JPS631946B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing vinylalkyldichlorosilane. Conventional vinylalkyldichlorosilanes include vinylmethyldichlorosilane and vinylethyldichlorosilane, but none having an alkyl group with a large number of carbon atoms are known. On the other hand, regarding its production method, methyldichlorosilane or ethyldichlorosilane and acetylene are combined into Pd-Al ₂ O ₃ ,
MFShostakorsli synthesizes vinylmethyldichlorosilane or vinylethyldichlorosilane by reacting in the presence of catalysts such as Pd-C, Pt-C, etc.
The method is described in Chemical Abstracts Vol. 51, p. 1826 (1957) and Vol. 52, p. 7134b (1958). In addition, methyldichlorosilane or phenyldichlorosilane and vinyl chloride can be added at a concentration of 550 to 650.
Vinylmethyldichlorosilane, which reacts at high temperatures of °C.
It is known from British Patent 752700 that vinyl phenyldichlorosilane is produced. However, the former has the disadvantage that side reactions are likely to occur and the production rate is low, while the latter requires a high temperature reaction. In view of the need for new vinylalkyldichlorosilanes due to the recent development of silicon chemistry, the present inventors have investigated the above-mentioned conventional problems and have proceeded with research. We succeeded in obtaining it using a new manufacturing method that produces fewer by-products. That is, an object of the present invention is to provide a novel method for producing vinylalkyldichlorosilane. The novel vinylalkyldichlorosilane of the present invention has the general formula CH ₂ =CHSiRCl ₂ (in the formula, R represents an alkyl group _having 3 or more carbon atoms). represents an alkyl group having 3 or more carbon atoms) and acetylene as Pt(PPh ₃ ) ₄ , PdCl ₂
(PPh ₃ ) ₂ , Pd(PPh ₃ ) ₄ and RuCl ₂ (PPh ₃ ) ₄ in the presence of a complex catalyst and a solvent. The vinylalkyldichlorosilane of the present invention is represented by the general formula CH ₂ =CHSiRCl ₂ , where R is an alkyl group having 3 or more carbon atoms. The alkyl group includes both chain and branched alkyl groups. Examples of compounds include vinylpropyldichlorosilanes, vinylbutyldichlorosilanes, vinylpentyldichlorosilanes, vinylhexyldichlorosilanes, vinylheptyldichlorosilanes, vinyloctyldichlorosilanes, vinyl nonyl Dichlorosilanes, vinyldecyldichlorosilanes, vinylundecyldichlorosilanes, vinyldodecyldichlorosilanes, vinylhexadecyldichlorosilanes, vinyloctadecyldichlorosilanes, vinyleicosyldichlorosilanes, etc. can be given. In the production method of the present invention, vinylalkyldichlorosilane () is obtained by the reaction represented by the following formula (1). The alkyldichlorosilane () to be used is not particularly limited, but the alkyl group preferably has 3 or more carbon atoms, more preferably 20 or less carbon atoms. Any acetylene can be used as long as it can be obtained by a conventional method. As a catalyst
Pt( _PPh3 ) ₄ , _PdCl2 ( _PPh3 ) ₂ , Pd( _PPh3 ) ₄ and
Phosphine complexes selected from RuCl ₂ (PPh ₃ ) are preferred, particularly Pt(PPh ₃ ) ₄ . Even the phosphine complexes RhCl(PPh ₃ ) ₃ , RhH(PPh ₃ ) ₄ , PtCl ₂
(PPh ₃ ) ₂ and the like are not preferred because they produce a large amount of bis(alkyldichlorosilyl)ethane () in a side reaction as shown in the following formula (2). The catalyst of the present invention produces only a small amount of (). Solvents used include benzene, toluene,
Aromatic hydrocarbons such as xylene are preferred, and the amount used is not particularly limited, but is preferably 0.3 to 5 parts of the solvent per 1 part of chlorosilane. The catalyst concentration is 0.001 to 1 mol%, preferably 0.05 to 0.5 mol%, based on the alkyldichlorosilane.
