JP2019127422A - Production method of cyclic hydrosilane - Google Patents

Abstract

To provide a production method of cyclic hydrosilane, which improves behavior of precipitates in purification of the cyclic hydrosilane, resulting in improved productivity.SOLUTION: The production method of cyclic hydrosilane comprises a step of, from a composition containing a cyclic hydrosilane represented by a general formula, (SiH)(n=3 to 8), separating the cyclic hydrosilane, wherein the composition contains a high-boiling-point solvent having a boiling point which is higher than that of the cyclic hydrosilane by 10°C or more.SELECTED DRAWING: None

Description

  The present invention relates to a process for the preparation of cyclic hydrogenated silanes. More specifically, the present invention relates to a method for producing a cyclic hydrogenated silane prepared using a high boiling point solvent.

Thin film silicon is used for applications such as solar cells and semiconductors, and this thin film silicon is conventionally produced by a vapor deposition method (CVD method) using monosilane as a raw material. As another method for producing a silicon film, a CVD method (Patent Document 1) using a cyclic silane compound represented by the general formula (SiH ₂ ) _n (n = 4, 5 or 6) as a raw material, cyclohexasilane A CVD method (Patent Document 2) used as a raw material, a method of forming a solution layer containing a cyclopentasilane or cyclohexasilane as a solute on a substrate, and producing polysilane by photopolymerization (Patent Document 3), etc. are reported. .

  As a method of producing a cyclic hydrogenated silane, the cyclization reaction of halosilane is carried out in the presence of a specific coordination compound to obtain a cyclic halogenated silane neutral complex, and then this is reduced as described in Patent Document 4 A process for producing cyclic hydrogenated silanes is disclosed.

JP 60-26664 A Special table 2013-537705 gazette JP 2013-187261 A JP2015-134755A

  As a method for producing this cyclic hydrogenated silane, for example, a method of distilling away a reaction solvent after distillation reaction of lithium aluminum hydride (hereinafter also referred to as LAH) reduction reaction of a halogenated cyclic silane salt and concentrating it may be mentioned. In this process, a large amount of aluminum residues and by-products are generated, but usually these residues and by-products are more soluble in cyclic hydrogenated silane than the solvent used for the reduction reaction. It tends to be difficult. Therefore, even if the above residue or by-product precipitated from the reaction liquid of the reduction reaction is removed by filtration, etc., the reaction solvent is distilled off and concentrated, or the residue or by-product is generated during the purification of the cyclic hydrogenated silane. Things will precipitate. Since concentration and purification usually involve heating, the precipitates strongly adhere to the kettle, which makes the washing complicated and reduces the productivity, causing safety problems, etc., and still has a problem in industrial scale production. Existed.

  Based on the above circumstances, an object of the present invention is to provide a method for producing a cyclic hydrogenated silane with improved productivity by improving the behavior of precipitates during purification of the cyclic hydrogenated silane.

The method for producing a cyclic hydrogenated silane according to the present invention, which solves the above-mentioned problems, comprises the steps from a composition containing cyclic hydrogenated silane represented by the general formula (SiH ₂ ) _n (n = 3-8). The step of removing, wherein the composition comprises a high boiling point solvent having a boiling point 10 ° C. or more higher than that of the cyclic hydrogenated silane.

  According to the present invention, since the behavior of precipitates during the purification of the cyclic hydrogenated silane is improved, the productivity of the cyclic hydrogenated silane can be improved.

Hereinafter, the present invention will be described in detail.
In addition, what combined two or more of each preferable form of this invention described below is also a preferable form of this invention.

In the present invention, as cyclohydrogensilanes represented by the general formula (SiH ₂ ) _n (n = 3 to 8), cyclotrisilane, cyclotetrasilane, cyclopentasilane, cyclohexasilane, cycloheptasilane, cycloheptasilane Unsubstituted (preferably not having a silyl group) cyclic hydrogenated silane such as octasilane; Substituted (preferably having a silyl group) cyclic hydrogenated silane such as silylcyclotetrasilane, silylcyclopentasilane, silylcyclohexasilane Etc.

  The cyclic hydrogenated silane includes at least cyclohexasilane, and this cyclohexasilane is included as a main component of the cyclic hydrogenated silane (a component of 50% by mass or more in 100% by mass of the cyclic hydrogenated silane). The cyclic hydrogenated silane is particularly preferably cyclohexasilane. That is, in the production method of the present invention, the form in which the cyclic hydrogenated silane is cyclohexasilane is one of the particularly preferred forms.

  The production method of the present invention further includes the step of reducing the cyclic halosilane compound (also referred to as “reduction step”), and the cyclic hydrogenated silane in the present invention is produced by a method including the step of reducing the cyclic halosilane compound It is one of the preferable embodiments of the present invention. The cyclic halosilane compound will be described later, but the cyclic halosilane compound is a quaternary ammonium salt of cyclic halosilane, a quaternary phosphonium salt of cyclic halosilane, a cyclic halosilane complex in which a ligand such as phosphine is coordinated to the cyclic halosilane, free cyclic A form which is a halosilane (for example, a non-complex type cyclic halosilane compound having no ligand) is one of the more preferred forms of the present invention. That is, in the present invention, unless otherwise specified, the cyclic halosilane compound includes free cyclic halosilane, cyclic halosilane salt, cyclic halosilane complex, and the like.

  In the present invention, the composition containing cyclic hydrogenated silane may contain cyclic hydrogenated silane. The composition containing the cyclic hydrogenated silane preferably contains 0.01% by mass or more and 90% by mass or less of the cyclic hydrogenated silane, more preferably 1% by mass or more and 80% by mass or less, and the remaining amount is For example, a solvent described later. It is one of the preferable embodiments of the present invention that the composition containing the cyclic hydrogenated silane is a composition produced by a method including a step of reducing a cyclic halosilane compound. The composition produced by the method including the step of reducing the cyclic halosilane compound may be, for example, the reaction solution itself obtained by reducing the cyclic halosilane compound, and the reaction solution is concentrated, and the solvent used for the reaction or other It may be subjected to treatments such as dilution with a solvent, solvent replacement, filtration, washing with a solvent that is not completely compatible, thin film evaporation, adsorption of insoluble matter, and the like.

  In the present invention, the composition containing a cyclic halosilane compound only needs to contain a cyclic halosilane compound. The composition containing a cyclic halosilane compound preferably contains 0.01% by mass or more of the cyclic halosilane compound, more preferably 0.1% by mass or more, and the remaining amount is, for example, a solvent described later. The upper limit of the content of the cyclic halosilane compound in the composition containing the cyclic halosilane compound may be 100% by mass, but as close to 100% by mass as possible for convenience to distinguish from the cyclic halosilane compound, ie about 100% by mass. There may be. It is one of the preferable embodiments of the present invention that the composition containing the cyclic halosilane compound is a composition produced by a method including a step of cyclizing the halosilane compound. The composition produced by the method including the step of cyclizing the cyclic halosilane compound may be, for example, the reaction liquid itself obtained by cyclizing the halosilane compound, and the reaction liquid is concentrated, the solvent used for the reaction or other Diluted with solvent, solvent substitution, filtration, drying, washing with a solvent that is not completely compatible at least completely, removal of light boiling, Lewis acid treatment, thin film evaporation, distillation, adsorption of insolubles, etc. It is also good.

The composition containing cyclic hydrogenated silane further includes a high boiling point solvent described later, and further includes a second solvent which is at least one selected from a reaction solvent and a low boiling point solvent having a boiling point lower than that of the high boiling point solvent. Good.
The high boiling point solvent does not react with the cyclic hydrogenated silane, and is higher than the boiling point of the cyclic hydrogenated silane by a predetermined amount or more, remains in the distillation vessel at the time of distillation of the cyclic hydrogenated silane, and maintains the dispersibility of the composition in the vessel Any solvent can be used.
Examples of the low boiling point solvent include a reaction solvent for reduction, a solvent for solvent replacement, and the like.

The high boiling point solvent has a boiling point of 10 ° C. or more higher than that of the cyclic hydrogenated silane at normal pressure, preferably 30 ° C. higher than that of the cyclic hydrogenated silane, more preferably 50 ° C. higher than that of the cyclic hydrogenated silane. More preferably, the boiling point is higher than the cyclic hydrogenated silane by 100 ° C. or higher, and even more preferably the boiling point is higher than the cyclic hydrogenated silane by 150 ° C. or higher. When the difference between the boiling points of the high-boiling solvent and the cyclic hydrogenated silane is 10 ° C. or more, it becomes easy to separate the high-boiling solvent in the step of taking out the cyclic hydrogenated silane, simplifying the purification equipment and improving the production efficiency. It tends to be possible to improve.
Further, the boiling point of the high boiling point solvent is preferably 230 ° C. or higher at normal pressure, more preferably 250 ° C. or higher, further preferably 300 ° C. or higher, and preferably 600 ° C. or lower. .

  With such a high boiling point solvent, even if the high boiling point solvent remains in the distillation pot at the time of distillation and the residue of the reducing agent or by-product precipitates, the dispersibility or fluidity of the precipitate is maintained, It can suppress sticking. Therefore, it is possible to improve the production efficiency by suppressing the distillation efficiency from being lowered due to the fixed wall of the distillation kettle wall surface or by facilitating washing of the distillation kettle. At normal pressure, the boiling point of cyclohexasilane is 226 ° C., and the boiling point of cyclopentasilane is 194 ° C.

  The high boiling point solvent is preferably at least one selected from the group consisting of hydrocarbon solvents, ether solvents and silicone solvents.

  As a hydrocarbon solvent, dodecane (boiling point 216 ° C.), cyclohexylbenzene (boiling point 240 ° C.), dipentyl benzene (boiling point 255 ° C.-280 ° C.), dodecylbenzene (boiling point 331 ° C.), tetradecane (boiling point 254 ° C.), biphenyl Boiling point 255 ° C.) and the like.

  As an ether solvent, dihexyl ether (boiling point 226 ° C.), pentyl phenyl ether (boiling point 214 ° C.), diphenyl ether (boiling point 258 ° C.), dibenzyl ether (boiling point 295 ° C.-298 ° C.), diethylene glycol dibutyl ether (boiling point 254) C., diethylene glycol monobutyl ether (boiling point 230 ° C.), triethylene glycol (boiling point 288 ° C.), triethylene glycol monomethyl ether (boiling point 249 ° C.), tetraethylene glycol (boiling point 327 ° C.) and the like.

  Examples of silicone solvents include dimethyl silicone oil, methylphenyl silicone oil, straight silicone oil such as methyl hydrogen silicone oil, higher fatty acid ester-modified silicone oil, alkyl-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, and polyether. Examples thereof include modified silicone oils such as modified silicone oils. Even when the viscosity of the same silicone oil is high, the boiling point of the silicone-based solvent tends to increase as well, and a solvent higher by 10 ° C. or more than the boiling point of the cyclic hydrogenated silane may be selected and used.

  Among these, a silicone solvent is preferable, straight silicone oil is more preferable, and dimethyl silicone oil is more preferable.

  The composition containing cyclic hydrogenated silane may contain cyclic hydrogenated silane, silicone-based solvent, and ether-based solvent, may be solid-liquid separated of these mixtures, and may be concentrated. It is also good.

  In the step of taking out the cyclic hydrogenated silane from the composition containing the cyclic hydrogenated silane, the composition amount of the high boiling point solvent in the composition is 10 parts by mass or more with respect to 100 parts by mass of the cyclic hydrogenated silane. Is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, and preferably 10,000 parts by mass or less.

In the present invention, the low boiling point solvent is a solvent having a boiling point lower than that of the high boiling point solvent, and is preferably a solvent having a boiling point lower than that of the high boiling point solvent and the cyclic hydrogenated silane.
Low boiling solvents include, for example, hydrocarbon solvents (eg, hexane, heptane, benzene, toluene, etc.), halogenated hydrocarbon solvents (eg, chloroform, dichloromethane, 1,2-dichloroethane, etc.), ether solvents (eg, Aprotic polar solvents such as diethyl ether, tetrahydrofuran, cyclopentyl methyl ether, diisopropyl ether, methyl tertiary butyl ether, etc.), acetonitrile and the like are preferably mentioned.
The low boiling point solvent is preferably an ether solvent or a hydrocarbon solvent, and more preferably an ether solvent.
The low boiling point solvent preferably has a boiling point 30 ° C. or more lower than that of cyclic hydrogenated silane, more preferably 60 ° C. or more lower than cyclic hydrogenated silane, and more preferably 90 ° C. or more higher than cyclic hydrogenated silane Low.

  The amount of the low-boiling solvent added is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, and further preferably 200 parts by mass or more with respect to 100 parts by mass of the cyclic hydrogenated silane. The amount is preferably 10,000 parts by mass or less.

In the present invention, solvents other than the solvents used in the step of reducing the high boiling point solvent and the cyclic halosilane compound (hereinafter, also referred to as “reduction reaction solvent”) may be referred to as other solvents.
Further, in the present invention, the solvent used in the step of reducing the cyclic halosilane compound is not limited to the solvent actually used in the reduction step, but includes the same type of solvent (for example, the same type of solvent added after the step). Be
Hereinafter, although the manufacturing method of cyclic | annular hydrogenated silane is demonstrated concretely, the manufacturing method of cyclic | annular hydrogenated silane is not specifically limited, A various well-known manufacturing method is employable. For example, a method of reducing a cyclic halosilane compound obtained by cyclization of halosilane (which may include other steps) is one preferred method.

  Examples of the above halosilanes (halogenated silanes) include dichlorosilanes such as dichlorosilane, dibromosilane, diiodosilane, difluorosilane, etc .; trihalosilanes such as trichlorosilane, tribromosilane, triiodosilane, trifluorosilane, etc .; tetrachlorosilane, tetrabromo Tetrahalosilanes such as silane, tetraiodosilane, tetrafluorosilane, etc. can be used. Among these, preferred is trihalosilane, and particularly preferred is trichlorosilane.

The method for cyclizing the above halosilane is not particularly limited, but for example, the following method (A) or (B) is preferable.
(A) A method for obtaining a salt of a cyclic halosilane, which includes a step of bringing a halosilane (halogenated monosilane) into contact with a phosphonium salt and / or an ammonium salt [hereinafter sometimes referred to as method A].
(B) A method of obtaining a cyclic halosilane neutral complex, which comprises the step of contacting a halosilane with at least one compound selected from the group consisting of (I) and (II) below (hereinafter referred to as method B) is there].

(I) compounds represented by the XR _n [hereinafter sometimes referred to as the compound I]. When X is P or P = O, n is 3, and R is the same or different and represents a substituted or unsubstituted alkyl or aryl group. When X is S, S = O, O, n is 2, and R is the same or different and represents a substituted or unsubstituted alkyl or aryl group. When X is CN, n = 1, and R represents a substituted or unsubstituted alkyl group or aryl group. However, the number of amino groups in the XR _n is 0 or 1.

  (II) At least one heterocyclic compound selected from the group consisting of N, O, S or P containing substituted or unsubstituted heterocyclic compounds having a noncovalent electron pair in the ring [hereinafter referred to as compound II There is]. However, the number of tertiary amino groups as substituents of the heterocyclic compound is 0 or 1.

  First, the method A will be described.

The phosphonium salt is preferably a quaternary phosphonium salt, and a salt represented by the following formula (11) is preferably mentioned. In the following formula (11), R ^{1 to} R ⁴ may be different from ^one another, but preferably all are the same group.

Moreover, it is preferable that the said ammonium salt is a quaternary ammonium salt, and the salt represented by following formula (12) is mentioned preferably. In the following formula (12), R ^{5 to} R ⁸ may be different from one another, but preferably all are the same group.

Shows the monovalent anion ^- above formula (11), the above formula (12), each independently of R ¹ to R ⁴ and R ⁵ to R ⁸ is a hydrogen atom, an alkyl group, an aryl group, A .

Examples of the alkyl group of R ^{1 to} R ⁴ and R ^{5 to} R ⁸ include carbon such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, cyclohexyl group and the like A C1-C16 alkyl group is mentioned preferably, A C1-C8 alkyl group is more preferable.

The aryl groups of R ¹ to R ⁴ and R ⁵ to R ^8, phenyl group, an aryl group having 6 to 18 carbon atoms such as naphthyl group, and more preferably an aryl group having 6 to 12 carbon atoms.

Each of R ^{1 to} R ⁴ and R ^{5 to} R ⁸ is preferably an alkyl group or an aryl group, and more preferably an aryl group. When R ^{1 to} R ⁴ and R ^{5 to} R ⁸ are aryl groups, as described later, when producing a salt of cyclic halosilane, a salt of cyclic halosilane precipitates in the reaction solution to form cyclic halosilane It becomes easy to obtain the salt in high purity. For the same reason, it is preferable to use a phosphonium salt rather than an ammonium salt.

The formula (11), wherein in (12), A ^- Examples of the monovalent anion represented by the halide ion ^{(e.g., Cl -, Br -, I} - , etc.), borate ions (e.g., BF ₄ ^-) And phosphorus anions (for example, PF ₆ ⁻ ) and the like. Among these, halide ions are preferable from the viewpoint of availability, more preferably Cl ⁻ , Br ⁻ , I ⁻ , and particularly preferably Cl ⁻ and Br ⁻ .

  Either one or both of the phosphonium salt and the ammonium salt may be used. Only one type of phosphonium salt may be used, or two or more types may be used in combination. An ammonium salt may use only 1 type and may use 2 or more types together.

  The amount of the phosphonium salt and / or ammonium salt used (the total amount used when two or more are used) is preferably 0.01 mol or more, more preferably 0.05 mol or more, still more preferably 1 mol of halosilane. It is 0.08 mol or more, preferably 1.0 mol or less, more preferably 0.7 mol or less, still more preferably 0.5 mol or less. When the amount of the phosphonium salt and / or ammonium salt is in the above range, the yield of the cyclic halosilane salt tends to be improved.

  The method A is preferably performed in the presence of a chelate ligand such as polyether, polythioether, and polydentate phosphine. By carrying out the cyclization coupling reaction in the presence of a chelate ligand, a salt of a cyclic halosilane can be produced efficiently. In addition, the number of hydrogens and the composition ratio in the obtained cyclic halosilane can be adjusted by appropriately selecting the type of chelate-type ligand to be used.

  Examples of the polyether include 1,1-dimethoxyethane, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dipropoxyethane, 1,2-diisopropoxyethane, 1,2 -Dibutoxyethane, 1,3-Dimethoxypropane, 1,3-Diethoxypropane, 1,3-Dipropoxypropane, 1,3-Diisopropoxypropane, 1,3-Dibutoxypropane, 1,4-Dimethoxy Dialkoxyalkanes such as butane, 1,4-diethoxybutane, 1,4-dipropoxybutane, 1,4-diisopropoxybutane, 1,4-dibutoxybutane, etc., 1,2-diphenoxyethane, 1 , 3-diphenoxypropane, diaryloxyalkanes such as 1,4-diphenoxybutane, and the like. Among these, particularly preferred is 1,2-dimethoxyethane.

  As said polythioether, what substituted the oxygen atom of the illustrated polyether by the sulfur atom is mentioned.

  Examples of the polydentate phosphine include 1,2-bis (dimethylphosphino) ethane, 1,2-bis (diethylphosphino) ethane, 1,2-bis (dipropylphosphino) ethane, 1,2- Bis (dibutylphosphino) ethane, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (dimethylphosphino) propane, 1,3-bis (diethylphosphino) propane, 1,3-bis ( Dipropylphosphino) propane, 1,3-bis (dibutylphosphino) propane, 1,3-bis (diphenylphosphino) propane, 1,4-bis (dimethylphosphino) butane, 1,4-bis (diethyl) Phosphino) butane, 1,4-bis (dipropylphosphino) butane, 1,4-bis (dibutylphosphino) butane, 1,4-bis (diphenyl) Phosphino) bis (dialkylphosphino) alkanes or bis (diarylphosphino) alkanes such as butane. Among these, particularly preferable is 1,2-bis (diphenylphosphino) ethane.

  The amount of the chelate-type ligand used may be appropriately set. For example, with respect to 1 mol of halosilane, it is preferably 0.01 mol or more, more preferably 0.05 mol or more, still more preferably 0.1 mol or more, and preferably Is 50 mol or less, more preferably 40 mol or less, and still more preferably 30 mol or less.

  As the salt of the cyclic halosilane obtained by the method A, for example, a salt represented by the following formula (13) is suitable.

In the above formula (13), X ¹ and X ² each independently represent a halogen atom, L represents an anionic ligand, and p represents an integer of −2 to 0 as the valence of the ligand L. , K represents a counter cation, q represents an integer of 0 to 2 as the valence of the counter cation K, n represents an integer of 0 to 5, and a, b and c are integers of 0 or more, 2n + 6 or less (Where a + b + c = 2n + 6, a and c are not 0 at the same time), d is an integer of 0 to 3 (however, a and d are not 0 simultaneously), e is an integer of 0 to 3 (however , D + e = 3), m is 1 to 2, s is an integer of 1 or more, and t is an integer of 1 or more.

The salt of the cyclic halosilane may be made into a free cyclic halosilane by contacting and reacting with a Lewis acid. By free cyclic halosilanes is meant non-complex cyclic halosilanes, such as, for example, Si ₅ Cl ₁₀ and Si ₆ Cl ₁₂ . Specifically, when a salt of a cyclic halosilane is brought into contact with a Lewis acid, the Lewis acid acts electrophilically on an anionic ligand contained in the salt of the cyclic halosilane, and the anionic coordination from the salt of the cyclic halosilane. As the child is pulled out, the counter cation is released, and the corresponding free cyclic halosilane can be obtained.

  Although the kind of said Lewis acid is not specifically limited, It is preferable to use a metal halide. Examples of the metal halide include metal chlorides, metal bromides, metal iodides, and the like, and metal chlorides are preferably used from the viewpoint of reactivity and ease of reaction control. Examples of the metal element constituting the metal halide include Group 13 elements such as boron, aluminum, gallium, indium and thallium, Group 11 elements such as copper, silver and gold, Group 4 elements such as titanium and zirconium, iron and zinc, Examples include calcium. Specific examples of Lewis acids include boron trifluoride, boron trichloride, boron halides such as boron tribromide; aluminum halides such as aluminum chloride and aluminum bromide; halogenation such as gallium chloride and gallium bromide Gallium; indium halides such as indium chloride and indium bromide; thallium halides such as thallium chloride and thallium bromide; copper halides such as copper chloride and copper bromide; silver halides such as silver chloride and silver bromide; Gold halides such as gold chloride and gold bromide; titanium halides such as titanium chloride and titanium bromide; zirconium halides such as zirconium chloride and zirconium bromide; iron halides such as iron chloride and iron bromide; zinc chloride And zinc halides such as zinc bromide; calcium halides such as calcium chloride and calcium bromide;

  The amount of the Lewis acid used may be suitably adjusted according to the reactivity of the salt of the cyclic halosilane and the Lewis acid, but for example, it is preferably 0.5 mol or more, more preferably 1 mol of the cyclic halosilane salt. It is 1.5 mol or more, preferably 20 mol or less, more preferably 10 mol or less.

  The reaction between the cyclic halosilane salt and the Lewis acid is preferably carried out in a solvent or dispersion medium (these are simply referred to as solvents). Examples of the solvent (reaction solvent) used in the reaction include hydrocarbon solvents such as hexane and toluene; and ether solvents such as diethyl ether, tetrahydrofuran, cyclopentyl methyl ether, diisopropyl ether and methyl tertiary butyl ether. These organic solvents may be used alone or in combination of two or more. The reaction solvent is preferably subjected to purification such as distillation or dehydration before the reaction in order to remove water and dissolved oxygen contained therein.

  The reaction temperature for the reaction between the cyclic halosilane salt and the Lewis acid may be appropriately adjusted according to the reactivity. For example, the reaction temperature is preferably −80 ° C. or higher, more preferably −50 ° C. or higher, and still more preferably. Is −30 ° C. or higher, preferably 200 ° C. or lower, more preferably 150 ° C. or lower, and still more preferably 100 ° C. or lower.

  Next, the method B will be described.

In XR _{n of} Compound I above, X coordinates to the cyclic halosilane to form a cyclic halosilane neutral complex. When X is P or P = O, X is trivalent and n indicating the number of R is 3. R is the same or different and represents a substituted or unsubstituted alkyl group or aryl group. R is more preferably a substituted or unsubstituted aryl group. When R is an alkyl group, a linear, branched or cyclic alkyl group may be mentioned, and a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group and a cyclohexyl group. A C1-C16 alkyl group, such as group, is mentioned preferably. Moreover, when R is an aryl group, C6-C18 aryl groups, such as a phenyl group and a naphthyl group, are mentioned preferably.

In XR _n of the compound I, also when X is N, X is coordinated to the annular halosilane to form an annular halosilane neutral complex. However, the number of amino groups in the XR _n is 1. When X is N, X is trivalent and n indicating the number of R is 3. R is the same or different and represents a substituted or unsubstituted alkyl group or aryl group. R is more preferably a substituted or unsubstituted alkyl group. When R is an alkyl group, examples thereof include a linear, branched, or cyclic alkyl group, preferably an alkyl group having 1 to 16 carbon atoms, and having 1 to 1 carbon atoms such as methyl, ethyl, propyl, and butyl groups. 4 alkyl groups are more preferable, and alkyl groups having 1 to 3 carbon atoms are more preferable. Moreover, when R is an aryl group, C6-C18 aryl groups, such as a phenyl group and a naphthyl group, are mentioned preferably.

In XR _n when X is P and P = O or when X is N, the alkyl group may have an alkoxy group, amino group, cyano group, carbonyl group, sulfonyl group. Examples of the substituent that the aryl group may have include an alkoxy group, an amino group, a cyano group, a carbonyl group, and a sulfonyl group. Examples of the amino group include a dimethylamino group and a diethylamino group, but the number of amino groups is 1 or less in XR ₃ and is intended to exclude tertiary polyamines. The three Rs may be the same or different.

  When X is S, S = O, O, X is divalent and n indicating the number of R is 2. R has the same meaning as R in the case where X is P and P = O, and is a substituted or unsubstituted alkyl group or aryl group. R is more preferably a substituted or unsubstituted aryl group. When X is CN, X is monovalent, and n indicating the number of R is 1. Also in this case, R has the same meaning as R in the case where X is P and P = O, and is a substituted or unsubstituted alkyl group or aryl group. R is more preferably a substituted or unsubstituted aryl group.

As specific examples of the above-mentioned compound I, X such as triphenylphosphine (PPh ₃ ), triphenylphosphine oxide (Ph ₃ P = O), tris (4-methoxyphenyl) phosphine (P (MeOPh) ₃ ), etc. is P or Compounds in which P = O; compounds in which X is S═O such as dimethyl sulfoxide; compounds in which X is CN such as p-tolunitrile (also referred to as p-methylbenzonitrile).

  In the heterocyclic compound of the above (II) (compound II), it is necessary to have a noncovalent electron pair in the ring, and this noncovalent electron pair is coordinated to the cyclic halosilane to form a cyclic halosilane neutral. Form a complex. Examples of such a heterocyclic compound include one or more substituted or unsubstituted heterocyclic compounds containing N, O, S, or P having a loan pair in the ring. The substituent that the heterocyclic compound may have is the same as the substituent that R may have when it is an aryl group. The heterocyclic compounds include pyridines, imidazoles, pyrazoles, oxazoles, thiazoles, imidazolines, pyrazines, thiophenes, furans and the like. Specific examples include N, N-dimethyl-4-aminopyridine, tetrahydrothiophene, tetrahydrofuran and the like.

  Of the compounds I and II, a compound that is liquid at the reaction temperature can also serve as a solvent.

  The usage-amount of the said compound I and the said compound II should just be determined suitably, and 0.1-50 mol may be used for the said compound with respect to 6 mol of halosilanes, and it is preferable to use 0.5-3 mol.

The cyclic halosilane neutral complex obtained by the above-mentioned method B is formed from 3 to 8 (preferably 5 or 6, especially 6) silicon atoms of a halosilane used as a raw material, and a ring in which silicon atoms are connected. a complex comprising, can be represented by the general formula _{[Y] l [Si m Z} 2m-a H a]. In the above general formula, Y is the above compound I or the above compound II, Z is the same or different, and represents a halogen atom of any of Cl, Br, I, F, l is 1 or 2, m is 3 To 8, preferably 5 or 6, particularly preferably 6, a is 0 to 2 m-1, preferably 0 to m.

  The halosilane cyclization reaction in Method A and Method B is preferably performed by adding a tertiary amine. The hydrochloric acid formed can be neutralized by the addition of a tertiary amine.

  Examples of the tertiary amine used in the cyclization reaction include triethylamine, tripropylamine, tributylamine, trioctylamine, triisobutylamine, triisopentylamine, diethylmethylamine, diisopropylethylamine (DIPEA), dimethylbutylamine. , Dimethyl-2-ethylhexylamine, diisopropyl-2-ethylhexylamine, methyl dioctylamine and the like are preferable.

1 type may be used for the said tertiary amine and it may use 2 or more types together. In addition, tertiary amines also include those that coordinate to cyclic halosilanes, for example, relatively bulky, highly symmetrical amines such as diethylmethylamine, triethylamine, etc. coordinate relatively efficiently. It is thought that. However, since the yield of the cyclic halosilane neutral complex tends to be low only with the tertiary amine represented by XR _n of the compound I, it is preferable to use a compound I other than the tertiary amine in combination.

  The tertiary amine is preferably used in an amount of 0.5 to 4 mol, particularly preferably 1 mol, relative to 1 mol of halosilane.

  In the present invention, although not limited, it is preferable not to use a tertiary polyamine having 2 or more carbon atoms and 3 or more amino groups. When the above-mentioned tertiary polyamine is used, a salt of a cyclic halosilane containing silicon as a counter cation is formed, and a silane gas is generated during storage or reduction reaction, which is not preferable from the viewpoint of safety.

  The halosilane cyclization reaction in Method A and Method B can be carried out in an organic solvent as necessary. As this organic solvent, a solvent which does not interfere with the cyclization reaction is preferable. For example, hydrocarbon solvents (eg, hexane, heptane, benzene, toluene etc.), halogenated hydrocarbon solvents (eg, chloroform, dichloromethane, 1,1 Aprotic polar solvents such as 2-dichloroethane and the like, ether solvents (eg, diethyl ether, tetrahydrofuran, cyclopentyl methyl ether, diisopropyl ether, methyl tertiary butyl ether and the like), acetonitrile and the like are preferably mentioned. Among these, chlorinated hydrocarbon solvents such as chloroform, dichloromethane and 1,2-dichloroethane are preferable, and 1,2-dichloroethane is particularly preferable. In addition, these organic solvents may use 1 type and may use 2 or more types together.

  The amount of the organic solvent used is not particularly limited, but it is usually preferable to adjust the halosilane concentration to be 0.5 to 10 mol / L, and more preferable concentration is 0.8 to 8 mol / L, even more preferable. The concentration is 1 to 5 mol / L.

  The reaction temperature in the cyclization reaction can be appropriately set according to the reactivity, and is, for example, about 0 to 120 ° C, preferably about 15 to 70 ° C. It is also recommended to carry out the cyclization reaction under an inert gas atmosphere such as nitrogen.

  After the cyclization reaction, it is preferable to include a step of washing the reaction solution containing the cyclic halosilane compound with a non-halogen solvent. That is, when the cyclization reaction is completed, a solution or dispersion of a cyclic halosilane compound (a cyclic halosilane salt, a free cyclic halosilane, a cyclic halosilane neutral complex, etc.) is formed. This may be concentrated or filtered, and the obtained solid may be purified by washing with a halogen solvent such as chloroform, dichloromethane, 1,2-dichloroethane or the like, acetonitrile, a non-halogen solvent such as hexane, or the like. By including the step of washing the cyclic halosilane compound using a non-halogen solvent, the content of impurities such as halogen elements contained in the hydrogenated silane composition tends to be significantly reduced.

  It is preferable to include a step of washing with a halogen solvent prior to washing with the non-halogen solvent. The amine hydrochloride can be removed by washing with a halogen solvent, and the halogen solvent can be removed by washing with a non-halogen solvent.

  The cleaning using the halogen solvent and the cleaning using the non-halogen solvent may be performed once each or twice or more.

  The above cyclic halosilane compound can be obtained as a highly pure solid by purification. However, if desired, it is also possible to obtain a composition containing a cyclic halosilane compound containing an impurity. The composition containing a cyclic halosilane compound preferably contains 80% by mass or more of the cyclic halosilane compound, more preferably 90% by mass or more, and still more preferably 95% by mass or more. The upper limit is, for example, 99.99% by mass. Examples of the impurity include a solvent, a residue of the compound I or the compound II, a decomposition product of a cyclic halosilane compound, a halosilane polymer, and the like. The content of the impurity in the composition containing a cyclic halosilane compound is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and the lower limit is, for example, 0.01. % By mass.

<Reduction reaction process>
The cyclic hydrogenated silane or the composition containing the cyclic hydrogenated silane used in the production method of the present invention is optional, but a step of reducing the cyclic halosilane compound (hereinafter, also referred to as "reduction reaction step" or "reduction step" It is preferable to use what was manufactured by the method containing). Although the cyclic halosilane compound used in the reduction step is arbitrary, it is preferable to use, for example, a salt of the above cyclic halosilane, a free cyclic halosilane, a cyclic halosilane neutral complex, or the like. The reduction step is preferably performed in the presence of a reducing agent.

The reducing agent that can be used in the reduction step is not particularly limited, but it is preferable to use one or more selected from the group consisting of an aluminum-based reducing agent and a boron-based reducing agent. Examples of the aluminum reducing agent include lithium aluminum hydride (LiAlH ₄ ; LAH), diisobutylaluminum hydride (DIBAL), sodium bis (2-methoxyethoxy) aluminum hydride [“Red-Al” (manufactured by Sigma-Aldrich). (Registered trademark)] and the like. Examples of the boron-based reducing agent include metal hydrides such as sodium borohydride and lithium triethylborohydride, and diborane. It is preferable to use metal hydrides. In addition, 1 type may be used for a reducing agent and it may use 2 or more types together.

  The amount of use of the reducing agent in the reduction step may be set appropriately, for example, it is preferable to set the equivalent of hydride in the reducing agent to at least 0.9 equivalent or more to one silicon-halogen bond of the cyclic halosilane compound. . The amount of the reducing agent used is more preferably 1.0 to 50 equivalents, still more preferably 1.0 to 30 equivalents, particularly preferably 1.0 to 15 equivalents, and most preferably 1.0 to 2 equivalents. When the amount of the reducing agent used is too large, post-treatment takes time and the productivity tends to decrease. On the other hand, when the amount of the reducing agent used is too small, the halogen remains without being reduced, and the yield tends to decrease.

  In the reduction step, a Lewis acid catalyst may be used in combination with the reducing agent as a reduction aid. Lewis acid catalysts include chlorides such as aluminum chloride, titanium chloride, zinc chloride, tin chloride and iron chloride; bromides such as aluminum bromide, titanium bromide, zinc bromide, tin bromide and iron bromide; iodide Iodides such as aluminum, titanium iodide, zinc iodide, tin iodide and iron iodide; Fluorides such as aluminum fluoride, titanium fluoride, zinc fluoride, tin fluoride and iron fluoride; A metal compound is mentioned. One of these may be used, or two or more may be used in combination.

  The reaction in the reduction step can be carried out in the presence of an organic solvent, if necessary. Examples of the organic solvent include hydrocarbon solvents such as hexane and toluene; ether solvents such as diethyl ether, tetrahydrofuran, cyclopentyl methyl ether, diisopropyl ether and methyl tertiary butyl ether; and the like. These organic solvents may be used alone or in combination of two or more. In addition, the organic solvent solution obtained when producing the cyclic halosilane compound may be used as it is as the organic solvent solution in the reduction step, or the organic solvent is distilled off from the organic solvent solution containing the cyclic halosilane compound, A new organic solvent may be added to carry out the reduction step. The organic solvent used for the reaction in the reduction step is preferably purified by distillation or dehydration before the reaction in order to remove water and dissolved oxygen contained therein.

  The amount of the organic solvent used for the reduction reaction is preferably adjusted so that the concentration of the cyclic halosilane compound is 0.01 to 1 mol / L, more preferably 0.02 to 0.7 mol / L, still more preferably. Is 0.03-0.5 mol / L. By performing the reaction in the above range, the content of impurities such as halogen elements contained in the hydrogenated silane composition tends to be significantly reduced.

  The reduction can be carried out by contacting the cyclic halosilane compound with a reducing agent. The contact between the cyclic halosilane compound and the reducing agent is preferably performed in the presence of a solvent. In order to contact the cyclic halosilane compound and the reducing agent in the presence of a solvent, for example, (b) the solution or dispersion of the cyclic halosilane compound is added to the solution or dispersion of the cyclic halosilane compound as it is. In addition, a mixing procedure such as adding a solution or dispersion in which a reducing agent is dissolved or dispersed in a solvent, or (c) simultaneously or sequentially adding a cyclic halosilane compound and a reducing agent to the solvent may be employed. Among these, the embodiment (b) is particularly preferable.

  Further, at the time of contacting the cyclic halosilane compound with the reducing agent, it is preferable to drop at least one of a solution or dispersion of the cyclic halosilane compound and a solution or dispersion of the reducing agent in a reaction system for reduction. . By thus dropping one or both of the cyclic halosilane compound and the reducing agent, the heat generated by the reduction reaction can be controlled by the dropping rate and the like, so that, for example, miniaturization of a condenser and the like becomes possible, productivity The effect which leads to improvement is acquired.

  Preferred embodiments when one or both of the cyclic halosilane compound and the reducing agent are added dropwise include the following three embodiments. That is, A) a solution or dispersion of a cyclic halosilane compound is charged into a reactor and a solution or dispersion of a reducing agent is dropped thereto, B) a solution or dispersion of a reducing agent is charged into the reactor A solution or dispersion of the cyclic halosilane compound is added dropwise, C) a solution or dispersion of the cyclic halosilane compound and a solution or dispersion of the reducing agent simultaneously or sequentially added to the reactor. is there. Among these, the aspect of the above A) is preferable.

  When one or both of the cyclic halosilane compound and the reducing agent are dropped in the above A) to C), the concentration of the solution or dispersion of the cyclic halosilane compound is preferably 0.01 mol / L or more, more preferably 0. 02 mol / L or more, more preferably 0.04 mol / L or more, particularly preferably 0.05 mol / L or more. If the concentration of the cyclic halosilane compound is too low, the amount of solvent that must be distilled off when isolating the target product increases, so that productivity tends to decrease. On the other hand, the upper limit of the concentration of the cyclic halosilane solution or dispersion is preferably 1 mol / L or less, more preferably 0.8 mol / L or less, and still more preferably 0.5 mol / L or less.

  The lower limit of the temperature at the time of dropping (specifically, the temperature of the dropping solution or dispersion) is preferably −198 ° C. or higher, more preferably −160 ° C. or higher, and further preferably −100 ° C. or higher. Moreover, the upper limit of the temperature at the time of dripping becomes like this. Preferably it is +150 degrees C or less, More preferably, it is +100 degrees C or less, More preferably, it is +80 degrees C or less, Most preferably, it is +40 degrees C or less. The temperature of the reaction vessel (reaction temperature) may be appropriately set according to the kind of the cyclic halosilane compound and the reducing agent, and usually the lower limit is preferably −198 ° C. or higher, more preferably −160 ° C. or higher. More preferably, it is -100 ° C or more. The upper limit of the temperature of the reaction vessel (reaction solution) is preferably + 150 ° C. or less, more preferably + 100 ° C. or less, still more preferably + 80 ° C. or less, and particularly preferably + 40 ° C. or less. When the reaction temperature is low, decomposition and polymerization of the intermediate product and the target product can be suppressed, so that the yield is improved. The reaction time may be appropriately determined according to the progress of the reaction, and is usually 10 minutes to 72 hours, preferably 1 hour to 48 hours, more preferably 2 hours to 24 hours.

As an example, a scheme example in which trichlorosilane is used as the halosilane, triphenylphosphine (PPh ₃ ) is used as the compound I, and N, N-diisopropylethylamine (DIPEA) is used as the tertiary amine in the method B is shown below.

When trichlorosilane is used as a starting material and compound I is triphenylphosphine (PPh ₃ ), a complex containing dodecachlorocyclohexasilane having a six-membered ring (dodecachlorocyclohexasilane and triphenylphosphine as described above) is generally used. Becomes a neutral complex ([PPh ₃ ] ₂ [Si ₆ Cl ₁₂ ]). Since this cyclic halosilane neutral complex contains no silicon atoms in addition to the silicon atoms forming the ring structure, no silane gas or organic monosilane is generated during reduction, alkylation or arylation. It can be suppressed.

  The yield / yield of the cyclic halosilane neutral complex generated by this cyclization reaction can be calculated using the methylation reaction represented by the following scheme in which the complex reacts quantitatively.

The method for obtaining a cyclic hydrogenated silane (for example, cyclohexasilane) by reducing the cyclic halosilane neutral complex (for example, [PPh ₃ ] ₂ [Si ₆ Cl ₁₂ ]) uses, for example, LiAlH ₄ as a reducing agent. If it is, it is represented by the following scheme.

  The reduction reaction is usually preferably performed in an atmosphere of an inert gas such as nitrogen gas or argon gas.

  In the case where the cyclic hydrogenated silane of the present invention or the composition containing the cyclic hydrogenated silane is a product obtained by a method including a reduction step, the production method of the present invention comprises the cyclic hydrogenated silane. A liquid layer containing a composition (for example, a reaction liquid for reduction reaction), the cyclic hydrogenated silane, and a solvent used in the step of reducing the cyclic halosilane compound (referred to as “reduction reaction solvent”); It may include a step of solid-liquid separation with agent residue, by-products and the like. By providing the solid-liquid separation step after the reduction reaction, the effects of the present invention tend to be more prominently exhibited. The production method of the present invention may include one or more solid-liquid separation steps, and preferably includes one or two.

  If the cyclic hydrogenated silane of the present invention or the composition containing the cyclic hydrogenated silane is a product obtained by a method including a reduction step, it is optional. And adding to the composition containing the solvent used in the step of reducing the cyclic halosilane compound (referred to as "reduction reaction solvent") other solvent (except for the above-mentioned high boiling point solvent, preferably except for the solvent used in the reduction step) The process of carrying out may be included.

  When the composition obtained by the step of adding the other solvent further distills off part or all of the solvent used in the reduction step, or the other solvent is not compatible with the solvent used in the reduction step. For example, a part or all of the reduction reaction solvent contained in the composition containing the cyclic hydrogenation silane and the reduction reaction solvent is extracted by extracting the cyclic hydrogenation silane compound with the other solvent. The solvent may be substituted by a solvent (hereinafter referred to as "solvent substitution step").

That is, the production method of the present invention may include a solvent replacement step. As the other solvent to be added or the solvent to be substituted, although it is optional, a solvent which promotes precipitation of a residue of a reducing agent or a by-product by addition or solvent substitution is used in the concentration step. In addition, since the amount of precipitates in the distillation step tends to be reduced, the effect of the present invention tends to be more significantly exhibited, which is preferable. As such a solvent, a hydrocarbon solvent such as hexane is preferably exemplified. From the viewpoint of facilitating concentration, a low boiling point solvent is preferred.
Although optional, the production method of the present invention may include a solid-liquid separation step after the addition step of the other solvent or the solvent replacement step.
In addition, a step of adding a high boiling point solvent may be provided before the addition step of the other solvent or the solvent replacement step.

The production method of the present invention is optional. From the composition containing (I) the cyclic hydrogenated silane and (II) the solvent used in the step of reducing the cyclic halosilane compound and / or other solvent, A step of distilling off a part of the solvent of (II) (hereinafter referred to as “concentration step”) may be included. When the content of the cyclic hydrogenated silane is increased in the absence of a high boiling point solvent, the residue of the reducing agent to be deposited and byproducts tend to stick to the wall of the kettle and the productivity tends to decrease, It is preferable to carry out the above-mentioned concentration step so as not to increase the concentration of the cyclic hydrogenated silane compound, or to carry out the step of adding the high-boiling point solvent during or before the above-mentioned concentration step.
Therefore, the step of distilling off the solvent of (II) from the composition containing (I) the cyclic hydrogenated silane and (II) the solvent and / or other solvent used in the step of reducing the cyclic halosilane compound. It is also one of the preferable modes of the process of the present invention that the step of adding the high boiling point solvent is carried out before the entire amount of the solvent of (II) is distilled off in the step.

In the concentration step, when the high boiling point solvent is absent, the content of the cyclic hydrogenated silane in the composition containing cyclic hydrogenated silane is less than 90% by mass with respect to 100% by mass of the composition. Preferably, it is 80 mass% or less.
In the concentration step, when the content of the cyclic hydrogenated silane is concentrated from the above range in the absence of the high boiling point solvent, it is preferable to select a method that does not require a thermal history as much as possible, such as thin film evaporation.

  As for the timing of addition of the high boiling point solvent to the composition containing cyclic hydrogenated silane, if addition of the high boiling point solvent is started by the time of taking out the cyclic hydrogenated silane from the composition containing cyclic hydrogenated silane Optionally, when the reduction step is included, it may be before, in the middle, and after, and when it includes the concentration step, it may be before, in the middle, and after, and the solvent replacement step is performed. When it is included, it may be before, during, or after it, and when it includes a solid-liquid separation step, it may be before, during or after that. However, as described above, it is preferably added when the content of the cyclic hydrogenated silane in the composition containing the cyclic hydrogenated silane is within the above range.

  The production method of the present invention comprises the step of adding a high boiling point solvent to at least one selected from a cyclic halosilane compound, a composition containing a cyclic halosilane compound, a cyclic hydrogenated silane, and a composition containing a cyclic hydrogenated silane, It is preferable to include 1 or 2 or more.

In the present invention, from the composition containing (I) the cyclic hydrogenated silane and (II) the solvent and / or other solvent used in the step of reducing the cyclic halosilane compound, a part of the solvent of (II) And a step of adding the high boiling point solvent before, during or after the step may be performed,
(I) including distilling off the solvent of (II) from the composition containing the cyclic hydrogenated silane and (II) the solvent and / or other solvent used in the step of reducing the cyclic halosilane compound. The step of adding the high boiling point solvent may be carried out before the entire amount of the solvent (II) is distilled off in the step.

  On the other hand, from the composition comprising (I) the cyclic hydrogenated silane, the solvent used in the step of reducing the cyclic halosilane compound (II) and / or the other solvent, and (III) the high-boiling solvent, One or more steps of distilling off at least a part of the solvent of (II) may be included.

In a preferred embodiment of the present invention, the case where the high boiling point solvent is added before the reduction step is, for example, before the step of cyclizing halosilane (added to halosilane or a composition containing halosilane), in the middle (cyclic halosilane compound is added). And (after addition to the composition containing the cyclic halosilane compound, or adding to the cyclic halosilane compound through the process of isolating the cyclic halosilane compound).
On the other hand, when the high boiling point solvent is added during or after the reduction step, it may be added, for example, to a composition containing cyclic hydrogenated silane, and cyclic hydrogenated silane obtained by the step of isolating cyclic hydrogenated silane. You may add to.
From the viewpoint of efficiently removing the precipitate, a step of adding the high-boiling point solvent is performed during or after the reduction step, and then a step of solid-liquid separation of the liquid composition containing the cyclic hydrogenated silane It may be done.

The production method of the present invention may include an optional step in addition to the step of taking out the cyclic hydrogenated silane. Examples of preferred production methods include the following (a) to (e).
(A) solid-liquid separation step (hereinafter referred to as "solid-liquid separation step (A)") of solid-liquid separation of a composition containing cyclic hydrogenated silane (typically, the reaction liquid obtained in the above-mentioned reduction step); A production method that essentially includes a step of concentrating the separated liquid phase (hereinafter referred to as “concentration step (A)”) and a step of taking out cyclic hydrogenated silane in this order.
(A) adding another solvent (except for the high boiling point solvent and the solvent used in the reduction step) to the composition containing the cyclic hydrogenated silane (typically, the reaction liquid obtained in the above reduction step) "Addition step (A)", solid-liquid separation of a composition containing cyclic hydrogenated silane and another solvent ("solid-liquid separation step (B)"), concentration of the liquid phase separated in solid-liquid separation A production method comprising, in the order mentioned, a step of conducting (hereinafter referred to as "concentration step (B)") and a step of taking out cyclic hydrogenated silane.
(C) Step of adding the solid-liquid separation step (A), the concentration step (A), and other solvents (excluding the high boiling point solvent and the solvent used in the reduction step) (hereinafter referred to as “addition step (B)”) Solid-liquid separation of a composition containing cyclic hydrogenated silane and another solvent (hereinafter referred to as “solid-liquid separation step (B)”), and concentrating a composition containing cyclic hydrogenated silane and another solvent A production method comprising a step (hereinafter referred to as "concentration step (B)") and a step of taking out cyclic hydrogenated silane in this order.
(E) A manufacturing method essentially including, in this order, the solid-liquid separation step (A), the concentration step (A), the addition step (B), the concentration step (B), and a step of taking out the cyclic hydrogenated silane.
(E) a step of concentrating a composition containing a cyclic hydrogenated silane (typically, the reaction liquid obtained in the above-mentioned reduction step) (hereinafter referred to as "concentration step (C)"), the above-mentioned addition step (B), A manufacturing method comprising the step of solid-liquid separation step (B), the step of concentration (B), and the step of taking out cyclic hydrogenated silane in this order.
Moreover, about the said (a)-(e), the process of adding a high boiling point solvent should just be started before or simultaneously with the process of taking out cyclic hydrogenated silane as above-mentioned, Preferably it is as above-mentioned.
In the present invention, the production method of the above (A) is preferable, and in the above (A), after the concentration step (A), the step of adding a high boiling point solvent is carried out to carry out the step of taking out cyclic hydrogenated silane. Preferably, after the addition of the high-boiling point solvent, it is more preferable to carry out a concentration step to carry out a step of taking out the cyclic hydrogenated silane.

  In the concentration step of distilling off the reaction solvent and / or other solvent from the reaction solution, a method of distilling off under reduced pressure is preferably employed as a method of distilling off the solvent.

  When solid-liquid separation is performed, the method of solid-liquid separation is preferably adopted because filtration is simple, but it is not limited to this. For example, known methods of solid-liquid separation such as centrifugation and decantation It can be adopted appropriately.

Hereinafter, the process of taking out the cyclic hydrogenated silane will be described. The step of taking out the cyclic hydrogenated silane is not limited to this, but preferably includes a step of distilling the cyclic hydrogenated silane (hereinafter also referred to as “distillation step”). In the distillation step, it is preferable to distill the cyclic hydrogenated silane while leaving the high boiling point solvent on the residue side.
The distillation is preferably vacuum distillation. The method for distillation under reduced pressure is not particularly limited, and may be performed in a known distillation column. The distillation is preferably performed by dividing the fraction into a plurality of fractions.

  In particular, one method for reducing the content of the chain hydrogenated silane includes performing the distillation (particularly, vacuum distillation) twice or more. For example, after the solution containing the hydrogenated silane composition is distilled under reduced pressure and a fraction having an appropriate cyclic hydrogenated silane (especially cyclohexasilane) content is recovered (first distillation), this recovered fraction is again distilled under reduced pressure Then, a fraction having an appropriate cyclic hydrogenated silane (particularly cyclohexasilane) content may be recovered (second distillation), and the second distillation may be repeated as necessary.

  The vacuum distillation is carried out batchwise to separate impurities having a higher boiling point and a lower boiling point than cyclic hydrogenated silane and to reduce the content of chain hydrogenated silane in the hydrogenated silane composition. It is also good.

  The content of the high boiling point solvent is preferably reduced as much as possible in 100% by mass of the cyclic hydrogenated silane after distillation, for example, preferably 1% by mass or less, more preferably 1000 ppm or less, and 100 ppm or less More preferably.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, implementation is also possible, and all of them are included in the technical scope of the present invention.

(Gas chromatography (GC) analysis method)
Measuring method: GC FID method analyzer: GC2014 manufactured by Shimadzu Corporation
Column: Agilent J & W GC column DB-5ms 0.25 μm (Film) × 0.25 mm (Diam) × 30 m (Length) (Agilent Technologies)
Vaporization chamber temperature: 250 degrees Detector temperature: 280 degrees Temperature rising condition: 50 degrees for 5 minutes, temperature increased to 20 degrees at 20 degrees / minute, temperature increased to 280 degrees at 10 degrees / minute for 10 minutes

Production Example 1 (Production of Cyclic Halosilane Compound)
After replacing the inside of a 3 L four-necked flask equipped with a thermometer, a condenser, a dropping funnel and a stirrer with nitrogen gas, 155 g (0.591 mol) of triphenylphosphine as a coordination compound and a basic compound in the flask And 458 g (3.54 mol) of diisopropylethylamine and 1789 g of 1,2-dichloroethane as a solvent were added. Subsequently, 481 g (3.54 mol) of trichlorosilane as a halosilane compound was slowly dropped from the dropping funnel under a condition of 25 ° C. while stirring the solution in the flask.
After completion of the dropwise addition, the mixture was stirred as it was for 2 hours, and then heated and stirred at 60 ° C. for 8 hours to carry out a cyclization coupling reaction to obtain a uniform reaction solution. The obtained reaction solution was concentrated, 7200 g of chloroform was added, the mixture was stirred and washed at room temperature for 1 hour, filtered, and the filtration residue was dried under reduced pressure to obtain a white solid (crude product).

Subsequently, 5-fold amount (based on mass) of dehydrated hexane was added to the white solid obtained above, and the mixture was stirred and washed at room temperature for 24 hours, followed by filtration. The obtained filtration residue was washed and filtered again with hexane in the same procedure as described above, and the obtained filtration residue was dried under reduced pressure to obtain a cyclic halosilane compound (bis (triphenylphosphine) dodecachlorocyclohexaci). A refined product of the run ([Ph ₃ P] ₂ [Si ₆ Cl ₁₂ ]) was obtained. All steps from washing to drying were performed in a nitrogen atmosphere. The purified product thus obtained was measured by gas chromatography. The purified product contained 1% by mass of chloroform and 1% by mass of amine salt (amine hydrochloride) as a halogenated hydrocarbon compound.

Example 100 g of the purified cyclic halosilane compound obtained in the above Preparation Example 1 and 591 g of cyclopentyl methyl ether (CPME) were placed in a 2000 mL flask under a nitrogen atmosphere, and the mixture was stirred at -60 ° C. Into this, 183 g of a 1 M diethyl ether solution of LiAlH ₄ was dropped from a dropping funnel. After completion of dropping, the mixture was stirred at −60 ° C. to −71 ° C. for 3 hours to carry out a reduction reaction. Thereafter, the reaction solution was heated to room temperature 20 ° C., and solid-liquid separation (filtration) was performed under a nitrogen atmosphere to obtain 783 g of a filtrate. The solvent of diethyl ether and cyclopentyl methyl ether was distilled off under reduced pressure from 195 g of the obtained filtrate. 79 g of dimethyl silicone oil (KF-96-20cs, boiling point 460 ° C.) was added as a high boiling point solvent to 18 g of the concentrated solution (containing 1.5 g of cyclohexasilane). Then, the solvent of cyclopentyl methyl ether and diethyl ether was further distilled off and concentrated. The concentrate obtained was distilled under reduced pressure conditions to obtain a purified product of cyclohexasilane (distillation conditions: pressure 1.7 to 2.3 Torr, internal temperature 25 to 60 ° C.).
When the inside of the flask was confirmed, the precipitate had fluidity and could be removed from the flask together with the high boiling point solvent.
From the above, it was confirmed that the production method of the present invention can improve the behavior of the precipitate and suppress the solidification of the precipitate in the container. Therefore, it became clear that productivity can be improved.

Claims (12)

A step of taking out the cyclic hydrogenated silane from a composition containing the cyclic hydrogenated silane represented by the general formula (SiH ₂ ) _n (n = 3 to 8),
A method for producing a cyclic hydrogenated silane, wherein the composition comprises a high boiling point solvent having a boiling point higher by at least 10 ° C. than the cyclic hydrogenated silane.   The production method according to claim 1, further comprising a step of reducing a cyclic halosilane compound, wherein the cyclic hydrogenated silane is obtained by a step of reducing the cyclic halosilane compound.   A liquid layer containing a composition containing the cyclic hydrogenated silane obtained in the step of reducing the cyclic halosilane compound, the cyclic hydrogenated silane, and a solvent used in the step of reducing the cyclic halosilane compound; The manufacturing method of Claim 2 including the process of carrying out solid-liquid separation to and.   Adding one or more steps of adding the high boiling point solvent to at least one selected from a cyclic halosilane compound, a composition containing a cyclic halosilane compound, a cyclic hydrogenated silane, and a composition containing a cyclic hydrogenated silane The manufacturing method of Claim 2 or 3.   During or after the step of reducing the cyclic halosilane compound, a step of adding the high-boiling point solvent is performed, and then a step of solid-liquid separation of the liquid composition containing the cyclic hydrogenated silane is performed. The manufacturing method in any one of 2-4.   (I) A part of the solvent of (II) is distilled off from the composition containing the cyclic hydrogenated silane and (II) the solvent and / or other solvent used in the step of reducing the cyclic halosilane compound. The manufacturing method in any one of Claims 2-5 in which the process of adding the said high boiling point solvent is performed before the process of the process including the process, or after.   Distilling off the solvent of (II) from the composition containing (I) the cyclic hydrogenated silane and (II) the solvent used in the step of reducing the cyclic halosilane compound and / or the other solvent The method according to any one of claims 2 to 6, wherein the step of adding the high boiling point solvent is performed before the total amount of the solvent of (II) is distilled off in the step.   The composition comprising (I) the cyclic hydrogenated silane, the solvent used in the step of reducing the cyclic halosilane compound (II) and / or the other solvent, and (III) the high-boiling solvent; The production method according to any one of claims 2 to 7, comprising one or two or more steps of distilling off at least a part of the solvent.   The manufacturing method according to any one of claims 1 to 8, wherein the high boiling point solvent is at least one selected from the group consisting of a hydrocarbon solvent, an ether solvent, and a silicone solvent.   The manufacturing method in any one of Claims 1-9 whose composition amount of the said high boiling point solvent in the said composition is 10 mass parts or more with respect to 100 mass parts of cyclic | annular hydrogenation silane.   The content of the high boiling point solvent contained in the cyclic hydrogenated silane taken out from the composition is 1% by mass or less based on 100% by mass of the cyclic hydrogenated silane. Production method.   The method according to claim 1, wherein the cyclic hydrogenated silane is cyclohexasilane.