US2252984A

US2252984A - Compounded hydrocarbon oil

Info

Publication number: US2252984A
Application number: US272154A
Authority: US
Inventors: John T Rutherford; Robert J Miller
Original assignee: Standard Oil Co
Current assignee: Standard Oil Co
Priority date: 1939-05-06
Filing date: 1939-05-06
Publication date: 1941-08-19
Anticipated expiration: 1958-08-19
Also published as: USRE22829E

Description

Patented Aug. 19, 1941 COMPOUNDED HYDROCARBON 01L John T. Rutherford and Robert J. Miller, Berkeley, CaliL, assignors to Standard Oil Company of California, San Francisco, Calif., a corporation of Delaware No Drawing. Application May 6, 1939, Serial No. 272.154

24 Claims.

This invention relates to a new and useful composition of matter and involves a composition comprising a hydrocarbon, such as a viscous hydrocarbon oil, and a polyvalent metal salt of sulfur containing substituted acids of phosphorus.

The production of improved hydrocarbon oils and particularly of lubricating oils having desired characteristics has been the subject of extensive research and investigation in recent years. Generally speaking, the compounding of hydrocarbon oils to obtain desired characteristics involves empirical phenomena and the action of untested types of compounding agents cannot be predicted.

A characteristic which has been the subject of extensive investigation is the tendency of hydrocarbon oils to deteriorate or partially decompose the Dies'el type, is the tendency of the elite cause or permit the sticking of piston rings.

The crankcase lubricant in internal combustion engines is subjected to extremely severe I operating conditions and in engines of the Diesel type the lubricant encounters in the piston ring zone temperatures of from approximately 425 to 650 F. and pressures from the oxidizing combustion gases as high as 750 to 1150 lbs. per sq. in. Addition agents which render hydrocarbon oils resistant to deterioration by heat at high temperature levels in the orde of those above mentioned usually impart to the oil the ability to inhibit piston ring sticking in internal combustion engines and permit longer periods of operation of such engines without the necessity of major overhauls heretofore occasioned by stuck piston rings.

It should be noted that stabilizing agents which are eiiective at low temperatures to impart increased stability to hydrocarbon oils, or which are effective at temperatures even as high as 200 or 250 F., are often ineffective under the more severe operating conditions and higher temperature levels to which lubricating oils are subjected in Diesel engines. Thus the operativeness of a stabilizer at atmospheric temperatures, or even temperatures as high as 200 to 300 F., gives no adequate basis for predicting the action of the same stabilizing agent at materially higher temperatures and under more severe operating conditions. The disclosures in the prior art relative to such stabilizers therefore cannot serve as a guide for one seeking stabilizing'agents or oxidation inhibitors effective at higher temperature levels. The phenomena involved are catalytic in nature, are highly empirical and require extensive experimentation to determine the action of a given type of addition agent.

The present invention involves the discovery that dispersion of polyvalent metal salts of sulfur containing substituted acids of phosphorus in hydrocarbon oils, such as mineral lubricating oil, imparts new, unpredictable and highly desirable properties to the composition. These new properties render the compounded oil particularly useful for various purposes. Although increased resistance to deterioration at high temperature levels comprises one of the principal advantages of the compounded oil of this invention, it is to be understood that the invention is not limited to this feature, that difierent compounds of the general type herein involved vary in their degree of effectiveness and may impart one or more other desirable properties to the lubricating composition. In eneral, however, it has been dis-- covered that the new compositions herein disclosed are more stable to heat than is a hydrocarbon oil with which the compositions are compounded. The new compositions of this invention are therefore useful where resistance to deterioration by heat is important. An example of such utility other than as a lubricating oil comprises use as a heat transfer fluid where it may be desirable to inhibit or prevent the formation of a deposit on the metal surfaces from or to which heat is being conveyed. Likewise, the increased resistance to oxidation imparted to oils on these bearing metals.

the oil by the compounds of this invention will find various applications as, for instance, in insulating, switch or transformer oils.

