US2353170A - Lubricant - Google Patents

Description

F'atented July 11, 1944 UNITED STATES PATENT OFFICE LUBRICANT Bert E. Lincoln and Waldo L. Steiner, Ponca City, Okla, aasignors, by mesne assignments, to The Lubri -Zol Development Corporation, Cleveland, Ohio, a corporation of Delaware is Claims.

This invention relates, as indicated, to lubricating oils and more particularly to such compositions as new compositions of matter.

This application is a continuation in-part of our copending application Serial 293,276, filed September 2, 1939.

The present design of mechanical devices including internal combustion engines calls for high pressures on rubbing surfaces and the tendency is toward a still greaterincrease in such pressures. While conventional hydrocarbon lubricants vary somewhat in film strength the best of them are unableto withstand the extreme pressures imposed by modern design and the still higher pressures designers of mechanical devices would like to employ to take advantage of the improvements which might be achieved with higher rubbing pressures.

For many uses, as in the crankcase of an internal combustion engine, it is necessary that the lubricant employed be also noncorrosive and stable to the rather high operating temperatures.

Other desirable propertiesv include high oiliness, low pour point and resistance to sludge formation.

It is therefore a principal object of our invention to provide an effective extreme pressure lubricating composition capable of withstanding the high pressures imposed'on rubbing surfaces by modern mechanical design.

Another object is to provide such a lubricant which also has the desirable property of high oiliness.

Still another object is to provide a lubricant having the foregoing advantages and which is stable and noncorrosive in use.

Other objects of this invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends this invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The following description sets forth in detail certain approved combinations of ingredients embodying our invention, such disclosed means constituting, however, but one of various forms in which the principle of the invention may be used.

Broadly stated, this invention comprises a lubricating composition comprising a major amount of a lubricating oil and minor amounts of both a halogen and sulfur bearing organic compound and a thionic material. The thionic material which may be either an organic sulfur compound or elemental sulfur and when thus employed may "have sulphur present in either relatively active or inactive form, depending upon the particular use to which the composition is to be placed.

More particularly, both the halogen and sulfur bearing addition agent and the thionic material will preferably have a vapor pressure less than atmospheric at C. and for certain uses, a

vapor pressure less than atmospheric at C. In the case of compounds which are stable at temperatures up to their boiling points, this conditlon may be expressed by stating that the boiling point of the compound should, in general, be higher than 140 C., and, for certain uses, such as in internal combustion engines, higher than 170 C.

While all of the halogens are eflective when employed in accordance with the present invention chlorine is generally preferred since it is the least expensive and one of the most effective of the halogens. Bromine and fluorine may be employed but are relatively expensive and the latter is somewhat difllcult to handle. Iodine, while effective, is at present too expensive to be employed on a large scale. It should also be noted that two or more different halogens may be present in the same molecule. The brom-chlor and fluorinated chlorine or bromine sulfur compounds give particularly satisfactory results.

The following list includes a number of typical halogen and sulfur bearing aliphatic organic compounds found generally suitable for use in accordance with this invention. Itwill be. un-

derstood, however, that such list is intended for purposes of illustration only and is not intended to limit the scope of the invention to those compounds herein enumerated.

HALOGEN AND SULFUR BEARING ORGANIC COMPOUNDS 1. ALIPHATIC 5. Sulfones and sulfoxides Beta-chloroethyl sulfone The thionic material to be employed in this invention may be either elemental sulfur or an organic sulfur compound. The organic sulfur compound may be carbooyclic, aliphatic or heterocyclic in nature. '-We have also found that those thionic materials made by the direct sulfurlzing of organic compounds by the use of sulfur or a sulfur compound are of value in our invention. Of particular value are those thionic materials made by sulfurizing chemically unsaturated olefinio organic compounds;

