Mfg, Method of cyclic diester using fermented lactic acid as raw materila and method for mfg, polylacgtic acid

A manufacturing method and lactate technology are applied in the field of manufacturing polylactic acid and ammonium lactate to manufacture lactate, which can solve the problems of slow reaction and low yield, and achieve the effect of less investment, investment and economy.

Inactive Publication Date: 2005-03-23
UNITIKA LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0021] In the case of reacting ammonium lactate and ethanol to produce ethyl lactate, there is a problem of low yield, and the boiling point of ethanol under normal pressure is low, 78°C, so there is a problem of slow reaction
[0022] When producing lactate by reacting a hydrophobic alcohol such as butanol with ammonium lactate, even if water is removed by a separator, there is a problem that the yield is as low as about 50%.

Method used

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  • Mfg, Method of cyclic diester using fermented lactic acid as raw materila and method for mfg, polylacgtic acid
  • Mfg, Method of cyclic diester using fermented lactic acid as raw materila and method for mfg, polylacgtic acid
  • Mfg, Method of cyclic diester using fermented lactic acid as raw materila and method for mfg, polylacgtic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0080] (1) Esterification and deamination process

[0081] In a flask with a volume of 1000ml with a stirrer, a cooling tube and a thermometer, 472g of L-ammonium lactate aqueous solution (68%) and 500g of ethanol are charged into a flask made by fermentation, the temperature of the reaction solution is maintained at 90-100°C, and the ethanol is refluxed For 3 hours, esterification proceeded. The ammonia that is not collected by the cooling pipe is recovered through the gas washing cylinder that is installed at the front of the cooling pipe and filled with ice water. Ammonia recovery was 98%.

[0082] (2) Removal of unreacted ethanol

[0083] The temperature of the reaction liquid obtained in (1) was kept at 80° C., and 360 g of unreacted ethanol was distilled off (recovered). Next, the temperature of the reaction liquid was raised to 120° C., and 150 g of water in the reaction liquid was distilled off.

[0084] (3) Refining process of ethyl lactate

[0085] The reaction ...

Embodiment 2

[0093] (1) Esterification and deamination process, (2) Unreacted ethanol removal process, (3) Ethyl lactate purification process were carried out exactly like Example 1.

[0094] (4) Ethyl lactate polycondensation process

[0095] In a 500ml flask with a stirrer, a reflux tube and a thermometer, 236g of the refined L-lactate obtained in (3) is charged, and the liquid temperature is raised to 160°C from 135°C in stages, and the pressure is changed from normal pressure Slowly depressurize for 3 hours to 5mmHg. During this period, L-lactic acid ethyl ester and the L-lactic acid oligomer produced by the polycondensation of L-ethyl lactate are refluxed in the flask, and in order to take the generated ethanol out of the system, the temperature of the cooling water in the reflux pipe is divided. Rise from 10°C to 60°C step by step. At this time, 91 g of ethanol produced was collected in a cold tank provided at the front of the return pipe. The weight-average molecular weight of th...

Embodiment 3

[0101] (1) Esterification and deamination process, (2) Unreacted ethanol removal process, (3) Ethyl lactate purification process were carried out exactly like Example 1.

[0102] (4) Ethyl lactate polycondensation process

[0103] In a 500ml flask with a stirrer, a reflux tube and a thermometer, 236g of refined L-lactate (optical purity 99.7%) obtained in (3) is charged, and the liquid temperature is gradually increased from 135°C under normal pressure. Rise to 220°C, during which L-lactic acid ethyl ester and L-lactic acid oligomers generated by the polycondensation of L-ethyl lactate are refluxed in the flask, and in order to take the generated ethanol out of the system, the reflux tube The cooling water temperature is set at 85°C.

[0104] Next, the pressure was gradually reduced from normal pressure to 5 mmHg for 3 hours. During this time, the L-lactic acid oligomer produced by the polycondensation of L-ethyl lactate was refluxed in the flask, and in order to take out th...

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Abstract

According to the present invention, a process for consistently producing lactide from ammonium lactate obtained by lactic fermentation, and a process for consistently producing polylactic acid from ammonium lactate obtained by lactic fermentation, are provided. A process for producing lactide, which comprises the steps of: (1) synthesizing lactate ester from ammonium lactate obtained by lactic fermentation; (2) polycondensing the lactate ester in the presence of a catalyst other than monobutyltin, whereby polylactic acid with a weight-average molecular weight of less than 15,000 (lactic acid prepolymer) is synthesized; and (3) depolymerizing the polylactic, whereby lactide is produced. A process for producing polylactic acid, which comprises the additional step of (4) ring-opening polymerizing said lactide, whereby polylactic acid is obtained. A process for producing lactate ester from ammonium lactate obtained by lactic fermentation.

Description

technical field [0001] The present invention relates to a method for producing lactide using fermented lactic acid as a raw material, a method for producing polylactic acid, a method for producing lactide from ammonium lactate obtained by fermentation of lactic acid, and a method for producing polylactic acid. Furthermore, the present invention relates to a method for producing lactate from ammonium lactate obtained by fermenting lactic acid. [0002] Lactic acid includes L-lactic acid, D-lactic acid, and a mixture of L-lactic acid and D lactic acid. Lactide is a cyclic dimer of lactic acid and is particularly useful as a raw material for polylactic acid production. The so-called polylactic acid is a polymer mainly composed of monomers constituting lactic acid, not only a single polymer, but also a copolymer with other monomers. Polylactic acid can be used as a biodegradable plastic made from biomass. Background technique [0003] Hitherto, polylactic acid has been produc...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D319/12
CPCC07D319/12C08G63/08C08G63/785C12P7/56C08G63/78
Inventor 小原仁实伊藤正博泽诚治
Owner UNITIKA LTD
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