It has also been discovered that certain metal salts of sulfur containing substituted phosphori acids have a combination of properties heretotore unknown and particularly desirable in compounded mineral oils, namely, the ability to inhibit oxidation and impart to lubricating oils increased resistance to deterioration by heat, the ability to inhibit piston ring sticking, freedom from the production of increased wear on cylinder walls and piston rings as compared with uncompounded mineral oils, low corrosivity as respects the chemical action of the compounded oil on bearing metals, such as cadmium-silver and copper-lead alloys, as well as the power to inhibit the corrosive action of highly parafllnic Although various compounded mineral oils are known which are capable of inhibiting piston ring sticking, the discovery of specific compounding agents capable of imparting the above combination of proper ties to hydrocarbon oils represents an unobvious and important contribution.

Salts of sulfur-containing substituted acids of phosphorus which may be added to hydrocarbon where M is a metal selected from Groups II, III,

IV and VI of Mendelyeevs Periodic Table of the Elements. Specific examples of such metals are calcium, barium, strontium, aluminum, chromium, lead and magnesium. Within the broader aspects of the invention M may also be selected from the group iron, cobalt, nickel, zinc and tin. In the above formula, B may bealkyl, aryl, alkaryl, aralkyl or cyclic non-benzenoid groups; x and Y each are either sulfur or oxygen and sulfur; H is hydrogen; P is phosphorus; a, b, d and e represent small whole numbers and c may be zero or a small whole number.

The metal salts of this invention are preferably formed from substituted acids of pentavalent phosphorus of one or more of the following type formulae:

monothioester of phosphoric acid;

di-thio ester of phosphoric acid;

di-ester of teira-thiophosphoric acid;

monothioester oi tetra-thiophosphoric acid;

di-thio ester of tetra-thiophosphoric acid;

monoestcr of mono-thiophosphoric acid;

dl-estcr of mono-thiopliosphoric add:

where R and R may be alkyl, aryl, alkaryl, aralkyl or cyclic non-benzenoid groups. Substituted acids containing at least approximately 12 carbon atoms are preferred. Examples of preferred type acids are alkyl or alkaryl sulfur containing substituted phosphoric acids having at least 12 carbon atoms in the molecule. However, it is to be understood that the broader aspects of the invention include other types of sulfur containing substituted acids of phosphorus containing more than 12 carbon atoms. Additional examples of such acids which may be used in forming the metal salts of the present invention' are as follows:

mono-thioester of phosphonic acid 7 mono-ester of trithiophosphonic acid mono-thioester of trithiophosphonic acid.

In all of the above formulae R and B may be alkyl, aryl, alkaryl, aralkyl or cyclic non-benzenoid groups.

In general, polyvalent metal salts of sulfur containing substituted derivatives of acids of phosphorus such as phosphorous acid, HaPOa; hypophosphoric acid, HzPOs; orthophosphorlc acid, H3PO4; pyrophosphoric acid, H4P2O7; monothiophosphoric acid, H*PSO: di-thiophosphoric acid, HsPSzOa; trithiophosphoric acid, HaPSsO; tetra-thiophosphoric acid, H3PS4; thiopyrophosphoric acid, H4PzS1; and trithiopyrophosphoric acid, H4P2S'O4 fall within the broadest aspects of the invention. By substituted acids or substituted derivatives of phosphorus, whenever used herein, it is intended to designate acids of .phosphorus containing an organic group of the inum cetyl thiophosphate, lead cetyl thiophosphate, calcium cetyl phenyl thiophosphate, chromium cetyl phenyl thiophosphate, aluminum cetyl phenyl thiophosphate, lead cetyl phenyl thiophosphate.- Salts such as calcium thio-cresyl phosphate, chromium thio-cresyl phosphate, aluminum thio-cresyl phosphate, and lead thio-cresyl phosphate, although less effective than the previously recited compounds, improve various properties of the oil, particularly its resistance to oxidation.

Additional examples of salts within the scope of the invention are aluminum lauryl thiophosphate, aluminum octadecyl thiophosphate, aluminum spermol thiophosphate, aluminum oleyl thiophosphate, aluminum spermenyl thiophosphate, aluminum di-(amyl phenyl) thiophosphate, aluminum naphthenyl thiophosphate, aluminum di-cyclohexanyl thiophosphate, aluminum tetra-chlorooctadecyl thiophosphate, aluminum di-(6-chloro, 2-phenyl phenyl) thiophosphate, aluminum di-(3-methyl, 4-chlorophenyl) thiophosphate, calcium lauryl thiophosphate, calcium octadecyl thiophosphate, calcium spermol thiophosphate, calcium oleyl thiophosphate, calcium spermenyl thiophosphate, calcium di-(amyl phenyl) thiophosphate, calcium naphthenyl thiophosphate, calcium di-cyclohexanyl thiophosphate, calcium tetra-chloro-octadecyl thiophosphate, calcium di-(fi-chloro, 2-phenyl phenyl) thiophosphate, calcium di-(3-methyl, 4-chlorophenyl) thiophosphate, barium lauryl thiophosphate, barium octadecyl thiophosphate, barium spermol thiophosphate, barium oleyl thiophosphate, barium spermenyl thiophosphate, barium di-(amyl phenyl) thiophosphate, barium naphthenyl thiophosphate, barium di-cyclohexanyl thiophosphate, barium tetra-chloro-octadecyl thiophosphate, barium di-(6-chloro, Z-phenyl phenyl) thiophosphate, barium di-(3-methyl, 4- chloro-phenyl) thiophosphate, chromium lauryl thiophosphate, chromium octadecyl thiophosphate, chromium spermol thiophosphate, chromium oleyl thiophosphate, chromium spermenyl thiophosphate, chromium di-(amyl phenyl) thio phosphate, chromium naphthenyl thiophosphate, chromium di-cyclohexanyl thiophosphate, chromium tetra-chloro-octadecyl thiophosphate, chromium di-(fi-chloro, Z-phenyl phenyl) thiophosphate, chromium di-(3-methyl, 4-chlorophenyl) thiophosphate, lead lauryl thiophosphate, lead octadecyl thiophosphate, lead spermol thiophosphate, lead oleyl thiophosphate, lead spermenyl thiophosphate, lead di-(amyl phenyl) thiophosphate, lead naphthenyl thiophosphate, lead di-cyclohexanyl thiophosphate, lead tetrachloro-octadecyl thiophosphate, lead di (6- chloro-2-phenyl phenyl) thiophosphate, lead di- (3-methyl, 4-chloro-phenyl) thiophosphate, magnesium lauryl thiophosphate, magnesium octadecyl thiophosphate, magnesium spermol thiophosphate, magnesium oleyl thiophosphate, magnesium spermenyl thiophosphate, magnesium di (amyl phenyl) thiophosphate, magnesium naphthenyl thiophosphate, magnesium di-cyclohexanyl thiophosphate, magnesium tetra-chloro-octadecyl thiophosphate, magnesium di-(S-chloro, 2-phenyl phenyl) thiophosphate, magnesium di- (3-methyl, 4-chloro-phenyl) thiophosphate.

It should also be understood that the sulfur containing substituted acids of phosphorus uti lized for preparing the metal salts of this invention may contain organic substituents other than pure hydrocarbon groups. The organic radical in the acid of phosphorus may comprise, in addition to carbon and hydrogen, substituents such as the halogens chlorine or bromine, hydroxy, sulfhydryl and similar groups. Likewise, the sulfur in the sulfur containing atom need not necessarily be directly attached to the phosphorus atom. An acid which illustrates these types of compounds comprises the phosphoric acid ester of di-(p-hydroxy phenyl) sulfide.

The acids of phosphorus utilized in the present composition may be prepared by various methods. For example, a mixture of a higher alcohol and phosphorus pentasulfide, a mercaptan and phosphorus pentoxide, a mercaptan and phosphorus pentasulfide or a three-component mixture such as a mercaptan, phosphorus pentoxide and pyrophosphoric acid, may be directly fused in proportions to give acid esters. The reaction by which the substituted phosphoric acid is formed in the last mentioned three-component mixture is believed to be represented by the following equations:

For example, thio-cresyl phosphoric acid may be prepared by reacting thio-cresol with phosphorus pentoxide and pyrophosphoric acid at a temperature not in excess of 250 F. The thio-cresol is charged to a stainless steel mixer equipped with a jacket. Steam is admitted in the jacket until a temperature of 200 F. is reached, at which temperature the phosphorus pentoxide and pyrophosphoric acid are added. Water is circulated through the jacket at this time to control the reaction temperature. Stirring is continued until the reaction is complete and the product withdrawn.

In preparing the metal salts involved herein the alkali metal salt of the above acid may be dissolved in aqueous solution and the heavy metal or alkaline earth metal salt precipitated therefrom. For instance, the calcium salt may be manufactured by precipitation as follows: Water and caustic potash are charged to a mixer and heated to a temperature of 180 F. The acid is added, thereby formingan alkali salt. An aqueous calcium chloride solution is incorporated with violent agitation during precipitation to prevent inclusion of the potassium salt. The precipitated curd is washed free of inorganic salts with hot fresh water. Mineral oil is then added and the solution is dehydrated as by heating to a temperature of 300-330 F. The concentrated oil solution so obtained may conveniently be used for mixing or blending with other oils to prepare the completed product.

Either normal or basic aluminum salts may be prepared by the precipitation method. The

normal salts will contain three equivalents of the acid per atom of aluminum, whereas the basic salt should contain less than three equivalents of the substituted acid of phosphorus.

Calcium salts may also be prepared in a nonaqueous environment as by the reaction of calcium carbide with the free substituted acid to give acetylene and the anhydrous calcium salt. Aluminum salts may likewise be prepared in an environment substantially free of water by the reaction of aluminum chloride with the free substituted acid of phosphorus. Such aluminum salts have properties different from the salts prepared by precipitation in aqueous solutions. Although these latter salts are useful, aluminum salts prepared by precipitation from aqueous solutions are preferred where the ability to inhibit piston ring sticking in lubricating oils is the property desired.

By way of illustration and to demonstrate the unusual properties possessed by the compounded Table I lubricating oils under severe operating conditions,

such as those encountered in the lubrication of Compound Method of manufacture of acid Oxidator test: c.c. Hours Percent oxygen to stick salt absorbed piston in 2.5 rings hours COMPOUNDED IN ACID REFINED WESTERN OIL S. A. E. 30

Mineral oil -Q o 324 Calcium phosphate of p-hydroxydip-Hydroxfidiphenylsulfide and P105 1 76 sulfide. +phosp oleum.

phenyl Calcium thiocresyl hos hate Calraigum cetylthiop osp ate Cetyl alcohoH-Pa o do Chromium cetylthiofihosphat Cetyl alcohol+PzSa Lead cetylthiophosp ate Cetyl alcohol+P1Sa 1 Do .d .05 148 Calcium cotylphenylthiophosphate. Cetyl phenol+P2Ss l 170 Calcium thiocresylthiophosphate. Th1ocrcso1+PaSs 1 76 Thiocresol and P1s05+phospholeum i 108 (1.5 hr.) v 110 COMPOUNDED IN PENNSYLVANIA OIL S. E. 30

Mineral oil 0 302 45 Calcium cetylphenylthiophosphete.-. l 180 Do 165+ Calcium cctyiphenylthiophosphate+ 5+. 12o

calcium cetylphcnate. Calcium thiccresylthiophosphats... Thiocresol+PiSs l 188 It will be observed that all of the compounding agents were effective to very substantially inhibit the absorption of oxygen in, and deterioration of, the mineral lubricating oil in the oxidator test. This test is described by Dornte in the Journal of Industrial and Engineering Chemistry, 1936, vol. 28, page 26, and was carried out in the present examples at 340 R, which represents very severe conditions.

In the piston ring sticking tests a single cylinder, 2%" bore, 2 stroke, Lauson gasoline en gine was operated under extremely severe conditions for the purpose of developing fully piston ring sticking and piston gumming tendencies under circumstances simulating severe operating conditions encountered in the field. Operation of the motor during test was continuous at 1600 R. P. M. except for periodic shut-downs at fifteenhour intervals for inspection. The jacket ternperature was maintained at approximately 375 F. and the sump oil temperature at approximately 220 F. during the test.

The compounding agents herein disclosed may have one or more advantages, depending upon the particular compound selected, the proportion utilized, and the environment which the lubricating oil is to encounter. It should be observed, for example, that even though a compounded oil may be somewhat corrosive to copper-lead or cadmium-silver bearing metals, Babbitt bearings are little, if at all, affected by such corrosive action. Hence, compounded oils which may not be particularly desirable for lubrication of copper-lead or cadmium-silver bearings may be highly useful and extremely advantageous in conjunction with the operation of internal combustion engines hav- 7 pistons and piston rings of internal combustion engines of the Diesel type, polyvalent metal salts of sulfur containing substituted acids of pentavalent phosphorus containing more than twelve carbon atoms in the molecule and preferably containing an alkyl or alkaryl substituent should be utilized. It is to be understood that by polyvalent metal salts" used inthe above connection the alkaline earth metals are included and the term polyvalent metal is adopted to distinguish from the alkali metals.

A moderately acid refined Western naphthenic base oil is the preferred oil stock used as a base for the compounded lubricants involved herein. The compounding ingredients appear to function more efficiently in such a base 011 than in a highly parafiinic oil stock or a highly refined Western oil. However, it is to be understood that the invention is not limited to any particular base stock since various of the present compounds are more eflicient in inhibiting oxidation and corrosion effects in highly parafilnic oil stocks than any compounds so far tested.

The proportion of metal salts of substituted acids of phosphorus added to mineral lubricating oils may vary widely depending upon the uses involved and the properties desired. As little as 0.05% by weight of the compound gives measurable improvements, particularly as respects inhibiting oxidation and color stability of the compounded oil. From approximately 0.25 to approximately 2% of the compound may be added to lubricants where increased stability'in internal combustion engines and resistance to erties desired. Solutions containing more than 2% of the compounds in mineral oil may be utilized for the purpose of.preparing lubricating greases and concentrates-capable of dilution with lubricating oils and the like. Such higher concentrations comprise a convenient method of handling the compounds and may be used as addition agents for lubricants in general as well as for other purposes.

The metal salts of this invention may be added I to hydrocarbon oils containing other compounding ingredients such aspour point depressors, oilmess agents, extreme pressure addition agents,

blooming agents, compounds for enhancing the viscosity index of the hydrocarbon oil, corrosion inhibitors andthe like. The invention in its broader aspects embraces mineral hydrocarbon oils containing, in addition to metal salts of the substituted acids of phosphorus, thickening agents and/or metal soaps in proportions or in amounts insufficien-t to form greases, as in the case of mineral castor machine oils or other compounded liquid lubricants.

The compounds of this invention may be added to oils other than hydrocarbon lubricating .oils, for example, fuel oils or non-drying vegetable or animal oils.

While the character of the invention has been described in detail and numerous examples of the composition given, this has been done by way of illustration only and with the intention that no limitation should be imposed on the invention hereby. It will be apparent to those skilled in the art that numerous modifications and variations of the illustrative examples may be effected in the practice of the invention which is of the scope of the claims appended hereto.

We claim:

1. A composition of matter comprising a hydrocarbon oil subject to deterioration at elevated temperature and a polyvalent metal salt of a sulfur containing substituted acid of phosphorus having an organic substituent therein, said salt being present in an amount suificient substantially to inhibit said deterioration.

2. A composition of matter comprising a hydrocarbon oil and more than approximately 0.05% by weight based on the oil of a chromium salt of a sulfur containing substituted acid-oi phosphorus having an organic substituent therein.

3. A composition of matter comprising a hydrocarbon oil and more than approximately 0.05% by weight based on the oil of an aluminum salt of a sulfur containing substituted acid of phosphorus having an organic substituent therein. y l l d. A composition of matter comprising a hydrocarbon oil and more than approximately 0.05% by weight based on the oil of a lead salt of a sulfur containing substituted acid of phosphorus having an organic substituent therein.

5. A composition of matter comprising a hydrocarbon oil subject to deterioration at elevated temperatures and a polyvalent metal salt of a sulfur containing substituted acid of pentavalent phosphorus having an organic substituent therein,.said salt being present in an amount sufficient substantially to inhibit said deterioration.

6. A composition of matter comprising a hydrocarbon oil and more than approximately 0.05% by weight based on the oil of a chromium salt of a sulfur containing substituted acid of pentavalent phosphorus having an organic substituent therein.

7. A composition of matter comprising a hydrocarbon oil and more than approximately 0.05% by weight based on the oil of an aluminum salt of a sulfur containing substituted acid of pentavalent phosphorus having an organic substituent therein.

8. A composition of matter comprising a hylubricating oil and more than approximately 0.05% by weight based on the oil of a polyvalent metal salt of a sulfur containing substituted acid of phosphorus having an organic substituent therein.

10. A stabilized-liquid lubricant comprising a lubricating oil and more than approximately 0.05% by weight based on the oil of a polyvalent metal salt of a sulfur containing substituted acid of pentavalent phosphorus having an organic substituent therein.

11. A composition of matter comprising a hydrocarbon oil subject to deterioration in the presence of oxygen and a polyvalent metal salt of a thioesterof phosphoric acid, said salt being present in an amount sufilcient substantially to inhibit said deterioration.

12. A composition of matter comprising a hydrocarbon oil subject to deterioration in the presence of oxygen and a chromium salt of a thioester of phosphoric acid, said salt being present in an amount sufficient substantially to inhibit said deterioration.

13. A composition of matter comprising a hydrocarbon oil subject to deterioration in the presence of oxygen and an aluminum salt of a thioester of phosphoric acid, said salt being present in an amount suficient substantially to inhibit said deterioration.

14. A composition of matter comprising a hydrocarbon o-il subject to deterioration in the presence of oxygen and a lead salt of a thioester of phosphoric acid, said salt being present in an amount suificient substantially to inhibit said deterioration.

15. A composition of matter comprising a hydrocarbon oil subject to deterioration in the presence of oxygen and a polyvalent metal salt of an ester of a thio-phosphoric acid, said salt being present in an amount sufilcient substantially to inhibit said deterioration.

, 16. A composition of matter comprising a hydrocarbon oil subject to deterioration in the presence of oxygen and a chromium salt of an ester of a thio-phosphoric acid, said salt being present in an amount suflicient substantially to inhibit said deterioration.

17. A composition of matter comprising a hydrocarbon oil subject to deterioration in the presence of oxygen and an aluminum salt of an ester of a thio-phosphoric acid, said salt being present in an amount suflicient substantially to inhibit said deterioration.

18. A composition of matter comprising a hydrocarbon oil subject'to deterioration in the presence of oxygen and a lead salt of an ester of a thio-phosphoric acid, said salt being present in an amount sufiicient substantially to inhibit said deterioration.

19. A composition of matter comprising a hydrocarbon oil subject to deterioration in the presence of oxygen and a polyvalent metal salt of a stituted acid of pentavalent phosphorus having more than approximately twelve carbon atoms in the molecule.

22. A compounded lubricant comprising a lu- I,

an aluminum salt of a sulfur-containing substituted acid of pentavalent phosphorus having more than approximately twelve-carbon atoms in the molecule.

24. A compounded lubricant comprising a lubricating oil and from approximately 0.05% to approximately 2% by weight based on the oil or a lead salt of a sulfur-containing substituted acid of pentavalent phosphorus having more 7 than approximatelytwelve carbon atoms in the molecule.

JOHN T. RUTHERFORD. ROBERT J. MILLER.

DISCLAIMER 2,252,984.JOIm T. Rutherford HYDROCARBON OIL.

and Robert J. Miller, Berkeley, Calif. COMPOUNDED Patent dated August 19, 1941.

Disclaimer filed May 10, 1944, by the assignee, Standard Oil Company of California. Hereby enters this disclaimer to claims 1, 4, 5, 8, 11, 13, 14, 15, 17, 18, 19, 20,

and 24 of said patent.

[Oficial Gazette Jane 20, 1944.]

DISCLAIMER 2,252,984.J0hn T. Rutherford and Robert J. Miller, Berkeley, Calif. COMPOUNDED HYDROCARBON 011.. Patent dated August 19, 1941. Disclaimer filed May 10, 1944, by the assignee, Standard Oil Company of California. Hereby enters this disclaimer to claims 1, 4, 5, 8, 11, 13, 14, 15, 17, 18, 19, 20, and 24 of said patent.

[oflic'ial Gazette June 20, 1944.]