US2254756A - Lubricating oil - Google Patents

Description

Patented Sept. 2, 1941 UNlTED sTATEsfriRrE T OFFICE.

LUBBICATING OIL Ernest Segessemann, Newark, N. J., assignor to National Oil Products Company, Harrison, N. J a corporation of New Jersey No Drawing. Application June 18, 1938, Serial No. 214,581

13 Claims. (01. 252-46) The invention relates in general to lubricants and more particularly to sulfur-containing lubricants adapted for use as cutting oils and extreme pressure lubricants and to correlated improvements in the process of producing such lubricants.

In the fabrication of metals into stock mate- I rials, articles, machine elements, etc., by methods involving cutting, grooving, turning, milling, brooching, boring, hobbin'g, gear cutting, grinding, stamping, drawing, etc., operations, frictional forces are created which cause overheating and accelerated dulling of the cutting tools, dies, etc., used in such operations. Moreover, the metals being subjected to the aforementioned /operations become overheated, thereby deleteriously affecting the uniformity and quality of the finished products.

In an attempt to combat these difliculties, it has been proposed to employ various oils and compositions containing oils for cooling and lubricating both the cutting tools, dies,-etc., as well as the metal being worked upon. In general, there are four main types of cutting oils, to wit, (1) straight mineral oil, (2) mineral lard oil,

, (3) sulfurized mineral or mineral lard oil and (4) soluble oils (emulsifiable with water). The present invention is directed in part to the socalled sulfurized cutting oils which may be used straight or in the emulsified form.

The two primary functions of a cutting oil in the metal working arts are cooling and lubricating'which in turn serve to increase production and yield products having a better surface finish. An ideal cutting oil should be endowed with the following characteristics: (1) high specific heat, (2) good wetting and spreading power, (3) adherence to the; essential elements and a adequate flow; (5) stability, (6) free of fire hazards, ('7) non-corrosive and. (8 non-injurious to health. While many soluble cutting oils have been proposed and preparechnone of these have even remotely satisfied the foregoing characteristics.

The invention is further directed to the socalled extreme pressure lubricants. In the lubrication of moving surfaces, such as transmissions, hypoid gears, etc., it is of prime importance to employ an oil having a high film strength 'to withstand the great pressure between the moving surfaces. While various'E. P. lubricants have been used to varying degrees ofsuccess, a-constant need for improvement exists.

good film strength, (4) a viscosity permitting fore been prepared either by incorporating sulfur into mineral oils in the form of a finely divided suspension or by compounding mineral lubricating oils with sulfur-containing fatty oils, such as sulfurized lard oil, cottonseed oil, etc.v All thesecompounds, while useful, often lack the stability required under storage and working conditions. The products. containing free sulfur show a tendency towards sedimentation and the come bacteria-infected and develop into carriers of disease among which skin irritations are the most prevalent.

The general object of the invention is toobviate the foregoing and other disadvantages.

A specific object of the invention is to provide an improved sulfur-containing lubricant characterized by being stable, non-corrosive and free from bacteria infection.

Another object of the invention is to provide an improved process of producing cutting oils and E. P. lubricants in general.

A furtherobject of the invention is to provide an emulsifiable cutting oil of enhanced stability and lubricating value.

Other objects of the invention will impart be obvious and will in part appear hereinafter.

It has now beenfound that a satisfactory sulfur base, which lends itself readily to the preparation of sulfurized mineral oils, can be made, according to the invention, by incorporating sulfur into unsaturated fatty alcohols. These sulfurized alcohols are soluble in all proportions with the hydrocarbon oils commonly used in formulating cutting oils and extreme pressure lubricants.

- The resulting sulfur-containing mineral oils exhibit a marked stability on storage and under rigorous working conditions. They are free from any tendency to develop rancidity, sludge or gum formation. Due to the absence of rancid- Sulfur-containing lubricating oils have heretoity, the hazard arising from bacterial impurities are greatly lessened. The novel lubricating oil may also have an emulsifier blendedtherewith "has exhibit a marked olliness" subjecting the to-produce an emulsified lubricant particularly adapted for use as a cutting oil.

Theinvention accordingly comprises the several steps and relation of one or more of such steps with respect to each of the others, and'a composition ofmatter g the characteristics, properties and relation of components, all of which will be exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.

Cutting oils prepared according to ,the invention from the sulfurized unsaturated fatty alcoand ability to penetrate into the smallest crevices of the work. Their high lubricating quality permits smooth cutting and cooling of the machined parts, enabling operations at high turning speeds. Their high stability towards decomposition permits reconditioning or reclaiming without deterioration over a longer period of time than in the case of lubricants containing fatty oils.

Extreme pressure lubricants prepared according to the invention from the sulfurized unsaturated fatty alcohols have been found to be particularly useful in transmissions and in hypoid gears where their freedom from gum and sludge formation during use and their marked film strength enables them to maintain a high loadcarrying capacity over extended periods of service hours and under extreme pressure conditions.

The sulfur may be incorporated into the unsaturated fatty alcohols byheating the unsaturated alcohol with the required amount of sulfur at a temperature usually ranging between 130-180 C. or the sulfur and the alcohol may be dissolved in a suitable solvent, such as xylene or toluene and heated at the boiling point of the solvent until all the sulfur has combined with the alcohol. During the operation small quantities of hydrogen sulfide are evolved and in order to free the finished product of the last traces thereof a stream of air may be passed through the liquid. Y

Any suitable unsaturated aliphatic primary, secondary or tertiary alcohols with normal or ramified carbon chains, may be used according to the present invention having 8 or more carbon atoms which are generally referred to as fatty alcohols. Examples of such alcohol include, inter alia, oleyl alcohol, linoleyl alcohol, ricinoleyl alcohol, hexadecenyl alcohol, undecylenic alcohol, erucyl alcohol or unsaturated alcohols, such as are obtainable by reducing unsaturated fatty acid esters. There also come into consideration the alcohols occurring in certain waxes, for example, in sperm oil or in Dbgling's oil wherein the unsaturated alcohols are obtained by saponiflcation and subsequent extraction or distillation thereof. It is also possible to start with unsaturated alcohols which are produced by treating chlorinated parafiins with alkalies, whereby double bonds are produced in consequence of the elimination of HCl.

The sulfurized unsaturated alcohols may also be produced from saturated fatty alcohols by latter to the action of sulfur at high temperatures, whereby dehydrogenation takes place with the evolution of Has. The resulting unsaturated alcohols may then be treated withadditional sulfur to bring about sulfurization thereof. Sufficient sulfur may be added to the saturated fatty alcohols at the outset to as sulfurization event,

cause dehydrogenation as well in a continuous operation. In any to be construed in a limiting sense, all parts are used as the starting material, the end product will comprise a sulfurired unsaturated fatty alcohol. The expression sulfurized unsaturated fatty alcohols is used herein to connote the end product produced by the chemical reaction of sulfur with an unsaturated fatty alcohol, which product may be completely saturated or only partially saturated depending upon the extent of sulfurization.

The sulfurized alcohols thus obtained are clear, oily liquids, free from sludge or sediment and are miscible with hydrocarbon oils in all proportions. Their sulfur content may range from 2 to 25%. The cutting oils or extreme pressure lubricants are prepared by blending with a suitable lubricating oil a proper portion of the sulfur base to give the desired sulfur content in the finished product.

To render the lubricant emulsiflable, any suitable emulsifying agent may be blended therewith, such for example, as sulfonated sperm oil, mineral oil sulfonates (mahogany soaps), fatty acid soaps, etc. The emulsifierandlor the other ingredients may be proportioned to yield an emul- :ion of either the water-in-oil or the oil-in-water For a fuller understanding of the nature and objects of the invention, reference should be had to the following examples which are given merely to further illustrate the invention and are not given being by weight:

Example I In an open vessel provided with mechanical agitation, 200 parts of alcohols obtained by the hydrolysis of sperm oil are heated to about 130 C. and parts of flowers of sulfur are then added in small portions. at frequent intervals. when all the sulfur has been added. the temperature is raised and maintained at about 160 C. for four hours. At the end of this period' all the sulfur has combined with the alcohol. when cooled, the oil is clear, liquid and free from any whether saturated or unsaturated fatty alcohols 76 sludge or free sulfur. Its sulfur content ranges from about 18 to 19%.

