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US 5,786,440 AGranted
Mixtures of cyclic oligocarbonates and their manufacture
AssigneeBayer Aktiengesellschaft
InventorsBurkhard Kohler, Duane B. Priddy, Jr., Yun Chen, Harald Pielartzik, Robert-Joseph Kumpf
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Abstract
A process for the manufacture of cyclic oligocarbonate is disclosed. The process comprises a reaction of a bis-chlorocarbonic acid ester with isatinbisphenol or with a bis-chlorocarbonic ester thereof. The mixture of cyclic oligocarbonates thus prepared is useful as a precursor in the preparation of modified polycarbonate or polyester resins.
Claims7
A process for the manufacture of cyclic oligocarbonate comprising a reaction of
- (a) bis-chlorocarbonic acid ester of the formula ##STR6## where Ar is a C.sub.6-30 -difunctional aromatic residue of a dihydroxy compound and w is an integer of 1 to 4, with
- (b) isatinbisphenols of the formula ##STR7## or with a bis-chlorocarbonic ester of said isatinbisphenol, where R.sub.1, R.sub.2, R.sub.3, and R.sub.4 independently denote hydrogen, halogen or a C.sub.1-4 -alkyl group.
Dependencies are inferred from the claim text.