TECHNICAL FIELD OF INVENTION
[0001] This invention relates to a detergent composition; particularly it relates to a fabric-washing
detergent composition having improved colour-care properties.
[0002] When washing coloured fabrics, various factors can contribute to a loss of colour
brightness. Thus, the redeposition of soil from the wash liquor may result in colour
dulling.
[0003] Also, when washing mixed coloured fabrics and mixed loads of coloured and white fabrics,
there is the risk of dye-transfer through the wash liquor from one fabric to another,
which will result in bleeding of colours, discolouration and/or staining of the fabrics.
With the fashion of moving towards more coloured clothing and textile materials, especially
multi-coloureds, the problem of dye-transfer in the wash has become more acute.
BACKGROUND AND PRIOR ART
[0004] Various proposals have been made in the art to resolve this problem, but so far without
much success. For example, in GB-A- 1 368 400 (Procter & Gamble), dye-transfer-inhibiting
compositions were proposed which comprise a peroxygen bleach compound, e.g. an organic
peroxyacid, combined with rather complex aldehyde or ketone compounds as bleach activators.
These compositions have several drawbacks in that not only do they use rather expensive
and complex chemical compounds, but also in that they are not very effective.
[0005] Other compositions having dry-transfer-inhibiting action are also disclosed in EP-A-
0024367 (Unilever) and EP-A-0024368 (Unilever) based on the activation of organic
peracids or organic peracid precursors with bromide ions. Still, the main drawback
of these compositions is that they too exert a rather strong direct fabric dye bleaching,
tending to cause fading of the coloured fabrics.
[0006] EP-A- 0058444 (Unilever) describes washing compositions comprising a bleach system
consisting essentially of an organic peracid or an organic peracid precursor in conjunction
with a water-soluble iodide salt. There are some snags in the use of iodide catalyst,
namely 1) the risk of staining due to iodine formation and 2) the effect of direct
fabric dye bleaching.
[0007] EP-A- 0143491 (Unilever) proposes the use of a copper catalyst together with a peracid
compound as the bleach system for reducing dye-transfer, and in GB Patent 1 450 234
(Kao Soap) there is disclosed a bleaching detergent composition comprising sodium
percarbonate together with polyethyleneglycol or polyvinylpyrrolidone.
[0008] Apart from the above-mentioned drawbacks, the proposed compositions of the art are
deficient in one way or another and are thus far from ideal for being satisfactory
as having real colour-care properties.
[0009] Efficient washing of coloured and mixed coloured/white fabrics requires more than
cleaning alone; it should also take good care of the colours in a way that colour-bleeding
due to dye-transfer, greying, dulling and/or fading, as well as changes in hue, are
minimised such that the original colours and brightness of the fabrics are preserved
as much as possible.
[0010] It is therefore an object of the present invention to provide an efficient detergent
composition which can be used for washing of mixed coloured and mixed loads of coloured
and white fabrics, having improved colour-care properties with only minimal to substantially
nil dye-transfer, wherein the drawbacks of the art are mitigated to a substantial
degree.
DEFINITION OF THE INVENTION
[0011] According to this invention, a detergent composition adapted for washing fabrics
and having improved colour-care properties is provided, comprising a detergent-active
material and a detergency builder characterised in that it further includes from 0.3%
to 15% by weight of a polymer mixture comprising the following polymeric materials
(a), (b) and (c):
(a) an alkali metal carboxymethylcellulose;
(b) a vinylpyrrolidone polymer having an average molecular weight within the range
of about 5000 to about 350,000;
(c) a polycarboxylate polymer selected from compounds having the empirical formula:
wherein X is 0 or CH₂; Y is a co-monomer or mixture of co-monomers; R¹ and R² are
bleach-and alkali-stable polymer-end groups; R³ is H, OH or C₁-C₄ alkyl; M is H, alkali
metal, alkaline earth metal, ammonium or other water-soluble cation; p is from 0 to
2; and n is at least 10; and mixtures therefore; at a mixing ration of a) to b) within
the range 1:2 to 2:1 and of b) to c) within the range of 1:1 to 1:4.
