Organic compounds -- part of the class 532-570 series – Organic compounds – Silicon containing
Reexamination Certificate
2000-06-26
2001-04-17
Shaver, Paul F. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Silicon containing
C548S110000
Reexamination Certificate
active
06218561
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a process for the preparation of organosilicon disulfide compounds. Organosilicon disulfides are known adhesion promoters in sulfur-vulcanizable rubber mixtures reinforced with inorganic materials such as glass SiO2, aluminosilicates and carbon black. For example, in GB 1,484,909, there is disclosed a process for the preparation of organo trialkoxysilane disulfides. In accordance with the teachings of this reference, mercaptopropyl trimethoxy silane or mercaptopropyl triethoxy silane is reacted with sulfuryl chloride in an inert solvent at temperatures of from 0° to 100°. The disulfide is then obtained by fractional distillation. The yields of desired product range in the neighborhood of 63 to 65 percent of theoretical.
U.S. Pat. No. 3,842,111 discloses a method for the preparation of organosilicon disulfide compounds by oxidizing mercaptoalkoxysilanes. Representative oxidizing agents include oxygen, chlorine, halogens of atomic weight 35 to 127, nitric oxide, sulfuryl chloride and sulfoxides.
U.S. Pat. No. 5,675,014 relates to a process for the preparation of organosilicon disulfide compounds by reacting a mercaptoalkoxysilane with a dithiobis (benzothiazole) compound. Unfortunately, this process does not produce high purity bis organosilicon disulfide compounds due to the formation of unsymmetrical organosilicon disulfides.
U.S. Pat. No. 5,663,358 relates to a process for the preparation of organosilicon disulfide compounds by reacting a mercaptoalkoxysilane with a sulfenamide compound. Unfortunately, due to the formation of unsymmetrical organosilicon compounds, the purity of bis organosilicon disulfide compounds are reduced.
Generally speaking, bis organosilicon disulfide compounds are very expensive and, with the increasing interest in silica-reinforced vulcanizable rubber, more cost-efficient methods of preparing these compounds are needed.
SUMMARY OF THE INVENTION
The present invention relates to a process for the preparation of bis organosilicon disulfide compounds. The present invention may be used to prepare symmetrical organosilicon disulfide compounds of the formula:
Z—R
1
—S
2
—R
1
—Z I
wherein Z is selected from the group consisting of
wherein R
2
may be the same or different and is independently selected from the group consisting of an alkyl group having 1 to 4 carbons and phenyl; R
3
may be the same or different and is independently selected from the group consisting of alkoxy groups having 1 to 8 carbon atoms and cycloalkoxy groups with 5 to 8 carbon atoms; and R
1
is selected from the group consisting of a substituted or unsubstituted alkylene group having a total of 1 to 18 carbon atoms and a substituted or unsubstituted arylene group having a total of 6 to 12 carbon atoms.
DETAILED DESCRIPTION OF THE INVENTION
There is disclosed a process for the preparation of bis organosilicon disulfide compounds comprising reacting
(a) the N-alkyl bis (benzothiazolsulfen) amide of the formula
with
(b) mercaptosilane compound of the formula
Z—R
1
—-SH III
wherein Z is selected from the group consisting of
wherein R1 is selected from the group consisting of a substituted or unsubstituted alkylene group having a total of 1 to 18 carbon atoms and a substituted or unsubstituted arylene group having a total of 6 to 12 carbon atoms; wherein R
2
may be the same or different and is independently selected from the group consisting of an alkyl group having 1 to 4 carbons and phenyl; R
3
may be the same or different and is independently selected from the group consisting of alkoxy groups having 1 to 8 carbon atoms and cycloalkoxy groups with 5 to 8 carbon atoms; and R
4
is an alkyl group having from 3 to 6 carbon atoms.
The present invention relates to a process for the preparation of bis organosilicon disulfide compounds. Representative organosilicon disulfide compounds of formula I which may be prepared in accordance with the present invention include 2,2′-bis(trimethoxysilylethyl) disulfide; 3,3′-bis(trimethoxysilylpropyl) disulfide; 3,3′-bis(triethoxysilylpropyl) disulfide; 2,2′-bis(triethoxysilylpropyl) disulfide; 2,2′-bis(tripropoxysilylethyl) disulfide; 2,2′-bis(tri-sec-butoxysilylethyl) disulfide; 2,2′-bis(tri-t-butoxysilylethyl) disulfide; 3,3′-bis(triisopropoxysilylpropyl) disulfide; 3,3′-bis(trioctoxysilylpropyl) disulfide; 2,2′-bis(2′-ethylhexoxysilylethyl) disulfide; 2,2′-bis(dimethoxy ethoxysilylethyl) disulfide; 3,3′-bis(methoxyethoxypropoxysilylpropyl) disulfide; 3,3′-bis(dimethoxymethylsilylpropyl) disulfide; 3,3′-bis(methoxy dimethylsilylpropyl) disulfide; 3,3′-bis(diethoxymethylsilylpropyl) disulfide, 3,3′-bis(ethoxy dimethylsilylpropyl) disulfide, 3,3′-bis(cyclohexoxy dimethylsilyipropyl) disulfide; 4,4′-bis(trimethoxysilylbutyl) disulfide; 3,3′-bis(trimethoxysilyl-3-methylpropyl) disulfide; 3,3′-bis(tripropoxysilyl-3-methylpropyl) disulfide; 3,3′-bis(dimethoxy methylsilyl-3 -ethylpropyl) disulfide; 3,3 ′-bis(trimethoxysi lyl-2-methylpropyl) disulfide; 3,3 ′-bis(dimethoxyphenylsilyl-2-methylpropyl) disulfide; 3,3 ′-bis(trimethoxysilylcyclohexyl) disulfide; 12,12′-bis(trimethoxysilyldodecyl) disulfide; 12,12′-bis(triethoxysilyldodecyl) disulfide; 18,18′-bis(trimethoxysilyloctadecyl) disulfide; 18,18′-bis(methoxydimethylsilyloctadecyl) disulfide; 2,2′-bis(trimethoxysilyl-2-methylethyl) disulfide; 2,2′-bis(tripropoxysilyl-2-methylethyl) disulfide; 2,2′-bis(trioctoxysilyl-2-methylethyl) disulfide; 2,2′-bis(trimethoxysilyl-phenyl) disulfide; 2,2′-bis(triethoxysilyl-phenyl) disulfide; 2,2′-bis(trimethoxysilyl-tolyl)disulfide; 2,2′-bis(triethoxysilyl-tolyl)disulfide; 2,2′-bis(trimethoxysilyl-methyl tolyl) disulfide; 2,2′-bis(triethoxysilyl-methyl tolyl) disulfide; 2,2′-bis(trimethoxysilyl-ethyl phenyl) disulfide; 2,2′-bis(triethoxysilyl-ethyl phenyl) disulfide; 2,2′-bis(trimethoxysilyl-ethyl tolyl) disulfide; 2,2′-bis(triethoxysilyl-ethyl tolyl) disulfide; 3,3′-bis(trimethoxysilyl-propyl phenyl) disulfide; 3,3′-bis(triethoxysilyl-propyl phenyl) disulfide; 3,3′-bis(trimethoxysilyl-propyl tolyl) disulfide; and 3,3′-bis(triethoxysilyl-propyl tolyl) disulfide.
With reference to formula I, preferably R
1
is a alkylene group having 2 to 3 carbon atoms,
and R
3
is an alkoxy group having from 1 to 3 carbon atoms.
The desired products are prepared by reacting the N-alkyl bis (benzothiazolesulfen) amide compound of formula II with a mercaptosilane compound of formula III. Representative examples of compounds of formula III include 2-mercaptoethyl trimethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-mercaptopropyl triethoxysilane, 2-mercaptopropyl triethoxysilane, 2-mercaptoethyl tripropoxysilane, 2-mercaptoethyl tri sec-butoxysi lane, 3 -mercaptopropyl tri-t-butoxysi lane, 3 -mercaptopropyl triisopropoxysi lane; 3-mercaptopropyl trioctoxysilane, 2-mercaptoethyl tri-2′-ethylhexoxysilane, 2-mercaptoethyl dimethoxy ethoxysilane, 3-mercaptopropyl methoxyethoxypropoxysilane, 3-mercaptopropyl dimethoxy methylsilane, 3-mercaptopropyl methoxy dimethylsilane, 3-mercaptopropyl ethoxy dimethylsilane, 3-mercaptopropyl diethoxy methylsilane, 3-mercaptopropyl cyclohexoxy dimethyl silane, 4-mercaptobutyl trimethoxysilane, 3-mercapto-3-methylpropyltrimethoxysilane, 3 -mercapto-3-methylpropyl-tripropoxysi lane, 3-mercapto-3-ethylpropyl-dimethoxy methylsilane, 3-mercapto-2-methylpropyl trimethoxysilane, 3-mercapto-2-methylpropyl dimethoxy phenylsilane, 3 -mercaptocyclohexyl-trimethoxysilane, 12-mercaptododecyl trimethoxy silane, 12-mercaptododecyl triethoxy silane, 18-mercaptoctadecyl trimethoxysilane, 18-mercaptooctadecyl methoxydimethylsilane, 2-mercapto-2-methylethyl-tripropoxysilane, 2-mercapto-2-methylethyl-trioctoxysilane, 2-mercaptophenyl trimethoxysilane, 2-mercaptophenyl triethoxysilane; 2-mercaptotolyl trimet
Folk Theodore Lamson
Wideman Lawson Gibson
Hendricks Bruce J
Shaver Paul F.
The Goodyear Tire & Rubber Company
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