JPS61270207A - Production of monosilane - Google Patents

Abstract

PURPOSE:To produce efficiently a monosilane useful as a raw material of high- purity silicon and to separate easily a catalyst from a reaction product, by disproportionating an alkoxysilane in the presence of a catalyst consisting of a specific metallic halide. CONSTITUTION:A halide (e.g., CuF2 or AgF2) of a metal selected IB group, III group, IV group except carbon and silicon of periodic table and iron is prepared as a catalyst. In the presence of the catalyst, an alkoxysilane (e.g., triethoxysilane) shown by the formula I (R is 1-6C alkyl; n is 1-3) is subjected to a disproportionation reaction as shown in the formula II. Then, the reaction product is filtered and the catalyst is separated to give the aimed monosilane. The amount of the catalyst used is properly about 0.1-50wt%, and the reaction temperature is properly about 50-80 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing monosilane using an alkoxysilane as a raw material.

[Conventional technology]

Monosilane is used as a raw material for high-purity silicon for semiconductors, as well as for amorphous silicon photoreceptors, solar cells,
It is widely used as a raw material for new ceramic materials.

Conventionally, many proposals have been made regarding the production method of Shimonoshi 2. Tokkosho, t/-2004tO, as one of the most promising methods for producing monosilane,
A method for disproportionating triethoxysilane using sodium ethoxide as a catalyst is described.

(]iXt O)s 8 i H, 8i H4+7El
i(OEt).

[Problem that the invention seeks to solve]

This method has excellent features such as extremely high catalytic efficiency, but since it is carried out in a catalytic enemy phase medium,
There are problems such as separation of the catalyst and by-products (nat-2-ethoxysilane, etc.) is not always easy. Similarly, as is clear from the above formula, this reaction produces a large amount of by-products, but these by-products are useful as raw materials for various silicon compounds, and it is necessary to remove the catalyst.

An object of the present invention is to provide a method for producing monosilane that can efficiently produce alkoxysilane caramonosilane as a raw material and easily separate the catalyst from the reaction product.

[Means for solving the problem]

As a result of research into catalysts that overcome the above-mentioned drawbacks, have high catalytic efficiency, and are easy to separate from reaction products, the present inventors have found that a certain type of solid catalyst is suitable for this purpose. This discovery led to the present invention.

That is, the present invention provides Hn81 (OR), -0... (I
) (wherein, R is an alkyl group with carbon number/~, n is /, λ
Or it represents 3. ) A method for producing monosilane by disproportionation, characterized in that the catalyst is a halide of a metal selected from IBM, Group (2), Group (2) excluding carbon and silicon, and iron. .

The present invention will be explained in detail below.

The alkoxysilane, which is a raw material used in the present invention, is disclosed in, for example, Japanese Patent Application Publication No. 2003-120003. λri, Tokukai Sho 1! -761, and the like.

The disproportionation reaction in the method of the present invention is performed in group IB of the periodic table,
The method is carried out using halides of the group I, excluding carbon and silicon, and iron as catalysts.

Specific examples of these metal halides include Ou, Mut, B, Aj, Ga, Bc, Y, La, Os
, T1, Zr.

Examples include halides of Ge%fin, Pb, and Fe, such as fluorides and chlorides. Furthermore, as for Mu 1, organoaluminum chloride can also be used.

Among these, metal halides with high Lewis acidic strength are preferred because they exhibit good properties. The above catalyst used in the present invention is substantially insoluble in the raw material alkoxysilane and the reaction product, and separation of the catalyst and the reaction product (rigid material) is extremely easy.

The intended purpose can be achieved when the amount of catalyst used is 0.07% by weight or more based on the alkoxysilane, but it is usually 0.7~! Conditions in the range 0 weight - are adopted.

The reaction may be carried out either batchwise or continuously. In particular, there are no restrictions on the material of the equipment.
The reaction type suitable for the catalyst shape can be freely selected.

Although the reaction can be carried out under normal pressure and room temperature, the purpose can be sufficiently achieved, but it is generally more preferable to carry out the reaction under normal pressure and heating. Although the method according to the present invention is not dependent on temperature, a particularly preferred device is to0~? At θ℃,
Ru.

The reaction pressure can be carried out at any pressure from reduced pressure to increased pressure, but normal pressure conditions are superior in operability since the product monosilane will instantly ignite when it comes into contact with air.

The raw material alkoxysilane in the present invention may be of a single composition or a mixture.

On the other hand, tetramethoxysilane, which is one of the disproportionation reaction products, and other substances, such as aliphatic saturated hydrocarbons such as hexane and heptane, and alicyclic saturated hydrocarbons such as cyclohexane, can also be used together as a solvent. I can do it.

The reaction is usually carried out under an inert gas atmosphere of nitrogen or argon.The use of 2% nitrogen is preferred when condensing and collecting monosilane; However, unless it exceeds the gist of the invention, the present invention is limited to the following examples.0 [Example] Example/JOd snare l'm7 equipped with a gas discharge pipe directly connected to gas chromatography /F Scooter, stir bar and catalyst pre-dried with a heated nitrogen stream, OuF, (FluoRC)OH
1! After charging the flask with nitrogen gas and purging the inside of the flask with nitrogen gas again, trimethoxysilane O1O4
tmol θ was added, and the mixture was reacted at room temperature for 2 hours with stirring.

Ta.

After the reaction, the reaction product was passed through and the catalyst was separated. The catalyst is insoluble in the raw materials and reaction products and can be easily separated.

Example 7 Table 7 shows the reaction results obtained by changing the type of catalyst in the same manner as in Example. Each of the catalysts used was substantially free of raw materials and reaction products, and the catalysts could be easily separated by exposing the reaction products to F.

TM8H: ) Rimethoxysilane QMEI ditetramethoxysilane Sin, : Monosilane Example 1 In a pressure-resistant glass autoclave with an internal volume of 100 d, equipped with a stirring blade, an i1 elementary gas introduction pipe, a gas discharge pipe with a cooling pipe, and a liquid charging pipe, The catalyst was previously dried under heating with a nitrogen stream.

Made by FLUOROOHEM Ti1F, 0. j I was charged and the autoclave system was replaced at a sufficiently steady state. After that, 0-mole of trimethoxycymene was added through the liquid charging tube at room temperature, and stirring was started.

The reaction was carried out at room temperature, and when the catalyst and trimethoxysilane came into contact, cymonosilane was produced.Then, the temperature was heated to 70°C and the reaction was carried out for 19 hours until no monosilane was produced.The produced monosilane changed over time. It was quantified by gas chromatography.

As a result, the conversion rate of trimethoxysilane ≦4 tmole
%, and monosilane production was 0.03λmole.

On the other hand, the catalyst was insoluble in the reaction product, and the PB medium could be easily separated from the reaction product by treating it with 69F.

Example? Fed as a catalyst in the method carried out in Example r;
(FLUOROO manufactured by iKM) θ, 2 liters was used to react for one hour. As a result, the conversion rate of trimethoxysilane/7. / mob Aichi, monosilane generation o, o da 3m
It was o'lechi. Further, separation of the catalyst was easy as in Example 1.

Example IQ htot3 as a catalyst in the method carried out in Example/
(manufactured by Wako N%), j, using 9N, 3. A time reaction was performed. As a result, the conversion rate of trimethoxysilane was 4/m
ole%, and monosilane production was 0.030 jmol. Similarly, the catalyst was insoluble in the reaction product, and it was easy to separate the catalyst.

〔effect〕

According to the method of the present invention, monosilane can be easily obtained from alcosilane as described above. Moreover, the catalyst used in the present invention is substantially insoluble in the reaction products;
Shading from reaction products is extremely easy. The reaction product (biological material) is useful as a raw material for various silicon products, such as raw material for high-purity silicon used in raw fibers, sealants, photomasks, etc., and as a catalyst. The ease of separation is of great industrial significance.

Claims (1)

[Claims] H_nSi(OR)_4_-_n...(I) (wherein R is an alkyl group having 1 to 6 carbon atoms, (n represents 1, 2 or 3.) In the method of producing monosilane by disproportionation, a halide of a metal selected from Group I_B, Group III, Group IV excluding carbon and silicon, and iron is used as a catalyst. A method for producing monosilane characterized by: