| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a lactide recovery apparatus which can thermally decompose polylactic acid or a thermoplastic resin containing polylactic acid to inhibit the lacemization of the produced lactide, thereby increasing the recovery of the lactide. <P>SOLUTION: A plasticization zone 4, a first decomposition zone 6a, a first seal portion 5a, a first pressure-reducing zone 7a, a second seal portion 5b, a second decomposition zone 6b, a second pressure-reducing zone 7b, a third seal portion 5c, a third decomposition zone 6c, and a third pressure-reducing zone 7c are sequentially arranged from a supply port 2-disposed upstream side to a die 21-disposed downstream side in a twin-screw extruder E in whose cylinder 1 two screws are disposed. A first vent port 17a of the first pressure-reducing zone 7a, a second vent port 17b of the second pressure-reducing zone 7b, and a third vent port 17c of the third pressure-reducing zone 7c are communicated with a cooling trap 9 through piping 8, and can be converted into a pressure-reduced state with a vacuum pump 13. The length of the first decomposition zone 6a is not smaller than three times and less than ten times the official diameter of the screw. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
