CH615217A5 - Hydraulic fluid - Google Patents

Description

The present invention relates to functional liquid mixtures which are capable of preventing and controlling the wear of mechanical parts which come into contact with these liquid mixtures.

Numerous functional liquids are known and are used for various uses. Such liquids serve, for example, as coolants for electronic systems and nuclear reactors, liquids in diffusion pumps, lubricants, damping agents, basics for greases, liquids for power transmission and hydraulic liquids, liquids for heat transfer, liquids for heat pumps, cooling liquids and as filter media for air conditioning systems.

Decomposition of the liquid during use and damage to mechanical parts, in particular metal parts in contact with the liquid, have been reported by various functional liquids used for the above purposes, measurable by a weight loss of these parts due to wear. Damage to hydraulic systems of aircraft, the bearings of gas turbines, the control systems of jet drives, the bearings of steam turbines and control systems of steam turbines, electrohydraulic control systems and control devices of space vehicles has been reported. Materials such as glass, "Teflon", "Plexiglas", "Mylar" and parts made from other non-metallic materials were also damaged in this way.

If the functional fluids are used in the hydraulic systems of aircraft and spacecraft, tough conditions are placed on these fluids. These hydraulic fluids not only have to be able to withstand the tough conditions of use, they also have to

615 217

meet various fire protection regulations. The hydraulic fluid must also operate in the hydraulic system for extended periods of time without appreciable damage to the various conduits, valves, pumps, and the like through which the fluid flows in use.

The damage caused by functional fluids in contact with valves and other parts has been attributed to the wear or erosion that occurs in contact with the functional fluid in the hydraulic system. The various undesirable results that such damage can include include a noticeable decrease in the strength of mechanical parts of the hydraulic system, such as pumps and valves, and a change in the geometry of these parts. Such changes can lead to a decrease in pump performance in the case of pumps, incorrect operation in the case of valves, excessive leakage and risk cases.

This damage requires expensive and time-consuming early overhaul of the mechanical parts. Metal removed from mechanical parts in contact with the functional fluid contaminates the fluid, clogs the filter and additional need for filter replacement, and also requires early draining and replacement of the fluid in the system. Metallic contamination can also change the physical and chemical properties of the functional liquid.

Metallic contaminants can also reduce the resistance to oxidation of a liquid, which adversely changes its behavior. The metallic contaminants in the liquid can manifest themselves in various ways, for example through changes in viscosity, increased acid number, precipitation, decrease in chemical resistance and discoloration.

Another difficulty is the inevitable contamination of aircraft and electro-hydraulic control systems by chlorinated solvents used to clean the systems and their parts. This problem has been discussed in detail in Vickers 22nd Fluid Power Conference Report, Oct. 1972, Section 4, pp. 25-29. Contamination with chlorinated solvents reduces the lifespan of functional fluids and accelerates damage caused by excessive internal leaks in the hydraulic system, which can prevent it from functioning. No previously known additive has been able to satisfactorily overcome the difficulties caused by the contamination of functional liquids by 5 chlorinated solvents.

A functional liquid has now been found which is improved in terms of low erosion action, increased resistance to shear forces, oxidation and heat exposure, and has improved fire safety; it is particularly suitable for use in aircraft hydraulic systems. The invention relates to the incorporation of a smaller amount of certain ammonium salts of phosphoric acids into various basic mixtures of functional liquids, whereby functional liquids are obtained by preventing damage to the metal parts surrounding the functional liquid.

The ammonium salts of phosphoric acids, which are suitable according to the invention for incorporation into functional liquids, are represented by the following formula:

25th

30th

I.

R

«.R1

i

NO"

t

R «« »

m

Zm -

wherein R, R 'and R ", which may be the same or different or linked to one another, are hydrogen, alkyl, aryl, alkaryl or aralkyl having 1 to 30 carbon atoms, R" alkyl, aryl, 35 alkaryl or aralkyl having 1 to 30 carbon atoms , X represents oxygen or sulfur, Y 'and Y "alkoxy, alkylthio, alkyl, aryl, alkaryl, aralkyl, aryloxy, arylthio or alkaryloxy, Z represents oxygen or sulfur and m represents the number 1 or 2. According to a preferred embodiment, m is the number 1.

Typical ammonium salts of acids of phosphorus or ammonium ions and phosphoric acid ester anions are listed below:

40

Ammonium ions

Phosphoric ester anions

Dodecyl trimethyl ammonium

Hexadecyl trimethyl ammonium

Qctadecyl trimethyl ammonium

Tridecyl trimethyl ammonium

Decyl trimethyl ammonium

Didodecyl dimethyl ammonium

Methyl butyl dodecyl ammonium

Dimethyl-propyl-dodecyl-ammonium

Dodecyl ammonium

Trioctyl ammonium

Dioctyl-methyl-ammonium

Dioctyl-dimethyl-ammonium

Dodecylbenzyl trimethyl ammonium

Nonylphenyl trimethyl ammonium

Dodecyl dimethyl butyl ammonium

Phenyl-dodecyl-dimethyl-ammonium

Phenyl trimethyl ammonium

Benzyl trimethyl ammonium

Allyl tributyl ammonium

Dimethyl dodecenyl ammonium

(unsaturated radical R)

Trimethyl-hexadecenyl-ammonium

(unsaturated radical R)

Diphenyl phosphate

Phenyl phosphate (bis-amine salt)

Dimethyl phosphate

Methyl phosphate (bis-amine salt)

Methyl methylphosphonate

Methylphosphonate (bis-amine salt)

Diethyl phosphate

Ethyl phosphate (bis-amine salt)

Dioctyl phosphate

Dibenzyl phosphate

Diallyl phosphate

Methyl phenyl phosphate

Bis (octylphenyl) phosphate

Di-n-dodecyl phosphate

Diethyl dithiophosphate

Di-n-butyl dithiophosphate

Dibenzyl dithiophosphate

Diphenyl dithiophosphate

Bis (nonylphenyl) phosphate

Dibutyl phosphate

Methyl octylphosphonate

615217

4th

Ammonium ions

Phosphoric ester anions

Heptadecyl-trimethyl-ammonium trioctyl-methyl-ammonium methyl-a-naphthyl-phenyl-ammonium

Cyclohexyl dimethyl ammonium

5

Methyl hexadecyl phosphonate methyl tert-butyl phosphonate methyl carbomethoxymethyl phosphonate

Hexadecylphosphonate

Nonyl trimethyl ammonium

Tris (n-tridecyl) methyl ammonium

Tris (n-dodecyl) methyl ammonium

Tris (isooctyl) methyl ammonium

Dimethylbutylhexadecyl ammonium

Triethyl methyl ammonium

1,3,5-trimethyl-pyridinium

2-ethylhexyl-dimethyl-dodecyl-ammonium

Dimethylethyl dodecyl ammonium

Dimethylbutyl dodecyl ammonium

Trimethyl dodecyl ammonium

Hexadecyl-dimethylethyl-ammonium

Tris (dodecyl) butyl ammonium

Tetramethyl-ammonium

Trimethyl benzyl ammonium

Trimethyl tert-octylphenyl ammonium

4-AcetyI-N-methyl-pyridinium l- (N, N-dimethyl) -l-imidazolium

1 - (N, N-Dimethyl) -1-pyrrazolium

N-methyl oxazolium

N-butyl quinolinium

N-methyl pyrrolium

N, N-diethyl-pyrrolidinium

N-methyl-N-hexyl-piperidinium

N-methyl-N-butyl-piperidinium

N-isopropyl thiazolium

N-ethyl-N-methyl-phenothiazinium

Pyridinium

N-methyl pyridinium.

Each of these ammonium ions can in turn be combined with any of the phosphorus ester anions to give typical compounds suitable for the purposes of the present invention. Particularly preferred ammonium salts of acids of phosphorus are: hexadecyl-trimethylammonium-diphenylphosphate decyl-trimethylammonium-diphenylphosphate dimethyl-propyl-dodecylammonium-diphenylphosphate dodecyl-ammonium-diphenylphylate dodecyldimethylammonium diphenylphosphate allyl tributylammonium diphenylphosphate