A cutting oil was prepared by blending one part of the sulfur base obtained in the above example with flve parts 'of a pale lubricating oil having a Saybolt viscosity of 80 seconds at F. The blend has a sulfur content of 3%. a lightcolored oil, free from sludge and was found to be highly satisfactory for threading joperations on atl'le tlypes of steel, including stainless and nickel s e s. I

This product may be rendered water-dispersible by adding thereto .5 parts of mahogany soaps or sulfonated sperm oil.

Example II reflux condenser are placed 220' parts of xylene and 43 parts of stick sulfur. The xylene is heated to its boiling temperature until all the sulfur has dissolved. 200 parts of alcohols obtained from the saponiflcation of sperm oil are then added in a thin stream and slow enough so that the nlene is kept boiling continually. Refluxing is continued for'seven hours or until a sample of the mixture does not precipitate any free sulfur upon cooling. The xylene is then distilled oil under reduced pressure. During or after the distillation, a stream of air is allowed to pass through the liquid for the purpose of freeing it of the last traces of hydrogen sulfide. The sulfur content of the product tests from about 16% to 17%.

viscosity of 150 seconds 100 F.

Example Hi In a closed vessel provided with a water-cooled reflux condenser 65 parts of stick sulfur and 220 parts of xylene are boiled until the largest portion of the sulfur has dissolved. 200 parts of oleyl alcohol are then added in a thin stream and at 'such a rate that the xylene does not cease boiling. The boiling is continued for 8 hours, at the end of which period the sulfur has completely combined with the alcohol. The xylene is then distilled oil. under atmospheric pressure and air is blown through the liquid until it is entirely free from objectionable odors. The sulfurized oleyl alcohol obtained according to the foregoing procedure contains from 23 to 24% of sulfur. 'I'he base may be blended with lubricating oils of such vlscosities and in such proportions as to obtain cutting oils or high pressure lubricants of the desired properties.

While the use of flowers of sulfur and stick sulfur has been suggested, other forms of sulfur may also be used such as colloidal sulfur and the like.

Since certain changes in carrying out the above process and certain modifications in the composition which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description shall be interpreted as illustrative limiting sense. D

It is also to be understood that the following claims' are intended to cover all the generic and specific features of the invention herein described and all statements of the scope of the invention, which as a matter of language might be said to fall therebetween; and that they are intended to be inclusive in scope and not exclusive, in that if desired, other materials may be added to my novel composition of matter herein claimed withg and not in a 3. out departing from'th'e spirit of the invention. Particularly it is to be understood that in said claims, ingredients or components recited in the singular are intended to include compatible mixtures of said ingredients wherever the sense permits.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A new composition of matter comprising a sulfurized unsaturated fatty alcohol. r

2. As a new composition of matter, a sulfur carrier for lubricants comprising a sulfurized unsaturated aliphatic alcohol having at least 8 carbon atoms.

3. As a new composition of matter, a sulfur carrier for lubricants comprising sulfurized sperm alcohols.

4. As a new composition of matter, a sulfur carrier for lubricants comprising sulfurized oleyl alcohol.

5. A lubricant comprising a sulfurized unsaturated fatty alcohol and a mineral oil.

6. A lubricant comprising sulfurized sperm alcohols and a mineral oil.

'7. A lubricant comprising sulfurized oleyl alecho] and a mineral oil. 4

8. An emulsiflable cutting oil comprising a sulfurizedunsaturated fatty alcohol, a mineral oil and an emulsifying agent.

9. An emulsiflable'cutting oil comprising sulfurized sperm alcohols, a mineral, oil and an emulsifying agent.

10. An emulsiflable cutting oil comprising a sulfurized oleyl alcohol, a mineral oil and an emulsifying agent. 11. An aqueous emulsion adapted for use as a cutting 011 comprising a sulfurized unsaturated fatty alcohol, a mineral oil and an emulsii'm agent.

12. A new composition of matter comprising I sulfurized sperm alcohols.

13. A new composition of matter comprising sulfurized oleyl alcohol. I

ERNEST SEGEBSEMANN.