JP6617062B2 - Polysilane and intermediates thereof, and production method thereof - Google Patents

Description

  The present invention has a high concentration of highly reactive silanol groups, an improved refractive index and solvent solubility (especially solubility in an alkaline aqueous solution, etc.), a polysilane that can be used as a coating agent, an additive, and an intermediate thereof, and production thereof. Regarding the method.

  Polysilane is a polymer compound with a silicon-silicon bond as the main chain, and has various physical properties such as high refractive index, heat resistance, photoreactivity, hole transportability, light emission, etching resistance, and low dielectric constant. Material. Polysilanes make use of such excellent physical properties, such as ceramic precursors, interlayer insulating films, and optoelectronic materials (for example, photoelectrophotographic materials such as photoresists and organic photoreceptors, optical transmission materials such as optical waveguides, and optical memories such as optical memories). It is attracting attention as a recording material, a material for an electroluminescence element, and the like.

  In such applications, polysilanes are often used or applied usually in thin film form. The formation of a thin film usually requires solubility in a solvent, but depending on the type of polysilane, the solubility in a solvent may not be sufficient, and in particular, a polysilane having a regular structure (for example, a homopolymer) Since the solvent to be dissolved is limited, its use may be limited.

  Japanese Patent No. 5010127 (Patent Document 1) discloses that a polysilane prepared by combining an aryl trihalosilane compound and a monohalosilane compound or a dihalosilane compound can improve the refractive index and the solubility in an organic solvent. However, since this polysilane is soluble only in an organic solvent such as toluene, its use is limited. For example, in consideration of an industrial viewpoint and an environmental load, it cannot respond to thin film formation using water or an alkaline aqueous solution instead of an organic solvent.

  Japanese Patent Application Laid-Open No. 7-252272 (Patent Document 2) discloses that a polysilane obtained by removing a protecting group from a polysilane intermediate having a catechol group protected with an alkyl group has solubility in an aqueous alkali solution. Is disclosed. In the examples of this document, dichloro (3,4-dimethoxyphenyl) obtained by preparing a Grignard reagent from 1-bromo-3,4-dimethoxybenzene and metal magnesium and reacting this reagent with phenyltrichlorosilane. ) After methylsilane is polymerized to obtain a polysilane intermediate, polysilane having a catechol group is synthesized by deprotection.

  However, this document requires a multi-step and extremely complicated process of preparing a Grignard reagent, Grignard reaction of this reagent with phenyltrichlorosilane, polysilane formation by polymerization, and deprotection of a catechol protecting group. Further, in the polymerization process, a special apparatus (ultrasonic irradiation apparatus, electrode reaction apparatus) is used, and manufacturing cost is high. Furthermore, since the preparation of the Grignard reagent is accompanied by a very intense exotherm, it is necessary to sufficiently control this exotherm, and the reaction operability is low.

  Moreover, in order to expand the application range of the use of polysilane, it is required to give a highly reactive substituent such as a silanol group to polysilane. However, the catechol group attached to the polysilane of this document is not sufficiently reactive. Further, in the process of synthesizing the polysilane, silanol groups having high reactivity are easily condensed to form a siloxane bond, so that the silanol group cannot be effectively introduced into the polysilane.

Japanese Patent No. 5010127 (Claims and Examples) JP-A-7-252272 (Claims, [0113], [0120] to [0123], [0130] to [0132], [0162] to [0163])

  Accordingly, an object of the present invention is to provide a polysilane having a highly reactive silanol group concentration and an intermediate thereof, and a production method thereof, even if it has a network structure, the formation of siloxane bonds is suppressed. is there.

  Another object of the present invention is to provide a polysilane and an intermediate thereof having improved refractive index, solvent solubility (particularly solubility in an aqueous alkali solution), and the like, and a method for producing them.

  Still another object of the present invention is to provide a method for producing the polysilane and its intermediate easily and efficiently without requiring complicated steps and special equipment.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have polymerized at least aryltrihalosilane, and protected the terminal group of the generated halosilane polymer having a network structure with a predetermined phosphate group. By desorbing (deprotecting), it was found that a polysilane having a high silanol group concentration can be produced, and that the refractive index and solvent solubility (especially solubility in an alkaline aqueous solution) of this polysilane has been improved. completed.

  That is, the polysilane intermediate of the present invention is a polysilane intermediate containing at least a silane unit represented by the following formula (1), and at least a part of the end groups is a protecting group represented by the following formula (2). Protected by

(In the formula, R ¹ represents an aryl group which may have a substituent, and R ¹¹ and R ¹² are the same or different, and may be a hydrocarbon group, a hydrogen atom or a halogen which may have a substituent. Z ¹ and Z ² are the same or different and represent a direct bond or an oxygen atom, and when R ¹¹ and R ¹² are a hydrogen atom or a halogen atom, adjacent Z ¹ or Z ² is It is a direct bond, n represents 1 to 10, and when n is 2 or more, Z ² not adjacent to R ¹² is an oxygen atom.)

R ¹ may be a C _6-10 aryl group (particularly a phenyl group).

In the protecting group represented by the formula (2), Z ¹ and Z ² may be an oxygen atom, and R ¹¹ and R ¹² may be the same or different and may have a substituent. Alternatively, it may be a branched alkyl group, and n may be 1. R ¹¹ and R ¹² may be the same or different and may be a linear or branched C _1-10 alkyl group (particularly a methyl group or an ethyl group).

  The polysilane intermediate may further contain a silane unit represented by the following formula (4).

(Wherein, R ² and R ³ represents a may have a substituent a hydrocarbon group.)

R ² is a linear or branched C _1-4 alkyl group (for example, methyl group or ethyl group) or C _6-10 aryl group (for example, phenyl group, naphthyl group) which may have a substituent. And R ³ may be a C _6-10 aryl group (particularly a phenyl group) which may have a substituent.

  The present invention is a polysilane containing at least a silane unit represented by the formula (1), wherein at least some of the terminal groups are formed of silanol groups, and the silanol group concentration relative to 1 mol of silicon atoms in the polysilane. Contains polysilane which is 0.005 to 0.1 mol.

  The present invention is a method for producing a polysilane intermediate by reacting a halosilane containing at least a trihalosilane represented by the following formula (1a) in an aprotic solvent in the presence of at least a metal magnesium component. And a method for producing a polysilane intermediate in which at least a part of the end groups of the halosilane polymer is protected by reacting the halosilane polymer with an organophosphorus compound represented by the following formula (2a).

^(Wherein, X 1 to X ³ are the same or different and each represents a halogen ^{atom, R 13} represents a hydrocarbon group which may have a ^{substituent, R 1, R 11, R} 12, Z 1 , Z ² and n are the same as above.)

  In the production method of the present invention, halosilane may be further reacted in the presence of a catalyst containing at least one selected from a lithium compound and a halide of a polyvalent metal.

In the formula (2a), Z ¹ and Z ² are oxygen atoms, and R ¹¹ and R ¹² are the same or different, and may be a linear or branched alkyl group which may have a substituent. , N may be 1.

The organophosphorus compound represented by the formula (2a) may be tri-phosphate linear or branched C _1-10 alkyl (for example, trimethyl phosphate or triethyl phosphate).

  In the method of the present invention, the ratio of the organophosphorus compound and the halosilane represented by the formula (1a) may be the former / the latter (molar ratio) = 5/95 to 99/1.

  The present invention also includes a method for producing polysilane by deprotecting the protecting group of the polysilane intermediate. In this method, deprotection may be performed by acid treatment using hydrochloric acid or the like.

  The present invention also includes a method for improving the solubility and / or refractive index of polysilane in an alkaline aqueous solution using the polysilane.

  In the polysilane intermediate of the present invention, since the terminal group of the halosilane polymer having a network structure is protected with a predetermined phosphate group, the polysilane from which this group has been removed (deprotected) does not generate a siloxane bond. Even if it has a network structure, the silanol group concentration is high because it is suppressed. Moreover, refractive index, solvent solubility (especially solubility with respect to alkaline aqueous solution), etc. can be improved. In addition, polysilane can be produced simply and efficiently without requiring complicated processes or special equipment.

  The polysilane intermediate of the present invention is composed of silane units, and at least some of the terminal groups are protected with a predetermined protective group.

(1) Silane Unit A polysilane intermediate increases the refractive index and forms a network structure to increase the silanol group concentration. Therefore, at least a silane unit represented by the following formula (1) (monoarylsilane unit (1)) including. The polymer having a network structure means a polymer having a network structure or a branched chain structure (particularly a network structure).

(In the formula, R ¹ represents an aryl group which may have a substituent.)

In the above formula (1), examples of the aryl group represented by R ¹ include C _6-12 aryl groups such as a phenyl group and a naphthyl group, and preferably a C _6-10 aryl group (for example, C _{6 And} more preferably a phenyl group. The aryl group may have a substituent, and the substituent may be a hydrocarbon group [eg, a linear group such as an alkyl group (eg, methyl, ethyl, propyl, isopropyl, butyl, t-butyl group, etc.). Or a branched C _1-10 alkyl group (preferably a C _1-6 alkyl group, particularly a C _1-4 alkyl group, etc.), a cycloalkyl group (eg, a C _5-8 cycloalkyl group such as a cyclohexyl group, In particular, C _5-6 cycloalkyl group, etc.), aryl group (eg, C _6-10 aryl group such as phenyl, naphthyl group, etc.), aralkyl group (eg, C _6-10 aryl-C ₁ such as benzyl, phenethyl group, etc.) _-6 alkyl group (for example, C _6-10 aryl-C _1-4 alkyl group and the like)], alkoxy group (for example, methoxy, ethoxy, propoxy, etc.) A linear or branched C _1-10 alkoxy group such as isopropoxy, butoxy, t-butoxy group (preferably a linear or branched C _1-6 alkoxy group, particularly a linear or branched chain) C _1-4 alkoxy group)), amino group, N-substituted amino group (for example, N-mono- or di-substituted amino group substituted with the aforementioned alkyl group, cycloalkyl group, aryl group, aralkyl group, acyl group, etc.) Etc.) and the like. The number of substituents is not particularly limited, and may be, for example, one or a plurality (for example, 2 to 4), and in the case of a plurality, the types of substituents may be different. Examples of the aryl group having such a substituent include a C _1-6 alkyl C _6-10 aryl group such as tolyl, xylenyl, ethylphenyl, methylnaphthyl group (for example, mono to tri C _1-4 alkyl C _{6). -10} aryl groups, especially mono or di C _1-4 alkylphenyl groups), C _1-10 alkoxy C _6-10 aryl groups such as methoxyphenyl, ethoxyphenyl, _{methoxynaphthyl} groups (eg C _1-6 alkoxy C) _6-10 aryl group, especially C _1-4 alkoxyphenyl group, etc.).

Specific examples of the monoarylsilane unit (1) include, for example, a mono C _6-12 arylsilane unit (for example, naphthylsilane unit (1-naphthylsilane unit, 2-naphthylsilane unit), phenylsilane unit, etc.), preferably Is a mono C _6-10 aryl silane unit, more preferably a mono C _6-8 aryl silane unit, especially a phenyl silane unit.

The polysilane intermediate may include other mono-substituted silane units (= Si (R ^a ) —), for example, a silane unit in which R ^a is an alkyl group, a cycloalkyl group, or an aralkyl group. The alkyl group of the unit is a linear or branched alkyl group (for example, a linear or branched C _1-10 alkyl group, preferably a linear or branched C _1-6 alkyl group, more preferably May be a linear or branched C _1-4 alkyl group, particularly a methyl group or an ethyl group.

  The polysilane intermediate only needs to contain at least the monoarylsilane unit (1), and includes not only the monoarylsilane unit (1) alone but also the monoarylsilane unit (1) and other silane units. Also good. The other silane unit is, for example, at least one selected from silane units represented by the following formulas (3) to (5) (silane units (3) to (5)), preferably silane units (3 ) And silane units (4), more preferably silane units (4).

(Wherein, R ² to R ⁶ represents the same or different and each represents a hydrogen atom, an organic group or a silyl group or a substituted silyl group.)

  The polysilane intermediate is advantageous for forming a network structure by including the silane unit (3). The ratio of the silane unit (3) to the entire silane unit is, for example, about 0 to 20 mol% (for example, 0 to 10 mol%, preferably 1 to 5 mol%).

Examples of the organic group represented by R ^{2 to} R ⁶ include the organic groups exemplified in the paragraph of the substituent of the aryl group in the formula (1). Examples of the substituted silyl group represented by R ^{2 to} R ⁶ include substitution substituted with a Si _2-10 silanyl group such as a disilanyl group or a trisilanyl group, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxy group. A silyl group (for example, a trimethylsilyl group etc.) can be illustrated.

In the silane unit (4), preferred R ² and R ³ are organic groups, for example, hydrocarbon groups (alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups). In the silane unit (4), for example, at least one of R ² and R ³ is an aryl group, for example, R ² may have an aryl group which may have a substituent, or may have a substituent. It is a chain or branched alkyl group, and R ³ is a silane unit (diarylsilane unit or alkylarylsilane unit) which is an aryl group which may have a substituent, and is an alkylarylsilane unit. preferable.

Specific examples of the alkylarylsilane unit (4) include, for example, a linear or branched C _1-10 alkyl C _6-12 arylsilane unit, preferably a C _1-6 alkyl C _6-10 arylsilane unit ( For example, a C _1-4 alkyl C _6-10 arylsilane unit), more preferably a C _1-2 alkylphenylsilane unit (eg, methylphenylsilane unit).

Examples of the combination of the monoarylsilane unit (1) and the alkylarylsilane unit (4) include, for example, a mono C _6-12 aryl silane unit (for example, a mono C _6-10 aryl silane unit, preferably a phenyl silane unit) Linear or branched C _1-10 alkyl C _6-12 aryl silane unit (eg C _1-6 alkyl C _6-10 aryl silane unit, preferably C _1-4 alkyl phenyl silane unit (eg C _{1 -2} alkylphenylsilane units, in particular methylphenylsilane units)).

  The ratio of the silane unit (4) with respect to the entire silane unit may be, for example, about 0 to 70 mol%, preferably 5 to 60 mol%, more preferably 10 to 50 mol%, particularly about 20 to 40 mol%. . When the ratio of the silane unit (4) (for example, the alkylarylsilane unit (4)) is increased, the refractive index gradually decreases, but the solubility in an organic solvent and the film formability are improved.

In the silane unit (5), preferred R ^{4 to} R ⁶ are organic groups, for example, hydrocarbon groups (alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups), and linear or branched alkyl groups ( For example, a linear or branched C _1-10 alkyl group, preferably a linear or branched C _1-6 alkyl group, more preferably a linear or branched C _1-4 alkyl group, especially Methyl group or ethyl group).

  The ratio of the silane unit (5) to the entire silane unit is, for example, about 0 to 10 mol% (for example, 0 to 5 mol%, preferably 0 to 2.5 mol%). Reducing the proportion of the silane unit (5) is advantageous for forming a polysilane having a high silanol group concentration.

  The polysilane intermediate of the present invention usually contains a monoarylsilane unit (1) as a main constituent unit. The ratio of the monoarylsilane unit (1) and other silane units (for example, silane unit (4)) is, for example, the former / the latter (molar ratio) = 30/70 to 100/0 (for example, 40/60 to 99/1), preferably 50/50 to 98/2 (for example, 60/40 to 97/3), more preferably about 70/30 to 95/5 (for example, 75/25 to 90/10). . It is preferable that the proportion of the monoarylsilane unit (1) is large because a high refractive index can be obtained.

(2) Protecting group At least a part of the end groups of the polysilane intermediate is protected with a protecting group represented by the following formula (2).

(Wherein R ¹¹ and R ¹² are the same or different and each represents a hydrocarbon group, a hydrogen atom or a halogen atom (fluorine, chlorine, bromine, iodine atom) which may have a substituent, Z ¹ and Z ² are the same or different and each represents a direct bond or an oxygen atom, and when R ¹¹ and R ¹² are a hydrogen atom or a halogen atom, adjacent Z ¹ or Z ² is a direct bond, and n is 1 to 10 and when n is 2 or more, Z ² not adjacent to R ¹² represents an oxygen atom.)

In the above formula (2), R ¹¹ and R ¹² are the same or different and each represents a hydrocarbon group (for example, an alkyl group, a cycloalkyl group, or an aryl group exemplified in the substituent group of the aryl group in the formula (1) And the hydrocarbon group may have a substituent such as the hydrocarbon group exemplified in the paragraph of the substituent of the aryl group in the formula (1). The hydrocarbon group represented by R ¹¹ and R ¹² is preferably a linear or branched alkyl group (for example, a C _1-6 alkyl group, preferably a C _1-4 alkyl group, particularly a C _1-2 alkyl group). Group, usually a methyl group).

  In said Formula (2), n is 1-10, for example, 1-5, Preferably it is 1-3, More preferably, it is 1-2, especially 1.

A preferred protecting group represented by the above formula (2) is a linear or optionally substituted group in which Z ¹ and Z ² are oxygen atoms, and R ¹¹ and R ¹² are the same or different. A dialkyl phosphate group in which n is 1 is a branched alkyl group.

The dialkyl phosphate group is, for example, a di-C _1-10 alkyl phosphate group, preferably a di-C _1-6 alkyl phosphate group, more preferably a di-C _1-4 alkyl phosphate group, particularly di-C. _1-2 alkyl phosphate group (for example, diethyl phosphate group or dimethyl phosphate group, preferably dimethyl phosphate group).

  Note that the polysilane intermediate may include a plurality of different types of protecting groups.

  The concentration (mol) of the protective group with respect to 1 mol of silicon atom in the polysilane intermediate is, for example, about 0.005 to 0.1 mol, preferably 0.01 mol or more (for example, 0.02 to 0.08). About 0.025 mol or more (for example, about 0.025 to 0.06 mol), and usually 0.03 mol or more (for example, about 0.03 to 0.04 mol). The concentration of the protecting group can be calculated based on, for example, the molar ratio (the former / the latter) of phosphorus derived from the protecting group and silicon derived from the silane unit by atomic absorption analysis or the like.

  The average degree of polymerization of the polysilane intermediate is not particularly limited, and is, for example, 2 to 500, preferably 3 to 300 (for example, 4 to 200), more preferably 5 to 150, particularly 7 to 100, usually 8 to 50. It may be about (for example, 9 to 25, preferably 10 to 20).

  The weight average molecular weight (Mw) of the polysilane intermediate is, for example, about 200 to 50000, preferably 500 to 10000, and more preferably about 1000 to 5000 (for example, 1200 to 2500).

  The molecular weight distribution [ratio Mw / Mn of weight average molecular weight (Mw) and number average molecular weight (Mn)] of the polysilane intermediate may be, for example, about 1 to 5. Usually, Mw / Mn has a narrow molecular weight distribution, and may be, for example, 1 to 2, preferably 1.1 to 1.7, and more preferably about 1.3 to 1.5.

  Mw and Mw / Mn can be measured by gel permeation chromatography (GPC) or the like, and may be values in terms of standard polystyrene.

  In the polysilane intermediate of the present invention, since at least a part of the terminal groups of the halosilane polymer having a network structure is protected by the protecting group represented by the formula (2), the condensation reaction between the polymers proceeds. Therefore, formation of a siloxane bond (—Si—O—Si—) can be suppressed. For this reason, when this protecting group is deprotected, a highly reactive polysilane having a high silanol group (hydroxyl group) concentration can be obtained.

  The polysilane of the present invention contains a silane unit corresponding to the polysilane intermediate, and at least a part of the end groups are formed of silanol groups.

The silanol group concentration with respect to 1 mol of silicon atoms in the polysilane is, for example, 0.005 to 0.1 mol, preferably 0.01 mol or more (for example, 0.02 to 0.08 mol), more preferably 0. 0.025 mol or more (for example, 0.025 to 0.06 mol), and usually 0.03 mol or more (for example, 0.03 to 0.04 mol). The silanol group concentration can be calculated based on, for example, a ¹ H-NMR spectrum. ^When calculating based on the ¹ H-NMR spectrum, for example, the silanol group relative to the integral value of the peak attributed to the proton of the hydrocarbon group of the silane unit of the polysilane (for example, the proton of the aryl group corresponding to R ¹ ). The silanol group concentration may be calculated by calculating the ratio of the integral value of the peak attributed to protons. When the polysilane contains a silane unit (3), based on the ²⁹ Si-NMR spectrum, the ratio of the silane unit (4) in the polysilane is calculated based on the assignment of Si in each silane unit, and the ¹ H-NMR spectrum The silanol group concentration can be calculated in combination with the analysis result based on it.

  The average degree of polymerization of the polysilane is not particularly limited, and may be the same as or higher than the average degree of polymerization of the polysilane intermediate. For example, it may be about 2 to 5000, preferably 3 to 3000, more preferably 5 to 2000, particularly 7 to 1000, and usually 8 to 500 (for example, 9 to 100, preferably 10 to 50).

  Examples of the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the polysilane include the ranges exemplified in the section of the polysilane intermediate.

  The refractive index of polysilane (refractive index for a wavelength of 589 nm (25 ° C.) of a 1 μm-thick thin film formed of polysilane) is 1.63 or more (for example, 1.635 to 1.85), preferably 1.64 or more, preferably Is 1.65 or more (for example, 1.66 to 1.85), more preferably about 1.67 or more (for example, 1.68 to 1.85). This refractive index can be measured using, for example, a reflection spectral film thickness meter (manufactured by Otsuka Electronics Co., Ltd.).

  Since the polysilane of the present invention is composed of at least a monoarylsilane unit (1) and the formation of siloxane bonds is suppressed, the refractive index of the polysilane can be further improved.

  Moreover, even if the polysilane of the present invention has a network structure, high solubility in a solvent can be imparted because the siloxane bond is suppressed. In particular, even a solvent that does not dissolve (or is difficult to dissolve) ordinary polysilanes such as alcohols and aqueous alkali solutions can be dissolved. Therefore, the polysilane of the present invention can be suitably used as a coating liquid (a coating agent or a component of the coating liquid) in a wide range of applications.

  The polysilane of the present invention has high solubility in a solvent even if the ratio of the monoarylsilane unit (1) to the entire silane unit is increased because of the high silanol group concentration. For this reason, it is possible to achieve both a high refractive index and a high solubility in a solvent.

  Since the polysilane of the present invention has a high silanol group concentration, it can be used as a resin composition (such as a thermosetting resin or a photocurable resin (photosensitive resin)) in combination with a resin. In the resin composition, polysilane may be used as a resin component, or may be used as an additive (for example, a curing agent, a curing accelerator, or a silane coupling agent). In particular, when combined with a resin having a reactive group with respect to a silanol group (for example, an epoxy resin), the characteristics of polysilane can be efficiently imparted to the resin as well as crosslinkability or curability. For this reason, the polysilane of this invention can be utilized suitably as a hardening | curing agent (or hardening accelerator or hardening catalyst) of an epoxy resin.

[Production method of polysilane intermediate and polysilane]
In the present invention, halosilane is polymerized in an aprotic solvent in the presence of at least a metal magnesium component (polymerization step), and the terminal group of the polymer is protected with a specific organophosphorus compound (protection step), Manufacture the body. Furthermore, the polysilane can be produced by deprotecting the protecting group of the polysilane intermediate. In the production method of the present invention, it is only necessary to polymerize a halosilane available from a commercially available product and react the produced polymer with an organophosphorus compound, because the number of steps from the raw material to the production of the polysilane intermediate is shortened, A polysilane intermediate and polysilane can be produced by a simple method.

(1) Polymerization process (Halosilane)
The halosilane includes at least an aryl trihalosilane (aryltrihalosilane (1a)) represented by the following formula (1a).

(In the formula, X ^{1 to} X ³ are the same or different and represent a halogen atom (fluorine, chlorine, bromine, iodine atom). R ¹ is the same as above.)

The halosilane is another trihalosilane, for example, a trihalosilane ((X) ₃ —Si—R ^a (wherein X is a halogen atom (fluorine, chlorine, bromine, iodine atom)) corresponding to the mono-substituted silane unit. R ^a may be the same as described above))).

  The halosilane is a halosilane (tetrahalosilane (3a)) or dihalosilane (4a) represented by the following formulas (3a) to (5a) corresponding to the halosilanes of (3) to (5). ), Or at least one selected from monohalosilane (5a). Said other halosilane preferably comprises at least one selected from tetrahalosilane (3a) and dihalosilane (4a), more preferably at least dihalosilane (4a).

(Wherein, X ^{4 to} X ¹⁰ are the same or different and represent a halogen atom (fluorine, chlorine, bromine, iodine atom). R ^{2 to} R ⁶ are the same as above.)

  Specific examples of the halosilane polymer include, for example, a homopolymer corresponding to the monoarylsilane unit (1) of the polysilane intermediate of the present invention described above, a monoarylsilane unit (1), and another silane unit (3). The copolymer corresponding to the combination with at least 1 silane unit of-(5) can be illustrated. Moreover, each ratio of halosilane (3a)-(5a) with respect to the whole halosilane respond | corresponds to each ratio of silane unit (3)-(5) with respect to the whole silane unit.

  The use ratio of the aryltrihalosilane (1a) and the other halosilane is, for example, the former / the latter (molar ratio) = 30/70 to 100/0 (for example, 40/60 to 99/1), preferably 50/50. It is about -98/2 (for example, 60 / 40-97 / 3), More preferably, it is about 70 / 30-95 / 5 (for example, 75 / 25-90 / 10).

  The total concentration (substrate concentration) of the halosilane in the reaction solution may be, for example, 0.05 to 20 mol / L, preferably 0.1 to 15 mol / L, more preferably about 0.2 to 5 mol / L. .

(Metallic magnesium)
The metallic magnesium component (magnesium component) may be any component that contains magnesium in the form of active metallic magnesium (ie, magnesium that is not magnesium ions, etc.), such as metallic magnesium (magnesium alone), magnesium alloy, and a mixture thereof. There may be. 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 metal magnesium components can be used alone or in combination of two or more.

  The shape of the magnesium component is not particularly limited as long as the reaction of the halosilane is not impaired, but examples thereof include powder particles (powder, granules, etc.), ribbons, lumps, rods, plates (plates, etc.), etc. Particularly preferred are powders, granules, ribbons and the like. The average particle diameter of the magnesium metal component (for example, powdered magnesium metal component) may be, for example, about 1 to 10000 μm, preferably 10 to 7000 μm, more preferably about 15 to 5000 μm (for example, 20 to 3000 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.

  In addition, you may use a metal magnesium component for superposition | polymerization as an active metal magnesium component by the method of Unexamined-Japanese-Patent No. 2002-226586, etc.

  The amount of the metal magnesium component used is, for example, 0.3 to 30 mol, preferably 0.5 to 20 mol, and more preferably about 1 to 15 mol in terms of magnesium with respect to 1 mol of halogen atoms in the entire halosilane. Yes, usually about 1.2 to 10 moles.

  The amount of the metallic magnesium component used is 1 to 500 parts by weight, preferably 3 to 300 parts by weight, more preferably 5 to 200 parts by weight, especially about 10 to 100 parts by weight with respect to 100 parts by weight of the entire halosilane. It may be.

  The metal magnesium component reduces halosilane to form polysilane, and magnesium itself is oxidized to form a halide. And the unreacted metallic magnesium component which is not used for reduction | restoration of halosilane is contained in a reaction mixture.

  The reaction may be carried out in the presence of at least a metal magnesium component, but in order to promote the polymerization of halosilane, it is carried out in the presence of at least one selected from a lithium compound and a polyvalent metal halide (promoter or catalyst). It is preferable to carry out in the presence of a lithium compound (particularly lithium halide) and a polyvalent metal halide.

(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 proportion of the lithium compound is, for example, 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) with respect to 100 parts by weight of the entire halosilane. Usually about 10 to 80 parts by weight.

  In addition, the density | concentration of the lithium compound in a solvent (reaction liquid) is 0.05-5 mol / L normally, Preferably it is 0.1-4 mol / L, Especially about 0.15-3 mol / L may be sufficient.

(Multivalent metal halide)
Examples of the polyvalent metal halide include transition metals (for example, periodic table group 3A elements such as samarium, periodic table group 4A elements such as titanium, periodic table group 5A elements such as vanadium, iron, nickel, cobalt, palladium, and the like. Periodic table group 8 elements, periodic table 1B elements such as copper, periodic table 2B elements such as zinc), periodic table 3B metals (such as aluminum), periodic table 4B metals (such as tin) Halides (such as chloride, bromide or iodide) can be mentioned. The valence of the metal constituting the polyvalent metal halide is not particularly limited, but is preferably 2 to 4, more preferably 2 or 3. These polyvalent metal halides can be used alone or in combination of two or more.

  The polyvalent 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 polyvalent metal halides include chlorides (iron chlorides such as FeCl ₂ and FeCl ₃ ; AlCl ₃ , ZnCl ₂ , SnCl ₂ , CoCl ₂ , VCl ₂ , TiCl ₄ , PdCl ₂ , SmCl _{2 and the} like. ), Bromides (such as iron bromide such as FeBr ₂ and FeBr ₃ ), iodides (such as SmI ₂ ), and the like. Of these polyvalent metal halides, chlorides (eg, iron chlorides such as iron chloride (II) and iron chloride (III), zinc chloride, etc.) and bromides are preferred. Usually, iron chloride and / or zinc chloride, especially zinc chloride and the like are used.

  The ratio of the polyvalent metal halide may be, for example, 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 halosilane.

  Moreover, the density | concentration of the polyvalent metal halide in a solvent (reaction liquid) is about 0.001-6 mol / L normally, Preferably it is 0.005-4 mol / L, More preferably, it is 0.01-3 mol / L. It may be about L.

(Aprotic solvent)
Examples of the aprotic solvent as the solvent (reaction solvent) include ethers (1,4-dioxane, tetrahydrofuran, tetrahydropyran, diethyl ether, diisopropyl ether, 1,2-dimethoxyethane, bis (2-methoxyethyl). Cyclic or linear C _4-6 ether such as ether), carbonates (such as propylene carbonate), nitriles (such as acetonitrile and benzonitrile), amides (such as dimethylformamide and dimethylacetamide), sulfoxides (such as dimethyl sulfoxide) , Aromatic hydrocarbons (benzene, toluene, xylene, etc.), aliphatic hydrocarbons (for example, chain or cyclic hydrocarbons such as hexane, cyclohexane, octane, cyclooctane) and the like.

These aprotic solvents can be used alone or in combination of two or more as a mixed solvent. Among these solvents, at least polar solvents [for example, ethers (for example, cyclic C _4-6 ethers such as 1,4-dioxane and tetrahydrofuran (particularly tetrahydrofuran), bis (2-methoxyethyl) ether, 1,2- It is preferred to use chain C _4-6 ethers such as dimethoxyethane)]. You may use a polar solvent individually or in combination of 2 or more types.

  In the production method of the present invention, for example, an aryltrihalosilane, any other halosilane, and the catalyst or catalyst system are accommodated together with a reaction solvent in a sealable reaction vessel, and mechanically or magnetically stirred as necessary. The reaction may be performed. When using an aryltrihalosilane compound and another halosilane as raw materials, the starting halosilane compound may be used in advance as a mixture of an aryltrihalosilane compound and another halosilane, and each halosilane compound is added to the reaction system separately. It may be added. For example, an aryltrihalosilane compound and another halosilane may be added to the reaction system in parallel, or one halosilane compound may be added to allow the reaction to proceed to some extent, and then the other halosilane compound may be added. Good.

  In addition, since halosilane reacts rapidly with water, it is preferable to use the raw materials to be used (that is, metal magnesium component, lithium compound, polyvalent metal halide, aprotic solvent, etc.) after drying in advance.

  The reaction temperature is usually in the temperature range from −20 ° C. to the boiling point of the solvent used, for example, 0 to 150 ° C., preferably 5 to 100 ° C., more preferably about 10 to 80 ° C. May be.

  The reaction time varies depending on the type of halosilane, the amount of metal halide and magnesium metal component, etc., but it may usually be 5 minutes or longer, for example, 30 minutes to 100 hours, preferably 1 to 80 hours, More preferably, it may be about 2 to 60 hours.

  In such a method, a halosilane polymer can be produced in high yield. Moreover, in such a method, since these halosilanes can be obtained from commercial products and can be stirred using a sealable reaction vessel, halosilanes can be polymerized simply and efficiently.

  The reaction mixture thus produced often contains unreacted metallic magnesium component (or remaining metallic magnesium component) in addition to the produced halosilane polymer. Such metallic magnesium component is filtered, etc. The separation step may be followed by the protection step.

(2) Protection process In a protection process, the terminal group of a halosilane polymer is protected by making the produced | generated halosilane polymer react with the organophosphorus compound represented by following formula (2a).

(In the formula, R ¹³ represents a hydrocarbon group which may have a substituent. R ¹¹ , R ¹² , Z ¹ , Z ² and n are the same as described above.)

In the above formula (2a), the hydrocarbon represented by R ¹³ and the substituent thereof are, for example, the same as R ¹¹ and R ¹² , for example, a linear or branched C _1-10 alkyl group, preferably a _{C 1-6} alkyl group, more preferably a _{C 1-4} alkyl group, particularly _{C 1-2} alkyl groups, typically methyl groups.

  In the above formula (2a), n is, for example, 1 to 5, preferably 1 to 3, more preferably 1 to 2, particularly 1.

In the organophosphorus compound represented by the above formula (2a), Z ¹ and Z ² are oxygen atoms, and R ¹¹ and R ¹² are the same or different and may have a substituent or It is preferably a phosphate ester compound which represents a branched alkyl group and n is 1.

Examples of the phosphoric acid ester compound include tri-phosphate linear or branched C _1-10 alkyl, preferably tri-phosphate linear or branched C _1-6 alkyl, and more preferably tri-phosphate phosphate. Linear or branched C _1-4 alkyl, especially tri-C _1-2 alkyl phosphate (eg trimethyl phosphate, triethyl phosphate, etc.), usually trimethyl phosphate.

  These organophosphorus compounds may be commercially available or may be prepared by a conventional preparation method. When these organic phosphorus compounds are prepared by a conventional preparation method, for example, “Masaaki Yokoyama, Journal of Synthetic Organic Chemistry, Vol. 28, No. 2 (1970)”, pages 114 to 130 can be referred to.

  The use ratio of the organophosphorus compound and the halosilane represented by the formula (1a) can be selected from a wide range of the former / the latter (molar ratio) = 1/99 to 99/1, for example, 5/95 to 99 / 1 (for example, 10/90 to 95/5), preferably 12.5 / 87.5 to 90/10 (for example, 15/85 to 85/15, preferably 20/80 to 80/20), more preferably Is 25/75 to 75/25 (for example, 30/70 to 70/30, preferably 40/60 to 65/45), particularly about 50/50 to 60/40.

  Examples of the solvent (reaction solvent) and reaction temperature used in the protection step include the aprotic solvents exemplified in the section of the polymerization step.

(3) Deprotection and separation / purification step In the deprotection step, polysilane is produced by deprotecting the protecting group of the polysilane intermediate. In the present invention, by deprotecting the protective group of the polysilane intermediate, a polysilane having excellent reactivity and improved refractive index, solvent solubility (especially solubility in an alkaline aqueous solution) and the like can be produced.

  The deprotection step is not limited as long as the protecting group of the polysilane intermediate can be converted into a silanol group (hydroxyl group), and a conventional method such as hydrolysis with a treating agent (for example, acid treating agent or base treating agent) can be used. It is preferable to utilize hydrolysis with an acid treatment agent. Examples of the acid treatment agent include inorganic acids (for example, hydrochloric acid, sulfuric acid and the like) and organic acids (for example, organic sulfonic acids such as p-toluenesulfonic acid and methanesulfonic acid). These acid treatment agents may be used alone or in combination of two or more. Among these acid treatment agents, inorganic acids (particularly hydrochloric acid) are preferable. Examples of the base treating agent include alkali metal hydroxides (eg, sodium hydroxide, potassium hydroxide, magnesium hydroxide) and alkali metal carbonates (sodium carbonate, potassium carbonate, etc.). These base treating agents may be used alone or in combination of two or more.

  The deprotection step is usually performed in an aqueous solvent. In the deprotection step, a hydrophilic solvent that is inactive with respect to the silanol group may be added in order to increase the hydrolysis efficiency. Examples of the hydrophilic organic solvent include cellosolve acetates (such as ethyl cellosolve acetate), ketones (such as acetone), ethers (such as cyclic ethers such as dioxane and tetrahydrofuran), and the like. These hydrophilic organic solvents may be used alone or in combination of two or more.

  The deprotection reaction of the protecting group can be performed under heating (for example, 30 to 100 ° C.) or at room temperature (for example, 15 to 25 ° C.).

  The produced polysilane can be easily separated and purified from the reaction mixture using conventional separation and purification means. Examples of the separation and purification means include separation and purification means such as concentration, distillation, extraction, crystallization, recrystallization, adsorption, column chromatography, and a combination of these. In particular, it is preferable to efficiently separate a water phase and an organic phase containing polysilane (hydrophobic organic solvent phase) by adding a hydrophobic organic solvent to the reaction mixture. Since the polysilane produced by the deprotection step has a high silanol group concentration, for example, a silanol group may be condensed with a treating agent (for example, an acid treating agent such as hydrochloric acid) to form a siloxane bond. Therefore, the production | generation of the siloxane bond of produced | generated polysilanes can be suppressed by moving the produced | generated polysilane to the hydrophobic organic solvent phase which does not contain a processing agent (for example, acid treatment agent etc.). The hydrophobic organic solvent may be added before, after, or with the addition of the treatment agent. It is advantageous to add the hydrophobic organic solvent before the addition of the treatment agent or together with the addition of the treatment agent because the formation of siloxane bonds can be efficiently suppressed.

  The hydrophobic organic solvent only needs to be a solvent that can be separated into the aqueous phase, and includes hydrocarbons [eg, aromatic hydrocarbons (eg, benzene, toluene, xylene, etc.), aliphatic hydrocarbons ( For example, chain or cyclic hydrocarbons such as hexane, cyclohexane, octane and cyclooctane)], ethers (for example, chain ethers such as diethyl ether and diisopropyl ether), ketones (for example, dialkyl ketones such as methyl ethyl ketone) Etc.), esters (for example, acetate esters such as ethyl acetate) and the like. These solvents can be used alone or in combination of two or more. Among these, hydrocarbons (for example, aromatic hydrocarbons) are often used. When the reaction solvent is a hydrophobic organic solvent, it is not always necessary to add the hydrophobic organic solvent.

  The addition amount of the hydrophobic organic solvent is not particularly limited, and for example, 0.1 to 20 parts by weight, preferably 0.3 to 15 parts by weight, and more preferably 0.5 to 10 parts by weight with respect to 1 part by weight of water. It may be about parts by weight.

  The polysilane produced by the method of the present invention can improve the refractive index and improve the solubility in an aqueous alkali solution. For this reason, in this invention, the organophosphorus represented by the said Formula (2a) is used for the terminal group of at least one part of the halosilane polymer produced | generated by making the halosilane containing the trihalosilane represented by the said Formula (1a) react. Also included are methods of adding compounds to improve the solubility and / or refractive index of the halosilane polymer in aqueous alkali.

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

[Molecular weight]
It measured on condition of the following using GPC (Tosoh Co., Ltd. product HLC-8320GPC).

  Flow rate: 1 mL / min, injection amount: 100 μL, temperature: 40 ° C., solvent: primary tetrahydrofuran, detector: RI (differential refraction).

(Example 1)
In a three-necked flask with an internal volume of 300 ml equipped with a three-way cock, 4.33 g (0.178 mol) of granular magnesium, 3.14 g of lithium chloride, and 2.02 g of zinc chloride were charged, and argon gas was introduced into the reactor for dehydration. 100 ml of grade tetrahydrofuran was added and stirred at room temperature for about 30 minutes. Then, 22 g (0.104 mol) of phenyltrichlorosilane was dropped into the reactor over 2 hours using a dropping funnel, and the reaction was allowed to stir for about 20 hours. After completion of the reaction, 1 g (0.007 mol) of trimethyl phosphate was added and stirred for about 20 hours to obtain a polysilane intermediate. Further, 160 mL of toluene and 21.95 g of 35% by weight hydrochloric acid were added, and the mixture was stirred at 25 ° C. for 0.5 hours or more. The lower phase was discarded, and magnesium chloride and magnesium hydroxide were removed. Further, after washing with 50 ml of pure water 10 times, 40 g of anhydrous magnesium sulfate was added and stirred for 1 hour or more, then dried through filter paper covered with anhydrous magnesium sulfate, and then at 65 ° C. and 1.3 kPa (10 torr). ) For 5 hours. As a result, 10.94 g of pale yellow powder polysilane was obtained. When the obtained polysilane was measured by ³¹ P-NMR and IR, the peak derived from trimethyl phosphate disappeared, and it was confirmed that the protective group was eliminated. As a result of measuring the molecular weight of polysilane by GPC, the weight average molecular weight (Mw) was 1300, and the molecular weight distribution Mw / Mn was 1.3. Moreover, when the silanol group density | concentration formed in the polysilane terminal group was computed using ¹ H-NMR, it was 0.0385 mol with respect to 1 mol of silicon atoms in polysilane.

(Example 2)
A reaction was carried out in the same manner as in Example 1 except that 1 g (0.007 mol) of trimethyl phosphate was changed to 2.5 g (0.018 mol) to obtain 9.9 g of light yellow powder polysilane. When the obtained polysilane was measured by ³¹ P-NMR and IR, the peak derived from trimethyl phosphate disappeared, and it was confirmed that the protective group was eliminated. As a result of measuring the molecular weight of polysilane by GPC, the weight average molecular weight (Mw) was 1300, and the molecular weight distribution Mw / Mn was 1.3. Moreover, when the silanol group density | concentration formed in the polysilane terminal group was computed using ¹ H-NMR, it was 0.0262 mol with respect to 1 mol of silicon atoms in polysilane.

(Example 3)
A reaction was carried out in the same manner as in Example 1 except that 1 g of trimethyl phosphate was changed to 5 g (0.035 mol) to obtain 12.1 g of a pale yellow powder of polysilane. When the obtained polysilane was measured by ³¹ P-NMR and IR, the peak derived from methyl phosphate disappeared, and it was confirmed that the protecting group was eliminated. As a result of measuring the molecular weight of the polysilane by GPC, the weight average molecular weight (Mw) was 1800, and the molecular weight distribution Mw / Mn was 1.5. Moreover, when the silanol group density | concentration formed in the polysilane terminal group was computed using ¹ H-NMR, it was 0.0074 mol with respect to 1 mol of silicon atoms in polysilane.

(Example 4)
The reaction was conducted in the same manner as in Example 1 except that 1 g of trimethyl phosphate was changed to 10 g (0.071 mol) to obtain 10.77 g of a light yellow powder of polysilane. When the obtained polysilane was measured by ³¹ P-NMR and IR, the peak derived from methyl phosphate disappeared, and it was confirmed that the protecting group was eliminated. As a result of measuring the molecular weight of polysilane by GPC, the weight average molecular weight (Mw) was 1300, and the molecular weight distribution Mw / Mn was 1.3. Moreover, when the silanol group density | concentration formed in the polysilane terminal group was computed using ¹ H-NMR, it was 0.0312 mol with respect to 1 mol of silicon atoms in polysilane.

(Comparative Example 1)
A reaction was carried out in the same manner as in Example 1 except that 1 g of trimethyl phosphate was changed to 10 g (0.556 mol) of water to obtain 10.06 g of a pale yellow powder of polysilane. As a result of measuring the molecular weight of the obtained polysilane by GPC, the weight average molecular weight (Mw) was 1300, and the molecular weight distribution Mw / Mn was 1.3. Moreover, when the silanol group density | concentration formed in the polysilane terminal group was computed using ¹ H-NMR, it was 0.0035 mol with respect to 1 mol of silicon atoms in polysilane.

[Evaluation of the physical properties]
(1) Solubility The polysilane obtained in Example 3 and Comparative Example 1 was mixed with a 20% aqueous potassium hydroxide solution (20% by weight aqueous solution) at a rate of 5% by weight, thereby allowing the polysilane to be dissolved in an alkaline aqueous solution. When the solubility was examined, in Comparative Example 1, it was not dissolved at all and insoluble matter was observed. However, in Example 3, it was sufficiently dissolved, and the solubility was improved as compared with Comparative Example 1. It was.

(2) Thin film refractive index The polysilane obtained in Examples 1 to 4 and Comparative Example 1 was mixed with propylene glycol-1-monomethyl ether-2-acetate (PGMEA) to prepare a 10% by weight mixed solution. Using this mixed solution, a coating film was formed on a substrate by spin coating so that the thickness after drying was 1 μm, and the obtained thin film was given a refractive index with respect to light having a wavelength of 589.4 nm as reflected by an analyzer. It measured using the spectral film thickness meter (FE-3000 by Otsuka Electronics Co., Ltd.).

  The results are shown in Table 1.

  The functional polysilane of the present invention has superior functionality (reactivity, solvent solubility (particularly solubility in an alkaline aqueous solution, etc.), refractive index, etc.) as compared to normal polysilane. For example, since the functional polysilane of the present invention has excellent solubility in various solvents, it can be suitably used as a coating solution (for example, a coating agent). Moreover, since it has the outstanding reactivity, it can be used as resin and can also be used as an additive (for example, hardening | curing agent of an epoxy resin etc.) of resin. Therefore, the polysilane of the present invention is used in various applications, for example, ceramic precursors, optoelectronic materials (for example, photoelectrophotographic materials such as photoresists and organic photoreceptors, optical transmission materials such as optical waveguides, and optical recording materials such as optical scales). , Materials for electroluminescent elements, etc.), optical members (for example, optical filters, mirrors, lenses, light-shielding films, diffractive elements, polarizing beam splitters, microlenses, etc.), flame retardants, curing agents, and the like.

Claims (11)

A polysilane intermediates containing a silane unit represented by at least the following formula (1), at least a portion of the end groups have been protected with dimethyl phosphoric acid ester group or diethyl phosphoric acid ester group as a coercive Mamorumoto Polysilane intermediate.

(In the formula, R ^1, indicates an aryl group which may have a substituent to.) The polysilane intermediate according to claim 1, wherein R ¹ is a C _6-10 aryl group. Furthermore, the polysilane intermediate of Claim 1 or 2 containing the silane unit represented by following formula (4).

(Wherein, R ² and R ³ represents a may have a substituent a hydrocarbon group.) R ² is may be substituted linear or branched _{C 1-4} alkyl group or a _{C 6-10} aryl group, ^{R 3} is an optionally substituted _{C 6-} The polysilane intermediate according to claim 3, which is a ₁₀ aryl group. The polysilane intermediate according to claim 4 , wherein R ² is a methyl group or an ethyl group, and R ³ is a phenyl group.   A polysilane containing at least a silane unit represented by the formula (1) according to claim 1, wherein at least a part of the terminal groups are formed of silanol groups, and the silanol group concentration relative to 1 mol of silicon atoms in the polysilane. Which is 0.005 to 0.1 mol. A method for producing a polysilane intermediate by reacting a halosilane containing at least a trihalosilane represented by the following formula (1a) in an aprotic solvent in the presence of at least a metal magnesium component, wherein the halosilane polymer is produced. When, and trimethyl phosphate or triethyl phosphate as organic phosphorus compound is reacted, method for producing polysilane intermediates for protecting at least a portion of the end groups of the halosilane polymer.

( Wherein , X ^{1 to} X ³ are the same or different and represent a halogen atom, and R ¹ is the same as in claim 1). 8. The method according to claim 7 , wherein the halosilane is reacted in the presence of a catalyst containing at least one selected from a lithium compound and a halide of a polyvalent metal. The method according to claim 7 or 8 , wherein a use ratio of the organophosphorus compound and the halosilane represented by the formula (1a) is the former / the latter (molar ratio) = 5/95 to 99/1. Method for producing a polysilane by deprotecting the protecting group of the polysilane intermediates according to any one of claims 1-5. The method according to claim 10 , wherein the deprotection is carried out by acid treatment.