FIELD OF INVENTION
The present invention relates to a process for making stable high viscosity
organopolysiloxane emulsion and in particular to an emulsion-polymerisation process
involving a simple and cost-effective faster completion of emulsiftcation of
organopolysiloxane and also subsequent polymerisation of the organopolysiloxane. The
process is directed to be simple and cost-effective and can be easily adapted for
emulsion production of stable organopolysiloxane emulsions for diverse beneficial end
use and application. Importantly, the silicone emulsion produced by the process of the
invention is in the range of average (i.e D50 value) up to 150 nanometer with 3 very-
narrow particle size distribution which is highly stable and found to have advantageous
and beneficial diverse use in various end applications including in personal care, textile -,
rubber, paper and other like applications/uses.
BACKGOUND ART
It is well known to provide organopolysiloxane emulsions with varying particle sizes to
suit different end applications.
. Organopolysiloxane emulsions having low partide size prepared by emulsion
polymerisation process are generally preferred which could provide the desired faster
and simple production with focus on emulsion stability and quicker organipolysitoxane
polymerisation during emulsification. Such emulsion polymerised products are known to
be prepared by various methods. For examples, JP-B 34-2041 disclosed a polymerisation
process wherein a strong acid and strong base are used as a polymerisation catalyst. US
3697469 used ion-exchange resin as polymerisation catalyst. US 3360491; US 3697469;
US 4228054; US 5726270; US 5817714; US 5895794; US 5925469 and US 6071975
disclosed polymerisation using alky I benzene sulphonic acid, alkyl naphthalene sulphonic
acid, aliphatic sulphonic acid, silylalkyl sulphonic acid, aliphatically substituted diphenyl
ether sulfonic acid or alkyl hydrogen sulphates as a catalyst. However all these processes
take longer time for polymerisation and completion of the emulsion making process.
Most of the processes are also only restricted to cydosiloxanes.
US 6245852, disdoses a process of preparation of organopolysiloxane emulsion having
improved stability within a short time. The process comprising the steps of emulsifying
and dispersing low molecular weight organopolysiloxane in water in presence of
essentially at least one anionic surfactant selected from organic sulphonic acid and
organic sulphates by using a high pressure homogeniser with a operating pressure range

from 700 to 3000 Kg/cm2 and produce an initial emulsion having partide size up to 300
ran, followed by allowing the emulsion for polymerisation and subsequent neutralization
of the emulsion at the end.
As would be clearly apparent from the disclosure in US'852 the process necessarily
involves the use of very sophisticated and highly capital-intensive machine system for
reduction of emulsion time in the emulsion polymerisation process. Also since the
process uses a high-pressure system, the emulsion machine needs lot of control system
for working safely in the production area.
Thus while the process according to the above US'852 stated to reduce the time of
emulsification by using a sophisticated high pressure homogeniser but the said process
does not seem to address the requirement for faster completion of the total emulsion
process including faster polymerisation. Emulsion polymerisation process usually consists
of emulsification of organopotysiloxane and subsequent polymerisation of the
organopolysiloxane. So, faster emulsification on its own is not sufficient to complete
emulsion polymerisation process or make the process faster. Therefore, it is also
important to make faster polymerisation in emulsion polymerisation processes.
The above state of art reveals the need to develop processes of making faster the total
emulsion polymerisation process .Also the reduction in the partide size which is found to
be of relevance for variety of end use/applications involving a faster emulsion
polymerisation process is desirable for wide scale commercial manufacturing and use of
such emulsions for diverse applications.
OBJECTS OF THE INVENTION
It is thus the basic object of the invention to provide a process of making silicone
emulsion having partide size up to 150 nm which would on one hand be simple, cost-
effective and fast and on the other hand would provide a simple and cost effective
alternative to the need for complex machinery for faster emulsification and also reduce
the polymerisation time in the emulsion polymerisation process and thus can be readily
adapted for large scale cost-effective commercial manufacture of such low particle size
silicone emulsions for diverse applications such as in personnel care and the like.
Another object of the invention is directed to provide a simple process of making silicone
emulsion having partide size up to 150 nanometer, which would reduce the total
"emulsion polymerisation time" significantly.

Another object of the present invention is directed to a process for the manufacture of
silicone emulsion having particle size up to 150 nanometer which would assist faster
polymer growth of the - organopolysiloxane during emulsion process.
Yet further object of the present invention is directed to making stable silicone emulsion
involving standard homogenizer having particle size up to 150 nanometer by way of a
selective emulsion formulation and avoiding the need for complex machinery to reduce
the emulsification and polymerisation stages in such manufacture of silicone emulsion.
SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention, there is provided a process
for the manufacture of a stable emulsion having particle size (D 50 value) up to 150
nanometer comprising:
i) providing a selective formulation comprising (a) an organopolysiloxane of. the Formula

where R1 is a hydroxyl and/or an alkoxy group having 1 to 8 carbon atom and where R,
which are the same or different, are monovalent hydrocarbon radical, and x is an integer
from 1 to 100, or mixtures thereof in an amount of 20 to 80 % by.wt. (b) water in an
amount of 5 to 30 % by wt. (c) selective non-ionic emulsifier(s) having HLB in the range
of 10-19 in amounts of 1 to 25% by wt. and (d) selective anionic emulsifier having HLB
in the range of 8 - 19 in an amount of 1 to 15 % by. wt.;
ii) homogenizing the mix of (i) using any standard homognizer and maintaining a
temperature of up to 50°C preferably in the range of 10-40°C such as to favour
organopolysiloxane polymer growth rate or rise in polymer viscosity to at least 20000
cps; and
iii) neutralising the emulsion by alkali to a pH range 6-8.
Importantly, it is found by way of the invention that one of the critical aspects which
enable obtaining of emulsion up to 150 nanometer following a simple process is the
selective use of a combination of non-ionic emulsifier together with an atleast one
anionic emulsifier to achieve the desired particle sized emulsion. For organopolysiloxane
emulsion, HLB value near to 12-15 is found to be the optimum value of the emulsifier or
a mixture of emulsifiers, which help to make low particle emulsion. It is also found that a
mixture of non-ionic and anionic emulsifiers having HLB value of the mixture near to 12-
15 shows optimum combinations to make low particle stable emulsion with a standard
homogenizer.

Another object of the present invention is directed to a process for the manufacture of silicone emulsion having particle size up to 150 nanometer which would assist faster
polymer growth of the - organopolysiloxane during emulsion process.
Yet further object of the present invention is directed to making stable silicone emulsion
involving standard homogenizer having particle size up to 150 nanometer by way of a
selective emulsion formulation and avoiding the need for complex machinery to reduce
the emulsification and polymerisation stages in such manufacture of silicone emulsion.
SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention, there is provided a process
for the manufacture of a stable emulsion having particle size (D 50 value) up to 150
nanometer comprising:
i) providing a formulation comprising (a) an organopolysiloxane of the Formula. (I)

where R1 is a hydroxyl and/or an alkoxy group having 1 to 8 carbon atom and where R,
which are. the same or different, are monovalent hydrocarbon radical, and x is an integer
from 1 to 100,
or mixtures thereof in an amount of 20 to 80 % by.wt. (b) water in an amount of 5 to 30
% by wt. (c) non-ionic emulsifier(s) having HLB in the range of 10-19 in amounts of 1 to
25% by wt. and (d) at least one anionic emulsifier selected from organic sulfonic acids
having HLB in the range of 8 - 19 in an amount of lto 15 % by. wt.;
ii) homogenizing the formulation of (i) using any standard homognizer and maintaining a
temperature in the range of 10-40°C so as to increase organopolysiloxane polymer
growth rate or rise in polymer viscosity to at least 20000 cps.; and
iii) neutralising the emulsion by alkali to a pH range 6-8.
. Importantly, it is found by way of the invention that one of the critical aspects which
enable obtaining of emulsion up to 150 nanometer following a simple process is the
selective use of a combination of non-ionic emulsifier together with an atleast one
anionic emulsifier to achieve the desired particie sized emulsion. For organopolysiloxane

emulsion, HLB value near to 12-15 is found to be the optimum value of the emulsifier or
a mixture of emulsifiers, which help to make low particle emulsion. It is also found that a
mixture of non-ionic and anionic emulsifiers having HLB value of the mixture near to 12-
15 shows optimum combinations to make low particle stable emulsion with a standard
homogenizer.
Also the quantity of the emulsifiers used in the above selective formulation have
selective contribution to make the emulsion stable. In particular, in the above process of
making low particle organopolysiloxane emulsion, the emulsion is also stabilized by use
of surfactants having critical HLB values that help to make faster low particle emulsion
by using standard homogenizer without need for complex ultra high pressure
homogeniser.
Moreover, it is also important to control temperature for achieving low particle size with
narrow distribution of the particle. Advantageously making of the emulsion with a
temperature up to 50°C, is found to further help faster polymer growth of
organopolysiloxane in the emulsion. Temperature during the emulsion preparation is
found to have great importance not only to control the particle size but also control the
particle size distribution and faster growth of internal phase viscosity.
In the above process of invention, preferably, a suitable biocide is added for preventing microbial growth.
Since, the process uses a mixture of surfactants for making low particle
organopolysiloxane by using standard homogenizer, it.is important to maintain the
selective formulation involving making a proper recipe of surfactants mix and recipe of
organopolisiloxane and surfactants to achieve particle size up to 150 nanometer.
In accordance with a preferred aspect the above process for the manufacture of stable
and faster production of low particle size emulsion having high internal phase oil
viscosity comprises of: (i) providing 8 to 30% mixed emulsifiers comprising atleast one anionic
emulsifier selected from the group consisting of organic sulfonic acids and
at least one non-ionic emulsifier having HLB value in the range of 10-19;
(ii) homogenising the formulation with standard homogenizer while
maintaining a temperature in the range of 20-40°C for a period of 10
minutes to 2 hr; (iii) allowing the emulsion to age in the range of 5 to 30°C wherein the
viscosity of the internal phase oil increases to at least 20,000 cps;

(iv) neutralising the emulsion with alkali and finally adding biocide for
microbial prevention in the emulsion.
The temperature of the material can be. controlled during homogenising, by passing cool
water. In the above process the desired ageing temperature for growth of very high
internal oil viscosity is in the range of 5 to 30 °C. Generally, 1 to 12 hr is required, to
. achieve very high viscosity internal phase oil viscosity. If internaloil viscosity is needed . * •
less than 500,000 cps, then neutralizing of the emulsion is carried out immediately after
completion of mixing. Moreover, it \s found that desired mixing time also varies for
target viscosity of the polymer and distribution of the particles in the emulsion.
Neutralise the emulsion after completion of dilution steps. Generally, water-soluble
inorganic alkali hydroxide or organic amine alcohol is used for neutralization. Preferably,
sodium hydroxide or potassium hydroxide or triethanol amine is used to neutralise the
emulsion.
According to the present invention, one of the critical parameters include the selection of
the right emulsifiers and combination of the emulsifiers to achieve the desired low
- particle size emulsion. The present invention thus achieves producing low particle
emulsion in a simple way where selective emulsifier combination and temperature of
emulsification and polymerisation which have a critical part to make the process simple
and avoiding the use of cost extensive and complex machinery.
According to a preferred aspect of said process said organopolysiloxanes of the formula
■'''.•* • , < ■
(I)is selected from the group consisting, of alpha omega hydroxy terminated
' organopolysiloxane; alpha omega alkoxy terminated organopolysiloxane or mixture
•thereof. . 'r f
According to yet another preferred aspect of said process a branched polysiloxane
emulsion is formed, comprising adding a tri- functional or tetra- functional or a mixture
thereof with the organopolysiloxanes.
According to another preferred aspect of said process said anionic emulsifier is selected
from alkyl aryl sulfonic acid; alkyl aryl polyoxyethylene sulphonic acid; alkyl sulfonic acid
and alkyl polyoxyethylene sulfonic acid.
Preferably in said process said sulfonic acids used comprise:
R2C6H4SO3H (V) R2C6H40(C2H40)mSO3H (VI)
R2SO3H (VI) R2 O (C2H40)m SO3 H (VIII)

Where R2, which may differ, is a monovalent hydrocarbon radial having atleast 6 carbon
atom,most preferable R2 groups, but not limited to the following groups, are hexyl, octyl,
decyl, dodecyl, cetyl, stearyl, myristyl; and oleyl, and 'm' is an integer from 1 to 25. "«(
According to yet another preferred aspect of said process said anionic surfactants;,is,.
used in amounts of 1-15% and are selected from octyl benzene sulfonic acid; dodecyl
benzene sulfonic acid; cetyl benzene sulfonic acid; Alpha octyl sulfonic acid; Alpha
dodecyl sulfonic acid; alpha cetyl sulfonic acid; polyoxyethylene octyl benzene sulfonic
acid; polyoxyethylene dodecyl benzene sulfonic acid; polyoxyethylene cetyl benzene
sulfonic acid; polyoxyethylene octyl sulfonic acid; polyoxyethylene dodecyl sulfonic acid
and polyoxyethylene cetyl sulfonic acid .
According to another preferred aspect of said process said non-ionic emulsifiers comprise
non-ionic surfactants in an amount of 1 to 25% selected from polyoxyalkylene alkyl
ether, polyoxyalkylene alkylphenyl ethers and polyoxyalkylene sbrbitan esters preferably
selected from polyethylene glycol octyl ether; Polyethylene glycol lauryl ether;
Polyethylene, glycol tridecyl ether; Polyethylene glycol cetyl ether; Polyethylene glycol
stearyl ether; polyethylene glycol nonylphenyl ether; polyethylene glycol dodecylphenyl
ether; polyethylene glycol cetylphenyl ether; polyethylene glycol staerylphenyl ether;
polyethylene glycol sorbitan mono stearate and polyethylene glycol sorbitan mono
oleate.
DETAILED DESCRIPTION OF THE INVENTION
The invention thus provides a process for making stable low particle emulsion from a low
molecular organopolysiloxane or a mixture of organopolysiloxane. Organopolysiloxanes
referred herein for the purpose of the invention include low molecular
organopolysiloxane such as.alpha omega hydroxy terminated organopolysiloxane; alpha
omega alcoxy terminated organopolysiloxane; organocyclopolysiloxanes or mixture
thereof.
In case of branched polysiloxane emulsion a tri functional or tetra functional or a mixture
thereof is used together with above organopolysiloxanes.
The alpha omega functional end blocked linear organopolysiloxane used herein are
preferably those of the general formula I:

Organopolysiloxane used according to the present invention may be branched by way of
incorporation of branching units. Branching units may be introduced to improve the film ■
forming behaviour of organopolysiloxane. Branching unit may be trifunctional silane or
tetrafunctional silane or a mixture thereof. Trifuntional silanes (III) and tetrafunctional
silanes (IV) have the following structure:
R—Si — (O^R)3 Ill Si — (O —R)4 IV
Where R, which may differ, is a monovalent hydro carbon radical. Examples of R are
alkyl radicals, such as methyl, ethyl, n-propyl, iso propyl, n-butyl, Isobutyl, tert-butyl, n-
pentyl, Isopentyl, neopentyl, tert pentyl, hexyl such as n-hexyl, heptyl such as n-heptyl,
octyl such as n-octyl and isooctyl such as 2,2,.4-trimethyl pentyl, nonyl such as n- nonyl,
decyl such as n decyl, dodecyl such as n-dodecyl, octadec'yl such as n-octadecyl; alkenyl
such as vinyl and allyl, cycloalkyl, such, as cyclopentyl, cyclohexyl, cycloheptyl and
methyl cyclohexyl, aryl such as phenyl, napthyl, anthryl and phenanthryl ; alkylaryl,
such as o-, m-, p-totyl, xylyl and ethylphenyf; aralkyl, such as benzyl, a and p-
v • ■ r
phehylathyl, of which methyl, ethyl, n-propyl, isopropyl are preferred and methyl is
particularly preferred'.)Depending on the desired requirement of branching of the '
organopolysiloxane,^branching units are adding during the emulsification process. 0.1 to i
5% branching units of the emulsion is useful to make an emulsion containing • i
organopolysiloxane having highly branched structure. Quantity used in the emulsion
must be controlled carefully, otherwise gelfation of the polymer may occur during
emulsion process and emulsiopi'destabilizes. If branched polysiloxane is not required, the/
silane addition is avoided^:
According to the present invention, anionic emulsifier has an important role for simple
and faster emulsion process of high internal phase viscosity emulsion having particle size
up to 150 nm. Anionic surfacta'ht is selected from organic sulfonic acids. Most common
sulfonic acids used in the present process are alkyl aryl sulfonic acid; alkyl aryl
polyoxyethylene sulphonic acid; alkyl sulfonic acid and alkyl polyoxyethylene sulfonic
acid. „ .

Structures of sulfonic acids are as below:
R2C6H4SO3H (V) R2C6H40(C2H40)mSO3H (VI)
R2SO3H (VI) R2 O (C2H40)m SO3 H (VIII)
Where R2, which may differ, is a monovalent hydrocarbon radial having atleast 6 carbon
atom. Most preferable R2 groups, but not limited to the following groups, are hexyl, octyl,
decyl, dodecyl, cetyl, stearyl, myristyl, and/oleyl. 'm' is an integer from 1 to 25. Most
preferable anionic surfactants used in the present inventions are octyl benzene sulfonic
acid; dodecyl benzene sulfonic acid; cetyl benzene sulfonic acid; Alpha octyl sulfonic
acid; Alpha dodecyl sulfonic acid; alpha cetyl sulfonic acid; polyoxyethylene octyl
benzene sulfonic acid; polyoxyethylene dodecyl benzene sulfonic acid; polyoxyethylene
cetyl benzene sulfonic acid; polyoxyethylene octyl sulfonic acid; polyoxyethylene dodecyl
sulfonic acid and polyoxyethylene cetyl sulfonic acid. Generally, 1 to 15% anionic .
surfactant is used in the present emulsion processing process. Preferably, 3-10% anionic
surfactant is used in the present emulsion to get the optimum result. Anionic surfactant
has a dual role in the present emulsion process. Anionic surfactant acts as a
condensation/ring opening catalyst in together with as a surfactant for emulsion making.
Thus, by using anionic emulsifier, process doesn't need any catalyst for polymer growth
of organopolysiloxane durfhg emulsion process. t; ' ^'

It is also observed according to the present invention, at least one additional emulsifier
together with anionic emulsifier is essential alongwith the controlled temperature of
efiTulsfficafaoni and polymerisation for making the emulsion in a simple raster way. It is
specially found by way of the present invention that at least one non-ionic emulsifier in
together with anionic surfactant helps for faster simple emulsion production. Non-ionic
emulsifiers having HLB value in between 10-19 are suitable to make the emulsion
process simpler. .Most useful surfactants of this category are polyoxyalkytene alkyl ether,
polyoxyalkylene alkylphenyf ethers and polyoxyalkylene sorbitan esters. Some useful
surfactants having HLB value in between 10-t9 are polyethylene glycol octyl ether;
Polyethylene glycol laury! ether; Polyethylene glycol tridecy! -ether;-Polyethylene glycol
cetyl ether; Polyethylene glycol stearyl ether; polyethylene glycol nonylphenyl ether;
polyethylene glycol dodecylphenyl ether; polyethylene glycol cetylphenyl ether;
polyethylene glycol staerylphenyl ether; polyethylene glycol sorbitan mono stearate and
polyethylene glycol sorbitan mono oleate. Non-ionic surfactant having HLB value in-
between 10-19 has a great importance in the present invention to make process more
simpler.
Generally, 1 to 25% nonionic surfactant is used in the emulsion processing process.
Preferably, 5- 20% nonionic surfactant is used in the present emulsion to get the
optimum result. It is well known in the art that Surfactant(s) having HLB value In-
between 12-15 is useful to make organopolysiloxane emulsion by using standard
homogenizer in shorter period and it is also well known to use a mixture of surfactants
that have HLB value in-between 12-15 to get an emulsion of organopolysiloxane having
long stability.
According to the present invention, it is also important to provide selective formulation of
the emulsifiers in a ratio such that the mix has HLB value preferably in-between 12-15
with at least one anionic surfactant and one non-ionic surfactant in the mixture.
An important aspect in the present emulsion process is the selective use of a mixture of
surfactants, which not only make stable emulsion in faster ,way by using standard
homogenizer but also to produce a low particle emulsion up to 150 nm. Particle size of
the emulsion is highly dependent on the ratio of anionic and non-ionic emulsifier (s)
having HLB value of the mixture in-between 12-15.