20th

5

615217

Trimethyl hexadecenylammonium diphenyl phosphate

Bis (dodecyl trimethyl ammonium) phenyl phosphate

Bis (octadecyI-trimethyl-ammonium) phenyl phosphate

Bis (phenyl-dodecyl-dimethyl-ammonium) phenyl phosphate

Decyl trimethyl ammonium dimethyl phosphate

Didodecyl dimethyl ammonium methyl methyl phosphonate

Bis (didodecyl-dimethyl-ammonium) methylphosphonate

Dodecyl trimethyl ammonium dimethyl phosphate

Dodecyl trimethylammonium dibenzyl phosphate

Dodecyl trimethyl ammonium methyl phenyl phosphate

Dodecyl trimethylammonium bis (nonylphenyl) phosphate

Dodecyl trimethyl ammonium diphenyl dithiophosphate

Octadecyl trimethylammonium diphenyldithiophosphate

Dioctyl methyl ammonium diphenyl dithiophosphate

Phenyl-dodecyl-dimethylammonium-diphenyldithiophosphate

Dodecyl trimethyl ammonium diethyl dithiophosphate

Phenyl trimethyl ammonium diethyl dithiophosphate

Dodecyl trimethylammonium diallyl phosphate

Dodecyl trimethylammonium diphenyl phosphate

Didodecyldimethylammonium di-n-dodecylphosphate

Dodecyl trimethylammonium di-n-dodecyl phosphate

Dioctyl methyl ammonium dioctyl phosphate

Trioctylammonium dioctylphosphate

Phenyltrimethylammonium methylphenyl phosphate

Benzyl trimethyl ammonium methyl phenyl phosphate

Trimethyl hexadecenylammonium methyl phenyl phosphate

Bis (trioctyl ammonium) ethyl phosphate

Octadecyl trimethylammonium diphenyl phosphate

Tridecyl trimethylammonium diphenyl phosphate

Heptadecyl trimethylammonium diphenyl phosphate

Nonylphenyl trimethylammonium di-n-butyl dithiophosphate

Benzyl trimethyl ammonium dibenzyl dithiophosphate

Hexadecyl trimethyl ammonium dimethyl phosphate

Trioctyl methyl ammonium diphenyl phosphate

Heptadecyl trimethyl ammonium dimethyl phosphate

Tris (n-tridecyl) methylammonium diphenyl phosphate

Tris (n-dodecyl) methylammonium diphenyl phosphate

Tris (isooctyI) methylammonium diphenyl phosphate

Dimethylbutylhexadecylammonium dibutyl phosphate

Triethyl methyl ammonium methyl methyl phosphonate

1,3> 5-trimethylpyridinium diphenyl phosphate

N-methyl-N-butylpiperidinium dibutyl phosphate

2-ethylhexyl dimethyl dodecylammonium diphenyl phosphate

Dimethylethyl dodecylammonium diethyl phosphate

Dimethyl butyl dodecyl ammonium dibutyl phosphate

Trimethyl dodecylammonium dimethyl methyl phosphonate

Hexadecyldimethylethylammonium diethylphosphate

Tris (dodecyl) butylammonium dibutyl phosphate

Tetramethylammonium methyl octylphosphonate

Trimethyl benzyl ammonium methyl octyl phosphonate

Tetramethylammonium methyl hexadecylphosphonate

Benzyl trimethyl ammonium methyl hexadecyl phosphonate

Tetramethylammonium methyl tert-butyl phosphonate

Benzyl trimethylammonium methyl tert-butyl phosphonate

Tetramethylammonium methyl carbomethoxymethylphosphonate

Benzyltrimethylammonium methyl carbomethoxymethylphosphonate

Trimethyl tert-octylphenylammonium diphenyl phosphate

Trimethyl tert-octylphenylammonium methyl methylphosphonate

Trimethyl tert-octylphenylammonium bis (nonylphenyl) phosphate

615217

Tetramethylammonium bis (nonylphenyl) phosphate benzyltrimethylammonium bis (nonylphenyl) phosphate

0

C8H17 "C10H21 ° -" "0; ÄCH3 <c6H50) 2PV

C8H17 C10H21 ° C \ /

0

0

■ C-f ^ SCTj (CgH ^ CgH ^ PO., -

C8H17 "C10H21 °" "~ \ ^^ CH3 (OH30) (CH3, P02-

0

CH ^ O-C - ^^ CH,

(c6h5o) 2po2-

0

CH ^ O-C - ^^ CH ^

(C9H19C6H40) 2P0;

0

CH ^ Q-C- ^ ~ ^ NCH3 (CH ^ O) (CH3) P02-

The quaternary ammonium salts of diesters of phosphoric acid, which have no NH bonds, can be held in front of the division according to the specification of GB-PS 1 119 015 and after the preprint of the Symposium on Deposit, Wear, and Emission Control by Lubricants and Fuel Additives of Petroleum Chemistry of the American Chemical Society, NY City Meeting, Sept. 1969, pp. A-110. These methods include:

R ^ N

+ R'O PCO) (OR ").

1. Reaction of an amine with a triester of phosphoric acid, the triester alkylating the amine. These reactions usually take place above 40 to 60 ° C and can be carried out neat or in alcoholic solvents. All volatile components are then distilled off, leaving behind the phosphoric acid diester salt of a quaternary ammonium cation:

A ->

R-jNR '

e

0P (0) (OR ").

R 'is preferably the benzyl, allyl or a lower alkyl radical (especially methyl). R "can be alkyl, aryl, alkaryl, aralkyl and the like.

2. Reaction of the phosphoric acid diester with a quaternary ammonium hydroxide to form the salt in such a neutralization reaction and subsequent removal of the water released:

(RO) P (0) (0h). + RjjN (OH)

© e r4n

0P (0) (0R) 2

h2o

3. Reaction of the quaternary ammonium halide with the sodium or potassium salt of the phosphoric acid diester and extraction of the phosphate with a solvent such as acetone to remove sodium or potassium chloride:

e © © e (R0) o P (0) (0) Na + Ri.N Cl ffi e

RnN 0P (0) (0R) 2 + NaCl

60

The erosion caused by hydraulic fluids has been related to the electrical properties of the fluid in Boeing Scientific Research Laboratories Document D1-82-0847. It has been proposed to reduce the erosion caused by hydraulic fluids by eliminating ionic impurities present in the fluid or by noticeably increasing the conductivity of the fluid.

Both considerations have been put into practice with some success. This is surprising due to the fact that by eliminating ionic contaminants, the guidelines

615 217

ability is actually reduced. Therefore, there appear to be two conflicting solutions to the problem of erosion. Recent experiments have shown that the elimination of ionic contaminants by filtration through activated clay reduces the erosion generated by a hydraulic fluid from phosphate ester. However, this is not a practical solution since erosion starts again soon after the filtration has ended. Filtration on an airplane is also impossible.

It was shown that the addition of ammonium salts of acids of phosphorus to various basic liquids effectively prevents the damage caused by these liquids. Conductivity measurements on these liquids containing the ammonium salts showed an increased conductivity. However, it is not yet possible to use the conductivity to explain the mechanism or to evaluate the effectiveness of the erosion inhibitors. However, conductivity initially serves as a certain indicator, although further studies in this area are necessary and desirable.

