US2228671A - Compounded mineral oil - Google Patents

Description

Patented Jan. 14, 1941 UNITED STATES OOMPOUNDED MINERAL OIL Q George L. Neely and Elmslie W.

Gardiner,

Berkeley, Calif., assignors to Standard Oil Company of California,

San Francisco, Calii'.,

a corporation of Delaware No Drawing. Application November 25, 1938,

Serial No. 242,292 I composition of matter and involves a composi-' tion comprising a hydrocarbon oil and a new combination of stabilizing ingredients. More particularly the invention pertains to a viscous hydrocarbon 011 containing a metal phenate and a salt of a substituted acid 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 combinations of different 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 and oxidize when subjected to high temperatures. This deterioration is evidenced by the deposition of adhesive deposits on hot metal surfaces over which the hydrocarbon oil may fiow. Itis important that resistance to such deterioration be imparted to hydrocarbon oils,

- particularly to lubricating oils, in order that such compositions may be relatively free from the tendency to form such deposits even under high temperatures and severe operating conditions.

A direct result of this type of deterioration during lubrication of internal combustion engines, such as engines of the Diesel type, is the tendency of the oil to cause or permit the sticking of piston rings.

The crankcase lubricant in internal combustion engines is subjected to extremely severe 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 oxidizing combustion gases as high as 750 to 1150 pounds per square inch. The present invention is directed to the improvement of hydrocarbon lubricating oils by imparting thereto increased resistance to deterioration by heat at high temperature levels in the order of those above mentioned. It has been discovered that hydrocarbon lubricating oils containing both a metal phenate and a salt of a substituted acid of phosphorus have a number of highly desirable properties and improve the lubrication and operation of internal combustion engines. More particularly, it has been discovered that a lubricating oil containing this combination oi ingredients permits longer periods of operation of engines without the necessity of major overhauls heretofore occasioned by stuck piston rings, wear of pistons and cylinder walls, or, vin some instances, corrosion of bearing metal alloys.

The broader aspects of the invention involve the discovery that salts of substituted acids of phosphorus in general and metal phenates in particular cooperate to give new results in hydrocarbon oil compositions. Hydrocarbon oils containing this combination of ingredients have greater stability imder various operating conditions than do oils containing either one of these types of ingredients alone. For example, the same stability is not obtainable with 1% of a metal phenate or with 1% of a salt of a substitutedacid of phosphorus in a lubricating oil as is obtained with of the phenate and 54% of the metal phosphate in the same lubricating oil. Although it has been discovered that salts of substituted acid of phosphorus in I general cooperate with the phenates in the aboveunpredictable manner, the mechanism of this cooperation has not been established and the inventors therefore refrain from any attempted explanation of the phenomena observed.

Although the broader aspects of the invention are not so limited, it is preferred to utilize in combination with metal phenates heavy metal salts of substituted acids of phosphorus and still more specifically, alkaline earth salts like calcium salts of said acids in hydrocarbon lubricating oils. It is to be understood, however, that sodium, potassium and ammonium salts are not precluded and are effective for some purposes in the invention.

Metal phenates, which may be added to hydrocarbon oils such as mineral lubricating oils to provide one component of the new composition of matter herein claimed, comprise the alkali, alkaline earth, and other metal phenates. Examples of such metal phenates are sodium phenates, potassium phenates, beryllium phenates, calcium phenates, strontium phenates, barium phenates, magnesium phenates, zinc phenates; cadmium phenates, and aluminum phenates.

The metal phenates are preferably formed from high molecular weight phenols of the type formula:

in which u, v, w, at, and 1/ are selected from the group consisting of hydrogen, hydrocarbon, oxy, and hydroxy radicals. The phenol preferably contains at least one alkyl group having more than four carbon atoms. The term hydrocarbon radicals" used in the above connection is intended to include alkyl, aryl, alkaryl, aralkyl, and cyclic non-benzenoid groups; and the term "oxy radicals refers to a group in which the hydrogen of a hydroxy radical has been replaced by esterification, neutralization, or the like. Although phenols containing at least one alkyl substituent are preferred, the invention does not preclude compounds containing no alkyl groups and embodies the. substitution of aryl, alkaryl, aralkyl, and cyclic non-benzenoid groups as well as conjugated rings in the aromatic nucleus to which the phenolic hydroxy group is directly attached.

Examples of specific metal phenates which may be utilized comprise sodium lauryl phenate, sodium cetyl phenate, calcium lauryl phenate, calcium cetyl phenate, calcium di-(amyl) phenate,

calcium heptyl phenate, calcium p-tertiary amyl phenate, calcium monochloramyl phenate, calcium p-cyclohexanol phenate, aluminum lauryl phenate, aluminum cetyl phenate, aluminum di- (cetyl phenate), magnesium cetyl phenate, barium cetyl phenate, calcium cetyl cresylate.

The metal phenates of this invention may be prepared by any suitable method. For example, the alkyl phenols may be obtained by alkylation of the phenols with an olefin or an olefin polymer, such as di-, tri-, and tetra-butylenes or di-, tri-, and tetra-iso-butylenes, in the presence of sulfuric acid. The alkylated phenol may then be reacted with the proper metal or metal ion or the sodium salt of the alkyl phenol may be reacted with the appropriate metal ion to obtain the desired salt. The preparation of the metal phenates comprises no part of this invention and may be efiected by those skilled in the art without undue difliculties.

Salts of substituted acids of phosphorus which may be added to hydrocarbon oils such as mineral lubricating oils to provide the second component of the new composition claimed herein comprise metal salts of substituted oXy-acids of phosphorus and preferably salts of metals selected from groups II, III, IV, and VI of Mendelyeevs Periodic Table of the Elements. Specific examples of such metals are aluminum, calcium, barium, strontium, chromium, and magnesium. Salts of iron, cobalt, nickel, tin, zinc, and lead comprise additional examples of compounds falling within the broader aspects of the invention. Ammonium salts of substituted acids of phosphorus are not precluded from the broader scope of the invention and may be utilized.

The salts of the substituted acids of phosphorus involved herein are preferably formed from substituted oxy-acids of pentavalent phosphorus of the following type formulae:

where R and R may be alkyl, aryl, alkaryl, aralkyl, or cyclic non-benzenoid radicals. Substituted phosphoric acids containing at least twelve carbon atoms are preferred, but where the salts are sufdciently soluble in oil acids containing fewer carbon atoms may be utilized. Examples of preferred type acids are alkyl or alkaryl substituted phosphoric acids having at least twelve phosphonic acid R- P mono-ester of phosphonic acid OH phosphomcacld R o In all of the above formulae R and R may be alkyl, aryl, alkaryl, aralkyl, or cyclic non-benzenoid groups, which in turn may be pure hydrocarbon constituents or oxygenated hydrocarbons such as alcohols, ketones, esters, and ethers, or hydrocarbons containing substituted constituents such as halogens (chlorine, bromine, iodine), amino, or nitro-substituents. Likewise R, may be an oil-soluble heterocyclic constituent, e. g., a nitrogen ring containing radical.

In general, metal salts of substituted derivatives of oxy-acids of phosphorus such as phosphorus acid, HaPOs; hypophosphoric acid, HzPOa; orthophosphoric acid, mPOi; pyrophosphoric acid, 114F207; fall within the broadest aspects of the invention. By substituted or substituted derivatives of acids of phosphorus whenever used herein, it is intended to designate acids containing an organic group of the type previously listed, 1. e., alkyl, aryl, alkaryl, aralkyl, or cyclic non-benzenoid groups. The organic groups may be either directly attached to the phosphorus atom of the compound or attached thereto through an intervening atom such as oxygen. The term oxy-acids of phosphorus is intended to designate throughout the specification and claims acids of phosphorus in which only an oxygen atom may intervene between the hydrogen and phosphorus atoms.

The preferred acids are substituted orthophosphoric acids and the preferred salts comprise the aluminum, calcium, barium and chromium salts of these acids. Examples of such salts are aluminum lauryl phosphate, aluminum cetyl phosphate, aluminum octadecyl phosphate, aluminum spermol" phosphate, aluminum oleyl phosphate, aluminum "spermenyP phosphate, aluminum (cetyl phenyl) phosphate, aluminum di-(amylphenyl) phosphate, aluminum naphthenyl phosphate, calcium lauryl phosphate, calcium cetyl phosphate, calcium octadecyl phosphate, calcium spermol phosphate, calcium oleyl phosphate, calcium spermenyl phosphate, calcium (cetyl phenyl) phosphate, calcium di-(amylphenyl) phosphate, calcium naphthenyl phosphate, chromium lauryl phosphate, chromium cetyl phosphate, chromium octadecyl phosphate, chromium spermol phosphate, chromium oleyl phosphate, chromium spermenyl phosphate, chromium (cetyl phenyl) phosphate, chromium di-(amyl phenyl) phosphate, chromium naphthenyl phosphate, barium lauryl phosphate, barium cetyl phosphate, barium octadecyl phosphate, barium "spermoP phosphate, barium oleyl phosphate, barium spermenyl phosphate, barium (cetyl phenyl phosphate, barium di- (amyl phenyl) phosphate, and barium naphthenyl phosphate.

