DE2423458A1 - SYNTHETIC OIL FORMULATION - Google Patents

Description

Patent assessor Hamburg, May 10th 1974

Dr. Gerhard Schupfher 726 / kr German Texaco A.G.

2000 Hamburg 76 T 74 029 (D 73023-FB)

Sextuple gate 2

TEXACO DEVELOPMENT CORPORATION

135 East 42nd Street New York, NY 10017

UNITED STATES.

Synthetic lubricating oil formulation

The invention relates to a lubricating oil formulation which is intended for use in gas turbines and jet engines.

Gas turbine engines are operated under extreme environmental conditions. The lubricating oil must be fluid at very low temperatures, however, also be more lubricating effect when the internal temperature of the engine is about 230 290 ⁰ C or more. These operating conditions place so high demands on the lubricating oil that the best mineral lubricating oil formulations and also many synthetic lubricating oils can no longer be used.

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2423453

For the lubrication of gas turbines and similar engines, synthetic ester lubricating oils are currently used, those used as base oils are esters of pentaerythritol or trimethylolpropane and also a carefully matched one Contains a mixture of additives or additives. These ester lubricating oil formulations are in a wide variety Effective temperature range and have good heat resistance and a high degree of oxidation and corrosion resistance. However, new and more powerful gas turbine engines developed for supersonic flight represent significantly higher demands on the resistance of the lubricating oil to thermal and oxidative loads.

Turbine or jet engines are used to cope with the high temperatures, speeds and forces The problems encountered are made of a variety of metals, and it is common to use the synthetic ester oil to add an inactivating additive that reduces metal corrosion under the operating conditions. This metal inactivator additive is said to be effective on the metal surfaces most exposed to corrosion form a monomolecular protective film bonded to the metal surface.

Numerous substances are already known which have been added to synthetic ester lubricating oils as such metal corrosion protection additives, including condensation products of salicylaldehyde with hydrazine derivatives and fatty acid salts of such condensation products, of which the salts of 1-salicylaminoguanidine and aliphatic C.λ-C ₁ g carboxylic acids are preferred .

Another class of such anti-corrosion additives are salicylaldehyde semicarbazones and their C. -CpQ-alkyl derivatives, such as methyl or isopropylsalicylaldehyde semicarbazone.

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Various hydroxyanthraquinones, such as 1,4-dihydroxyanthraquinone (Quinizarine) are effective anti-corrosive additives, while other related anthraquinones as ineffective apply.

Another class of known corrosion protection substances comprises the C 1 -C ₂ Q-alkyl gallates, in particular propyl gallate, and neopentyl glycol disebazate, sebacic acid, azelaic and adipic acid.

Another class of corrosion inhibitors includes Pyridylamines and dipyridylamines, such as 2,2'-dipyridylamine.

The triazole compounds also form a class of effective anti-corrosion agents and include 1,2,3-benzotriazole and its methyl derivative, as well as 3-amino-5-methyl-, 3-amino-5-phenyl- and 3-amino-5-pyridyl-1,2,4-triazole and 5,5'-di-amino-3,3-bi- (1,2,4-triazoles).

The conditions under which ester lubricating oils work must are so sharp that the choice of metal anti-corrosion agent is critical to formulating a low residue lubricating oil. Albeit the well-known ones Corrosion inhibitors are effective for the intended purpose, but often cause others serious problems when using such lubricating oils. For example, anti-corrosion agents are usually used for the increasing formation of deposits in the engine, which are determined in the "Alcor Deposition Test". Furthermore, they can also have seizures, pitting or erosion caused by magnesium components of the engine or the ancillary units.

The US-PS 3,344,068 describes a synthetic ester

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Lubricating oil formulation that contains numerous corrosion inhibitors, including substituted amino and benzotriazoles.

U.S. Patent 3,330,764 describes a synthetic lubricating oil formulation with improved load-bearing properties, whose pentaerythritol ester base oil is a combination of an ammonium thiocyanate and a cyclic amine compound such as phenyl-s ^ -naphthylamine.

U.S. Patent 3,427,111 discloses a synthetic lubricating oil formulation described whose pentaerythritol ester base oil 1) an arylamine antioxidant such as diphenylamine and phenyl-c £ -naphthylamine, 2) as passivating agents for Copper a salt of 1-salicylalaminoguanidine and one aliphatic C ^ -C ^ g-carboxylic acid, 3) as a corrosion protection substance a polyhydroxyanthraquinone and 4) an organic phosphoric acid ester in the form of a phosphate or contains phosphite.

GB-PS 1 180 387 describes a synthetic lubricating oil formulation, which contains an azole-type copper passivator, salicylaldehyde, and hydrazine.

The invention relates to a synthetic lubricating oil formulation, the main component of which is a lubricating aliphatic ester base oil, obtained by reaction of pentaerythritol or trinethylolpropane with a honoearboxylic acid of 2-18 carbon atoms, characterized by the following combination of additives (Additives):

a) 0.001-0.10 wt .-? o 3-Amino-1 H-1,2,4-triazole,

b) 0.3-5% by weight of an alkyl- or alkaryl-phenylnaphthylamine in which the alkyl or alkaryl radical is 3-12

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Has carbon atoms,

c) 0.3-5% by weight of a dialkyldiphenylamine in which the Alkyl radicals have 4 - 12 carbon atoms and

d) 0.25-10% by weight of a tri-hydrocarbon phosphate, in which each hydrocarbon residue has 2-12 carbon atoms.

In a preferred composition, the lubricating oil formulation according to the invention contains the additives as well as the additives a) - d) as a further component

e) 0.01-2.5% by weight of an aramonium thiocyanate of the formula

R - N ^ 'Ro SCN ^v <ι. * -

^R 3

, in which R is an optionally amino-substituted hydrocarbon radical with 1-30 carbon atoms or a radical of the formula "R ₁

SCN ^κ ~ '

is, in which R ^ is a polymethylene radical with 2-4 C atoms is, where R ^, Rp and R, each hydrogen or one Represent a hydrocarbon radical with 1 - 30 carbon atoms.

Ester lubricating oil formulations having the above additive combination including an ammonium thiocyanate have improved resilience. This improvement is surprising in that it is found in known ester lubricating oil formulations to increase the load capacity ammonium thiocyanate in combination with cyclic amines or

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- Ό -

other additives can be used.

In a further preferred composition, the lubricating oil formulations according to the invention also contain the Additives a) - e) as a further component

f) 0.005-0.2% by weight of benzotriazole or anthranilamide.

Lubricating oil formulations with the last mentioned additive combination have exceptional oxidation / corrosion resistance and good load-bearing capacity at high Tooth flank loads. The new lubricating oil formulations according to the invention have exceptional heat and oxidation resistance, reduced formation of deposits and prevent pitting and pitting phenomena on and Corrosion of magnesium components. Because of these valuable properties, surprisingly, the lubricating oil formulations according to the invention the best commercially available synthetic ester lubricating oil formulations with regard to oxidation resistance and deposit reduction at least equivalent and have more a protective effect for magnesium against pitting or pitting.

The base oil of the lubricating oil formulations of the invention is a known ester, which is composed of a pentaerythritol or trimethylolpropane and a mixture of organic monocarboxylic acids is produced. Polypentaerythrites, use such as di-, tri- or tetrapentaerythritol.

The monocarboxylic acids that can be used to produce the ester base oils include the ge.radke.ttigen and branched-

zykloaxitmat.tscnen

chain aliphatic and aromatic acids and mixtures of these acids. The acids used have

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2-18, preferably 5-10 carbon atoms per molecule. Examples of suitable acids are: acetic, propionic, butyric, valeric, isovaleric, caproic acid, decanecarboxylic acid, Cyclohexanecarboxylic acid, naphthenic, benzoic acid, phenylacetic acid, t-butylacetic acid and 2-ethylhexanecarboxylic acid.

The acids are generally reacted in proportions which lead to a fully esterified pentaerythritol or trimethylolpropane, the preferred esters being the tetraesters of pentaerythritol. Examples of such commercially available tetraesters are: An example of this is the tetraester of pentaerythritol with caproic acid, which is available in the trade and which is produced from purified pentaerythritol and crude caproic acid, which also contains other Cf - CrfQ-eiribasic acids. Another suitable tetraester is prepared from a technical grade pentaerythritol and an acid mixture which contains 38 % valeric acid, 13 % 2-methylpentanecarboxylic acid, 32 % octanecarboxylic acid and 17 % pelargonic acids. Another suitable ester is the triester of trimethylolpropane with a mixture of monobasic acids containing 2 % valeric acid, 9 % caproic acid, 13 % heptanoic acid, 7 % octanoic acid, 3 % caprylic acid, 65 % pelargonic acid and 1 % capric acid. The triester with heptane carboxylic acid can also be used.

These ester base oils form the main component of the ready-to-use lubricating oil formulation of the invention. The proportion of the ester base oil in the formulation is generally 90-98% by weight.

The important 3-aminotriazole component a) of the invention Lubricating oil formulation corresponds to the following formula:

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N C-NH ₂

HC N

Ν '

It is particularly preferred in the formulation in a proportion of 0.001-0.10, preferably 0.002-0.02

Ο, from 003 to 0.008 wt -.% By weight.

The important alkyl- or alkaryl-phenylnaphthylamine component b) corresponds to the formulation according to the invention the formula:

R '

, in which R is an alkyl or alkaryl radical with 3-12 carbon atoms and R ^{f is} hydrogen or has the same meaning as R, which is a straight-chain or branched-chain alkyl radical, the tert, structure being preferred, or an alkaryl radical can. The Napb.thyla.min can be either an oC- or ß -naphthylamine. Active compounds of this class include N- (pt-octyl-phenyl) - - oL -naphthylamine, N- (4-cumylphenyl) -6-cumyl- ^ - ii-naphthylamine, N- (pt-octylphenyl) - / 5 -naphthylamine as well as the corresponding pt-dodecylphenyl-, pt-butylphenyl- and p-dodecylphenyl-1X- and - / 5> -naphthylamines. The preferred naphthylamines are those in which R is a tert. Is an alkyl radical with 6-10 carbon atoms. The preferred concentration of the

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Additive component b) is 0.5-2.5% by weight.

As a further important component c) contain those according to the invention Lubricating oil formulations a dialkyldiphenylamine. These compounds correspond to the formula:

, in which R is an alkyl radical with 4-12 C atoms. Suitable Alkyl amines include dioctyl diphenyl amine and similar compounds. The preferred class of dialkyldiphenylamines are those in which R is an alkyl radical with 8-10 carbon atoms. The preferred connection is Dioctyldiphenylamine, and the preferred concentration is 0.5-2.0 wt. #.

Component d) of the lubricating oil formulations according to the invention is a tri-hydrocarbon phosphate with the formula (RO) JPO, in which R is a hydrocarbon radical, for example an alkyl, aryl, alkaryl, cycloalkyl or aralkyl group or a mixture thereof-, represents and 2-12, before- · preferably has 4-8 carbon atoms. The effective compounds include Tricresy! Phosphate, Cresyldipheny! Phosphate, Triphenyl phosphate, tributyl phosphate, tri- (2-ethylhexyl) phosphate and tricyclohexyl phosphate. These connections should preferably be contained in the lubricating oil formulation in a concentration of 0.5-5% by weight.

A preferred composition of the lubricating oil formulation according to the invention contains as 5th component e) a

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Ammonium thiocyanate compound of the formula:

RN ⁺ -R ₉ "SCN"

^R 3

, in which R is an optionally amino-substituted hydrocarbon radical with 1-30 carbon atoms or a radical with the formula:

N ⁺ - R ₂

- Rj. - N ⁺ - Ro SCN "

is, in which R ^ a bridging Polytnethylenrest with 2-4 carbon atoms and R ^, Rp and R, alkyl, cycloalkyl, Represent aryl groups or mixtures thereof. In the preferred compounds, R is aliphatic Hydrocarbon radical with 8-22 carbon atoms and R,., Rp and R ^ are each "hydrogen or aliphatic hydrocarbon radicals with 1-4 carbon atoms.

The effective ammonium thiocyanates include bis (2-ethylhexyl), tert-C ₁₈ -C ₂₂ -alkyl, sec-C ^ -C ^ -alky! -, tert-octyl, n-dodecyl, tert .-C ^ 2Γ ^ Λ 4 " ^Alkvl ~» nonyl, lauryl, stearyl, dimethyl-2-ethylhexyl, dibutyl-octylammonium thiocyanate and N, N'-di- (t-octyl) -1,2-ethanediammonium thiocyanate and Ν, Ν ¹ -Di-Ct-C ^ QC ₂₂ -alkyl) -1,2-ethanediammonium thiocyanate The ammonium thiocyanate component should normally be in a concentration of 0.01-2.5, preferably 0.05-0.5 Weight .-? £ are used.

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The preferred concentration of the 3-amino-1H-1,2,4-triazoles in these lubricating oil formulations is 0.005-0.05% by weight.

The lubricating oil formulations according to the invention can be used as constituent f) Contain benzotriazole or anthranilamide. This ingredient is used in the lubricating oil formulation used in a proportion of 0.005-0.2, preferably 0.02-0.1 wt.

The invention is to be explained further in the following examples.

example 1

A number of lubricating oil formulations have been prepared, the compositions of which are based on the following Table I can be seen and the properties of these formulations were set.

The oxidation and corrosion resistance of these lubricating oil formulations was based on the standard test No. 791s (published December 31, 1961), which, however, has to be fulfilled modified to the Pratt and Whitney 521B specification. The bath temperature was at 218.3 ± 0.6 ° C (instead of 121.1 ° C) and the test was over a period of 48 hours (instead of 168 Hours in the original test).

The ester base oils used to make the formulations consisted of pentaerythritol, which contained a small amount of dipentaerythritol, and a mixture of fatty acids was esterified.

The base oil A was a technical pentaerythritol ester, the

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prepared from the following carboxylic acid mixture (in mol%) was:

ic ₅ 8 ± 3 96 η - Cc
5 23 - 5 η - C ₆ 20 ί 5 η - Cj 27 ± 5 η - C ₈
η - C ₀ 7 ^ 3
16 ± 3

This base oil A has the following properties:

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cSt. ⁰ C at 98 - 13 - 5.01 2423458 Il Il 37 , 9 ° C 25.6 Viscosity, η It -40 , 8 ⁰ C 7005 It Viscosity index ⁰ C 140 It Flash point, 268.3

Base oil B was similar to base oil A, but existed
from pentaerythritol esters obtained from the following mixture
of carboxylic acids (in mol%) were made:

i - C ₅ 12 ± 3

η - C ₅ 28 ί 5

η - C ₆ 11 i 5-

n - C ₇ 17 + 5

η - C ₈ 20 - 5

η - C _g 12 ± 5

η - C..Q 1 Max.

Table I gives the compositions of the ester lubricating oil formulations, which contained the constituents a) - d), and Table II those obtained with these formulations Test results again.

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Table I.

Composition 1 2 34 5 678 910

of the formulations,% by weight

Base oil A 95.495 95.45 95.4 - - 95.5 95.5 95.45 95.475 -

Base oil B - - - 95.49 95.495 -. - - - 95.48

p ₁ p'-di-tert.-
^ octyl-diphenyloamine 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

^ Tricresyl phosphate 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0

^ naphthylamine 1v, 5 1.5 - 1.5 1.5 1.5 - 1.5 1.5 1.5

⁰⁰ N- (4-cumylphenyl) <£ 6-cumyl-2-

naphthylamine - - 1.5 - - - 1.5 -

3-amino-1 H-

1,2,4-triazole 0.005 0.05 0.1 0.01 0.005 - - - - 0.02

Benzotriazole - - - - - - - 0.05

Quinizarine - - - - - - - - 0.025

Table II

Test lubricating oil - results of the oxidation / corrosion test (48 h at 218.3 - 0.6 ⁰ C)

No. . Formulation No. ■

Metal weight _? "Viscous.-To-Increase in

change *) mg / em. would take (37.8 C) total acid number Cu Mg

1 . 1 -0.02 0 21.1 1.57

£ 2 2 -0.04 -0.02 '-22.4 1.05

S 3 3 -0.04 0 19.1 x 1.42.

2 4 4 -0.09 0 23.8 1> 68

^ 5 5 -0.06 0 21.6 1.74 -! »

S 6 6 -1.35 -0.04 22.2 2.10 '

^ 7 7 - -2.13 '-0.04 28.2 2.60

*) The weight changes of all other metals (Fe, Al, Ag, Ti) were within the specifications

Formulations No. 1-'5 in Table I and Tests No. 1-5 in Table II relate to the ester lubricating oil formulations according to the invention. These all passed the specified oxidation / corrosion test.

