Continuous production method and device of diphenyldimethoxysilane

Abstract

The invention provides a continuous production method and device of diphenyldimethoxysilane. The method comprises the following steps: 1) continuously adding a fresh first solvent, halogenated benzene, a fresh second solvent a and magnesium chips into a Grignard reactor at the same time, and carrying out Grignard reaction to generate a Grignard reagent; 2) continuously overflowing the Grignard reagent into a substitution reactor, and mixing the Grignard reagent with a continuously pumped fresh monomer and a fresh second solvent b for substitution reaction to obtain a substitution reaction solution; 3) filtering the substitution reaction liquid, and continuously rinsing the filter cake with a fresh second solvent c to obtain a wet filter cake, filtrate and rinsing liquid; 4) drying and dehumidifying the rinsed wet filter cake under reduced pressure to obtain a liquid-phase material flow and magnesium salt; (5) continuously feeding the filtrate and the rinsing liquid in the step (3) and the liquid-phase material in the step (4) into a solvent distillation system, and distilling to obtain a crude product, a circulating first solvent, a circulating monomer and a circulating second solvent; recycling the circulating first solvent, the circulating monomer and the circulating second solvent; and 6) product distillation.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of organosilicon compounds, and particularly relates to a continuous production method of diphenyldimethoxysilane. Background Art

[0002] Diphenyldimethoxysilane (DPDMS) is an important functional organosilicon compound. Its molecular structure contains two active groups, phenyl and methoxy, which give it unique chemical properties. In industrial applications, DPDMS is mainly used as a silicone rubber crosslinker, which can significantly improve the heat resistance and mechanical strength of rubber products. In the field of electronic materials, DPDMS is used as a precursor to prepare high dielectric constant films and is widely used in semiconductor packaging and integrated circuit manufacturing. In addition, DPDMS can also be used as a surface modifier to improve the interfacial compatibility between inorganic fillers and organic polymer matrices, playing a key role in the preparation of composite materials.

[0003] In the prior art, diphenyldimethoxysilane is primarily prepared by a direct process, which uses benzene and silicon powder as raw materials and reacts them directly under high temperature and pressure to produce diphenyldimethoxysilane. This process uses inexpensive and readily available raw materials, but has the following disadvantages: (1) harsh reaction conditions, high equipment requirements, and high energy consumption; (2) poor reaction selectivity, numerous byproducts, and difficulty in separating and purifying the product; and (3) high catalyst cost and susceptibility to deactivation.

[0004] Another preparation method is the alcoholysis method, which uses phenyltrichlorosilane or diphenyldichlorosilane as raw materials and reacts with methanol to synthesize DPDMS. As described in patent CN109796488B, methanol entering from the bottom of an esterification column undergoes a countercurrent esterification reaction with diphenyldichlorosilane entering from the top of the esterification column. The hydrogen chloride gas produced by the esterification reaction is discharged from the top of the esterification column, and the crude diphenyldimethoxysilane produced remains at the bottom of the esterification column and is pumped to a distillation column for distillation and separation. After distillation, qualified diphenyldimethoxysilane product is obtained at the top of the column, and high-boiling products are obtained at the bottom. However, the hydrogen chloride produced in the esterification column is prone to corroding equipment pipes, and this method only has one monomer available: diphenyldichlorosilane, which has significant limitations.

[0005] CN115466282A provides a diphenyldimethoxysilane and a production method and system thereof. The method uses 1,4-dioxane or a mixture of 1,4-dioxane and chlorobenzene as a solvent, reacts chlorobenzene with magnesium at an initiator and a first reaction temperature to produce a phenyl Grignard reagent, then drops methoxysilane into the Grignard reagent to produce alkoxymagnesium chloride and crude diphenyldimethoxysilane at a second reaction temperature, which are then separated to obtain a finished product. However, the method has the following disadvantages: (1) the process lacks a solvent recovery section, making it impossible to efficiently recycle the solvent; (2) both the Grignard preparation reactor and the substitution reactor are kettle-type reactors, which can only perform batch reactions and intermittent operations, greatly reducing the yield; and (3) the material ratio of the substitution reaction is single, and can only be used to produce diphenyldimethoxysilane as a single product. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a continuous production method and apparatus for diphenyldimethoxysilane, which can realize continuous production and efficient recycling of solvents, thereby solving the problems in the prior art.

[0007] The technical solution of the present invention is:

[0008] One aspect of the present invention provides a continuous production method of diphenyldimethoxysilane, the continuous production method comprising:

[0009] 1) Grignard reaction: a fresh first solvent, a halogenated benzene, a fresh second solvent a, and magnesium chips are added simultaneously and continuously into a Grignard reactor to undergo a Grignard reaction to generate a Grignard reagent;

[0010] 2) Substitution reaction: the Grignard reagent obtained in step 1) is continuously overflowed into the substitution reactor, mixed with continuously pumped fresh monomer and fresh second solvent b to undergo a substitution reaction to obtain a substitution reaction liquid; wherein the fresh monomer is selected from methyl orthosilicate and / or phenyltrimethoxysilane;

[0011] 3) Filtration and washing: filtering the substitution reaction liquid continuously overflowing from the substitution reactor in step 2) through a filtration and washing machine, and continuously rinsing the filter cake with fresh second solvent C to obtain a wet filter cake, a filtrate, and a rinse liquid;

[0012] 4) filter cake drying: drying the wet filter cake after rinsing in step 3) under reduced pressure to obtain a liquid phase stream and magnesium salt, wherein the magnesium salt is a by-product;

[0013] 5) Solvent distillation: The filtrate and rinse liquid continuously produced in step 3) and the liquid phase material obtained in step 4) are continuously fed into a solvent distillation system, and a crude product, a circulating first solvent, a circulating monomer, and a circulating second solvent are obtained through distillation, wherein the circulating second solvent includes a circulating second solvent a, a circulating second solvent b, and a circulating second solvent c; the circulating first solvent is recovered and circulated to the Grignard reactor in step 1) for recycling, the circulating monomer is recovered and circulated to the substitution reactor in step 2) for recycling, the recovered circulating second solvent is respectively circulated to the Grignard reactor in step 1) for use, the recovered circulating second solvent b is recovered and circulated to the substitution reactor in step 2) for use, and the recovered circulating second solvent c is recovered and circulated to the filtering and washing integrated machine in step 3) for recycling;

[0014] 6) Product distillation: The crude product obtained after the solvent distillation in step 5) enters the product distillation system, and is distilled to obtain a main product, a by-product, a transition fraction and a distillation residue, wherein the main product is diphenyldimethoxysilane, and the by-products are monophenyltrimethoxysilane and triphenylmonomethoxysilane.

[0015] The present invention also provides a continuous production device for diphenyldimethoxysilane, which includes a Grignard reactor, a substitution reactor, a filter-washing integrated machine, a solvent distillation system, and a product distillation system that are connected in sequence; and also includes a dryer, the filter-washing integrated machine including a filtrate outlet and a wet cake outlet, the dryer including a wet cake inlet, a liquid phase logistics outlet, and a magnesium salt outlet, the wet cake outlet is connected to the wet cake inlet, and the liquid phase logistics outlet is connected to the solvent distillation system; the filtrate outlet is connected to the solvent distillation system; the solvent distillation system also includes a circulating first solvent outlet, a circulating second solvent outlet, and a circulating monomer outlet, the circulating first solvent outlet is connected to the Grignard reactor; the circulating second solvent outlet is respectively connected to the Grignard reactor, the substitution reactor, and the filter-washing integrated machine; the circulating monomer outlet is connected to the substitution reactor; the Grignard reactor includes a fresh first solvent inlet, a magnesium chips inlet, a halogenated benzene inlet, and a first inlet for a fresh second solvent; the substitution reactor includes a fresh monomer inlet and a second inlet for a fresh second solvent, and the filter-washing integrated machine includes a third inlet for a fresh second solvent.

[0016] By adopting the above technical solution, the beneficial effects of the present invention are:

[0017] 1. Grignard reaction, substitution reaction, filtration and washing, drying, and solvent distillation are performed in a continuous manner, which has high production efficiency and is easy to automate, while saving labor costs. In addition, the temperature, flow rate, and composition do not change over time during the continuous operation, and the product quality is good and stable.

[0018] 2. By changing the molar ratio of halogenated benzene to silicon monomer, the production ratio of main and by-products can be flexibly adjusted, and the adjustment process will not produce transitional waste.

[0019] 3. The Grignard reaction is operated continuously and does not require an initiator. There is no problem of difficulty in initiation, and there is no situation of sudden initiation due to accumulation of unreacted materials, which improves process safety.

[0020] 4. The magnesium salt drying process obtains magnesium salt by-products, and also recovers the solvent and product to a great extent.

[0021] 5. Grignard reaction, substitution reaction, filtration and rinsing are all micro-positive pressure processes. The fully closed system greatly reduces the loss of raw materials and solvents, is green and environmentally friendly, and the solvent recovery rate of the whole process is as high as over 98%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a production process schematic diagram of the present invention.

[0023] Figure 2 It is a schematic diagram of the production device of the present invention.

[0024] Component numbers in the figure

[0025] 1 Grignard reactor

[0026] 11 Fresh first solvent inlet

[0027] 12 Import of magnesium chips

[0028] 13 Halogenated benzene imports

[0029] 14 Circulation of the second solvent first inlet

[0030] 15. Grignard reagent export

[0031] 16 First solvent inlet

[0032] 17 Circulation first solvent inlet

[0033] 18 Second fresh solvent first inlet

[0034] 19 Second solvent first inlet

[0035] 2 Replacement reactor

[0036] 21 Grignard reagent import

[0037] 22 Fresh monomer import

[0038] 23 Circulation of the second solvent second inlet

[0039] 24 Replacement reaction liquid outlet

[0040] 25 monomer imports

[0041] 26 Recycled monomer imports

[0042] 27 Fresh second solvent second inlet

[0043] 28 Second solvent second inlet

[0044] 3. Filter and washing machine

[0045] 31 substitution reaction liquid inlet

[0046] 32 Fresh second solvent third inlet

[0047] 33 Wet cake outlet

[0048] 34 Filtrate outlet

[0049] 35 Second solvent third inlet

[0050] 36 Circulation second solvent third inlet

[0051] 4 Dryer

[0052] 41 Wet filter cake import

[0053] 42 Magnesium salt export

[0054] 43 Liquid phase logistics outlet

[0055] 5 Solvent distillation system

[0056] 51 Liquid logistics import

[0057] 52 Circulation first solvent outlet

[0058] 53 Circulation second solvent outlet

[0059] 54 Recycled monomer outlet

[0060] 55 Product Export

[0061] 6 Product distillation system

[0062] 61 Product imports

[0063] 62 First by-product export

[0064] 63 Main product exports

[0065] 64 Second by-product outlet

[0066] 65 Transition fraction and distillation residue outlet DETAILED DESCRIPTION

[0067] Hereinafter, embodiments of a continuous production method and apparatus for diphenyldimethoxysilane provided by the present invention will be described in detail.

[0068] The "ranges" disclosed herein are defined in terms of lower and upper limits, where a given range is defined by selecting a lower limit and an upper limit, and the selected lower and upper limits define the boundaries of the particular range. Ranges defined in this manner can be inclusive or exclusive of the end values ​​and can be combined arbitrarily, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also contemplated. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise indicated, the numerical range "a to b" is a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0069] [Continuous production method of diphenyldimethoxysilane]

[0070] The present invention provides a continuous production method of diphenyldimethoxysilane, such as Figure 1 , the continuous production method comprises:

[0071] 1) Grignard reaction: a fresh first solvent, a halogenated benzene, a fresh second solvent a, and magnesium chips are added simultaneously and continuously into a Grignard reactor to undergo a Grignard reaction to generate a Grignard reagent;

[0072] 2) Substitution reaction: the Grignard reagent obtained in step 1) is continuously overflowed into the substitution reactor, mixed with continuously pumped fresh monomer and fresh second solvent b to undergo a substitution reaction to obtain a substitution reaction liquid; wherein the fresh monomer is selected from methyl orthosilicate and / or phenyltrimethoxysilane;

[0073] 3) Filtration and washing: filtering the substitution reaction liquid continuously overflowing from the substitution reactor in step 2) through a filtration and washing machine, and continuously rinsing the filter cake with fresh second solvent C to obtain a wet filter cake, a filtrate, and a rinse liquid;

[0074] 4) filter cake drying: drying the wet filter cake after rinsing in step 3) under reduced pressure to obtain a liquid phase stream and magnesium salt, wherein the magnesium salt is a by-product;

[0075] 5) Solvent distillation: The filtrate and rinse liquid continuously produced in step 3) and the liquid phase material obtained in step 4) are continuously fed into a solvent distillation system, and a crude product, a circulating first solvent, a circulating monomer, and a circulating second solvent are obtained through distillation, wherein the circulating second solvent includes a circulating second solvent a, a circulating second solvent b, and a circulating second solvent c; the circulating first solvent is recovered and circulated to the Grignard reactor in step 1) for recycling, the circulating monomer is recovered and circulated to the substitution reactor in step 2) for recycling, the circulating second solvent a is recovered and circulated to the Grignard reactor in step 1) for recycling, the circulating second solvent b is recovered and circulated to the substitution reactor in step 2) for recycling, and the circulating second solvent c is recovered and circulated to the filtering and washing integrated machine in step 3) for recycling;

[0076] 6) Product distillation: The crude product obtained after the solvent distillation in step 5) enters the product distillation system, and is distilled to obtain a main product, a by-product, a transition fraction and a distillation residue, wherein the main product is diphenyldimethoxysilane, and the by-products are monophenyltrimethoxysilane and triphenylmonomethoxysilane.

[0077] In the method provided by the present invention, step 1) is a Grignard reaction: a fresh first solvent, a halogenated benzene, a fresh second solvent a, and magnesium chips are added simultaneously and continuously to a Grignard reactor to undergo a Grignard reaction to generate a Grignard reagent. Specifically:

[0078] In step 1) of the present invention, the halogenated benzene is one or more of chlorobenzene, bromobenzene and iodobenzene.

[0079] In step 1) of the present invention, the fresh first solvent is selected from one or more of tetrahydrofuran, methyltetrahydrofuran, and diethyl ether.

[0080] In step 1) of the present invention, during the initial reaction, the fresh first solvent is 4-10 times the mass of the halogenated benzene. Alternatively, the fresh first solvent is 4-6 times, 6-8 times, or 8-10 times the mass of the halogenated benzene. All initial reactions herein refer to the first feeding, before the cycle occurs.

[0081] In step 1) of the present invention, during the initial reaction, the fresh second solvent a is 4-10 times the mass of the halogenated benzene. Alternatively, the fresh second solvent a is 4-6 times, 6-8 times, or 8-10 times the mass of the halogenated benzene.

