US2603602A - Addition agents and mineral oil lubricant compositions containing the same - Google Patents

Description

v Patented July 15, 1952 THE SAME Herschel o. Smith, Wallingf ord, and

Cantrell, Lansdowne, Pa., assignors toGuJfOiI Corporation,. Pittsburgh, Pa.,.

' Pennsylvania a corporation of vNo'Drawing. Applicationdanuany 511949, 7

Serial No. 73,218

This inventionrelates toaddition agents and mineraloil lubricant compositions'containing the same andymore" particularly; it-isconcerned with improvement agentswhich'confer improved-antioxidant;"corrosion inhibiting and detergency properties on mineral oil lubricants.

It is recognized in the art'that mineral oil lubricantsarereadily oxidized underservice conditions thereby reducing the service life of interna'l combustion engines and steam' turbines. A concomitant effect is" corrosion of bearing surfaces. These problem's'become particularly acute when a highly refined para'flinic' base mineral oil i'siemployeda's'thelubricant;

' In thelubrication 'of 'internalcombustion enginesof all types,- particularly when severe op- ..erating conditions"are'enc'ountered; mineral lubricating;oils"frequentlyproveunsatisfactory because they tend" to' depositvarnish, gum" and sludge on' the engine surfaces; such as the cylin defwall's, pistons and ring's and" also" to induce corrosion 'of bearing materials" thereby causing failure of the engine: These'problemshave'become"; increasingly serious because'of the trend towaril" higher efficiency or higher" power output peri'unit' weight-of"engineywhich"results in conditions'tendingto acceleratethe'deteriorating in fluencesf on the mineral" oil' lubricant; The fori'nation arise-called varnishes and "sludges on" engir'i'e surfaces is a" result of oxidation" efie'ctson the lubricatingioils. 'I'hepre'senceof gums, var= nishes and 'slud'ges'is detrimental formanyreasons.- "These substances ten'd'to increase *rin'g stickingand accelerate the" formation of further deposits on piston surfaces and in fixed" parts or thecombustion chamber. Thesludgesformed iii'the crankcase Ofthe' engine increase the rate of" corrosion-of bearing surfaces, especiallvof bearing'alloys-offthe types now'inuse;

steam" 'tu'rbines;,. the" corrosion problem" is particularly acute becauseof" the" presence of watefim the mineral" on "lubricant" and in addi= tion to hearing corrosion, rusting? may also" be encountered. V j

- Itis an object of" this; invention, therefore" to prepare an improvement agent'which' will obviate the oxidation and corrosiondiflicultiesi encountered in the use" of'mineral oil lubricants;

It is -a further object of this invention. toiiprovideumproved mineral'oil' lubricant composi= tions which are stable" in storage anduse and" in which oxidationandcorrosioni effects are" mate'- riallyinhibited.

' In our copending=- application Serial No. 718;- 902; "filed December 27; i946,- there isdisclosed and claimed an addition agent for' mineral oil lubricants which coi'ifersexcellent anti oxidant, corrosion inhibitingandpressuracarrying properties -on'mineral oil lubricants. Such improve mentfagent is preparcd by heating an essentially I provem'ent agentfor mineraloil lubricants which is prepared by-h'eating an essentially p'araffin'icbase lubricating-oil with phosphorus pentasulfide-in thepresence of a surface active silica-contai'ningf solid catalyst, It is shown in'that patent that when phosphorus pentasulfide is reacted withan essentially-paraflinic base lubricating oil in the presence of a surfaceactive silica-containing 'so'lid catalyst, the prior aluminum chloride treatment of the lubricating oil as'disclosed' in our application Serial No. 718.902 may? be omitted; It is" also shown in our patent that when the prior aluminum chloride treatment o f' t'he arafiinic base lubricating oil is combined with 1 reaction of the aluminum chloride treated prod l h phosphorus pentasulfidein the presence of' a surface active "silica-containin'g catalyst.

lighter coloredv products are obtained.