DESCRIPTION OF THE INVENTION
[0012] The individual components of the polymer additive system are well known in detergent
technology and may have found commercial exploitation. However, the specific combination
is especially beneficial in fabric-washing detergent compositions having improved
colour-care properties.
THE DETERGENT ACTIVE MATERIAL
[0013] The detergent composition of the invention contains at least one detergent-active
material which may be anionic, nonionic or cationic in nature, but mixtures of anionic
and nonionic materials are preferred.
[0014] The anionic detergent-active material can be a soap or a non-soap (synthetic) anionic
material. Anionic detergent-active materials are commercially available and are fully
described in the literature, for example in "Surface Active Agents and Detergents",
Volumes I and II, by Schwartz Perry and Berch.
[0015] Synthetic anionic detergent-active materials useful in the present invention are
water-soluble alkali metal salts of 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 acyl radicals. Examples of suitable synthetic
anionic detergent compounds are sodium and potassium alkyl sulphates, especially those
obtained by sulphating higher (C₈-C₁₈) alcohols produced for example from tallow or
coconut oil, sodium and potassium alkyl (C₉-C₂₀) benzene sulphonates, particularly
sodium linear secondary alkyl (C₁₀-C₁₅) benzene sulphonates; especially those ethers
of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived
from petroleum; sodium coconut oil fatty monoglyceride sulphates and sulphonates;
sodium and potassium salts of sulphuric acid esters of higher (C₈-C₁₈) fatty alcohol-alkylene
oxide, particularly ethylene oxide, reaction products; the reaction products of fatty
acids such as coconut fatty acids esterified with isethionic acid and neutralised
with sodium hydroxide; sodium and potassium salts of fatty acid amides of methyl taurine;
alkane monosulphonates such as those derived by reacting alpha-olefins (C₈-C₂₀) with
sodium bisulphite and those derived from reacting paraffins with SO₂ and C₂ and then
hydrolysing with a base to produce a random sulphonate; water-soluble salts of dialkyl
esters of sulphosuccinic acid; and olefin sulphonates, which term is used to describe
the material made by reacting olefins, particularly C₁₀-C₂₀ alpha-olefins, with SO₃
and then neutralising and hydrolysing the reaction product. The preferred anionic
detergent compounds are sodium (C₁₁-C₁₅) alkyl benzene sulphonates and sodium (C₁₆-C₁₈)
alkyl sulphates.
[0016] Mixtures of anionic compounds may also be used in the detergent compositions.
[0017] Examples of suitable nonionic surfactants include:
1. The polyethylene oxide condensates of alkyl phenol, e.g. the condensation products
of alkyl phenols having an alkyl group containing from 6 to 12 carbon atoms in either
a straight chain or branched chain configuration, with ethylene oxide, the said ethylene
oxide being present in amounts equal to 3 to 30, preferably 5 to 14 moles of ethylene
oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived,
for example, from polymerised propylene, di-isobutylene, octene and nonene. Other
examples include dodecylphenol condensed with 9 moles of ethylene oxide per mole of
phenol; dinonylphenol condensed with 11 moles of ethylene oxide per mole of phenol;
nonylphenol and disooctylphenol condensed with 13 moles of ethylene oxide.
2. The condensation product of primary or secondary aliphatic alcohols having 8 to
24 carbon atoms, in either straight chain or branched chain configuration, with from
2 to about 40 moles, preferably 2 to about 9 moles of ethylene oxide per mole of alcohol.
Preferably, the aliphatic alcohol comprises between 9 and 18 carbon atoms and is ethoxylated
with between 2 and 9, desirably between 3 and 8 moles of ethylene oxide per mole of
aliphatic alcohol. The preferred surfactants are prepared from primary alcohols which
are either linear (such as those derived from natural fats or prepared by the Ziegler
process from ethylene, e.g. such as the Lutensols, Dobanols and Neodols which have
about 25% 2-methyl branching (Lutensol being a Trade Name of BASF, Dobanol and Neodol
being Trade Names of Shell), or Synperonics, which are understood to have about 50%
2-methyl branching (Synperonic is a Trade Name of I.C.I.) or the primary alcohols
having more than 50% branched chain structure sold under the Trade Name Lial by Liquichimica.
Specific examples of nonionic surfactants falling within the scope of the invention
include Dobanol 45-4, Dobanol 45-7, Dobanol 45-9, Dobanol 91-2.5, Dobanol 91-3, Dobanol
91-4, Dobanol 91-6, Dobanol 91-8, Dobanol 23-6.5, Synperonic 6, Synperonic 14, the
condensation products of coconut alcohol with an average of between 5 and 12 moles
of ethylene oxide per mole of alcohol, the coconut alkyl portion having from 10 to
14 carbon atoms, and the condensation products of tallow alcohol with an average of
between 7 and 12 moles of ethylene oxide per mole of alcohol, the tallow portion comprising
essentially between 16 and 22 carbon atoms. Secondary linear alkyl ethoxylates are
also suitable in the present compositions, especially those ethoxylates of the Tergitol
series having from about 9 to 15 carbon atoms in the alkyl group and up to about 11,
especially from about 3 to 9, ethoxy residues per molecule.
[0018] The compound formed by condensing ethylene oxide with a hydrophobic base formed by
the condensation of propylene oxide with propylene glycol. The molecular weight of
the hydrophobic portion generally falls in the range of about 1500 to 1800. Such synethetic
nonionic detergents are available on the market under the Trade Name of "Pluronic",
supplied by Wyandotte Chemicals Corporation.
[0019] When the detergent-active material comprises a mixture of anionic and nonionic materials,
the preferred nonionic material or mixtures thereof for use in this invention will
have an HLB (hydrophilic-lipophilic balance) of not more than 10.5, preferably in
the range of from 6 to 10, most preferably in the range of 8 to 9.5. As explained,
the composition can contain one or a mixture of more than one nonionic detergent-active
materials. The mixture can contain one or more nonionic materials having an HLB of
more than 10.5, providing the average HLB of the mixture of nonionic materials is
not more than 10.5. The HLB scale is a known measure of hydrophilic-lipophilic balance
in any compound. It is fully defined in the literature, for example in "Nonionic Surfactants",
Volume I, edited by M.J. Schick. A method of determining the HLB of a mixture of nonionic
materials is also defined in this reference.
[0020] Preferred nonionic materials are the alkoxylate adducts of fatty compounds selected
from fatty alcohols, fatty acids, fatty esters, fatty amides and fatty amines. The
fatty compound contains at least 10 carbon atoms and the nonionic material contains
an average of less than 8 alkylene oxide groups per molecule.
[0021] Alkylene oxide adducts of fatty alcohols useful in the present invention, preferably
have the general formula:
R¹⁰ - O - (C
nH
2nO)
yH
wherein R¹⁰ is an alkyl or alkenyl group having at least 10 carbon atoms, most preferably
from 10 to 22 carbon atoms, y is preferably not more than 10, such as from 0.5 to
about 3.5, and n is 2 or 3. Examples of such materials include Synperonic A3 (ex I.C.I.),
which is a C₁₃-C₁₅ alcohol with about three ethylene oxide groups per molecule, and
Empilan KB3 (ex Marchon) which is lauric alcohol 3EO.
[0022] Alkylene oxide adducts of fatty acids useful in the present invention, preferably
have the general formula:
R¹⁰ - C - O (C
nH
2nO)
yH,
wherein R¹⁰, n and y are as given above. Suitable examples include ESONAL 0334 (ex
Diamond Shamrock), which is a tallow fatty acid with about 2.4 ethylene oxide groups
per molecule.
[0023] Alkylene oxide adducts of fatty esters useful in the present invention include adducts
of mono-, di- or triesters of polyhydric alcohols containing 1 to 4 carbon atoms;
such as coconut or tallow oil (triglyceride) 3EO (ex Stearine Dubois).
[0024] Alkylene oxide adducts of fatty amides useful in the present invention preferably
have the general formula:
wherein R¹⁰ is an alkyl or alkenyl group having at least 10 carbon atoms, most preferably
from 10 to 22 carbon atoms, n is 2 or 3 and x and z in total are not more than 4.0,
preferably from about 0.5 to about 3.5, while one of x and z can be zero. Examples
of such materials include tallow monoethanolamide and diethanolamide, and the corresponding
coconut and soya compounds.
[0025] Alkylene oxide adducts of fatty amines useful in the present invention preferably
have the general formula:
wherein R¹⁰ and n are as given above, and x and z in total are preferably not more
than 4.0, most preferably from about 0.5 to about 3.5. Examples of such materials
include Ethomeen T12 (tallow amine 2EO, available from AKZO), Optameet PC5 (coconut
alkyl amine 5EO) and Crodamet 1.02 (oleylamine 2EO, available from Croda Chemicals).
[0026] Cationic detergent-active materials suitable for use herein include quaternary ammonium
surfactants and surfactants of a semi-polar nature, for example amine oxides.
[0027] Amounts of amphoteric or zwitterionic detergent compounds can also be used in the
composition of the invention, but this is not normally desired owing to their relatively
high cost. If any amphoteric or zwitterionic detergent compounds are used, it is generally
in small quantities relative to the much more commonly used anionic and/or nonionic
detergent-active compounds.
[0028] The effective amount of the detergent-active compound or compounds used in the composition
of the invention will generally be in the range of from 5 to 50% by weight, preferably
from 6 to 30% by weight based on the total composition.
[0029] The mixing ratio of anionic to nonionic materials is not very critical and can be
varied as desired by the skilled artisan. However, preference here is given to ratios
within the range of 4:1 to 1:4, preferably from 2:1 to 1:2.
THE DETEGENCY BUILDER
[0030] The detergent composition according to the invention also contains a detergency builder,
which can be an inorganic builder or an organic builder, in an amount generally within
the range of from about 5% to about 80%, preferably from 10% to 60% by weight.
[0031] Examples of phosphorus-containing inorganic detergency builders, when present, include
the water-soluble salts, especially alkali metal pyrophosphates, orthophosphates and
polyphosphates. Specific examples of inorganic phosphate builders include sodium and
potassium tripolyphosphtes, phosphates and hexametaphosphates.
[0032] Examples of non-phosphorus-containing inorganic detergency builders, when present,
include water-soluble alkali metal carbonates, bicarbonates, silicates and crystalline
and amorphous alumino silicates. Specific examples include sodium carbonate (with
or without calcite seeds), potassium carbonates, sodium and potassium bicarbonates
and silicates.
[0033] Examples of organic detergency builders, when present, include the alkali metal,
ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates, polyacetal
carboxylates and polyhydroxysylphonates. Specific examples include sodium, potassium,
lithium, ammonium and substituted ammonium salts of ethylenediaminetetraacetic acid,
nitrilotriacetic acid, oxydisuccinic acid, melitic acid, benzene polycarboxylic acids
and citric acid.
THE POLYMER MIXTURE
[0034] The alkalimetal carboxymethyl cellulose is preferably the sodium or the potassium
salt. All known types can be used, with different degrees of substitution and viscosities.
The degree of substitution generally lies between 0.5 and 0.9 and is mostly about
0.7. The term "cellulose" as used above is intended to include starch; thus the corresponding
alkyl starch ethers and carboxy methyl starches are also suitable. The cellulose-based
compounds are however preferred.
