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Apparatus and method both relating to polymer synthesis

A manufacturing method, ring-opening polymerization technology, applied in the field of lactide manufacturing, can solve problems such as deterioration, wide molecular weight distribution, and reduced crystallinity, and achieve the effect of improving quality and improving utilization efficiency

Inactive Publication Date: 2010-09-29
HITACHI PLANT TECH LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When conveying to the ring-opening polymerization process, there are problems such as mixing lactic acid oligomers with low molecular weight into polylactic acid, widening the molecular weight distribution, and deteriorating the crystallinity of the polymer, etc.

Method used

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  • Apparatus and method both relating to polymer synthesis
  • Apparatus and method both relating to polymer synthesis
  • Apparatus and method both relating to polymer synthesis

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0161] use figure 1 The polylactic acid production apparatus shown is for producing polylactic acid. A lactic acid oligomer having a number average molecular weight of 630 was charged into the depolymerization device 11 as a raw material. The reaction in the depolymerization device 11 is carried out at a temperature of 200° C. under reduced pressure to 10 torr or less. The residence time of the lactic acid oligomer in the depolymerization device 11 is 5 hours, and the liquid film thickness (liquid depth) is 5cm, and catalyst (2-ethylhexanoate tin) concentration is 0.7kg / m 3 .

[0162] The reaction in the catalyst regeneration unit 27 was performed at a temperature of 200° C. under reduced pressure to 10 torr or less.

[0163] The increase in the optical isomerization rate in the depolymerization step was 0.9% (measured before the lactide refining device 15).

[0164] Here, the residence time of the oligomer is defined as the supply flow rate of the molten oligomer / oligomer...

Embodiment 2

[0168] use image 3 The polylactic acid production apparatus shown is for producing polylactic acid.

[0169] A lactic acid oligomer having a number average molecular weight of 630 was charged into the depolymerization device 11 as a raw material. The reaction in the depolymerization device 11 is carried out at a temperature of 200° C. under reduced pressure to 10 torr or less. The residence time of the lactic acid oligomer in the depolymerization device 11 is 5 hours, and the liquid film thickness (liquid depth) is 5cm, and catalyst (2-ethylhexanoate tin) concentration is 0.7kg / m 3 .

[0170] The reaction in the catalyst regeneration unit 27 was performed at a temperature of 200° C. under reduced pressure to 10 torr or less.

[0171] The increase in the optical isomerization rate in the depolymerization step was 0.9% (measured before the lactide refining device 15).

[0172] Here, the residence time of the oligomer is defined as the molten oligomer supply flow rate / low T...

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Abstract

Disclosed is a means for producing lactide efficiently in the production of a poly(lactic acid) by depolymerizing a lactic acid oligomer to produce lactide and ring-opening-polymerizing lactide. Also disclosed is a lactide production apparatus for producing lactide continuously or intermittently, which comprises: a depolymerization unit (11) for depolymerizing a lactic acid oligomer; a catalyst regeneration unit (27) for depolymerizing a residue in the depolymerization unit to reduce the molecular weight of the lactic acid oligomer contained in the residue; and a distillation column (29) for condensing lactide which has been produced in the depolymerization unit in the form of a gas phase.

Description

technical field [0001] The present invention relates to a method and an apparatus for producing lactide, and a method and an apparatus for producing polylactic acid using them. Background technique [0002] Polylactic acid is an aliphatic polyester made from lactic acid. One method of synthesizing polylactic acid is as follows: After concentrating lactic acid to reduce the water content, condensing it to generate lactic acid oligomers, adding a catalyst such as antimony oxide to it and causing primary depolymerization to generate The cyclic dimer (lactide) is subjected to ring-opening polymerization by adding a catalyst such as tin isooctanoate to the lactide after purification such as crystallization if necessary. [0003] In the concentration step, the lactic acid monomer may contain about 10 to 15% of water as an impurity, and since this water tends to cause esterification between monomers, it is necessary to remove this water. In this concentrating step, moisture is re...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D319/12C08G63/08C08L101/16
CPCB01J19/20C08J2367/04B01J2219/00779B01J2219/00083B01J19/1887B01J19/1862C07D319/12C08G63/78C08J11/16B01J2219/00009C08G63/08Y02P20/584Y02W30/62
Inventor 上川将行松尾俊明冈本成恭冈宪一郎矢次贵志藤井康宏川本达司
Owner HITACHI PLANT TECH LTD