RU2387703C2 - Lubricant composition for aviation power installations - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to lubricant compositions for aviation power installations and more specifically: for gas-turbine engines of aeroplanes, main reduction gears and heavy loaded transmission assemblies and the oil system of the turbocharger of helicopter engines. The composition contains the following in wt %: bis [4-(1,1,3-tetramethylbutyl)phenyl]amine 1-3; C₇-C₉ alkyl ether 3,5-bis-(1,1 dimethylethyl)-4-hydroxybenzo propanoic acid 0.5-4; N,N-bis-(2ethylhexyl)-4 methyl-1H-benzotriazole-1-methylamine 0.05-0.25; tricresyl phosphate 1-5; 3-(bis-isobutoxy-thiophosphoryl sulphanyl)-2-methyl-propanoic acid 0.05-1.5; ester of neopentylpolyol and fatty acids C₅ - C₁₀ - the rest.

EFFECT: improved anticorrosion properties at high temperature (more than 200°C) with retention of lubricating power.

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Description

The invention relates to lubricant compositions for power plants of aircraft, namely for gas turbine engines of aircraft, main gearboxes and heavily loaded transmission units and oil systems of a turbocharger of a helicopter engine with improved anti-corrosion and lubricating properties, in particular anti-wear.

Known lubricating oil of gas turbines (RU 2185423 C1, 2002) of the following composition in wt.%:

- thermostable diisooctylsebacinate 10.0-15.0 - 2.6 ditretbutyl paracresol 0.5-3.0 - n, n'-dinonyldiphenylamine or mixture of butyl-n-octyldiphenylamines 0.2-0.5 - tricresyl phosphate or diphenyl paratretbutyl phenyl phosphate 1.0-3.0 - benzotriazole 0.005-0.1 - base oil (synthetic polyalphaolefin) - the rest

The disadvantage of this oil is unsatisfactory lubricating properties.

The known composition of lubricating oil for helicopters (SU 120626 A, 1958) of the following composition, wt.%:

- ether of polyhydric alcohols and monobasic fatty acids, for example triethylene glycol ether and fatty acids C ₇ -C ₉ as a base oil 67.0-75.0 - esterified polymerized castor oil as a thickener 25.0-33.0 - mercaptobenzothiazole as antiwear additives 1-1.5 - paraoxydiphenylamine as antioxidant additives 0.3-0.5

The disadvantage of this oil is unsatisfactory anti-corrosion properties at 200 ° C and evaporation at 250 ° C.

The closest in composition and achieved result to the proposed lubricating composition is lubricating oil for gearboxes of aircraft (RU 2322481, publ. 04/20/2008) of the following composition, wt.%:

bis [4- (1,1,3,3-tetramethylbutyl) phenyl] amine 1.0-3.0 - C ₇ -C ₉ alkyl ether 3,5-bis- (1,1-dimethylethyl) -4- hydroxybenzopropanoic acid 0.5-4.0 - N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole - -1-methylamine 0.05-0.25 - mercaptobenzothiazole 1.0-2.4 pentaerythritol ester and fatty acids C ₅ -C ₁₀ rest

The lubricating oil according to this invention has a number of positive properties, in particular the best lubricating properties in comparison with other oils, which makes it possible to use it as a single for engines and helicopter gearboxes at a maximum oil temperature at the engine outlet up to 175 ° C.

At the same time, the experience of operating helicopters in this oil showed that it has a significant drawback associated with the tendency to oxidize EP additives captax (2-mer-captobenzothiazole) with its conversion to altax (dithiobenzothiazole) - a compound poorly soluble in oil. Forming a jelly-like mass with the products of oil oxidation, in the autumn-winter and spring-winter transition periods in some cases altax can clog oil filters, nozzles, pipelines with a small cross-section, radiators, etc. Although this precipitate quickly dissolves after starting the engine and its particles can be forced through a filter grid, the likelihood of its re-formation on oil filters with significant cooling of the oil is not excluded. Therefore, in such cases, a complete drainage of oil from the engine and gearbox and its replacement with fresh is required.

Due to the presence of mercaptan sulfur in captax, which has a high reactivity, the oil is also characterized by high corrosiveness in relation to some structural materials (copper, copper and magnesium alloys, a silver coating on bearing cages) and causes increased wear of rubbing surfaces (d and> 0.5 mm).

Known synthetic oil PTS-225 (TU 38.401-58-1-90) on esters of pentaerythritol and FFA C ₅ -C ₉ that meets the requirements of the US specification MIL-PRF 23699F.

PTS-225 oil, having high operational properties, causes increased corrosion on copper at 225 ° C 2.5 mg / cm ³ (GOST 23797) and corrosion of the oxidized alloy ML-10 - 18.4 g / m ² . (Domestic and foreign fuels and lubricants. L.S. Yanovsky, F.M. Galimov, V.A. Alyaev. Pages 84-86.) The oil was developed using a complex set of various additives, the technology for its preparation is complex, and its industrial production is absent.

The technical result of the invention is to improve the anticorrosive properties of the lubricant composition at 225 ° C and when exposed to metals and galvanic coatings while maintaining high lubricity of the composition.

To achieve the technical result, a lubricating composition for aeronautical power plants comprising an ester of neopentylpolyol and C ₅ -C ₁₀ fatty acids, as well as bis [4- (1,1,3-tetramethylbutyl) phenyl] amine and C ₇ -C ₉ 3,5-bis- (1,1-dimethylethyl) -4-hydroxybenzopropanoic acid alkyl ester as antioxidant additives and N, N-bis- (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine corrosion inhibitors, antiwear and extreme pressure additives, in accordance with the invention as antiwear and anti ozadirnyh additive composition comprises tricresyl phosphate and 3- (bis-isobutoxy-tiofosforilsulfanil) -2-metipropionovuyu acid with the following ratio of components, wt.%:

bis [4- (1,1,3-tetramethylbutyl) phenyl] amine 1.0-3.0 C ₇ -C ₉ alkyl ester 3,5-bis- (1,1-dimethylethyl) -4- hydroxybenzopropanoic acid 0.5-4.0 N, N-bis- (2-ethylhexyl) -4-methyl-1H-benzotriazole- 1-methylamine 0.05-0.25 tricresyl phosphate 1.0-5.0 3- (bis-isobutoxy-thiophosphorylsulfanyl) - 2-metipropionic acid 0.05-1.5 neopentyl polyol and fatty ester acids C ₅ -C ₁₀ rest

A lubricating composition is known in the art containing triaryl phosphate, including tricresyl phosphate, and dialkyl dithiophosphate, in particular 3- (bis-isobutoxy-thiophosphoryl sulfanyl) -2-metipropionic acid (WO 02/53687 A2, 11, as anti-wear and extreme pressure additives). 2002). However, high anticorrosion properties at temperatures above 200 ° C have not been confirmed for these lubricant compositions.

In examples 1-7, the compositions of lubricating compositions and the results of their tests are presented (Tables 1 and 2).

As can be seen from the data in table 2, composition No. 2 does not provide the required level of Pk. Composition No. 6 causes increased corrosion of copper during oxidation according to GOST 23797 and increased corrosion of oxidized magnesium alloy - 12.1 g / cm ³ . The compositions according to examples No. 1, 3, 5 and 7 retain their anticorrosion properties within the established standards, allow to increase the critical load and reduce the rate of wear.

The joint use of additives in the composition of the lubricant composition: 3- (bis-isobutoxythiophosphoryl-sulfanyl) -2-methyl-propionic acid and tricresylphosphate together with other components eliminates the loss of altax under operating conditions, improves the anticorrosion properties and tribological characteristics of the lubricant composition at temperatures above 200 ° C.

The following ingredients were used to prepare the lubricant composition:

- as a corrosion inhibitor of the ester of dialkyl dithiophosphate methylpropionic acid contains 3- (bis-isobutoxythiophosphoryl sulfanyl) -2-methylpropionic acid, which is a yellow liquid with a density of 1.06 g / cm ³ , acid number 190 mg KOH / g and sulfur content of at least 17% with tests according to STO 93407622-006-2008 and specification P8-3662 (analytical method KVS-3662).

- as an antiwear additive - tricresyl phosphate according to GOST 5728.

In addition, [4- (1,1,3,3-tetramethylbutyl) phenyl] amine is introduced as antioxidant additives, which is a white to yellow crystalline powder with a density of 1.02 g / cm ² , a flash point in a closed crucible above 150 ° C with tests according to STO 93407622-002-2007 and specification PS-1551 (analytical method KVS-1551) and compound C ₇ -C ₉ , alkyl ether 3,5-bis- (1,1 dimethylethyl) -4- hydroxybenzopropanoic acid, a yellow to brown liquid with a melting point below minus 30 ° C, a flash point above 150 ° C, a self-ignition temperature I am above 365 ° C with tests according to 93407622-002-2007 and according to specification IN 2244 (analytical method KVS-506/1).

A toluutriazole derivative is also introduced into the oil in the form of N, N-bis- (2 ethylhexyl) -4methyl-1H-benzotriazole-1-methylamine - a colorless liquid with a boiling point of 271 ° C, density 0.94-0.96 g / cm ³ , flash point above 280 ° C with tests according to STO 93407622-002-2007 and specification PS-184210 (analytical method 184210).

