DE2116778B2 - Traction fluid preparation - Google Patents

Description

The invention relates to that in the claims featured item.

Traction in the broadest sense is called adhesive friction of a body defined on a surface on which it moves A traction drive is a device that in which from a drive element to an output element through nominal point or nominal line contact a torque due to traction between the contacting elements, typically with a rolling effect, is transmitted.

When traction elements are in contact, there is a film of liquid between them. Almost all traction drives require liquids to dissipate heat, prevent wear on the contact surfaces, and to lubricate bearings and other moving parts associated with the drive. Instead of the metal-to-metal rolling contact, a liquid film is introduced into the load zone. The nature of this liquid determines to a large extent the limits in the mode of operation and in the performance of the drive. Desired properties for traction fluids are (1) a high traction coefficient, (2) a viscosity in the range of about 4 to centistokes over a temperature range of 99 ° to -18 "C ₁ (3) good oxidation resistance, (4) non-corrosive behavior against the usual Materials of construction, and (5) good load-bearing capacity and low degree of wear and tear,

A detailed discussion of traction drives and fluids is found in U.S. Patents 3411369 and US Pat 3440894 to be found. These patents define certain classes characterized by high traction coefficients and preferred molecular structures of fluids found to be superior to traction drives. The use of these liquids increases the torque capacity of the traction drives and allows a reduction in the Amount of drive required for a given force requirement.

Although the liquids of the type described in the referenced patents are related to the Ability to transmit torque to the best of all fluids known for traction drives belong, however, they show load-bearing capacity * and Anti-wear properties, which are used in restrict certain traction drives. It is therefore desirable to have these special properties of the liquids to improve,

The object of the present invention was to obtain a certain amount of traction fluids with improved load-bearing and anti-wear properties without sacrificing the traction coefficient or to adversely affect the oxidation resistance at high temperatures.

The object is achieved according to the invention in that the traction fluid is sufficient

