1. A method for preparing methyl styryl silicone oil is characterized in that: step one, sequentially adding 300kg of octamethylcyclotetrasiloxane 200-;

and step two, adding 50kg of styrene and a catalyst accounting for 0.001-0.003 percent of the total weight of reactants into a reaction kettle, dropwise adding 100kg of the hydrogen-containing silicone oil obtained in the step one at 70-120 ℃, reacting for 3-8h, and removing low-boiling-point substances under reduced pressure to obtain transparent liquid, thus obtaining the methyl styrene-based silicone oil.

2. The method for preparing methyl styrene-based silicone oil according to claim 1, wherein: the hydrogen-containing silicone oil obtained in the first step is end-side-group hydrogen-containing silicone oil, and the molecular formula is as follows:

。

3. the method for preparing methyl styrene-based silicone oil according to claim 1, wherein: the solid acid in the first step is one or a combination of more of polystyrene sulfonic resin, phosphotungstic acid, kaolin, bentonite and ferric sulfate.

4. The method for preparing methyl styrene-based silicone oil according to claim 1, wherein: the molecular formula of the methyl styryl silicone oil obtained in the step two is as follows:

。

Background

At present, two main synthetic methods of methyl phenyl silicone oil exist, wherein in the first method, difunctional methyl, phenyl chlorosilane or alkoxy silane is used as a raw material, and linear silicone oil is prepared by hydrolytic condensation; in the second method, a cyclic methyl or phenyl monomer is subjected to open-loop bridging under the catalysis of acid and alkali to prepare the methyl phenyl silicone oil. The methyl phenyl silicone oil has the performances of high temperature resistance, lubricity, radiation resistance and the like, and the amount of phenyl determines the compatibility of the silicone oil and other organic resins. Although the methyl phenyl silicone oil has the advantages, the preparation cost is high, the process is complex, and particularly, the price of the phenyl silane raw material is high, so that the production cost of an enterprise is seriously influenced.

Disclosure of Invention

The invention aims to solve the problems of high preparation cost and complex process of the traditional methyl phenyl silicone oil and provides a preparation method of methyl styryl silicone oil.

The invention takes self-made hydrogen-containing silicone oil as a raw material and chloroplatinic acid or kast as a catalyst to prepare the methyl styryl silicone oil. The performance of the synthesized methyl styrene silicone oil is higher than that of the traditional methyl phenyl silicone oil.

In order to solve the technical problems, the invention adopts the following technical scheme:

the preparation method of the methyl styryl silicone oil comprises the following steps:

step one, sequentially adding 300kg of octamethylcyclotetrasiloxane 200-;

and step two, adding 50kg of styrene and a catalyst accounting for 0.001-0.003 percent of the total weight of reactants into a reaction kettle, dropwise adding 100kg of the hydrogen-containing silicone oil obtained in the step one at 70-120 ℃, reacting for 3-8h, and removing low-boiling-point substances under reduced pressure to obtain transparent liquid, thus obtaining the methyl styrene-based silicone oil.

The molecular formula of the methyl styryl silicone oil is as follows:

wherein the solid acid is one or more of polystyrene sulfonic resin, phosphotungstic acid, kaolin, bentonite and ferric sulfate.

Wherein the solid acid in the first step plays a role in catalyzing the ring opening of the cyclic silane monomer.

Wherein the molecular formula of the hydrogen-containing silicone oil obtained in the step one is as follows:

the hydrogen-containing silicone oil obtained in the first step is end-side-group hydrogen-containing silicone oil, and a silicon-hydrogen bond provides a reaction functional group for introducing styryl in the next step.

Wherein the temperature in step one is optimally 25 ℃.

Wherein the reaction time in the first step is optimally 8 h.

Wherein the optimal amount of solid acid in the first step is 12-15 kg.

Wherein the catalyst in the second step is one of chloroplatinic acid and kast, and the optimal amount of the catalyst accounts for 0.0015 to 0.002 percent of the total weight of the reactants.

Wherein the temperature in the second step is preferably 80-100 ℃.

Wherein the optimal reaction time in the second step is 4-6 h.

The styrene used in the invention is a common chemical raw material and has low cost. The self-made hydrogen-containing silicone oil is reacted with styrene to prepare the methyl styryl silicone oil. The introduction of styryl improves the mold release property, lubricity, high temperature resistance, compatibility with organic resin and the like of the silicone oil.

The invention has the beneficial effects that: the methyl styryl silicone oil has simple production process, the introduction of styryl reduces the production cost, and the performance of the synthesized methyl styryl silicone oil is higher than that of the traditional methyl phenyl silicone oil.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto.

Example 1:

the preparation method of the methyl styryl silicone oil comprises the following steps:

step one, sequentially adding 300kg of octamethylcyclotetrasiloxane, 100kg of tetramethylcyclotetrasiloxane and 25kg of hydrogen-containing double end enclosure into an enamel reaction kettle, stirring, adding 10kg of solid acid, keeping the temperature at 20-50 ℃, reacting for 7-8h, and filtering the solid acid after the reaction is finished to obtain hydrogen-containing silicone oil;

and step two, adding 50kg of styrene and a catalyst accounting for 0.001 percent of the total weight of reactants into a reaction kettle, dropwise adding 100kg of the hydrogen-containing silicone oil obtained in the step one at 70-120 ℃, reacting for 3-8h, and removing low-boiling-point substances under reduced pressure to obtain transparent liquid, namely the methyl styrene-based silicone oil.

Example 2:

the preparation method of the methyl styryl silicone oil comprises the following steps:

step one, sequentially adding 200kg of octamethylcyclotetrasiloxane, 100kg of tetramethylcyclotetrasiloxane and 20kg of hydrogen-containing double end enclosure into an enamel reaction kettle, stirring, adding 12kg of solid acid, keeping the temperature at 25 ℃, reacting for 8 hours, and filtering the solid acid after the reaction is finished to obtain hydrogen-containing silicone oil;

and step two, adding 50kg of styrene and a catalyst accounting for 0.0015 percent of the total weight of reactants into a reaction kettle, dropwise adding 100kg of the hydrogen-containing silicone oil obtained in the step one at 80-100 ℃, reacting for 4-6h, and removing low-boiling-point substances under reduced pressure to obtain transparent liquid, namely the methyl styrene-based silicone oil.

Example 3:

the preparation method of the methyl styryl silicone oil comprises the following steps:

step one, adding 250kg of octamethylcyclotetrasiloxane, 150kg of tetramethylcyclotetrasiloxane and 20kg of hydrogen-containing double end enclosure in an enamel reaction kettle in sequence, stirring, adding 15kg of solid acid, keeping the temperature at 40 ℃, reacting for 7.5 hours, and filtering the solid acid after the reaction is finished to obtain hydrogen-containing silicone oil;

and step two, adding 50kg of styrene and a catalyst accounting for 0.002 percent of the total weight of reactants into a reaction kettle, dropwise adding 100kg of the hydrogen-containing silicone oil obtained in the step one at 100 ℃, reacting for 3-8h, and removing low-boiling-point substances under reduced pressure to obtain transparent liquid, thus obtaining the methyl styrene-based silicone oil.

The present invention is not limited to the above examples, but may be combined in many ways, and all cases that can be derived or suggested by those skilled in the art from the disclosure of the present invention should be considered as the protection scope of the present invention.