Patent US4094894A successfully refreshed from Google Patents.
US4094894A
Expired / Lapsed
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Process of purifying aliphatic isocyanates
Assignee: Bayer Corp
•
Filing: 1977-03-23
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Granted: 1978-06-13
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Expires: 1997-03-23
Abstract
Abstract Aliphatic isocyanates are purified by mixing with a finely divided alkali metal carbonate at 180° to 235° C.
Inventors
- 👤 Julian Theron Blackwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:28
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/18; C07C263/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
35 words
A process for purifying an aliphatic isocyanate containing hydrolyzable chlorine which comprises mixing finely divided dry alkali metal carbonate with the aliphatic isocyanate containing the hydrolyzable chlorine, at a temperature between 180° and 235° C.
Claim 2
Dependent Claim
35 words
A process for purifying an aliphatic isocyanate containing hydrolyzable chlorine which comprises mixing finely divided dry alkali metal carbonate with the aliphatic isocyanate containing the hydrolyzable chlorine, at a temperature between 180° and 235° C.
Claim 3
Dependent Claim
25 words
The process of claim 1 in which the alkali metal carbonate is selected from the class consisting of sodium carbonate, potassium carbonate, and lithium carbonate.
Claim 4
Dependent Claim
28 words
The process of claim 1 in which the finely divided dry alkali metal carbonate is formed by grinding the metal carbonate in the presence of the aliphatic isocyanate.
Claim 5
Dependent Claim
26 words
The process of claim 1 in which the alkali metal carbonate is ground in aliphatic isocyanate and then added to the impure isocyanate to be treated.
Claim 6
Dependent Claim
20 words
The process of claim 1 in which the carbonate is finely divided by grinding it in another inert organic liquid.
Claim 7
Dependent Claim
26 words
The process of claim 1 which includes the additional step of separating the aliphatic isocyanate from the reaction product of the carbonate and the hydrolyzable chlorine.
Claim 8
Dependent Claim
13 words
The process of claim 6 in which the separation is accomplished by distillation.
Claim 9
Dependent Claim
13 words
The process of claim 6 in which the separation is accomplished by filtration.
Claim 10
Dependent Claim
13 words
The process of claim 1 in which the aliphatic isocyanate is 4,4'-methylenebis(cyclohexyl diisocyanate).
Claim 11
Dependent Claim
14 words
The process of claim 9 in which sodium carbonate is the alkali metal carbonate.
Claim 12
Dependent Claim
26 words
The process of claim 1 in which most of the finely divided dry alkali metal carbonate particles have a diameter of no greater than 5 microns.
References Cited (Backward Citations)
US2885423A
Cited
US3465023A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-12 | 1981-12-12 | 1982-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-12 | 1985-12-12 | 1986-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-12 | 1989-12-12 | 1990-06-13 | $7700.00 | Window Closed / Lapsed |