LIQUID LAUNDRY DETERGENT COMPOSITION
Field of Invention
The present invention provides an enzymatic and dispersant formulation for use in domestic laundry.
Background of Invention
Isotropic laundry liquid detergent formulations containing a high fraction of anionic surfactant relative to non-ionic surfactant are ubiquitous. Protease enzymes are used in Isotropic Laundry detergent formulations to remove protein containing stains from fabrics.
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. DE 3320340 discloses laundry detergent formulations containing and alkyl ether carboxylate with 4.5 ethoxylate units and protease enzyme. In Example A of DE 3320340 it is shown that such formulations do not stabilise the protease enzyme during storage. In Example B, D and E of DE 3320340 formulations containing alkyl ether carboxylate with 3.8 ethoxylate units and protease enzyme are stabilized for some proteases.
There is a need to increase stain removal in isotropic Laundry detergent formulations containing a high fraction of anionic surfactant relative to non-ionic surfactant.
Summary of the Invention
Surprisingly the combination of a protease with specific alkyl ether carboxylic acid, provides enhanced cleaning and stain removal.
In one aspect the present invention provides an isotropic laundry liquid detergent formulation comprising:
(i) from 10 to 40 wt% of a surfactant selected from: anionic and non-ionic surfactants, preferably from 12 to 25 wt%, more preferably 14 to 21 wt%, 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;
(ii) from 2 to 10 wt%, preferably 3 to 8 wt%, most preferably 3 to 6 wt% of an alkyl ether carboxylic acid dispersant of the following structure:
R-(OCH2CH2)n-OCH2-COOH, wherein:
R is selected from saturated C8 to C18 linear alkyl chains, preferably C12, to C18 linear alkyl chains, more preferable a C12 or C18 linear alkyl chain, most preferably a C12 linear alkyl chain;
n is the average ethoxylation and n is selected from 5 to 20, preferably 7 to 14, more preferably 8 to 12, most preferably 9 to 1 1 and,
(iii) from 0.002 to 0.2wt% of a subtilisin protease enzyme, preferably from 0.005 to 0.05 wt%.
Subtilisin protease enzymes are members of the subtilase type serine proteases family.
The wt% of anionic surfactants are calculated as the sodium salt. The wt% of the alkyl ether carboxylic acid dispersant is calculated as the COOH form. The wt% of protease enzyme is/are for the pure active protein.
In another aspect the present invention provides a domestic method of treating a textile, the method comprising the step of: treating a textile with an aqueous solution of 0.5 to 20 g/L of the laundry detergent composition as defined herein. Preferably the aqueous laundry detergent solution to remains in contact with the textile for 10 minutes to 2 days then rinsing and drying the textile.
Detailed Description of the Invention
Detergent format
The laundry detergent formulation is 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.
The laundry detergent is an aqueous isotropic liquid laundry detergent, preferably with a pH of from 7 to 9.
The detergent formulation may be present in a polvyinylalcohol pouch for ease of dispensing.
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.sanqer.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: W092/19729, WO96/034946, WO98/201 15, WO98/201 16, WO99/01 1768, WO01/44452, WO03/006602, WO04/03186, WO04/041979, WO07/006305, W01 1/036263, W01 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.
Subtilisin are commercially available, for example, from Novozymes™ and Genencor™
Alkyl Ether Carboxylic acid
In the context of the current invention alkyl ether carboxylic acid dispersants are not included as anionic surfactants. Weights of alkyl ether carboxylic acid are calculated as the protonated form, R-(OCH2CH2)n-OCH2COOH. They may be used as salt version for example sodium salt, or amine salt.
The alkyl chain is aliphatic and linear and may be selected from: CH3(CH2)7-; CH3(CH2)8-;
CH3(CH2)9-; CH3(CH2)io-; CH3(CH2)l1-; CH3(CH2)l2-; CH3(CH2)l3-; CH3(CH2)l4-; CH3(CH2)l5-;
CH3(CH2)i6-;and CH3(CH2)i7-; The alkyl chain is preferably selected from CH3(CH2)n- and CH3(CH2)i7- The alkyl ether carboxylic acid is most preferably of the structure:
CH3 (CH2)ii(OCH2CH2)ioOCH2COOH.
Alkyi ether carboxylic acid are available from Kao (Akypo ®), Huntsman (Empicol®) and Clariant (Emulsogen ®)
Alkyi ether carboxylic acids may be prepared by the modified Williamson synthesis:
R-(OCH2CH2)n-OCH2COOH+ NaOH +CICH2COONa→
R-(OCH2CH2)n-OCH2COONa + NaCI + H20
An alternative is via on oxidation reaction with a Pt or Pd catalyst as described in
DE3135946; DE2816127 and EP0304763.
Surfactants
The laundry composition comprises anionic charged surfactant (which includes a mixture of the same). 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 alkyi radicals containing from about 8 to about 22 carbon atoms, the term alkyi being used to include the alkyi portion of higher alkyi radicals. Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyi sulphates, especially those obtained by sulphating higher Cs to Cis alcohols, produced for example from tallow or coconut oil, sodium and potassium alkyi Cg to C20 benzene sulphonates, particularly sodium linear secondary alkyi Cio to C15 benzene sulphonates; and sodium alkyi 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 alkyi benzene sulphonate; alkyi sulphates; alkyi ether sulphates; soaps; alkyi (preferably methyl) ester sulphonates, and mixtures thereof.
The most preferred anionic surfactants are selected from: linear alkyi benzene sulphonates ; alkyi sulphates; soaps; alkyi ether sulphates and mixtures thereof. Preferably the alkyi ether sulphate is a Ci2-Ci4 n-alkyl ether sulphate with an average of 1 to 3EO (ethoxylate) units. Sodium lauryl ether sulphate is particularly preferred (SLES). Preferably the linear alkyi benzene sulphonate is a sodium Cn to C15 alkyi 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 Cis saturated fatty acids, preferably they are present at levels of less than 3wt% of the formulation.
The level of anionic surfactant in the laundry composition is from (i) 10 to 40 wt% of the formulations. It is preferable that LAS is the dominate anionic surfactant present.
In Isotropic Laundry detergent formulations preferably two or more anionic surfactant are present, preferably linear alkyl benzene sulphonate together with an alkyl ether sulphate.
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 Cs to Cis 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 Cs to C18 primary alcohol, most preferably a C12-C16 primary alcohol, with an average ethoxylation of 7EO to 9EO units. Builders or Complexinq Agents
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.
The Builder is preferably an organic sequestrant containing carboxylic acid groups. The most preferred builder is citric acid.
Fluorescent Agent
The composition 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 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 composition 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.
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.
It is preferred that the detergent formulations of the invention does not contain a peroxygen bleach, e.g., sodium percarbonate, sodium perborate, and peracid. Polymers
The composition may comprise one or more further polymers. Examples are
carboxymethylcellulose, poly (ethylene glycol), polyvinyl alcohol), polycarboxylates such as polyacrylates, maleic/acrylic acid copolymers and lauryl methacrylate/acrylic acid copolymers.
Further Enzymes
One or more further enzymes are preferred present in a laundry composition of the invention and when practicing a method of the invention.
Preferably the level of each further enzyme in the laundry composition 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 composition 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 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 2009/141 173 (Unilever), WO 2010/099997 (Unilever), WO 2010/102861 (Unilever), WO 2010/148624 (Unilever), WO2008/087497 (P&G), WO201 1/01 1799 (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:
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 1 1 , 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:
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(0)CH3; and, C(0)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 shading dye is most preferably a reactive blue anthraquinone dye covalently linked to an alkoxylated polyethyleneimine. The alkoxylation is preferably selected from ethoxylation and propoxylation, most preferably propoxylation. Preferably 80 to 95 mol% of the N-H groups in the polyethylene imine are replaced with iso-propyl alcohol groups by propoxylation.
