DE1083010B - Power transmission fluid - Google Patents

Description

The invention relates to power transmission fluids for use in apparatus in which mechanical forces are transmitted or absorbed, as in automobiles, traction transmissions, hydraulic brakes, clutches and other mechanical devices.

The good work of various force-transmitting mechanisms, especially when it comes to complex force transmission in automobiles, in liquid-cooled braking devices, lubricated by oil Fluid couplings, planetary gears and hydraulic rain mechanisms depend on a suitable one Cooling and lubrication of the device. There have been strict requirements for this Purpose to select suitable liquids, with resistance within a wide temperature range at both high and low temperatures and a low pour point are required to achieve a to ensure adequate pumpability and flowability at low temperatures. The liquids must not have any harmful effect on machine parts with which they come into contact, e.g. B. on metal surfaces such as copper and solid, non-metallic surfaces such as organic resins and the like desired friction properties and in some cases favorable behavior at extremely high pressures have adequate lubrication of gears, clutch disks and other parts of the device, in which they are used, e.g. B. in automobiles and tractors. The liquids may also be caused by the effect of frictional vibration and / or by sticking and grinding of the clutch disks or other machine parts do not cause rattling, creaking or whistling or other noises cause.

Various power transmission fluids are known in the art known that are based on mineral or synthetic oils (organic esters and polyethers) and, as additives, organic phosphates, fatty acids and their esters or contain halogenated compounds and polymers such as polyacrylates. But there are no mixtures of this type fully satisfactory because there is a rattling and other noises caused by frictional vibration and / or cannot prevent such clutch disks from getting stuck, especially with Facilities that operate at high speed and at high temperatures.

For example, it has been recommended to improve the cleaning effect and friction-preventing properties of a mineral oil-based lubricating oil used for power transmission through the combined addition of H ₂ S-free alkaline earth salts of an alkylphenol sulfide, of fatty acids with 12 to 22 carbon atoms in the molecule

Applicant:

N. V. DeBataafschePetroleumMaatschappij, The hague

Representative: Dr. K. Schwarzhans, patent attorney,
Munich 19, Romanplatz 9

Claimed priority:
V. St. v. America June 14, 1957

Theodore W. Havely, Alton, 111.,

Stanley Richard Sprague, East Alton, HL,

and Laurence Clayton Westcott, Edwardsville, 111.

(V. St. Α.),
have been named as inventors

as well as an alkyl mercaptoacetic acid with 8 to 24 carbon atoms in the alkyl radical.

For the same purpose, the combination of a P ₂ S ₅ -treated alkaline earth metal salt of an alkylphenol sulfide with oleic acid and optionally a triester of phosphoric acid has been described as an additional mixture.

Furthermore, it is known to use lubricating oils as rust preventive agents, which contain salts of ester acids of phosphorus z. B. can be obtained by esterification of phosphoric acid with loro alcohol, with cyclic amines, such as bicyclohexylamine.

Further, the suitability of salts of a branched chain primary aliphatic amine with at least 8 carbon atoms and a halogenated organic acid of pentavalent phosphorus, such as trichloromethane phosphonic acid, has been described as a high-pressure additive for lubricating oils.

However, the technical problem on which the invention is based can be solved by means of these known additives do not solve satisfactorily.

It has now been found that excellent power transmission fluid can be obtained which satisfactorily meets the above requirements when this liquid is a predominant part of a mineral oil and minor parts of a) an aliphatic monocarboxylic acid having at least 18 carbon atoms and b) a

009 529/267

Neutralization product of an aliphatic amine with at least 8 carbon atoms and an acidic one Contains mono- or dialkyl pyrophosphate with at least 8 carbon atoms.

The additional component a) preferably contains 18 to 30 and very particularly advantageously 18 to 26 carbon atoms. Examples of suitable acids are: stearic, arachidic, behenic, cerotinic, montanic acid and mixtures the same.

The amine from which additive b) is derived preferably contains 8 to 18 carbon atoms and very particularly advantageously 16 to 18 carbon atoms. Preferred amines are the primary and secondary saturated or unsaturated aliphatic amines. Mixtures of amines can be used if desired. Examples of suitable amines are: octylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, octadecenylamine, octadecadienylamine, dioctylamine, didodecylamine, dioctadecylamine, diqctadecadienylamine and amines, which are derived from fatty oils or tallown oil, coconut oil, soybean oil or tallow oil, such as fatty oils or cottonseed oil . B. the amines of soybean oil, coconut oil, tallow, or mixtures of such substances. Amines of this type are z. B. dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, mixture of tetradecyl-, hexadecyl- and octadecylamines, mixtures of hexadecyl-, octadecyl-, octadecenyl- and octadecadienylamine. The unsaturated amines, such as octadecadienylamine, are preferred. Polyamines can also be used. Preferred polyamines are the N-alkylalkylene that by the process according USA. Patent 2,736,658 are prepared, it is C ₁₂ - to Cig-Alkyltrimethylendiamine is derived from coconut or soybean oil or tallow.

The acidic mono- or dialkyl pyrophosphates, from which the additional component b) is derived, include Mono- and dioctyl pyrophosphates, mono- and didodecyl pyrophosphates, mono- and ditetradecyl pyrophosphates, Mono- and dihexadecyl pyrophosphates, mono- and dioctadecyl pyrophosphates. Preference is given to monooctyl pyrophosphate, Dioctyl pyrophosphate, monododecyl pyrophosphate, didodecyl pyrophosphate, monooctadecyl pyrophosphate, Dioctadecyl pyrophosphate and mixtures of such compounds.

• The reaction between the amines and the pyrophosphate is exothermic and must be controlled in such a way that decomposition is prevented. In general, the reaction temperature is between 50 and 100 ° C and preferably to entertain at 8O ⁰ C. The molar ratio of the reactants is generally between 1 and 5 moles of the amine per mole of pyrophosphate, and it is preferred that the reaction be carried out under conditions such that the end product does not contain free acid but may contain some free amine.

Examples of amine pyrophosphate reaction products are listed in the table below.

at
game Amine Acid pyrophosphate Mole
relationship Reaction
temperature I. Amine A * Dioctyl pyrophosphate 2: 1 70 ° C II Amine A * Dioctyl pyrophosphate 5: 1 70 ° C III Amine A * Dioctyl pyrophosphate 2.2: 1 70 ° C IV Octadecyl Lauryl pyrophosphate 5: 1 80 ° C amine V Dodecyl Dodecyl pyrophosphate 5: 1 80 ° C amine VI Amine B ** Dioctyl pyrophosphate 4: 1 70 ° C

* Amine A = mixture of 10% hexadecylamine, 10% octadecylamine, 35% octadecenylamine and. 45% octadecadienylamine.
** Amine B = C ₁₂ - to Cjg-trimethylenediamine, derived from tallow.

Liquids of the type described above operate noiselessly and their static coefficient of friction is low. For certain applications, however, the static coefficient of friction should be high. For example, in the case of fluids used in parking brakes, it is desirable that the degree of friction is high (at least 0.125 μ.), So that this creates a coefficient of friction that is sufficient to overcome the pull caused by gravity at an incline of 30 °. This can be achieved by adding a small amount (generally from 0.1 to 10 ° / _0, preferably x ^1, 0.5 to 5 weight percent) of an oil-soluble alkali or alkaline earth metal salt of an organic sulfonic acid. Special sulfonates are oil-soluble sodium, potassium, calcium and barium petroleum sulfonate, -tetratert. butyl naphthalene sulfonate, dinonyl naphthalene sulfonate, diwax naphthalene sulfonate, diwax benzene sulfonate, stearyl benzene sulfonate, tert. octylphenolsulphonate, -wax phenolsulphonate and mixtures of such compounds. Oil-soluble sodium, calcium and / or barium petroleum sulfonate and dinonylnaphthalene sulfonate are preferred.

Preferably, a small amount (preferred ^ 0.1 ° to 5 ° / ₀₎ of a suitable Antioxydationsmittels the liquid incorporated. Two groups of antioxidants are particularly suitable, namely, firstly, an oil-soluble organic thiophosphate of a metal of Group II of the Periodic Table with an atomic number of 12 to 56 or, secondly, a mixture of an alkylphenol and an arylamine. The antioxidants of group 1 include salts of metals of group II of the periodic table with alkyl, aryl, alkaryl or cycloalkyl mono- and. -di, -thio- or -ditHophosphorsäuren, such as calcium, barium or zinc alkyl, -cycloalkyl- or -aryl -monor and -dithiophosphate. Preferred compounds are calcium, barium and zinc methylphenyldithiophosphate, dimethylcyclohexyldithiophosphate, dihexyldithiophosphate, laurylbenzyldithiophosphate and mixtures thereof.

A particularly preferred group of such Verbinr fertilize includes the zinc and barium salts of dimethylcyclohexyldithiophosphate, the barium salt of P ₂ S ₅ -

Polybutylene reaction products and / or P ₂ S ₅ terpene (pinene) reaction products.

The group 2 anti-oxidant mixture contains alkylphenols, e.g. B. Di- and trialkylphenols, such as 2,4-, 2,3-, 3,4-, 2,6- or 3,5-diamylphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-Ditert.butyl-4-methylphenol, as well as arylamines such as phenyl-a-naphthylamine or phenyl - /? - naphthylamine.

Other optional additives for the mixtures according to the invention are anti-foaming mit-ία tel, such as silicone polymers, preferably with a viscosity in the range of 100 to 1000 cSt at 25 ° C.

The mineral oil preferably has a high viscosity index and a low pour point. The viscosity can vary within wide limits, e.g. B. from SUS at 37.78 ° C to ISO SUS at 98.89 ° C. Suitable Oils are mineral spray oils, transformer oils and lubricating oils with an SAE number of 10, 20, 30 etc. Well refined oils are preferred. Examples of suitable oils are:

Oil A (mineral oil SAE-10)

Viscosity at 38 ° C 175 SUS

Viscosity at 99 ^° C. 45.2 SUS

Viscosity index 106

Flash point 202 ° C

Fire point 227 ° C

Pour point -37 ⁰ C

Oil B (highly refined transformer oil)

Specific gravity 30.9 ° API

Color 30

Viscosity at 38 ° C 56.9 SUS

Flash point 143 ° C

Focus 160 ⁰ C

Pour point below -57 ° C

Oil C (refined lubricating oil)

Specific gravity 31.2 ° API

Color (ASTM) -1

Pour point -3O ⁰ C

Flash point 132 ° C

Focus 146 ° C

Viscosity at 38 ⁰ C 48 SUS

Viscosity index 33

Mixture C

Stearic acid 0.2 percent by weight

Additive according to Example 2 0.2 percent by weight

Dimethyl silicone polymer

(500 cSt at 25 ° C) 0.0005%

to 1 million parts

Transformer oil B rest

Mixture D

Cerotic acid 0.3 percent by weight

Additive according to Example 6 0.2 percent by weight

Transformer oil B rest

Examples of mixtures according to the invention are given below:

Mixture A

Mixtures according to the invention prevent noise, frictional vibration and sticking of a wide variety Devices such as liquid-cooled hydraulic braking systems in which the Friction parts made of steel and elastic or semi-metallic or consist of fully sintered metallic friction material. It became an evaluation carried out by practical automobile tests, measuring the noise made after acceleration and caused by sudden stopping of the vehicle. Here the value 10 was awarded as excellent (without making a noise or getting stuck) and the value 0 as bad with a lot of noise and severe sticking. The values were for mixtures A, B, C and D. between 8 and 10. The mineral oils B and C, each containing 0.2% stearic acid or 0.2% cerotic acid, resulted in values of 4 and 5, respectively, while the same Oils with 0.2% stearic acid and 5% neutral calcium petroleum sulfonate each gave a value of 5.

Transformer oil B or mineral oil C with 0.5% each of acid n-octyl phosphate, dioctyl phosphate or triisooctyl phosphate gave values of 4, 1 and 1. The transformer oil B, the 0.4% acid lauryl phosphate contained the value 3.

The static coefficient of friction of mixtures B, C and D was about 0.04 μ., While the static coefficient of friction of Mixture A, which contained 2.5% neutral calcium petroleum sulfonate, was 0.130μ. The addition of 2.5% neutral calcium dinonyhiaphtha insulfonate or barium dinonymaphtha unsulfonate or of Neutral calcium petroleum sulfonate to mixture C increased the static coefficient of friction of the mixtures from 0.04 to 1.52 or 1.88 or 1.42 μ. These values are well above the required minimum of 0.125 µ. On the other hand, the addition of 2.5% CaI-

Stearic acid 0.2 percent by weight of cium naphthenate or calcium C ₁₄ to C ₁₈ alkyl alkoxide

Addition according to Example 1 0.2 percent by weight or of zinc dimethylcyclohexyldithiophosphate or

Calcium petroleum sulfonate 5.0 percent by weight tricresyl phosphate to mixture C a static

Zinc dimethylcyclohexyldithio coefficients of friction of 0.086, 0.49 and 0.052, respectively

phosphate 0.5 percent by weight 55 or 0.091 μ. These values are below the required

Dimethyl silicone polymer minimum value of 0.125 μ.

(1000 cSt at 25 ⁰ C) 0.0005%

on 1 Mülion Teüe mineral oil C rest

Mixture B

60

Stearic acid 0.2 percent by weight

Additive according to Example 1 0.2 percent by weight

2,6-di-tert-butyl-4-methylphenol 0.2 percent by weight

Phenyl-a-naphthylamine 0.1 weight percent

Dimethyl silicone polymer

(500 cSt at 25 ° C) 0.0005%

on 1 Mülion Teüe transformer oil B rest

Claims (10)

Patent claims: 1. Power transmission fluid based on a mineral oil with a content of an aliphatic monocarboxylic acid, characterized by a low content of a) an aliphatic saturated monocarboxylic acid with at least 18 carbon atoms in the molecule and b) a neutralization product of an aliphatic amine with at least 8 carbon atoms and an acidic mono - Or dialkyl pyrophosphates also having at least 8 carbon atoms in the molecule. 2. Power transmission fluid according to claim 1, characterized in that the additive a) 18 to 30 and especially 18 to 26 carbon atoms contains in the molecule. 3. Power transmission fluid according to claim 1 and 2, characterized in that the additive a) Is stearic acid or cerotic acid. 4. Power transmission fluid according to claim 1 to 3, characterized in that the content of the additive a) 0.01 to 10 percent by weight, preferably 0.05 to 2 percent by weight and in particular 0.1 to 1 percent by weight, based on the total liquid. 5. Power transmission fluid according to claim 1 to 4, characterized in that the amine des Additive b) an aliphatic.es amine with 8 to 18 carbon atoms and in particular with 16 to There are 18 carbon atoms in the molecule. 6. Power transmission fluid according to claim 1 to 5, characterized in that the phosphate des Additive b) is mono- or dioctyl pyrophosphate. 7. Power transmission fluid according to claim 1 ao to 6, characterized in that the content of the additive b) 0.01 to 10 percent by weight, preferably 0.05 to 2 percent by weight and in particular 0.1 to 1 percent by weight, based on the total liquid. 8. Power transmission fluid according to claim 1 to 7, characterized by the further content of Compounds known per se as additives for power transmission fluids from the group of Alkali or alkaline earth salts of an organic sulfonic acid, in particular sodium, calcium and / or Barium petroleum sulfonate or dinonylnaphthalene sulfonate in amounts of preferably 0.5 to 5 percent by weight based on the total liquid, and the silicone polymers such as dimethyl silicone polymers. 9. Power transmission fluid according to claim 1 to 8, characterized by the further content of a per se known as an additive antioxidant, e.g. B. an oil-soluble organic thiophosphate a metal of Group II of the Periodic Table with an atomic number from 12 to 56, such as Zinc dimethylcyclohexyldithiophosphate, or a mixture of an alkylphenol and an arylamine, such as from 2,6-Ditert.butyl-4-methylphenol and phenyla-naphthylamine, in amounts of preferably 0.1 to 5 percent by weight, based on the total liquid. 10. Liquid according to claim 1 to 9, characterized in that the mineral oil base has a viscosity has between 40 SUS at 38 ° C and 150 SUS at 99 ° C. Considered publications:
German Patent No. 958 325;
U.S. Patents Nos. 2,605,226, 2,731,418,
768 953. © 009 529/267 5.60