US4816548A
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Cyclic polycarbonate oligomers: inhibition and control of polymerization to linear polycarbonates
Assignee: Cyclics Corp
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Filing: 1987-08-24
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Granted: 1989-03-28
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Expires: 2007-08-24
Abstract
Abstract Lewis acids such as triphenyl borate, triphenylborane and aluminum isopropoxide are employed to inhibit or control the formation of linear polycarbonates from cyclic polycarbonate oligomers. Inhibition of polymerization initiated by impurities in the cyclics is noted. When polymerization is effected by basic polycarbonate formation catalysts, the Lewis acids can act as reaction rate accelerators or inhibitors depending on reaction parameters.
Inventors
- 👤 Thomas L. Evans
- 👤 Carol B. Berman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:51
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/30
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
66 words
A method for stabilizing a composition consisting essentially of cyclic polycarbonate oligomers which comprises incorporating therein about 0.1-0.5 mole percent, based on structural units in said oligomer composition, of a Lewis acid of the formula ##STR4## wherein Z is boron or aluminum and each of R 1 , R 2 and R 3 is a hydrocarbon or hydrocarbonoxy radical containing up to about 10 carbon atoms.
Claim 2
Independent Claim
66 words
A method for stabilizing a composition consisting essentially of cyclic polycarbonate oligomers which comprises incorporating therein about 0.1-0.5 mole percent, based on structural units in said oligomer composition, of a Lewis acid of the formula ##STR4## wherein Z is boron or aluminum and each of R 1 , R 2 and R 3 is a hydrocarbon or hydrocarbonoxy radical containing up to about 10 carbon atoms.
Claim 3
Dependent Claim
47 words
A method according to claim 1 wherein the cyclic polycarbonate oligomer composition comprises structural units having the formula ##STR5## wherein at least about 60% of the total number of R 4 avlues are aromatic organic radicals and the balance thereof are aliphatic, alicyclic or aromatic organic radicals.
Claim 4
Dependent Claim
52 words
A method according to claim 2 wherein each R 4 value has the formula --A.sup.1 --Y--A.sup.2 --, (III) wherein each of A 1 and A 2 is a monocyclic divalent aromatic radical and Y is a bridging radical in which one or two carbon atoms separate A 1 from A 2 .
Claim 5
Dependent Claim
23 words
A method according to claim 3 wherein Z is boron and each of R 1 , R 2 and R 3 is aromatic.
Claim 6
Dependent Claim
34 words
A method according to claim 4 wherein each of R 1 , R 2 and R 3 is phenyl or phenoxy, each of A 1 and A 2 is p-phenylene and Y is isopropylidene.
Claim 7
Dependent Claim
59 words
A composition comprising at least one cyclic polycarbonate oligomer and about 0.005-5.0 mole percent, based on structural units in said oligomer, of a Lewis acid of the formula ##STR6## wherein Z is boron or aluminum and each of R 1 , R 2 and R 3 is a hydrocarbon or hydrocarbonoxy radical containing up to about 10 carbon atoms.
Claim 8
Dependent Claim
59 words
A composition comprising at least one cyclic polycarbonate oligomer and about 0.005-5.0 mole percent, based on structural units in said oligomer, of a Lewis acid of the formula ##STR6## wherein Z is boron or aluminum and each of R 1 , R 2 and R 3 is a hydrocarbon or hydrocarbonoxy radical containing up to about 10 carbon atoms.
Claim 9
Dependent Claim
46 words
A composition according to claim 6 wherein the cyclic polycarbonate oligomer comprises structural units having the formula ##STR7## wherein at least about 60% of the total number of R 4 values are aromatic organic radicals and the balance thereof are aliphatic, alicyclic or aromatic organic radicals.
Claim 10
Dependent Claim
51 words
A composition according to claim 7 wherein each R 4 value has the formula --A.sup.1 --Y--A.sup.2 --, (III) wherein each of A 1 and A 2 is a monocyclic divalent aromatic radical and Y is a bridging radical in which one or two atoms separate A 1 from A 2 .
Claim 11
Dependent Claim
23 words
A composition according to claim 8 wherein Z is boron and each of R 1 , R 2 and R 3 is aromatic.
Claim 12
Dependent Claim
34 words
A composition according to claim 9 wherein each of R 1 , R 2 and R 3 is phenyl or phenoxy, each of A 1 and A 2 is p-phenylene and Y is isopropylidene.
References Cited (Backward Citations)
US4746726A
Cited
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