Formulation Nos. 6 and 7 were of similar composition but did not contain any aminotriazole. These lubricating oil formulations caused unduly severe copper corrosion and failed this test.

The lubricating oil formulations according to the invention were also tested with other ester lubricating oils in the Erdco bearing test, Type 1.5 compared. This test determines the cleanliness of the lubricating oil in operation in which the deposits formed are measured. Furthermore, the lubricating oil consumption is important, which is in the specification USA Marine MIL-L-23699 B. The results of a 100 hour test are in the following Table III compiled.

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Tabel

III

test
No. Lubricating oil (Negat.)
Grading Erco storage test Total-
SZ
(Rise) Type 1.5 Oil consumption
(ml) 8th formulation No.5 ¹ ^ 24 Viscous,
increasing
(37.8OC) 1.22 filter
deposit
gen X 9.) 1087 9 10 ^ΐ; 26th 19.4 1.20 0.1951 1052 to 10 A ² ^ 34.5 22.0 0.78 0.225 1678 00 11 · B ² ) 23 18.5 1.30 0.466 1700 £ ->
CD 12th ρ » 41 23.0 0.90 0.472 2025 O 24.0 • 0.253 00
CO Specification limit 80 max 2 max 2000 max ' co -5 to
+25 3 max

1) From Table I.

2) Lubricating oils A, B and C were commercially available synthetic. Ester lubricating oils for gas turbines

Table III shows that the lubricating oils used in tests nos. 8 and 9 are 40 and 60% better than the lubricating oils used in tests nos. 10 and 12 with regard to the (negative) marks for deposits and the Tests 10-12 lubricating oils are superior in oil consumption. Tests Nos. 8 and 9 showed remarkably low filter deposits; Tests Nos. 10 and 11 showed these were about 140 % higher. Test No. 12, in which the commercial lubricating oil C was used, produced about 30 % more filter deposits than in Test No. 8, and the oil consumption was 2025 ml, which exceeded the maximum value of 2000 ml of the stated US marine specification.

The lubricating oil formulations were further examined in the Alcor high temperature deposit test. This test is included in the (proposed) US Marine Specification XAS-2354. The deposits are determined as pipe deposits in a tubular column and as filter deposits. The maximum permissible pipe deposit is 15.0 mg. The temperature of the tubular column was maintained at 288 ⁰ C. The results of this test are summarized in Table IV:

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Table IV

test
No. . Lubricating oil
formulation
No. Alcor - high temperature - deposit test Filter deposits, mg 13th 4th Pipe deposits, mg. , Tube grading 25.4 14th 5 ■ 3.7 ' 3.0 39 15th 8th 2.8 1.8 • 65.7 r "Ί
CD 16 A ¹ > 11.1 11.0 47.7 OO 17th B ¹ ' 3.4 1.7 69.6 -i CD 18th 2.4 1.2 58 *? / 083 16.5 14.0

1) The lubricating oils A, · B and C were commercially available synthetic. Ester lubricating oils for Gas turbine engines

Tests Nos. 13 and 14 in Table IV were performed with the Lubricating oil formulations of the invention were made giving pipe deposits of 3.7 and 2.8 mg, respectively, and filter deposits of 25.4 and 39 mg, respectively. That in test Ntf. 15 The lubricating oil used contained benzotriazole as a corrosion inhibitor and gave pipe deposits of 11.1 mg. The commercial lubricating oil C exceeded the specification limit for pipe fouling, and all of the commercial lubricating oils showed filter fouling that was significant greater than that of the lubricating oil formulations according to the invention was. The Alcor test thus shows an improved behavior of the formulations according to the invention with regard to these deposits.

Example 2.

Lubricating oil formulations according to the invention which contained the ammonium thiocyanate component e) were examined for their load-bearing capacity in the IAE transmission test, which is described in specification XAS-2354 of the US Navy and in British DERD-2497. In accordance with the test method 166 of the Institute of Petroleum, this test was conducted at a speed of 6000 per minute and at a temperature of 110 ⁰ C.

