Field of the invention
[0001] The present invention relates to fabric softening compositions and more particularly
to compositions which reduce the amount of dyes released from coloured fabrics upon
wet treatment such as those which occur in a laundry operation.
Background of the invention
[0002] The domestic treatment of coloured fabrics is a problem known in the art to the formulator
of laundry compositions. More particularly, the problem of formulating laundry compositions
which reduce the amount of dyes released from coloured fabrics upon wet treatment
is a particular challenge to the formulator. This problem is now even more acute with
the trends of consumer to move towards more colored fabrics.
[0003] Numerous solutions have been proposed in the art to solve this problem such as by
treating the fabric with a dye scavenger during the washing process as described in
EP 0,341,205, EP 0,033,815 and with a polyvinyl substance as described in WO 94/11482
or in the rinse cycle with a dye fixing agent as described in EP 0,462,806. However,
a problem encountered with these solutions is that the dye fixing agents when used
in the washing process may be destroyed or damaged by contact on storage and/or during
the process, whilst when used in the rinse cycle the need for a detergent active and
a high level of dye fixing agent is required to provide effective dye fixation performance.
Furthermore, a problem related with the use of dye fixing agents in a softening composition
is that of its weight efficiency. So that, although levels of dye fixing agents above
10% by weight would provide effective dye fixation, such use would result in an increase
in the formulation cost. Another problem relating to the use of a high level of dye
fixing agents in fabric softening compositions is that the resulting products show
phase instability. On the other hand, lowering the level of dye fixing agents would
not provide sufficient dye fixing properties and the need for a detergent material
would be required.
[0004] Accordingly, notwithstanding the advances in the art, there is still a need for a
fabric softening composition which effectively reduces the amount of dyes released
from coloured fabrics upon wet treatment.
[0005] The Applicant has now found that the use of a liquid composition comprising a cationic
fabric softener having at least two long chains, a cationic dye fixing agent in amount
of 0.1% to 10% by weight, said composition being free of detergent materials, fulfills
such a need.
[0006] It is therefore an advantage of the invention to provide liquid fabric softening
compositions which provide effective reduction of the amount of dyes released from
coloured fabrics upon wet domestic treatments.
[0007] It is another advantage of the invention to provide liquid fabric softening compositions
with effective softening properties.
[0008] It is another advantage of the invention to provide liquid fabric softening compositions
with effective storage stability properties.
[0009] For the purpose of the invention, the term "detergent materials" encompasses detergent
surfactant materials selected from soaps, non-soap anionic, nonionic, zwitterionic
and amphoteric synthetic and natural detergent surfactants which are not softeners.
Not included by this definition are the fatty acids which are fabric softeners, contrary
to said soaps components which do not have fabric softener properties.
Summary of the invention
[0010] The present invention relates to a liquid fabric softening composition comprising
a cationic fabric softener having at least two long chains as defined in claim 1 and
a cationic dye fixing agent in amount of 0.1% to 10% by weight, said composition being
free of detergent materials.
[0011] In accordance with another aspect of the present invention, a method for treating
fabrics is provided. The method comprises contacting the fabrics during the rinse
cycle of a consumer laundry process with an aqueous medium containing at least 50
ppm of a fabric softening composition of the invention.
Detailed description of the invention
Cationic fabric softeners
[0012] An essential component of the invention is a cationic fabric softener component having
at least two long chains as defined in claim 1. By component having at least two long
chains is meant a component containing at least two alkyl or alkenyl chains, each
comprising from 10 to 25 carbon atoms. Such fabric softener provides effective softness
benefit to the treated fabrics.
[0013] Typical levels of said fabric softener components within the liquid softener compositions
are from 1% to 80% by weight of the compositions. Depending on the composition execution
which can be dilute with a preferred level of fabric softening components from 1%
to 5%, or concentrated, with a preferred level of fabric softening components from
5% to 80%, more preferably 10% to 50%, most preferably 15% to 35% by weight.
[0014] Typical cationic fabric softening components as defined in claim 1 having at least
two long chains include the water-insoluble quaternary-ammonium fabric softening actives,
the most commonly used having been di-long alkyl chains ammonium chloride.
[0015] In recent years, the need has arisen for more environmental-friendly materials, and
rapidly biodegradable quaternary ammonium compounds have been presented as alternatives
to the traditionally used di-long chain ammonium chlorides. Such quaternary ammonium
compounds contain long chain alk(en)yl groups interrupted by functional groups such
as carboxy groups. Said materials and fabric softening compositions containing them
are disclosed in numerous publications such as EP-A-0,040,562, and EP-A-0,239,910.
[0016] The quaternary ammonium compounds and amine precursors herein have the formula (I)
or (II), below:

wherein Q is selected from -O-C(O)-, -C(O)-O-, -O-C(O)-O-, -NR
4-C(O)-,
-C(O)-NR
4-;
R
1 is (CH
2)
n-Q-T
2 or T
3;
R
2 is (CH
2)
m-Q-T
4 or T
5 or R
3;
R
3 is C
1-C
4 alkyl or C
1-C
4 hydroxyalkyl or H;
R
4 is H or C
1-C
4 alkyl or C
1-C
4 hydroxyalkyl;
T
1, T
2, T
3, T
4, T
5 are independently C
11-C
22 alkyl or alkenyl;
n and m are integers from 1 to 4; and
X
- is a softener-compatible anion.
[0017] Non-limiting examples of softener-compatible anions include chloride or methyl sulfate.
[0018] The alkyl, or alkenyl, chain T
1, T
2, T
3, T
4, T
5 must contain at least 11 carbon atoms, preferably at least 16 carbon atoms. The chain
may be straight or branched.
[0019] Tallow is a convenient and inexpensive source of long chain alkyl and alkenyl material.
The compounds wherein T
1, T
2, T
3, T
4, T
5 represents the mixture of long chain materials typical for tallow are particularly
preferred.
[0020] Specific examples of quaternary ammonium compounds suitable for use in the aqueous
fabric softening compositions herein include:
1) N,N-di(tallowoyl-oxy-ethyl)-N,N-dimethyl ammonium chloride;
2) N,N-di(tallowoyl-oxy-ethyl)-N-methyl, N-(2-hydroxyethyl) ammonium chloride;
3) N,N-di(2-tallowyl-oxy-2-oxo-ethyl)-N,N-dimethyl ammonium chloride;
4) N,N-di(2-tallowyl-oxy-ethylcarbonyl-oxy-ethyl)-N,N-dimethyl ammonium chloride;
5) N-(2-tallowoyl-oxy-2-ethyl)-N-(2-tallowyl-oxy-2-oxo-ethyl)-N,N-dimethyl ammonium
chloride;
6) N,N,N-tri(tallowyl-oxy-ethyl)-N-methyl ammonium chloride;
7) N-(2-tallowyl-oxy-2-oxo-ethyl)-N-(tallowyl-N,N-dimethyl-ammonium chloride;
8) N - methyl - N - (3 - tallowamidopropyl) , N-(2-tallowoyloxyethyl) ammonium chloride;
9) 1,2-ditallowyl-oxy-3-trimethylammoniopropane chloride;
and mixtures of any of the above materials.
[0021] Of these, compounds 1-8 are examples of compounds of Formula (I); compound 9 is a
compound of Formula (II). Particularly preferred is N,N-di(tallowoyl-oxy-ethyl)-N,N-dimethyl
ammonium chloride, where the tallow chains are at least partially unsaturated. The
level of unsaturation of the tallow chain can be measured by the Iodine Value (IV)
of the corresponding fatty acid, which in the present case should preferably be in
the range of from 5 to 100 with two categories of compounds being distinguished, having
a IV below or above 25. Indeed, for compounds of Formula (I) made from tallow fatty
acids having an IV of from 5 to 25, preferably 15 to 20, it has been found that a
cis/trans isomer weight ratio greater than 30/70, preferably greater than 50/50 and
more preferably greater than 70/30 provides optimal concentrability. For compounds
of Formula (I) made from tallow fatty acids having an IV of above 25, the ratio of
cis to trans isomers has been found to be less critical unless very high concentrations
are needed.
Other examples of suitable quaternary ammoniums of Formula (I) and (II) are obtained
by, e.g.:
- replacing "tallow" in the above compounds with, for example, coco, palm, lauryl, oleyl,
ricinoleyl, stearyl, palmityl, or the like, said fatty acyl chains being either fully
saturated, or preferably at least partly unsaturated;
- replacing "methyl" in the above compounds with ethyl, ethoxy, propyl, propoxy, isopropyl,
butyl, isobutyl or t-butyl;
- replacing "chloride" in the above compounds with bromide, methylsulfate, formate,
sulfate, nitrate, and the like.
[0022] In fact, the anion is merely present as a counterion of the positively charged quaternary
ammonium compounds. The nature of the counterion is not critical at all to the practice
of the present invention. The scope of this invention is not considered limited to
any particular anion.
[0023] By "amine precursors thereof' is meant the secondary or tertiary amines corresponding
to the above quaternary ammonium compounds, said amines being substantially protonated
in the present compositions due to the pH values.
