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US 5,859,172 AGranted
Polycarbonate, copolycarbonate resin compositions and preparing method thereof
AssigneeGeneral Electric Company
InventorsTakeshi Sakashita, Tomoaki Shimoda, Takashi Nagai
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Abstract
A copolycarbonate and a copolycarbonate composition having oustanding hardness and a method for their manufacture. A copolycarbonate containing the component units shown in Formula I!below in the amount of 50-99 mole %: ##STR1## X is ##STR2## R1 and R2 are hydrogen atoms or monovalent hydrocarbon groups, and R3 is a bivalent hydrocarbon group.) The Rockwell hardness (M scale) of this polycarbonate should preferably be 45-90.
Claims7
A method for manufacturing a copolycarbonate composition, comprising:
- melt polycondensing (A) an aromatic dihydroxy compound mixture of two or more kinds of aromatic dihydroxy compounds, said mixture comprising in the amount of 50-99 mole % the aromatic dihydroxy compound shown in Formula II below ##STR9## wherein X is ##STR10## wherein R.sup.1 and R.sup.2 are hydrogen atoms or monovalent hydrocarbon groups, and R.sup.3 is a bivalent hydrocarbon group, and (B) a carbonic acid diester in the presence of a catalyst, thereby forming a carbonate;
- comprising an alkali metal compound or alkaline earth metal compound,
- adding both an acidic compound and an epoxy compound to the carbonate, and treating the composition under reduced pressure.
Dependencies are inferred from the claim text.