KR20090056646A - Preparation method of polychlorocarbosilanes - Google Patents

Abstract

A method for preparing polychlorocarbosilanes is provided to prepare polychlorocarbosilanes in a mild reaction condition with a simple reactor and to recover 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane with high yield without complicated processes. A method for preparing polychlorocarbosilanes comprises a step of preparing cyclic polychlorocarbosilanes represented by chemical formula 1 and linear polychlorocarbosilanes represented by chemical formula 2 by heating a bis(chlorosilyl)methane compound represented by chemical formula 3 in the presence of a quaternary organic salt represented by chemical formula 4. In chemical formula 1, m is 3 or 4. In chemical formula 2, X^1 and X^2 are the same or different and represent hydrogen or chloro, and n is 1 or 2.

Description

Preparation method of polychlorocarbosilane {Preparation method of polychlorocarbosilanes}

The present invention relates to a method for producing a linear polychlorinated carbosilane simultaneously with a cyclic polychlorinated carbosilane by heating a bis (chlorosilyl) methane compound under a quaternary organic salt catalyst.

The process for preparing 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane (hereinafter referred to as 'HCTSCH'), which is a hexagonal polycyclic carbosilane, has been very long ago. Since it is well known in the art, it will be described in detail as follows.

Petrov and co-workers report that HCTSCH is obtained as a by-product when dichloromethane is reacted with metallic silicon at 300 ° C under a copper catalyst [Petrov, AD; Ponomarenko, VA Doklady Akademii Nauk SSSR , 90, 387 (1953); CA 48, 28464 (1954).

The Fritz Group also found that a wide variety of carbosilane compounds can be obtained by pyrolyzing methylchlorosilanes at 700 ° C, including HCTSCH, a hexagonal cyclic carbosilane [Fritz, G. and Matern, E. Carbosilanes]. Synthesis and Reactions ; Springer-Verlag: NY, 1986, pp. 19-30].

Michalczyk reports the synthesis of polychlorocarbosilane by reacting Cl ₃ SiCH ₂ Cl with magnesium metal in an ether solvent.

However, this presented method is difficult to selectively synthesize low-boiling cyclic carbosilanes, and the separation process of polychlorocarbosilanes is complicated and complicated because of the excessive use of ether solvents and the production of magnesium chloride (MgCl ₂ ) as a by-product. There are disadvantages. In other words, it is difficult to selectively synthesize low-boiling carbosilane compounds [Michael J. Michalczyk, US Pat. 5,202,405 abandoned (1993, 4, 13) " Polychlorocarbosilane and polycarbosilane precursors for manufacture of silicon carbide ceramics "]

As indicated above, methods known to date are not obtained by directly selecting volatile compounds of 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane, A method for obtaining a detailed separation from a mixture of various molecular weights is presented. This method has a low yield of low boiling point carbosilane, high reaction temperature, a ignitable solvent in the synthesis method, and there is a problem that the economic efficiency is lowered by using complicated manufacturing equipment.

The present invention does not require a process for separating and recovering from a variety of mixtures using a complex process as in the prior art, and 1,1,3,3,5, which is a 6-membered cyclic polychlorinated carbosilane in high yield under mild reaction conditions. The present invention proposes a method for preparing 5-hexachloro-1,3,5-trisilacyclohexane more efficiently.

In the present invention, a bis (chlorosilyl) methane compound represented by the following Formula 3 is heated and reacted with a cyclic polychloride carbosilane represented by the following Formula 1 under a quaternary organic salt catalyst represented by the following Formula 4. There is a characteristic in the method for producing a polychlorinated carbosilane for producing the linear polychlorinated carbosilane.

In Formula 1, m is 3 or 4.

In Formula 2, X ¹ and X ² are the same as or different from each other, hydrogen or chloro, and n is 1 or 2.

CH ₂ (SiY ¹ Cl ₂ ) (SiY ² Cl ₂ )

In Formula 3, Y ¹ and Y ² are the same as or different from each other, and hydrogen or chloro.

R ₄ B ⁺ Z ^-

In Formula 4, R is the same as or different from each other, a linear or branched alkyl group of 2 to 6 carbon atoms or a phenyl group of 2 to 6 carbon atoms, B is nitrogen (N) or phosphorus (P), Z is fluoro , Chloro, bromo or iodo groups.

The method for preparing polychlorinated carbosilanes by heating a bis (chlorosilyl) methane compound according to the present invention under an organic salt catalyst enables the production of polychlorinated carbosilanes under mild reaction conditions and a simple reaction device, and particularly high yield. Of 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane (HCTSCH) can be recovered, and the purity is high by simple distillation without the complicated separation process required in the prior art. Recovery of 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane (HCTSCH) is possible.

Thus prepared 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane (HCTSCH) is the ideal raw material of silicon carbide because the ratio of silicon and carbon in the same 1: 1 In addition, since the boiling point is not high, thin film coating is possible by the vapor phase method, and it is thermally stable, and it is an optimal material for manufacturing silicon carbide, which is easy to handle and does not cause corrosion of equipment because there is no corrosive functional group such as chlorine.

As shown in the following Scheme 1, the bis (chlorosilyl) methane compound is thermally reacted under a quaternary organic salt catalyst to give a polychlorinated carbosilane containing a cyclic polychlorinated carbosilane and a linear polycarbosilane simultaneously. It relates to a manufacturing method.

The prepared polychlorinated carbosilane is a cyclic polychlorinated carbosilane is the main product, the linear polychlorinated carbosilane is contained as a by-product, the cyclic polychlorinated carbosilane ranges from 70 to 95% by weight, linear polychlorinated carbosilane Maintains the range of 5 to 30% by weight.

Specifically, the cyclic polychloride carbosilane has 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane (HCTSCH) in which the main skeleton has Si and C in a 1: 1 atomic ratio. ) And 1,1,3,3,5,5,7,7-octachloro-1,3,5,7-tetrasilacyclooctane as the main product, and as a byproduct a linear skeleton of carbosilanes It is created at the same time. In particular, among the cyclic polychlorinated carbosilanes represented by the above formula (1), hexagonal cyclic 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane (HCTSCH) is Compared to octagonal cyclic compounds, it is produced in a much larger amount, specifically in the range of 90 to 96% molar ratio.

Si-Cl bonds of these polychlorinated carbosilanes are easily converted to carbosilanes having Si-H bonds by reducing with a reducing agent such as LiAlH ₄ , which is high in hardness, light weight, and resistant to temperature and abrasion. Silicon carbide (SiC) precursors are very useful.

Furthermore, the cyclic polychloride carbosilane represented by the formula (1) is a volatile liquid compound having a silicon atom and a carbon atom in a 1: 1 ratio, and is used as a very useful starting material to prevent the deterioration of physical properties due to excess carbon when manufacturing a silicon carbide thin film. It is possible.

Since the preparation method according to the present invention uses only the bis (chlorosilyl) methane compound of Chemical Formula 3 as a reactant, no other reactants are required, and the organic salt of Chemical Formula 4 is very economical because it is used in a catalytic amount. In comparison, a high yield of cyclic polychlorinated carbosilane is possible. In addition, the cyclic polychlorinated carbosilane can be separated from the polychlorinated carbosilane mixed with the cyclic and linear by an easy method such as a simple distillation method.

As the quaternary organic salt catalyst of Chemical Formula 4 used in the preparation method according to the present invention, a quaternary phosphonium salt or quaternary amine salt may be used. The quaternary organic salt catalyst is used in the range of 1 to 50 mol%, preferably 1 to 30 mol%, and more preferably 5 to 20 mol% with respect to the bis (chlorosilyl) methane compound of the formula (3). If the amount is less than 1 mol%, there is a problem that the reaction rate is too slow, and if it exceeds 50 mol%, there is a problem in that the separation of the product is not easy due to the excessive amount of catalyst, it is preferable to maintain the above range. .

The bis (chlorosilyl) methane compound of Chemical Formula 3, which is a reactant used in the preparation method according to the present invention, is specifically, bis (dichlorosilyl) methane, (dichlorosilyl) (trichlorosilyl) methane and bis (trichlorosilyl) methane Etc. can be used. Such a bis (chlorosilyl) methane compound can be easily prepared and used by the direct method generally used in the art [Jung, Il Nam; Yeon, Seung Ho; Han, Joon Soo US Patent 5,233,069 (August 3, 1993) 'Bis (silyl) methanes and Their Direct Synthesis'.

