SU1310380A1 - Method for purifying chlorbenzol used in synthesis of organochlorsilanes - Google Patents

Abstract

The invention relates to galloid hydrocarbons, in particular the purification of chlorobenzene (CB) used in the synthesis of organosilanes. The goal — an increase in the degree of purification of CB from impurities of titanium, silicon and aluminum chlorides — is achieved in a new way. The latter is carried out by passing nitrogen dioxide humidified with water at a variable temperature of 20–70 ° C. Nitrogen is taken in 150–250-fold excess with the total amount of water supplied in HB, 1.5–2 times the calculated amount for the hydrolysis of salts metals. The method provides a degree of purification of titanium salts to 0.003%, aluminum salts of 0.0001% and the complete absence of SSTS. The content of moisture in the CB of 0.02%, Table I from 00

Description

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The invention relates to methods for the purification of chlorobenzene used in the synthesis of organochlorosilanes. After these syntheses, the recoverable chlorobenzene contains impurities of aluminum, silicon and titanium chlorides and is not suitable for reuse without further purification.

The aim of the invention is to increase the degree of purification.

The invention is illustrated by examples 1-4. Comparative examples 5-8 show the inexpediency of carrying out the process outside the selected parameter ranges. Examples 9-11 show the possibility of re-using chlorobenzene, purified in accordance with the invention, in the synthesis of organosilanes (example 10), and the deterioration of the α-process is insignificant compared to using pure chlorobenzene (example 9), while chlorobenzene that has not been purified (example 11), is not suitable for further use.

Example 1, 100 ml of returnable chlorobenzene containing 0.7% (SiC) 0.12% Ti and 1-10% A1 are charged to a contact apparatus. For the complete hydrolysis of these impurities, it is necessary to calculate 0.25 g of water, 0.5 g of water (2-fold excess) is supplied with humidified nitrogen at the initial temperature of the humidifier of 20 ° C and the final temperature of 70 ° C with a total nitrogen flow of 25 liters (250 times excess to chlorobenzene),

Purified chlorobenzene contains 0.003% Ti and AI with no SiCl. The moisture content is 0.02%, which meets the requirements of technical chlorobenzene.

Example 2 Under the conditions of Example 1, 0.5 g of water is fed to the hydrolysis at a nitrogen flow rate of 15 liters (150-fold excess). Purified chlorobenzene contains 0.004% Ti, Mo A1 and 0.015% moisture in the absence. Phase separation is clear.

Examples 3-8. The process is carried out analogously to examples 1 and 2. The conditions and results of purification of benzene are given in the table.

Example 9. Synthesis of phenyltrichlorosilane at 600 ° C in a quartz reactor.

five

380.2

The reaction is carried out in a hollow quartz tube with an inner diameter of 24 mm and a length of 460 mm. A reaction mixture consisting of trichlorosil-5 and commercial chlorobenzene, taken in a ratio of 1: 2, is fed into the reactor at a rate of 12 g / h.

The resulting condensate contains, wt%:

Trichlorosilane 1,8 Silicon Chloride 16.4

Benzene9,6

Chlorobenzene33,5

Phenyltrichlorosilane 34.7 Vat residues 4.0 Phenyltrichlorosilane yield per 44.7% of chlorobenzene reacted.

Example 10. Under the conditions of Example 5 (cm, table), utilized crude chlorobenzene containing 0.7% SiCl, 0.12% Ti and 1 A1 is used. The resulting condensate contains,

JC7

May ,,::

Trichlorosilane 0.1 tetrachloride

silicon25.0

Benzene 13,4

Chlorobenzene40,6

Phenyltrichlorosilane 13,5

Diphenyl3,4

Vat residues4.0

0

The output of phenyltrichlorosilane on the reacted chlorobenzene 16.1%,

Example 11. Under the conditions of example 5 (cm, table), purified utilized chlorobenzene according to example 2 |, containing 0.004% Ti and 1% A1 „was used.

The resulting condensate contains, wt.%:

Trichlorosilane 0.1

Tetrachloride

silicon22,8

Benzene9.3

Chlorobenzene33,6

Phenyltrichlorosilane 30.2 Vat residues 4.0

The output of phenyltrichlorosilane on the reacted chlorobenzene 38.5%,

Thus, the purification of chlorobenzene in accordance with the proposed method makes it possible to lower the content of titanium and aluminum chlorides and completely eliminate silicon chloride. The resulting chlorobenzene contains water

3131

within acceptable limits and suitable for reuse in the synthesis of organochlorosilanes,

Claims (1)

Invention Formula The method of purification of chlorobenzene, used in the synthesis of organochlorosilanes, from impurities of titanium chlorides, silicon and aluminum, is characterized by the fact that one Phase separation is difficult. Emulsion formation. Compiled by N.Gozalova Editor L.Veselovska Tekhred L.Oleinik Proofreader A, Zimokosov 1864/23 Circulation 372. Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 03804 purification, nitrogen is passed through chlorobenzene, moistened with water at a variable temperature from 20 to 70 ° C, taken in 150-250 times the volume of the change from the initial chlorobenzene, with a total amount of water fed into chlorobenzene in 1.5- 2 times the calculated amount required for the hydrolysis of chlorine-containing impurities containing 0 s in chlorobenzene.