[0024] For the preceding biodegradable fabric softening agents, the pH of the compositions
herein is an essential parameter of the present invention. Indeed, it influences the
stability of the quaternary ammonium or amine precursors compounds, especially in
prolonged storage conditions. The pH, as defined in the present context, is measured
in the neat compositions at 20°C. For optimum hydrolytic stability of these compositions,
the neat pH, measured in the above-mentioned conditions, must be in the range of from
2.0 to 4.5. Preferably, where the liquid fabric softening compositions of the invention
are in a diluted form, the pH of the neat composition is in the range of 2.0 to 3.0.
The pH of these compositions herein can be regulated by the addition of a Bronsted
acid. Examples of suitable adds include the inorganic mineral acids, carboxylic acids,
in particular the low molecular weight (C
1-C
5) carboxylic acids, and alkylsulfonic acids. Suitable inorganic acids include HCI,
H
2SO
4, HNO
3 and H
3PO
4. Suitable organic acids include formic, acetic, citric, methylsulfonic and ethylsulfonic
acid. Preferred acids are citric, hydrochloric, phosphoric, formic, methylsulfonic
acid, and benzoic acids.
Cationic dye fixative agent
[0025] The other essential component of the invention is a cationic dye fixative agent.
Cationic dye fixing agents, or "fixatives", are well-known, commercially available
materials which are designed to improve the appearance of dyed fabric by minimizing
the loss of dye from fabrics due to washing. Cationic dye fixatives are based on various
quaternized or otherwise cationically charged organic nitrogen compounds. Cationic
fixatives are available under various trade names from several suppliers. Representative
examples include: CROSCOLOR PMF (July 1981, Code No. 7894) and CROSCOLOR NOFF (January
1988, Code No. 8544) from Crosfield; INDOSOL E-50 (February 27, 1984, Ref. No. 6008.35.84;
polyethyleneamine-based) from Sandoz; SANDOFIX TPS, which is also available from Sandoz
and is a preferred polycationic fixative for use herein and SANDOFIX SWE (cationic
resinous compound), REWIN SRF, REWIN SRF-O and REWIN DWR from CHT-Beitlich GMBH.
[0026] Other cationic dye fixing agents are described in "Aftertreatments for improving
the fastness of dyes on textile fibres" by Christopher C. Cook (REV. PROG. COLORATION
Vol. 12, 1982). Dye fixing agents suitable for use in the present invention are ammonium
compounds such as fatty acid - diamine condensates e.g. the hydrochloride, acetate,
metosulphate and benzyl hydrochloride of oleyldiethyl aminoethylamide, oleylmethyl-diethylenediaminemethosulphate,
monostearyl-ethylene diaminotrimethylammonium methosulphate and oxidized products
of tertiary amines; derivatives of polymeric alkyldiamines, polyamine-cyanuric chloride
condensates and aminated glycerol dichlorohydrins.
[0027] The amount of dye fixing agent to be employed in the composition of the invention
is in amount of from 0.1% to 10% by weight of the composition, preferably from 0.5%
to 8% by weight, more preferably from 0.8% to 5.5% by weight of the composition.
[0028] For optimum dye fixing benefit as well as softness benefit, the weight ratio of fabric
softener to dye fixing agent is of from 60:1 to 1.5:1, more preferably from 20:1 to
3.5:1, most preferably from 10:1 to 3.5:1.
Detergent materials
[0029] For the purpose of the invention, the term "detergent materials" encompasses detergent
surfactant materials selected from soaps, non-soap anionic, nonionic, zwitterionic
and amphoteric synthetic and natural detergent surfactants which are not softeners.
Not included by this definition are the fatty acids which are fabric softeners, contrary
to said soaps components which do not have fabric softener properties.
[0030] Soaps and non-soaps anionic materials are the linear and branched primary alkyl sulfates,
alkyl ethoxysulfates, fatty oleyl glycerol sulfates, alkyl phenol ethylene oxide ether
sulfates, the C5-C17 acyl-N-(C1-C4 alkyl) and -N-(C1-C2 hydroxyalkyl) glucamine sulfates,
and sulfates of alkylpolysaccharides; anionic sulfonate surfactants such as the salts
of C5-C20 linear alkylbenzene sulfonates, alkyl ester sulfonates, C6-C22 primary or
secondary alkane sulfonates, C6-C24 olefin sulfonates, sulfonated polycarboxylic acids,
alkyl glycerol sulfonates, fatty acyl or oleyl glycerol sulfonates, alkyl ethoxy carboxylates,
and the alkali metal sarcosinates.
[0031] Nonionic detergent materials are the polyhydroxy fatty acid amides, polyethylene,
polypropylene, and polybutylene oxide condensates of alkyl phenols; alkyl ethoxylate
condensation products of aliphatic alcohols with from about 1 to about 25 moles of
ethylene oxide; ethoxylated C
6-C
18 fatty alcohols and C
6-C
18 mixed ethoxylated/propoxylated fatty alcohols; alkylpolysaccharides and the fatty
acid amides.
[0032] Zwiterrionic and amphoteric materials are the amine oxides, the alkyl amphocarboxylic
acids, the betaines such as coconut acylamidopropyldimethyl betaine and hexadecyl
dimethyl betaine.
Additional components
[0033] The composition may also optionally contain additional components such as additional
fabric softener materials, electrolyte concentration aids, stabilisers, such as well
known antioxidants and reductive agents, soil release polymers, bacteriocides, colorants,
perfumes, preservatives, optical brighteners, anti ionisation agents, antifoam agents
and chelating agents.
Additional fabric softener materials
[0034] Additional fabric softening materials may be used in addition to the di-long chain
cationic fabric softener. When used, such additional fabric softening materials will
typically be present in an amount of from 0 to 15% by weight of the composition. Such
materials are the single long chain alkyl cationic softeners and/or the fatty acids.
Single long chain alkyl cationic softeners
[0035] Such mono-long-chain-alkyl cationic softeners suitable for use herein are, preferably,
quaternary ammonium salts of the general formula
[R
2N
+R
3] X
-
wherein the R
2 group is C
10-C
22 hydrocarbon group, preferably C
12-C
18 alkyl group of the corresponding ester linkage interrupted group with a short alkylene
(C
1-C
4) group between the ester linkage and the N, and having a similar hydrocarbon group,
e.g., a fatty acid ester of choline, preferably C
12-C
14 (coco) choline ester and/or C
16-C
18 tallow choline ester at from 0.1% to 20% by weight of the softener active. Each R
3 is a C
1-C
4 alkyl or substituted (e.g., hydroxy) alkyl, or hydrogen, preferably methyl, and the
counterion X
- is a softener compatible anion, for example, chloride, bromide, methyl sulfate, etc.
Other cationic materials with ring structures such as alkyl imidazoline, imidazolinium,
pyridine, and pyridinium salts having a single C
12-C
30 alkyl chain can also be used. Very low pH is required to stabilize, e.g., imidazoline
ring structures.
[0036] Some alkyl imidazolinium salts and their imidazoline precursors useful in the present
invention have the general formula :

wherein Y
2 is -C(O)-O-, -O-(O)C-, -C(O)-N(R
5)-, or -N(R
5)-C(O)- in which R
5 is hydrogen or a C
1-C
4 alkyl radical; R
6 is a C
1-C
4 alkyl radical or H (for imidazoline precursors); R
7 and R
8 are each independently selected from R
3 and R
2 as defined hereinbefore for the single-long-chain cationic surfactant with only one
being R
2.
[0037] Some alkyl pyridinium salts useful in the present invention have the general formula:

wherein R
2 and X- are as defined above. A typical material of this type is cetyl pyridinium
chloride.
Fatty acids
[0038] Suitable fatty acids include those containing from 10 to 25, preferably from 12 to
25 total carbon atoms, with the fatty moiety containing from 10 to 22, preferably
from 16 to 22, carbon atoms. The shorter moiety contains from 1 to 4, preferably from
1 to 2 carbon atoms. The level of unsaturation of the tallow chain can be measured
by the Iodine Value (IV) of the corresponding fatty acid, which in the present case
should preferably be in the range of from 5 to 100, more preferably in the range of
from 0 to 25.
[0039] Specific examples of fatty acid compounds suitable for use in the liquid fabric softening
compositions herein include compounds selected from lauric acid, myristic acid, palmitic
acid, stearic acid, arachidic acid, behenic acid, oleic acid, coconut fatty acid,
tallow fatty acid, partially hydrogenated tallow fatty acid and mixtures thereof.
A most preferred fatty acid compound is tallow fatty acid with an Iodine Value (IV)
of 18.
[0040] When the above mentioned fatty acids are used, the fatty acid will be present in
a weight ratio of said cationic fabric softening agents having di-long chains to said
fatty acid compounds of from 25:1 to 6.5:1, more preferably from 20:1 to 10:1 and
most preferably from 20:1 to 15:1. Indeed, if used outside of these ratios, the resulting
product will tend to exhibit phase instability and/or viscosity problems.
Electrolyte Concentration Aids
[0041] Inorganic viscosity control agents which can also act like or augment the effect
of the surfactant concentration aids, include water-soluble, ionizable salts which
can also optionally be incorporated into the compositions of the present invention.
Incorporation of these components to the composition must be processed at a very slow
rate.
[0042] A wide variety of ionizable salts can be used. Examples of suitable salts are the
halides of the Group IA and IIA metals of the Periodic Table of the Elements, e.g.,
calcium chloride, magnesium chloride, sodium chloride, potassium bromide, and lithium
chloride. The ionizable salts are particularly useful during the process of mixing
the ingredients to make the compositions herein, and later to obtain the desired viscosity.
The amount of ionizable salts used depends on the amount of active ingredients used
in the compositions and can be adjusted according to the desires of the formulator.
Typical levels of salts used to control the composition viscosity are from 20 to 20,000
parts per million (ppm), preferably from 20 to 11,000 ppm, by weight of the composition.
[0043] Alkylene polyammonium salts can be incorporated into the composition to give viscosity
control in addition to or in place of the water-soluble, ionizable salts above. In
addition, these agents can act as scavengers, forming ion pairs with anionic detergent
carried over from the main wash, in the rinse, and on the fabrics, and may improve
softness performance. These agents may stabilise the viscosity over a broader range
of temperature, especially at low temperatures, compared to the inorganic electrolytes.
Specific examples of alkylene polyammonium salts include L-lysine monohydrochloride
and 1,5-diammonium 2-methyl pentane dihydrochloride.
[0044] Another ingredient is a liquid carrier. Suitable liquid carriers are selected from
water, organic solvents and mixtures thereof. The liquid carrier employed in the instant
compositions is preferably at least primarily water due to its low cost relative availability,
safety, and environmental compatibility. The level of water in the liquid carrier
is preferably at least 50%, most preferably at least 60%, by weight of the carrier.
Mixtures of water and low molecular weight, e.g., <200, organic solvent, e.g., lower
alcohol such as ethanol, propanol, isopropanol or butanol are useful as the carrier
liquid. Low molecular weight alcohols include monohydric, dihydric (glycol, etc.)
trihydric (glycerol, etc.), and higher polyhydric (polyols) alcohols.
Form of the composition
[0045] The fabric softening composition can take a variety of physical forms including liquid
such as aqueous or non-aqueous compositions.
Such compositions may be used as a rinse added product, or as a spray or foam product.
Preferably, the present composition is in a rinse added form.
[0046] The compositions of the invention can be added directly in the rinse both to provide
adequate usage concentration, e.g., at least 50 ppm and more preferably from 100 to
10,000 ppm of the liquid rinse added fabric softener compositions of the present invention.
[0047] Accordingly, a method is provided for treating fabrics comprising contacting said
fabrics in the rinse cycle with an aqueous medium containing at least 50 ppm, preferably
from 100 to 10,000 ppm of the liquid fabric softening composition of the invention.
Process
[0048] The fabric softening composition can conveniently be made according to well-known
processes to the skilled person. An exemplary disclosure is given in EP-A-0,668,902.
[0049] The invention is illustrated in the following non-limiting examples, in which all
percentages are on a weight basis unless otherwise stated.
[0050] In the examples, the abbreviated component identifications have the following meanings:
- DEQA :
- Di-(tallowoyl-oxy-ethyl) dimethyl ammonium chloride
- Fatty acid :
- Stearic acid of IV=18
- Electrolyte :
- Calcium chloride
- PEG :
- Polyethylene Glycol MW 4000
Example 1
[0051] The following fabric softening composition according to the present invention was
prepared:
| Component |
A |
| DEQA |
19.0 |
| Hydrochlorid acid |
0.02 |
| Soil Release Polymer |
0.2 |
| PEG |
0.6 |
| Perfume |
1.0 |
| Electrolyte |
1200ppm |
| Dye |
50ppm |
| Sandofix TPS |
5.0 |
| Water and minors to balance to 100% |
Example 2
[0052] The following fabric softening compositions are in accordance with the invention:
| Component |
B |
C |
D |
| DEQA |
2.6 |
2.9 |
18.0 |
| Fatty acid |
0.3 |
- |
1.0 |
| Hydrochlorid acid |
0.02 |
0.02 |
0.02 |
| Soil Release Polymer |
- |
- |
0.2 |
| PEG |
- |
- |
0.6 |
| Perfume |
1.0 |
0.5 |
1.0 |
| Electrolyte |
- |
- |
600ppm |
| Dye |
10ppm |
10ppm |
50ppm |
| Sandofix TPS |
1.6 |
1.6 |
5.0 |
| Water and minors to balance to 100% |