Field of the Invention
[0001] The present invention relates to detergent compositions for the non-oxidative laundering
of fabric stains.
Background and Prior Art
[0002] Significant efforts have been invested in recent years towards improving the washing
performance of laundry detergents at low temperatures. Lifecycle studies show that
the largest environmental impact of the laundry process is during the use phase, especially
when the water of the main wash is heated. Consequently, a temperature reduction is
a pivotal driver to improve the overall sustainability profile of the laundry process.
Washing at cooler temperatures is also advisable for care of coloured and/or delicate
fabrics.
[0003] At the same time, environmental regulations are becoming more stringent in many countries,
making it necessary for formulators to produce detergents that reduce potential negative
impacts on wastewater and water ways, and reduce greenhouse gas emissions.
[0004] As consumers move to lower wash temperatures and seek products with improved environmental
credentials, the satisfactory removal of stains presents a continuing challenge. Stains
are usually caused by molecules of coloured substances deposited on or in fibres or
in residual soil. Highly coloured stains are particularly difficult to remove. They
often originate from polyphenolic compounds, such as the natural flavonoids found
in tea and red wine.
[0005] Oxidizing bleaches such as peroxygen compounds have been used for the oxidative degradation
and decolorisation of highly coloured stains. However, peroxygen compounds have reduced
efficacy at lower temperatures and cannot generally be incorporated into liquid laundry
detergents without storage stability problems. Oxidizing bleaches may also be unsuitable
for prolonged or intensive use on coloured or delicate fabrics.
[0006] Transition metal sequestrants have been used to improve stain removal at low temperatures.
However, the most effective of these tend to be phosphorus-based compounds. It would
be desirable to improve the weight efficiency of such materials.
[0007] It is an object of the present invention to solve one or more of the above problems.
Summary of the Invention
[0008] The present invention provides a detergent composition for the non-oxidative laundering
of fabric stains, the composition comprising:
- (a) from 1 to 10% (by weight based on the total weight of the composition) of one
or more 1-hydroxy-1,1-bisphosphonates of formula (I):
in which R1, R2 and R3 are each independently selected from hydrogen or an ammonium or alkali metal (preferably
sodium or potassium) cation, and A is selected from aliphatic hydrocarbyl groups having
4 to 22 carbon atoms; and
- (b) from 3 to 80% (by weight based on the total weight of the composition) of one
or more detersive surfactants.
[0009] The invention also provides a method for the non-oxidative laundering of fabric stains,
comprising diluting a dose of the detergent composition defined above to obtain a
wash liquor, and washing the stained fabric with the wash liquor so formed.
Detailed Description and Preferred Embodiments
[0010] In general formula (I), A is preferably selected from linear or branched alkyl or
alkenyl groups containing from 6 to 18 (more preferably from 10 to 14) carbon atoms
and 0 or 1 (more preferably 0) double bonds. Specific examples of such groups include
n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n- and iso-nonyl, n- and iso-decyl, n-undecyl,
n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl and oleyl and mixtures thereof (as
may typically be derived from natural fats and/or optionally hydrogenated natural
oils, such as coconut oil, palm kernel oil or tallow). A is most preferably selected
from linear, saturated C
10-14 alkyl groups such as n-dodecyl.
[0011] Mixtures of any of the above described materials may also be used.
[0012] The total amount of 1-hydroxy-1,1-bisphosphonates (a) in a composition of the invention
preferably ranges from about 0.25 to 7.5%, more preferably from 0.5 to 6%, most preferably
from 1 to 5% (by weight based on the total weight of the composition).
Detergent Compositions
[0013] The term "detergent composition" in the context of this invention denotes formulated
compositions intended for and capable of wetting and cleaning domestic laundry such
as clothing, linens and other household textiles. The term "linen" is often used to
describe certain types of laundry items including bed sheets, pillow cases, towels,
tablecloths, table napkins and uniforms. Textiles can include woven fabrics, non-woven
fabrics, and knitted fabrics; and can include natural or synthetic fibres such as
silk fibres, linen fibres, cotton fibres, polyester fibres, polyamide fibres such
as nylon, acrylic fibres, acetate fibres, and blends thereof including cotton and
polyester blends.
[0014] Examples of detergent compositions include heavy-duty detergents for use in the wash
cycle of automatic washing machines, as well as fine wash and colour care detergents
such as those suitable for washing delicate garments (e.g. those made of silk or wool)
either by hand or in the wash cycle of automatic washing machines.
[0015] The term "detersive surfactant" in the context of this invention denotes a surfactant
which provides a detersive (i.e. cleaning) effect to laundry treated as part of a
domestic laundering process.
