DE1128069B - Grease - Google Patents

Description

Lubricating grease In order to meet the requirements of modern technology for high-temperature lubricating greases, which have to maintain their consistency and lubricity even at working temperatures between 200 and 250 ° C during the practically relevant periods, special organic compounds and pigments from the class of indogenous compounds are already available, Phthalocyanine compounds, the antraquinones and the azines are used as gelling agents. Particularly suitable for this purpose are lubricating oil-based greases which, as a thickener, are a water-insoluble compound with two units contains in the molecule. The three-ring radical has at least one carbonyl radical on the middle ring of the group.

These compounds fall under the well-known »INDANTHREN dyes«. The word "INDAN-THREN" is for the company Badische Anilin- und Sodafabrik AG, Ludwigshafen am Rhein, protected as a trademark under number 51 151.

To get a satisfactory grease consistency with this type of thickener To achieve this, however, exceptionally high amounts of the substances in question must be used so that such greases are quite disadvantageous from an economical point of view are. In addition, in some cases they have the disadvantage that the service life of bearings treated with it is not always sufficient.

It has now been found that the consistency of lubricating greases which contain the above-described compounds with a three-ring system as thickening agents can be significantly improved if they are additionally given at least 2.5 percent by weight and up to 20 percent by weight of a diarylamine with the general formula incorporated, in which each R is an aromatic hydrocarbon radical from the group of phenyl, naphthyl, alkylated phenyl and alkylated naphthyl radicals.

Although these diarylamines do not have any thickening properties at all and are also less heat-resistant than the thickeners themselves, they have the very unexpected property that is required for a specific grease consistency considerably reduce the required amount of thickener and also the The service life of the bearings lubricated with it increases considerably at high temperatures raise. However, they only practice this effect in combination with the above labeled thickeners because 'the addition of the same amines to with other high temperature gelling agents did not gelate greases either Affects the consistency or even softens the grease.

The main advantage achieved by the present invention is in an extraordinary reduction in the cost of the greases in question. This is important because the actual gelling agents are very costly substances represent, while the amines are much cheaper. As a result, each yields Reduction of the content of the grease in the thickener by a corresponding Adding amine provides about a 20 fold saving on the cost of the grease thickener. However, it is not only this cost reduction that is essential, but also the unexpected improvement in bearing life brought about by the Presence of large amounts of amines is conditioned.

Diarylamines are already used as antioxidants in lubricating greases been used, in particular in soap greases, but will only very small amounts of a maximum of about 1 percent by weight are used for this purpose. In many cases the concentration of these antioxidants is only between 0.1 and 0.25 percent by weight. It was therefore impossible to foresee that there would be very definite ones Diarylamines in combination with the aforementioned class of thickeners even exert a thickening effect when used in larger amounts of at least 2.5 percent by weight are used.

While the amount of amine normally used to increase the consistency of the grease mixtures under consideration is between 2.5 and about 20 percent by weight (of the grease), another measure of the appropriate proportions can be expressed in equivalents of the amine per 100 g of grease . The maximum effect is achieved using about 0.02 to 0.1 equivalents of the amine per 100 grams of grease. Suitable diarylamines are, for. B. the following: phenyl-a-naphthylamine, phenyl-ß-naphthylamine, diphenylamine, di- (a-naphthyl) -amine, di- (ß-naphthyl) -amine, (a-naphthyl) - (ß-naphthyl) - amine, di- (tert-butylphenyl) -amine, (sec.amylphenyl) -phenylamine, (methylphenyl) -naphthylamine. Preferably all of the alkyl substituents on the aryl nucleus each have 1 to 10 carbon atoms.

A preferred example of a suitable diarylamine is phenyl-a-naphthylamine.

The amines are preferably incorporated by mixing them together with the finished grease, which is the actual thickener and the Contains lubricating oil, homogenized.

The gelling agents used in the present lubricating greases contain 2 units per molecule with the following structure: Some special representatives, such as the N-dihydro-1,2-1 ', 2'-antlirachinonazine, contain two such carbonyl residues on the center ring. Other representatives, such as B. Flavanthron contain only one carbonyl radical, the three-membered ring group being linked to a second such group by nitrogen bonds, while the pyranthrone is linked by means of hydrocarbon bonds.

Another essential characteristic of thickeners is that they that nitrogen does not occur as a core element in those rings which form the three-ring group form.

The most important compound from the group is N-dihydro-1,2-1 ', 2'-anthraquinone azine. It is best to use the thickeners in amounts of 5 to 35 percent by weight, in their non-metallic form, to be used, d. H. without neutralization the carbonyl groups with ions, such as sodium or potassium, calcium, etc. more for Compounds suitable for the present purpose are the following: flavanthrone, pyranthrone, Violanthron, -3,3'-dichloro-N-dihydro-1,2-l ', 2'-anthraquinonazine, trichloro-N-dihydro-1,2-1', 2'-anthraquinonazine. The lubricating oil which is used to produce the lubricating greases according to the invention, can be varied over a wide range. The base oil used should be in the Be able to perform the lubricating function when used in the form of a liquid could be. Mineral lubricating oils have a viscosity in the range of about 35 to about 200 SUS at 98.9 ° C and can be used for most purposes in the frame of the invention can be used. The mineral oil can be paraffinic depending on its origin or naphthenic in character, and all distillates are usable that are purified through the various refining processes.

Synthetic lubricating oils can also be used to produce the lubricating greases of the present invention can be used. Such oils include monobasic esters Acids such as oxo acid; Esters of dibasic acids such as di-2-ethylhexanesebazate; Esters of glycols, e.g. B. the C13 oxyacid diester of tetraethylene glycol or complexes Esters such as those obtained by reacting 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid are formed. A recently edited liaison group, namely, diaryldialkylsilanes (e.g., diphenyldidodecylsilane) can also be used will. Phosphoric acid esters can also be used; how they z. B. through implementation obtained from 3 moles of the monomethyl ether of ethylene glycol with 1 mole of phosphorus oxychloride will. Also suitable are halogenated hydrocarbon oils, such as the polymers of Chlorotrifluoroethylene, as well as the alkyl silicone compounds, such as methylpolysiloxanes, Cphenylsilicones and the like. By reacting 1 mole of sulfur oxychloride with 2 moles of the methyl ether of ethylene glycol formed sulfite esters and carbonates such as them z. B. be formed by reacting 8-oxo alcohol with ethyl carbonate with formation of a half-ester and reacting this half-ester with tetraethylene glycol are also possible suitable: also polyglycols, e.g. B. obtainable by condensing butyl alcohol with up to 50 units of propylene oxide or mixtures of any of the above synthetic oils in any proportions can be used as base oils.

It has been proposed to use polyphenyl ethers as lubricants or lubricant components in the related field of lubrication under conditions where ionizing radiation occurs. The highest resistance is obtained when the polyphenyl ethers are not substituted. However, very stable lubricants can also be obtained if the polyphenyl ethers in question have α-cumyl or tert-butyl substituents. Although ortho, meta or parabonds can be present between phenyl residues, it is preferred that at least 25% of the ether bonds are meta to one another. Appropriately included. such polyphenyl ethers an average of three to six phenyl radicals per molecule. The combination of the group of thickeners according to the invention with such base lubricating oils has led to exceptionally stable lubricating greases, the stability relating both to temperatures above 175 ° C. and to conditions at which ionizing radiation occurs. The following examples illustrate the unexpected increase in the consistency of a lubricating grease which contained 28 percent by weight N-dihydro-1,2-1 ', 2'-anthraquinone azine as a thickening agent, while the base oil was a residual lubricating oil, namely a so-called bright stock. Change in change in the Additional weight percent W-60 penetration *) Added equivalent W-60 penetration *) per equivalent per 100g after addition of amine per 100 g of grease grease Diphenylamine ............. 4 -37 0.024 -1540 Dinaphthylamine ........... 3 -16 0.011 -1460 Phenyl-ß-naphthylamine ..... 4 -37 0.018 -2050 Phenyl-cx-naphthylamine ..... 4 -40 0.018 -2220 Phenyl-a-naphthylamine ..... 7.5-71 0.034-2080 Phenyl-a-naphthylamine .....; 15 -86 0.068 -1260 *) Milled penetration with 60 strokes, measured with a cone (1 / ..) in a crucible »o«.

Claims (5)

PATENT CLAIMS: 1. Lubricating grease based on lubricating oil, which as a thickener is a water-insoluble compound with 2 units contains in the molecule, characterized by the further content of 2.5 to 20 percent by weight of a diarylamine with the general formula in which each Ar is an aromatic hydrocarbon radical from the group consisting of phenyl, naphthyl, alkylated phenyl and alkylated naphthyl radicals. 2. Grease according to claim 1, characterized in that it contains the thickener in an amount contains from 5 to 35 percent by weight. 3. Lubricating grease according to claim 1 or 2, characterized characterized in that it contains phenyla-naphthylamine as diarylamine. 4. Grease according to claim 1 or 2, characterized in that it is a diarylamine with alkylated Contains phenyl and / or alkylated naphthyl radicals in which the alkyl substituents each have 1 to 10 carbon atoms. 5. Lubricating grease according to one of claims 1 to 4, characterized in that the lubricating oil base is a polyphenyl ether. Considered publications: German Patent Nos. 832 032, 832 787, 850 049, 872 626, 943 428, 944 628, 944 629; German Auslegeschrift No. 1006 996; French patent specification No. 1 159 210.