Patent US4556681A successfully refreshed from Google Patents.
US4556681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polycarbonate resin foam
Assignee: General Electric Co
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Filing: 1985-01-02
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Granted: 1985-12-03
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Expires: 2005-01-02
Abstract
Abstract Epoxy compounds are added to polycarbonate resin to reduce or eliminate the necessity of drying the resin prior to a foaming process.
Inventors
- 👤 Frank N. Liberti
- 👤 Gerald F. Macke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:57
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08K; C08K5/00; C08K5/04; C08K5/15; C08K5/151; C08K5/1515; C08J2369/00; C08J2463/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
60 words
A method for producing a foamed polycarbonate article comprising a step of heating and foaming a polycarbonate resin composition comprising a polycarbonate resin, a blowing agent, and an impact enhancing amount of from about 0.2% to about 1.0% by weight of resin content of an epoxy compound provided that the resin composition contains greater than about 0.02% by weight water.
Claim 2
Independent Claim
60 words
A method for producing a foamed polycarbonate article comprising a step of heating and foaming a polycarbonate resin composition comprising a polycarbonate resin, a blowing agent, and an impact enhancing amount of from about 0.2% to about 1.0% by weight of resin content of an epoxy compound provided that the resin composition contains greater than about 0.02% by weight water.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein said epoxy functionalized material is an aromatic epoxy compound.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein said epoxy functionalized material is an aliphatic epoxy compound.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein said epoxy functionalized material is a cycloaliphatic epoxy compound.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein said polycarbonate resin composition contains reinforcing filler.
Claim 7
Independent Claim
62 words
A method for producing a foamed polycarbonate article consisting essentially of heating and a step of foaming a polycarbonate resin composition comprising a polycarbonate resin, a blowing agent, and an impact enhancing amount of from about 0.2% to about 1.0% by weight of resin content an epoxy functionalized material, provided that the resin composition contains greater than about 0.02% by weight water.
Claim 8
Independent Claim
62 words
A method for producing a foamed polycarbonate article consisting essentially of heating and a step of foaming a polycarbonate resin composition comprising a polycarbonate resin, a blowing agent, and an impact enhancing amount of from about 0.2% to about 1.0% by weight of resin content an epoxy functionalized material, provided that the resin composition contains greater than about 0.02% by weight water.
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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) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |