KR860000993B1 - Preparation for silans - Google Patents

Abstract

Inorg. catalyst contg. tertiary amine and quaternary ammonium salt was specialized in the heterogeneous reaction of silane chloride. Silane chloride was prepd. from dichlorosilane which had been prepd. from trichlorosilane. The inorg. catalyst contg. tertiary amine and quaternary ammonium was used in both reactions.

Description

Method for preparing silanes for disproportionation of chloride silanes

The present invention uses a catalyst in which tertiary amines and quaternary ammonium salts are bonded to inorganic substances such as silica, zeolites, silicone resins, and the like. It is a manufacturing method of.

Chlorinated silanes with hydrogen-bonded silicon (Si-H) are very useful silicon compounds that can be used to synthesize various organochlorinated silanes because they can cause side reactions to organic compounds with unsaturated bonds. (E.Y. Lukevits & M.G. Voronkov, "Organic Insertion Reactions of Group IV Elements" Consultants Bureau, New York, 1966)

In the process of manufacturing semiconductor silicon from industrial metal silicon, trichlorosilane is widely known as an intermediate material.In order to produce high-purity semiconductor silicon, industrial metal silicon containing impurities is converted to trichlorosilane by reacting with hydrogen chloride, and then purified. Reduction to obtain high purity semiconductor silicon. (FA Padovani, U.S. Patent No. 4092466) As the semiconductor industry develops, the demand for semiconductor silicon increases and interest in improving the manufacturing process increases, thereby converting the semiconductor silicon into a dichlorosilane or silane which is easy to reduce and purify trichlorosilane. The way of getting it was improved. (L.M. Coleman, US Patent 4340574)

Therefore, the industrial importance of chlorinated silanes can be seen as adding day by day.

When trichlorosilane is disproportionated, it is converted into dichlorosilane and tetrachloride silane, and silane can be obtained by the same reaction from dichlorosilane. (C.J. Litteral, US Patent 4113845)

The disproportionation reaction is a reaction in which hydrogen bonded to silicon collects as hydrogen, chlorine collects as chlorine, and one side becomes hydrogen-rich and the other is separated into compounds that increase chlorine. This reaction requires a catalyst. Various kinds of catalysts have been used in the past, but many of them are not industrially important.

In other words, nitrile or amine compounds have been reported as disproportionation catalysts (DL Bailey, GH Wagner, U.S. Patent 2732282), but this method requires a high temperature of 150-200 ° C. Because it does not have to use a high-pressure reactor, there is a disadvantage in that the activity of the catalyst is lowered not much. Moreover, this method is not suitable for continuous processes since a distillation step for separating the catalyst is required after the reaction.

As described above, a catalyst that reacts at a relatively low temperature, and the reaction occurs at a relatively low temperature is a polyvinylpyrrolidine combined with a tertiary amine, which is a heterogeneous catalyst that does not dissolve in the reactant because it is a polymer. It is known that the reaction temperature is relatively low and can be used at 50 to 100 ° C. (KK Seth, US Patent 4395389) As a similar catalyst, an ion exchange resin having a quaternary ammonium salt is used. (C.J. Litteral, U.S. Pat.No. 4113845) is a heterogeneous catalyst in which a reaction takes place below 100 ° C even with ion exchange resins, and is produced under the trademark Amberyst A-21 by Tom End Haas, USA.

Since the catalyst made of such an organic resin is an organic material, the specific gravity is light, and therefore, special care needs to be taken because it is easily swept away by the reactants when it is charged to the reactor in a continuous process. Moreover, since the reactants are inorganic, they have low affinity and are difficult to use for a long time.

In order to compensate for the above disadvantages, the present inventors have developed a method of preparing an inorganic catalyst by combining tertiary amine or quaternary ammonium salt with silica, zeolite or silicone resin.

The present invention relates to an advanced process for disproportionating trichlorosilane using an inorganic catalyst in which tertiary amine and quaternary ammonium salts are combined to synthesize dichlorosilane and converting the dichlorosilane into a silane disproportionation reaction using the same catalyst. will be.

The catalyst used in the present invention is suitable for both batch and continuous forms in which tertiary amines and quaternary ammonium salts are simultaneously bonded to the inorganic substance, but are particularly advantageous for the continuous type.

Since the catalyst used in the present invention has a high specific gravity, it is easy to fill the reaction tank and is not swept away when passing the chloride silanes.

The reaction for preparing the dichlorosilane by disproportionation of the trichlorosilane with the catalyst used in the present invention may be performed at a reaction temperature between 0 ° C and 200 ° C, but from room temperature to 100 ° C is a suitable temperature.

The reaction pressure can be both atmospheric pressure and high pressure, but at low pressure, the breakage point of the reactants or products is low, so the reaction rate is low because the gas phase reaction is low, and the liquid phase reaction at high pressure is advantageous in terms of reaction rate.

However, besides the reaction temperature and reaction pressure, one thing to be aware of should give sufficient contact time between catalyst and reactant. This can be solved by increasing the amount of catalyst and sufficient reaction time in a batch reaction, and in a continuous process, it is possible to increase the length of the reactor filled with the catalyst and to slow down the flow rate of the reactants. Silane can be obtained by reacting the starting material with dichlorosilane instead of trichlorosilane and using the same catalyst.

Example 1

In a 300 ml glass tube reactor with a slight pressure-resistant Teflon valve attached to the spout, 100 g of an inorganic catalyst in which tertiary amines and quaternary ammonium salts were bonded to silica, zeolite, or silicone resin was added, followed by 150 ml of SiHCl ₃ , followed by Teflon Valve. The mixture was heated to 100 ° C. for 1 hour, and analyzed by gas chromatography. HSiCl ₃ was 80.9% and SiCl ₄ was 9. 52%, 8.81% of SiH ₂ Cl ₂ and 0.24% of SiH ₃ Cl were obtained.

Example 2

Example 1 using the catalyst as in the SiH ₂ Cl ₂ was reacted to produce sikyeotdeoni SiH ₄ is 10.6%, SiHCl ₃ is 32.2%, SiH ₄ is 0.1%, and the remainder was recovered starting material.

Example 3

300g of the catalyst as in Example 1 was filled in a reaction tank made of staninless Steel 316 type, and the heating wire was wound around the reaction tank to maintain 80 ° C with a thermostat. The reactor was connected to a pump capable of injecting SiHCl ₃ and a valve was installed to control the pressure on the reactor. The outside of the valve was connected to gas chromatography to analyze the composition of the product. SiHCl _3, the time is 20 to to 30 minutes sikyeotdeoni reaction by controlling the injection rate of SiHCl ₃ looked is 4-8% of the SiH ₂ Cl ₂ to stay in the reaction tank, 6-12% of SiCl ₄ and 0.02 ~ 0.03% of SiH ₃ Cl was obtained.

Claims (2)

A method for producing a silane by disproportionation of silane chloride, wherein the silane chloride is converted to silane using a catalyst in which a tertiary amine or quaternary ammonium salt is bound to an inorganic material. The method for producing a silane by disproportionation of silane chloride according to claim 1, wherein trichlorosilane, dichloride or a mixture thereof is used as the silane chloride.