FABRIC SOFTENING COMPOSITION

COMPOSITION ADOUCISSANTE DE TISSUS

English Abstract

A fabric softening composition comprising a water
insoluble cationic fabric softening agent and a nonionic
stabilising agent wherein the water insoluble cationic
fabric softening agent is a biodegradable quaternary
ammonium material with at least one ester link and the
nonionic stabilising agent is selected from:
i. a linear C8 to C22 alcohol alkoxylated with 10 to
20 moles of alkylene oxide, or
ii. a C10 to C20 alcohol or mixtures thereof.
The invention also provides a process for making the
liquid fabric softening composition comprising the steps
of
i. mixing and heating the cationic fabric softening
agent and nonionic stabilising agent to form a
melt and
ii. dispersing the melt in water.

French Abstract

Composition assouplissante pour tissus, renfermant un assouplissant cationique pour tissus, insoluble dans l'eau, et un stabilisateur non ionique. L'assouplissant cationique pour tissus, insoluble dans l'eau, est un composé d'ammonium biodégradable quaternaire avec au moins une liaison ester. Le stabilisateur non ionique est choisi parmi : i) un alcool linéaire en C8-C22, alcoxylé avec 10 à 20 moles d'oxyde d'alkylène; ii) un alcool en C10-C20 ou un mélange de ce type d'alcools. L'invention porte également sur un procédé pour la production d'une composition assouplissante liquide pour tissus, comprenant les étapes suivantes : i) mélange et chauffage de l'assouplissant cationique pour tissus et du stabilisateur non ionique, donnant un produit fondu; ii) dispersion du produit fondu dans l'eau.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A fabric softening composition comprising a water insoluble
cationic fabric softening agent and a nonionic stabilising
agent characterised in that the water insoluble cationic
fabric softening agent is a biodegradable quaternary ammonium
material represented either by the formula:
<IMG>
wherein each R1 group is independently selected from C1-4
alkyl, or alkenyl groups; each R2 group is independently
selected from C8-28 alkyl or alkenyl groups;
T is <IMG> or <IMG> ; and
n is an interger from 0-5,
or by the formula:
<IMG>
wherein R1, n and R2 are as defined above, and in that the
nonionic stabilising agent is
i. a linear C8 to C22 alcohol alkoxylated with 10 to 20
moles of alkylene oxide,

2. A composition as claimed in claim 1 comprising at least 1% by weight of
the quaternary ammonium material.
3. A composition as claimed in claim 1 comprising from 0.1 to 10% by weight
of the nonionic stabilising agent.
4. A composition as claimed in claim 1 further comprising more than 0.1%
by weight of a fatty acid material.
5. A composition as claimed in claim 4 comprising from 3% to 50% by weight
of the quaternary ammonium material, from 0.5% to 5% by weight of the
nonionic stabilising agent and from 0.5 to 20% by weight of fatty acid
material.
6. A composition as claimed in claim 1 wherein the nonionic stabilising
agent has an HLB of between 10 and 20.
7. A composition as claimed in claim 6 wherein the nonionic stabilising
agent has an HLB of between 12 and 20.
8. A fabric softening composition as claimed in claim 1 wherein the water
insoluble cationic fabric softening agent comprises a compound having
two C12-28 alkyl or alkenyl groups connected to the N atom via one or
more ester links.
9. Process for making a liquid fabric softening composition as claimed in any
of claims 1 to 8 comprising the steps of
i. mixing and heating the cationic fabric softening agent and nonionic
stabilising agent to form a melt and
ii. dispersing the melt in water.

Description

- 2063463
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FA8RIC SOFTENING COMPOSITION
The present invention relates to fabric softening
compositions, in particular the invention relates to
aqueous dispersions of biodegradable fabric softening
compositions comprising a water insoluble cationic fabric
softening agent and a nonionic stabilising agent suitable
as rinse-added fabric softener compositions.
Rinse added fabric softener compositions are well known.
Typically such compositions contain a water insoluble
quaternary ammonium fabric softening agent dispersed in
water at a level of softening agent up to 7~ by weight in
which case the compositions are considered dilute, or at
levels from 7% to 50% in which case the compositions are
considered concentrates. In addition to softening, fabric
softening compositions desirably have other benefi~s. One
is the ability to confer soil release properties ~o
fabrics, particularly those woven from polyester fibres.
One of the problems associated with fabric softening
compositions is the physical instability of such
compositions when stored. This problem is accentuated by
having a concentrated composition and by storage at low
temperatures.

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Concentrates and storage stability at low temperatures are
however desired by the consumer. Physical instability
manifests as a thickening on storage of the composition to
a level where the composition is no longer pourable and
can even lead to the formation of an irreversible gel.
The thickening is very undesirable since the composition
can no longer be conveniently used.
In the past physical stability of rinse added fabric
softener compositions has been improved by the addition of
viscosity control agents or anti-gelling agents. For
example in EP 13780 (Procter and Gamble) viscosity control
agents are added to certain concentrated compositions.
The agents may include C1O_C18 fatty alcohols. More
recently in EP 280550 (Unilever) it has been proposed to
improve the physical stability of dilute compositions
comprising biodegradable, ester-linked quaternary ammonium
compounds and fatty acid by the addition of nonionic
surfactants.
With concentrated compositions comprising biodegradable
ester-linked quaternary ammonium compounds the problem of
physical instability is more acute than with traditional
quaternary ammonium compounds.
In EP 0 040 562 (Lesieur Cotelle) a nonionic
emulsifier/stabiliser is added to a concentrate comprising
an ester-linked quaternary ammonium compound to form a
viscous gel. The stabiliser is a Cl2 to Cl4 alcohol
ethoxylated with 9 molecules of ethylene oxide. The
degree of branching of the alcohol is not, however,
mentioned.
Certain nonionic stabilising agents not only stabilise
concentrated compositions comprising biodegradable

4 ~ ~
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quaternary ammonium compounds but are also environmentally
friendly, in that they show acceptable biodegradability
and are not substantially toxic in aquatic systems.
Soil release properties ar~ generally imparted to fabrics
by the use of separate soil-release agents, usually a high
molecular weight polymer, in a detergent composition or
separate treatment. For example in EP 0 398 133A (Procter
& Gamble) there is disclosed a cationic polymeric soil
release agent for use in a fabric conditioning
composition.
A disadvantage of such compositions is that the soil
release agent increases the number of components in the
formulation, in-reasing cost and making the product less
environmentally acceptable.
We have now found that fabric softening compositions
comprising biodegradable ester-linked guaternary ammonium
compounds may confer improved soil release properties to
fabrics.
Thus, according to one aspect of the invention there is
provided a fabric softening composition comprising a water
insoluble cationic fabric softening agent and a nonionic
stabilising agent characterised in that the water
insoluble cationic fabric softening agent is a
biodegradable quaternary ammonium material with at least
one ester link and the nonionic stabilising agent is
i. a linear C8 to C22 alcohol alkoxylated with 10 to 20
moles of alkylene oxide.
D

C~404 ~A
Advantageously the nonionic stabilising agent is a linear C8
to C22 alcohol alkoxylated with 10 to 20 moles of alkylene
oxide.
Preferably the compositions of the invention are liquids
comprising an aqueous base.
Advantageously the fabric softening composition comprises a
water insoluble cationic which is a compound having two Cl228
alkyl or alkenyl groups connected to the N atom via one or
more ester links.
A preferred type of ester-linked quaternary ammonium material
for use in the compositions according to the invention can be
represented by the formula:
- Rl
I
Rl N~ (CH2)n~T~R2
I
(CH2)n~T~R2
wherein each Rl group is independently selected from Cl4
alkyl or alkenyl groups; and wherein each R2 group is
independently selected from C828 alkyl or alkenyl groups;

C~404 CA
4 ~ ~i
- 4a -
O O
Il 11
T is -0-C- or -C-0-; and
n is an interger from 0-5,
A second preferred type of quaternary ammonium material
can be represented by the formula:
~C

C~404 ~A
O OCR2
(R1)3N~- (CH2)n CH
I
CH2 0 OCR2
wherein Rl n and R2 are as defined above.
Preferred materials of this class and their method of
preparation are, for example, described in US 4 137 180
(Lever Brothers). Preferably these materials comprise small
amounts of the corresponding monoester as described in US 4
137 180 for example 1-tallowoxy, 2-hydroxytrimethyl ammonium
propane chloride.
Preferably the level of ester linked quaternary ammonium
compounds is at least 1% by weight of the composition, more
preferably more than 3% by weight of the composition;
especially interesting are concentrated compositions which
comprise more than 7~ of ester-linked quaternary ammonium
compound. The level of ester-linked quaternary ammonium
compounds preferably is between 1% and 80% by weight, more
preferably 3% to 50%, most preferably 8~ to 50%.
Suitable nonionic stabilisers which can be used include the
condensation products of C8-C22 primary linear alcohols with
10 to 20 moles of ethylene oxide. The term linear alcohol
means a primary alcohol attached directly to a hydrocarbon
backbone structure. Use of less than 10 moles of ethylene
oxide, especially when the alkyl chain is in the tallow
,,F C

C3404 CA
~ Q ~
- 5a -
range, leads to unacceptably high aquatic toxicity. Since
the aquatic toxicity is related to both the number of moles
of ethylene oxide and the length of the alkyl chain we have
found that the HLB value can be used as an indication of
likely aquatic toxicity. An HLB

CA 02063463 1999-01-26
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of greater than about 12 gives rise to an acceptable acute
aquatic toxicity value of >lmg/l;EC50 48 hours for daphnia and
algae and EC50 96 hours for fish. The selection of linear
alcohols and the use of 20 moles or less of ethylene oxide
gives acceptable biodegradability to the nonionic stabiliser.
However the use of nonionic stabilisers with more than 20
ethylene oxide units will also provide the stability benefit.
The alcohols may be saturated or unsaturated. In particular
Genapol*T-110, Genapol T-150, Genapol T-200, Genapol C-200 all
ex Hoeschst AG, Lutensol* AT18 ex BASF, Genapol 0-100 and
Genapol 0-150 ex Hoechst, or fatty alcohols for example
Laurex*CS, ex Albright and Wilson or Adol*340 ex Sherex.
Preferably the nonionic stabiliser has an HLB of between 10
and 20, more preferably 12 and 20.
Preferably, the level of nonionic stabiliser is within the
range from 0.1 to 10% by weight, more preferably from 0.5 to
5% by weight, most preferably from 1 to 4% by weight.
The mole ratio of the ~uaternary ammonium compound to the
nonionic stabilising agent is within the range from 40 : 1 to
about 1:1, preferably within the range from 18:1 to about 3:1.
The composition can also contain fatty acids for example C8 -
C24 alkyl or alkenyl monocarboxylic acids or polymers thereof.
Preferably saturated fatty acids are used, in particular,
hardened tallow C16 - C18 fatty acids. Preferably the fatty acid
is non-saponified, more preferably the fatty acid is free for
example oleic acid, lauric acid or tallow fatty acid.
The level of fatty acid material is preferably more than 0.1%
by weight, more preferably more than 0.2% by weight.
Especially preferred are concentrates comprising from 0.5
Denotes Trade Mark

- 2~63~fi~'
- 7 - C3404
to 20% by weight of fatty acid, more preferably 1% to 10%
by weight. The weight ratio of quaternary ammonium
material to fatty acid material is preferably from 10:1 to
1:10.
s
The compositions of the invention preferably have a pH of
more than 2.0, more preferably less than 5.
The composition can also contain one or more optional
ingredients, selected from non-aqueous solvents, pH
buffering agents, perfumes, perfume carriers, fluorescers,
colourants, hydrotropes, antifoaming agents,
antiredeposition agents, enzymes, optical brightening
agents, opacifiers, anti-shrinking agents, anti-wrinkle
agents, anti-spotting agents, germicides, fungicides,
anti-oxidants, anti-corrosion agents, drape imparting
agents, antistatic agents and ironing aids.
The composition may also contain nonionic fabric softening
agents such as lanolin and derivatives thereof.
The invention will now be illustrated by the following
non-limiting examples. In the examples all percentages
are expressed by weight.
Example 1
Liquid fabric softening compositions were made as follows.
The cationic fabric softening agent, fatty acid and
nonionic stabilising agent where appropriate were premixed
and heated together to form a clear melt. The molten
mixture thus formed was added over a period of at least
one minute, to water at 70~C to 80~C with constant
stirring to form a dispersion.

CA 02063463 1999-01-26
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The viscosity of the compositions was measured by Haake
rotoviscometer following 21 days storage at ambient
temperature or at 5~C.
5 Composition A B C D E
Arquad*2HT1 12.8
HT TMPAC2 - 16 16 16 16
Fatty Acid3 3.2 2.7 2.7 2.7 2.7
10 Tallow llEO4 - 3
Coco 10EO5 - - 2
Tallow 20EO6 ~ ~ ~ 3
Water + minors ----------------balance-------------
Viscosity at 110s-
Ambient mPas 159 77 34 43 90
5~C mPas 155 66 38 47 gel
Composition F G
HT TMPAC2 11.6 12.6
Fatty acid3 1.9 2.1
Alcohol7 1.5 1.5
Water + Minors -- balance--
25 Viscosity at 110s-1
Ambient mPas 53 50
5~C mPas 50 50
Notes
Formulation A corresponds to a commercially available fabric
softening composition currently sold in the UK by Lever under
the trade mark COMFORT.
* Denotes trade mark

CA 02063463 1999-01-26
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1. Arquad 2HT is dihardened tallow dimethyl ammonium
chloride ex Akzo Chemie.
2. HT TMAPC is 1,2 dihardened tallowyloxy-3-trimethyl-
ammonio propane chloride ex Hoescht.
3. Pristerine*4916 a hardened tallow fatty acid ex
Unichema.
4. tallow alcohol ethoxylated with 11 moles of ethylene
oxide of HLB 13.
5. coco alcohol ethoxylated with 10 moles of ethylene
oxide of HLB 14.
6. tallow alcohol ethoxylated with 20 moles of ethylene
oxide of HLB 20.
7. Laurex CS a tallow alcohol comprising 65-80% Cl8 and
20-23% Cl6 ex Albright and Wilson.
The results show that while known fabric softening
compositions comprising conventional quaternary ammonium
compounds do not show physical instability on short term
storage at 5~C (composition A) a problem is experienced
with compositions comprising ester-linked quaternaries and
fatty acid (composition E). The results also show that
addition of selected nonionic stabilising agents
counteract destabilization to give stable concentrated
compositions.
Example 2
Liquid fabric softening compositions as given below were
made as described in Example 1. The soil release
properties imparted to polyester test pieces by treatment
with the compositions was assessed by measuring the
change in reflectance following staining and a subsequent
wash in a proprietary detergent composition. The pieces
were first rinsed for 5 minutes in 1 litre of 14~FH water
containing 0.67 ml of either composition. The pieces were
* Denotes Trade Mark
. _ . . .

CA 02063463 1999-01-26
- lo - c3404
then line dried and stained with 100 micro litres of olive
oil containing 0.06% sudan red dye. The stain was allowed
to spread for a m;n;ml~m of two days following which the
reflectance of the stained piece (Rl) was measured using an
ICS micromatch. The pieces were then washed, rinsed and
line dried using Sg/l New System Persil Automatic*ex Lever
in 14~FH water for a 15 minute wash cycle. The
reflectance of the pretreated, washed piece (R2) was
measured and the percentage detergency calculated according
to the following equation:
Ksl _ KS2
% Detergency = x 100
Ksl
(1 - Rl)2 (1 - R2)2
where Ksl = and Ks2 =
2R1 2R2
The higher the percentage detergency, the greater the soil
release benefit.
ComPosition % by weight
A B
25 Arquad 2HTl - 12.8
HT TMAPC2 11.6
Fatty acid3 1.9 3.2
Tallow llEO4 2.5
Water and minors to balance
30 % Detergency 30 21
* Denotes Trade Mark

2063463
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Notes
Formulation B corresponds to a commercially available
~ fabric softening composition, currently sold in the UK by
Lever under the trade mark COMFORT. 1, 2, 3 and 4 are-as
in Example 1.
These results show that known compositions comprising
conventional quaternary ammonium compositions (Composition
B) show a smaller soil release benefit than compositions
according to the invention (Composition A).
Example 3
Preferred compositions according to the invention are as
follows:
Composition % by weight
A B C
HTTMAPC2 11.6 11.6 11.6
Fatty acid3 1.9 1.9 1.9
Tallow llEO4 - 2.5
Tallow Alcohol7 1.5
Tallow 15EO8 - - 1.5
Isopropyl alcohol 1.6 1.6 1.6
Glycerol 1.6 1.6 1.6
Perfume, Dye + minors 0.8 0.8 0.8
Water to balance
Notes
2, 3, 4 and 7 are as in Example 1
8. is tallow alcohol ethoxylated with 15 moles of ethylene
oxide.