KR100407518B1 - Method for manufacturing dimethyldichlorosilane - Google Patents

Abstract

PURPOSE: Provided is a novel method for manufacturing dimethyldichlorosilane by reacting metallic silicone and methylchloride, thereby increasing production yield of silane based compound and reducing the production cost thereof. CONSTITUTION: A novel method for manufacturing dimethyldichlorosilane by reacting metallic silicone and methylchloride, it is characterized by using an alloy type of contact mass in which metallic silicone is mixed with 0.78-1.56 wt.% of CuCl, 0.63-2.10 wt.% of ZnCl2, 0.63-2.1 wt.% of CsCl, 50-3000ppm of Sn and 0.1-0.2 wt.% of Al and the mixture thereof is melted, or a contact mass in which 0.78-1.56 wt.% of CuCl, 0.63-2.10 wt.% of ZnCl2, 0.63-2.1 wt.% of CsCl, 50-3000ppm of Sn and 0.1-0.2 wt.% of Al are precipitated in metallic silicone.

Description

Method for preparing dimethyldichlorosilane

The present invention relates to a method for preparing dimethyldichlorosilane, and more particularly, a contact mass and methyl chloride in which metal silicon (Si), copper compound, zinc compound, Cs, Sn and Al are mixed in an appropriate ratio. A method for preparing a new dimethyldichlorosilane, which can increase the conversion rate of metal silicon, increase the production rate of silane compounds per unit time by reacting (methylchloride), and maintain the mild reaction conditions, thereby reducing the production cost.

Among organochlorosilanes, in particular, a method for preparing dimethyldichlorosilane has been suggested in several documents [US Patent No. 2,380,995; Organohalosilanes Precursors to silicones, Elsevier Publishing Company (1967); Catalyzed Direct reactions of silicon, ELSEVIER Press (1993) and the like.

In general, organic chlorosilanes are produced by so-called direct synthesis or Rochow synthesis, and in the case of dimethyldichlorosilane, methyl chloride and metal silicon are directly reacted under a copper catalyst. This is the most common.

However, in addition to the dimethyldichlorosilane (hereinafter referred to as "M2"), a small amount of methyltrichlorosilane (hereinafter referred to as "M1") and trimethylchlorosilane (hereinafter referred to as "M3") are formed in the manufacturing method. In addition, methyldichlorosilane, dimethylchlorosilane, disilane and the like are produced as by-products.

Among the organochlorosilane compounds, M2 is most widely applied industrially, and M2 is an oil or a gum used as a basic raw material of a silicone product by hydrolysis reaction and polymerization. You can make Polyorganosiloxane resins (US Pat. Nos. 2,258,218, 2,258,222), oils (US Pat. Nos. 2,469,888, 2,469,830), and elastomers (US Pat. No. 2,448,756) were prepared based on M2.

In the direct synthesis method using a catalyst, factors affecting the reaction results are as follows: first, reactivity of a contact mass composed of a catalyst and metal silicon (Si), second, types of catalyst and additives, fourth, type of reactor, There are other synthetic conditions (temperature, etc.).

However, among the above factors, the reactivity of contact mass is the most important factor.The contact agent is a method of mixing the catalyst and the silicon of silicon, the characteristics of the compound produced, the type of catalyst, the size of the catalyst particles, the catalyst. Since the reactivity with methyl chloride can vary greatly depending on the particle size distribution of the, contact manufacturing technology is very important. Common methods for preparing a contact include a method of simply physically mixing the catalyst and the metal silicon, melting the catalyst and the metal silicon together to form an alloy, or chemical deposition.

As a reactor for the reaction of methyl chloride and metal silicon, fixed bed reactors, agitated bed reactors or fluidized bed reactors are used, each of which has advantages and disadvantages, but it is advantageous to use a fluidized bed reactor in industrial production. In the reaction of metal silicon with methyl chloride, the surface of the metal silicon is contaminated with carbon and thus gradually loses reactivity. The reactor must be able to solve such a problem.

In addition, various cocatalysts and additives may be added in addition to the copper catalyst in order to increase the yield of M2 during the reaction of methyl chloride and metal silicon. For example, zinc or zinc compounds (US Pat. No. 2,464,033), aluminum (US patent) 2,403,370), tin, manganese or nickel (UK Patent No. 1,207,466), cobalt (UK Patent 907,161), potassium chloride (USSR 306,650), and the like. However, the addition of these promoters and additives has the effect of improving the direct synthesis reaction, the following problems have been pointed out. The problems include low selectivity of M2 in the produced silane compounds, long initial reaction induction time or high initial reaction temperature, low product of silane compounds produced per unit time, low conversion rate of metal silicon, catalyst system ( The catalyst system reacts sensitively to impurities and produces high polymers such as disilane.

Therefore, in the present invention, as a result of research efforts to solve the problems appearing in the conventional direct synthesis method, a new reactor of methyl chloride and metal silicon was newly devised, and copper compound, zinc compound, Cs, Sn, and Al were mixed with metal silicon at an appropriate ratio. The present invention has been completed by preparing and using a contact mass.

Therefore, the present invention can increase the selectivity of M2 as much as possible and increase the conversion rate of the metal silicon to increase the use efficiency of raw materials, as well as improve the production rate of silane compounds per unit time and maintain the mild reaction conditions, which can also reduce the production cost. The purpose is to provide a new M2 manufacturing method.

Hereinafter, the present invention will be described in detail.

The present invention provides a method for producing dimethyldichlorosilane by reacting metal silicon (Si) with methyl chloride, 0.78 to 1.56% by weight of CuCl, 0.63 to 2.10% by weight of ZnCl ₂ , and CsCl to the metal silicon (Si). Dimethyldichlorosilane using a contact form in the form of alloys melted by mixing 0.63 to 2.1% by weight, 50 to 3,000 ppm Sn and 0.1 to 0.2% by weight of Al or metal silicon (Si). The manufacturing method is characterized by that.

In addition, the present invention is made of a stainless steel material having an internal diameter of 2.5 to 5 cm and a reaction tube (1) having a length of 45 to 60 cm, the heating method by electric heating wire is selected by dividing into three sections and the temperature according to the position Temperature controller (2) for minimizing the error of the device, vibrator (3) for fluidizing the reactants in the reaction tube, ultrasonic oscillator (4) for preventing the formation of contact mass and breaking up the generated mass, and the reaction product And an apparatus for producing dimethyldichlorosilane, which consists of a cooling device 5 for cooling and a gas chromatography 6 for analyzing the composition of the product.

Referring to the present invention in more detail as follows.

The present invention provides a contact mass in which metal silicon reacts with a copper compound, zinc compound, Cs, Sn, and Al or an alloy in which metals are deposited around metal silicon when methyl chloride reacts with metal silicon. The present invention relates to a new M2 manufacturing method that can increase the selectivity of M2, increase the conversion rate of metal silicon, and reduce the production cost due to the mild reaction conditions.

Since the particle size of the metal silicon (Si) used in the present invention has a great influence on the selectivity of M2 and the conversion of Si, it is very important to select Si having an appropriate particle size. It is 325 mesh (mesh), Preferably it is 100-325 mesh, Especially preferably, it is a case where 70% is 130-150 mesh and the remainder does not exceed 200 mesh.

In the present invention, a copper compound such as cuprous chloride (CuCl), cuprous chloride (Cul ₂ ), cuprous oxide (Cu ₂ O), cuprous oxide (CuO), and the like are used as the catalyst. The conversion rate and selectivity for M2 were high. The particle size of the catalyst is 1 to 100 µm, preferably 5 to 10 µm. The copper compound is used in an amount of 5 to 25% by weight (in terms of metal), preferably 5 to 12% by weight, based on the metal silicon. If the catalyst is used in an amount less than 5% by weight, the reaction rate is too slow and 25% by weight. If it exceeds, there is a problem that the Si conversion and M2 selectivity are lowered.

In the present invention, and it decided to use the ZnCl _2, ZnO, etc., for example a zinc compound as a promoter (promoter), particularly preferred is the use of ZnCl _2. Zinc compound is used 0.2 to 1.5% by weight relative to the metal silicon, if the promoter is used less than 0.2% by weight can not obtain a shortening effect of the induction period aimed in the present invention, if it exceeds 1.5% by weight M2 selection There is a problem that the degree is lowered.

In addition, one or two or more selected from Cs, Sn, Al, and the like may be added as other additives. Preferably, CsCl, Sn, and (CH ₃ ) ₄ Sn are suitably mixed and used. When Cs is used as an additive, 0.1 to 3.0% by weight, preferably 0.5 to 1.5% by weight, of metal silicon is added. If the amount is less than 0.1% by weight, the effect of addition is insufficient. The selectivity to decreases. When Sn or (CH ₃ ) ₄ Sn is added, it can be made into a vapor phase to obtain a better effect, and the addition of a small amount can double the initial reactivity and production rate. It seems that the heterogeneous mixing phenomenon was excluded. Sn adds 50 to 3,000 ppm with respect to the metal silicon, but if the amount is out of the above range, good results cannot be obtained. In the case of using the catalyst and the promoter, the production rate of the silane compound was increased by about 20 times or more when the catalyst, the promoter and the additive were used. Among the additives, the use of Sn and Cs rather than the Sn is used. Si conversion rate rose significantly. Al is added in an amount of 0.01 to 0.3% by weight, preferably 0.1 to 0.2% by weight, based on the metal silicon. If the amount is less than 0.01% by weight, the effect of addition is insufficient. There is a problem that the selectivity of.

Therefore, the best reaction system for the production of M2 by the reaction of methyl chloride and metal silicon is a state in which copper compound, zinc compound, Cs compound, Sn and Al are mixed in an appropriate ratio. 0.5 to 1.0% by weight, zinc compound (in terms of metal) 0.3 to 1.0% by weight, Cs compound 0.5 to 1.5% by weight, Sn 50 to 3,000 ppm and Al 0.1 to 0.2% by weight.

In addition, it is preferable to maintain the reaction temperature in the range of 250 to 340 ° C. In the above temperature range, the production rate of the silane-based compound tends to increase as the reaction temperature increases. Will be done. Therefore, the most preferable reaction temperature is 290-310 degreeC.

If this reaction persists, the metal silicon is inevitably consumed, and the particles gradually become smaller and eventually form a mass having pores therein, making contact with methyl chloride gas (CH ₃ Cl) difficult. Elevations and imbalances are generated to lower selectivity to M2, conversion of Si, production rate of product, and the like. Therefore, in the present invention, the reactor was designed to suppress the formation of lumps by maximizing the friction between the homogeneous temperature distribution and the particles and to directly crush the produced lumps.

The reactor used in the present invention is as shown in the accompanying drawings, the reaction tube (1) is made of a stainless steel pipe (SUS 316) material having an internal diameter of 2.5 to 5 cm and a length of 45 to 60 cm. The heating method was selected by the heating method by electric heating wire, divided into three sections and heated and controlled by the temperature controller 2 of the automatic temperature control (PID) method with a 1 ° C error. Thus, heating is divided into three sections to minimize the temperature error according to the position and to control the temperature accurately. The entire reactor is vibrated by the vibrating device 3 at the lower end of the reaction tube, so that the reactants inside the reaction tube generate friction between particles while forming a fluidized bed. In addition, the ultrasonic oscillator 4 installed in the middle of the reaction tube prevented the formation of contact masses due to the reaction of the metal silicon and methyl chloride, so that the produced masses were crushed. This maximizes the homogeneous temperature distribution and friction between the particles during the reaction to create a new metal silicon surface to promote the adsorption of methyl chloride gas to the metal silicon for the production of silane compounds.

M2 manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, a contact mass in the form of an alloy or Cs, Sn, Al, Mn in the form of an alloy, or in the form of depositing them around a metal silicon in the reaction of the metal silicon and methyl chloride gas Was used. In more detail, the process of preparing the contact mass is first mixed with a catalyst, a cocatalyst, and an additive, and then weighed in a sealed box of a nitrogen atmosphere and placed in a bottle, followed by homogeneous mixing in a vibration mixer. . Then, metal silicon is mixed and mixed in a vibration mixer for 2 hours to obtain a physically homogeneous mixture. The mixture was introduced into the raw material inlet 1-1 of the reaction tube 1, the nitrogen gas (N ₂ ) was introduced into the gas inlet 1-2, and the reactor was gradually heated up at 5 ° C./1 min to 350 to 400. After the temperature is raised to 3 ° C. and maintained for 3 to 6 hours, the metal silicon and the catalyst, the promoter and the additive react to form an alloy or a contact mass in which they are deposited on the metal silicon surface.

The above prepared contact agent was cooled to 250 ° C. or lower, the temperature controller 2 was adjusted to maintain the internal temperature of the reaction tube in the range of 250 to 340 ° C., and then a nitrogen gas (N ₂ ) to the gas inlet (1-2). The inlet was stopped and the methyl chloride gas (CH ₃ Cl) was introduced. The methyl chloride gas was preheated to about 250 ° C. in the preheating zone (1-3) prior to the inflow and introduced at a rate of 15 to 50 l / hour. In addition, the glass frit filter (1-4) is mounted inside the reaction tube (1) to evenly classify the methyl chloride gas. During the reaction, the vibration device 3 vibrates at a frequency of 5 to 10 m / sec to fluidize the reactants so as to react smoothly with the methyl chloride gas. Also, the ultrasonic oscillator 3 causes friction between materials to occur. Probes 4-1 were placed on both sides of the reactor to break up the fine mass formed during the reaction. The reaction product discharged through the reaction product outlet (1-5) is collected in the cooler (5), the cooling is to be carried out at -30 ℃. The composition of the product was also analyzed by gas chromatography (6) connected on-line.

In the manufacturing method of the present invention as described above, the weight ratio of M1 / M2 is 0.02 or less, which greatly reduces the production rate of M1 which can be easily produced as a by-product, the selectivity of M2 is up to 90%, and the conversion rate of Si is up to 87. %, Methylchlorosilane production rate was 260 g / h / Si Kg. This is to suppress the agglomerates that can be produced by the reaction with methyl chloride in the reaction and to provide a new surface.