The conductivities of commercially available hydraulic fluids based on phosphate esters for aircraft which are on the market today are between about 0.02 and about 0.06 microohmcm "1.

Functional liquids to which the ammonium salt of the acid of the phosphorus is added are referred to here as basic liquids. These include, without limitation, esters and amides of acids of phosphorus, mineral oils and synthetic hydrocarbon oils, hydrocarbyl silicates, silicones, aromatic ether and thioether compounds, chlorinated biphenyls, monoesters, dicarboxylic acid esters, esters of polyhydric hydroxyl compounds, polyalkylene ether glycols and -alcohols and their esters.

The concentration of the ammonium salts of the phosphoric acids in the functional liquid is selected in accordance with the respective system and the functional liquid so that wear is prevented and reduced. It was shown that the response of the additive, that is to say the concentration of the ammonium salt of phosphoric acid, which is required to prevent and reduce wear from the base liquid, depends on the base liquid used or the mixture of base liquids.

In the case of the base liquids suitable for carrying out the invention, the concentration of ammonium salts of phosphoric acid is about 0.01 to about 15% by weight. The preferred additive concentration is from about 0.025 to about 5% by weight, in particular from about 0.1 to about 0.5% by weight. The invention therefore relates to a mixture comprising a functional liquid and a wear-preventing amount of an ammonium salt of phosphoric acids, that is to say an addition of ammonium salt, which gives a concentration which reduces and prevents wear. The functional liquids according to the invention can be prepared in any known manner by incorporating the additive into a base liquid, the ammonium salt of the phosphoric acids preferably being added to the base liquid with stirring and stirring until a flowable mixture is obtained.

As already mentioned, various base liquids can be present in the mixtures according to the invention. Suitable base fluids are discussed in more detail below:

The functional liquids suitable as base liquids for the purposes of the present invention can be esters and amides of an acid of phosphorus, which can be represented by the following formula:

10th

0

r- (y) a-p-cyi) c-r2

r,

where Y is oxygen, sulfur or the rest

R.

3 -n-

15 yi oxygen, sulfur or the rest

-N-

20 and Y2 oxygen, sulfur or the rest

? 5

-N-

25 and R, Ri, R2, R3, R4 and R5 represent alkyl, alkoxy, aryl or substituted alkyl, where R, Ri, R2, R3, R4 and Rs may be the same or different; a, b and c are integers from 0 to 1 and the sum of a + b + c is a number from 1 to 3.

In general, the number of carbon atoms in 30 of the alkyl radicals is 1 to 30. The alkyl radicals also include cycloalkyl radicals and alkyl-substituted cycloalkyl radicals.

The above radicals also include aralkyl radicals, for example the benzyl, α- or β-phenylethyl, α, α-dimethyl-benzyl radical and the like, which have alkyl moieties with 1 to 30 carbon atoms. Also included are the cyclobutyl, cyclohexyl, cycloheptyl and the like, furthermore alkaryl such as the methylphenyl, ethylphenyl and the like. Also included are alkoxyalkyl radicals such as the methoxyethyl, ethoxyethyl, butoxyethyl, butoxybutyl and the like.

Typical examples of substituted alkyl radicals are the halo-alkyl radicals of the formula

GnHal2n + 1 ~ mHmG ^ Hal ^ 2 ^ "

R?

50 wherein shark is halogen, m is a number less than or equal to 2n + 1 and n is a number from 0 to 18 and Re and R7 are hydrogen, halogen such as fluorine, chlorine, bromine or iodine, or alkyl radicals. Preferred radicals are those with shark = fluorine. The halogenated alkyl radicals can be primary, secondary or tertiary. 55 Other suitable fluorine-containing radicals are fluorine-containing alkoxyalkyl radicals. Hydrogen and fluorine in the haloalkyl radicals described can also be replaced by other halogen atoms such as chlorine or bromine.

Typical examples of aryl radicals are the phenyl, cresyl-60 and xylyl radicals, halogenated phenyl, cresyl and xylyl radicals, in which available hydrogen on the aryl or substituted aryl nucleus is partly or completely replaced by a halogen which is o-, m- and p-trifluoromethylphenyl-, o-, m- and p-2,2,2-trifluoro-ethylphenyl-, o-, m- and p-3,3,3-trifluoropropylphenyl- and o-, m-65 and p4, 4,4-trifluorobutylphenyl residue. These also include the isopropylphenyl, butylphenyl radical, a-alkylbenzylphenyl and a, a-dialkylbenzylphenyl radicals, for example the a-methylbenzylphenyl and a, a-dimethylbenzylphenyl radical.

615217

8th

The orthosilicates suitable as base liquids include tetraalkyl orthosilicates such as the tetra (octyl) orthosilicate, tetra (2-ethylhexyl) orthosilicates and the tetra (isooc-tyI) orthosilicates and orthosilicates, in which the isooctyl radical is derived from isooctyl alcohol from the oxo process. furthermore the (trialkoxysilico) trialkyl orthosilicates, which are also referred to as hexa- (alkoxy) disiloxanes, for example hexa (2-ethylbutoxy) disiloxane and hexa (2-ethylhexoxy) disiloxane.

