FIELD OF INVENTION
[0001] The present invention relates to the delivery of shading dyes to fabrics.
BACKGROUND OF THE INVENTION
[0002] WO 2005/003274, to Unilever, discloses that shading dyes are added to laundry detergents to increase whiteness.
One drawback with these powders is that under certain conditions localised spotting
occurs on fabric treated with the detergent powder.
WO 2006 /020162 and
WO 2006/053598 disclose laundry compositions comprising granules containing a dye.
SUMMARY OF THE INVENTION
[0003] A shading dye granule present in a laundry detergent formulation is susceptible to
providing unwanted spotting of fabrics.
[0004] This problem is ameliorated by having an anti-dye transfer agent present in the shading
dye granule.
[0005] In one aspect the present invention provides a shading dye granule comprising:
- (i) from 0.001 to 95 wt% of a shading dye;
- (ii) from 0.1 to 99.999 wt% of a dye transfer polymer selected from: polyamine N-oxide
polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidone
polymers, polyvinyloxazolidones and polyvinylimidazoles;
- (iii) from 0 to 80 wt% of a non-ionic surfactant;
- (iv) from 0 to 20 wt % of an anionic or cationic surfactant;
- (v) from 0 to 99.5 wt% of a carrier; and,
- (vi) from 0 to 50 wt% of a binder, wherein the weight ratio of the dye transfer polymer:the
charged surfactant is from 1:0 to 1:1, wherein the shading dye is blue or violet.
[0006] In another aspect the present invention provides a granular laundry detergent composition
comprising:
- 1. (a) from 0.00005 to 10 wt% of visually distinct laundry detergent granule as defined
in any one of claims 1 to 3;
- 2. (b) from 99.99995 % to 90 wt % of a granular base powder, wherein the granular
laundry detergent composition comprises 10 to 50 wt % of an anionic surfactant.
[0007] The surfactant that comes from the base powder may be a mixture of different types
of surfactants but the total concentration of anionic surfactant in the granulate
laundry detergent is in the range from 10 to 50 wt %. The surfactant that comes from
the base powder is preferably greater than 70% anionic surfactant.
DETAILED DESCRIPTION OF THE INVENTION
[0008] Preferably, the shading dye granule is visually distinct (VD) from a granular background
powder in order to provide a visual cue.
[0009] The shading dye granule is for adding to a base powder (main detergent powder).
[0010] Preferably the shading dye granule does not contain an anionic surfactant. When the
shading dye granule is admixed with the base powder, which must contain an anionic
surfactant, there may be some migration of anionic surfactant to the shading dye granule.
[0011] The ratio of the dye transfer polymer:the charged surfactant prevents spotting whilst
permitting dye deposition of substantive dyes from the wash liquors.
Shading Dye
[0012] The shading dye is blue or violet. It is preferred that the shading dye(s) have a
peak absorption wavelength of from 550nm to 650nm, preferably from 570nm to 630nm.
A combination of dyes which together have the visual effect on the human eye as a
single dye having a peak absorption wavelength on polyester of from 550nm to 650nm,
preferably from 570nm to 630nm. This may be provided for example by mixing a red and
green-blue dye to yield a blue or violet shade.
Direct dyes
[0015] Direct violet and direct blue dyes are preferred. Preferably the dyes are
bis-azo or
tris-azo dyes. The carcinogenic benzidene based dyes are not preferred.
[0016] Bis-azo copper containing dyes such as direct violet 66 may be used.
[0017] Most preferably the direct dye is a direct violet of the following structures:

or

wherein:
ring D and E may be independently naphthyl or phenyl as shown;
R1 is selected from: hydrogen and C1-C4-alkyl, preferably hydrogen;
R2 is selected from: hydrogen, C1-C4-alkyl, substituted or unsubstituted phenyl and
substituted or unsubstituted naphthyl, preferably phenyl;
R3 and R4 are independently selected from: hydrogen and C1-C4-alkyl, preferably hydrogen or
methyl;
X and Y are independently selected from: hydrogen, C1-C4-alkyl and C1-C4-alkoxy; preferably
the dye has X= methyl; and, Y = methoxy and n is 0, 1 or 2, preferably 1 or 2.
[0018] Preferred dyes 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, and direct violet 99.
Acid dyes
[0019] Cotton substantive acid dyes give benefits to cotton containing garments. Preferred
acid dyes are:
- (i) azine dyes, wherein the dye is of the following core structure:

wherein Ra, Rb, Rc and Rd are selected from: H, an branched or linear C1 to C7-alkyl chain, benzyl a phenyl,
and a naphthyl;
the dye is substituted with at least one SO3- or -COO- group;
the B ring does not carry a negatively charged group or salt thereof;
and the A ring may further substituted to form a naphthyl;
the dye is optionally substituted by groups selected from: amine, methyl, ethyl, hydroxyl,
methoxy, ethoxy, phenoxy, Cl, Br, I, F, and NO2.
[0020] Preferred azine dyes are: acid violet 50 and acid blue 98.
(ii)DANSA dyes of the following core structure:-

wherein R is selected from: H; a branched or linear C1 to C7-alkyl chain; COR1 wherein R1 is a branched or linear C1 to C7-alkyl chain; and, a -SO2Ar group, wherein Ar is phenyl or methyl substituted phenyl group;
Y is selected from: NO2; CN; I; Br; Cl; F; H; OCOR2; NHCOR3; R4; R5O; and, NR6R7, wherein R2, R3, R4, and R5 are independently selected from a branched or linear C1 to C7-alkyl chain and R6 and R7 are independently selected from: H; a branched or linear C1 to C7-alkyl chain that
is unsubstituted or is substituted by groups independently selected from: OH; Cl;
F; OCOCH3; COOCH3; OCOC2H5; and, COOC2H5; and,
X is selected from: H; SO2N (R8) COCH3; SO2N (R8) -Ar; SO2N (R8) -Ar; and SO2-Ar, wherein Ar is an aromatic group and R8 is H, CH3 or C2H5,
with the proviso that the Y ring does not carry a negatively charged group or salt
thereof.
(iii) MAAD dyes the following core structure:

wherein:
X is selected from -OH, CH3O-, CH3CH2O-, and -NR1R2, wherein R1 and R2 are independently selected from: H, a branched or linear -C1-C7-alkyl chain, -COR3, wherein R3 is a branched or linear -C1-C7-alkyl chain, and a -SO2Ar group, wherein Ar is a phenyl or methyl substituted phenyl group;
Y is an aromatic group selected from: phenyl and napthyl, and Y may be substituted
by R4O-, R4CONH-, R4-, C1, Br, I, F, NO2, and -NR4R5, wherein R4 and R4 are independently selected from: H, a branched or linear -C1-C7-alkyl chain or a
phenyl group.
[0021] Other preferred acid dyes are acid violet 17, acid black 1, acid red 17 and acid
blue 29.
[0022] Preferably the acid dye is present at 0.001 wt% to 0.006 wt% of the formulation.
Hydrophobic dyes
[0023] The composition may comprise one or more hydrophobic dyes selected from benzodifuranes,
methine, triphenylmethanes, napthalimides, pyrazole, napthoquinone, anthraquinone
and mono-azo or di-azo dye chromophores. Hydrophobic dyes are dyes which do not contain
any charged water solubilising group. Hydrophobic dyes may be selected from the groups
of disperse and solvent dyes. Blue and violet anthraquinone and mono-azo dye are preferred.
[0024] Preferred dyes include solvent violet 13, disperse violet 27 disperse violet 26,
disperse violet 28, disperse violet 63 and disperse violet 77.
[0025] Preferably the hydrophobic dye is present at 0.0005 wt% to 0.004 wt% of the formulation.
Basic dyes
[0026] Basic dyes are organic dyes which carry a net positive charge. They deposit onto
cotton. They are of particular utility for used in composition that contain predominantly
cationic surfactants. Dyes may be selected from the basic violet and basic blue dyes
listed in the Colour Index International.
[0027] Preferred examples include triarylmethane basic dyes, azo basic dye, methane basic
dye, anthraquinone basic dyes, basic blue 16, basic blue 65, basic blue 66, basic
blue 67, basic blue 71, basic blue 159, basic violet 19, basic violet 35, basic violet
38, basic violet 48; basic blue 3, basic blue 75, basic blue 95, basic blue 122, basic
blue 124, basic blue 141 and thiazolium dyes.
Reactive dyes
[0028] Reactive dyes are dyes which contain an organic group capable of reacting with cellulose
and linking the dye to cellulose with a covalent bond. They deposit onto cotton.
[0029] Preferably the reactive group is hydrolysed or reactive group of the dyes has been
reacted with an organic species such as a polymer, so as to the link the dye to this
species. Dyes may be selected from the reactive violet and reactive blue dyes listed
in the Colour Index International.
[0030] Preferred examples include reactive blue 19, reactive blue 163, reactive blue 182
and reactive blue, reactive blue 96.
ANTI-DYE TRANSFER POLYMER
[0031] The shading dye granule according to the present invention comprising from 0.1 to
99.999 wt%, preferably from 0.5 to 18 wt%, more preferably from 0.5 to 2 wt% by weight
of an anti-dye transfer polymer (ADTP) selected from: polyamine N-oxide polymers,
copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidone polymers,
polyvinyloxazolidones and polyvinylimidazoles.
[0032] 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.
[0033] The preferred anti-dye transfer polymer is PVP.
CARRIERS
[0034] The shading dye granule preferably contains a carrier preferred examples of carrier
are bentonite, sodium chloride, zeolite, and sodium sulphate.
BINDER .
[0035] A binder is a material used to bind together two or more other materials in mixtures.
Its two principal properties are
adhesion and
cohesion. The binder is other than a non-ionic surfactant. Binders are standard in the art
of laundry detergent granules, examples of which are: Sokalan® CP45, Sokalan® CP5,
ethylene glycol, surfactants, anionic surfactants, polyethylene glycol, polyvinyl
pyrrolidone, polyacrylates, citric acid and mixtures thereof.
[0036] Preferably, the binder has a melting point above 30 °C.
[0037] Preferably the binder is selected from the group consisting of a polyacrylate, polyethylene
glycol, and polyacrylate/maleate copolymer.
[0038] Suitable polymers for use herein are water-soluble. By water-soluble, it is meant
herein that the polymers have a solubility greater than 5 g/l at 20 °C in demineralised
water.
[0039] The binder is preferably an acidic polymer. By an acidic polymer, it is meant herein
that a 1% solution of said polymers has a pH of less than 7, preferably less than
5.5.
[0040] Suitable polymers for use herein have a molecular weight in the range of from 1000
to 280,000, preferably from 1500 to 150,000.
[0041] Suitable polymers which meet the above criteria and are therefore particularly useful
in the present invention, include those having the following empirical formula I

wherein X is 0 or CH2; Y is a comonomer or comonomer mixture; R1 and R2 are bleach-stable
polymer-end groups; R3 is H, OH or C1-4 alkyl; M is H, and mixtures thereof with alkali
metal, alkaline earth metal, ammonium or substituted ammonium; p is from 0 to 2; and
n is at least 10, and mixtures thereof. The proportion of M being H in such polymers
is preferably such as to ensure that the polymer is sufficiently acidic to meet the
acidity criteria as hereinbefore defined.
[0042] Polymers according to formula I are known in the field of laundry detergents, and
are typically used as chelating agents, as for instance in
GB-A-1,597,756. Preferred polycarboxylate polymers fall into several categories. A first category
belongs to the class of copolymeric polycarboxylate polymers which, formally at least,
are formed from an unsaturated polycarboxylic acid such as maleic acid, citraconic
acid, itaconic acid and mesaconic acid as first monomer, and an unsaturated monocarboxylic
acid such as acrylic acid or an alpha -C1-C4 alkyl acrylic acid as second monomer.
Referring to formula I, therefore, preferred polycarboxylate polymers of this type
are those in which X is CHO, R3 is H or C1-4 alkyl, especially methyl, p is from about
0.1 to about 1.9, preferably from about 0.2 to about 1.5, n averages from about 10
to about 1500, preferably from about 50 to about 1000, more preferably from 100 to
800, especially from 120 to 400 and Y comprises monomer units of formula II

[0043] Such polymers are available from BASF under the trade name Sokalan® CP5 (neutralised
form) and Sokajan® CP45 (acidic form).
[0044] Binder materials are commercially readily available. The water soluble polymers of
the Sokalan® type sold by BASF® are preferred. The following is a list of such suitable
products: Sokalan CP 10; Sokalan CP 10 S; Sokalan CP 12 S; Sokalan CP 13 S; Sokalan
CP 45; Sokalan CP 5; Sokalan CP 7; Sokalan CP 9; Sokalan DCS; Sokalan HP 165; Sokalan
HP 22 G; Sokalan HP 25; Sokalan HP 50; Sokalan HP 53; Sokalan HP 53 K; Sokalan HP
56; Sokalan HP 59; Sokalan HP 60; Sokalan HP 66; Sokalan PA 110 S; Sokalan PA 15;
Sokalan PA 15 CL; Sokalan PA 20; Sokalan PA 20 PN; Sokalan PA 25 CL; Sokalan PA 30;
Sokalan PA 40; Sokalan PM 70; and, Sokalan SR 100.
Granules
[0045] The granules are preferably of the size from 50 to 1800 microns. The granule size
is as determined by passing through a mesh sieve. Preferably the size is in the range
100 to 800 microns.
EXAMPLES
Example 1
[0046] The dye solvent violet 13 was mixed in non-ionic surfactant (7EO) to form a 0.5 wt%
solution. To this was added the [nitrolotris(2,1-ethanediyloxy)] tris[propanol] salt
of direct violet 9, DV9, (Ex Ciba Speciality Chemicals). The non-ionic was added to
the carrier in a high shear mixer. Following this the binder, Sokalam CP5 (ex BASF)
was added. Where appropriate polyvinylpyrrolidone, PVP, was added to the starting
non-ionic solution.
[0047] The resultant granules were dried in an oven at 353K finally sieved to give granules
in the size range 500 to 1400 microns.
[0048] The granules had the following composition. All percentages refer to dry weight%.
| Granule |
bentonite |
7EO |
DV9 |
PVP |
CP5 |
| 1* |
69.93 |
20.56 |
0.20 |
0.00 |
9.41 |
| 2 |
69.71 |
20.68 |
0.20 |
0.21 |
9.51 |
| 3 |
69.41 |
20.65 |
0.08 |
0.21 |
9.83 |
| 4* |
69.38 |
20.93 |
0.08 |
0.00 |
9.58 |
Example 2
[0049] The granules of example 1 were separately added to a detergent powder (20% linear
alkyl benzene sulphonate, 30% sodium carbonate, 40% sodium chloride, remainder minors
including fluorescer and moisture), at 2 wt%. 10 g of the powder was sprinkled onto
a 25 by 25 cm piece of white cotton sheeting, immersed in 1 cm of demineralised water.
The cloth was soaked for 90 minutes, then thoroughly rinsed and dried. Each experiment
was repeated four times. Cloths soaked with Granule 1 and 2 were compared, and Granule
3 and 4 were compared, as they had equivalent levels of DV9. The eight clothes from
each comparison were ranked in terms of the degree of dye staining/spotting. The cloth
with the least staining/spotting received a score of 1, that with the second lowest
level of staining a score of 2, and so on, so that the most stained/spotted cloth
had a score of 8.
[0050] The total score across the 4 cloths for each granule were then compared:
Granules containing 0.20 wt% DV9
| Granule 1 |
(no PVP) |
total score = 24 |
| Granule 2 |
(PVP) |
total score = 12 |
Granules containing 0.08 wt% DV9
| Granule 3 |
(PVP) |
total score = 11 |
| Granule 4 |
(no PVP) |
total score = 25 |
[0051] The granules containing the dye transfer inhibition polymer show reduced levels of
spotting/staining.
Example 3
[0052] The granules of example 1 were added to the base washing powder of example 2, such
that when the washing powder was dissolved at 2g/L the wash liquor contained 200ppb
of SV13.
[0053] To the wash liquor was added pieces of woven cotton and knitted nylon-elastane fabric
such the liquor:cloth was 100:1. The liquor was agitated for 60 minutes at 293K, the
clothes rinsed twice and the colour change measured by reflectometry and expressed
as CIE L*a*b* values.
[0054] The results are given below expressed as the ΔE values relative to the control washed
without dye
[0055] All granules gave good deposition of the dyes to the fabrics evidenced by the ΔE
values.
| Granule |
Cotton |
Nylon-elastane |
| |
ΔE |
ΔE |
| 1 |
4.2 |
4.0 |
| 2 |
3.3 |
4.2 |
| 3 |
1.4 |
4.2 |
| 4 |
1.3 |
4.2 |
Example 4
Exemplary Base Powder Formulation A, B, C and D
[0056]
| Formulation |
A |
B |
C |
D |
| NaLAS |
15 |
20 |
10 |
14 |
| NI(7EO) |
- |
- |
- |
10 |
| Na tripolyphosphate |
- |
15 |
- |
- |
| Soap |
- |
- |
- |
2 |
| Zeolite A24 |
7 |
- |
- |
17 |
| Sodium silicate |
5 |
4 |
5 |
1 |
| Sodium carbonate |
25 |
20 |
30 |
20 |
| Sodium sulphate |
40 |
33 |
40 |
22 |
| Carboxymethylcellulose |
0.2 |
0.3 |
- |
0.5 |
| Sodium chloride |
- |
- |
- |
5 |
| Lipase |
0.005 |
0.01 |
- |
0.005 |
| Protease |
0.005 |
0.01 |
- |
0.005 |
| Amylase |
0.001 |
0.003 |
- |
- |
| Cellulase |
- |
0.003 |
- |
- |
| Fluorescer |
0.1 |
0.15 |
0.05 |
0.3 |
| Water/impurities/minors |
remainder |
remainder |
remainder |
remainder |
[0057] Granule 2 and granule 3 were individually added to exemplary powder formulations
A, B, C and D at 1 wt % to generate final formulations for use in washing and shading
textiles.