Process for manufacturing an improved acrylonitrile polymer melt
AssigneeJapan Exlan Company Limited
InventorsHirotaka Shiota, Ryosuke Nishida, Takahisa Kida, Noriyuki Kohara, Yoshihiro Watanabe, Ryuichi Kasahara
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Abstract
Saturated or superheated steam, or an inert gas, or a combination thereof is introduced into a gas phase above a molten acrylonitrile polymer in a vessel having a stirrer, while the polymer has a temperature of at least 120.degree. C. and a pressure at least equal to its autogenous pressure. Any unreacted acrylonitrile monomer, or both any such monomer and any acrylonitrile monomer or water used as a plasticizer are removed by evaporation from the vessel.
Claims6
In a process for manufacturing an improved acrylonitrile polymer melt from a starting melt comprising the polymer, water and an acrylonitrile monomer, the melt having a temperature of at least 120.degree. C. and a pressure at least equal to its autogenous pressure, and containing a plasticizer selected from the group consisting of a mainly acrylonitrile monomer and water, the improvement which comprises:
- introducing a gaseous medium into a gas phase in a vessel holding said starting melt, said medium being selected from the group consisting of saturated steam, superheated steam and an inert gas, while maintaining said temperature of at least 120.degree. C. and said pressure at least equal to the autogenous pressure of the melt in said vessel, whereby at least an unreacted acrylonitrile monomer is removed from said melt.
Dependencies are inferred from the claim text.