Title of Invention

PROCESS FOR THE PREPARATION OF SULFUR-CONTAINING ORGANOSILICON COMPOUNDS.

Abstract A process for the production of organosilicon compounds of the formula (RO)3-mRmSi-Alk-Sn-Alk-SiRm(OR)3-m where R is independently a monovalent hydrocarbon of 1 to 12 carbon atoms, Alk is a divalent hydrocarbon of 1 to 18 carbon atoms; m is an integer of 0 to 2, n is a number from 1 to 8, is disclosed. The process comprises: (A) reacting sulfur, a phase transfer catalyst, a sulfide compound having the formula M2sn or MHS, where H is hydrogen, M is ammonium or an alkali metal, n is the same as above, and water to form an intermediate reaction product; (B) reacting said intermediate reaction product with a silane compound of the formula (RO)3-mRmSi-Alk-X where X is Cl, Br or I, and m is the same as above. The invention provides an improvement process characterized by adding the phase transfer catalyst to the aqueous phase prior to mixing the aqueous phase with the silane compound for the reaction.
Full Text PROCESS FOR THE PREPARATION OF SULFUR-CONTAINING ORGANOSILICON
COMPOUNDS
FIELD OF THE INVENTION
[0001] This invention relates to a process for the production of sulfur containing
organosilicon compounds by phase transfer catalysis techniques. The process involves
reacting a phase transfer catalyst with the aqueous phase components of the process to create
an intermediate reaction product, which is then reacted with a silane compound.
BACKGROUND OF THE INVENTION
[0002] Sulfur containing organosilicon compounds are useful as reactive coupling agents in
a variety of commercial applications. In particular, sulfur containing organosilicon
compounds have become essential components in the production of tires based on rubber
vulcanates containing silica. The sulfur containing organosilicon compounds improve the
physical properties of the rubber vulcanates containing silica resulting in automotive tires
with improved abrasion resistance, rolling resistance, and wet skidding performance. The
sulfur containing organosilicon compounds can be added directly to the rubber vulcanates
containing silica, or alternately, can be used to pre-treat the silica prior to addition to the
rubber vulcanate composition.
[0003] Numerous methods have been described in the art for the preparation of sulfur
containing organosilicon compounds. For example, U.S. 5,399,739 by French et al. describes
a method for making sulfur-containing organosilanes by reacting an alkali metal alcoholate
with hydrogen sulfide to form an alkali metal hydrosulfide, which is subsequently reacted
with an alkali metal to provide an alkali metal sulfide. The resulting alkali metal sulfide is
then reacted with sulfur to provide an alkali metal polysulfide which is then finally reacted
with a silane compound of the formula X-R2-Si(R1)3, where X is either chlorine or bromine to
produce the sulfur-containing organosilane.
[0004] U.S. Patent Nos. 5,466,848, 5,596, 116, and 5,489,701 describe processes for the
preparation of silane polysulfides. The "848 patent process is based on first producing
sodium sulfide by the reaction of hydrogen sulfide with sodium ethoxylate. The sodium
sulfide is then reacted with sulfur to form the tetrasulfide, which is subsequently reacted with

