RU2476586C2 - Lubricant composition of noncombustible working fluid for aviation equipment - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a lubricant composition of noncombustible working (hydraulic) fluid which contains a base which is based on a mixture of phosphoric esters, containing 67.0-73.0 wt % tributyl phosphate, 19.0-25.0 wt % dibutyl phenyl phosphate and 7.0-9.0 wt % triisobutyl phosphate, and a synergetic mixture of additives. The composition of additives includes a thickener additive - polybutyl methacrylate with molecular weight of 5000-6500, epoxy resin, an anticorrosion additive - Chromoxan B, a stabilising additive - Irganox 1010 FF, an oxidation inhibitor - Irganox L 57, a corrosion inhibitor - 1,2,3-benzotriazole, a metal passivating agent - Amino O and a dye, in defined ratios.

EFFECT: obtaining a lubricant composition of noncombustible working fluid with high explosion and fire safety for aviation equipment, which provides stable operation of hydraulic systems.

1 cl, 4 tbl

Description

The invention relates to the creation of explosion-proof working (hydraulic) fluid, intended for use in hydraulic systems of aviation, aircraft devices, in particular aircraft with high stable properties in a wide temperature range from sub-zero temperatures to plus temperatures, in particular up to 150 ° C.

Strict requirements are imposed on aviation working fluids: they must be flame retardant, thermally and thermally oxidatively stable, and not cause damage and wear to metal parts in contact with the liquid due to the aerosol activity of the liquid.

Known aviation explosion-proof working fluid for aircraft hydraulic systems, having the composition, wt.% (US 3976585, 1976):

Epoxy compound 0.1-10.0 Polyalkyl methacrylate 2.0-20.0 Water 0.2 Dibutyl phenyl phosphate Up to 100

As the epoxy compound, alkyl-3,4-epoxycyclohexane is used.

The specified composition has high fire resistance. The disadvantage of this composition is the low thermal stability: the liquid can withstand without deterioration the properties of 200 hours of temperature control at 125 ° C; over 200 hours the acid number rises to 0.5 mg KOH, g, corrosion of copper reaches 0.4 mg / cm ³ .

In addition, the disadvantage of this composition is its high erosion activity, as evidenced by the low value of conductivity.

From US 4076642, 1978, a working fluid for aircraft hydraulic systems is known having the composition: epoxy compound — 0.1-0.5 wt.%, Polyalkyl methacrylate — 2.0-20.0 wt.%, Water, dibutyl phenyl phosphate up to 100%.

As the epoxy compound, 2-ethylhexyl-5,6-epoxy-1,4-ethylenecyclohexane-2-carboxylate is used. Its disadvantage is: low thermal stability and high erosion activity. These shortcomings limit the life of the fluid, as well as hydraulic units in contact with the fluid.

FROM RU 2009185, 03.15.1994, another working fluid used in hydraulic systems of aircraft is known, which contains, wt.%: Epoxy compound (resin UP-632) - 0.5-5.0, polybutyl methacrylate - 5.0-7, 5, 4-trifluoromethylperfluoro-3,6-dioxaoctanesulfonate potassium 0.05-0.2, anthraquinone dye 0.0015-0.0025, the rest dibutylphenylphosphate.

The specified working fluid does not provide operability in a wide temperature range from minus (from minus 60 ° C) to plus temperatures of about 150 ° C and the stability of its main characteristics during operation.

Functional fluids used in aviation hydraulic systems and consisting of 50% trialkyl phosphate (50-75%) and at least one aryl compound (5-20%) are known from MX 2007005385, July 9, 2007; its typical composition is the following - about 60% tributyl phosphate, about 10% triisobutyl phosphate and 10% isopropylate naphthalene, and from 10 to 20% additives, such as viscosity index improver (poly (butyl) hexyl methacrylate), Ionol antioxidant, 1.3 antioxidant 5-trimethyl1-2,4,6-tris (3,5-di-tert-butylhydroxyphenyl) benzene; dioctyl diphenylamine, 1,2-di (phenylthio) ethane, a copper corrosion inhibitor, 2-ethylhexylepoxycyclohexylcarboxylate MCS-1562 and other additives. This composition is fireproof, but very difficult in composition and preparation due to its many different additives. The composition does not have stable characteristics in a wide temperature range from minus (from minus 60 ° C) to plus (up to plus 150 ° C).

The technical task of the claimed invention is to obtain a lubricating composition of a non-combustible working (hydraulic) liquid with increased explosion and fire safety for aircraft, ensuring stable operation of hydraulic systems in the temperature range from minus 60 ° C to plus 150 ° C, with improved other properties.

The stated technical problem is achieved in that the lubricating composition of a non-combustible working fluid for aviation contains a base base based on a mixture of phosphoric acid esters containing 67.0-73.0 wt.% Tributyl phosphate, 19.0-25.0 wt.% Dibutyl phenyl phosphate and 7 , 0-9.0 wt.% Triisobutyl phosphate, thickening additive polybutyl methacrylate with a molecular weight of 5000-6500, epoxy resin, antioxidant additive Agidol 1 2,6-di-tert-butylparacresol, anti-corrosion additive Chromoxane B perfluoro-4-methyl-3,6- potassium dioxo octensulfonate stabilizing additive ku Irganox 1010FF tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) pentaerythritol, oxidation inhibitor Irganox L57 product of the reaction of N-phenylbenzylamine with 2,4,4-trimethylpentene, corrosion inhibitor 1,2,3- benzotriazole, metal passivator Amino O 2- (8-heptadecenyl) -4,5-dihydro-1H-imidazole-1-ethanol, organic fat-soluble violet anthraquinone dye in the following ratio of starting components, wt.%:

thickening additive polybutyl methacrylate with mol. weighing 5000-6500  6.0-9.0 epoxy resin  6.1-6.5 Chromoxane B above  0.06-0.1 the above additive Agidol 1  0.025-0.35 stabilizing additive Irganox 1010FF  0.45-0.55 oxidation inhibitor Irganox L 57  0.45-0.55 1,2,3-benzotriazole corrosion inhibitor  0.008-0.012 the above passivator Amino O  0.008-0.012 the specified base mixture of phosphoric esters acid the rest is up to 100% the above dye 0,0008-0,0012 (over 100%)

In the claimed composition, epoxy resins (diepoxides) of the type of epoxy resin Araldit-SU 179-1 CH or ERa-4221 (Union Carbay firm), in particular the epoxy compound 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate ( US 4206067, 06/03/1980; RU 2167921, 05.27.2001); salts of fluorine-containing beta-keto acids according to TU 6-00-02-09321-26-89 (RU 2005718, 01/15/1984) are used as an anti-corrosion additive Chromoxane B.

Table 1 shows the regulatory documents for the components used in the lubricant composition of a non-combustible working fluid for aviation (aviation devices) according to the invention.

Table 2 presents an example of a lubricating composition according to the invention. Table 3 presents the main characteristics of the base mixture based on phosphoric acid esters used in the lubricating composition of the non-combustible working fluid according to the invention.

Table 4 presents the main properties of the lubricating composition of a non-combustible working fluid according to the invention.

The lubricating composition of a non-combustible working fluid (hydraulic fluid) according to the invention is prepared as follows.

To prepare the base, the components are loaded into the mixer in a predetermined ratio in any sequence: tributyl phosphate, dibutyl phenyl phosphate, triisobutyl phosphate. The mixture is heated to 60-80 ° C and stirred at this temperature until the components are completely mixed.

To the resulting base mixture, the calculated amount of a thickener, polybutyl methacrylate, is added when heated. A mixture of a base with a thickener is mixed with heating.

Calculated amounts of epoxy resin, Chromoxane B, Agidol-1, stabilizer Irganox 1010FF, inhibitor Irganox L57, 1.2.3-Benzotriazole, inhibitor Amino O, dye are introduced into the prepared thickened base.

The resulting mixture was stirred with heating, cooled. As follows from the data presented, the lubricating composition of non-combustible working fluid for aviation (aviation devices) has increased fire and explosion safety, provides stable operation in the temperature range from minus 60 ° C to plus 150 ° C, with overheating up to plus 150 ° C; with improved anti-corrosion, anti-erosive, anti-oxidative, anti-hydrolysis and viscous properties.

These properties are ensured by experimentally selected qualitatively-quantitative combinations of a combination of a mixture of certain phosphoric acid esters (with their certain ratios) with certain additives, which together provides a synergistic effect and allows us to expand the working fluid working area when used in aviation.

Table 1 Components: Normative documents The basic mixture of phosphoric acid esters: TU 0253-005-07548712-2010 a) tributyl phosphate TU 2435-305-05763458-2001 b) dibutyl phenyl phosphate TU 2435-305-05763458-2004 c) triisobutyl phosphate TU 2435-437-057634-58-2010 Additives: - polybutyl methacrylate with a molecular weight of 5000-6500 STP 019950-401-016-81 - Epoxy resin cycloaliphatic grade UP-632 or grade ARALDITE-CY-179-1 SN TU 38.402-62-114-90 with amendment 1-2
HUNTSMAN Certificate Agidol 1 oxidation inhibitor. (-2,6-ditretbutylparacresol) TU 38.5901237-90 rev. 2 Oxidation inhibitor Irganox 1010FF. (tetraxis-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) pentaerythritol Certificate of the company BASF CE (ciba) Germany Oxidation inhibitor. Irganox L-57. (reaction product of N-phenylbenzylamine with 2,4,4-trimethylpentene). Certificate of the company BASF CE (ciba) Germany Corrosion inhibitor. Chromoxane B. (potassium perfluoro-4-methyl-3,6-dioxaoctensulfonate) TU 6-00-0209321-26-89 rev. 1 Corrosion Inhibitor 1,2,3-Benzotriazole TU 6-09-1297-87 amendment 1-5 Passivator metal. Amino 0. (2- (8-heptadecenyl) -4,5-dihydro-1H-imidazole-1-ethanol) Certificate of the company BASF CE (ciba) Germany Organic Fat-Soluble Purple Anthraquinone Dye TU 6-14-118-80 amendment 1-3

table 2 No. p / p Name of components Normative document Content, wt.% one 2 3 four Basic mixture of phosphoric acid esters (BSEF) or Basic mixture composition: TU 0253-005-07548712-2010 Up to 100
Up to 100 one. a) tributyl phosphate TU 2435-305-05763458-01 70.0 ± 3.0 b) dibutyl phenyl phosphate TU 2493-370-05763458-2004 22.0 ± 3.0 c) triisobutyl phosphate TU 2435-437-05763458-2010 8.0 ± 1.0 2. Polybutylmethacrylate M.V. 5000 STP 019950-401-016-81 7.5 ± 1.5 3. Epoxy resin brand ARALDITE-CY 179-1 СН HUNTSMAN certificate 6.3 ± 0.2 four. Surfactant Chromoxane (grade B) TU 6-00-0209321-26-89, amend. 1 0.08 ± 0.02 5. Antioxidant additive "Agidol-1" TU 38.5901237-90, amendment 2 0.3 ± 0.05 6. Additive Irganox 1010 FF BASF certificate 0.5 ± 0.05 7. Oxidation additive Irganox L-57 BASF certificate 0.5 ± 0.05 8. 1,2,3-benzotriazole pure TU 6-09-1291-87 amendment 1-5 0.01 ± 0.002 9. Corrosion Inhibitor Amine 0 BASF certificate 0.01 ± 0.002 10. Organic Fat-Soluble Purple Anthraquinone Dye TU 6-14-118-80 amendment 1-3 0.001 (over 100)

Table 3 The name of indicators The properties 2. The kinematic viscosity, mm ² / s at a temperature in the range: 50 ° C 2.0-3.0 GOST 33 minus 60 ° C 300-400 3. Density at 20 ° C, g / cm ³ , within 0.9900-0.9950 GOST 3900 4. Acid number, mg KOH / g per 1 g GOST 5985 oil, no more 0.007 5. Mass fraction of water,% no more 0.05 GOST 2477 not standardized or 14870 section 2

