DE1644900A1 - Hydraulic and heat transfer fluids - Google Patents

Description

Hydraulic and heat transfer: excretion of fluids Patent ....... (Patent application G 48 147 _ IVc / 23c) J On hydraulic and heat transfer fluids, used in machines and equipment operating at high temperatures, e.g. in gas turbines from aircraft engines, very high demands are made, E.g. 1. You have to be fluid and able to use the conditions of use have, on a wide variety of materials, - especially metals,, lubricating films to build. -2. .- They have to withstand high temperatures and oxidative influences to a large extent to be constant.

3. They should not have a corrosive effect and, above all, should not be acidic Form decomposition products.

4. You should have as deep a freezing point as possible and on the other hand a; have the highest possible boiling point.

There is considerable difficulty in finding hydraulic and thermal transmission fluids which largely meet all of the above conditions. - So far have been considered high-boiling hydraulic and Heat transfer fluids including polyphenyl ether and Polyalkyl melamines used. The viscosity of this bindings is too high for some purposes, especially at low temperatures. There are now high quality hydraulic heat transfer fluids, including damping and braking liquids P with a relatively low viscosity found. They consist of a mixture of a) below 75 ° C and preferably below 35 ° C melting polyalkylamino-di- and / or -triazines and b) Polyphenyl ethers in a weight ratio of 1: 9 to 9: 1, advantageous 3: 7 to 7: 3. The mixtures according to the invention are important . less viscous than those normally found in the viscous materials of the individual components on which they are based Mean values. Their logarithms should be according to hubricant. Testing by EG Ellis: B.Sc., F. Znst. Pet. Seientific Publ. (Great Britain) Ltd., 19531 pp. 51 - 53 approximates the arith metic mean of the logarithms of the components: As polyalkylamino-di- or. -triazines, which are used as compo- components a) are suitable in the mixtures according to the invention, especially those of the formula I come into consideration. In this formula:. XN or CH ,.

R1 is hydrogen or an alkyl radical containing 1 to 16 carbon atoms, R3 is an alkyl solid containing 1 to 16 carbon atoms, and -R2, R4., R5 and R6 are each an alkyl radical containing 1 to -6 carbon atoms, the sum of the carbon atoms of all oxygen substituents being at least 12 :.

Advantageously, R1, R2, R3, R41, R5 and R6 each denote an n-alkyl radical.-X preferably represents nitrogen @, jar; 6.h. they are polyalkylamino-1,3,5-triazines. These compounds are described in French Patent No. 1,328,168. You are, for example, by stepwise conversion of the 3 chlorine atoms of the cyanuric chloride with the desired alkylamines by methods known per se.

Examples of such polyalkylamino-1,3,5-triazines are 2-dimethylamino-4,6-bis-dibutylamino-1,3,5-triazine, 2-diethylamino-4,6-bis-dibutylamino-1,3,5-triazine, 2; 4,6-tris: diethylamino-1,3-, 5-triazine, -2,4,6-Tris-dibutylamino-1,3,5-t.riazine 2,4,: 6-Tris-dihexylamino-1,3,5-triazine, 2- (N-methyl-N-decylamino) -4- (N-methyl-N-butylamino) -6-dimethyiamino-1,3,5-triazine, 2- (Butylamino) -4- (dibutylamine #) - 6- (diethylamino-, -didecvlamino- or -didodecylamino) -1,3,5-triazine, -: 2-Dimethylamino-4,6 --- bis (N-methyl-N-butylamino) -1,3e5-triazine.

Polyalkylamino compounds of the formula I in which X denotes CH, ie Polyalkylaminopyrimidines are obtained, for example, by a stepwise reaction of the three chlorine atoms of the 2nd, 4,6-trichloropyrimidine with the desired alkylamines according to methods known per se: Examples of such polya.lkylamino-pyrimidines are 2-diethylamino-4,6-bis-dibutylamino-pyrimidine-L # j or 2,4,6-tris-dibutylamino-pyrimidine.

Of course, as component a) in the inventive Mixtures and mixtures of polyalkylamino-di- or triazines of the formula I can be used.

.Polyphenyl ethers which are suitable as component b) in the mixtures according to the invention are, in particular, those of the formula II. In this, n denotes 1 to 4, preferably 2 to 3. The phenyl rings can contain alkyl or alkoxy groups with preferably 1 to 20 carbon atoms, but advantageously they are urisubstituted especially mixtures of isomeric polyphenyl ethers with a high content of components with. M-position ether linkages are particularly suitable as components b) because the mixtures according to the invention containing them have particularly low solidification ranges. Examples of such polyphenyl ethers are listed in French Patent 1,394,304 on page 2: Their preparation is for example in R, G.-Gunderson and AW Hart "Synthetic Lubricants", The Dow Chemical Company, Midland Wichigan Ed.- Reinhold -Publishing Corp. London, and RL Hatton, "Hycraulia Fluids" So 297-308 (same publisher) -described.

