US2043961A - Lubricants - Google Patents

Description

Patented June 9, .1936

STATES PATENT OFFICE LUBRICANTS tion of Delaware No Drawing. Application ch 11 1933, Serial N0. 669,441

of, an unsatisfactory product-is often obtained due to the poor physical appearance, darkened color, and the tendency toward sludge deposition of the, finished product.

'An important object of the present invention is to provide a simple and practical manner of intrjoducing the desired amount of sulfurinto any An important object of the invention is to produce a high grade sulfur-containing lubricant which is stable, and free from sludge-forming tendencies.

Another object of the invention is to produce a high grade sulfur cutting oil free from sludge and light in color.

A further object of the present invention is to provide an improved method. of introducing sulfur into lubricants, such as mineral lubrieating oils, by the use of cyclic unsaturated compounds or compounds of the nature of pine oil, such as terpenes, terpineols, pine oil, pine tars, etc. K v

The incorporation of sulfur into mineral oils through the agency of terpene compounds has been known heretofore and according to the prior art, so far as I am aware, this has been done by heating the terpenes and, sulfur under atmospheric pressure to dissolve sulfur in the terpene to form a sulfur base which is then admixed with the lubricating oil. The sulfur base thus prepared is apparently a solution 'of sulfur in the terpene, stable only at higher temperatures 45 and on cooling to room temperatures the sulfur will settle from a concentrated solution thereoi; but, when the base is mixed with a mineral oil in small amounts, the terpene acts sumciently as a solvent-aid to eiiect solution of the sulfur in 50 the resulting mixture of base. and lubricating oil. Sulfurized oils, however, prepared according to the above method, have the disadvantage of be ing relatively unstable due to the ireesulfur con'-, tent and the tendency, particularly at low temtures or in service, to precipitate free sulfur or sludge unless large amounts of terpenes are used.

In accordance with the present invention instead of incorporating the sulfur into theterpenetype of compound under atmospheric pressure I 5 maintain a substantial superatmospheric' pres-- sureon the terpene and sulfur during the sulfurizing operation. I'have found that by maintaining a superatmospheric pressure on the terpene and sulfur undergoing reaction, much higher tem- 1o peratures, even above the boiling point of the sulfur or terpene, may be employed, andthe time of digestion regulated to any time desiredwith out substantial loss of the reagents. It has been found also that a much improved product may 15 be obtained, according: to my invention, in that the sulfur apparently exists essentially in a chemically combined state, and accordingly large v quantities thereof may be combined with terpenes in a highly stable form. f The sulfur base so pre;

pared may be blended in a concentrated form and in any proportions with a mineral oil to give a sulfur-containing oil which is of good physical appearance, color, and highly stable.

More particularly, according to the invention, a suitable unsaturated cyclic compound such as terpene hydrocarbons or their derivatives, for example, terpenes, terpineols, pin'e tars, etc, are reacted with sulfur. Pine oil.or a material of that nature is particularly suitable and I prefer to use,- especially for themanufacture of light colored 'cutting oils, a light pine oil, such as steam distilled Yarmor pine oil, having an iodine value of around 100-125. The pine oil is mixed with about 5-30% of sulfur and the mixture heated to a temperature in the region of 300- 500" Enter about 1-5 hours under a superatmos-, pheric pressure of around -500 lbs. per sq. in. For a light pine oil I have found that the optimum conditions are a temperature of about 400 F., a digestion period of about 1-2 hours and a superatmospheric pressure of around 100-150 lbs. per sq. in. It will be understood, of course, that 'these conditions may vary with different oils but in any'case I prefer to use a temperature of at least 300 F. and a superatmospheric pressure of 50 lbs. per sq. in. or more.

The pressure may be convenientlyagenerated by merely confining the vapors evolved. It has been found that a copious evolution of hydrogen sul= flde occurs and by confining the gases and vaporsa self-generated pressure of as much as 425 lbs., or more maybe obtained at temperatures around 400 F., and even higherpressures are possible at more elevated temperatures. In case insufllcient pressure is generated, an extraneous gas pressure, say of natural gas, hydrogen sulfide, or; nitrogen, may be applied. I I

The pine oil sulfur base,

in all proportions and having a sulfur content ranging from 525% or over. It may be admixed with the desired lubricanti'n suitable proportions.

' For-a cutting oil I prefer to use a quantity sufficient toprovide from -l-% or more of sulfur I in the resulting mixture.

In case thesulfur base has an objectionable odor, for instancedue to dissolved hydrogen'sulj fide, a vacuum may be applied to the oil or a gas such as airbubbled therethrough to carry out the volatile materials of bad odor. The'objectionable odor may also be removed, if desired, insubstantially the same manner after the sulfur base has;

I been blended with the lubricating oil. v I

The invention will now be described in connection with thepractical application thereof to the heated with 101105.101 powdered sulfur in ajflre-' preparation of a sulfur cutting oil; although the invention is not limited thereto.

. Thirty pounds of steam distilled Yarmor pine oil having an iodine value of 110, an A. P. I. grave ity of 195 and a sulfur content of 0.11% were heated pressure kettle at 400 F. for 2 hours.

Gases and vapors were released sufficiently to 'maintain a gauge pressure of about; 100 lbs. per

, sq. in. The materialswere found to be completely present.

reacted and neither free sulfur nor sludge was I The, resulting product was reddish brownin color, clear, and tested22.1% sulfur and I 1.? A. P. I. gravity. Onepart of the resulting sulfurbase was blended at room temperatures with 7 three parts of a pale lubricating oil having a Say-' Y bolt viscosity of'70 seconds at 100 F. The blend A tested 5.77% sulfur and waslight redincolor clear. free from sludge, exhibited extreme pressure lubrication characteristics and proved highly satisfactory as acutting oil. 7

Instead of viscosity pale oil other pale oils thus prepared, is a bright reddish oil, misciblewith hydrocarbon oils theinvention, I I

made withoutdeparting from the spirit and scope 20 I 1 from -200 seconds Saybolt universal at 100 F. may be used for preparing cutting, Oils. It is 1 also contemplated that the sulfur may be added during the digestion operation matter the oil has reached a'reaction temperature instead of I jfirst mixing the oil and sulfur and then heating the. mixture.

While the above described specific, embodiment I of the invention has to do with cutting-oils the invention is by no means so limited. Itis 0011-.

templated that heavier oils, such as motor oils or I gear lubricants with viscosities ranging from 200 seconds at 100 F. to 250 seconds at 210? F. Saybolt universal maybe sulfuriz ed by my method.

also find valu+ ,15'

In some cases the invention may able application for the incorporationof sulfur into greases. I

Obviou'slymany modiflcations'and variations of as hereinbefore set forth, maybe thereof, and therfore only such limitations should be imposed as are indicated. in the, ap-

pended claims.

Iclaimz.

y ,1'. A sulfur base, soluble in hydrocarbon oils, 25 consisting essentially latter-present in an and 25% and incorporated in theoil undersuperof pineoil and sulfur, the amount ranging between 5 atmospheric pressure, said base having an 1121- 1 proved odor and precipitating less sulfur on storage and on cooling than a base-containing sulfur incorporated therein under atmospheric pres-ji sure in sulfur base, soluble in mineral lubricatin under I superatmospherio Us KAUFMAN.