Patent US3816377A successfully refreshed from Google Patents.
US3816377A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid state polymerization process
Assignee: Goodyear Tire and Rubber Co
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Filing: 1972-09-21
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Granted: 1974-06-11
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Expires: 1992-09-21
Abstract
Abstract Linear condensation polyester resins are treated with a compound selected from metal salts of phosphorous acids, organophosphosphorus compounds, and phenolic compounds under solid state polymerization conditions to prevent sticking of the resin to itself or the equipment during solid state polymerization.
Inventors
- 👤 Y Okuzumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:35
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/04; C08K5/13; C08G; C08G63/00; C08G63/78; C08G63/80; C08K3/00; C08K3/32; C08K5/49; C08K5/51
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
12 words
The process of claim 1 wherein the polyester resin is polyethylene terephthalate.
Claim 2
Dependent Claim
20 words
The process of claim 1 wherein the polyester resin in the form of chips is treated with diphenyl phenyl phosphonate.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the metal of Group I is selected from lithium, sodium and potassium.
Claim 4
Dependent Claim
92 words
In the process of preparing a linear condensation polyester resin derived from terephthalic acid and ethylene glycol by solid state polymerization the improvement which comprises preventing the sticking of polyester chips by quenching the polyester melt polymer from the polymerization vessel with of from 0.5 percent to about 20 percent by weight of a compound selected from the group consisting of a salt of a phosphorous acid with a metal of Group I of the Periodic Table of the elements, followed by chipping the quenched polyester and then drying above 100* C.
Claim 5
Dependent Claim
95 words
In the process of preparing a linear condensation polyester resin derived from terephthalic acid and ethylene glycol by solid state polymerization the improvement which comprises preventing the sticking of polyester chips by quenching the polyester melt polymer from the polymerization vessel with an aqueous solution of from 0.5 percent to about 2 percent by weight of a compound selected from the group consisting of a salt of a phosphorous acid with a metal of Group IV of the Periodic Table of the elements, followed by chipping the quenched polyester and then drying above 100* C.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |