Note: Descriptions are shown in the official language in which they were submitted.
134q298
DETERGENT LIQUID
The invention relates to a liquid detergent
composition, in particular to a liquid detergent
composition for washing fabrics and imparting a softness
thereto.
Our European Patent Application published under No.
EP-A-225 142 describes an aqueous built fabric softening
heavy duty liquid detergent which contains a low-swelling
clay as a fabric softening material. A number of
specific builder salts and clays are suggested for use.
The low-swelling clays are chosen to avoid significant
increase in product viscosity by virtue of their
incorporation, especially in compositions which exist as
structured liquids. This is important because too low a
viscosity can ~esult in long term product instability when
the product contains undissolved material in suspension,
w~ereas too high a viscosity makes product processing and
use by the consumer difficult.
13~02g8
- 2 -
We have now found that the degree of swelling of the
clay is not only governed by the clay type itself but also
by the presence of builder salt or other electrolyte,
which tends to inhibit swelling, although in some
circumstances may actually promote it. We have discovered
that there is a variation in the 'efficiency' of
electrolytes to inhibit swelling, i.e. they differ in the
minimum concentration in aqueous solution at which they
demonstrate such inhibition. In this context, we have
found it convenient to classify electrolytes into two
broad categories, namely:-
- peptising electrolytes, which tend to promote
swelling of the clay, except at the highest
concentrations; builder salts are generally
peptising electrolytes
- non-peptising electrolytes, which tend to
inhibit clay swelling, even at relatively low
concentrations.
This phenomenon will be described in more detail
hereinbelow.
It is the use in aqueous structured detergent liquids
of one class of non-peptising electrolytes, namely
non-peptising/non-building electrolytes (hereafter terms
NPNB's) which is novel and surprisingly confers the
advantage of efficient inhibition of clay swelling. Thus,
a reduction in viscosity is achievable, even with medium,
and to some extent high swelling clays without an
unacceptable rise in viscosity.
The present invention now provides a liquid detergent
composition comprising
1~02~8
-- 3
(i) an aqueous base;
(ii) detergent active material; and
(iii)electrolyte;
in proportion sufficient to create a structuring system
with solid-suspending properties;
the composition further comprising a fabric softening clay
material and the electrolyte comprising a
non-peptising/non-building electrolyte (as hereinbefore
defined) in an amount sufficient to limit the viscosity
increase due to incorporation of the clay;
said composition at 25~C having a viscosity of no greater
than 2.5 Pas at a shear rate of 21s 1 and yielding no more
than 2% by volume phase separation upon storage at 25~C
for 21 days from the time of preparation.
Aqueous liquid detergents in which the aqueous base,
detergent active(s) and electrolyte result in a
structuring system with solid suspending properties are
very well known in the art, although these known
compositions do not contain the clay/NPNB combination.
Thus, those skilled in the art are readily able to select
from a very wide range of surfactant and electrolyte types
and amounts to achieve such a system. These systems are
known both with and without solids actually being
suspended in them.
One particular form of such a structuring system
comprises a dispersion of lamellar droplets in an aqueous
phase which contalns dissolved electrolyte. These
lamellar disperslons are just one of a number of
structuring systems with solid suspending properties which
.. . . . . . .
-- 1340~98
are already known from a variety of references, e.g.
H.A.Barnes, 'Detergents', Ch.2. in K.Walters (Ed),
'Rheometry: Industrial Applications', J.Wiley & Sons,
Letchworth 1980.
Lamellar droplets consis': cf an onion-like
configuration of concentric bilayers of surfactant
molecules, between which is trapped water or electrolyte
solution (aqueous phase). Systems in which such droplets
are close-packed provide a very desirable combination of
physical stability and solid-suspending properties with
useful flow properties. Their presence in a liquid
detergent product may be detected by means known to those
skilled in the art for example, optical techniques,
various rheometrical measurements, x-ray or neutron
diffraction, and electron microscopy.
In practice, such lamellar dispersions not only used
for their solid suspending properties but are also used to
endow properties such as consumer preferred flow behaviour
and/or turbid appearance.