It is also well known of the art that polymer growth rate of the orgaopolyisiloxane is also
highly dependent on the partide size of the emulsion. So polymer growth rate of the^/
organopolysiloxane during the emulsion process is much higher compared to
organopolysiloxane emulsion having partide size above 150 nm.
According to the present invention, the temperature during the emulsion process has an
important role to control the partide size of the emulsion, distribution of the particle size
distribution (i.e polydispersibility, value 1 is poor and value 0.1 or less than 0.1 is very
good) and polymer growth rate of the organopolysiloxane during emulsion process. It is
also observed in the present emulsion process, particle size, and distribution of the
partide and polymer viscosity became out of control if temperature is not maintained
within a selective Iftnit. It is found a significant deviation of final emulsion spedfications
take place where temperature control is not within the said selective range even though
emulsion is produced by using an optimum combination of emulsifiers with a proper
combination of fluid to emulsifier. Maintaining a temperature below of 50°C is useful to* |
control the partide size, distribution of partide in the emulsion and polymer growth rate '
of the organopolysiloxane in the emulsion.
Further, it is also important to control the emulsion temperature during the ageing of the
emulsion in case of ultra high (more than 2 million cps) organopolysiloxane polymer in
the emulsion. A temperature below of 30°C is useful to make the polymerisation faster in
case of ultra high organopolysiloxane polymer required in the inner phase of the
emulsion. Emulsion polymerisation is significantly dropped if temperature is more than
30°C during ageing process, even difficult to achieve ultra high viscosity at high
temperature. So, it is dear that faster completion of emulsion process for high
organopolysiloxane polymer to ultra high polymer emulsion by emulsion polymerisation
process, temperature has great role during the emulsion making process and during the
ageing process. So, according to the present process, a combination of mixed emulsifiers
having HLB Value 12-15 (contains atleast one anionic emulsifier and atleast one non-
ionic emulsifiers) in together with temperature control during emulsion making and
during ageing helps the emulsion process useful to produce emulsion below 150 nm by
standard homogenjzer. ^*
The components are homogenised by standard homogenizers. Useful standard shear
stirring system may be used such as conventional single stage stator-rotor homogeriser
or other types of standard homogeniser which are used in the normal homogenising
process. Homogenising can be carried out in batch or continuous depend on the design
of emulsion process. From the capital investment point of view, it is also dear that the

process also needs a economic homogenising system and avoids the use of the
expensive very high pressure homogenising system.
Importantly, it is found by way of the present invention that the emulsion obtained
following the process of the invention was highly stable .In particular, tests revealed that
when the emulsion obtained was put in the oven in the range of 45 to 60°C and most
preferably, 55°C for one month, no creaming or separation or deformation in the
emulsion was observed. A study of 12 hr freeze/thaw cydes in 10°C/50°C temperature
for one month also showed no creaming or separation or deformation in the emulsion.
The details of the invention, its objects and advantages are explained hereunder in
greater detail in relation to non- limiting exemplary illustrations of the process:
EXAMPLES :
Example I
In the emulsion process, transferred 4.5 kg linear alkyl benzene sulfonic acid, 7 Kg
tridecyl alcohol ethoxylate having HLB value 14, 4.5 Kg water in a 100 lit mixing tank
having cold water jacket. Mixed the components for 5 min. Added 31.22 Kg Wacker PDM
siioxane (a 40 Cps alpha omega hydroxy terminated polydimethyl siloxane) and mixed
the component by single stage stator-rotor homogeniser till particle size dropped to
70nm. Mixing was continued for 25 min to reach particle size 70nm. During mixing,
temperature of the components were maintained below3J)0C. Then, the emulsion was
diluted with 30 kg water and the material maintained at temperature below 30°C
Thereafter neutralized the emulsion with 85% triethanol amine and added 4 ppm Kathon
CG as a biocide. Total process was completed within one hr.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
l|was 1,85,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed
W7Q.3 nm particle size of the emulsion having 0.09 polydispersibility-

Comparative Example IA
A milky white emulsion was prepared by following Example I except non-ionic surfactant
replaced by linear alkyl benzene sulfonic acid. Maintained temperature below 30°C like
Example I and completed total emulsification process within one hr. Finally neutralized
the emulsion with 85% triethanol amine and added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol.-Dried-the-polymer-sn-vaeuum-oven—Viscosity of the polymer
was 70,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 168
nm particle size of the emulsion having 0.40 polydispersibility .1/
The above reveals that due to the use of one emulsifier in the comparative example IA,
it was not possible to reach the same partide like example I and higher particle size
emulsion in IA compared to I hindered the polymer growth. So, after achieving particle
size 168nm even, viscosity of the dimethylpolysiloxane was much less than example I.
Also Polydispersibility in IA is higher compared to I.
Comparative Example IB
A milky white emulsion was prepared by following Example I except non-ionic surfactant
replaced by linear alkyl benzene sulfonic add and didn't control temperature during the
emulsification process. Temperature was increased to 55°C during emulsification process
and completed total emulsification process within one hr. Finally Neutralized the
emulsion with 85% triethanol amine and added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
tt was 8,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 185
nm particle size of the emulsion having 0.80 polydispersibility.

