DE1594357A1 - lubricant - Google Patents

Description

PATENT ANWAtTE "~ _ .... Ν, ν,

DR.-ING. BY KREISLER DR.-ING. SCHÖNWALD DR.-ING. TH. MEYER DR. FUES

COLOGNE 1, DEICHMANNHAUS 1594357

Cologne, July 18, 1966 fu / Ax / st

The British Petroleum Company Limited,

Britannic House, Finsbury Circus, London, E-, C.2 (England)

lubricant

The invention relates to lubricating oils containing additives to improve wear-reducing properties the oils contain.

It is known that disulfides, for example di-n-butyl disulfide, can be used to improve the load-bearing capacity of sehmier oil base oils. More information on this can be found in a paper ¹ in Journal of the Institute of Petroleum, Volume 51 »No. 497, Pages 145-161, May 1965.

The use of certain ester disulfides was also discussed in certain British patents, e.g. Mr. 714 497 and 748 404> described.

It has now been found that certain ester disulfides when used in particularly low concentrations in base oils a surprisingly large increase in the resilience of The effect of lubricating oils is that this increase is particularly great at certain concentrations of the ester disulfides.

The invention relates to lubricants based on a Lubricating oil, which are characterized in that they are in

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Solution 0.1-10 mmol, preferably 0.5-5 mmol of one or more diester disulfides of the general formula

wherein the radicals R are saturated alkyl radicals having 1-3 C atoms and the radicals R1 are saturated polymethylene radicals with 2 or 3 carbon atoms, contain per 100 g of base oil.

Of course, neither the two residues H nor the two R1 residues must be the same in each molecule. Furthermore, the lubricants can be a mixture of different ester disulfides the formula above.

Mineral oils or synthetic oils or their can be used as base oils Mixtures are used «Refined mineral oils are suitable Oils from petroleum, e.g. those with a viscosity in

Range of 3 - 50 cS at 99 ° C and a viscosity index in the range of 50 -. 1 <$ 0. Organic oils are suitable as synthetic oils Esters, polyglycol ethers, polyphenyl ethers, silicate esters and silicone oils.

The additive of the formula given is preferably 0.5-5 mmol per 100 g of base oil. These additives are suitable particularly suitable for use in lubricants intended for the Lubrication of heavily loaded surfaces that run on top of each other, e.g. for certain gears. These additives have certain high pressure properties, namely under boundary lubrication conditions, but they are primarily for use as wear-reducing additives, i.e. under hydrodynamic lubrication conditions. These additives are also non-corrosive, especially at low concentrations.

The additives of the formula mentioned can be used in conjunction with other common lubricating oil additives, e.g. those used in gear oils, e.g. with antioxidants and viscosity index improvers can be used.

The lubricating oil additives of the formula mentioned can be 909835/12 30

different methods can be produced. Of this two methods are described below.

Method 1

An alkyl ester of a halogenated alkaneartonic acid is reacted with thiourea to a thiuronium salt, which then hydrolyzed to a mercaptoester. The kercapto The ester then becomes the diester disulfide of the formula given oxidized.

The following process is suitable for production: 1 hol of an alkyl ester of a halogenated alkane is used carboxylic acid with 1 mole of thiourea in ethanol for 24 hours um, which is refluxed. The ethanol is then removed under reduced pressure and the resulting thiuronium salt washed with cold ethyl acetate. The thiuronium salt (1 hol) is then dissolved in water and with 1 hol one 30% aqueous sodium hydroxide solution hydrolyzed at 30 ° C. The reaction temperature is increased to 85 ° C. for 3 hours and the animals apt ο ester separated and distilled cleaned. The llereaptoester is then used according to the procedure oxidized, which is described in Journal of the American Chemical Society (1951) 73,3627. This method can be represented as follows:

BriHCÖOH _HS1UGG 0R 2. HaOH

HSR1C00H - ^> Formula I.

. 2. I.

Ilethoüe 2

A lercaptoalkanecarboxylic acid is first esterified and the ester obtained oxidizes, with a diester disulfide of formula I is obtained. A suitable esterification process is in Journal of t ^ .e American Chemical Society (1948), 70, 1069. The oxidation level is in JAGS (1951), 73, 3627. This procedure can be as-

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being asked
HSR1C00H

p.GH ₅ C ₆ H ₄ SO ₅ H

HSR1C00R> Formula I.

2. I ₂ / KI

The anti-fouling properties were used as an example of the two diester disulfides according to a modified form of the test with the four-ball tester, which is used to determine the resilience of lubricating oils is determined. This Test was carried out at 50 ° C under a load of 15 kg. The grindings on the balls were measured after 30, 45 and 60 minutes. Liquid was used as the base oil Paraffin (for medical purposes) with a viscosity of 3.38 cS at 99 ° C and a viscosity index of 83. The following additives were tested:

Additive A: 2,2'-dicarboethoxydiethyl disulfide, produced

according to method 2 described above, (R = C ₂ H ₅ -, R1 = - (CHg) ₂ -).

Additive 'B: 3,3' -dicarboethoxy-dir-n-propyl disulfide,

produced according to method 1 (R = C ₂ H ₅ -, R1 = - (OHg) ₃ -).

In order to create a possibility of comparison, tests with lubricants were also carried out; the diethyl disulfide (Additive P) and di-n-propyl disulfide (additive Q), the two well-known lubricating oil additives to increase the load capacity and which can be regarded as the starting disulfides of the diester disulfides A and B. Exams were also with di-n-butyl disulfide (additive ϊ), another known addition to increase the load capacity made. The results of these tests are as follows Table compiled. '

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• without G-round oil - 5th - Per
g G-round- 4th of 0 1 594357 45
Min. 60
Min. A- paraffin , 52 2 G 0 Diameter of the out
loops (in
mm) after 0.835 0.888 additive concentration
Addition , 26. 1 , 926 0 30th
Min. 0.753 0.755 A. mmol
100
oil , 63 0 , 463 0 , 787 0.643 p, 69O 18th , 32 0 , 231 0 , 680 0.547 0.602 9 , 16 'o , 617 _ 0 , 555 0.457 0.507 4th , 58 0 , 309 0 , 492 0.440 0.453 2 , 29 0 , 155 0 , 405 0.445 0.463 without 1 , 15 0 , 077 0 , 412 0.630 0, '660 P. paraffin 0 4th , 039 0 , 433 0.718 0.780 B. Di-iso- 0 , 52 2
1 0
0 , 610 0.429 0.464 octyl
sebacat 0 , 26
, 63 0 , 926 0 , 603 0.402
0.359 0.426
0.368 0 , 32 0, , 463
, 231 ■ 0: , 398 0.629 0.642 18th , 16 O. , 617 O. , 385
, 339 0.628 0.657 4th , 58 0: , 309 ο '. , 566 0.692 0.734 2 / 29 O. , 155 O. , 568 0., 734 0.762 1, , 15 0 , 077 'V ö, , 639 0.712 0.774 Di-iso-
'octyl-
sebacat • o. 2, , 039 O ₁ , 675 0.750 0.810 Q paraffin ■ 0: , 52 5, O ₁ , 682 0.908 0.915 paraffin , 52 2, , 259 O, , 660 0.687 0.747 - 0 , 26 1, , 445 O, , 792 0.593 0.618 ■ 1.8, 63 0, , 722 O, , 667 0.538 0.568 18 32 0, , 361 O, , 568 0.468 0.492 9, 16 O, , 681 O, , 527 0.475 0.501 " 4, 58 O, , 340 O, 432 0.670 0.750 2, 29 0, 170 O, , 412 0.740 0.860 1, 15th 2, 085 0, 545 0.740 0.830 paraffin 0 » 52 043 620 0.810 0.805 O, 778 670 ο, 792 18

9 0 9 8 3 5/1230

T Paraffin". 18.52 3,296 0.738 0.742 0.732 9.26 1.648 0.690 0.757 0.818 4.63 0.824 0.690 0.757 0.818 2.32 0.412 0.823 0.857 0.823

The above results make a loan more interesting Recognize features. First, the addition A shows a certain Superiority in wear-reducing properties over the starting disulfide, the addition P, if these compounds when using the same concentrations in the same. Base oil be compared.

Second and surprising are additives A and B both in a refined mineral oil or in an 01 ester-based particularly effective at certain low concentrations. A graphical representation of the diameter of the grinding in mm depending on the concentration shows a pronounced "dent" (depression) at these concentrations.

Third and surprising is the effectiveness of these additives compared to known additives at low Concentrations, namely 0.1-10 mmol / 100 g base oil am highest.

From the results for the additive I ¹ it can be seen that the "dent effect" does not occur with .Alkyldisulfiden.

When using di-isooctyl sebacate instead of paraffin The optimal effectiveness with regard to reducing wear and tear is indeed somewhat higher with these additives Concentrations shifted, but there is an improved one Performance of the additive.

A compound such as 2,2'-diearbodecoxydiethyl disulfide is outside the scope of the invention, but also shows this "dent" to a certain extent in the above-mentioned kruve. This depression occurred at a concentration of 4.40 mmol of this compound per 100 g of paraffin (2,200 wt. ^C / o). The diameters of the grindings were as follows (in mm)

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-7- 60 a. 1 594357 45 min. 0.578 50 min. 0.503 0.438

This result shows that "when the Chain of the ester alkyl radical still a maximum reduction in wear At a certain concentration of the additive that takes place, however, this concentration somewhat is higher than the compounds used according to the invention.

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Claims (3)

Claims 1) Lubricant based on a lubricating oil, characterized in that it contains 0.1 to 10 mmoles, preferably 0.5 to 5 mmoles, of one or more diester disulfides in solution the general formula ROOCR ₁ SSR ₁ COOr, in which the radicals R are saturated alkyl radicals having 1 to 3 carbon atoms and the radicals R _{1 are} saturated polymethylene radicals having 2 or 3 carbon atoms, per 100 g of orund oil. - 2) lubricant according to claim 1, characterized in that it contains mineral oil and / or synthetic oil as Orundöl. 3) lubricant according to claim 1 and 2, characterized in that that there are other common · Cooking oil additives, in particular Contains antioxidants and viscosity index improvers. 909835/1230 BATH ORIGINAL