Filter alignment in a polycarbonate production process
AssigneeSabic Global Technologies B.V.
InventorsIgnacio Vic Fernandez, William E. Hollar, Jr., Donald E. Owens, III
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Abstract
In an embodiment, a polycarbonate polymerization process comprises interfacially polymerizing a carbonate compound and dihydroxy compound in the presence of an interfacial catalyst to form a polycarbonate and adding a viscosity reducing agent and a transesterification catalyst to polycarbonate upstream of a first filter to form an adjusted polycarbonate. The first filter can be replaced with a replacement filter and the adjusted polycarbonate can be introduced to the replacement filter. The flow can be diverted to a replacement filter. The process further comprises reducing the addition rate of the viscosity reducing agent and the transesterification catalyst until the addition rate is 0 mol/hr.
Claims16
A method of switching filters in a polycarbonate polymerization process, comprising:
- interfacially polymerizing phosgene and a dihydroxy compound in the presence of a solvent, a chain stopper, and an interfacial catalyst to form a polycarbonate;
- temporarily adding a viscosity reducing agent and a transesterification catalyst to the polycarbonate upstream of a first filter to form an adjusted polycarbonate;
- replacing the first filter with a replacement filter;
- introducing the adjusted polycarbonate to the replacement filter;
- and
- reducing the addition rate of the viscosity reducing agent and the transesterification catalyst until the addition rate is 0 mol/hr.
A method of switching filters in a polycarbonate polymerization process, comprising:
- interfacially polymerizing phosgene and dihydroxy compound in the presence of a solvent, a chain stopper, and an interfacial catalyst to form a polycarbonate;
- temporarily adding a viscosity reducing agent and a transesterification catalyst to the polycarbonate upstream of a first filter to form an adjusted polycarbonate;
- diverting the flow of the adjusted polycarbonate to a replacement filter;
- and
- reducing the addition rate of the viscosity reducing agent and the transesterification catalyst until the addition rate is 0 mol/hr.
Dependencies are inferred from the claim text.