Preparation method of cyclosiloxane

A technology of cyclosiloxane and alkoxysilane, which is applied in the field of preparation of cyclosiloxane, can solve the problems of reduced purity of cyclosiloxane, high reaction temperature, fast hydrolysis speed, etc., and achieve the reduction of linear polysilicon The production of oxane, the promotion of cyclization reaction, and the effect of reducing environmental pollution

Inactive Publication Date: 2012-07-11
NEW MATERIAL INST OF SHANDONG ACADEMY OF SCI +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

But it has the following problems: (1) the purity of chlorosilane is not high, the hydrolysis speed is fast, and it is difficult to control, and the purity of the cyclosiloxane can not meet the requirements of high-purity ring body; (2) in the hydrolyzate vacuum During the cracking process, due to the high reaction temperature, some side reactions will occur, resulting in a decrease in the purity of cyclosiloxane.
However, under certain conditions, the acidic catalyst can destroy the silicon-carbon bond, which will bring some side reactions to the system.

Method used

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  • Preparation method of cyclosiloxane
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  • Preparation method of cyclosiloxane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] In a 1000ml three-necked flask equipped with a stirring, thermometer and dropping funnel, add 40ml of dioxane, 200ml of toluene, 200ml of deionized water, and 4g of NaOH, stir evenly, and control the temperature of the system at 60°C. A mixture of 200ml of methylphenyldimethoxysilane and 200ml of toluene was slowly added dropwise, and after the dropwise addition was completed, the reaction was continued for 2h. Then gradually raise the temperature to 80°C to distill off the methanol generated by the reaction. Stop the reaction, let stand to separate the water layer, wash the oil layer with water until neutral, dry, and evaporate the solvent to obtain 134.6 g of hydrolyzate with a yield of 90%.

Embodiment 2

[0029] According to the same method as in Example 1, the catalyst type was changed, and the amount was fixed at 2% of the mass of the alkoxysilane. The results obtained are shown in Table 1 below.

[0030] Table 1

[0031]

Embodiment 3

[0033] By the same method as in Example 1, tetramethylammonium hydroxide was selected as the catalyst to change the catalyst consumption, and the obtained results are shown in Table 2 below.

[0034] Table 2

[0035]

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Abstract

The invention discloses a preparation method of cyclosiloxane. The method comprises the following steps: evenly mixing bifunctional alkoxy silane and aromatic hydrocarbon; dropwise adding the mixture into a mixed solvent system containing basic catalyst, the aromatic hydrocarbon, water and dioxane or tetrahydrofuran for reacting for a while at a certain temperature; and then separating to obtain the cyclosiloxane. The invention has the best advantages of greatly improving the yield of products, reducing by-products, and being widely applied to the production field of preparing the cyclosiloxane by utilizing the bifunctional alkoxy silane.

Description

technical field [0001] The invention relates to a preparation method of cyclosiloxane, which belongs to the technical field of organosilicon synthesis. Background technique [0002] Cyclosiloxane is an important intermediate raw material in the silicone industry, and is widely used in the synthesis of silicone oil, silicone resin and raw silicone rubber. Regarding the preparation of cyclosiloxane, there are three main methods: hydrolysis, thermal cracking and dechlorination. The traditional preparation method is the hydrolytic cracking method of chlorosilane or alkoxysilane, that is, the silane is first hydrolyzed to form a hydrolyzate composed of a mixed ring body and a linear siloxane body, and then the hydrolyzate is subjected to vacuum catalytic cracking under the action of a catalyst. A mixed ring is obtained. But it has the following problems: (1) the purity of chlorosilane is not high, the hydrolysis speed is fast, and it is difficult to control, and the purity of t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07F7/21B01J31/02B01J23/04
Inventor 牟秋红李金辉律微波
Owner NEW MATERIAL INST OF SHANDONG ACADEMY OF SCI
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