chloropropyltriethoxysilane to form 3, 3"-bis (triethoxysilylpropyl) tetrasulfide. The " 116
patent teaches a process for the preparation of polysulfides, without the use of hydrogen
sulfide, by reacting a metal alkoxide in alcohol with elemental sulfur, or by reacting sodium
metal with elemental sulfur and an alcohol, with a halohydrocarbylalkoxysilane such as
chloropropyltriethoxysilane. The "701 patent claims a process for the preparation of silane
polysulfides by contacting hydrogen sulfide gas with an active metal alkoxide solution and
subsequently reacting the reaction product with a halohydrocarbylalkoxysilane such as
chloropropyltriethoxysilane.
[0005] U.S. Patent No. 5,892,085 describes a process for the preparation of high purity
organosilicon disulphanes. U.S. Patent No. 5,859,275 describes a process for the production
of bis (silylorganyl) polysulphanes. Both the "085 and "275 patents describe anhydrous
techniques involving the direct reaction of a haloalkoxysilane with a polysulphide.
[0006] U.S. Pat. No. 6,066,752 teaches a process for producing sulfur-containing
organosilicon compounds by reacting sulfur, an alkali metal, and a halogenalkoyxsilane in the
absence of a solvent or in the presence of an aprotic solvent.
[0007] Most recently, U.S. Pat. No. 6,140,524 describes a method for preparing short chain
polysulfide silane mixtures of the formula (RO)3SiC3H6SnC3HeSi(RO)3 having a distribution
where n falls in the range of 2.2 typically Na2Sn with a halogenopropyltrialkoxysilane having the formula
(RO)3SiC3H6X wherein X is a halogen, in alcohol solvent.
[0008] Alternative processes for the preparation of sulfur-containing organosilanes have
been taught in the art based on the use of phase transfer catalysis techniques. Phase transfer
catalysis techniques overcome many of the practical problems associated with the
aforementioned prior art processes for producing sulfur-containing organosilicon compounds.
Many of these problems are related to the use of solvents. In particular, the use of ethyl
alcohol can be problematic because of its low flash point. Additionally, it is difficult to
obtain and maintain anhydrous conditions necessary in many of the aforementioned prior art
processes on an industrial scale.
[0009] Phase transfer catalysis techniques for producing sulfur-containing organosilicon
compounds are taught for example in U.S. Patent Nos. 5,405,985, 5,663,396, 5,468,893, and
5,583,245. While these patents teach new processes for the preparation of sulfur containing
organosilicon compounds using phase transfer catalysis, there still exist many practical
problems with the use of phase transfer techniques at an industrial scale. For example, there

is a need to control the reactivity of the phase transfer catalyst in the preparation of sulfur-
containing organosilanes so as to provide efficient, yet safe reactions, that can be performed
on an industrial scale. Furthermore, there is a need to improve the final product stability,
appearance and purity. In particular, the phase transfer catalysis process of the prior art
results in final product compositions containing high quantities of un-reacted sulfur species.
These un-reacted sulfur species can precipitate in stored products with time causing changes
in product sulfide distribution.
[0010] It is therefore an object of the present invention to provide an improved process for
the production of sulfur containing organosilicon compounds based on phase transfer
catalysis techniques.
[0011] It is a further object of the present invention to provide a process for producing
sulfur containing organosilicon compounds based on phase transfer catalysis techniques that
result in a final product composition of greater stability, purity, and appearance.
SUMMARY OF THE INVENTION
[0012] The present invention provides a process for the production of sulfur containing
organosilicon compounds by phase transfer catalysis techniques. The process involves
reacting a phase transfer catalyst with the aqueous phase components of the process to create
an intermediate reaction product, which is then reacted with a silane compound.
[0013] The improvement of the present invention is characterized by adding the phase
transfer catalyst to the aqueous phase prior to mixing the aqueous phase with the silane
compound for the reaction. The improvements of the present invention result in a process
that is controlled and operable on an industrial scale and produces a final product
composition of greater purity and appearance.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention is a process for the production of organosilicon compounds of
the formula:
(RO)3-mRmSi-Alk-Sn-Alk-SiRm(OR)3-m
where R is independently a monovalent hydrocarbon of 1 to 12 carbon
atoms; Alk is a divalent hydrocarbon of 1 to 18 carbon atoms;

m is an integer of 0 to 2, n is a number from 1 to 8,
comprising:
(A) reacting sulfur, a phase transfer catalyst, a sulfide compound having the
formula M2Sn or MHS,
where H is hydrogen, M is ammonium or an alkali metal, n is the
same as above,
and water to form an intermediate reaction product;
(B) reacting said intermediate reaction product with
a silane compound of the formula;
(RO)3-mRmSi-Alk-X where X is Cl, Br or I, and m is the
same as above.
[0015] Examples of sulfur containing organosilicon compounds which may be prepared in
accordance with the present invention are described in U.S. Pat. Nos. 5,405,985, 5,663,396,
5,468,893, and 5,583,245, which are hereby incorporated by reference. The preferred sulfur
containing organosilicon compounds which are prepared in accordance with the present
invention are the 3,3"-bis(trialkoxysilylpropyl) polysulfides. The most preferred compounds
are 3,3"-bis(triethoxysilylpropyl) disulfide and 3,3"-bis(triethoxysilylpropyl) tetrasulfide.
[0016] The first step of the process of the present invention involves reacting sulfur, a
phase transfer catalyst, a sulfide compound having the formula M2Sn or MHS, where H is
hydrogen, M is ammonium or an alkali metal, n is the same as above, and water to form an
intermediate reaction product. The sulfur used in the reaction of the present invention is
elemental sulfur. The type and form are not critical and can include those commonly known
and used. An example of a suitable sulfur product is 100 mesh refined sulfur powder from
Aldrich, Milwaukee WI.
[0017] Sulfide compounds of the formula M2Sn or MHS are also added to the aqueous
phase in the first step of the present invention. M represents an alkali metal or ammonium
group and H represents hydrogen. Representative alkali metals include potassium, sodium,
rubidium, or cesium. Preferably M is sodium. Generally, MHS compounds are used
preferentially when the average value of n in the resulting product formula, (RO)3-mRmSi-
Alk-Sn-Alk-SiRm(OR)3-m is desired to be 2. Suitable examples of the MHS compound
include, but are not limited to NaHS, KHS, and NH4HS. When the sulfide compound is an
MHS compound, NaHS is preferred. Suitable examples of the NaHS compound include, but

are not limited to NaHS flakes (containing 71.5 - 74.5% NaHS) and NaHS liquors
(containing 45 - 60 % NaHS) from PPG of Pittsburgh, PA. M2Sn compounds are used
preferentially when the average value of n in the resulting product formula, (RO)3-mRmSi-
Alk-Sn-Alk-SiRm(OR)3-m is desired to be 4. Suitable examples of compounds of M2Sn
include, but are not limited to; Na2S, K2S, Cs2S, (NH4)2S, Na2S2, Na2S3, Na2S4, Na2S6, K2S2
K2S3, K2S4, K2S6, and (NH4)2S2. Preferably the sulfide compound is Na2S. A particular
preferred sulfide compound is sodium sulfide flakes (containing 60 - 63% Na2S) from PPG
of Pittsburgh, PA.
[0018] The amount of sulfur and sulfide compound used in the process of the present
invention can vary, but preferably the molar ratio of S/ M2Sn or S/MHS ranges from 0.3 to
5. The molar ratio of sulfur/sulfide compound can be used to affect the final product
distribution, that is the average value of n in the formula, (RO)3-mRmSi-Alk-Sn-Alk-
SiRm(OR)3-m. When the average value of n is desired to be 4 in the product formula, (RO)3-
mRmSi-Alk-Sn-Alk-SiRm(OR)3-m, the preferred range for the ratio of sulfur/sulfide compound
is from 2.7 to 3.2. When the average value of n is desired to be 2 in the product formula,
(RO)3-mRmSi-Alk-Sn-Alk-SiRm(OR)3-m, the preferred range for the ratio of sulfur/sulfide
compound is from 0.3 to 0.6.
[0019] The phase transfer catalysts operable in the present invention are the quaternary
onium cations. Examples of the quaternary onium cations that can be used as phase transfer
catalysts in the present invention are described in U.S. 5,405,985, which is hereby
incorporated by reference. Preferably, the quaternary onium cation is tetrabutyl ammonium
bromide or tetrabutyl ammonium chloride. The most preferred quaternary onium salt is
tetrabutyl ammonium bromide. A particularly preferred quaternary onium salt is tetrabutyl
ammonium bromide (99%) from Aldrich Chemical of Milwaukee, WI.
[0020] The amount of the phase transfer catalyst used in the process can vary. Preferably
the amount of phase transfer catalyst is from 0.1 to 10 weight %, and most preferably from
0.5 to 2 weight % based on the amount of silane compound used.
[0021] The phase transfer catalyst, sulfur, and sulfide compounds are mixed in water and
allowed to react to form an intermediate reaction product. The amount of water used to
create the intermediate reaction product can vary, but is preferably based on the amount of
the silane compound used in the process. Water can be added directly, or indirectly, as some
water may already be present in small amounts in other starting materials. For purposes of
the present invention, it is preferable to calculate the total amount of water present, that is,

accounting for all water added either directly or indirectly. Preferably, the total amount of
water used to create the intermediate reaction product is 1 to 100 weight % of the silane
compound used, with a range of 2.5 to 70 weight % being more preferred. Most preferred is
a range of 20 to 40 weight % of water used for the intermediate reaction product based on
the amount of silane compound used.
[0022] The reaction of the first step involves mixing sulfur, a sulfide compound, a phase
transfer catalyst, and water together in a reaction vessel. The reaction of the first step can be
conducted at a variety of temperatures, but generally in the range of 40 - 100°C. Preferably,
the reaction is conducted at a temperature ranging from 65 - 95°C. Generally, the first step
can be conducted at various pressures, but preferably the first step reaction is conducted at
atmospheric pressure. The time needed for the reaction of the first step to occur is not
critical, but generally ranges from 5 to 30 minutes.
[0023] The second step of the process of the present invention involves reacting the
intermediate reaction product with a silane compound of the formula;
(RO)3-mRmSi-Alk-X
Each R is an independently selected hydrocarbon group containing 1 to 12 carbon atoms.
Thus, examples of R include methyl, ethyl, propyl, butyl, isobutyl, cyclohexyl, or phenyl.
Preferably, R is a methyl or ethyl group. In the formula (RO)3-mRmSi-Alk-X, m is an integer
and can have a value from 0 to 2. Preferably, m is equal to 0. Alk is a divalent hydrocarbon
group containing 1 to 18 carbon atoms. Alk can be for example; ethylene, propylene,
butylene, or isobutylene. Preferably Alk is a divalent hydrocarbon group containing 2 to 4
carbon atoms, and most preferably, Alk is a propylene group. X is a halogen atom selected
from chlorine, bromine, or iodine. Preferably X is chlorine. Examples of silane compounds
that may be used in the present invention include chloropropyl triethoxy silane, chloropropyl
trimethoxy silane, chloroethyl triethoxy silane, chlorobutyl triethoxy silane,
chloroisobutylmethyl diethoxy silane, chloroisobutylmethyl dimethoxy silane,
chloropropyldimethyl ethoxy silane. Preferably, the silane compound of the present
invention is chloropropyl triethoxy silane (CPTES).
[0024] The silane compound, (RO)3-raRmSi-Alk-X, can be reacted directly with the
intermediate reaction product described above, or alternatively, the silane compound can be
dispersed in an organic solvent. Representative examples of organic solvents include toluene,

xylene, benzene, heptane, octane, decane, chlorobenzene and the like. When an organic
solvent is used, the preferred organic solvent is toluene.
[0025] When conducting the process of the present invention, preferably the silane
compound is reacted directly with the intermediate reaction product described above.
[0026] The amount of the silane compound (RO)3-mRmSi-Alk-X used in the process of the
present invention can vary. An example of a suitable molar range includes from 1/10 to 10/1
based on the amount of sulfide compound used. When the average value of n is desired to be
4 in the product formula, (RO)3-mRmSi-Alk-Sn-Alk-SiRm(OR)3-m, the silane compound (RO)3-
mRmSi-Alk-X is generally used from 2.0 to 2.10 in molar excess of the M2Sn sulfide
compound, with a range of 2.01 to 2.06 being the most preferable. When the average value
of n is desired to be 2 in the product formula,
(RO)3-mRmSi-Alk-Sn-Alk-SiRm(OR)3-m, the silane compound (RO)3-mRmSi-Alk-X is
preferably used from 1.8 to 2.1 in molar excess of the MHS sulfide compound, with a range
of 1.9 to 2.0 being the most preferable.
[0027] When conducting the second step of the present invention, preferably the silane
compound is added to the intermediate reaction product at such a rate so as to maintain a
constant reaction temperature. The reaction of the second step of the present invention can be
conducted at a variety of temperatures, but generally is conducted in the range of 40 - 100°C.
Preferably, the reaction is conducted at a temperature ranging from 65 - 95°C. Generally, the
second step can be conducted at a various pressures, but preferably the second step reaction is
conducted at atmospheric pressure. The time needed for the reaction of the second step to
occur is not critical, but generally ranges from 5 minutes to 6 hours.
[0028] The process of the present invention produces organosilicon compounds that are
dialkyl polysulfides, containing on average 2 -6 sulfur atoms, via a phase transfer catalyzed
reaction of an aqueous phase containing a polysulfide and a silane compound. A typical
reaction of the present invention is exemplified according to the following equation;
Na2S + 3 S + 2 Cl(CH2)3Si(OEt)3 ? (EtO)3Si(CH2)3SSSS(CH2)3Si(OEt)3 + 2 NaCl
In a typical run, stoichiometric amounts of sulfur, Na2S are added to water, heated to 65°C
and mixed until all solids are dispersed. An aqueous solution of the phase transfer catalyst is
added. The organosilane compound is then added to the aqueous solution at such a rate to
control the exothermic reaction, and maintain a temperature in the range of 40 to 110°C.

Preferably the reaction temperature is maintained at 60 to 95°C. The reaction progress can
be monitored by the consumption of the organosilane starting material. The precipitation of a
salt, for example sodium chloride if Na2S is used as a starting reactant, also indicates
progression of the reaction. The amount of catalyst and reaction temperature affects the
reaction time necessary for completion. At the end of the reaction, additional water can be
added to dissolve some or all of any precipitated salts.
[0029] The following examples are provided to illustrate the present invention. These
examples are not intended to limit the scope of the claims herein.
EXAMPLES
Example 1
[0030] The following general procedure was used to conduct runs 1-6, shown in Table I.
A 100 ml 3 necked round bottom flask, fitted with a condenser, nitrogen sweep, and magnetic
stirrer, was charged with varying amounts of Na2S, sulfur, (as shown in Table I) and 6.25 g of
water. The contents were heated to 70°C while stirring under nitrogen. After the Na2S and
sulfur dissolved, varying amounts of the catalyst (Table I) tetrabutylammonium bromide
obtained from Aldrich of Milwaukee, WI, were added and allowed to mix for 10 minutes.
Then, a solution containing 25 g of chloropropyltriethoxysilane (CPTES) and 1.25 g of
toluene (used for a reference standard for gas chromatographic analysis) was added dropwise
at such a rate to maintain the reaction temperature in the range of 70 - 80 °C. The reaction
was monitored by gas chromatographic methods and allowed to proceed until all the CPTES
had been consumed or until no further change in its concentration was observed. After
completion of the reaction, the reaction mixture was allowed to cool to 25°C and then 14.2 g
of water were added to the reaction mixture to dissolve precipitated sodium chloride. The
reaction mixture was then phase separated. The resulting organic phase was then treated with
sodium sulfate and filtered. The resulting filtrate was then cooled and stored at a temperature
of-13°C, and subsequently filtered again.
[0031] The distribution of the various sulfur containing organosilicon compounds were
analyzed by high-pressure liquid chromatography (HPLC). Typical run conditions for HPLC
analysis were as follows: 8-9 drops of the reaction sample were diluted in 8.5 g of
cyclohexane, which was then filtered through a 0.2 µm PTFE membrane (e.g. PURADISC™
25TF of Whatman®) into a vial, a 10 µl sample of the filtrate was injected via an

autosampler into a HPLC system (e.g. Hewlett-Packard 1050). The sample was fractionated
on a Lichrosorp RP18 column (e.g. Alltech Assoc, Inc; 250 mm x 4.6 mm, 10 µm) using a
mixture of 96 % acetonitrile and 4 % tetrahydrofurane (vol/vol) as mobile phase. The
fractions were investigated via UV-absorption detector using 254 nm as the appropriate
excitation wavelength. Different UV-sensitivities of every single sulfide species were
averaged by division of the respective peak area through specific, empirically evaluated,
response factors* (RF) listed below that reflect the hyperchromy with every sulfur atom in
the chain and elemental sulfur.
HPLC Response Factors.

