CS232318B1 - Organosilicon esters and process for their preparation - Google Patents

Abstract

Organosilicon esters of the general formula with a method of their preparation by allowing phenyltrichlorosilane, neopentyl glycol and monohydric alcohols to react at a temperature of 70 to 160 °C, after the reaction is complete 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 high viscosities, a low freezing point and are thermally stable up to 360 °C. They are suitable for the preparation of plastic lubricants, hydraulic fluids and oils.

Description

The invention relates to organosilicon esters and a method for their preparation from phenyltrichlorosilane, dimethylol-2,2-propene (neopentyl glycol) and monohydric alcohols.

For the purposes of lubrication technology, many types of oils have been tested, 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, and the like are usually used as acceptors.

When using them, 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. The procedure is therefore unsuitable for industrial practice. Therefore, new types of substances and more advantageous procedures and their preparations were sought, described, for example, in the descriptions of inventions to Czechoslovak copyright certificates No. 231 224, No. 231 232 and No. 228 443.

It has now been found that new organosilicon esters according to the invention are suitable for the purposes of lubrication technology. The new esters and the method of their preparation have not yet been described in the literature. They exhibit high viscosities and at the same time low freezing points and are thermally stable up to 360 °C. They are suitable for the preparation of oils, hydraulic fluids and plastic lubricants.

Organosilicon esters of the general formula c ₆ h ₅ ch ₃

CH ₃ (CH ₂ ) ₃ CH CH ₂ O--Si O-CHg— C — CHgO •Si OCHgCH (CH ₂ ) ₃ CH ₃ ^C 2 ^H 5

CH, c ₂ h ₅

OCHgCH _{( CH2} ) _3CH3

OCHgCH (CH ₂ ) ₃ CH ₃ c ₂ h ₅ x CgHj where χ = 1, 5 or 4, are prepared according to this invention by allowing phenyltrichlorosilane, neopentyl glycol and 2-ethylhexanol to react at a temperature of 70 to 160 °C, after the reaction is complete 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 examples below illustrate embodiments of the invention.

Example 1

Into a 2.5 l Keller flask equipped with a stirrer, thermometer, reflux condenser, addition vessel, heating bath and outlet pipe with manometer were introduced 156 g of neopentyl glycol and 100 g of 2-ethylhexanol heated to 70 °C and with stirring and further heating of the flask 527 g of phenyltrichlorosilane and then 550 g of 2-ethylhexanol were added over 1 h. The addition was controlled according to the pressure of escaping hydrogen chloride and towards the end of the addition the temperature in the flask reached 120 °C, at which it was maintained.

Then nitrogen was introduced to the bottom of the flask through a tube and, while stirring, the hydrogen chloride content in the flask was reduced by a nitrogen stream over 30 to 60 min to an acid number of 1.7 mg KOH/g. Then, the amount of saturated sodium hydroxide in 2-ethylhexanol calculated from stirring was added to the flask. The contents of the flask were then transferred to a vacuum distillation apparatus and the volatile components were distilled off at a pressure of 1,250 Pa to a boiling point of 240 °C.

After cooling, the distillation residue was filtered through paper. 360 g of a clear yellowish ester of the previously mentioned general formula were obtained, where χ = 1.5, with an acid number of 0.01, n ²⁵ ^ 1.478 3, flash point 198 °C, combustion temperature 257 °C, pour point -55 °C, viscosity at 100 °C 7.38 nnAs ¹ , at 50 °C 28.10 mm ² .s ^-1 , at -20 °C 2 604 bsb ² . .s ^-1 , at -40 °C 35 280 mm ² .s'.

Example 2

By the same procedure as in Example 1 and on the same apparatus, 280 g of neopentyl glycol, 480 g of 2-ethylhexanol and 527 g of phenyltrichlorosilane were processed. After distillation at a pressure of 1,400 Pe to a temperature of approximately 244 °C, 428 g of a clear, yellowish ester were obtained, which corresponds to the previously mentioned formula, where x = 4, with an acid number of 0.01, n^ = 1.4 831, flash point 200 °C, combustion temperature 236 °G, pour point -48 °C, viscosity at 100 °C 7.40 mm ² .s', at 50 °C 32.4 mm ² .s ^-1 , at -20 °C 5 348 mm ² .s“ ¹ .

Example 3

Similar to Example 1, an ester was synthesized from 208 g of neopentyl glycol, 844 g of phenyltrichlorosilane, and 1,040 g of 2-ethylhexanol. The obtained ester of the previously mentioned formula, where χ = 1, was rectified on a vacuum column at a pressure of 50 Pa. It was found that the ester is stable up to a temperature of 360 °C.

It was obtained:

427 g fraction 366 g fraction boiling point °C at 50 Pa 190 to 220 220 to 320 flash point °C 186 219 freezing point °C -67 -55 1,467 1 1 ,475 3 density at 25 °C 0.940 2 0.969 1 viscosity at 100 °C in mm ² .s ^-1 2.68 4.47 viscosity at 50 °C in mm ² .s ^-1 7.29 13.91 viscosity at -20 °C in mm ² .s ^-1 2.54 798 viscosity at -40 °G in mm ² .s ^-1 1,911 7,726

Claims (2)

SUBJECT OF THE INVENTION 1. Organotin esters of the general formula ?6 ^H 5 CH, °6 ^H 5 ch ₃ (ch ₂ ) ₃ ch ch ₂ o ^C 2 ^H 5 Si--0-CHg-C-CH ₂ 0 CH, Sí.OCH ₂ QH (CH ₂ ) ₃ CH ₃ ^C 2 ^H 5 OCHgCH _{( CH2} ) _3CH3 OCHgCH (CH ₂ ) ₃ CH ₃ c ₂ h ₅ c ₂ h ₅ where x = 1, 1.5 or 4. 2. A method for preparing organosilicon esters according to item 1, characterized in that phenyltrichlorosilane, neopentyl glycol and 2-ethylhexanol are allowed to react at a temperature of 70 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.