US4433096A
Expired / Lapsed
US
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Polymerization of polydiorganosiloxane in the presence of filler
Assignee: Dow Silicones Corp
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Filing: 1983-03-14
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Granted: 1984-02-21
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Expires: 2003-03-14
Abstract
Abstract A method of polymerizing hydroxyl-endblocked polydiorganosiloxane in the presence of filler, including acidic filler such as fumed silica, through the use of basic diorganosilanolates as catalysts is claimed. Preferred diorganosilanolates are tetra-n-butylphosphonium dimethylsilanolate and potassium dimethylsilanolate. The silicone polymer-filler mixture produced is useful in silicone greases and elastomers. Methods of combining the silicone polymer-filler mixture with various curing agents to yield curable compositions are claimed.
Inventors
- 👤 Gary N. Bokerman
- 👤 Neal R. Langley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:45
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/06; C08G77/08; C08K; C08K3/00; C08K3/01; C08K3/013
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
196 words
A method of polymerizing a hydroxyl endblocked polydiorganosiloxane in the presence of filler comprising (A) mixing (i) 100 parts by weight of polydiorganosiloxane of the formula HO(R.sub.2 SiO).sub.x H wherein each R is a monovalent radical having from 1 to 18 carbon atoms selected from the group consisting of hydrocarbon radicals, halogenated hydrocarbon radicals, and cyanoalkyl radicals, and x is from 3 to 200 and (ii) from 1 to 150 parts by weight of filler selected from the group consisting of inorganic reinforcing filler and inorganic extending filler to form a mixture, (B) admixing sufficient catalyst of the formula MO(R.sub.2 SiO).sub.z Q wherein M is an alkali metal, tetraalkylphosphonium, or tetraalkylammonium radical; Q is an alkali metal, tetraalkylphosphonium, tetraalkylammonium, or hydrogen radical; R is as defined above; and z is at least 1, to cause condensation of the polydiorganosiloxane (i), and (C) dehydrating the mixture by heating, at a temperature below that at which decomposition of the catalyst would occur, removing moisture for a time sufficient to polymerize the mixture, then (D) inactivating the catalyst, to yield a stable silicone polymer-filler mixture in which the silicone polymer has a molecular weight greater than that of (i).
Claim 2
Independent Claim
196 words
A method of polymerizing a hydroxyl endblocked polydiorganosiloxane in the presence of filler comprising (A) mixing (i) 100 parts by weight of polydiorganosiloxane of the formula HO(R.sub.2 SiO).sub.x H wherein each R is a monovalent radical having from 1 to 18 carbon atoms selected from the group consisting of hydrocarbon radicals, halogenated hydrocarbon radicals, and cyanoalkyl radicals, and x is from 3 to 200 and (ii) from 1 to 150 parts by weight of filler selected from the group consisting of inorganic reinforcing filler and inorganic extending filler to form a mixture, (B) admixing sufficient catalyst of the formula MO(R.sub.2 SiO).sub.z Q wherein M is an alkali metal, tetraalkylphosphonium, or tetraalkylammonium radical; Q is an alkali metal, tetraalkylphosphonium, tetraalkylammonium, or hydrogen radical; R is as defined above; and z is at least 1, to cause condensation of the polydiorganosiloxane (i), and (C) dehydrating the mixture by heating, at a temperature below that at which decomposition of the catalyst would occur, removing moisture for a time sufficient to polymerize the mixture, then (D) inactivating the catalyst, to yield a stable silicone polymer-filler mixture in which the silicone polymer has a molecular weight greater than that of (i).
Claim 3
Dependent Claim
24 words
The method of claim 1 in which each R is selected from the group consisting of methyl, ethyl, vinyl, phenyl, 3,3,3,- trifluoropropyl, and 2-cyanoethyl.
Claim 4
Dependent Claim
31 words
The method of claim 2 in which the catalyst of (B) is the product obtained by mixing an alkali metal hydroxide with diorganosilicon compound or low molecular weight diorganosiloxane and dehydrating.
Claim 5
Dependent Claim
31 words
The method of claim 3 in which the alkali metal hydroxide is potassium hydroxide wherein potassium diorganosilanolate is the catalyst, and the inactivating step (D) comprises neutralization with a weak acid.
Claim 6
Dependent Claim
86 words
The method of claim 2 in which the catalyst of (B) is the product obtained by mixing a quaternary phosphonium compound of the formula R'.sub.4 PX wherein each R' is a monovalent hydrocarbon radical of 1 to 18 carbon atoms free of aliphatic unsaturation and X is chlorine, bromine, or iodine; a basic compound of the formula MOH where M is an alkali metal; and water, in at least sufficient quantity to dissolve the basic compound; with diorganosilicon compound or low molecular weight diorganosiloxane and dehydrating.
Claim 7
Dependent Claim
74 words
The method of claim 2 in which the catalyst of (B) is the product obtained by mixing a quaternary phosphonium compound of the formula R'.sub.4 POR" wherein R' is a monovalent hydrocarbon radical of 1 to 18 carbon atoms free of aliphatic unsaturation and R" is hydrogen or alkyl radical of 1 to 6 carbon atoms with diorganosilicon compound or low molecular weight diorganosiloxane and dehydrating wherein the product is a quaternary phosphonium diorganosilanolate.