Although the present invention embraces many
aqueous/surfactant/electrolyte systems with solid
suspending proper'ies (either without, or preferably with
solids additional to the clay suspended therein), the
embodiments comprising lamellar dispersions are especially
preferred.
1310238
The present invention requires the claimed
compositions at 25~C to have a viscosity of no greater
than 2.5 Pas at a shear rate of 21s . However, most
preferred are those which have a viscosity of no greater
than 1.75 Pas at the latter temperature and shear rate.
The fabric softening clays in general, may be classed
as low, medium or high swelling. For the purposes of the
present invention, the following definitions apply. The
lG low swelling types (substantially as used in compostions
described in our aforementioned unpublished specification)
are those having a swellability (determined as herein
described) in an 8% sodium tripolyphosphate solution of
less than 25%.
The medium swelling types are those having a
swellability in an 8% sodium tripolyphosphate solution of
from 25% to 75%.
The high swelling clays are those having a
swellability in an 8% sodium tripolyphosphate solution of
greater than 75%.
The swelling behaviour of the clays is quantified by
the following test.
A dispersion is prepared at room temperature
containing 435g of water, 40g sodium tripolyphosphate and
25g of clay material (the sodium tripolyphosphate is
3Q conlpletely dissalved in the water before the addition of
the clay).
The dispersion is stirred for 5 minutes with a
magnetic stirrer and then placed in a 1000 ml measuring
cylinder. The dlspersion is then left to stand,
undisturbed for two weeks. After this time the
1~'102~8
.
_ - 6 -
dispersion is examined. Generally some separation will
have Qccurred. A lower layer of dispersion or gel
containing the clay will be visibly distinguishable from a
relatively clear upper layer. The height of the lower
layer (h) and the overall height of the total liquid (H)
are determined and percentage swellability (S) s
calculated using the expression
S = h x 100
H
The following Table classifies a number of typical
fabric softening clays according to this rule:-
TABLE
SWELLING
TRADE NAME CLAY TYPE S(%) CLASS
~LAPORTE CP103 ) 95 HIGH
~CLARSOL KC1 ) Ca Bentonite 86 HIGH
~M~X~ 77/84 ) 73 MEDIUM
~ LEY NO 1 ) white 14 LOW
25 STEETLEY NO 2 ) bentonite 20 LOW
The level of fabric softening clay material in theproduct is preferably at least 1% by weight, but not more
than 10% by weight. A most preferred level is from 3% to
7% by weight.
The NPNB's ~re those electrolytes which have the
property of prt~ nting peptisation (and hence swelling) of
the clay by any p~ptising electrolyte and/or detergent
active which may be present in the formulation. This is
useful because lt 15 the swelling which causes a viscosity
"denotes trade mark
.
1 ~ 4 û ~ 3 8
- 7 -
increase and that is what the present invention seeks to
reduce. Here it must be mentioned that we believe that
knowledge of the link between swelling and viscosity was
not in the public domain prior to publication of our
aforementioned co-pending application. The peptising
phenomenon is one which can be determined by experime:lt.
One suitable methodology for this determination is
using a medium- to high-swelling natural sodium bentonite.
This is preferred over calcium bentonite, which could
result in deviating initial effects being observed on
first addition of the electrolyte under test. This effect
may be due to ion-exchange and consequent transformation
of the calcium clay to the sodium (or other relevant
cation) form. For each test composition, the chosen
amount of electrolyte is first added with stirring to
water, followed by the clay. The amount of clay is
determined by prior experiment (as hereinbefore described)
as that resulting in a swellability (S) of the sodium
bentonite in water is about 75%. After addition of the
clay to the test composition, the swellability (S) is
again tested as a function of electrolyte concentration.
A peptising electrolyte will exhibit an increase in
swellability up to moderate electrolyte concentrations,
whereas a non-peptising electrolyte will show a decrease
in swellability, even at relatively low concentrations.
Thus, by way of Example, Figure 1 shows a plot of the
swellability of a high-swelling natural sodium bentonite
*(Clarsol W100) in water, as a function of clay
concentration. From this, a clay concentration of 1.5% by
weight is chosen as corresponding to a swellability of
about 75%. The swellability of this amount of clay is
plotted as a function of the concentration of a dissolved
electrolyte under consideration. A typical result is
~denotes trade mark
. ~ . . .
~40~98
-- 8
shown in Figure 2, the clay and its concentration being
those derived from Figure 1. It can be seen that with
sodium tripolyphosphate (STP) and sodium citrate, there is
first an increase, then a decrease in swellability of the
clay, with increasing electrolyte concentration and so by
the present definition, these are peptising electrolytes.
On the other hand, with sodium chloride and sodium
formate, an immediate and marked decrease in swellability
is seen as electrolyte concentration is increased from
zero. Thus, the latter two are non-peptising
electrolytes.
Thus, as stated, even if demonstrating at least some
non-peptising properties, the NPNB's are not those
electrolytes which are known as calcium ion sequestrant
and/or precipitant builders, such as the various alkali
metal carbonates, bicarbonates, phosphates, silicates,
borates etc. These are already known as ingredients in
clay containing liquid detergents. What is surprising in
the present invention is that other electrolytes can be
used and they mitigate the swelling induced viscosity
increase when incorporated in amounts which are low
relative to the proportions in which builder salts are
commonly used. It should also be noted that the
definition of NPNB's also excludes those salts which are
usually employed for purposes other than building but
which are known to have subsidiary builder properties, or
are converted to builders in the wash solution. One
example of such a material is sodium perborate bleach.
By inhibiting the swelling of the clay, the NPNB's
limit the resultant viscosity increase of the composition.
For the avoidance of doubt, viscosity increase means the
viscosity rise substantially immediate upon introduction
of the clay in the manufacturing process and it also
refers to a clay swelling induced rise in viscosity on
13~02~8
standing or during storage. It does not encompass any
viscosity increase due to progressive ordering in any
active stLucturing phase which also may be present.
The NPNB's do not in general totally negate the
viscosity rise due to the clay but they are certainly
capable of reducing it to an a-ceptable level. As a rule,
they are incorporated in amounts such as to limit the clay
swelling (by the test hereinbefore described) to no more
than 45%, preferably 35%, especially 25%. To achieve
this, it is normally necessary for them to be present from
about 0.5 to about 10% by weight of the total composition,
typically from about 1 to 5%, even from about 1.5 to 2%.
In one gen~rally preferred class of embodiments, the
amount of NPNB is less than 5% by weight.
The use of NPNB's in clay containing compositions is
especially useful when the structuring system is used to
suspend solid builder particles. In such compositions,
most, if not all of the NPNB will be in solution in the
aqueous phase, which may contain other dissolved
electrolyte material such as builder salts. It is well
known that care must be taken in formulating and
manufacturing active structured systems in order to avoid
increase of viscosity to an unacceptable level. This
problem is exacerbated when clay is present and the NPNB's
help to mitigate this effect.
The NPNB's may be selected from a very wide range of
organic and inor~anlc salts of metals, preferably alkali
metals, for example formates, acetates, halides (such as
chloride) and sulphate. The potassium, and especially
sodium salts are preferred.
13~0298
-- 10 --
The detergent compositions of the present invention
necessarily contain one or more detergent active
materials.
The detergent compounds may be selected from anionic,
nonionic, zwitterionic and amphoteric synthetic detergent
active materials. Many suitable detergen-t compounds are
commercially available and are fully described in the
literature, for example in "Surface Active Agents and
Detergents", Volumes I and II, by Schwartz, Perry and
Berch.
