US3883577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing high molecular weight polyisocyanates
Assignee: Montedison SpA
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Filing: 1973-09-21
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Granted: 1975-05-13
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Expires: 1993-09-21
Abstract
Abstract There is disclosed an improvement in the process for producing high molecular weight polyisocyanates by the reaction of volatile diisocyanate and an active hydrogen-containing substance. The improvement consists in using, as solvent medium for the reaction between the volatile diisocyanate and hydrogen-containing substance, a solvent, in particular acetonitrile, which has a strong affinity for the high molecular weight polyisocyanate, is only partially miscible with the aliphatic and/or cycloaliphatic hydrocarbons used as solvents for the extraction of unreacted volatile isocyanate, has a low boiling point by virtue of which it is easily distillable without causing collateral reactions and, finally, may be replaced by the solvents which are normally used in applying the high molecular weight polyisocyanates in practice, such as ethyl acetate, butyl acetate, acetic acid esters in general, alkyl carbonates, ketones, chlorinated hydrocarbons, etc.
Inventors
- 👤 Antonio Rabizzoni
- 👤 Aldo Trovati
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:07
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/80; C08G18/8003; C08G18/8006; C08G18/8009
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
136 words
PROCESS FOR PREPARING HIGH MOLECULAR WEIGHT POLYISOCYANATES BY REACTION OF ADDITION BETWEEN AN ALKYL OR ALKYLARYLDIISOCYANATE AND AN ACTIVE HYDROGEN-CONTAINING COMPOUND SELECTED FROM ALIPHATIC DIOLS, TRIOLS A POLYHYDRIC ALCOHOLS, CHARACTERIZED IN THAT A. THE ALKYL OR ALKYLARYLDIISOCYANATE IS REACTED AT A TEMPERATURE COMPRISED BETWEEN 20* AND 100*C WITH THE ACTIVE HYDROGEN-CONTAINING COMPOUND IN A SOLVENT HAVING A STRONG AFFINITY FOR THE REACTION PRODUCT, SAID SOLVENT BEING ONLY PARTLY MISCIBLE WITH ALIPHATIC AND/OR CYCLOALIPHATIC HYDROCARBONS AND HAVING A LOW BOILING POINT, THE MOLAR RATIO ISOCYANIC EQUIVALENTS -NCO/HYDROXY EQUIVALENTS -OH BEING COMPRISED BETWEEN 2 AND 3; B. THE ALKYL OR ARYLDIISOCYANATES ARE EXTRACTED AT A TEMPERATURE FROM 20* TO 50*C FROM THE SOLUTION OBTAINED IN (A) EITHER BATCHWISE OR CONTINUOUSLY WITH AN EXTRACTION MIXTURE COMPRISING ALIPHATIC AND/OR CYCLOALIPHATIC HYDROCARBONS, PREFERABLY IN ADMIXTURE WITH THE SAME REACTION SOLVENT MEDIUM.
Claim 2
Dependent Claim
136 words
PROCESS FOR PREPARING HIGH MOLECULAR WEIGHT POLYISOCYANATES BY REACTION OF ADDITION BETWEEN AN ALKYL OR ALKYLARYLDIISOCYANATE AND AN ACTIVE HYDROGEN-CONTAINING COMPOUND SELECTED FROM ALIPHATIC DIOLS, TRIOLS A POLYHYDRIC ALCOHOLS, CHARACTERIZED IN THAT A. THE ALKYL OR ALKYLARYLDIISOCYANATE IS REACTED AT A TEMPERATURE COMPRISED BETWEEN 20* AND 100*C WITH THE ACTIVE HYDROGEN-CONTAINING COMPOUND IN A SOLVENT HAVING A STRONG AFFINITY FOR THE REACTION PRODUCT, SAID SOLVENT BEING ONLY PARTLY MISCIBLE WITH ALIPHATIC AND/OR CYCLOALIPHATIC HYDROCARBONS AND HAVING A LOW BOILING POINT, THE MOLAR RATIO ISOCYANIC EQUIVALENTS -NCO/HYDROXY EQUIVALENTS -OH BEING COMPRISED BETWEEN 2 AND 3; B. THE ALKYL OR ARYLDIISOCYANATES ARE EXTRACTED AT A TEMPERATURE FROM 20* TO 50*C FROM THE SOLUTION OBTAINED IN (A) EITHER BATCHWISE OR CONTINUOUSLY WITH AN EXTRACTION MIXTURE COMPRISING ALIPHATIC AND/OR CYCLOALIPHATIC HYDROCARBONS, PREFERABLY IN ADMIXTURE WITH THE SAME REACTION SOLVENT MEDIUM.
Claim 3
Dependent Claim
33 words
The process according to claim 1, in which the aliphatic and/or cycloaliphatic hydrocarbons used to extract the alkyl or alkylaryl diisocyanates from the solution obtained in (a) are mixed with the reaction solvent.
Claim 4
Dependent Claim
34 words
The process according to claim 1, in which the alkyl or alkylaryl diisocyanate is selected from the group consisting of ethylene diisocyanate, hexamethylene diisocyanate, diaryl methane diisocyanate, toluene diisocyanate, cumene diisocyanate and ethylbenzene diisocyanate.
Claim 5
Dependent Claim
13 words
The process according to claim 1, in which the reaction solvent is acetonitrile.
Claim 6
Dependent Claim
31 words
The process according to claim 1, in which the aliphatic diol is selected from the group consisting of ethylene gycol, propylene glycol, diethylene glycol, dipropylene diol, butane diol and hexane diol.
Claim 7
Dependent Claim
23 words
The process according to claim 1, in which the triol is selected from the group consisting of glycerol, butanetriol, hexanetriol, trimethylolethane and trimethylolpropane.
Claim 8
Dependent Claim
24 words
The process according to claim 1, in which the polyhydric alcohol is selected from the group consisting of pentaerytriol, diglycerol, triglycerol, sorbitol and mannitol.
References Cited (Backward Citations)
US3804844A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |