JPS61274749A - Preparation of disproportionation catalyst - Google Patents

Abstract

PURPOSE:To enhance the activity of a disproportionation catalyst, by forming the disproportionation catalyst of halogenated silanes by contacting an inorg. compound carrier impregnated with an oxidizing agent with pyrrole vapor containing oxygen. CONSTITUTION:An inorg. compound carrier formed by using inorg. compound particles with a particle size of about 0.1-10mm, pref., about 1-5mm such as silica, silica-alumina, alumina, diatomaceous earth or talc are ground along with an oxidizing agent to contain the oxidizing agent in the carrier. As the oxidizing agent, there is chloride of iron or molybdenum and the oxidizing agent is used in a wt. ratio of about 0.001-0.5 to the carrier 1. The inorg. compound carrier impregnated with the oxidizing agent is contacted with pyrrole vapor containing oxygen to prepare a disproportionation catalyst. The ratio of oxygen to pyrrole is usually 0.1mol or more to 1mol of pyrrole.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a disproportionation catalyst for halogenated silanes. Specifically, the present invention relates to a method for producing a disproportionation catalyst in which a pyrrole polymer is supported on an inorganic compound carrier.

<Prior Art> Silanes such as monosilane, monohalogenated silane, and dihalogenated silane are used for applications such as semiconductors, solar cells, and photosensitive drums, and the demand for them has increased significantly in recent years. Known methods for producing these silanes include reducing tetrahalogenated silanes, reacting silicon alloys with hydrochloric acid or ammonium chloride, and disproportionating trihalogenated silanes. .

<Problems to be solved by the invention> Since trihalogenated silanes can be easily obtained by reacting hydrogen halogenide with silicon, the method of disproportionating trihalogenated silanes is the industrially cheapest way to produce silane. The method using nitriles such as adiponitrile as a disproportionation catalyst (U.S. Pat. No. 2,732,282), and the method using aliphatic cyanamide (
Homogeneous methods such as U.S. Pat. No. 2,732,280), methods using amines (U.S. Pat. No. 2,834,648),
Alternatively, a method using an anion exchange resin (Japanese Patent Publication No. 52-1
Heterogeneous methods are known, such as a method using a reaction product of amino alcohol and silica (Japanese Unexamined Patent Publication No. 156907/1983). Homogeneous systems require a large amount of energy to separate the catalyst from raw materials and products, while known heterogeneous systems require expensive catalysts, poor heat resistance, and low catalytic activity. There was a problem.

<Disclosure of the Invention> The present inventors have earnestly searched for a method for producing a highly active solid catalyst by solving the above problems, and have arrived at the present invention.

That is, the present invention is a method for producing a disproportionation catalyst for rhodanized silanes, which comprises bringing an inorganic compound carrier impregnated with an oxidizing agent into contact with oxygen-containing virol vapor.

In the present invention, the disproportionation of rhodanized silanes refers to a reaction in which silanes with fewer rhodane atoms are produced compared to the applied rhodanized silanes, and for example, disproportionation of trichlorosilane This reaction produces a mixture of monosilane, monochlorosilane, dichlorosilane, trichlorosilane, and tetrachlorosilane.

The catalyst produced by the method of the present invention can be suitably used for disproportionation of the above-mentioned silanes.

Preferred examples of the pyrroles in the present invention include pyrrole, N-alkylpyrrole, N-arylpyrrole, 3-alkylpyrrole, 3-arylpyrrole, 3,4-dialkylpyrrole, and 3-arylpyrrole.

In the present invention, in addition to the above pyrroles, other complex 5
It is also possible to copolymerize membered ring compounds, ie furan, thiophene, selenophene, tellurophene or derivatives thereof.

The inorganic compound carrier used as a carrier in the present invention is not particularly limited, but has a particle size of about 0.1 to 10 mm, preferably about 1 to 5 mm, such as silica, silica alumina, alumina, diatomaceous earth, talc, pumice, asbestos, zeolite,
Inorganic compound particles such as china clay, diatomaceous earth, magnesia, activated clay, and silicates can be used.

Various oxidizing agents can be used in the present invention; inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and chlorosulfonic acid; aluminum, tin, titanium, zirconium, chromium, manganese, iron, copper, molybdenum, tungsten;
Chlorides, sulfates, nitrates, and acetylacetonate compounds of metals such as ruthenium, palladium, and platinum; or chlorides, sulfates, and peroxosulfates of iron, molybdenum, titanium, and ruthenium, among which peroxosulfuric acid or their salts are available. Preferred examples include salt.

There are no particular restrictions on the method of impregnating the oxidizing agent, but the carrier and the oxidizing agent may be co-pulverized (if necessary, the carrier may be granulated after co-pulverizing), or the carrier may be dispersed in a solution in which the oxidizing agent is dissolved. Preferred examples include a method in which the solvent is then removed by filtration or evaporation, or a method in which the carrier is exposed to oxidizing agent vapor.

There are no particular restrictions on the ratio of the oxidizing agent to the carrier, but carrier 1
o, ooi to 0.5, usually about 0.01 to 0.3.

In the present invention, a disproportionation catalyst can be produced by bringing the inorganic compound carrier impregnated with an oxidizing agent obtained by the above method into contact with oxygen-containing pyrrole vapor, where the oxygen-containing pyrrole vapor is Oxygen-containing gases (e.g. oxygen,
Alternatively, it can be easily obtained by introducing oxygen diluted with an inert gas such as nitrogen, helium, argon, etc. (air is inexpensive) into the pyrrole liquid.
In some cases, the vapor of pyrroles may be obtained by reducing the pressure to below the vapor pressure of pyrroles or heating above the boiling point of pyrroles, and further mixing with oxygen or an oxygen-containing gas to obtain a desired oxygen content. The preferred ratio of oxygen to pyrroles cannot be specified because it varies depending on the temperature, but it is usually 0.1 to 1 mole of pyrroles.
The amount is 1 mole or more, usually 1 mole or more.

In the present invention, there is no particular restriction on the method of contacting the inorganic compound carrier with the oxygen-containing pyrrole vapor, but preferably, the inorganic compound carrier is packed into a fixed bed or fluidized bed type reactor, and the inorganic compound carrier is charged into the reactor. This is achieved by introducing a pyrrole vapor containing oxygen. There are no particular restrictions on the introduction temperature, and room temperature is also possible, and it is usually 0°C to 100°C.
It is sufficient to carry out the test at ℃. There is no particular restriction on the introduction time, but it is sufficient to select a time that allows the desired amount of pyrrole polymer to be supported on the carrier, and usually the introduction time is 0,001 to 0 per carrier.
．． It is sufficient to introduce it until it becomes about 1.

The catalyst obtained by the method of the present invention can be used as it is as a disproportionation catalyst, but if necessary, excess oxidizing agent or unreacted pyrroles can be washed away and further heat treatment can be performed.

<Effects> The catalyst obtained by the method of the present invention is extremely useful as a disproportionation catalyst for halogenated silanes and is extremely valuable industrially.

<Example> The present invention will be further explained with reference to Examples below.

Example 1 Silica gel having a particle size of 10 to 40 mesh was used as a carrier. 0.35' of ferric chloride to 20ml of ethylene dichloride!
After dispersing and mixing 10 g of the above silica gel in the solution, ethylene dichloride was removed by evaporation by introducing nitrogen to obtain an oxidizing agent-impregnated carrier. This oxidizing agent-impregnated silica gel was placed in a glass tube with an inner diameter of 50 mm equipped with a glass filter, and a mixed gas of N-methylpyrrole and oxygen (N-
0.2 ml/h (as methylpyrrole) and 12 Nl/h (oxygen gas) were introduced into the glass tube for 8 hours of contact. Thereafter, the mixture was extracted with methanol for 4 hours using a Soxhlet extractor to obtain a catalyst. 4.8w from elemental analysis
t% of N-methylpyrrole polymer was supported.

The catalyst 101 obtained by the above method was
It was filled into a TL U-shaped SUS tube flow reactor. It was heated to 120° C. while flowing helium, and when the temperature reached 120° C., the supply of helium was stopped and trichlorosilane with a purity of 99.9% was supplied at a rate of 16 cc/min. The product was collected by cooling with methanol-dry ice, and the composition of the product was analyzed by gas chromatography. Trichlorosilane 80.5mai1%, dichlorosilane 9
．． 6 mol%, silicon tetrachloride was 9.9 mol%.

Example 2 The same procedure as in Example 1 was carried out except that spherical alumina having a diameter of about 1 dragon was used as the carrier. The supported N-methylpyrrole polymer was 4.1 wt%, and the reaction products were 82.3 mo1% trichlorosilane and 8.4 mo1 dichlorosilane.
o1%, and silicon tetrachloride was 9.3 ma1%.

Example 3 Using 0.31 potassium peroxosulfate as the oxidizing agent 2
The solution dissolved in 1 ml of water was sprayed onto a spherical alumina about 1 ml in diameter. After introducing air at 20 Nil/h for 2 hours at room temperature, 0.2 ml/h as N-methylpyrrole was added.
Contact treatment was carried out for 20 hours as a mixed gas with h.

The reactor was filled in the same reactor as in Example 1, heated at 150°C for 5 hours while circulating helium, and after the temperature was lowered to 140°C, trichlorosilane was introduced and reacted.

The composition of the reaction product gas is: 81.5 mol% trichlorosilane, 8.3 mol% dichlorosilane, 10% silicon tetrachloride.
．． It was 2 mol%.

Claims (1)

[Claims] A method for producing a disproportionation catalyst for halogenated silanes, which comprises bringing an inorganic compound carrier impregnated with an oxidizing agent into contact with pyrrole vapor containing oxygen.