Polycarbonate production method, dihydroxy compound recovery method, and polycarbonate production apparatus
AssigneeAsahi Kasei Kabushiki Kaisha
InventorFuminori HAYASHI
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Abstract
A method for producing a polycarbonate, comprising a polymerization step of polymerizing a dihydroxy compound and a diaryl carbonate, or a prepolymer thereof in a polymerization reactor, a washing step of contacting a discharged vapor containing the hydroxyaryl compound, the diaryl carbonate and the dihydroxy compound, discharged from the polymerization reactor in the polymerization step, with a washing liquid in a scrubber, and a condensation step of condensing the discharged vapor washed in the washing step, wherein at least a portion of a bottom liquid of the scrubber in the washing step is supplied to the polymerization reactor.
Claims13
A method for producing a polycarbonate, comprising
- a polymerization step of polymerizing a dihydroxy compound and a diaryl carbonate, or a prepolymer thereof in a polymerization reactor,
- a washing step of contacting a discharged vapor containing the hydroxyaryl compound, the diaryl carbonate and the dihydroxy compound, discharged from the polymerization reactor in the polymerization step, with a washing liquid in a scrubber, and
- a condensation step of condensing the discharged vapor washed in the washing step, wherein
- at least a portion of a bottom liquid of the scrubber in the washing step is supplied to the polymerization reactor.
A method for recovering a dihydroxy compound, comprising
- a washing step of contacting a discharged vapor containing a hydroxyaryl compound, a diaryl carbonate and a dihydroxy compound, discharged from a polymerization reactor that polymerizes the dihydroxy compound and the diaryl carbonate, or any prepolymer thereof, with a washing liquid in a scrubber, and
- a condensation step of condensing the discharged vapor washed in the washing step.
An apparatus for producing a polycarbonate, comprising
- a polymerization reactor that polymerizes a dihydroxy compound and a diaryl carbonate, or a prepolymer thereof,
- a scrubber that brings a discharged vapor containing a hydroxyaryl compound, a diaryl carbonate and a dihydroxy compound, discharged from the polymerization reactor, into contact with a washing liquid, and
- a condenser that condenses the discharged vapor washed by the scrubber, and
- a supply path that allows at least a portion of a bottom liquid of the scrubber to be supplied to the polymerization reactor.
Dependencies are inferred from the claim text.