Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/21—Cyclic compounds having at least one ring containing silicon, but no carbon in the ring
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/60—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule in which all the silicon atoms are connected by linkages other than oxygen atoms

Definitions

• the present invention relates to a method for producing a cyclic silane compound.
• the present invention was made in consideration of the above circumstances, and aims to provide a method for producing cyclic silane compounds that reduces production costs and makes separation and purification easier.
• a method for producing a cyclic silane compound comprising: a first step of polymerizing a silane compound in a mixture containing metallic sodium and an aromatic hydrocarbon solvent to obtain a reaction liquid containing a linear polysilane compound; and a second step of decomposing the linear polysilane compound in a solution obtained by mixing the reaction liquid with a polycyclic aromatic hydrocarbon or a polyphenyl hydrocarbon, and tetrahydrofuran to obtain a cyclic silane compound.
• the solution contains the tetrahydrofuran and the aromatic hydrocarbon solvent, and a volume ratio of the tetrahydrofuran contained in the solution is 75 volume % or more and 95 volume % or less with respect to a total volume of the aromatic hydrocarbon solvent and the tetrahydrofuran.
• the method for producing a cyclic silane compound according to [1]. [3] The method for producing a cyclic silane compound according to [1] or [2], wherein in the first step, the mixture is heated to a melting point of the metallic sodium or higher.
• the present invention provides a method for producing cyclic silane compounds that reduces production costs and facilitates separation and purification.
• the above-mentioned sodium dispersion is a mixture in which solid sodium with an average particle size of 1 ⁇ m to 100 ⁇ m is dispersed in electrical insulating oil or an aromatic hydrocarbon solvent, and has higher reactivity than metallic sodium. From the standpoint of reactivity and safety, the average particle size of the solid sodium in SD is preferably 2 ⁇ m to 10 ⁇ m, more preferably 3 ⁇ m to 5 ⁇ m.
• electrical insulating oils include aliphatic hydrocarbons such as liquid paraffin and mineral oil.
• lump metallic sodium has a small specific surface area, which makes it difficult for the polymerization reaction of silane compounds to proceed, and the reaction yield is likely to decrease.
• metallic sodium can be liquefied (made into a mixed liquid) by heating it in an aromatic hydrocarbon solvent.
• liquid sodium breaks down more easily with stirring than solid sodium
• the specific surface area of liquid sodium is larger than that of solid sodium, and this can promote the polymerization reaction of silane compounds.
• a first step of polymerizing a silane compound in a mixture of an aromatic hydrocarbon solvent and liquid metallic sodium to obtain a linear polysilane compound
• a second step of decomposing the linear polysilane compound in the presence of a specified catalyst to obtain a cyclic silane compound it is possible to obtain a cyclic silane compound without using a sodium dispersion.
• First Step A silane compound is polymerized in a mixture containing metallic sodium and an aromatic hydrocarbon solvent.
• the metallic sodium contained in the mixture is preferably molten.
• the molten state means that the metallic sodium has become liquid, for example, by heating, and is different from the state in which solid sodium is uniformly dispersed in particulate form, such as in sodium dispersion.
• the aromatic hydrocarbon solvent may have a boiling point higher than the melting point of metallic sodium (98° C.). That is, the boiling point of the aromatic hydrocarbon solvent is preferably 100° C. or higher and 210° C. or lower, and more preferably 110° C. or higher and 170° C. or lower.
• aromatic hydrocarbon solvents examples include toluene, xylene, ethylbenzene, mesitylene, etc.
• toluene, xylene, and ethylbenzene are preferred, and toluene is more preferred.
• the molar equivalent of metallic sodium relative to each functional group of the alkoxy group or halogen atom of the silane compound is preferably 1.00 eq. or more and 1.80 eq. or less.
• the rate of the polymerization reaction of the silane compound in the first step can be further increased.
• the above molar equivalent of metallic sodium is 1.80 eq. or less, the proportion of sodium remaining unreacted can be further reduced. From the same viewpoint, it is more preferable that the above molar equivalent of metallic sodium in the above mixture is 1.05 eq. or more and 1.25 eq. or less.
• silane compound is added to the mixture.
• the silane compound is preferably a compound represented by the following formula (1):
• X1 and X2 each represent an alkoxy group or a halogen atom.
• the alkoxy group include a methoxy group and an ethoxy group.
• the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. These have a large electronegativity difference with silicon, and are prone to intramolecular polarization in the silane compound, so they are highly reactive and are substituents that function as leaving groups in the reaction.
• X1 and X2 are preferably halogen atoms, and more preferably chlorine atoms.
• R1 and R2 are each a hydrogen atom or a hydrocarbon group.
• R1 and R2 are preferably a hydrocarbon group, more preferably an alkyl group having 1 to 6 carbon atoms, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
• n1 is an integer of 1 or more. From the viewpoint of increasing the reactivity of the silane compound, n1 is preferably 1 or 2, and more preferably 1.
• Examples of the compound represented by formula (1) include dichlorodimethylsilane, dichlorodiethylsilane, dichlorodipropylsilane, dichlorodibutylsilane, dichlorodipentylsilane, dichlorodihexylsilane, dibromodimethylsilane, dibromodiethylsilane, dibromodipropylsilane, dibromodibutylsilane, dibromodipentylsilane, dibromodihexylsilane, dichlorotetramethyldisilane, and the like. Of these, dichlorodimethylsilane is preferred.
• the silane compound may be one type or two or more types.
• the polymerization reaction of the silane compound is preferably carried out under heating, from the viewpoint of carrying out the polymerization reaction while the metallic sodium is in a liquid state, that is, the polymerization reaction is preferably carried out while heating to a temperature equal to or higher than the melting point of the metallic sodium.
• the heating temperature is preferably equal to or higher than the melting point of sodium, more preferably equal to or higher than 98°C and equal to or lower than the solvent reflux temperature, and even more preferably equal to or higher than 100°C and equal to or lower than the solvent reflux temperature.
• the above reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon.
• the above reaction is also preferably carried out under normal pressure or under pressure.
• the silane compound may be added continuously or intermittently, but from the standpoint of production efficiency, it is preferable to add a constant amount continuously.
• the above reaction produces a reaction liquid containing crude polydialkylsilane (chain polysilane compound).
• Chain polysilane compound has a repeating unit represented by the following formula (2).
• R 1 and R 2 in formula (2) are the same as R 1 and R 2 in formula (1).
• the groups bonded to the silicon atoms at both ends of the molecule may be hydrogen atoms, hydrocarbon groups, alkoxy groups, sodium atoms, or halogen atoms.
• the alkoxy groups or halogen atoms are the same as X1 and X2 in formula (1).
• the sodium atoms are cationized and may be coordinated to the anionized silicon atoms. Since the alkoxy groups and halogen atoms have a large electronegativity difference with the silicon atoms, they may be easily reduced by sodium and may easily generate active sites. Furthermore, since the sodium atoms have a particularly large electronegativity difference with the silicon atoms, they may easily function as active sites. Therefore, the groups at both ends of the molecule of the chain polysilane compound may be alkoxy groups, halogen atoms, or sodium atoms.
• the number of repeating units is not particularly limited, but is, for example, an integer of 2 or more, and preferably an integer of 6 or more and 12,000 or less.
• Tetrahydrofuran and a polycyclic aromatic hydrocarbon or a polyphenyl-based hydrocarbon are mixed with the reaction liquid obtained in the first step.
• tetrahydrofuran and a polycyclic aromatic hydrocarbon or a polyphenyl-based hydrocarbon are mixed with the reaction liquid.
• the aromatic hydrocarbon solvent contained in the reaction solution obtained in the first step alone is not sufficient to form the complex between sodium and polycyclic aromatic hydrocarbons or polyphenyl hydrocarbons required for the decomposition reaction of the linear polysilane compound in the second step, and therefore the decomposition reaction of the linear polysilane compound does not proceed easily.
• tetrahydrofuran added to the reaction solution, a complex between sodium and polycyclic aromatic hydrocarbons or polyphenyl hydrocarbons is formed and can exist stably, thereby increasing the decomposition reactivity of the linear polysilane compound.
• the solution in the second step contains an aromatic hydrocarbon solvent and tetrahydrofuran.
• the amount of tetrahydrofuran added is preferably such that the volume ratio of tetrahydrofuran in the solution after addition is 60% by volume or more and 98% by volume or less with respect to the total volume of the aromatic hydrocarbon solvent and tetrahydrofuran.
• the volume ratio of tetrahydrofuran is 60% by volume or more, the decomposition reaction of the chain polysilane compound can be further promoted, and the yield of the cyclic silane compound can be further increased.
• the total volume of the aromatic hydrocarbon solvent and tetrahydrofuran contained in the solution is preferably 50.0 mL or more per 10 parts by mass of metallic sodium.
• the total volume of the aromatic hydrocarbon solvent and tetrahydrofuran contained in the solution is 50.0 mL or more per 10 parts by mass of metallic sodium, the decomposition of the generated cyclic silane compound can be further suppressed.
• the total volume of the aromatic hydrocarbon solvent and tetrahydrofuran contained in the solution is 700.0 mL or less per 10 parts by mass of metallic sodium, the concentration of the silane compound in the system increases, so that the reaction of the second step is easily promoted.
• the total volume of the aromatic hydrocarbon solvent and tetrahydrofuran contained in the solution is more preferably 80.0 mL or more and 580 mL or less per 10 parts by mass of metallic sodium, and particularly preferably 100 mL or more and 560 mL or less per 10 parts by mass of metallic sodium.
• polycyclic aromatic hydrocarbons or polyphenyl hydrocarbons The polycyclic aromatic hydrocarbon or the polyphenyl-based hydrocarbon can function as a catalyst for the decomposition reaction of the chain polysilane compound. Either the polycyclic aromatic hydrocarbon or the polyphenyl-based hydrocarbon or both of them may be mixed in the reaction liquid.
• the polycyclic aromatic hydrocarbon or polyphenyl-based hydrocarbon is preferably one that forms a complex with sodium.
• Polycyclic aromatic hydrocarbons are hydrocarbon compounds containing two or more condensed aromatic rings.
• Polyphenyl-based hydrocarbons are hydrocarbon compounds containing two or more aromatic rings bonded by single bonds. These compounds have conjugated ⁇ electrons in multiple aromatic rings, and therefore these complexes can act as reducing agents. This is thought to cleave the silicon-silicon bond of the chain polysilane compound or the bond between the silicon at the end of the chain polysilane and the functional group, accelerating the decomposition reaction.
• the complex of polycyclic aromatic hydrocarbons or polyphenyl-based hydrocarbons with sodium is preferably formed in the presence of tetrahydrofuran.
• Such polycyclic aromatic hydrocarbons include naphthalene, anthracene, and phenanthrene.
• polyphenyl aromatic hydrocarbons include biphenyl and terphenyl. Among these, from the viewpoint of further promoting the decomposition reaction, biphenyl, naphthalene, and anthracene are preferred, and naphthalene and biphenyl are more preferred.
• the total molar equivalent of the polycyclic aromatic hydrocarbons and polyphenyl-based hydrocarbons relative to the silicon atoms of the charged silane compound (monomer) is preferably 0.01 eq. or more and 0.50 eq. or less.
• the above total molar equivalent of the polycyclic aromatic hydrocarbons and polyphenyl-based hydrocarbons is 0.01 eq. or more, the decomposition reaction of the chain polysilane compound is more easily promoted, and the yield of the cyclic silane compound is more easily increased.
• the above total molar equivalent of the polycyclic aromatic hydrocarbons and polyphenyl-based hydrocarbons is 0.50 eq.
• the decomposition of the generated cyclic silane compound can be further suppressed.
• the above total molar equivalent of the polycyclic aromatic hydrocarbons and polyphenyl-based hydrocarbons is more preferably 0.04 eq. or more and 0.32 eq. or less, even more preferably 0.06 eq. or more and 0.20 eq. or less, and particularly preferably 0.08 eq. or more and 0.16 eq. or less.
• the order of mixing the reaction liquid, the polycyclic aromatic hydrocarbon or the polyphenyl-based hydrocarbon, and the tetrahydrofuran is not particularly limited.
• the reaction liquid may be added with the polycyclic aromatic hydrocarbon or the polyphenyl-based hydrocarbon and the tetrahydrofuran at the same time, or the reaction liquid may be added with tetrahydrofuran and stirred, and then the polycyclic aromatic hydrocarbon or the polyphenyl-based hydrocarbon may be added.
• the reaction liquid may be added after mixing the polycyclic aromatic hydrocarbon or the polyphenyl-based hydrocarbon with tetrahydrofuran, or the reaction liquid may be mixed with tetrahydrofuran and then the polycyclic aromatic hydrocarbon or the polyphenyl-based hydrocarbon may be added.
• the chain polysilane compound is decomposed to obtain a cyclic silane compound.
• the decomposition reaction may be carried out at room temperature or under heating. From the viewpoint of obtaining the cyclic silane compound in a higher yield, it is preferable to carry out the decomposition reaction under heating, that is, to heat the chain polysilane compound in the solution.
• the heating temperature may be equal to or lower than the reflux temperature, but is preferably equal to or higher than 40°C, more preferably equal to or higher than 50°C, and even more preferably equal to or higher than 60°C.
• the upper limit of the heating temperature is preferably equal to or lower than 200°C, from the viewpoint of suppressing decomposition of the reaction product.
• the heating method is not particularly limited, but may be, for example, a method in which the solution is placed in an atmosphere at a predetermined temperature, or a method in which the solution is heated by a heater, a water bath, an oil bath, electromagnetic waves, or the like.
• the reaction time indicates the time elapsed after the target reaction temperature is reached.
• the reaction time depends on the temperature of the solution, but if the reaction is carried out under heating, it is preferably, for example, from 1 hour to 35 hours, and more preferably from 3 hours to 10 hours.
• the mechanism of the decomposition reaction is presumed to be as follows.
• the bond between the group (e.g., halogen atom) and silicon at the molecular end of the chain polysilane compound, or the silicon-silicon bond is cleaved by the action of a complex formed by polycyclic aromatic hydrocarbon or polyphenyl hydrocarbon and metallic sodium, the electronic state changes and active sites are generated.Then, the molecular chain is cut at a predetermined interval by these active sites, and cyclization occurs, producing a cyclic silane compound.
• Cyclic Silane Compound The cyclic silane compound obtained by the method for producing a cyclic silane compound according to this embodiment has, for example, a structure represented by the following formula (3).
• R 1 and R 2 in formula (3) are the same as R 1 and R 2 in formula (1), respectively.
• n2 is an integer of 3 or more. n2 is preferably 3 or more and 10 or less, more preferably 5 or more and 7 or less, and even more preferably 6.
• the cyclic silane may have any structure depending on R 1 and R 2 , and examples include decamethylcyclopentasilane, dodecamethylcyclohexasilane, and tetradecamethylcycloheptasilane.
• the obtained cyclic silane compound may contain a plurality of kinds of cyclic silane compounds with different n2 .
• the molar yield of the cyclic silane compound (6-membered ring) with n2 being 6 is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more.
• the yield of the cyclic silane compound can be obtained by analyzing the reaction product by gas chromatography. The measurement conditions can be the same as those in the examples described below.
• the resulting cyclic silane contains as many six-membered rings as possible.
• the selectivity of six-membered rings is preferably 80% or more, and more preferably 85% or more.
• the selectivity of six-membered rings is the percentage obtained by dividing the molar yield (%) of six-membered rings by the total yield (%) of cyclic silanes.
• Example 1 (1) First Step: In a 200 mL four-neck flask that had been purged with argon, 12 mL of toluene (aromatic hydrocarbon solvent, solvent [A]) and metallic sodium having a molar equivalent X of 2.4 eq. relative to dimethyldichlorosilane were placed, and the mixture was stirred while being heated at the reflux temperature (110° C.) to melt the metallic sodium.
• toluene aromatic hydrocarbon solvent, solvent [A]
• metallic sodium having a molar equivalent X of 2.4 eq. relative to dimethyldichlorosilane
• the total volume of toluene and tetrahydrofuran in the reaction solution relative to 10 parts by mass of metallic sodium used in the first step was 167 mL, and the volume ratio of tetrahydrofuran to the total volume of toluene and tetrahydrofuran was 83% by volume.
• Examples 2 to 5 A solution containing a cyclic silane compound was obtained in the same manner as in Example 1, except that the amount of toluene charged in the first step and the amount of tetrahydrofuran (THF) added in the second step were changed so that the volume ratio of tetrahydrofuran to the total volume of toluene and tetrahydrofuran in the solution obtained in the second step was the volume ratio shown in Table 1.
• Comparative Example 1 A solution containing a cyclic silane compound was obtained in the same manner as in Example 1, except that toluene was added to the reaction solution obtained in the first step instead of tetrahydrofuran (THF).
• THF tetrahydrofuran
• Comparative Example 2 A solution containing a cyclic silane compound was obtained in the same manner as in Example 1, except that in the first step, tetrahydrofuran (THF) was used instead of toluene.
• THF tetrahydrofuran
• Example 6 to 10 In the first step, a solution containing a cyclic silane compound was obtained in the same manner as in Example 1, except that the amount of toluene added (parts by mass relative to 10 parts by mass of the silane compound) was changed as shown in Table 1.
• Example 11 to 14 A solution containing a cyclic silane compound was obtained in the same manner as in Example 2, except that the amount of naphthalene added in the second step (molar equivalent relative to the silane compound) was changed as shown in Table 1.
• Example 15 to 16 A solution containing a cyclic silane compound was obtained in the same manner as in Example 1, except that in the first step, an aromatic hydrocarbon solvent shown in Table 1 was used instead of toluene.
• Example 17 A solution containing a cyclic silane compound was obtained in the same manner as in Example 1, except that in the first step, biphenyl was used instead of naphthalene.
• the solution in the second step contains an aromatic hydrocarbon solvent and THF; specifically, by dissolving metallic sodium in toluene in the first step and mixing THF with a polycyclic aromatic hydrocarbon or a polyphenyl hydrocarbon in the second step, the complex of sodium and the polycyclic aromatic hydrocarbon or the polyphenyl hydrocarbon promotes the decomposition reaction of the linear polysilane compound, and thus a cyclic silane compound can be obtained without using a sodium dispersion.
• the present invention provides a method for producing cyclic silane compounds that reduces production costs and facilitates separation and purification.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Silicon Polymers (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=94395057

Family Applications (1)

Country Status (3)

Citations (5)

• 2024
  • 2024-07-31 JP JP2025537462A patent/JPWO2025028549A1/ja active Pending
  • 2024-07-31 CN CN202480044970.3A patent/CN121464142A/zh active Pending
  • 2024-07-31 WO PCT/JP2024/027269 patent/WO2025028549A1/ja active Pending

Patent Citations (6)

Non-Patent Citations (5)

Also Published As

Similar Documents

Legal Events