US3135718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymerization of formaldehyde
Assignee: Bayer AG
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Filing: 1960-04-19
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Granted: 1964-06-02
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Expires: 1980-04-19
Abstract
No abstract record available.
Inventors
- 👤 Wagner Kuno
- 👤 Kritzler Helmuth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:55
CPC Classifications
C; C08; C08G; C08G2/00; C08G2/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
143 words
A PROCESS FOR THE PRODUCTION OF HIGH MOLECULAR WEIGHT POLYOXYMETHYLENES HAVING NO FREE TERMINAL HYDROXYL GROUP IN THE POLYOXYMETHYLENE CHAIN WHICH COMPRISES POLYMERIZING SUBSTANTIALLY ANHYDROUS FORMALDEHYDE AT A TEMPERATURE BETWEEN -70 AND +50*C. IN THE PRESENCE OF CATALYTIC AMOUNTS OF A CARBODIIMIDE SELECTED FROM THE GROUP CONSISTING OF AN ALKYL-, A CYCLO-ALKYL-, AN ARYL- AND AN ARALKYLCARBODIIMIDE IN A REACTION MEDIUM WHICH IS A REAGENT FOR HYDROXYL GROUPS, WHICH REAGENT IS SELECTED FROM THE GROUP CONSISTING OF AN ALKYL CARBOXYLIC ACID ANHYDRIDE, AN ARYL CRABOXYLIC ACID ANHYDRIDE, AR ORTHOFORMIC ACID TRIALKYLESTER, A SLICIC ACID TETRAALKYLESTER METHY-TER.BUTYLETHER, AND AN ALKYLADEHYDE-DIMETHYL ACETAL, AND AT THE CONCLUSION OF THE FORMALDEHYDE POLYMERIZATION RAISING THE TEMPERATURE OF SAID REACTION MEDIUM TO AT LEAST 80*C. TO PERMIT IT TO REACT WITH HYDROXYL GROUPS, AND RECOVERING A POLYOXYMETHYLENE HAV ING NO FREE TERMINAL HYDROXYL GROUP IN THE POLYOXYMETH YLENE CHAIN.
Claim 2
Dependent Claim
143 words
A PROCESS FOR THE PRODUCTION OF HIGH MOLECULAR WEIGHT POLYOXYMETHYLENES HAVING NO FREE TERMINAL HYDROXYL GROUP IN THE POLYOXYMETHYLENE CHAIN WHICH COMPRISES POLYMERIZING SUBSTANTIALLY ANHYDROUS FORMALDEHYDE AT A TEMPERATURE BETWEEN -70 AND +50*C. IN THE PRESENCE OF CATALYTIC AMOUNTS OF A CARBODIIMIDE SELECTED FROM THE GROUP CONSISTING OF AN ALKYL-, A CYCLO-ALKYL-, AN ARYL- AND AN ARALKYLCARBODIIMIDE IN A REACTION MEDIUM WHICH IS A REAGENT FOR HYDROXYL GROUPS, WHICH REAGENT IS SELECTED FROM THE GROUP CONSISTING OF AN ALKYL CARBOXYLIC ACID ANHYDRIDE, AN ARYL CRABOXYLIC ACID ANHYDRIDE, AR ORTHOFORMIC ACID TRIALKYLESTER, A SLICIC ACID TETRAALKYLESTER METHY-TER.BUTYLETHER, AND AN ALKYLADEHYDE-DIMETHYL ACETAL, AND AT THE CONCLUSION OF THE FORMALDEHYDE POLYMERIZATION RAISING THE TEMPERATURE OF SAID REACTION MEDIUM TO AT LEAST 80*C. TO PERMIT IT TO REACT WITH HYDROXYL GROUPS, AND RECOVERING A POLYOXYMETHYLENE HAV ING NO FREE TERMINAL HYDROXYL GROUP IN THE POLYOXYMETH YLENE CHAIN.
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) | 1967-06-02 | 1967-12-02 | 1968-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-06-02 | 1971-12-02 | 1972-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-06-02 | 1975-12-02 | 1976-06-02 | $7700.00 | Window Closed / Lapsed |