[0035] Polymer (b) is a vinyl pyrrolidone polymer. As is disclosed in the art, polyvinyl
pyrrolidone is not a single individual compound but may be obtained in almost any
degree of polymerisation. The degree of polymerisation, which is most easily expressed
in terms of average molecular weight, is not critical provided the material has the
designed water solubility and soil-suspending power. In general, suitable soil-suspending
vinyl pyrrolidone polymers are linear in structure, and have an average molecular
weight within the range of about 5,000 to about 350,000, and preferably from about
15,000 to about 50,000. Suitable polymers will also, generally, have a water solubility
of greater than 0.3% at normal wash temperatures.
[0036] The polycarboxylate polymers (c) are disclosed and further characterised in EP-A-
0137669 (Procter & Gamble), the most important members of which are:
(i) those belonging to the class of copolymeric polycarboxylates which, formally at
least, are formed from an unsaturated polycarboxylic acid such as maleic acid, citraconic
acid, itaconic acid and metaconic acid as first monomer, and an unsaturated monocarboxylic
acid such as acrylic acid or an alpha-C₁-C₄-alkyl acrylic acid as second monomer.
Preferred copolymers of this class are copolymers of maleic acid (anhydride) and (meth)
acrylic acid, as disclosed in EP-B- 25551 and GB Patent 1 596 756.
(ii) those belonging to the class of poly (alpha-hydroxyacrylates);
(iii) those belonging to the class of polyacetal carboxylates or acetal polycarboxylates;
and
(iv) those belonging to the class of homopolymeric polyacrylates.
[0037] Any polymer of these classes can be chosen as polymer (c) in the polymer additive
system, either alone or as mixture, though preference is given to polymers of the
classes (i) and (iv).
OTHER INGREDIENTS
[0038] The compositions of the invention may also contain a peroxyacid compound bleach system
which includes the organic peroxyacids per se, organic and inorganic peroxyacid salts
and bleach systems or compounds which form organic peroxyacids in aqueous media by
perhydrolysis or hydrolysis.
[0039] Examples of organic peroxyacids per se usable in the present invention are monoperoxyazelaic
acid, diperoxyazelaic acid, diperoxyadipic acid, diperoxydodecanedionic acid, decylbutanediperoxoic
acid, monoperoxy phthalic acid, peroxybenzoic acid, m-chloroperbenzoic acid and diperoxyisophthalic
acid.
[0040] Examples of peroxyacid salts usable here include magnesium monoperoxyphthalate, potassium
monopersulphate and peroxymonophosphate.
[0041] Examples of compounds which form organic peroxyacids in situ by hydrolysis are benzoyl
peroxide, which generates peroxybenzoic acid, and diphthaloyl peroxide which generates
monoperoxyphthalic acid.
[0042] These compounds can be used in the composition in amounts from 1 to 25% by weight,
preferably from 2 to 10% by weight.
[0043] The invention, however, prefers the use of peroxyacid compound bleach systems comprising
a mixture of an inorganic or organic peroxide compound and a peroxyacid bleach precursor.
These systems generate peroxyacids in situ from the perhydrolysis reaction between
the peroxide compound and the peroxyacid bleach precursor.
[0044] The inorganic or organic peroxide compounds as meant here are the so-called peroxyhydrates
and include alkali metal perborates, percarbonates, persilicates and perphosphates
and also urea peroxide, which liberate hydrogen perioxide in aqueous solution. Preferred
peroxide compounds are sodium perborate, which can be in the mono- or tetrahydrate
form.
[0045] Any organic peroxyacid bleach precursors generating peroxyacid on perhydrolysis known
in the art, as described in, for example, British Patents 836 988, 970 950, 907 356,
855 735 and 1, 246 339; US Patents 4 128 494 and 3 332 882; Canadian Patent 844 481;
and European Patent Applications EP-A- 0098021 and EP-A- 0185522, can in principle
be used.
[0046] As used such can be named glycerol triacetate, glucose pentaacetate, tetraacetyl
xylose, N,N,Nʹ,Nʹ-tetraacetyl ethylene diamine (TAED), tetraacetyl glycoluril, N,Nʹ-diacetyl
acetoxy methyl malonamide, triacetyl cyanurate, sodium acetoxy benzene sulphonate,
sodium nonanoyloxy benzene sulphonate and sodium 3,5,5- trimethyl hexanoyloxy benzene
sulphonate.
[0047] A particularly preferred peroxyacid compound bleach system for use in the present
invention is a mixture of sodium perborate and tetraacetyl ethylene diamine (TAED).
[0048] The peroxide compound and the peroxyacid bleach precursor in the compositions of
the invention can be used at the usual levels of from about 2 to 30% by weight and
from about 0.5 to 20% by weight, respectively, at any ratio by weight of peroxide
compound to peroxyacid precursor ranging from about 60:1 to about 1:10.
[0049] Preferred ranges in the composition of the invention are 2-15% by weight of peroxide
compound, e.g. sodium perborate, and from 0.5-10% by weight of peroxyacid precursor,
e.g. TAED, in a weight ratio of from 5:1 to 1:5, preferably from 3:1 to 1:2.
[0050] Bleach system and the polymer mixture of the invention are important parameters for
achieving good colour-care properties. Beneficial effects can be seen already at a
polymer mixture level as low as 0.3% which can be increased to about 15% by weight.
Generally, however, a polymer mixture level of not more than 10% by weight will be
sufficient, with an optimum range of from about 0.6% to 6% by weight.
[0051] As explained, detergent compositions formulated according to the invention have the
advantage over the compositions of the art in that they show efficient cleaning combined
with improved colour-care characteristics.
[0052] It should, however, be appreciated that the detergent composition according to the
invention may further contain any of the conventional additives in amounts in which
such materials are normally employed in fabric-washing detergent compositions and
which serve to further improve the laundering characteristics and/or add aesthetic
appear to the composition. Examples of these additives include lather boosters, anti-foaming
agents, alkaline materials such as sodium silicates, fabric-softening agents, enzymes
such as proteolytic, lipolytic and amylolytic enzymes, corrosion inhibitors, inorganic
salts, sequestering agents, colouring agents and perfumes, so long as these additives
do not adversely influence the basic objective of the invention.
[0053] In a preferred embodiment of the invention, the composition is free from copper ions
or other heavy metal ions of the transition series, e.g. cobalt, iron, manganese,
chromium and zinc, which can form coloured reaction products and thereby may negate
the benefit of colour-care.
[0054] In a further preferred embodiment, the invention omits the use of fluorescent agents
or optical bleaching agents, as these additives could change the hue of the original
fabric colours.
[0055] The detergent composition of the invention can be manufactured and presented in the
form of a powder, including granules, flakes, etc.; liquid; paste; or bar.
[0056] Detergent powder compositions according to the invention can be prepared using any
of the conventional manufacturing techniques commonly used or proposed for the preparation
of fabric-washing detergent powder compositions. These include slurry-making of the
basic ingredients followed by spray-drying or spray-cooling and subsequent dry-dosing
of sensitive ingredients not suitable for incorporation prior to the drying or heating
step. Other conventional techniques, such as noodling, granulation, dry-mixing, and
mixing by fluidisation in a fluidised bed, may be utilised as and when necessary and
desired. Such techniques are familiar to those skilled in the art of detergent powder
composition manufacture.
[0057] In use, the detergent compositions according to the invention are particularly suitable
for washing, at lower to medium temperatures, of both cotton and synthetic or mixed
cotton/synthetic fabrics.
Examples
[0058] The invention will now be illustrated in the following examples.
Example 1
[0059] Detergent compositions were prepared having the formulations set out below:
[0060] The above compositions were very good at displaying excellent cleaning and detergency
performance across the range of wash temperatures with outstanding colour-care performance
on coloured fabrics and mixed loads of coloured and white fabrics. No substantial
bleeding of colours was observed and, after several washes, the coloured fabrics remained
remarkably bright with no substantial dulling or fading being observed. Comparisons
between these compositions and similar compositions in which one or more components
of the polymer mixture were absent showed a preference for the compositions of the
invention, particularly in terms of soil redeposition.