The preferred detergent compounds which can be used
are synthetic anionic and nonionic compounds. The former
are usually water-soluble alkali metal salts of organic
sulphates and sulphonates having alkyl radicals containing
from about 8 to about 22 carbon atoms, the term alkyl
being used to include the alkyl portion of higher acyl
radicals. Examples of suitable synthetic anionic
detergent compounds are sodium and potassium alkyl
sulphates, especially those obtained by sulphating higher
(C8-C18 ) alcohols produced for example from tallow or
coconut oil, sodium and potassium alkyl (Cg-C20) benzene
sulphonates, particularly sodium linear secondary alkyl
(C10-Cl5) benzene sulphonates; sodium alkyl glyceryl ether
sulphates, especially those ethers of the higher alcohols
derived from tallow or coconut oil and synthetic alcohols
derived from petroleum; sodium coconut oil fatty
monoglyceride sulphates and sulphonates; sodium and
potassium salts of sulphuric acid esters of higher
(C8-C18) fatty alcohol-alkylene oxide, particularly
ethylene oxide, reaction products; the reaction products
of fatty acids s~ch as coconut fatty acids esterified with
isethionic acid and neutralised with sodium hydroxide;
sodium and potasslum salts of fatty acid amides of methyl
taurine; alkane monosulphonates such as those derived by
3~02~8
reacting alpha-olefins (C8-C20) with sodium bisulphite and
those derived from reacting paraffins with SO2 and C12 and
then hydrolysing with a base to produce a random
sulphonate; and olefin sulphonates, which term is used to
describe the material made by reacting olefins,
particularly C10-C20 alpha-olefins, with SO3 cnd then
neutralising and hydrolysing the reaction product~ The
preferred anionic detergent compounds are sodium (Cll-C15)
alkyl benzene sulphonates and sodium (C16-C18) alkyl
sulphates.
Suitable nonionic detergent compounds which may be
used include in particular the reaction products of
compounds having a hydrophobic group and a reactive
hydrogen atom, for example aliphatic alcohols, acids,
amides or alkyl phenols with alkylene oxides, especially
ethylene oxide either alone or with propylene oxide.
Specific nonionic detergent compounds are alkyl (C6-C22)
phenols-ethylene oxide condensates, generally 5 to 25 EO,
ie 5 to 25 units of ethylene oxide per molecule, the
condensation products of aliphatic (C8-C18) primary or
secondary linear or branched alcohols with ethylene oxide,
generally 5 to 40 EO, and products made by condensation of
ethylene oxide with the reaction products of propylene
oxide and ethylenediamine. Other so-called nonionic
detergent compounds include long chain tertiary amine
oxides, long chain tertiary phosphine oxides and dialkyl
sulphoxides.
Amounts of amphoteric or zwitterionic detergent
compounds can also be used in the compositions of the
invention but thls is not normally desired due to their
r~iatively high cost. If any amphoteric or zwitterionic
detergent compounds are used it is generally in small
amounts in compositions based on the much more commonly
, . . ~ . ... .... .
~ 3~0~38
-
- 12 -
used synthetic anionic and/or nonionic detergent
compounds.
Mixtures of detergent active materials may be used.
In particular, we prefer a mixture of an anionic detergent
active and a nonionic detergent active. Especially when
the product is in the form of a structured liquid, soap
may also be present.
Where the detergent active material is soap, this i5
preferably selected from alkali metal salts of fatty acids
having 12 to 18 carbon atoms. Typical such fatty acids
are oleic acid, ricinoleic acid, and fatty acids derived
from castor oil, rapeseed oil, groundnut oil, coconut oil,
palmkernel oil or mixtures thereof. The sodium or
potassium salts of these acids can be used.
The level of detergent active material in the product
is preferably at least 2% by weight, but not more than 45%
by weight, most preferably from 6% to 15% by weight.
Although the present invention centres on the use of
NPNB's, this does not preclude the incorporation of a
detergency builder material to reduce the level of free
calcium ions in the wash liquor and thereby improve
detergency. This material may be selected from
precipitating detergency builder materials such as alkali
metal carbonates and ortho-phosphates, ion-exchange
builder materials such as alkali metal aluminosilicates
and sequestering builder materials such as alkali metal
tripolyphosphates, citrates and nitrilotriacetates.
Particularly preferred is sodium tripolyphosphate for
reasons of product structure and building efficiency. At
least 5% by weight of the detergency builder material is
required to provide a noticeable effect upon detergency.
13~02g8
- 13 -
In general, it is preferred that the level of
deter~ency builder material in the product is more than
would dissolve at 20~C. In the case of sodium
tripolyphosphate, a preferred level is from 22 to 35% most
preferably from 15 to 35%, based on the weight of the
product.
The liquid detergent composition of the invention may
further contain any of the adjuncts normally used in
fabric washing detergent compositions, eg sequestering
agents such as ethylenediamine tetraacetate; buffering
agents such as alkali silicates; soil suspending and
anti-redepositon agents such as sodium carboxymethyl
cellulose and polyvinylpyrrolidone; fluorescent agents;
perfum~s; germicid~s; and colourants.
Further, the addition of lather depressors such as
silicones, and enzymes, particularly proteolytic and
amylolytic enzymes; and peroxygen bleaches, such as sodium
perborate and potassium dichlorocyanurate, including
bleach activators, such as N,N,N',N',- tetraacetyl
ethylene diamine, may be useful to formulate a complete
heavy duty detergent composition suitable for use in
washing machines.
Also particularly beneficial are agents for improving
the thermal stability of the product, such as sodium
toluene sulphonate, xylene sulphonate or cumene
sulphonate, at levels of up to 1% by weight, such as from
0.4% to 0.5%.
In addition to the active-structuring system, it is
also possible to include so-called 'external' structuring
agents, e.g. of the polymeric type.
.... ..... , .,.. . .. ~, .
1 3 '~ 9 8
- 14 -
The products of the present invention may be prepared
by a variety of methods. However, we have found that
benefits arise from mixing ingredients in a particular
order. Thus, it is preferable to add at least a portion
of the NPNB and optionally also, any detergency builder
which may be present, to water, before adding the clay and
the detergent active material. In this way products
having uniform rheological properties from batch to batch
can be obtained. In particular, an example outline of one
preferred method comprises adding the necessary quantity
of water to a mixing vessel provided with a stirrer. An
amount of from one part in four up to the full amount of
the total electrolyte (NPNB plus detergency builder) is
then added, with stirring. This amount must include at
least part, preferably all, of the NPNB. Where the NPNB
is water-soluble, this amount will dissolve in the water
and prevent the clay material from swelling but will not
be sufficient to impair the stability of the composition.
The clay material is then added and dispersed with
stirring. Anionic and nonionic detergents, including soap
where this is present, are then added. The remaining part
of the electrolyte is then added with stirring until a
homogeneous mass is obtained.
Finally, the mixture is cooled (if necessary) under
constant agitation and water is added, if necessary, to
compensate evaporation loss. Thereafter perfume may be
added when the product is at substantially ambient
temperature.
Thus, we may also claim a novel and inventive process
for preparing compositions according to the present
invention, comprising the steps of:-
(i) admixture with an aqueous base, of at
1~ 10298
- 15 -
least some of the non-peptising/non-
building electrolyte, and optionally, any
builder salt which is non-peptising;
(ii) then admixing therewith, the fabric
softening clay material;
(iii) admixing with the product of step (ii),
the remainder (if any) of the non-
peptising/non-building electrolyte and
optionally, some or all of the remainder
(if any) of any builder salt which is
non-peptising;
(iv) admixing with the product of step (iii),
the detergent active material; and
(v) admixing with the product of step (iv), any
peptising builder salt and the remainder
(if any) of any builder salt which is
non-peptising.
However, we prefer that substantially all of the
non-peptising/non-building electrolyte is incorporated in
step (i).
Generally, the aqueous base incorporated in step (i)
will be substantially only water. Furthermore, in some
instances, it is advantageous to hold back part of the
water (whether or not the aqueous base in step (i)
contains other components) so contacting the clay with an
even higher eletrolyte concentration, this remaining water
then being added after incorporation of the clay.
In some cases, when the NPNB is added to a stable
formulation, a product may result which separates on
~02~8
- 16 -
standing. Addition of the clay to such an unstable
formulation may result in restabilisation.
For the avoidance of doubt, where any step in the
process of the present invention entails admixture of more
than three components, these may be contacted sequentially
or with any two or more simultaneously, in any desired
order.
The invention will now be illustrated by the
following examples.
Example 1
Formulations A-E were prepared with the ingredients
listed in Table I. In each case the components were added
to the water in the order reading from the top of the
table to the bottom.
