Method for preparing organic silicon microspheres from methyltrimethoxysilane high-boiling residues

Abstract

The invention discloses a method for preparing organic silicon microspheres from methyltrimethoxysilane high-boiling residues, efficient utilization and continuous production are realized through innovative pretreatment, hydrolysis and polymerization processes, and an efficient, economical and environment-friendly solution is provided for comprehensive utilization of the methyltrimethoxysilane high-boiling residues. The method mainly comprises the following steps: (1) pretreating a high-boiling-point substance, blending the byproduct high-boiling-point substance in the production process of methyltrimethoxysilane with methanol and methyltrimethoxysilane to form a material A, blowing instrument gas, adding a treating agent, reacting under specific temperature and pressure conditions, and removing redundant impurities through a multi-stage filter; (2) mixing the purified material with deionized water according to a certain proportion, completing a hydrolysis reaction under the catalysis of sulfuric acid with the mass fraction of 98%, then preliminarily mixing with prefabricated alkali liquor in a mixer, and feeding into a polymerization kettle to complete a polymerization reaction to obtain a polymerization solution; and (3) filtering, drying and crushing the polymerization liquid to obtain pure white organic silicon microspheres.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and specifically relates to a method and a device for preparing organic silicon microspheres from high boiling point methyltrimethoxysilane. Background Art

[0002] As an important organosilicon compound, methyltrimethoxysilane is increasingly used in many fields, including the rubber industry, coating industry, adhesive industry, etc. Its production process can be simplified to the process of alcoholysis of monomethyltrichlorosilane and methanol followed by neutralization and distillation. However, in this process, since the raw material methanol inevitably contains trace amounts of water, a series of side reactions occur and polymers are generated. These polymers are deposited during the deweighting process and eventually form high-boiling products. High-boiling products mainly contain unreacted methanol, methyltrimethoxysilane and methyltrimethoxysilane polymers, which have great combustion hazards.

[0003] At present, the methods for treating these high boiling products mainly include cracking and direct incineration. Although the cracking reaction can recycle the high boiling products, it is relatively expensive and not suitable for large-scale production. Although direct incineration is easy to operate and low in cost, it cannot effectively utilize the high boiling products and will pollute the environment. Therefore, how to effectively treat the high boiling products generated in the production process of methyltrimethoxysilane while reducing costs and reducing the impact on the environment has become a key issue facing this field. In order to solve the above problems, the present invention provides a method for preparing organosilicon microspheres from high-boiling methyltrimethoxysilane, which effectively solves the above problems.

[0004] A method for preparing organosilicon microspheres from high boiling point methyltrimethoxysilane, comprising the following steps: (1) Pretreatment of high boiling products: The high boiling products produced as by-products in the production process of methyltrimethoxysilane are mixed with methanol and methyltrimethoxysilane to form material A, and then instrument gas is blown in and a treatment agent is added to react. Subsequently, the excess impurities are removed through a multi-stage filter to obtain a purified material; (2) The purified material is mixed with deionized water in a certain proportion, and a hydrolysis reaction is completed under the catalysis of sulfuric acid with a mass fraction of 98% or more, and then preliminarily mixed with a prefabricated alkali solution in a mixer and sent to a polymerization kettle to complete a polymerization reaction to obtain a polymerization solution; (3) The polymer solution can be filtered, dried and crushed to obtain pure white silicone microspheres.

[0005] The high-boiling by-product in the production process of methyltrimethoxysilane is a polymer with uneven polymerization degree formed by the alcoholysis reaction of monomethyltrichlorosilane and methanol to generate methyltrimethoxysilane. The polymer is discharged as a high-boiling by-product in the production process of methyltrimethoxysilane.

[0006] For example, in the preparation process of methyltrimethoxysilane reported in CN113861233 A in the related patent of the present applicant, in the process of obtaining the crude methyltrimethoxysilane, some by-products, i.e., high boiling products, are also obtained. The high boiling products are obtained by adding methanol and solvent into a mixer in proportion and mixing them evenly, and then monomethyltrichlorosilane and the mixed liquid in the mixer are simultaneously introduced into the venturi mixer in proportion. The two are fully mixed and reacted. In the reaction process, some high boiling products are produced, which are separated by a distillation tower to obtain the methyltrimethoxysilane high boiling product.

[0007] The contents of the components in the material A in step (1) are prepared as follows: 2% to 5% methanol, 20% to 30% methyltrimethoxysilane, and 65% to 78% high-boiling by-products produced during the production of methyltrimethoxysilane.

[0008] In the material A of the present invention, the polymerization degree of high-boiling substances is uneven, and stratification is easy to occur. In the production of methyltrimethoxysilane, the production parameters fluctuate within a certain range, so that the content of high-boiling substances is high or low. In order to make the substances in the raw material A more balanced, a certain amount of methanol is added as a solvent to make the high-boiling substances more evenly mixed. Adding a certain amount of methyltrimethoxysilane: avoids the problem of difficult control of the content of by-product high-boiling substances and controls the stability of the raw materials.

[0009] After material A is put into the pretreatment kettle, instrument gas is continuously introduced for bubbling during the stirring process, and the oxygen in the instrument gas is used to oxidize some substances in material A; the water content in the instrument gas is less than 50ppm; then the treatment agent is added to the pretreatment kettle, and the amount added is 0.5%~1% of material A. The temperature of the pretreatment kettle is controlled to be maintained at 70~80℃, the pressure is 0.1Mpa~0.15Mpa, and the reaction time is controlled to be 60min~90min.

[0010] The treating agent is one of sodium methoxide, sodium ethoxide, aluminum chloride, ferric chloride and the like.

[0011] After the pretreatment kettle, the material A is passed through a primary filter for primary filtration, and the filter medium is quartz sand to remove the granular crystals or mechanical impurities that may appear in the solution; after the primary filtration, the material A enters a secondary filter for fine filtration, and the filter medium is a microporous filter membrane, exchange resin, etc., to further reduce the content of fine particles and improve the transparency of the material A. Step (2) The material A is transferred to the hydrolysis kettle, and pure water and 98% sulfuric acid are added from the top of the hydrolysis kettle to the bottom of the kettle at the same time, and the mass ratio is material A: water: sulfuric acid = 100: 500~800: 0.01~0.05, and the temperature of the hydrolysis kettle is controlled to be 60~75°C. The prefabricated alkali solution contains water, a surfactant, and an alkali catalyst. The surfactant is one or more of nonylphenol polyoxyethylene ether, polyoxyethylene fatty alcohol ether, sulfonate and the like. The alkali catalyst is one of sodium hydroxide solution, ammonia water, potassium hydroxide solution, alcohol amine and the like. The mass ratios of the substances are: water: surfactant = 100: 0.05~2. The molar concentration of the alkali catalyst is controlled at 0.1mol / L~0.35mol / L, and the added amount is 5~9% of the mass of the hydrolyzate of material A.

[0012] The water used in the present invention is deionized water.

[0013] The treated material A is introduced into the hydrolysis kettle by bottom feeding. At the same time, the side of the hydrolysis kettle has one or more openings, which can make the liquid in the kettle overflow into the transfer tank, and the mixed solution stays in the kettle for 30~45min (i.e., the hydrolysis reaction time is 30-45min). The hydrolyzed solution and the pre-made alkaline solution are introduced into the mixer at a mass ratio of hydrolyzate: pre-made alkaline solution = 1:1~1.5 to complete the preliminary mixing, and then the material is fed from the bottom of the polymerization kettle, and further mixed evenly under the action of stirring. At the same time, the side of the polymerization kettle has one or more openings, which can make the polymerization liquid overflow into the static tank, ensuring that the polymerization liquid stays in the kettle for 15~25min (i.e., the polymerization reaction time is 15-25min).

[0014] After the polymer solution in step (3) is placed in a standing tank for 1 to 2 hours, the polymer solution is centrifuged to separate the solid matter, and then flash drying and air flow pulverization are used to quickly obtain a particle size distribution of 1 to 20 μm, a refractive index of 1.41 to 1.43, and a bulk density of 0.4 to 0.6 g / cm 3 Pure white silicone microspheres are produced, and the yield of silicone microspheres is >80%.