Additional examples of salts within the scope of the invention are: Aluminum'di-cyclohexanyl phosphate, aluminum di-stearo-glyceryl phosphate, aluminum tetra-chioro-octadecyl phosphate, aluminum di-(G-chloro, 2-phenyl phenyl) phosphate, aluminum di-(3-methyl, 4-chloro phenyl) phosphate, calcium dl-cyclohexanyl phosphate, calcium di-stearo-glyceryl Phosphate, calcium tetra-chloro-octadecyl phosphate, calcium di-(6-chloro, 2-phenyl phenyl) phosphate, calcium di-(3-methyl, 4-chloro phenyl) phosphate, chromium di-cyclohexanyl phosphate, chromium di-stearo-glyceryl phosphate, chromium tetra-chloro-octadecyl phosphate, chromium di-(G-chloro, 2-phenyl phenyl) phosphate, chromium di-(3-methyl, 4-chloro .phenyl) phosphate, magnesium di-cyclohexanyl phosphate, magnesium di-stearo-glyceryl phosphate, magnesium tetra-chloro-octadecylphosphate, magnesium di- (fi-chloro, 2-phenyl phenyl) phosphate, magnesium di-(3-methyl, 4-chloro .phenyl) phosphate, magnesium lauryl phosphate, magnesium cetyl phosphate, magnesium octadecyl phosphate, magnesium "spermol phosphate, magnesium oleyl phosphate, magnesium spermenyl. phosphate, magnesium cetyl phenyl phosphate, magnesium di-(a'mylphenyl) phosphate, magnesium naphthenyl phosphate, barium di-cyclo-hexanyl phosphate, barium di-stearo-glyceryl phosphate, barium tetra-chloro-octadecyl phosphate, barium di-(fi-chloro, 2-phenyl phenyl) phosphate, and barium di-(3-methyl, 4-chloro phenyl, phosphate.

The substituted oxy-acids of phosphorus utilized in the present invention may be prepared by methods known in the art. For example, a mixture of a higher alcohol and phosphorus pentoxide in ethyl ether may be refluxed for several hours. The reaction by which the substituted phosphoric acid is formed in this operation is believed to be represented by the following equation:

Table 1 Acid Method oi preparation Monocetylphosphoric 9.25 lb. cetyl alcohol and 5.61 lb.

P105 were refluxed with 5 gal. ethyl ether (or 24 hr. Cetylphosphoric acid solution decanted.

112 gms. solid sperm alcohols, gms. P 05 and 400 gms. ethyl ether treated as above.

Mono-spermol phosphoric-..

Mono-octadecyl-phosphorimgms. octadecanol and c. c. benzene treated with 56.8 gms. POGh. Product was hydrolyzed to give a tree acidic hydrogen.

Di-(6-chloro-2-phenyl-phenyl) 100 gms. oi the phenol and 50 gms.

phosphoric.

P 0 heated to for 18 hr.

107 gms. oleyl alcohol and 28.5 ms.

Mono-oleylphosphoric for 24 hr.

107 gms. liquid sperm alcohols and 27 gms P10. refluxed in ethyl Mono;"spermenyl" phosether for 24 hours.

phone P20; were refluxed in ethyl ether Acid Method olpreparation Dicyclohexanyl hos horic 150 cyclohexanol and 87 gms. p p Pfgz reliuxed with 150 gms. ethyl ether for 24 hrs.

688 gms. cetyl phenol and 316 gms.

(Cetyl henyl) hos horic..;...

p p p P 0 refluxed with ethyl ether tor24br.

100 gms. amyl phenol and 43 grns. P 0, heated to F. (or 15 hr.

Di-(emylphenyl) phosphoric.

Mono (tetrachloro) octa-decylphosphoric.

In preparing the metal salts herein involved, the ethyl group in the ethyl phosphoric acid above mentioned may be hydrolyzed off to form the metal salt of the mono-alkyl-ortho-phosphoric acid, i. e., the salt of RHaPO4. This type of operation is not limited to the alkyl derivatives but includes aryl-ethyl-phosphoric acid, alkarylethyl-phosphoric acid, aralkyl-ethyl-phosphoric acid and ethyl phosphoric acids containing 8. cyclic non-benzenoid group.

The metal salts oi the .various substituted oxyacids of phosphorus may be conveniently prepared by reacting the acid with sodium hydroxide or potassium hydroxide and then precipitating the desired metal salt from thesolution of the sodium or potassium salt by the addition of the appropriate metal ion. The salt may also be prepared .by the direct neutralization oi the acid as, for example, with lime where the calcium salt is to be obtained.

Basic aluminum salts prepared by the precipitation method are preferred by reason of their low corrosivity to alloy bearing metals although the so-called normal salts are not precluded. It is also preferred to maintain the amount of coprecipitated alkali metal salt in the heavy metal compounds at a minimum because the alkali metal salts decrease the stability of the oil solution in the presence of water; However, the presence and use of alkali metal salts are not precluded.

The calcium salts may also be prepared in the non-aqueous environment by the reaction 01 calcium carbide with the free substituted acids of phosphorus.