21 16
3 5 778
4th Amount of ZjnkdHneoalkyO-djtMophQsphftt with a l ^ rjsopropyltercyplohexyt, Neo-alkyl group of 5 to 3 carbon atoms Bis- (J ^ cyclQhexyjoxy) -cyclohexane, adds, The addition of this connection? 5W Grundkom l ^ bis (methyIcyclohexyl) -cyclohexane, position increases the measured in the Smnd ^ rdYeric white test Dicyclohexylcyclohexane-lß-diearboxylate, ne load-carrying capacity of the traction fluid 10 Wfi-Quatercyclohexyl, tend, but without dje by changing the viscosity 6-Ethyl-2 ^, 4,4, li, l U ^ lS-octymethyltetradecane and the susceptibility to corrosion and -2 ₁ 2,4r4,13,13,15,15-octamethylhexadecane, resistance at elevated temperatures increases significantly Tricyclohexylmethane, decrease, A preferred additive is zinc di (neo N-cyclohexylpiperidine, hexyl) -ditiuophosphak IS Neopentyl glycol dineotridecanoate, Typical ones useful in the present invention Bicyclooctyl, Traction fluids include those that exclude Bicyclododecyl, at length in the US PS. 3411369 and 3440 894 Cyclohexylcyclododecane, are described. These fluids are through in theirs Cycloheptylcyclohexane carboxylate, Structural units or elements present in molecules 20th Cyclooctylcyclohexane carboxylate, te defines which liquids are to be used in Cyclododecyl cyclohexane carboxylate, Make traction drives particularly suitable. As in bis-, cis- and trans-l ^ -CycIohexylcycIohexan- defined in US-PS 34 40 894 are suitable traction dicarboxyiat, liquids those organic compounds that 25th 1,1 -dicyclohexyl ^ -methylpropane, (1) about 12 to 7i> Have carbon atoms of which ll-dicyclohexyl ^ -methylbutane,
II-dicyclohexyl-2 _J 5-dimethylhexane, up to 8 by other atoms such as oxygen, l-dicyclohexylpentane, Replaced nitrogen, phosphorus or silicon atoms l ^ -dicyclohexylpropane, can be, and l ^ -Di- {x-ethylcyclohexyl) propane, (2) (a) at least one saturated carbon atom 30th ^ -Dicyclohexylpropane, me-containing ring with at least 6 23-dicyclohexy ^ 23-dimethylbutane, Ring atoms or l ^ -DicycIohexyl-2-methylbutane, (b) contain an acyclic structure in which lß-dicyclohexylbutane, at least 3 quaternary carbon atoms lÄS-Tricyclöhexylpropane and are present, and 35 Cydopentamethylene dicyclohexylsilane. (3) one measured with a pressure bearing tester a traction coefficient of at least 0.06 Other suitable and useful traction fluids exhibit. thes as defined in U.S. Patent 3,411,369 are those organic compounds that condensed 2 to 9, Examples of typical, given in the vüten 40 have saturated, carbon-containing rings Definition included traction fluids are and have 9 to 60 carbon atoms, of which to Cyclododecane, bicyclohexyl, 1,2-tercyclohexyI, dicyclo- to 8 by other atoms such as oxygen, nitrogen, hexylmethane and 2ß-dicyclohexyI-2ß-dimethylbutane. Phosphorus and silicon atoms can be replaced. Except are cycloalkanes, as reported in that A comprehensive description of suitable Patent listed, also saturated heeterocyclic 45 condensed ring compounds is referenced in the cal compounds substituted with hydrocarbons Find patent. Preferred in this invention Cycloalkanes, oxygen-containing substituted cyclo- Connections should be measured with one pressure alkanes, certain esters and certain oligomers of bearing test apparatus a traction coefficient of min saturated rings containing carbon 50 result in at least 0.06. locked in. A non-exclusive review of some special A non-exclusive list of special more preferred connections, as indicated by the preferred traction fluids referenced patent is shown Isodecyclohexane, cis-decalin, cis and trans-decalin, Isopentadecyclohexane, 55 2,3-dimethyldecalin, Cyclododecane, Isopropyldecalin, Bicyclohexyl, tert-butyldecalin, 4- (l-methylethyl) bicyclohexyl, Perhydrofluorene, 4,4'-bis (l * methylethyl) bicyclohexyl, Perhydrophenanthrene, x-lsohexyW-isopropylbicyclohexyl, 60 Perhydromethylcyclopentadiene (trimer), jr-cyclopentylbicyclohexyl, Perhydrofluoranthene, Dicyclohexylmethane, 1 'cyclohexyl-1 ^' trimethylhydrindane, (x-ethylcyclohexyl) -cyclohexylmethane, j-hexylpefhydrofluoranthene, fjr-Cyclohexyl-il -methylethyl)] - JF-Cyclohexylperhydrofluoranthene, cyclohexylmethane, 65 Poly * (ethyl 1 -methyl) 'perhydrofluoranthene, Bis ^ trimethylcyclohexyl-methane, jr-isopropyl perhydrofluoranthene, l.i-dicyclohexylethane, Perhydrofluoren-j-cyclohexyl, 1,1 ^ -Tricyclohexylpropane, Perhydrofluoren-x-isododecyl, Trimethylolpropane tricyclohexane carboxylate, I -cyclohexyldecalin, 1,2-tercyclohexyl, 2- (Cyclohexyl - * - methyl) -bicyclo (2Äl) heptari, U-tercyclohexyl, Perhydropyrene, * - (1,1-Dimethylbutyl) -1,2-tercyclohexyl), Ethyl perhydrofluorene, l ^ -Isopropyltercyclohexyl, Perhydroanthracene,

2) 16

Bis-2rdeca | in, ■

l ^ -Dihydrmdan,.

Perbydrocjyclopentiidien-Trimer,

l-cyclohexyldecaUm,

2-CycIobexyldecalii »,

Djmethyl-cyclobexyjdecalin and

4,5-methylene perbydropbenanthrene.