The above-mentioned unexpected decrease in the viscosity special ity becomes ins / with very specific viscosity ratios of the two mixture components of the formulas Z and II obtained from one another. As a rule, the quotient of the logarithms of the viscosities of the two components, each increased by 0.6 and measured in centistokes, must be 0.7 to 1.4. Viscosities of the mixtures according to the invention are then obtained which are 20% or more below the expected arithmetic mean viscosity values and usually even 5-10; 6 or more below the value of the component with a lower viscosity. h hydraulic and heat transfer fluids The new @ @@ z @ =. 1-e @ l @@@ i- are not very volatile Oils. They have good thermal stability and do not have any significant amounts of acidic decomposition products at high temperatures, as prescribed for gas turbine oils for aircraft engines. Therefore, in practical use, they have no or only a very slight corrosive effect. They also swell. Plastics such as those used for seals, for example, only marginally. You can in one. A wide temperature range are used, have a good lubricating effect. low pour point and have good acid and alkali resistance.

The hydraulic and heat transfer fluids of the invention can be used on their own or with additives. About their heat stability above "150 ° C., you can add antioxidants to them, whereby : their service life becomes satisfactory even with increased oxidative stress.

Possible such antioxidants are customary homo- or heterocyclic aromatic amines, hydroxyaryl and aminohydroxyaryl compounds and heterocyclic compounds without free amino groups, preferably in amounts of 0.01-5% by weight. (These and the following percentages relating to additives to the mixtures according to the invention always relate to the total weight of the latter) , N'-diphenyl-p-phenylenediamine, N, N '- Uioctvl-p-phenylenediamine, NN'-dicyclohexyl-p-phenylenediamine, N-sec-butyl-N'-phenyl-p-phenylenediamine, N, N' -Bis- (y-aminopropyl) -p-phenylenediamine, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butylphenol, 2,6-bis- (1- methyl-cyclohexyl) -4-methyl-phenol, 2,6-di-tert. butyl-4-dimethylamino-methyl-phenol, 2,2'-methylene-bis- (4-methyl-6-tert-butyl-phenol), 2,2'-thio-bis (4-methyl-6 -tert.butylphenol), 4,4'-dhydroxy-2,2'-dimethyl-5,5 '' - di-tert.butyl-diphenylsulfide and -diphen,; rl-disulfide, 2,6-bis- (2 -hydroxy-3-tert-butyl-5-methyl-benzyl) -4-meth- # rlphenol, 2-tert-butyl-1-hydroxynaphthalene, 4,6-di-tert. butyl-5-hydroxy-indane, 5-hydroxy-acenaphthene, butylpyrocatechol, octyl gallate, butylhydroxy anisole, -p-hydroxy-diphenylamine, p-hydroxy-octylaniline, p-hydroxy-. N-y_aminopropyl-aeniline, p'henothiazine, iminodibenzyl, 2-tert-octylimino-dibenzyl, 5-ethyl-10,10-diphenyl-phenosilazine, -6-methoxy- or 6-ethoxy- or 6-ethvlamino-2, , 24-trimethyl-1,2-dihvdrochinol.n or their telomers, 3-hydroxy-7,8: -benzo-1,2,3,4-tetrahydroquinoline, tocopherol or dialkyl selenides, hydraulic and heat transfer fluids according to the invention can also be used also contain anti-corrosive agents such as sarcosines or benzotriazoles, agents that lower the pour point and - if necessary - also contain anti-foaming agents, e.g. those based on silicone. All of these additives are preferably mixed in in amounts of about 0.5-5%. The following examples show the surprisingly low viscosity of the mixtures according to the invention in comparison with the individual components. It uses the units of measurement of the metric system. The viscosities are measured in gentistokes. Example 1ß- hydraulic and Production of an antioxidant containing '_ "' = t; _" @@@ _ '^ Heat transfer fluid st. 98 g mixture of polyalkylamino-triazine and. Polyphenyl ethers according to No. 1 in the table above are mixed with 2 g of di-tert-octyl-diphenylamine as an antioxidant until the latter has completely dissolved.

Compared to the antioxidant-free mixture, the mixture obtained is stronger Oxidation resistance.

In the same way, the other mixtures given in the table above can also be made more resistant to oxidative influence. _ 9 Instead of 2 g of di-tert-octyl-diphenylamine, 2 g of one of the following anti-oxidants is used. and otherwise proceed as indicated: the oxidation resistance of the polyalkylamino-triazine-polyphenyl ether mixture is also increased: di-dodecyl selenide, 1,1,3-tri- (2'-methyl-4'-hydroxy-51- tert-butylphenyl) butane, 2,6-di-tert-butyl-4-methyl-phenol, 2-tert-octylimino-dibenzyl or 5-ethyl-10,10-diphenyl-phenosilazine, Example 20 Manufacture of a corrosion protection agent containing drainage and heat transfer liquid. 99.8 g mixture of polyalkylamino-triazine and polyphenyl ether according to No. 1 of the table above are mixed with 0.2 g of benzotriazole. The mixture obtained shows compared to the mixture no. 1 a lower corrosion effect especially: compared to copper and its alloys.

Similar results are obtained with the other mixtures according to the table above. Example 21 Egg preparation of a hydraulic and heat transfer fluid containing a pour point depressant.

97 g mixture of polyalkylamino-triazine and polyphenyl ether according to No. 1 of the above table are mixed homogeneously by stirring with 3 g of polymeric methacrylic acid ester, in particular poly-2-ethylhexyl methacrylate (HF 825 from Röhm and Haas Co. Philadelphia USA). This mixture has a lower pour point than the mixture free of this active ingredient.

Similar results are obtained with the other mixtures in the table above. - Example 2: 2 hydraulic and heat transfer fluid, Making a Which Contains antioxidants and anti-corrosive agents If you mix 97 = '8 g mixture of polyalkylamino-triazine and polyphenyl ether according to No. 1 of the table above with 2 g of di-tert-octyl-diphenylamine as an antioxidant and 0.2 g of henzotriazole as an anti-corrosive agent, a functional liquid is obtained that is less sensitive to oxidation and less corrosive than the corresponding functional liquid that is free from the active ingredients mentioned .

Similar results are obtained with the other mixtures of the above Tabel: The boiling points mentioned in the table above Polyalkylaminotriazine Nos. 1-11 are in French patent specification no. 1 328 168 specified ..

The boiling points of the Polyalkylamno-dazine Nos. 12-18 of the formula Ia be: R1 R2 R3 R ^ R5 R6 Kp ° C n-butyl n-butyl n-butyl n-butyl-n-butyl n-butyl 190-4 (0.3 goal :) do do do. #.? o n-Hexyl n-Hexyl 217-22 (0.3 Torr) do do d0 do 'n-Decyl n-Decyl 250-70 (0.003-0.005 [ _ Torr) do do do do n-Dode- @ n-Dode- 252-8 cyl cyl (0.004 Torr) Aethyl Aethyl do do n-Hexyl n-Hexy1 200-2 - - (0.3 Torr)

Claims (1)

. Claims-1. Hydraulic and heat transfer fluid, which is characterized in that it consists of a mixture of a) polyalkylamino-di- and / or triazines and b) polyphenyl ethers, the weight ratio of compounds a) to compounds b) being 1: 9 to 9 : 1 is. _ s 2. Hydraulic and heat transfer fluid according to claim 1, characterized in that the polyalkylaminodi- or -triazines according to a) of the formula I, in the . XN or —CH, R 1 is hydrogen or an alkyl radical having 1 to 16 carbon atoms, R7 is 1 to 16 carbon atoms. having alkyl radical and R2, R4, R5 and R6 each denote an alkyl radical having 1 to 6 carbon atoms, the sum of the carbon atoms of all nitrogen substituents being at least 12, and the polyphenyl ethers according to b), the formula @ II, in d ex denotes -nl to 4 and die.Phenylringe may contain alkyl or alkoxy groups. 3. Hydraulic and heat transfer fluid according to claim 2, in which X in formula 1 is N -. 4. Hydraulic and heat transfer fluid according to claims 1 .to 3, irr which the Gewic_ht.sv:errat the compounds of the formula I to those of the formula II is 37 to 7: 3. , 5. Hydräulisch & and heat transfer tragungsflüs: fluid according to claims 1 to. 4, which is characterized in that the quotation of the logarithms of the viscosities of the mixing partners, each increased by 0.6 and measured in centistokes, is 0.7 to 1.4. 6. Hydraulic and heat transfer fluid according to Claims 1 to 5, which is characterized in that it also contains at least one other substance from the series. the antioxidants, the pour points: r-lowering agents :, and the anti-corrosive agents.