Back to results
US 2016/0237210 A1Published application
Process to prepare high heat polycarbonates
AssigneeSabic Global Technologies B.V.
InventorsJames Alan Mahood, Pankaj Singh Gautam
Life of this patent
Estimating the term…
Abstract
A catalyzed interfacial phosgenation process with controlled feed ratios and controlled reaction pH levels allows for the formation of high heat polycarbonate random copolymers having high loadings of bis (4-hydroxyphenyl)-2-phenylisoindolin-1-one (“PPPBP”) or a structurally related comonomer. The process produces a polycarbonate copolymer having improved hydrolytic stability.
Claims20
A method for preparing polycarbonate copolymer by an interfacial method, comprising
- phosgenating a mixture comprising an aromatic dihydroxy compound, water, an organic solvent substantially immiscible with water, and a condensation catalyst to form a reaction mixture;
- cofeeding an aqueous high heat comonomer feed to the reaction mixture during the phosgenation step at a ratio of about 1.75 to about 9 high heat comonomer/phosgene weight/weight dry basis;
- and
- maintaining the pH of the reaction mixture during the phosgenation step at greater than 7 to less than 11,
- to form a polycarbonate copolymer comprising greater than about 30 mole % structural units derived from the high heat comonomer.
2 more elements
Dependencies are inferred from the claim text.