As from the above Lyste von Traktionsfluider can be seen, the condensed ring connections be substituted or unsubstituted. The substituents can be alkyls, alicyclic hydrocarbons or heterocyclic. Rings containing carbon be. The alkyl substituents can either be straight-chain or branched seaijlund 1 to about 18 or more is Contained carbon atoms.

It is known that traction fluids are certain Additives, 2. B. to improve the viscosity index, to be added to meet the requirements of viscosity in relation to temperature. It was too suggested that small amounts of other additives such as antioxidant, anti-wear, Anticorrosive agents, dispersants, dyes and other useful substances can be incorporated if necessary this is required.

In accordance with this invention, the load bearing and anti-wear properties of the traction fluids preferably by incorporating zinc di (neoaikyl) dithiophosphate, in which the neo-alkyl group contains 5 to 13 carbon atoms, e.g. B. zinc di (neo-pentyl) dithiophosphate or zinc di (neo-hexyl) dithiophosphate, improved Although zinc dialkyldithiophosphate and especially zinc 2-ethylhexyl isopropyldithiophosphate Known as antiwear agents, these compounds were classified as a class for use in traction fluids found unsuitable because of an unfavorable influence on the resistance to oxidation the traction fluids. Examples of such known antiwear agents based on zinc alkyl alkyldithiophosphates, which have been tested and found to be unsuitable are except for the 2-ethylhexylisopropyl derivative even those that are called an alkyl-alkyl group Di- (1,3-dimethylbutyl), 2-ethylhexyl-isobutyl, di- (n-hexyl) or isobutyl-2-ethylhexy! own.

In view of the constantly negative results with regard to the oxidation resistance of traction fluids which were obtained with some of the zinc dialkyldithiophosphates, it was very surprising and unexpected to find that a subclass of these compounds, namely the zinc di-so (neo-alkyl) dithiophosphates according to the invention and especially the preferred zinc di (neo-hexyl) dithiophosphate, significantly improve the load-bearing capacity of traction fluids without reducing the resistance to oxidation. The effectiveness of the additive was particularly surprising because many of the unsatisfactory compounds were generally recognized as antiwear agents in functional fluids. The normal alkyl derivative corresponding to the preferred additive, namely zinc di (n-hexyl) dithiophosphate, for example, reduced the resistance to oxidation of the traction fluid, which is indicated by a large increase in viscosity of the traction fluid after it has been exposed to oxidation. In the same way, the 1,3-dimethyl butyl derivative caused a considerable increase in viscosity in the oxidation test, and the isobutyl-2-ethylhexyl and 2-ethylhexyl isopropyl derivative both caused a substantial increase in the susceptibility to corrosion of the tract fluids. taking into account the _ev ^ \. The expressed results obtained with the di- (neo-alkyl) -dithiophosphates could not be foreseen for the better results.

According to a preferred embodiment of the invention is a zinc di (neo-alkyl) dithiophosphate in one concentration of at least about 0.1% by weight and expediently about 0.5 to 2% by weight, on the traction fluid related, added It has been found that higher concentrations do not result in any advantage.

The advantages to be gained with the present invention are illustrated in the following examples These examples are illustrative only and it is not intended to limit the invention to the here presented to restrict specific embodiments.

In the following examples, the traction coefficient was determined with a pressure bearing tester, as in the article by F. G Rounds, "Effect of Lubricant Composition on Lines with Thrust Ball Bearings measured friction "(J. Chem. and Eng. Data, Vol 5, No. 4, p. 499 [1960]). This apparatus measures that of a central shaft through two ball bearings immersed in the test liquid on one Rotary arm transmitted torque The ball bearings are mounted on the shaft and can be rotated, while being subjected to an axial compressive load. Will the pressure loads? hydraulic or generated by compression of calibrated Belleville springs, coupled to the drive shaft Tachometer measures the speed of rotation Thermocouples mounted within 032 cm of the balls measure the temperature of the test liquid, the latter at different, predetermined temperatures is held by heating or cooling the jacket fluid in the surrounding area of the test chamber Casing.

