Laundry composition

Abstract

 The present invention concerns laundry compositions that reduce dye transfer between garments in a wash.

Description

FIELD OF INVENTION

[0001] The present invention concerns detergent compositions having reduced dye transfer properties

BACKGROUND OF THE INVENTION

[0002] Consumers wear white and coloured clothes. On washing the whites and coloured are separated in a laboriously sorting task, to prevent dye being transferred from the coloured to the white garments and ruining their aesthetic appeal. The problem occurs predominately with the water soluble, direct, acid and hydrolysed reactive dyes. It would be most convenient if coloured and white garments could be washed together without the occurrence of the dye transfer problem. Many technical approaches have been taken to attempt to solve this problem, however none solves it for a wide range of dyes and the consumer is left sorting whites and coloured.

[0003] GB1348212, to Procter and Gamble, discloses detergent composition comprising a mixture of a nonionic detergent and a partially or completely water-soluble polymeric ingredient which is a homo-polymer of vinyl pyrrolidone or a copolymer of vinyl pyrrolidone and a suitable comonomer and a builder salt, the weight ratio of nonionic detergent to polymeric ingredient being from 95:5 to 60:40, The weight ratio of builder salt to total surface-active agent is required to be in the range from 20:1 to 1: 5.

[0004] US 4753750, to Colgate, discloses liquid heavy duty laundry detergent composition comprising a suspension of builder salt in liquid nonionic surfactant. To improve dispensibility in automatic washing machines, the composition contains as a viscosity and gel controlling agent an alkylene glycol monoalkyl ether, especially diethyleneglycol monobutyl ether.

SUMMARY OF INVENTION

[0005] Surprisingly we have found that wash systems comprising non-ionic surfactants with dye transfer inhibiting polymers and very low ionic strength, effectively prevent dye transfer for a wide range of dyes.

[0006] In one aspect the present invention provides a laundry detergent composition comprising:

a) 10 to 95 wt% of non-ionic surfactant;

b) 0.01 to 20 wt % of an anti-dye transfer polymer;

c) 0 to 0.1 wt % of a colourant; and,

d) 0 to 2 wt of a perfume, wherein the ionic strength of a solution of 10g L^-1 of the composition in distilled water has an ionic strength of less then 0.05.

[0007] In another aspect the present invention provides a domestic method of washing coloured and white fabrics together comprising the following steps:

(i) adding the composition to water provide an aqueous medium comprising from 0.2 to 20 g/l of the composition;

(ii) washing fabrics in the aqueous medium; and,

(iii) rinsing and drying the fabrics.

DETAILED DESCRIPTION OF THE INVENTION

NON-IONIC SURFACTANT

[0008] The composition comprises from 10 to 95 wt%, preferably from 35 to 70 wt% of a non-ionic surfactant. Mixtures of non-ionic surfactant may be used.

[0009] The non-ionic surfactant may be selected from alcohol ethoxylates, from C₆-C₁₂ alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), block alkylene oxide condensate of C₆ to C₁₂ alkyl phenols, alkylene oxide condensates of C₈-C₂₂ alkanols and ethylene oxide/propylene oxide block polymers (Pluronic™-BASF Corp.).

[0010] Preferably the non-ionic surfactant is an alcohol ethoxylates, R-(OCH₂CH₂)_nOH, where R is an alkyl chain typically C10 to C18, preferably C12 to C15, and n is 3 to 80, preferably greater than or equal to 6, most preferred n = 9 to 30.

[0011] Other non-ionic surfactant may be selected.

IONIC STRENGTH

[0012] Ionic strength, I, of an aqueous solution is defined as:

where m_j is the molarity in mol L^-1 of ionic species j, and z_j is the amount of charge on the ion irrespective of whether it is +ve or -ve. For example for Na⁺ and Cl^- z_j =1, for Mg²⁺ and SO₄^2- z_j = 2.

[0013] Ionic species include charged surfactants, charged organic species, and inorganic ions.

[0014] The ionic strength of a solution of 10g L^-1 of the composition in distilled water is less then 0.05, preferably less than 0.007, more preferably less than 0.001.

[0015] Many components can affect the ionic strength of the composition but in totality the components must be such that the ionic strength is kept below the threshold value when dissolved in distilled water.

[0016] In this regard, the composition should contain less than 1 wt% of charged surfactant, for example Linear alkyl benzene sulphonates salts (LAS), Alkyl sulphate surfactants, alkyl ethoxylated sulphate surfactants, cationic surfactant, soaps and zwiterionic surfactants. Preferably the formulation should contain less than 0.1 wt% of charged surfactants, most preferably charged surfactants should be absent. In practice, small amount of charged components will always be present due to contaminants.

ANTI-DYE TRANSFER POLYMER

[0017] The laundry detergent compositions according to the present invention comprising from 0.01% to 20 %, preferably from 0.5% to 5%, more preferably from 0.2% to 2 % by weight of an anti-dye transfer polymer (ADTP). The ADTPs are normally incorporated into cleaning compositions in order to inhibit the transfer of dyes from coloured fabrics onto fabrics washed therewith. Especially suitable ADTPs are polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidone polymers, polyvinyloxazolidones and polyvinylimidazoles or mixtures thereof.

[0018] The anti-dye transfer polymers (ADTPs) discussed above are well known in the art and commercially available, reference in made to US6833336 and references found therein.

Colorants

[0019] Colorants may be selected from pigments, acid dyes, direct dyes, basic dyes, solvent and disperse dyes. It is preferred that the colorants pigments, solvent and disperse dyes to avoid addition of ionic strength.

[0020] Dyes and pigments are listed in the Color Index International published by Society of Dyers and Colourists and the American Association of Textile Chemists and Colorists.

[0021] Blue and violet shading dyes that deposit onto fabric are often used at low levels in detergent formulations to enhance the whiteness of fabrics as discussed in WO2006/032327 (Unilever). In the current formulations, fluorescer do not deposit effectively so it is preferred that the formulation contains a shading dye to counteract fabric yellowing due to ageing. Acid, direct and basic dye shading dyes are not suitable for the current application, as they are water soluble and the formulation will prevent them from depositing. Preferably shading dyes selected from Blue and violet solvent and disperse dyes and pigments are used. These shading agents deposit via different mechanism to the water soluble dyes and still deposit with the current formulations. Preferred dyes are solvent violet 13, disperse violet 27, disperse violet 26, disperse violet 28, disperse violet 77.

[0022] Organic pigments are described in 'Industrial Organic Pigments', Wiley VCH 2004 by W.Herbst and K.Hunger. Dyes are organic chemicals that are soluble in their application medium. Pigments are inorganic or organic particles that are insoluble in their application medium.

[0023] When pigments are present they are preferably present at levels of 0.0001 to 0.1%, preferably 0.0005 to 0.005 wt%.

[0024] Inorganic pigments such as pigment blue 29 or pigment pigment violet 15 may be used, however organic pigments are preferred.

[0025] Preferred pigments are pigment blue 1, 1:2, 1:3, 2, 2:1, 2:2, 3, 4, 5, 7, 9, 10, 10:1, 11, 12, 13, 14, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 34, 35, 36, 56, 57, 58, 59, 60, 61, 61:1, 62, 63, 64, 65, 66, 67, 69, 71, 72, 73, 74, 75, 79, 80, 83 and pigment violet 1, 1:1, 1:2, 2, 3, 3:1, 3:3, 3:4, 5, 5:1, 7:1, 8, 9, 11, 12, 13, 14, 15, 16, 18, 19, 23, 25, 27, 28, 29, 31, 32, 35, 37, 39, 41, 42, 43, 44, 45, 47, 48, 50, 54, 55 and 56

[0026] More Preferred organic pigments are pigment violet 1, 1:1, 1:2, 2, 3, 5:1, 13, 23, 25, 27, 31, 37, 39, 42, 44, 50 and Pigment blue 1, 2, 9, 10, 14, 18, 19, 24:1, 25, 56, 60, 61, 62, 66, 75, 79 and 80.

[0027] More preferred pigments are pigment violet 3, 13, 23, 27, 37, 39, pigment blue 14, 25, 66 and 75.

[0028] The most preferred is pigment violet 23.

PERFUME

[0029] Preferably the composition comprises a perfume. The perfume is preferably in the range from 0.001 to 2 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.

OTHER INGREDIENTS

[0030] The formulation may also contain enzymes to enhance the cleaning and care of the garments. Suitable enzymes maybe selected from lipases, proteases, cellulases, mannases.

[0031] The formulation may also contain H₂O₂, however this is not preferred.

[0032] The formulation may also contain hydroxyethyl cellulose, sequestrants, and sunscreens.

[0033] The formulation may contain a radical photoinitiator to enhance cleaning and perfume as discussed in WO 01/44424 (Unilever) and WO2004/072217 (Unilever).

[0034] Small amounts of alkali salts, subject to the ionic strength limits may be added to increase the pH. Preferably the pH of a 10g/L solution of the formulation in distilled water is between 5 and 11.

[0035] "The term "comprising" is meant not to be limiting to any subsequently stated elements but rather to encompass non-specified elements of major or minor functional importance. In other words the listed steps, elements or options need not be exhaustive. Whenever the words "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above."

[0036] The composition of the present invention preferably does not comprise a fluorescent agent (optical brightener).

[0037] Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material ought to be understood as modified by the word "about".

Examples

[0038] In the examples non-ionic,NI(7EO) refers to an alcohol ethoxylates, R-(OCH₂CH₂)_nOH where R is an alkyl chain of 12 to 15 carbon chain length with about 7 ethylene oxide groups per molecule. Similarly NI(30EO) a C12-13 mixture with about 30 moles of ethylene oxide, and NI(3EO) a C12-13 mixture with about 3 moles of ethylene oxide.

[0039] LAS is linear alkyl benzene sulphonate. SLES (3EO) is a C₁₂-C₁₈ alkyl polyethoxylate (3.0) sulphate.

[0040] PVP is polyvinylpyrolidone.

Example 1

[0041] White woven cotton cloth was washed in demineralised water for 30 minutes at a liquor to cloth ratio of 30:1 and 293K. The washes were conducted with the following surfactant systems: 1g/L NI(7EO) + 1g/L NaCl 1g/L LAS + + 1g/L NaCl 1g/L NI (7EO)

[0042] To the wash liquor was added nominal 4 ppm of various direct dyes, to represent a situation of extreme dye transfer, an order of magnitude larger than will be found under most domestic wash conditions. After the wash the clothes were rinsed twice in water, dried and the colour of the cloth measured using a reflectometer and expressed as the CIELAB ΔE values measured relative to clothes washed without dye.

[0043] The results are shown in the table below:

	1g/L NI (7EO) + 1g/L NaCl	1g/L LAS + + 1g/L NaCl	1g/L NI (7EO)
Direct Blue 199	0.2	1.6	0.3
Direct Blue 78	0.6	11.4	0.3
Direct Brown 115	8.6	17.3	1.8
Direct Green 26	1.0	8.9	0.3
Direct Orange 34	11.8	21.6	1.9
Direct Red 111	9.3	20.2	1.1
Direct Red 227	8.4	16.2	0.6
Direct Red 89	13.4	19.5	6.0
Direct Violet 47	16.9	16.6	7.6
Direct Yellow 44	6.3	40.4	1.4
Direct Yellow 86	12.0	24.1	4.3
Direct Black 112	8.9	10.4	5.5

[0044] The all non-ionic formulation give much lower dye transfer to the cloth, shown by the lower ΔE values. The all non-ionic formulation without ionic strength (provided by NaCl) shows the least dye transfer.

Example 2

[0045] The experiment of example 1 was repeated using different non-ionic surfactants: 1g/L NI (3EO) 1g/L NI (7EO) 1g/L Ni (30EO).

[0046] The results are shown in the table below:

	1g/L NI (3EO)	1g/L NI (7EO)	1g/L NI (30EO)
Direct Blue 199	5.8	0.3	0.5
Direct Blue 78	4.4	0.3	0.2
Direct Brown 115	7.2	1.8	0.8
Direct Green 26	3.6	0.3	0.2
Direct Orange 34	11.1	1.9	0.6
Direct Red 111	9.1	1.1	0.7
Direct Red 227	8.4	0.6	0.5
Direct Red 89	12.2	6.0	1.7
Direct Violet 47	6.0	7.6	5.4
Direct Yellow 44	11.3	1.4	1.1
Direct Yellow 86	11.1	4.3	0.9
Direct Black 112	4.6	5.5	2.2

[0047] The non-ionic surfactant with longer EO chains are more effective at reducing dye transfer.

Example 3

[0048] The experiment of example 1 was repeated using the following surfactants: 1g/L SLES(3EO) an anionic surfactant 1g/L NI (7EO) 1g/L NI (7EO) + 0.1g/L PVP

[0049] The results are shown in the table below:

	1g/L SLES (3EO)	1g/L NI (7EO)	1g/L NI (7EO) +0.1g/L PVP
Direct Blue 199	0.4	0.3	0.0
Direct Blue 78	1.5	0.3	0.4
Direct Brown 115	7.4	1.8	0.5
Direct Green 26	2.2	0.3	0.4
Direct Orange 34	9.1	1.9	0.6
Direct Red 111	9.9	1.1	0.6
Direct Red 227	4.2	0.6	0.2
Direct Red 89	8.0	6.0	0.7
Direct Violet 47	2.9	7.6	0.8
Direct Yellow 44	21.0	1.4	1.8
Direct Yellow 86	6.0	4.3	0.5
Direct Black 112	1.7	5.5	0.6

[0050] The 1g/L NI (7EO) + 0.1g/L PVP effectively prevents nearly all of the dyes from transferring to the white cotton, unlike the other surfactants systems.

Claims

1. A laundry detergent composition comprising:

a) 10 to 95 wt% of non-ionic surfactant;

b) 0.01 to 20 wt % of an anti-dye transfer polymer;

c) 0 to 0.1 wt % of a colourant; and,

d) 0 to 2 wt of a perfume, wherein the ionic strength of a solution of 10g L^-1 of the composition in distilled water has an ionic strength of less then 0.05.

2. A laundry detergent composition according to claim 1,
wherein the non-ionic surfactant is an alcohol ethoxylate, R-(OCH₂CH₂)_nOH, where R is an alkyl chain and n is 6 to 80.

3. A laundry detergent composition according to claim 1 or 2, wherein the anti-dye transfer polymer is selected from the group consisting of: polyamine N-oxide polymers; copolymers of N-vinylpyrrolidone and N-vinylimidazole; polyvinylpyrrolidone polymers; polyvinyloxazolidones; and, polyvinylimidazoles.

4. A laundry detergent composition according to any one of the preceding claims, wherein the colourant is selected from the group consisting of colorants pigments, solvent and disperse dyes.

5. A domestic method of washing coloured and white fabrics together comprising the following steps:

(i) adding the composition as defined in any one of claims 1 to 4 to water provide an aqueous medium comprising from 0.2 to 20 g/l of the composition;

(ii) washing fabrics in the aqueous medium; and,

(iii) rinsing and drying the fabrics.