US2212020A - Lubricant - Google Patents

Description

Patented Aug. 20, 1940 PATENT OFFICE LUBRICANT Waldersce .B; Hendrey, Beacon, N. Y., assignor to The Texas Company, New York, N. Y., a corporation of Delaware No Drawing.

Application April 1, 1937,

Serial No. 134,214 5 Claims. (01. 252-51) This invention relates to lubricants and has to do particularly with improvements in lubricating oil compositions intended for the lubrication of automotive engines, especially under severe conditions, wherein bearing corrosion, cylinder and piston ring wear may be encountered.

The invention contemplates the addition to lubricating compositions of certain materials which are specific for overcoming the above mentioned diflicultles and for generally improving the lubricant.

It has been found that the incorporation of high molecular weight alcohols or their esters, especially lanolin and the high molecular weight alcohols obtained from this material, usually designated as wool fat alcohols, greatly improves bearing corrosion and static coefllcient friction test. Materials of the above type, however, do not greatly improve the ring sticking behavior of the oil, and accordingly it has been found that the incorporation of a phosphatide or a complex glyceride phosphoric acid ester, such as lecithin and cephalin or combinations of these, is very desirable to reduce the ring sticking property. The combination of one or more of the above mentioned bearing corrosion inhibitors, together with one or more materials from the class of ring sticking inhibitors, when added to oil. has been found to produce a product of much improved character.

The following example will illustrate the invention as applied to an airplane oil but the invention is not limited to this specific example.

To separate samples of airplane base oil were added 1% lanolin, 0.2% soybean lecithin and a combination of 1% lanolin and 0.2% soybean lecithin respectively. The following table gives the tests on the three samples so made up, as comparedwith the airplane base oil alone:

The ring sticking time was determined on a cooperative fuel research, single cylinder, fixed compression engine running at 900 R. P. M. op-

erated at a jacket temperature of 375 F., throttle wide open and with mixture ratio adjusted for maximum power. At six hour intervals the cylinder was removed and piston examined for sticking piston rings. If none were found, the 6 test was continued but if any were found to be stuck, the engine was cleaned and the test rerun with a fresh supply of the same oil. This time,

however. the test was run continuously for a period of three hours less than that found pre- 10 viously necessary to stick the rings. Since the ring sticking time for any given oil will vary considerably with engine condition, it is necessary to run a reference oil preceding and following each oil rated. Then the ring sticking 1 quality of an oil is rated'as the per cent increase or decrease of the time required for it to stick rings for comparison with the reference oil. The reference oil was a commercial airplane oil of approximately 120 Saybolt viscosity at 20 210 F.

The method of determining coefficient of static friction is as follows:

The coefllcient is referred to highly polished surfaces, one of tungsten carbide having a 25 spherical contour, a radius inch, the other surface being a hard steel flat. This flat is the edge of a Timken ring, lying in a horizontal plane. The intensity of loading between the tungsten carbide and the steel is of the order of 30 100,000 lbs/sq. in.

A drop of the test oil is applied to the carefully cleaned steel surface and is spread thinly all over with a clean glass rod.

Before determining the coefficient, a run-in 35 treatment is given the steel surface, by rotating it at low speed in contact with the tungsten carbide under load. A cold worked circular track is thus formed. The coeflicient is now determined by measuring the force just sumcient to 40 balance frictional drag when the steel flat is caused to move very slightly from a position of rest. This force divided by the load is the coefficient of static friction. Ten determinations around the circular track are made, and the 4 mean value reported as the coefflcient of static friction. v

It will be noted from the above test that lanolin has substantially no effect in improving the ring sticking property but is effective in reducing the coefficient of friction. On the other hand, lecithin is very effective for decreasing ring sticking but has substantially no effect on the coefficient of friction. The combination of the two materials, however, increases both the ring sticking and coemcient of friction to a greater extent than either one separately.

The amounts of wool fat and phosphatide are not limited to the. quantities given in the specific example. In general. the amount of wool fat with the preparation of airplane oils which are used in engines operating at high cylinder temperatures, it is contemplated within the scope of the invention to use these materials in various types of lubricants, such as lubricating oils ranging from light motor oils to heavy cylinder stocks, compounded lubricating oils, greases, etc.

Obviously many modifications and variations of the invention, as hereinbei'ore set forth, may be made without departing from the spirit and scope thereof and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. The method of lubricating the bearings and cylinders of an internal combustion engine which comprises supplying to the bearings and cylinders of said engine a mineral lubricating oil within the motor oil viscosity range containing aaiaoao about 0.l-l.0$ ofa phosphatide and about 054.0% ofacompolmdcontainingahighmolecular weight alcohol.

2.'Ihemethodaccordingtoclaimiinwhich the phosphatideis'iecithinandthemvmmd I containing a high molecular weight alcohol is 3. A composition of the character described comprising a mineral lubricating oil containing about 0.l-1.0% by weight of lecithin and about 1. 05-50% by weight of lanolin suilicient to substantially improve the olliness and anti-corrosive properties of the oil.

4. A composition of the character described comprising a mineral lubricating oil containing about 0.2% by weight of lecithin and about 1% by weight of lanolin sumcient to substantially improve the oiliness and antioorrosive properties of the oil.

5. A lubricating oil adapted for the lubrication of the cylinders and bearings of an internal combustion engine comprising a mineral lubricating oil within the motor oil viscosity range containing about 0.1-1.0% by weight of a phos phatide, and about 054.0% by weight of a compound containing a high molecular weight alcohol.

WALDERSEE B. HENDREY.