DE1148342B - Additives to lubricating oils of mineral or synthetic origin - Google Patents

Description

Additives to lubricating oils of mineral or synthetic origin Es it is known that additives can improve the pressure lubricity of lubricating oils. It is advantageous if these additives in addition to improving the pressure lubricity also to avoid corrosion and to improve the aging stability of the Lubricants contribute. A variety of compounds, such as reaction products from derivatives of thiocarbon acids, especially xanthates, with halogenated ones organic compounds are used as lubricant additives to increase pressure lubricity known.

Test results are used as a measure of the effectiveness of these compounds which were found in the four-ball apparatus or in the Almen machine. It It is well known that the test results in the four-ball apparatus as in the ancestral machine are not sufficient for assessing the pressure lubricity alone. On the other hand, allowed the gear tension test bench (FZG test) evaluates the pressure lubricity of lubricating oils under conditions similar to those of highly loaded gearboxes or Correspond to hypoid drives. First a lubricating oil, its testing both in the four-ball apparatus (VKA) as in the FZG test shows a good pressure lubricity, can be used in highly stressed Gearboxes are used. The previously known lubricating oil additives give the Lubricating oils have a pressure lubricity that is found differently in the VKA and FZG is such that the lubricating oils in the VKA are assessed as good, but in the FZG as poorly will.

The previously known compounds also have the disadvantage that they promote foam formation, especially when mixed with low-viscosity base oils or not decrease. Especially the use of such low-viscosity alloyed oils As fluid transmission oils, the foam-reducing property of the pressure lubricity improving additive dependent, so that the use of the previously known compounds in fluid transmission oils is disadvantageous, since the foam formed leads to increased wear the unit leads or makes the units inoperable.

It has been found that compounds with the general formula in which Ri and R2 denote an aliphatic hydrocarbon radical, Ra denotes hydrogen or the radical OH or H, can be used as additives to lubricating oils of mineral or synthetic origin to improve the pressure lubricity.

The compounds to be used according to the invention are distinguished by particularly easy to manufacture, which in a relatively short time with simple means can be done.

The production of the connections, which are not placed under protection here is advantageously carried out by reacting xanthates in aqueous solution with organic hydroxyl compounds and hydrocarbons containing a halogen atom in the Molecule included. Especially the use of water-soluble organic hydroxyl compounds with a halogen atom in the molecule causes a better reaction with those in aqueous Solution present xanthates than in the reaction products previously known for the same purpose. Due to the better conversion, which takes place under mild reaction conditions, will decomposition of starting and reaction products during the manufacture of the Reaction products are avoided and pure end products are obtained. The conversion products are so pure that they can be worked up by distillation to promote decomposition unnecessary.

The compounds are more mineral and synthetic with lubricating oils Origin can be mixed in any ratio. An addition of 2 percent by weight is sufficient such a compound to a base oil to achieve a medium pressure lubricity at to achieve a seizure load of 320 kg in the four-ball apparatus, with the lubricant contains about 0.70% sulfur. By increasing the additional amount, the pressure lubricity of a lubricating oil can be improved to such an extent that it is used to lubricate the most heavily loaded Gear can be used. So by adding 7 percent by weight of such In connection with a base oil, an eating load of 500 kg, measured in a four-ball apparatus, achieved with the lubricant containing about 2.0% sulfur.

The compounds according to the invention are characterized in that compared to the previously known compounds, they are much lower Adding quantity to give a base oil pressure lubricity. So gives z. B. a known addition only with an admixture of 5 percent by weight of a base oil Pressure lubrication capacity of 290 kg, measured in a four-ball apparatus. The pressure lubricity a lubricating oil mixed with the compounds according to the invention is linearly dependent of the additional amount. However, 7 percent by weight of such an additive is sufficient to a base oil to obtain a lubricating oil that is very high for use in loaded gears of various designs is suitable.

The following examples explain the preparation of the compounds used according to the invention, which are not protected in the context of the present invention. EXAMPLE 1 40 parts of ethylene chlorohydrin are added to a solution of 100 parts of potassium isohexyl xanthate in 180 parts of water and the mixture is Table I base oil Load level Oil temperature Torque Flank pattern Wear Rust formation Foam height ° G mg now 5 90 - unchanged - - 20 6 98 - - - - 20 7 101 - Kraizer / Umspr. - - 22 8 113 0.15 weak grooves 20 - 22 9 125 t% 65 deep grooves 30 - 80 10 135 0.95 very strong grooves 60 - foam escapes from venting 11 Start-up blocked immediately; Termination of the attempt Base oil with 2 percent by weight additive according to Example 1 Load level Oil temperature Torque Flank pattern Wear Rust formation Foam height ° C - now mg 5 90 - unchanged - - 20 6 100 - unchanged - - 20 7 100 - unchanged - - 20 8 107 0; 01 unchanged - - 20 9 117 0.35 unchanged - - 20 10 126 0.80 unchanged - - 100 11 130 1.00 unchanged - - 2 (p 12 145 1.50 unchanged - - 200 Stirred for 60 minutes at 80 ° C '. 86 parts of a reaction product are obtained which, after washing with water and centrifuging, is an oily liquid which, in the four-ball apparatus, reaches an eating load of 420 kg. If 2 percent by weight of such a reaction product is added to a base oil with a seizure load of 170 kg in the four-ball apparatus, a lubricant with a seizure load of 320 kg is obtained.