The preferred tetraalkyl orthosilicates and hexa (alkoxy) disiloxanes are those whose alkyl or alkoxy radicals have 4 to 12 carbon atoms and in which the total number of carbon atoms in the orthosilicate is 16 to 60.

In addition to the hexa (alkoxy) disiloxanes mentioned, other hexa (alkoxy) disiloxanes can also be used in which the aliphatic radical of the alkoxy group consists, for example, of 1-ethylpropyl, 1,3-dimethylbutyl, 2-methylpentyl, 1-methylhexyl -, 1-ethylpentyl, 2-butylhexyl or l-methyl-4-ethyloctyl.

The orthosilicates and alkoxypolysiloxanes can be represented by the following formula:

Typical examples of aryl radicals are the o-, m- and p-chlorophenyl-, o-, m- and p-bromophenyl-, o-, m- and p-fluorophenyl-, a, a, a-trichlorocresyl, a, a, a-trifluorocresyl, o-, m- and p-cresyl and xylyl.

Suitable dicarboxylic acid esters have the formula

10th

R

20th

- 0

0 II

- C -

R

21st

0 II

- C - 0 - R

22

Rg - 0

Î »

0

1

Si

I.

0

R

10th

R

11

(0)

m

0 - X -

I.

(0)

R

m

12

wherein R20 and R22 are alkyl, substituted alkyl or aryl and R21 is a divalent alkylene or substituted alkylene radical. They are obtained by esterifying dicarboxylic acids such as adipic acid, azelaic acid, suberic acid, sebacic acid, hydroxysuccinic acid, fumaric acid, maleic acid and the like with alcohols such as butyl alcohol, hexyl alcohol, 2-ethylhexyl alcohol, dodecyl alcohol, 2,2-dimethylheptanol, 1-methyl-cyclohexyl meth receive.

Polyesters suitable as base liquids can be represented by the following formula:

(0) - R._ m 13

n

35

wherein R8, R9 and Rio, which may be the same or different, alkyl, substituted alkyl or aryl, X carbon or silicon, m is the number 0 or 1 and n is an integer from 1 to about 200 or more, where if X Carbon means m is 0 and n is 1 and R11, R12 and R13 are hydrogen, alkyl, substituted alkyl or aryl and, when X is silicon, m is 1 and n is an integer from 1 to means about 200 or more and represents Ru, R12 and R13 alkyl, substituted alkyl or aryl.

Typical examples of substituted aryl radicals are the o-, m- 45 and p-chlorophenyl, o-, m- and p-bromophenyl, o-, m- and p-fluorophenyl, a, a, a-trichlorocresyl, a, a, a-trifluorocresyl,

Xylyl and o, m and p cresyl. Typical examples of alkyl and haloalkyl radicals are described above.

The siloxanes or silicones suitable as base liquids can be represented by the following formula:

0

0 - C - R

2 4

0

CH,

R23— (C-O ^ -CH2-C - CH2-

CH0

0

C '= 0

R

25th

R

26

R

14

R

15

Si

I.

R

0

16

R

17th

Si!

R

R

n

18th

wherein Rw, R15, Rie, R17, Ris and Ria are each alkyl, substituted alkyl or aryl and n is an integer from about 0 to about 2000 or more. Typical examples of alkyl and haloalkyl radicals and their number of carbon atoms have already been mentioned above. Typical examples of such siloxanes 65 are poly (methyl) siloxane, poly (methyl, phenyl) siloxane, poly (methyl, chlorophenyl) siloxane and poly (methyl, 3,3,3-trifluoropropyl) siloxane.

wherein R23 is hydrogen or an alkyl radical, Rm and R25 are each alkyl, substituted alkyl or aryl, a is 0 or 1 and Z is 1 or 2, where, when Z is 1, R26 is hydrogen, alkyl, acyloxy or substituted acyloxy and when Z is 2, Ra> represents oxygen. They are obtained by “esterifying polyalcohols such as pentaerythritol, dipentaery-19 3 thritol, trimethylolpropane, trimethylolethane and neopentylglycol with acids such as propionic acid, butyric acid, isobutyric acid, n-yaleric acid, caproic acid, n-heptyl acid, caprylic acid, 2-ethylhexanoic acid -Dimethylheptanoic acid and pelargonic acid. Typical examples of alkyl, substituted alkyl and aryl radicals have been given above.

Other esters suitable as base liquids are the monoesters.

Another class of base liquids suitable according to the invention are the polyphenyl ether, polyphenylthioether or mixtures thereof, of the formula

9

615 217

A

wherein A, Ai, A2 and A3 each represent a chalcogen with an atomic number of 8 to 16, X, Xi, C2, C3 and X4 each represent hydrogen, alkyl, haloalkyl, halogen, aralkyl or substituted aralkyl, m, n and o are integers from 0 to 8 and a represent the number 0 to 1, provided that if a = 0, n is the number 1 or 2. Typical examples of alkyl and substituted alkyl radicals are mentioned above. Typical examples of such basic liquids are 2- to 7-ring o-, m- and p-polyphenyl ethers and their mixtures, 2- to 7-ring o-, m- and p-polyphenylthioethers and their mixtures, mixed polyphenyl ethers / thio- ether compounds in which at least one of the chalcogens represented by A, Ai, A2 and A3 differs from the others, dihalogenated diphenyl ethers, for example 4-bromo-3'-chlorodiphenyl ether and bis-phenoxy-biphenyl compounds and mixtures from that.

