Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
:~LZ~6~i
- 1 - C.1344
DETERGENT COMPOSITIONS
The present invention relates to high-foaming liquid
detergent compositions suitable for use in fabric washing,
shampoos, and above all, in manual dishwashing operations
in both hard and soft water.
The term "dishes" as used herein means any utensils
involved in food preparation or consumption which may be
required to be washed to free them from food particles and
other food residues, greases, proteins, starches, gums,
10 dyes, oils and burnt organic residues.
GB 1 429 637 (Unilever~ discloses hand dishwashing
compositions containing as detergent-active material a
water-soluble salt of a di(C7-Cg) alkyl ester of
15 sulphosuccinic acid, in combination with an alkyl sulphate
or an alkyl ether sulphate. Various Cll-C15 alkyl
ether sulphates having different chain length distributions
and degrees of ethoxylation are used, as follow~:
(i) Sulphated C12-C14 linear primary alcohols with
degrees of ethoxylation of I to 12, exemplified by
Empimin (Trade Mark) 3023 and Empimin (Trade Mark~
3003 ex Albright & Wilson, which are sulphated
58E220
- 2 - C.13~4
narrow-cut coconut alcohols with average degrees of
ethoxylation of 10 and 3 respectively~ and by Alfol
(Trade Mark) 1214-7E0 ex Conoco, which is sulphated
55% C12/45% C14 straight-chain alcohols with an
average degree of ethoxylation of 7.
(ii) Sulphated C12-C15 primary alcohols (about 75%
linear, 25% 2-methyl-branched) having average
degrees of ethoxylation of 1 to 12, exemplified by
Dobanol (Trade Mark) 25-3 èx Shell, which has an
average degree of ethoxylation of 3.
(ili) Sulphated random Cll-C15 secondary alcohols
having average degrees of e~hoxylation of 7 to 30,
~5 exemplified by Tergitol (Trade Mark) 15-S-7 and
15-S-12 ex Union Carbide which are believed to have
average degrees oE ethoxylation of 7 and 12
respectively.
GB 2 108 520, GB 2 104 913, GB 2 105 325,
EP 71413 and EP 71414 (Unilever) disclose high-foaming
combinations of certain dialkyl sulphosuccinates,
particularly those having C6 and C8 chains, with
C10-Cl8 alkyl ether sulphates having degrees of
ethoxylation of from 1 to 12, and in particular with
Dobanol (Trade Mark) 25-3A ex Shell which, as indicated
above, is a sulphated C~2-C15 primary alcohol (about
75% linear and 25% 2-methyl branched) (ammonium salt)
having an average degree of ethoxylation of 3.
The present invention is based on the ob~ervation
that in liquid detergent composi~ions based on dialkyl
sulphosuccinates and alkyl ether sulphates both:
formulation and perfor~ance benefits may be obtained by
~5 using a particular selected group of alkyl ether sulphates.
~L2~
_ 3 _ C.1344
These benefits are especially apparent at relatively low
ratios of sulphosuccinate to ether sulphate.
The present invention accordingly pr~vides a foaming
liquid detergent composition in the form of a clear aqueous
solution containing at least 2% by weight of an active
detergent mixture comprising:
(a) a water-soluble salt of a dialkyl ester of
sulphosuccinic acid in which the alkyl groups may be
the same or different, and
(b~ a C10 Cl8 primary alkyl polyethoxy sulphate
containing 20~ by weight or less of Cl~ and above
chain length material and having an average degree
of ethoxylation of from l to 12,
the weight ratio of (a) to (b) being within ~he range of
from 5:1 to 0.5 to 1, preferably 4:1 to l:l and especially
3:1 to l:l.
Although in principle the concentration of the
active detergent mixture in the composition may be as high
as desired, provided that an aqueous solution can be
obtained, it is preferably in the 2 to 60% by weight range
and more preferably in the 5 to 40% by weight range.
Th~ composition of the present invention may if
3 desired contain other detergent-active materials within its
active detergent mixture, provided that the composition is
substantially free of alkyl polyethoxy sulphates (ether
sulphates) other than those defined under (b) above.
It is, however, preferred that at least 2% by weight of the
whole composition~ preferably at least 5% and more
`: preferably 10%, is constituted by dialkyl sulpho
6~
- 4 - C.1344
succinate(s). Preferred additional ingredients are
discussed in more detail below.
The dialkyl sulphosuccinate component (a) may if
desired by constituted by a mixture of materials o
different chain lengths, of which the individual dialkyl
sulphosuccinates themselves may be either symmetrical (both
alkyl groups the same) or unsymmetrical (with two different
alkyl groups~.
The detergent-active dialkyl sulphosuccinates are
compounds of the formula I:
CH2 - CH - S0 X
CE~l CR2
wherein each of Rl and R2, which may be -the same or
different, represents a straight-chain or branched-chain
alkyl group having from 3 to 12 carbon atoms, preferably
from 4 to 10 carbon atoms and more preferably from 6 to 8
carbon atoms, and Xl represents a solubilising cation,
that is to say, any cation yielding a salt of the formula I
sufficiently soluble to be detergent-active. The
solubilising cation Xl will generally be monovalent, for
example, alkali metal, especially sodium; ammonium; or
substituted ammonium, for example, ethanolamine. Certain
divalent cations, notably magnesiumr are however also
suitable.
3o
The alkyl groups Rl and R2 are preferably
straight-chain or (in mixtures) predominantly straiyht-
chain.
Among dialkyl sulphosuccinates that may
advantageously be used in the composition of the invention
- 5 - C.1344
are the C6/C~ unsymmetrical materials described and
claimed in GB 2 105 325 (Unilever); the dioctyl
sulphosuccinate/ dihexyl sulphosuccinate mixtures described
and claimed in GB 2 104 913 (Unilever); and the mixtures of
symmetrical and unsymmetrical dialkyl sulphosuccinates
described and claimed in GB 2 108 520 (Unilever).
If desired the co~position of the invention may
additionally include one or more of the sulphonate-type
detergents conventionally used as the main detergent~
active agent in liquid compositions, for example, alkyl-
benzene sulphonates (especially Cg-Cl5 linear alkyl-
benzene sulphonates), secondary alkane sulphonates,
alpha-olefin sulphonates, alkyl glyceryl ether sulphonates,
and ~atty acid ester sulphonates. Of course dialkyl
sulphosuccinates are themselves sulphonate-type detergents.
If such additional sulphonate-type materials are present,
the total sulphonate preferably predominates in the active
dëtergent mixture of the composition of the invention. If
no such additional sulphonate-type materials are present,
the sulphosuccinate alone preferably predominates.
If desired there may also be present one or more
primary or secondary alkyl sulphates. If present, these
together with any sulphonate material as mentioned above,
including the dialkyl sulphosuccinate, preferably
predominate in the active detergent mixture of the
composition of the invention.
The alkyl polyethoxy sulphates or alkyl ether
sulphates constituting component ~b) of the composition of
the invention are compounds of the general formula II:
R3 - O - (CH2CH2O)n S3X2 (II)
wherein R3 is an alkyl group haYing from 10 to 18 carbon
~z~
- 6 - C.1344
atoms, X2 is a solubilising cation, and n, the average
degree of ethoxylation, is from 1 to 12, preferably from 1
to 8. In any given alkyl ether sulphate, a range of
differently ethoxylated materials, and some unethoxylated
material, will be present and the value of n represents an
average. The unethoxylated material is, of course, alkyl
sulphate. If desired, additional alkyl sulphate may be
admixed with the alkyl ether sulphate, to give a mixture in
which the ethoxylation distribution is more weighted
towards lower values.
The particular ether sulphates used according to ~he
present invention are derived from primary aliphatic
alcohols and are distinguished by a content of 20% by
weight or less of material having a chain length of C14
and above. The content of such long-chain material is
preferably less than 10~ by weight, and it is especially
advantageous to use an ether sulphate substantially free of
such material.
It is also preferred that the content of C11 and
shorter chain length material is as low as possible. Thus
the ether sulphate used according to the present in~ention
preferably consists predominantly of C12 and C13
material.
Table 1 shows typical chain length distributions for
some commercially available alkyl ether sulphates. Degrees
of ethoxylation are omitted from the Table since most
manufacturers provide a range of differently ethoxylated
materials.
- ~7 c.~
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Z o ~ I o I ~o O ~ ' x
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- ~ - C.134~
Preferred materials for use in the present invention
are the Dobanol (Trade Mark) 23 series from ~hell, which
are virtually free of C14 and higher chain length
material.
Materials such as Dobanol (Trade Mark~ 25 ex Shell
and Alfol (Trade Mark) 12-14 ex Conoco are clearly outside
the scope of the present invention.