The base oil used is an ester of pentaerythritol and monobasic fatty acids C ₅ -C ₁₀ with a viscosity at 100 ° C of at least 4.8 mm ² / s, pour point not lower than minus 60 ° C, flash point in an open crucible not lower than 255 ° C, acid number not more than 0.05 mg KOH / g with tests according to STO

93407622-001-2007 or

ester of trimethylolpropane and monobasic fatty acids C ₅ -C ₁₀ with a viscosity at 100 ° C of at least 4.0 mm ² / s, pour point not lower than minus 60 ° C, flash point in an open crucible not lower than 248 ° C, no acid number more than 0.05 mg KOH / g with tests according to STO 93407622-007-2008.

A lubricant composition was prepared by dissolving the components in a basic ether with heating to 70-80 ° C with stirring, followed by cooling and filtration. The technological scheme for the manufacture of lubricating compositions corresponded to the technology recommended for subsequent industrial production.

Table 1 Lubricant Compositions No. Components Lubricant Compositions No. 1 Number 2 Number 3 Number 4 Number 5 Number 6 one bis [4- (1,1,3,3-tetramethylbutyl) phenyl] amine 1,0 2.0 1,0 1.8 3.0 1,5 2 C ₇ -C ₉ , 3,5-bis (1,1-dimethyl ethyl) -4-hydroxybenzo-propanoic acid alkyl ester 4.0 2.2 1,5 3,1 1,0 1.8 3 N, N-bis- (2 ethylhexyl) -4 methyl-1H-benzotriazole-1-methylamine 0.05 0.10 0.125 0.20 0.25 0.165 four 3- (bis-isobutoxy-thiophosphorylsulfanyl) -2-methylpropionic acid 0.1 1,5 0.05 1,0 1,2 0.08 5. tricresyl phosphate 5,0 1,5 1,0 3.0 4.0 2.5 6. C ₅ -C ₁₀ fatty acid pentaerythritol ester 89.85 92.70 - - 90.55 - 7. C ₅ -C ₁₀ fatty acid trimethylolpropane ester - - 96,325 90.90 - 93,955

table 2 The test results of the proposed compositions Lubricant Compositions The name of indicators No. 1 Number 2 Number 3 Number 4 Number 5 Number 6 Prototype 1. Anticorrosion properties under oxidation conditions at 225 ° C, 50 hours (GOST 23797). Weight indicator of corrosion on copper plates Not withstand. Abundant
sedimentation M-1 or M-2 (GOST 495), mg / cm ³ 0.08 0.10 Ots. 0.06 0,03 0.05 2. Corrosion aggressiveness for 100 hours (175 ° С - 10 hours, 200 ° С - 80 hours, 225 ° С - 10 hours) in contact with metals and Not withstand. electroplated coatings, weight loss, oil / vapors, g / cm ³ : - magnesium alloy ML-10 1.1 / 0.9 1.3 / 0.95 0.8 / 0 1.1 / 1.0 1.1 / 0.9 0.9 / 0.3 3. Tribological characteristics on the FWM at 20 ° C: - critical load (Rk) 106 126 94 one hundred 119 one hundred 89 - diameter of the wear spot (Di), mm, axial load 196 N 0.33 0.36 0.33 0.33 0.35 0.33 0.50-0.54

Claims (1)

Lubricating composition for aeronautical power plants, including C ₅ -C ₁₀ fatty acid ester of neopentylpolyol and bis [4- (1,1,3-tetramethylbutyl) phenyl] amine and C ₇ -C ₉ alkyl ester 3,5 -bis- (1,1 dimethylethyl) -4-hydroxybenzopropanoic acid as antioxidant additives and N, N-bis- (2 ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine as a corrosion inhibitor, anti-wear and extreme pressure additives, characterized in that, as antiwear and extreme pressure additives, the composition contains tricresyl phosphate and 3- (b c-isobutoxy-tiofosforilsulfanil) -2-methylpropionic acid with the following ratio of components, wt.%:
Bis [4- (1,1,3-tetramethylbutyl) phenyl] amine 1.0-3.0 C ₇ -C ₉ Alkyl ether 3,5-bis- (1,1 dimethylethyl) - -4-hydroxybenzopropanoic acid 0.5-4.0 N, N-Bis- (2 ethylhexyl) -4 methyl-1H-benzotriazole-1- methylamine 0.05-0.25 Tricresyl phosphate 1.0-5.0 3- (Bis-isobutoxy-thiophosphorylsulfanyl) -2- methylpropionic acid 0.05-1.5
Neopentylpolyol ester and
fatty acids C ₅ -C ₁₀ Rest