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AssigneesTianjin University, China Petro-Chemical Corporation
InventorsMinhua Zhang, Zongzhang Liu, Shenbo Yu, Shenghua Qian, Chuanzhao Li
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A process for producing high-quality polycarbonate grade bisphenol A directly by removing phenol from the adduct crystal of bisphenol A with phenol via a gas-solid reaction at low temperature comprises directly feeding the adduct crystal into a vacuum or pneumatic dephenolizing device under vacuum a inert gas stream, controlling the temperature of the adduct crystal below its melting point, decomposing the adduct crystal into gas phase and solid phase, removing the gas phase phenol and condensing phenol for recovery, well leaving the rest being the desirable bisphenol A. The process possesses easy operation, short procedure, low energy consumption, and high purity and good color of bisphenol A obtained. Bisphenol A produced according to the process of the invention may be used as the raw material for producing polycarbonates for optical use.
A process for the production of high-quality polycarbonate grade bisphenol A by removing phenol from an adduct crystal of phenol with bisphenol A comprising the steps of directly feeding the adduct crystal of phenol with bisphenol A into a vacuum or pneumatic dephenolizing device under a vacuum or in an inert gas stream, controlling the temperature of the adduct crystal below its melting point, and decomposing the adduct crystal to a gas phase and a solid phase, wherein phenol which is removed from the dephenolizing device by the vacuum or inert gas stream is condensed for recovery and is reused, and wherein solid phase high-quality polycarbonate grade bisphenol A is obtained directly from the dephenolizing device.
Dependencies are inferred from the claim text.