JP2011162792A - Purifying method of polysilane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a purifying method capable of efficiently removing metallic components preliminarily contained in a polysilane. <P>SOLUTION: The purifying method of polysilane is carried out by bringing the polysilane containing the metallic components (1) (for example, polysilane containing ≥500 ppm metallic components (1)) into contact with a metallic component (2) constituted of a metal (b) (for example, iron, cobalt, nickel, copper or the like) having ionization tendency smaller than that of a metal (a) (for example, zinc or the like) constituting the metallic components (1). In such a method, the ratio of the metallic component (1) and the metallic component (2) expressed in terms of weight of the metal (a) and the metal (b) is ≤100 ppm per total quantity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for removing a metal component previously contained in polysilane, and a polysilane obtained by removing the metal component by this removal method.

  Polysilanes are attracting attention as ceramic precursors, optoelectronic materials (for example, photoelectrophotographic materials such as photoresists and organic photoreceptors, optical transmission materials such as optical waveguides, optical recording materials such as optical memories, and materials for electroluminescent elements). ing.

  As a typical method for synthesizing polysilane, dialkyldihalosilane or dihalotetraalkyldisilane in a toluene solvent is vigorously stirred at a temperature of 100 ° C. or higher using an alkali metal such as sodium metal, and reductively coupled. Method [J. Am. Chem. Soc., 103 (1981) 7352 (non-patent document 1), commonly known as “Kipping method”]. However, this method needs to heat and strongly stir and disperse the alkali metal that ignites in the air, so there is concern about safety in production on an industrial scale, and the molecular weight distribution is multimodal. The quality is not enough.

  As a method for solving these problems, for example, WO98 / 29476 (Patent Document 1) and JP-A-2003-277507 (Patent Document 2) describe polysilanes by polymerizing halosilanes using a magnesium component. A method of obtaining is disclosed. The method described in these documents is a method of performing polymerization by using a magnesium component alone or a magnesium component and a metal halide as a catalyst. (1) Using a general-purpose chemical synthesis apparatus, a stable and inexpensive raw material is produced. Can be synthesized, and has safety and cost advantages. (2) Impurities that are not suitable for optoelectronic materials (such as sodium and insoluble matter in organic solvents) are not mixed. (3) There is little variation in molecular weight. It has excellent characteristics such as a polysilane having high solubility and transparency in an organic solvent, and (4) high yield.

  However, in the above two methods, and in any of the other methods for producing polysilanes that have been conventionally developed, since a metal or a metal salt is always used, a metal component remains in the polysilane, so that it can be used as an optoelectronic material. It may not be suitable.

  In addition, polysilanes having many terminal structures using trihalosilane compounds or tetrahalosilane compounds as raw materials are not clear in details of the mechanism, but in particular, they seem to tend to incorporate metal components into the structure.

WO98 / 29476 (Claims) Japanese Patent Laying-Open No. 2003-277507 (Claims)

J. Am. Chem. Soc., 103 (1981) 7352

  Accordingly, an object of the present invention is to provide a purification method capable of efficiently removing a metal component previously contained in polysilane, and a polysilane obtained by this method.

  Another object of the present invention is to provide a purification method that can easily and efficiently remove a metal component even if it is difficult to remove a metal component such as zinc by a conventional method, and a polysilane obtained by this method. Is to provide.

  Still another object of the present invention is to provide a method for purifying polysilane that can significantly reduce the content of metal components contained in polysilane.

  Another object of the present invention is to provide a high-purity polysilane in which the content of metal components is significantly reduced.

  As a result of intensive studies to solve the above problems, the present inventors have (1) polysilane obtained by using a metal or a metal compound as a catalyst. A large amount of metal component remains because of some affinity for (2) polysilane containing such a metal component (A) and a specific index for the metal component By contacting the different metal component (B), the affinity of the metal component (A) for polysilane is reduced, and the metal constituting the metal component (A) and the metal constituting the metal component (B) are replaced. The metal component (A) can be easily removed, or (3) the contacted metal component (B) (or its constituent metal) has a relatively low affinity for polysilane, elution, etc. By poly Easily removed from the run, it found that significantly less high-purity polysilane content of the metal components are obtained, and have completed the present invention.

  That is, the method of the present invention is a method for purifying a polysilane containing a metal component (1), and is a metal (b) having a smaller ionization tendency than the polysilane and the metal (a) constituting the metal component (1). The metal component (1) contained in the polysilane is removed by contacting the metal component (2) composed of In the purification method (or removal method), polysilane (polysilane containing metal component (1)) may contain 500 ppm or more of metal component (1) based on the weight of metal (a). .

  Polysilane synthesized using a metal catalyst often contains a metal component (1) corresponding to the metal catalyst. In addition, the polysilane is more likely to incorporate the metal component (1) as it has a branched structure than a linear structure. In the present invention, even with such polysilane, the metal component (1) can be efficiently removed. For example, in the removal method, the polysilane may be a polysilane having a branched structure obtained by polymerizing at least one selected from trihalosilanes and tetrahalosilanes in the presence of a magnesium metal component and a metal halide. Good.

  In the removal method, the combination of the metal (a) and the metal (b) may be such that the metal (a) is iron and / or zinc. Typically, the water-soluble metal compound in which the metal (a) is zinc and the metal component (2) is composed of at least one metal (b) selected from iron, cobalt, nickel and copper. (For example, a metal halide, a salt of a metal and an inorganic acid, etc.) may be used.

  The said refinement | purification method (removal method) can be normally performed by making the polysilane containing a metal component (1) and a metal component (2) contact in presence of a solvent. For example, the removal method can dissolve the polysilane containing the metal component (1), the solvent (a) capable of dissolving the polysilane, the metal component (2), and the metal component (2). A step of mixing a solvent (b) that does not dissolve the solvent and is capable of layer separation (or phase separation) in combination with the solvent (a), and a liquid containing polysilane from the mixed system obtained through this mixing step The process of isolate | separating a layer (or liquid phase) may be included. This removal method comprises a step of washing a liquid layer containing polysilane (a liquid layer separated through a separation step) with a solvent that does not dissolve polysilane and can be separated in combination with the solvent (a). May be included.

  In a typical purification method, a step of mixing a solution in which a polysilane containing a metal component (1) is dissolved in a solvent composed of at least a hydrophobic organic solvent and an aqueous solution in which the metal component (2) is dissolved, and this mixing A step of separating a liquid layer (organic layer) containing polysilane from the mixed system obtained through the steps and a step of washing the liquid layer containing polysilane with water may be included.

  In the method of the present invention, the ratio of the metal component (1) can be reduced at a remarkably high level. For example, the polysilane having a metal component (1) ratio of about 50 ppm or less based on the weight of the metal (a). Can be obtained. Further, in the method of the present invention, not only the metal component (1) but also the residue of the metal component (2) used for contact with respect to polysilane can be suppressed at a high level. For example, the metal component (1) and the metal component (2) It is also possible to obtain polysilane having a ratio of (total ratio of metal component (1) and metal component (2)) of about 100 ppm or less based on the weight of metal (a) and metal (b).

  The present invention also includes a polysilane obtained by the purification method (polysilane from which the metal component has been removed by the purification method), and in such a polysilane, the ratio of the metal component (1) and the metal component (2) May be 100 ppm or less based on the weight of the metal (a) and the metal (b).

  In the present invention, the metal component preliminarily contained in the polysilane can be efficiently removed by bringing the polysilane containing the metal component into contact with a metal component different from the metal component in a specific index. Further, according to the method of the present invention, a metal component can be easily and efficiently removed even with a polysilane in which removal of a metal component such as zinc is difficult by a conventional method (for example, washing with a solvent). Furthermore, in the present invention, the metal component used for removal (or the metal constituting the metal component) can be easily removed because of its low affinity for polysilane, so the content of the metal component contained in polysilane can be significantly reduced. . The polysilane obtained by such a method is a high-purity polysilane in which the content of the metal component is remarkably reduced. Therefore, such a high-purity polysilane can be suitably used for applications that require a reduction in metal components, such as optoelectronic material applications. Moreover, since the content of the metal component is reduced at a remarkably high level, the polysilane can be prevented from being deteriorated over a long period of time.

  In the purification method (or removal method) of the present invention, the polysilane containing the metal component (1) (hereinafter sometimes simply referred to as metal-containing polysilane) and the metal (a) constituting the metal component (1), The metal component (1) contained in the polysilane is removed by contacting the metal component (2) composed of a metal (b) different from the metal (a) in a specific index.

[Polysilane containing metal component (1)]
(Polysilane)
In the polysilane containing the metal component (1), the polysilane is not particularly limited as long as it is a linear, cyclic, branched, or network compound having a Si—Si bond. It is often composed of polysilane having at least one structural unit among the structural units represented by (1) to (3).

(Wherein R ^{1 to} R ³ are the same or different and represent a hydrogen atom, an organic group or a silyl group, r, s and t each represent an integer of 0 or more, and the sum of r, s and t is It is an integer of 2 or more.)
In the formulas (1) and (2), examples of the organic group represented by R ^{1 to} R ³ include a hydrocarbon group (an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, and an aralkyl group). , Ether groups (alkoxy groups, cycloalkyloxy groups, aryloxy groups, aralkyloxy groups, etc.) corresponding to these hydrocarbon groups, hydroxyl groups, optionally substituted amino groups [for example, amino groups (—NH ₂ ), A substituted amino group (such as N-mono or N, N-disubstituted amino group substituted with the above alkyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, etc.). In addition, these substituents are further substituted with one or more other substituents [for example, an alkyl group (for example, a C _1-10 alkyl group, preferably a C _1-6 alkyl group, more preferably a C _1-4 alkyl group). ) And other exemplified substituents such as C _1-10 alkoxy group, preferably C _1-6 alkoxy group, more preferably C _1-4 alkoxy group, and acyl groups (for example, And a C _1-10 alkyl-carbonyl group such as an acetyl group, preferably a C _1-6 alkyl-carbonyl group, more preferably a C _1-4 alkyl-carbonyl group, etc.].

In R ^{1 to} R ³ of the above formulas (1) and (2), examples of the alkyl group include C _1-14 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl (preferably C _1-10 alkyl group, more preferably C _1-6 alkyl group).

Examples of the alkoxy group include C _1-14 alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy and pentyloxy (preferably C _1-10 alkoxy groups, more preferably C _1-6 alkoxy groups). Is mentioned.

Examples of the alkenyl group include C _2-14 alkenyl groups such as vinyl, allyl, butenyl, pentenyl (preferably a C _2-10 alkenyl group, more preferably a C _2-6 alkenyl group).

Examples of the cycloalkyl group include C _5-14 cycloalkyl groups (preferably C _5-10 cycloalkyl groups, more preferably C _5-8 cycloalkyl groups) such as cyclopentyl, cyclohexyl, and methylcyclohexyl. _{Examples of the} cycloalkyloxy group include C _5-14 cycloalkyloxy groups such as cyclopentyloxy and cyclohexyloxy (preferably C _5-10 cycloalkyloxy groups, more preferably C _5-8 cycloalkyloxy groups). . Examples of the cycloalkenyl group include C _5-14 cycloalkenyl groups such as cyclopentenyl and cyclohexenyl (preferably a C _5-10 cycloalkenyl group, more preferably a C _5-8 cycloalkenyl group).

Examples of the aryl group include C _6-20 aryl groups (preferably C _6-15 aryl group, more preferably C _6-12 aryl group) such as phenyl, methylphenyl (tolyl), dimethylphenyl (xylyl), and naphthyl. Can be mentioned. Examples of the aryloxy group include C _6-20 aryloxy groups such as phenoxy and naphthyloxy (preferably a C _6-15 aryloxy group, more preferably a C _6-12 aryloxy group). Examples of the aralkyl group include C _6-20 aryl-C _1-4 alkyl groups (preferably C _6-10 aryl-C _1-2 alkyl groups) such as benzyl, phenethyl, and phenylpropyl. Examples of the aralkyloxy group include C _6-20 aryl-C _1-4 alkyloxy groups (preferably C _6-10 aryl-C _1-2 alkyloxy groups) such as benzyloxy, phenethyloxy, and phenylpropyloxy. It is done.

Examples of the silyl group include Si _1-10 silanyl groups (preferably Si _1-6 silanyl groups) such as silyl group, disilanyl group, and trisilanyl group.

Usually, the groups R ^{1 to} R ³ are each a hydrocarbon group (an optionally substituted hydrocarbon group) or an ether group corresponding to a hydrocarbon group (an optionally substituted hydrocarbon group). A bonded or substituted ether group). Preferred groups R ¹ include, for example, hydrocarbon groups such as an alkyl group, a cycloalkyl group, and an aryl group, and in particular, an alkyl group (for example, a C _1-4 alkyl group such as a methyl group) or an aryl group (for example, And C _6-10 aryl groups such as a phenyl group) are preferred. The substituents R ^{1 to} R ³ may be the same or different depending on r, s, or t.

  When the polysilane has an acyclic structure (straight, branched, or network), the terminal group (terminal substituent) is usually a hydrogen atom, a hydroxyl group, a halogen atom (such as a chlorine atom), an alkyl group, or an alkoxy group. Or a silyl group.

  Specific examples of the polysilane include a linear or cyclic polysilane having a structural unit represented by the formula (1), a branched polysilane having a structural unit represented by the formula (2) or (3) ( Or a network-like polysilane), and a branched polysilane having a combination of structural units represented by the above formulas (1) to (3). When the polysilane is a copolymer, it may be a block copolymer or a random copolymer. Furthermore, the polysilane may be a polysilane having each of the structural units represented by the formulas (1) to (3) alone or in combination of two or more.

  The branched polysilane having at least one branched structural unit selected from the structural unit represented by the formula (2) and the structural unit represented by the formula (3) is represented by the formula (1). Compared to a linear or cyclic polysilane having a structural unit, it has excellent properties such as solvent solubility, and is a polysilane suitable for a wide range of uses, but has a branched structure. This is because the metal component is easily taken up and it is difficult to remove the metal component. In this invention, even if it is polysilane which has such a branched structure, the metal component contained can be removed efficiently.

  In the branched polysilane, the ratio of the branched structural unit is, for example, 1 mol% or more (for example, 3 to 100 mol%) of the whole polysilane, preferably 5 mol, in terms of silicon atoms constituting the polysilane (molar conversion). % Or more (for example, about 10 to 95 mol%), more preferably 15 mol% or more (for example, about 20 to 90 mol%).

Typical polysilanes include, for example, polydialkylsilanes [for example, polydimethylsilane, polymethylpropylsilane, polymethylbutylsilane, polymethylpentylsilane, polydibutylsilane, polydihexylsilane, dimethylsilane-methylhexylsilane copolymer. Polydi C _1-6 alkyl silanes such as coalescence, preferably polydi C _1-4 alkyl silanes], polyalkyl aryl silanes [eg, poly C _{1- 1} such as polymethylphenyl silane, methylphenyl silane-phenyl hexyl silane copolymer, etc. ₆ alkyl _{C 6-15} aryl silane, preferably poly _{C 1-4} alkyl _{C 6-10} aryl silane, polydiene aryl silanes (e.g., polydiene _{C 6-15} aryl silanes such as polydiphenylsilane, preferably polydiene _{C 6- 0} aryl silane), dialkyl silane - alkylaryl silane copolymer (e.g., dimethylsilane - methylphenyl silane copolymer, dimethylsilane - phenyl hexyl silane copolymer, dimethyl silane - di-C, such as methyl naphthyl silane copolymer _1-6 alkyl silane-C _1-6 alkyl C _6-15 aryl silane copolymer, preferably di-C _1-6 alkyl silane-C _1-4 alkyl C _6-10 aryl silane copolymer) A polysilane having the structural unit represented by (1); a polyarylsilane [for example, a _{polyC 6-15} arylsilane such as polyphenylsilane (polyphenylsilin), preferably a _{polyC 6-10} arylsilane] The structural unit represented by the formula (2) or the structural unit represented by the formula (3) Branched polysilanes; dialkyl silane - aryl silane copolymer (e.g., dimethylsilane - _{di-C 1-6} alkylsilanes _{-C 6-15} aryl silane copolymers such as phenyl silane copolymers, preferably di _{C 1-6} Alkyl silane-C _6-10 aryl silane copolymer), alkyl aryl silane-aryl silane copolymer (for example, C _1-6 alkyl C _6-15 aryl silane-C such as methyl phenyl silane-phenyl silane copolymer) A structural unit represented by the formula (1) such as a _6-15 arylsilane copolymer, preferably a C _1-6 alkyl C _6-15 arylsilane-C _6-10 arylsilane copolymer) and the formula ( Examples thereof include branched polysilanes having the structural unit represented by 2) or the structural unit represented by the formula (3). Details of such polysilanes are described in, for example, R.A. D. Miller, J.M. Michl; Chemical Review, 89, 1359 (1989); Matsumoto; Japan Journal of Physics, Volume 37, p. 5425 (1998). The polysilane may be a copolymer of a polysilane raw material (such as halosilanes) and a vinyl compound. Details of such a copolymer are disclosed in, for example, JP-A-2002-128897.

  These polysilanes can be used alone or in combination of two or more.

  The number average degree of polymerization of the polysilane (for example, the sum of r, s and t in the structural units (1) to (3)) may be 2 or more, for example, 5 to 400, preferably 10 to 350, more preferably. May be about 20-300.

  The molecular weight of the polysilane may be about 200 to 100,000, preferably 300 to 50,000, and more preferably about 400 to 30,000 in terms of weight average molecular weight. When the polysilane is cyclic, the number of cyclic polysilane rings may be usually 4 to 12, preferably 4 to 10, more preferably 5 to 10 (especially 5 to 8). May be.

  The polysilane may be a commercially available product or may be prepared using various known methods. As a typical synthesis method of polysilane, dialkyldihalosilane or dihalotetraalkyldisilane in toluene solvent is vigorously stirred at a temperature of 100 ° C. or higher using an alkali metal such as sodium metal, and reductively coupled. Method [J. Am. Chem. Soc. , 103 (1981) 7352]. However, in this method, it is necessary to heat and strongly stir and disperse the alkali metal that ignites in the air, so there is a concern about safety in production on an industrial scale, and the molecular weight distribution of the resulting polysilane is In many cases, it is multimodal and the quality is not sufficient.

  Other polysilane production methods include (a) anionic polymerization of disilene masked with biphenyl or the like (JP-A-1-23063), and (b) method of ring-opening polymerization of cyclic silanes (JP-A-5-1993). 170913), (c) a method of dehydrocondensation of hydrosilanes using a transition metal complex catalyst (Japanese Patent Publication No. 7-17753), (d) dihalosilanes are electrode-reduced at a temperature below room temperature to produce polysilanes (E) a method of dehalogenating polycondensation of halosilanes using magnesium as a reducing agent (a so-called “magnesium reduction method”, for example, WO 98/29476, JP 2003-277507 A). And the method described in JP-A-2005-36139).

  In particular, in the magnesium reduction method, (1) it is possible to synthesize using a stable and inexpensive raw material with a general-purpose chemical synthesizer, and it is superior in terms of safety and cost. (2) Insoluble matter in sodium and organic solvents, etc. Impurities that are not suitable for applications such as optical and electronic materials are not mixed in. (3) Polysilanes with low molecular weight variations and high solubility and transparency in organic solvents can be obtained. (4) Polysilanes are produced in high yields. It has excellent characteristics such as being obtained.

  Therefore, the polysilane obtained by the magnesium reduction method may be suitably used as the polysilane. In such a magnesium reduction method, polysilane can be synthesized by polymerizing halosilanes in the presence of at least a magnesium metal component. In particular, in the magnesium reduction method, a magnesium metal component and other metal components [for example, lithium compounds, metal halides (lithium compounds (lithium halides, lithium halides), etc., are used as catalysts in order to obtain a high-performance polysilane more efficiently. In many cases, the metal halide is not used.

  And polysilane obtained by such various methods (especially polysilane obtained by magnesium reduction method) uses various metal components as a catalyst, and such a catalyst causes polysilane to contain a metal component. Often becomes.

  Hereinafter, the magnesium reduction method will be described in detail.

  In the magnesium reduction method, polysilane is obtained by reacting halosilanes (halosilane compounds) in the presence of at least a magnesium metal component.

  Examples of halosilanes include dihalosilanes, trihalosilanes, and tetrahalosilanes. When the polysilane is a polysilane having at least one structural unit among the structural units represented by the formulas (1) to (3), these di to tetrahalosilanes are each represented by the following formula. Among the halosilanes, at least one halosilane (di to tetrahalosilanes) may be used.

^(Wherein, X 1 to X ⁹ is a halogen ^{atom, R 1 ~R 3, r,} s and t are as defined above.)
In the above formulas (1A) to (3A), the halogen atoms represented by X ^{1 to} X ⁹ are the same as described above, preferably a chlorine atom and a bromine atom (particularly a chlorine atom), and the same or different halogen atoms. May be. In the above formulas (1A) to (3A), r, s, and t may each be 1 or more as described above, and may be a monomer (r = s = t = 1). , Multimers (r, s, and t are 2 or more) may be used. For example, in the dihalosilane represented by the formula (1A), r may be about 1 to 1000, preferably about 1 to 500, and more preferably about 1 to 100 (for example, 1 to 10). When a polymer having a large r is used, a block copolymer is easily obtained, and when a monomer or a polymer having a small r is used, a random copolymer is easily obtained. From the viewpoint of the production efficiency of the copolymer, a monomer or a multimer having a small r (for example, a halosilane having r of about 1-2) may be preferably used. In addition, trihalosilanes and tetrahalosilanes are usually used as monomers (s = t = 1) in many cases.

Representative halosilanes include, for example, dihalosilanes [eg, dialkyldihalosilanes (eg, diC _1-4 alkyldihalosilanes such as dimethyldichlorosilane and multimers thereof), alkyl-aryldihalosilanes (eg, C _1-4 alkyl-C _6-10 aryl dihalosilanes and their multimers such as methylphenyldichlorosilane, alkyl-cycloalkyldihalosilanes (eg, C _1-4 alkyl-C ₅ such as methylcyclohexyldichlorosilane). _-10 cycloalkyldihalosilanes and multimers thereof), diaryldihalosilanes (eg diphenyldihalosilane, ditolyldihalosilane, dixylyldihalosilane, phenyltolyldihalosilane, dimethoxyphenyldihalosilane, etc.) C _6-10 aryl dicarboxylic halo Sila And multimers thereof, etc.) such as dihalosilane compounds of the formula (1A), such as, trihalosilane rocks [e.g., alkyltrihalosilane (e.g., C _1-4 alkyl trihalosilane such as methyl trichlorosilane), cycloalkyl trihaloalkyl Formulas such as silanes (eg C _5-10 cycloalkyltrihalosilanes such as cyclohexyltrichlorosilane and multimers thereof), aryltrihalosilanes (eg C _6-10 aryltrihalosilanes such as phenyltrichlorosilane and multimers thereof) 2A), tetrahalosilanes (for example, tetrahalosilanes represented by formula (3A) such as tetrahalosilane such as tetrachlorosilane), and the like. These halosilanes may be used alone or in combination of two or more.

  The branched polysilane is selected from trihalosilanes (or trihalosilanes represented by the formula (2A)) and tetrahalosilanes (or tetrahalosilanes represented by the formula (3A)). Further, it is obtained by polymerizing halosilanes composed of at least one kind.

In addition, since the halosilanes block the end of polysilane, if necessary, monohalosilanes [for example, trialkylhalosilanes (for example, tri-C _1-4 alkylhalosilanes such as trimethylchlorosilane), triarylhalo Silane (for example, tri-C _6-10 arylhalosilane such as triphenylchlorosilane) may be used.

  The halosilanes are preferably as highly pure as possible. For example, liquid halosilanes are preferably dried by using a desiccant such as calcium hydride and distilled, and solid halosilanes are preferably purified and used by recrystallization. Is preferred.

The reaction of halosilanes is usually performed in the presence of a solvent inert to the reaction. As the solvent, an aprotic solvent (inert solvent) can be widely used. For example, ethers (cyclic C _4-6 ether such as 1,4-dioxane, tetrahydrofuran, tetrahydropyran, diethyl ether, diisopropyl ether, 1, Chain C _4-6 ethers such as 2-dimethoxyethane and bis (2-methoxyethyl) ether), carbonates (ethylene carbonate, propylene carbonate, etc.), nitriles (acetonitrile, benzonitrile, etc.), amides (dimethylformamide) , Dimethylacetamide), sulfoxides (dimethylsulfoxide, etc.), halogen-containing compounds (halogenated hydrocarbons such as methylene chloride, chloroform, bromoform, chlorobenzene, bromobenzene), aromatic hydrocarbons (base) Zen, toluene, xylene), aliphatic hydrocarbons (hexane, cyclohexane, octane, linear or cyclic hydrocarbons such as cyclooctane), and the like, these solvents may be used as a mixed solvent. As the solvent, a polar solvent alone (tetrahydrofuran, 1,2-dimethoxyethane, etc.), a mixture of two or more polar solvents, a mixture of a polar solvent and a nonpolar solvent, and the like are preferable. When a mixture of a polar solvent and a nonpolar solvent is used, the ratio between the two is the former / the latter (weight ratio) = 1 / 0.01 to 1/20.

  The concentration of the halosilanes in the solvent (reaction solution) is usually 20 mol / L or less (for example, 0.05 to 20 mol / L), preferably 10 mol / L or less (for example, 0.2 to 10 mol / L). L), particularly about 5 mol / L or less (for example, 0.3 to 5 mol / L).

(Magnesium metal component)
The reaction of the halosilanes (halosilanes containing at least a dihalosilane corresponding to the structural unit represented by the formula (1)) can be suitably performed in the presence of a magnesium metal component, and the magnesium metal component is allowed to act. Thus, polysilane can be generated efficiently.

  The magnesium metal component only needs to contain at least magnesium, and may be a magnesium metal alone or a magnesium alloy, or a mixture containing the magnesium metal or alloy. The kind of magnesium alloy is not particularly limited, and examples thereof include conventional magnesium alloys such as magnesium alloys containing components such as aluminum, zinc, rare earth elements (scandium, yttrium, etc.). These magnesium metal components can be used alone or in combination of two or more.

  The shape of the magnesium metal component is not particularly limited as long as it does not impair the reaction of the halosilane compound, but it is a powder (powder, granule, etc.), ribbon, cut piece, lump, rod, plate ( Flat shape etc.) etc. are illustrated, and it is preferable that it is a shape (powder, a granular material, a ribbon-like body, a cutting piece body etc.) with a large surface area especially. When the magnesium metal component is granular, the average particle size is about 1 to 10,000 μm, preferably about 10 to 5000 μm, and more preferably about 20 to 1000 μm.

  Depending on the storage status of the magnesium metal component, a film (such as an oxide film) may be formed on the metal surface. Since this coating may adversely affect the reaction, it may be removed by an appropriate method such as cutting or elution (pickling such as hydrochloric acid cleaning) as necessary.

  The amount of magnesium metal component used is usually 1 to 20 equivalents, preferably 1.1 to 14 equivalents, more preferably 1.2 to 10 equivalents (for example, based on the halogen atom of the halosilane). 1.2 to 5 equivalents). Moreover, the usage-amount of a magnesium metal component is 1-20 times as magnesium normally with respect to a halosilane compound as a magnesium number, Preferably it is 1.1-14 times, More preferably, it is 1.2-10 times ( For example, about 1.2 to 5 times.

  The magnesium metal component reduces the halosilane to form polysilane, and magnesium itself is oxidized to form a halide.

  The reaction may be performed at least in the presence of the magnesium metal component. In order to promote the polymerization of the halosilane, in the presence of at least one selected from a lithium compound and a metal halide (promoter or catalyst), in particular, magnesium. It is advantageous to carry out in the presence of metal components and metal halides. These magnesium metal components, lithium compounds and metal halides as catalyst components are incorporated into polysilane obtained by polymerization.

(Lithium compound)
Lithium compounds include lithium halides (lithium chloride, lithium bromide, lithium iodide, etc.), inorganic acid salts (lithium nitrate, lithium carbonate, lithium hydrogen carbonate, lithium hydrochloride, lithium sulfate, lithium perchlorate, lithium phosphate Etc.) can be used. These lithium compounds can be used alone or in combination of two or more. A preferred lithium compound is lithium halide (especially lithium chloride).

  The concentration of the lithium compound in the solvent (reaction solution) is usually 0.05 to 5 mol / L, preferably 0.1 to 4 mol / L, particularly about 0.15 to 3 mol / L.

  The proportion of the lithium compound is 0.1 to 200 parts by weight, preferably 1 to 150 parts by weight, more preferably 5 to 100 parts by weight (for example, 5 to 75 parts by weight) based on 100 parts by weight of the total amount of halosilanes. Usually, it is about 10 to 80 parts by weight.

(Metal halide)
Examples of metal halides (metal halides excluding lithium halide) include polyvalent metal halides such as transition metals (for example, periodic table group 3A elements such as samarium, periodic table group 4A elements such as titanium, vanadium, etc. Periodic table 5A group element, periodic table 8 group element such as iron, nickel, cobalt, palladium, periodic table 1B group element such as copper, periodic table 2B group element such as zinc), periodic table 3B group metal (such as aluminum) And metal halides (such as chloride, bromide or iodide) such as Group 4B metals (such as tin) in the periodic table. Although the valence of the metal constituting the metal halide is not particularly limited, it is preferably 2 to 4 valence, particularly 2 or 3 valence. These metal halides can be used alone or in combination of two or more.

  The metal halide is preferably a chloride or bromide of at least one metal selected from iron, aluminum, zinc, copper, tin, nickel, cobalt, vanadium, titanium, palladium, samarium and the like.

Examples of such metal halides include chlorides (iron chloride such as FeCl ₂ and FeCl ₃ ; AlCl ₃ , ZnCl ₂ , SnCl ₂ , CoCl ₂ , VCl ₂ , TiCl ₄ , PdCl ₂ , and SmCl ₂ ). Examples thereof include bromides (such as iron bromide such as FeBr ₂ and FeBr ₃ ) and iodides (such as SmI ₂ ). Of these metal halides, chlorides (for example, iron chlorides such as iron (II) chloride and iron (III), zinc chloride) and bromides are preferred. Usually, iron chloride and / or zinc chloride, especially zinc chloride and the like are used.

  In addition, although such metal halide can improve catalyst activity, it tends to remain in polysilane.

  The concentration of the metal halide in the solvent is usually about 0.001 to 6 mol / L, preferably about 0.005 to 4 mol / L, more preferably about 0.01 to 3 mol / L. It is.

  The ratio of the metal halide may be 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight, and more preferably about 2 to 20 parts by weight with respect to 100 parts by weight of the total amount of the halosilanes.

(Metal component (1))
In the polysilane containing the metal component (1), the metal component (1) may be composed of the metal (a). The metal (a) is not particularly limited, and various metal atoms (or metal ions), for example, alkali or alkaline earth metals (for example, sodium, magnesium, etc.), transition metals (for example, samarium, etc.) 3A group elements, periodic table 4A elements such as titanium, periodic table 5A elements such as vanadium, periodic table 8 group elements such as iron, nickel, cobalt and palladium, periodic table 1B elements such as copper, Etc.), Periodic Table Group 2B elements (for example, zinc), Periodic Table Group 3B metals (for example, aluminum), Periodic Table Group 4B metals (for example, tin), and the like. The metal (a) may be a single metal or may be composed of different metals.

  Among these metals (a), metals such as Group 8 elements (especially iron) and Group 2B elements (such as zinc) of the periodic table are particularly effective as metals constituting polymerization catalysts for halosilanes. On the other hand, it is easy to be incorporated into polysilane, and not only by conventional purification methods (for example, washing with an organic solvent, water, etc.), but also by washing with an acid, alkali, ion exchanger (cation exchange resin, etc.), It is difficult to remove from polysilane. In the method of the present invention, even such a metal (especially zinc) that is extremely difficult to remove can be removed from polysilane at a high level.

  The content of the metal component (1) is not particularly limited. For example, the metal component (1) may be incorporated into the polymer structure of the polysilane in the form of a metal compound or the like, and coordinated with a constituent atom (for example, a silicon atom) of the polysilane. May be bonded to polysilane.

  The metal component (1) may be contained in the polysilane for any reason, but usually appears to be incorporated into the polysilane in the process of synthesizing the polysilane. Examples of such metal component (1) include: (i) polysilane by polymerizing a raw material of polysilane (for example, halosilane) in the presence of a metal catalyst (for example, the magnesium component and metal halide). Metal components derived from the metal catalyst to be incorporated into (ii) metal components contained in the raw material of polysilanes (halosilanes and the like). Usually, most of the metal component (1) contained in polysilane is often a metal component derived from a metal catalyst.

  In the metal-containing polysilane, the ratio of the metal component (1) can be selected from a range of 200 ppm or more based on the weight of the metal (a), for example, 500 ppm or more (for example, about 500 to 100,000 ppm), preferably Is 1000 ppm or more (for example, about 2000 to 80000 ppm), more preferably 3000 ppm or more (for example, about 4000 to 50000 ppm), particularly 5000 ppm or more (for example, about 7000 to 40000 ppm), usually 8000 ppm or more (for example, about 10000 to 30000 ppm). There may be. In the present invention, even such polysilane containing a large amount of the metal component (1) in advance can be efficiently removed.

  The reason why metal (a) (or metal component (1)) is taken into polysilane is not clear, but metal (a) seems to have some affinity for polysilane. In addition, metal components (particularly iron components, zinc components, etc.) as catalysts used in the synthesis of polysilane have a high affinity (or persistence) for polysilane because they are involved in polymerization, and are once taken into polysilane. If it remains, even if it can be slightly removed by a method such as washing (washing with a solvent, washing with an acid or alkali), it is difficult to remove it at a high level.

  Therefore, in the present invention, the metal-containing polysilane and the metal component (2) composed of the metal (b) different from the metal (a) in a specific index are contacted efficiently from the metal-containing polysilane. The metal component (1) is removed.

[Method for removing metal component (1)]
The metal component (2) should just be comprised with the metal (b) different in a specific parameter | index mentioned later from a metal (a). As the metal (b), various metal atoms (or metal ions) different from the metal (a) (or all metals when the metal (a) is a plurality of metals), for example, transition metals (for example, scandium) Periodic Table Group 3A elements such as Titanium, Zirconium and Hafnium, Periodic Table Group 4A Elements such as Vanadium and Niobium, Periodic Table Group 5A Elements such as Vanadium and Niobium, Periodic Table Group 6A Elements such as Molybdenum and Tungsten, etc. Periodic Table Group 7A elements, iron, nickel, cobalt, ruthenium, rhodium, palladium, rhenium, osmium, iridium, platinum and other periodic table Group 8 elements, copper, silver, gold and other periodic table Group 1B elements) Periodic Table Group 2B elements (eg, zinc, cadmium, mercury, etc.), Periodic Table Group 3B elements (eg, aluminum, gallium, indium, etc.), Table Group 4B elements (e.g. germanium, tin, and lead), periodic table Group 5B elements (e.g., antimony, bismuth), and the like. As long as the metal (b) is different from the metal (a), the metal (b) may be a single metal or may be composed of different metals.

  The metal (b) constituting the metal component (2) may be any metal that has a smaller ionization tendency than the metal (a). The reason why the metal component (1) can be removed at a high level by using the metal component (2) satisfying such conditions is not clear, but the metal (a) (or the form) incorporated into polysilane in some form (or The metal component (1)) seems to be removed from the polysilane due to a decrease in affinity for the polysilane due to contact with the metal (b) (or the metal component (2)) satisfying the above conditions. And elution is because the metal component (2) (or metal (b)) used for the removal of the metal component (1) has lower affinity for polysilane than the metal (a) (or metal component (1))? It can be removed from polysilane easily and efficiently.

(Metal with low ionization tendency)
In the metal (b) having a small ionization tendency, “ionization tendency” means “a tendency of the metal to come into contact with the liquid to become a cation” and “quantitatively, the metal (in the liquid ( M) / standard cation potential of metal cation (M ^{Z +} ) system ^* The order is determined by the magnitude of E (M ^{Z +} / M) ”(Chemical Dictionary 1st edition, Tokyo Chemical Dojin Co., Ltd., 1994 10 Excerpt from “Issued on the 1st of January”).

  That is, that the ionization tendency of the metal (b) is smaller (or lower) than the ionization tendency of the metal (a) quantitatively indicates that the standard electrode potential of the metal (b) (usually, the standard electrode potential in an aqueous solution). Is larger than the standard electrode potential of the metal (a), and the ionization tendency of typical metals (metal elements, metal atoms) is shown below (the greater the inequality sign, the greater the ionization tendency (higher)).

  Li> K> Ca> Na> Mg> Ti> Al> Mn> Zn> Cr> Ga> Fe (II)> Cd> In> Ta (I)> Co> Ni> Sn> Pb> Fe (III)> Cu (II)> Cu (I)> Hg> Ag> Pd> Pt> Au.

  According to such an indicator, the metal component (2) for removing the metal component (1) by easily contacting with the polysilane can be selected. For example, when the metal (a) is zinc (Zn), From the viewpoint of ionization tendency, Cr, Ga, Fe (Fe (II), Fe (III)), Cd, Co, Ni, Sn, Pb, Cu (Cu (II), Cu (I)), Ag, Pd, A metal component composed of a metal (or metal ion) such as Pt or Au can be used as the metal component (2).

  The metal component (2) may be composed of the metal (b), for example, a metal simple substance, a metal ion, a metal compound (the metal compound exemplified in the section of the metal component (1), for example, a metal halogen). And any of them may be used. As will be described later, in order to efficiently contact the polysilane and the metal component (2), the metal component (2) is a metal component that can be used as a solvent, for example, a metal compound (for example, a metal halide, A salt of a metal such as a metal sulfate and an inorganic acid is preferred.

  In particular, since the polysilane is usually soluble in an organic solvent (especially a hydrophobic organic solvent) and facilitates removal of the metal component (1) and the metal component (2) after contact, the metal component (2) is: It is preferably a water-soluble metal compound (water-soluble metal compound, for example, a salt of a metal such as a metal halide or metal sulfate and an inorganic acid). In particular, the copper compound is easy to remove after contact with the polysilane, and can be suitably used.

(Contact method)
The method for bringing the polysilane and the metal component (2) into contact is not particularly limited, but usually the polysilane and the metal component (2) are contacted in the presence of a solvent (or via a solvent or in a solvent system). In many cases. The solvent may be a solvent capable of dispersing polysilane and metal component (2), but usually a solvent capable of dissolving at least one of the components, for example, (i) polysilane and metal component (2). Soluble solvent, (ii) Solvent that can dissolve polysilane, (iii) Solvent that can dissolve polysilane (a) (or good solvent for polysilane (a)), and solvent that does not dissolve polysilane (or poor solvent for polysilane) And a mixed solvent with a solvent (b) that can dissolve the metal component (2) (or a good solvent for the metal component (2)).

  A preferable solvent includes the solvent (iii) from the viewpoint of bringing the metal component (2) into contact and finally removing it from the polysilane. In particular, the solvent (b) may be a layer-separable solvent (or an immiscible solvent) in combination with the solvent (a). When such a mixed solvent is used, the metal component (2) is brought into contact with the polysilane to efficiently remove the metal component (1), and the metal component (metal component) is added to a layer that does not dissolve the polysilane (for example, an aqueous layer). (1) and the metal component (2)) are easily transferred, and the polysilane and the metal component are easily separated.

As the solvent (a), any solvent that can dissolve polysilane (or a solvent that is easily soluble in polysilane) may be used, and a wide range of aprotic solvents such as ethers (for example, 1,4-dioxane, tetrahydrofuran, Tetrahydropyran, diethyl ether, diisopropyl ether, 1,2-dimethoxyethane, cyclic or chain ethers such as bis (2-methoxyethyl) ether (for example, C _4-6 ether), carbonates (propylene carbonate, etc.) , Nitriles (eg acetonitrile, benzonitrile etc.), amides (dimethylformamide, dimethylacetamide etc.), sulfoxides (dimethyl sulfoxide etc.), halogen-containing solvents (eg methylene chloride, chloroform, bromoform, chlorobenzene, Halogenated hydrocarbons such as bromobenzene), aromatic hydrocarbons (benzene, toluene, xylene, etc.), aliphatic hydrocarbons (for example, chained or cyclic aliphatic hydrocarbons such as hexane, cyclohexane, octane, cyclooctane) And the like). These solvents may be used alone or in combination of two or more.

  Among these solvents, hydrophobic solvents such as aromatic hydrocarbons (for example, toluene, xylene and the like) and halogen-containing solvents (for example, chloroform and the like) are easy to dissolve polysilane, and as the solvent (b) Since it is difficult to mix with water and is easy to separate, it can be suitably used. In particular, aromatic hydrocarbons such as toluene and xylene are preferable from the viewpoint of not causing interaction with polysilane. Therefore, when the solvent (b) is water, the solvent (a) may be composed of at least a hydrophobic solvent, and the hydrophobic solvent alone (for example, one or two of the aromatic hydrocarbons) The above-mentioned hydrophobic solvent), a mixed solvent of a hydrophobic solvent and a hydrophilic solvent (for example, cyclic ethers such as 1,4-dioxane and tetrahydrofuran, and ketones such as acetone) may be used. When a mixed solvent of a hydrophobic solvent and a hydrophilic solvent is used, the ratio of both is, for example, the former / the latter (weight ratio) = 1 / 0.01 to 1/20, preferably 1 / 0.1 to 1 / 10, more preferably about 1 / 0.3 to 1/5 (for example, 1 / 0.5 to 1/3).

  The ratio of polysilane and solvent (a) is, for example, the former / the latter (weight ratio) = 1/99 to 50/50, preferably 5/95 to 40/60, more preferably about 10/90 to 30/70. It may be. If the concentration of polysilane in the solvent (a) is too low, the separation efficiency and pot efficiency of the metal component (1) may be deteriorated. Further, when the solvent is distilled off later, a great deal of time and energy may be required. On the other hand, when the concentration of polysilane is too high, the liquid separation efficiency may be deteriorated. For example, when an intermediate layer is formed, the recovery efficiency of polysilane may be reduced.

  Further, the solvent (b) capable of dissolving the metal component (2) can be appropriately selected according to the type of the metal component (2). For example, water, a solvent similar to the above-mentioned solvent [for example, alcohols ( For example, alkanols such as methanol, ethanol, isopropyl alcohol, etc.), ethers (eg, chain or cyclic ethers such as diethyl ether, 1,4-dioxane, tetrahydrofuran), halogen solvents (eg, methylene chloride, etc.) Halogenated hydrocarbons, etc.), ketones (eg, acetone, methyl ethyl ketone, etc.), hydrocarbons (eg, aliphatic or alicyclic hydrocarbons such as pentane, hexane, heptane, cyclohexane, benzene, toluene, xylene, etc. And the like). These solvents may be used alone or in combination of two or more. The solvent (b) may be an acidic solvent, an alkaline solvent, or the like.

  Preferred solvents (b) include hydrophilic solvents such as water and lower alcohols (eg, methanol, ethanol, etc.), with water being particularly preferred. Such a hydrophilic solvent (especially water) does not dissolve polysilane (or is hardly soluble in polysilane) in many cases, so it is easy to separate from polysilane, and in particular, at least a hydrophobic organic solvent (for example, the aromatic In combination with a solvent (a) composed of a group hydrocarbon or the like, polysilane and metal components (metal components (1) and (2)) can be easily separated, so that they can be preferably used.

  The ratio of the metal component (2) to the solvent (b) is, for example, the former / the latter (weight ratio) = 1/99 to 50/50, preferably 3/97 to 30/70, more preferably 5/95 to It may be about 20/80. In addition, when the ratio of a metal component (2) is too low, there exists a possibility that removal of a metal component (1) cannot fully be performed. Further, if the ratio of the metal component (2) is too high, there is a possibility that it may lead to alteration depending on the type of polysilane, and there is a possibility that the amount remaining in the production facility or mixed in the polysilane solution may increase.

  In the contact method using the solvent (iii), polysilane (polysilane containing a metal component (1)), solvent (a), metal component (2), and solvent (b) may be contacted. For example, the removal of the present invention The method comprises a step of mixing the polysilane, the solvent (a), the metal component (2), and the solvent (b) (particularly the solvent (b) that does not dissolve in the combination with the solvent (a)) (mixing step). ) May be included.

  The mixing method is not particularly limited, and each component may be mixed at once or in an appropriate order. In particular, from the viewpoint of separation efficiency of a liquid layer in which polysilane is dissolved, the solution (A) in which the polysilane is dissolved in the solvent (a) (for example, a solution in which the polysilane is dissolved in a solvent composed of at least a hydrophobic organic solvent). And a solution (B) in which the metal component (2) is dissolved in the solvent (b) (for example, an aqueous solution) may be mixed.

  In the contact (or mixing), the proportion of the metal component (2) (or the total amount of the metal component (2) to be contacted with the polysilane) depends on the content of the metal component (1) contained in the polysilane, but the polysilane (metal For example, 1 to 300 parts by weight, preferably 5 to 200 parts by weight, more preferably 10 to 100 parts by weight, and particularly about 20 to 80 parts by weight with respect to 100 parts by weight of the polysilane containing component (1). Also good.

  The ratio of the solution (A) to the solution (B) is the former / the latter (weight ratio) = 1/100 to 1 / 0.1, preferably 1/5 to 1 / 0.2, Preferably, it may be about 1/3 to 1 / 0.3.

  The contact (or mixing) of the polysilane and the metal component (2) can be performed in the same manner as a conventional mixing method in organic synthesis or the like, and may be performed using a conventional mixer or disperser, with stirring. You may go. The longer contact time (mixing time) between the polysilane and the metal component (2) is preferable, but from the viewpoint of production efficiency, it may be about 5 to 180 minutes, preferably about 10 to 120 minutes.

  After contact (or after the mixing step), the separation of polysilane (or a solution containing polysilane) from the mixed system (mixture) obtained through the mixing step is a conventional method depending on the type of solvent used. For example, it can be performed using extraction, liquid separation, filtration, or the like. For example, when the solvent (a) and the solvent (b) are layer-separable solvents, a liquid layer containing the polysilane (polysilane from which the metal component (1) has been removed) is used from the mixed system. You may isolate | separate polysilane (or the liquid layer containing polysilane) through the process (separation process) which isolate | separates using liquid separation operation etc.

  The contact between polysilane and metal component (2) (and separation of polysilane) can efficiently remove metal component (1) from polysilane even at a single contact operation, but is required. Depending on the metal concentration, it may be repeated.

  Since the polysilane (or solution containing polysilane) separated from the mixed system has the metal component (1) in the polysilane removed, it can be used in the form of a solid or solution as it is depending on the application. You may wash | clean further in order to reduce content of a component. That is, when the removed metal component (1), metal component (2), etc. still remain in the polysilane (or solution containing polysilane) separated from the mixed system after contacting with the metal component (2). There is. For this reason, the removal method uses a polysilane (or a liquid layer containing polysilane) obtained through the mixing step and the separation step and a solvent that does not dissolve polysilane (or a poor solvent or non-solvent for polysilane, or polysilane). And a step of washing with a hardly soluble solvent) (washing step).

  The solvent used in the washing step (washing solvent) may be any solvent that does not dissolve polysilane, but from the viewpoint of separation, it usually does not dissolve polysilane and can be separated into layers in combination with solvent (a). A suitable solvent may be used. The washing solvent is preferably a solvent capable of dissolving the metal component (2) (and the metal component (1)) (for example, the exemplified solvent (b) such as water) from the viewpoint of removing the metal component. In particular, the cleaning solvent is preferably a solvent that contains as little metal component as possible from the viewpoint of removing the metal component from polysilane. For example, when water is used as the cleaning solvent, the electrical conductivity of water is, for example, 10 μS / cm or less at 25 ° C. [for example, electrolytic conductivity of pure water at 25 ° C. (μS / cm) to about 9 μS / cm], Preferably, it is 8 μS / cm or less [for example, electrolytic conductivity of pure water at 25 ° C. (about μS / cm) to 7.5 μS / cm], more preferably 7 μS / cm or less [for example, electrolytic conductivity of pure water at 25 ° C. Rate ([mu] S / cm) to about 6.5 [mu] S / cm]. Examples of such low conductivity water include pure water and ion exchange water.

  In the washing step, washing can be performed by mixing polysilane (or a solvent layer containing polysilane) and a washing solvent, and removing the washing solvent using a liquid separation operation or the like. The cleaning step may be performed once or a plurality of times (for example, 2 to 10 times, preferably about 2 to 5 times).

  Moreover, the ratio of the cleaning solvent used in the cleaning step (the amount of the cleaning solvent used per cleaning) is, for example, 30 to 1000 parts by weight, preferably 100 parts by weight of polysilane (polysilane contained in the liquid layer). May be about 50 to 800 parts by weight, more preferably about 100 to 500 parts by weight.

  In addition, the solution containing polysilane after the washing step may be used as it is depending on the application, and may be used after removing (or distilling off) the solvent by distillation (such as vacuum distillation). In any case, the solution may be dehydrated using a dehydrating agent (or a desiccant such as magnesium sulfate). The dehydrating agent can be removed by filtration or the like.

  In the polysilane obtained by the method of the present invention, the content of the metal component (1) is reduced at a very high level. For example, the ratio of the metal component (1) is the whole in terms of the weight of the metal (a). 100 ppm or less (for example, about 0 to 80 ppm), preferably 70 ppm or less (for example, about 0.5 to 50 ppm), more preferably 40 ppm or less (for example, about 1 to 35 ppm), particularly 20 ppm or less (for example, 1 About 5 to 10 ppm).

  In addition, in the polysilane obtained by the method of the present invention, the content of the residual metal component including the metal component (2) can be reduced by passing through a washing step, for example, the metal component (1) and the metal component (2). Is not more than 150 ppm (for example, about 0 to 120 ppm), preferably 100 ppm or less (for example, about 1 to 90 ppm), more preferably 80 ppm, based on the weight of the metal (a) and the metal (b). It may be below (for example, about 1.5 to 75 ppm), particularly 30 ppm or less (for example, about 2 to 20 ppm).

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

  In the examples, the content of the metal component was measured by ICP and WDX fluorescent X-ray analysis.

Example 1
A round flask with an internal volume of 1000 ml equipped with a three-way cock is charged with 25.0 g of granular (particle size 20 to 1000 μm) magnesium and 16.2 g of anhydrous zinc chloride (ZnCl ₂ ), and 1 mmHg (= 133 kPa) at 50 ° C. The reaction mixture was dried by heating under reduced pressure, dry argon gas was introduced into the reactor, 500 ml of tetrahydrofuran previously dried with sodium-benzophenone ketyl was added, and the mixture was stirred at room temperature for about 30 minutes. To this reaction mixture, 105.8 g (0.50 mol) of phenyltrichlorosilane purified in advance by distillation was added and stirred at 20 ° C. for about 18 hours. After completion of the reaction, 300 ml of toluene was added, and then magnesium chloride produced by the reaction and excess magnesium were removed by filtration under reduced pressure. The filtrate was washed 10 times with 200 ml of pure water, the toluene layer was dried over anhydrous magnesium sulfate, and then toluene and tetrahydrofuran were distilled off to obtain 50 g of polyphenylsilin containing about 15000 ppm or more of zinc.

The obtained polyphenylsilin was dissolved in a mixed solution of 150 g of toluene and 150 g of tetrahydrofuran, and further 200 g of an aqueous copper chloride solution containing 10% by weight of copper (II) chloride (CuCl ₂ ) was mixed and stirred for 60 minutes. After that, the organic layer containing polyphenylsilin and the aqueous layer containing copper chloride were separated. The organic layer containing polyphenylsilin was washed three times with 200 ml of pure water, and then the solvent component was distilled off to obtain 48 g of polyphenylsilin containing 2.0 ppm of zinc and 4.0 ppm of copper.

(Example 2)
The polyphenylsilin obtained in Example 1 was replaced with 200 g of an aqueous copper chloride solution containing 10% by weight of copper (II) chloride (CuCl ₂ ) in Example 1, and iron (III) chloride (FeCl ₃ ) Was stirred, washed, and distilled off in the same manner as in Example 1 except that 200 g of an aqueous iron chloride solution containing 10 wt% was mixed to obtain 49 g of polyphenylsilin containing 30 ppm zinc and 40 ppm iron.

(Example 3)
The polyphenylsilin obtained in Example 1 was replaced with 200 g of an aqueous copper chloride solution containing 10% by weight of copper (II) chloride (CuCl ₂ ) in Example 1, but copper (II) sulfate (CuSO ₄ ) Is stirred, washed and distilled off in the same manner as in Example 1 except that 200 g of an aqueous copper sulfate solution containing 15 wt% is mixed, to obtain 49 g of polyphenylsilin containing 15 ppm zinc and 3.0 ppm copper. It was.

(Comparative Example 1)
The polyphenylsilin obtained in Example 1 was replaced with 200 g of an aqueous copper chloride solution containing 10% by weight of copper (II) chloride (CuCl ₂ ) in Example 1, except that 200 g of pure water was mixed. Stirring, washing and distillation were performed in the same manner as in Example 1 to obtain 49 g of polyphenylsilin containing about 15000 ppm of zinc.

(Comparative Example 2)
The polyphenylsilin obtained in Example 1 was replaced with 200 g of an aqueous copper chloride solution containing 10% by weight of copper (II) chloride (CuCl ₂ ) in Example 1, and 10% by weight of hydrogen chloride (HCl). The mixture was stirred, washed, and distilled off in the same manner as in Example 1 except that 200 g of hydrochloric acid contained at a ratio of% was mixed to obtain 49 g of polyphenylsilin containing about 12000 ppm of zinc.

(Comparative Example 3)
The polyphenylsilin obtained in Example 1 was replaced with 200 g of an aqueous copper chloride solution containing 10% by weight of copper (II) chloride (CuCl ₂ ) in Example 1, and 10 mg of sodium hydroxide (NaOH) was added. Stirring, washing and distilling were carried out in the same manner as in Example 1 except that 200 g of an aqueous sodium hydroxide solution contained in a proportion by weight was mixed to obtain 45 g of polyphenylsilin containing about 8000 ppm of zinc.

(Comparative Example 4)
The polyphenylsilin obtained in Example 1 was dissolved in a mixed solution of 150 g of toluene and 150 g of tetrahydrofuran, washed 10 times with 200 ml of pure water, the solvent (water) was distilled off, and polyphenyl containing about 13,000 ppm of zinc. 45 g of syringe was obtained.

(Comparative Example 5)
The polyphenylsilin obtained in Example 1 was dissolved in a mixed solution of 150 g of toluene and 150 g of tetrahydrofuran, and further activated carbon (trade name “Shirasagi” manufactured by Nippon Enviro Chemicals Co., Ltd.) was stirred for 60 minutes. By filtering the mixed liquid after stirring, the organic layer containing polyphenylsilin and activated carbon were separated. And after wash | cleaning the organic layer containing the obtained polyphenyl syrin 3 times with 200 ml of pure waters, the solvent component was distilled off and 49.5 g of polyphenyl syrin containing about 14,000 ppm of zinc was obtained.

  The results are summarized in Table 1.

  As is clear from Examples, Comparative Examples and Table 1, zinc contained in polysilane can hardly be removed by cleaning of Comparative Examples, but by washing once with a metal (iron or copper) having a low ionization tendency, It could be removed very efficiently. Moreover, in the Examples, the metal used for the cleaning hardly remained in the polysilane, and a high-purity polysilane having a remarkably low metal component content was obtained.

  In the method of the present invention, the metal component previously contained in the polysilane can be efficiently removed. In addition, because the metal component used for removing the metal component has a relatively low affinity for polysilane or can be easily removed by washing or the like, a high-purity polysilane with a significantly reduced content of the metal component is obtained. Can do. Therefore, the polysilane obtained by the method of the present invention is used for conventional polysilanes, for example, ceramic precursors, photoelectron materials (for example, photoelectrophotographic materials such as photoresists and organic photoreceptors, optical transmission materials such as optical waveguides, and optical memories). Optical recording materials such as materials for electroluminescent elements), optical members (for example, optical filters, mirrors, lenses, light shielding films, diffraction elements, polarizing beam splitters, microlenses, etc.), resin additives (flame retardants, etc.) It can be used for such purposes. In particular, a high-purity polysilane from which a metal component has been removed at a high level is extremely useful in applications where the metal component contained affects the properties, for example, optoelectronic materials.

Claims (5)

A polysilane containing a metal component (1) is brought into contact with a metal component (2) composed of a metal (b) that is smaller in ionization tendency than the metal (a) constituting the metal component (1), to thereby contact the polysilane A polysilane obtained by a method of removing and purifying the metal component (1) contained in
A polysilane containing a metal component (1) is obtained by reacting halosilanes in the presence of a magnesium metal component and at least one metal halide selected from iron halides and zinc halides. It has at least one structural unit among the structural units represented by (1) to (3), and is selected from the structural unit represented by the following formula (2) and the structural unit represented by the following formula (3). A branched polysilane having a weight average molecular weight of 200 to 100,000 having at least one branched structural unit,

(Wherein R ^{1 to} R ³ are the same or different and represent a hydrogen atom, a hydrocarbon group or a silyl group, r, s and t each represent an integer of 0 or more, and the sum of r, s and t Is an integer greater than or equal to 2.)
Polysilane in which the metal (a) is iron and / or zinc, and the ratio of the metal component (1) is 100 ppm or less based on the weight of the metal (a).   The polysilane according to claim 1, wherein the polysilane containing the metal component (1) contains 500 ppm or more of the metal component (1) based on the weight of the metal (a).   The metal (a) is zinc and the metal component (2) is a water-soluble metal compound composed of at least one metal (b) selected from iron, cobalt, nickel and copper. The polysilane described.   The polysilane according to claim 1, wherein the ratio of the metal component (1) is 50 ppm or less based on the weight of the metal (a).   The polysilane according to claim 1, wherein the ratio of the metal component (1) and the metal component (2) is 100 ppm or less based on the weight of the metal (a) and the metal (b).