Patent US3975249A successfully refreshed from Google Patents.
US3975249A
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US
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Aromatic polymers of increased resistance to flow and molecular weight obtained by irradiation
Assignee: Imperial Chemical Industries Ltd
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Filing: 1974-04-16
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Granted: 1976-08-17
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Expires: 1994-04-16
Abstract
Abstract Aromatic polymers of increased resistance to flow and molecular weight are obtained by irradiation using beta -rays or gamma -rays at temperatures up to 400 DEG C of an aromatic polymer whose molecular chains comprise benzenoid groups and bivalent linking groups, and where irradiation is gamma -rays by heating subsequent to irradiaton at 200 DEG C to 400 DEG C. The polymeric materials having increased molecular weight are useful for coating non-cooking surfaces of cookware.
Inventors
- 👤 Philip Anthony Staniland
- 👤 Graham Jarrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:20
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/20; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
95 words
An aromatic polymer having increased molecular weight and resistance to flow produced by the exposure to a total dose of 10 to 150 Mrads of β-ray ionizing radiation at a temperature of 100°C to 400°C of at least one aromatic polysulphone containing repeat units --Ar-SO 2 -- (where Ar is a bivalent aromatic residue which may vary from unit to unit in the polymer chain and at least some of the Ar units have an aromatic ether or thioether group in the polymer chain ortho or para to at least one --SO 2 -- group).
Claim 2
Dependent Claim
95 words
An aromatic polymer having increased molecular weight and resistance to flow produced by the exposure to a total dose of 10 to 150 Mrads of β-ray ionizing radiation at a temperature of 100°C to 400°C of at least one aromatic polysulphone containing repeat units --Ar-SO 2 -- (where Ar is a bivalent aromatic residue which may vary from unit to unit in the polymer chain and at least some of the Ar units have an aromatic ether or thioether group in the polymer chain ortho or para to at least one --SO 2 -- group).
Claim 3
Dependent Claim
23 words
An aromatic polymer according to claim 1 produced by exposure to a total dose of 25 to 100 Mrads of β-ray ionizing radiation.
Claim 4
Dependent Claim
22 words
An aromatic polymer according to claim 2 which has been heated subsequent to said radiation at a temperature of 250°C to 400°C.
Claim 5
Dependent Claim
15 words
An aromatic polymer, according to claim 1 which contains repeating units of the formula ##SPC11##
Claim 6
Dependent Claim
15 words
An aromatic polymer, according to claim 1 which contains repeating units of the formula ##SPC12##
Claim 7
Dependent Claim
14 words
An aromatic polymer, according to claim 1 in the form of a shaped article.
Claim 8
Dependent Claim
13 words
An aromatic polymer, according to claim 1 in the form of a film.
Claim 9
Dependent Claim
14 words
Cookware having non-cooking surface coated with an aromatic polymer as claimed in claim 1.
Claim 10
Dependent Claim
12 words
Cookware according to claim 1 in which the coating contains a pigment.
Claim 11
Independent Claim
92 words
A method of forming a cross-linked aromatic polymer comprising exposing at least one aromatic polysulphone containing repeat units --Ar--SO 2 --, where Ar is a bivalent aromatic residue, which may vary from unit to unit in the polymer chain, and at least some of the Ar units have an aromatic ether or thioether group in the polymer chain ortho or para to at least one --SO 2 -- group, to a total dose of 10 to 150 Mrads of β-ray ionizing radiation at a temperature of 100°C to 400°C to effect cross-linking.
Claim 12
Independent Claim
92 words
A method of forming a cross-linked aromatic polymer comprising exposing at least one aromatic polysulphone containing repeat units --Ar--SO 2 --, where Ar is a bivalent aromatic residue, which may vary from unit to unit in the polymer chain, and at least some of the Ar units have an aromatic ether or thioether group in the polymer chain ortho or para to at least one --SO 2 -- group, to a total dose of 10 to 150 Mrads of β-ray ionizing radiation at a temperature of 100°C to 400°C to effect cross-linking.
Claim 13
Dependent Claim
25 words
A method according to claim 10 wherein the aromatic polysulphone is subjected to a total dose of 25 to 100 Mrads of said ionizing radiation.
Claim 14
Dependent Claim
19 words
A method according to claim 11 wherein the irradiated polymer is subjected to a temperature of 250°C to 400°C.
Claim 15
Dependent Claim
18 words
A method according to claim 10 in which the aromatic polysulphone contains repeating units of the formula ##SPC13##
Claim 16
Dependent Claim
18 words
A method according to claim 10 in which the aromatic polysulphone contains repeating units of the formula ##SPC14##
Claim 17
Dependent Claim
35 words
A method according to claim 10 wherein the irradiated aromatic polysulphone is subjected to a temperature of 200° to 400°C and is fabricated into a shaped article prior to or during the post-irradiation heating step.
Claim 18
Dependent Claim
21 words
A method according to claim 15 wherein the aromatic polysulphone is fabricated into a shaped article prior to the irradiation step.
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) | 1979-08-17 | 1980-02-16 | 1980-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-17 | 1984-02-16 | 1984-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-17 | 1988-02-16 | 1988-08-17 | $7700.00 | Window Closed / Lapsed |