DE1074796B - Lubricating and hydraulic oils - Google Patents

Description

GERMAN

The technical progress of the last few years in the field of engines and turbines, especially in the field of jet engines for aviation, the development of new products for lubricating fast moving Parts made necessary. The lubricants 5 should above all have a high viscosity index, good oxidation and have heat resistance, a low pour point and a high flash point. on Certain areas of application have similar requirements for hydraulic fluids: Also they should have a high viscosity index within as wide a temperature range as possible be usable, show good lubricating properties in the work area, do not foam, do not have a corrosive effect and do not ignite or only ignite at a high temperature.

In the so-called ester oils, of which z. B. the esters of aliphatic dicarboxylic acids and primary aliphatic Alcohols with a branched chain containing 6 to 14 carbon atoms are particularly favorable representatives are mentioned, lubricating and hydraulic oils are available, each part of the stated requirements fulfill.

A certain class of esters has been found to be of particular benefit as lubricating and hydraulic oils can be used because these esters have a surprisingly good cross-section that of high-quality Lubricants and hydraulic oils have properties to be demanded. The esters can, advantageously, after Produce known process steps in such a way that acrylonitrile, methacrylonitrile or ethacrylonitrile or dimerization or oligomerization products of these nitriles with monohydric alcohols with at least 4 carbon atoms or attached to polyhydric alcohols with up to 10 carbon atoms and in this way The saturated nitriles formed are then saponified and with monovalent, at least 4 carbon atoms Alcohols are esterified. - The degree of oligomerization in the case of acrylonitrile should be up to about 10, in the case of of methacrylonitrile up to about 6 and in the case of ethacrylonitrile up to 5.

The above construction principle of the esters which are particularly suitable as lubricants reveals numerous possible variations. Furthermore, different Use esters of the type mentioned in a mixture with one another, whereby the lubricants largely the good properties of the individual components are preserved.

Products with particularly favorable behavior are obtained when the esterification of alcohols and unsaturated nitriles obtained cyanoethylation products at least partially with branched ones Alcohols is carried out.

The following describes the preparation of a number of esters to be used according to the invention, which with Advantage in the context of the present invention uses lubricating and hydraulic oils

Applicant:

Röhm & Haas GmbH,
Darmstadt, Mainzer Str. 42

Alfred Neumann, Raunheim (Hess.),

and Dr. Theodor Völker, Darmstadt,

have been named as inventors

can be described together with the viscosity and pour point values. The viscosities were determined at 37.8 and 98.9 ° C. The preparation of the ester-based compounds is within the scope of the present Invention not protected.

The superiority of the esters used according to the invention over the esters already known as lubricants probably has its reason in the incorporation of at least one ether oxygen in the ester molecule, namely as connecting link between the alkyl radical and the component bearing the ester group.

Additives of a known type, e.g. B. of polymers to improve viscosity, of anti-rust and Anti-foaming agents and anti-oxidation or sludge inhibitors can reduce the good properties of the continue to improve the compounds mentioned. Also the simultaneous use of mineral oils or of Synthetic lubricants of the known type can be advantageous in certain cases.

example 1

5 moles of hexanediol are cyanoethylated in the presence of 1% sodium methylate and 0.1% pyrogallol with 10 moles of acrylonitrile at 60 to 65 ° C. and the resulting nitrile is saponified _{in a known manner with H 3} O and H ₂ SO _4. The acid formed is esterified at the same time with 10 mol of iso-decanol. The product is cleaned by. Flash distillation.

Properties of the resulting ester-based compound :

Viscosity at 37.8 ° C 21.07 cSt

Viscosity at 98.9 ° C 4.63 cSt

Viscosity Index 154

Pour point -68 ° C

Flash point 233 ° C

VKA number 1000 kg

Corrosion protection number 84.1

909 728/487

The VKA number can be determined in the four-ball apparatus or in the Zimmermann Lang test (M. Zimmermann, "Lubrication Technology", Düsseldorf, 1954). The corrosion protection number is determined according to the Daimler-Benz standard L 6774 (Appendix 2) according to the provisions of Philippowich ("Petroleum and Coal", April 1952).

Comparative experiment to Example 1

The corresponding values for the di-2-ethylhexyl sebacate known as a lubricating and hydraulic oil are from can be seen in the table below:

Viscosity at 37.8 ° C 12.6 cSt

Viscosity at 98.9 ° C 3.32 cSt

Viscosity Index 154

Pour point - 70 ° C

Flash point 4-224 ° C

VKA number 950 kg

Corrosion protection number 33.1

20th

Even the flash point of the ester oil according to Example 1 is higher than that of the known Esters, so that a broader technical applicability is possible. In addition, the high pressure properties and above all the anti-corrosive properties, which are a crucial consideration represent for the properties of a lubricating oil, in the case of the ester oil according to Example 1, much more favorable.

Is it also taken into account that the corrosion protection numbers determined by the above-mentioned method for non-formulated high-quality mineral oils are only 10 to 15 and for pronounced branded anti-corrosion oils Key figures of about 90 are determined, so not only the clear superiority of the invention Oils can be seen compared to the best known oils based on dicarboxylic acids, but beyond also apparently that with regard to the corrosion protection effect even made-up special oils are practically achieved will.

Example 2

40

10 moles of hexanediol are in the presence of sodium methylate (1%) and pyrogallol (0.1%) with the equivalent Amount of acrylonitrile cyanoethylated, the resulting nitrile saponified in the manner indicated above and the resulting acid esterified in molar amounts with iso-decanol and n-octanol.

The resulting product shows the following viscosity temperature behavior :

Viscosity at 37.8 ° C 18.32 cSt

Viscosity at 98.9 ° C 4.3 cSt

Viscosity index 164.6

Pour point -30 ° C

Example 3

55

1 mole of glycerol is cyanethylated in a known manner with 3 moles of acrylonitrile, the resulting nitrile is _{saponified with H 2} O and H ₂ SO ₄ and at the same time the resulting acid is esterified with 2 moles of 2-ethylhexane and 1 mole of n-octanol. Working up is carried out as indicated in Example 1.

Ester oil properties of the resulting product:

Viscosity at 37.8 ° C 15.48 cSt

Viscosity at 98.9 ° C 3.42 cSt

Viscosity index 106

Pour point -65 ° C

Example 4

5 mol of n-dodecyl alcohol are cyanäthyliert in the usual manner with acrylonitrile (6 moles) in the presence of 1 ° / ₀ sodium methylate and 0.1 ° / ₀ pyrogallol. The resulting nitrile is saponified with sulfuric acid and water and the acid formed is esterified with 2-ethylhexanol. The yield anjS-dodecoxy-propionic acid-2-ethylhexyl is 60.7 ° / _0th

Kp. _{0, 2} = 180 ° C

Viscosity at 37.8 ° C 14.75 cSt

Viscosity at 98.9 ° C 3.57 cSt

Viscosity index 143.2

Pour point -45 ° C

Example 5

175 moles of the completely cyanoethylated glycol (2 moles of acrylonitrile + 1 mole of glycol) are mixed with 50 moles of the monocyanoethylation product of glycol with acrylonitrile (1 mole of glycol + 1 mole of acrylonitrile). After adding 400 mol of water and 205 mol of H ₂ SO ₄ , the mixture is saponified. A partial esterification of the dicarboxylic acid formed by saponification of the ditrile occurs with the oxycarboxylic acid formed by saponification of the monocyanethylation product. Then 350 mol of 2-ethylhexanol are added and esterification is carried out completely in a manner known per se.

The crude ester, shaken out with water and deacidified in the process, is dried. The up to 190 ° C in a vacuum (0.5 mm Hg) volatile components are drawn off. What remains is an ester oil with the following properties:

Viscosity at 37.8 ° C 20.33 cSt

Viscosity at 98.9 ° C 4.5OcSt

Viscosity index 158.2

Pour point -58 ° C

Flash point 211 ° C

Claims (2)

Patent claims: 1. Use of ester-based compounds that result from the addition of acrylonitrile, methacrylonitrile or ethacrylonitrile or from dimerization or oligomerization products of these nitriles to monovalent Alcohols with at least 4 carbon atoms, or polyhydric alcohols with up to 10 carbon atoms and by subsequent simultaneous saponification and esterification of the cyanoethylation products formed with monohydric alcohols containing at least 4 carbon atoms are available as lubricating and hydraulic oils. 2. Embodiment of the invention according to claim 1, characterized by the use of such esters as lubricants in which the esterification component is at least partially made up of branched chain Alcohols. > 90 »728/487 1.60