Note: Descriptions are shown in the official language in which they were submitted.
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1
A yirocess and a device for the preparation of silicone emulsions
The invention relates to a device and to a process for the preparation of fine-
particle
and stable silicone emulsions, particularly for the preparation of oil in
water
emulsions with the lowest possible emulsifier content.
A number of processes are known for the emulsification of insoluble silicones
and
silanes in water. Generally speaking, prior to the actual homogenisation,
either small
quantities of water are stirred slowly into the silicone in which the
emulsifier is
finely dispersed, so that a water in oil emulsion is obtained which is
inverted by
dilution afterwards with water before it is homogenised to a fine-particle
emulsion in
a special plant, under th: action of shear forces, or the silicone is
introduced slowly,
with stirring, into an aqueous emulsifier mixture before the resulting coarse-
particle
emulsion undergoes actual homogenisation.
The mixture initially stirred together may already be a sufficiently stable
emulsion,
depending on the nature of the process and the active substance, the
emulsifier
concentration, the stirring energy introduced and, above all, the time
invested. As a
rule, these emulsions, which are known as pre-emulsions, are coarse-particle,
however, and must be passed immediately to the actual homogenisation due to
lack
of stability. Homogenising devices and processes are described in Ullmann's
Encyclopedia of Industrial Chemistry Vol A9 Edition 1987, page 309 to 310. The
preparation of the pre-emulsion takes place in stirring units and is the rate
determining step, depending on the type of downstream homogenising machine.
Further processes for the preparation of silicone emulsions are known from EP-
A-
043 091 and EP-A 0 579 458. In the process of EP-A-043 091, the entire amount
of
silicone is fed to a little water with all the emulsifier, so that a high-
viscosity paste or
a gel is obtained which is then converted to the final emulsion by dilution.
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2
The preparation of the pre-emulsion according to the conventional processes by
the
addition of the siloxane or silane to the excess water/emulsifier phase
becomes
problematic, particularly if silicon compounds are used, which may be composed
of
both monomeric, linear and resin-like structures optionally diluted with low
molecular weight siloxanes or organic compounds, if these structures are
capable, in
principle, of reacting with the aqueous phase. These include, for example,
alkylalkoxysilanes, resins bearing alkoxy groups, and optionally mixtures of
the two.
A further problem lies in the fact that the preparation of the pre-emulsion
according
to the known processes is particularly time-consuming. The feed of the
siloxane
component into the aqueous phase takes place in a controlled manner with
stirring,
i.e. in such a ma~-uisr that optimum mixing is obtained. This does not permit
a rapid
addition.
The first molecules of the active substance meet a huge excess of water which
approaches the desired concentrations only during the course of time, and
provides a
coarse-particle, unstable pre-emulsion which must be fed to the homogeniser as
quickly as possible.
r 20 During this addition, water-sensitive components, if used, are protected
only
inadequately from the attack of the aqueous phase, even if the latter is
buffered, so
that the reaction of the corresponding components amongst themselves may
occur.
This may cause the subsequent homogenisation to be more difficult due to a
condensation process, followed by a build up of viscosity in the resulting
coarse
emulsion particles, or may cause the pre-emulsion to become so unstable that
it can
no longer be fed to the homogeniser. Although this shortcoming may be
counteracted by a substantial increase in the emulsifier (in the region of
5%), this
leads to unwanted results in many applications and to environmental pollution.
_.--
----~___._~___
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3
Moreover, e.g. in the case of alkylalkoxysilan.es, hydrolysis and condensation
reactions during emulsification usually lead to the ineffectiveness of the
resulting
emulsion during use, and thus to its unsuitability.
If the pre-emulsion is prepared by way of a paste or a gel, which are diluted
afterwards in a special process, emulsions with low average particle sizes can
be
prepared in cases where no importance is attached to emulsifier contents,
although
no details are given about the particle size distribution thereof.
As there are a number of silicone active substances which provide pastes only
to an
unsatisfactory degree, at least with the emulsifier quantities required, these
processes
are restricted ua terms of their range of application. Moreover, a number of
emulsions such as, e.g., defoamer emulsions or emulsions with a low emulsifier
content (<5%) and at the same time a low active substance content (<_ 20%)
cannot
be prepared satisfactorily according to this process. So emulsions with very
large
particles in the region of 3-60 m are obtained in a very time-consuming
manner in
the process according to EP 0 579 458 (see examples therein).
The object of the present invention was, therefore, to provide a rapid and
thus
economic process which does not have the disadvantages described and permits
the
preparation of fine-particle emulsions with narrow particle size distributions
and low
emulsifier contents and low to high concentrations of active substance, and to
provide a device suitable for said process. Water-sensitive active substances
were to
lead to stable - even for more than a year - and above all effective
emulsions.
A particular aim, i.a. in order to achieve high reproducibility, was to bring
the
quantities of emulsion required for a certain surface coating of the active
substance
particles into contact ab initio with the active substance and to match the
mechanical energy hereto. This presupposed a process with emulsifying devices
that
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4
can be described precisely mathematically. Devices that are greatly affected
by the
residence time are unsuitable (e.g. stirring units, etc.).
Finally, the energy to be introduced was to cover a broad range - a situation
which
could be achieved hitherto only by means of several devices with different
structures. It is thus possible to prepare, in the same plant, emulsions which
have to
be protected from a high energy input, - e.g. defoamer emulsions - as well as
emulsions which require a multiple of the energy supplied by conventional
homogenisers.
The object in question could be achieved by means of a device composed of
storage
vessels, pumps and nozzles, hereinafter referred to as a mixing station. It
proved to
be particularly advantageous if this mixing station was followed by a jet
disperser of
the kind described for the preparation of pharmaceutical or cosmetic
dispersions
(Bayer AG / EP 0 101 007).
