US2346808A - Lubricant - Google Patents

Description

Patente d Apr. 18, 1944 LUBRICANT Carl Winning, Union, and John G. McNab, Cran- Iord, N. J., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application May 7, 1940, Serial No. 333,772

1'3 Claims.

to be typified by a Diesel engine lubricating oil,

base stock containing dissolved therein 0.5% of stearyl alcohol and 1.0% of the magnesium salt oitertiary amyl phenol sulfide.

It has now been found, and is a primary obiect of the present invention, that the addition to lubricants oi higher alcohols in conjunction with small amounts of certain oil-soluble organic metal compounds results in improvements of a quite unexpected nature. For instance, the certain metal compounds of this invention have been found to have the unexpected property of appreciably reducing the pour point of a lubricating oi], containing a small amount of stearyl alcohol, in a number of cases bringing the pour point of the three-component mixture down to the pour point of the original mineral lubricating oil base stock. Another object. of the invention is to blend the several constituents mentioned into a single lubricant which will remain a homogeneous solution both during storage and during use.

A further and more valuable advantage of such mixtures accrues from the co-operation of these metal compounds with the higher alcohols to improve the engine performance of lubricating oils by maintaining the engine in a for cleaner condition during use than does a similar lubricant without these compounds. This improved engine performance is not directly interrelated with the reduction in pour point of the oil. The exact cause is not thoroughly understood though certain factors, probably involved, are discussed in later paragraphs,

As to the type of metal compounds to be used, many oil-soluble salts of sodium, potassium, magnesium, calcium, barium, aluminum, tin, zinc,

formula M-YAr (X) a where M is a metal, Y is an element in the right hand side of group 6 of the periodic table (Mendeleefi), Ar is an arctic nucleus which contains like or unlike substituents X, n in n .11 her, replacing nuclear hydrogen, n being at least one.

The substituents X may be organic, inorganic, or both. For example, they may be 1 radicals or groups containing one or more of the non-metallic elements belonging to oups V, Vi, and VII of the periodic system (Mendeleefi): nitrogen, phosphorus, oxygen, sulfur, a halogens, as in amino, nitro, phosphite, phosphate, hydroxy, aikoxy, sulfide, thioether. mercapto, chloro groups, and the like, or they may be organic radicals containing one or more of the inorganic groups.

Thus, the metal compounds to be used in this invention may be said to be etal salts oi phenols and thio-phenols and derivatives thereof.

It should be understood, 01? course, that if the metal present in the compound is a monovalent metal such as sodium or poti the me will be connected through its only 1 ge to the con-=- stituent Y, whereas if the metal is polyvalent one of the metal valent linkages is coected to the Y and the other one or more valences of the metal may be connected to similar groups such as YAr(X)n or to other organic groups or to inorganic constituents.

In order to illustrate more fully thevarious types of metal compounds which can be used. a number of different formulas are given herebelow, in which barium is used as the example of the metal, it being understood, of course,'. that other metals can be used instead ofbarium.

For convenience, non-phenolic groups a tached to the metal are indicated broadly by R in the following types of compositional formulas, which broadly represent barium derivatives of substituted phenolic compounds containing the characteristic compositional grouping described:

o-Ar(X).-.

OAr(X)- i o-Ai-(x').'

O-Ar(X)- 16 (i Where oxygen is shown in these formulas it may Corresponding barium or other metal derivatives of the following illustrative types of substituted phenolic compounds are among those that can be used, in which R represents an alkyl group, preferably having at least 4 carbon atoms:

Group A Some of these compounds when employed in high temperature lubrication service tend to corrode such sensitive engine parts as copper-lead and cadmium-silver bearings. This characteristic can usually be corrected by including, in the lubricating composition, suitable anti-oxidants or other anti-corrosion agents, e. g. benzyl paraamino phenol, alpha naphthol, tertiary amyl phenol sulfide, triphenyl phosphite, dibutyl amine, etc. It may be mentioned that metal soaps of carboxylic acids are considerably more corrosive than the phenolic salts of this invention and that their corrosiveness is less amenable to correction by the use of anti-oxidants, etc.

However, this corrosion problem can also be at least partially and in most cases completely taken care of by chemically incorporating an element of the sulfur family (i. e. S, Se, and Te), preferably sulfur, into the structure of the substituted phenolate metal salts, thus making unnecessary the addition of any separate anti-corrosion agent. li'hus the barium andother metal derivatives of the following illustrative types of substituted phenolic compounds are preferred over those listed in Group A above.

Group B These preferred phenolates may also contain sulfur in other positions or groups at the same time as in the places shown in the formulas in Group B. Furthermore, the formulas in Group A may have sulfur incorporated therein in other ways than as shown in Group B, for instance, in the hydrocarbon groups. More broadly it may be stated that inorganic substituents, particularly J negative inorganic groups containing non-metallic elements of groups V, Vii, and VII of the Mendeleeif Periodic System, beneficially influence the phenolates by increasing their potency for stabilizing the lubricating oils and by making the phenolates, in themselves, more stable, as for instance, against hydrolysis,

Especially preferred, because they are both very efllcient and also lend themselves to easy and economical manufacture, are compounds containing at least one grouping having the general formula:

where M is a polyvalent metal, Ar is an aromatic nucleus, R is an organic group, Z is a member of the sulfur family, and n is an integer of 1 to 5. Z is preferably sulfur, and n is preferably 1 or 2. R represents an organic group which may be either aryl, alkyl, alkaryl, aralkyl or cycloalkyl, and which may contain substituent groups such as halogen, particularly chlorinejnitro, nitroso, amino, hydroxy, carboxy, alkoxy, aroxy, mercapto. and the like, but" R preferably is or contains an alkyl or alkenyl group and preferably contains at least 4 carbon atoms but may contain many more, such as 8, 10, 16,18, etc.

