JPS6077119A - Production of halogenated silane or monosilane having low halogenation degree - Google Patents

Abstract

PURPOSE:To produce the titled product economically in high efficiency, from a halogenosilane, by contacting the halogenosilane with an S-containing organic compound. CONSTITUTION:A halogenated silane or monosilane having low halogenation degree can be produced easily, by contacting a halogenosilane with an S-containing organic compound composed of C, H and S atoms. The S-containing organic compound composed of C, H and S atoms and used in the above process is preferably an compound having one or more SH groups, for example the mercaptan represented by the general formula RSH wherein R is 1-20C saturated or unsaturated alkyl, or 6-26C phenyl or benzyl.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing low-halogenated silane or monosilane from halogenated silane, and more particularly, relates to a method for producing low-halogenated silane or monosilane at low cost and in a volume by bringing halogenated silane into contact with an organic sulfur-containing compound.

In particular, monosilane is a useful substance as a raw material for high-purity central body silicon or amorphous silicon for colon batteries, and also as a raw material for epitaxial materials, and demand is expected to further expand in the future. Therefore, cheaper and more efficient monosilane production is desired.

Conventionally, monosilane f[methods include (2) a method of reacting 11 magnesium silicide with dilute hydrochloric acid, (3) a method of reacting tetonchlorosilane with LiH in a molten salt, and (3) a method of reacting trichlorsilane with tertiary A method of causing a disproportionation reaction with an anionic powder resin containing an amine 7 group or a quaternary 7 ammonium base (4) A method of reacting hydrogen gas with metallic silicon using fine Ni powder under conditions of high temperature and 9 knitting pressure. However, in (1) above, the preparation of raw materials is complicated, and the equipment cost increases when considering the reuse of by-product high-order silane.In (2), the yield of monosilane is good, but L +
H is extremely expensive, and since molten salt is used, there are disadvantages in terms of energy consumption and corrosion. Although (3) is superior in terms of energy cost and mass production, there remains a problem with the thermal stability of the ion exchange resin. Since (4) is a reaction at high temperature and high pressure, the equipment cost is high and there is also the drawback that high-order silane is produced as a by-product.

In view of the problems in the production method of monosilane as described in L, we have conducted intensive research on a method for producing monosilane at low cost and efficiency (3).
As a result, they discovered that a low-hap silane or monosilane can be easily obtained from a halogen silane by contacting it with an organic sulfur-containing compound consisting of carbon, hydrogen, and sulfur atoms, and the present ff=BA This is what we have come to offer.

As the halogen silane which is a raw material of the present invention, general formula 5
It is represented by iHX8+5iH8X, +SiH, Therefore, according to the present invention, the above-mentioned halogen silane is converted into a low-density compound, and S i H
From XB, 5iH2X, +5iH8X+S iH4, from SiH,,X, SiH8X, SiH.

, and from S IT (B

Further, as the organic sulfur-containing compound composed of carbon, hydrogen and sulfur atoms used in the present invention, an organic compound having one or more S 2 H groups is generally preferred. For example, -formula RS
Mercaptans represented by H, where R is C1-
C2° saturated or unsaturated alkyl group IC6 to C116
phenyl or benzyl groups, and specific examples include methyl mercaptan, ethyl mercaptan, propyl mercaptan, 7lyl mercaptan, butyl mercaptan, octyl mercaptan, dodecyl mercaptan, phenyl mercaptan, and pendino mercaptan. Furthermore, examples of organic sulfur-containing compounds having two or more SH groups bonded to them include ethylene mercaptan, propylene mercaptan, butylene mercaptan, and the like.

Furthermore, the above-mentioned sulfur-containing compound can also be used by bonding it to a bridged polymer such as styrene-divinylbenzene.

Logensilane, which is the raw material of the present invention, is generally used in gas or liquid form, and the organic sulfur-containing compound used as a catalyst can also be used in either liquid or solid form, depending on the type.

Therefore, the reaction mode of the present invention is extremely flexible and an advantageous mode can be selected as required, but liquid phase reaction is particularly preferred. For example, when both izqgensilane and the organic sulfur-containing compound are provided as liquids to the reaction system and a liquid phase-liquid phase contact mode is established, the capacitance is lower than that of a gas phase-solid phase contact mode. Since the reactor is small in size, not only can the reaction apparatus be made compact, but also the continuous replenishment and control of the liquid organic sulfur-containing compound becomes easy, and a good reaction state can be maintained for a long time. Therefore, a liquid organic sulfur-containing compound is preferably used, and the liquid organic sulfur-containing compound is, for example, activated carbon.

A mode in which the catalyst is supported on a carrier such as alumina or silica-alumina is also appropriately adopted in order to control the optimum amount as a catalyst.

Amount of organic sulfur-containing compound used in the present invention.

Conditions such as reaction temperature and contact time vary depending on the type of organic sulfur-containing compound used, the reaction mode, etc., and cannot be determined unconditionally. Generally, the organic sulfur-containing compound may be used in a ratio of 11500 to 1/2000 (by weight) to the halogen silane.

The reaction temperature is generally 25-350°C, especially 50-120°C.
is preferable from the viewpoint of reactivity and energy economy. Further, a contact time of 01 to 60 seconds, particularly 1 to 20 seconds is sufficient.

The target low-halogenated silane or monosilane is separated from the reaction product obtained by the present invention, and other reaction products and unreacted products are generally separated by appropriately refluxing the other reaction products using a cooler or the like. This can be easily achieved under favorable conditions such as distillation by utilizing the difference in boiling point between the product and the polyamine compound.

Examples will be shown below, but the present invention is not limited thereto.

Example 1 Activated carbon 30I was immersed in a bath liquid in which 10.8 g of butyl mercaptan was dissolved in methylene chloride, and then the methylene chloride was removed by distillation under reduced pressure.

Next, a stainless steel reaction vessel was filled with the above treated activated carbon, and after the reaction temperature was maintained at 60'C, dichlorosilane was flowed in at a flow rate of 1.817 ml. As a result, 23.9 mo1% of monosilane and 1 mole of monochlorosilane
7.8 mo1% product was obtained.

Example 2 The same procedure as in Example 1 was carried out except that trichlorosilane/1.3517 mL was flowed in place of dichlorosilane in Example 1. As a result, monosilane 11.3 mo1%
A product containing 19.3 mo1% of t-monochlorosilane and 21.6 mo1% of dichlorosilane was obtained.

Example 3 The same procedure as in Example 1 was carried out except that 1 ethylene mercaptan was used instead of butyl mercaptan in Example 1. As a result, a product containing 21.3 mo1% of monosilane and 16.5 mo1% of monochlorosilane was obtained.

Example 4 The same procedure as in Example 1 was carried out, except that instead of butyl mercaptan in Example 1, a resin in which methyl mercaptan was bonded to a polymer bed made of a copolymer of polystyrene crosslinked with divinylbenzene was used. . As a result, monosilane 722.5 mo1% and monochlorosilane 19.6 mo
1% product was obtained.

patent applicant Tokuyama ¥: ftatsu Co., Ltd.

Claims (3)

[Claims] (1) A method for producing a low lff gunned silane or monosilane, which comprises bringing it into contact with an organic sulfur-containing compound consisting of carbon, hydrogen, and sulfur atoms, which is a halogen silane. (2) The manufacturing method according to claim 1, wherein the organic sulfur-containing compound is a mercaptan. (3) The yoke of a patent in which the organic sulfur-containing compound is selected from mercaptans! ! lThe method described in paragraph 1