The individual balls tend to rotate on an axis parallel to the main bearing axis and roll also around the walkway. As a result, both rolling and gliding contribute to traction. The output torque is measured by the rotary arm, which is attached between the two bearings The measured torque is then determined by the terms of the traction coefficient for the Traction fluid interpreted The traction coefficients obtained with this test apparatus are with comparable to those measured in real traction drives. Thus the apparatus for Evaluation of traction fluid candidates effective. When determining the in Tables I and II The traction coefficient shown was the temperature at 933 ° C, the Hertzian pressure at 34,000 atm and the ball linear velocity was maintained at 244 m / min.

The oxidation and corrosion test (O and K test) was according to the US. Federal Test Method No. 791-5308.4 UG '. Executed under the following special conditions:

temperature 176.7 "C Time 72 hours air 5 liters Metals Mg, Al, Cu, Fe

The wear test data were based on the standard Shell 4-ball tester with balls made of "52100" steel

at 93.3 ° C and 1260 tours / min under 40 kg load.

The results compiled in Table I illustrate the advantages of zinc di (neo-alkyl) dithiophosphates compared to similar compounds in

a typical traction fluid composition consisting of a mixture of dicyclohexyl, tercyclohexyl and 23-dicyclohexyl-2,3-dimethylbutane which is 1.5% of an alkyl methaeryl vinyl pyrrolidone copolymer to improve the viscosity index.

Table I.

Verse. Additive) Traction K and O test Cu corrosion ') Wear and tear coefficient -0.04 dome test ⁴ ) Viscosity) + 0.40 1 None (control) 0.0618 6th -1.3 0.62 2 1% di (neo-hexyl) 0.0638 13th -1.03 0.43 3 1% di (neo-pentyl) - 5 -0.7 0.44 4th 1% di (n-hexyl) 0.0629 2050 -3.5 - 5 1.2% 1,3-dimethylbutyl - 180 - 7, / 0.46 6th 1% 2-ethylhexyl-isopropyl - 2344 -5.4 - 7th I ¹ TO isuuuiyi-i-auiyiiicAyi - ι SOC 8th 2% 2-Ethylhexyl-isoDroDvl 0.0623 24

Zinc (alkyl-alkyl) dithiophosphate,% by weight based on liquid. Viscosity increase at 37.8 ° C. Norm: less than 30 centistokes. mg metal loss per cm ² surface. Norm: less than -0.6 mg. Wear cap diameter. Norm: less than 0.45mm.

The results of Table I clearly show the use of zinc di (neo-alkyl) dithiophosphate as Benefits gained from additive. In Example 2 - a preferred embodiment of this invention - decreased the addition of zinc di (neo-hexyl) dithiophosphate to the traction fluid mixture of Example 1 the diameter of the closure cap of 0.62 0.43 mm. The small increase in viscosity of 13% in the O and K tests was well within that for these Property set standard. The slight increase in weight with copper corrosion in the O and K test proves the formation of a protective coating on the metal surface. Test results and visual Observations have shown that this coating does not interfere with the function of the traction fluid.

The same improvement in the wear cap test was achieved by adding 1% zinc di (neo-pentyl) dithiophosphate obtained for the traction fluid mixture of Example 1, as from the results of Example 3 In this case, however, the addition of an additive was slight in the O and K tests Accompanied increase in copper corrosion In certain applications where a degree of corrosion of this magnitude does not appear permissible, it is contemplated that a deactivator may be used in the formulation of the copper metal Traction fluid composition can be included.

The additives in Examples 4 and 5 were unsatisfactory because of the large increase in viscosity.

Examples 6, 7 and 8 show the effect of other known zinc alkyl alkyl dithiophosphates in the O and K tests on the resistance to oxidation of traction fluids and further illustrate that Considered as a whole class, zinc dithiophosphates are not suitable additives for reaction liquids. The results in Table II below illustrate the effectiveness of the preferred additive Zinc di (neo-hexyl) dithiophosphate in the reduction of the diameter of the wear cap, if it is the Traction fluid base mixture is added in a concentration in the range from 0.1 to 1.0% by weight. The composition of the masterbatch was essentially the same as for those in Table I. experiments shown.

Table II Zinc di-ineo wear and tear Verbs ₄₅ attempt hexyl) -dithio- dome, eruption phosphate- diameter concentration Wt% mm % 0 0.76 50 9 0.1 0.66 13th 10 0.25 0.49 35 11 0.50 0.43 43 12th 1.0 0.44 42 13th

,,. 0.76 - diameter of the wear cap

! Improvement =

0.76

From the above data it can be seen that with the addition of as little as 0.1% zinc di (neo-hexyl) dithiophosphate a substantial improvement in the load carrying capacity of the traction fluid is obtained.

Although the foregoing description and examples are based on the use of zinc di-tneo-pentyi) - and zinc di (neo-hexyl) dithiophosphates are directed, the neoalkyl groups can contain up to about 13 carbon atoms. Examples are zinc di (neoalkyl) dithiophosphates, in which the neo-alkyl group neo-heptyl, neo-octyl, neo-nonyl, neo-decyl, neo-undecyl, Representing neo-dodecyi or neo-tridecyi

Claims (10)

Claims; I ₁ traction fluid preparation with improved load-bearing capacity, characterized in that it consists of a predominant part of a traction fluid, which is a cyclic compound containing carbon atoms with a traction coefficient of at least 0.06, and a sufficient amount of zinc di (neo-alkyl ) dithiophosphate with a neoalkyl group of 5 to 13 carbon atoms as an additive to improve load-bearing capacity 2. traction fluid preparation according to claim 1, characterized in that it is as Traction fluid is a cyclic compound containing 12 to 70 carbon atoms, of which up to 8 can be replaced by oxygen, nitrogen, phosphorus and / or silicon atoms and either at least one saturated ring containing carbon atoms with at least 6 ring atoms or has an acyclic structure with at least 3 quaternary carbon atoms, or one cyclic compound with 9 to 60 carbon atoms, of which up to 8 are replaced by oxygen, nitrogen, phosphorus and / or silicon atoms can be and has 2 to 9 saturated, condensed rings contains 3. traction fluid preparation according to claim 2, characterized in that the traction fluid is a mixture of different, cyclic, Contains compounds containing carbon atoms 4. traction fluid preparation according to claim 1, characterized in that it contains at least 0.1 percent by weight of zinc di (neoalkyl) diethyl phosphate contains 5. traction fluid preparation according to claim 2 or 3, characterized in that the traction fluid is dicyclohexyl, alkyldicyclohexyi, Tercyclohexyl, alkyltercyclohexyl, quatercyclohexyl, Quinquecyclohexyl or 2ß-dicyclohexyI-23-dimethyibutane contains 6. traction fluid preparation according to claim 2 or 3, characterized in that the traction fluid decalin, cyclohexyldecalin, alkyl-substituted Contains decalin or cyclohexyldecalin, where the alkyl contains I to 18 carbon atoms having 7. traction fluid preparation Vach claim 1, characterized in that it is used as Zinc di (neo-alkyl) dithiophosphate zinc di (neo-pentyl-dithiophosphate or zinc di (neo-hexyl) dithiophosphate contains 8. traction fluid preparation according to claims 5 and 7, characterized in that it as cyclic compounds a mixture of dicyclohexyl, tercyclohexyl and 2ß-dicyclohexyl-2,3-dimethylbutane, and as an additive zinc di (neohexyty dithiophosphate contains 9. traction fluid preparation according to one of claims 1 to 8, characterized in that it contains another additive to improve the viscosity index 10. Using the traction fluid preparation according to one of claims 1 to 9 in a traction drive.