US4423205A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cationic polymerization of cyclic carbonates
Assignee: Ethyl Corp
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Filing: 1982-05-24
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Granted: 1983-12-27
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Expires: 2002-05-24
Abstract
Abstract A process for the production of a polycarbonate glycol wherein a cyclic carbonate is catalyzed at elevated temperature by a cationic initiator. Compounds of structure (I) ##STR1## where R is alkylene, R' and R" are independently hydrogen, alkyl, alkaryl, aralkyl, or aryl, are heated at an elevated temperature in the presence of cationic initiators such as trimethyl aluminum to form a polymer. Production of a glycol product is assured by subsequent heating at about 200°-220° C. to form a polymer containing carbonate units of ##STR2## and having hydroxy end units bonded to a carbon not part of a carbonate function. The molecular weight of polycarbonate glycol is preferably at least about 1,000.
Inventors
- 👤 Sundar J. Rajan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:19
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/30
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
27 words
A process for the production of a polycarbonate glycol, said process comprising heating a cyclic carbonate in the presence of a catalytic amount of a cationic initiator.
Claim 2
Dependent Claim
27 words
A process for the production of a polycarbonate glycol, said process comprising heating a cyclic carbonate in the presence of a catalytic amount of a cationic initiator.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein said cationic initiator is a member selected from the group consisting of Lewis Acids, aluminum alkyls, boron halides, and aluminum alkyl halides.
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein said member is an aluminum alkyl.
Claim 5
Dependent Claim
12 words
The process of claim 3 wherein said aluminum alkyl is trimethyl aluminum.
Claim 6
Dependent Claim
12 words
The process of claim 3 wherein said aluminum alkyl is triethyl aluminum.
Claim 7
Dependent Claim
15 words
The process of claim 1 wherein the polymerization is carried out at least 50°-250° C.
Claim 8
Dependent Claim
15 words
The process of claim 6 wherein said process is carried out at about 150°-200° C.
Claim 9
Dependent Claim
15 words
The process of claim 1 wherein the polymerization is carried out in an organic solvent.
Claim 10
Dependent Claim
12 words
The process of claim 8 wherein said solvent is hexane or xylene.
Claim 11
Dependent Claim
19 words
The process of claim 1 further comprising the subsequent step of heating the polymerized product at about 200°-220° C.
Claim 12
Dependent Claim
54 words
A process for the production of a polycarbonate glycol containing units of ##STR17## said process comprising heating a cyclic carbonate of structure I: ##STR18## in the presence of a cationic initiator, where R is an alkylene group of 2 or more carbons, and R' and R" are independently hydrogen, alkyl, alkaryl, aralkyl, or aryl.
Claim 13
Dependent Claim
54 words
A process for the production of a polycarbonate glycol containing units of ##STR17## said process comprising heating a cyclic carbonate of structure I: ##STR18## in the presence of a cationic initiator, where R is an alkylene group of 2 or more carbons, and R' and R" are independently hydrogen, alkyl, alkaryl, aralkyl, or aryl.
Claim 14
Dependent Claim
15 words
The process of claim 11 wherein the cyclic carbonate is 1,3-dioxan-2-one of structure II: ##STR19##
Claim 15
Dependent Claim
12 words
The process of claim 12 wherein the cyclic carbonate is 5,5-dimethyl-1,3-dioxan-2-one ##STR20##
Claim 16
Dependent Claim
21 words
The process of claim 11 wherein the cationic initiator is triethyl aluminum and the carbonate is heated at about 135°-200° C.
Claim 17
Dependent Claim
18 words
The process of claim 14 and further comprising subsequently heating the product so formed at about 200°-220° C.
Claim 18
Dependent Claim
11 words
The polycarbonate glycol product formed by the process of claim 11.
Claim 19
Dependent Claim
34 words
The process of claim 1 further comprising the subsequent step of mixing the product from heating the cyclic carbonate with a basic solution and then recovering the polycarbonate glycol from the mixture so formed.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-26 | 1987-06-27 | 1987-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-26 | 1991-06-27 | 1991-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-26 | 1995-06-27 | 1995-12-27 | $7700.00 | Window Closed / Lapsed |