DE1041622B - High temperature lubricating oil - Google Patents

Description

GERMAN

Applicant:

N. V. De Bataafsche Petroleum Maatsctiappij, The Hague

Representative: Dr. K. Schwarzhans, patent attorney,
Munich 19, Romanplatz 9

Claimed priority:
V. St. v. America February 25, 1955

High temperature lubricating oil

It is known that for lubricating a wide variety of devices, e.g. B. for automobile engines, diesel engines and even certain aircraft engines, under normal working temperatures suitable lubricating oils are completely ineffective when used in gas turbine engines, at which extremely high temperatures of the order of 200 ^° C. and above come into consideration. At such high temperatures, the known lubricants deteriorate rapidly, they are corrosive, volatilized and become unusable for the intended purpose.

Also lubricants based on mineral oils and synthetic oils, such as chlorinated hydrocarbons, Silicones, organic phosphorus compounds, silicate esters, polyglycols and diesters, which if desired protective substances or may contain improvers, have been found for use at very high temperatures and pressing have not been found to be entirely satisfactory. In most cases, these lubricants lack one or more of the following properties: high load capacity, good resistance to oxidation and exposure to heat, resistance to hydrolysis, good pumpability and low oil consumption. For example, the silicones and silicates have the disadvantage that they do not have a favorable effect with regard to wear. The esters and polyglycols do not show sufficient thermal and hydrolytic resistance, while the

chlorinated hydrocarbons and those containing phosphorus

Connections also have the disadvantage, "

that they are generally corrosive. Mineral oils

or even synthetic hydrocarbon oils, which special It has now been found that improved high-

are intended specifically for high-temperature lubrication, temperature lubricating oils for jet engines and similar such as z. For example, oils of quality 1010 and 1100 (cf. units with excellent thermal and oxidation April 1954 issue of the journal Lubrication), resistance, pumpability at low temperatures, are also not completely satisfactory because they are suitable for the 35th Low consumption and excellent resilience - starting the engine at low temperatures can be kept if you are an aromatic-free, overly viscous one. At the high temperatures, which are essentially smaller isoparaffinic lubricating oil bases normally found in jet injection engines, quantities of an oil-soluble zinc, cadmium and / or they are also extremely volatile, resulting in the green-lead salt of a thiocarbamic acid incorporated. It has stigsten case only a moderate lubrication, tend to 4.0 shown that the isoparaffinic base oils characterized sludge formation and to decompose and can not even the extremely high temperatures of 220 ⁰ C and

over it become resistant to heat and oxidation. Metal salts of thiocarbamic acid are inherent known lubricating oil additives, but they always will

thermal stabilizers on lubricants at higher 45 in combination with other special additives Temperatures do not differ from those used at ordinary tempera- tures, and they then show in the context of such

Combination of special synergetic effects. However, so far they are the only effective additive has not been used for lubricating oils because they are im

Hyman Diamond and Clarence Lynn Mahoney,

Emeryville, Calif. (V. St. Α.),
have been named as inventors

be secured against adverse effects by known additives. It has also been found that the effect of the antioxidants and the

The results obtained can be derived from the doors. It has been observed that known antioxidants such as alkylphenols, organic phosphorus

bonds, organic sulfides, amines, etc., at higher 50 generally no special technical effects

Temperatures can become completely ineffective or even promote oxidation. An addition of well-known Oxidation inhibitors for oils of the type mentioned above has therefore not been successful.

visible stabilization, corrosion prevention and antioxidant effect. As already mentioned, can also be derived from the mode of action of additives under normal working conditions

8OJ 65W85

3 4

Lubricants do not allow conclusions to be drawn about their applicability. Isomerization is a preferred method of production

Pull under high temperatures and pressures. of paraffin, such as those in the U.S. Patents

For example, 2 668 866 and 2 668 790 have been described for stabilization.
Consistency of lubricating greases an additive mixture of To produce the aromatic-free isoparaffinic, a high molecular weight naphthylamine, a reactive lubricating oil, any normally solid carbon product of phosphorus sulfide and dicyclic terpenes hydrogen wax, e.g. B. from petroleum, shale oil, ozokerite or any metal salt of thiocarbamic acid and a synthetic wax, which is used by fishermen. Another substance that is suitable for stabilizing the lubricant-Tropsch synthesis or is produced as a by-product of other fat structure processes at higher temperatures can be used. In all of these cases the combination consists of an oxyanthraquinone and paraffin chain of the wax molecules to form a dithiocarbamate of any metal. Even product that has a more branched structure can be isomerized to the catalytic action of the lubricant.

lithium soap used as a gelling agent. The paraffin wax can be used in the vapor phase, the liquid

the oxidation of the lubricating oil and the oxidative decomposition phase or in droplet-shaped distribution in an

The soap itself is disturbed by the addition of a small amount of a catalyst such as platinum, palladium, nickel,

Avoid amounts of any metal thiocarbamates. Furthermore cobalt, molybdenum or an oxide or a sulfide of these

Thiocarbamates are already isomerized together with organic metals. The isomerization is said to be

Amines with at least 6 carbon atoms in the molecule at a higher temperature of at least 300 up to 550 ° C or

has been used as grease additives. more and in the presence of a large amount of water

But it is readily understandable that the effect 20 are carried out substance. The molar ratio of water

Such additive mixtures in lubricating greases because of their substance to paraffin should be at least 1 and preferably

special gel structure and the influence of the specific over S and can be much higher. In the

The gelling agent used is technologically different to practical implementation, however, one is rarely involved with

than with pure lubricating oils. work a ratio over 30. Treatment will

Attempts have also been made to use the oxidation 25 advantageously at pressures between about 0.7 and 350 kg / cm ²

resistance carried out by mineral and synthetic. Pressures on the order of 21 to

Lubricating oils by the addition of certain synergistic 70 kg / cm ² are generally preferred when one

To increase mixtures that work as a component with platinum, palladium or nickel catalysts,

may contain a metal salt of thiocarbamic acid, while pressures of 0.7 to 3.5 kg / cm ² when applied

but the salts in question are not in themselves any particular of a catalyst consisting of molybdenum or a metal

Have an effect. Examples of such mixtures are the VI. Group contains, are preferred,

the systems zinc dithiocarbamate aromatic amine with, if necessary, can after isomerization a

at least two aromatic rings or dithiocarbamate dearomatization and / or fractionation

Metal phenolate (specially designed for a lubricating effect to be connected.

Composition of 25 to 75 percent by weight poly- 35 if produced by isomerization of waxes in the

oxyalkylenes and 75 to 25 percent by weight of the carbon oils produced in the manner described above

hydrogen oils) or thiocarbamate condensation product containing naphthenic and aromatic components,

from an aldehyde and phenol. so these must first be completely removed.

In particular, the combined application is also suitable. Suitable measures for this are a chemical one of thiocarbamates such as Zn-n-dibutylthiocarbamate 40 (acid) treatment, solvent extraction, adsorption and α-hydrocarbon-substituted naphthalenes, on solids, or a combination of such substances an α-alkylnaphthalene, has been recommended. The actions. Before or after the dearomatization process Results at z. B. White oil can show the lubricating oil in order to eliminate the treatment however, that the volatiles achieved with the individual additives, the fractions with low viscosity effects only a very low antioxidant index and the fractions with a high dropping point Effect correspond and also the overall effect of the fractionated, so that the end product is free of Combination is not particularly favorable. Aromatics and is essentially isoparaffinic and

This prior art, therefore, confirms the a dropping point of at least - 40 ⁰ C and preferential fact that similar catalysts not as -45 to -55 ° C and a molecular weight of general conclusions about the effect of a 5 ° at least 350 and preferably from 40Q,: _j to 650 of the known additive or a combination of.

Additives are possible and each system for itself The following examples explain the preparation

must be treated. suitable base oils, but im

It was therefore not at all foreseeable that a scope of the present invention would not be subject to protection.

very narrow group of additives, namely only the 55 addressed.
Thiocarbamates of three metals that have the ability

would be an excellent example of a certain group of oils

High-temperature and high-pressure properties comparable _It ^^ ^ _{dn Parafimwachs following} s own lending, while they isomerized at other lubricating oils virtually _sc stick ·
are ineffective. This surprising effect gives 60
also when comparing the experimental melting point AMP 54/57 C summarized in tabular form at the end of the description

Results. Average molecular weight. 411

The base oil used according to the invention should have aro refractive index, η 70 / D 1.4363

be mat-free and essentially or completely made up of 65 specific gravity, d 70/4 0.7849

Isoparaffins exist. It preferably has a through- _{v M. β} . _Ofmr . ,,

, ^r ., ...,.,,. ,, · J, "<-n 1 · carbon 85.50 percent by weight

Small molecular weight of at least 350 and an ' ^F

Dropping point not above - 40 ⁰ C. The base oil can be hydrogen 14.55

obtained by any known process, sulfur 0.02 "

which results in an oil of the desired type. 70 nitrogen less than 0.01 "

5 6

Aromatic carbon 0 percent by weight 475 ° C, a pressure of 35 kg / cm ² and a space

Naphthenic carbon ... isomerized at a rate between 2.5 and 5.2;

