DE1273103B - Lubricating oil - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

ClOm

German class: 23 c -1/01

Number: 1273 103

File number: P 12 73 103.2-43 (E 29165)

Filing date: April 22, 1965

Opening day: July 18, 1968

Lubricating oil

There are many cases, especially under "boundary lubrication" conditions, where two rubbing surfaces to be lubricated by a very thin film are separated from lubricant. In these cases it is desirable to have very little friction between occurs on moving surfaces. To reduce this friction, it is common practice to use conventional Reinforce lubricants with additives known as oiling agents. It has now been found that very small amounts of iodine in a lubricating oil are unusually effective oiling agents. Besides this use of elemental iodine in such carrier media leads to notable secondary ones Advantages, d. H. for improvements in load capacity and wear resistance properties.

For example, only 0.00375 percent by weight of iodine in a mineral oil can reduce the coefficient of friction decrease by more than 50%. In aqueous lubricating oil emulsions, too, the coefficient of friction becomes greatly reduced.

Hydrocarbons are preferred as lubricating oils. They are there to no longer contain as 50% saturated hydrocarbons and at most 50% aromatics than 20% ^of other unsaturated hydrocarbons such as olefins or cycloolefins.

Neutral oils with a viscosity between 50 SUS at 37.8 ° C and 2000 SUS at 37.8 ⁰ C, or Bright Stocks having a viscosity from 90 to 300 SUS at 99 ° C are particularly suitable. However, solid hydrocarbons can also be used.

Synthetic lubricating oils such as ester, polysiloxane, Carbonate, formal, polyglycol oils or mixtures thereof are used. The iodine (iodine crystal) can also be introduced into closed systems. Here the gas of the system is that Carrier medium. This latter application is important for the lubrication of rockets or missile systems, where the rubbing surfaces can be occluded and the circulating iodine provides the necessary lubrication.

Aqueous solutions containing iodine are effective metalworking fluids. Since iodine is well known reacts with titanium, especially at higher temperatures, these solutions are suitable for machining Machining of titanium.

Appropriate aqueous metalworking solutions that contain iodine are:

1. Iodine alone dissolved in water.

2. Iodine in combination with inorganic iodides, such as KI, dissolved in water.

Applicant:

Esso Research and Engineering Company,

Elizabeth, N. J. (V. St. A.)

Representative:

Dr. K. Th. Hegel, patent attorney,

2000 Hamburg 50, Große Bergstr. 223

Named as inventor:

Michael J. Furey, Berkeley Heights, N. J.

3. Complexes of iodine with compounds with several hydroxyl groups, dissolved in water. to Compounds with multiple hydroxyl groups include starches, amylose, amylopectin, sorbitol, Polyethylene glycols and all other compounds that contain a considerable number of OH groups (polyols are preferred over glycols).

4. Combinations of the above.

Other additives can also be incorporated into all of the above solutions. These include corrosion inhibitors (ζ. Β. Nitrites, chromates, phosphates, imidazolines, sulfonates, amines), wetting agents, thickeners and dyes. Common solvents, such as alcohols or ethers, can also be used be introduced.

In lubricating oils, the iodine is used in amounts of 0.0001 to 0.99, preferably 0.001 to 0.90 percent by weight, in aqueous emulsions in amounts of 0.0001 to 5, for example 0.001 to 3 percent by weight.

Example I.

The measurements were made with a device described in a publication entitled "Metallic Contact and Friction between Sliding Surfaces" by M. J. F u r e y at the 1960 Joint ASLE-ASME Lubrication Conference, October 19, 1960 in Boston, Mass., Published in the ASLE Transactions, Vol. 4, No. 1, pp. 1-11, April 1961, or U.S. Patent 3,129,580.

