Note: Descriptions are shown in the official language in which they were submitted.
56Z
- 1 C. 1362
METHOD FOR PREPARING FABP.IC SOFTE21ING COMPC)SITIONS
.
~hP present invention relates to a method of
prepaxing fabric softening compositions, in particular for
preparing concentrated aqueous liquid fabric softening
compositions containing water-insoluble cationic fabric
softenins cents and fatty acids or other nonionic
materials with a low HLB.
It is known from GB 039 556 ~U~-lLEV~ - Case
C.567~ to fox~l aqueous liquid fabric softening
compositions containing up to 20~ of a mixture of a
water-insoluble cationic matexial and fatty acid, the
fatty acid acting to improve the efficiency of softening,
thereby enabling the level of the cationic material to be
reduced withsut loss of performance. It is also known
from EP 13780-A lPROCTER & GALE to form concentrated
aqueous liquid fabric softening compositions from a
mixture of a water-insoluble cationic material and a
nonionic material selected from hydrocarbons, fatty acids,
fatty esters and fatty alcohols, the nonionic material
acting to improve the viscosity characteristics of the
,
5;~
- 2 - C.1362
product when the level of cationic material i6 above 8%.
It is also known from Go 2 039 556 and EP 13780 that
preferred compositions can also include low levels of
electrolyte such as respectively sodium chloride or
calcium chloride, to further control product viscosity.
It is found that when such a composition is prepared
by dispersing a pre-mix of the cationic and nonionic
materials in water to which the electrolyte has already
been added, followed by thorough mixing, the viscosity of
the end product is often still higher than desired,
particularly when the total active level exceeds about 8
It has been proposed in EP 52517 (PROCTER & GAMBLE)
that where the composition is based on a mixture of
cationic materials, some electrolyte is added, together
with a premix of the cationic materials, to water with
vigorous agitation and thereafter a remaining portion of
the electrolyte is added. Also in US 3 681 241 (RUDY it
is proposed that compositions based on a mixture of
~ationic materials are preferably formed in such a manner
as to be substantially free of electrolytes, electrolytes
being optionally added to the resultiny product to
regulate the viscosity thereof. Further, GB 1 104 441
(UNILEV~R) discloses that products based on a cationic
softener and a fatty acid ethanolamide may be made by
adding water to a premix of the cationic and nonionic and
then, after cooling, adding an electrolyte such as sodium
carbonate to thin the product.
We have surprisingly found that, where the
composition is based on a mixture of a cationic fabric
softener and a nonionic material of low ~LB, and is formed
by adding a premix of the ~ationic and the nonionic to
water, if the electrolyte is added only after the mixing
stage but not before, the end product viscosity is lower.
- 3 - C.1362
This enables the level of electrolyte used to be reduced
without detriment to the properties of the product. It
has also surprisingly been found that this post-addition
of electrolyte can improve the long term stability of the
product.
Thus, according to the invention there is provided a
process for preparing a cGncentrated aqueous liquid fabric
softening composition containing at least 8% by weight
water-insoluble cationic fabric softener, said process
comprising the steps ofO
( i) forming a molten mixture containing the water-
insoluble cationic fabric softener and a nonionic
material having an HLB of not more than lo;
( ii) addir.g the molten mixture to water at an elevated
temperature;
(iii) mixinq the molten mixture and the water together to
form a dispersion of the molten mixture in droplet
form in the water; and
ivl adding electrolyte in the form of a source of
lithium, sodium, potassium, calcium, magnesium or
aluminium ions thereto, characterised in that the
electrolyte is added after, but not before, the
formation of said dispersion.
The water insoluble cationic fabric softener can be
any fabric-substantive cationic compound that has a
solubility in water at pi 2.5 and 20C of less than 10
g/l. Highly preferred materials are quaternary ammonium
salts having two C12-C2~ alkyl or alkenyl chains,
optionally substituted or interrupted by functional groups
such as OH, C -CONH, -COO-, etc.