[0015] Compared with the prior art, the present invention has the following advantages: 1. Efficient use of by-product resources: Most organosilicon microspheres are prepared using high-purity methylalkoxysilane. The present invention makes full use of the by-product high-boiling substances produced in the production of methyltrimethoxysilane to prepare organosilicon microspheres, which not only reduces the requirements and costs for raw materials, but also significantly reduces the processing costs of high-boiling substances, greatly improving their utilization value.

[0016] 2. Pretreatment is economical and efficient: The application of instrument gas bubbling technology not only promotes the reaction of unoxidized substances in high-boiling products, but also reduces process costs compared to the direct use of dry oxygen. At the same time, by adding any one of the treatment agents sodium methoxide, sodium ethoxide, aluminum trichloride, and ferric chloride, some unsaturated substances and chloride ions in high-boiling products are effectively removed, avoiding the agglomeration phenomenon caused by rapid hydrolysis and ensuring the quality of silicone microspheres.

[0017] 3. Precise particle size control: By adjusting the proportion of components in the high-boiling material, this method can effectively control the size and distribution of the silicone microspheres and produce microspheres of uniform size to meet the strict requirements of different application fields.

[0018] 4. High impurity removal efficiency: The secondary filter uses microporous filter membrane, exchange resin and other filter materials, which can effectively remove fine impurities and some salt substances in high-boiling products, reduce the conductivity of the solution, prevent abnormal agglomeration due to excessively high conductivity during the polycondensation stage, and improve the quality of silicone microspheres.

[0019] 5. High efficiency of production equipment: hydrolysis and polymerization reactions are carried out by overflow mixing, which increases the contact time between the catalyst and the material, realizes continuous production, and reduces power energy consumption. By properly adjusting the catalyst concentration, the phenomenon of excessive local concentration during the mixing of hydrolyzate and alkaline catalyst, which leads to abnormal enlargement and agglomeration of organosilicon microspheres, is avoided, and the consistency and stability of organosilicon microspheres are further ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the particle size distribution diagram of the silicone microspheres in Example 2.

[0021] Figure 2 This is an electron microscope scanning image of the organosilicon microspheres in Example 3.

[0022] Figure 3 This is the particle size distribution diagram of the microspheres in the abnormal state of Example 4.

[0023] Figure 4 This is an electron microscope scanning image of the microsphere in the abnormal state of Example 4. DETAILED DESCRIPTION

[0024] Example 1 (1) The high-boiling products produced as by-products in the production process of methyltrimethoxysilane are used to form a methyltrimethoxysilane composite high-boiling product after mixing with methanol and methyltrimethoxysilane. The content distribution after mixing is: 2.3% methanol, 21% methyltrimethoxysilane, and 76.7% methyltrimethoxysilane high-boiling products. 100 parts of the mixed methyltrimethoxysilane high-boiling product mixture is passed into the treatment kettle, and the dried instrument gas is inserted below the liquid level of the methyltrimethoxysilane composite high-boiling product for bubbling operation. 0.6 parts of sodium methoxide are added to the treatment kettle, and the reaction temperature is controlled to 75°C, the pressure is 0.1MPa, and the reaction time is 60min to remove unsaturated alkanes and a small amount of chlorine.

[0025] (2) The methyltrimethoxysilane composite high boiling point product treated in the pretreatment kettle is passed through a primary filter for primary filtration, and then the methyltrimethoxysilane composite high boiling point product after primary filtration is passed through a secondary processor. The secondary processor filter material is a microporous filter membrane to remove fine crystals, sodium chloride and other fine impurities in the solution.

