, more preferably 0.01 to 0.1 wt %. Preferred classes of fluorescer are: Di-styryl biphenyl compounds, e.g. Tinopal (Trade Mark) CBS-X, Di-amine stilbene di-sulphonic acid compounds, e.g. Tinopal DMS pure Xtra and Blankophor (Trade Mark) HRH, and Pyrazoline compounds, e.g. Blankophor SN. Preferred fluorescers 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.
It is preferred that the main wash aqueous solution used in the method has a fluorescer present. When a fluorescer is present in the aqueous solution used in the method it is preferably in the range from 0.0001 g/l to 0.1 g/l, preferably 0.001 to 0.02 g/l.

Perfume

Preferably the rinse conditioner and main wash formulation both comprises a perfume. The perfume is preferably in the range from 0.001 to 3 wt %, most preferably 0.1 to 1 wt %. Many suitable examples of perfumes are provided in the CTFA (Cosmetic, Toiletry and Fragrance Association) 1992 International Buyers Guide, published by CFTA Publications and OPD 1993 Chemicals Buyers Directory 80th Annual Edition, published by Schnell Publishing Co.
It is commonplace for a plurality of perfume components to be present in a formulation. In the compositions of the present invention it is envisaged that there will be four or more, preferably five or more, more preferably six or more or even seven or more different perfume components. Encapsulated perfume may be used.
In perfume mixtures preferably 15 to 25 wt% are top notes. Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80 [1955]). Preferred top-notes are selected from citrus oils, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol.
Perfume and top note may be used to cue the cleaning and whiteness benefit of the invention.

Polymers

The main wash formulation may comprise one or more further polymers. Examples are carboxymethylcellulose, ethoxylated polyethyleneimine (EPEI), polymeric ester of aromatic dicarboxylic acids, poly (ethylene glycol), poly(vinyl alcohol), polycarboxylates such as polyacrylates, maleic/acrylic acid copolymers and lauryl methacrylate/acrylic acid copolymers. EPEI is preferably a base (unreacted) polyethylene imine of 400 to 1200 molecular weight that has been ethoxylated with 10 to 30 mole equivalent of ethylene oxide per N-H in the a base (unreacted) polyethylene imine.

Further Enzymes

One or more further enzymes are preferred present in main wash formulation and when practicing a method of the invention.
Preferably the level of each further enzyme in the main wash formulation of the invention is from 0.0001 wt% to 0.1 wt% protein.
The further enzyme is preferably selected from: amylases, Mannanases, lipases; and, cellulases, most preferably amylases and lipases. Suitable lipases include those sold under the tradenames lipex®, Lipoclean® and Lipolex® by Novozymes, Bagsvaerd Denmark.
Any enzyme present in the main wash formulation may be stabilized using conventional stabilizing agents, e.g., a polyol such as propylene glycol or glycerol, a sugar or sugar alcohol, lactic acid, boric acid, or a boric acid derivative, e.g., an aromatic borate ester, or a phenyl boronic acid derivative such as 4-formylphenyl boronic acid, and the composition may be formulated as described in e.g. WO 92/19709 and WO 92/19708 .

Shading Dyes

Shading dyes are preferably present in the main wash formulation formulation at a level from 0.002 to 0.2 wt%.
Dyes are described in Color Chemistry Synthesis, Properties and Applications of Organic Dyes and Pigments, (H Zollinger, Wiley VCH, Zurich, 2003) and, Industrial Dyes Chemistry, Properties Applications. (K Hunger (ed), Wiley-VCH Weinheim 2003).
Shading Dyes for use in laundry detergents preferably have an extinction coefficient at the maximum absorption in the visible range (400 to 700nm) of greater than 5000 L mol^-1 cm^-1, preferably greater than 10000 L mol^-1 cm^-1. The dyes are blue or violet in colour.
Preferred shading dye chromophores are azo, azine, anthraquinone, and triphenylmethane.
Azo, anthraquinone, phthalocyanine and triphenylmethane dyes preferably carry a net anionic charged or are uncharged. Azine preferably carry a net anionic or cationic charge.
Blue or violet shading dyes deposit to fabric during the wash or rinse step of the washing process providing a visible hue to the fabric. In this regard the dye gives a blue or violet colour to a white cloth with a hue angle of 240 to 345, more preferably 250 to 320, most preferably 250 to 280. The white cloth used in this test is bleached non-mercerised woven cotton sheeting.
Shading dyes are discussed in WO2005/003274 , WO2006/032327 (Unilever),
WO 2006/032397 (Unilever), WO2006/045275 (Unilever), WO06/027086 (Unilever),
WO 2008/017570 (Unilever), WO 2008/141880 (Unilever), WO2009/132870 (Unilever),
WO 2009/141173 (Unilever), WO 2010/099997 (Unilever), WO 2010/102861 (Unilever),
WO 2010/148624 (Unilever), WO2008/087497 (P&G), WO2011/011799 (P&G),
WO2012/054820 (P&G), WO2013/142495 (P&G), and WO2013/151970 (P&G).
Mono-azo dyes preferably contain a heterocyclic ring and are most preferably thiophene dyes. The mono-azo dyes are preferably alkoxylated and are preferably uncharged or anionically charged at pH=7. Alkoxylated thiophene dyes are discussed in WO/2013/142495 and WO/2008/087497 . Preferred examples of thiophene dyes are shown below:
and,
Bis-azo dyes are preferably sulphonated bis-azo dyes. Preferred examples of sulphonated bis-azo compounds are direct violet 7, direct violet 9, direct violet 11, direct violet 26, direct violet 31, direct violet 35, direct violet 40, direct violet 41, direct violet 51, Direct Violet 66, direct violet 99 and alkoxylated versions thereof. Alkoxylated bis-azo dyes are discussed in WO2012/054058 and WO2010/151906 .. An example of an alkoxylated bis-azo dye is:
Azine dye are preferably selected from sulphonated phenazine dyes and cationic phenazine dyes. Preferred examples are acid blue 98, acid violet 50, dye with CAS-No 72749-80-5, acid blue 59, and the phenazine dye selected from:
wherein:

