US4985477A
Expired / Lapsed
US
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Method of producing treated silica filler for silicone rubber
Assignee: Dow Silicones Corp
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Filing: 1989-08-30
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Granted: 1991-01-15
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Expires: 2009-08-30
Abstract
Abstract An improved method of producing treated silica filler for use with silicone rubber operates at ambient temperature in a short period of time. The method consists essentially of mixing reinforcing silica with a volatile treating agent of the formula R x Si(OR') 4 - x , wherein R is a substituted or unsubstituted, saturated or unsaturated, alkyl or aryl radical having from 1 to 6 carbon atoms, R' is an alkyl radical having from 1 to 3 carbon atoms, x is 1 or 2, and R and R' are chosed so that the vapor pressure of the alkoxysilane exceeds 10 Pa (0.0001) atmosphere) at treatment temperature, in combination with a volatile catalyst selected from the group consisting of acid A, base B, and mixtures thereof; wherein acid A is a volatile acid or acid progenitor, and base B is a silylamine or silazane, acid A and base B being chosen so that the vapor pressure of either acid A or base B exceeds 500 Pa (0.005 atmosphere) at treatment temperature, for a period of time sufficient to allow the desired amount of treating agent to be absorbed onto the surface of the particulate filler.
Inventors
- 👤 Warde T. Collins
- 👤 Kenneth R. Cottrell
- 👤 John C. Saam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:13
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/28; C09C1/30; C09C1/3081; C08; C08K; C08K9/00; C08K9/04; C08K9/06; C01; C01P; C01P2006/00; C01P2006/12; C01P2006/80; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2995
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
255 words
A method of rapidly treating the surface of reinforcing silica filler consisting essentially of mixing, at a temperature of from about -10° to 130° C., (A) 100 parts by weight of reinforcing silica filler, having a surface area of greater than 50 m 2 /g, and having from 0.5 to 6 parts by weight of absorbed moisture, (B) from 3 to 30 parts by weight of volatile treating agent of the formula R x Si(OR') 4-x , wherein R is a alkyl, alkenyl, or aryl radical having from 1 to 6 carbon atoms which may be substituted with halogen atoms, R' is an alkyl radical having from 1 to 3 carbon atoms, x is 1 or 2, and R and R' are chosen so that the vapor pressure of the alkoxysilane exceeds 10 Pa at treatment temperature, (C) from 0.001 to 5.0 parts by weight of volatile catalyst selected from the group consisting of base B, and mixtures of acid A and base B, wherein acid A is a volatile acid or acid progenitor, and base B is a silylamine or silazane, acid A and base B being chosen so that the vapor pressure of either acid A or base B exceeds 500 Pa at treatment temperature, for a period of time sufficient to allow the desired amount of treating agent to be adsorbed onto the surface of the particulate filler, to yield a filler which requires a minimum of energy to disperse rapidly into polydiorganosiloxane and which gives improved properties to cured silicone elastomers.
Claim 2
Independent Claim
255 words
A method of rapidly treating the surface of reinforcing silica filler consisting essentially of mixing, at a temperature of from about -10° to 130° C., (A) 100 parts by weight of reinforcing silica filler, having a surface area of greater than 50 m 2 /g, and having from 0.5 to 6 parts by weight of absorbed moisture, (B) from 3 to 30 parts by weight of volatile treating agent of the formula R x Si(OR') 4-x , wherein R is a alkyl, alkenyl, or aryl radical having from 1 to 6 carbon atoms which may be substituted with halogen atoms, R' is an alkyl radical having from 1 to 3 carbon atoms, x is 1 or 2, and R and R' are chosen so that the vapor pressure of the alkoxysilane exceeds 10 Pa at treatment temperature, (C) from 0.001 to 5.0 parts by weight of volatile catalyst selected from the group consisting of base B, and mixtures of acid A and base B, wherein acid A is a volatile acid or acid progenitor, and base B is a silylamine or silazane, acid A and base B being chosen so that the vapor pressure of either acid A or base B exceeds 500 Pa at treatment temperature, for a period of time sufficient to allow the desired amount of treating agent to be adsorbed onto the surface of the particulate filler, to yield a filler which requires a minimum of energy to disperse rapidly into polydiorganosiloxane and which gives improved properties to cured silicone elastomers.
Claim 3
Dependent Claim
47 words
The method of claim 1 in which the mixing is in the form of a stirred or fluidized bed in a container purged with an inert gas, the treatment temperature is from about 10° to 30° C., and the treatment time is from 3 to 10 minutes.
Claim 4
Dependent Claim
13 words
The method of claim 2 in which R and R' are methyl radical.
Claim 5
Dependent Claim
48 words
The method of claim 1 in which base B is selected from the group consisting of (R'' 3 Si) 2 NR'', (R'' 3 Si) 2 NH, R'' 3 SiNR'' 2 , and R'' 3 SiNHR'', where R'' is an alkyl radical having from 1 to 3 carbon atoms.
Claim 6
Dependent Claim
25 words
The method of claim 1 in which the volatile catalyst is admixed with the reinforcing silica filler before the mixing of the volatile treating agent.
Claim 7
Dependent Claim
21 words
The method of claim 3 in which the treating agent is Me 2 Si(OMe) 2 , where Me represents methyl radical.
Claim 8
Dependent Claim
15 words
The method of claim 6 in which the catalyst is (Me 3 Si) 2 NH.
Claim 9
Dependent Claim
14 words
The method of claim 3 in which the treating agent is MeSi(OMe) 3 .
Claim 10
Dependent Claim
15 words
The method of claim 8 in which the catalyst is (Me 3 Si) 2 NH.
Claim 11
Dependent Claim
21 words
The method of claim 3 in which the catalyst is a mixture of MeSiCl 3 and (Me 3 Si) 2 NH.
Claim 12
Dependent Claim
21 words
The method of claim 6 in which the catalyst is a mixture of MeSiCl 3 and (Me 3 Si) 2 NH.
Claim 13
Dependent Claim
21 words
The method of claim 8 in which the catalyst is a mixture of MeSiCl 3 and (Me 3 Si) 2 NH.
Claim 14
Dependent Claim
23 words
The method of claim 6 in which the catalyst is a mixture of Me 2 SiCl 2 and (Me 3 Si) 2 NH.
Claim 15
Dependent Claim
23 words
The method of claim 8 in which the catalyst is a mixture of Me 2 SiCl 2 and (Me 3 Si) 2 NH.
Claim 16
Dependent Claim
22 words
The method of claim 10 in which the treating agent is a mixture of MeSi(OMe) 3 and Me 2 Si(OMe) 2 .
Claim 17
Dependent Claim
22 words
The method of claim 11 in which the treating agent is a mixture of MeSi(OMe) 3 and Me 2 Si(OMe) 2 .
Claim 18
Dependent Claim
22 words
The method of claim 12 in which the treating agent is a mixture of MeSi(OMe) 3 and Me 2 Si(OMe) 2 .
Claim 19
Dependent Claim
10 words
The treated silica produced by the method of claim 1.
Claim 20
Dependent Claim
10 words
The treated silica produced by the method of claim 10.
Claim 21
Dependent Claim
10 words
The treated silica produced by the method of claim 11.
Claim 22
Dependent Claim
10 words
The treated silica produced by the method of claim 12.
Claim 23
Dependent Claim
10 words
The treated silica produced by the method of claim 13.
Claim 24
Dependent Claim
10 words
The treated silica produced by the method of claim 14.
Claim 25
Dependent Claim
10 words
The treated silica produced by the method of claim 15.
Claim 26
Dependent Claim
13 words
Silicone elastomer containing treated silica filler produced by the method of claim 1.
Claim 27
Dependent Claim
10 words
A silicone elastomer containing the treated silica of claim 19.
Claim 28
Dependent Claim
10 words
A silicone elastomer containing the treated silica of claim 20.
Claim 29
Dependent Claim
10 words
A silicone elastomer containing the treated silica of claim 21.
Claim 30
Dependent Claim
10 words
A silicone elastomer containing the treated silica of claim 22.
Claim 31
Dependent Claim
10 words
A silicone elastomer containing the treated silica of claim 23.
Claim 32
Dependent Claim
10 words
A silicone elastomer containing the treated silica of claim 24.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
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