I. CAssooYcuo Com'omms Examples of materials within this classification are:

Diphenyl sulfide Dibenzyl sulfide Di naphthyl sulfide Di paratolyl sulfide Di xylyl sulfide Di phenyl disulfide Di benzyl disulfide Di naphtyl disulfide Di para tolyl disulfide I Dibenzyl trisulfide Di phenol disulfide Diphenyl sulfone Dibenzylsuli'one Di par'atoyl sulfone Di naphthyl sulfone Di xylyl sulfone Di phenyl'sulioxide Dibenzyl sulioxide Dipara tolyl sulfoxide Di xylyl sulfoxide Di naphthyl sulfoxide Diphenyl 'thio urea Dibenzyl thio urea Dibenzyl thio urea Ortho tolyl thio urea Phenyl thio cyanate Benzyl thio cyan'ate Naphthyl thio cyanate Methyl phenyl thio ether Ethyl benzyl thio ether Propylnaphthyl thio ether Thioanthraquinone Thio phenol Ortho thio oresol Thio carvacrol Thio anisol Thio naphthol I l Ortho nitro thio phenol Phenyl thio carbonic chloride Chlor phen'yl mercaptan Phenyl thio glycolic acid Thio ben zoic acid Sodium thio benzoate: 4

Calcium thio benzoate Tin thio benzoate Benzene sulfonic acid Naphthalene sulionic acid 'I'hio aldehydes R,CHS in which R is any carbocyclic'i'adical including phenyl, tolyl, naphthyLxylyl, etc. v

Thio ketones R.CS.'R' in which either R or R' is Heterocyclic Dibenzothiophene 7 Thianthrene (diphenylene disulfide) 'I'rithioacetaldehyde Trithioacetaldehyde trisulfone Tetrahydrofurfuryl sulfide Methylmercaptobenzothiazole S-sulfhydryl quinoline Mercaptodibenzomrane Methylmercaptochlorodioxane Ethylene sym.-dithiocarbonate Aliphatic compounds Butyl sulfide Amyl sulfide Hexyl sulfide Octadecyl sulfide Heptyl sulfide Butyl disulfide Amyl disulfide Hexyl disulfide Hextyl disulfide Octadecyl disulfide Amy] sulfone Butyl sulfone Hexyl sulfone Hentyl sllJfOne Octadecyl sulfone Ethyl thio cyanate I Butyl thio cyanate Hexyl thio cyanate Heptyl thio cy'anate Octadecyl thio cyanate Naphtha xanthate Ethyl thio carbonic acid Amy] thio carbonic acid Thio ethyl carbonic ethyl ester Methyl'ester of dithio carbonic acid lAJnyl ester of dithio carbonic acid Sodium ethyl xanthate Calcium amyl xanthate Tri thio carbonic amyl ester Dithiodiglycol Ethyl di thio-oxalate Octadecyl mercaptan Sodium amyl thisulfate 'I'hiocarbamylamine (reaction product of amyl' amine and CS2) Amyl sulfate Mercapto stearic acid Calcium mercaptostearate Methyl mercaptostearate Sulfurized materials Sulfurized methyl linoleate Sulfurized methyl oleate' Sulfurized methyl aryl substituted linoleate Sulfurized animal and vegetable oi Sulfurized lard oil Sulfurized corn oil Sulfurized cottonseed oil Sulfurized sperm oil Sulfurized oleic acid Sulfurized olefinic hydrocarbons from P troleum any carbooyclic radical including phenyl tolyl,

xylyl;-naphthyl, etc. Thlophenates such as calcium thiocresolate Sulfurized olefinic material derived by halogenating, dehalogenating, and suliurizing petroleum Suliurized calcium oleate Sulfurized calcium'linoleate Sulfurized tin oleate Sulfurized tin linoleate Sulfurizedpotassium oleate Sulfurized potassium linoleate Where extreme or violent extreme pressure characteristics are encountered, the thionic material to be used will be selected from those which will turn a copper strip black in less than 30 minutes at 210 1''. An example of such active thionic material is obtained by employing a physical solution or colloidal suspension of elemental sulphur in the lubricating composition. For many uses,

however, where stability and freedom from corrosion and the like are of greater importance than extreme pressure characteristics, thenthe thionic material will be selected from .those which will not turn a copper strip black in less than 30 minutes at a temperature of 210 F. The copper strip test as above indicated is conducted by mixing of the addition agent with 90% of the base oil and then maintaining a clean copper strip therein for a period of 30 minutes at a temperature of 210 F.

Sulfur compounds for use in this invention may be made by controlling the composition and by varying the physical and chemical factors involved in manufacturing until a sulfur compound is formed that will not blacken a copper strip when blended with mineral oil and heated to 210 I", for 30 minutes. For example, a chemically unsaturated glyceride may be suifurized with 5, 10, or percent of sulfur and mineral oil blends of each of these may turn a copper strip black in less than 30 minutes at 210 F. However, control of the time and temperature of sulfurizing will convert all three of these to compounds that will not blacken a copper strip under the conditions of the foregoing test. Obviously, less time and lower temperatures will satisfactorily condition the glycerlde containing. 5 per cent sulfur than will be required for the glyceride containing 15 percent sulfur. To accomplish this result we regularly test the batch during manufacture and impose the minimum severity of manufacturing conditions. For some lubricating problems. it is necessary to have a controlled amount of both active and inactive sulfur in the lubricant.

In some instances sulfur compounds for use in this invention may be manufactured according to the above general method and the manufacturing process stopped short of complete conditioning of the sulfur compound to the copper strip test. In these instances, only small amounts of sulfur or. sulfur compounds present in the desired product have a tendency to blacken the copper strip in the test prescribed. In these instances we remove the small amount of objectionable material by contacting the entire mass with treating agents that make the product satisfactory. Examples of these treating agents are finely divided metal such as copper, iron. mercury, etc., either as such or mixed with inert carriers like clay, fullers earth, pumice, kieselguhr, and the like. Other treating methods are known and may be employed to accomplish the desired ends. v

The oil base employed may be any suitable lubricating oil such as mineral oil or animal and vegetable oils of lubricating viscosity, and including synthetic, hydrogenated and volatilized oils.

It is also within the contemplation of this invention to provide the addition agents in the form of a concentrate in a suitable oil, said oil containing a rather high percentage of the addition agents. Such concentrates may beemployed for future blending with a lubricating oil in the proportions desired for the particular conditions of use.

- permanently homogeneous composition when incorporated inthe 011 base.

In general, the invention contemplates the employmentof iron about .5 percent to about 10 percent by weight of thealiphatic halogen and sulfur bearing compound, based on the amount of mineral oil, and an equal or less amount of the thionic material. However, as little as .02 percent of one or the other addition agent may be eifective for certain uses, while for other uses as much as 20% may be employed.

For each combination of a specific halogen and sulfur compound and a specific thionic material, it will be found that there is a certain optimum proportional relationship which may be found by comparative tests. This also holds true where the halogen and sulfur or sulfur bearing component is in the form of a complex material.

It has been found that the addition of the thionic material in which the sulfur is present in relatively inactive form and the addition of the halogen and sulfur bearing organic compound to the same mineral oil results in lubricants far superior to lubricants made with the same mineral oil and only one or the other of the two classes of compounds. The lubricants of this invention are superior in one or more respects depending upon the particular thionic material and halogen and sulfur bearing compound added to the mineral oil. For example, the corrosion or metal wear; is less with the combination lubricant. than with a lubricant containing only one of the addition agents. The sludging and oxidation characteristics of the lubricant in use are usually improved to a marked degree. The loadcarrying capacity of the lubricants of this invention may be higher than a lubricant made with the same mineral oil and only a thionic material or a. halogenand sulfur compound as such are defined by the invention. The load-carrying capacity of lubricants of this invention'will remain fairly constant throughout the entire period of use of the lubricant which is one of the greatest practical advantages of these lubricants. The oiliness character of the lubricants of this invention reflects the combined oiliness effect of the two separate types of compounds, namely, thionic material and halogen and sulfur compounds. The unexpected joint effectof the halogen and sulfur compound and the thionic material makes these lubricants outstanding. From these unexpected results we are of the opinion that there is a specific but incompletely understood effect of the thionic material on the halogen and sulfur compound and of the latter on the former.

The addition agents, should of course, be stable at the operating temperatures to which they will be subjected.

While the lubricating compositions which have been described herein as illustrating one embodiment of the invention have been generally referred' to as "oils," i. e., liquids, this invention is, however, also applicable to the solid and semisolid types of lubricants commonly referred to in the trade as greases, bodied oils, etc., which contain metallic or nonmetallic salts or soaps such as calcium oleate. sodium stearate, aluminum naph- The addition agents must, of course, be soluble thenate, calcium phenyl stearate, calcium dichlorostearate, ammonium oleate, or cadmium, nickel, zinc, or tin salts or soaps of various organic acids.

- The following examples of our invention are not given as a limitation but to show certain practical combinations:

I Per cent (1) SAE 10 mineral oil.... 9B

' Chlorolauryl mercaptam 1 Sulfurized methyl linoleate 1 (2) SAE 20 mineral oil 98 Chloro amyl disulfide 1 Sulfurized methyl oleate 1 (3) SAE mineral oil 97 Chloro lauryl thio cyanide 2 Dibenzyl disulfide 1 (4) SAE 50 mineral oil 98 Chloroamyi suliate 1 Butyl disulfide. 1

(5) SAE 60 mineral oil 98 Chloro naphtha sulfate 1 Benzyl thiocyanate 1 We, therefore, particularly point out and dis- I tinctly claim as our invention: I

I 1. A lubricating composition comprising a major proportion of lubricating oil and a minor amount of a halogen and sulfur bearing aliphatic {compound and a. minor amount of a thionic material.

2. A lubricating composition comprising a major proportion of lubricating oil and a minor amountof a halogen and sulfur bearing aliphatic compound and a minor amount ofelemental sulfur.

3. A lubricating composition comprising a major proportion of lubricating oil and a minor amount of a halogen and sulfur bearing aliphaticcompound and a minor amount of an organic sulfur compound.

4. A "lubricating composition comprising a major proportion of lubricating oil'anda minor amount of a halogen and sulfur bearing aliphatic compound and a separate-organic sulfur compound of the type which does not blacken a copper strip placed in the composition at a temperature of 210 F. for thirty minutes.

the composition'at a temperature of 210 F. for I thirty minutes.

.7. A lubricating composition comprising major proportion of lubricating oil and from 2,sss,170

about 5 percent to about 10 percent each of a halogen and sulfur bearing aliphatic compound having a'vapor pressure less than atmospheric at C. and a relatively inactive organic sulfur-bearing compound having a vapor pressure less than atmospheric at 140 C.

proportions of both an organic sulfur compound and a halogen and sulfur-jbearing aliphatic hydrocarbon, said addition agents hav-,

ing vapor pressures of less than atmospheric at 140 C. a

9. A lubricating composition comprising a majorproportion of lubricating oil and minor proportions of both an organic sulfur-bearing compound and a halogen" and sulfur bearing aliphatic ester, said addition agents having vapor pressures of less than atmospheric at 140 C.

10. A lubricating composition comprising a major proportion of lubricating oil and minor proportions of both an organic sulfur-bearing compound and a halogen and sulfur bearing salt of an aliphatic acid, said addition agents having vapor pressures of less than atmospheric at 140 C.

11. A lubricating composition comprising a major proportion of lubricating oil and a minor amount of an aliphatic organic compound containinghalogen, sulphur and oxygen in the molecule, and a minor amount of an organic sulphur compound.

12. A lubricating composition comprising a major proportion of lubricating oil and from about .02% to 20% of a halogen and sulphur bearing aliphatic compound having a vapor pressure less than atmospheric at 140 C. and'from about .02% to20% of a separate organic sulphur compound of the type which will blacken a copper strip placed in the composition at a temperature of 210 F. for thirty minutes.

13. A lubricating composition comprising a major proportion of lubricating oil and from about .02% to 20% of a halogen and sulphur bearing aliphatic hydrocarbon having a vapor pressure less than atmospheric at 140 C. and from about .02% to 20% of a separate organic sulphur compound.

14. A lubricating composition comprising a -major proportion of lubricating oil and minor proportions of both an organicgsulphur bearing compound and a chlor naphtha xanthate, said addition agents having vapor pressures of less BlliRT H. Lmco'm.

WALDO L. s'rzmna.