US3884876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Partially crosslinked linear aromatic polyesters
Assignee: Unifrax I LLC
•
Filing: 1973-08-31
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Granted: 1975-05-20
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Expires: 1993-08-31
Abstract
Abstract Partially crosslinked thermoplastic polyesters of recurring linear moieties of the formula ARE DESCRIBED WHEREIN N IS 0 OR 1, AND P, Q AND R ARE INTEGERS WHICH TOTAL 30 TO 600. The polyester is partially crosslinked by oxidizing meltable polymer to a ''''gelled'''' thermoplastic state, producing molecules of average molecular weights in the range of 10,000 to 1,000,000, preferably of 100,000 to 500,000.
Inventors
- 👤 Steve G Cottis
- 👤 James Economy
- 👤 Arnold A Wosilait
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:42
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/91; C08G63/02; C08G63/60; C08G63/605
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
11 words
A MOLDABLE PARTIALLY CROSSLINKED POLYESTER CONTAINING RECURRING MOIETIES OF THE FORMULA
Claim 2
Dependent Claim
11 words
A MOLDABLE PARTIALLY CROSSLINKED POLYESTER CONTAINING RECURRING MOIETIES OF THE FORMULA
Claim 3
Dependent Claim
62 words
A polyester according to claim 1 wherein the molecular weight of the linear polyester prior to partial crosslinking is in the range of about 2,000 to 25,000, the molecular weight after crosslinking is in the range of about 100,000 to 500,000, the ratio of q:r is between 10:15 and 15:10 and the ratios of p:q and p:r are between 1:100 and 100:1.
Claim 4
Dependent Claim
46 words
A polyester according to claim 2 wherein n is 0, the oxygens of the dioxyphenyl moiety resulting are located para to each other and the carbonyls of the dicarbonyl phenyl moiety are para to each other or are in a mixture of meta- and para-carbonyl-substituted moieties.
Claim 5
Dependent Claim
62 words
A polyester according to claim 2 wherein n is 1, the ratio of q:r is about 1, the ratios of p:q and p:r are from 1:1 to 10:1, the oxygens of the bisphenol are located para to each other and the carbonyls of the dicarbonyl phenyl moiety are para to each other or are in a mixture of meta- and para-carbonyl-substituted moieties.
Claim 6
Dependent Claim
6 words
A molded polyester of claim 1.
Claim 7
Dependent Claim
6 words
A molded polyester of claim 3.
Claim 8
Dependent Claim
6 words
A molded polyester of claim 4.
Claim 9
Dependent Claim
80 words
A method of producing a partially crosslinked polyester according to claim 1 which comprises heating a linear polyester of the formula given in that claim to an elevated temperature in the range of 250* to 500*C. in the presence of oxygen for a period of time long enough to make the polymer produced incapable of being fiber forming by drawing or spinning from a melt and incapable of being deposited as a film, while still retaining thermoplasticity and being moldable.
Claim 10
Dependent Claim
62 words
A method according to claim 8 wherein the molecular weight of the linear polyester prior to partial crosslinking is in the range of about 2,000 to 25,000, the molecular weight after crosslinking is in the range of about 10,000 to 1,000,000, the ratio of q:r is between 10:15 and 15:10 and the ratios of p:q and p:r are between 1:100 and 100:1.
Claim 11
Dependent Claim
21 words
A method according to claim 9 wherein the linear polyester so treated and the product resulting are those of claim 30.
Claim 12
Dependent Claim
26 words
A method according to claim 8 wherein the polyester being heated is in particulate form and the heating is to a temperature below its melting point.
Claim 13
Dependent Claim
62 words
A polyester according to claim 2 wherein n is 1, the ratio of q:r, before crosslinking, is about 1, the ratio of p:q, before crosslinking is about 1:2, the ratio of p:r, before crosslinking, is about 1:2, the oxygens of the bisphenol are located para to each other and the carbonyls of the dicarbonyl phenyl moiety are located meta to each other.
Claim 14
Dependent Claim
6 words
A molded polyester of claim 12.
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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |