DE2129003A1 - Lubricating oil mixture - Google Patents

Description

Esso Research and (prio 24.7.70 - GB 36OO9 / 7O

Engineering Company - 8097) 2129003

linden, NJ / V.St.A. Hamburg, June 9th, 1971

Lubricating oil mixture

The invention relates to lubricating oil mixtures with an additive to improve load-bearing capacity.

Specifications applicable to lubricating oils of 5 cSt for gas turbine engines for aviation, such as the specification DERD 2497 of the US Department of Defense or the US Navy specification XAS 2354, require lubricating oils based on synthetic esters a resilience which is mostly outside the capacity of the base oil itself. To meet these requirements So additives must be used to improve the load capacity. Lots of so far for this purpose However, the proposed additives have a corrosive effect or have a harmful influence on silicone rubber or are hydrolytically unstable, so that a lubricating oil mixed with them is mostly for general use in aviation is unsuitable.

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An additive has now been found, which is not only the resilience of lubricating oils based on synthetic esters but also those based on mineral, animal or vegetable oils improved and not to a lubricating oil with the disadvantages mentioned above leads.

Accordingly, the present invention proposes a lubricating oil mixture which is characterized by this is that they have a major part by weight of lubricating oil and a smaller part by weight of the amine salt of a halogen-substituted Carboxylic acid in which there is at least one halogen atom in (X-position, as well as one Contains a small percentage by weight of antioxidants. Preferably such a lubricating oil mixture also contains still a small percentage by weight of corrosion inhibitor.

The lubricating oil itself can consist of any mineral, animal, vegetable or synthetic oil, such as from petroleum fractions from naphtha oils to spindle oils to lubricating oils with SAE grades of 30, 40 or 50, from oxidized mineral oil or from vegetable, animal or fish oils such as castor oil, palm oil, lard oil, Tallow oil, peanut oil, or sperm oil.

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A synthetic ester is preferably used as the lubricating oil. Suitable esters are, for example, diesters the general formulas

BCOOCR'COOS and RCOOR ¹ OOCH, in which R is an alkyl group with 6 to 12 carbon atoms and R ^{1 is} a saturated aliphatic hydrocarbon residue with 4 to 10 carbon atoms or a saturated aliphatic hydrocarbon residue interrupted by ether groups. These esters can be made from alcohols and dicarboxylic acids or glycols and monocarboxylic acids.

Another class of esters suitable as lubricants comprises the polyesters, which are polyvalent by reaction Alcohols, e.g. those with 2 to 12 hydroxyl groups and 2 to 40 carbon atoms in the molecule, such as Trimethylpropane, pentaerythritol and dipentaerythritol, with Monocarboxylic acids, such as butyric acid, caproic acid, caprylic acid and pelargonic acid, to the corresponding tri- or tetraesters can be obtained.

Complex esters, which can be used as base oils, are obtained by esterifying a dicarboxylic acid with a Glycol and an alcohol and / or a monocarboxylic acid. These esters can be represented by the following formulas will!

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R ₁ -OOCR ₂ COO- (R ₃ -OOCR ₂ COO) _n -R ₁ R ₁ - (OOCR ₂ COO-RJ _n OOCR ₄

where R ₁ for alkyl radicals of monohydric alcohols, R ₂ for hydrocarbon radicals of dicarboxylic acids, e.g. alkanedioic acids, R ₃ for divalent hydrocarbon or hydrocarbonoxy radicals, such as -CH ₂ (CH ₂ ) - or -CH ₂ CH ₂ (OCH ₂ CH ₂ ) _n - or '-CH ₂ CH (CH ₃ ) (OCH ₂ CH (CH ₃ )) _n ~, of alkylene glycols or polyalkylene glycols and R _{4 stands} for alkyl radicals of monocarboxylic acids, where η is an integer of 1 depending on the viscosity desired for the product to 6, which can be adjusted by the molar ratio of the glycol or polyglycol to the dicarboxylic acid. Somewhat simple esters are always formed during the production of the complex esters, ie esters in which n = 0, but the proportion is usually only small. In general, these complex esters contain a total of 15 to 80, for example 20 to 65, carbon atoms in the molecule.

Particularly suitable lubricants are the esters of polyhydric alcohols of the general formula

CH ₀ OH

RC-CH ₂ OH

CH ₂ OH

wherein R is the group -CHgOH or an alkyl group, e.g.

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is one with 1 Ms 6 carbon atoms. Suitable esters of this type are accordingly the neopentyl polyol esters of trimethylol ethane, trimethylol propane, trimethylol butane and pentaerythritol or dipentaerythritol.

Monocarboxylic acids are used to esterify trimethylolpropane with 4 "to 12 carbon atoms" are preferred. Particularly The esters of C ~ - to C ^ -acids, such as, for example, are suitable the caprylic acid ester (Co) and the pelargonic acid ester (Cq) »One can also use mixtures of C 1 to C 4 acids where a mixture average between Cg and Cq is preferred. Even more preferred are those somewhat more difficult to prepare compounds in which a methylol group with a neoheptanoic acid, e.g. 2,2-dimethylpentanoic acid, and the remaining methylol groups Esterified with unhindered acids, e.g. pelargonic acid are. These particular esters are essentially as heat resistant as the fully hindered esters, but have better properties in terms of volatility and behavior at low temperatures.

The preferred acids for esterifying pentaerythritol

are the C-- to C ^ -monocarboxylic acids, the esters 4 10

the Cc to Cq acids are particularly preferred, e.g. the esters of n-valeric acid, isovaleric acid, 2-ethyl

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butyric acid, caproic acid, n-heptylic acid, n-octanoic acid or 2-ethylhexanoic acid or mixtures of Gc to Cq acids.

Mixtures of diesters with small amounts of one or more thickening agents can also be used as lubricants be used. For example, you can use mixtures that contain up to 50 vol. # Of one or several water-insoluble polyoxyalkylene glycols, such as polyethylene or polypropylene glycol or an oxyethylene / oxypropylene glycol mixture.

For the lubrication of grass turbines, mixtures are suitable which contain 65 to 90 vol ₁₀ alcohols consisting of oxo alcohols or mixtures of such alcohols, and 35 to 10 # polyoxyalkylene glycol ethers of the general formula

RO-

-CHo CH-O-

H,

-R

^l 2

contain, wherein R ₁ , R and R _{2 are} hydrogen or alkyl groups with 1 to 12 carbon atoms and not more than 2 of these symbols stand for hydrogen and

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- ^? - 2129QQ3

where η is an integer greater than 1. Particularly suitable compounds are polyoxypropylene glycol monoethers and the appropriate dieters.

The heat resistance of these diester / polyoxyalkylene glycol ether mixtures can be improved by adding small amounts of a complex ester to them, which is derived from three or more carboxylic acids or alcohols, of which at least two are difunctional acids or Alcohols are. Such complex esters can have glycols or dicarboxylic acids in the middle and at the end of the molecule Contain monohydroxy or monocarboxylic acids. Particularly preferred complex esters of this type are derived from polyethylene glycol with a molecular weight of 200, 2 molecules of sebacic acid or azelaic acid and 2 molecules of a branched aliphatic monohydric Cg to C.q alcohol, in particular 2-ethylhexanol, from.

The amine salts of halogen-substituted carboxylic acids used as additives are derived from such halogen-substituted carboxylic acids Carboxylic acids in which at least one halogen atom is in the Oi position. Suitable monocarboxylic acids correspond to the general formula

R ²

- 1

Β ^Ί - C - COOH (I)

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1 2

wherein R and R are hydrogen atoms, halogen atoms or Radicals containing hydrogen and carbon or radicals containing hydrogen, carbon and halogen are, while X is a halogen atom. Suitable dicarboxylic acids are acids of the general polymer

RP Tr

R ³ - A ¹ - C - COOH and R ⁵ - C - COOH

IX ^! 2

L 'A ^d - COOH

k ^d - COOH

(II) (III)

1 2

wherein A and A are hydrogen and carbon-containing radicals or hydrogen, carbon and halogen-containing radicals and R ^J and R are hydrogen atoms, halogen atoms, hydrogen and carbon-containing radicals or hydrogen, carbon and halogen-containing radicals, while X is a halogen atom. In the case of the dicarboxylic acids, there are preferably halogen atoms in both c * positions.

The monocarboxylic acids should have at least 2 carbon atoms and preferably 2 to 20 carbon atoms per molecule contain. The dicarboxylic acids must contain at least 3 and preferably 3 to 25 carbon atoms per molecule. Saturated carboxylic acids are preferred to unsaturated ones.

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The halogen substituent is preferably chlorine, but fluorine, bromine and iodine can also be present. Preferably there are at least 3 halogen atoms per molecule. If there is more than one halogen atom per molecule, it is advantageous if the halogen atoms are as close as possible to the carboxyl group, for example 3 halogen atoms in the oi position "for a halogenated acetic acid, 2 halogen atoms in the οι position for longer-chain monocarboxylic acids and 4 halogen atoms in" Χ position in dicarboxylic acids.

The halogenated acids are preferably aliphatic Acids, however, aralkyl carboxylic acids can also be used which have at least one halogen atom in ot-gtellung own. Further halogen atoms are preferably in the alkyl radical of the molecule, but some or even all of the other halogen atoms in the aryl radical, for example in the - ^ enzene ring, may be substituted.

Examples of suitable halogenated carboxylic acids are, inter alia, monochloroacetic acid, dibromoacetic acid, difluoroacetic acid, trichloroacetic acid, trifluoroacetic acid, ctf -chloropropionic acid, ctf-iodopropionic acid, cx, ß-dichloropropionic acid, « o ^ oc-dibromopropionic acid, **» <* »t -dibromopropionic acid, ** <* - dibromocaproic acid, ^, ßj ^ pelargonic acid, chiomalonic acid, dibromomalonic acid,

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© S <* - dichloroglutonic acid, ex, 06, Oc-TrIfIuOrglutonic acid, oc, ° c-dibromosuberic acid, <x, oc ^ ß-tetraiodosuberic acid and <*, <>: - dichlorophenylacetic acid.

The amine salt of the halogenated carboxylic acid can be derived from primary, secondary, tertiary or quaternary amines. Suitable primary amines include w primary alkylamines, especially those with 2 to 20 carbon atoms in the alkyl group, such as propylamine, n-butylamine, n-hexylamine, dodecylamines, tetradecylamines or eicosylamines, and branched primary amines of an analogous composition, such as the primary tert.Alkylamine with 12 to 14 carbon atoms, which is traded under the name "Primene 81-R". Although aliphatic primary amines are preferred, aromatic amines, for example arylamines such as aniline, or aralkylamines such as benzylamine, can also be used.

Suitable secondary amines include secondary alkylamines, especially those in which each alkyl radical Has 2 to 15 carbon atoms, such as diethylamine, dipropylamine, dihexylamine, octylnonylamine or didodecylamine. Aliphatic secondary amines are preferred, but aromatic amines can also be used, e.g. arylamines, such as diphenylamine or methylaniline, or • aralkylamines, such as dibenzylamine.

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Suitable tertiary amines include tertiary Alkylamines, especially those in which any alkyl radical 2 Ms 12 carbon atoms ", such as triethylamine, Tri-n-propylamine, tri-n-butylamine, trihexylamine, heptyldioctylamine or tridecylamine. Aliphatic tertiary Amines are preferred, but aromatic amines, e.g. arylamines such as dimethylaniline or triphenylamine, can also be used. or aralkylamines such as tribenzylamine can be used.

Alternatively, polyamines of the general formula can also be used

NH ₂ (CH ₂ ) _n - (HH (CH ₂ ) _n ) _m -NH ₂

are used, in which η is an integer and m O or an integer from 1 to 10. For example, hexylenediamine, diethylenetriamine, tetraethylene pentamine, Use dipropylene triamine, octaethylene nonamine and tetrapropylene pentamine.

Likewise, N-hydrocarbyl- or N, N'-dihydrocarbyl-substituted ones can also be used Use ethylene or propylene diamines in which the hydrocarbon radical has at least 3 carbon atoms e.g. 3-laurylamino-i-butylamine or N, N'-didodecyl-1,3-propylenediamine.

Further suitable polyamino compounds are the aminoalkylpiperazines the general formula

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CH ₂ - CH ₂

CH ₂ "- CH ₂

in which η is a number from 1 to 3 and R is hydrogen or is an aminoalkyl radical having 1 to 3 carbon atoms. So For example, N- (2-aminoethyl) piperazine, N- (2-aminoisopropyl) piperazine or N, N'-di (2-aminoethyl) piperazine can be used.

To produce the desired amine salt, the halogenated acid and the amine in practically stoichiometric Quantities mixed together, i.e. 1 mole of amine per mole of monocarboxylic acid or 2 moles of amine per mole Dicarboxylic acid etc., the reaction mixture preferably being is heated.

In a preferred embodiment of the invention the amine salt of the halogenated carboxylic acid is a quaternary one Ammonium salt. Such salts are usually made by heating a tertiary amine with an alkyl halide for the formation of the quaternary ammonium halide after equation

R R

RN + R ¹ XR - N ® - R ¹ X ^θ

I I

R - R

manufactured. The halide thus obtained is under

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Stirring the reaction mixture mixed with a solution of silver oxide in water, where "with silver halide precipitates and a solution is obtained which contains quaternary ammonium cations and hydroxydanions. These Solution is then reacted with the halogenated carboxylic acid, where the desired quaternary ammonium salt halogenated acid is obtained. So if you react e.g. tri-n-butylamine with n-butyl chloride, you get Tetra-n-butylammonium chloride. This is made with silver oxide reacted in water, with tetra-n-butylammonium hydroxide is obtained which, when reacted with trichloroacetic acid, leads to tetra-n-butylammonium trichloroacetate.

The second addition to the lubricant blend is an antioxidant. Numerous antioxidants for synthetic lubricants are known, including, for example, diarylamines and thiodiarylamines. Suitable diarylamines include diphenylamine, phenyl - ** naphthylamine, phenyl-ß-naphthylamine, ar, (x -dinaphthylamine, ß, ß-dinaphthylamine or c *, ß-dinaphthylamine. Suitable antioxidants are also diarylamines in which one or both the aryl groups are alkylated, for example with alkyl radicals having 1 to 10 carbon atoms, such as diethyldiphenylamines, dioctyldiphenylamines, methylphenyl- OL- naphthylamines, phenyl-β- (butylnaphthyl) amine, di (4-methylphenyl) amine or phenyl (3-propylphenyl) amine.

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-U-

Suitable thiodiarylamines include phenothiazine, alkylated phenothiazines, phenylthio-C-naphthylainin, Phenylthio-ß-naphthylamine, Oi, oc-thiodinaphthylamine, ß, ß-thiodinaphthylamine, phenylthio-cX- (methylnaphthyl) amine, Thiodi (ethylphenyl) amine and (butylphenyl) thiophenylamine.

Further suitable antioxidants are the s-triazines of the general formula

R ¹

in which R ⁸ , R ⁹ , R ¹⁰ and R ^{11 are} hydrogen, C ₁ - to hydrocarbyl radicals or pyridyl radicals and R 'is a to Cg-hydrocarbyl, C * - to CpQ-hydrocarbylamine, pyridyl or pyridylamine.

If appropriate, mixtures of antioxidants can also be used in the lubricant mixture according to the invention will.

The lubricating oil mixture according to the invention can also be a or contain several corrosion inhibitors. A particularly suitable corrosion inhibitor is sebacic acid,

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however, other dicarboxylic acids, such as adipic acid, be used. The corrosion inhibitor can also be a metal deactivator, such as quinizarin, alizarin, anthrarufin, an azole, e.g. imidazo1, benzotriazole or faphthotriazole, or an alkyl gallate, e.g., a Cj to CgQ alkyl gallate like propyl gallate.

Further additives which are used in the lubricating oil mixtures according to the invention Foam inhibitors, e.g. silicone polymers such as dimethyl silicone, can also be used or methylphenyl silicone. If necessary, anti-wear agents or high-pressure additives, such as neutral alkyl phosphates or neutral alkyl aryl phosphates, can be added.

The amount of additive to improve resilience, i.e. the amine salt of a halogen-substituted carboxylic acid, is preferably between 0.01 and 10.0% by weight, for example between 0.1 and 5.0% by weight, based on the total weight the lubricating oil mixture. The amount of antioxidant or antioxidant mixture is preferably between 0.01 and 10.0% by weight, e.g. between 0.1 and 5% by weight, based on the total weight the lubricating oil mixture.

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When using a corrosion inhibitor, this preferably in an amount between 0.001 and 2.0 wt. e.g. between 0.01 and 1.0 wt. $, based on the total weight of the lubricating oil mixture, added. Using of a foam inhibitor, this is based on the total weight the lubricating oil mixture, preferably in an amount of 0.0001 to 0.05 wt. $ - used.

example

To produce a lubricant, a synthetic ester, which was obtained by esterifying commercial pentaerythritol (90 wt. ^ Pentaerythritol plus 10 wt. $ Dipentaerythritol) with a mixture of CL to CL carboxylic acids, was obtained with 0.1 wt. n-butylammoniumtrichloracetat (TBTA), 1.6 wt. $ bis (p-octylphenyl) amine, 0.4 wt. $ of phenothiazine and 0.02 wt.% sebacic acid (in each case based on the total weight of the lubricant) is added.

A test of this lubricating oil mixture according to the "IAB Gear Machine Load Test "(load capacity), the" Pentagon OCS Test "(wear) and the" Silicone Elastomer Compatibility Test "(compatibility with silicone elastomers) gave the following values:

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Base oil
alone Base oil plus
$ 0.1 TBTA IAB Gear Machine Load
at 110 ° C / 600 rpm 70 ok $ 110> Pentagon OCS test
at 425 ° F / 72 Stan. • Weight change
in mg / cm ² Pe -0.01 Al -0.02 Ag -0.03 Mg 0 Gu -0.43

Silicone Elastomer Compatibility Test, Rolls-Royce Method 1009 at 175 ° C / 192 hours.

1/2 hour swelling 48 hours swelling

9.6 6.1

specification

$ 100>

no shrinkage

ti w

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Claims (11)

Claims 1. Lubricating oil mixture, characterized in that it has a main weight fraction and a lubricating oil smaller proportion by weight of the amine salt of a halogen-substituted carboxylic acid, "in which at least a halogen atom is in the d-position, as well as one Contains a small percentage by weight of antioxidants. 2. Mixture according to claim 1, characterized. that the lubricating oil is a synthetic ester, preferably a polyester of a polyol and a monocarboxylic acid, is. 3. Mixture according to claims 1 and 2 _t characterized in that the halogen-substituted carboxylic acid is a halogen-substituted monocarboxylic acid having preferably from 2 to 20 carbon atoms per molecule of the general formula R ¹ - 0 ■ - COOH I.
X is where R * and R hydrogen atoms, halogen atoms 109885/1653 or radicals containing hydrogen and carbon, or radicals containing hydrogen, carbon and halogen Are radicals and X is a halogen atom. 4. Mixture according to claims 1 and 2, characterized in that the halogen-substituted carboxylic acid is a halogenated dicarboxylic acid having 3 to 25 carbon atoms per M _o lekül. 5. Mixture according to claims 1 to 4, characterized in that the halogen-substituted carboxylic acid an aliphatic acid and preferably trichloroacetic acid is. 6. Mixture according to claims 1 to 5, characterized in that the amine salt is from a primary alkyl ' derived, in which the alkyl radical 2 to 20 carbon contains atoms. 7. Mixture according to claims 1 to 5 _? characterized in that the amine salt is derived from a secondary alkylamine in which each alkyl radical has 2 to 15 carbon atoms. 8. Mixture according to claims 1 to 5 »characterized in that that the amine salt is from a tertiary 109885/1653 Alkylamine derives, in'dem each .Alkylrest 2 Ms 12 Contains carbon atoms. 9 · Mixture according to claims 1 Ms 5, characterized in that the amine salt is a quaternary ammonium salt, preferably letra-n-butylammonium trichloroacetate, is. 10. Mixture according to claims 1 to 9 »characterized marked W is characterized in that it contains as antioxidant a diarylamine or a Thiodiarylamin. 11. Mixture according to claims 1 to 10, characterized in that that it still contains a corrosion inhibitor. ue / hb: hb 109885/1653