*As reported by H.-D. Luginsland, "Reactivity of the Sulfur Functions of the Disulfane Silane TESPD and the
Tetrasulfane Silane TESPT"; Rubber Division, American Chemical Society; Chicago, IL, April 13-16, 1999.
[0032] The products were consistent with the general formula (EtO)3Si-CH2CH2CH2-Sn-
CH2CH2CH2-Si(OEt)3. The percentage of each discrete organosilicon sulfur species in the
composition, as represented by the value of Sn in the above formula, is shown in Table II.
[0033] The results from Runs 1-6 show the effects of using various stoichiometric ratios of
CPTES and sodium sulfides based on sodium and sulfide, effect of catalyst concentration,
reaction temperature, and mole ratio of S/S-2.


a) based on amount of CPTES; b) approximate run time from start of CPTES addition until cooling cycle; c)
Na2S flakes containing 56.20 wt% Na2S and 5.20 wt% NaSH; d) Na2S flakes containing 59.75 wt% Na2S and
0.26 wt% NaSH; e) reaction was stopped incompletely because of high peak value of ethanol in gas
chromatogram; f) washed with brine; g) washed with 1.0-normal HC1 solution.



Example 2
[0034] The following general procedure was used to conduct runs 7-15, as summarized in
Table III. A 1 liter or 1.5 liter 3 necked reactor, fitted with a condenser, internal
thermometer, one baffle, nitrogen sweep, and stirrer, was charged with varying amounts of
Na2S, sulfur, (as shown in Table III) and 112.5 g of water. Contents were mixed at a constant
stirring speed of 300 rpm and heated to 70°C under nitrogen. After the Na2S and sulfur
dissolved, varying amounts of the catalyst, tetrabutylammonium bromide obtained from
Aldrich of Milwaukee, WI, were added and allowed to mix for 10 minutes. Then, CPTES
(amount as shown in Table III) was added dropwise at such a rate to maintain the reaction
temperature. The reaction was monitored by gas chromatographic methods and allowed to
proceed until all the CPTES had been consumed or until no further change in its
concentration was observed. After completion of the reaction, the reaction mixture was
allowed to cool to 25°C and then 137.5 g of water was added to the reaction mixture to
dissolve precipitated sodium chloride. The reaction mixture was then phase separated. The
resulting organic phase was filtered then treated with sodium sulfate and re-filtered. The
resulting filtrate was then cooled and stored at a temperature of -13°C, and subsequently
filtered again.
[0035] The final organic product from these runs was analyzed for the various polysulfide
organosilicon compounds by HPLC. The products were consistent with the general formula
(EtO)3Si-CH2CH2CH2-Sn-CH2CH2CH2-Si(OEt)3. The percentage of each discrete
organosilicon sulfur species in the composition, as represented by the value of Sn, is shown in
Table IV.




Example 3
[0036] A 1-1-reactor, equipped with mechanical stirrer, 1 baffle, condenser, dropping
funnel, and thermometer, was loaded at 79°C with 121.50 g of flaked disodium sulfide (59.75
% Na2S, 0.26 % NaHS), 89.82 g of elemental sulfur and 112.50 g of water. The mixture was
vigorously stirred until all salts were dissolved. Then, 28.8 g of a 25 % aqueous catalyst
solution (7.20 g of tetrabutyl ammonium bromide in 21.6 g of water) were added. Then
463.50 g of chloropropyltriethoxysilane were added dropwise within 85 minutes and the
reaction temperature raised to about 83°C. After the decrease of the exotherm, the mixture
was stirred at a temperature level of 80°C, and the reaction progress was followed by gas
chromatography analysis until chloropropyltriethoxysilane has reached a stable level after 2
1/4 hours. The mixture was cooled to 15°C, and 137.50 g of water were added to dissolve the
formed salts. The aqueous phase was separated (431.50 g). The remaining organic phase was
also drained off and filtered in a Buchner funnel. The filter residue consisted of 4.33 g of
green and black particles, and 504.83 g of a clear, reddish-brown filtrate liquid were
collected. A total of 511.92 g of product was collected (99.0 % of theory). High pressure

liquid chromatography analysis showed an average sulfur rank of 3.86. Quantitative gas
chromatography analysis showed 2.35 % un-reacted chloropropyltriethoxysilane.
Example 4 (comparative example)
[0037] A 1-1-reactor, equipped with mechanical stirrer, 1 baffle, condenser, dropping
funnel, and thermometer, was loaded at 75°C with 121.50 g of flaked disodium sulfide (59.75
% Na2S, 0.26 % NaHS), 89.82 g of elemental sulfur and 112.50 g of water. The mixture was
vigorously stirred until all salts were dissolved. Then, 463.50 g of
chloropropyltriethoxysilane were added to the aqueous solution. Then, 28.8 g of a 25 %
aqueous catalyst solution (7.20 g of tetrabutyl ammonium bromide in 21.6 g of water) were
added in one portion, the mixture was stirred, and the reaction temperature uncontrollably
increased to 103°C within 7 minutes causing the water to reflux. The heating circulator had to
be cooled by addition of ice, and with this action, the reaction temperature could be lowered
to 80°C within the next 8-10 minutes. After the decrease of the exotherm, the mixture was
stirred at a temperature of 78°C, and the reaction progress was followed by gas
chromatography analysis until the chloropropyltriethoxysilane reached a stable level, in 2 1/2
hours. The mixture was cooled to 15°C, and 135.00 g of water were added to dissolve the
formed salts. The aqueous phase was separated (433.07 g). The remaining organic phase
was also drained off and filtered in a Buchner funnel. The filter residue consisted of 7.14 g of
green and black particles, and 501.33 g of a clear, light orange liquid were collected. High-
pressure liquid chromatography analysis showed an average sulfur rank of 3.86. Quantitative
gas chromatography analysis showed 1.46 % un-reacted chloropropyltriethoxysilane.
[0038] The results from example 4, vs example 3, demonstrates the order of addition of the
phase transfer catalyst is important. When added to the aqueous phase, as in Example 3, the
exotherm can be controlled and allows for the process to be conducted on an industrial scale.

We Claim:
1. A process for the production of organosilicon compounds of the formula
(RO)3-mRmSi-Alk-Sn-Alk-SiRm(OR)3-m
where R is independently a monovalent hydrocarbon of 1 to 12 carbon
atoms; Alk is a divalent hydrocarbon of 1 to 18 carbon atoms;
m is an integer of 0 to 2, n is a number from 1 to 8,
comprising:
(A) reacting sulfur, a phase transfer catalyst, a sulfide compound having the
formula M2Sn or MHS,
where H is hydrogen, M is ammonium or an alkali metal, n is
the same as above,
and water to form an intermediate reaction product;
(B) reacting said intermediate reaction product with
a silane compound of the formula;
(RO)3-mRmSi-Alk-X where X is Cl, Br or I, and m is
the same as above.
2. The process as claimed in claim 1 where the weight percent of the phase transfer
catalyst to the silane compound is .1 to 10%.
3. The process as claimed in claim 1 wherein there is a 2.0 to 2.1 molar excess of
the (RO)3-mRmSi-Alk-X silane compound to the sulfide compound.
4. The process as claimed in claim 1 where the weight percentage of water in the
intermediate reaction product to the silane compound is 2.5 to 70%.
5. The process as claimed in claim 1 where the weight percentage of water in the
intermediate reaction product to the silane compound is 20 to 40 %.

6. The process as claimed in claim 1 where the silane compound is selected from
the group consisting of chloropropyl triethoxy silane, chloropropyl trimethoxy silane,
chloroethyl triethoxy silane, chlorobutyl triethoxy silane, chloroisobutylmethyl
diethoxy silane, chloroisobutylmethyl dimethoxy silane, and chloropropyldimethyl
ethoxy silane.
7. The process as claimed in claim 1 where the sulfide compound is selected from
the group consisting of Na2S, K2S, Cs2S, (NH4)2S, Na2S2, Na2S3, Na2S4, Na2S6, K2S2
K2S3,K2S4, K2S6, and (NH4)2S2.
8. The process as claimed in claim 1 where the phase transfer catalyst is a
quaternary onium salt.
9. The process as claimed in claim 1 where the silane compound is dispersed in an
organic solvent selected from the group consisting of toluene, xylene, benzene,
heptane, octane, decane, and chlorobenzene.
10. The process as claimed in claim 1 where the reaction of said intermediate
reaction product with the silane compound is conducted at a temperature in the range
of 40 to 100°C.
The invention discloses a process for the production of organosilicon compounds of the formula
(RO)3-mRmSi-Alk-Sn-Alk-SiRm(OR)3-m where R is independently a monovalent
hydrocarbon of 1 to 12 carbon atoms; Alk is a divalent hydrocarbon of 1 to 18 carbon
atoms; m is an integer of 0 to 2, n is a number from 1 to 8, comprising: (A) reacting
sulfur, a phase transfer catalyst, a sulfide compound having the formula M2Sn or MHS,
where H is hydrogen, M is ammonium or an alkali metal, n is the same as above, and
water to form an intermediate reaction product; (B) reacting said intermediate reaction
product with a silane compound of the formula; (RO)3-mRmSi-Alk-X where X is Cl,
Br or I, and m is the same as above.

Documents:

1514-KOLNP-2003-FORM-27.pdf

1514-kolnp-2003-granted-abstract.pdf

1514-kolnp-2003-granted-claims.pdf

1514-kolnp-2003-granted-correspondence.pdf

1514-kolnp-2003-granted-description (complete).pdf

1514-kolnp-2003-granted-examination report.pdf

1514-kolnp-2003-granted-form 1.pdf

1514-kolnp-2003-granted-form 18.pdf

1514-kolnp-2003-granted-form 2.pdf

1514-kolnp-2003-granted-form 3.pdf

1514-kolnp-2003-granted-form 5.pdf

1514-kolnp-2003-granted-gpa.pdf

1514-kolnp-2003-granted-letter patent.pdf

1514-kolnp-2003-granted-reply to examination report.pdf

1514-kolnp-2003-granted-specification.pdf


Patent Number 213805
Indian Patent Application Number 1514/KOLNP/2003
PG Journal Number 03/2008
Publication Date 18-Jan-2008
Grant Date 16-Jan-2008
Date of Filing 20-Nov-2003
Name of Patentee DOW CORNING CORPORATION
Applicant Address 2200 WEST SALZBURG ROAD, MIDLAND, MI 48686-0994
Inventors:
# Inventor's Name Inventor's Address
1 BANK HOWARD MARVIN 8233 CRESTON DRIVE, FREELAND, MI 48623
2 GOHNDRONE JOHN MICHAEL 2304 PARKWOOD DRIVE, MIDLAND, MI 48642
3 MAKI WILLIAM CHARLES 811 STILLMEADOW LAND, MIDLAND, MI 48642
4 SKINNER CHARLES EDMUND 1203 WEST SUGNET, MIDLAND, MI 48640
5 TOMAR ANIL KUMAR 1904 WESTBURY COURT, MIDLAND, MI 48642, USA.
6 YUE HONGJUN 610 SCENIC DRIVE , MIDLAND, MI 48642
7 BACKER MICHAEL WOLFGANG 34GELYN-Y-CLER, BARRY, VALE OF GLAMORGAN CF63 IFN, GREAT BRITAIN
PCT International Classification Number C07F 7/18
PCT International Application Number PCT/US02/15190
PCT International Filing date 2002-05-13
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 09/895,700 2001-06-29 U.S.A.