The device consists essentially of a fixed metal ball which is rotating against a Steel cylinder is loaded. The extent of metallic contact is determined by measuring both the instantaneous as well as the average electrical resistance between the two surfaces

809 570/492

certainly. It is expressed as a percentage of the time metallic contact is in a given amount of time occurs. The friction between the ball and the cylinder is recorded simultaneously with the contact. This is given as the coefficient of friction, which is the ratio of frictional force is a burden. It has been found that in general there is a good relationship between this Metallic contact measured in a manner and the extent of surface damage occurring.

The evaluations of the preparations were carried out under the following conditions, if nothing other information is given:

System AISI 52100 steel

12.7 mm (V2 inch) diameter ball on cylinder
of 44.45 mm (l _^3/4 in)
diameter

Load 240 g (3849 kg / cm ² resp.

54 700 psi mean hertz pressure)

Speed ... 240 rpm (56 cm / sec sliding speed)

Time 32 minutes

Temperature 25.0 ⁰ C.

A solution with a content of 0.75 weight percent iodine was prepared by addition of elemental iodine in a solvent extracted paraffinic neutral mineral oil having a viscosity of 100 SUS at 37.8 ⁰ C and mixing at room temperature. The resulting mixture was clear with a dark amber color. A portion of this mixture was set aside and the remainder was diluted to give a mixture having a concentration of 0.075 weight percent iodine. The latter mixture was further diluted in the same manner and treated identically as the first mixture. This procedure was carried out until five mixtures were obtained containing concentrations of 0.75, 0.075, 0.0075, 0.00375 and 0.00075 weight percent iodine. The iodine mixtures and the mineral oil base alone with no additives were evaluated in the ball-on-cylinder device. The evaluation was made as the percentage of metallic contact and the coefficient of friction. The mixtures were designated A through F. The average results of several evaluations and the designations of the particular blends are given in Table I below.

Table I.

Effect of iodine on metallic contact and

the friction

55

Base oil ... mineral oil (100 SUS at Average 37.8 ° C) Time . ,, 32 minutes percent
more metallic concentration Contact average mixture of iodine
Weight 85 licher
Frictional percent 89 coefficient A. 0 65 0.090 B. 0.00075 13th 0.090 C. 0.00375 1 0.040 D. 0.0075 1 0.005 E. 0.075 0.005 F. 0.75 0.020

As can be seen from the above data in Table I, the iodine has a pronounced effect in reducing the friction with metallic contact. What is even more remarkable is that the effect on a Concentration of iodine of only 0.00375 percent by weight occurs. With an iodine concentration of 0.0075 weight percent is a significant reduction in metallic contact and one more than 50% reduction in friction.

These effects are unusually large. For example, the average reduction in friction for blends containing 0.0075% J ° d ° ^ ^ST more was 89% The average reduction in metallic contact for the same oils was about 94%

Example II

As is known, the solutions of iodine generally fall into two classes, amber and purple. In Example I above, it was observed that the mixtures of iodine in the mineral oil with 100 SUS showed various shades of amber color. It was observed that upon preparation of iodine mixtures in white oil the mixtures were purple in color. Therefore, to determine whether the form in which the iodine was present has an influence on the metallic contact and on the coefficient of friction had been ball-on-cylinder tests with mixtures of iodine in a white oil which was a highly refined mineral oil. This white oil had a viscosity of 100 SUS 37.8 ° C. The manufacturing method and evaluation were similar to that described in Example I. White oil alone with no iodine or any other additive was used as a control. The mixes were made with G to M designated. The results (average) of the tests and the designation of the mixtures are summarized in Table II below.

Table II

Effect of iodine on metallic contact and friction

Base oil white oil (100SUS at 37.8 ° C)

Time 32 minutes

concentration 0 -r percent
more metallic
Contact Frictional
coefficient mixture of iodine
Weight 0.00375 percent 0.0075 82 0.105 G 0.075 0 0.005 H 0.75 9 0.005 I. 1.00 0 0.020 J 1.25 11 0.020 K 3 0.020 L. 1 0.020 M.

60

65 As can be seen from Table II above, the results obtained with iodine in a white oil are very good. On average, iodine reduces the metallic contact and the friction by about 95 resp. 85% in these attempts.

Example III

To check the effectiveness of various additives in preventing staining on metal To determine iodine, a series of four mixtures

gen manufactured. One blend was the base oil of Example I, one blend was the same base oil plus 0.85 weight percent iodine, and the other two blends were the base oil plus 0.85 weight percent iodine plus 1 weight percent each of a number of other additives. The question to be answered was whether these compounds would reduce staining and, if they did reduce staining, whether they would have any adverse effect on the ability of iodine to reduce contact and friction. The mixtures as described above were designated N through S. Each test piece was then immersed in 50 cm ³ of the oil mixture for 72 hours at room temperature. 52100 - - Steel -12.7 - In this test, the test ball was an AISI mm - (V ₂ inches) - test sphere, and the test time was 72 hours at room temperature. The results of the test and the names of the mixtures are summarized in Table III below.

Table III

Effect of iodine and other additives on staining, metallic contact and friction Base oil .. Neutral mineral oil (100 SUS at 37.8 ⁰ C)

mixture oil Dark spot? percent
more metallic
Contact Frictional
coefficient N
O
P.
Q
R.
S. neutral mineral oil
Mineral oil + 0.85% iodine
Mixture O + 1% C ₁₈ -C ₁₈ olefin oxide
Mixture O + 1% barium sulfonate
Mixture N + 3% Cd-naphthenate
Mixture R + 0.85% iodine no
Yes
no
no
no
no 85
3
9
0
88
84 0.090
0.004
0.002
0.002
0.090
0.050

As can be seen from the table above, the additives in the iodine mixture removed the dark spots Completely.

Example IV

In order to evaluate the preparations according to the invention, the mixtures D, E and F and I, J, and K in a SAE machine and a Shell 4-ball E.P. test checked. These are tests known in the lubricant industry.

The results of these tests are summarized in Table IV below.

Table IV

Extreme pressure properties
mineral oils containing iodine

SAE machine, 4-ball E.P. test Sweat
Point lubricant Load
capacity Feeding
Point kg kg kg Neutral solution middle 100 Extracted distillate <45.4 ¹ ) 63 100 + 0.0075% J ₂ <45.4 ^X ) 56 141 + 0.075% J ₂ <45.4 ¹ ) 100 > 355 ² ) + O, 757o J ₂ 1810 178 89 White oil <45.4 ^X ) 36 100 + 0.0075% J ₂ <45.4 ¹ ) 45 178 + 0.075% J ₂ 1180 112 > 355 ² ) + 0.75% J ₂ 1720 141

standing metals were both aluminum. The test was carried out over a load range of 240, 960 and 4000 g carried out. The results of this test are given in Table V below.

Table V

Effect of iodine on lubrication

from aluminum-on-aluminum

Base oil white oil

Time 32 minutes

Ball-on-cylinder tests at 240 rpm

load
G H
in the oil ¹ ) percent
more metallic
Contact Frictional
coefficient wear and tear
scratch
mm ⁴⁵ 240
960
⁵⁰ 4000 no
Yes
no
Yes
no
Yes 91
39
48 ² )
92
86
88 0.09
0.041
l, 89 ^a )
0.01
0.12
0.04 0.36
0.48
0.87
0.63
1.25
0.74

² ) Scratching and rattling occurred in this test (excessive bumping probably explains the 48% metallic contact).

^x ) Failure in less than 5 seconds during break-in.

² ) Test terminated at this load without welding.

Example V

Mixture J was used in the ball-on-cylinder test evaluated, the in contact with each other. The above values show that the inventive Preparations have a low coefficient of friction and low wear in an aluminum-on-aluminum system result.

Claims (1)

Claim: Natural or synthetic lubricating oil, optionally containing customary lubricating oil additives or water as an emulsion, characterized that it additionally contains 0.0001 to 0.99 percent by weight iodine. 809 570/492 7.68 © Bundesdruckerei Berlin