DE2046368B2 - Additive for lubricant mixtures - Google Patents

Description

The present invention relates to additives for training mixtures.

Lubricant mixings should reduce the friction between Minimize moving parts, generally using more viscous lubricants a better separation of the moving parts at the relevant working temperatures cause when these parts are pressed against each other under load. On the other hand show

Ί highly viscous lubricants compared to low viscosity Lubricants of the same chemical composition have several disadvantages, such as one greater tendency to decompose under the action of heat and non-volatile deposits such as coke to form

in form. These difficulties occur in particular Storage of turbine cores in gas turbines, but also in other contexts.

Relatively low viscosity lubricants should be used to overcome these difficulties - '> det, which at higher temperatures leads to less deposition of non-volatile decomposition products tend. However, these mixtures are generally less resilient. But the resilience exists generally related to the

2 »kinematic viscosity, and it is useful to provide such mixtures with additives in order to improve the load-bearing capacity.

According to the invention, an additive for lubricant mixtures is now proposed, which from the

r> combination of two components A and B. Component A is a neutral hydrocarbon phosphate and component B is a neutral alkylamine hydrocarbon phosphate. The component B contains at least one monohydric

i »material dialkylamine phosphate.

From US-PS 27 86 028 phosphates are already known as additives for lubricant mixtures that the Component A are similar, while from US-PS 25 16 913 alkylamine phosphates according to component B

r> are known as lubricant additives. However, it must be regarded as surprising that a combination of a neutral phosphate with an amine salt of a phosphate a synergistic increase, especially with regard to the load-bearing capacity of the lubricant

"I tel composition results.

Derivatives of phosphoric acid are called neutral phosphates, all three of which are replaceable Hydrogen atoms of each phosphoric acid molecule are substituted.

The alkylamine radical of component B can be 8 to 18 Carbon atoms and preferably 10 to 14 carbon atoms, and the alkyl radical can be at least one of the alkylamine radicals can be a tertiary alkyl radical.

> »The hydrocarbon radicals of component B can be alkyl radicals or aryl radicals with 1 to 9 Be carbon atoms. The hydrocarbon radicals are preferably aliphatic Ci to Ci radicals.

The hydrocarbon residues of component Λ

"'" ■ can be the same or different and can either Be alkyl, aryl or aralkyl radicals.

The proportion of component A is preferably greater than the proportion of component B, the Component A 50 to 97.5% by weight and preferably

<> <> 85 to 97.5 wt .-% of the additive can make up.

In addition to components A and B, the additive according to the invention can also contain a metal deactivator included to prevent corrosion of the metal /.u, the one with the additive in the lubricant in

i'i is connected, furthermore an oxidation inhibitor be present to prevent oxidation of the mixture of cuttings to prevent; Furthermore, anti-foaming agents can be added.

The additives according to the invention result in a surprising improvement in terms of load-bearing capacity of lubricants, so that it is now possible. Use lubricants at elevated temperatures less prone to the deposition of non-volatile constituents, without the resilience of the itself to reduce parts that move towards one another and have to be lubricated.

Accordingly, the invention also includes a lubricant mixture, which consists of a major portion of a Lubricant and a smaller proportion of the mentioned lubricant additive.

The lubricant can be of any type including, for example, a hydrocarbon or a polyether but preferably at least one ester, the esters being so-called "hindered" esters, in which a quaternary carbon atom is either in the beta position in the or in the alcohol residues to the ester bond and / or in the acid residue or residues in the alpha position relative to the ester bond.

The ester lubricant may have a viscosity measured at 99 ° C of 7 cSt or less, such as 2 to 6 and, for example, about 3.3 cSt. Obgleicii the lubricant so proportionately can have low viscosities and correspondingly low load properties - as in general with a given lubricant, the load capacity is improved with increasing viscosity - has the Lubricant mixture containing additive according to the invention load-bearing properties that are surprising are good in comparison with the pure lubricant, and in comparison with combinations of the Lubricant that contains either component A alone or component B alone.

Component A can make up from 1 to 4, preferably 1.5 to 2.5% by weight of the lubricant mixture, while component B makes up 0.025 to 1.0, preferably 0.05 to 0.25% by weight of the total mixture.

Several lubricant mixtures are described below to explain the advantages of the additives according to the invention are described.

Two basic lubricants with different viscosities but with the same chemical composition were examined to determine the load capacity.

A lubricant I was used once as the starting lubricant, which had a viscosity of 99.degree possessed of 5.3 cSt and which was a tetraester of pentaerythritol, the nit a mixture of C, - to Gr monocarboxylic acid was esterified, while the other lubricant II had a viscosity of 99 ° C 3.3 cSt and consisted of an ester mixture composed of 92% by weight of the triester of trimethylolpropane, which was esterified with a mixture of about C-, bis (^ -monocarboxylic acids and 8 wt .-% Composed of neopentyl glycol dipelargonal.

In the investigation methods, known additives were added to lubricants I and II in order to prevent oxidation of the lubricants and corrosion of the metal surfaces with which the lubricant is in contact. The concentrations of oxidation inhibitor and corrosion inhibitor corresponded to the optimal concentration for the inhibiting effect. In addition, a small amount of about 0,001 ⁰ / "of a known anti-foam silicone w.irde / us.itzes added. The lubricants each contained 2.00% by weight of the oxidation inhibitor, 0.07% by weight of the corrosion inhibitor and 0.001% by weight of the foam-preventing additive.

The Schiniermitte! I was mixed with various additives consisting of components A and B. and examined. Cresyl diphenyl phosphate was used as component A, which is obtained by reacting > Phosphorus oxychloride with a mixture of cresols and phenols.

An alkylamine hydrocarbon phosphate was used as component B, which was obtained as an easy-to-prepare reaction product from a mixture of methyl mono- and dihydrogen phosphates with a commercially available alkylamine. A primary amine of the formula R-NH _{2 was} used as the alkylamine, where R is a tertiary alkyl radical with an average of about 13 carbon atoms. The ι '·> component B was produced as follows:

3 moles of anhydrous methanol were carefully mixed with 1 mole of phosphorus pentoxide according to the following equation implemented.

^J "3 CII ₁ OII + 1 ', Os

- - CH ₁ OIO (OII), + (CH, O), P (O> OH

Excess methanol was removed from the obtained mixture of acidic phosphates by vacuum distillation removed.

If essentially a pure monomethyl dihydrogen phosphate is required, 1 mole of trisodium phosphate can be converted into disodium phosphate with 1 mole of methyl iodide implement, in a mixture with only a small amount of dimethyl sodium phosphate after following equation:

NiI ₁ I ¹ O, f CHJ - ► CII.OlNiiOM'O + N; ü

The reaction product is acidified with hydrochloric acid, the corresponding methyl substituents being acidic Phosphates are obtained, which are extracted with ether.

If there. ¹ : The end product of component B is to be a dialkylamine monohydrocarbon phosphate which does not contain any dihydrocarbon alkylamine phosphate, the small amount of dimethyl hydrogen phosphate can be separated from the dihydrogen methyl phosphate by fractional distillation under reduced pressure. Preliminary investigations showed, however, that the presence of the monoalkylamine derivative does not call into question the advantages of the additive according to the invention, especially if the dialkylamine derivative makes up the greater proportion of component B.

Component B was thus derived from the above-mentioned mixture of acidic methyl phosphates obtained from the process described first by neutralization with the primary amine R - NH2, in which R is a tertiary alkyl radical with im Average is 13 carbon atoms, with the water present in the product being through azeotropic distillation was removed. In the tests with this lubricant I with a content of about 60 percent by weight dimethyl tert-dodecylamine phosphate and 40 percent by weight of Metliyldi-ftert.-doih Cylaminjphosphat were with and without additives, dt 1 Components A and B in a standard 4-ball prül machine obtained the following results.

attempt

Lubricant composition

middle Hertzbelaslunn in kg

Try lubricant / usam no. setting

Limit load
in% at

1 lubricant I 26.7

2 lubricants 1 + 2 wt% 41.4
Cresyl diphenyl phosphate
Component A

3 lubricants 1 + 2 wt% 41.7
Component B

4 lubricant I + 0.1 wt% 47.0
Component A + 0.1% by weight
Component B

Improving resilience by adding the Component A results from a comparison of tests 1 and 2, while a comparison of tests 1 and FIG. 3 shows that a component B addition to lubricant I is even better. Experiment 4 shows an extremely surprisingly good value in relation to the previous attempts and shows a mutual Influence or a synergistic effect between the various additives, where still to it must be taken into account that a small increase in the load capacity in two attempts is approximately logarithmic Relation. Since there is no reason for the synergistic effect, this represents Improving the load capacity is an extremely surprising effect. The load capacity of the lubricant I in experiment no. 4 suggests that the somewhat poorer loading capacities of the lower viscosity Lubricating Oil II can be significantly improved so that it can now be used under such stress for which it was previously not suitable.

Experiments have confirmed that the conclusion drawn from the experiments with lubricant I also applies to lubricant II. These experiments were conducted with a standard IAE transmission conducted with the lubricant or the lubricant mixture was at a temperature of 110 ⁰ C. The values of the limit load with the IAE test gear have a simple linear relationship to one another and are given below as a percentage of a reference lubricant that consists of a mixture of esters of Gt to Ce dicarboxylic acids with C ₈ to Cin alcohols with a viscosity of 7.5 cSt, which is much more viscous than the lubricant II at this temperature. As component A, tricresyl phosphate was used, which can be prepared analogously to cresyl diphenyl phosphate.

attempt Lubricant composition Cirenzhe burden No. composition in% at 2 (X) O MIC) RPM. I l / min. 1 Lubricant II 63.4 73.2 ?. () Weight .- "· ,, component Λ 7th Lubricant II + 90 KK) ¹ J (I 100 (II (iew.- ¹¹ · ;, Component B

2000
RPM.

6 (KX)
RPM

Lubricant II + 185 140

2.0% by weight of component A + 0.1% by weight /.
Component B

These test values show that between the components of the additive according to the invention a synergistic effect occurs, which leads to a significant improvement in the resilience of lubricants Base of a lubricant II leads. The resilience values in this test exceed the resilience values of the more viscous reference oil by a considerable amount.

Furthermore, the high temperature stability of these oil mixtures was tested in a Rolls-Royce stability test determined when the lubricant to be tested was sampled for 192 hours in closed containers stainless steel were examined. After 192 hours, the portion of the insoluble in toluene became Materia! determined, which is a measure of the amount of non-volatile deposits at the test temperature represents. Here the temperature, the so-called S3 temperature, is determined at which a content of 0.5 % By weight of material insoluble in toluene is obtained. If no sample is 0.5 wt% toluene-insoluble Material supplies, a theoretical Sj temperature can be obtained by interpolation or extrapolation from the Toluene-insoluble content in material can be calculated. In detail, the following values were obtained:

lubricant + 2.0 Wt. - ¹ Xn Si-'I "cnipcratur in ( Sehmiermittel Il + 2.0 Wt .- "/ ,, 290 Component Λ ■ 0.1 ( iew .- "/, Lubricant Il 315 Component Λ -t Component H

These values show that a composition according to the invention does not result in fewer deposits volatile material at elevated temperatures, as for example the same lubricant 11 with a Addition of component A alone.

Component A can not only have cresyl or phenyl radicals as hydrocarbon radicals, but also as Component A can also be used other neutral hydrocarbon phosphates in the Base lubricants are soluble, with neutral aryl or alkali phosphates being particularly preferred, although neutral aliphatic phosphates can also be used. The hydrocarbon residue can also the component is an alkyl group, a phenyl group or an aralkyl group. but preferably one Be an alkyl radical, the radicals 1 to 9 preferably having 1 to 4 carbon atoms. As already mentioned, the alkylamine radical can have 8 to 18, preferably 10 to 14 carbon atoms and can in each Alkylamine radical have a tertiary alkyl radical.

Claims (10)

Patent claims: 1. Additive for lubricant mixtures, including uus A) a neutral hydrocarbon phosphate with all three replaceable hydrogen atoms the phosphoric acid have been replaced by hydrocarbon residues, B) a neutral alkylamine hydrocarbon phosphate component, the at least one Monohydrocarbon dialkylamine phosphate
contains and where applicable C) a metal deactivator, an oxidation inhibitor and / or an anti-foaming agent. 2. Additive according to claim 1, characterized in that it contains a component B whose Alkylamine radicals from 8 to 18, preferably from 10 to 14 carbon atoms. 3. Additive according to claim 1 or 2, characterized in that it contains a component B, whose alkylamine radicals have at least one tertiary alkyl radical. 4. Additive according to claims 1 to 3, characterized in that it contains a component B, whose hydrocarbon radicals have 1 to 9, preferably 1 to 4 carbon atoms and in particular are aliphatic radicals. 5. Additive according to claims I to 4, characterized in that it is used as component B. neutral monoilkylamine dihydrocarbyphosphate contains. 6. Additive according to claim 5, characterized in that it contains a component B, the proportion of which of monohydrocarbyklialkylaminophosphate is greater than the proportion of monoalkylamine dihydrocarbyl phosphate. 7. Additive according to claims I to h, characterized in that it contains a larger proportion, preferably 85 to 97.5% of component A. 8. Use of the component mixture according to claims 1 to 8 as an additive in one A lubricant which contains at least one ester, which is preferably a quaternary carbon atom either in the alcohol residue in the beta position to the ester bond and / or in the restoration residue in the alpha position possesses for ester linkage. 9. Use of the component mixture according to Claim 8 as an additive in a lubricant having a viscosity of 5 cSt or less at 99 ° C. 10. Use of the component mixture according to claims 8 and 9 as an additive in one Lubricant, with component A 1 to 4, preferably 1.5 to 2.5 wt .-% of the oil mixture and component B makes up 0.025 to 1.0, preferably 0.05 to 0.25% by weight of the mixture.