The" objects of the present invention are'.*ac'- complishedby. providingv improvement agents for mineralfioil, lubricants by reacting an essentially paraffinicba'se lubricating oil or the aluminum chloride treated product thereofwith phosphorus penta'sulfidethroughthe useflof any. of the mefth-f I ods disclosedin ourlcopending application Serial No. '7l8;9o2 and'our PatentNo. 2.456;:336 andwith an alkylorthophosphate' having at least 5 carbon atoms in" the alkyl group. Such improvement agents;'asfwellas the mineral oil lubricantcc'im-- positions containing them, are" believed to be novel and are; considered parts of our invention.

The present invention maybe regarded asan improvementoverthe inventions disclosed in our above-identified copending' application and pat ent; While the additionfagents disclosed therein confer excellent antioxidant}corrosion-inhibiting and pressure car'rying properties on mineral oil lubricants, they sometimes failto pass the well known Copper'Strip Test (Meth0d-5 30.31, Fed- Mal-Specification VV-L-'791c, May 12,1945, page 259) thus indicating the presence of elementary sulfur or the so-called corrosive sulfur. While We-id0-'IlOt.-WiSh"t0 be bound by any theory astto the exact-nature of the-phosphoruspentasullide reaction-products with anessentially. paraifinic base lubri'cating oil,.it is our present belief that either elementary sulfur or incompletelybound sulfur or both; are formed in the reaction; I I :In accordance with: the present; invention,:such elementary'; or'aincompletely' bound sulfur is: non

tralizedi or -acc'e'pte by gcombination' witlithe 2,603,602 STATES PATENT OFF-VICE,

It is still necessary for the purposes of the 7 present invention to employ an essentially paraff finic base lubricating oil as theinitial material,- because other hydrocarbon materials produce a black, sludge-like, difiicultly soluble product regardless'of whether the prior "aluminum'chloride treatment or reaction in the presence of 'a' surface active silica-containing solid" catalyst are employed. The reasons for the advantageous effects of the prior aluminum chloride treatment or of the surface active silica-containing-solid catalyst on the reaction when an essentially paraffinic base lubricating oil is employed are not fully understood. However, the use of atleast one of these methods is essentialfor the practice of. ouninve'ntion'since, the prior aluminum chloride treatment or the use of a surface active silica-containing catalyst is omitted, the advan tageous results of our invention are not obtained. In order to obtain the results of our invention, therefore, it 'is necessary (1) to employ an es-. sentiallyparafiinic base lubricating oil, and 2) to' conduct'the reaction of the oil and alkylorthophosphate with phosphorus 'pentasulfide only afteraluminum chloride hasjbeen reacted with the oil and/or the reaction with phosphorus pentasulfidelis conducted in'the presence of. a surface active SiliOflrCOIltfiiIliDQSOlid catalyst. Theessentially paraffinic base lubricating oil used as a starting m'aterial'in accordance with our invention 'may be derived from any paraffinic crude,.such as Pennsylvania, Mid-conti nent, or other parafiinic base crudes. The lubri: ca'ting' oil rnanufactured from such crudes in ac'cordance with conventional methods and may loci-refined in accordance with methods known in the art If 'itis desired to treat the essentially parafiinic base lubricating oil with aluminum chloride, such treatmentis accomplished as, described in four copending application Serial No. 718,902. Briefly, such treatment comprises heating the essentially paraflinic base lubricating oil with from 1 to 20 per cent by weight ofanhydrous alur'riinumchloride at a temperature of from 15.0? to-1300'iv F. while the mixtureis vigorously agitatedl' fThetir'ne of treatment mayvary in accordance 'with the amount of aluminum chloride used and the temperature'of'treatment, longer times being required with less aluminum chloride and lower temperatures' In general," the treatment will be completed after four,or five hours. After, the treatment is completed, agita tion is stopped'and the sludge containing most of the'aluminum chloride settles out from the main body of the oil and is drawn 0111' The supernatant body of the treated oil may contain furthergquantities of aluminum chloride'finely dispersed therethrough, andin order to insure the removalof all aluminum chloride from the treated oil, agitation with an adsorbent clay followed by filtration maybe employed. At the higher temperatures of treatment with aluminum chloride some conversion of the paraflinic base oil to lower boiling products may take place. Althoughsuch conversion is slight, the product mayLbetOpped if desired; that is, distilled to TB! move the lower boiling products overhead and to recover .as' a residue the bulk of the'aluminum chloride treated oil having a minimum initial boiling point in the range 490 to 530 F.

The essentially parafiinic base lubricating .oil treated with aluminum; chloride as disclosed hereinabove may then bereacted with the alkyl tinsel-era and t horus' pentasulfide. This may be accomplished either by reacting I with phosphorus pentasulfide per se, as disclosed in our copending application Serial No. 718,902,

orin the presenceiof a surface active silica-containing' solid catalyst as disclosed in our Patent No. 2,456,336; i v

If it is desired "to react the aluminum chloride treated oil and-the alkyl orthophosphate with phosphorus penta'sulfide per se, this reaction is accomplished by'a'dding from 2 to 20 per cent by -we ight of P2355011 the mixture of oil and alkyl orthophosphate, preferably 5 to 10 per cent, and heating with agitation at a minimum reaction temperature of 450 F. and a maximum reaction temperature below the temperature where cracking of the oil begins. Hydrogen sulfide isievolved and when the evolution of hydrogen sulfide has nearly ceased, the temperature of Ythereaction mixture may be increased within. the maximum temperature disclosed above, saytd about'500 F. for thecompletion of the reaction.

If desired; the aluminum chloride treated parafiini'c base lubricating oil and the alkyl orthophosphate may be reacted with phosphorus pentasulfide in" the presence of a surface active silica-containing solid catalyst; or, the prior aluminum chloride treatment may be omitted and the essential parafiinic base lubricating oil and alkyl orthophosphate maybe 'reactedwith phosphorus pentasulfideinthe presence of a surface active silica-containing solid catalyst. The re'actionof the essentially parafiinic base 1ubri-' catingoil and alkyl orthophosphate, whether or not pretreated with aluminum chloride, with phosphorus pentas'ulfide in the presence of a surface active silica-containing solid catalyst is accomplished by adding 2 to 20 per cent by weight of P285, preferably from 5 to 10 per cent, to the mixture of essentially paraffinic" base lubricating oil and alkyl orthophosphate and heating with agitation at atemperature in'the range from 300 F. to: a maximum temperature below 'theltern-l perature where cracking of the oil, that is, pyro-T lytic decomposition of the oil, begins. Generally the minimum cracking temperature of theoil variesbe'tween 490 to 530? F., depending upon the particular oil used. The surface active silica containing solid catalyst is employed in amounts of from 2 to' 25 per cent by' weight'of the reaction mixture charged and preferably in an amount of lopercent byweight. Larger amounts than 10 percent are ordinarily not necessary; but larger amounts will produce a product having .allghter color. During-the course. of the reaction hydrogen sulfide is evolved and the phosphorus and sulfur become incorporated-in the reaction product. When the evolution of hydrogen sulfidehas nearly ceased, the temperature of thereac'tion mixture may be increased within the maximum temperature mentioned above, say to about 500? F.. for completion o1? the. reaction. The mixture is then'filtered to remove the-catalyst. t t The surface -active silicaecontaining solid catalysts may comprise'activated clays, silicaalumina cracking catalysts and the like. Thus, activated clays, that mammal clays such; as bentonite, smectite, fluoridin, fullers earth and the like which have been treatedwith acid, such as aredescribed in U. S. Patent No. 1,898,165, for example, may be advantageously employed. Synthetic silica-alumina .catalysts'of the type used for the crackin ofqhydrocarbon oils, ex-

' ,a'mples-ofwhich are described. in U. S. Patent No.

207 4945 nd. U.-. s. Pa -N0. 2,283,173, mayalso be employed. Activated silica gel is also suitable. Asmay be seen, the term surface active silicacontaining solid catalyst comprises a wide variety ofmaterials, the predominant characteristic of .which is the presence of silica in a surface active, thatis, activated form. r I r In accordance with the present invention, analkyl orthophosphate is admixed withthe e'ssentially parafiinic base lubricating oiland the mixture reacted with phosphorus pentasulfide as disclosed hereinaboveyor thealkyl orthophosphate maybe added to the mixture of the phosphorus pentasulfide and the essentially paraffinic base lubricating oil during thereaction after the evolutionof hydrogen. sulfidehas substantially ceased, but; prior. to; completion of the. reaction. The alkyl: orthophosphate'isv ordinarily added in proe portionsrrangingirom to '75 per cent byweightv of its mixture with the parafiinic base lubricating oil, sufficient to remove free or corrosive sulfur in the phosphorus pentasulfide reaction product. Ordinarily not more than 50 per cent of the alkyl orthophosphate is sufficient for most purposes.

The alkyl orthophosphate with which this invention is concerned may be mono-, di-, or trialkyl esters of orthophosphoric acid having the following general formulas: 3

wherein R represents a saturated aliphatic hydrocarbon radical of at least 5 carbon atoms, preferably from 8 to 18 carbon atoms. The-upper limit of 18 ;carbo,n atoms is 'noticritical, it being dictated by considerations of commercial avail:

While any of the esters mentioned above may be used, we .preferto-use trialkylphosphates and, of these, trioctyl phosphate." In view ofthe fact that these esters of phosphoric acid are commercially available, methodsfor their preparation need not be described here.

' 'Ifhefollowing examples illustrate the preparation of our new improvement agents. 7

Example I.-In,the presence of 5 per cent by weight of;- an activated clay catalyst (Filtrol),

50;: parts by weightiof tri-s ec octyl phosphateand50 parts by weightof an SAE 30 Mid-Continent paraffinic base lubricating oil were treated with 10 per cent by weight of phosphorus pentasulfide by agitating for 1 hour while raisingthe temperature to 490 F., and agitating at that temperature for two hours or until the evolution.

ofi hydrogen sulfide subside'df Then; the tem'- perature was raised-to 520= where "it was held fon-6 hours with continuecl -agitatiorr of "the reactants.- Tha mixture was ,thencooled: and: filtered. I, The. properties; of this product were; as; iollowsz; a q: J Gravity,- 1 114-; r 113.2 o horu i e en ome pg c n .1 Neutralization No. C0101; 1

Example, IL- An; additive was prepared insaccordancewiththe procedure of Example. I, in, which 5 parts. by weight of tri-Sec octyl. phosphate and, 25 parts by weight: of an SAE'30 par-aflinic; baseI lubricating oil were reacted withl2 parts,.-by. weightv of phosphorus pentasulfidein the presence of 10 per cent byweightoiFiltrol, The; additive so prepared had'the followingprop erties:

Gravity, API

Color, NPA. 2.25 .Sulfur, percent 3.2 Phosphorus, per cent 3.0 Neutralization No. 14.0

Erample III.Into a reactionjvesseLjthere were placed parts by weight of an essentially parafiinic base lubricating oil which hadbelen treated with aluminum chloride in accordance with v;copending application Serial No. 718,902 and 50 parts by weight of tri-sec octyl phosphate. To this mixture were added.l2.5 partsby weight of phosphorus pentasulfide. The mixture was agitated and the temperature raised to 490 F; during the course of 1 hour. It was held at that temperature for 2 hours and then raised to .520 where .it washeldr for 6'hours. The mixture wasv thencooled and .had they following properties:. g I

Gravity, API 14.2 Phosphorus, per cent 3.0 Sulfur, per cent 3.2 Neutralization No. 6.0 Color, NPA 4.5

l "Gravity, API .4 14.1

Phosphorus, per cent 2.4 Sulfur, percent i 2.6 Neutralization No. 11.0 Color,,,NPA- 4.5

The reaction' products' obtained in accordance with the preceding examples are excellent improvement agents for mineral oil lubricant compositions. They are light colored and readily soluble in all types of mineral oils, that is paraffinic, naphthenic or mixed base mineral oils and, as a matter of fact, can be blended with mineral oils in proportions as high as 50 per cent by weight or higher. This excellent solubilityof our new improvement agents enables the preparation of concentrated solutions, which may then be diluted down to the proportion desired in the final mineral oil lubricant composition. As stated, our new improvement agents confer excellent anti-oxidant and corrosion-inhibiting-properties f on the mineral lubricating oils with which they are incorporated, and-are characterized by a high degree of potency at high temperatures. For these purposes, our new improvement agents are generally added to mineral oils in minor amounts, say from 0.1 to 20 per cent by weight of mineral oil, sufiicient to confer improved antioxidant and corrosion-inhibiting properties on the mineral lubricating oils with which they are incorporated. Lubricating oils containing our new improvement, agents successfully pass the Copper Strip Test.

The following examples illustrate the use of our new improvement agents to obtain improved mineral oil lubricant compositions.

Example 'V.-A motor oil was prepared by treating a-solvent refined SAE 30 motor oil with 1 per cent of the additive prepared in accordance with the procedure of Example I. The following is a summary of the test values in comparison with that of the untreated oil:

Unimproved Improved Motor Oil Motor Oil Gravity: API 29.0 28.9 Viscosity, SUV 549 661 Color, NPA 4. 4. 25 Oxidation and B Corrosion Test Method 257, Gulf: I 7

Duration of Test: hr '48 48 Oil Bath Temper'aturezPF 347 347 Air Rate: cc./hr 2,000 2,000 Quantity of Oil: cc. 300 Bearing Type Cd-Ag CdAg Wt.-Change: Grams. -0. 2040 +0. 0018 Wt. Change: Percent. 0. 93 +0.01 Copper StripTesL, Passes Passes In order to determine'the comparative improvement in properties obtained by using the additive of the present invention, additives prepared in accordance with the disclosures of Serial No.

Unimproved Motor Improved Motor Oil Oil Gravity: API 29.0 29.1 Viscosity, SUV: 100 F 521 520 -Color, NBA 1. 1.75

Oxidation and Bearing Corrosion Test Method 257, Gulf: 1 I

7 Duration of Test: hrs r 48 48 vOil Bath Temperature: F. 347 347 Air Rate: cc./hr 2,000 2, 000 Quantity of Oil: cc. 300 300 Bearing Type Od-Ag Cu-Pb Cd-Ag Cu-Pb Wt. Change: Grams" -0. 1744 0. 0133 0.048 0. 0018 Wt. Change: Percent. 0. 96 0.08 0. 01 0. 01 Copper Strip Test Passes Passes Example VI .An SAE 30 motor oil was treated with l'per cent of the additive prepared in accordance with the procedure of Example II. Comparison of the tests of the treated oil and untreated oil are:

718,902, Patent No. 2,456,336 and the present invention were subjected to the well known Falex Wear Test and the Copper Strip Test. In each instance 2 parts by weight of the additive were compounded with 98 parts by weight of a highly Example VII .An SAE 30 motor oil was treated with 1 per cent of the additive prepared in acrefined motor oil. The uncompounded oil is included for purposes of comparison.