The aluminum salts may also be prepared in an environment substantially free of water by the reaction of aluminum chloride with the free substitute'd acids of phosphorus. However, such aluminum salts have properties difi'erent from the salts prepared by precipitation from aqueous solutions. The salts prepared in a non-aqueous environment are soft, low melting solids, while the corresponding salts prepared by precipitation trom aqueous solutions are hard, non-melting solids. Although the former type of salt may be utilized for imparting some desirable properties to hydrocarbon oils, it is preferred to use a salt prepared by precipitation from aqueous solutions where the ability to inhibit piston ring sticking in lubricating oils is desired.

As has been previously pointed out, the present invention embraces the discovery that hydrocarbon oils containing both a metal phenate and. a metal salt of a substituted acid of phosphorus have new and unpredictable advantages, The properties of hydrocarbon oils containing this combination of ingredients are illustrated by the following discussion and data.

A lubricating 011 containing a metal phenate and a metal salt of a substituted acid of phosphorus is more eflicient in maintaining piston cleanliness and inhibiting piston ring sticking than is an oil containing either of the components alone. For example, an acid refined western lubricating oil, S. A. E. 30 containing metal phenatespermits the formation of an orange colored gum on the lower portion of pistons of Diesel engines after short periods of operation. The same oil containing a metal salt of substituted acid of phosphorus such as an alkaline earth cetyl phosphate permits slight thermal decomposition of the lubricating oil and some deposition of carbon in the'top piston ring grooves of Diesel engines under severe conditions of operation. By using these two ingredients in combination in a lubricating 011, each of which has a disadvantage, a lubricating oil having neither of the above described objections is obtained and both formation of gum on the piston skirt and deposition of carbon in the piston ring grooves are prevented or inhibited. The general imor above.

cium cetyl phosphate forms a black deposit when contacted with metal surfaces heated at 425 F. The presence of the phenate in an 011 containing such metal phosphate salts prevents deposits up to temperatures as high as 550 F. This property of and cooperation between the two ingredients is illustrated by a test in which a heated metal surface (hot wire) is contacted with the compounded oil at 300 F. and the temperature gradually raised to 550 F., at which point it is maintained for one hour. In this test the hot wire is partially immersed and partially exposed in air and the amount of deposition at the oil surface is observed. The temperature at which initial decomposition of the oil at the surface of the wire and the weight of the deposit on this wire after the test is completed are ascertained. The following data illustrate the improvements resulting in the above described test from the combination of ingredients disclosed herein:

Table III Decomposition y Gum at all surface ggga g at Z; :1 immersed wire deposited Western oil, acid refined, S. A. E. Heavy at 400 F.. None at 550 F... .0005 Wegterntoil, acid refined, S. A. E. 30+l% calcium cctyl Trace at 550 None at 550 .0000

one o. s eiternhoitl, acid refined, S. A. E. 30+l% calcium oetyl Light at 500 F. 425 F.... .0707 p osp a c. Western oil, acid refined, S. A. E. 30+%% calcium cctyl Clean None at 550 F. .0000

phcnate+%% calcium cetyl phosphate.

Deposit heavy on immersed portion of the wire.

provement in the appearance of engine parts, the very low corrosivity of oils containing the new combination of ingredients, and inspections on the used lubricating oils after the engine test and the efiect of various properties are shown by the data in Table II.

An additional new result obtained by the combination of inhibitors utilizing this invention comprises increased stability of the oil solution of each of said components. Lubricating oils containing the metal phosphates alone may become cloudy in storage and the metal salts of Table 12' Time to Relative Relative Oil stick ring piston rings Cu Pb Cd Ag Sl t carbon cleanliness Acid refined Western oil (S. A. E. 30).. 1.0 Veryflow.-. Poor, Ditto+1% calcium cetyl phenate-.- 4. 0 Medium. Good+. lDitto-i-y z, calcium cetyl phosphate..- 5.0 Very low Good, Ditto+ calcium cetyl phenate+%% cetyl phosphate 5. 0 do Excellent, Ditto (S; A. E. 20)+%% calcium cetyl phcnate+%% calcium cetyl 5.0 do

phosp ate. Ditto (S. A. E. l0)+A% calcium cetyl phenatc+%% calcium cetyl 5.0 do Very good.

phosphate. Ditto (Sh. A. E. 30)+%% calcium cctyl phenate+%% calcium cetyl 5.0 Medium. Fair.

hos ate.

Ditto-l yfZ, calcium cetyl phenate+ calcium cetyl phosphate.-..- 5. 0 Very lowm. Fxcclleiit Ditto+%% calcium cetyl phenate+%% calc um oetyl phosphate....- 1. 5+ Medium. d air. Ditto+%% calcium cetyl phenate+%% calcium cetyl phosphate.. 5.0 Low Low.. Very good... Good. Ditto+%% calcium cetyl phenate+%% calcium cetyl phosphate. 5. 0 Excellent...- Very good. Ditto+%% calcium cctyl phenate+0.35% calcium cetyl phosphate.-. 5. 0 Medium Medium. Good. Do. Ditto+%% calcium cotyl primate-+36% calcium cetyl phosphatc.- 5. 0 ow ow Very good... Good.

Expressed as ratio of time to stick rings for compounded oil and uncompounded oil.

In the above engine tests a single-cylinder 2% inch bore and 2 /2 inch stroke Lauson gasoline engine 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 tests was continuous at 1600 R. P. M. speed with periodic shutdowns at 15-hour intervals for inspection. The jacket temperature was maintained at 375 F. and the sump oil temperature at 220 F.

It has also been observed that hydrocarbon oils containing an inhibitor comprising a metal salt of a substituted phosphorus acid such as calsubstituted acids of phosphorus tend to precipitate from the oil solution in the presence of moisture. The presence of the phosphates alone in the oil also increases susceptibility to foaming. Metal phenates are susceptible to precipitation from solution in lubricating oils or cloud formation in the presence of water. When both the phenate and phosphate are present in the lubricating oil the solution is stable in the presence of water and precipitation or cloud formation does not occur in storage. Likewise, the foaming tendency of the oil is no longer apparent. Thus, the metal phenates act as a stabilizing agent for the metal salts of the substituted acids of phosphorus and permit the preparation of more concentrated solutions of the salts than might otherwise be obtained.

An additional indication of the properties possessed by mineral lubricating oils containing the combination of ingredients herein disclosed comprises an oil wetting test in which the ability of the oil to wet and adhere to hot metal surfaces is ascertained. In this test a trough is tilted at a 1 oil in inhibiting piston ring sticking but that these salts decrease corrosion of copper-lead and cadmium-silver bearing metals by lubricating oils containing metal phenates. The phosphates also lower viscosity increase, neutralization number, and A. S. T. M. naphtha insolubles of the used oils. These improvements are illustrated by the following data:

Table IV Corrosion and oxidation Copper-lead Cadmium-silver viscosity increase Ncut. A. S. T. M.

N o. v naph. 24 48 72 24 48 72 100 210 Mineral oil. 0. 5 l. 8 4. 7 +0. 3 0 314 8. 3 l. 80 86 Mineral oil+1% calclum cetyl phenate 6.8 63. 3 125. 7 2. 2 l2. 1 l2. 1 457 11. 7 3. 08 93 Mineral oil+0.25% calcium cetyl phenate+0.75% calcium cetyl phosphate 6. 8 7. 3 8. 0 0. 2 0. 3 0. 2 246 9. 1 1. 34 35 Mineral oil+0.5% calcium eetyl phosphate .s 0- 2 0.0 0. 4 0 0 0- 1 188 a 5. 7 0. 38 .Mineral oil (S. A. E. l0)+0.5% calcium oetyl phenate+0.25%

calcium cetyl phosphate 0.6 2 9 3. 2 0.2 0.4 0.5 0 Mineral oil (S. A. E. 20)+0.6% calcium cetyl phenate+0.25%

calcium cetyl phosphate 0. 7 .0 2. 2 0.0 0.4 0. 5 85 2. 6 0,31 Mineral oil (5. A. E. 30)+0.5% calcium cetyl phenate+0.25%

calcium oetyl phosphate 1 0. 2 1. 0 1. 2 0 0. 2 0. 1 210 5. 2 1. 49 27 Mineral oil+0.5% calcium cetyl phenate+0.3% calcium cetyl phosphate I 5. l 5. 9 7. 9 0 0. 1 0. 8 207 11. 6 1. 19 54 Mineral oil+0.5% calcium cetyl phenate+0.35% calcium oetyl phosphate l. 2 1.9 1.8 0.3 0.2 0. 2 191 6.4 l. 13 15 Mineral oil+0.5% calcium cetyl phenate+0.5% calcium cetyl Mphosplh n ca] 1 l h +0 257 ca 1 t l 1.8 1.9 2.5 0.2 0.2 0.3 100 2.9 0.40 5

inera oil 0.6 e um eat one c um ce y Mphospha can wwas'y'imn H 4.8 25.0 420 0 0.0 0.4 an 7.0 2.35 22 ineral oil .67 e um ce ena e um ce y phglsglh il 7 H m+oa s;can H 0.3 3.4 5.3 +0.1 +0.1 0.1 170 4.6 0.18 2

in 0. 0 ea e um ce ena e um oe y Mphosphez +0 l i t 1 0.0 2.0 2.3 o 0.2 0.3 230 6.0 1.38 7 moral oil .75 calcium 00 one ea e um ce y MlilxllloSglhat cal t l h +0 57 w i t l 2.4 5.0 6.0 0 0 0 200 6.0 0. 53 5 er oil 0.75 cium ce ena c um ce y mi' y p 1.1 7. 0 16.6 +0.2 0 0.2 146 a o 0. a2 2 angle and heated at its lower end only so that a temperature gradient from the hotter lower end to the cooler upper end of the trough is obtained. The 1 angle at which the trough is tilted producesa force of 0.2 dyne, by reason of the action of gravity, upon oil placed in the trough. In this apparatus oil placed in the trough will flow uphill against gravity to the cooler metal surface until an equilibrium is reached between the force of gravity and the forces producing preferential wetting of the cooler metal surface. The hottest point to which the oil will flow is designated the limiting adhesive temperature and is a measure of the ability; of the oil to lubricate and spread over hot surfaces such as the upper portions of the cylinder walls of internal combustion engines. Obviously, the higher the limiting adhesive temperature, the greater the efiiciency' of the lubricant under the adverse conditions typified. The following data show the novel coordination between the ingredients of applicants composition:

It has also been observed that the presence of metal salts of substituted acids of phosphorus not only increases the efilciency of the compounded The above corrosion tests were carried out in the following manner: Glass tubes 2 inches in diameter and inches long were immersed in an oil bath, the temperature of which was automatically controlled to within plus or minus 1 F. of the test temperature which was 300 F. Approximately 300 c. c. of oil under test was placed in each tube and air was bubbled through it at the rate of 10 liters per hour. Strips of the different types of bearing metal were placed in the oils; in most cases the copper-lead mixture and cadmium-silver bearing alloys were tested simulta-- neously in the same sample of oil. The weight loss of each strip was recorded. Before weighing, each strip was washed in petroleum ether and carefully wiped with a soft cotton cloth. The duration of the test was 72 hours.

It has also been determined that the wear rate on aluminum is materially improved by the presence of metal salts of substituted acids of phosphorus in compounded lubricating oils containing metal phenates. Also the wear rate of oils containing metal salts of substituted acids of phosphorus on steel surfaces is materially improved by the presence of the phenate. Thus one addition agent gives higher wear 'on aluminum and the other higher wear on steel surfaces, whereas the combination gives low wear on both aluminum and steel surfaces.

From the above detailed descriptions it will be apparent that the combinations of ingredients herein disclosed give a new composition having new and highly useful properties. It is immaterial for the purpose of the present invention whether the components be separately new or old, since it is the discovery of the combination of ingredients and the unexpected properties obtained thereby which comprise the applicants contribution to the art.

The compounded lubricants herein disclosed may have one or more advantages, depending upon the particular compounds 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, afiected by such corrosive action. Hence, compounded oils which may not be particularly desirable for lubrication of copper-lead or cadmium-silver bearings at high temperatures where corrosion becomes a factor of importance may be highly useful and extremely advantageous in conjunction with the operation of internal combustion engines having bearings of Babbitt or other corrosive resistant bearing metals. The present invention in its broader aspects is therefore not limited to the particular combination of ingredients having all or the greatest number of advantages but embraces various of the less advantageous addition agents which will find utility in particular applications where all the possible improvements in the properties may not be required or where the standard of performance may not be so high.

A moderately acid refined Western naphthenic base lubricating oil is the preferred base oil stock for the compounded lubricants involved herein. The compounding ingredients appear to function more efficiently in such a base oil than in paraffinic oil stocks or highly refined Western oils. However, it is to be understood that the invention is not limited to any particular base stock since advantages herein disclosed may be obtained, at least to some degree, with various 011 stocks, the selection of which will be determined by conditions and service which the compounded lubricant is to encounter.

The proportion of metal salts of substituted acids of phosphorus which may be added to mineral lubricating oils according to the principles of the present invention may vary widely depending upon the uses involved and the properties desired. As little as 0.05% by weight of the metal phosphates gives measurable improvements, particularly as respects the color stability of the compounded oil. From approximately 0.25 to 2% of a metal phosphate may be added to lubricantscontaining metal phenates where stability at high temperature comprises the principal property desired. Solutions containing more than 2% of metal salts of substituted acids of phosphorus in mineral oils may be utilized for various purposes. Likewise, the proportion of metal phenates present in compounded lubricants may vary widely, depending on the uses involved and the properties desired. As little as 0.05% of the phenate gives measurable improvement, although from approximately 0.10% to 2% of the phenate is preferred where the compounded oil is to be used as a crankcase lubricant for internal combustion engines. As much as 50% or more by weight of the various phenates may be dissolved in mineral oil for the purpose of preparing a concentrate capable of dilution with lubricating oils and the like. Concentrates containing high percentages of the phenate and the metal salts of substituted acids of phosphorus comprise a convenient method of handling these ingredients and may be used as addition agents for lubricants in,generai as well as for other purposes.