Hydrocarbon oils including mineral oils from petroleum and synthetic hydrocarbon oils are also suitable as base liquids. The physical properties of functional liquids from a mineral oil are selected based on the requirements of the liquid system, and therefore mineral oils with a wide range of viscosities and volatilities, for example naphthenic, paraffinic and mixed mineral oils, are suitable in accordance with the invention.

The synthetic hydrocarbon oils include, but are not limited to, oils obtained by oligomerizing olefins such as polybutenes, as well as oils made by acid catalyzed dimerization and oligomerization with aluminum malkylene and titanium halides as catalysts, or with Friedel-Crafts or with peroxide catalysts higher a-olefins with 4 to 20 carbon atoms have been prepared.

Chlorinated biphenyls and terphenyls are also suitable as basic liquids.

When used as a functional or hydraulic liquid, the liquid mixtures according to the invention can also contain acid acceptors, dyes, pour point depressants, thickeners, antioxidants, anti-foaming agents, agents for improving the viscosity index, such as polyalkyl acrylates, polyalkyl methacrylates, polycyclic polymers, polyurethanes, polyalkylene oxides and polyesters, lubricants, water and the like contain.

The basic liquids described above can also be used individually or in the form of liquid mixtures which contain two or more basic liquids in varying amounts. The basic liquids can also be liquid in addition to the functional liquid

Contain components which can originate, for example, from coal tar products, synthesis products and synthetic oils, for example alkylene polymers (for example polymers of propylene, butylene and the like and mixtures thereof), alkylene oxide polymers (for example porpylene oxide polymers) and their derivatives, including alkylene oxide polymers, which can be produced by Polymerizing the alkylene oxide in the presence of water or alcohol, e.g. ethyl alcohol, 30 alkylbenzenes (e.g. monoalkylbenzenes such as dodecylbenzene, tetradecylbenzene and the like) and dialkylbenzenes (e.g. n-nonyl-2-ethylhexylbenzene), polyphenyls ( for example biphenyls and terphenyls), halogenated benzenes, halogenated (lower alkyl) benzenes and monohalogenated 35 diphenyl ethers.

According to a preferred embodiment of the invention, the ammonium salt of phosphoric acid is combined with a base liquid made of phosphate ester. The basic liquid then consists mainly of trialkyl phosphates, which are present in quantities of 50 to 95 and preferably 60 to 90% by weight. The best results are provided by trialkyl phosphates whose alkyl radicals have 1 to 20, preferably 3 to 12 and particularly preferably 4 to 9 carbon atoms. The alkyl radicals are preferably straight-chain. A single triylkyl phosphate can have the same alkyl radical in all three positions or one

Have mixture of different alkyl radicals. Mixtures of different trialkyl phosphates can also be used. Trialkyl phosphates which are suitable as base liquids are, for example, tripropyl phosphate, tributyl phosphate, trihexylpho-5o sphat, trioctyl phosphate, dipropyloctyl phosphate, dibutyl octyl phosphate, dipropyl hexyl phosphate, dihexyl octyl phosphate, dihexyl propyl butyl propyl butyl phosphate.

The trialkyl phosphates can be combined with triaryl phosphates or alkylaryl phosphates. Preferred trialkyl-55 phosphates are tricresyl phosphate, cresyl diphenyl phosphate, trixylenyl phosphate, tert-butylphenyl phenyl phosphate, ethyl phenyl dicresyl phosphate or isopropyl phenyl diphenyl phosphate, phenyl bis (4-a-methylbenzylphenyl), phenyl -decyl phosphate, diphenyl octyl phosphate, methyl diphenyl 60 phosphate, butyl di-cresyl phosphate and the like. According to a preferred embodiment, a base liquid mainly containing trixylenyl phosphate is used. The triaryl phosphate acts as a thickener for the trialkyl phosphates. The amount of triaryl phosphate can therefore be between 0 and 35% by weight. The preferred amount of the triaryl phosphates is from about 5 to about 30% by weight of the mixture.

To achieve the desired viscosity, the

615217

10th

Mixture of trialkyl and triaryl phosphate, conventional polymeric thickeners or agents for improving the viscosity index can be added. Typical thickeners are polyacrylates, polymethacrylates, polyethylene oxides, polypropylene oxides, polyesters and the like.

A polyester of azelaic acid and a diol such as propylene glycol or the like is preferably used in a quantity of 0.3 to 20% by weight.

Combinations of antioxidants and / or acid acceptors in amounts of about 0.1 to about 5% by weight can also be added to the hydraulic fluid, for example epoxides and / or amines. The mixture of 3,4-epocycyclohe-xylmethyl-3,4-epoxycyclohexane carboxylate and phenyl-a-naphthylamine was found to be particularly effective.

Corrosion inhibitors such as benzotriazole, quinizarin or the like can be added in amounts of 0.001 to 0.5% by weight with thorough mixing. A dye can also be added in a concentration of 5 to 20 ppm in a conventional manner. Effective amounts of a silicone anti-foaming agent, usually most effective in amounts of 5 to 50 ppm, can also be added.

