US4616077A
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Method for preparing cyclic polycarbonate oligomer from bischloroformate composition
Assignee: Cyclics Corp
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Filing: 1985-11-22
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Granted: 1986-10-07
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Expires: 2005-11-22
Abstract
Abstract Cyclic polycarbonate oligomers are prepared by a method which is adaptable to continuous operation, by the reaction of a bisphenol bischloroformate (e.g., bisphenol A bischloroformate) with an amine (e.g., triethylamine) and an alkali metal hydroxide in a tank reactor (preferably a continuous stirred tank reactor) in a mixed aqueous-organic system, with agitation (preferably by stirring) at a rate just sufficient to prevent segregation of the aqueous and organic liquid phases. The residence time of the mixture in the reactor is preferably about 8-12 minutes.
Inventors
- 👤 James M. Silva
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:39
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/26; C07; C07C; C07C68/00; C07C68/02; C08G64/04; C08G64/06
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
156 words
A method for preparing a composition comprising cyclic polycarbonate oligomers characterized by structural units of the formula ##STR3## where R is a divalent aromatic radical, which comprises: simultaneously charging the following to a tank reactor: (A) a bischloroformate composition consisting essentially of bischloroformates of the formula ##STR4## wherein n is at most 3 in a major proportion of said bischloroformates; (B) at least one aliphatic or heterocyclic tertiary amine which dissolves preferentially in the organic phase of the reaction mixture; (C) an aqueous alkali metal hydroxide solution; and (D) a substantially non-polar organic liquid which forms a two-phase system with water; reagent A being charged separately from reagents B and C: while maintaining the reaction mixture in said tank reactor under agitation conditions just sufficient to prevent segregation of the aqueous and organic liquid phases; allowing said reagents to react for a period of time sufficient to form the desired cyclic oligomers; and recovering said oligomers.
Claim 2
Independent Claim
156 words
A method for preparing a composition comprising cyclic polycarbonate oligomers characterized by structural units of the formula ##STR3## where R is a divalent aromatic radical, which comprises: simultaneously charging the following to a tank reactor: (A) a bischloroformate composition consisting essentially of bischloroformates of the formula ##STR4## wherein n is at most 3 in a major proportion of said bischloroformates; (B) at least one aliphatic or heterocyclic tertiary amine which dissolves preferentially in the organic phase of the reaction mixture; (C) an aqueous alkali metal hydroxide solution; and (D) a substantially non-polar organic liquid which forms a two-phase system with water; reagent A being charged separately from reagents B and C: while maintaining the reaction mixture in said tank reactor under agitation conditions just sufficient to prevent segregation of the aqueous and organic liquid phases; allowing said reagents to react for a period of time sufficient to form the desired cyclic oligomers; and recovering said oligomers.
Claim 3
Dependent Claim
48 words
A method according to claim 1 wherein R has the formula --A.sup.1 --Y--A.sup.2 --, (III) wherein each of A 1 and A 2 is a single-ring divalent aromatic radical and Y is a bridging radical in which one or two atoms separate A 1 from A 2 .
Claim 4
Dependent Claim
18 words
A method according to claim 2 wherein the reaction temperature is in the range of about 20°-50° C.
Claim 5
Dependent Claim
26 words
A method according to claim 3 wherein reagents A, B, C and D are introduced under the surface of the reaction mixture in the tank reactor.
Claim 6
Dependent Claim
21 words
A method according to claim 4 wherein the reactor is a continuous stirred tank reactor and the reaction is conducted continuously.
Claim 7
Dependent Claim
11 words
A method according to claim 5 wherein reagent B is triethylamine.
Claim 8
Dependent Claim
14 words
A method according to claim 6 wherein reagent C is a sodium hydroxide solution.
Claim 9
Dependent Claim
12 words
A method according to claim 7 wherein reagent D is methylene chloride.
Claim 10
Dependent Claim
18 words
A method according to claim 8 wherein the reaction temperature is in the range of about 25°-39° C.
Claim 11
Dependent Claim
20 words
A method according to claim 9 wherein each of A 1 and A 2 is p-phenylene and Y is isopropylidene.
Claim 12
Dependent Claim
26 words
A method according to claim 10 wherein reagent A is a crude bischloroformate product comprising a major proportion of bischloroformates containing up to 4 structural units.
Claim 13
Dependent Claim
22 words
A method according to claim 11 wherein the residence time of the reaction mixture is in the range of about 8-16 minutes.
Claim 14
Dependent Claim
22 words
A method according to claim 12 wherein the ratio of equivalents of B to A is in the range of about 0.15-4.0:1.
Claim 15
Dependent Claim
30 words
A method according to claim 13 wherein the concentration of reagent B is in the range of about 0.07-0.20 mole per liter of total reagent D in the reaction mixture.
Claim 16
Dependent Claim
22 words
A method according to claim 14 wherein the ratio of equivalents of C to A is in the range of about 1.9-3.0:1.
Claim 17
Dependent Claim
22 words
A method according to claim 15 wherein the volume ratio of aqueous to organic phase is in the range of about 0.1-3.0:1.
References Cited (Backward Citations)
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