[0082] In step 1) of the present invention, during the initial reaction, the fresh second solvent a is selected from one or more of toluene, o-xylene, and ethylene glycol dimethyl ether.

[0083] In step 1) of the present invention, the molar ratio of the magnesium chips to the halogenated benzene is 1.001-1.02: 1. Alternatively, the molar ratio of the magnesium chips to the halogenated benzene can be, for example, 1.001-1.01: 1, 1.01-1.02: 1, 1.001-1.005: 1, 1.005-1.01: 1, 1.01-1.015: 1, 1.015-1.02: 1, etc.

[0084] In step 1) of the present invention, the reaction temperature is 25-75° C. Alternatively, the reaction temperature can be, for example, 25-50° C. or 50-75° C.

[0085] In step 1) of the present invention, the pressure is 0.02-0.2 MPaG. Optionally, the pressure is 0.02-0.1 MPaG, 0.1-0.2 MPaG, 0.02-0.06 MPaG, 0.06-0.1 MPaG, 0.1-0.15 MPaG, or 0.15-0.2 MPaG.

[0086] In step 1) of the present invention, the residence time is 1-20 hours. Optionally, the residence time is 1-10 hours, 10-20 hours, 1-5 hours, 5-10 hours, 10-15 hours, or 15-20 hours.

[0087] In step 1) of the present invention, the Grignard reactor is an overflow kettle reactor, which is a horizontal overflow reactor or a vertical overflow reactor. The mixing method of the reactor is mechanical stirring.

[0088] In the method provided by the present invention, step 2) is a substitution reaction: the Grignard reagent obtained in step 1) is continuously overflowed into the substitution reactor, mixed with continuously pumped fresh monomer and fresh second solvent b to undergo a substitution reaction to obtain a substitution reaction liquid; wherein the fresh monomer is selected from methyl orthosilicate (tetramethylsilane), phenyltrimethoxysilane, or a mixture thereof. Specifically:

[0089] In step 2) of the present invention, during the initial reaction, the molar ratio of the halogenated benzene to the fresh monomer is 0.5-2.5: 1. Alternatively, the molar ratio of the halogenated benzene to the fresh monomer can be, for example, 0.5-1.5: 1, 1.5-2: 1, 2-2.5: 1, 0.5-1: 1, 1-1.5: 1, or 1.5-2.5: 1.

[0090] In step 2) of the present invention, during the initial reaction, the fresh second solvent b is 4-10 times the mass of the fresh monomer. Alternatively, the fresh second solvent b is 4-6 times, 6-8 times, or 8-10 times the mass of the fresh monomer.

[0091] In step 2) of the present invention, the reaction temperature is 15-70°C. Alternatively, the reaction temperature is 15-45°C, 45-70°C, 15-30°C, 30-45°C, 45-60°C, or 60-70°C.

[0092] In step 2) of the present invention, the reaction pressure is 0.02-0.2 MPaG. Alternatively, the reaction pressure can be, for example, 0.02-0.1 MPaG, 0.1-0.2 MPaG, 0.02-0.06 MPaG, 0.06-0.1 MPaG, 0.1-0.15 MPaG, or 0.15-0.2 MPaG.

[0093] In step 2) of the present invention, the residence time is 0.5-10 h. Alternatively, the residence time can be, for example, 0.5-5 h, 5-10 h, 0.5-3 h, 3-5 h, 5-8 h, or 8-10 h.

[0094] In step 2) of the present invention, the replacement reactor is an overflow kettle reactor, which is a horizontal overflow reactor or a vertical overflow reactor. The mixing method of the reactor is mechanical stirring.

[0095] In the method provided by the present invention, step 3) is filtration and washing: the substitution reaction liquid continuously overflowing from the substitution reactor in step 2) is filtered through a filtering and washing integrated machine, and the filter cake is continuously rinsed with a fresh second solvent c to obtain a wet filter cake, a filtrate and a rinsing liquid.

[0096] In step 3) of the present invention, the fresh second solvent c is selected from one or more of toluene, o-xylene, and ethylene glycol dimethyl ether.

[0097] In step 3) of the present invention, during the initial reaction, the mass of the fresh second solvent c is 6-12 times the mass of the halogenated benzene. Alternatively, the mass of the fresh second solvent c can be, for example, 6-8 times, 8-10 times, 8-12 times, 6-10 times, or 10-12 times the mass of the halogenated benzene.

[0098] It should be noted that the fresh second solvent a, fresh second solvent b, and fresh second solvent c used in the present invention are the same solvent. During the initial reaction, the mass ratio of fresh second solvent a, fresh second solvent b, and fresh second solvent c is 21.4% to 54.5%: 14.3% to 45.5%: 21.4% to 54.5%.

[0099] In step 3) of the present invention, the temperature is 50-120° C. Alternatively, the temperature may be, for example, 50-70° C., 70-100° C., or 100-120° C.

[0100] In step 3) of the present invention, the pressure is 0.02-0.5 MPaG. Alternatively, the pressure may be, for example, 0.02-0.1 MPaG, 0.1-0.3 MPaG, 0.3-0.5 MPaG, 0.02-0.3 MPaG, 0.3-0.4 MPaG, or 0.4-0.5 MPaG.

[0101] In the method provided by the present invention, step 4) is filter cake drying: the wet filter cake after rinsing in step 3) is dried under reduced pressure to obtain a liquid phase stream and magnesium salt, wherein the magnesium salt is a by-product.

[0102] In step 4) of the present invention, the drying temperature is 80-150° C. Alternatively, the drying temperature may be, for example, 80-100° C., 100-120° C., or 120-150° C.

[0103] In step 4) of the present invention, the pressure is 5-20 kPa. Alternatively, the pressure can be, for example, 5-10 kPa, 10-20 kPa, 10-15 kPa, or 15-20 kPa.

[0104] In the method provided by the present invention, step 5) is solvent distillation: the filtrate and rinse liquid continuously generated in step 3) and the liquid phase material obtained in step 4) are continuously fed into a solvent distillation system, and a crude product, a circulating first solvent, a circulating monomer and a circulating second solvent are obtained through distillation, wherein the circulating second solvent includes a circulating second solvent a, a circulating second solvent b and a circulating second solvent c; the circulating first solvent is recovered and circulated to the Grignard reactor in step 1) for recycling, the circulating monomer is recovered and circulated to the substitution reactor in step 2) for recycling, the circulating second solvent a is recovered and circulated to the Grignard reactor in step 1) for recycling, the circulating second solvent b is recovered and circulated to the substitution reactor in step 2) for recycling, and the circulating second solvent c is recovered and circulated to the filtering and washing integrated machine in step 3) for recycling.

[0105] In step 5) of the present invention, the solvent distillation system is composed of three continuous distillation towers, which are used to recover the circulating first solvent, the circulating second solvent and the circulating monomer respectively. The circulating monomer is the unreacted monomer.

[0106] In step 5) of the present invention, the product distillation system is a batch distillation system, the bottom temperature is 50-250°C, and can be selected from 50-150°C, 150-250°C, 50-100°C, 100-150°C, 150-200°C, and 200-250°C. The pressure is 1-20 kPa, and can be selected from 1-10 kPa, 10-20 kPa, 1-5 kPa, 5-10 kPa, 10-15 kPa, and 15-20 kPa.

