Patent US4655131A successfully refreshed from Google Patents.
Patent US3337503A successfully refreshed from Google Patents.
US3337503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyoxymethylene polymer and polymerization process
Assignee: Celanese Corp
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Filing: 1961-02-15
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Granted: 1967-08-22
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Expires: 1981-02-15
Abstract
No abstract record available.
Inventors
- 👤 Arthur W Schnizer
- 👤 Walter E Heinz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:19
CPC Classifications
C; C08; C08G; C08G2/00; C08G2/04; C08G2/06; C08G2/18; C08G2/22; C08G2/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
157 words
IN THE METHOD OF PREPARING OXYMETHYLENE COPOLYMERS HAVING RECURRING OXYMETHYLENE UNITS AND RECURRING OXYALKYLENE UNITS HAVING AT LEAST TWO CARBON ATOMS, WHEREIN TRIOXANE AND A CYCLIC ETHER HAVING AT LEAST TWO ADJACENT CARBON ATOMS ARE COPOLYMERIZED BY CONTACTING SAID TRIOXANE AND SAID CYCLIC ETHER WITH A CATIONIC CATALYST, THE IMPROVEMENT WHICH COMPRISES ADDING TO SAID TRIOXANE FROM ABOUT 0.1 TO ABOUT 3.0 MOLES PER 1000 MOLES OF TRIOXANE, OF A CHAIN TRANSFER AGENT SELECTED FROM THE GROUP CONSISTING OF ACETALS, ALCOHOLS, CARBOXYLIC ACIDS AND CARBOXYLIC ACID ANHYDRIDES, SAID ALCOHOLS AND CARBOXYLIC ACIDS HAVING UP TO EIGHTEEN CARBON ATOMS, SAID ANHYDRIDES BEING THOSE OF CARBOXYLIC ACIDS HAVING UP TO EIGHTEEN CARBON ATOMS, AND SAID ACETALS BEING SELECTED FROM THE GROUP CONSISTING OF (1) POLYOXYMETHYLENE DIALKYL ETHERS OF THE FORMULA A RO(CH2O)XR WHERE X IS AN INTEGER FROM 1 TO 10 AND R IS AN ALKYL GROUP HAVING UP TO 18 CARBON ATOMS, (2) POLYOXYMETHYLENE DIESTERS OF THE FORMULA
Claim 2
Dependent Claim
157 words
IN THE METHOD OF PREPARING OXYMETHYLENE COPOLYMERS HAVING RECURRING OXYMETHYLENE UNITS AND RECURRING OXYALKYLENE UNITS HAVING AT LEAST TWO CARBON ATOMS, WHEREIN TRIOXANE AND A CYCLIC ETHER HAVING AT LEAST TWO ADJACENT CARBON ATOMS ARE COPOLYMERIZED BY CONTACTING SAID TRIOXANE AND SAID CYCLIC ETHER WITH A CATIONIC CATALYST, THE IMPROVEMENT WHICH COMPRISES ADDING TO SAID TRIOXANE FROM ABOUT 0.1 TO ABOUT 3.0 MOLES PER 1000 MOLES OF TRIOXANE, OF A CHAIN TRANSFER AGENT SELECTED FROM THE GROUP CONSISTING OF ACETALS, ALCOHOLS, CARBOXYLIC ACIDS AND CARBOXYLIC ACID ANHYDRIDES, SAID ALCOHOLS AND CARBOXYLIC ACIDS HAVING UP TO EIGHTEEN CARBON ATOMS, SAID ANHYDRIDES BEING THOSE OF CARBOXYLIC ACIDS HAVING UP TO EIGHTEEN CARBON ATOMS, AND SAID ACETALS BEING SELECTED FROM THE GROUP CONSISTING OF (1) POLYOXYMETHYLENE DIALKYL ETHERS OF THE FORMULA A RO(CH2O)XR WHERE X IS AN INTEGER FROM 1 TO 10 AND R IS AN ALKYL GROUP HAVING UP TO 18 CARBON ATOMS, (2) POLYOXYMETHYLENE DIESTERS OF THE FORMULA
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) | 1970-08-21 | 1971-02-20 | 1971-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-08-21 | 1975-02-20 | 1975-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-08-21 | 1979-02-20 | 1979-08-22 | $7700.00 | Window Closed / Lapsed |