[0016] The choice of detersive surfactant, and the amount present, will depend on the intended
use of the detergent composition. For example, different surfactant systems may be
chosen for hand-washing products and for products intended for use in different types
of automatic washing machine. The total amount of detersive surfactant present will
also depend on the intended end use. In compositions for machine washing of fabrics,
an amount of from 5 to 40%, such as 15 to 35% (by weight based on the total weight
of the composition) is generally appropriate. Higher levels may be used in compositions
for washing fabrics by hand, such as up to 60% (by weight based on the total weight
of the composition.
[0017] Preferred detersive surfactants may be selected from non-soap anionic surfactants,
nonionic surfactants and mixtures thereof.
[0018] Non-soap anionic surfactants are principally used to facilitate particulate soil
removal. Non-soap anionic surfactants for use in the invention are typically salts
of organic sulfates and sulfonates having alkyl or alkenyl (preferably alkyl) groups
containing from about 8 to about 22 (preferably from 10 to 18) carbon atoms, the terms
"alkyl" and "alkenyl" being used to include the alkyl or alkenyl portions, respectively,
of higher acyl groups. Examples of such materials include alkyl sulfates, alkyl ether
sulfates, alkaryl sulfonates, alpha-olefin sulfonates and mixtures thereof, in which
the alkyl groups contain from 10 to 18 carbon atoms. The alkyl ether sulfates may
contain from one to ten ethylene oxide or propylene oxide units per molecule, and
preferably contain one to three ethylene oxide units per molecule. The counterion
for anionic surfactants is generally an alkali metal such as sodium or potassium;
or an ammoniacal counterion such as monoethanolamine, (MEA) diethanolamine (DEA) or
triethanolamine (TEA). Mixtures of such counterions may also be employed.
[0019] A preferred class of non-soap anionic surfactant for use in the invention includes
alkylbenzene sulfonates, particularly linear alkylbenzene sulfonates (LAS) with a
linear alkyl group having an alkyl chain length of from 10 to 18 carbon atoms. Commercial
LAS is a mixture of closely related isomers and alkyl chain homologues, each containing
an aromatic ring sulfonated at the "para" position and attached to a linear alkyl
group at any position except the terminal carbons. The linear alkyl group typically
has an alkyl chain length of from 11 to 15 carbon atoms, with the predominant materials
having a chain length of about C12. Each alkyl chain homologue consists of a mixture
of all the possible sulfophenyl isomers except for the 1-phenyl isomer. LAS is normally
formulated into compositions in acid (i.e. HLAS) form and then at least partially
neutralized in-situ.
[0020] Also suitable are alkyl ether sulfates having a straight or branched chain alkyl
group having 10 to 18, more preferably 12 to 14 carbon atoms and containing an average
of 1 to 3EO units per molecule. A preferred example is sodium lauryl ether sulfate
(SLES) in which the predominantly C12 lauryl alkyl group has been ethoxylated with
an average of 3EO units per molecule.
[0021] Some alkyl sulfate surfactant (PAS) may be used, such as non-ethoxylated primary
and secondary alkyl sulphates with an alkyl group having an alkyl chain length of
from 10 to 18.
[0022] Mixtures of any of the above described materials may also be used. A preferred mixture
of non-soap anionic surfactants for use in the invention comprises linear alkylbenzene
sulfonate (preferably C
11 to C
15 linear alkyl benzene sulfonate) and sodium lauryl ether sulfate (preferably C
10 to C
18 alkyl sulfate ethoxylated with an average of 1 to 3 EO).
[0023] In a detergent composition according to the invention, the total level of non-soap
anionic surfactant may suitably range from 5 to 30% (by weight based on the total
weight of the composition).
[0024] Nonionic surfactants may provide enhanced performance for removing very hydrophobic
oily soil and for cleaning hydrophobic polyester and polyester/cotton blend fabrics.
Nonionic surfactants for use in the invention are typically polyoxyalkylene compounds,
i.e. the reaction product of alkylene oxides (such as ethylene oxide or propylene
oxide or mixtures thereof) with starter molecules having a hydrophobic group and a
reactive hydrogen atom which is reactive with the alkylene oxide. Such starter molecules
include alcohols, acids, amides or alkyl phenols. Where the starter molecule is an
alcohol, the reaction product is known as an alcohol alkoxylate. The polyoxyalkylene
compounds can have a variety of block and heteric (random) structures. For example,
they can comprise a single block of alkylene oxide, or they can be diblock alkoxylates
or triblock alkoxylates. Within the block structures, the blocks can be all ethylene
oxide or all propylene oxide, or the blocks can contain a heteric mixture of alkylene
oxides. Examples of such materials include aliphatic alcohol ethoxylates such as C
8 to C
18 primary or secondary linear or branched alcohol ethoxylates with an average of from
2 to 40 moles of ethylene oxide per mole of alcohol.
[0025] A preferred class of nonionic surfactant for use in the invention includes aliphatic
C
8 to C
18, more preferably C
12 to C
15 primary linear alcohol ethoxylates with an average of from 3 to 20, more preferably
from 5 to 10 moles of ethylene oxide per mole of alcohol.
[0026] Mixtures of any of the above described materials may also be used.
[0027] In a detergent composition according to the invention, the total level of nonionic
surfactant may suitably range from 0 to 25% (by weight based on the total weight of
the composition).
[0028] A detergent composition of the invention may contain one or more cosurfactants (such
as amphoteric (zwitterionic) and/or cationic surfactants) in addition to the non-soap
anionic and/or nonionic detersive surfactants described above.
[0029] Specific cationic surfactants include C8 to C18 alkyl dimethyl ammonium halides and
derivatives thereof in which one or two hydroxyethyl groups replace one or two of
the methyl groups, and mixtures thereof. Cationic surfactant, when included, may be
present in an amount ranging from 0.1 to 5% (by weight based on the total weight of
the composition).
[0030] Specific amphoteric (zwitterionic) surfactants include alkyl amine oxides, alkyl
betaines, alkyl amidopropyl betaines, alkyl sulfobetaines (sultaines), alkyl glycinates,
alkyl carboxyglycinates, alkyl amphoacetates, alkyl amphopropionates, alkylamphoglycinates,
alkyl amidopropyl hydroxysultaines, acyl taurates and acyl glutamates, having alkyl
groups containing from about 8 to about 22 carbon atoms, the term "alkyl" being used
to include the alkyl portion of higher acyl groups. Amphoteric (zwitterionic) surfactant,
when included, may be present in an amount ranging from 0.1 to 5% (by weight based
on the total weight of the composition).
[0031] A detergent composition according to the invention may suitably be in liquid or particulate
form, or a mixture thereof.
[0032] The term "particulate" in the context of this invention denotes free-flowing or compacted
solid forms such as powders, granules, pellets, flakes, bars, briquettes or tablets.
[0033] One preferred form for a particulate detergent composition according to the invention
is a free-flowing powdered solid, with a loose (unpackaged) bulk density generally
ranging from about 200g/l to about 1,300 g/l, preferably from about 400 g/l to about
1,000 g/l, more preferably from about 500g/l to about 900 g/l.
[0034] The detergent composition according to the invention is most preferably in liquid
form.
[0035] The term "liquid" in the context of this invention denotes that a continuous phase
or predominant part of the composition is liquid, and that the composition is flowable
at 15°C and above. Accordingly, the term "liquid" may encompass emulsions, suspensions,
and compositions having flowable yet stiffer consistency, known as gels or pastes.
The viscosity of the composition may suitably range from about 200 to about 10,000
mPa.s at 25°C at a shear rate of 21 sec
-1. This shear rate is the shear rate that is usually exerted on the liquid when poured
from a bottle. Pourable liquid compositions generally have a viscosity of from 200
to 2,500 mPa.s, preferably from 200 to 1500 mPa.s.
[0036] Liquid compositions which are pourable gels generally have a viscosity of from 1,500
mPa.s to 6,000 mPa.s, preferably from 1,500 mPa.s to 2,000 mPa.s.
[0037] A liquid detergent composition according to the invention may generally comprise
from 5 to 95%, preferably from 10 to 90%, more preferably from 15 to 85% water (by
weight based on the total weight of the composition). The composition may also incorporate
non-aqueous carriers such as hydrotropes, co-solvents and phase stabilizers. Such
materials are typically low molecular weight, water-soluble or water-miscible organic
liquids such as C1 to C5 monohydric alcohols (such as ethanol and n- or i-propanol);
C2 to C6 diols (such as monopropylene glycol and dipropylene glycol); C3 to C9 triols
(such as glycerol); polyethylene glycols having a weight average molecular weight
(M
w) ranging from about 200 to 600; C1 to C3 alkanolamines such as mono-, di- and triethanolamines;
and alkyl aryl sulfonates having up to 3 carbon atoms in the lower alkyl group (such
as the sodium and potassium xylene, toluene, ethylbenzene and isopropyl benzene (cumene)
sulfonates).
[0038] Mixtures of any of the above described materials may also be used.
[0039] Non-aqueous carriers, when included in a liquid detergent composition according to
the invention, may be present in an amount ranging from 0.1 to 20%, preferably from
1 to 15%, and more preferably from 3 to 12% (by weight based on the total weight of
the composition).
Builders
[0040] A detergent composition according to the invention may contain one or more builders.
Builders enhance or maintain the cleaning efficiency of the surfactant, primarily
by reducing water hardness. This is done either by sequestration or chelation (holding
hardness minerals in solution), by precipitation (forming an insoluble substance),
or by ion exchange (trading electrically charged particles).
[0041] Builders for use in the invention can be of the organic or inorganic type, or a mixture
thereof. Non-phosphate builders are preferred.