Claim 8
Dependent Claim
38 words
The method of claim 5 wherein the catalyst is tetraalkylphosphonium diorganosilanolates and the inactivating step (D) comprises heating at a temperature above the temperature at which decomposition of the quaternary phosphonium compound occurs until the decomposition is completed.
Claim 9
Dependent Claim
30 words
The method of claim 6 in which the inactivating step (D) is heating at a temperature above which decomposition of the quaternary phosphonium diorganosilanolate occurs until the decomposition is completed.
Claim 10
Dependent Claim
32 words
The method of claim 4 in which the potassium diorganosilanolate is present in an amount sufficient to yield one atom of potassium from 1,000 to 10,000 atoms of silicon in the polydiorganosiloxane.
Claim 11
Dependent Claim
33 words
The method of claim 7 in which the tetraalkylphosphonium diorganosilanolate is present in an amount sufficient to yield one atom of phosphorus for from 1,000 to 10,000 atoms of silicon in the polydiorganosiloxane.
Claim 12
Dependent Claim
34 words
The method of claim 8 in which the quaternary phosphonium diorganosilanolate is present in an amount sufficient to yield one atom of phosphorus for from 1,000 to 10,000 atoms of silicon in the polydiorganosiloxane.
Claim 13
Dependent Claim
39 words
The method of claim 11 in which the mixture of (A) is heated in a controlled system to a temperature of higher than 100° C., but lower than the boiling point of (i) to remove water before step (B).
Claim 14
Dependent Claim
26 words
The method of claim 1 in which the filler (ii) is acidic and is present in an amount of from 1 to 40 parts by weight.
Claim 15
Dependent Claim
12 words
The method of claim 13 in which the filler is colloidal silica.
Claim 16
Independent Claim
28 words
The method of claim l in which the filler (ii) is basic or neutral and is present in an amount of from 1 to 150 parts by weight.
Claim 17
Dependent Claim
12 words
The method of claim 15 in which the filler is calcium carbonate.
Claim 18
Dependent Claim
92 words
The method of claim 10 in which the tetraalkylphosphonium diorganosilanolate is tetra-n-butylphosphonium dimethylsilanolate in an amount sufficient to yield one atom of phosphorus for from 1,000 to 5,000 atoms of silicon in the polydiorganosiloxane, the filler is from 1 to 40 parts by weight of a colloidal silica, the heating temperature of step (C) is from 100° C. to 130° C. and the catalyst is inactivated in step (D) by heating the mixture to a temperature of from 160° C. to 200° C. for a time sufficient to decompose the tetra-n-butylphosphonium diorganosilanolate.
Claim 19
Dependent Claim
22 words
The method of claim 1 in which the silicone polymer-filler mixture is further mixed with curing agent to yield a curable composition.
Claim 20
Dependent Claim
19 words
The method of claim 18 in which the curing agent is an organic peroxide suitable for curing silicone elastomers.
Claim 21
Dependent Claim
40 words
The method of claim 18 in which the curing agent is a crosslinking agent capable of combining with the polydiorganosiloxane to yield a composition stable in the absence of moisture which cures to a silicone elastomer upon exposure to moisture.
Claim 22
Dependent Claim
141 words
The method of claim 18 in which the polydiorganosiloxane has from 0.01 to 2.0 percent vinyl or allyl radicals, there being at least 2 vinyl or allyl radicals per molecule, and the curing agent comprises an organohydrogensiloxane in sufficient amount to provide at least 1 silicon-bonded hydrogen atom per vinyl or allyl radical in the polydiorganosiloxane, said organohydrogensiloxane having an average of greater than two silicon-bonded hydrogen atoms per molecule, and consisting of R"'HSiO, R 2 "'SiO, R 2 "'HSiO 0 .5, R 3 "'SiO 0 .5, and SiO 2 units in which each R"' is selected from the group consisting of methyl, ethyl, vinyl, phenyl, 3,3,3-trifluoropropyl, and 2-cyanoethyl; and a platinum catalyst in an amount sufficient to provide at least one part by weight of platinum per million parts by weight of silicone polymer in the silicone polymer filler mixture.
Claim 23
Dependent Claim
11 words
The silicone polymer-filler mixture produced by the method of claim 1.
Claim 24
Dependent Claim
11 words
The silicone polymer-filler mixture produced by the method of claim 9.
Claim 25
Dependent Claim
11 words
The silicone polymer-filler mixture produced by the method of claim 12.
Claim 26
Dependent Claim
11 words
The silicone polymer-filler mixture producted by the method of claim 13.
Claim 27
Dependent Claim
11 words
The silicone polymer-filler mixture produced by the method of claim 15.
Claim 28
Dependent Claim
11 words
The silicone polymer-filler mixture produced by the method of claim 17.
Claim 29
Dependent Claim
10 words
The curable composition produced by the method of claim 18.
Claim 30
Dependent Claim
10 words
The curable composition produced by the method of claim 19.
Claim 31
Dependent Claim
10 words
The curable composition produced by the method of claim 20.
Claim 32
Dependent Claim
10 words
The curable composition produced by the method of claim 21.
Claim 33
Dependent Claim
6 words
The cured product of claim 28.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-20 | 1987-08-22 | 1988-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-20 | 1991-08-22 | 1992-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-20 | 1995-08-22 | 1996-02-21 | $7700.00 | Window Closed / Lapsed |