US4137386A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compounds and process
Assignee: Pharmacia and Upjohn Co
•
Filing: 1978-05-03
•
Granted: 1979-01-30
•
Expires: 1998-05-03
Abstract
Abstract Modified polystyrenes are described which are catalysts for the conversion of organic isocyanates to the corresponding carbodiimides. The modified polystyrenes are characterized by the presence of recurring units of the formula: ##STR1## R 1 and R 2 are hydrocarbyl which is free of substituents reactive with isocyanate groups, R 3 is hydrogen, chloro or methyl, R 4 is hydrogen or methyl, and n is 0 or 1. The use of the above polymers to catalyze the formation of carbodiimides from organic isocyanates is also disclosed.
Inventors
- 👤 Curtis P. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:52
CPC Classifications
B; B01; B01J; B01J31/00; B01J31/02; B01J31/06; B01J31/069; C; C08; C08F; C08F8/00; C08F8/42
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
96 words
In a process for the preparation of a carbodiimide by heating the appropriate organic isocyanate in the presence of a catalyst the improvement which comprises employing as said catalyst a polymer characterized by the presence therein of a recurring unit having the formula: ##STR8## wherein n is 0 or 1, R 1 and R 2 each independently represents hydrocarbyl, said hydrocarbyl being free of substituents which are reactive with isocyanate, R 3 is selected from the class consisting of chlorine, methyl and hydrogen and R 4 is selected from the class consisting of hydrogen and methyl.
Claim 2
Dependent Claim
96 words
In a process for the preparation of a carbodiimide by heating the appropriate organic isocyanate in the presence of a catalyst the improvement which comprises employing as said catalyst a polymer characterized by the presence therein of a recurring unit having the formula: ##STR8## wherein n is 0 or 1, R 1 and R 2 each independently represents hydrocarbyl, said hydrocarbyl being free of substituents which are reactive with isocyanate, R 3 is selected from the class consisting of chlorine, methyl and hydrogen and R 4 is selected from the class consisting of hydrogen and methyl.
Claim 3
Dependent Claim
27 words
A process according to claim 1 wherein the said catalyst is a polymer having a recurring unit of the formula: ##STR9## wherein n is 0 or 1.
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) | 1982-01-29 | 1982-07-31 | 1983-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-29 | 1986-07-31 | 1987-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-29 | 1990-07-31 | 1991-01-30 | $7700.00 | Window Closed / Lapsed |