Method for purifying alpha,omega-dihydroxy-polydimethylsiloxane

A technology of hydroxypolydimethylsiloxane and purification method, which is applied in the field of silicone rubber raw material preparation, can solve the problems of unsatisfactory removal effect and inability to produce materials, and achieve easy operation, improved performance and quality, and good effect Effect

Active Publication Date: 2011-10-05
MAOMING XINLONG TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this removal effect is usually very unsatisfactory, and a large amount of low molecules still remain, and the low molecular content is still above 5000ppm
Can not be used as a production material for the manufacture of high-quality silicone room temperature vulcanized electronic silicone rubber

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Continuously inject 500kg of 107 rubber material into the thin-film evaporator at a rate of 150g / s, and perform wipe-film evaporation at 170°C and an absolute pressure of 70Pa, and vacuum the evaporated low molecular weight to an external condenser for condensation After forming a liquid, it flows into the recovery tank; the 107 glue treated by the thin-film evaporator is continuously injected into the short-path still at a speed of 150g / s, and distilled at 160°C and an absolute pressure of 40Pa, and the evaporated low-molecular part is absorbed To the external condenser, condensed into a liquid and then flowed into the recovery tank; the other part was condensed into a liquid by the built-in condenser of the short-path distiller and directly flowed into the recovery tank. The purified product was tested, and the residual low molecular content was 70ppm. Compared with the low molecular content before treatment of 11500 ppm, the removal rate was 99.4%.

Embodiment 2

[0027] Continuously inject 500kg of 107 rubber material into the thin-film evaporator at a speed of 150g / s, and carry out wipe-film evaporation at 190°C and an absolute pressure of 60Pa, and vacuum the evaporated low molecular weight to an external condenser for condensation After forming a liquid, it flows into the recovery tank; the 107 glue treated by the thin-film evaporator is continuously injected into the short-path still at a speed of 150g / s, and distilled at 170°C and an absolute pressure of 35Pa, and the evaporated low-molecular part is absorbed To the external condenser, condensed into a liquid and then flowed into the recovery tank; the other part was condensed into a liquid by the built-in condenser of the short-path distiller and directly flowed into the recovery tank. The purified product was tested, and the residual low molecular content was 50ppm. Compared with the low molecular content before treatment, the removal rate is 99.6%.

Embodiment 3

[0029] Continuously inject 500kg of 107 rubber material into the thin-film evaporator at a speed of 150g / s, and carry out wipe-film evaporation at 210°C and an absolute pressure of 60Pa, and vacuum the evaporated low molecular weight to an external condenser for condensation After forming a liquid, it flows into the recovery tank; the 107 glue treated by the thin film evaporator is continuously injected into the short-path still at a speed of 150g / s, and distilled at 200°C and an absolute pressure of 45Pa, and the evaporated low-molecular part is absorbed To the external condenser, condensed into a liquid and then flowed into the recovery tank; the other part was condensed into a liquid by the built-in condenser of the short-path distiller and directly flowed into the recovery tank. The purified product was tested, and the residual low molecular content was 65ppm. Compared with the low molecular content before treatment, the removal rate is 99.4%.

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PUM

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Abstract

The invention discloses a method for purifying alpha,omega-dihydroxy-polydimethylsiloxane, which comprises the following steps: injecting raw material 107 rubber into a film evaporator, and carrying out primary purification at 170-220 DEG C under the absolute pressure of 50-90 Pa; and injecting into a short-range distiller, carrying out secondary purification at 160-200 DEG C under the absolute pressure of 20-50 Pa, thereby obtaining the product. The method disclosed by the invention can effectively eliminate low-molecular polymers in the 107 rubber, and also can recycle the low-molecular polymers. The removal rate of low-molecular polymers in the alpha,omega-dihydroxy-polydimethylsiloxane product treated by the method disclosed by the invention is up to more than 99%; in general cases, the content of low-molecular polymers in the alpha,omega-dihydroxy-polydimethylsiloxane product treated by the method disclosed by the invention is 50-120 ppm; and room-temperature cured electronic silicon rubber made from the high-purity 107 rubber can enhance the properties and quality of electronic and electric appliances.

Description

technical field [0001] The invention relates to the field of silicone rubber raw material preparation, in particular to a method for purifying α, ω dihydroxy polydimethylsiloxane. Background technique [0002] α, ω dihydroxypolydimethylsiloxane (107 glue) is the main raw material for the production of room temperature vulcanized silicone rubber, and room temperature vulcanized silicone rubber is a kind of potting, fixing and bonding materials that can be used for electronic and electrical components . 107 glue contains low-molecular substances that often contain polydimethylcyclosiloxane as the main component. When these substances are in contact with conductors such as copper and aluminum for a long time, a layer of foggy film will be formed and have a certain degree of corrosion. , when the silicone rubber made of it is used for potting, fixing, and bonding of electronic and electrical components, it will affect the electrical conductivity and contact conductivity of elec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G77/34C08G77/16
Inventor 李伟瑞
Owner MAOMING XINLONG TECH
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