US4586995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymer and irradiation treatment method
Assignee: RESEARCH Corp A NOT-FOR-PROFIT CORPORATION
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Filing: 1982-09-17
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Granted: 1986-05-06
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Expires: 2002-09-17
Abstract
Abstract A novel polymer and polymer treatment method are provided. The method involves irradiation of a polymer under non-gelling conditions at a temperature above the polymer melting temperature and in the absence of oxygen. The polymer is characterized by a unique long chain Y-branched molecular structure.
Inventors
- 👤 James C. Randall
- 👤 Frederick J. Zoepfl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:59
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/28; C08F; C08F10/00; C08F10/02; C08F110/00; C08F110/02; C08J2323/00; C08J2323/02; C08J2323/04
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
52 words
A method comprising: irradiating a polymer selected from ethylene homopolymers and copolymers in the absence of oxygen under non-gelling conditions at a temperature above the crystalline melting temperature of the polymer and greater than about 130° C., and cooling the resulting irradiated, non-gelled polymer to a temperature below its crystalline melting point.
Claim 2
Independent Claim
52 words
A method comprising: irradiating a polymer selected from ethylene homopolymers and copolymers in the absence of oxygen under non-gelling conditions at a temperature above the crystalline melting temperature of the polymer and greater than about 130° C., and cooling the resulting irradiated, non-gelled polymer to a temperature below its crystalline melting point.
Claim 3
Dependent Claim
12 words
The method of claim 1 in which the polymer is ethylene homopolymer.
Claim 4
Dependent Claim
21 words
The method of claim 1 in which the polymer is a copolymer of ethylene and at least one other α-olefin monomer.
Claim 5
Dependent Claim
14 words
The method of claim 1 in which the non-gelling conditions include an inert atmosphere.
Claim 6
Dependent Claim
13 words
The method of claim 1 in which the irradiation is conducted in vacuo.
Claim 7
Dependent Claim
26 words
The method of claim 1 in which the irradiation is carried out at a temperature in the range of about 130° C. to about 300° C.
Claim 8
Dependent Claim
28 words
The method of claim 1 in which the irradiation is provided in the form of gamma rays in a dose of about 0.1 MRad to about 4 MRad.
Claim 9
Dependent Claim
14 words
The method of claim 1 which comprises cooling the irradiated polymer to ambient temperature.
Claim 10
Dependent Claim
19 words
The method of claim 1 in which the irradiated polymer is cooled by quenching in a relatively cool liquid.
Claim 11
Dependent Claim
23 words
The method of claim 1 in which the polymer has an average of about 0.1 to about 0.5 vinyl end groups per molecule.
Claim 12
Dependent Claim
23 words
The method of claim 1 in which the polymer is the product of a low-pressure polymerization reaction catalyzed with a supported chromium catalyst.
Claim 13
Dependent Claim
19 words
The method of claim 1 in which the irradiated polymer has a g value of less than about 0.9.
Claim 14
Dependent Claim
23 words
The method of claim 1 in which the irradiation is carried out at a temperature of about 200° C. to about 280° C.
Claim 15
Independent Claim
64 words
A method comprising the steps of heating a polymer selected from ethylene homopolymers and copolymers in the absence of oxygen under non-gelling conditions at a temperature above the melting point of the polymer for a time of from about 0.5 to about 36 hours; irradiating the thus-treated polymer under non-gelling conditions; and cooling the thus-irradiated polymer to a temperature below its crystalline melting point.
Claim 16
Independent Claim
64 words
A method comprising the steps of heating a polymer selected from ethylene homopolymers and copolymers in the absence of oxygen under non-gelling conditions at a temperature above the melting point of the polymer for a time of from about 0.5 to about 36 hours; irradiating the thus-treated polymer under non-gelling conditions; and cooling the thus-irradiated polymer to a temperature below its crystalline melting point.
Claim 17
Dependent Claim
13 words
The method of claim 14 in which the polymer is an ethylene homopolymer.
Claim 18
Dependent Claim
28 words
The method of claim 14 in which the polymer is a copolymer of ethylene and at least one other α-olefin having from 3 to about 20 carbon atoms.
Claim 19
Dependent Claim
9 words
The method of claim 14 carried out in vacuo.
Claim 20
Dependent Claim
19 words
The method of claim 17 carried out at a temperature of about 130° C. to about 300 ° C.
Claim 21
Dependent Claim
30 words
The method of claim 18 in which the polymer is maintained in a melt state for a time of from about 16 hours to about 36 hours prior to irradiation.
Claim 22
Dependent Claim
22 words
The method of claim 19 in which the irradiation is maintained for a time of about 30 seconds to about 4 hours.
Claim 23
Dependent Claim
23 words
The method of claim 19 in which the radiation treatment provides a dose of gamma rays from about 0.1 to about 4 MRad.
Claim 24
Dependent Claim
37 words
The method of claim 18 in which the heating is maintained for a time sufficient to produce polymer having terminal vinyl unsaturation at a level of at least about 10 per 10,000 carbon atoms prior to irradiation.
Claim 25
Dependent Claim
21 words
The method of claim 18 in which the dose of radiation is sufficient to increase long chain Y-branching in the polymer.
Claim 26
Dependent Claim
26 words
The method of claim 23 which further comprises the step of recovering a polymer having at least about 2 long chain Y-branches per 10,000 carbon atoms.
Claim 27
Dependent Claim
19 words
The method of claim 24 in which the recovered polymer has a g value of less than about 0.9.
Claim 28
Dependent Claim
22 words
The method of claim 23 in which the treated polymer is a product of low pressure polymerization employing a supported chromium catalyst.
Claim 29
Dependent Claim
29 words
The method of claim 14 in which the heating step is performed under conditions of temperature and time effective for increasing the vinyl end group unsaturation in the polymer.
Claim 30
Dependent Claim
22 words
The method of claim 14 in which the irradiation step is performed under conditions effective for formation of long chain Y-branched molecules.
Claim 31
Dependent Claim
18 words
The method of claim 17 carried out at a temperature of about 200° C. to about 280° C.
Claim 32
Dependent Claim
8 words
A product of the process of claim 1.
Claim 33
Dependent Claim
8 words
A product of the process of claim 11.
Claim 34
Dependent Claim
8 words
A product of the process of claim 12.
Claim 35
Dependent Claim
8 words
A product of the process of claim 14.
Claim 36
Dependent Claim
8 words
A product of the process of claim 23.
Claim 37
Dependent Claim
8 words
A product of the process of claim 25.
Claim 38
Dependent Claim
14 words
An article of manufacture produced from the product of the process of claim 1.
Claim 39
Dependent Claim
14 words
An article of manufacture produced from the product of the process of claim 14.
Claim 40
Dependent Claim
29 words
A product of the process of claim 1 having about 7 to about 50 long chain Y-branches and 0 to about 10 short chain branches per 10,000 carbon atoms.
Claim 41
Dependent Claim
29 words
A product of the process of claim 14 having about 7 to about 50 long chain Y-branches and 0 to about 10 short chain branches per 10,000 carbon atoms.
Claim 42
Dependent Claim
14 words
The product of claim 38 having a g value of less than about 0.9.
Claim 43
Dependent Claim
14 words
The product of claim 39 having a g value of less than about 0.9.
Claim 44
Dependent Claim
11 words
An article of manufacture produced from the product of claim 38.
Claim 45
Dependent Claim
11 words
An article of manufacture produced from the product of claim 39.
Claim 46
Dependent Claim
20 words
The method of claim 1 in which the polymer comprises molecules having at least one vinyl end groups per molecule.
Claim 47
Dependent Claim
14 words
The product of the process of claim 1 which is soluble in boiling xylene.
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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) | 1989-05-05 | 1989-11-04 | 1990-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-05 | 1993-11-04 | 1994-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-05 | 1997-11-04 | 1998-05-06 | $7700.00 | Window Closed / Lapsed |