Patent US2875226A successfully refreshed from Google Patents.
US2875226A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of isocyanates
Assignee: GAF Chemicals Corp
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Filing: 1956-07-09
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Granted: 1959-02-24
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Expires: 1976-07-09
Abstract
No abstract record available.
Inventors
- 👤 Bloom Albert
- 👤 Harlan B Freyermuth
- 👤 James B Normington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:29
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/10; C07C263/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
154 words
IN THE PROCESS FOR THE PREPARATION OF AROMATIC POLYISOCYANATES WHEREIN AN AROMATIC POLYAMINE IS REACTED WITH PHOSGENE AT A LOW TEMPERATURE AND IN AN INERT ORGANIC SOLVENT TO PRODUCE A SLURRY OF THE CARBAMYL CHLORIDE-HYDROCHLORIDE OF SAID POLYAMINE IN SAID SOLVENT AND THE THUS OBTAINED SLURRY IS REACTED AT AN ELEVATED TEMPERATURE IN THE RANGE OF 100 TO 200*C. WITH FURTHER PHOSGENE WHEREBY CARBAMYL CHLORIDE-HYDROCHLORIDE REACTS WITH THE PHOSGENE TO FORM A POLISOCYANATE AND THE THUS OBATAINED POLISOCYANATE IS RECOVERED; THE IMPROVEMENT WHICH COMPRISES FORMING A SOLUTION OF PHOSGENE IN AN INERT ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF DIALKYL ETHERS OF MONO-, DI- AND TRIALKYLENE GLYCOLS AND INTRODUCING THE POLYAMINE INTO THE THUS FORMED SOLUTION OF PHOSGENE TO THEREBY FORM THE SLURRY OF THE CARBAMYL CHLORIDE-HYDROCHLORIDE AND HEATING THE THUS FORMED SLURRY IN THE SAME SOLVENT TO A TEMPERATURE OF 100 TO 200*C. WHILE INTRODUCING FURTHER PHOSGENE WHEREBY THE POLYISOCYANATE IS FORMED.
Claim 2
Dependent Claim
154 words
IN THE PROCESS FOR THE PREPARATION OF AROMATIC POLYISOCYANATES WHEREIN AN AROMATIC POLYAMINE IS REACTED WITH PHOSGENE AT A LOW TEMPERATURE AND IN AN INERT ORGANIC SOLVENT TO PRODUCE A SLURRY OF THE CARBAMYL CHLORIDE-HYDROCHLORIDE OF SAID POLYAMINE IN SAID SOLVENT AND THE THUS OBTAINED SLURRY IS REACTED AT AN ELEVATED TEMPERATURE IN THE RANGE OF 100 TO 200*C. WITH FURTHER PHOSGENE WHEREBY CARBAMYL CHLORIDE-HYDROCHLORIDE REACTS WITH THE PHOSGENE TO FORM A POLISOCYANATE AND THE THUS OBATAINED POLISOCYANATE IS RECOVERED; THE IMPROVEMENT WHICH COMPRISES FORMING A SOLUTION OF PHOSGENE IN AN INERT ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF DIALKYL ETHERS OF MONO-, DI- AND TRIALKYLENE GLYCOLS AND INTRODUCING THE POLYAMINE INTO THE THUS FORMED SOLUTION OF PHOSGENE TO THEREBY FORM THE SLURRY OF THE CARBAMYL CHLORIDE-HYDROCHLORIDE AND HEATING THE THUS FORMED SLURRY IN THE SAME SOLVENT TO A TEMPERATURE OF 100 TO 200*C. WHILE INTRODUCING FURTHER PHOSGENE WHEREBY THE POLYISOCYANATE IS FORMED.
References Cited (Backward Citations)
US2706733A
Cited
US2625561A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-02-23 | 1962-08-25 | 1963-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-02-23 | 1966-08-25 | 1967-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-02-23 | 1970-08-25 | 1971-02-24 | $7700.00 | Window Closed / Lapsed |