US3933730A
Expired / Lapsed
US
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Thermally stable translucent polycarbonate composition
Assignee: General Electric Co
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Filing: 1974-08-09
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Granted: 1976-01-20
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Expires: 1994-08-09
Abstract
Abstract A thermally stable translucent polycarbonate composition comprising in admixture an aromatic carbonate polymer and a minor amount of a mixture of a poly(dimethylsiloxane) gum and divided silica.
Inventors
- 👤 Thomas J. Hoogeboom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:22
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/34; C08K3/36; C08L; C08L69/00; C08L83/00; C08L83/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
87 words
A thermally stable translucent polycarbonate composition comprising in admixture, an aromatic carbonate polymer and from 0.01 to about 5.0 weight percent based on the weight of the polycarbonate composition of a mixture of a poly(dimethylsiloxane) gum and finely divided silica having a surface area in the range of 50 to 380 cm 2 /g; wherein the mixture of poly(dimethylsiloxane) gum and finely divided silica is present in a ratio of from about 30 to about 120 parts of the silica to 100 parts of the poly(dimethylsiloxane) gum.
Claim 2
Dependent Claim
87 words
A thermally stable translucent polycarbonate composition comprising in admixture, an aromatic carbonate polymer and from 0.01 to about 5.0 weight percent based on the weight of the polycarbonate composition of a mixture of a poly(dimethylsiloxane) gum and finely divided silica having a surface area in the range of 50 to 380 cm 2 /g; wherein the mixture of poly(dimethylsiloxane) gum and finely divided silica is present in a ratio of from about 30 to about 120 parts of the silica to 100 parts of the poly(dimethylsiloxane) gum.
Claim 3
Dependent Claim
17 words
The composition of claim 1 wherein the aromatic carbonate polymer is the reaction product of 2,2-bis(4-hydroxyphenyl) propane.
Claim 4
Dependent Claim
20 words
The composition of claim 1 wherein the poly(dimethylsiloxane) gum has a molecular weight of between 50,000 to about 500,000 grams/mole.
References Cited (Backward Citations)
US2999835A
Cited
US3360498A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |