JPH0471009B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD OF THE INVENTION The present invention relates to the disproportionation and/or
Or it relates to a method for producing silanes, particularly monosilane and/or chlorosilane, by a redistribution reaction. BACKGROUND OF THE INVENTION Silane, particularly monosilane, is a raw material useful for semiconductors, amorphous solar cells, IC devices, photoreceptors, and the like. It is known that chlorosilane or monosilane can be obtained by a disproportionation or redistribution reaction using chlorosilane as a raw material, as shown in the following formula. Catalysts useful for these reactions are being developed. 2SiHCl ₃ SiH ₂ Cl ₂ +SiCl ₄ 2SiH ₂ Cl ₂ SiHCl ₃ +SiH ₃ Cl 2SiH ₃ ClSiH ₄ +SiH ₂ Cl _2The above catalyst is an insoluble solid anion exchange resin containing amino groups etc. ), trimethylamine or dimethylethylamine (JP-A-59-121110), palladium (JP-A-54-59230), tris (tertiary amino) phosphine oxide (JP-A-42-22926), Inorganic solid bases (JP 59-174515), compounds containing α-oxoamine groups (JP 59-54617), tetraalkylureas (JP 55-14046), hydrocarbon groups containing N -substituted α-pyrrolidone (Japanese Patent Publication No. 55-14045), a cation exchanger having a sulfonic acid group (Japanese Patent Publication No. 59-164614),
Reaction product of amino alcohol and silica (JP-A-Sho
59-156907), phosphoric acid ester compounds (Japanese Patent Application Laid-Open No. 60-71513), compounds that combine tertiary phosphine with styrene-divinylbenzene polymer (Japanese Patent Application Laid-Open No. 60-60915), etc. . In particular, heterogeneous catalysts that allow easy separation of reaction products and catalysts are attracting attention. Problems to be Solved by the Invention As mentioned above, various catalysts mainly containing nitrogen or phosphorus atom-containing groups (or compounds) as active ingredients have been proposed as disproportionation catalysts for chlorohydrogenated silanes. The activity level and duration of activity are not necessarily sufficient for use on a commercial scale. In particular, a reduction in activity, most often accompanied by partial decomposition of the catalyst, results in increased levels of impurities in the product, which is undesirable for processes requiring ultra-high purity products such as monosilane. SUMMARY OF THE INVENTION Means for Solving the Problems In order to solve the above problems, the present inventors particularly studied phosphorus atom-containing catalyst components, and as a result, they discovered the following excellent catalyst system and completed the present invention. That is, in the present invention, three carbon atoms and one chalcogen atom X (X=O, S or Se) form a pentavalent phosphorus atom.

In the presence of a catalyst containing as an essential component phosphine chalcogenide bound in the binding mode of [formula],
The present invention relates to a method for producing silane, characterized by disproportionation and/or redistribution of chlorosilane represented by SiH _o Cl _4-o (where 1≦n≦3). The carbon bonded to the phosphorus atom above may contain a heteroatom such as oxygen or halogen _.
C20 is the carbon in the hydrocarbon group. Non-limiting examples of these hydrocarbon groups include alkyl groups such as methyl, ethyl, butyl and octyl groups, aryl groups such as phenyl, tolyl and naphthyl groups, aralkyl groups such as benzyl and phenethyl groups, and cycloalkyl groups such as cyclohexyl groups. A monoradical group such as a group or a heteroatom-containing derivative group thereof,
The bond end of the carbon bonded to the phosphorus atom that is not bonded to the phosphorus atom is or

As shown in [Formula], carbon-carbon bonds may be bonded to the polymer base,

【formula】

[Formula] or

It may be bonded to the same phosphorus atom to form a cyclic structure as in [Formula],

【formula】

or

As in [expression], other

[Formula] may be bonded to the structure. Compounds having the above structure can be synthesized via various known routes, for example,
Kosolapoff, Organophosphorous Compounds, Wiley, 1950, Chapter 6.
A typical preparation method (reaction formula) is described below, but it does not necessarily limit the present invention. (1) Method by oxidation of phosphine (or phosphine bound to a polymer) (2) Method by hydrolysis of phosphine dihalide In these reactions, if a phosphorus compound in which R ¹ , R ² , or R ³ is bonded to a polymer in advance is used as a raw material, or if it is bonded to a polymer later, a polymer-bonded catalyst can be obtained. can. Among the above-mentioned phosphine chalcogenides, the type of catalyst bonded to a polymer can be used as it is as a gas-phase or liquid-phase chlorosilane disproportionation catalyst, and is particularly excellent in activity and activity persistence. Phosphine chalcogenide, which does not bind to polymers, can be used as a homogeneous catalyst by dissolving it in a solvent or in chlorosilane as a reaction material, or using a porous carrier (styrene divinylbenzene copolymer beads,
By dispersing and supporting the catalyst on the surface of activated carbon, silica gel, etc., it can be used as a heterogeneous catalyst in the gas or liquid phase. Also, the chalcogen atom X is O,
selected from S or Se, but S and Se, especially S
has excellent activity and ability to maintain activity. The reaction can be carried out in either a flow system or a batch system, but a flow system is generally preferred. The reaction temperature is 0°C to 300°C, preferably 10°C to 200°C,
Although the reaction pressure is not particularly limited, it can generally be carried out within a range of 1 to 50 atmospheres. The reaction time (contact time) is generally 0.01 to 20 seconds in the gas phase and 1 to 600 seconds in the liquid phase, but is not necessarily limited. The raw material chlorosilane is SiH _o Cl _4-o (1≦n
≦3).
That is, one type of monochlorosilane, dichlorosilane, or trichlorosilane, or a mixture of two or more types of arbitrary composition can be used, and it may be diluted with an inert fluid such as nitrogen gas. Effects of the Invention The catalyst used in the present invention, which contains phosphine chalcogenide as an essential component, is thermally and chemically stable and is therefore suitable for use as a chlorosilane disproportionation catalyst at high temperatures for long periods of time. In addition, since the activity per unit amount of active component is large, the amount of active component required is small, and contamination of the reaction product due to deterioration and decomposition of the catalyst is suppressed, making it possible to produce silane industrially advantageously. Examples Hereinafter, the present invention will be explained by examples. Example 1 (1) Preparation of styrene-divinylbenzene copolymer beads having a diphenylphosphino group in the aromatic nucleus A bead having a bromine atom in the aromatic nucleus prepared according to Example 1 of JP-A-58-80307 Porous styrene-dipynylbenzene copolymer beads 15.0
g to 10 g of diphenylchlorophosphine and
150ml with 0.86g metallic lithium flakes
of tetrahydrofuran and stirred at room temperature under nitrogen atmosphere for 40 hours. After quenching the reaction by adding 100 ml of methanol to the reaction solution, the copolymer beads were collected on a filter and mixed with methanol (200 ml x 2) and chloroform (200 ml).
x 2 times), dried in a nitrogen stream, and then vacuum-dried at room temperature for 1 hour. Obtained. (2) Synthesis of polymer-bound phosphine oxide 20g of beads of comparative catalyst 1 prepared in (1) above were added to
20 ml of carbon tetrachloride was added to form a suspension, and bromine was slowly added dropwise to this until the orange color of bromine remained. The beads were collected by filtration, added to a water-methanol solution of sodium hydroxide (1 g NaOH/10 ml water-10 ml methanol), and stirred for 1 hour. After washing and air drying, a polymer-bound phosphine oxide (Catalyst No. 1) was obtained. (3) Disproportionation reaction of trichlorosilane using a polymer-bound phosphine oxide catalyst The polymer-bound phosphine oxide obtained in (2) above
10.68 ml was filled into a glass normal pressure flow reactor (inner diameter 5 mm) and heated at 120°C in a nitrogen stream for 1 hour. SiHCl ₃ /N ₂ (molar ratio 3/7) was added under normal pressure while keeping the reaction layer at a specified temperature. The disproportionation reaction was carried out using a mixed gas of ) as feed. The product obtained 5 hours after setting the reaction conditions was analyzed using a gas chromatograph (TCD) using helium as a carrier gas. The results are shown in Table 1. The activity of the catalyst was determined by the values per catalyst active site (Kc) and per volume (Kv) using the following formula. Kc=lnCeq/Ceq-C・SV/N, Kv=lnCeq/Ceq-C・SV (Ceq: equilibrium conversion rate of trichlorosilane, C:
Measured conversion rate of trichlorosilane, SV: space velocity, N: concentration of phosphorus in catalyst: meq/ml) Under the above reaction conditions, the disproportionation reaction of trichlorosilane was carried out continuously for 42 hours, and from 5 hours to 42 hours. It was found that the activity half-life of the catalyst under the above reaction conditions was 103 hours. Example 2 (1) Preparation of triphenylphosphine oxide catalyst supported on polystyrene beads 1.13 g of triphenylphosphine oxide was
The mixture was dissolved in 20 ml of chloroform, and 10.0 g of styrene-divinylbenzene copolymer beads (manufactured by Nippon Rensui Co., Ltd., trade name, HP-20) were added thereto and mixed well. The beads were then air-dried and subsequently heated to 100°C.
Polystyrene bead-supported triphenylphosphine oxide catalyst (catalyst no. 2)
I got it. (2) Disproportionation reaction of trichlorosilane Using 24.5 mg of the catalyst prepared in (1) of Example 2 above, a disproportionation reaction of trichlorosilane was carried out using the method described in 3) of Example 1. Table 1 shows the results.
It was shown to. Example 3 (1) Preparation of polystyrene bead-supported diphosphine dioxide catalyst 3.76 g of bis(diphenylphosphino)ethane is dissolved in 30 ml of chloroform, and bromine is added dropwise to this solution until the orange color of bromine remains. I added up to. This liquid was stirred with 100 ml of 5% NaOH aqueous solution and hydrolyzed to synthesize bis(diphenylphosphino)ethane dioxide. 20 g of this diphosphine dioxide (0.81g)
Dissolve in 1 ml of chloroform and add 10 g of polystyrene beads (manufactured by Nippon Rensui, trade name: HP-).
20), mix well, air dry, and then
The mixture was dried at 100°C for 8 hours to obtain a polystyrene bead-supported diphosphine dioxide catalyst (Catalyst No. 3). (2) Disproportionation reaction of trichlorosilane A disproportionation reaction of trichlorosilane was carried out in the same manner as in (3) of Example 1 using 46.3 mg of the catalyst (catalyst number 3) prepared in (1) of Example 3 above. I did it. The results are shown in Table 1. Example 4 (1) Preparation of phosphine sulfide catalyst bound to polymeric carrier Comparative catalyst 1 (2.0
After adding g) to 20 ml of toluene and removing oxygen by nitrogen bubbling, 1.0 g of tetraethylthiuram disulfide was added and heated under reflux for 30 hours. Filter the beads and add methanol (50ml x 3)
The phosphine sulfide catalyst bonded to polystyrene beads (Catalyst No. 4) was obtained by washing with air and drying at 100° C. for 8 hours. (2) Disproportionation reaction of trichlorosilane A disproportionation reaction of trichlorosilane was carried out in the same manner as in (3) of Example 1 using 21.7 mg of the catalyst prepared in (1) of Example 4 (catalyst number 4). I did it. The reaction is
The catalyst activity was carried out at 120℃ for 146 hours, during which time the catalytic activity slowly increased until 70 hours, then stabilized.
No deterioration in activity was observed between 70 and 146 hours. Comparative example 1 Comparative catalyst 1 (10.4 mg) prepared in (1) of Example 1
The disproportionation reaction of trichlorosilane was carried out in the same manner as in Example 1 (3). The results are shown in Table 1. Example 5 (1) Preparation of triphenylphosphine sulfide catalyst supported on polystyrene beads In a 100 ml flask purged with nitrogen, 2.0 g of triphenylphosphine (7.63 mmol) and 0.26 g
Add sulfur (8.01 mmol) and add 30 ml to this.
of chlorobenzene was added as a solvent. After heating this solution at 70°C for 20 hours in a nitrogen atmosphere, chlorobenzene was distilled off under reduced pressure (0.5 mmHg) to form triphenylphosphine sulfide (Ph ₃ P=S).
was obtained as a white solid. To a solution of 260 mg of triphenylphosphine sulfide dissolved in 3 ml of methylene chloride, 2.0 g of polystyrene beads (manufactured by Nippon Rensui, trade name HP-20) were added, mixed well, air-dried, and then heated at 100°C. After drying for 5 hours, a triphenylphosphine sulfide catalyst supported on polystyrene beads (Catalyst No. 5) was obtained. (2) Disproportionation reaction of trichlorosilane 181.4 mg of the catalyst prepared in (1) of Example 5 above
A disproportionation reaction of trichlorosilane was carried out using the method described in Example 1 (3). The reaction was carried out for 24 hours, during which time the activity increased linearly with time, so Table 1 shows the catalyst activity at 24 hours. Example 6 (1) Preparation of phosphine selenide catalyst bound to polymeric carrier Comparative catalyst 1 prepared in (1) of Example 1 above
(2.9 g), 0.8 g of selenium and 30 ml of chlorobenzene were placed in a 50 ml flask, and
The mixture was heated under reflux for an hour. The beads were collected by filtration, washed with methanol (50 ml x 3), and subjected to Soxhlet extraction using air-dried chlorobenzene as a solvent for 12 hours. After air drying the beads, 100
It was dried under vacuum at 0.degree. C. to obtain a phosphine selenide catalyst (catalyst number 6) bound to polystyrene beads. (2) Disproportionation reaction of trichlorosilane A disproportionation reaction of trichlorosilane was carried out in the same manner as in Example 1-(3) using 14 mg of the catalyst prepared in (1) of Example 6 (catalyst number 6). Summer. however,
The reaction temperature was 127°C, and the reaction was continued for 65 hours. Table 1 shows the data for 30 to 65 hours, when the activity was stable. During this period, no deterioration of activity was observed at all, indicating that this catalyst has excellent ability to maintain activity.

【table】

Claims (1)

[Claims] 1 3 carbon atoms and 1 chalcogen atom X
In the presence of a catalyst containing as an essential component a phosphine chalcogenide in which (X=O, S or Se) is bonded to a pentavalent phosphorus atom in the bonding manner of [formula],
A method for producing silane, which comprises disproportionating and/or redistributing a chlorosilane represented by SiH _o Cl _4-o (where 1≦n≦3).