CS231234B1 - Process for preparing organosilicon esters - Google Patents

Abstract

Method for preparing organosilicon esters of the general formula where R. to R. denote an alkyl group with 8 to 14 carbon atoms and x is 1 to 3» so that phenylenetrichlorosilane, diane and monohydric alcohols are allowed to react, after the reaction is complete the hydrogen chloride content is reduced, then sodium hydroxide is added and the volatile components are distilled off. The esters obtained can be used for the preparation of oils, hydraulic fluids, plastic lubricants, or as plasticizers.

Description

(54) Method for preparing organosilicon esters

Method for preparing organosilicon esters of the general formula ^C A

I ⁶⁵

R.O.Si’ I

STEED,

CH, ^6 ^H 5

-0-C ₆ H ₄ -CC ₆ H ₄ -0-Si-OR,

CH,

OR, where R. to R. denote an alkyl group with 8 to 14 carbon atoms and x is 1 to 3» so that phenylenetrichlorosilane, diane and monohydric alcohols are allowed to react, after the reaction is complete the hydrogen chloride content is reduced, then sodium hydroxide is added and the volatile components are distilled off.

The obtained esters can be used for the preparation of oils, hydraulic fluids, plastic lubricants, or as plasticizers.

43,234

The invention relates to a method for preparing organosilicon esters from phenyltrichlorosilane, bis p,p-hydroxyphenyl-2,2-propane (diane) and monohydric alcohols.

The issue of the preparation of organosilicon compounds generally falls under the methods of esterification of halosilanes. The conditions of the reactions of alcohols with chlorosilanes are the subject of a number of publications (Organosilicon compounds, vol. I, Academia, Prague 1965, Ladenburg Ber. 6, 376 /1983/. An overview of various methods of esterification of halosilanes is given in Chem. Revs. 42.97 (1974).

Many types of oils have been tested for lubrication purposes, from mineral oils, to esters of organic alcohols with mono- or dicarboxylic acids, to organosilicon compounds. Organosilicon esters are usually prepared using solvents and hydrogen chloride acceptors.

Amines such as pyridine, aniline, triethylamine, etc. are usually used as acceptors. When they are used, a large amount of bulky salt is formed, as a result of which a large amount of solvents must be used to enable the mixture to be miscible. For this reason, the procedure is unsuitable for industrial practice. Therefore, new types of substances and more advantageous procedures for their preparation were sought, for example, those given in Czechoslovak patent certificates No. 231 224, 228 443, 231 232 and elsewhere. It has now been found that the new organosilicon esters according to the invention, which have not yet been described in the literature, are unsuitable for the purposes of lubrication technology.

Method for preparing organosilicon esters of the general formula ?6 ^H 5

R,0 - Si

STEED"

CH, ^C 6 ^H 4 ^{C C} 6 ^K 4

CH,

CA

I ⁶⁵

You are I

OR, x

where Rj to denotes an alkyl group with 8 to 14 carbon atoms and x is 1 to 3, according to the invention, consists in reacting phenyltrichlorosilane, diane and monohydric alcohols at a temperature of 100 to 160 °C, after which the hydrogen chloride content is reduced by displacement with a stream of nitrogen, then a solution of sodium hydroxide in the alcohol used is added and the volatile components are distilled off. The esters obtained have sufficiently high viscosities and at the same time a low freezing point. They can be used for the preparation of oils, hydraulic fluids, plastic lubricants, or as a plasticizer.

The example below illustrates an embodiment of the method according to the invention.

Example of execution

Claims (1)

In a 2.5 l Keller flask equipped with a stirrer, thermometer, reflux condenser, addition vessel, heating bath and outlet pipe with manometer, 260 g of 2-ethylhexanol and 228 g of diane were introduced, heated to .10 °C and, while stirring and maintaining the temperature at 110 to 120 °C, 422 g of phenyltrichlorosilane and then 260 g of 2-ethylhexanol were added over 1 hour. The addition was controlled according to the pressure of the escaping hydrogen chloride. Then, nitrogen was introduced to the bottom of the flask through a tube and, while stirring and heating the flask to 120 °C, the acidity content in the flask was reduced by a stream of nitrogen over 30 to 60 minutes to an acidity number of 0.45. Then, the calculated amount of saturated sodium hydroxide solution in 2-ethylhexanol was added to the flask with stirring. The contents of the flask were then admitted to a vacuum distillation apparatus and the volatile components were distilled off at a pressure of 2,600 Pa to a boiling point of 255 °C. After cooling, the distillation residue was filtered through paper. 764 g of a clear yellowish ester with an acid number of 0.02 mg KOH/g, n^ ⁵ - 1.4909, flash point 20. °C, combustion temperature 235 °C, freezing point -52 °G were obtained. The viscosity at 200 °C was 1.51 mm ² .s ^- ' 150°C 2.58 100 °C 5.93 nm ² .s~' 50 °C 25.42 mm ² .s”' -20 °C 3,653 w ² .s~ ¹ The moisture content of the ester at 80% relative humidity at 20 °C for 90 h is very low, namely 0.11% by weight. The ester prepared in this way corresponds to the general formula given above, where R1 to R2 are the same and represent alkyl with 8 carbon atoms and x = 1. The seventh invention Method for preparing organosilicon esters of the general formula C,H _r I ^{6 J} CH, 1 °6 ^H 5 1 R,0 - Si - 1 - 0 - G _r H. - C - 6 4 , c ₆ h ₄ - 0 - Si - - <® ₄ or ₂ o — sc ^0K 3 X where R1 to R2 represent an alkyl group with 8 to 14 carbon atoms and x is 1 to 3. characterized in that phenylenetrichlorosilane, diane and monohydric alcohols are allowed to react at a temperature of 100 to 160 °C, after the reaction is complete, the hydrogen chloride content is reduced by displacement with a nitrogen stream, then a solution of sodium hydroxide in the alcohol used is added and the volatile components are distilled off.