6~
- 4 - C.1362
Well known species of substantially water-insoluble
quaternary ammonium compounds have the fo~ula
R~ R3
N X
R2 ~4
wherein l and R~ represent hydrocarbyl groups of from
about 12 to about 24 carbon atoms; R3 and R4 represent
hydrocarbyl groups containing from 1 to about 4 carbon
atoms; and X is an anion, preferably selected from halide,
methyl sulfate and ethyl sulfate radicals. representative
examples of these quaternary softeners include ditallow
dimekhyl ammonium chloride; ditallow dimethyl ammonium
methyl sulfate; dihexadecyl dimethyl amm~nium chloride;
di(hydxogenated tallow alkyl~ dimethyl ammonium chloride;
dioctadecyl dimethyl ammonium chloride; dieicosyl dimethyl
ammonium chloride; didocosyl dimethyl ammonium chloride;
di~hydrogenated tallow dimethyl ammonium methyl sulfate;
dihexadecyl diethyl ammonium chloxid~; di(coconut alkyl)
dimethyl ammonium chlorideO Ditallow dimethyl ammor.ium
chloride, di(hydrogena~ed tallow alkyl) dimethyl ammonium
chloride, di(coconut alkyl~ dime~hyl ammonium chloride and
dilcoconut alkyl) dimethyl ammonium methosulfate are
preferred.
Another class of preferred water-insoluble cationic
matexial~ are the alkylimidazolinium salts believed to
have the formula:
5~
- 5 - C.1362
CH Ch2
N / N - C2H~ T - c_~7
f ~9
X6
~8
wherein R6 is an alkyl or hydroxyal~yl group containing
from 1 to I, preferably 1 or 2 carbon atoms, R7 i5 an
alkyl or alkenyl group containing from 8 to 25 carbon
atoms, R8 is an alkyl or alkenyl group contairling from &
to 25 carbon atoms, and Rg is hydrogen or an alkyl group
containing from 1 to 4 carbon atoms and A is an anior"
preferably a halide, methosulfate or ethosulfate.
Preferreu imidazolinium salts include 1-methyl-1-
(tallow~lamido-) ethyl -2-tallowyl-4,5-dihydro-
imidazolinium methosulfate and l-methyl-l-(palmitoylamido)
ethyl -2-octadecyl-4,5- dihydro-imidazolinium chloriùe.
Other useful imidazolinium materials are 2-heptadecyl-1-
meth~l-l- [2-stearylamido)-ethyl-imidazolinium chloride
and 2-lauryl-1-hydroxyethyl-1-oleyl-imidazolinium
chioride. Also suitable herein are the imidazolir.ium
fabric softening components of US Patent No 4 127 489.
In the present invention, the water-insoluble
cationic softener is present at a total level ol at least
8%. The maximum level of cationic softener is determined
by practical considerations; even with the nonionic
materials to control viscosity it is not generally
possible to prepare stable, pourable emulsions containing
more than 26~ of cationic softener. When particularly
hiqh concentrations are desired, it is preferred to use an
if
- 6 - C.1362
imidazolinium softener and preferred compositions contain
from 12% to 26~ of imidazolinium softener. When a
di-long chain non-cyclic mono-quaternary softener is
employed, it is preferred not to exceed a level of 22~,
and a preferred range is 10% to 18%.
The compositions further contain nonionic materials
having an ~LB of not more than 10, preferably not more
than 8. The HLB scale is a known measure of the
hydrophilic-lipophilic balance in any compound and can be
determined from trade literature Nonionic materials
having lower HLB values are less hydrophilic than those
having higher HLB values.
Preferred nonionic materials are selected from:
( i) C8-C24 fatty acids;
( ;i) esters of C8-C24 fatty acidc with monohydric
alcohols containing from 1-3 carbon atoms;
(iii) C10-C g fatty alcohols;
( iv) lanolin and derivatives thereof; and
v) fat y acid esters of C2-C8 polyhydric alcohols.
Particularly prelerred examples of such nonionic
materials include lauric acid, myristic acid, palmitic
acid, iso-stearic acid, stearic acid, oleic acid, linoleic
acid, undecanoic acid, methyl laurate, ethyl myrista~e,
ethyl stearate, methyl palmitate, dodecanol, tetradecanol,
hexadecanol, octadecanol, lanolin, lanolin alcohols,
hydrogenated lanolin, ethylene glycol monostearate,
glycerol monostearate and mono-iso~ stearate, sorbitan
monostearate and mono-iso-stearate.
- 7 - C.1362
The nonionic material may be present at a level ox
about 1~0% to about 6.0%, preferably between about 1.6
and about 4.0~.
The electrolyte is selected from the salts of
lithium, sodium, potassium, calcium, magnesium, aluminium
and mixtures thereof. Aluminium salts are most
preferred. Sodium and potassium salts are least
preferred. Preferably the salts contain monovalent
anions. Pxeferred examples include aluminium chloride,
aluminium chlorhydrate, calcium chloride, calcium bromide,
calcium nitrate and magnesium chloride. The preferred
level of highly ionic electrolyte in the inal product is
at least 10 ppm and less than 3,00~ ppm, most preferably
50 ppm to 2,OGO ppm. In the case of elcctrolytes with a
more covalent character such as aluminium chlorhydrate,
the preferred level is at least 50 ppm and less than
12,000 ppm, most preferably from 120 to 6,0~0 ppm.
The first step in the process of toe invention i5
the formation of a molten mixture oE cationio and nonionic
romponents. The temperature of this mixture is suitably
less than lOO~C. When this molten mixture is added to
water at an elevated temperature, such as above 40~C,
preferably above 60C, and thorollghly mixed, a dispersion
of the active materials in droplet form is created. The
water preferably contains substantially no electrolyte at
this stageO Some electrolyte may be tolerated however
provided that the weight ratio of electrolyte in the final
product to thaw initially present is a least 3:1 and
provided that the water initially contains no more than
300 ppm electrolyte. It is preferred thaw the level of
cationic material in this dispexsion is from 8% to 40~ by
weight and the level of the nonionic material is
pxeferably l Jo 9~ by weight. While this dispersion may
be cooled to ambient temperature at this stage, it is
so
.1362
preferred not to cool the dispersion until after the
addition of the electrolyte. The electrolyte must be
added after the dispersion of the active material in
droplet form has been created. it this stage, provided
that at least 8% cationic fabric softener has been addeu,
further amounts of the molten mixture may be added. The
electrolyte is preferably added in the form of a
concentrated solution, such as about 1-10% by weight.
Thus in a preferred embodiment of the invention the
electrolyte is added in the form of a concentrated
solution, after the formation of the dispersion but before
the dispersion is cooled below 40C. This is of
particular benefit if the cationic softener contains
hardened (ie mainly saturated) alkyl groups.
Where the cationic raw material used for making the
product already contains electrolyte, we have found it to
be of advantage ii at least a portion of the added
electrolyte contains the tame cation. Thus, where for
example the cationic raw material contains sodium ions,
the added electrolyte preferably also contains some sodium
ions, advantageously together with an electrolyte
containing more highly charged ions, such as calcium ions.
The compositions may also contain one or more
optional ingredients selected from non-aqueous solvents
such as Cl-C4 alkanols and polyhydric alcohols, pi
buffering agents such as weak acids eg phosphoric, benzoic
or citric acids (the pH of the compositions are preferably
less than 6.0), antigelling agents, perfumes, perfume
carriers, fluorescers, colourants, hydrotropes,
antifoaming agents, antiredeposition agents, enzymes,
optical brightening agents, opacifiers, stabilisers such
as guar gum and polyethylene glycol, anti-shrinkillg
agents, anti-wrinkle agents, fabric crisping agents,
5~
- 9 - C.1362
spotting agents, soil-release agents, germicides,
fungicides, ~nti-oxidants, anti-corrosion agents,
preservatives, dyes, bleaches and bleach precursors, drape
imparting agents and antistatic agents.
These optional ingredients may be added to the
active melt, to the water before forming the dispersion or
after adding the electrolyte as appropriate.
It is particularly advantageous if the water to
which the molten cationic/nonionic mixture is added
already contains a dispersing aid. This dispersing aid
should be a water-soluble non-anionic surfactant having an
HLB of greater than 10, ideally greater than 12. In this
context, the term ~Iwater-soluble~ means having a
solubility of more than l.Og/l in water at pH 205 and at
, 20C. Preferred examples include ~-ater-soluble
quaternary ammonium salts (such as Arquad ~6, Arquad~2C),
ethoxylated quaternary ammonium salts (such as Ethoquad
2~ 0/12), quaternary diamine and ethoxylated diamine salts
(such as Duoquad T3, ethoxylated amines and diamines (such
as Ethoduomee ~'r~25, Ethomeen T/lS) and their acid salts,
ethoxylated fatty esters of polyhydric alcohols such as
sorbitan monolaurate 20 EO), ethoxylated fatty alcohols
such as Brij~58 - cetyl alcohol 20 EO) and ethoxylated
fatty acids (such as Myra 49 stearic acid 20 EO).
