DE2357199A1 - LUBRICANT - Google Patents

Description

Lubricants generally contain various additives such as those that add to to protect lubricating devices from wear and tear due to friction. These prevent wear and tear or the load-carrying capacity-improving additives are mostly organic phosphorus and sulfur-containing Links. In particular, salts of dialkyldithiophosphoric acid or dialkylaryldithiophosphoric acid, mostly the zinc salts

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of these acids.

These are known to improve the load-carrying capacity However, additives attack silver and can therefore not be used to lubricate devices such as Bearings are used that are made of silver or silver-containing alloys or the parts with a Have silver plating.

The invention is therefore based on the object of developing lubricants which, in addition to excellent properties to improve the load-bearing capacity and which at the same time have no corrosive effect Unfold silver.

To solve the problem, lubricants are proposed which are characterized in that they are used as additive A a triester of phosphorothionic acid of the general formula which is soluble in hydrocarbon oils

0 -

in the R .., Rp and R ^ monovalent same or different Hydrocarbon radicals such as alkyl, aryl or alkylaryl

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groups mean, and that they either as an addition B. Esters of orthophosphoric acid which are soluble in hydrocarbon oils and have the general formula

OR ₁ O = P-

OR,

in which R _1. , R ₁ - and Rg denote monovalent hydrocarbon-containing identical or different radicals such as alkyl, aryl or alkylaryl groups, or that, as additive C, they are a neutralization product, soluble in hydrocarbon oils, of mono- and diesters of phosphoric acid with a monovalent nitrogen-containing one organic base according to the following general formula

O = P

O = P

in which X is the organic base, a and b are zero or positive numbers with the proviso that a and b cannot both be 0, and in which 2a + b = c

and R., R. and R-. monovalent hydrocarbons -i-j * t

identical or different groups such as alkyl, aryl or alkylaryl radicals contain.

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Surprisingly, it was found that by dissolving on the one hand a triester of phosphorothionic acid SP (OH) ₇ as additive A and on the other hand either a triester of orthophosphoric acid as additive B or a mixture C of hydrocarbyl phosphates of organic bases or both B and C in low concentrations in lubricant mixtures these are given significantly improved load-bearing properties than would be expected if the combination had only a cumulative effect. Indeed, the phenomenon was found that under certain conditions additives of type B and type C have practically no effect on the wear of the metal by themselves, but that under identical conditions the wear and tear of a device which is treated with a lubricant containing the combination A and at least either B or C is lubricated, 5 to 10 times less than when a lubricant containing only A alone is used.

This synergistic effect is particularly pronounced if the additive A in amounts of about 0.1 to 3 wt.% And either additive% B in amounts of 0.1 to 3 wt. And / or the addition of C in amounts of about 0, 01 to 0.3 wt. % Can be used. The concentration in which the additives A, B and C are present, however, is in no way

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critical, so that these additives are also added in much smaller or very much larger amounts can.

The wear and tear of a device can thus be reduced by lubrication with a lubricant mixture containing of small amounts of additive A and a small amount of additive B and / or additive C is significantly reduced will.

Additive A is a triester of phosphorothionic acid with the following formula

in which R ₁ , Rp and R ^ are monovalent identical or different hydrocarbon-containing radicals such as alkyl, aryl or alkylaryl groups. The number of carbon atoms in the _f radicals R ₁ , Rp and R is not critical, provided that the compound A is soluble in hydrocarbon oils; As a rule of thumb, this condition is met if molecule A contains a total of 12 or more than 12 carbon atoms.

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Additive D is an ester of orthophosphoric acid with the following formula:

OR ₁₁

O = P

-0R _r

OR,

identical or different in the Rh, Rj and Rg monovalent Hydrocarbon radicals such as alkyl, aryl or alkylaryl groups mean. The number of carbon atoms in Rj., Rj- and Rg is also not critical provided that compound B is soluble in hydrocarbon oils; here, too, this requirement is met, \? enn Molecule B contains a total of 12 or more than 12 carbon atoms.

Additive C is a neutralization product of monoesters and diesters of phosphoric acid with a monovalent one nitrogen-containing organic base. Addition C can be represented by the following general formula:

O = P

a b j

in which X is the organic base and a and b are O or whole or fractional positive numbers mean, a and b can

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however, they cannot both be 0. The numbers a, b and c are connected by equation 2a + b = c.

In the above formula, R., R. and R. are monovalent identical or different hydrocarbon radicals such as alkyl, aryl or alkylary groups. The number of C atoms in R-, R- and R- and in the base X is not critical provided that additive C is completely soluble in hydrocarbon oils.

R., R. and R. are preferably alkyl groups each having 1 to U carbon atoms.

The organic base can in particular be a primary , secondary or tertiary aliphatic monoamine; but optionally the base can also be an aromatic amine such as aniline or its alkyl derivatives, an unsaturated cyclic base such as pyridine or its alkyl derivatives, a saturated cyclic base such as piperidine or its alkyl derivatives or similar compounds. The organic base is preferably an aliphatic amine with, for example, about 10 to 18 carbon atoms or a mixture of such amines.

As already stated, the addition A is preferably used in

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Added in amounts of about 0.1 to 0.3 wt.%. The same applies to the addition B. Additional C is preferably used in amounts of about 0.01 to 0.3 wt.%.

As additive A, for example, the following can be used: tri-n-butyl phosphorothionate, tri-i-sobutyl phosphorothionate, Triphenyl phosphorothionate, tricresyl phosphorothionate and similar connections.

The following can be used as additive B: tri-n-butyl phosphate, tri-isobutyl phosphate, triphenyl phosphate, Tricresyl phosphate or similar compounds.

The addition C can be an ester of the following type:

O = P:

-0

* ^0R ii

In this case b = 0.

XH®

2.

However, the addition C can also be an ester of the following type:

O = P-

OR. OR ₁

In this case a = 0.

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Finally, the addition C can also be any desired mixture of these two types of esters. Preferably is C then an essentially equimolar mixture of the two types of esters, which are represented by the following formula can:

O = P

O = P.

In this case, a = b = 1 in the general formula.

The phosphoric acid esters contained in additive C are preferably acidic methyl or ethyl phosphates In this case, the base of the phosphate salts in product C is preferably either a primary aliphatic amine with 10 to 18 carbon atoms per molecule such as laurylamine or a mixture of primary aliphatic Amines each with about 10 to 18 carbon atoms.

To carry out the invention is preferably first a mixture or a concentrated solution with a Content of additive A and at least one of the additives B or C and then this mixture into the Incorporated lubricant whose load-bearing properties are to be improved.

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The load-carrying capacity-improving additive compositions according to the invention contain product A and at least one of products B or C. For each part by weight of A, the mixtures contain about 0.2 to 5 parts by weight of B and / or about 0.02 to 0.5 part by weight of C. The sum of these amounts may be between about 10 to 100 wt.% Of the total mixture. If necessary, can die'Additivmischung on 100 wt.% With a suitable solvent to be filled, optionally containing also other additives may include for lubricants.

The addition of a solvent to the additive mixture is beneficial for further mixing; the additive mixtures preferably contain about 20 to 80 % by weight of solvent. The solvents used are light lubricating oils. These lubricating oils can either be synthetically produced or represent hydrocarbon oils from petroleum fractions. If appropriate, esters or ester mixtures with high boiling points, such as, for example, the diesters of, adipic acid or sebacic acid with primary alcohols having ^ to 8 carbon atoms, can also be present.

The additive mixtures can be incorporated into other components of lubricants such as lubricating oils for

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internal combustion engines, in synthetic oils for aircraft turbines or incorporated into hydraulic oils. The load-bearing capacity improving additive mixture is added to a base oil mixture in such quantities that the finished Lubricant about 0.2 to 5 wt. Contains active ingredients.

According to the invention, the lubricants should contain a small amount of additive A and a small amount of at least one of additives B or C. The concentration of A is preferably about 0.1 to 3 wt. #, The concentration of B is preferably also 0.1 to 3 Gew.5 ?, C during preferably in amounts of about 0.01 to 0.3 wt.% is added.

According to the invention, the lubricants can be, for example, lubricating greases, lubricating oils for internal combustion engines, liquids for hydromechanical power transmission, lubricating oils for aircraft turbines or the like. This above The list is by no means exhaustive.

Lubricating oils for internal combustion engines are mixtures of liquids with a viscosity of about 6 to 23 cSt at 100 ^° C. These mixtures contain hydrocarbon oils as the main component and contain up to 6 dissolved in the oil

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Wt.% Detergent and dispersant additives, such as alkaline earth metal salts of alkyl benzene sulfonates of alkenyl succinic acids or similar compounds, up to 8% viscosity index improvers, mostly

Polymers of unsaturated esters, about 0.05 to 0.3 % Fliessbzw. Pour point depressants, such as polycondensates of naphthalene and chlorinated paraffins. In addition to these conventional additives% addition contain the ER according to the invention a lubricant for internal combustion engines, preferably about 0.5 to 2 wt.% Additive A and 0.5 to 2 wt. B.

