DE1149480B - Lubricants based on lubricating oil - Google Patents

Description

Lubricating Oil Based Lubricants The invention relates to a lubricant based on lubricating oil, which contains certain chlorinated aromatic sulfur compounds. The novel lubricant mixtures according to the invention are generally available as extreme pressure additives effective. There can be pressures between sliding metal surfaces, such as B. for tail units, Rollers, spindles, articulated joints, bearing gears and ball bearings, up to 7000 up to 10500 kg / cm2 occur in a working temperature range of -55 to 320 ° C. The present invention is to be evaluated particularly in that mixtures are detected, that provide effective lubricity under these heavy loads.

Synthetic lubricants, such as silicone oils and polyesters, are inadequate Lubricity, and the silicone oils show poor wear properties. Around the more these base oils pose a particular problem as they are very bad respond to treatment with additives. Furthermore, the above-described extreme pressure additives have the tendency to cause corrosion, and this corrosion instability occurs especially when lubricant mixtures containing such additives can be used at higher temperatures.

The purpose of the invention is to provide lubricant mixtures, i. H. Lubricating oils and lubricating greases with improved application properties, to be proposed in particular lubricant mixtures having high pressure resistance, which up to now have not become known. A particular purpose of the invention is to find new To propose mixtures of lubricants that are extremely good due to their good lubricating properties high pressure conditions at extremely high loads.

Furthermore, the lubricant mixtures according to the invention are corrosion-free marked.

The lubricants according to the invention consist of base oils, the chlorinated Contain aromatic sulfur compounds, derived from pentachloro biophenol, heavy metal salts of pentachlorothiophenol, pentachlorophenyl mercaptoacetic acid (pentachlorophenyl mercaptoglycolic acid), Heavy metal salts of pentachlorophenyl mercaptoacetic acid and certain esters consist of pentachlorophenyl mercaptoacetic acid.

The mixtures according to the invention are made by dispersing one of the obtained chlorinated aromatic sulfur compound according to the invention in the base oil.

The new lubricant mixtures have excellent properties on which the effective lubrication of machine parts under significantly sharper Enable conditions than before. The loading pressures obtained with the inventive Lubricant mixtures can be achieved include a range in which- it has hitherto not been able to obtain satisfactory lubricity. Even under severe conditions of use at high temperatures, they have a compressive strength which is practically associated with corrosion resistance. A particularly noteworthy one The point of the present invention is that the aromatic sulfur compounds described to significantly improve the extreme pressure properties of synthetic lubricants can be applied. The additives specified in low concentrations can the original pressure resistance of the = like base oils triple, whereby Synthetic base oils of this type achieve lubricity ranges suitable for them make extremely high load pressures applicable.

The lubricants according to the invention based on lubricating oil are characterized by the addition of small amounts of a compound of the general formula in which n is the free valence of a heavy metal, X is hydrogen or the radical CH @ COOY (where the CH, group can be alkyl-substituted), a heavy metal or a heavy metal partially linked to inorganic anions, and Y is hydrogen or a hydrocarbon radical with 1 to 8 carbon atoms , optionally with non-interfering substituents.

A number of the compounds include pentachlorothiophenol and its Heavy metal salts. Pentachlorothiophenol itself is highly effective for its manufacture of mixtures according to the invention. In terms of acidic properties, more aromatic Thiophenols and in view of the usually pronounced corrosion properties of chlorine compounds is surprising that pentachlorothiophenol practically none Has corrosive properties and is successful in lubricant mixtures can be used, which are used in high pressure and temperature ranges.

The heavy metal salts of pentachlorothiophenol are also available as high pressure additives effective for base oils, d. H. Salts of metals with a specific weight of 4 or higher.

Both the partial and the complete with the thioaryl residue substituted metal salts fall within the scope of the invention. For practical purposes the aryl-substituted anions will be inorganic radicals, in general have a relatively low molecular weight, e.g. B. a halogen ion, like that Chloride, bromide or fluoride ion, or an oxygen-containing residue, such as hydroxyl, Carbonate, bicarbonate or sulfate groups.

The preparation of these salts can e.g. B. can be achieved in that an easily accessible salt of pentachlorothiophenol in solution, such as B. its water-soluble sodium salt, on a salt of the particular heavy metal can act in order to effect an ion exchange.

Characteristic for such heavy metal salts are the zinc, cadmium, Mercury, copper, silver, tin, lead, thorium, antimony, bismuth, tungsten, Cobalt and nickel salts of pentachlorothiophenol, furthermore the basic zinc, cadmium and Lead salt of pentachlorothiophenol, the lead chloride pentachlorothiophenolate, the Tin sulfate pentachlorothiophenolate.

The invention also relates to the use of compounds of pentachlorophenylmereaptoacetic acid, and these also include substituted acetic acids such as pentachlorophenyl mercaptoacetic acid, Heavy metal salts of pentachlorophenyl mercaptoacetic acid or esters of pentachlorophenyl mercaptoacetic acid, a, In the mentioned substituted acetic acids are the substituents on the carbon atom of acetic acid, apart from the pentachlorophenyl mercapto radical, preferably either hydrogen or also lower alkyl substituents. This compound class has compared to the pentachlorophenyl mercapto compounds discussed above have the advantage that the Phenylmercaptoacetic acid derivatives in base oils that synthetic lubricating oils such as Silicones, include, are soluble.

Pentachlorophenyl mercaptoacetic acid is a preferred lubricant component of the present invention homologues include alkyl-substituted acetic acids, such as pentachlorophenyl mercaptoacetic acid, pentachlorophenyl mercaptoethyl acetic acid, Pentachlorophenyl mercaptoisopropyl acetic acid and the like, which are also effective and can be used according to the invention.

Heavy metals of these acids can also be used within the scope of the invention Find application.

Examples include: pentachlorophenyl mercaptozinc acetate, x- (Pentachlorophenylmercapto) -x-methylzinc acetate, basic zinc salt of pentachlorophenylmercaptoacetic acid and pentachlorophenyl mercaptotin chloride acetate.

The derivatives of pentachlorophenyl mercaptoacetic acid which are effective according to the invention also include substituted acetic acid esters of the above type. The type of ester residue can vary widely. Said ester radical can be an organic radical which Contains at least 1 carbon atom, and can be a hydrocarbon radical having 1 to 8 carbon atoms, such as an alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl radical, be, the optionally a plurality of any non-interfering substituents contains, such as halogen atoms, hydroxy radicals, carboxy radicals, sulfo radicals, alkoxy radicals; Oxyalkoxy residues, aryloxyl residues, cycloalkoxy residues, sulfamoyl residues, thio residues, acyl residues, such as Acetyl, benzoyl, cyano, and the like are a preferred class the ester for the purposes of the invention includes aliphatic esters, such as alkyl, Haloalkyl and hydroxyalkyl, including hydroxyalkyl, alkoxyalkyl and Hydroxyalkyl esters containing up to 8 carbon atoms.

Examples of the esters according to the invention are esters such as methyl pentachlorophenyl mercaptoacetate, Pentachlorophenylmercaptoacetic acid pentarythritol ester, rx- (pentachlorophenylmercapto) -x- (methyl) -acetic acid methyl ester, Cyclopentyl pentachlorophenyl mercaptoacetate, phenyl pentachlorophenyl mercaptoacetate and 2-hydroxyethyl pentachlorophenyl mercaptoacetate.

The chlorinated aromatic sulfur compounds used to manufacture of the high-pressure-loadable oil and grease-like lubricants according to the invention are used in amounts sufficient to produce a Significant increase in the originally existing compressive strength of the base oils to achieve. In general, a small amount of the in relation to the base oil is described additive effective to achieve the desired improvement. the the amount to be used can vary within a fairly wide range and depends on the type of additive used and the type of base oil as well as on the Severity of the working conditions to which the lubricant is subjected in practice is off. An increase in the amount added generally results in an improvement the pressure resistance of the base oil. For practical use it is not necessary to apply an additional amount that - based on the weight of the end product - is significantly more than 15 percent by weight, excellent results will be achieved usually achieved at concentrations that are on the order of 0.1 to 10 Weight percent lie. Generally at least 0.05% will be used of the addition applied.

The base oil that is used for these blends can be selected from the extensive Number of naturally occurring and synthetic lubricants to be selected. As naturally occurring base oils, mineral oils, vegetable oils, animal oils and their Mixtures are used. Synthetic base oils that can be used include polysiloxanes, various polyesters, hydrocarbon oils can be used.

Occasionally, mixtures of base oils and individual lubricants are used before. It has been found that silicone / polyester oil blends have certain advantages exhibit. A mixture of this compilation, which is described below, is a preferred base oil incorporating the above chlorinated compounds became.

Thickeners have proven to be useful for the production of lubricating greases proven, of which the following may be mentioned: soaps, e.g. B. lithium soaps the Fatty acids, such as hydroxystearic acid, silicates, and preferably amide compounds, such as urea derivatives, e.g. B. the reaction product of tolylene diisocyanate with Aniline and / or p-chloroaniline.

The lubricant mixtures according to the invention can optionally be used Thickeners, such as phthalimides, phthalocyamines, anthraquinone derivatives instead of the above-mentioned thickener.

In order to process the lubricants according to the invention into lubricating greases, the thickeners are added in proportions according to customary procedures. The base oil is preferably mixed with the thickener Table I. Starting welding, shell 4-ball device Average- Additional exposure to corrosion Oil type meter of the load wear mark kg mm kg - 126 3.13 17.6 PCTP (a) 224 37 Polymethylphenyl silicone. . . . . . . . . . . . . . . . . . . . . . . . . 2 PCPME (b) 158 2.36 31.0 2 - 126 2.32 23.8 PCTP> 316 2.20 85.4 Chlorinated polymethylphenyl silicone. . . . . . . . . . ... . . 3 PCPME> 355 1.23> 100 3 - 112 2.48 1 9.0 Chlorinated polymethylphenyl silicone. . ... . . . . . . . . . . PCTP 200 2.27 45.0 2 - 89 2.75 12.2 Polyester ....................................... PCPME 158 3.43 22 3 - 56 <2.5 10 Didodecyldioctylsilane ... . . . . . . . . ... . . . . . . . . . . . . . PCTP 112 2.45 19 3 (a) Pentachlorothiophenol. (b) pentachlorophenyl mercaptoacetic acid. ASTM apparatus designated as FC 4140. mixed, the mixture being subjected to high shear forces in a colloid mill or homogenizer. The ratio of the thickener to be used can vary widely and depends on the type of base oil and thickener.

The mixtures according to the invention can also contain further modifiers, such as antioxidants, Agents to lower the pour point or to improve the viscosity properties, Contains anti-foaming agents. Suitable antioxidants can be used, for. B. from the group of alkylphenols, such as 2,4,6-trimethylphenol, pentamethylphenol, 2,4,6-tritert.butylphenol, or the aminophenols, such as benzylaminophenol, the amines, such as dibutylphenyldiamines, Diphenylamine, phenyl-ß-naphthylamine, phenthiazine and dinaphthylamine, the metal salts, such as iron octoates.

The production of the compounds specified below is carried out within the framework of present invention is not protected.

Example 1 The lubricants and base oils were tested for their lubricity properties Tested in a shell 4-ball device, which is in the United States regulation MIL-G-7118 is described.

The results of the test are given as the load at which the seizure occurs, and furthermore, the average diameter of the wear marks on the test balls at the time of seizure is given. Table I (continued) Average- Additional exposure to corrosion Oil type meter of the load wear mark ° @ o kg mm kg - 79 2.7 11 Didodecyldiphenylsilane. . . . . . . . . . . . . . . . . . . . . . . . . Zn-PCTP (c) 158 2.3 32 3 (- 79 2.55 11 Octadecyltridecylsilane. . . . . . . . . . . . . . . . . . . . . . . . . . . Zn-PCTP (c) 178 2.12 41 3 - 79 2.27 13 Hexa- (2-ethyl) -hexoxy-siloxane. . . . . . . . . . . . . . . . . . . ZnPCTP (c) 251 2.05 68 3 (c) pentachlorozinc thiophenolate. ASTM apparatus designated as FC 4140. The following table shows the »mean Hertz load values« (MHB) of lubricating greases based on polymethylphenyl silicone with aryl-substituted urea thickeners. Table 1I Addition ° / ° MHB None ...................... - 15 Zn-PCTP. . . . . . . . . . . . . . ... . . . 3 30 Zn-PCTP. . . . . . . . . . . . . . . . . . . . 6 40 PCPME ..................... 6 12 Zn-PCPM-acetate ............. 6 27 Table III gives the mean Hertz load values for lubricating greases - on a chlorinated polymethylphenyl silicone base. Table III Addition ° / ° (MHB None ...................... - 30 PCTP ....................... 3 50 Zn-PCTP. . . . . . . . . . . . . . ... .... 1.5 36 Zn-PCTP. . . . . . . . . . . . . . . . . ... 3 53 Zn-PCTP. . . . . . . . . . . . . . . . . . . . 6 77 Pb-PCTP .................... 3 54 PCPME ..................... 3 72 PCPME .................... 3.5 94 PCPME methyl ester .......... 3 53 PCPME isopropyl ester. . . . . . . . 3 to 6 47 PCPME-2-ethylbutyl ester ...... 3 40 PCPME-2-ethylbutyl ester ...... 6 63 PCPME-4-chloro-l-butyl ester ... 3 48 Zn PCPM acetate ............. 3 47 Pb-PCPM acetate ............. 3 54 The numerical values given under the designation MHB in the table above represent calculated values for the average Hertz load on lubricating greases. This is a measure of the lubricity of oils under extremely high loads. The mean Hertz load is calculated from the measurement results of the 4-ball device. This value shows the load capacity of a lubricant and evaluates the highest load level to which a lubricant can be subjected, together with the diameter of the wear mark formed during the test. The calculation is based on the regulations in accordance with MIL-G-7118.

Example 2 It has been found that mixtures of silicone lubricating oils and ester oils Lubricants with the good wear properties of ester oils and the excellent compressive strength of the silicone oils. The results in in the following table refer to lubricating greases based on the specified base oil thickened with aryl substituted urea thickeners in an amount of about 200% became.

Table IV gives results for lubricating greases which each contain as base oil a polymethylphenyl silicone, a polyester and a mixture of 50 percent by weight each of the above base oils. Table IV Estimated "mean Hertz load" the greases Base oils additive ° t ° (MHB Polymethyl phenyl silicone. . - - <15 Polyester ....... - - 20 to 30 Mixture A ..... - - 26 Mixture A ..... Zn-PCTP 6 62 Mixture A ..... Zn-PCPM-acetate 6 80 Tables IV and V contain information on polymethylphenyl silicone oil based greases. Mixture A relates to a mixture of 50 percent by weight of a polymethylphenyl silicone and a polyester base oil. Mixture is a mixture of 75 percent by weight of a polymethylphenyl silicone and 25% of a polyester oil. Mixture C relates to a mixture of 37.5 percent by weight of a chlorinated polymethylphenyl silicone and 25 percent by weight of a polyester. Table V Base oil additive ° 'o MHB I. Polymethylphenyl silicone. . . . . . . . . . . . . - - 15 Polymethylphenyl silicone. . . . . . . . . . . . . PCPME 6 65 Mixture A. . . . . . . . . . PCPME 3 90 Mixture B. . . . . . . . . . PCPME 6 90 Mixture C. . . . . . . . . . . PCPME 4 92 Example 3 The thickener used to prepare the grease (test results below) was 17 percent by weight of the grease and consisted of an aryl-substituted urea; which was produced by reacting ditolylene diisocyanate with p-chloroaniline and p-toluidine in situ in the base oil. The base oil used in this grease consisted of a 50:50 weight percent mixture of a chlorinated polymethylphenyl silicone oil and a polyester oil. To this mixture, 3 percent by weight of zinc pentachlorothiophenolate was added as a high-pressure additive according to the process according to the invention.

This grease showed the following properties penetration, worked through (60) ASTM method D 217-52 T ......................... 308 100,000 revolutions MIL -G-3278 A .... 321 drop point ASTM method D 566-42, 'C .. 246 evaporation loss 22 hours at 204 ° C, ASTM method D912-42, ° / 0 ........ ................ 16.7 Gel deposition (exudation) 30 hours at 204 ° C, Federal Standard Procedure 321.1, ° / o. . . . . . . . . . . . . . . . . . 6.97 humidity test MIL-L-4343 A, 100 ° / a relative humidity. . . . . . . . . . . . . . . . . . . . 2 Water corrosion test MIL-G-3278 A ...... no mean Hertz exposure value, estimated MIL-G-7118 ...................... .... 58 Water resistance MIL-G-3287 A, ° / o. . . . 0.69 Shell 4-Ball Device Wear Test, 2 hours 1200 rpm, 75 ° C. . 52 100 steel balls load, kg. . . . . . . . . . . . . . . 10 40 Average diameter of wear mark, mm ... 0.651 1.309 Apparent viscosity in poise for 20-1 seconds, ASTM method D 1092-55. . . . . . . . . . . . . . . 15,000 at -43'C. The test procedures identified as ASTM in the above are the testing methods of the American Society for Testing Materials, and the tests identified by MIL are the standard military testing methods of the American government. As an example, consider the Federal Standard Oil Separation Procedure, cited above. The Shell 4-ball test is carried out essentially in the manner already indicated in an earlier example, with the difference that this test method is carried out under constant and not under increasing loads.

EXAMPLE 4 3% of the indicated additives were in each case incorporated into lubricating greases which consisted of a chlorinated polymethylphenyl silicone as an oil component and which were thickened with an aryl-substituted urea. 4340 steel plates were cleaned and polished and then coated with a 3.2 mm thick layer of the grease and held in a sealed wide-mouth bottle at 204 ° C for 24 hours. The results are shown in the table below. The evaluation was carried out by qualitative comparison of the plates with the naked eye. The higher number corresponds to more corrosion or damage to the plate. Table VI Corrosion test, 24 hours at 204'C Weight Addition change of judgment comment the plate None 200 mg 4 surface corrosion sion PCPME 0 mg 1 slight oxide discoloration exercise, no display corrosive sion ZnPCTP 10 mg 2 purple fog when heating, no sign from corrosion As can be seen from the above information, the additives used to produce the lubricant mixtures according to the invention are actually capable of reducing the corrosion properties of lubricating greases and thus show a corrosion-preventing effect. In contrast, greases containing the same base oil and a commercial extreme pressure additive cause severe corrosion within 24 hours at 204 ° C.

Results similar to those given in Table VI were obtained obtained using Federal Standard Method 191-5319-T at 100 "/, moisture. Greases, which are thickened with an aryl-substituted urea and each one is chlorinated Polymethylphenyl silicone oil and the mixture of chlorinated polymethylphenyl silicone oil with a polyester oil, were processed with 3% of an additive that Zinc, zinc pentachlorophenyl mercaptoacetic acid, zinc pentachlorophenyl mercaptoacetate and cadmium pentachlorophenyl mercaptoacetate. The greases show overall a rating of 2 which, according to the standard procedure indicated, is acceptable Represents valuation.

Claims (3)

PATENT CLAIMS: 1. Lubricant based on lubricating oil, characterized by the addition of small amounts of a compound of the general formula: in which X is hydrogen or the radical CHZCOOY (which can be alkyl-substituted), a heavy metal or a heavy metal partially linked with inorganic anions, n is the free valence of a heavy metal and Y is hydrogen, a heavy metal or a hydrocarbon radical with 1 to 8 carbon atoms, optionally with non-interfering substituents. 2. Lubricant according to claim 1, characterized in that the lubricant base is a synthetic oil, such as a silicone oil or a mixture of a silicone oil and a polyester oil. 3. Lubricant according to claim 1 or 2, characterized in that it has a known thickener, such as a aryl-substituted urea. References contemplated: United States Patent Specification No. 2,546,941; British Patent No. 765 553.