US2228252A - Extreme pressure lubricant - Google Patents

Description

20 withstanding these high pressures.

Patented Jan. 14, 1941 PATENT OFFICE EXTREME PRESSURE LUBRICANT Henry G. Berger and Darwin E. Badertscher, Woodbury, and Francis M. Seger, Pltman, N. J assignors to Socony-Vacuum Oil Compa y, Incorporated, New York, N. Y., a. corporation of New York No Drawing. Original application December 3,

1937, Serial No. 177,891.

Divided and this application June 28, 1933, Serial No. 281,634

3 Claims.

the art of lubrication and is more particularly concerned with the development of a lubricant composition adapted for use under extreme pres- 5 sure conditions.

As is well known to those familiar with the art, the ordinary type of hydrocarbon lubricant, comprised only of a petroleum fraction, is incapable of withstanding the enormous pressures encountered between engaged surfaces in various types of modern machinery, such as the hypoid gears used in motor vehicles. This fact has led to the development of the so-called extreme pressure lubricant, which is comprised of a suitable carrying agent, such as a mineral oil, containing a minor proportion of an ingredient which, under the extreme pressure conditions encountered, will provide or form. between the engaged surfaces a lubricating film capable of Ingredients of the type just referred to are known as extreme pressure ingredients or extreme pressure (E. P.) bases, and numerous materials have been proposed for such use. Among the various E. P.

bases which have been proposed and which have met with varying degrees of success are organic materials which contain sulfur and chlorine. Our present invention is related to this general type of compound. This application is a division of our copending application Serial No. 177,891,

filed December 3, 1937.

It is a primary object of this invention to provide an extreme pressure lubricant which contains a new and novel sulfur-and-chlorine-contalning material or compound capable of giving extreme pressure lubricant properties to a carrying agent such as a hydrocarbon lubricant oil otherwise incapable of withstanding extreme pressure conditions. In this regard we have dis.

covered that perchloromethyl mercaptan and the class or group of compounds obtained by reacting various reactive materials with perchloromethyl mercaptan are very effective extreme pressure lubricant addition agents. The present invention 5 is concerned specifically with the production of scribed and claimed in our copending applications Serial Nos. 177,891 and 177,890, filed December 3, 1937.

Perchloromethyl mercaptan is a chlorinated substituted sulfur chloride having the formula ClaC--SC1 and can be prepared by the chlorina- This invention has to do in a general way with tion of carbon disulfide according to the method of Helfrich and Reid (JounAmeriChem. Soc. 43, 591 (1921)). For example, carbon disuliide containing about .4% by weight of iodine was chlorinated in the absence of direct sunlight at a temperature maintained below 25 C. until the volume of the reaction mixture had doubled. This crude reaction product, which contains carbon tetrachloride and sulfur chlorides in addition to perchloromethyl mercaptan, can be used in the preparation of the lubricants contemplated by this invention, but it is preferable to purify the crude product by distillation on a water bath at 100 0., followed by steam distillation. Subsequent vacuum distillation of the material, refined in this manner indicated that the steam distillated material was practically pure.

To demonstrate the effectiveness of perchloromethyl mercaptan as an extreme pressure lubricant ingredient we have prepared and tested compositions comprised of a mineral oil to which perchloromethyl mercaptan has been added. More specifically, we have added a minor proportion of perchloromethyl mercaptan to a mineral oil having a Saybolt Universal Viscosity of to 90 seconds at 210 F. and have subjected samples of such blended lubricants to the Almen Pin test, described by Wolf and Mougey, Free. A. P. I., 1932, pages 118-130, and the S. A. E. test, described in S. A. E. Journal 39, 234 (1936).

These two tests are commonly accepted in the art as standards to determine the extreme pressure characteristics of a lubricant. In the table below we show typical results obtained with such tests, using the oil alone and a sample of the same oil blended with perchloromethyl mercaptan.

Extreme Pres- (1000 P. M. 14.6:1 rubbing ratio, 8.35 lbs/sec. loadiug rate Percent Product in on Almen Oil without addition agent 15 Perchloromcthyl mercaptam.-. l

mercaptan used may vary irom say 0.1 per cent to 20 per cent, but in general lower percentages, say from 0.1 per cent to 10 per cent, are preierred.

Although we have indicated in the foregoing description that a mineral lubricating oil is a preferred carrying agent for the extreme pressure ingredients contemplated by our invention, it is not our intention that the invention be limited to any particular carrying or blending medium, but our invention includes broadly extreme pressure lubricants containing the perchloromethyl mercaptan described above, dissolved. dispersed, or emulsified in any other suitable carryin: medium, such, for example, as fatty vegetable such as kerosene, etc., benzene and r drocarbons; alcohols, esters: ethers, etc.

captan.

We claim:

1. An extreme pressure lubricant comprising a hydrocarbon lubricant oil to which a minor proportion of perchloromethyl mercaptan has been added.

2. An extreme pressure lubricant comprising a hydrocarbon lubricant oil to which has been added a minor proportion of from about 0.1% to about 10% of perchloromethyl mercaptan.

3. An extreme pressure lubricant comprising a viscous mineral oil to which has been added about one percent of perchloromethyl mer- HENRY G. BERGER. DARWIN E. BADERTSCHER. FRANCIS M. SEGER.