There is also a preferred range of ratios between the amount of metal salts of substituted acids of phosphorus and the amount of metal phenates in the compounded oil where stability at high temperatures and ability to improve operation of internal combustion engines are the properties to be obtained. This range of ratios may vary from approximately two parts of the metal phenate to one part of the metal salts of substituted acids of phosphorus on the one hand to approximately five parts of the metal phenate and four parts of the metal salts of substituted acids of phosphorus on the other hand. This preferred ratio of the compounding ingredients is based on the relative amounts of the two ingredients, irrespective of the total amount which may be in the oil or of other addition agents which may be present.

The combination of ingredients of this invention may be present in hydrocarbon oils containing other compounding agents such as pour point depressants, oiliness agents, extreme pressure addition agents, blooming agents, and com. pounds for enhancing the viscosity index of the hydrocarbon oil. The invention in its broader aspects embraces mineral hydrocarbon oils containing, in addition to the metal phenate and the salts of substituted acids of phosphorus, thickening agents and/or metal soaps in grease forming proportions or in amounts insufficient to form grease, as in the case of mineral castor machine oils or other compounded liquid lubricants. I

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 thereby. It will be apparent to those skilled in the art that numerous modifications and variations of the illustrative examples may be eifected in the practice of the invention which is of the scope of the claims appended hereto.

We claim:

1. A lubricating composition comprising a hydrocarbon oil subject to deterioration and the formation of adhesive deposits at elevated temperature, a metal phenate in an amount sufiicient substantially to inhibit said deterioration, and from approximately 0.05 to approximately 2.0% by weight based on said hydrocarbon oil of a salt of a substituted acid of phosphorus containing an organic substituent, said salt being capable of enhancing the inhibiting action of said metal phenate.

2. A composition of matter comprising a hydrocarbon lubricating oil subject to deterioration and the formation of adhesive deposits at elevated temperature, a polyvalent metal phenate in an amount suificient substantially to inhibit said deterioration, and a metal salt of a substituted acid of phosphorus containing an organic substituent, said salt being present in an amount sufilcient to augment the action of said metal phenate.

3. A composition of matter comprising a hydrocarbon oil containing a metal salt of a phenol having at least one alkyl group of more than four carbon atoms, and from approximately 0.05 to approximately 2.0% by weight based on said hydrocarbon oil of a metal salt of a substituted acid of phosphorus containing an organic substituent. said compounds cooperating to impart to said hydrocarbon oil enhanced stability against deterioration at elevated temperatures. 7

4. A composition of matter comprising a hydrocarbon oil, from approximately 0.05 to approximately 2.0% by weight based on said oil of a metal phenate, and from approximately 0.05 to; approximately 2.0% by weight based on said oil of a salt of a substitutedacid of phosphorus containing an organic substituent.

5. A composition of matter comprising a hydrocarbon oil, a metal phenate and a salt 01a substituted acid of phosphorus containing an organic substituent, the ratio of said phenate to said salt 7 being from approximately two parts of the metal phenate to one part of the metal salt on the one hand to approximately five parts or the metal phenate to four parts of the metal salt on the other hand.

6. A lubricating composition comprising a hydrocarbon lubricating oil subject to deterioration and the formation of adhesive deposits at elevated temperature, a small amount or a polyvalent'metal phenate capable ofdnhibiting said deterioration, and from approximately 0.05 to approximately 2.0% by weight based on said oil of a polyvalent metal salt of a substituted oxy acid'of phosphorus containing an organic substituent, said salt being present in an amount suificient to augment the action of said metal-phenate.

7. A composition of matter comprising a hydrocarbon oil. a metal phenate in an amount sufficient to inhibit deterioration of the oil, and .an

alkaline earth metal salt of a substituted acid of phosphorus containing an organic substituent, said salt being presentin an amount sumcient to augment the action of'said phenate.

8. A composition of matter comprising a hydrocarbon oil, a metal phenate in an amount sufllcient to inhibit deterioration of the oil, and a calcium salt of a substituted acid of phosphorus containing an organic substituent, said salt being present in an amount sufficient to augment the action of said phenate.

9. A composition of matter comprising a hydrocarbon oil, a metal phenate in an amount suflicient to inhibit deterioration oi the oil, and a chromium salt of a substituted acid of phosphorus containing-an organic substituent, said salt being present in an amount suificient to augment the action of said phenate.

10. A composition of matter comprising a hydrocarbon oil, a metal phenate in an amount sumcient to inhibit deterioration of the oil, and an aluminum salt of a substituted acid of phosphorus containing an-organic substituent, said salt being present in an amount sufiicient to augment the action of said phenate.

11. A composition of matter comprising a viscous hydrocarbon oil, a metal phenate, and from approximately 0.05 to approximately 2.0% by weight based on said oil of a salt of an acid of the type formula:

wherein R is a radical of hydrocarbon structure.