The ether sulphates used according to the present
invention containing 20~ or less of C14 and above chain
length material are preferably based on straight-chain or
predominantly straight-chain alcohols. The Dobanol 23
series ex Shell, which are highly preferred for use
1~ according to the invention, consist of 75~ straight-chain
material and 25% 2-methyl-branched material.
Difficulties have been encountered in preparing
clear, stable liquid detergent compositions based on
dialkyl sulphosuccinates and alkyl ether sulphates. At
relatively high ratios of sulphosuccinate to ether suIphate
(3:1 and above) relatively large quantities of hydrotrope
are required in order to obtain homogeneous solutions
having acceptable low temperature stability, as manifested
by a low cloud point, and in some cases acceptable
formulations cannot be obtained even using large quantities
of hydrotrope. Hydrotropes are materials present in a
formulation to control solubility, viscosity, clarity and
stability, but which themse:Lves make no active contribution
to the performance of the product. Examples of hydrotropes
include lower alipha~ic alcohols, especially ethanol; urea;
lower alkylbenzene sulphonates such as sodium toluene and
xylene sulphonates; and combinations of these. The lower
alcohols function mainly as viscosity reducers, and urea
and lower alkylbenzene sulphonates mainly as solubilisers.
- Hydrotropes are expensive and take up room in a formulation
~2203~
~ 9 - C~1344
without contributing to its performance, and it is
therefore desirable to use as small quantities of them as
possible.
The clarity and stability of compositions based on
dialkyl sulphosuccinates and conventional ether sulphates
such as Dobanol 25 can be improved by lowering the ratio of
sulphosuccinate to ether sulphate, but this also causes a
drop in foaming performance. With the speci~ic ether
sulphates used according to the invention, however, the
ratio can be lowered much further without a drop in
performance, so that compositions having both acceptable
physical characteristics and excellent foaming performance
can be obtained.
~5
For example r sulphosuccinate/Dobanol 25 and
sulphosuccinate/Dobanol 23 mixtures have very similar
foaming performances at a ratio of 4:1, but at 2:1 the
performance of the former mixture has deterioriated
considerably while that of the latter mixture is virtually
unchanged.
The ether sulphate used in the composition of the
invention has a degree of ethoxylation n of 1 to 12,
preEerably 1 to 8. Materials having n values of 2, 3 and
6.5 have all been found to give excellent results in
compositions according to the invention. The range of 1 to
8 apparently gives optimum detergent properties in
conjunction with the predominant chain lengths of C12 and
3 ~13-
As previously mentioned, additional detergent-
active materials may be present in the composition,
provided that ether sulphates other than those ~peci~ied
under ~b) above are absent. Thus the ether sulphates may
be supplemented or partially replaced by other sulphate-
10 - C.1344
type detergents, notably primary and secondary alkyl
sulphates, and/or by ethoxylated nonionic detergents having
from 8 to 15 carbon atoms and average degrees of
ethoxylation of from 5 to 14.
Preferred nonionic detergents are short-chain
high-foaming ethoxylated alcohols of the general formula
III:
4 G (CH2CH20)m (III)
wherein R4 is an alkyl group, preferably straight-chain,
having from 8 to 12 carbon atoms, and the average degree of
ethoxylation m is from 5 to 1~.
The weight ratio of alkyl ether sulphate to nonionic
detergent is preferably at least 1:1 and more preferably
within the range of from 1.5:1 to 3:1, especially about
2:1. An especially preerred nonionic detergent is Dobanol
(Trade Mark) 91-8 ex Shell, in which R4 is Cg-C
(predominantly straight-chain) and m is 8~
The stable liquid detergent compositions of the
invention, preferably containing 2 to 60% by weight of
active detergent, may be used for all normal detergent
purposes where oaming is advantageous, for example, fabric
washing products, general purpose domestic and industrial
cleaning c~mpositions, carpet shampoos, car wash products,
~0 personal washing products, shampoos~ foam bath products,
and, above all, manual dishwashing.
As well as active detergent, water and (if
necessary) hydrotrope, the compositions may contain the
usual minor ingredients such as perfume, colour,
preservatives and germicides.
~ C.1344
The invention is further illustrated by the
following non-limiting Examples.
EXAMPLES
In the Examples the foaming performances of various
formulations were compared using a plate washing test.
In the test, plates soiled with a standard starch/fat/
fatty acid mixture were washed in a standard manner with
5 litres of test solution (total concentration of the
product 1.0 g/litre or 1.5 g/litre in 5H or 24H (French
hardness) water at 45C) in a bowl, until only a third of
~5 the surface of the solution in the bowl was covered with
~oam. The number oE plates washed before this arbitrary
end-point was reached was taken as an indicator of
dishwashing and foaming performance.
