DE906455C - Process for the production of AEthylchlorosilanes - Google Patents

Description

Process for the preparation of ethylchlorosilanes It is known that organohalosilanes by the action of gaseous alkyl or aryl halides at elevated temperature on silicon. It will be easier to implement this and not To be able to carry out too high a temperature, silicon is a catalytically active one Metal, such as copper, iron, nickel, tin, antimony, manganese, silver or titanium, added, or the silicon is used in the form of an alloy with one of these metals. It is further from the article by Rochow z> The direct synthesis of organosilicon compoundsa, Journ. At the. Chem. Soc. 67 (19q.5), pp. 963 to 965, known, silicon with about 98 % To activate the Si content by means of copper chloride and the mass obtained in this way Use in the manufacture of ethylchlorosilanes. If you put ethyl chloride with such Si contact compounds are converted into ethylchlorosilanes on an industrial scale, so this occurs often considerable difficulties, which result in both undesirable inhibitions to react as well as in undesired acceleration of the reaction. Often the reaction is not to start at the light-off temperature that is normal for them, so that a a much higher temperature must be set, whereupon the reaction often occurs starts too violently. Also in the course of the implementation often occur for no apparent reason Changes in reaction speed in terms of acceleration or deceleration a, which disturb the smooth process very much, reduce the throughput or the reaction steer towards the formation of undesirable products. The appearance and the elimination such disturbances in the smooth course of the reaction require very careful, continuous monitoring and the application of technical Countermeasures, which focus on the continuous production of each desired Products have a very adverse effect.

It has now been found that ethylchlorosilanes, in particular, can also be used those with a hydrogen content on silicon, in particularly smooth and substantial smoothly, steadily and evenly proceeding implementation in high yield then obtained when ethyl chloride is reacted with silicon alloys at elevated temperature, those with metal salts, especially with copper chloride or iron chloride, their derivatives or, in particular, are activated with mixtures of such metal salts. The activation the silicon alloy can be made in a wide variety of ways. You can before or be made during the reaction of the silicon alloy with the ethyl chloride. The various stages of oxidation of the metal salts can take place before or during the reaction adjusted or maintained. In the simplest embodiment, mixes a powdered silicon alloy, such as. B. ferrosilicon, with the activating Metal salt or a mixture of such salts, e.g. B. iron and copper chloride, forms Pressed pieces, for example pills, from it and used them for the implementation. One can also proceed so that one crushed silicon alloys with a solution or impregnated with a paste of the metal salt. In addition, one can also act by acting an acid, e.g. B. hydrochloric acid, on which with a heavy metal, e.g. B. Iron or copper, covered silicon alloy form the corresponding salts, optionally also during the preparation of the silanes. To use the activator with the To bring silicon alloy into contact, one can do this continuously at the same time or temporarily with the ethyl chloride in liquid or solid form in the Conversion vessel, e.g. B. as dust, vapor or mist, introduce. One conducts ethyl chloride When silicon alloys are activated in this way, the silicon quickly subsides smooth course of the reaction with the ethyl chloride in high yield to ethylchlorosilanes, in particular ethyl hydrogen chlorosilanes to.

The products obtained are valuable water repellants. Organosilicon oils, resins, rubbers and the like can also be obtained from them will.

Example A powdered alloy of ferrosilicon (5 ° lo iron) is treated with a mixture of copper or iron halides, e.g. B. copper and iron chlorides, which can be used as a dry powder or as a solution or as a paste is activated. The activated mass is dried, expediently in the preheater of the reaction vessel, at a temperature which is below the formation temperature of the silanes, im generally at 16o to 2oo °. Ethyl chloride is passed over this mass at 3q.0 °, and 32 g of one per hour are obtained from 28 g of the total silicon present Mixture of ethylchlorosilanes containing up to 70% ethyldichlorosilane. Of the The remainder is ethyltrichlorosilane and diethyldichlorosilane.

Claims (4)

PATENT TA NS TEST: i. Process for the production of ethylchlorosilanes by reacting ethyl chloride with silicon at elevated temperature, characterized in that that a silicon alloy is used with metal salts, in particular with Copper chloride or iron chloride, their derivatives or mixtures of such metal salts is activated. 2. The method according to claim i, characterized in that the used Silicon alloy is activated with metal salts of various degrees of oxidation. 3. The method according to claim i and 2, characterized in that the oxidation stages before or during the implementation. 4. The method according to claim i to 3, characterized in that the silicon alloy before or during the implementation with a powder or a mist or with a solution or a paste of the activator is brought into contact. Attracted pamphlets Ullmanns, Encyclopedia dertechnischen Chemie <,, Vol. 9, p. 484 (1940); Journ. At the. Chem. Soc. 67, 963-965 (i945).