Production process of alpha-hydroxy organic acid cyclic ester

A manufacturing method and organic acid technology, applied in the direction of organic chemistry, can solve the problems of difficult process control, increase the complexity of the process, and reduce the temperature in the tank, so as to simplify the separation and purification steps of products, reduce the troubles of separated products, and increase the surface area Effect

Inactive Publication Date: 2007-06-27
CHI MEI CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In U.S. Patent No. 5,091,544, in order to achieve the purpose of rapidly separating lactic acid cyclic esters, the ratio of the carrier gas volume flow rate to the oligomer volume flow rate is as high as 2750:1 (high gas-liquid volume flow ratio). The characteristics of this technology In order to use a large amount of gas to separate the cyclic ester compound from the oligomer, complex equipment is required to separate the cyclic ester compound from the large amount of gas; in addition, using a large amount of carrier gas to enter the reaction tank will reduce the temperature in the tank, and it is easy to cause Flooding, difficult process control
In addition, special equipment is required to disperse the carrier gas into microbubbles, otherwise the microbubbles may condense into large bubbles and lose their function, which also increases the complexity of the process

Method used

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  • Production process of alpha-hydroxy organic acid cyclic ester
  • Production process of alpha-hydroxy organic acid cyclic ester
  • Production process of alpha-hydroxy organic acid cyclic ester

Examples

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Effect test

preparation example 1

[0043] Preparation Example 1: Polymerization of Lactic Acid Oligomers:

[0044] 1000 grams of lactic acid raw material (concentration 88% by weight), which is equivalent to 880 grams of pure lactic acid, is placed in a 2-liter three-port reactor attached to a distillation device, and a small amount of nitrogen is introduced to aerate and the temperature is raised to 170° C. for 2 hours, until no more Until the water was distilled off, a lactic acid oligomer with a molecular weight of 800 was obtained.

preparation example 2

[0045] Preparation Example 2: Polymerization of Glycolic Acid Oligomers:

[0046] Glycolic acid (concentration 70%) 1000 grams and polytetramethylene glycol ether (polytetramethylene ether glycol; Dalian company PTMEG-2000) 1000 grams and antimony trioxide (Sb 2 o 3 ) of 2 grams, placed in a 2-liter three-port reactor attached to a distillation device, dehydrated under nitrogen, the dehydration temperature is 195°C, and the dehydration is until the water droplet distillation speed is very slow, the whole time takes about 2 hours, and the water is released , connected to a vacuum system, and evacuated at 195-200°C until the pressure dropped to 25mmHg, about 2 hours until no water dripped out completely, and the glycolic acid oligomer was obtained with a molecular weight of 2850.

Embodiment 1

[0048]Using the batch method high gravity cracking system shown in Figure 2, the lactic acid oligomers prepared in Preparation Example 1 are added to the liquid circulation tank, and then the lactic acid oligomers are transported in batches by a pump to be heated by a heater. After the lactic acid oligomer in the vessel reaches a temperature of 190°C, most of the lactic acid oligomer is cracked into liquid lactide. Then the liquid mixture of the aforementioned lactic acid oligomer and lactide is sent into the rotating disk of the supergravity device, the rotating speed of the rotating disk is 1300rpm, and the volume flow rate of the aforementioned liquid mixture is 0.35 (L / min); in addition, a carrier gas (nitrogen) Inflow from the entrance of the supergravity device, the volume flow rate of the carrier gas is 35 (L / min), the temperature of the carrier gas is 63°C, the ratio of the volume flow rate of the gas to liquid (the volume flow rate of the carrier gas (L / min) / the volume...

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Abstract

The production process of alpha-hydroxy organic acid cyclic ester is to treat oligomer of alpha-hydroxy organic acid or its ester into alpha-hydroxy organic acid cyclic ester in a hyperravitational apparatus at certain decomposition temperature. The present invention has lowered resistance of decomposing, fast cracking of the oligomer and high yield of alpha-hydroxy organic acid cyclic ester.

Description

technical field [0001] The invention relates to a method for producing cyclic esters of α-hydroxycarboxylic acid compounds, which utilizes a high-gravity device to process the oligomerization of α-hydroxyorganic acids (α-hydroxycarboxylic acid) or esters thereof α-hydroxy organic acid cyclic ester compounds with fast cracking and high yield. Background technique [0002] α-Hydroxy organic acid, for example: lactic acid (Lactic acid referred to as LA) or polymers of its esters, such polymers as polylactic acid (polylactic acid referred to as PLA) or polyglycolic acid (polyglycolic acid referred to as PGA) and their copolymers, etc., These polymers are biodegradable and will be the main products of future environmentally friendly plastics. The production of polylactic acid can be polymerized by lactic acid into lactic acid oligomers, which are cracked into lactic acid cyclic ester compounds, and then polymerized by lactic acid cyclic ester compounds to become high-molecular p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D319/12
Inventor 王天路刘旭峰简龙舜余铧堂姜亨波黄辰宝
Owner CHI MEI CORP
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