The invention relates, therefore, to a device for the preparation of a
silicone, silane
or silicone/silane emulsion composed of a silicone-containing and/or silane-
containing active substance component and an aqueous phase (component), with a
first mixing station for the emulsion components fed via pumps P1, P2, P3 from
storage tanks (VA, VB, VC), the first mixing station having a mixing apparatus
Ml
in which nozzles 2,4 mix a jet of active substance with the aqueous phase 3 to
a pre-
emulsion (see Fig. 1 and 2).
In a preferred embodiment of the device according to the invention, the first
mixing
station is connected to a high-pressure homogeniser, the high-pressure
homogeniser
containing the pre-emulsion leaving the mixing station.
The invention also relates to a process for the preparation of fine-particle
aqueous
silicone and/or silane emulsions with a narrow particle size distribution,
comprising
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29657-33
- the preparation of a pre-emulsion by injecting
the silicone and/or silane component into an aqueous phase
containing emulsifier in a mixing station and
- homogenisation in a high-pressure homogeniser,
5 and the emulsions of silicone compounds and/or silanes which
may be obtained according to this process.
In particular, the invention relates to a process
for the preparation of fine-particle aqueous silicone and/or
silane emulsions with a U90 value of less than 1.2 (i.e. with
a narrow particle size distribution), comprising
- the preparation of a pre-emulsion by injecting
the silicone and/or silane component into an aqueous phase
containing emulsifier in a mixing station, whereby a
pressure difference of a maximum of 10 bar is maintained
between both streams, depending on the nozzle dimensions,
with an absolute pressure drop of less than 100 bar, and
- homogenisation of the pre-emulsion.
The invention also relates to a device for the
preparation of an aqueous emulsion comprising an active
substance component and an aqueous phase, said active
component is selected from a silicone and a silane, with a
first mixing station for the emulsion components fed by
means of pumps from storage tanks wherein
- the first mixing station has a mixing apparatus,
in which nozzles comprising a first nozzle and a second
nozzle, mix a jet of active substance with the aqueous phase
to a pre-emulsion,
- the distance between the nozzles is 1 to 10
times the diameter of the second nozzle,
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29657-33
5a
- the diameter of the second nozzle is about 2
to 3 times as large as the diameter of the first nozzle,
- the mixing station is connected to a jet
disperser, whereby the jet disperser receives the pre-
emulsion leaving the mixing station,
- the pressure drop in the jet disperser is
between 2 and 1000 bar, and
- an intermediate container acting as a buffer
vessel is connected to the mixing apparatus, and wherein the
jet disperser receives the pre-emulsion via the intermediate
container.
The invention further relates to a process for the
preparation of fine-particle aqueous emulsions comprising an
active component selected from a silicone and a silane with
a Uyo value of less than 1.2 using the device as described
herein, comprising
- the preparation of the pre-emulsion by injecting
the active component selected from silicone and silane into
the aqueous phase containing emulsifier in the mixing
station, whereby a pressure difference depending on the
nozzle dimensions of a maximum of 10 bar is maintained
between the two streams with an absolute pressure drop of
less than 100 bar,
- the homogenisation of the pre-emulsion is
accomplished by means of the jet disperser, whereby the U90
value is determined according to the following formula:
d90 - d 10
U90 d50
in which dlO represents the diameter of the smallest and d90
represents the diameter of the largest particles remaining
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29657-33
5b
after subtraction of 10% by weight of the particles with the
smallest and the largest diameters from a given quantity of
particles, and in which the d50-value represents the
diameter of the particle, that is larger as 50% by weight of
all the particles and smaller than 50% by weight of all the
particles.
The present invention is explained in more detail
by the attached Figures and Examples.
Fig. 1 shows a mixing station;
Fig. 2 is a schematic representation of the device according
to the invention with a high-pressure homogeniser;
Fig. 3 shows the nozzle arrangement of a jet disperser;
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6
Fig. 4 shows a high-pressure homogeniser;
Fig. 5, 6, 7 and 8 show the differential and integral particle size
distribution of
Example 10, 9,18 and 19.
In the device according to the invention with a known pressure drop (Op)sTR D
a
known emulsifier content and surface requirement, a known nozzle diameter
(D)sTR-
D, a known interfacial surface tension (y), a known viscosity (ri) of the
disperse
phase and a known number of passes (n)sTR D the expected average particle size
(d)
may be calculated from the following formula:
d = k A(dp)-.6 A,qo.a9s A yo.36s A Do.i6s A n.36
k = constant (relating to emulsifier content/surface requirement).
The core of the mixing station is a nozzle arrangement in a mixing apparatus
Ml, the
dimensions of which depend on the consistency of the two phases to be
combined,
their concentration with respect to one another, the pressure drop chosen, and
the
throughput.
Fig. 1 shows a possible embodiment. For example, the silicone oil 1 is
injected into
the aqueous phase 3 via the first nozzle 2 and immediately afterwards is mixed
intensively and homogenised in the second nozzle 4. The final fine dispersion
then
takes place in the downstream jet disperser STR-D. The jet disperser STR-D may
be
immediately downstream or, in a batchwise operation, only after the
preparation of
the entire pre-emulsion 5.
The nozzle arrangement according to Fig. 1 is preferably fed by means of two
pumps
P1, P3 with a pressure difference of 2-3 bar in such a way that - where the
coating
speed of the emulsifier permits - the aqueous emulsifier solution and the
silicone are
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7
fed together in the final emulsion concentration and homogenised directly by
means
of the jet disperser STR-D in one or a maximum of three passes.
The number of passes usually depends on the nature and content of the
emulsifier.
Emulsifier contents in the region of 3% make only one pass necessary -
exceptions
apart.
If emulsifiers are present that coat the surfaces of the resulting particles
of certain
silicone active substances only relatively slowly, the process may be modified
in
such a way that operations are carried out with any deficient amount of water
containing the entire quantity of emulsifier. The more concentrated emulsion
obtained in this case may be returned to the aqueous emulsifier solution and
fed with
the latter back to the nozzle and to the inflowing active substance, so that a
circuit is
obtained. Whether the circuit remains intact for a few minutes after the
substances
have been combined depends on the concentration and nature of the emulsifier
and
on the silicone to be emulsified. The remainder of the water to which further
additives e.g. thickeners or preservatives are optionally added may be added
to the
circuit by way of a further nozzle and pump before this pre-emulsion is fed to
the jet
disperser STR-D.
Fig. 4 shows the jet disperser STR-D which is used as high-pressure
homogeniser 6.
The jet disperser STR-D is composed more specifically of a pump 14, optionally
a
pulsation damper 16 and a nozzle arrangement 18, which is shown in detail in
Fig. 3.
The two-stage nozzle arrangement 18 has a first nozzle 10 and a downstream
second
nozzle 12, with the aid of which the pre-emulsion 5 is homogenised. Each
nozzle 10,
12 is composed of an insert part 11 in a tube 9, each insert part 11 having a
cylindrical section 13 protruding against the direction of flow of pre-
emulsion 5,
with two opposite capillary holes 15. The cylindrical section 13 forms an
annular
space 17 in the tube 9, pre-emulsion 5 flowing through the tube 9 into the
annular
space 17 and from there through capillary holes 15 into an intermediate
chamber 20.
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8
As the capillary holes 15 are opposite each other, the emerging jets of
emulsion
collide with one another inside the cylindrical section 13. As a result, a
particularly
good dispersion is achieved. The emulsion flows out of intermediate chamber 20
into a second annular space 22 of the second nozzle 12 where it again passes
through
the capillary holes 24 of the second nozzle 12. The homogenised emulsion 25
leaves
the jet disperser STR-D through the outlet 26.
The present invention also allows the ratio of the water - containing all the
emulsifier- to active substance to be chosen in such a way that gels and
pastes are
also obtained. The proviso is that the pumps chosen are of the positive
conveying
type and control the consistency of the pastes.
An advantage of the present invention is that it is able to operate
practically
continuously, is not very time-consuming, and has outstanding reproducibility.
It
provides stable emulsions of which the average particle sizes have values of
<1 m,
with emulsifier contents in the region of 0.5 - 3%. The particle size
distribution
which is important for the stability and for many applications lies in a
narrower
range than is the case with the conventional processes.
There are also a few cases, however, where rather unstable emulsions are
produced
in which both the particle size and the particle size distribution do not play
an
important part, with the result that, for cost or other reasons, a subsequent
homogenisation is dispensed with after the passage through the mixing station.
The
lack of stability of these emulsions may be offset in such cases by
substantially
increasing the emulsion viscosity by adding a neutral thickener. In view of
the often
poor processability of such emulsions, attempts are usually made to avoid this
method of production.
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9
The above-mentioned emulsions also include a few emulsions with a high
viscosity
in which an indispensable high-viscosity active substance - e.g. of an organic
nature
- is responsible for this.
Naturally, it would be uneconomic in such cases to emulsify such emulsions
afterwards additionally in the jet disperser STR-D because - were the present
state of
the emulsion to be essentially maintained - the jet disperser would not be
able make
a significant contribution towards improving the physical properties of the
emulsion
~ under the process conditions required for this purpose.
in this case it is advisable to homogenise the pre-emulsion leaving the mixing
station
in a second mixing station with a higher pressure, e.g. up to 100 bar.
This method is also reconunended if readily emulsifiable Si compounds are to
be
emulsified with emulsifiers that have a sufficient particle surface coating
speed. In
this case, it is possible to dispense with thickeners.
In order to minimise the apparatus required, however, it is preferable to
transfer the
pre-emulsion to a storage tank upstream of the first mixing station and to
bring it
from there via the same mixing station under different pressure conditions to
the
desired emulsion state.
The invention thus also relates to a process for the preparation of fine- to
coarse-
particle aqueous silicone and/or silane emulsions in the region of about 0.4
to 5.0
m with a Ugo value greater than 1.1 (i.e. broader particle size distribution)
which
require only low shear forces for emulsification and are stabilised by
thickeners,
comprising
- the preparation of a pre-emulsion by injecting the silicone and/or silane
component into an aqueous phase containing erinulsifier in a mixing station, a
CA 02304644 2000-03-24
pressure difference, dependent on the nozzle dimensions, of a maximum of
10 bar being maintained between the two streams with an absolute pressure
drop of less than 80 bar,
5 - homogenisation of the pre-emulsion in a downstream mixing station or at a
later stage in the same mixing station with an absolute pressure drop of up to
100 bar.
An embodiment is obtained from Fig. 2, in which
VA: active sl.ibstance container
VB: residual water container (+ additives)
VC: buffer vessel / intermediate container
VE: storage tank / intermediate container
VD: buffer vessel
P1, P2:pumps (optionally forced conveying pumps)
P3, P4, P5: pumps
Ml: mixing nozzle for active substance/water
STR-D: jet disperser.
In the active substance circuit VA-+P1-+M1-+VA the aqueous phase is injected
at
low pressure via VC-+P3--+M1 and after the addition is completed the circuit
VA--+P1--aMl-*VA is switched to higher pressure, Ml acting as a downstream
homogeniser. The emulsion may be removed behind Ml.
The proviso is, of course, that the emulsifiers have a sufficiently high
particle
coating speed, a property which also depends on the ability of the active
substance to
adsorb these emulsifiers.
Examples of the silicone and silane component are
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11
- silicone compounds with the usual composition:
(CH3)3S1O[(CH3)2S1O]50-500S1(CH3)3
HO(CH3)2SiO[(CH3)2SiO]5ooSi(CH3)20H
(CH3)3S1O[(CH3)(H)S1O]SOSi(CH3)3
(CH3)3Si(O)1.1(OCH3)0.8;
- organoalkoxysilanes, hydrolysis products thereof, e.g.:
CH3(CH2)7Si(OEt)3
CH3(CH2)3Si(OEt)3
CH3(CH2)11-13(CH3)Si(OMe)2
CH3(CH2)7Si(OEt)20(OEt)2Si(CH2)7CH3
CH3(CH2)3S1(OEt)2[O(EtO)Sl(CH2)3CH3]0-5OS1(OEt)2(CH2)3CH3+
- linear polyorganosiloxanes with and/or without silicon-functional bound
groups such as hydrogen, alkoxy, polyether and hydroxy groups, with and/or
without organofunctionally attached groups such as polyethers, amines or
halogens or pseudohalogens, e.g.:
(CH3)3S1O[(CH3)2S1O]50-500S1(CH3)3
HO(CH3)2SiO[(CH3)2SiO]SOOSi(CH3)20H
(CH3)3S1O[(CH3)(H)S1O]5oSI(CH3)3
(CH3)3S1O[(CH3)CH2=CHS1O]3 [(CH3)2S10]50-500S1(CH3)3
(CH3)3S1O[CH3(OCH2CH,)80(CH2)3(CH3)S1O]3[(CH3)2S1O]6OoSl(CH3)3
- branched polyorganosiloxanes with andlor without attached silicon-
functional groups such as hydrogen, alkoxy, polyether and hydroxy groups
with and/or without organofunctionally attached groups such as polyethers,
amines or halogens or pseudohalogens, e.g.:
CH3S1 {[(CH3)2S1O]50OS1(CH3)3} 3
CH3 Si 1[(CH3)2S1O] 80OSi(CH3)2CH2=CH3 ) 3
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12
CH3Si {[(CH3)2SiOlgoOSi(CH3)2(CH2)3(OCH2CH2)8OCH3} 3
H2N(CH2)3 S i{ [(CH3)2S iOl 180Si(CH3) } 3;
- silicone resins with aryl-, alkyl- organofunctionally modified alkyl groups,
alkoxyfunctional resins with or without diluents, e.g.:
(CH3)1.16Si1O1.42
(CH3)0.8(C12H25)0.2s1(O)1(OCH3)1
(Si02) l o[(CH3)3 S iO 1v210.8
S102[(CH3)CH2=CHSiOl0.3[O1/2S1(CH3)3}1.2
- mixtures of the above components or with insoluble additives of a mineral or
organic nature.
The term emulsifiers means ionic and nonionic emulsifiers of the kind
customarily
used in silicone emulsification, and mixtures thereof.
Suitable ionic emulsifiers are, depending on the active substance, e.g.:
- alkylsulfonates with 8 to 18 C atoms with or without ethylene- or propylene
oxide units;
- sulfate esters such as, e.g., CH3(CH2)6CH20(C2H4O)6-19SO3H;
- alkylarylsulfonates, such as, e.g., dodecylbenzene sulfonate;
- quaternary ammonium compounds such as, e.g., dodecyltrimethylammonium
hydroxide, octyldimethylbenzylammonium hydroxides and salts thereof.
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13
Nonionic emulsifiers of which the HLB value is from 10 to 16 are, however,
preferred. If mixtures within this range are present they may be composed of
combinations of emulsifiers with an HLB value between 2.7 and 18.7.
Suitable nonionic emulsifiers are adducts of ethylene oxide and fatty
alcohols, alkyl
phenols, triglycerides or sugar; polyethylene oxide sorbitan laurates,
palmitates and
stearates; adducts of ethylene oxide and alkylamines; and polyvinylalcohols
(such as
Mowiol), particularly ethoxy adducts with tridecyl alcohol, ethoxy adducts
with
sorbitan monooleates (Tween products from ICI), sorbitan monooleates and
mixtures thereof.
The average particle diameter - in the text also called the particle size - is
calculated
from the volumetric mean which is obtained from the total volume of all the
particles of the emulsion divided by the number of particles.
The numerical value of the breadth of the particle size distribution was
calculated in
such a way that, out of the given quantity of particles, the particles with
the smallest
diameters up to a quantity of 10 wt.% of the particle quantity (d10) and the
particles
with the largest diameters up to a quantity of 10 wt.% of the particle
quantity (d90)
are not taken into account, and the difference in the diameters of the
remaining
largest particle and of the remaining smallest particle is divided by the
diameter of
that particle (d50) that is greater than 50 wt.% of all the particles and
smaller than 50
wt. % of all the particles. This numerical value is hereinafter called Ugo:
Ugo = d22Q- d1Q
d50
(see Fig. 5, 6, 7 and 8).
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14
The average particle sizes were measured by Fraunhofer diffraction,
ultracentrifugation or by photometry with the aid of Mie theory. The
distribution
curves were measured by means of the ultracentrifuge.
The apparatus shown in the appendix in a schematic flow diagram (Fig. 2)
allows
process adjustments tailored in a flexible manner to the active substance, the
emulsifier and the concentrations thereof.
For example, in the favourable case when readily emulsifiable products are
present,
the emulsifier is "rapid" and present in a favourable concentration, the
active
substance (from VA) may be fed together with the water/emulsifier mixture
(from
VC) in the desired ratio to Ml, and the resulting pre-emulsion fed directly or
via a
buffer vessel (VD) to the jet disperser STR-D, homogenised in one pass and
then fed
to the filling station.
