US3431243A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparation of poly(ethylene terphthalate) from compressed terephthalic acid
Assignee: Teijin Ltd
•
Filing: 1963-12-04
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Granted: 1969-03-04
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Expires: 1983-12-04
Abstract
No abstract record available.
Inventors
- 👤 Seiji Uno
- 👤 Seiji Kazama
- 👤 Fumio Uno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:14
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; B; B01; B01J; B01J2/00; B01J2/22; C07; C07C; C07C51/00; C07C51/42; C07C63/00; C07C63/14; C07C63/15; C07C63/26; C08G63/82
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
145 words
IN A PROCESS FOR THE PREPARATION OF POLYESTERS BY DIRECT ESTERIFICATION WHEREIN A TEREPHTHALIC ACID COMPONENT SELECTED FROM TEREPHTHALIC ACID OR A MIXTURE OF TEREPHTHALIC ACID WITH LESS THAN 20% OF ANOTHER ORGANIC BIFUNCTIONAL CARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF DICARBOXYLIC ACIDS AND OXYCARBOXYLIC ACIDS IS REACTED DIRECTLY WITH AGLYCOL OF 2 TO 10 CARBON ATOMS TO FORM BIS(HYDROXY ALKYL)- TEREPHTHALATE OR A LOW-MOLECULAR-WEIGHT POLYMER THEREOF WITH SUBSEQUENT POLYMERIZATION OF THE RESULTANT REACTION PRODUCT BY HEATING UNDER REDUCED PRESSURE, THE IMPROVEMENT WHICH COMPRISES EMPLOYING A TEREPHTHALIC ACID COMPONENT PRODUCED BY MECHANICALLY COMPRESSING SAID TEREPHTHALIC ACID COMPONENT WITH A SUFFICIENT COMPRESSIONAL FORCE SO AS TO PRODUCE PARTICLES HAVING AN AVERAGE DIAMETER OF NOT MORE THAN 8 MM. AND BULK DENSITY OF AT LEAST 0.8, THE AVERAGE DIAMETER OF SAID PARTICLES BEING AT LEAST THAT NECESSARY TO OBTAIN A BULK DENSITY OF AT LEAST 0.8.
Claim 2
Dependent Claim
145 words
IN A PROCESS FOR THE PREPARATION OF POLYESTERS BY DIRECT ESTERIFICATION WHEREIN A TEREPHTHALIC ACID COMPONENT SELECTED FROM TEREPHTHALIC ACID OR A MIXTURE OF TEREPHTHALIC ACID WITH LESS THAN 20% OF ANOTHER ORGANIC BIFUNCTIONAL CARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF DICARBOXYLIC ACIDS AND OXYCARBOXYLIC ACIDS IS REACTED DIRECTLY WITH AGLYCOL OF 2 TO 10 CARBON ATOMS TO FORM BIS(HYDROXY ALKYL)- TEREPHTHALATE OR A LOW-MOLECULAR-WEIGHT POLYMER THEREOF WITH SUBSEQUENT POLYMERIZATION OF THE RESULTANT REACTION PRODUCT BY HEATING UNDER REDUCED PRESSURE, THE IMPROVEMENT WHICH COMPRISES EMPLOYING A TEREPHTHALIC ACID COMPONENT PRODUCED BY MECHANICALLY COMPRESSING SAID TEREPHTHALIC ACID COMPONENT WITH A SUFFICIENT COMPRESSIONAL FORCE SO AS TO PRODUCE PARTICLES HAVING AN AVERAGE DIAMETER OF NOT MORE THAN 8 MM. AND BULK DENSITY OF AT LEAST 0.8, THE AVERAGE DIAMETER OF SAID PARTICLES BEING AT LEAST THAT NECESSARY TO OBTAIN A BULK DENSITY 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) | 1972-03-03 | 1972-09-02 | 1973-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-03-03 | 1976-09-02 | 1977-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-03-03 | 1980-09-02 | 1981-03-04 | $7700.00 | Window Closed / Lapsed |