Since, temperature was not maintained during the emulsification p.ocess, it was not
possible to achieve the same fluid viscosity and particle size like IA.
Example IC
A milky white emulsion was prepared by following Example I except the temperature
was not maintained within the selective range during the emulsification process.
Temperature was increased to 55°C during emulsification process and completed total
emulsification process within one hr. Finally Neutralized the emulsion with 85%
triethanol amine and added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was 80,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 125
nm particle size of the emulsion having 0.80 polydispersibility.
Since, temperature was not maintained during the emulsification process, it was not
possible to achieve the same fluid viscosity and particle size like I.
Example jrj
In the emulsion process, transferred the 3.0 kg linear alkyl benzene sulfonic acid, 3 Kg
tridecyl alcohol ethoxylate having HLB value 14, 4.5 Kg water in a 100 lit mixing tank
having cold water jacket. Mixed the components for 5 min. Added 31.22 Kg Wacker PDM
siloxane (a 40 Cps alpha omega hydroxy terminated polydimethyl siloxane) and mixed
the component by single stage stator-rotor homogeniser till particle size dropped to 117
nm. Mixing was continued for 25 min to reach particle size 117 nm. During mixing,
temperature of the components were maintained below 30°C. Add 0.22 Kg methyl
triethoxy silane and continued the mixing for 10 min. Then, dilute the emulsion with 31
kg water and maintained the material temperature below 30°C. Neutralized the emulsion
with 85% triethanol amine and added 4 ppm Kathon CG as a biocide. Total process was
completed within one hr.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer

three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was 8,26,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 116
nm particle size of the emulsion having 0.03 polydispersibllity.
Comparative Example IIA
A milky white emulsion was prepared by following Example n except non-ionic surfactant
replaced by linear alkyl benzene sulfonic acid. Maintained-temperature below 30°C like
example II and completed total emulsification process within one hr. Finally Neutralized
the emulsion with 85% triethanol amine and added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was 1,96,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 185
nm particle size of the emulsion having 0.40 polydispersibility.
Since, under this example (comparative example HA) only one emulsifier was used , it
was not possible to reach the same particle like example II and higher partide size
emulsion in IIA in compared to II hindered the polymer growth. So, after achieving
particle size 185nm even, viscosity of the dimethylpolysiloxane was much less than
example II.
Comparative Example MP
A milky white emulsion was prepared by following Example II except non-ionic surfactant
replaced by linear alkyl benzene sulfonic acid and didn't maintain temperature as per the
proposed selective range of the invention during the emulsification process. Temperature
was increased to 55°C during emulsification process and completed total emulsification
process within one hr. Finally Neutralized the emulsion with 85% triethanol amine and
added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer

three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was 87,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 235
nm particle size of the emulsion having 0.70 polydispersibility.
Since, temperature was not maintained during the emulsification process, it was not
possible to achieve the same fluid viscosity and particle size like IIA.
A milky white emulsion was prepared as in Example II except didn't maintain the
temperature in the selective range as proposed under the invention during the
emulsification process. Temperature was increased to 55°C during emulsification process
and completed total emulsification process within one hr. Finally Neutralized the
emulsion with 85% triethanol amine and added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum drier. Viscosity of the polymer
was 1,80,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 140
nm particle size of the emulsion having 0.80 polydispersibility.
Since, temperature was not maintained during the emulsification process,it was not
possible to achieve the same fluid viscosity and particle size like II.
Example m
In the emulsion process, transferred the 4.0 kg linear alkyl benzene sulfonic acid, 7 Kg
tridecyl alcohol ethoxylate having HLB value 14, 4.5 Kg water in a 100 lit mixing tank
having cold water jacket. Mixed the components for 5 min. Added 31.22 Kg Wacker PDM
siloxane (a 40 Cps alpha omega hydroxy terminated polydimethyl siloxane) and mixed
the component by single stage stator-rotor homogeniser till particle size dropped to 117
nm. Mixing was continued for 25~mtn to reach particle size 117nm. During mixing,
temperature of the components were maintained below 30°C. Add 0.22 gm tetraethyl
orthosilicateand-continued the mixing for 10 min. Then, dilute the emulsion with 31 kg

water and maintained the material temperature below 30°C. Then, kept the emulsion 5
hr below 25°C. Neutralized the emulsion with 85% Methanol amine after 5 hr ageing
and added 4 ppm Kathon CG as a biocide. Total process including ageing was completed
within six hr.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was 45,26,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 117
nm particle size of the emulsion having 0.09 polydispersibility.
Comparative Example IIIA
A milky white emulsion was prepared by following Example III except non-ionic
surfactant replaced by a mixture of 5.5 kg linear alkyl benzene sulfonic acid and 5.5 Kg
Sodium lauryl sulphate. Maintained temperature below 30°C like example III. Then, kept
the emulsion 5 hr below 25°C. Neutralized the emulsion with 85% Methanol amine after
5 hr ageing and added 4 ppm Kathon CG as a biocide. Total process including ageing
was completed within six hr.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was 7,50,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 170
nm particle size of the emulsion having 0.50 polydispersibility.
Since, uner this comparative example IIIA two anionic emulsifiers were used , it was not
possible to reach the same particle like example ill and higher particle size emulsion in
IIIA compared to ni hindered the polymer growth. So, after achieving particle size 170
nm even> viscosity of the dimethylpolysiloxane was much less than example III.

A milky white emulsion was prepared as in Example in except non-ionic surfactant
replaced by linear alkyl benzene sulfonic acid and didn't maintain temperature during the
emulsification process. Temperature was increased to 55°C during emulsiflcation
process. Then, kept the emulsion 5 hr at 40-45°C. Neutralized the emulsion with 85%
triethanol amine after 5 hr ageing and added 4 ppm Kathon CG as a biocide. Total
process including ageing was completed within six hr.
Separated the polymer by adding isoproparto! in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was 1,50,000 Cps
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed 230
nm particle size of the emulsion having 0.78 polydispersibility.
Since, temperature was not maintained during the emulsification process, it was not
possible to achieve the same fluid viscosity and particle size like IIIA.
Example UK
A milky white emulsion was prepared by following Example III except didn't maintain
temperature within the selective range during the emulsification process. Temperature
was increased to 55°C during emulsification process. Then, kept the emulsion 5 hr at 40-
45°C. Neutralized the emulsion with 85% triethanol amine after 5 hr ageing and added 4
ppm Kathon CG as a biocide. Total process including ageing was completed within six hr.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was 9,73,000 Cps
Emulsion particle size was measured by Malvern Zetasizer NanoZS. Result showed 138
nm particle size of the emulsion having 0.80 polydispersibility.
Since, temperature was not maintained during the emulsification process,it was not
possible to achieve the same fluid viscosity and particle size like_III.

Example IV
In the emulsion process, transferred the 4.5 kg linear alkyl benzene sulfonic acid, 7 Kg
tridecyl alcohol ethoxylate having HUB value 14, 4.5 Kg water in a 100 lit mixing tank
having cold water jacket. Mixed the components for 5 min. Added 31.22 Kg
decamethyicyclopentasiloxane and mixed the component by single stage stator-rotor
homogeniser till particle size dropped to 70nm. Mixing was continued for 25 min to reach
particle size 70nm. During mixing, temperature of the components were maintained
below 30°C. Then, dilute the emulsion with 30 kg water and maintained the material
temperature below 30°C. Neutralized the emulsion with 85% triethanol amine and added
4 ppm Kathon CG as a biodde. Total process was completed within one hr.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was found 1,05,000 Cos
Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed
90.5 nm particle size of the emulsion having 0.08 polydispersibility.
Comparative Example IV A
A milky white emulsion was prepared by following Example IV except non-ionic
surfactant replaced by linear alkyl benzene sulfonic acid. Maintained temperature below
30°C like example IV and completed total emulsification process within one hr. Finally
Neutralized the emulsion with 85% triethanol amine and added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was found 24,500 Cps
Emulsion particle size was mcdsuied by Maivern Zetasizer Nano -ZS. Result showed 180
nm particle size of the emulsion having 0.30 polydispersibility.

Since, under th's comparative example IV A only one emulsifiers was used , it was not
possible to reach the same partide like example IV and higher parade size emulsion in
IV A compared to IV hindered the polymer growth. So, after achieving partide size
180nm even , viscosity of the dimethylpolysiloxane was much less than example IV.
Comparative Example IVB
A milky white emulsion was prepared by following Example IV except non-ionic
surfactant replaced by linear alkyl benzene sulfonic add and didn't maintain the
temperature-wlthin-the-selected-range-under-Jthe-invention -during the emulsification
process. Temperature was increased to 55°C during emulsification process and
completed total emulsification process within one hr. Finally Neutralized the emulsion
with 85% Methanol amine and added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was found 6,000 Cps
Emulsion partide size was measured by Malvern Zetasizer Nano -ZS. Result showed 185
nm partide size of the emulsion having 0.80 polydispersibility.
Since, temperature was not maintained during the emulsification process, we even didn't
able to achieving the same fluid viscosity and partide size like IV A.
Example w c
A milky white emulsion was prepared by following Example IV except didn't maintain
temperature as per the selective range proposed under the invention during the
emulsification process. Temperature was increased to 55°C during emulsification process
and completed total emulsification process within one hr. Finally Neutralized the
emulsion with 85% triethanol amine and added 4 ppm Kathon CG.
Separated the polymer by adding isopropanol in the emulsion in a ratio 3:1 of
isopropanol to emulsion. Drained out the isopropanol layer and washed the fluid layer
three times by isopropanol. Dried the polymer in vacuum oven. Viscosity of the polymer
was found 7,000 Cps *" '

Emulsion particle size was measured by Malvern Zetasizer Nano -ZS. Result showed
148.5 nm particle size of the emulsion having 0.80 polydispersibility.
Since, temperature was not maintained during the emulsification process, it was not
possible to achieve the same fluid viscosity and particle size like IV.
Above results clearly demonstrate the findings under the invention that
organopolysiloxane emulsion haying particle size below is only possible to produce by
simple single stage stator-rotor homogeniser when emulsifier mixture comprises atleast
one anionic emulsifiers and atleast one non-ionic emulsifiers. Anionic emulsifiers or a
mixture of anionic emulsifier can not produce an organopolysiloxane emulsion below 150
nm by using simple homogeniser. According to the present invention, it is also clearly
understood that temperature control during emulsion process has an important role to
control the particle size, polydispersibility of the emulsion particles and polymer growth
rate. It also observed in the examples that when same recipe followed with out
controlling the temperature, emulsion produced in the process had worse result in
compare to the emulsion produced with same recipe at controlled temperature during
the emulsion process. It is observed that low ageing temperature for ultra high polymer
also enhances the polymer growth rate in-compare to ageing at higher temperature. Also
the above results further demonstrate that particle size below 150 nm has a substantial
influence in the faster organopolysiloxane polymer growth in compare of silicone
emulsion having particle size more than 150 nm.

WE CLAIM:
1. A process for the manufacture of a stable emulsion having particle size (D 50 value) up
to 150 nanometer comprising:
(i) providing a selective formulation comprising (a) an organopolysiloxane of the formula (I)

where R1 is a hydroxyl and/or an alkoxy group having lto 8 carbon atom and where R,
which are the same or different, are monovalent hydrocarbon radical, and x is an integer
from 1 to 100, or mixtures thereof in an amount of 20 to 80 % by. wt. (b) water in an
amount of 5 to 30 % by wt. (c) selective non-ionic emulsifier(s) having HLB in the range of
10-19 in amounts of 1 to 25% by wt. and (d) selective anionic emulsifier having HLB in the
range of 8 - 19 in an amount of 1 to 15 % by. wt.;
(ii) homogenizing the mix of (i) using any standard homogenizer and maintaining a
temperature of up to 50°C preferably in the range of 10-40°C such as to favour
organopolysiloxane polymer growth rate or rise in polymer viscosity to at least 20000 cps;
and
(iii) neutralising the emulsion by alkali to a pH range 6-8.
2. A process for the manufacture of a stable emulsion as claimed in claim 1 wherein the
emulsifier or a mixture of emulsifiers have HLB value in the range of 12-15 for low particle
organopolysiloxane emulsion.
3. A process for the manufacture of a stable emulsion as claimed in anyone of claims 1 to 2
wherein for internal oil viscosity of less than 500,000 cps, neutralizing of the emulsion is
carried out immediately after completion of the mixing.

4. A process for the manufacture of a stable emulsion as claimed in anyone of claims 1 to 3
wherein said organopolysiloxanes of the formula (I) is selected from the group consisting of
alpha omega hydroxy terminated organopolysiloxane; alpha omega alkoxy terminated
organopolysiloxane or mixture thereof.
5. A process for the manufacture of a stable emulsion as claimed in anyone of claims 1 to 4
wherein a branched polysiloxane emulsion is formed, comprising adding a tri- functional or
tetra- functional or a mixture thereof with the organopolysiloxanes.
6. A process for the manufacture of a stable emulsion as claimed in anyone of claims 1 to 5
wherein said anionic emulsifier is selected from alkyl aryl sulfonic acid; alkyl aryl
polyoxyethylene sulphonic acid; alkyl sulfonic acid and alkyl polyoxyethylene sulfonic acid.
7. A process for the manufacture of a stable emulsion as claimed in 6 wherein the sulfonic
acids used comprise:
R2C6H4SO3H ........ (V) R2C6H4 O(C2H40)mSO3H (VI)
R2SO3H (VI) R2 O (C2H4O)m SO3 H (VIII)
Where R2, which may differ, is a monovalent hydrocarbon radial having atleast 6 carbon
atom,most preferable R2 groups, but not limited to the following groups, are hexyl, octyl,
decyl, dodecyl, cetyl, stearyl, myristyl, and oleyl and 'm' is an integer from 1 to 25.
8. A process for the manufacture of a stable emulsion as claimed in anyone of claims 1 to 7
wherein the anionic surfactants is used in amounts of 1-15% and are selected from octyl.
benzene sulfonic acid; dodecyl benzene sulfonic acid; cetyl benzene sulfonic acid; Alpha
octyl sulfonic acid; Alpha dodecyl sulfonic acid; alpha cetyl sulfonic acid; polyoxyethylene
octyl benzene sulfonic acid; polyoxyethylene dodecyl benzene sulfonic acid; polyoxyethylene
cetyl benzene sulfonic acid; polyoxyethylene octyl sulfonic acid; polyoxyethylene dodecyl
sulfonic acid and polyoxyethylene cetyl sulfonic acid.

9. A process for the manufacture of a stable emulsion as claimed in anyone of claims 1 to 8
wherein said non-ionic emulsifiers comprise non-ionic surfactants in an amount of 1 to 25%
selected from polyoxyalkylene alkyl ether, polyoxyalkylene alkylphenyl ethers and
polyoxyalkylene sorbitan esters preferably selected from polyethylene glycol octyl ether;
Polyethylene glycol lauryl ether; Polyethylene glycol tridecyl ether; Polyethylene glycol cetyl
ether; Polyethylene glycol stearyl ether; polyethylene glycol nonylphenyl ether;
polyethylene glycol dodecylphenyl ether; polyethylene glycol cetylphenyl ether;
polyethylene glycol staerylphenyl ether; polyethylene glycol sorbitan mono stearate and
polyethylene glycol sorbitan mono oleate.

ABSTRACT

TITLE: A PROCESS FOR THE MANUFACTURE OF STABLE LOW
PARTICLE SIZE ORGANOPOLYSILOXANE EMULSION
A process for making stable high viscosity organopolysiloxane emulsion having particle
size up to 150 nanometer and in particular to an emulsion-polymerization process
involving a simple and cost-effective faster completion of emulsification of
organopolysiloxane by using standard homogenizer and also subsequent polymerization
of the organopolysiloxane at controlled temperature. The process involves a selective
combination of non-ionic emulsifier together with an at least one anionic emulsifier to
achieve the desired particle size emulsion. Importantly, the selective mix of non-ionic
and anionic emulsifiers having HLB value of the mixture near to 12-15 and maintaining a
temperature of up to 50°C is found to favour obtaining low particle stable emulsion with
any standard homogenizer avoiding need for high pressure homogenizing.