Uncom- Lubricant Lubricant Lubricant pounded of S. .N. 01' Pat. of Presen Lubricant 718,902 2,456,336 Invention Gravity: API 29.3

Viscosity, SUV: 100 F 246 242 34 ((llgigglslzggi zgtflu- P 1'. 75 T 1. 75 1. 75 1. 75 asses Fallex Wear Test 1000 lb. Gaug wished Tamlshed Passes 5 min:

Wear: No. 01' Teeth Fails 5 Gauge Load at Seizure: Lb.-- 1, 753' l, 758 2, 508

cordance with the procedure of Example: IV. Comparison of the tests of the treated and untreated motor oil are:

F'rqm the above table. it isobvious that not only do'the additives of -the present invention confer enhanced pressure carrying properties, but lubri Bi .cantscontairnng' them passthe Copper Strip Test. The Oxidation and Bearing Corrosion.= -Test,

Method :25'7?,:Gulf*referred to inithe foregoing .ex-

it "is advantageous to employ commercial bearing.

shells. 1 These shells comprise a' suitable-metal backing faced with the alloy bearing metal. In this Way the actual bearing face is subjected to severe deterioration conditions. By comparison of the results of such tests with actual service tests, we have found them to be in substantial agreement as to the suitability of particular lubricants.

As shown in the above examples, the addition of our new improvement agents to mineral oil lubricant compositions confers excellent antioxidant, corrosion-inhibiting and pressure carrying properties. At the same time the compositions so obtained are stable in storage and use and have a color which is substantially unaffected by the addition of the improvement agent. The lubricants obtained pass the Copper Strip Test..

While we have shown in the examples the preparation of compounded lubricating oils, our invention is not limited thereto but comprises all mineral oil lubricant compositions containing our new improvement agents, such as greases and the like. Furthermore, conventional addition agents such as viscosity index improvers, pour point depressants, anti-foam agents and the like may be added without departing from the spirit of the invention.

Resort may be had to such modification and variations as fall within the spirit of the invention and the scope of the appended claims.

We claim:

1. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially paraffinic base lubricating oil with anhydrous aluminum chloride at a temperature of from 150 to 300 F., removing aluminum chloride from the reaction product, and reacting said product and from 10 to '75 per cent by weight of an alkyl phosphate having at least 5 carbon atoms in the alkyl group with phosphorus pentasulfide at an elevated temperature not below 300 F. and not in excess of the minimum cracking temperature of said product to incorporate phosphorus and sulfur therein.

2. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially paraiiinic base lubricating oil with anhydrous aluminum chloride at a temperature of from 150 to 300 removing aluminum chloride from the reaction product, and reacting said product and from to '75 per cent by weight of an alkyl phosphate having at least 5 carbon atoms in the alkyl group with phosphorus pentasulfide at a temperature of from 450 F. to a maximum temperature below the minimum cracking. temperature of said product to incorporate phosphorus and sulfur therein. 3. The process of preparing an improvement agent for mineral oil lubricants which comprises h atin an s nt l a af e u r a oilgwithfrom 1,.to 20;,per; cent by weight -of anhydrous 1 aluminum chloride at. a I temperature I f m 5 L-r o-3'00? Fsxremov l m n m' chloride. from the reaction product; andvreact ing said product and from 10 to '75 percent by wei ht o aa alkyl ph p a rms: at l a ;5,;car bei i atoms; in the alkyl group with from 2 .20; n r went: b I e t ofgphospborus e as fide=- at-eztem r o omem t0. maximum-- temperature belowthe mm'mum cracking temperature of said production-in: corporate ;.,phosphorus and. sulfur-therein r; l.-.The process of claim ,3, wherein1-the product is; dissolved :in armineral lubricating oil, 5-.The process of claim Bywherein; theqalkyl phosphate contains from 8 to 18 carbon atoms inan alkyl group.