The compositions were prepared in four series, where
the 'clay' was
a) - absent, i.e. replaced by an equivalent
quantity of water
b) - Laporte CPl03, a high swelling clay
c) - MDO 77/84, a medium swelling clay
d) - Steetl~y, a low swelling clay.
In addition to compositions A-E, a reference
formulation, containing no sodium formate (but an
equivalent quantity of water) was also prepared for each
of the four clay series (a)-(d).
0298
- 17 -
The viscosity of each composition was measured after
2 weeks, 4 weeks and 3 months. The results are presented
in Tables IA, IB and IC respectively. The tables also
show the aqueous concentration of the initial dose of
sodium formate upon addition.
After three months, four of the compositions with the
low swelling clay and two with the medium swelling, showed
si~rns of instability. The % phase separation is shown
beside the viscosity figures in Table IC. In this and all
other examples, viscosity and stability were determined at
25~C unless explicitly stated to the contrary:-
Table I : all amounts ~ w/w
A B C D E
Water 51.651.6 51.6 51.6 25.8
order of addition
NaFo 0 0.5 1 2 2
Clay 5 5 5 5 5
Water 0 0 0 0 25.8
ABS-acid 7.0
Synp. 7 3.0
NaOH 0.9
25 Glycerol 5.0
Borax 3.5
STP 22
NaFo 2 1.5 l 0 0
These results demonstrate that inclusion of clay in
the presence of a builder electrolyte (STP) but in the
absence of an NPNB electrolyte (sodium formate) results in
a high viscosity product. When an NPNB is also
incorporated, the viscosity is reduced and this effect is
13~0298
- 18 -
most marked when this electrolyte is added before the
clay.
~ . . . .. . .
-- 19 --
TABLE IA
At beginning (Viscosity (mPas) at 21s aft~r 2 wks)
% NaFo % waterNaFo Conc. No clayLaporte MDO Steetley
g/100 g water (a)CP103 (b)77/84 (c) (d)
- -* - - 7202490->1910 1660 1430->1200
A 0 51.6 0 700 2380 1430 1450
B a. 5 Sl . 6 1.0 730 1980 1540 1450
1() C 1 51.6 1.9 730 1830 1230 1220
D 2 51.6 3.9 740 1620 1280 960
E 2 25.8 7.8 800 1420 1170 1300
* No sodium formate in formulation
00
- 20 -
TABLE IB
At beginning (Viscosity (mPas) at 21s 1 after 4~wks)
~ NaFo % waterNaFo Conc. No clayLaporte MDO Steetley
g/100 g water (a)CP103 (b)77/84 (c)(d)
_ -* - - 7201820-1900 1660 1200-1240
A 0 51.6 0 680 2010 1660 960
B 0.5 51.6 1.0 670 1800 1440 1090
C 1 51.6 1.9 710 1600 iO80 780
1(~ D 2 51.6 3.9 680 1390 iO90 70Q
E 2 25.8 7.8 630 1230 930 65Q
* No sodium formate in formulation
o
:D
TABLE IC
At beginning (Viscosity (mPas) at 21s aft~r 3 mths)
% NaFo % waterNaFo conc. No clay Laporte MDO Steetley
g/100 g water (a) CP103 (b)77/84 (c) (d)
- -* _ _ 840 2030 1520 1080
A 0 51.6 0 560 1630 1580 960
B 0.5 51.6 1.0 560 2150 1480 1090(10)
10 C l 51.6 1.9 560 1740 1060 760(8)
D 2 51.6 3.9 570 1540 890(2) 570(8)
E 2 25.8 7.8 630 1230 800(2) 660(5)
* No sod ium formate in formulation
2 9 8
- 22 -
Example 2
Experiments were performed to test the effect of
sodium sulphate and sodium chloride as NPNB's, as well as
the optimum order for their addition in the total
formulation. The quantities and order of addition of
components is shown in Table II. The order is as
descending in the table. Two control formulations are
listed in the first column; the first preceding the
slash(/) is without clay or electrolyte (NPNB) and the
second after it, is only minus the electrolyte. The final
row expresses where the electrolyte is added relative to
the actives and clay. The final entry "2/1" before clay
means that all electrolyte is added before the clay but
the water is added in two aliquots one before and one
after the clay, thus doubling the initial electrolyte
concentration in solution, relative to the 1/1 before clay
entry.