η cc ■ -u ν Ui *. it QQ the oil obtained was, as described in Example 1,

Paraffinic carbon by ,, ". , _ ",,,,, ,, ^r . - ^ r ,

refined. The final product had a dropping point

5 below -40 ⁰ C, a viscosity index of about 136 and

On isomerization, the wax together was noted to have a volatility loss of less than 10% about 20 moles of hydrogen per mole of paraffin evaporated is correct according to the ASTM method.

and this vapor mixture through a bed of platinum die used in the additives of the invention

Alumina catalyst that has about 0.3% platinum thiocarbamic acid is preferably the general contained, under the following reaction conditions i ° formula

passed through: χ

R _{1 χ} I! ^x

Temperature 420 ⁰ C \

, JN - Vw <-Λ-Ρ XT,

Pressure 35 kg / cm ² ^ /

Space velocity *) 2.5 ²

*) Space velocity is the volume of the wax in which R ₁ a hydrocarbon radical, such as alkyl, is processed per hour per part of the space of the catalyst. Aralkyl, alkaryl, cycloalkyl, R _{2 is the} same or

various hydrocarbon radicals or hydrogen,

The product was obtained by distilling off the volatile 20 χ _{χ un (} j χ ₂ denotes oxygen or sulfur, but refined fractions, whereby the rear side must be at least one X sulfur. Preferably used thiocarbamic acids of this type are the N-alkyl

and Ν, Ν-dialkylthiocarbamic acids, where the to the Average molecular weight .. about 420 nitrogen atoms of bonded alkyl groups in particular

Drop point 36.1 ° C ^{25 should have} 4 to 16 carbon atoms. Both

Refractive index at 70 ⁰ C 1.4418 NN-Dialkylthiocarbaminsäuren are connected to the N atom

", TT iih preferably two isoalkyl groups of the same chains

length but different structure.

The zinc and cadmium used as additives The residues were fractionated and dewaxed 30 _and or or lead salts can be put down in any way using methyl isobutyl ketone in the ratio, z. B. by converting an amine or from solvent to oil equal to 5: 1 and with one of mixtures of amines with COS or CS ₂ and etching temperature of - 55 ° C. The dewaxed oil, which is alkaline and producing the desired cadmium, Zinc contained about 14% aromatics, was charged with silica gel or lead salt was made from it by double conversion,
acts at a gel: oil ratio of around 8: 1. 35 Examples of suitable thiocarbamates are zinc, the adsorbent was then cadmium or lead dipropyl mono- and dithiocarbamate, with isopentane in order to separate successive fractions of the oil -diisobutyldithiocarbamate, N-amyl-N-methyhnono- and. The isopentane was removed and the in -dithiocarbamate N-octyl-N '^ - äthylhexyldithiocarbamat, consisting essentially of isoparaffins, fraction N-ethyl-N'-phenylmono- and -dithiocarbamate, dicyclo- (determined by ultraviolet adsorption analysis) was dithiocarbamate. If desired, mixtures of these additives can also be used, isolated and used as the base oil for the Ge according to the invention. This aromatic-free will be isoparaffinic.

Oil had the following properties: The amount of thiocarbamate used

generally not to exceed a total of 10%,

Drop point 40 ° C 45 and in most cases an amount from 0.1 to

Viscosity, cSt at 99 ° C 5.08 5%, especially 1 to 4%, is sufficient. This percent viscosity cSt at 38 ° C 24.57 sentences relate to weight and are based on the total

Viscosity index 148 mixture calculated.

", .., ^. ,. _A. """..", ^ _{1 n} The high-temperature lubricating oils according to the invention

Volatility, ASTM method, 50 can be improved by adding under-

6V ₂ hours at 204 C 7.4 weight percent g _eordn eter amounts of an organic amine, beispiels-

wise phenyl-a-naphthylamine, dicyclohexylamine, N-

BeisDiel 2 phenylmorpholine, octadecylamine, paraffin waxamine,

Cocoamine (made from coconut oil acids) and theirs

A paraffin wax with the 55 mixtures given in Example 1. These additives are preferably used in Properties was calculated on amounts of 0.01 to 2 percent by weight under the same conditions isomerized and refined as in Example 1, but used in the overall mixture.

a space velocity of 6.8 and with a To the valuable properties of the invention

Hydrogen ratio to starting material of 30: 1. In order to show suitable lubricating oils, the ^mixtures given below were also used for the fractionation stage
medium methyl isobutyl ketone in a ratio to

Oil used like 10: 1. The final product was a 1st after the MIL-L-7808 Oxidative Corrosion Test

aromatic-free isoparaffinic oil with a drip-tested, as described in the journal Scientific Lubrication,

point of about -48 ° C. September issue 1954, vol. 6, number 9, p. 24,

⁶ 5 is written, with the change that the temperature Example 3 was increased to 204 ⁰ C,

2. They passed the high temperature oxidation test

A distillate wax with a melting point of 70 to, as described in the magazine Industrial and

71 ° C and a molecular weight of about 500 was in Engineering Chemistry, August 1952, Vol. 44, p. 1834,

liquid phase at a temperature between 450 and 70 has been described.

7th additive lot 8th High temperature Modified oxidation test MIL-L test Cu catalyst
220 ° C Starting oil Cd diamyl dithiocarbamate 1 percent by weight Cu catalyst
204 ° C Induction Cd diamyl dithiocarbamate 1 percent by weight Induction period Phenyl-a-naphthylamine 1 percent by weight period _ 1010 mineral oil Neutral Ca petroleum sulfonate 0.5% sulfated ash 6th - Di-2-ethylhexyl sebacate Basic Ca petroleum sulfonate 0.5% sulfated ash 10 36 example 1 Ca basic alkyl salicylate 0.5% sulfate matter 6th 0 example 1 Zn alkyl salicylate 0.59% sulfated ash - 0 example 1 Zn petroleum sulfonate 0.59% sulfated ash - • - example 1 Cd petroleum sulfonate 0.77% sulfated ash - 32 example 1 Sn-diamyldithiocarbamate 1 percent by weight - 28 example 1 Cu-di-2-ethylhexyldithiocarbamate 1 percent by weight - · 1 example 1 Ni dibutyl dithiocarbamate 1 percent by weight - 5 example 1 Zn dibutyl dithiocarbamate 1 percent by weight - 10 example 1 Cd diamyl dithiocarbamate 1 percent by weight - 35 example 1 Zn diamyl dithiocarbamate 1 percent by weight - 135 example 1 Pb-diamyldithiocarbamate 1 percent by weight - 260 example 1 Cd diamyl dithiocarbamate 1 percent by weight 44 115 example 1 Zn diamyl dithiocarbamate 1 percent by weight 28 - example 1 Cd diamyl dithiocarbamate 0.5 percent by weight 32 411 example 1 Zn diamyl dithiocarbamate 0.5 percent by weight Tl X example 1 I ~ example 1 1 OJ.U example 1

Mixtures according to the present invention can be obtained by adding smaller amounts, e.g. B. 0.01 to 1 percent by weight, of corrosion inhibitors, extreme pressure additives, anti-wear agents or mixtures such substances are further improved.

35

Claims (8)

Patent claims: 1. High-temperature lubricating oil, characterized in that it consists of an essentially isoparaffinic lubricating oil base with preferably an average molecular weight of at least 350 and a dropping point not above - 40 ⁰ C and a small amount of an oil-soluble zinc, cadmium known per se as an additive of lubricants and / or lead salt of a thiocarbamic acid. 2. High-temperature lubricating oil according to claim 1, characterized in that it is the salt of thiocarbamic acid in an amount up to 10 percent by weight, preferably from 0.1 to 5 percent by weight, calculated on the total mixture. 3. High-temperature lubricating oil according to claim 1 and 2, characterized in that the oil-soluble Salt of a thiocarbamic acid of the general formula 55 R ₁ N-C-Xp-H 60 is derived, in which R _{1 is} a hydrocarbon radical, R _{2 is} a hydrocarbon radical or hydrogen and X ₁ and X _{2 are} oxygen or sulfur, but at least one X must be sulfur. 4. high temperature lubricating oil according to claim 1 to 3, characterized in that the oil-soluble salt of is derived from an N-alkylthiocarbamic acid or an N, N-dialkylthiocarbamic acid, the an the alkyl groups bonded to the nitrogen atom preferably have 4 to 16 carbon atoms. 5. High-temperature lubricating oil according to claim 1 to 4, characterized in that the isoparaffic Lubricating oil base has an average molecular weight of 400 to 650 and a dropping point between - 45 and -55 ° C. 6. high-temperature lubricating oil according to claim 1 to 5, characterized in that the isoparaffinic Lubricating oil base through isomerization of paraffin, optionally with subsequent dearomatization and / or fractionation has been obtained. 7. High-temperature lubricating oil according to claim 1 to 6, characterized in that the isoparaffinic lubricating oil base has been obtained by isomerization of paraffin in the vapor phase with at least 1 mole of hydrogen per mole of wax in the presence of a platinum catalyst and at a temperature between 300 and 550 ^° C. 8. high temperature lubricating oil according to claim 1 to 7, characterized in that there is also a Contains a minor amount of an organic amine. Considered publications:
U.S. Patent Nos. 2,504672, 2,614,987, 652362, 2,691,632, 2,694,682, 2,696,472. British Patent Nos. 660 355, 693 697, 713 186. © 309 659/385 10.58