[0107] The definition of the first solvent includes a fresh first solvent and a circulating first solvent. It should be noted that during the initial reaction, there is no circulating first solvent, only a fresh first solvent, and the amount of the circulating first solvent is 0. During this process, the fresh first solvent is the first solvent. After the cycle starts, the first solvent includes a fresh first solvent and a circulating first solvent. The amount of the first solvent is unchanged, so there is a circulating first solvent, so after the cycle starts, the amount of the fresh first solvent used needs to be appropriately reduced according to the addition of the circulating first solvent. In step 5) of the present invention, after the cycle is stable, the circulating first solvent can replace part of the fresh first solvent and be used. The mass of the circulating first solvent in the Grignard reactor in step 1) is 0.9 to 0.99 times the mass of the first solvent, which can be selected from 0.9 to 0.95 times and 0.95 to 0.99 times. The cyclic stability appearing in the full text refers to that after multiple cycles, the feed amount and the circulating amount of each part in the continuous reaction process no longer change during the cycle and tend to be stable.

[0108] The definition monomer includes fresh monomer and circulating monomer. It should be noted that during the initial reaction, there is no circulating monomer, only fresh monomer, and the amount of circulating monomer is 0. Fresh monomer is monomer in this process. After the cycle starts, monomer includes fresh monomer and circulating monomer. The amount of monomer does not change, so there is circulating monomer, so after the cycle starts, the usage of fresh monomer needs to be appropriately reduced according to the addition of circulating monomer. In step 5) of the present invention, after the cycle is stable, the circulating monomer replaces part of the fresh monomer and is used. The mass of the circulating monomer in the reactor that is circulated to step 2) is 0 to 0.3 times of the mass of the monomer, which can be selected from 0 to 0.01 times, 0.01 to 0.3 times, 0.01 to 0.1 times, 0.1 to 0.2 times, 0.2 to 0.3 times, and 0.1 to 0.3 times.

[0109] After the circulation is stabilized (i.e., after steady-state operation is reached), the circulating second solvent a can be used instead of the fresh second solvent a in step 1). Fresh second solvent a does not need to be added, and the fresh second solvent a can be covered with the circulating second solvent a. In step 5) of the present invention, after the circulation is stabilized, the mass of the circulating second solvent a circulated to the Grignard reactor is 4-10 times the mass of the halogenated benzene. Alternatively, the mass of the circulating second solvent a circulated to the Grignard reactor can be, for example, 4-6 times, 6-8 times, or 8-10 times the mass of the halogenated benzene.

[0110] After the cycle stabilizes (i.e., after steady-state operation is reached), the monomers include fresh monomers and recycled monomers. The recycled second solvent b can replace the fresh second solvent b in step 2). It is not necessary to add fresh second solvent b, and the fresh second solvent b can be covered with the recycled second solvent b. In step 5) of the present invention, after the cycle stabilizes, the mass of the recycled second solvent circulated to the substitution reactor is 4-10 times the mass of the monomers; alternatively, the mass of the recycled second solvent circulated to the substitution reactor is 4-6 times, 6-8 times, or 8-10 times the mass of the monomers.

[0111] In step 5) of the present invention, except for the circulating second solvent circulated to the Grignard reactor and the circulating second solvent circulated to the substitution reactor, the remaining circulating second solvent is circulated to the filtering and washing integrated machine.

[0112] After the circulation is stable, the second solvent includes a fresh second solvent and a circulating second solvent, and the circulating second solvent here includes a circulating second solvent a circulated to the Grignard reactor, a circulating second solvent b circulated to the substitution reactor, and a circulating second solvent c circulated to the filter-washing integrated machine. It should be noted that during the initial reaction, there is no circulating second solvent, only fresh second solvent a, fresh second solvent b, fresh second solvent c, and the amount of the circulating second solvent is 0. During this process, the total amount of fresh second solvent a, fresh second solvent b, and fresh second solvent c is the second solvent. After the circulation starts, the second solvent includes fresh second solvent and circulating second solvent. The amount of the second solvent remains unchanged, because there is a circulating second solvent, so after the circulation starts, the usage of the fresh second solvent needs to be appropriately reduced according to the addition of the circulating second solvent, and after the circulation is stable, there is no need to add fresh second solvent a and fresh second solvent b, only add fresh second solvent c, step 5), after the circulation is stable, the mass of the fresh second solvent c is 0.01 to 0.2 times the mass of the second solvent. The options are 0.01~0.1 times, 0.01~0.05 times, 0.05~0.1 times, 0.1~0.15 times, 0.15~0.2 times, and 0.1~0.2 times.

[0113] In some embodiments, the mass ratio of the circulating second solvent including the circulating second solvent a circulated to the Grignard reactor, the circulating second solvent b circulated to the substitution reactor, and the circulating second solvent c circulated to the filter-washer integrated machine is (3-6):(2-5):(3-6).

[0114] In some embodiments, after the circulating first solvent and the circulating second solvent circulating to the Grignard reactor are circulated back to the Grignard reactor, step 1) is to continuously add the first solvent (fresh first solvent and circulating first solvent), halobenzene, magnesium chips, and circulating second solvent a to the Grignard reactor at the same time, so that halobenzene and magnesium chips produce a Grignard reaction. Specifically, the first solvent is selected from one or more of tetrahydrofuran, methyltetrahydrofuran, and ether. After the circulation is stable, the first solvent is 4-10 times the mass of halobenzene. The first solvent can be, for example, 4-6 times, 6-8 times, or 8-10 times the mass of halobenzene. The mass of the circulating first solvent circulating to the Grignard reactor in step 1) is 0.9 to 0.99 times that of the first solvent, which can be optionally 0.9 to 0.95 times or 0.95 to 0.99 times. The mass of the circulating second solvent circulated to the Grignard reactor is 4-10 times the mass of the halogenated benzene. Optionally, the mass of the circulating second solvent a circulated to the Grignard reactor can be, for example, 4-6 times, 6-8 times, or 8-10 times the mass of the halogenated benzene.

[0115] In some embodiments, after the circulating second solvent b and the circulating monomer circulate in the substitution reactor and circulate to the substitution reactor, step 2) is to continuously flow the Grignard reagent overflowing from step 1) into the substitution reactor, mix it with the continuously pumped monomer (including fresh monomer and recycled monomer) and the circulating second solvent, and the Grignard reagent and the monomer produce a substitution reaction. Specifically: the second solvent is selected from one or more of toluene, o-xylene, and ethylene glycol dimethyl ether. After the cycle is stable, the mass of the circulating second solvent b circulating in the substitution reactor is 4-10 times the mass of the monomer; alternatively, the mass of the circulating second solvent b circulating in the substitution reactor is 4-6 times, 6-8 times, or 8-10 times the mass of the monomer. Alternatively, the mass of the circulating second solvent b circulating in the substitution reactor can be, for example, 6-8 times, 8-10 times, 8-12 times, 6-10 times, or 10-12 times the mass of the halogenated benzene. The molar ratio of the halogenated benzene to the monomer is 0.5-2.5:1. Optionally, the molar ratio of the halogenated benzene to the monomer can be, for example, 0.5-1.5:1, 1.5-2:1, 2-2.5:1, 0.5-1:1, 1-1.5:1, or 1.5-2.5:1.

[0116] In some embodiments, after the recycled second solvent is circulated to the filter-washer, step 3) involves filtering the substitution reaction liquid continuously overflowing from the substitution reactor in step 2) through the filter-washer, and continuously rinsing the filter cake with the second solvent (including fresh second solvent c and recycled second solvent) to obtain a wet filter cake, a filtrate, and a rinse liquid. Specifically, after the circulation stabilizes, the amount of fresh second solvent c added is 0.01 to 0.2 times the total amount of the second solvent.

[0117] After the circulation is stabilized, the mass ratio of the circulating second solvent a: the circulating second solvent b: (the fresh second solvent c and the circulating second solvent c) is 21.4% to 54.5%: 14.3% to 45.5%: 21.4% to 54.5%.

[0118] In the method provided by the present invention, step 6) is product distillation: the crude product obtained after solvent distillation in step 5) enters the product distillation system, and after distillation, a main product, a by-product, a transition fraction and a distillation residue are obtained, wherein the main product is diphenyldimethoxysilane, and the by-products are monophenyltrimethoxysilane and triphenylmonomethoxysilane.

[0119] In the method provided by the present invention, the Grignard reaction, substitution reaction, filtration and washing, filter cake drying and solvent distillation processes are operated continuously.

[0120] [Continuous production equipment for diphenyldimethoxysilane]

[0121] like Figure 2 The present invention also provides a continuous production device for diphenyldimethoxysilane, comprising a Grignard reactor 1, a substitution reactor 2, a filtering and washing integrated machine 3, a solvent distillation system 5, and a product distillation system 6 connected in sequence; and also comprising a dryer 4.

[0122] In the device provided by the present invention, the Grignard reactor 1 includes a fresh first solvent inlet 11, a magnesium chips inlet 12, a halogenated benzene inlet 13, a Grignard reagent outlet 15, a circulating second solvent first inlet 14, a first solvent inlet 16, a circulating first solvent inlet 17, a second fresh solvent first inlet 18, and a second solvent first inlet 19. Among them, the fresh first solvent enters the Grignard reactor 1 from the fresh first solvent inlet 11 via the first solvent inlet 16, the fresh second solvent a enters the Grignard reactor 1 from the second fresh solvent first inlet 18 via the second solvent first inlet 19, the magnesium chips enter the Grignard reactor 1 from the magnesium chips inlet 12, and the halogenated benzene enters the Grignard reactor 1 from the halogenated benzene inlet 13. The first solvent subsequently recovered enters the Grignard reactor 1 for recycling through the circulating first solvent inlet 17 and the first solvent inlet 16, and the circulating second solvent a subsequently recovered enters the Grignard reactor 1 for recycling through the circulating second solvent first inlet 14 and the second solvent first inlet 19.

[0123] In the device provided by the present invention, the substitution reactor 2 includes a Grignard reagent inlet 21 and a fresh monomer inlet 22, a second inlet for a circulating second solvent 23, a substitution reaction liquid outlet 24, a monomer inlet 25, a circulating monomer inlet 26, a second inlet for a fresh second solvent 27, and a second inlet for a second solvent 28. The Grignard reagent inlet 21 is connected to the Grignard reagent outlet 15 for continuously overflowing the Grignard reagent into the substitution reactor 2, the fresh monomer enters the substitution reactor 2 from the fresh monomer inlet 22 via the monomer inlet 25, the fresh second solvent b enters the substitution reactor 2 from the fresh second solvent second inlet 27 via the second solvent second inlet 28, and the subsequently recovered recycled monomer can enter the substitution reactor 2 through the recycled monomer inlet 26 via the monomer inlet 25 for recycling, and the subsequently recovered recycled second solvent b enters the substitution reactor 2 through the recycled second solvent second inlet 23 via the second solvent second inlet 28 for recycling.

[0124] In the device provided by the present invention, the filtering and washing integrated machine 3 includes a substitution reaction liquid inlet 31, a fresh second solvent third inlet 32, a wet filter cake outlet 33, a filtrate outlet 34, a second solvent third inlet 35, and a circulating second solvent third inlet 36. Among them, the substitution reaction liquid inlet 31 is connected to the substitution reaction liquid outlet 24, and is used to allow the substitution reaction liquid continuously overflowing from the substitution reactor 2 to enter the filtering and washing integrated machine 3 for filtration. The fresh second solvent enters the filtering and washing integrated machine 3 from the fresh second solvent third inlet 32 ​​via the second solvent third inlet 35, and the filtrate outlet 34 is connected to the solvent distillation system 5. The filtered filtrate and rinsing liquid flow out from the filtrate outlet 34, and the filtered wet filter cake further enters the dryer 4. The third part of the circulating second solvent recovered later enters the filtering and washing integrated machine 3 through the circulating second solvent third inlet 36 via the second solvent third inlet 35.

[0125] In the apparatus provided herein, dryer 4 includes a wet cake inlet 41, a liquid stream outlet 43, and a magnesium salt outlet 42. The wet cake enters dryer 4 through wet cake inlet 41 for drying, and the magnesium salt obtained after drying flows out of magnesium salt outlet 42 as a by-product. The liquid stream flows out of liquid stream outlet 43. Liquid stream outlet 43 is connected to solvent distillation system 5, and the liquid stream enters solvent distillation system 5.

[0126] In the device provided by the present invention, the solvent distillation system 5 includes a liquid phase logistics inlet 51, a circulating first solvent outlet 52, a circulating second solvent outlet 53, a circulating monomer outlet 54, and a product outlet 55.

[0127] The circulating first solvent outlet 52 is in communication with the Grignard reactor 1. Specifically, the circulating first solvent flows out through the circulating first solvent outlet 52 and further enters the Grignard reactor 1 through the fresh first solvent inlet 11 for recycling.

[0128] The circulating second solvent outlet 53 is respectively connected to the Grignard reactor 1, the substitution reactor 2, and the filtering and washing integrated machine 3. Specifically, the circulating second solvent flows out from the second circulating outlet and enters the Grignard reactor 1 through the circulating second solvent first inlet 14, enters the substitution reactor 2 through the circulating second solvent second inlet 23, and enters the filtering and washing integrated machine 3 through the circulating second solvent third inlet 36 for recycling.

[0129] The circulating monomer outlet 54 is in communication with the substitution reactor 2 . Specifically, unreacted circulating monomer enters the substitution reactor 2 from the circulating monomer outlet 54 through the fresh monomer inlet 22 and is recycled.

[0130] In the apparatus provided by the present invention, the product distillation system 6 includes a product inlet 61, a main product outlet 63, a first by-product outlet 62, a second by-product outlet 64, and an intermediate fraction and distillation residue outlet 65. Diphenyldimethoxysilane flows out of the main product outlet 63. Monophenyltrimethoxysilane flows out of the first by-product outlet 62, and triphenylmonomethoxysilane flows out of the second by-product outlet 64. The intermediate fraction and distillation residue flow out of the intermediate fraction and distillation residue outlet 65.

[0131] In the device provided by the present invention, the Grignard reactor 1 is an overflow kettle reactor, and the overflow kettle reactor is a horizontal overflow reactor or a vertical overflow reactor.

[0132] In the device provided by the present invention, the substitution reactor 2 is an overflow kettle reactor, and the overflow kettle reactor is a horizontal overflow reactor or a vertical overflow reactor.

[0133] In the device provided by the present invention, the integrated filter-washer 3 is a positive-pressure rotary drum filter-washer 3 .

[0134] In the device provided by the present invention, the solvent distillation system 5 consists of three continuous distillation towers.

[0135] The beneficial effects of the present invention are further illustrated below with reference to the examples.

[0136] In order to make the invention objectives, technical solutions and beneficial technical effects of the present invention clearer, the present invention is further described in detail below with reference to the examples. However, it should be understood that the examples of the present invention are only for the purpose of explaining the present invention and are not intended to limit the present invention, and the examples of the present invention are not limited to the examples given in the specification. In the examples, where no specific experimental conditions or operating conditions are specified, the products were prepared under conventional conditions or under the conditions recommended by the material supplier.

[0137] Furthermore, it should be understood that the one or more method steps mentioned in the present invention do not exclude the presence of other method steps before or after the combination step, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. It should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the presence of other devices / apparatuses before or after the combination device / apparatus, or the insertion of other devices / apparatuses between two explicitly mentioned devices / apparatuses, unless otherwise specified. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be considered within the scope of the present invention.

[0138] In the following examples, unless otherwise specified, various raw materials of the present invention can be purchased commercially or prepared according to conventional methods in the art.

[0139] Example 1

[0140] The specific operation process is as follows:

[0141] The Grignard raw material used in this embodiment is bromobenzene, the first solvent is tetrahydrofuran, and the second solvent is o-xylene.

[0142] The Grignard reaction equation is:

[0143]

[0144] Initial reaction:

[0145] The Grignard overflow reactor is a horizontal overflow reactor, the stirring form is mechanical stirring, the reactor pressure is set to 0.05 MPaG, and 100 kg / h bromobenzene, 500 kg / h fresh tetrahydrofuran (5 times the weight of bromobenzene), 500 kg / h fresh o-xylene (5 times the weight of bromobenzene), and 15.64 kg / h magnesium chips (1.01 eq of bromobenzene mole) are continuously added to the horizontal overflow reactor. The reaction residence time is 6 hours and the reaction temperature is controlled at 65°C.

[0146] The Grignard reagent prepared in the Grignard preparation reactor continuously overflows into the substitution reactor and continuously reacts with 53.86 kg / h of fresh methyl orthosilicate monomer (bromobenzene: fresh methyl orthosilicate molar ratio = 1.8) and 269.30 kg / h of fresh o-xylene solvent (5 times the weight of methyl orthosilicate monomer) continuously pumped in a horizontal overflow reactor (substitution kettle). The reactor pressure is 0.05 MPaG, the reaction temperature is 20°C, and the reaction residence time is 4 hours.

[0147] The substitution reaction liquid prepared in the substitution overflow reactor continuously overflows and continuously enters the positive pressure filtration and washing integrated machine for continuous filtration in the feed area. The filter cake obtained by continuous filtration is rotated to the washing area and continuously rinsed with 600 kg / h fresh o-xylene solvent (6 times the weight of bromobenzene). The operating temperature of the filtration and rinsing is 60°C and the operating pressure is 0.3 MPaG.

[0148] The wet filter cake after filtration and rinsing by the positive pressure filter-washer is fed into a vacuum dryer for continuous drying and dehumidification at a pressure of 5 kPa and a drying temperature of 100°C. The rate of production of methoxymagnesium bromide byproduct is 85.16 kg / h, and the dry loss rate of the byproduct is 0.30%. The liquid phase produced after drying is combined with the filtrate and fed into the solvent distillation system.

[0149] The filtrate and rinse liquid produced in the continuous filtration and washing section are combined with the liquid material dried in the dryer and then continuously pumped into the continuous distillation tower of the solvent distillation system. They pass through the continuous distillation tower one, tower two, and tower three in sequence. The operating pressures are 0.05 MPaG, 0.05 MPaG, and 15 kPa, respectively. The distillation temperatures are 110°C, 130°C, and 130°C, respectively. The evaporated materials are circulating tetrahydrofuran solvent, circulating methyl orthosilicate monomer, and circulating o-xylene solvent, respectively, and are circulated back to the corresponding sections.

[0150] The crude product after the solvent is distilled off in the continuous distillation tower enters the product distillation system. The operation process is vacuum intermittent distillation with a distillation pressure range of 1.05-15kPa and a distillation temperature of 140-167℃.

[0151] After the cycle reaches steady state:

[0152] The Grignard overflow reactor is a horizontal overflow reactor, the stirring form is mechanical stirring, the reactor pressure is set to 0.05 MPaG, and 100 kg / h bromobenzene, 500 kg / h tetrahydrofuran (5 times the weight of bromobenzene, 3.35 kg / h fresh tetrahydrofuran, 496.65 kg / h recycled tetrahydrofuran), 500 kg / h recycled o-xylene (5 times the weight of bromobenzene), and 15.64 kg / h magnesium chips (1.01 eq of bromobenzene mole) are continuously added to the horizontal overflow reactor. The reaction residence time is 6 hours, and the reaction temperature is controlled at 65°C.

[0153] The Grignard reagent prepared in the Grignard preparation reactor continuously overflows into the substitution reactor and reacts continuously with 53.86 kg / h of methyl orthosilicate monomer (bromobenzene:methyl orthosilicate molar ratio = 1.8, of which 43.16 kg / h of fresh methyl orthosilicate monomer and 10.7 kg / h of recycled methyl orthosilicate monomer) and 269.30 kg / h of recycled o-xylene solvent (5 times the weight of methyl orthosilicate monomer) continuously pumped in a horizontal overflow reactor (substitution kettle). The reactor pressure is 0.05 MPaG, the reaction temperature is 20°C, and the reaction residence time is 4 hours.

[0154] The substitution reaction liquid prepared in the substitution overflow reactor continuously overflows and continuously enters the positive pressure filtration and washing integrated machine for continuous filtration in the feed area. The filter cake obtained by continuous filtration is rotated to the washing area and continuously rinsed with 600 kg / h o-xylene solvent (6 times the weight of bromobenzene, of which fresh o-xylene solvent is 12.05 kg / h and recycled o-xylene solvent is 587.95 kg / h). The operating temperature of the filtration and rinsing is 60°C and the operating pressure is 0.3 MPaG.

[0155] The wet filter cake after filtration and rinsing by the positive pressure filter-washer is fed into a vacuum dryer for continuous drying and dehumidification at a pressure of 5 kPa and a drying temperature of 100°C. The rate of production of methoxymagnesium bromide byproduct is 85.16 kg / h, and the dry loss rate of the byproduct is 0.30%. The liquid phase produced after drying is combined with the filtrate and fed into the solvent distillation system.

[0156] The filtrate and rinse liquid produced by the continuous filtration and washing section are combined with the liquid material obtained by drying in the dryer and then continuously pumped into the continuous distillation tower of the solvent distillation system. They pass through the continuous distillation tower one, tower two, and tower three in sequence. The operating pressures are 0.05 MPaG, 0.05 MPaG, and 15 kPa, respectively. The distillation temperatures are 110°C, 130°C, and 130°C, respectively. The evaporated materials are tetrahydrofuran solvent, methyl orthosilicate monomer, and o-xylene solvent, respectively, and are recycled back to the corresponding section. Since the cycle is already in a stable state, the amount of each substance in the circulation process is the same as before. The tetrahydrofuran solvent recovery rate was 99.33% (fresh tetrahydrofuran 3.35 kg / h, recycled tetrahydrofuran 496.65 kg / h, tetrahydrofuran solvent recovery rate = 496.65 / 500 = 99.33%), and the o-xylene solvent recovery rate was 99.12% (return to the Grignard overflow reactor 500 kg / h, return to the substitution reactor 269.30 kg / h, return to the positive pressure filter-washer integrated machine 587.95 kg / h, fresh o-xylene 12.05 kg / h, o-xylene solvent recovery rate = (500 + 269.3 + 587.95) / (500 + 269.3 + 600) = 99.12%).

[0157] After the solvent is distilled off in a continuous distillation tower, the crude product enters the product distillation system. The operation process is vacuum batch distillation. The distillation pressure range is 1.05-15 kPa, and the distillation temperature is 140-167°C. The flow rate of the obtained diphenyldimethoxysilane product is 52.68 kg / h, the purity is 99.73%, and the yield is 62.45%. The flow rate of monophenyltrimethoxysilane is 13.06 kg / h, the purity is 99.79%, and the yield is 19.09%. The flow rate of triphenylmonomethoxysilane is 7.99 kg / h, the purity is 99.82%, and the yield is 7.97%.

[0158] Example 2

[0159] The raw material of the Grignard reaction is changed to chlorobenzene, the first solvent is tetrahydrofuran, and the second solvent is o-xylene.

[0160] The Grignard preparation reaction equation is:

[0161]

[0162] The Grignard overflow reactor selected a horizontal overflow reactor, the stirring form was mechanical stirring, the reactor pressure was 0.05 MPaG, the reaction residence time was 6 h, the reaction temperature was adjusted to 55 ° C, the molar amount of magnesium chips was 1.01 times that of chlorobenzene, and the other reaction conditions were basically the same as in Example 1.

[0163] The Grignard reagent prepared from the Grignard overflow reactor continuously overflowed into the substitution reactor and reacted with the continuously pumped-in methyl orthosilicate monomer and o-xylene solvent. The reaction temperature was 20° C., the reaction pressure was 0.05 MPaG, the molar ratio of chlorobenzene to methyl orthosilicate was still 1.8:1, and the other conditions were basically the same as in Example 1.

[0164] The process conditions, solvent ratios and other data for the filtration and rinsing, filter cake drying, solvent recovery and continuous distillation, and product batch distillation sections are basically the same as those in Example 1.

[0165] Finally, the flow rate of the magnesium salt by-product obtained in the drying step is 79.49 kg / h, the mass content of methoxymagnesium chloride is 98.43%, the dry loss rate is 0.20%, and the solvent recovery rate of the whole process is calculated. The recovery rate of tetrahydrofuran solvent is 99.22%, and the recovery rate of o-xylene solvent is 99.39%; among the main products obtained, the mass purities of monophenyltrimethoxysilane, diphenyldimethoxysilane, and triphenylmonomethoxysilane are 99.84%, 99.68%, and 99.59%, respectively, and the yields are 19.28%, 66.06%, and 4.66%, respectively.

[0166] Example 3

[0167] Example 3 is basically the same as Example 1, except that, based on the reaction process of Example 1, the feed rate of methyl orthosilicate monomer in the substitution reactor is changed to 107.72 kg / h, so that the molar ratio of bromobenzene:methyl orthosilicate = 0.9, and the other conditions and proportions remain basically unchanged.

[0168] Finally, the flow rate of the magnesium salt byproduct obtained in the drying step was 85.33 kg / h, the mass content of methoxymagnesium bromide was 98.93%, and the dryness loss rate was 0.49%; in the solvent calculation of the whole process, the recovery rate of tetrahydrofuran solvent was 99.02%, and the recovery rate of o-xylene solvent was 99.40%; among the main products obtained, the mass purities of monophenyltrimethoxysilane, diphenyldimethoxysilane, and triphenylmonomethoxysilane were 99.95%, 99.40%, and 99.61%, respectively, and the yields were 48.68%, 13.70%, and 1.85%, respectively.

[0169] Example 4

[0170] Example 3 is basically the same as Example 1, except that, based on the reaction process of Example 1, the feed rate of methyl orthosilicate monomer in the substitution reactor is changed to 38.78 kg / h, so that the molar ratio of bromobenzene:methyl orthosilicate is 2.5, and the other conditions and proportions remain basically unchanged.

[0171] Finally, the flow rate of the magnesium salt byproduct obtained in the drying step was 85.25 kg / h, the mass content of methoxymagnesium bromide was 99.03%, and the dryness loss rate was 0.40%; in the solvent calculation of the whole process, the recovery rate of tetrahydrofuran solvent was 99.17%, and the recovery rate of o-xylene solvent was 99.12%; among the main products obtained, the mass purities of monophenyltrimethoxysilane, diphenyldimethoxysilane, and triphenylmonomethoxysilane were 97.51%, 99.27%, and 99.96%, respectively, and the yields were 2.06%, 32.13%, and 55.83%, respectively.

[0172] The data of Examples 1, 3, and 4 are shown in Table 1.

[0173] Table 1

[0174]

[0175] As can be seen from Table 1, the present invention can adjust the production ratios of monobenzene, diphenyl, and triphenyl by changing the equivalent of bromobenzene to methyl orthosilicate, that is, changing the feed flow rate of methyl orthosilicate relative to bromobenzene in the substitution reactor. No transitional waste is generated during the adjustment process, and the production requirements of different product ratios can be adapted.

[0176] The present invention can also better adapt to the production conditions of different raw materials. By changing the Grignard raw materials in the Grignard preparation process or changing the silicon monomer raw materials in the substitution reaction process, the production of different raw materials can be completed. The selectivity of the production conditions is good, and the recovery and utilization of the solvents is also relatively high. The recovery rate of each solvent can reach more than 98%.

[0177] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0178] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A continuous production method of diphenyldimethoxysilane, characterized in that, The continuous production method comprises: 1) Grignard reaction: a fresh first solvent, a halogenated benzene, a fresh second solvent a, and magnesium chips are added simultaneously and continuously into a Grignard reactor to undergo a Grignard reaction to generate a Grignard reagent; 2) Substitution reaction: the Grignard reagent obtained in step 1) is continuously overflowed into the substitution reactor, mixed with continuously pumped fresh monomer and fresh second solvent b to undergo a substitution reaction to obtain a substitution reaction liquid; wherein the fresh monomer is selected from methyl orthosilicate and / or phenyltrimethoxysilane; 3) Filtration and washing: filtering the substitution reaction liquid continuously overflowing from the substitution reactor in step 2) through a filtration and washing machine, and continuously rinsing the filter cake with fresh second solvent C to obtain a wet filter cake, a filtrate, and a rinse liquid; 4) filter cake drying: drying the wet filter cake after rinsing in step 3) under reduced pressure to obtain a liquid phase stream and magnesium salt, wherein the magnesium salt is a by-product; 5) Solvent distillation: The filtrate and rinse liquid continuously produced in step 3) and the liquid phase material obtained in step 4) are continuously fed into a solvent distillation system, and a crude product, a circulating first solvent, a circulating monomer, and a circulating second solvent are obtained through distillation, wherein the circulating second solvent includes a circulating second solvent a, a circulating second solvent b, and a circulating second solvent c; the circulating first solvent is recovered and circulated to the Grignard reactor in step 1) for recycling, the circulating monomer is recovered and circulated to the substitution reactor in step 2) for recycling, the circulating second solvent a is recovered and circulated to the Grignard reactor in step 1) for recycling, the circulating second solvent b is recovered and circulated to the substitution reactor in step 2) for recycling, and the circulating second solvent c is recovered and circulated to the filtering and washing integrated machine in step 3) for recycling; 6) Product distillation: The crude product obtained after the solvent distillation in step 5) enters the product distillation system, and is distilled to obtain a main product, a by-product, a transition fraction and a distillation residue, wherein the main product is diphenyldimethoxysilane, and the by-products are monophenyltrimethoxysilane and triphenylmonomethoxysilane.

