发明名称 |
Method for producing polylactic acid and apparatus used therefor |
摘要 |
<p>A method for producing a polylactic acid includes the steps of (a) crystallizing polylactic acid pellets obtainable by direct polymerization of lactic acid or ring-opening polymerization of lactide; and (b) removing low-molecular components having a weight-average molecular weight of 1,000 or less in the resulting crystallized, solid polylactic acid pellets by gasifying the low-molecular components to obtain polylactic acids with substantially no low-molecular components. In this method, an apparatus for removing low-molecular components in polylactic acid pellets includes a crystallizing means for maintaining a temperature between equal to or higher than a glass transition temperature of polylactic acid pellets and equal to or lower than the melting point thereof, while fluidizing the polylactic acid pellets; and a reactor for allowing a heated inert gas and/or heated air to pass through the resulting crystallized, solid polylactic acid pellets obtained by the crystallizing means.</p> |
申请公布号 |
EP0755956(A3) |
申请公布日期 |
1997.10.01 |
申请号 |
EP19960110853 |
申请日期 |
1996.07.04 |
申请人 |
SHIMADZU CORPORATION |
发明人 |
OHARA, HITOMI;SAWA, SEIJI;FUJII, YASUHIRO;ITO, MASAHIRO;OOTA, MASAAKI |
分类号 |
C08G63/88;C08G63/90;(IPC1-7):C08G63/88 |
主分类号 |
C08G63/88 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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