US4145466A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Melt strength improvement of PET
Assignee: Zeneca Inc
•
Filing: 1977-09-02
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Granted: 1979-03-20
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Expires: 1997-09-02
Abstract
Abstract Composition and method for improving the thermoplastic processing characteristics of poly(ethylene terephthalate) (PET) in amphorous form are disclosed, as well as PET with improved melt strength.
Inventors
- 👤 John P. Leslie
- 👤 Constance A. Lane
- 👤 R. Peter Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:22
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0014; C08J9/0023; B; B29; B29C; B29C49/00; B29C49/0005; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/16; C08G63/20; C08K; C08K5/00; C08K5/04; C08K5/09; C08K5/15; C08J2367/00; C08J2367/02; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1397; Y10T428/31504; Y10T428/31786
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
A method for preparing thin-walled shaped articles comprising: (a) extruding a composition comprising PET and about 0.1 to 5% by weight of a polyanhydride selected from the group consisting of pyromellitic dianhydride, mellitic trianhydride, tetra hydrofuran dianhydride, and polyanhydride containing at least two unsubstituted or substituted phthalic anhydride radicals to a molten self-supporting preform wherein said polyanhydride causes increased melt strength; (b) shaping said molten composition into a final non-crystalline form; (c) allowing said composition to cool to a shaped article.
Claim 2
Independent Claim
81 words
A method for preparing thin-walled shaped articles comprising: (a) extruding a composition comprising PET and about 0.1 to 5% by weight of a polyanhydride selected from the group consisting of pyromellitic dianhydride, mellitic trianhydride, tetra hydrofuran dianhydride, and polyanhydride containing at least two unsubstituted or substituted phthalic anhydride radicals to a molten self-supporting preform wherein said polyanhydride causes increased melt strength; (b) shaping said molten composition into a final non-crystalline form; (c) allowing said composition to cool to a shaped article.
Claim 3
Dependent Claim
9 words
Non-crystalline, thin-walled articles prepared in accordance with claim 1.
Claim 4
Dependent Claim
17 words
A method in accordance with claim 1 wherein the molten composition is shaped by injecting a fluid.
Claim 5
Dependent Claim
27 words
A method in accordance with claim 3 wherein the molten composition is shaped in the form of a hollow bubble which is subsequently collapsed to a film.
Claim 6
Dependent Claim
11 words
Clear amorphous blow-molded bottles prepared by the process of claim 1.
Claim 7
Dependent Claim
33 words
A method in accordance with claim 1 wherein said composition further includes a fatty acid or N-substituted fatty acid amide having at least 10 carbon atoms in the acid portion of the molecule.
Claim 8
Dependent Claim
22 words
A method in accordance with claim 6 wherein the ratio of dianhydride to fatty acid is about 0.1/1 to 10/1 by weight.
Claim 9
Dependent Claim
15 words
A method in accordance with claim 1 wherein said shaping is accomplished by blow molding.
Claim 10
Dependent Claim
15 words
Blow molded amorphous articles, blown film, or foam produced by the method of claim 8.
References Cited (Backward Citations)
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US3822332A
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US3660557A
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US3733309A
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US3733309B1
Cited
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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) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |