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Method for preparing medical high-purity lactide

A lactide and high-purity technology, applied in directions such as organic chemistry, can solve problems such as the drop in the yield of the lactide product, the inability to separate impurities, and the purity of the lactide cannot meet the requirements, and the effect of simple and environmentally friendly method is achieved.

Active Publication Date: 2014-06-25
上海绿色盛世生态材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] 1) Chinese patent applications 91103421.8, 200710135532.6 and 200710302479.4 all use solvents in the process of purifying lactide, which has environmental protection and safety problems;
[0015] 2) Chinese patent applications 01815139.6, 94112795.8, 200710302479.4 and 200910234132.X all use water extraction or water washing to purify lactide. Lactide is sensitive to water (especially under certain temperature conditions) and is prone to hydrolysis to generate lactic acid Dimer or lactic acid impurities, so water also hydrolyzes lactide while dissolving and separating lactic acid or lactic acid oligomers, resulting in a decrease in the yield of lactide products and inability to separate impurities;
[0016] 3) U.S. patents US5521278 and US6326458 mentioned melting crystallization and rectification process to purify lactide, the acid value of the obtained lactide can reach within 10meq / kg, and the number average molecular weight of the polylactic acid obtained by polymerization is between 50,000 and 100,000 , can meet the requirements of general-purpose polylactic acid, but the purity of lactide in the medical field is still not up to the requirements. Within 1meq / kg

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] 1. The raw material is crude L-lactide with a purity of 92.50%wt. Other ingredients include: 5.74%wt lactic acid, 0.84%wt meso-lactide, 0.2%wt D-lactide, 0.15%wt moisture, low lactic acid Polymer 0.57%wt.

[0042] 2. The preparation process of high-purity lactide is:

[0043] 1) Crude lactide raw material melting: 500kg of crude L-lactide raw material is placed in a storage tank, which is equipped with a nitrogen system to ensure that the material is in a constant pressure 0.15MPa nitrogen protection state; the temperature of the storage tank is kept at 105°C Crude L-lactide raw material is melted.

[0044] 2) Primary molecular distillation: The molten crude L-lactide raw material is continuously injected into the primary molecular distillation device through a pump, and the distillation is carried out at 80Pa and 90°C to separate the remaining light components in the crude L-lactide raw material components (including lactic acid, meso-lactide and moisture).

[0045]...

Embodiment 2

[0048] 1, raw material is with embodiment 1.

[0049] 2. The preparation process of high-purity lactide is:

[0050] 1) Crude lactide raw material melting: 500kg of crude L-lactide raw material is placed in a storage tank, which is equipped with a nitrogen system to ensure that the material is in a constant pressure 0.12MPa nitrogen protection state; the temperature of the storage tank is kept at 105°C Crude L-lactide raw material is melted.

[0051] 2) Primary molecular distillation: The molten crude L-lactide raw material is continuously injected into the primary molecular distillation device through a pump, and the distillation is carried out at 60Pa and 90°C to separate the residual light components in the crude L-lactide raw material components (including lactic acid, meso-lactide and moisture).

[0052] 3) Secondary molecular distillation: the crude L-lactide raw material from the primary molecular distillation is continuously injected into the secondary molecular dist...

Embodiment 3

[0055] 1, raw material is with embodiment 1.

[0056] 2. The preparation process of high-purity lactide is:

[0057] 1) Crude lactide raw material melting: 500kg of crude L-lactide raw material is placed in a storage tank, which is equipped with a nitrogen system to ensure that the material is in a constant pressure 0.18MPa nitrogen protection state; the temperature of the storage tank is kept at 105°C Crude L-lactide raw material is melted.

[0058] 2) Primary molecular distillation: The molten crude L-lactide raw material is continuously injected into the primary molecular distillation device through a pump, and the distillation is carried out at 60Pa and 100°C to separate the remaining light components in the crude L-lactide raw material components (including lactic acid, meso-lactide and moisture).

[0059] 3) Secondary molecular distillation: the crude L-lactide raw material from the primary molecular distillation is continuously injected into the secondary molecular di...

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Abstract

The invention relates to a method for preparing medical high-purity lactide. The method includes steps of fusion of crude lactide, primary molecular distillation and secondary molecular distillation. The method provided can realize continuous operation, is free of solvent, simple and environment-friendly in the whole purification process and can be used for preparation of medical high-purity lactide.

Description

technical field [0001] The invention relates to the field of fine chemicals, in particular to a method for preparing high-purity medical lactide. Background technique [0002] Polylactic acid is a polymer resin produced from lactic acid obtained from starch-based crops fermented by modern biotechnology, and then undergoes a special polymerization reaction. Polylactic acid has good biocompatibility and degradability, can be completely degraded by microorganisms in nature after use, and can be slowly absorbed and metabolized by the human body after implantation. [0003] Due to its good biocompatibility, biodegradability and non-toxic properties, polylactic acid can be used in medicine as surgical sutures, bone repair materials, drug controlled release materials, artificial bones, artificial skin, Ophthalmic implant materials, etc. At present, some polylactic acid products in developed countries such as the United States, the European Union, and Japan have passed clinical tr...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D319/12
Inventor 王竹梅王伟王威朱士燕
Owner 上海绿色盛世生态材料有限公司