Table 4 Name of indicator Indicator value Note one 2 3 1. Appearance Transparent liquid from violet to blue According to clause 7.3 of this standard 2. Density at 20 ° C, g / cm ³ 1,02 GOST 3900 no more not standardized ASTM D 4052 or ASTM D 4052-09 3. Kinematic viscosity, mm ² / s: GOST 33 or ASTM D 445 - at 50 ° C, not less 8.5 - at minus 60 ° C, no more 4200 4. Pour point, ° C, not higher minus 65 GOST 20287 not standardized ASTM D 97 5. Acid number, mg GOST 5985 or KOH / g per 1 g of oil, no more 0.08 GOST 11362 not standardized ASTM D 664 6. The content of water-soluble acids and alkalis lack of GOST 6307 7. Flash point determined in open crucible, ° C, not lower 155 GOST 4333 method A not standardized ASTM D 92

Table 4 (continued.) 8. Thermo-oxidative stability at a temperature of plus (150 ± 1) ° C for 100 hours: GOST 20944 with the addition of clause 7.4. of this standard a) kinematic viscosity after oxidation, mm ² / s, not more than: - at 50 ° C 10.5 - at minus 60 ° C 5000 b) the acid number after oxidation, mg KOH / g, no more 0.15 c) weight indicator of corrosion, mg / cm ^{2 of the} surface of each metal, not more than: ± 0.1 - copper M1; - steel 30HGSA; - aluminum D16; - bronze BrAzh-9-4 9. Mass fraction of water,%, no more 0.1 GOST 2477 or GOST 14870, section 2 10. The purity of the liquid according to GOST 17216, not coarser 10th grade OST 1.41144 with the addition of clause 7.5. this standard or ASTM 4898 11. Lubricating properties on a four-ball friction machine at a load of 196 N and a temperature of 20 ° C: GOST 9490 or ASTM D4172 - diameter of the wear spot, mm not standardized 12. Electrical conductivity, μS / m, not less 40 According to clause 7.6. of this standard 13. Mass fraction of epoxy resins,%, not less than 0.7 according to GOST 12497 with the addition of clause 7.7. of this standard 14. Mass concentration of calcium,%, no more 0,0002 ASTM D 4628 15. Mass concentration of sodium,%, no more 0.0011 ASTM D 5863-00

Claims (1)

Lubricating composition of non-combustible working fluid for aviation, containing a base base based on a mixture of phosphoric acid esters containing 67.0-73.0 wt.% Tributyl phosphate, 19.0-25.0 wt.% Dibutyl phenyl phosphate and 7.0-9.0 wt.% triisobutyl phosphate, thickening additive polybutyl methacrylate with a molecular weight of 5000-6500, epoxy resin, antioxidant additive Agidol 1 2,6-ditretbutylparacresol, anticorrosive additive Chromoxane B perfluoro-4-methyl-3,6-dioxo-alkanoic acid-calcium hydroxide tetrakis (3- (3,5-di-tert-butyl-4-hydrox phenyl) propionate) pentaerythritol, oxidation inhibitor Irganox L57 reaction product of N-phenylbenzylamine with 2,4,4-trimethylpentene, corrosion inhibitor 1,2,3-benzotriazole, metal passivator Amino O 2- (8-heptadecenyl) -4,5- dihydro-1H-imidazole-1-ethanol, an organic fat-soluble violet anthraquinone dye in the following ratio of starting components, wt.%:
thickening additive polybutyl methacrylate 6.0-9.0 epoxy resin 6.1-6.5 Chromoxane B above 0.06-0.1 the above additive Agidol 1 0.025-0.35 the above stabilizing additive Irganox 1010 FF 0.45-0.55 the above oxidation inhibitor Irganox L57 0.45-0.55 1,2,3-benzotriazole corrosion inhibitor 0.008-0.012 metal passivator Amino O 0.008-0.012 the specified base mixture of phosphoric acid esters rest up to 100% organic fat-soluble dye 0,0008-0,0012 purple anthraquinone (over 100%)