This procedure requires reliable control or synchronisation of the pumps. If
this is to
be dispensed with and if an exact ratio of emulsifier/active substance is not
absolutely necessary during the combined feed to Ml, it is possible, in order
nevertheless to guarantee the necessary active substance concentration in the
emulsion, to feed the active substance to a calculated deficient amount of
water/emulsifier mixture via Ml, to return the resulting pre-emulsion
constantly to
the water/emulsifier mixture (after VC) and to feed it together again with the
active
substance in the circuit via Ml. If the entire active substance is consumed,
the pre-
emulsion is brought to the final concentration via the nozzle Ml by adding the
remaining water (from VB) by means of a circuit similar to the one just
described
(Ml->VC-*M1) and homogenised as above.
In the case of active substances that are difficult to emulsify, "slow"
emulsifiers or
very low emulsifier concentrations, pre-emulsification can be carried out a
couple of
CA 02304644 2000-03-24
times via VC and MI in the circuit before feeding to STR-D, prior to operating
as
above.
If a paste or a gel is considered important and if the active substance is
suitable for
5 this, it may be fed together with any deficient amount of water (from VC) -
but all
the emulsifier - into Ml, and resulting emulsion returned to VC, as above, and
atomised with its contents repeatedly via Ml with the active substance. A high-
viscosity pre-emulsion is thereby obtained, which may have a paste or gel
{ consistency depending on the conditions chosen.
Said emulsions may - depending on the intended application - be filled as such
or
processed further as described below.
Before being homogenised above in STR-D, it is passed via Ml, where the
remaining water (from VB), optionally with thickener and other conventional
additives, is injected so that the calculated composition is obtained.
If more than one pass through STR-D is required, another cycle via VE-+STR-D
may be carried out before the emulsion is filled.
If several discrete passes are desired, however, it is possible to carry out
emulsification from the buffer vessel VD via STR-D in one pass after VE, after
completion from there in a second pass via STR-D again to VD, etc.
In the examples that follow, all the data relate to weight, unless otherwise
specified.
The following abbreviations are used:
Me: -CH3
Et: -C2H5
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16
Octeo: C$Ht7Si(OEt)3
V: pre-emulsion
Only the time required for the preparation of the pre-emulsion is given in the
Tables,
since the preparations for the water/emulsifier mixtures are practically the
same in
the examples according to the invention and those not according to the
invention.
The actual homogenisation stage was likewise not included in the consideration
of
time, since it is largely dependent on the capacity of the emulsifying devices
in the
comparison.
In the Tables, the examples according to the invention are printed in bold and
the
comparative examples in italics.
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17
Examples
A. Resin emulsions
Example 1 (Comparative example)
238.7 g of distilled water were heated to 60 C in a 2 1 vessel and 55 g of a
melted
mixture - corresponding to 2.50% based on the total batch - of a POE-stearyl
alcohol .
and a POE-cetyl alcohol with a total HLB value of 15.5 were added with
stirring.
After cooling to 40 C, 1447.6 g of an Isopar R G solution with 80% resin with
an
average composition (CH3)1.16 Sil 01A2 and a viscosity of 1620 mPa.s were
added
within one hour at a rate of stirring of 250 - 400 rpm. Stirring was continued
for 10
min at a rate of stirring of - 400 rpm. 458.7 g of an aqueous solution of 1.76
g of
carboxymethylcellulose (Walocel CRT 5000 GA) were added with stirring within
25
min. Stirring was continued for 40 min.
The pre-emulsion was homogenised in six passes in a conventional high-pressure
homogeniser of the Gaulin type with a pressure drop of AP = 250 bar. The
results are
given in Table 1.
Example 2 (Comparative example)
Example 1 was repeated with a total emulsifier content of 3.00%. The results
are
given in Table l.
Example 3
The same batch as in Example 1 - but with 2.2% emulsifier mixture - was
increased
by a factor of 2.7273. 645.0 g of distilled water were heated to 50 C in VC
(see
CA 02304644 2000-03-24
18
attachment Fig. 2) and 133 g of a melted mixture - corresponding to 2.20%
based on
the total batch - of a POE-stearyl alcohol and an PEO-cetyl alcohol with a
total HLB
value of 15.5 were added with stirring, and forced by means of P3 at 3 bar
through
Ml (nozzle diameters 2.1/1.0 mm) to VC and circulated for 30 s by means of P3
through Ml to VC. 3948 g of the same resin as in Example 1 were injected into
this
circuit within 17 min from VA by means of P1 at 5 bar into Ml. The circuit was
then maintained for 10 min, then an aqueous solution of 4.8 g of
carboxymethylcellulose (Walocel CRT 5000 GA) in 1264.2 g of water were
injected
into the circuit within 9 min from VB via M1. After the addition was
completed, the
circuit was maintained for another 40 min before the pre-emulsion was
homogenised
in three passes in the jet disperser STR-D (nozzle diameter: 0.2828 mm) with a
pressure drop of dP = 250 bar. The results are given in Table 1.
Example 4
Example 3 was repeated with a total emulsifier content of 2.5%. The results
are
given in Table 1.
Example 5
Example 3 was repeated with a total emulsifier content of 2.8%. The results
are
given in Table 1.
Example 6
Example 3 was repeated with a total emulsifier content of 3.0%. The results
are
given in Table 1.