Preferably the polyethylene imine before reaction with the dye and the propoxylation has a molecular weight of 600 to 1800.
An example structure of a preferred reactive anthraquinone covalently attached to a propoxylated polyethylene imine is:
(Structure I).
Preferred reactive anthraquinone dyes are: Reactive blue 1 ; Reactive blue 2; Reactive blue 4; Reactive blue 5; Reactive blue 6; Reactive blue 12; Reactive blue 16; reactive blue 19;
Reactive blue 24 ; Reactive blue 27; Reactive blue 29; Reactive blue 36; Reactive blue 44;
Reactive blue 46 ; Reactive blue 47; reactive blue 49; Reactive blue 50; Reactive blue 53;
Reactive blue 55; Reactive blue 61 ; Reactive blue 66; Reactive blue 68; Reactive blue 69;
Reactive blue 74; Reactive blue 86; Reactive blue 93; Reactive blue 94; Reactive bluel 01 ; Reactive bluel 03; Reactive bluel 14; Reactive bluel 17; Reactive bluel 25; Reactive blue141 ; Reactive blue142; Reactive blue 145; Reactive blue 149; Reactive blue 155;
Reactive blue 164; Reactive blue 166; Reactive blue 177; Reactive blue 181 ; Reactive blue
185; Reactive blue 188; Reactive blue 189; Reactive blue 206; Reactive blue 208; Reactive blue 246; Reactive blue 247; Reactive blue 258; Reactive blue 261 ; Reactive blue 262; Reactive blue 263; and Reactive blue 172.
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 Isotropic Laundry detergent formulations are present in 0.5 to 5 kg packs.
Experimental Example 1 An aqueous liquid laundry detergent was prepared of the following formulation:
The weight fraction of non-ionic surfactant/anionic surfactant is 2.1/(8.4+10.5)=1/9=0.1 1 .
The formulation was used to wash eight 5x5cm EMPA 1 17 stain monitor (blood/milk/ink stain on polycotton) in a tergotometer set at 200rpm. A 60 minute wash was conducted in 800ml of 26° French Hard water at room temperature (293K), with 2.3g/L of the formulation. To simulate oily soil (7.5 g) of an SBL2004 soil strip (ex Warwick Equest) cut into 4 equal pieces was added to the wash liquor.
Once the wash had been completed the cotton monitors were rinsed once in 400ml clean water, removed dried and the colour measured on a reflectometer and expressed as the CIE L*a*b* values.
An equivalent Formulations but with the addition of 8.7wt% alkyl ether carboxylic acid, wherein the alkyl group was linear C12 (lauryl), was tested. The average number of ethoxy groups was 10. Experiments were repeated with and without the addition of a subtilisin serine protease ((EC no. 232-752-2) to the wash liquor (Evity® 16L ex Novozymes). The enzyme was added to give 0.018 wt% pure active protein to the formulation.
The stain removal was measured as ΔΙ_, wherein:
ΔΙ_ = L(test formulation) - L(control)
A larger ΔΙ. value indicates more stain removal. 95% confidence limits are also given calculated from the standard deviation on the measurements from the 8 monitors.
The results are given in the table below
The combination of the protease enzyme and alkyl ether carboxylic acid than expected from combination of the effects of the single components. For the combination a ΔΙ_* = 5.4 + 3.2 = 8.6 would be expected but 12.0 obtained.
The formulation was remade with the addition of mix of amylase, mannase and pectinase enzymes (Stainzyme ® Novozyme, Mannaway ® Novozymes, Pectawash ® Novozymes)
Examples of Isotropic liquid formulation
Nl (9EO) is a C12-C15 alcohol ethoxylate with 9 moles of ethylene oxide. Perfume includes core shell melamine formaldehyde encapsulates of perfume.