Liquids for hydromechanical power transmission are mixtures with a viscosity at 100 ^° C. of about 2 to 12 cSt. These blends may contain, as a major component, a hydrocarbon oil such as a lubricating oil base obtained by refining a heavy fraction of crude oil. Such mixtures include, for example, about 1 to 8 wt.% Viscosity index improver, from about 0.4 to 0.8 wt.? an antioxidant, for example 2,6-di-t-butyl-paracresol, about 0.05 to 0.3 % of a pour point depressant, up to 0.1 % of a corrosion inhibitor, for example derivatives of imidazole or acidic alkyl succinates of diethylene glycol or similar compounds , about 10 to 50 ppm of a defoaming agent such as a silicone oil and the like

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Links. In addition to these conventional additives include liquids for the hydromechanical power transmission according to the invention is preferably about 0.1 to 0.5 wt.% A, about 0.1 to 0.5% B, and about 0.02 to 0.1 Ji C-

The lubricating mixtures used to lubricate aircraft turbines must retain their properties over a very wide temperature range. Such mixtures usually contain esters with a high boiling range as base oil, such as, for example, esters of adipic acid or sebacic acid, which, depending on the desired viscosity, are esterified with alcohols with about 4 to 8 Cr atoms. These mixtures usually contain about 0.3 to 0.6 % oxidation inhibitors such as aromatic amines, for example paraphenylenediamine, tetramethyldiaminophenymethane or similar compounds. In addition to the usual additives, the lubricants for aircraft turbines according to the invention contain about 1 to 3 % A, about 1 to 3 % B and about 0.05 to 0.2 % C.

The percentages in the description relate to on the percentage of active ingredients.

The invention is explained in more detail below with reference to the examples.

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example 1

In order to produce a number of fluids for hydromechanical power transmission, one Basic mix (Fo) additives to achieve the desired Load-bearing properties added. The weight-based The composition of the basic mixture Po was as follows:

Hydrocarbon oil 99.35 %

Pour point depressant 0.20 %

Antioxidant 0.40 %

Rust inhibitor 0.05 %

The oil used was a mineral lubricating oil with a viscosity of 31 cSt at 37i8 ° C and a Viscosity index of 97 · The pour point depressant was a polycondensate made from naphthalene and chlorinated Used paraffins. The antioxidant used was 2,6-di-t-butyl-paracresol. Was used as a rust preventive an acidic alkenyl succinate of diethylene glycol is used. The mixture Fo also contained 10 ppm a silicone oil as a defoaming agent.

Hydraulic fluids with the designation Fl to F8 were made from the mixture Fo by adding the specified Quantities of additives A, B and C prepared according to the following table 1:

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As additive A, triphenyl phosphorothionate SP (OGgH ^) - * ve π * ends.

Additive B was tricresyl phosphate OP (OC 'H „) ,.

The addition C consisted of an essentially equimolar one Mixture of homomethyl and dimethyl phosphates of laurylamine, which can be represented by the following formula:

O = P

O = P.

OCH,

Lauryl - NH

For comparative purposes, a further hydraulic fluid was dihexyldithiophosphate zinc-F9% by the addition of 0, i * wt., A compound of _a usually used as Lasttragevermögenverbesserer made to the basic mixture Fo.

These fluids were tested for load carrying capacity and silver corrosion.

To evaluate the load-bearing capacity or the wear-reducing properties of the hydraulic fluids produced were each used in a hydraulic system a vane pump examined and the wear and tear in the course

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of the experiment as weight loss of the ring and the wings. This test is known as the Vickers test ETN8 and is described in detail by A. Dalibert and R. Renard (Journal of the Institute of Petroleum, Volume 55, March 1969). In this experiment, the liquid circulates at a pressure of ¹ IO I bar by means of a vane pump (produced by Vickers, type V 104 C) at 1450 U / min. The hydraulic fluid is kept at a temperature at which its viscosity is 13 cSt. The length of the experiment is set at 250 hours. The pump ring and blades are weighed before and after the experiment. The difference in weight gives the wear in mg.

The test results for the liquids according to the invention are given in the following table 1 (test duration 250 hours):

Table 1 - Wear according to Vickers test E.T.N.8

Additives in Fo in % Wear in

mg AB C

250 250

35

M 250

250

63 78

6.4 21

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Fo - - - Fl - ■ 1 - F2 1 - - F3 1 1 - F4 - - 0.1 P5 - 1 0.1 P6 0.25 - 0.05 F7 0.25 0.25 F8 0.25 0.25 0.05 F9 Zn-dihexyldithiophosphate (0.42)

If the weight loss of the ring and wings is very substantial, the surface erosion will be from chipping accompanied by metal particles. In this case the measurement cannot be reproduced. In practice it rules Agreement that wear and tear cannot be numerically measured - and is totally unacceptable - if the weight loss exceeds 250 mg.

When comparing the mixture Fo and the liquid Fl, it can be seen that the additive B in a concentration of 1 % itself has no measurable effect. On the other hand, a comparison of liquids F2 and F3 shows that B in a concentration of 1 % and when used at the same time with 1 % A reduces wear by 7/8.

Testing of liquids F ² J and F5 shows that additive C in a concentration of 0.1 % shows no measurable effect, even when it is used together with 1 % B in the absence of A. On the other hand, when comparing fluids F7 and F8, it is again evident that C in a concentration of 0.05 % together with 0.25 % A and 0.25 % B reduces wear by 11/12.

When comparing liquids F6 and F8, one thing is clear.

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put that ß at a concentration of 0.25. % when using 0.25% A and 0.05 % C at the same time, wear is reduced by 9/10.

The liquid P9 with a content of Oyk% zinc dihexyl dithiophosphate shows satisfactory results with regard to wear in the Vickers ETN test. However, this liquid leads to silver corrosion.

In order to examine silver corrosion, a silver sample was immersed in the liquid to be examined, which was kept in a drying chamber at a constant temperature for a predetermined time. The changes in the weight of the sample were determined by weighing with an accuracy of + _ 0.1 before and after the experiment. In addition, the corrosion was determined by visual inspection of the test pieces subjected to the test; Ratings from S to S "were used to indicate the coloration of the sample, where S _{1 was} the rating for an intact sample, while S" denoted a completely blackened sample.

The results compiled in Table 8 below enable the behavior to be compared

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the liquid F8 according to the invention and the liquid F9, which contains a common additive to improve load-bearing capacity.

Table 2 - Corrosion test on silver specimens

(Change in weight F9 l40 ° C in grams; coloring ; with S ^ to ⁺ 1 S _7. Evaluated) ⁺ 1 "Temperature 160 ° C Time Time • Time ^S 7 180 ° C 16 h 32 h ^S 7 64 h ^S 7 200 ⁰ C -0.0005S I. -0.0005S I. F8 l40 ° C +0.0004 ^S -1 +0.0014 160 ° C +0.0009 S ₁ ¹ +0.0019 180 ° C ql
^{3 S} 3 -0.0002 -0.0003 -0.0000 0.0000 +0.0002 +0.0002 -0.0004S 1 -0.003 S ₉ -0.0000 Sj. +0.0006 S, _t -0.0001 S ₁ • o.oooo S ₁ 0.0000 S *

The experiment shows that the liquid F9 corresponding to the prior art completely blackens the test piece in 32 hours at 180 ° C. and in 6U hours at 160 ° C. The increase in weight of the test piece of 0.0009 or 0.0014 g under the same conditions is caused by the embedded chemical urea products between silver and the components of the tested liquid.

The silver specimen shows when in contact with the inventive Liquid F8 practically no change.

Example 2

The extraordinary load-bearing properties of the inventive Lubricants also result from the

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Results of the experiments with the four-ball machine and with the FZG gear machine. It has also been shown that the lubricants according to the invention are excellent for Application in pumps with a silver plating are suitable.

The mixture F8 from Example 1 was subjected to the above tests and gave the following results:

With the four-ball machine (ASTM Standard D-2596) of the wear test showed the following results: At a load of 30 kg at 1500 U / min for 1 hour at 70 ⁰ C had the impression formed a diameter of O, 4l mm. With a load of 40 kg under the specified conditions, the diameter of the indentation was 0.0 ^ 3 mm.

The extreme pressure test described in the same standard regulation yielded the following results:

Average heart load 26 daN

Load up to the plague seizure 71 daN Load up to seizure 158 daN.

These results clearly show the excellent effectiveness

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The ability of the P8 mixture as a lubricant with a high load-bearing capacity and at extreme pressure.

With the FZG gear machine (DIN standard 51254 test 1/8, 3/90) the following results were obtained:

The mixture P8 endured the load 12, with the temperature was 1 ^ 7 C at the end of the test.

The specific wear was 0.02 mg / megajoule.

It is known that the load 12 is the highest im DIN standard 5125 * 1 is the prescribed load. About that In addition, it can be stated that the measured specific wear is very low.

Mixture P8 was dispensed in a piston pump with a silver-plated rotary distributor circulated. After 500 hours of work, the pump was drained and the distributor examined. Included it showed that the plating was like new.

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Claims (1)

PATENT CLAIMS 1. Mixture to reduce wear and tear and to improve load-carrying capacity, characterized in that that they, as additive A, are a triester of phosphorothionic acid which is soluble in hydrocarbon oils the general formula S = P in which R ₁ , R ₂ and R are monovalent identical or different hydrocarbon radicals viie alkyl, aryl or alkylaryl groups, as additive B is an ester of orthophosphoric acid which is soluble in hydrocarbon oils and has the general formula O = R in which R ^, R ₁ - and Rg are monovalent identical or different hydrocarbon radicals such as alkyl, aryl or alkylaryl groups, and as an additive C 409831/0702 - 21st a neutralization product of mono- and diesters of phosphoric acid which is soluble in hydrocarbon oils a monovalent nitrogen-containing organic base with the following general formula: O = P- -OR. OR ₁ . XIf in which X is the organic base, a and b are 0 or positive Numbers on the assumption that a and b. are not both 0 and that 2a + b = c, and in the R., R. and R, monovalent identical or different hydrocarbon radicals such as alkyl, aryl or mean alkylaryl groups. 2. Mixture according to claim 1, characterized in that for each part by weight of A 0.2 to 5 parts by weight of B or 0.02 to 0.5 parts by weight of C or the corresponding amounts of B and C are present, and that the sum of the concentrations of A, B and C in the mixture is 10 to 100 wt.%, and optionally 90 to 0 Gew.ft of a suitable solvent or another suitable additive are present. 409831/0702 3. Mixture according to claim 1 or 2, characterized in that the additive A tri-n-butyl phosphorothionate, tri-isobutyl phosphorothionate, Is triphenyl phosphorothionate or tri-cresyl phosphorothionate. 4. Mixture according to claim 1 to 3 *, characterized in that that the addition B tri-n-butyl phosphate, tri-isdbutyl phosphate, Is triphenyl phosphate or tri-cresyl phosphate. 5. Mixture according to claim 1 to * l, characterized in that that in the general formula of addition CR., R. and R, methyl or ethyl groups are that the base X is a primary aliphatic amine with 10 to 18 carbon atoms each Molecule or a mixture of primary aliphatic amines each with about 10 to 18 carbon atoms per molecule is. 6. Lubricant mixture, characterized by a content of lubricating oil and the mixture accordingly Claims 1 to 5. 7. Lubricant mixture according to claim 6, characterized by a content of total active ingredients from 0.2 to 409831/0702 8. Lubricant mixture according to claim 6 or 7 *
characterized by a content of about 0.1 to
3 wt.% Additive A, about O ₉ I to 3 wt. # Additive B
and / or about 0.01 to 0.3 wt% addition. C. 9. Lubricant composition according to claim 6 to 8, characterized in that a lubricating oil for internal combustion engines about 0 ₉ 5 to 2 wt.% Additive A and about 0.5 to 2 wt.% Additive B contains. 10 «lubricant mixture according to claims 6 to 8 ₉ thereby characterized that a liquid for the hydro- mechanical power transmission to about 0 _s l 0 ₉ 5% by weight. Additive A _s about 0 _s 1 to 0 _s 5 wt. % Additive B and about
O ₉ 02 to O ₉ I wt, $ additive C contains. I !. Lubricant composition according to claim 6 to 8 _9, characterized in that a lubricating oil composition for flight generating turbines on Esterbasis about 1 to 3 wt.%
additive A, about 1 to 3 wt. % Additive B and about
0 ₉ 05 to 0.2 wt. % Additive C contains. 12. Methods of reducing wear in devices in which metal surfaces are opposed to one another
rub or roll, characterized in that
the device with a lubricant mixture is lubricated according to claim 6 to 11. 409831/0702 si: go