[0026] (3) The methyltrimethoxysilane composite high-boiling product after pretreatment was transferred to a hydrolysis kettle, 600 parts of deionized water and 0.02 parts of 98% sulfuric acid were added, the temperature of the hydrolysis kettle was controlled at 60°C, the hydrolysis reaction was carried out, the solution residence time was maintained at 30 minutes, and then overflowed into the transfer tank; (4) 553 parts of deionized water, 11 parts of nonylphenol polyoxyethylene ether, and 36 parts of 0.3 mol / L sodium hydroxide solution were prepared into 700 parts of prefabricated alkaline solution. The prefabricated alkaline solution was mixed with the methyltrimethoxysilane hydrolyzate through a mixer, and then introduced into the reactor from the bottom of the polymerization kettle. The residence time was maintained for 15 min, and then the solution was introduced into the standing tank through the overflow. The solution was allowed to stand for 1.5 h, and the solid matter was separated. The solid matter was then dried and crushed to obtain a particle size of D50 = 6.89 μm, a refractive index of 1.42, and a bulk density of 0.45 g / cm 3 Pure white silicone microspheres were prepared, and the yield of silicone microspheres was 82.1%.

[0027] Example 2 (1) The high-boiling products produced as by-products in the production process of methyltrimethoxysilane are used to form a methyltrimethoxysilane composite high-boiling product after mixing with methanol and methyltrimethoxysilane. The content distribution after mixing is: 5% methanol, 25% methyltrimethoxysilane, and 70% methyltrimethoxysilane high-boiling products. 100 parts of the mixed methyltrimethoxysilane high-boiling product mixture is passed into the treatment kettle, and the dried instrument gas is inserted below the liquid level of the methyltrimethoxysilane composite high-boiling product for bubbling operation. 0.6 parts of sodium methoxide are added to the treatment kettle, and the reaction temperature is controlled to 75°C, the pressure is 0.1MPa, and the reaction time is 60min to remove unsaturated alkanes and a small amount of chlorine.

[0028] (2) The methyltrimethoxysilane composite high boiling point product treated in the pretreatment kettle is passed through a primary filter for primary filtration, and then the methyltrimethoxysilane composite high boiling point product after primary filtration is passed through a secondary processor. The secondary processor filter material is a microporous filter membrane to remove fine crystals, sodium chloride and other fine impurities in the solution.

[0029] (3) The methyltrimethoxysilane composite high-boiling product after pretreatment was transferred to a hydrolysis kettle, 600 parts of deionized water and 0.02 parts of 98% sulfuric acid were added, the temperature of the hydrolysis kettle was controlled at 60°C, the hydrolysis reaction was carried out, the solution residence time was maintained at 30 minutes, and then overflowed into the transfer tank; (4) Take 553 parts of deionized water, 11 parts of nonylphenol polyoxyethylene ether, and 36 parts of 0.3 mol / L sodium hydroxide solution to prepare 700 parts of prefabricated alkaline solution. After mixing the prefabricated alkaline solution with the methyltrimethoxysilane hydrolyzate through a mixer, the solution enters the reactor from the bottom of the polymerization kettle and is kept for 15 minutes. The solution then enters the standing tank through the overflow and is allowed to stand for 1.5 hours. The solid matter is separated and then dried and crushed to obtain a particle size of D50 = 4.68 μm, a refractive index of 1.42, and a bulk density of 0.48 g / cm 3 The yield of pure white silicone microspheres was 83.2%.

[0030] Example 3 (1) The high-boiling products produced as by-products in the production process of methyltrimethoxysilane are used to form a methyltrimethoxysilane composite high-boiling product after mixing with methanol and methyltrimethoxysilane. The content distribution after mixing is: 5% methanol, 25% methyltrimethoxysilane, and 70% methyltrimethoxysilane high-boiling products. 100 parts of the mixed methyltrimethoxysilane high-boiling product mixture is passed into the treatment kettle, and the dried instrument gas is inserted below the liquid level of the methyltrimethoxysilane composite high-boiling product for bubbling operation. 0.5 parts of ferric chloride are added to the treatment kettle, and the reaction temperature is controlled to 75°C, the pressure is 0.1MPa, and the reaction time is 60min to remove unsaturated alkanes and a small amount of chlorine.

[0031] (2) The methyltrimethoxysilane composite high boiling point product treated in the pretreatment kettle is passed through a primary filter for primary filtration, and then the methyltrimethoxysilane composite high boiling point product after primary filtration is passed through a secondary processor. The secondary processor filter material is a microporous filter membrane to remove fine crystals, sodium chloride and other fine impurities in the solution.