A useful test for whether a particular material will
be a suitable dispersing aid is one which xesults in a
lower product viscosity after the addition of the
electrolyte.
The dispersing aid may be present at a level of at
least 0.1%, prefexably at least 0.2~ by weight based on
the final product. Usually, it will not be necessary to
~e~o~leS no my
S62
- 10 - C.136
use more than 2.5%, preferably not more than 1.0%
dispersing aid.
It is preferred that the weight ratio of the
catior.ic fabric softener material to the low HLB nonionic
material is in excess of about 2.0:1, such as in excecs ox
about 3O0:1, most preferably within the range of 5:1 to
20:1. A preferred composition contains about 8~ to about
22% of the cationic material, about 1.0% to about 6% of
the nonionic material and from about 0.01~ to about 0.2%
of the electrolyte.
The invention will now be illustrated by the
following non-limiting examples, in which parts and
percentages are by weight, based on the weight of the end
product. Where materials are referred to by their
commercial names, the percentages quoted are percentages
of the active materials.
EXAMPLE 1
A homogenous molten premix was prepared containing
10.~ dl~soft tallow dimethyl ammonium chloride (Arquad
d~'~ 2T) and 2.6% hardened tallow fatty Acid (Prist~rene 916).
This premix was added at a temperature of 60C to
demineralised water at the same temperature. After
thorough mixing with a high speed constant torque stirrer
the dispersion formed was allowed to cool to 25C and
thereafter 0.1% calcium chloride (in the form vf a 10%
solution) and l perfume were added.
The viscosity oi the product measured llO sec 1 was
30cP.
~e,70~5 Z/~Q~e, ~?~
is
C.1362
The experiment was repeated with the only difference
that the calcium chloride was pre-dissolved in the water.
In this case the product viscosity was 438 cP.
This example demonstrates the benefit of
post-addition of the electrolyte.
EXAMPLE 2
Example 1 was repeated using a molten pre-mix of 17%
dilsoft tallow imidazolinium metllosulphate ~Varisoft 475)
and 3% Pristerene 4916. In this example, various levels
of various electrolytes were added. The viscosity of the
product was measured immediately after preparatior. and
then again after lZ weeks storage at room temperature.
The results are set out in the followins Table.
Electrolyte Level Viscosity
Initial After storaqe
_ . _ .,
NaCl 0.2% 72 400
CaCl~ 0.2% 62 12C
MgCl2 0.17% 48 91
~lCl3 ~15~ ~0 67
This example illustrates the benefit of using
calcium, magnesium or aluminium salt as the electrolyte,
rather than sodium salts
EXAMPLE _
Similarly beneficial results can be obtained by
processing in the same manner compositions with the
following formulations:
56~
- 12 - C.13~2
A. Arquad 2HT 12.0%
Pxisterene 4916 1.5~
CaC12 (added at 60C) 0.03%
Water balance
Similar results are obtained when the calcium
chloride is replaced by the same level of aluminium
chloride or sodium chloride, added at 60C and/or when the
level of Arquad 2HT and Prist~rene 4916 are changed to
10~9% and 2.6% respectively. A lower initial viscosity
is achieved with these products than if identical
formulations are prepared by adding the electrolyte after
cooling.
. .
B. Varis~ft~475 14.5
Hardened xape seed fatty acid 3.5
CaC12 or ~gC12 0.~
water balance
20 C. Arquad 2T 17.0%
Pristerene 4916 1.0%
Aluminium chlorhydrate 1.0%
Water balance
25 D. Arquad 2T 10.9~
Pristerene 4916 2.6%
Perfume 1.0%
CaC12 tadded at 60C) 0.0~5%
Water balance
E. Di(hardened tallow) imidazolinium
methosulphate IVariso~t 445) 11. 0
Commercial iso-~tearic acid lex Emery) 2.5
NaCl 0.15~
water ba:Lance
c~/eno fez z,~
5~
- 13 - C.1362
This composition is particularly beneficial if the
sodium chloride is added at 60C, and still more
beneficial if the sodium chloride is replaced by calcium
chloride, magnesium chloride or aluminium chlor.ide.
F Varisoft 445 12.2%
. 1 Prifac~796~ (unhardened soyabean
fatty acid containing 54~ linoleic
acid and 30% oleic acid ~8~
Calcium chloride 0~%
Water balance
EXAMPLE 4
15 Similarly beneficial results can be obtained by
processing in the same manner compositions with the
following formulations:
XAMPLE NO 4~, 4B 4C 4D 4E 4F 4G
20 Ingredients
Arquad ZHT 22 12 12 8 18 12 8
Lanolin 4 2 6 4 - - -
Lanolin alcohol (Hartolan) - - 6
Z5 Calcium chloride* 0.1 O.D7 0.05 0.03 0.1 0.1 0.1
Perfume
Water --balance------------
*Added to the dispersion aftex cooling. The calcium
chlorite may be replaced by a similar level of aluminium
chlorideO Beneficial results may be obtained by adding
the calcium chloride or other electrolyte before cooling
the dispersion.
In this Example the Arquad 2~T may be replaced by
Varisoft 445.
'I-
~e~o fes f k-
- l - C.13~2
EXAMPLE 5
Similarly beneficial results can be obtained by
processing in the same manner compositions with the
following formulations:
EXAMPLE N0 5A 5B 5C 5D 5E
In~redient~
Arquad 2HT 12 8 9 15 12
Octadecanol 1 l 3 5 6
Calcium chloride 0.1 0.1 0.06 0.1 0.05
Perfume 0.6 - - l.0 0.6
Water balance
In this Example the calcium chloride may be added
after or (more preferably) before cooling the dispersion.
Calcium chloride may be replaced by magnesium or aluminium
chloride. Arquad 2HT may be replaced by Varisoft 445.
The octadecanol may be replaced by glycerol monostearate,
glycerol mono-iso-stearate, sorbitan monost~arate or
~orbitan mono-iso-stearate. Any two or more of these
modifications may be combined.
~5 EXAMPLE 6
The following formulation was prepared by the method
set out below.
30 Arquad 2HT 12.0%
Lanolin 4.0~
Phosphoric acid 0~03%
Perfume 0.
Calcium chloride Q.05%
Dye 0.0075%
Water balance
so
- 15 - C.1362
The molten mix the Arquad 2HT and the lanolin was
formed at 60C. This molten mix was added to
demineralised water at 60C, which already contained the
phosphoric acid (added as a pH buffer). After thorough
mixing to form a dispersion of the active materials in
droplet form, the calcium chloride was added in the form
of a 10~ solution. ThPreafter the mixture was cooled to
ambient temperature and the perfume and dye added.
EXA~iPLE 7
The following formulations demonstrate the range OL
active levels that are possible within the scope of this
invention. In each case the active materials were
premixed at 60C, added to ~-ater at the same temperature
and shear mixed to form a dispersion in droplet form.
Then the calcium chloride was added in the form of a 10~
solution. After further mixing the perfume and dye were
added and thereafter the mixture was cooled to ambient
temperature.
EXAMPLE NO 7~ 7B 7C 7D
Ingredients %
Arquad 2HT (hard) 12.5 14.7 17.6 14O5
Pristerene 4916 1.7 2.0 2.4 3.5
CaC12 0.05 0.06 0.07 0.05
Perfume 0.55 0.75 0O75 1.0
Dye 0.0075 0.0075 0.0075
Water balance
Total active level 14O2 16O7 ~0.0 18.G
56Z
- l C.1362
EXAMPLE NO 7E 7F 7G 7H 7I
_
In redients t%)
_ _ _ _
Axquad 2T (soft) 12.0 14~0 16.53 11.5 11.5
Pristerene 4916 1.5 2.0 2.07 2.0 2.3
CaC12 0.04 0.06 0~07 0.03 0.03
~erf~e 0.55 0.75 0.75 0.55 0.55
Dye 0.0075 0.0075 0.0075 0.0075 0.0075
~JatPr balance----------------
EXAMPLE 8
the benefit of including a dispersi~.s aid in the
water to which the active premix is added is illustrated
as follows. An active premix was prepared by mixing 10. 5
parts of Arquad 2HT with 2.5 parts Pristerene 4961 arld
heating to 70C. This premix was then added to distilled
water at 70C containing the dispersing aid. After
stirring to form a dispersion in droplet form calcium
chloride was added to the hot mixture using a 10%
solution. The end product composition was:
Arquad 2HT 10.5%
Pristerene 4916 2.5%
CaC12 0.03%
Dispersing aid 0.5%
fter cooling to room temperature the viscosity Gf
each product was measured at 110 sec at 25C. Various
materials were used as dispersing aidsO The results were
as follows:
56~
- 17 C.1362
EXAMPLE NO DISPERSING I (HLB) VISCOSITY (cP)
PA Ethoduomeen T/25 (18.5) 40
8B ~yrj 4g (15.0) 30
8C Brij 76 (12.4) 24
8D None (Control) 204-~40
8E Span ~0 ( 8.6) 351
In a further set of experiments using an appar~tu~
lC of slightly different dimensions but otherwise using a
similar technique, the results were:
EXAMPLE NO DISP_ SIN RID (HLB) VISCOCITY (cP)
l 8F Arquad 16 (15. 8) 3
8G Ethoqua~d 0/12(about 15) 27
8H Duo~,~c~T (10.7) 219
8I None (controi) 300
These results demonstrate that the product YiSCosity
is lowered when the dispersing aid has an HL~ of more than
lG (Example 8H for instance) but not when the dispersing
aid is less than 10 (Example 8E). Alto it it apparent
that the benefit is most noticeable where the dispersing
aid has an HLB above 12.0 (Examples 8A to 8C~ 8F and 8G~.
The dispersing aids used in this Example are
commercial ~laterials which are approximately as follows.
Ethoduomeen T/25: Ethoxylated ~-tallowyl 1,3 propane
diamine with 15 ethoxylene oxlde groups pex molecule
Myr] 49: Ethoxylated stearic acid with 20 ethylene
oxide groups per molecule.
O/e~s a ks
- 18 - C.1362
~rij 76: Ethoxylated stearyl alcohol with ~0
ethylene oxide groups per molecule.
Span 20: Sorbitan monolaurate.
Arquad 16: Cetyl trimethyl ammonium chloride.
~thoquad 0/12: Oleyl, methyl bis (2 hydroxyethyi)
ammonium chloride.0
Duomac T: N-tallowyl 1,3 propane diamine diacetate.
EXAMPLE 9
Using the procecs described in Example 1, a product
was formed contair.ing 10.9% Arquad 2T, 2.6% Pristerene
4916, 0.05% calcium chloride and 0.75% post-dosed perfume.
The calcium chloride was added either before addition of
the molten active to the water (pre-dosed), after
formation of the dispersion lpost-dosed) or part pre~dcsed
and part post-dosed. In each case the viscosity of the
product was measuredO The results were:
Pre-dosed CaCl~%) Post-dosed Ca 17 to) Viscosity (cP)
2~
0 ~.05 38
0.02 0.03 322
0~05 0 948
These results demonstrate the particular benefit of
adding all the electxolyte after the formation of the
dispersion.
5~i~
- 19 - C.1362
In all the above Examples, the initial level of
electrolyte in the process water was less than 10 ppm.
EXAMPLE lO
82.5 parts of water containing 50 ppm Ca/~.gCO3 water
hardness and small amounts of dye were heated to 66C in a
vessel containing 3 inclined paddles of 0.88 x vessel
dia~.eter. 17.5 parts of a premix of Arquad 2H5~ (75%
active) and Pris~erene 4916 at 65C was added to the
stirred hot water over a period of lO minutes via a jet
manifold between the top two agitators. This mixture was
stirred for 20 minutes at which point 0.25 parts of a 10%
CaCl2 solution was added. After stirring for a further
10 minutes the mixture was cooled to 35C. 0.72 parts of
perfume were added and stirring continued for a further 5
minutes. The product was finally cooled to 30C and
stored.
The final product had the following composition
Arquad 2HT 12O0
Pristerene 4916 1.5
Perfume 0.72
Added CaCl2 0.025
Water and minor ingredientsto 100