Further, the reaction temperature is not particularly limited, but is preferably 30 to 200°C, and conditions of 100°C or lower are ideal from the viewpoint of industrial production and safety. In the production method of the present invention, any apparatus of batch type, flow type, or semi-batch type can be used. For example, by bubbling acetylene into a mixture of alkyldichlorosilane, catalyst, and solvent, the reaction proceeds to yield vinylalkyldichlorosilane. The novel vinylalkyldichlorosilane of the present invention is used as a crosslinking agent and polymerization degree increasing agent for silicone rubber to improve its hydrolyzability. In addition, compared to the use of methylvinyldichlorosilane, it has better compatibility with other resins, and has the advantage of preventing repelling of paint when applied, which is a drawback of conventional silicone resins. Furthermore, drying properties and flexibility when forming a coating film are improved. A feature of the production method of the present invention is that the production of disilyl compounds obtained in conventional production methods of vinylmethyldichlorosilane and vinylethyldichlorosilane is extremely small, and the conversion rate is higher than that of alkyldichlorosilane. , a novel vinylalkyldichlorosilane, which has not previously existed, can be obtained with a high yield. Furthermore, it is extremely advantageous from the viewpoint of industrial production and safety that the reaction temperature is sufficient at a low temperature of 100° C. or less. Examples will be described below. Example 1 Glass reactor with cooler (diameter 50 mm, length 20
30 ml of paraxylene, 40 mmol of n-hexyldichlorosilane, and 0.5 mol % of catalyst [Pt(PPh ₃ ) ₄ ] based on the dichlorosilane were added to the mixture and the temperature was raised to 80°C. Dry acetylene is then spouted into the reaction solution from the bottom of the reactor for 2 hours. The reaction solution was analyzed by gas chromatography, and the results are shown in Table 1. As a result of distilling the reaction solution, the boiling point
A 78% yield of product was obtained at 113-115°C/51 mmHg. The nuclear magnetic resonance spectrum of this product (below
Figure 1 shows the infrared spectrum (hereinafter referred to as NMR).
IR) is shown in Figure 2, and it was confirmed that it was n-hexylvinyldichlorosilane. Example 2 Glass reactor with cooler (diameter 50 mm, length 200 mm)
70 ml of benzene, 40 mmol of n-hexyldichlorosilane, and 0.5 mol% of the catalyst [PdCl ₂ (PPh ₃ ) ₂ ] based on the dichlorosilane were added to the solution at a temperature of 80 to 90 mm).
℃. On the other hand, dry acetylene is jetted into the reaction solution from the bottom of the reactor for 4.5 hours.
The reaction solution was analyzed by gas chromatography, and the results are shown in Table 1. Examples 3-4 The same procedure as in Example 2 was carried out except that the catalyst, temperature, time, and amounts of benzene and n-hexyldichlorosilane were changed as shown in Table 1. Comparative Examples 1 to 4 The same procedures as in Example 2 were carried out except that the catalyst, temperature, time, and amounts of benzene and n-hexyldichlorosilane were changed as shown in Table 1. Comparative Examples 5-6 The same method as in Example 2 was carried out except that n-hexyldichlorosilane was replaced with methyldichlorosilane. The results are shown in Table 2.

【table】

[Table] Solvent xylene
[A′]=CH ₃ SiCl ₂ CH=CH ₂
[B′]=(CH ₃ SiCl ₂ CH ₂ )CH ₂

[Brief explanation of the drawing]

Figure 1 shows n-hexylvinyldichlorosilane.
IR, and Figure 2 is its NMR.

Claims (1)

[Claims] 1 Alkyldichlorosilane with the general formula RHSiCl ₂ (in the formula, R represents an alkyl group having 3 or more carbon atoms) and acetylene are combined with Pt(PPh ₃ ) ₄ and PdCl ₂
(PPh ₃ ) ₂ , Pd(PPh ₃ ) ₄ , and RuCl ₂ (PPh ₃ ) ₄ in the presence of a complex catalyst and solvent selected from the general formula CH ₂ =CHSiRCl ₂ (wherein R
represents an alkyl group having 3 or more carbon atoms. ) A method for producing vinylalkyldichlorosilane.