EXAMPLES 1 - 3
The performances of mixtures of dialkyl sulpho-
succinate with two different ether sulphates (one accordingto the invention, the other not) at various ratios were
compared at a dosage of 1~0 g/litre in hard (24H) water.
The dialkyl sulphosuccinate used was a statistical
mixture (mole ratio 1:2:1) of di-n-octyl sulphosuccinate,
n-hexyl n-octyl sulphosuccinate and di-n-hexyl sulpho-
succinate (sodium salts), prepared from a 1:1 mixture of
n-hexanol and n~octanol by the method descrlbed in Example
1 of GB 2 108 520 (Unilever).
- 35
::~L2~
12 ~ Cnl344
The ether sulphate according to the invention was
Dobanol 23-3A ex Shell (50% C12, 50% C13; n = 3;
ammonium salt) while the comparison material was
Dobanol 25-3A ex Shell (25% each of C12l C13, C14 and
C15; n = 3; ammonium salt~.
The total active detergent concentration in each
formulation tested was 25%~
The results obtained were as follows:
_______ _____________________________~______________ _____
A B ¦ 1 2 3
I
(a) Sulphosuccinate 20 16~6 1 20 16~6 12~5
I
(b) Dobanol 25-3A 5 8~3
i
(b~ Dobanol 23-3A ~ ~ ¦ 5 8~3 12~5
Ratio (a):(b) 4:1 2 1 ¦ 4 1 2 1 1 1
____________________________________ I ________________ ____
I
PerEormance 29 20 ¦ 30 28 23
-----______________
Comparison of Compositions A and B (outside the
invention) shows that a reduction in the (a):~b) ratio from
4:1 to 2:1 gives a considerable performance reduction.
~0 When Compositions 1, 2 and 3 according to the invention are
compared it may be seen that at 2:1 the performance is not
significantly worse than at 4 1~ and even at 1:1 it has not
fallen as low as that of Composition B.
~5
- 13 - C.13~4
EXAMPLE 4
Example 2 was repeated using Dobanol 23-2A (having
n = 2 but otherwise identical to Dobanol 23-3A~ in both
hard and soft water. The results were as follows:
_ _ _ ._ _ _ _ _. _ _ _ _ _ _ _ . _ _ _ _ _ _ ~ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _
1 2 4
I
(a~ Sulphosuccinate ¦ 16.6 1606
(b) Dobanol 23-3A ¦ 8.3
I
(b) Dobanol 23-2A ¦ _ 8.3
I
~5 Ratio (a):(b) ¦ 2:1 2:1
~ _ __ _ _ _ _ _ _ _ ._ _ _ _ . _ _ _ _ _ . _ _ ~_ I ___ __ . __ _ _ _ _ _ _ _ _ _ . __
I
Performance 24H ¦ 28 28
5 H 1 33 31
______________________ ____~____________________
No significant difference in performance was
observed.
EXAMPLES 5 & 6
The hard water performance of the dialkyl
sulphosuccinate/Dobanol 23-3A system at an (a):(b) ratio of
2:1 was compared with those of similar systems containin~
three other alkyl ether sulphates, the tests being carried
out at product dosages of both l.0 and 1.5 gJlitre. The
ether sulphates used were Dobanol 23-3A and Dobanol 25-3A
as in Example l; Empimin 3003 ex Albright & Wilson, as used
~2~2~6~i
14 - C.13~4
in GB i 429 637 (Unilever) discussed previously, and
Dobanol 23-6.5~ ex Shell, which has an averaye degree of
ethoxylation of 6.5 but is otherwise similar to Dobanol
23-3A. The chain leng-th distributions of all these
materials are given in Table 1 previously. Each test
formulation contained 16% by weight of the dialkyl
sulphosuccinate mix used in earlier Examples and 8~ by
weight of the ether sulphate.
10 The results were as follows,
Alkyl ether Performance at 24H
sulphate (b) 1.0 g/litre 1.5 g/litre
15 C Dobanol 25-3A 20 33
D Empimin 3003 23 34
Dobanol 23-3A 27 40
6 Dobanol 23-6.5A 28 45
The results obtained at a product dosage of 1~0
g/litre show a similar effect to that observed in Examples
1-3, with Compositions 5 and 6 according to the invention
being clearly superior to Comparative Compositions C and D.
The higher-ethoxylated material ~obanol 23-6.5A gave
even better results than Dobanol 23-3A.
EXAMPLES 7-9
Fully formulated compositions containing the
sul~phosuccinate mix of previous Examples and various ether
sulphates were prepared and their physical characteristics
~2~9~
- 15 - C.1344
were measured. Comparative Composi-tions Al and A2
correspond in active detergent constituents and levels to
Comparative Composition A in Examples 1 to 3, and
Composition 5 here corresponds to Composition 5 of Example
5. Dobanol 23-2S is the sodium salt correspondin~ to
Dobanol 23-2A used in Example 4.
_______________________________________ __~_________________
¦A1 ¦ A2 ¦ 5 ¦ 7 ¦ 8 ¦ 9
(a) Sulpho-
succinate ¦20 ¦ 20 ¦ 16¦ 16 ¦ 16 ¦ 27
(b) Dobanol 25-3A I 515 ¦ -¦ ~ ¦ ~ ¦ ~
I I I l I I
15(b) Dobanol 23-3A ¦ -¦- ¦ 81 ~ ¦ _ ¦ 13
l l l l l l
(b) Dobanol 23-2A ¦ -¦~ ¦ -¦ 8 ¦ _ ¦ _
l l l l l l
(b) Dobanol 23-2S ¦ ~ 8
_ _______________
Urea ¦ 201 12 ¦ 12¦ 12 ¦ 12 ¦ 12
Ethanol ¦ -~ - ¦ 6
____ _____________________________________ ________________
~atio (a):(b) ¦4:1¦ 4:1 ¦2:1¦ 2:1 ¦2:1 ¦2.08:1
l l l l l l
Total active ¦ 25¦ 25 ¦ 24¦ 24 ¦ 24 ¦ 40
detergent (%)
__________________________________________ _________________
Cloud point (C) ¦ -7¦Unstable¦ -81) Clear ¦ -8 ¦ +1
¦ lat room ¦ ¦) to
¦ ¦ temp. I I -10 l l
Viscosity (cp) I 96l 1138l 166 !153 1 85
-- ------_--_-_________________________~______
- 16 - C.134~
Comparative Example Al shows a 4:1 dialkyl sulpho-
succinate/ether sulphate composition outside the invention;
the relatively high level (20%) of hydrotrope will be
noted. Comparative Example A2 shows that when an attempt
was made to reduce that level to 12%, a completely unstable
product was obtained. Stability was regained only by
reducing the sulphosuccinate to ether sulphate ratio to
2:1, as in Compositions 5, 7 and 8 according to the
invention. These Compositions also exhibited the
~0 advantageous attribute of higher viscosity.
Composition 9 according to the invention, having a
higher active detergent level, required some ethanol as
well as urea to achieve a low cloud point, and the
viscosity was lower, but not unacceptably so.
EXAMPLES 10 & 11
-
The effect on performance of including a nonionic
detergent in compositions of the invention was investigated
in both hard and soft water, at a dosage of 1.~ g/litre.
The nonionic detergent used was Dobanol 91-8 ex
Shell, which as mentioned previously is Cg-Cll
predominantly straight-chain primary alcohol with an
average degree of ethoxylation of 8. The ratio of
sulphosuccinate to the other detergents was 2:1 in each
case, the total active detergent concentration being 27%.
The results were as follows:
~:2al6~
- 17 - C.1344
10 1 11
Sulphosuccinate 1 18 ¦ 18
Dobanol 23-3A ¦ 9 ¦ 6
Dobanol 91-8 ¦ _ ¦ 3
________ ____________I_____ __I_ .____
Performance 24H I 30 1 32
5H ¦ 39 ¦ 39
No significant difference in performance was
observed.
EXAMPLE 12
15 ~ composition according to the invention containing
an additional ingredient - primary alkyl sulphate - was
prepared. This latter material was Dobanol 23-A ex Shell,
which is the unethoxylated analogue of Dobanol 23-3A. The
composition contained 12~ by weight of the dialkyl
sulphosuccinate mix used in previous Examples, 8% by weight
of Dobanol 23-A, and 8% by weight of Dobanol 23-3A. It
required only 4% by weight of urea to achieve a cloud poin~
of -4C, and its viscosity - 430 cp - was high. The foaming
performance in hard water, as demonstrated by the plates
test at a dosage of 1.0 g/litre, was comparable to that of
similar compositions containing no alkyl sulphate.
3o
* * * * *