Hereinafter, the present invention will be described in more detail with reference to the following Examples, but the present invention is not limited thereto.

Example 1

CuCl (13.2 g), ZnCl ₂ (1.57 g), CsCl (1.35 g), Al (0.3 g), and Sn (750 ppm) are mixed, weighed in a sealed box in a nitrogen atmosphere, and bottled. Homogenously mixed in a vibrating mixer. Then, silicon silicon (150 g) was mixed thereto and then mixed in a vibration mixer for 2 hours. The mixture is introduced into the raw material inlet 1-1 of the reaction tube 1, the nitrogen gas (N 2) is introduced into the gas inlet 1-2, and the reaction tube is gradually heated to 5 ° C./1 min to 310 ° C. The temperature was raised and then maintained for 3 hours to form a contact mass.

The above prepared contact agent was cooled to 250 ° C. or lower, and the temperature controller 2 was operated to maintain the temperature inside the reactor in the range of 360 ° C., and then the inflow of nitrogen gas (N 2) into the gas inlet (1-2) was stopped. Instead, methyl chloride gas (CH ₃ Cl) was introduced. The methyl chloride gas was preheated to about 250 ° C. in advance in the preheating zone (1-3) prior to the introduction, and introduced at a rate of 30 L / hour.

During the reaction, the vibrator 3 vibrated at a frequency of 7 m / sec to fluidize the reactants to react smoothly with the methyl chloride gas, and also to facilitate friction between the raw materials using the ultrasonic oscillator 4. The reaction product was discharged through the outlet (1-5) and collected in the cooler (5), the cooling was to be carried out at -30 ℃. The composition of the product was also analyzed by gas chromatography (6) connected on-line, and the results are shown in Table 2 below.

Examples 2 and 3 and Comparative Examples 1 to 4

The same method as in Example 1 except that the composition, the reaction temperature and the total reaction time of the reactants were different as shown in the following Table 1. In addition, the composition of the product is shown in Table 2 below.

The figure is a schematic of the reactor used in the present invention.

[Explanation of symbols on the main parts of the drawings]

1: reaction tube 1-1: raw material inlet

1-2: gas inlet 1-3: preheating zone

1-4: glass frit filter 1-5: Product outlet

2: temperature controller 3: vibration system

4: ultrasonic oscillator 4-1: ultrasonic probe

5: cooling device 6: gas chromatography

Claims (3)

In the method for producing dimethyl dichlorosilane by reacting metal silicon (Si) and methyl chloride (methylchloride), Cu8 0.78 to 1.56% by weight of CuCl, 0.63 to 2.10% by weight of ZnCl ₂ , 0.63 to 2.1% by weight of CsCl, 50 to 3,000 ppm of Sn and 0.1 to 0.2% by weight of Al alloy Method for producing dimethyldichlorosilane, characterized in that using a contact agent of the form in which they are deposited on the agent or metal silicon (Si). The contact agent composition of claim 1 is introduced into the raw material inlet (1-1), the nitrogen gas (N ₂ ) is introduced into the gas inlet (1-2) while raising the internal temperature of the reactor to 350 ~ 400 ℃ the contact agent after making contact mass, The contactant was cooled to 250 ° C. or lower and the temperature controller 2 was adjusted to maintain the internal temperature of the reaction tube in the range of 250 to 340 ° C., and then the inflow of nitrogen gas (N ₂ ) into the gas inlet (1-2) was stopped. And reacted with methyl chloride gas (CH ₃ Cl) preheated to 250 ° C. at a rate of 15 to 50 l / hour, and evenly classifying methyl chloride gas by the glass frit filter (1-4). By vibrating at a frequency of 5 to 10 m / sec by (3), the reactant is fluidized, and the friction between the raw materials is caused by the ultrasonic oscillator 3 well, and the ultrasonic probe 4-1 is disposed on both sides of the reactor. To pulverize the fine mass formed during the reaction, The reaction product discharged through the reaction product outlet (1-5) is collected in a cooler (5) fixed at -30 ℃ a process for producing dimethyldichlorosilane. Reaction tube (1) made of stainless steel with internal diameter of 2.5 to 5 cm and length of 45 to 60 cm (1), heating method by electric heating wire is selected, and heating is divided into three sections to minimize the temperature error according to the location. A temperature controller 2, a vibrator 3 for fluidizing the reactants in the reaction tube, an ultrasonic oscillator 4 for preventing the formation of contact masses and crushing the formed masses, and a cooling device for cooling the reaction product ( 5) and a gas chromatography (6) for analyzing the composition of the product.