X₃ is selected from: -H; -F; -CH₃; -C₂H₅; -OCH₃; and, -OC₂H₅;
X₄ is selected from: -H; -CH₃; -C₂H₅; -OCH₃; and, -OC₂H₅;
Y₂ is selected from: -OH; -OCH₂CH₂OH; -CH(OH)CH₂OH; -OC(O)CH₃; and, C(O)OCH₃

The shading dye is present is present in the composition in range from 0.0001 to 0.5 wt %, preferably 0.001 to 0.1 wt%. Depending upon the nature of the shading dye there are preferred ranges depending upon the efficacy of the shading dye which is dependent on class and particular efficacy within any particular class. As stated above the shading dye is a blue or violet shading dye.
A mixture of shading dyes may be used.
The dyes are listed according to Colour Index (Society of Dyers and Colourists/American Association of Textile Chemists and Colorists) classification.
For ease of use it is preferred if the carbonate built powder detergent formulations are present in 0.5 to 5kg packs.

Experimental

Example 1:

The following powder formulation was produced:

Ingredient	Weight%
Sodium LAS	8.0
Sodium Silicate	7.1
Light soda ash	22.9
Sodium sulphate	59.4
Sokalan CP5 (BASF)	0.4
Sodium carboxy methyl cellulose	0.1
Fluorescer (Tinopal CBSx ex BASF)	0.02
moisture	remainder

The following rinse conditioner formulation was produced:

Ingredient Weight%

methyl bis-[ethyl (tallowoyl)]- 2-hydroxyethyl ammonium methyl sulphate 11.7

1M HCL 0.01

Water and Minors including antifoam and perfume remainder
Eight, 5 x 5cm, white knitted cotton pieces were agitated in 800ml of 26° French Hard water at 25°C for 1 hour in a tergotometer (200 rpm) this provide control fabric. Eight, 5 x 5cm, white knitted cotton pieces were agitated in 800 ml of 26° French Hard water containing 0.8 g/L of the rinse conditioner formulation at 25°C for 1 hour in a tergotometer (200rpm), this provided rinse conditioner treated fabric. The fabric was then dried in air for 24 hours. The powder detergent was used at 2g/L to wash the eight, 5 x 5cm, control white knitted cotton pieces in 800ml of 26 French Hard water at 37.5°C for 1 hour in a tergotometer (200rpm). 0.04g/L of 100% compressed Carbon Black (Alfa Aesur) was added to the wash liquor, alongside 1/3^rd sheet/L of an SBL2004 soil sheet cut into 20 equal sized pieces. This simulates oily soil in the wash and deposition of carbon based particulates. Following the wash the swatches are rinsed in 400ml 26 26 French Hard water and dried in air. The colour of the cloth was measured using a reflectometer and expressed as the CIE L*a*b* values. The experiment was repeated with using the rinse conditioner treated fabrics. The entire experiment was then repeated but with the addition of 0.2g/L of alkyl ether carboxylate (oleyl, 10EO) to the main wash solution.
The results are summarised in the table below

Rinse treated with water Rinse treated with rinse conditioner

L* 95% L* 95%

Main wash control 73.6 0.4 71.5 0.4

Main wash with alkyl ether carboxylate 77.2 0.4 81.0 0.3
In the main wash control washed clothes, the rinse conditioner treated cloths were dirtier (L*=71.5) than the control (L*=73.6). However, in the main wash with alkyl ether carboxylate washed clothes the clothes treated with rinse conditioner were cleaner (L*=81.0) than the control (L*=77.2).
Treatment with rinse conditioner then a main wash with alkyl ether carboxylate provides the best cleaning, as evidenced by the greatest L* value (81.0).

Example 2

The experiment of example 1 was repeated. In the experiment, no prior rinse step was conducted. The fabric was washed in the powder formulation plus or minus the addition of 0.2g/L of alkyl ether carboxylate (oleyl, 10EO) to the wash solution and with the powder formulation and rinse conditioner added to the wash solution again plus or minus the addition of 0.2g/L of alkyl ether carboxylate (oleyl, 10EO).

The results are shown in the table below

	L*	95%
Main wash detergent control	73.3	0.3
Main wash detergent with alkyl ether carboxylate	76.6	0.5
Main wash detergent & rinse conditioner control	74.5	0.3
Main wash detergent & rinse conditioner with alkyl ether carboxylate	77.2	0.3

For use of the main wash detergent alone, there is good agreement with the results of experiment 1 and experiment 2, with L* values of 73.6 and 73.3 which are within the 95% confidence limits.
This is also true for the main wash detergent with alkyl ether carboxylate, with L* of 77.2 and 76.6 for experiment 1 and experiment 2 respectively, again with the 95% confidence limits. When the main wash detergent and rinse conditioner are used together in a method that combines the rinse conditioner with quaternary ammonium compound and main wash detergent in the same step the L* is 74.5 and increases to 77.2 on further addition of alkyl ether carboxylate. The benefit of alkyl ether carboxylate for main wash detergent alone is 76.6-73.3 = 3.3 and for main wash detergent with rinse conditioner in the same step 77.2-74.5 = 2.7. There is no additional advantage to using alkyl ether carboxylate in the method that combines the main wash detergent and rinse conditioner in the same step. This is in contrast to example 1 where increased performance is seen when the rinse conditioner and main wash detergent are used sequentially.

Claims

A wash method, the wash method comprising the sequential steps of:
(i) agitating a textile garment in an aqueous solution of from 0.5 to 10g/L of a rinse conditioner, wherein the rinse conditioner comprises from 1 to 25 wt% of a quaternary ammonium compound wherein in step (i) the quaternary ammonium compound has the general formula (I):

[N⁺(R₁)(R₂)(R₃)(R₄)]_y X^- (I),

wherein:
R₁, R₂, R₃ and R₄, are independently selected from a C1-C30 hydrocarbon group, optionally containing a heteroatom or an ester or amide group; wherein at least one of R₁, R₂, R₃ and R₄ are selected from C10 to C20 hydrocarbons group;

X is an anion; and,

y is the valence of X;

(ii) drying the textile garment;

(iii) agitating the textile garment in an aqueous solution of from 0.5 to 10g/L of a main wash detergent formulation comprising from 5 to 40 wt% of an anionic surfactant, the anionic surfactant providing from 0.02 to 1g/L, of an alkyl ether carboxylic acid or carboxylate salt thereof of the following structure:

R-(OCH₂CH₂)_n-OCH₂-COOH,

wherein R is a saturated or mono-unsaturated C10 to C18 alkyl chain and n is greater than 4, most preferably from 10 to 20; and,

(iv) optionally treating again with the rinse conditioner and drying the fabric;
wherein in step (iii) the main wash detergent formulation has a weight fraction of non-ionic surfactant/anionic surfactant of from 0 to 0.3.
A wash method according to claim 1, wherein in step (iii) from 0.04 to 0.4g/L of the alkyl ether carboxylic acid or carboxylate salt thereof is present.
A wash method according to claim 1 or 2, wherein R is selected from the group consisting of: lauryl; stearyl; and, oleyl alkyl chain and n is selected from 5 to 20.
A wash method according to any one of the preceding claims, wherein in step (i) 3 to 15 wt% of a quaternary ammonium compound is present.
A wash method according to any one of the preceding claims, wherein in step (iii) the main wash detergent formulation comprises from 10 to 20 wt% of an anionic surfactant.
A wash method according to any one of the preceding claims, wherein in step (iii) the main wash detergent formulation contains less than 1 wt% of phosphate.
A wash method according to any one of the preceding claims, wherein in step (iii) the anionic surfactant, other than the alkyl ether carboxylic acid or carboxylate salt thereof, is selected from: linear alkyl benzene sulphonates; alkyl sulphates; soaps; alkyl ether sulphates; and, mixtures thereof.
A wash method according to any one of the preceding claims, wherein in step (iii) the main wash detergent formulation comprises from 0.002 to 0.2wt% of a subtilisin protease enzyme.
A wash method according to any one of the preceding claims, wherein the pH of the aqueous solution of step (i) is less than 7, more preferably from pH 3 to 6.5, wherein said in use pH is provided by the rinse conditioner formulation.
A wash method according to any one of the preceding claims, wherein the pH of the aqueous solution of step (iii) is from pH 7 to 11, wherein said in use pH is provided by the main wash detergent formulation.
A wash method according to any one of the preceding claims, wherein the rinse conditioner used in step (i) comprises at most 1% anionic surfactant, preferably the rinse conditioner is free from anionic surfactant.
Awash method according to any one of the preceding claims, wherein the rinse conditioner used in step (i) comprises at most 1% nonionic surfactant, preferably the rinse conditioner is free from nonionic surfactant.
A wash method according to any one of the preceding claims, wherein the main wash detergent formulations used in step (iii) comprises at most 1% quaternary ammonium compounds, preferably the main wash detergent is free from quaternary ammonium compounds.