The functional liquids according to the invention can contain up to about 1% by weight of water. However, the amount of water is preferably kept below 0.6 and particularly preferably below about 0.3% by weight.

In the following examples, all parts and percentages are by weight unless otherwise stated.

example 1

A base liquid of 78.98% by weight of tributyl phosphate and 9.70% by weight of mixed cresyl and xylenyl phosphates with a viscosity of about 220 Saybolt Universal seconds at 37.8 ° C is mixed with 9.00% by weight of a polyester -Thickening agent ("Plastolein 9789", manufacturer Emery Industries) mixed. Then 1.0% by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate and 1.0% by weight of phenyl-a-naphthylamine are added. Then 0.02% by weight of benzotriazole is mixed in with a conventional dye and anti-foaming agent in amounts of 20 and 15 ppm. Then dodecyltrimethylammonium diphenyl phosphate is mixed in various amounts between 0.1 and 0.3% by weight.

The above mixture was tested in a device which consisted of the tailgate valve of a Boeing 737, the associated Vickers axial piston pump and corresponding devices which ensure that the device meets the requirements of section 10.2 of SAE regulation AS 1241, which the erosion resistance of fire-safe hydraulic fluids for aircraft works. The fluids were rated based on the increase in leakage loss when the valve was closed or in the O position. The results with dodecyltrimethylammonium diphenylphosphate as an additive to the hydraulic fluid from phosphate ester were as follows:

% By weight

Leakage

conductivity

Dodecyl-trimethylammo-

consumption (ml / min / hour) (Micromho / cm)

nium diphenyl phosphate

no

7.0

0.021

0.1

2.0

0.10

0.3

0.0

0.29

These results show that by adding an effective amount of dodecyltrimethylammonium diphenylpho-

sphat to a hydraulic fluid from phosphate ester the wear of the hydraulic system is prevented.

Example 2

A similar erosion test was carried out with the hydraulic fluid from phosphate ester according to Example 1 and 0.3% by weight of dodecyltrimethylammonium diphenylphosphate. In this test, the concentration of chlorinated solvents was gradually increased to a final value of 2000 ppm chlorine.

Total chlorine (ppm)

Total trial leakage loss increase (h) (ml / min / h)

20th

40 (basic value) 440

275 (as CH3CCI3) 625

444 (as CH3CCI3) 730

938 (as CH3CCI3) 830 2000 (as CH3CCI3 and

CF2CICCI2F) 910

0 0 0 0

25 These values show the usefulness of dodecyltrimethylammonium diphenylphosphate for the prevention of wear which a hydraulic fluid contaminated with chlorine from phosphate ester adds to the hydraulic system.

30 Example 3

An erosion test was carried out with a proven hydraulic fluid from aircraft phosphate ester (Boeing Material Spec. 31 IC) (RMS-311-C) which was contaminated by 1000 ppm chlorine (as 1,1,1-trichloroethane). To

35 Determining the rate of erosion, increasing amounts of the hydraulic fluid from phosphate ester according to Example 1 + 0.3% by weight of dodecyltrimethylammonium diphenylphosphate were added to the contaminated fluid. The following values were determined:

40

BMS 311-C phosphate ester containing hydraulic. Liquid t 1000 ppm chlorine as CH3CCI3

Gew.-0 / «phosphate ester liquid.

Leakage loss increase containing 0.3% by weight

(ml / min / hour)

Dodecyltrimethylammonium diphenyl

phosphate

no

6.0

20th

6.0

35

0.8

50

0

55

60

These values illustrate the usefulness of a formulation containing dodecyltrimethylammonium diphenylphosphate for stopping the hydraulic system wear caused by the hydraulic fluid contaminated with chlorine from phosphate ester.

Example 4

In an erosion test similar to the experiment in Example 1, the properties 65 of the liquid according to Example 1 that caused wear were completely stopped by adding 0.5% by weight of a mixed mono- and bis- (dode-cylammonium) methylphosphate. This experiment illustrates the usefulness of mixed mono- and bis- (dodecylammo-

nium) methyl phosphate to stop the wear caused by liquids containing phosphate esters in hydraulic systems. The conductivity was before the addition Microohm _, / cm_I, then 0.24 Microohirr '/ cm-1.

Example 5

A mixture similar to the mixture of Example 1 was prepared. Two formulations were made with this mixture. The first contained 0.2% by weight of dodecyltrimethylammonium diphenylphosphate, the second 0.2% by weight of trioctylmethylphosphoniumdimethylphosphate. These formulations were subjected to the stability test described in Boeing Material Specification 311-C, with the following results being achieved:

Boeing thermal stability test:

Test conditions: 121 ° C; 168 hours of experiment; available as catalysts steel, magnesium, cadmium-plated steel, copper and aluminum.

Viscosity change Increase in the (cSt) acid number

Liquid 37.8 ° C 99 ° C (mgKOH / g)

Basic mixture + 0.2% by weight

Dodecyl-trimethylammo-

nium

diphenyl phosphate +0.10

+0.03

0

Basic mixture + 0.2% by weight

Trioctyl-methylphospho-

nium dimethyl phosphate - 1.11

-0.42

1.2

BMS 311-C Specification

Error limit +1.0

-0.3

+0.5

H 615217

These values show that formulations with dodecyltrimethylammonium diphenylphosphate as an additive show better thermal and oxidation resistance than formulations prepared with trioctylmethylphosphoniumdimethylphosphate.

Example 6

In an erosion test carried out according to Example 1, a hydraulic polyphenyl ether liquid from io mixed meta- and para-pentaphenylene tetroxides, which contained 0.2% bis (dodecylbenzyltrimethyiammonium) phenyiphosphate, was used, with this liquid less metal wear than with the same liquid without the addition of bis-ammonium phosphate occurred.

15

Example 7

In an erosion test carried out according to the procedure of Example 1, a liquid resulted from approximately 85% of a synthetic hydrocarbon oil (for example product of the 20 Royal Lubricants for use in hydraulic fluids MIL-H-83282), 15% trimethylolpropane triheptanoate and 0.2% Didodecyldimethylammoniumdidodecylphosphat less metal wear than the same base liquid without the ammonium phosphate.

Example 8

In an erosion test carried out according to the instructions of Example 1, a liquid consisting of about 50% mixed 30 alkyl-substituted phosphate ester, 40% aromatic mineral oil (for example "NUSO 95", Sun Oil Co. sales), 10% pentaerythritol tetraheptanoate and 0.2 % Nonylphenyltrimethylam monium dioctyl phosphate less metal wear than the same liquid without the ammonium phosphate.

G

, 1 sheet of drawings

Claims (15)

615217 2. Hydraulic liquid according to claim 1, characterized in that m is the number 1. 2nd PATENT CLAIMS 1. Hydraulic fluid, characterized by a content of (1) a basic fluid forming the main component, which esters or amides of an acid of phosphorus, mineral oils, synthetic hydrocarbon oils, orthosilicates, 5 alkoxypolysiloxanes, silicones, polyphenyl ethers, polyphenyl thioethers, chlorinated biphenyls, Contains dicarboxylic acid esters of monohydric alcohols, monocarboxylic acid esters of monohydric alcohols, monocarboxylic acid esters of polyhydric alcohols or mixtures thereof, polyalkylene ether alcohols or their esters or mixtures thereof, and (2) an ammonium salt of a phosphoric acid of the formula I. R ^ R1> -N-R »1 R '»' + m - m, 20th wherein R, R 'and R ", which may be the same, different or connected to one another, are hydrogen, alkyl, aryl, alkaryl or aralkyl having 1 to 30 carbon atoms, R" alkyl, aryl, alkaryl or aralkyl having 1 to 30 carbon atoms, X represents oxygen or sulfur, Y 'and Y "alkoxy, alkylthio, alkyl, aryl, alkaryl, aralkyl, aryloxy, arylthio or alkaryloxy, Z represents oxygen and m represents the number 1 or 2. 3. Hydraulic liquid according to claim 1, characterized in that the base liquid consists of a mineral oil, synthetic hydrocarbon oil, ester or amide of a phosphoric acid or mixtures thereof, the esters or amides having the formula O ir MYL-MyiL-KI! (Ts) b Ri, wherein Y is oxygen, sulfur or the rest b -N- Yi oxygen, sulfur or the rest 4. Hydraulic liquid according to claim 3, characterized in that the basic liquid consists of a mixture of an ester of a phosphoric acid with a mineral oil. ! 4th 25th 30th 35 Y2 oxygen, sulfur or the rest -N- and R, Ri, R2, R3, R 'and Rs are alkyl, alkoxy, aryl or substituted alkyl and a, b and c are integers from 0 to 1, the sum of a + b + c being a number from 1 -3 is. 5. Hydraulic fluid according to claim 3, characterized 40 45 50 55 60 65 characterized in that the base liquid consists of a mixture of an ester of a phosphoric acid with a synthetic hydrocarbon oil. 6. Hydraulic liquid according to claim 3, characterized in that it contains as an ester of a phosphoric acid trial-kylphosphate, triaryl phosphate, alkaryl phosphate, aralkyl phosphate or mixtures thereof. 7. Hydraulic liquid according to claim 6, characterized in that it contains a mixture of trialkyl phosphates and triaryl phosphates as the ester of a phosphoric acid. 8. Hydraulic liquid according to claim 7, characterized in that it contains 50 to 90% by weight of trialkyl phosphates and up to 50% by weight of triaryl phosphates. 9. Hydraulic liquid according to claim 7, characterized by a thickener. 10. Hydraulic liquid according to claim 3, characterized in that it contains the ammonium salt in an amount of 0.01 to 10 wt .-%. 11. Hydraulic liquid according to claim 3, characterized in that it contains the ammonium salt in an amount of 0.1 to 2.0 wt .-%. 12. Hydraulic liquid according to claim 3, characterized by an acid acceptor. 13. Hydraulic liquid according to claim 3, characterized by a dye and a silicone antifoam. 14. Hydraulic liquid according to claim 3, characterized by an antioxidant. 15. Hydraulic liquid according to claim 1, characterized in that Y * and Y "of the formula mean lower alkyl or phenyl.