If the same base oil is 7 percent by weight with such a reaction product offset, the result is a lubricant with a seizure load of 500 kg, measured in the four-ball apparatus. Example 2 To a solution of 174 parts of isopropyl xanthate in 1200 parts of water .109 parts of ethyl bromide are added and the mixture is 60 Stirred at 35 ° C for minutes. 120 parts of a reaction product are obtained, which according to Excess ethyl bromide is removed by distillation at room temperature represents an oily liquid, which in the four-ball apparatus is an eating load of 420 kg reached. If a base oil, as described in example 1, becomes 2 Such a reaction product is added in percent by weight to obtain a Lubricant with a seizure load of 300 kg, measured in a four-ball apparatus.

The versatility of the compounds according to the invention can be seen from the tests in the FZG test. The following overview compares the test results of an unalloyed base oil and the base oil mixed with 2 percent by weight of the compounds according to the invention according to Example 1 (FZG test with gear pairing A = normal test). Reaction products of dithiocarbaminates and halogen compounds which contain 2 atoms of chlorine bonded to the carbon are known for use as lubricant additives. The testing of such a product (reaction product of dimethyldithioca.rbaminate with 1,4-dichlorobutane) in the FZG (gear pairing A = normal test) gave the following results, which will be listed below to characterize the state of the art. The eating load in the VKA is 280 kg. Table II Base oil with 2 percent by weight additive according to the prior art Load tem- 1. Turn- Rust- Foam- level peratun MO- flank pattern wear build- height ° C ment mg Jung now 5 94 0.05 unchanged - - - 6 98 0.05 unchanged - - - 7 99 0.1 scratches - - - 8 108 0.3 scratches - - 5 9 122 0.6 scratches - - 5 10 127 1.0. Scratches - - 5 11 130 1.2 i strong 40 - 10 scratch 12 138 1.63 1 grooves 50 - 15 The sulfur content of the lubricating oils to which the compounds according to the invention have been added in sufficient quantities is far below the previously known minimum content of sulfur considered necessary. With these known additives, a minimum content of 2.5% sulfur in the lubricating oil is considered necessary to achieve sufficient pressure lubricity.

Because even a low content of these compounds is a Lubricating oil gives increased pressure lubricity, corrosion behavior and Favorably influenced aging stability of the lubricating oil. The compounds according to the invention and the lubricating oils added with these compounds do not cause corrosion. An addition of 0.25 percent by weight of such a compound is sufficient a base oil to achieve effective anti-aging protection.

The advantages of the compounds according to the invention are more intense High pressure effect with simultaneous increase in aging stability and anti-corrosive Effect of the lubricating oils mixed with these compounds, whereby even such Base oils that are unalloyed in terms of pressure lubrication resistance and aging stability and corrosion behavior are not satisfactory after the addition of these compounds lubricating oils result, which can be used advantageously in highly loaded transmissions.

The advantage of the compounds according to the invention over the previous ones known lies in the fact that they do not tend to foam. These connections are therefore advantageous z. B. heavily used malfunction gear oils to increase the pressure lubricity added, the admixture of other additives to reduce the tendency to foam is unnecessary.

The test of a fluid transmission oil, which consists of a base oil of 2 parts transformer oil and 1 part turbine oil, to which 3% of the compounds according to the invention are added, gives the following results in the FZG test: Table III Base oil with 3 percent by weight additive according to Example 1 Load tÖm rotary V ER- rust foam level rat mo- flank pattern wear bil- height Peoc ment mg dang 1 78 - unchanged - - 30 2 78 - unchanged - - 30 3 90 - unchanged - - 30 4 97 0.05 unchanged - - 30 5 95 0.05 unchanged - - 30 6 102 0.05 unchanged - - 30 7 105 0.2 unchanged - - 30 8 115 0.4 weak - - 30 scratch 9 130 0.6 scratches - - 60 10 125 0.8 grooves 70 - 60 11 occurrence of clutch slippage; Termination of the attempt The unalloyed base oil foamed so much after starting in load level 1 that testing was impossible.

The results of the testing of such a base oil with an above-mentioned known additive (Table II), given below, clearly show the advantages of the compounds according to the invention. Table IV Base oil with 3 percent by weight additive according to the prior art

Claims (1)

PATENT CLAIM: Use of compounds of the general formula in which R and R2 are an aliphatic hydrocarbon radical, R3 is hydrogen or the radical OH, as additives to lubricating oils of mineral or synthetic origin. Considered publications: German Patent Specifications No. 879 003, 923 318; German Auslegeschriften Nos. 1028 269, 1031919; U.S. Patent Nos. 2,498,863, 2,637,696, 2,673,839, 2,734,869, 2,756,249; British Patent No. 636118.