JPH0339965B2 - - 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), inorganic solid bases (JP-A-59-Sho 59)
-174515) Compounds containing an α-oxoamine group (Japanese Patent Application Laid-Open No. 59-54617), tetraalkylureas (Japanese Patent Publication No. 14046-1983) with a hydrocarbon group
Substituted α-pyrrolidone (Japanese Patent Publication No. 55-14045), cation exchanger having a sulfonic acid group (Japanese Patent Publication No. 59-164614), reaction product of amino alcohol and silica (Japanese Patent Publication No. 59-156907) Publication No.) etc. In particular, heterogeneous catalysts that allow easy separation of reaction products and catalysts are attracting attention. Problems to be Solved by the Invention Several catalysts useful for the disproportionation and/or redistribution reaction of chlorohydrogenated silanes have been proposed, but in particular, conventional solid anion exchange resin-based catalysts have poor heat resistance, It was inferior in mechanical strength, had problems such as swelling peculiar to ion exchange resins, and had unsatisfactory activity and catalyst life. On the other hand, homogeneous catalysts such as Lewis acids and amines require a large amount of energy to separate the product from the catalyst. Summary of the Invention as a Means for Solving Problems The present invention is based on the general formula (R ₃ P) ₂ N・X (in the formula, R
are _C1 to _C10 hydrocarbon groups which may be the same or different from each other and may contain an oxygen atom or a halogen atom, and may be saturated or unsaturated. X is
F ^- , Cl ^- , Br ^- , I ^- , CN ^- , N ₃ ^- , BF ₄ ^- , BH ₄ ^- ,
Monoanions such as OH ^- , alkoxide, acetate, etc. ) Silanes characterized by disproportionation and/or redistribution of a chlorosilane represented by SiHnCl _4-o (where 1≦n≦3) using a bisphosphine iminium salt represented by the following as a catalyst component. In particular, it relates to a method for producing monosilane and/or chlorosilane. The bisphosphine iminium salt can be dissolved in a suitable solvent and used as a homogeneous reaction catalyst or as a gas phase heterogeneous reaction catalyst.
In the former case, the solvent may be a halogenated aromatic compound such as chlorobenzene or dichlorobenzene, an aromatic compound such as benzene, toluene, or xylene, a halogenated hydrocarbon such as chloroform or methylene chloride, acetonitrile, or benzonitrile. These include nitrites such as nitriles, nitro compounds such as nitromethane, and nitrobenzene. Also, chlorosilanes themselves can be used. In the latter case, it is preferable to disperse and support the bisphosphine iminium salt on the surface of a porous solid. Porous solids suitable for this purpose include carbonaceous materials such as activated carbon, graphite, and molecular sieving carbon. Solids, polymeric solids with a polystyrene structure such as styrene-divinylbenzene copolymers, poly(p-methylstyrene) and their halides, non-aromatic olefin polymers represented by polyethylene and polypropylene, and the like. halides, organic polymers containing heteroatoms such as oxygen, nitrogen, sulfur, and silicon in the main chain, polysiloxanes, carbides such as silicon carbide, titanium carbide, and boron carbide, and nitrides such as silicon nitride, boron nitride, and zirconium nitride. material, quartz, novaculite,
Silica such as colloidal silica and silica aerogel, kaolin, talcum olastonite, asbestos,
Silicates such as calcium silicate, aluminum silicate, and zeolite, and metal oxides such as titania and zirconia can be used. Also, its surface area is 2~
2000m ² /g is used. A known impregnation method is suitable as a method for supporting the bisphosphine iminium salt on a porous solid.
The solvent is preferably a liquid that dissolves the bisphosphine iminium salt, has an affinity for the porous solid, and has appropriate volatility. Especially suitable are alcohols such as methanol and ethanol,
Water, halogenated hydrocarbons such as methylene chloride and chloroform, ketones such as acetone and methyl ethyl ketone, and mixtures thereof. Bisphosphine iminium salt, ( _R3P ) _2NX
can be prepared by a known method. That is, it can be made from phosphine, chlorine, and hydroxylamine hydrochloride. For example, the reaction of triphenylphosphine (Ph ₃ P) with chlorine produces Ph ₃ PCl ₂
(Ph ₃ P + Cl ₂ → Ph ₃ PCl ₂ ), and this and H ₂ NOH・
Reaction with HCl and Ph ₃ P gives bisphosphine iminium halides (Ph ₃ PCl ₂ + Ph ₃ P+
H ₂ NOH・HCl→(Ph ₃ P) ₂ NCl＋Ph ₃ P=O
+4HCl). This synthetic method is described, for example, in "Inorganic Synthesis", Vol. 15, pages 85-86. Examples of bisphosphineiminium salts used as catalysts are as follows. Bis(triphenylphosphine)iminium chloride, polyhydride, or tetrafluoroborate, bis[tri(p-tolylphosphine)iminium azide, bis(diphenylethylphosphine)iminium chloride, bis(phenyldimethyl) (phosphine) iminium chloride, bis(tributylphosphine) iminium chloride, bis(triethylphosphine) iminium chloride, bis(tricyclohexylphosphine) iminium chloride Particularly preferred is (R ₃ P) ₃ N. X is a bis(triarylphosphine)iminium salt in which R is an aromatic group such as phenyl or tolyl.The conditions for the disproportionation and/or redistribution reaction are as follows:
Reaction temperature: 0°C to 300°C, preferably 10°C to 200°C,
Reaction time (contact time) 0.1-20 seconds, preferably
The reaction is carried out for 0.2 to 10 seconds, and the reaction pressure is normal pressure to 50 Kg/cm ² , usually normal pressure to 20 Kg/cm ² . Feeds include trichlorosilane, dichlorosilane, monochlorosilane, and mixtures thereof, which may be diluted with an inert fluid. Effects of the Invention The bisphosphine iminium salt catalyst used in the present invention has higher activity per mole of catalyst component than conventionally known catalysts (quaternary ammonium salts or quaternary phosphonium salts), and therefore has a relatively low activity. It can also be used for reactions at low temperatures, and can also be supported on porous solids to perform heterogeneous reactions, making it unnecessary to separate the catalyst and products. Example 1 587 mg (1.02 mmole) of bis(triphenylphosphine)iminium chloride, [(C ₆ H ₅ ) ₃ P] ² N ⁺ Cl ^- (manufactured by Aldrich) was mixed with 5.8 ml of methanol-water (1/ 1) Dissolve in the mixed solution and add 5.8 to this solution.
g silica (Fuji Davison silica gel, ID
Type, surface area 350 m ² /g, 30 to 60 meshes dried in air at 120° C. for 12 hours) were added and stirred well. After air drying, the catalyst was prepared by drying in air at 100°C for 12 hours. 0.64 g (2.0 ml) of this catalyst was filled into a glass gas phase flow reactor (inner diameter 10 mm) and placed in a nitrogen stream.
After heating at 110°C for 1 hour, the raw material gas (SiHCl ₃ /N ₂ , molar ratio
30/70) The reaction was carried out as a feed. One hour after the reaction conditions were established, the product was analyzed using a gas chromatograph (TCD) using helium as a carrier gas. The results are shown in Table-1.

[Table] Examples 2 to 5 Bis(triphenylphosphine)iminium chloride (hereinafter abbreviated as PPNCl) according to the procedure of Example 1
Styrene-divinylbenzene copolymer beads (Diaion HP-20 - trade name manufactured by Mitsubishi Kasei Corporation -), activated carbon (trade name manufactured by Tsurmicol Co., Ltd., 4GV,
30~60 meshes, after treatment with 15% _HNO3 , in the air,
(dried at 100°C for 24 hours), titania (manufactured by Dia Catalyst Co., Ltd.), and kaolin (manufactured by Koso Chemical Co., Ltd.) were supported and catalyzed. The catalyst preparation conditions are shown in Table-2. Using these catalysts, a disproportionation reaction of trichlorosilane (SiHCl ₃ /N ₂ =3/7, molar ratio) was carried out in the same manner as in Example 1. Table 3 shows the experimental results.
It was shown to.

【table】

[Table] Example 6 The raw material gas was dichlorosilane (manufactured by Steel Chemical Co., Ltd., >
The disproportionation reaction was carried out in the same manner as in Example 1, except that the disproportionation reaction was 98.5%). The results are shown in Table 4.

[Table] Example 7 ¹ Hnmr (hydrogen nuclear magnetic resonance) 29 mg (0.05
After introducing bis(triphenylphosphine)iminium chloride (mmol) and a benzene-filled capillary (external standard), connect the sample tube to a vacuum line to degas it, then place the sample tube in a dry ice-isopropanol bath. Cool and add 1.0g (7.4
After the sample tube was charged with 1 mmol of trichlorosilane by vacuum distillation, the top end of the sample tube was sealed off with a gas burner. After the sample tube was heated to room temperature, the enclosed sample was thoroughly shaken and left at 30°C for 1 hour.
The ¹ Hnmr spectrum of the sample contains the external standard benzene peak (τ2.8) and bis(triphenylphosphine)iminium chloride peak (τ2.6~
3.0), three singlets (τ3.9, τ4.6, and τ5.4, area ratio = 8:2:0.1) were observed.
These are derived from the Si-H resonances of trichlorosilane, dichlorosilane, and monochlorosilane, respectively, and indicate that monochlorosilane, dichlorosilane, and trichlorosilane were produced by the disproportionation reaction of trichlorosilane.

Claims (1)

[Claims] 1 General _formula (R _{3 P} ) ₂ N.
It may be saturated or unsaturated. X is F ^- , Cl ^- , Br ^- ,
These are monoanions such as I ⁻ , CN ⁻ , N ₃ ⁻ , BF ₄ ⁻ , BH ₄ ⁻ , OH ⁻ , alkoxide, and acetate. ) is used as a catalyst component, SiHnCl _4-o (1≦n≦3)
A method for producing silanes, which comprises disproportionating and/or redistributing a chlorosilane represented by: