US4225403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for improving films of poly(p-methylstyrene) and copolymers thereof by high energy radiation treatments
Assignee: Mobil Oil AS
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Filing: 1979-02-21
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Granted: 1980-09-30
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Expires: 1999-02-21
Abstract
Abstract This invention provides a method for improving properties of thermoplastic films that comprises irradiating films of poly(p-methylstyrene) of p-methylstyrene copolymers with acrylonitrile, or of high impact poly (p-methylstyrene) with ionizing radiation at a dosage between about 30 megarads and about 70 megarads (preferably between about 40 megarads and about 60 megarads), whereby said films are heat resistant and have increased tensile properties at elevated temperatures.
Inventors
- 👤 Harold A. Arbit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:51
CPC Classifications
B; B29; B29C; B29C71/00; B29C71/04; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0844; B29C2035/085; B29C35/0866; B29C2035/0877; B29K; B29K2025/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
54 words
A method for improving properties of thermoplastic films that comprises irradiating films of poly (p-methylstyrene), of p-methylstyrene copolymers with acrylonitrile, or of high impact poly (p-methylstyrene) with ionizing radiation at a dosage between about 30 megarads and about 70 megarads, whereby said films are heat resistant and have increased tensile properties at elevated temperatures.
Claim 2
Independent Claim
54 words
A method for improving properties of thermoplastic films that comprises irradiating films of poly (p-methylstyrene), of p-methylstyrene copolymers with acrylonitrile, or of high impact poly (p-methylstyrene) with ionizing radiation at a dosage between about 30 megarads and about 70 megarads, whereby said films are heat resistant and have increased tensile properties at elevated temperatures.
Claim 3
Dependent Claim
17 words
The method of claim 1, wherein said dosage is between about 40 megarads and about 60 megarads.
Claim 4
Dependent Claim
13 words
The method of claim 2, wherein said film is a film of poly(p-methylstyrene).
Claim 5
Dependent Claim
19 words
The method of claim 2, wherein said film is a film of p-methylstyrene-acrylonitrile copolymer containing about 70 percent p-methylstyrene.
Claim 6
Dependent Claim
15 words
The method of claim 2, wherein said film is a film of high impact poly(p-methylstyrene).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-30 | 1984-03-31 | 1984-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-30 | 1988-03-31 | 1988-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-30 | 1992-03-31 | 1992-09-30 | $7700.00 | Window Closed / Lapsed |