US4649005A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a liquid silicone rubber base
Assignee: DuPont Toray Specialty Materials KK
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Filing: 1985-07-12
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Granted: 1987-03-10
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Expires: 2005-07-12
Abstract
Abstract Filled silicone rubber bases can be prepared without plasticizer by passing all of the filler together with from 30 to 100 percent of the total weight of the polyorganosiloxane ingredient of the base through the first kneading section of a compounding extruder and adding my remaining polyorganosiloxane before passing the composition through a second kneading section of the compounding extruder. The two kneading sections are maintained at temperatures of from 200 DEG to 300 DEG C.
Inventors
- 👤 Masaru Kobayashi
- 👤 Hironobu Koyanagi
- 👤 Takahiro Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:38
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/20; C08J3/22; C08J3/226; B; B29; B29B; B29B7/00; B29B7/80; B29B7/82; B29B7/86; B29C; B29C48/00; B29C48/25; B29C48/285; B29C48/297; B29C48/36; B29C48/375; B29C48/39; B29C48/395; B29C48/40; B29C48/405; B29C48/50; B29C48/505; B29C48/625; B29C48/64; B29C48/645; B29C48/655; B29C48/76; B29C48/765; B29C48/766; B29K; B29K2083/00; B29K2105/00; B29K2105/06; B29K2105/16; C08J2383/00; C08J2383/04; C08J2483/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
124 words
A method for producing a filled liquid silicone rubber base in the absence of a plasticizer where said base consists essentially of a polyorganosiloxane having at least two silicon-bonded alkenyl groups per molecule and an inorganic filler, said method consisting essentially of passing all of said filler together with from 30 to 100 percent of the total weight of said polyorganosiloxane through a first kneading section of a twin screw compounding extruder to form a mixture, adding any remaining portion of said polyorganosiloxane to said mixture prior to passing it through a second kneading section of said extruder and discharging the resultant base from said extruder, where the temperatures of said first and second kneading sections are maintained at from 200° to 300° C.
Claim 2
Independent Claim
124 words
A method for producing a filled liquid silicone rubber base in the absence of a plasticizer where said base consists essentially of a polyorganosiloxane having at least two silicon-bonded alkenyl groups per molecule and an inorganic filler, said method consisting essentially of passing all of said filler together with from 30 to 100 percent of the total weight of said polyorganosiloxane through a first kneading section of a twin screw compounding extruder to form a mixture, adding any remaining portion of said polyorganosiloxane to said mixture prior to passing it through a second kneading section of said extruder and discharging the resultant base from said extruder, where the temperatures of said first and second kneading sections are maintained at from 200° to 300° C.
Claim 3
Dependent Claim
12 words
A method according to claim 1 where said alkenyl groups are vinyl.
Claim 4
Dependent Claim
32 words
A method according to claim 1 where the silicon-bonded organic groups other than alkenyl that are present in said polyorganosiloxane are individually selected from the group consisting of methyl, phenyl and 3,3,3-trifluoropropyl.
Claim 5
Dependent Claim
13 words
A method according to claim 3 where said polyorganosiloxane is a vinyl-terminated polydimethylsiloxane.
Claim 6
Dependent Claim
18 words
A method according to claim 1 where the viscosity of said polyorganosiloxane is from 0.3 to 30 Pa.s
Claim 7
Dependent Claim
21 words
A method according to claim 1 where said inorganic filler is a silica or a mixture of silica and diatomaceous earth.
Claim 8
Dependent Claim
23 words
A method according to claim 1 where said first and second kneading sections are maintained at temperatures of from 200° to 280° C.
References Cited (Backward Citations)
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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) | 1990-03-09 | 1990-09-08 | 1991-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-09 | 1994-09-08 | 1995-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-09 | 1998-09-08 | 1999-03-10 | $7700.00 | Window Closed / Lapsed |