Table 1
Pass Particle size Stability
no. 0 [ m] [months]
F-Example-+ E-Example--> E-Example-+
1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6
V V V V V V >5.000 >5.000 >5000 >5000 5000 >5000 0 0 0 0 0 0
1 1 1 1 1 1 4.954 4.760 2.915 2.550 2.453 2.106
2 2 2 2 2 2 4.687 4.487 2.143 0.653 0.660 0.634 0.5 0.5 >6 >6 >6 >6
3 3 3 3 3 3 4.423 4.390 1.617 0.642 0.593 0.589 0.5 0.5 >6 >6 >6 >6
4 4 4.343 4.202 0.5 0.5
5 4.216 4.068 0.5 0.5
6 6 4.094 3.989 0.5 0.5
CA 02304644 2000-03-24
B. Resin/silane (water-sensitive) emulsions
Examli(e 7 (Comparative example)
5 In a 4 1 agitated vessel, 816.22 g of water and 2.18 g of diethanolaaznine
were added
to 22 g of emulsifier mixture - corresponding to 1 wt.%, based on the total
batch - of
an ethoxylated sorbitan monolaurate and an ethoxylated oleyl alcohol with a
total
HLB value of 15.3 and stirred for 2 hours at 80 C, a clear solution being
obtained.
1359.6 g of a mixture of 49.2% octyl triethoxysilane and 50.8% of a resin with
the
10 composition (CH3)o.s(Ci2H2s)o.2 Si(O)1 (OCH3)t were added to the cooled
solution
within 65 min at a rate of stirring of 700 rpm. After the addition was
completed,
stirring was continued for 30 min at 550 rpm. A sample was taken after 30 min
for
particle size determination. The pre-emulsion was homogenised in 2 passes in a
conventional homogeniser of the Gaulin type with a pressure drop of AP = 250
bar.
15 The results are given in Table 2.
Example 8
The batch from Example 7 was doubled. 1632.44 g of water and 4.36 g of
20 diethanolamine were added to 44 g of emulsifier mixture - corresponding to
1 wt.%,
based on the total batch - of an ethoxylated sorbitan monolaurate and an
ethoxylated
oleyl alcohol with a total HLB value of 15.3 in VC (see Fig. 2) and stirred
for 2
hours at 80 C, a clear solution being obtained. After cooling, the solution
was
pumped for one minute at 3 bar in the circuit VC--+P3-->M1-*VC. 2719.2 g of a
mixture of 49.2% octyltriethoxysilane and 50.8% of a resin with the
composition
(CH3)o.g(CiZH25)o.2Si(0)t(OCH3)1 were injected into this circuit at 5 bar from
VA by
means of P1 and through Ml (nozzle diameters: 2.1/1.0 mm) within 3.5 min.
After
the addition was completed, the above circuit was maintained for another 15
min at
3 bar. A sample was taken after 5 and 15 min for a particle size
determination. The
CA 02304644 2000-03-24
21
pre-emulsion was homogenised in 2 passes with a pressure drop of AP = 100 bar.
The results are given in Table 2.
Example 9 (Comparative example)
In a 4 1 agitated vessel, 163.2 g of water and 2.18 g of diethanolamine were
added to
22 g of emulsifier mixture - corresponding to 1 wt.%, based on the total batch
- of an
ethoxylated sorbitan monolaurate and an ethoxylated oleyl alcohol with a total
HLB
value of 15.3 and stirred for 2 hours at 80 C, a clear solution being
obtained. 1359.6
g of a mixture of 49.2% octyltriethoxysilane and 50.8% of a resin with the
composition (CH3)0,8(C12H,5)0.2 Si(O)I (OCH3)t were added to the cooled
solution
within 65 min at a rate of stirring of 700 rpm. After the addition was
completed,
stirring was continued for 15 min at 550 rpm, a high-viscosity paste being
obtained.
653.0 g of water were added at the above-mentioned rate of stirring within 30
min
and stirring was continued until the particle size had fallen below 5 m (45
min).
The pre-emulsion was homogenised in 2 passes in a conventional homogeniser of
the Gaulin type with a pressure drop of AP = 200 bar. The results are given in
Table
2.
Example 10
The batch from Example 9 was tripled. 489.60 g of water and 6.54 g of
diethanolamine were added to 66 g of emulsifier mixture - corresponding to I
wt.%,
based on the total batch - of an ethoxylated sorbitan monolaurate and an
ethoxylated
oleyl alcohol with a total HLB value of 15.3 in VC (see Fig. 2) and stirred
for 2
hours at 80 C, a clear solution being obtained. After cooling, the solution
was
pumped for one minute at 3 bar in the circuit VC-+P3-+M1--+VC. 4078.8 g of a
mixture of 49.2% octyltriethoxysilane and 50.8% of a resin with the
composition
(CH3)0.8(C12H25)0.2 Si(O)l (OCH3)1 were injected into this circuit at 5 bar
from VA
by means of P1 and through M1 (nozzle diameters: 2.1/1.0 mm) within 5 min.
After
the addition was completed, the above circuit was maintained for another 4 min
at 3
CA 02304644 2000-03-24
22
bar. 1959 g of water were then injected into the above circuit via M1 from VB
within 10 min. After all the water had been added, the pre-emulsion was pre-
homogenised in the circuit for another I min, a sample was taken for
determining
the particle size, and homogenisation was carried out in two passes in the jet
disperser with a pressure drop of dP = 100 bar. The results are given in Table
2.
~~.
Table-2
Pass no. Pressure drop Particle size Pre-emulsion Distribution
OP [bar] 0 [ m] Time required [min] U90
Example Example Example Example Example
7 8 9 10 7 8 9 10 7 8 9 10 7 8 9 10 7 8 9 10
V V V g1250 0 3/5 0 3/5 >5.000 3.773 4.241 4.371 95 20* 110 21
I I I 100 200 100 1.766 0.647 0.763 0.632 2.03 1.21 1.75 1.21
2 2 2 250 100 200 100 1.707 0.609 0.548 0.583 1.32 1.02 1.21 1.10 y
* with a double batch
+ with a triple batch N o
ca ~
W
CA 02304644 2000-03-24
24
Example 11
390.83 g of water and 3.17 g of diethanolamine were added to 32 g of
emulsifier
mixture - corresponding to 0.64 wt.%, based on the total batch - of an
ethoxylated
sorbitan monolaurate and an ethoxylated oleyl alcohol with a total HLB value
of
15.3 in VC (see Fig. 2) and stirred for 2 hours at 80 C, a clear solution
being
obtained. After cooling, the solution was pumped for one minute at 3 bar in
the
circuit VC-~P3-+M1-+VC. 1980 g of a mixture of 49.2% octyltriethoxysilane and
50.8% of a resin with the composition (CH3)o.s(Ci2H2s)o.2Si(O)1(OCH3)1 were
injected into this circuit at 5 bar from VA by means of P1 and through Ml
(nozzle
diameters: 1.8/0.9 mm) within 3 min. After the addition was completed, the
above
circuit was maintained for another 2 min at 3 bar. 2594 g of water were then
injected
into the above circuit via MI from VB within 13 min. After all the water had
been
added, the pre-emulsion was pre-homogenised for 4 min in the circuit, a sample
was
taken for determi-n;ng the particle size and homogenisation was carried out in
2
passes in the jet disperser with a pressure drop of AP = 95 bar. The results
are given
in Table 3.
Table 3
Pass Pressure Particle size Pre-emulsion Emulsifier Emulsion
no. drop dP 0 [[im] time required content stability
[bar] [min] [%] [months]
V 3/5 4.326 25 0.64 -
1 95 0.621 >6
2 95 0.611 >6
CA 02304644 2000-03-24
C. Silicone oil emulsions
Example 12
5 1850 g of water were added at 50 C to 150 g of melted emulsifier mixture -
corresponding to 3 wt.% based on the total batch - of an ethoxylated
triglyceride and
an ethoxylated tridecylalcohol with a total HLB value of 13.5 in VC (see Fig.
2) and
pumped for 2 min at 3 bar in the circuit VC-+P3-+M1-*VC, cooled, and 3000 g of
a diorganopolysiloxane having a viscosity rl = 350 mPas were injected into
this
10 circuit within 18 min from VA by means of Pl at 5 bar into Ml (nozzle
diameters
1.4/0.7 mm). Homogenisation was then carried out in STR-D with a pressure drop
of
250 bar. The results are given in Table 4.
FxampLe 13
1550 g of water were added at 45 C to 200 g of melted emulsifier mixture -
corresponding to 4 wt.% based on the total batch - of an ethoxylated
triglyceride and
an ethoxylated tridecylalcohol with a total HLB value of 15.4 in VC (see Fig.
2) and
pumped for 2 min at 3 bar in the circuit (nozzle diameters 1.4/0.7 mm),
cooled, and
1750 g of a diorganopolysiloxane having a viscosity rl = 350 mPas were
injected
into this circuit within 5.5 min from VA by means of P1 at 5 bar into Ml
(nozzle
diameters 2.1/1.0 mm). After the addition was completed, pumping was continued
in
the circuit for another 5 minutes at 3 bar. 1500 g of water from VB were then
injected via Ml at 5 bar within 8 minutes. After a further 5 min circuit at 3
bar,
homogenisation was carried out in STR-D with a pressure drop of 250 bar. The
results are given in Table 4.
CA 02304644 2000-03-24
26
Example 14
1240 g of water were added at 50 C to 180 g of melted emulsifier mixture -
corresponding to 4.5 wt.% based on the total batch - of an ethoxylated
triglyceride
and an ethoxylated tridecylalcohol with a total HLB value of 15.4 in VC (see
Fig. 2)
and pumped for 1 min at 3 bar in the circuit VC-*P3--+M1-->VC, cooled, and 800
g
of a diorganopolysiloxane having a viscosity rI = 350 mPas were injected into
this
circuit within 1.5 min from VA by means of P1 at 5 bar into M1 (nozzle
diameters
2.1/1.0 mm). After the addition was completed, pumping was continued in the
circuit for another 2 minutes at 3 bar. 1780 g of water from VB were then
injected
via Ml at 5 bar within 8.5 minutes and homogenisation was carried out in the
same
circuit for 2.min at 3 bar. Homogenisation was then carried out in STR-D with
a
pressure drop of 200 bar. The results are given in Table 4.
Example 15 (Comparative example)
620 g of water were added at 50 C to 90 g of melted emulsifier mixture -
corresponding to 4.5 wt.% based on the total batch - of an ethoxylated
triglyceride
and an ethoxylated tridecylalcohol with a total HLB value of 15.4 in an
agitated
vessel and stirred for 3 min, cooled, and 400 g of a diorganopolysiloxane
having a
viscosity rj = 350 mPas were added via a dropping funnel with stirring within
13
min. After the addition was completed, stirring was continued for another 5
minutes
at 400 rpm before 890 g of water were added within 27 minutes at 300 rpm
(considerable foaming). The pre-emulsion was homogenised in a conventional
homogeniser of the Gaulin type in 2 passes with a pressure drop of AP = 200
bar.
The results are given in Table 4.
i ,.
Table 4
Pass Particle size Pre-emulsion time Active substance Emulsion stability
no. 0 [ m] required [min] concentration [%] [months]
Example Example Example Example
12" 13" 1431 1 5 ' 12 13 14 15 12 13 14 15 12 13 14 15 12 13 14 15
V V V v - - - 18 23.5 14 45 60 35 20 20 - - - -
1 1 1 1 1.0 0.960 2.743 3.411 60 35 20 20 >6 >6 6
2 2 2 2 0.9 0.832 0.910 3.317 60 35 20 20 >6 >6 6 n
3 3 3 3 0.8 0.787 0.822 2.534 60 35 20 20 >6 >6 6 <6
4 4 4 0.777 0.798 2.406 >6 6 <6 4.
4.
2.362 <6 4.
1 N
O
2.254 <6 N o
1) 5000 g batch
2) 5000 g batch
3) 4000 g batch
4) 2000 g batch
CA 02304644 2000-03-24
28
Example 16
2800 g of water, 4.6 g of 37% hydrochloric acid, 5.25 g of glycine, 51.3 g of
glycerol, 200 g of an alkylbenzylammonium bromide, 30 g of an ethoxylated
tridecylalcohol with an HLB value of 11.4 and 22.6 g of glycol were charged to
VC
(see Fig. 2) and pumped in the circuit VC-*P3-)~M1-+VC for 30 s at 3 bar. 2056
g
of a hydrogen-bearing organopolysiloxane having a viscosity rl = 40 mPas were
injected into the above circuit at 7 bar within 100 s from VA by means of Pl
into
Ml (nozzle diameters: 1.8/0.9 mm). After the addition was completed, the pre-
emulsion was pumped into the buffer vessel VD and homogenised at a slightly
later
stage by means of P4 in one pass in jet disperser STR-D with a pressure drop
of
OP = 250 bar. The results are given in Table 5.
Table 5
Example Pass Particle Time Total Stability
no. no. size [min/s] emulsific- [months]
0 [ m] ation time
[min/s]
16 V 2'10"
1 0.368 4'40" >6
6'50"
D. Silicone emulsion in the mixing station
Example 17
A mixture of 96.6 g of an ethoxylated tridecylalcohol with an HLB value of
11.4,
552.72 g of a polydimethylsiloxane with a viscosity rl = 500 mPas, 994.84 g of
a
mineral oil raffinate with a boiling range of 382 - 432 C and 691.04 g of a di-
(2-
ethylhexyl) phthalate was pumped out of the vessel VA at a pressure of 3 bar
first
for one minute via Ml (nozzle diameters: 1.4/0.6 mm) in the circuit
CA 02304644 2000-03-24
29
VA-+P1-+M1--+VA. A solution of 464.52 g of water and 0.28 g of benzylalcohol
monohemiformal was then injected into this circuit within 3 minutes at a
pressure of
3.5 - 4 bar via VC-+P3-+Ml. After all the water had been added, pumping was
continued in the circuit VA-+P1-*M1-+VA for another 3 minutes at a pressure of
3
bar. This circuit was maintained for another 10 minutes with a pressure of 12
bar. A
high-viscosity stable emulsion is obtained. The results are given in Table 6.
Table 6
Example no. Time Particle size Viscosity Stability
[min/sec] 0 [ m] [mPas] [months]
17 17 1.748 2670 >6
Example 18 (according to the invention)
2800 g of a polydimethylsiloxane with a viscosity rl = 1000 mPas were injected
via
the active substance circuit VA-+P1->M1-+VA into a solution of 171.9 g of an
ethoxylated triglyceride with an HLB value of 18.1 and 148.1 g of an
ethoxylated
tridecyl alcohol with an HLB value of 11.4 in 800 g of water which was
situated in
the circuit VC--+P3-*M1. The initial absolute pressure of the active substance
circuit
was raised in so doing from 5 to 12 bar within 9 minutes. The pressure of the
circuit
VC-+P3--+M1 accompanied this increase - 2 bars lower in each case. After a
total of
12 minutes, the feed of active substance had ended and a viscous white paste
was
obtained. This is pumped, with cooling, for another 14 minutes in the circuit
VC-).P3-*M1 at 10 bar.
4080 g of water were then injected at 25 C from VB by means of P2 at a
pressure of
12 bar in approx. 5 minutes. In so doing, the pressure fell to 4.5 bar as the
dilution
increased in the circuit VC-)-.P3-+M1, the pump P2 accompanying this fall at a
pressure 2 bars higher. After all the water had been added, the pressure in
the circuit
CA 02304644 2000-03-24
VC-*P3-),M1 was raised to 80 bar and the emulsion was removed from the mixing
station via Ml.
A low-viscosity, stable emulsion was obtained.
5
The results are given in Table 7.
Example 19 (according to the invention)
10 2800 g of a polydimethylsiloxane with a viscosity rj = 350 mPas were
injected via
the active substance circuit VA->Pl--*M1-).VA into a solution of 171.9 g of an
ethoxylated triglyceride with an HLB value of 18.1 and 148.1 g of an
ethoxylated
tridecylalcohol with an HLB value of 11.4 in 800 g of water which was situated
in
the circuit VC->P3-+M1. The initial absolute pressure of the active substance
circuit
15 was raised in so doing from 7 to 10 bar within 6 minutes. The pressure of
the circuit
VC-+P3--+M1 accompanied this increase - 2 bars lower in each case. After a
total of
6 minutes, the feed of active substance had ended and a viscous white paste
was
obtained. This was pumped, with cooling, for another 20 minutes in the circuit
VC-->P3-+M1 at 10 bar.
4080 g of water were then injected at 25 C from VB by means of P2 at a
pressure of
10 bar within approx. 5 minutes. In so doing, the pressure fell to 4 bar as
the dilution
increased in the circuit VC-.>P3--*M1, the pump P2 accompanying this fall at a
pressure 2 bars higher. After all the water had been added, the pressure in
the circuit
VC--+P3-+M1 was raised to 80 bar and the emulsion was removed from the mixing
station via M l .
A low-viscosity, stable emulsion was obtained.
The results are given in Table 7.
CA 02304644 2000-03-24
31
Table 7
Example no. Time Particle size Ugo Stability
[min/sec] 0 [ m] [months]
18 32 0.689 1.541 >6
19 32 0.531 1.168 >6
