US3886056A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing a high melting temperature polyethylene employing irradiation and orienting
Assignee: Individual
•
Filing: 1972-11-01
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Granted: 1975-05-27
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Expires: 1992-11-01
Abstract
Abstract A process for producing a high melting temperature polyethylene which comprises irradiating a polyethylene with an ionizing radiation to produce crosslinked polyethylene having a gel content of at least one weight percent, extending the crosslinked polyethylene in at least one direction at a temperature at least an anisotropic melting point of the crosslinked polyethylene and cooling the crosslinked polyethylene, said starting polyethylene having a viscosity average molecular weight of at least 1 X 105 and having a melting point of 137* to 138*C when crystallized isothermally from the melt at a temperature of 130*C.
Inventors
- 👤 Ryozo Kitamaru
- 👤 Hyon Don Chu
- 👤 Waichiro Tsuji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:42
CPC Classifications
B; B29; B29C; B29C43/00; B29C43/003; D; D01; D01D; D01D10/00; D01F; D01F6/00; D01F6/02; D01F6/04; D06; D06M; D06M10/00; D06M10/001; D06M10/008; B29C43/32; B29C43/58; B29C2043/5833; D06M2101/00; D06M2101/16; D06M2101/18; D06M2101/20; Y; Y10; Y10S; Y10S522/00; Y10S522/911; Y10S522/912
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
113 words
A PROCESS FOR PRODUCING A HIGH MELTING TEMPERATURE POLYETHYLENE WHICH COMPRISES IRRADIATING A POLYETHYLENE WITH X-RAYS, Y-RAYS OR ELECTRON BEAM TO A DOSAGE OF FROM 0.2 TO 16 MEGARADS TO PRODUCE CROSSLINKED POLYETHYLENE HAVING A GEL CONTENT OF AT LEAST ONE WEIGHT PERCENT, EXTENDING THE CROSSLINKED POLYETHYLENE IN AT LEAST ONE DIRECTION AT A TEMPERATURE OF AT LEAST THE ANISOTROPIC MELTING POINT OF AT LEAST 150*C OF THE CROSSLINKED POLYETHYLENE AND COOLING THE CROSSLINKED POLYETHYLENE, SAID STARTING POLYETHYLENE HAVING A VISCOSITY AVERAGE MOLECULAR WEIGHT OF FROM 1 X 10**5 TO 4 X 10**5 AND HAVING A MELTING POINT OF 137* TO 138*C WHEN CRYSTALLIZED ISOTHERMALLY FROM THE MELT AT A TEMPERATURE OF 130*C.
Claim 2
Dependent Claim
113 words
A PROCESS FOR PRODUCING A HIGH MELTING TEMPERATURE POLYETHYLENE WHICH COMPRISES IRRADIATING A POLYETHYLENE WITH X-RAYS, Y-RAYS OR ELECTRON BEAM TO A DOSAGE OF FROM 0.2 TO 16 MEGARADS TO PRODUCE CROSSLINKED POLYETHYLENE HAVING A GEL CONTENT OF AT LEAST ONE WEIGHT PERCENT, EXTENDING THE CROSSLINKED POLYETHYLENE IN AT LEAST ONE DIRECTION AT A TEMPERATURE OF AT LEAST THE ANISOTROPIC MELTING POINT OF AT LEAST 150*C OF THE CROSSLINKED POLYETHYLENE AND COOLING THE CROSSLINKED POLYETHYLENE, SAID STARTING POLYETHYLENE HAVING A VISCOSITY AVERAGE MOLECULAR WEIGHT OF FROM 1 X 10**5 TO 4 X 10**5 AND HAVING A MELTING POINT OF 137* TO 138*C WHEN CRYSTALLIZED ISOTHERMALLY FROM THE MELT AT A TEMPERATURE OF 130*C.
Claim 3
Dependent Claim
14 words
The process according to claim 1, in which said polyethylene is a polyethylene film.
Claim 4
Dependent Claim
14 words
The process according to claim 1, in which said polyethylene is a polyethylene fiber.
Claim 5
Dependent Claim
20 words
The process according to claim 1, in which said temperature of extending is in the range of 160* to 190*C.
Claim 6
Dependent Claim
22 words
The process according to claim 1, in which said extending step is conducted under an increased pressure of 1 to 50 kg/cm2.
Claim 7
Dependent Claim
21 words
The process according to claim 1, in which said gel content is in the range of 40 to 70 weight percent.
Claim 8
Dependent Claim
29 words
The process according to claim 1, in which said extending of the crosslinked polyethylene is conducted biaxially in the range of 2.5 X 2.5 to 3.5 X 3.5 times.
Claim 9
Dependent Claim
25 words
The process according to claim 1 in which said extending of the crosslinked polyethylene is conducted uniaxially in the range of 6 to 10 times.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |