JP3468680B2 - Method for producing carborane-containing silicon-based polymer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a novel carborane-containing silicon-based polymer useful as a functional material having excellent heat resistance and flame retardancy. It is. [0002] Conventionally, silicon polymers having excellent heat resistance and flame retardancy have been developed. In addition, attempts have been made to improve molecular weight and mechanical strength by a method of crosslinking a polymer by a polymer reaction (Organometallics, 15, 75 (1996)).
Heat resistance and flame retardancy were not always sufficient. On the other hand, some carborane-containing silicon-based polymers are known, for example, J. Macromol.
i. -Rev. Macromol. Chem., C17 (2), 173-208 (1979) reports on poly (dodecacarborane-siloxane). [0004] Japanese Patent Publication No. 8-505649 discloses an organoboron polymer, and reports that the introduction of carborane improves the thermal stability of a siloxane polymer. However, the above-mentioned organic boron polymer is obtained from the reaction of an acetylene group-containing dilithio salt and a chloro group-containing carborane siloxane at both ends, and requires several steps to synthesize a monomeric carborane-containing silicon compound. Did not. [0005] In addition to the above-mentioned conventional organic boron polymers, carborane-containing silicon-based polymers are scarcely known, and development of a novel carborane-containing silicon-based polymer having excellent heat resistance is expected. SUMMARY OF THE INVENTION In view of the above disadvantages, the present invention provides a method for producing a carborane-containing silicon-based polymer having excellent heat resistance and flame retardancy, which can be obtained by a simple synthesis method. />. The present inventors have attempted to complex a silyl-substituted carborane derivative with a silicon-based polymer having a reactive double bond group in a side chain. The reaction between the double bond group and the silyl group is very efficient, and it can be expected that carborane is easily introduced into the polymer.
Further, since a reactive double bond is present in the side chain of the polymer, more carborane can be efficiently introduced, and further improvement in heat resistance and flame retardancy of the polymer can be expected. [0008] The process according to claim 1, wherein the inventions of carborane-containing silicon-based polymer of the general formula (1), the general formula (2)
And a recurring unit represented by the general formula (3), or, a repeating unit represented by the general formula (1) and the general formula (3)
A silicon-based polymer comprising the general formula (4) or general formula (5)
Characterized by reacting with a silyl-substituted carborane derivative represented by the formula :
This is a method for producing a silicon-containing polymer containing ruborane . [0009] In the formula (1), R ¹ , R ² , R ³ and R
⁴ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms, which may be the same or different. The positions of the two ethynylene groups and R ^{1 to} R ⁴ with respect to the benzene ring are arbitrary. In the formula (2), R ⁵ is a hydrogen atom, having 1 carbon atom.
Represents an alkyl group having 20 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms, and R ⁶ represents an alkylene group having 1 to 20 carbon atoms or an arylene group having 6 to 30 carbon atoms, but may be omitted. When R ⁶ is not present, a vinyl group is directly bonded to a silicon atom. In the formula (3), R ⁷ and R ^{8 each} have 1 to 1 carbon atoms.
20 alkylene groups or arylene groups having 6 to 30 carbon atoms
Or -C ₆ H ₄ -CH ₂ - may be omitted but is shown. When R ⁷ and R ⁸ are present, they may be the same or different. When R ⁷ and R ⁸ are not present, a vinyl group is directly bonded to a silicon atom. In the formulas (4) and (5), R ^{9 to} R ¹¹ represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms. Carborane is a bivalent cage-like boron compound represented by CBxHx'C, and x and x 'are 3 to
Represents an integer of 16. When the number of carbon atoms in the hydrocarbon group represented by R ^{1 to} R ¹¹ increases, the bond is easily broken and the heat resistance decreases when the number of aliphatic groups increases, and when the number of aromatic groups increases, the number of carbon atoms in the solvent increases. Therefore, the content is limited to the above range. The alkyl groups represented by R ^{1 to} R ⁵ and R ^{9 to} R ¹¹ include, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, Nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl and the like. The aryl groups represented by R ^{1 to} R ⁵ and R ^{9 to} R ¹¹ include, for example, a phenyl group, a tolyl group,
Examples include a xylyl group, a biphenyl group, and a naphthyl group. The alkylene groups represented by R ^{6 to} R ⁸ include, for example, methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, Examples include an undecylene group, a dodecylene group, a tridecylene group, a tetradecylene group, a pentadecylene group, a hexadecylene group, a heptadecylene group, an octadecylene group, a nonadecylene group, and an eicosylene group. The arylene group represented by R ^{6 to} R ⁸ includes, for example, a phenylene group, a tolylene group, a xylylene group, a biphenylene group, a naphthalenylene group, an anthracenylene group and the like. Examples of the carborane include dodecacarborane, decacarborane, heptacarborane, hexacarborane, pentacarborane and the like. The structural units of the silicon-based polymer represented by the general formula (1) include, for example, 1,4-diethynylbenzene,
1,4-diethynyl-2-methylbenzene, 1,4-diethynyl-
2,3-dimethylbenzene, 1,4-diethynyl-2,5-dimethylbenzene, 1,4-diethynyl-2,6-dimethylbenzene, 1,
4-diethynyl-3,5-dimethylbenzene, 1,4-diethynyl
2,3,5,6-tetramethyl benzene, 1, 3-diethynylbenzene, 1,3-diethynyl-2-methylbenzene, 1,3-diethynyl-4-methylbenzene, 1,3-diethynyl - 5-methylbenzene, 1,3-diethynyl-2,4-dimethylbenzene, 1,3-
Diethynyl-2,5-dimethylbenzene, 1,3-diethynyl-
4,5-dimethylbenzene, 1,3-diethynyl-4,6-dimethylbenzene, 1,3-diethynyl-2,4,5,6-tetramethylbenzidine <br/> Nze emissions, 1, 2-diethynylbenzene, 1,2-diethynyl-3-
Methylbenzene, 1,2-diethynyl-4-methylbenzene,
1,2-diethynyl-3,4-dimethylbenzene, 1,2-diethynyl-3,5-dimethylbenzene, 1,2-diethynyl-3,6-dimethylbenzene, 1,2-diethynyl-4,5-dimethyl benzene, 1,2-diethynyl-3,4,5,6-tetramethyl benzene, etc. <br/> like. The structural units of the silicon-based polymer represented by the general formula (2) include, for example, methylvinylsilane, ethylvinylsilane, propylvinylsilane, butylvinylsilane, pentylvinylsilane, hexylvinylsilane, phenylvinylsilane, tolylvinylsilane, xylyl Vinyl silane, methyl allyl silane, ethyl allyl silane, propyl allyl silane, butyl allyl silane,
Pentyl allyl silane, hexyl allyl silane, phenyl allyl silane, tolyl silane, xylyl allyl silane, methyl propenyl silane, ethyl propenyl silane, propyl propenyl silane, butyl propenyl silane, pentyl propenyl silane, hexyl propenyl silane, phenyl propenyl silane, tolyl propenyl silane, xylyl Propenyl silane, methyl butenyl silane, ethyl butenyl silane, propyl butenyl silane, butyl butenyl silane, pentyl butenyl silane,
Hexylbutenylsilane, phenylbutenylsilane, tolylbutenylsilane, xylylbutenylsilane and the like can be mentioned. Examples of the structural unit of the silicon-based polymer represented by the general formula (3) include divinylsilane, diallylsilane, dipropenylsilane, dibutenylsilane, vinylallylsilane, vinylpropenylsilane, vinylbutenylsilane, and allylpropenyl. Silane, allylbutenylsilane, propenylbutenylsilane, bis (vinylphenylene) silane, bis (allylphenylene) silane,
(Vinyl phenylene) vinyl silane, (vinyl phenylene) allyl silane, (vinyl phenylene) propenyl silane, (allyl phenylene) vinyl silane, (allyl phenylene) allyl silane, (allyl phenylene) propenyl silane, and the like. Examples of the silyl-substituted carborane derivative represented by the general formula (4) include m-bis (dimethylsilyl) carborane, m-bis (diethylsilyl) carborane, m-bis (dipropylsilyl) carborane, -Bis (dibutylsilyl) carborane, m-bis (dipentylsilyl) carborane, m-bis (dihexylsilyl)
Carborane, m-bis (diphenylsilyl) carborane, m-bis (ditolylsilyl) carborane, m-bis (dixylsilyl) carborane, m-bis (dibiphenylsilyl) carborane, m-bis (dinaphthylsilyl) carborane, m-bis (Dianthracenylsilyl)
Carborane, m-bis (methylethylsilyl) carborane, m-bis (methylpropylsilyl) carborane, m
-Bis (methylbutylsilyl) carborane, m-bis (methylpentylsilyl) carborane, m-bis (methylhexylsilyl) carborane, m-bis (ethylpropylsilyl) carborane, m-bis (ethylbutylsilyl) carborane, m -Bis (ethylpentylsilyl) carborane, m-bis (ethylhexylsilyl) carborane, m-bis (propylbutylsilyl) carborane, m
-Bis (propylpentylsilyl) carborane, m-bis (propylhexylsilyl) carborane, m-bis (pentylhexylsilyl) carborane, m-bis (methylphenylsilyl) carborane, m-bis (ethylphenylsilyl) carborane, m -Bis (propylphenylsilyl) carborane, m-bis (butylphenylsilyl) carborane, m-bis (pentylphenylsilyl)
Carborane, m-bis (hexylphenylsilyl) carborane, and their o- and p-isomers. Examples of the carborane include dodecacarborane, decacarborane, heptacarborane, hexacarborane, pentacarborane and the like. Examples of the silyl-substituted carborane derivative represented by the general formula (5) include, for example, dimethylsilylcarborane, diethylsilylcarborane, dipropylsilylcarborane, dibutylsilylcarborane, dipentylsilylcarborane, dihexylsilylcarborane, diphenylsilylcarborane, Ditolylsilylcarborane, dixylylsilylcarborane, dibiphenylsilylcarborane, dinaphthylsilylcarborane, dianthracenylsilylcarborane, methylethylsilylcarborane, methylpropylsilylcarborane, methylbutylsilylcarborane, methylpentylsilylcarborane, methylhexylsilylcarborane , Ethylpropylsilylcarborane, ethylbutylsilylcarborane, ethylpentylsilylcarborane, Lehexylsilylcarborane, propylbutylsilylcarborane, propylpentylsilylcarborane, propylhexylsilylcarborane, pentylhexylsilylcarborane, methylphenylsilylcarborane, ethylphenylsilylcarborane, propylphenylsilylcarborane, butylphenylsilylcarborane, pentylphenylsilylcarborane, hexyl Phenylsilylcarborane and the like. Examples of the carborane include dodecacarborane, decacarborane, heptacarborane, hexacarborane, pentacarborane and the like. The weight-average molecular weight of the carborane-containing silicon-based polymer obtained in the present invention is limited to 500 or more because if it is too small, sufficient heat resistance cannot be obtained, and if it is too large, the solubility in a solvent decreases. It is preferably not more than 10,000. Examples of the catalyst used for the reaction between the silicon polymer and the silyl group-substituted carborane derivative include chloroplatinic acid and hexarhodium hexadecacarbonyl [Rh ₆ (CO) ₁₆ ]. If the amount of the catalyst used is too small, the reaction does not proceed sufficiently. If the amount is too large, the catalyst tends to remain in the polymer after synthesis and the heat resistance is lowered. Is preferably 0.001 to 20 mol% with respect to
More preferably, it is 0.01 to 10 mol%. The molar ratio between the silicon polymer and the silyl-substituted carborane derivative used in the above reaction is such that the heat resistance of the silicon polymer obtained if the amount of carborane introduced is too small,
Since the flame retardancy is not significantly improved, the vinyl group in the silicon-based polymer: silyl-substituted carborane derivative = 1: 0.01 to
20 is more preferable, and it is more preferably 1: 0.1-10. The solvent used in the above reaction may be either polar or non-polar, but is preferably an aprotic solvent such as toluene or tetrahydrofuran. The amount of the solvent used is 0.01 to 0.01% in terms of the concentration of the structural unit of the silicon-based polymer.
50 mol / L is preferred, and more preferably 0.05 to
5 mol / L. The above reaction is carried out between room temperature and the boiling point of the solvent. This reaction can be carried out either in air or under an inert gas atmosphere, but preferably under an argon gas or nitrogen gas atmosphere. If the reaction time of the above reaction is too short, the carborane introduction reaction does not proceed sufficiently, so that the heat resistance does not improve. Conversely, if the reaction time is too long, the crosslinking reaction proceeds and the solvent does not dissolve in the solvent, making it difficult to handle. Therefore, 1 to 72 hours are preferable. The silicon-based polymer obtained by the above reaction is purified by, for example, a reprecipitation method after completion of the reaction or a fractionation method by gel permeation chromatography (GPC). Embodiments of the present invention will be described below. (Example 1) A 1 L three-necked flask equipped with a reflux tube and a dropping funnel was purged with argon. To this, 12.62 g (100.0 mmol) of 1,4-diethynylbenzene was added and dissolved in 500 ml of tetrahydrofuran. After cooling the reactor with a dry ice / methanol bath, 125 ml of a hexane solution of n-butyllithium (1.6 mol / L) was added dropwise over 30 minutes, and the mixture was stirred for 2 hours. 60 ml of a tetrahydrofuran solution of 15.38 g (100.5 mmol) of divinyldichlorosilane was added dropwise over 30 minutes, and the mixture was stirred at room temperature for 24 hours. The obtained reaction solution was poured into 400 ml of a saturated aqueous solution of ammonium chloride, and after stirring for several minutes, a tetrahydrofuran layer was separated. Next, the aqueous layer was extracted three times with diethyl ether, and the organic layers were combined and dried over anhydrous magnesium sulfate. The organic solvent was concentrated and dried under vacuum to obtain 5.89 g of tan poly (1,4-diethynylbenzene / divinylsilylene). Next, 300 m with a reflux tube replaced with argon
l in a two-necked flask, 5.16 g of the above-mentioned poly (1,4-diethynylbenzene / divinylsilylene) (25.0 m
mol) was dissolved in 150 ml of toluene. The reaction mixture was heated to 55 ° C., the catalyst (H ₂ PtCl ₆ · 6H
Put isopropanol solution 3ml of ₂ O) 0.131g (0.25mmol), and stirred for 10 minutes. further,
1,7-bis (dimethylsilyl) dodecacarborane6.
After dropping 60 ml of a toluene solution of 53 g (25.1 mmol), the temperature of the oil bath was set to 120 ° C., and the mixture was heated under reflux for 10 hours. After distilling off the reaction solution under reduced pressure, methanol 1
L. The precipitate was separated by filtration to obtain 9.7 g of a yellowish white powder (polymer). The polymer of the yellowish white powder obtained in Example 1
¹ H-NMR spectrum (“DRX30 manufactured by Bruker”)
1 is shown in FIG. 1, and the IR spectrum (measured with a Bio-Rad FTS135 system) is shown in FIG. In FIG. 1, a peak of a proton based on carborane is observed from 0.7 to 4 ppm. Also, 0.0
The peak of the proton of the methyl group and the methylene group bonded to the silicon atom was confirmed at 7 to 0.6 ppm, the peak of the proton of the phenyl group was observed at 7 to 8 ppm, and the peak of the proton of the vinyl group was confirmed at around 6 ppm. . In FIG. 2, absorption due to carborane was observed at 2594 cm ⁻¹ . From these, it was confirmed that the polymer of Example 1 was, for example, a carborane-containing silicon-based polymer partially having the structures of general formulas (6) and (7). The weight average molecular weight of this polymer was 9,600 in terms of polystyrene. Embedded image Embedded image (Comparative Example 1) 1 with a reflux tube replaced with argon
In a 00 ml two-necked flask, 0.41 g of poly (1,4-diethynylbenzene / divinylsilylene) (2.0 mm
ol) and dissolved in 20 ml of toluene. The resulting reaction mixture was heated to 55 ° C., the catalyst (H ₂ PtCl ₆ · 6H
Put isopropanol solution 1ml of ₂ O) _0.010g (0.02mmol), and stirred for 10 minutes. Then
0.34 g of 1,4-bis (dimethylsilyl) benzene
After dropping 10 ml of a toluene solution of (2.0 mmol),
The temperature of the oil bath was set to 120 ° C., and the mixture was heated and refluxed for 10 hours. Cool the reaction solution to room temperature, and add 500 ml of methanol.
