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EP0119092A2
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Method of polymerizing hydroxyl endblocked polydiorganosiloxanes
Assignee: Dow Silicones Corp
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Filing: 1984-03-13
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Granted: —
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Expires: 2004-03-13
Abstract
Abstract Hydroxyl-endblocked polydiorganosiloxane oligomer is polymerized through the use of a catalyst mixture of quaternary ammonium carboxylate and carboxylic acid. The method heats the mixture of oligomer and catalyst to a temperature in the range of from 90°C to 150°C, removing water from the mixture, until the desired degree of condensation is achieved. When cooled, the product is a stable polydiorganosiloxane of increased molecular weight. The catalyst can be inactivated by heating and removing volatile byproducts. One embodiment of the method adds an acidic or neutral reinforcing filler to the mixture before polymerization to yield a storage stable silicone polymer-filler mixture which is useful in a manner similar to conventionally produced silicone polymer-filler mixtures.
Inventors
- 👤 Sheryl Annette Bowman
- 👤 James Robert Falender
- 👤 Jonathan Lipowitz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 15:12
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/04; C08K5/09; C08G; C08G77/00; C08G77/04; C08G77/06; C08G77/08; C08K5/16; C08K5/17; C08K5/19
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
205 words
A method of polymerizing polydiorganosiloxane oligomer characterised by the steps of: (A) removing water from a mixture of (i) 100 parts by weight of polydiorganosiloxane (a) of the formula HO(R 2 Si O ) x H where each R is selected from the group consisting of methyl, ethyl, propyl, phenyl, vinyl, allyl, and 3,3,3,-trifluoropropyl radicals, x being an average of from 3 to 50, (ii) from 0.05 to 5.0 parts by weight of quaternary ammonium carboxylate of the formula where each R 1 is selected from the group consisting of monovalent aliphatic radicals having from 1 to 20 carbon atoms and aralkyl radicals and each R 2 is selected from the group consisting of monovalent aliphatic hydrocarbon radicals of 5 or fewer carbon atoms, phenyl radical, or benzyl radical, at least one R having 4 or more carbon atoms, and (iii) at least 0.05 part by weight of carboxylic acid of the formula R 2 COOH where R 2 is as defined above, at a temperature in the range of from 90°C to 150°C until the predetermined increase in molecular weight of (a) is achieved by condensation polymerization, then (B) cooling to ambient temperature to produce a polydiorganosiloxane having a higher molecular weight than (i).
Claim 2
Independent Claim
205 words
A method of polymerizing polydiorganosiloxane oligomer characterised by the steps of: (A) removing water from a mixture of (i) 100 parts by weight of polydiorganosiloxane (a) of the formula HO(R 2 Si O ) x H where each R is selected from the group consisting of methyl, ethyl, propyl, phenyl, vinyl, allyl, and 3,3,3,-trifluoropropyl radicals, x being an average of from 3 to 50, (ii) from 0.05 to 5.0 parts by weight of quaternary ammonium carboxylate of the formula where each R 1 is selected from the group consisting of monovalent aliphatic radicals having from 1 to 20 carbon atoms and aralkyl radicals and each R 2 is selected from the group consisting of monovalent aliphatic hydrocarbon radicals of 5 or fewer carbon atoms, phenyl radical, or benzyl radical, at least one R having 4 or more carbon atoms, and (iii) at least 0.05 part by weight of carboxylic acid of the formula R 2 COOH where R 2 is as defined above, at a temperature in the range of from 90°C to 150°C until the predetermined increase in molecular weight of (a) is achieved by condensation polymerization, then (B) cooling to ambient temperature to produce a polydiorganosiloxane having a higher molecular weight than (i).
Claim 3
Dependent Claim
21 words
The method of claim 1 in which the mixture of step (A) includes a solvent which is non-reactive with the ingredients.
Claim 4
Dependent Claim
77 words
The method of claim 1 in which step (A) includes in the mixture a polydiorganosiloxane (b) of the formula where each R is as defined above, R is selected from the group consisting of monovalent hydrocarbon radicals of 5 or fewer carbon atoms, phenyl radical, or benzyl radical, z is an average value of from 0 to 50 inclusive, the amount of polydiorganosiloxane (b) being determined by the desired average molecular weight of the polymer being produced.
Claim 5
Dependent Claim
38 words
The method of claim 3 in which the mixture of step (A) includes a solvent which is non-reactive with the ingredients and has a boiling point in the range of from 90°C to 150°C at the operating pressure.
Claim 6
Dependent Claim
35 words
The method of claim 1 in which the mixture of step (A) includes from 2 to 70 parts by weight of reinforcing filler, said filler being acidic or neutral, to yield a silicone polymer-filler mixture.
Claim 7
Dependent Claim
45 words
The method of claim 1 in which from 2 to 70 parts by weight of reinforcing filler, said filler being acidic or neutral, is admixed with (i) before the addition of the quaternary ammonium carboxylate and the carboxylic acid to yield a silicone polymer-filler mixture.
Claim 8
Dependent Claim
53 words
The method of claim 6 in which the reinforcing filler is from 10 to 50 parts of fumed silica, the quaternary ammonium carboxylate is present in an amount of from 0.1 to 2 parts by weight, and the carboxylic acid is present in an amount of from 0.5 to 10 parts by weight.
Claim 9
Dependent Claim
22 words
The method of claim 7 in which the quaternary ammonium carboxylate is lauryltrimethylammonium acetate and the carboxylic acid is glacial acetic acid.
Claim 10
Dependent Claim
22 words
The method of claim 8 in which the silicone polymer-filler mixture is further mixed with curing agent to yield a curable composition.
Claim 11
Dependent Claim
33 words
The method of claim 1 in which polydiorganosiloxane (a) contains R radicals selected from the group consisting of methyl and vinyl radicals, (ii) is lauryltrimethylammonium acetate in an amount of from 0.1 to
Claim 12
Dependent Claim
22 words
0 parts by weight, and the glacial acetic acid is present in an amount of from 0.5 to 10 parts by weight.
Claim 13
Dependent Claim
22 words
0 parts by weight, and the glacial acetic acid is present in an amount of from 0.5 to 10 parts by weight.
Claim 14
Dependent Claim
29 words
The method of claim 10 in which the mixture of step (A) includes from 10 to 50 parts by weight of fumed silica, to yield a silicone polymer-filler mixture.
References Cited (Backward Citations)
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