US4092458A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous laminar pellets of waste poly(ethylene terephthalate) film, and processes for drying and polymerization
Assignee: EIDP Inc
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Filing: 1976-04-12
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Granted: 1978-05-30
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Expires: 1996-04-12
Abstract
Abstract Porous laminar pellets of comminuted crystalline poly(ethylene terephthalate) waste film are formed. The pellets do not contain a binder, but are coherent since the polymer flakes making up the pellets are mechanically interlocked or intertwined. Rapid drying and solid state polymerization rates are achieved, and the pellets have sufficient structural integrity to survive such processes, but may be readily disintegrated upon completion of such processes if so desired. The pellets are also well adapted for dissolution, such as in glycol monomer for glycolysis, and in molten polymer.
Inventors
- 👤 Frank Edward Hoffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:15
CPC Classifications
B; B29; B29B; B29B9/00; B29B17/00; B29B17/0026; B29B17/0036; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
31 words
A pellet consisting of a plurality of flakes of a crystalline ethylene terephthalate polymer, the flakes being crenulated and in laminar configuration with adjacent flakes being mechanically interlocked at flake edges.
Claim 2
Dependent Claim
31 words
A pellet consisting of a plurality of flakes of a crystalline ethylene terephthalate polymer, the flakes being crenulated and in laminar configuration with adjacent flakes being mechanically interlocked at flake edges.
Claim 3
Dependent Claim
43 words
The pellet of claim 1 wherein the flakes are 1.5 to 10 mm long in each of the two planar dimensions of the flake, and the pellet has a diameter of 2 to 7 mm and a length of 6 to 13 mm.
Claim 4
Dependent Claim
14 words
The pellet of claim 2 wherein the flakes are, at most, 0.125 mm thick.
Claim 5
Dependent Claim
14 words
The pellet of claim 2 wherein the flakes are 0.002 to 0.050 mm thick.
Claim 6
Dependent Claim
18 words
The pellet of claim 1 wherein the ethylene terephthalate polymer has an intrinsic viscosity of 0.5 to 0.6.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-29 | 1981-11-28 | 1982-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-29 | 1985-11-28 | 1986-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-29 | 1989-11-28 | 1990-05-30 | $7700.00 | Window Closed / Lapsed |