[0042] Inorganic, non-phosphate builders for use in the invention include hydroxides, carbonates,
silicates, zeolites, and mixtures thereof.
[0043] Suitable hydroxide builders for use in the invention include sodium and potassium
hydroxide.
[0044] Suitable carbonate builders for use in the invention include mixed or separate, anhydrous
or partially hydrated alkali metal carbonates, bicarbonates or sesquicarbonates. Preferably
the alkali metal is sodium and/or potassium, with sodium carbonate being particularly
preferred.
[0045] Suitable silicate builders include amorphous forms and/or crystalline forms of alkali
metal (such as sodium) silicates. Preferred are crystalline layered sodium silicates
(phyllosilicates) of the general formula (I)
NaMSi
xO
2x+1.yH
2O (I)
in which M is sodium or hydrogen, x is a number from 1.9 to 4, preferably 2 or 3 and
y is a number from 0 to 20. Sodium disilicates of the above formula in which M is
sodium and x is 2 are particularly preferred. Such materials can be prepared with
different crystal structures, referred to as α, β, γ and δ phases, with δ-sodium disilicate
being most preferred.
[0046] Zeolites are naturally occurring or synthetic crystalline aluminosilicates composed
of (SiO
4)
4- and (AlO
4)
5- tetrahedra, which share oxygen-bridging vertices and form cage-like structures in
crystalline form. The ratio between oxygen, aluminium and silicon is O:(Al + Si) =
2:1. The frameworks acquire their negative charge by substitution of some Si by Al.
The negative charge is neutralised by cations and the frameworks are sufficiently
open to contain, under normal conditions, mobile water molecules. Suitable zeolite
builders for use in the invention may be defined by the general formula (II): Na
x[(AlO
2)
x(SiO
2)
y]·zH
2O (II) in which x and y are integers of at least 6, the molar ratio of x to y is in
the range from about 1 to about 0.5, and z is an integer of at least 5, preferably
from about 7.5 to about 276, more preferably from about 10 to about 264.
[0047] Preferred inorganic, non-phosphate builders for use in the invention may be selected
from zeolites (of the general formula (II) defined above), sodium carbonate, δ-sodium
disilicate and mixtures thereof.
[0048] Suitable organic, non-phosphate builders for use in the invention include polycarboxylates,
in acid and/or salt form. When utilized in salt form, alkali metal (e.g. sodium and
potassium) or alkanolammonium salts are preferred. Specific examples of such materials
include sodium and potassium citrates, sodium and potassium tartrates, the sodium
and potassium salts of tartaric acid monosuccinate, the sodium and potassium salts
of tartaric acid disuccinate, sodium and potassium ethylenediaminetetraacetates, sodium
and potassium N(2-hydroxyethyl)-ethylenediamine triacetates, sodium and potassium
nitrilotriacetates and sodium and potassium N-(2-hydroxyethyl)-nitrilodiacetates.
Polymeric polycarboxylates may also be used, such as polymers of unsaturated monocarboxylic
acids (e.g. acrylic, methacrylic, vinylacetic, and crotonic acids) and/or unsaturated
dicarboxylic acids (e.g. maleic, fumaric, itaconic, mesaconic and citraconic acids
and their anhydrides). Specific examples of such materials include polyacrylic acid,
polymaleic acid, and copolymers of acrylic and maleic acid. The polymers may be in
acid, salt or partially neutralised form and may suitably have a molecular weight
(Mw) ranging from about 1,000 to 100,000, preferably from about 2,000 to about 85,000,
and more preferably from about 2,500 to about 75,000.
[0049] Preferred organic, non-phosphate builders for builders for use in the invention may
be selected from polycarboxylates (e.g. citrates) in acid and/or salt form and mixtures
thereof.
[0050] Mixtures of any of the above described materials may also be used.
[0051] Preferably the level of phosphate builders in a detergent composition of the invention
is no more than 0.2%, preferably from 0 to 0.1%, more preferably from 0 to 0.01% and
most preferably 0% (by weight based on the total weight of the composition). The term
"phosphate builder" in the context of this invention denotes alkali metal, ammonium
and alkanolammonium salts of polyphosphate, orthophosphate, and/or metaphosphate (e.g.
sodium tripolyphosphate).
[0052] The overall level of builder, when included, may range from about 0.1 to about 80%,
preferably from about 0.5 to about 50% (by weight based on the total weight of the
composition).
Transition metal ion sequestrants
[0053] In addition to the 1-hydroxy-1,1-bisphosphonates (a) as described above, a detergent
composition according to the invention may contain additional transition metal ion
sequestrants. Specific examples of such materials include aminotris(methylene phosphonic
acid) (ATMP), 1-hydroxyethylidene diphosphonic acid (HEDP) and diethylenetriamine
penta(methylene phosphonic acid (DTPMP) and their respective sodium or potassium salts.
Mixtures of any of the above described materials may also be used.
