US2628939A - Mineral oil composition - Google Patents

Description

Patented Feb. 17, 1953 MINER-AL OIL COMPOSITION Edward S. Blake, 'Medford, Mass, assi'gnor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application November 21, 1947, Serial No. 787,485

4 Claims. (01. 25246.6)

This invention relates to lubricating compositions and to methods of preparing the same and more particularly to lubricating compositions adapted for use under extreme pressure conditions.

Various types of modern machinery such as the hypoid gears in motor vehicles develop enormous pressures'between engaged surfaces. The ordinary type of hydrocarbon lubricant composed only of a petroleum fraction is incapable of satisfying the severe requirements demanded in the proper lubricant of hypoid gears, bearing surfaces, metal cutting tools, and the like subjected to unusually heavy loads per unit area of surface. This invention has to do with ingredients which may be added to a suitable carrying agent such as mineral oil and are capable of maintaining between the engaged surfaces a lubricatin film under high pressures.

A primary object of this invention is to provide a new and novel sulfur bearing material capable of imparting desirable properties to a lubricating oil composition otherwise unsatisfactory under the conditions encountered. A further object is to provide a mineral oil adjuvant which is not corrosive and does not decrease the oxidation stability of the oil. A still further object is to provide a class of lubricants capable of maintaining a lubricating film between surfaces engaged under high pressures. A still further object is to provide a class of lubricants which reduce wear. hereinafter.

"In accordance with the present invention it has been discovered that di-esters of dihydric alcohols and unsaturated fatty acids can be readily sulfurized to 'produce sulfurized diesters having valuable properties which render them valuable as ingredients in mineral oil lubricants. In general, the compositions of this invention comprise amajor proportion of mineral lubricating oil and a minor proportion of the sulfurized ester, as for example 0.1% to 30%. Other ingredients may be present as desired, it being particularly advantageous to have a phosphorus ingredient present. Apparently phosphorus exerts a. synergistic effect on the sulfurized neutral esters since the wear resisting properties are greater than would be predicted from the properties of the separate components. Phosphorus may be introduced by reacting the sulfurized ester with a suitable phosphorus component as hereinafter described or added as a separate component. Examples of suitable phosphorus compounds are mono oleyl phosphate, dioleyl phosphate, mono lauryl phosphate, di lauryl phosphate, mono cresyl phosphate, di cresyl phosphate, di cetyl phosphataand di octyl phosphate.

Other objects will be disclosed The presence of a small amount ofan organic halogen bearing compound is also desirable in the compounding of some types of lubricants.

The esters to be sulfurized are prepared by esterifying dihydric alcohols of the type where R is an alkylene group which may contain one or more sulfur or oxygen atoms in the chain. Typical examples are alcohols possessing the formula HOC2I-l4OI-I, HOC2H4SC2H4OH, OHC2H4OC2H4OH, HOC2H4OC2H4OC2H4OH and the like. The alcohols are esterified with long chain unsaturated fatty acids,,as for example oleic acid, elaidic acid, erucic acid, linoleicacid, and ricinoleic acid.

The di-esters may be sulfurized in any suitable manner, the sulfurized products being readily soluble and miscible with mineral oil fractions. Sulfurization may be effected by heating the ester with sulfur or a mixture of sulfur and a sulfur halide at 150-200 C. Where the material is then phosphorized, it is preferred to carry out the reaction under milder conditions, say -125 C. The phosphoru sulfides, as for example phosphorus pentasulfide or sesquisulfide are satisfactory phosphorizing agents. The following example demonstrates the sulfurization and phosphorization of glycol di-oleate and. is not limitative of the invention.

EXAMPLE I Into a container of suitable capacity there was charged 2268 parts by weight of glycol di-oleate and 193 parts by weight of sulfur. The mixture was heated for 7 hours at 177-183 C under an atmosphere of nitrogen. 13 parts by Weight of phosphorus sesquisulfide was then added and heating continued for 9 hours at -110 C. The product contained 8.02% sulfur, 0.29 phosphorus and had a neutralization number of 7.12. The effectiveness of the sulfurizedandphosphorized glycol di-esters may be demonstrated by the conventional tests on compositionscomprised of these ingredients and a lubricating oil carrying agent. 'More specifically, aminor amount of the product described, in Example I was addedl'to a high viscosity hydrocarbon lubricating oil (Saybolt Universal viscosity of 101 secondsgat 210 F.) and samples of the blended lubricant subjected to the Almen pin test described'in a paper presented before the. 13th Annual Meetingof the American Petroleum Institute, Division of Refilling, on November 17, 1932, by H. E. Wolf and H. C. Mougey-see Proc..A. P. I.. 1932, pages 118-430. In addition, the material was subjected to the S. A. E. test described in the S. ,Al.. E. Jour- 3 nal 39, 23-4 (1936). The results are summarized below:

Additionally, the aforedescribed sulfurized and phosphorized glycol di-oleate passed the more important tests forming the basis of U. S. Army Specification 2-105B. Recognition by the Ordnance Department of the need for a universal gear oil specification which wouldmore nearly define a satisfactory lubricant under field operating conditions in all types of automotiv gear drives, led through the efforts of the Coordinating Lubricants Research Committee to the formulation and adoption of U. S. Army Specification 2-105B.

-One of the important tests under this specification is that designated by the Ordnance Department as AXS-1570 (C. R. C. Designation 1920-545). This test is a high torque low speed axle test and is described in the C. C. Handbook 1946, page 469.. A good pass was obtained with a solvent refined Mid-Continent oil containing of the sulfurized and .phosphorized 4 weight of sulfur monochloride in 25 parts by weight of mineral oil (S. A. E. 10) and 37 parts by weight of sulfur. The air in the container wa replaced by hydrogen sulfide and the mixture heated with stirring for 7 hours at l69-l71 C. .4 parts by weight of P483 was then added and heating continued for 5 hours at 104109 C. in an atmosphere of hydrogen sulfide. The product contained 8.59% sulfur, 0.40% phosphorus and had a neutralization number of 4.85.

,A series of preparations were carried out in which glycol di-oleate was sulfurized by heating with sulfur in the ratio of parts of sulfur to 436 parts by weight of glycol di-oleate. For the most part the reactions were carried out either undernitrogen or hydrogen sulfide except Examples 4 and 1 0 which were preparedin ,air. No significant differences have been observed due to the presence or absence of an inert atmosphere. However, since hydrogen sulfide is evolved in the reaction, there may have been an effective atmosphere of hydrogen sulfide in every case. Phosphorus sesquisulfide was then added and the composition heated'to effect phosphorization. The-table below illustrates a variety of conditions and ratios under which the reactions may be successfully carried out. In Example 7 there was presentin addition to the sulfur a small amount of a solution of sulfur chloride 'in mineral oil. 3 parts orszcn dissolved in 25 parts of mineral oil was. used for 436 parts of glycol di-oleate.

Example 4 5 6 7 8 0 l0 11 Time of sulfurizatiou, hours 7, 5 7.5 7. 5 18 18" '7. 5 7. 5 7. 5 Approximate average temperature of sulfurization, O v 170 170 -170 .170 170 180 180 180 Pisa, parts by weight 3 4- 8 '2 4 2 3 4 Timeofphosphorization, hours 5. 5 a 5 5 5 5- 5. 5 5 5 Approximate average temperature of phcsphorization, C.. 107 107 107 107 107 107 107 107 glycol di-oleate. The composition also passed the high speed axle test designated by the Ordnance Department as AXS-1569 (C. R. C. Designation 'Ll9 -645) described page 467 of the c. R. c. Handbook 1946. Thus, the'preferred: additives have been found to bee'ntirely satisfactory under conditions simulating actual Working conditions. In order further to demonstrate the invention, as-lar e umber f suliuri ed and phosphoriz d t ve re pr pared der di e en cor uticns and tested as components of mineral oil lubricating, compositions. Again, the examples :areito be taken as illustrative of the invention and not limitati-ve thereof.

' EXAMPLE 2 Into av glassor glass lined reactor of suitable .capacity there wascharged 436 part by weight of glycol di-oleate, 2.5 parts by weight of sulfur ingnochloride dissolved in 25 parts by weight of mineral oil (8. A. E. 10) and 3'7 parts by weight Analysis gave 7.03% sulfur, 0.27% phosphorus and a neutralization number of 2.4.

7 EXAMPLE 3 {Into a glass or glass lined reactor of suitable capacity there was charged 436 parts byweight of-*glycol di-oleate, a solution of 2.5 parts by Analysisof the compositions of Examples 2-11 gave an average sulfur content of 6.8% and phosphorus ranging from 0.22% in the case of- Ex-. ample 7 to 0.6% depending upon the amount charged. The neutralization number varied from 5.6 to 13.6. These compositions were evaluated as components of gear lubricants under-high torque and low speed conditions by an adaptation of the S. A, E. extreme pressure lubricant testing machine. p I The machine employed for the test was an S. A. E. extreme pressure lubricant testingmachine manufactured bythe Highway Trailer Co., Edgerton, Wisconsin. This machine, suitably modified, provides. a simpl convenient means of imitating the rubbing of gear teeth by rotating two Timken test cups in line contact with each other and in opposite directions, undercontrolled rotation speeds. For these tests the speed of the main shaft was reduced from 1000 to 264 R. P. M. and the lower shaft drive gears of 20 and 81 teeth replaced with'gears of 52 and 49 teeth to change the rubbing ratio from 14.611 to 'over the test cups to prevent direct heating of the cups.

Test procedure Two Timken test cups are weighed to the nearest milligram and fastened in place on their respective shafts. the carriage with knife edges in place; the thermocouple junction is adjusted to one quarter of an inch below the lower cup; the plate holding the oil seal is tightened; the coupling links are inserted on the upper and lower shafts and the oil box locked into position.

A twenty pound scale load is applied by hand and the cup alignment checked for perfect contacting edges and adjusted if necessary. The twenty pound load is released and the water lines are connected.

The oil is to be tested is then added until the lower test cup is half immersed. This oil level is maintained for the duration of the run by adding more oil when'necessary. The oil box bearings are lubricated with the oil to be tested.

With the temperature recorder-regulator in operation, the machine is started and the load is taken up to fifty pounds, where it is maintained for a break-in run of one-half hour. the end of the break-in the load is brought up The oil box is positioned in to 110 pounds by the automatic loading device face disturbance than does'the top ring, a phe-';

nomenon for which there are several theoretical explanations.

The inspection terminology used in describing the ring surface is essentially that given in the C. R. C. Designation 1,-20-545, namely: (a) burnish, (b) smoothing, (c) rippling, (d) ridging, (e) pitting and (f) galling. Burnish is an alteration from the original ground dull surface to a brightly polished surface and is usually accompanied by some alteration in or elimination of the grinding marks. Smoothing is the elimination or near elimination of the grinding marks where the surface finish usually remains dull. surface patterns, dull or shiny, resembling fish scales or ripples on water. Ridging as here used is a longitudinal furrowing or channeling as a result of a wearing force. This is actually a misnomer as grooving would be a more accurate descriptive term. Frequently rippling appears in the base of the groove indicating this may have been the precursor 'of grooving or ridging. Pitting is the formation of small pit-like cavities. Galling is difficult to describe but refers to a surface alteration which appears to be a slight lengthening, widening, deepening and blackening of individual grinder marks. This may be due to localized chemical attack.

Rating 7 correlation. By a study of a backlog of samples .upon which the L-ZO results were known, a

basis for the overall appraisal of the test specimens was established permitting a final classification as an L-20 pass or failure. A passing test rarely shows a total weight loss of more than 20 mg. and no light ridging. A test rated fail usually shows a weight loss of appreciably more than 20 mg. although it may in some cases be appreciably less. However, all of the described surface disturbance conditions may app-ear and usually do in the more severe failures.

A tabulation of top and bottom test ring observations is shown in the table below:

2 18 a }pass.

3 18 2 Do. 4 1s Do. 5 10 3 Do. 6 1s Do. 1 18 g Do. 8 1s Do. 9. 10 g Do. 10 18 g Do. 11 is g Do. 11 10 g Do.

Inspection A series of preparations were carried out in Upon completion of the test, the test cups are cleaned and reweighed to the nearest milligram for total weight loss, then inspected microscopically, oiled and filed for future reference. The rating, of the completed test depends primarily uponthe visual inspection of the test cups. In

which glycol di-oleate was sulfurized by heating with sulfur in the ratio of 37 parts by weight of sulfur to 436 parts by weight of glycol dioleate. Except, for Example 13, an atmosphere of hydrogen sulfide or nitrogen was employed. Phosphorus sesquisulfide was then added and most instances the'bottom ringshows more sur- 75 the mixture heated to effect phosphorization;

Rippling is the formation of transverse 8 The sulfur and phosphorus figures :given in the above table are :in general :the average from several Iidentical preparations. The neutralization number varied :from 4.51: 16.6, the average being EXAMPLE J26 Sulfurization iand :phosphorization of diethyl- Example .Q. .I 12 is 14 is 'I-ime -of sulphurization,hrs; 7 7 13.5 17.5

Aggroximate ave. temp. of sulphuriza'tion,

P483, parts by 'weight 2 4 2. 5 1

Time of phosphorization, hrs-. 5 5 5 Approximate ave. temp. of phosphor-im i tion, C .107 107 107. 107

The sulfur content of Examples 12-21 aver-' aged about '7.6'%"and phosphorous ranged from 0.14% in Example 'to 0.47% in "Example 19.

The neutralization number varied from 3.7 to 10.6, the average being 7.3. I

"Afsummary cf the modified S. A. E. test described above on .oils' containing these products is tabulated below ene glycol di-oleate was carried out in at atmosphere of hydrogen sulfide. 436 parts by weight of 'diethylene glycol di-oleate .was heated 7 hours at'169171 C. with 34.5 parts by weight of sulfur. 6 parts by weight of phosphorus sesquisulfide was then added and heating under hydrogen sulfide continued for 5 hours at 104-110'9" C. The product was soluble in mineral oil and had'a neutraliza- Ewe O11 Additive, Percent a Final Ratin EXamPleNa l on on Ring Rldgm Rippling I Lglsgs, t 12; 1'8 2 }pass. 13-. "18f Do.

, 4 borderline. 14 11 pass. 15 1s g Do.

is 1s Do.

16.. 10 Do. 17 10 "Do. 18 10' Do.

20 18 1g Do.

9i borderline. 17 }pass.

As still vfurther embodiments of the invention,

glycol di-oleate was sulfurized by heating with conditions of reaction are set forth in the following table. Examples '22 and 25 were prepared by heating in an atmosphere of hydrogen sulfide or nitrogen but no extraneous atmosphere was used in the case of Examples 23 and 24.

Example 22 23 24 25 Time of sullurization, hrs 7. 5 7. 5 7. 5 7. 5 Approximate average temperature of suliurizatiou,'C 180 180 180 180 P sa, parts by weight... l 2 3 4 'limeof phcsphorization, hrs. 5 5 5 5 Approximate average temperature of phosphorization, C 107 107 107 107 Sulfur in final product, percent- 8.2 8. 3 8. 4 8.6 Phosphorus in final product,

percent 0. 11 0. 23 0. 35 0. 46

tion number of 10.6. Analysis gave 0.80, 0.90% phosphorus and 8.02% sulfur.

EXAMPLE 2'7 Sulfurization and phosphorization of dithio diglycol di-oleate was carried out in an atmosphere of nitrogen. 250 parts by weight of dithio diglycol di-oleate was heated with 14.9 parts by weight of sulfur for 7 hours at 178-182 C. 1.5 parts by weight of phosphorus sesquisulfide was then added and heating under nitrogen continued for 5 hours at 104-110 C. The product was diluted with petroleum ether, filtered through a bed of clay and the solvent removed by vacuum stripping u to C./3 mm. Anoil soluble product was obtained which contained 11.4% sulfur and 0.16% phosphorus.

The compositions of Examples 22-27 were added to mineral oil and subjected to the .modie 55.5 parts by weight of sulfur under an atmosphere of nitrogen for 7 /2 hours at 181-186 C. In another typical preparation glycol di-oleate 35 *w'as sulfurized by heating 1275 parts by weight fled S. A. E. test described. The results are summarized below I 1 Ring Ridging Rippling g Final Rating 22 18 3 }pass.

23 18 g Do.

24 1o Do.

25 1s Do.

I some pittin l2 borderline. 18 light 13 }pass.

27 1o ,3 Do.

It is evident from the foregoing examples that glycol di-esters of unsaturated fatty acids may addition, the esters may be reacted with sulfurizing and phosphorizin agents in difierent ratios than those specifically mentioned. Obviously,

sulfurized esters may be produced by elimination 30 of the phosphorizing step. For example, 654 parts by weight of glycol di-oleate was heated with of the ester and 96 parts by weight of sulfur for 8 hours at 181-184 C. The reaction product was then heated with approximately 5% by weight of Attapulgus clay at 100 C. and filtered. Other Composition A: Oil+6.0% product of Example 28.

2.0% chlorinated kerosene (58-67% Cl), 0.5% mixture of monoand di-lauryl phosphate.

Composition B: Oil+ 10.0% product of Example 29.

2.0% chlorinated paraffin wax (40% Cl) 0.4% mixture of monoand di-lauryl phosphate. r

Composition C:

, Oil+6.0% product of Example 30.

2.0% chlorinated kerosene (58-61% Cl). 0.5% mixture of monoand di-oleyl'phosphate.

These compositions were subjected to the modified S. A. E. test to determine their wear resisting properties. The results are summarized below:

Wt. Composition Ring Ridging Rippling Ifioss Final Rating p 0 0 2 A bottom 0 0 9 Pass. B tqp. incipient trace 1 borderline.

""""""""""" bo 2 0 8 pass.

O {bo f m n 0 2 Do.

sulfurizations were carried out in similar manner. The glycol .di-oleate was heated with sulfur at a temperature within the range of 180-188 C. for

' 7 hours, then heated with Attapulgus clay and i'filtered'through a layer of diatomaceous silica.

The series of preparations is summarized in the following table in which the sulfur is expressed as parts by. weight per 436 parts by weight of 60 glycol di-oleate. i

. Example 28 29 30.

Sulfur 32. 8 37 42. 7 Percent Sulfur in product 6. 11 7. 68 8. 2

Copper strip tests showed that the sulfurized products were not corrosive to copper. The tests were conducted by immersing a clean bright cop- 7 per strip in mineral oil containing 5% of the sulfurized ester and heating 1 hour at 150 C. In addition, S. A. E. grade gear oil lubricant compositions were compounded from a Mid-Continent solvent refine oil as follows: 7

In addition to gear lubricants, other types of compositions may be compounded from the new adjuvants, as for example crankcase lubricants, spindle oils, turbine oils, insulating andtransformer oils, slushing compositions, greases,etc. Effective non corrosive cutting oils have been prepared. For instance, the addition of either of 5% or 10% of sulfurized and phosphorized glycol di-oleate to a paraflin oil provided compositions exhibiting high Oster threading .efiiciency and high tapping efiiciency. Copper be prepared by heating the base with l-12% sulfur and then with 02-20% phosphorus sesquisulfide. In some instances. substantially neutral products have been prepared but. for themost part they exhibit a mildly acid reaction. So far 5 as is known, this is not a critical feature since all of the products proved to. be substantially, equivalent over the range stated. Products having neutralization numbers up to 18.6 have. been. examined.

The conditions of carrying out the reaction are. also subject to variation. However, in general no advantage is obtained by conducting the sulfurization at higher temperatures: or for longer times than those illustrated above In fact, the 15..

products are then generally less satisfactory'and contain less sulfur than products. preparedunder milder conditions. Lower temperatures may beemployed where desired in which case it is advantageous to employ a sulfurization catalyst in order to secure a rapid rate of reaction. Small amounts of acidic materials, as for example toluene sulfonic acid, sulfuric acid, phosphoric acid and the like may be employed to catalyze the sulfurization.

Although thepreparation of the phosphorized esters. by' means of phosphorus. sesquisulfide has .been described in specific examples; it. will be properties and may be employed in conjunction with othert-ypes ofadditives which would. otherwise be corrosive; They are compatible with mineral oil fractions in high proportions and.- with most other types of materials employed in the 40 compounding of mineral oil lubricants. They may be used in conjunction with such products as chloronaphtha ethyl xanthate, di-trichlorohenzyltrithiocarbonate. di(ethylene glycol mono.

oleate) malate, and other esters, halogen bear:- ing esters, halogenated hydrocarbons,phosphorusbearing esters and thelike'. In. addition, the additivesv maybe supplied in the form'of' concenI-- trates or in other words, mixtures of lubricating oil and of additives in which the additives are present in amounts appreciably higher than those ultimately'appearing in the mineral oil lubricant, as for example 75' parts-of sulfurized ester and 25 parts of mineral oil.

The present invention is limited: only by the claims attached heretoas part of the present specification.

What'is claimed is:

1'. A composition'of matter useful as a lubricant consisting essentially of a major amount of mineral oilthelubricating properties of which are enhancedin-the respect that the-Wearing of lubricated metal surfaces isreducedby'havi'ngincorporated therein in amount effective toreduce wear an additive composition containing 5.8%-11.4% sulfur and 0.11%-0.80% phosphorus. suppliedessentially by a sulfurized and phosphorized ester ofthe-group'consisting of ethylene glycol dioleate, diethylene. glycol dioleate and dithio diglycol dioleate obtained by" heating with sulfur at 150- 200 C. and phosphorizing at IOU-125 C.

2. A composition of matter useful as a lubricant consisting essentially of a major amount of mineral oil the lubricating properties of which are-enhancedin the respect that the wearing of lubricated metalsurfaces is reducedby having incorporated therein 5%1-18% based on the oil ofa sulfurized and phosphorized di-oleate of a dihydric glycol selected" from the group consisting of ethyleneg-lycol, diethylene glycol and dithio diglycol containing 5.8 %-11.4% sulfur and 0.11%- 0;80%, phosphorus obtained by sulfurizi'ng'at 150- 200"C. and phosphorizing at IOW -125 C.

3'. A composition of matter useful as a lubricant consisting essentially-- of a major amount of mineral oil the lubricating properties of which are enhanced in therespect that the wearing of lubricated metal surfaces is reduced by having incorporated therein 5%-18% based on the oilof sulfurized' and phosphorized ethylene glycol dioleate containing: 5.8%'-8.6% sulfur and 0.11%- 0280 phosphorus obtained by sulfurizing' at 150- 200 C. and phosphorizi'ng at 100425 C.

4} A composition of matter useful as a. lubricant consisting essentially "of at major amount of mineral oil the lubricatingproperties of which are enhanced in the. respect that the wearing. of lubricated; metal surfaces. is reduced by having incorporated" therein at least: 0.1 by'weight based upon the mineraloil' of a: sulfurized and phosphorized: ethylene. glycol di-olea-te: containing 5.8%11.4% sulfur and 0.11 %-0.80% phosphorus obtained by heating the ester with sulfur at 150- 20.0. C. and with aphosphorus sulfide at C.

EDWARD S. BLAKE.

REFERENCES CITED The following references are of record in the file of' this patentz.

UNITED STATES PATENTS Number Name Date 2,179,067- Smith Nov. '7, 1939 2186;646 Lincoln et'al. Jan. 9, 19.40 2,211,231 Henderson Aug; 13,1940 23211306- Whittier Aug. 13, 1940 2,225,365 Bray Dec. 17, 19.40 2,415,838 Musselman et al; Feb..18, 19.47 2,422,630 Musselman et a1. .June 17,1947 $441,587 Musselman May 18, 1948 2,483,600 Stucker Oct. 4, 1949 2,541,789 Stucker Feb. 13, 1951 2 ,542,161 Stucker ..Eeb. 20, 1951

Claims (1)

1. A COMPOSITION OF MATTER USEFUL AS A LUBRICANT CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF MINERAL OIL THE LUBRICATING PROPERTIES OF WHICH ARE ENHANCED IN THE RESPECT THAT THE WEARING OF LUBRICATED METAL SURFACES IS REDUCED BY HAVING INCORPORATED THEREIN IN AN AMOUNT EFFECTIVE TO REDUCE WEAR AND ADDITIVE COMPOSITION CONTAINING 5.8%-11.4% SULFUR AND 0.11%-0.80% PHOSPHORUS SUPPLIED ESSENTIALLY BY A SULFURIZED AND PHOSPHORIZED ESTER OF THE GROUP CONSISTING OF ETHYLENE GLYCOL DIOLEATE, DIETHYLENE GLYCOL DIOLEATE AND DITHIO DIGLYCOL DIOLEATE OBTAINED BY HEATING WITH SULFUR AT 150200* C. AND PHOSPHORIZING AT 100-125* C.