12. A composition of matter comprising a viscous hydrocarbon oil, a metal phenate, and from approximately 0.05 to approximately 2.0% by weight based on said oil of a metal salt of an acid 01. the type formula:

wherein R is a radical of hydrocarbon structure.

13. A composition of matter comprising a hydrocarbon oil, a metal phenate in an amount sufficient to inhibit deterioration of the oil, and an alkaline earth metal salt of an acid of the type formula:

wherein R is a radical of hydrocarbon structure, said salt being present in an amount sufilcient to augment the action of said phenate.

,14. A composition or matter comprising a hydrocarbon oil, a metal phenate in an amount sufficient to inhibit deterioration of the oil, and a calcium salt of an acid of the type formula:

I H wherein R is a radical of hydrocarbon structure, said salt being present in an amount sufiicient to augment the action of said phenate.

15. A composition oi' matter comprising a hydrocarbon oil, a metal phenate in an amount sufficient to inhibit deterioration of the oil, and a a chromium salt of an acid of the type formula: n

wherein R. is a radical of hydrocarbon structure, said salt being present in an amount sufflcient to augment the action of said phenate.

16. A composition of matter comprising a hydrocarbon oil, a metal phenate in an amount suificient to inhibit deterioration of the oil, and an aluminum salt of an acid 01' the type formula:

wherein R is a radical of hydrocarbon structure, said salt being present in an amount sufficient to augment the action of said phenate.

1'7. A composition of matter comprising a viscous hydrocarbon oil, an alkaline earth metal phenate in an amount suflicient to inhibit deterioration of the oil, and an alkaline earth metal salt or a substituted oxy acid of phosphorus, said salt being present in an amount sumcient to augment the action of said phenate.

18. A composition of matter as defined in claim 17, further characterized in that said salt contains an alkyl substituent and has more than twelve carbon atoms in the molecule.

. m mmmmtmmmi 19. A composition as defined in claim 17, further characterized in that said phenate contains at least one alkyl group having more than four carbon atoms.

20. A composition as defined in claim 17, further characterized in that said phenate is a calcium phenate of a phenol containing at least one alkyl group having more than four carbon atoms and said salt is a calcium salt of a substituted acid of phosphorus containing an alkyl substituent and having more than twelve carbon atoms in the molecule.

21. A composition of matter comprising a viscous hydrocarbon oil, more than 0.05% by weight based on the oil of calcium cetyl phenate and more than 0.05% by weight based on the oil of calcium cetyl phosphate.

22. A composition of matter comprising a viscous hydrocarbon 011, more than 0.05% by weight based on the oil of chromium cetyl phenate and more than 0.05% by weight based on the oil of chromium cetyl phosphate.

23. A composition of matter comprising a viscous hydrocarbon oil, more than 0.05% by weight based onthe oil '01. aluminum cetyl phenate and more than 0.05% by weight based on the oil of aluminum cetyl phosphate.

24. An addition agent. capable of inhibiting piston ring sticking, for lubricating oils, which comprises a concentrated solution in a hydrocarbon oil of a polyvalent metal phenate having an oilsolubilizing substituent in an aryl radical thereof, and a polyvalent metal salt of a substituted acid of phosphorus containing an organic substituent, said concentrated solution containing more than 2% by weight based on the oil of said metal phenate and more than 2% by weight based on the oil of said polyvalent metal salt, said solution being capable of dilution with mineral lubricating oil to form a homogeneous mixture containing from approximately 0.05% to 2% by weight of the metal phenate and from approximately 0.05% to 2% by weight of said metal salt.

GEORGE L. NEE'LY. ELMSLIE W. GARDINER.

CERTIFICATE OF CORRECT-ION.

Patent No. 2,228,671.

January lLL 1 9l l osoaes L. NEELY, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 19, for '.'phosphonic read -phosphinic-; page 5, first column, line 1, after "phenyl" first occurrence," insert a closing parenthesis mark; line 514., for "phenyl," read phenyl)--; page 6 second column, line 61 claim 2, strike out the word "polyvalent" and insert the same before "metal" in line 65, same claim; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office. I

Signed and sealed this l th day of i'iarchQA. D. 19lil;

(Seal) Henry llan Arsdale, Acting Commissioner of Patents,

CERTIFICATE or CORRECI'lON. Patent No. 2,228,671. January 11;, l91 .1.

GEORGE L-. mm, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 19, for "phosphonic read --phosphinic--; page 5,-first column, line 1, after "phenyl" first occurrence inserte closing parenthesis mark; line 5b., for "phenyl,"- read: -o-phenyl)--; page 6 second column, line 61, claim 2, strike out the word "polyvalent" and insert the same before "metal" in line 65, same claim; and that the said Letters Patent shOuld be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this hth day of March, 'A. D. 19M;

Henry Yan Arsdale, (Seal) Acting commissioner of Patents.