US3405098A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing high viscosity linear condensation polyesters from partially polymerized glycol terephthalates
Assignee: EIDP Inc
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Filing: 1965-10-29
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Granted: 1968-10-08
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Expires: 1985-10-29
Abstract
No abstract record available.
Inventors
- 👤 Harold H Heighton
- 👤 Jr Elmer E Most
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:48
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/80
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
140 words
IN THE PREPARATION OF LINEAR CONDENSATION POLYESTERS WHEREIN GLYCOL TEREPHTHALATE IS PARTIALLY POLYMERIZED TO FORM AN AMORPHOUS MELT OF POLYESTER, THE MELT IS SOLIDIFIED AND THE POLYMERIZATION IS CONTINUED IN THE SOLID PHASE, THE PROCESS FOR PREPARING POLYESTER OF UNUSUALLY HIGH INTRINSIC VISCOSITY WHICH COMPRISES THE COMBINATION OF STEPS: (A) QUENCHING THE MELT RAPIDLY TO FORM A SUBSTANTIALLY AMORPHOUS SOLID POLYESTER, THE MOLTEN POLYESTER BEING PARTIALLY POLYMERIZED TO AN INTRINSIC VISCOSITY OF 0.20 TO 0.65 WHEN QUENCHED, (B) HEATING THE SOLID POLYESTER AT 150* TO 200*C. TO FORM A PARTIALLY CRYSTALLIZED POLYESTER, (C) GRINDING THE PARTIALLY CRYSTALLIZED POLYESTER INTO PARTICLES PASSING A 20-MESH SCREEN, WITH LESS THAN 10% FINE ENOUGH TO PASS THROUGH A 200-MESH SCREEN, AND (D) POLYMERIZING THE GROUND POLYESTER AT 200* TO 235* C. IN A FLUIDIZED-BED SOLID-PHASE POLYMERIZATION TO AN INTRINSIC VISCOSITY OF AT LEAST 0.8.
Claim 2
Dependent Claim
140 words
IN THE PREPARATION OF LINEAR CONDENSATION POLYESTERS WHEREIN GLYCOL TEREPHTHALATE IS PARTIALLY POLYMERIZED TO FORM AN AMORPHOUS MELT OF POLYESTER, THE MELT IS SOLIDIFIED AND THE POLYMERIZATION IS CONTINUED IN THE SOLID PHASE, THE PROCESS FOR PREPARING POLYESTER OF UNUSUALLY HIGH INTRINSIC VISCOSITY WHICH COMPRISES THE COMBINATION OF STEPS: (A) QUENCHING THE MELT RAPIDLY TO FORM A SUBSTANTIALLY AMORPHOUS SOLID POLYESTER, THE MOLTEN POLYESTER BEING PARTIALLY POLYMERIZED TO AN INTRINSIC VISCOSITY OF 0.20 TO 0.65 WHEN QUENCHED, (B) HEATING THE SOLID POLYESTER AT 150* TO 200*C. TO FORM A PARTIALLY CRYSTALLIZED POLYESTER, (C) GRINDING THE PARTIALLY CRYSTALLIZED POLYESTER INTO PARTICLES PASSING A 20-MESH SCREEN, WITH LESS THAN 10% FINE ENOUGH TO PASS THROUGH A 200-MESH SCREEN, AND (D) POLYMERIZING THE GROUND POLYESTER AT 200* TO 235* C. IN A FLUIDIZED-BED SOLID-PHASE POLYMERIZATION TO AN INTRINSIC VISCOSITY OF AT LEAST 0.8.
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) | 1971-10-08 | 1972-04-08 | 1972-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-10-08 | 1976-04-08 | 1976-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-10-08 | 1980-04-08 | 1980-10-08 | $7700.00 | Window Closed / Lapsed |