CS254484B1 - Production method of/cyclohexenylethyl/trichlorsilan - Google Patents

Abstract

Process for the preparation of (cyclohexenylethyl) trichlorosilane by hydrosilylation of vinylcyclohexene catalysed by chloroplatinic acid and by catalytic systems formed by chloroplatinic acid and target. phosphines, phosphites or phosphine oxides, in which the hydro-silylation is carried out with 85-99.8% trichlorosilane containing 0.2-15% of a mixture of dichlorosilane with tetrachlorosilane.

Description

The present invention relates to a process for the production of (cyclohexenylethyl) trichlorosilane by hydrosilylation of vinylcyclohexene in the presence of chloroplatinic acid and catalytic systems containing chloroplatinic acid and tert-phosphines or phosphine oxides by trichlosilane in admixture with tetrachlorosilane and dichlorosilane.

It is known that the above-mentioned compound is formed by the reaction of vinylcyclohexene with trichlorosilane in the presence of a number of catalyst systems such as a three-component system consisting of chelates of nickel, molybdenum or vanadium, triphenylphosphine and triethylalan (Zh. Chim. 4 7, 355 (1977)), chloroplatinic acid ( No. 2 601 913), chloroplatinic acid and up to Ο _{2% of} carboxylic acids (No. AO No. 195 549) or tertiary phosphines, phosphites or phosphine oxides (No. AO No. 240 704).

All of these processes are based on the use of trichlorosilane free of other chlorosubstituted silica compounds produced in its manufacture.

This drawback, which increases production costs, can be overcome by the process according to the invention, in which the mixtures containing trichlorosilane, tetrachiorsilane and dichlorosilane are used as the starting silicon-containing components. This mixture is formed, for example, as a waste fraction in the preparation of highly pure trichlorosilane for the production of semiconductor silicon. It has been found that the trichlorosilane-carrying chlorosilanes do not have a negative effect on the course of the hydrosilation reaction. Although the reaction may be carried out from any of the above catalyst systems, it may advantageously be used as a catalyst for chloroplatinic acid, and in particular for systems containing chloroplatinic acid and tert-phosphines, phosphites or phosphine oxides, which exhibit enhanced resistance to catalytic poisons. These saturated catalysts already catalyze the reaction in amounts of 1 mol of chloroplatinic acid per 10 mol of vinylcyclohexene. The optimum ratio is given by the degree of purity of vinylcyclohexene and the composition of the chlorosilane mixture. For the purposes of the invention, 85 to 99.8% of trichlorosilane containing 0.2 to 15% of a mixture of dichlorosilane and tetrachlorosilane, preferably 90 to 95% of trichlorosilane can be used for hydrosilylation.

Hydrosilation of vinylcyclohexene with trichlorosilane of the above purity is preferably carried out without solvent and in the presence of atmospheric oxygen by heating the reaction mixture containing vinylcyclohexene and the catalyst while adding the chlorosilane mixture at such a rate that the reaction mixture is kept boiling. After completion of the reaction, (cyclohexenylethyl) trichlorosilane can be obtained by distillation under reduced pressure. It is a starting compound for the preparation of derivatives useful as coupling agents between inorganic materials and organic polymers. Thus, for example, (cyclohexenylethyl) trialcosilanes improve the mechanical properties of rubbers filled with light fillers, as is known from U.S. Pat. For example, reaction mixtures after hydrosilylation can be used directly for the production of these compounds, without separation of the product, for example by said distillation.

The following examples illustrate the process of the invention without limiting or limiting it. Unless otherwise stated, parts are by volume.

Example 1

A reaction vessel equipped with a reflux condenser, stirrer, thermometer, and separatory funnel was charged with 32.5 parts of 95% vinylcyclohexene and 0.05 parts of 0.1 M chloroplatinic acid in isopropanol. The mixture was heated with stirring, and after reaching 90 ° C, a gradual addition of a mixture containing 91.8% trichlorosilane, 2.6% dichlorosilane and 5.6% tetrachlorosilane was started to maintain the temperature of the reaction mixture while boiling the trichlorosilane. 105-115 ° C. After the total addition of 29 parts of the chlorosilane mixture, the reaction mixture was heated until the temperature of the reaction mixture reached 130 ° C. By this procedure, distillation of the reaction mixture under reduced pressure at 30 minutes yielded (cyclohexenylethyl trichlorosilane in 97% yield (based on the vinylcyclohexene present)).

Example 2

Example 1 was repeated except that 0.04 parts of a 0.1 M solution of chloroplatinic acid in isopropanol and 0.04 parts of a 0.1 M solution of triphenylphosphine in benzene were used as catalyst. The reaction was complete in 20 minutes. Distillation under reduced pressure gave (cyclohexenylethyl) trichlorosilane in 95% yield.

Example 3

Example 1 was repeated except that the chlorosilane mixture contained 85.3% trichlorosilane, 9.5% tetrachlorosilane and 5.2% dichlorosilane. The reaction was complete in 55 minutes. Distillation under reduced pressure gave (cyclohexenylethyl) trichlorosilane in 90% yield.

Example 4

Example 1 was repeated except that the chlorosilane mixture contained 96.2% trichlorosilane, 0.7% dichlorosilane and 3.9% tetrachlorosilane. The reaction was complete in 25 minutes. Distillation under reduced pressure gave (cyclohexenylethyl) trichlorosilane in 96% yield.

Claims (1)

SUBJECT OF THE INVENTION Process for the production of (cyclohexenylethyl) trichlorosilane by the hydrosilation of chloroplatinic acid-catalyzed vinylcyclohexene and catalytic systems comprising chloroplatinic acid and tert-phosphines, phosphites or phosphine oxides, characterized in that the hydrosilylation is carried out with 85-99.8% trichlorosilane containing 0.2-15% dichlorosilane mixture with tetrachlorosilane.