The ester base oil used was Example 1 base oil and had the following properties:

Viscosity, cSt. ⁰ C at 98 , 9 "C 5.01 Il Il Il 37 , 8 ⁰ C 25.6 Il Il η -40 ⁰ C 7005 Viscosity index 140 Flash point, 268.3

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This base oil B was initially added at around 1.0% by weight ρ, ρ'-di-tert-octyldiphenylamine, 1.5% by weight of N- (4-tert-octylphenyl) -oi.-naphthylamine and 2.0 wt% tricresyl phosphate mixed. This base oil blend were a Ammonium thiocyanate and / or 3-amino-1H-1,2,4-triazole added. Table V shows the composition of the mixtures produced and their load-bearing capacity.

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Table V

Formulation together- IAE - load bearing - test IAE maximum load, kg

No settlement

Salt of thiocyanate-benzo-3-amino-1H-acid, conc.,% By weight triazole 1,2,4-triazole IT 'weight-96

1-1 base oil mixture ^ " ^c i8-22 ~

Monium thiocyanate 0.1 - 26.3

caj monium thiocyanate 0.1 0.03 --- 26.3

CO '

- y? · · 18— ??

monium thiocyanate 0.1-0.03 30.8

As Table V shows, Formulation II-2 an addition of benzotriazole with no effect on the IAE maximum load of 26.3 kg.

In contrast, formulation II-3 increases by adding the triazole compound increases this maximum load to 30.8 kg. This improvement in load carrying capacity was surprising.

Example 3

There have been a few formulations of oil formulations that contain the ingredient f) contained, produced. The base oil was again B of Example 1. Table VI below gives the Composition of lubricating oil formulations according to the invention and comparative lubricating oils again. Therein the formulations III-1 to III-4 are according to the invention, and the Formulations III-5 to III-9 are comparative lubricating oils.

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Table formulation no.

Additive, % by weight III-1 IU-Z ilI-3 1II-4, .II-5 111-6 iII-7 1II-8 LU-9

ρ, p'-di-tert-octyldi

phenylamine 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

coN ~ (4-tert.-octylpheoo ny3 ^ -1-naphthylamine

Tricresyl phosphate

^ t-octylamine salt of
^ j thiocyanic acid

CO-

Priming JMT Salt *) der
Thiocyanic acid

Benzotriazole

Anthranilamide - 0.05 - 0.05 - - - - 0.05

3-Amino-1HTi, 2,4-triazoltf, 03 0.03 0.03 i?, 03 0.03 - - 0.03 base oil 1 95.37 95.37 95.32 95.32 95.37 95.4 95.35 95.47 95.35

*) t-Cj ^ -C _1. -Alkylammoniumthiocyanat,

5 ι, 5 2, 5 1, 5 I. 1 1.5 1 , 5 1.5 1, 5 1.5 2, O 2, O m 0 2, 0 2.0 2 , 0 2.0 2, 0 2.0 O ₁ 05 ο, 05 - - - ■ m - - m 1 Λ 0.1 0 ,1 0.1 m * 0.1 05 m 05 - - 0.05 m P. -

The lubricating oils indicated in Table VI were tested in the oxidation / corrosion test (at 218.3 ⁰ C, 48 h). The results are given in Table VII.

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Tabel

VII

Metal-weighted change, mg / cm

Cu O Fe co OO Al ■ E- CO O Mg CO
OO Ag CX)

Oxidation / corrosion test (218.3 ⁰ C / 48 h) -

• Ti

% Increase in viscosity (37.8 ⁰ C)
Overall acid number increase

Formulation no.

iU -1 III-2

m-4

tH-5

iII-6

III-7

iU-8 III-9

09 -O, 09 rO, 09 -O, 09 /•1, 69 -2, 83 ■ · 4th "H 28 -0.06 -3.63 O 0 40, 02 O 0 40, 05 8th 0 -0.03 0 O 0 O O 0 40, 06 0 -0.03 40.02 ■ o, 03 0 O O -O, 02 40, 11 -O, 11 - -0.03 +0.06 O 0 O -O, 02 -O, 05- 0 -O, , 03 -0.07 -0.04 O 0 40, 02 0 -O, , 02 0 0 -0.06 -0.02 19 2 18 7th 22 5 21 0 28, 4th 31, 30th ,8th 18.2 26.6 1" 2 1" 0 2 H 0 5 1, 2, 15th 1.3 I, S IK)
it> -P "
r> ro
I Cx)
cn
OO

As can be seen from this, formulations III-1 show to III-4 according to the invention have a high Degree of oxidation and corrosion resistance. In contrast, the formulations III-5, III-6, III-7 and III-9 excessive copper corrosion, which exceeds the maximum value of the 521-C specification of 0.3 mg / cm metal · «- weight change far exceeded.

The lubricating oil formulations according to the invention were tested for their load-bearing capacity with other lubricating oils in the IAE transmission test examined. Lubricating oils with a maximum load of 20.4 kg or less are considered to be insufficiently resilient considered. Lubricating oils with a maximum load of 22.7 - 27.2 kg have a medium load capacity. Lubricating oils with a maximum load of 27.2 kg and more are considered to be highly resilient. The results of this Comparative tests are shown in Table VIII.

Table VIII

Resilience in the IAE transmission test

Formulation No. Maximum load, kg

. (60OO rpm, 110 ⁰ C)

1 29.4

ΙΙΪ-2 29.4

III-3 28.6

III-4. 30.8

III-5 30.8

III-6 26.3

III-7 · 26.3 III-8 '20, 4

III-9 - 26.3

As this test shows, all have lubricating oil formulations the invention high load capacities. From the comparison

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For lubricating oils, this only applies to formulation III-5. The comparative formulations III-6, III-7 and III-9 show medium and III-8 insufficient load capacities.

The above comparisons therefore indicate that the lubricating oil formulations of the invention are exceptional Oxidation and corrosion resistance at high temperatures and also one for high performance turbine engines have the necessary high resilience.

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Claims (7)

Claims 1) Synthetic lubricating oil formulation as the main ingredient a lubricating aliphatic ester base oil, obtained by reacting pentaerythritol or Trimethylolpropane with a monocarboxylic acid of 2-18 carbon atoms, contains, labeled through the following combination of additives: a) 0.001-0.10% by weight 3-amino-1H-1,2,4-triazole, b) 0.3 to 5 wt .-% in which the alkyl or alkaryl radical 3-12 carbon atoms having an alkyl or alkaryl phenyl naphthylamine \. c) 0.3-5% by weight of a dialkyldiphenylamine in which the Alkyl radicals have 4-12 carbon atoms, and d) 0.25-10% by weight of a tri-hydrocarbon phosphate, in which each hydrocarbon residue has 2-12 carbon atoms. 2) lubricating oil formulation according to claim "1, characterized in that that in addition to the additives a) - d) it is a further component e) 0.01-2.5% by weight of an ammonium thiocyanate of the formula R - NJti R ₂ ^ ") 409849 / 0838- contains, in which R is an optionally amino-substituted hydrocarbon radical with 1-30 carbon atoms or a radical of the formula R ₂ SCH (-) «3 in which R ^ is a polymethylene radical with 2-4 C atoms, where R «j, R ₂ and R * are each hydrogen or a hydrocarbon radical with 1-30 C atoms
represent. 3) lubricating oil formulation according to claim 2, characterized in that that besides the additives a) - e) they are further
component f) 0.005-0.2% by weight of benzotriazole or anthranilamide contains. 4) Lubricating oil formulation according to one of claims 1 - 3 »characterized in that that the monocarboxylic acid residue of the ester base oil has 5 - 10 carbon atoms. 5) lubricating oil formulation according to one of claims 1 - 4, characterized, that it contains 90-98% by weight of the ester base oil. 6) lubricating oil formulation according to any one of claims 1-5, characterized in, that it contains the following proportions of additives a) to f): 409849/0838 a) 0.002. - 0.02, in particular 0.003-0.008 wt .- #, b) 0.5 - 2.5, • c) 0.5-2.0% by weight, d) 0.5 - 5.0 % by weight, e) 0.05-0.5% by weight, and f) 0.005-0.2, in particular 0.02-0.1% by weight. 7) Lubricating oil formulation according to any one of claims 1-6, characterized in that in additive e) R is an aliphatic hydrocarbon radical with 8-22 carbon atoms and R ₁ , R ₂ and R ₅ each have hydrogen or aliphatic hydrocarbon radicals 1-4 carbon atoms are. 409849/0838