In addition, in the production method of the present invention, it is preferable not to use a solvent, but in order to facilitate temperature control, a generally used aromatic hydrocarbon such as toluene and xylene may be used as the solvent. Such aromatic hydrocarbons are used in the range of 1 to 20 vol / vol relative to the bis (chlorosilyl) methane compound of Chemical Formula 3.

The above reaction is preferably to use a simple distillation apparatus generally used in the art, because it is easy to effectively remove the low boiling point chlorosilane produced as a by-product during the reaction. Specifically, the synthesis method of the present invention proceeds by adding a bis (chlorosilyl) methane compound of the formula (3) and the organic salt catalyst of the formula (4) in the flask and react by heating. At this time, the receiver flask for receiving the by-products during the reaction is preferably cooled in an ice bath.

The reaction temperature is in the range of 70 to 200 ° C, preferably 100 to 170 ° C. However, if the reaction temperature is less than 70 ℃ there is a problem that the reaction time is too long, if it exceeds 200 ℃ it is preferable to maintain the above range because the production of the polymer compound is promoted.

The reaction time is in the range of 1 to 24 hours, preferably 2 to 15 hours. However, if the reaction time is less than 1 hour, a large amount of unreacted material remains, and if the reaction time exceeds 24 hours, a problem arises in that the polymer compound is increased.

When the reaction was completed, the receiver flask was changed and simple distillation under reduced pressure, and the hexagonal cyclic 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane (HCTSCH) Octagonal cyclic 1,1,3,3,5,5,7,7-octachloro-1,3,5-trisilacyclooctane can be separated respectively. In addition, linear polychlorosilanes can also be separated by fractional distillation.

As described above, the manufacturing method of the present invention is a very economical and efficient way to selectively obtain a compound of Formula 1 that can be used as a precursor of silicon carbide as compared to the prior art has the advantage of very easy process progress and low production cost .

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples.

Example 1: Reaction of (dichlorosilyl) (trichlorosilyl) methane under tetrabutylphosphonium chloride catalyst

In a 500 mL flask, 30.00 g of bis (trichlorosilyl) (dichlorosilyl) methane and 3.60 g of tetrabutylphosphonium chloride were added under nitrogen. A simple distillation apparatus connected to a 250 mL flask on the receiving side was connected to the flask under nitrogen, and the distillation flask was immersed in an oil bath heated to 170 ° C. and stirred. At this time, the flask receiving the low-boiling products generated during the reaction was cooled in an ice bath. Thereafter, the reaction was carried out at 170 ° C. for a total of 2 hours, and then changed into a new flask and subjected to simple vacuum distillation by applying a vacuum of 1 mmHg to obtain a product as a white solid.

Normal hexane was added to the solid obtained above, it was heated, dissolved, and left to refrigerate at -24 ° C to obtain 8.60 g (yield 63%) of pure HCTSCH (m = 3).

The HCTSCH obtained solution was concentrated again and left in a refrigerator at -24 ° C to yield 1.41 g (yield 8%) of 1,1,3,3,5,5,7,7-octachloro-1,3,5, 7-tetrasilacyclooctane (m = 4) was obtained.

The remaining solution is again 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane, a linear backbone carbosilane produced as a by-product under reduced pressure under 1 mmHg. (n = 1) was obtained 1.03 g (yield 4%) at a temperature of 88 ~ 97 ℃, 1,1,1,3,3,5,5,7,7,7-decachloro-1,3,5 0.47 g (2% yield) of, 7-tetrasilaheptane (n = 2) were obtained at the temperature of 130-140 degreeC.

Each compound obtained above confirmed the product by gas chromatography / mass spectrometry, and the cyclic carbosilane chloride compound as a main product confirmed the structure by NMR.

1) 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexane

¹ H-NMR (CDCl ₃ , ppm) 1.58 (s, SiC H ₂ Si); ¹³ C-NMR (CDCl ₃ , ppm) 17.2 (Si C H ₂ Si).

2) 1,1,3,3,5,5,7,7-octachloro-1,3,5,7-tetrasilacyclohexane

¹ H-NMR (CDCl ₃ , ppm) 1.55 (s, SiC H ₂ Si); ¹³ C-NMR (CDCl ₃ , ppm) 18.5 (Si C H ₂ Si).

3) 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane

MS (70 eV, EI), m / z (%) [363 (2.1), 361 (3.4), 359 (3.5), 357 (1.5), (M-Cl) ⁺ ], [253 (5), 251 ( 27), 249 (73), 247 (100), 245 (62), (M-CH ₂ SiCl ₃ ) ⁺ ]

4) 1,1,1,3,3,5,5,7,7,7-decachloro-1,3,5,7-tetrasilaheptane

MS (70 eV, EI), m / z (%) [479 (0.4), 477 (1.1), 475 (2.0), 473 (2.5), 471 (1.9), 469 (0.7), (M-Cl) ⁺ ], [365 (22), 363 (66), 361 (100), 359 (99), 357 (44), (M-CH ₂ SiCl ₃ ) ⁺ ], [251 (13), 249 (36), 247 (51), 245 (31), (M-CH ₂ SiCl ₂ CH ₂ SiCl ₃ ) ⁺ ]

Example 2: Reaction of bis (dichlorosilyl) methane in the presence of tetrabutylphosphonium chloride

In the same manner as in Example 1, using a bis (dichlorosilyl) methane as a reaction material and reacted at 150 ℃ for a total of 2 hours m = 3 (yield 60%), m = 4 (cyclic carbosilane compound) Yield 2%), n = 1 (yield 2%) and n = 2 (yield 4%) as linear carbosilane compounds.

Example 3 Reaction of Bis (trichlorosilyl) methane in the Presence of Tetrabutylphosphonium Chloride

In the same manner as in Example 1, using bis (trichlorosilyl) methane as a reactant for 12 hours at 170 ℃ a total cyclic carbosilane compound m = 3 (yield 40%), m = 4 (Yield 2%), n = 1 (yield 12%) and n = 2 (yield 2%) which are linear carbosilane compounds were obtained, respectively.

Example 4: Reaction of (dichlorosilyl) (trichlorosilyl) methane in the presence of tetrabutylammonium chloride

In the same manner as in Example 1, 10 mol% of tetrabutylammonium chloride was used as a catalyst, and (dichlorosilyl) (trichlorosilyl) methane was used as a reactant, followed by a total reaction at 120 ° C. for 12 hours. The cyclic carbosilane compound m = 3 (yield 39%), m = 4 (yield 2%) and the linear carbosilane compound n = 1 (yield 7%) and n = 2 (yield 3%) were obtained, respectively. .

Example 5: Reaction of bis (dichlorosilyl) methane in the presence of tetrabutylammonium chloride

In the same manner as in Example 1, 10 mol% of tetrabutylammonium chloride was used as a catalyst, and bis (dichlorosilyl) methane was used as a reactant. Compounds m = 3 (yield 43%), m = 4 (yield 2%) and linear carbosilane compounds n = 1 (yield 7%) and n = 2 (yield 3%) were obtained, respectively.

Claims (4)

Under a quaternary organic salt catalyst represented by the following formula (4), by heating the bis (chlorosilyl) methane compound represented by the following formula (3) Method for producing a polychlorinated carbosilane, characterized in that to prepare a linear polychlorinated carbosilane represented by the following formula (2) simultaneously with the cyclic polychloride carbosilane represented by the formula (1): [Formula 1]

In Formula 1, m is 3 or 4. [Formula 2]

In Formula 2, X ¹ and X ² are the same as or different from each other, hydrogen or chloro, and n is 1 or 2. [Formula 3] CH ₂ (SiY ¹ Cl ₂ ) (SiY ² Cl ₂ ) In Formula 3, Y ¹ and Y ² are the same as or different from each other, and hydrogen or chloro. [Formula 4] R ₄ B ⁺ Z ^- In Formula 4, R is the same as or different from each other, a linear or branched alkyl or phenyl group having 2 to 6 carbon atoms, B is nitrogen (N) or phosphorus (P), and Z is fluoro, chloro, bromo Or Io. The method of claim 1, wherein the heating reaction is carried out in the range of 50 to 200 ℃. The method of claim 1, wherein the quaternary organic salt catalyst is used in the range of 1 to 50 mol% based on the bis (chlorosilyl) methane compound. The method according to claim 1, wherein the prepared polychlorinated carbosilane maintains 70 to 95% by weight of cyclic polychlorinated carbosilane and 5 to 30% by weight of linear polycarbosilane.