The viscosity of each composition, measured in mPas
at 21s 1 after 1 day storage is shown for compositions
where the NPNB is sodium sulphate and sodium chloride, in
Tables IIA and IIB respectively. In both cases, the
medlum and low swelling clays were those used in Example 1
but the high swelling clay was Clarsol KCl.
The results in Table IIA suggest that to achieve the
effect of the present invention, namely low viscosity,
with sodium sulphate, it is preferable to use medium or
low swelling clays. In the case of the former, at least
half of the NPNB should be added before the actives and
preferably, also before the clay. With the high swelling
clay, viscosity reduction was only observed where the NPNB
was added before the clay, although not in too high a
concentration.
., . -- . , .
9 8
- 23 -
Table IIB shows very comparable results with sodium
chloride, except that with the high swelling clay, a small
viscosity reduction was also observed when all the NPNB
was added immediately after the clay.
~ 3~-~0~98
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u~ U~ L
11 o
~ O ~
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l x U~ Ll
1~ U
3 U~
oP Ll:~
H r~ n ~ ~ g
li u~ ~
a
LO In
~ ~ , .
U~
o
Z ~ ~
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u ~ I I I r~ I ~ ~ I S
~1 ~1 ~O O ~,1
~3 0 3
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~Y
a~ ~ a
L~ ~ ~~ ~ ~ 3 5~ ~ ,0~
J ~ aJ X ~ ~ O
v ~ ~ u ~ u ~ u -~
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3 ~ ~ 3 ~ * z ~ ~ m ~ *
~ o u o
-25-
TABLE IIA
Na2SO4 addition in process
Clay type without endafterafter ~ 1/1 "2/1"
Na2S~4 activesclay before before before
clay clay clay
1~ Without clay 660 990*(+) (+) (+) (+) (+)
Clarsol KCl 1660 21602070 1740 1820 1570 1740
MDO 77/84 1660 20702650 1310 1550 1290 1240
Steetley 1240 10101190 750* 560* 610* 480*
* showing (some) instability after two weeks
(+) not measured - presumed to be as 'end' figure
~a
o
c~
00
-26-
TABLE IIB
NaCl addition in process
Clay type without endafterafter ~ 1/1 "2/1"
NaCl activesclay before before before
clay clay clay
Without clay 660 740 (+) (+) (+) (+) (+)
Clarsol KCl 1660 1820 2320 1570 1910 1490 1660
MDO 77/84 1660 2150 2730 1610 1570 1260 1510
Steetley 1240 1210 1090 860 580 610 1040-1280
(+) not measured - presumed to be as 'end' figure
o
-27- -~ 3 ~ 8
Comparative Example 3
The viscosities (mPas at 21s ) after one day, of the
compositions in Example 2 are presented in Table III. For
comparison, the two week figures from Example 1 are also
quoted.
The results suggest that the viscosity reducing
ability of sodium sulphate is approximately the same as
that for sodium chloride, these being somewhat better than
with sodium formate. The overall trend also shows that it
is generally better for the NPNB to be added before the
clay.
TABLE III
i
Non-peptising Without end after ~ before 1/1 before"2/1" b~fore Clay Type
Electrolyte non-peptiser clay clay clay clay
; NaFo (2.G~) 2490* (2380)* - (1830)* (1620)* (1420)* Laport~ *
NaCI (1.5%) 1660** 1820** 1570** 1910** 1490** 1660** CP103
2 4 ( )1660** 2160** 1740** 1820** 1570** 1740** Clarsol**
NaF~ ? (1430) - (1230) (1280) (1170)
NaCl 1660 2150 1610 1570 1260 1510 MDO 77/84
lG Na2S~4 1660 2070 1310 1550 1290 1240
NaFo 1430 (1450) - (1220) ( 960) (1300)
NaC1 1240 1210 860 580 610 1040-1280 Steetley
N 2S 4 1240 1010 750(+) 560(+) 610(+) 480(+)
(+) = (some) instability
C~