I put it inside. Next, the obtained precipitate was separated by filtration to obtain 0.53 g of a yellow-white powder (polymer). The weight average molecular weight of this polymer was 68,300 in terms of polystyrene. This polymer is represented by the general formula (8) or (9),
Contains no carborane in the structure. Embedded image Embedded image About the polymer obtained in Example 1 and Comparative Example 1, "SSC5200 system" manufactured by Seiko Instruments Inc.
Was used for thermogravimetric analysis, and the obtained thermal decomposition curve is shown in FIG. In addition, 5% by weight decomposition temperature [Td ₅ (° C.)] in an air atmosphere, and the weight residual ratio at 800 ° C. [W
₈₀₀ (%)] is shown in Table 1. The measurement results shown in Table 1 show that the carborane-containing silicon-based polymer of Example 1 is a material having extremely excellent heat resistance. [Table 1] The carborane-containing silicon-based polymer obtained by the production method of the present invention has excellent heat resistance as described above, and is suitably used for space / aviation materials, building materials and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a ¹ H-NMR spectrum of a polymer of Example 1. FIG. 2 is an IR spectrum of the polymer of Example 1. FIG. 3 is a thermal decomposition curve of the polymers of Example 1 and Comparative Example 1.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-273535 (JP, A) JP-A-50-44299 (JP, A) JP-A-5-262878 (JP, A) JP-A-6-28 49430 (JP, A) JP-A-6-172712 (JP, A) JP-A-11-1561 (JP, A) JP-B-44-2240 (JP, B1) JP-A 8-505649 (JP, A) JP-T-8-507795 (JP, A) JP-T-10-509750 (JP, A) US Patent 3,388,090 (US, A) US Patent 3,388,091 (US, A) US Patent 5,552,505 (US, A) (58) Field (Int.Cl. ⁷ , DB name) C08G 77/00-77/62 C08G 79/00-79/14 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claim 1] The repeating unit represented by the general formula (1), the general formula (2) and the general formula (3), or the general formula (1) and the general formula (3) wherein a silicon-based polymer, the general formula (4) or represented by reacting a silyl-substituted carborane derivative with the general formula (5) consisting of repeating units represented by)
Method of manufacturing a weight average molecular weight of 500 or more der Luke Ruboran containing silicon-based polymer to be. Embedded image [In the formula (1), R ¹ , R ² , R ³ and R ^{4 each} represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms. May be. The positions of the two ethynylene groups and R ^{1 to} R ⁴ with respect to the benzene ring are arbitrary. In the formula (2), R ⁵ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms;
⁶ is an alkylene group having 1 to 20 carbon atoms or ⁶ to 3 carbon atoms.
An arylene group of 0 is shown but need not be present. When R ⁶ is not present, a vinyl group is directly bonded to a silicon atom. In the formula (3), R ⁷ and R ⁸ represent an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 30 carbon atoms, or —C ₆ H
₄ -CH ₂ - may or may not, but the show. Note that R ⁷ and R
^{When 8} is present, they may be the same or different. When R ⁷ and R ⁸ are not present, a vinyl group is directly bonded to a silicon atom. In the formulas (4) and (5), R ^{9 to} R ¹¹ represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms. Carborane is a divalent cage-shaped boron compound represented by CBxHx'C, and x and x 'represent integers of 3 to 16.]