发明授权
- 专利标题: Process for the production of thermoplastic polycarbonates
- 专利标题(中): 用于生产热塑性聚碳酸酯的方法
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申请号: US155309申请日: 1993-11-19
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公开(公告)号: US5373082A公开(公告)日: 1994-12-13
- 发明人: Hermann Kauth , Steffen Kuhling , Wolfgang Alewelt , Dieter Freitag
- 申请人: Hermann Kauth , Steffen Kuhling , Wolfgang Alewelt , Dieter Freitag
- 申请人地址: DEX Leverkusen
- 专利权人: Bayer Aktiengesellschaft
- 当前专利权人: Bayer Aktiengesellschaft
- 当前专利权人地址: DEX Leverkusen
- 优先权: DEX4240314 19921201
- 主分类号: C08G64/20
- IPC分类号: C08G64/20 ; C08G64/30 ; C08G64/40 ; C08G64/42 ; C08J11/28 ; C08K5/00 ; C08L69/00 ; C08G64/00
摘要:
A process for the production of polycarbonates by melt transesterification is disclosed. Accordingly, polycarbonate waste is dissolved in monophenols and at an elevated temperature and in the presence of a catalyst degraded to yield oligocarbonates, diaryl carbonates and diphenols. Following the optional separation of fillers and other additives there is produced by partial recondensation and the distillation of monophenol a higher viscosity oligocarbonate having a OH and aryl carbonate terminal groups and a weight average molecular weight of 8000 to 18000, the oligocarbonate thus produced is then polycondensed to form a polycarbonate resin.
公开/授权文献
- US4290834A Web splicing method 公开/授权日:1981-09-22
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