6. The process of claim 5, wherein the alkyl ester of phosphoric acid is tri-sec octyl phosphate.

'7. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially paraffinic base lubricating oil, phosphorus pentasulfide and from 10 to '75 per cent by weight of an alkyl orthophosphate having from 3 to 18 carbon atoms in an alkyl group, in the presence of a surface active silicacontaining solid catalyst and at a temperature of from 300 F. to a maximum temperature below the minimum cracking temperature of said lubricating oil to incorporate phosphorus and sulfur therein.

B. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially paraffinic base lubricating oil, from 2 to 20 per cent by weight of phosphorus pentasulfide, and from 10 to 50 per cent by weight of an alkyl orthophosphate having from 8 to 18 carbon atoms in an alkyl group, in the presence of from 2 to 25 per cent by Weight of a surface active silica-containing solid catalyst and at a temperature of from 300 F. to a maximum temperature below the minimum cracking temperature of said oil to incorporate phosphorus and sulfur therein.

9. The process of claim 8 wherein the alkyl orthophosphate is tri-sec octyl phosphate.

10. The process of preparing an improvement agent for mineral oil lubricants which comprises heating an essentially parafiinic base lubricating oil with from 1 to 20 per cent by weight of anhydrous aluminum chloride at a temperature of from 150 to 300 F., removing aluminum chloride from the reaction product, heating said product with from 2 to 20 per cent by weight of phosphorus pentasulfide in the presence of a surface active silica-contained solid catalyst and from 10 to 75 per cent by weight of an alkyl orthophosphate having from 8 to 18 carbon atoms in an alkyl group at a temperature of from 300 F. to a maximum temperature below the minimum cracking temperature of the aluminum chloride treated oil 14. The product obtainable by the process of claim 7.

15. The product obtainable by the process of claim 10. 7 16. A lubricant composition comprising a major amount of a mineral lubricating oil and a minor amount,;sufficient to confer improved'antioxidant and corrosion-inhibiting properties on the'composition, of the product obtainable by the process of claim 1. g I e '17. A lubricant composition comprising a major amount of a mineral lubricating oil and a minor amount, sufficient to confer improved antioxidant and corrosion-inhibiting properties on the composition, of the product obtainable by the process of claim 3.

18. A lubricant composition comprising a major amount of a mineral lubricating oil and a minor amount, sufficient to confer improved antioxidant and corrosion-inhibiting properties on the composition; of the product obtainable by the process ofc1aim'7. V

'19. A lubricant composition comprising a major amount of a mineral lubricating oil anda minor amount; sufficient to confer improved antioxidant and corrosion-inhibiting properties on the composition, of the product obtainable by the process of claim 10, 5 pq '1 V HERSCHEL G. SMITH.

TROY L. CANTRELL.

REFERENCES CITED 1 The following references are'of record i file of this patent: 7

UNITED STATES PATENTS 1 1 e. f? Number Name" r Date r 2,167,867 Benning Aug. 1, 1939 2,315,072 Nelson Mar. 30,- 1943 2,456,336 Smith Dec; 14, 19518

Claims (1)

1. THE PROCESS OF PREPARING AN IMPROVEMENT AGENT FOR MINERAL OIL LUBRICANTS WHICH COMPRISES HEATING AN ESSENTIALLY PARAFFINIC BASE LUBRICATING OIL WITH ANHYDROUS ALUMINUM CHLORIDE AT A TEMPERATURE OF FROM 150* TO 300* F., REMOVING ALUMINUM CHLORIDE FROM THE REACTION PRODUCTS, AND REACTING SAID PRODUCT AND FROM 10 TO 75 PER CENT BY WEIGHT OF AN ALKYL PHOSPHATE HAVING AT LEAST 5 CARBON ATOMS IN THE ALKYL GROUP WITH PHOSPHORUS PENTASULFIDE AT AN ELEVATED TEMPERATURE NOT BELOW 300* F. AND NOT IN EXCESS OF THE MINIMUM CRACKING TEMPERATURE OF SAID PRODUCT TO INCORPORATE PHOSPHORUS AND SULFUR THEREIN.