[0032] (3) The methyltrimethoxysilane composite high-boiling product after pretreatment was transferred to a hydrolysis kettle, 600 parts of deionized water and 0.02 parts of 98% sulfuric acid were added, the temperature of the hydrolysis kettle was controlled at 60°C, the hydrolysis reaction was carried out, the solution residence time was maintained at 30 minutes, and then overflowed into the transfer tank; (4) Take 803 parts of deionized water, 16 parts of nonylphenol polyoxyethylene ether, and 81 parts of 0.3 mol / L sodium hydroxide solution to prepare 900 parts of prefabricated alkaline solution. After mixing the prefabricated alkaline solution with the methyltrimethoxysilane hydrolyzate through a mixer, the solution enters the reactor from the bottom of the polymerization kettle and is kept for 15 minutes. The solution then overflows and enters the standing tank. The solid matter is allowed to stand for 1.5 hours, and then the solid matter is separated. The solid matter is dried and crushed to obtain a particle size of D50 = 3.25 μm, a refractive index of 1.43, and a bulk density of 0.58 g / cm 3 The yield of pure white silicone microspheres is 80.5%.

[0033] Example 4 (1) The high-boiling products produced as by-products in the production process of methyltrimethoxysilane are used to form a methyltrimethoxysilane composite high-boiling product after mixing with methanol and methyltrimethoxysilane. The content distribution after mixing is: 5% methanol, 25% methyltrimethoxysilane, and 70% methyltrimethoxysilane high-boiling products. 100 parts of the mixed methyltrimethoxysilane high-boiling product mixture is passed into the treatment kettle, and the dried instrument gas is inserted below the liquid level of the methyltrimethoxysilane composite high-boiling product for bubbling operation. 0.5 parts of ferric chloride are added to the treatment kettle, and the reaction temperature is controlled to 75°C, the pressure is 0.1MPa, and the reaction time is 60min to remove unsaturated alkanes and a small amount of chlorine.

[0034] (2) The methyltrimethoxysilane composite high boiling point product after treatment in the pretreatment kettle is used directly without filtering.

[0035] (3) The methyltrimethoxysilane composite high-boiling product that has been pretreated but not filtered is transferred to a hydrolysis kettle, 600 parts of deionized water and 0.02 parts of 98% sulfuric acid are added, the temperature of the hydrolysis kettle is controlled at 60°C, the hydrolysis reaction is carried out, the solution residence time is maintained at 30 minutes, and then overflows into the transfer tank; (4) 803 parts of deionized water, 16 parts of nonylphenol polyoxyethylene ether, and 81 parts of 0.3 mol / L sodium hydroxide solution were prepared into 900 parts of prefabricated alkaline solution. The prefabricated alkaline solution was mixed with the methyltrimethoxysilane hydrolyzate through a mixer, and then entered the reactor from the bottom of the polymerization kettle. The residence time was kept for 15 minutes, and then the overflow entered the standing tank. The solid matter was separated after standing for 1.5 hours. Some of the organosilicon microspheres had impurities as the core and were adsorbed on the surface of the impurities to form large particles. Agglomeration occurred. After drying and pulverization, the organosilicon microspheres had uneven particle sizes, with a particle size D50>15 μm and a yield of 70.6%.

[0036] Example 5 (1) Directly utilize the high boiling point byproduct in the production process of methyltrimethoxysilane as raw material, without adding appropriate amount of methanol and methyltrimethoxysilane, pass 100 parts of methyltrimethoxysilane high boiling point into the treatment kettle, insert the dried instrument gas below the liquid level of methyltrimethoxysilane composite high boiling point, perform bubbling operation, add 0.5 parts of ferric chloride into the treatment kettle, control the reaction temperature to 75℃, pressure to 0.1MPa, and reaction time to 60min, so as to remove unsaturated alkanes and a small amount of chlorine.

[0037] (2) The high boiling point of methyltrimethoxysilane is passed through a primary filter for primary filtration, and then the high boiling point of methyltrimethoxysilane after primary filtration is passed through a secondary processor. The secondary processor uses a microporous filter membrane as the filter material to remove fine crystals, sodium chloride and other fine impurities in the solution.

[0038] (3) The treated high-boiling methyltrimethoxysilane was transferred to a hydrolysis kettle, and 800 parts of deionized water and 0.05 parts of 98% sulfuric acid were added. The temperature of the hydrolysis kettle was controlled at 60°C to carry out the hydrolysis reaction. The solution residence time was maintained at 30 minutes, and then overflowed into the transfer tank. During the hydrolysis reaction, a translucent film appeared on the surface of the liquid. (4) Take 803 parts of deionized water, 16 parts of nonylphenol polyoxyethylene ether, and 81 parts of 0.3 mol / L sodium hydroxide solution to prepare 900 parts of prefabricated alkaline solution. After mixing the prefabricated alkaline solution with the methyltrimethoxysilane hydrolyzate through a mixer, the solution enters the reactor from the bottom of the polymerization kettle and is kept for 15 minutes. The solution then overflows and enters the standing tank. The solid matter is allowed to stand for 1.5 hours, and then the solid matter is separated. The solid matter is dried and crushed to obtain a particle size of D50 = 12.81 μm, a refractive index of 1.41, and a bulk density of 0.41 g / cm 3 The light yellow organosilicon microspheres were prepared, and the yield of organosilicon microspheres was 68.6%.

[0039] Example 6 (1) The high-boiling products produced as by-products in the production process of methyltrimethoxysilane are used to form a methyltrimethoxysilane composite high-boiling product after mixing with methanol and methyltrimethoxysilane. The content distribution after mixing is: 5% methanol, 25% methyltrimethoxysilane, and 75% methyltrimethoxysilane high-boiling product. 100 parts of the mixed methyltrimethoxysilane high-boiling product mixture is passed into the treatment kettle, and the dried instrument gas is inserted below the liquid level of the methyltrimethoxysilane composite high-boiling product for bubbling operation. No treatment agent is added to the treatment kettle. The reaction temperature is controlled to be 75°C, the pressure is 0.1MPa, and the reaction time is 60min.

[0040] (2) The methyltrimethoxysilane composite high boiling point product that has not been treated with a treatment agent is passed through a primary filter for preliminary filtration, and then the methyltrimethoxysilane composite high boiling point product after preliminary filtration is passed through a secondary processor. The secondary processor filter material is a microporous filter membrane to remove fine crystals, sodium chloride and other fine impurities in the solution.

[0041] (3) The methyltrimethoxysilane composite high-boiling product was transferred to the hydrolysis kettle, 800 parts of deionized water and 0.05 parts of 98% sulfuric acid were added, the temperature of the hydrolysis kettle was controlled at 60°C, the hydrolysis reaction was carried out, the solution residence time was maintained at 30 minutes, and then overflowed into the transfer tank. Oily substances appeared on the surface of the liquid, and the solution was yellowish overall; (4) Take 803 parts of deionized water, 16 parts of nonylphenol polyoxyethylene ether, and 81 parts of 0.3 mol / L sodium hydroxide solution to prepare 900 parts of prefabricated alkaline solution. After mixing the prefabricated alkaline solution with the methyltrimethoxysilane hydrolyzate through a mixer, the solution enters the reactor from the bottom of the polymerization kettle and is kept for 15 minutes. The solution then overflows and enters the standing tank. The standing tank is left for 1.5 hours. A yellow crystalline substance appears at the bottom of the standing tank, along with some hard block solids. The solid substance is separated, dried, and crushed to obtain an irregularly shaped, yellow or even brown powder.

Claims

1. A method for preparing organosilicon microspheres from high boiling products of methyltrimethoxysilane, characterized in that: The following steps are involved: (1) The high-boiling byproducts produced during the production of methyltrimethoxysilane are mixed with methanol and methyltrimethoxysilane to form material A, after which instrument gas is blown in and a treatment agent is added to react, and then excess impurities are removed through a multi-stage filter to obtain a purified material; (2) The purified material is mixed with water to complete a hydrolysis reaction under the catalysis of sulfuric acid, and then preliminarily mixed with a prefabricated alkali solution in a mixer and sent to a polymerization kettle to complete a polymerization reaction to obtain a polymerization solution; (3) The polymer solution can be filtered, dried and crushed to obtain pure white silicone microspheres.

2. The method for preparing organosilicon microspheres from methyltrimethoxysilane high boiling point according to claim 1, characterized in that: The high-boiling by-product in the production process of methyltrimethoxysilane is a polymer with uneven polymerization degree produced by the alcoholysis reaction of monomethyltrichlorosilane with methanol to produce methyltrimethoxysilane. The high-boiling by-product is discharged as the high-boiling by-product in the production process of methyltrimethoxysilane. The high-boiling by-product is mixed with methanol and methyltrimethoxysilane to prepare the material A in step (1).

3. The method for preparing organosilicon microspheres from methyltrimethoxysilane high boiling point according to claim 2, characterized in that: The content of each component is prepared as follows: 2%~5% methanol, 20%~30% methyltrimethoxysilane, and 65%~78% high-boiling by-products in the production process of methyltrimethoxysilane.

4. The method for preparing organosilicon microspheres from high boiling methyltrimethoxysilane according to claim 1, characterized in that: The water content in the instrument gas is less than 50ppm; the treatment agent includes any one of sodium methoxide, sodium ethoxide, aluminum trichloride, and ferric chloride, and the amount of the treatment agent added is 0.5wt%~1wt% of material A.

5. The method for preparing organosilicon microspheres from methyltrimethoxysilane high boiling point according to claim 1, characterized in that: During the reaction in step (1), the temperature is maintained at 70-80° C., the pressure is maintained at 0.1 MPa-0.15 MPa, and the reaction time is controlled at 60 min-90 min.

6. The method for preparing organosilicon microspheres from high boiling methyltrimethoxysilane according to claim 1, characterized in that: The mass ratio of the purified material in step (2): water: sulfuric acid is 100:500-800:0.01-0.05, and the sulfuric acid has a mass fraction of ≥98%; The hydrolysis reaction temperature is 60~75℃.

7. The method for preparing organosilicon microspheres from high boiling methyltrimethoxysilane according to claim 1, characterized in that: The prefabricated alkali solution contains water, surfactant, and alkali catalyst; The surfactant is one or more of nonylphenol polyoxyethylene ether, polyoxyethylene fatty alcohol ether, and sulfonate substances; The alkaline catalyst is one of sodium hydroxide solution, ammonia water, potassium hydroxide solution and alcohol amine.

8. The method for preparing organosilicon microspheres from high boiling methyltrimethoxysilane according to claim 7, characterized in that: The mass ratio of pure water: surfactant is 100: 0.05~2, and the molar concentration of the base catalyst is controlled at 0.1mol / L~0.35mol / L; The amount of prefabricated alkali solution added is 5~9% of the mass of the hydrolyzate of material A.

9. The method for preparing organosilicon microspheres from high boiling methyltrimethoxysilane according to claim 1, characterized in that: The purified material is introduced into the hydrolysis kettle by bottom feeding, and water and sulfuric acid are added to the hydrolysis kettle for a retention time of 30 to 45 minutes. At the same time, the side of the hydrolysis kettle is provided with one or more openings to enable the liquid after hydrolysis in the hydrolysis kettle to overflow into the transfer tank, and the hydrolyzed solution and the prefabricated alkali catalyst are introduced into the mixer at a mass ratio of hydrolyzate: prefabricated alkali solution = 1:1 to 1.5 to complete preliminary mixing, and then the material is fed from the bottom of the polymerization kettle and mixed evenly under stirring. At the same time, the side of the polymerization kettle is provided with one or more openings to enable the polymerization liquid to overflow into the standing tank, and ensure that the polymerization liquid stays in the kettle for 15 to 25 minutes.

10. The organic silicon microspheres are prepared by using the high boiling methyltrimethoxysilane prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The prepared organosilicon microspheres have a particle size distribution of 1-20 μm, a refractive index of 1.41-1.43, and a bulk density of 0.4-0.6 g / cm 3 Pure white silicone microspheres are produced, and the yield of silicone microspheres is >80%.

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