2. The continuous production method of diphenyldimethoxysilane according to claim 1, wherein Also includes any one or more of the following conditions: A1) in step 1), the halogenated benzene is one or more of chlorobenzene, bromobenzene, and iodobenzene; A2) in step 1), the fresh first solvent is selected from one or more of tetrahydrofuran, methyltetrahydrofuran, and diethyl ether; A3) in step 1), during the initial reaction, the fresh first solvent is 4-10 times the mass of the halogenated benzene; A4) in step 1), during the initial reaction, the fresh second solvent a is 4-10 times the mass of the halogenated benzene; A5) in step 1), the fresh second solvent a is selected from one or more of toluene, o-xylene, and ethylene glycol dimethyl ether; A6) In step 1), the molar ratio of the magnesium chips to the halogenated benzene is 1.001-1.02:1; A7) In step 1), the reaction temperature is 25-75°C; A8) In step 1), the pressure is 0.02-0.2 MPaG; A9) in step 1), the residence time is 1-20 hours; A10) In step 1), the Grignard reactor is an overflow tank reactor, and the overflow tank reactor is a horizontal overflow reactor or a vertical overflow reactor.

3. The continuous production method of diphenyldimethoxysilane according to claim 1, characterized in that Also includes any one or more of the following conditions: B1) In step 2), during the initial reaction, the molar ratio of the halogenated benzene to the fresh monomer is 0.5-2.5:1; B2) In step 2), during the initial reaction, the fresh second solvent b is 4-10 times the mass of the fresh monomer; B3) in step 2), the fresh second solvent b is selected from one or more of toluene, o-xylene, and ethylene glycol dimethyl ether; B3) In step 2), the reaction temperature is 15-70°C; B4) in step 2), the reaction pressure is 0.02-0.2 MPaG; B5) in step 2), the residence time is 0.5-10h; B6) In step 2), the replacement reactor is an overflow tank reactor, and the overflow tank reactor is a horizontal overflow reactor or a vertical overflow reactor.

4. The continuous production method of diphenyldimethoxysilane according to claim 1, characterized in that Also includes any one or more of the following conditions: C1) in step 3), the fresh second solvent c is selected from one or more of toluene, o-xylene, and ethylene glycol dimethyl ether; C2) in step 3), during the initial reaction, the mass of the fresh second solvent c is 6-12 times the mass of the halogenated benzene; C3) The fresh second solvent a, the fresh second solvent b, and the fresh second solvent c are the same solvent. C3) In step 3), the temperature is 50-120°C; C4) In step 3), the pressure is 0.02-0.5 MPaG.

5. The continuous production method of diphenyldimethoxysilane according to claim 1, characterized in that Also includes any one or more of the following conditions: D1) In step 4), the drying temperature is 80-150°C; D2) In step 4), the pressure is 5-20 kPa.

6. The continuous production method of diphenyldimethoxysilane according to claim 1, characterized in that Also includes any one or more of the following conditions: E1) In step 5), the solvent distillation system is composed of three continuous distillation towers, which are used to recover the recycled first solvent, the recycled second solvent, and the recycled monomer respectively; E2) In step 5), the product distillation system is a batch distillation system with a bottom temperature of 50-250° C. and a pressure of 1-20 kPa; E3) After the circulation is stable, the recycled first solvent can replace part of the fresh first solvent, the first solvent includes the fresh first solvent and the recycled first solvent, and in step 5), the recycled first solvent recycled to the Grignard reactor in step 1) is 0.9 to 0.99 times the mass of the first solvent; E4) After the cycle is stable, the recycled monomer replaces part of the fresh monomer, the monomer includes the fresh monomer and the recycled monomer, and in step 5), the mass of the recycled monomer recycled to the reactor replaced in step 2) is 0 to 0.3 times the mass of the monomer; E5) After the circulation is stable, the recycled second solvent a can be used instead of the fresh second solvent a in step 1); in step 5), the mass of the recycled second solvent a recycled to the Grignard reactor is 4-10 times the mass of the halogenated benzene; E6) After the cycle is stabilized, the monomers include fresh monomers and recycled monomers, and the recycled second solvent b can be used instead of the fresh second solvent b in step 2); in step 5), the mass of the recycled second solvent b recycled to the substitution reactor is 4-10 times the mass of the monomers; E7) After the cycle is stabilized, in step 5), the mass of the recycled second solvent c circulated to the filter-washing integrated machine is 6-12 times that of the halogenated benzene; the recycled second solvent c can replace a portion of the fresh second solvent c in step 3); E8) After the circulation is stabilized, the second solvent includes the fresh second solvent c and the recycled second solvent. In step 5), the mass of the fresh second solvent c is 0.01 to 0.2 times the mass of the second solvent.

7. The continuous production method of diphenyldimethoxysilane according to claim 1, characterized in that The Grignard reaction, substitution reaction, filtration and washing, filter cake drying and solvent distillation processes are operated in a continuous manner.

8. A continuous production device for diphenyldimethoxysilane, characterized in that: The device comprises a Grignard reactor (1), a substitution reactor (2), a filter-washing integrated machine (3), a solvent distillation system (5), and a product distillation system (6) which are connected in sequence; and further comprises a dryer (4); the filter-washing integrated machine (3) comprises a filtrate outlet (34) and a wet cake outlet (33); the dryer (4) comprises a wet cake inlet (41), a liquid phase flow outlet (43), and a magnesium salt outlet (42); the wet cake outlet (33) is connected to the wet cake inlet (41); the liquid phase flow outlet (43) is connected to the solvent distillation system (5); the filtrate outlet (34) is connected to the solvent distillation system (5); the solvent distillation system (5) further comprises a circulating first solvent outlet (52), a circulating second solvent outlet (53), and a circulating first solvent outlet (54). A solvent outlet (53) and a circulating monomer outlet (54) are provided, wherein the circulating first solvent outlet (52) is in communication with the Grignard reactor (1); the circulating second solvent outlet (53) is in communication with the Grignard reactor (1), the substitution reactor (2), and the filter-washing integrated machine (3); the circulating monomer outlet (54) is in communication with the substitution reactor (2); the Grignard reactor (1) comprises a fresh first solvent inlet (11), a magnesium chips inlet (12), a halogenated benzene inlet (13), and a fresh second solvent first inlet (18); the substitution reactor (2) comprises a fresh monomer inlet (22) and a fresh second solvent second inlet (27); and the filter-washing integrated machine (3) comprises a fresh second solvent third inlet (32).

9. The continuous production device of diphenyldimethoxysilane according to claim 8, characterized in that Also includes any one or more of the following conditions: F1) The Grignard reactor (1) is an overflow tank reactor, wherein the overflow tank reactor is a horizontal overflow reactor or a vertical overflow reactor; F2) the replacement reactor (2) is an overflow tank reactor, and the overflow tank reactor is a horizontal overflow reactor or a vertical overflow reactor; F3) the filtering and washing integrated machine (3) is a positive pressure rotary drum filtering and washing integrated machine (3); F4) The solvent distillation system (5) consists of three continuous distillation towers.

10. The production system of diphenyldimethoxysilane according to claim 8, characterized in that: The product distillation system (6) includes a main product outlet (63), a first by-product outlet (62), a second by-product outlet (64), and a transition fraction and distillation residue outlet (65).

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