[0054] However, the level of such additional transition metal ion sequestrants in a detergent
composition of the invention is typically no more than 0.2%, preferably from 0 to
0.1%, more preferably from 0 to 0.01% and most preferably 0% (by weight based on the
total weight of the composition).
[0055] A particulate detergent composition of the invention may include one or more fillers
to assist in providing the desired density and bulk to the composition. Suitable fillers
for use in the invention may generally be selected from neutral salts with a solubility
in water of at least 1 gram per 100 grams of water at 20° C; such as alkali metal,
alkaline earth metal, ammonium or substituted ammonium chlorides, fluorides, acetates
and sulfates and mixtures thereof. Preferred fillers for use in the invention include
alkali metal (more preferably sodium and/or potassium) sulfates and chlorides and
mixtures thereof, with sodium sulfate and/or sodium chloride being most preferred.
[0056] Filler, when included, may be present in a total amount ranging from about 1 to about
80%, preferably from about 5 to about 50% (by weight based on the total weight of
the composition).
Polymeric cleaning boosters
[0057] A detergent composition according to the invention may include one or more polymeric
cleaning boosters such as antiredeposition polymers, soil release polymers and mixtures
thereof.
[0058] Anti-redeposition polymers stabilise the soil in the wash solution thus preventing
redeposition of the soil. Suitable anti-redeposition polymers for use in the invention
include alkoxylated polyethyleneimines. Polyethyleneimines are materials composed
of ethylene imine units -CH
2CH
2NH- and, where branched, the hydrogen on the nitrogen is replaced by another chain
of ethylene imine units. Preferred alkoxylated polyethylenimines for use in the invention
have a polyethyleneimine backbone of about 300 to about 10000 weight average molecular
weight (M
w). The polyethyleneimine backbone may be linear or branched. It may be branched to
the extent that it is a dendrimer. The alkoxylation may typically be ethoxylation
or propoxylation, or a mixture of both. Where a nitrogen atom is alkoxylated, a preferred
average degree of alkoxylation is from 10 to 30, preferably from 15 to 25 alkoxy groups
per modification. A preferred material is ethoxylated polyethyleneimine, with an average
degree of ethoxylation being from 10 to 30, preferably from 15 to 25 ethoxy groups
per ethoxylated nitrogen atom in the polyethyleneimine backbone. Another type of suitable
anti-redeposition polymer for use in the invention includes cellulose esters and ethers,
for example sodium carboxymethyl cellulose.
[0059] Mixtures of any of the above described materials may also be used.
[0060] The overall level of anti-redeposition polymer, when included, may range from 0.05
to 6%, more preferably from 0.1 to 5% (by weight based on the total weight of the
composition).
[0061] Soil release polymers help to improve the detachment of soils from fabric by modifying
the fabric surface during washing. The adsorption of a SRP over the fabric surface
is promoted by an affinity between the chemical structure of the SRP and the target
fibre.
[0062] SRPs for use in the invention may include a variety of charged (e.g. anionic) as
well as non-charged monomer units and structures may be linear, branched or star-shaped.
The SRP structure may also include capping groups to control molecular weight or to
alter polymer properties such as surface activity. The weight average molecular weight
(M
w) of the SRP may suitably range from about 1000 to about 20,000 and preferably ranges
from about 1500 to about 10,000.
[0063] SRPs for use in the invention may suitably be selected from copolyesters of dicarboxylic
acids (for example adipic acid, phthalic acid or terephthalic acid), diols (for example
ethylene glycol or propylene glycol) and polydiols (for example polyethylene glycol
or polypropylene glycol). The copolyester may also include monomeric units substituted
with anionic groups, such as for example sulfonated isophthaloyl units. Examples of
such materials include oligomeric esters produced by transesterification/oligomerization
of poly(ethyleneglycol) methyl ether, dimethyl terephthalate ("DMT"), propylene glycol
("PG") and poly(ethyleneglycol) ("PEG"); partly- and fully-anionic-end-capped oligomeric
esters such as oligomers from ethylene glycol ("EG"), PG, DMT and Na-3,6-dioxa-8-hydroxyoctanesulfonate;
nonionic-capped block polyester oligomeric compounds such as those produced from DMT,
Me-capped PEG and EG and/or PG, or a combination of DMT, EG and/or PG, Me-capped PEG
and Na-dimethyl-5-sulfoisophthalate, and copolymeric blocks of ethylene terephthalate
or propylene terephthalate with polyethylene oxide or polypropylene oxide terephthalate
[0064] Other types of SRP for use in the invention include cellulosic derivatives such as
hydroxyether cellulosic polymers, C
1-C
4 alkylcelluloses and C
4 hydroxyalkyl celluloses; polymers with poly(vinyl ester) hydrophobic segments such
as graft copolymers of poly(vinyl ester), for example C
1-C
6 vinyl esters (such as poly(vinyl acetate)) grafted onto polyalkylene oxide backbones;
poly(vinyl caprolactam) and related co-polymers with monomers such as vinyl pyrrolidone
and/or dimethylaminoethyl methacrylate; and polyester-polyamide polymers prepared
by condensing adipic acid, caprolactam, and polyethylene glycol.
[0065] Preferred SRPs for use in the invention include copolyesters formed by condensation
of terephthalic acid ester and diol, preferably 1,2 propanediol, and further comprising
an end cap formed from repeat units of alkylene oxide capped with an alkyl group.
Examples of such materials have a structure corresponding to general formula (II):
in which R1 and R2 independently of one another are X-(OC2H4)n-(OC3H6)m;
in which X is C1-4 alkyl and preferably methyl;
n is a number from 12 to 120, preferably from 40 to 50;
m is a number from 1 to 10, preferably from 1 to 7; and
a is a number from 4 to 9.
[0066] Because they are averages, m, n and a are not necessarily whole numbers for the polymer
in bulk.
[0067] Mixtures of any of the above described materials may also be used.
[0068] The overall level of SRP, when included, may range from 0.1 to 10%, preferably from
0.3 to 7%, more preferably from 0.5 to 5% (by weight based on the total weight of
the composition).
Fatty Acid
[0069] A detergent composition according to the invention may in some cases contain one
or more fatty acids and/or salts thereof.
[0070] Suitable fatty acids in the context of this invention include aliphatic carboxylic
acids of formula RCOOH, where R is a linear or branched alkyl or alkenyl group containing
from 6 to 24, more preferably 10 to 22, most preferably from 12 to 18 carbon atoms
and 0 or 1 double bond. Preferred examples of such materials include saturated C12-18
fatty acids such as lauric acid, myristic acid, palmitic acid or stearic acid; and
fatty acid mixtures in which 50 to 100% (by weight based on the total weight of the
mixture) consists of saturated C12-18 fatty acids. Such mixtures may typically be
derived from natural fats and/or optionally hydrogenated natural oils (such as coconut
oil, palm kernel oil or tallow).
[0071] The fatty acids may be present in the form of their sodium, potassium or ammonium
salts and/or in the form of soluble salts of organic bases, such as mono-, di- or
triethanolamine.
[0072] Mixtures of any of the above described materials may also be used.
[0073] Fatty acids and/or their salts, when included, may be present in an amount ranging
from about 0.25 to 5%, more preferably from 0.5 to 5%, most preferably from 0.75 to
4% (by weight based on the total weight of the composition).
[0074] For formula accounting purposes, in the formulation, fatty acids and/or their salts
(as defined above) are not included in the level of surfactant or in the level of
builder.
Rheology modifiers
[0075] A liquid detergent composition according to the invention may comprise one or more
rheology modifiers. Examples of such materials include polymeric thickeners and/or
structurants such as hydrophobically modified alkali swellable emulsion (HASE) copolymers.
Exemplary HASE copolymers for use in the invention include linear or crosslinked copolymers
that are prepared by the addition polymerization of a monomer mixture including at
least one acidic vinyl monomer, such as (meth)acrylic acid (i.e. methacrylic acid
and/or acrylic acid); and at least one associative monomer. The term "associative
monomer" in the context of this invention denotes a monomer having an ethylenically
unsaturated section (for addition polymerization with the other monomers in the mixture)
and a hydrophobic section. A preferred type of associative monomer includes a polyoxyalkylene
section between the ethylenically unsaturated section and the hydrophobic section.
Preferred HASE copolymers for use in the invention include linear or crosslinked copolymers
that are prepared by the addition polymerization of (meth)acrylic acid with (i) at
least one associative monomer selected from linear or branched C
8-C
40 alkyl (preferably linear C
12-C
22 alkyl) polyethoxylated (meth)acrylates; and (ii) at least one further monomer selected
from C
1-C
4 alkyl (meth) acrylates, polyacidic vinyl monomers (such as maleic acid, maleic anhydride
and/or salts thereof) and mixtures thereof. The polyethoxylated portion of the associative
monomer (i) generally comprises about 5 to about 100, preferably about 10 to about
80, and more preferably about 15 to about 60 oxyethylene repeating units.
[0076] Mixtures of any of the above described materials may also be used.
[0077] Polymeric thickeners, when included, may be present in an amount ranging from 0.1
to 5% (by weight based on the total weight of the composition).
[0078] A liquid detergent composition according to the invention may also have its rheology
modified by use of one or more external structurants which form a structuring network
within the composition. Examples of such materials include hydrogenated castor oil,
microfibrous cellulose and citrus pulp fibre. The presence of an external structurant
may provide shear thinning rheology and may also enable materials such as encapsulates
and visual cues to be suspended stably in the liquid.
Enzymes
[0079] A detergent composition according to the invention may comprise an effective amount
of one or more enzymes selected from the group comprising, pectate lyase, protease,
amylase, cellulase, lipase, mannanase and mixtures thereof. The enzymes are preferably
present with corresponding enzyme stabilizers.
[0080] A liquid detergent composition according to the invention preferably has a pH in
the range of 5 to 9, more preferably 6 to 8, when measured on dilution of the composition
to 1% (by weight based on the total weight of the composition) using demineralised
water.
Other Ingredients
[0081] A detergent composition of the invention may contain further optional ingredients
to enhance performance and/or consumer acceptability. Examples of such ingredients
include fragrance oils, foam boosting agents, preservatives (e.g. bactericides), antioxidants,
sunscreens, anticorrosion agents, colorants, pearlisers and/or opacifiers, and shading
dye. Each of these ingredients will be present in an amount effective to accomplish
its purpose. Generally, these optional ingredients are included individually at an
amount of up to 5% (by weight based on the total weight of the composition).
[0082] A detergent composition of the invention generally contains no more than 0.2%, preferably
from 0 to 0.1%, more preferably from 0 to 0.01% and most preferably 0% (by weight
based on the total weight of the composition) of transition metal ions selected from
Fe (III), Co (II), Co (III), Mn (II), Mn (III), Ce (III), Ce (IV), Zn (II) and Bi
(III) and mixtures thereof.
[0083] A detergent composition of the invention generally contains no more than 0.2%, preferably
no more than 0.1%, more preferably no more than 0.01% and most preferably 0% (by weight
based on the total weight of the composition) of oxidising agents selected from halogen-based
bleaches (e.g. alkali metal hypochlorites and alkali metal salts of di- and tri-chloro
and di- and tri-bromo cyanuric acids), oxygen-based bleaches (e.g. sodium perborate
(tetra-or monohydrate), sodium percarbonate and hydrogen peroxide) and mixtures thereof.
Packaging and dosing
[0084] The detergent composition of the invention may be packaged as unit doses in polymeric
film soluble in the wash water. Alternatively, the detergent composition of the invention
may be supplied in multidose plastics packs with a top or bottom closure. A dosing
measure may be supplied with the pack either as a part of the cap or as an integrated
system.
[0085] A method for the non-oxidative laundering of fabric stains using a detergent composition
according to the invention comprises diluting a dose of the detergent composition
to obtain a wash liquor and washing the stained fabric with the wash liquor so formed.
[0086] The method may suitably be carried out in a top-loading or front-loading automatic
washing machine or can be carried out by hand.
[0087] In automatic washing machines, the dose of detergent composition is typically put
into a dispenser and from there it is flushed into the machine by the water flowing
into the 5 machines, thereby forming the wash liquor. Dosages for a typical front-loading
washing machine (using 10 to 15 litres of water to form the wash liquor) may range
from about 10 ml to about 100 ml, preferably about 15 to 75 ml. Dosages for a typical
top-loading washing machine (using from 40 to 60 litres of water to form the wash
liquor) may be higher, e.g. 100 ml or more. Lower dosages of detergent (e.g. 50 ml
or less) may be 10 used for hand washing methods (using about 1 to 10 litres of water
to form the wash liquor).
[0088] A subsequent aqueous rinse step and drying the laundry is preferred. Any input of
water during any optional rinsing step(s) is not included when determining the volume
of the wash liquor. Laundry drying can take place either in an automatic dryer or
in the open air.
[0089] The invention will now be further described with reference to the following non-limiting
Examples.
EXAMPLES
[0090] All weight percentages are by weight based on total weight unless otherwise specified.
[0091] Liquid laundry detergent formulations were prepared by sequential mixing of the ingredients
as shown in
Table 1.
[0092] Compositions according to the invention are indicated by a number; and comparative
examples (not according to the invention) are indicated by a letter.
Table 1
Ingredient |
wt.% (active ingredient) |
Formulation |
Example |
|
A |
B |
C |
D |
1 |
2 |
3 |
4 |
5 |
6 |
Glycerol |
2.0 |
2.0 |
2.0 |
2.0 |
2.0 |
2.0 |
2.0 |
2.0 |
2.0 |
2.0 |
Alcohol ethoxylate |
4.3 |
4.3 |
4.3 |
4.3 |
4.3 |
4.3 |
4.3 |
4.3 |
4.3 |
4.3 |
LAS acid |
5.8 |
5.8 |
5.8 |
5.8 |
5.8 |
5.8 |
5.8 |
5.8 |
5.8 |
5.8 |
TEA |
8.8 |
8.8 |
8.8 |
8.8 |
8.8 |
8.8 |
8.8 |
8.8 |
8.8 |
8.8 |
Lauric acid |
0.9 |
0.9 |
0.9 |
0.9 |
0.9 |
0.9 |
0.9 |
0.9 |
0.9 |
0.9 |
SLES 1 EO |
4.4 |
4.4 |
4.4 |
4.4 |
4.4 |
4.4 |
4.4 |
4.4 |
4.4 |
4.4 |
Preservative |
0.03 |
0.03 |
0.03 |
0.03 |
0.03 |
0.03 |
0.03 |
0.03 |
0.03 |
0.03 |
Sequestrant(1) |
- |
0.5 |
1.0 |
1.5 |
- |
- |
- |
- |
- |
- |
Sequestrant(2) |
- |
- |
- |
- |
0.5 |
1.0 |
1.5 |
- |
- |
- |
Sequestrant(3) |
- |
- |
- |
- |
- |
- |
- |
0.5 |
1.0 |
1.5 |
Water |
q.s. to 100 |
(1) Dequest®2010 (HEDP)
(2) 1-hydroxy-1,1-bisphosphonate of formula (I): A is n-hexyl
(3) 1-hydroxy-1,1-bisphosphonate of formula (I): A is n-dodecyl |
[0093] The formulations were evaluated for their cleaning performance at 30°C using a Heraeus
12-pot Linitester to mimic the mechanical action of a front-loading automatic washing
machine.
[0094] Hard model wash water (a) was prepared by dissolving 0.235g calcium chloride dihydrate
and 0.163g magnesium chloride hexahydrate into 1 litre of demineralised water to give
24° FH hardness and a 2:1 calcium to magnesium ratio.
[0095] Hard, transition metal doped model wash water (b) was prepared by first dissolving
5.18 g of ammonium iron (III) sulphate dodecahydrate, 1.298 g of copper (II) sulphate
pentahydrate, 3.034 g of zinc sulphate heptahydrate and 0.111 g manganese sulphate
monohydrate in 0.5 litres of demineralized water, then acidifying the solution to
pH 1.0 by dropwise addition of concentrated sulfuric acid. 2.5 ml of the acidified
solution was then added to 3 litres of hard model wash water (a), immediately prior
to use.
[0096] Test wash liquors were prepared by diluting 2.9 g of the selected test formulation
in 1 litre of hard, transition metal doped water (b), and dosing a 100 ml aliquot
of the test wash liquor into the Linitest pot. 2.0 cm x 2.0 cm swatches of black tea
stained cotton and 20 cm x 20 cm swatches of unstained cotton ballast were placed
into each Linitest pot. The pots were sealed and attached to the Linitester cradle
and rotated at 40 rpm for 30 minutes at 30°C.
[0097] The swatches were then removed from the pots and wrung out by hand to drain residual
test wash liquor. The Linitest pots were rinsed and 100 ml of water was added. The
swatches were returned to the pots and rinsed for 5 minutes. The swatches were then
removed, wrung out and the rinse water drained and replaced with fresh water before
returning the swatches to the pot and carrying out a second 5-minute rinse. The swatches
were placed on laboratory paper towel and allowed to air dry in the open laboratory.
[0098] The extent of black tea stain removal was measured by making diffuse reflectance
measurements using a spectrometer, and expressed as the Stain Removal Index (SRI),
defined as:
SRI = 100 - ΔE, where ΔE is the difference in colour of the stained cloth compared
to an unstained cloth.
[0099] A higher SRI value indicates cleaner swatches. Three replicate swatches were measured
for each test wash liquor. The results are shown in
Table 2.
Table 2
Formulation used in test wash liquor |
SRI |
A (control) |
83.39 ± 0.26 |
B |
86.83 ± 0.28 |
C |
87.45 ± 0.14 |
D |
86.94 ± 0.12 |
1 |
86.42 ± 0.34 |
2 |
87.01 ± 0.21 |
3 |
87.83 ± 0.24 |
4 |
86.77 ± 0.37 |
5 |
87.71 ± 0.28 |
6 |
88.31 ± 0.21 |
[0100] The testing was repeated using the same protocol, but with red wine stained cotton
swatches in place of the black tea stained cotton swatches. The results are shown
in
Table 3.
Table 3
Formulation used in test wash liquor |
SRI |
A (control) |
90.08 ± 0.19 |
B |
92.46 ± 0.15 |
C |
91.89 ± 0.42 |
D |
92.24 ± 0.59 |
1 |
92.59 ± 0.36 |
2 |
92.89 ± 0.16 |
3 |
91.93 ± 0.12 |
4 |
92.58 ± 0.35 |
5 |
92.87 ± 0.47 |
6 |
93.71 ± 0.11 |
[0101] The results show that Examples 1 to 6 according to the invention (with 1-hydroxy-1,1-bisphosphonates
of formula (I)) provide equivalent or superior performance on the black tea and red
wine stains compared to the comparative examples B to D (with Dequest®2010). This
enables the phosphorus content in the formulation to be reduced without impairing
stain removal performance.