The configurations f the compounds are not limited to certain positions for the substituent groups, for these may be in ortho, para, or meta relations to one another. Also, the substituents, x, in broader formulas discussed previously, in any aromatic nucleus may be alike or different.

The aromatic nucleus may be polycyclic as in naphthalene, phenanthrene, diphenyl, etc. Where oxygen occurs, it may be replaced by sulfur, selenium, or tellurium, as in the case of thio-phenolic compounds.

An important feature of this invention issues from the observation that metal phenolates are benefited in solubility and effectiveness as hydrocarbon lubricating oil blending agents when they contain a total of at least 8 and preferably 10 or more carbon atoms per molecule in-aiiphatic groupings when sulfur is present in the molecule, and at least 16 carbon atoms and preferably 18 or more, if no sulfur is present.

Specific examples of preferred substituted phenolates falling into the classes mentioned, having at least one alkyl radical as a substituent and, using M to represent a divalent metal, are formulated as follows:

I. Alkyl phenolates e. g. salts of diisobutyl phenol, salts of octadecyl phenol, salts of ditert. amyl phenol.

II. Alkyl chlorophenolates e. g. salts of 2-chloro-4-octadecyl phenol, salts of 2, 6-dich1oro-4-diisobutyl phenol, salts of 6- chloro-2, 4-ditert. amyl phenol.

where CrHy represents a monovalent hydrocarbon group, e. g. salts of dicyclohexyl amino methyl diisobutyl phenol.

IV. Thioethers of alkyl phenolatcs e. g. thioether of salts of diisobutyl phenol, thioether of salts of tertiary amyl cresol. V. Disulfides of alkyl phenolates e. g. disulilde of salts of tert-amyl phenol, dithioether of salts of diisobutyl phenol.

VI. Phosphorus acidesters of alkyl phenol sulildes e. g. salts of tert-amyl phenol sulfide monophosphite, salts of diisobutyl phenol disulflde monopotassium) hydroxide and converting the resulting alkali metal phenolate into the corresponding salt or the desired metal'by double decomposition with a suitable salt of that metal, e. g. the chloride, nitrate, ethylate, etc. According y. the amount of metal in the final'phenolate product will depend on proportions of reactants used? and since products having difi'erent proportions are possible, the product will usually consist of a mixture, which may be used as such or be separated into its several constituents.

As suggested above, the compounds of this invention preferably have the general empirical formula:

where M is the metal, 11. is one half the valence of the metal, a: is 1 or more, R represents one or more alkyl groups, having enough carbon atoms, preferably a total in the molecule.of at least 10, to insure solubility of the compounds in mineral oil.

For the objects stated, the metal phenolates have been preferably prepared from phenolic compounds readily obtainable by alkylation of the simple phenols and cresols or by extraction from high-boiling petroleum oils.

Suitable synthetic alkyl phenols for preparing the desired phenolate are those containin one or more substituents which provide a desired number of carbon atoms in groups having the form of straight chains, branched chains, or rings. Mono-alkyl or poly-alkyl phenols are synthesized conveniently by alkylating a phenol with branched chain olefin polymers, such as diisobutylene, triisobutylene, di-tert-amylene, or other suitable agents, such as alcohols, alkyl sulfates, alkyl phosphates, or alkyl halides, thereby forming carbon-to-carbon bonds between the aromatic nucleus and the alkyl group.

Commonly, the alkylation reaction involves a condensation of olefins with the simple phenols, the reaction being catalyzed by anhydrous metal halides, sulfuric acid, phosphoric acid, or certain activated clays. As olefinic reactants, refinery gases containing propylene, butylenes, amylenes, etc., are economicall useful, although individual olefins, e. g., isobutylene, iso-amylene, diisobutylene, triisobutylene, etc., or olefin-containing mixtures from other sources may be used. The reaction temperature is usually controlled to avoid side reactions. In employing sulfuric acid, a liquid phase reaction at relatively low temperature is preferred; with phosphoric acid the reaction may be carried out in the vapor phase.

Petroleum phenols are considered to contain polymethylene or cycloalkyl substituents, as evidenced by their hydrogen and carbon analysis. The petroleum phenols are obtained by extraction of various stocks, chiefly cracking process heating oil stocks, with caustic soda, and acidification of the alkaline extract with a weak mineral acid followed by a non-destructive distillation if desired.

By using the described methods or any other well-known method for obtaining alkyl phenols, the following alkylated phenols may be procured for preparing the phenolates: tort-amyl phenol,

iso-hexyl phenol, diisobutyl phenol, di-tert-butyl phenol, di-(dl-isobutyl) phenol, etc. By diisobutyl phenol" is meant phenol having a branched octyl group, which may be obtained by reacting phenol with diisobutylene; this product might also be called tetramethylbutyl phenol.

Inorganic substituents are introduced into alkyl phenols by well-known methods; For example, an alkyl phenol, e. g. tert-amyl phenol, is reacted with sulfur monochloride, sack, in about a 2:1 mole ratio and preferably in a solvent such as dichlorethane, to produce the alkyl phenol disulfide. Using substantially the same procedure but substituting sulfur dichloride, SClz, for the monochloride, the alkyl phenols are given a thioether linkage; about 0.5-2 moles, preferably 1.25 to 1.5 moles of SClz are used per two moles of alkyl phenol. The reaction with the, sulfur chlorides is usually attended by the introduction of some chlorine to the molecule so that in a mixture of reaction products a varying proportion of the molecules contain chlorine as well as sulfur. Because the chlorine may be present in very minor proportions, the reaction products are referred to in this invention as phenol sulfides, for convenience, but it is to be understood that they may contain chlorine as well.

Alkyl chlorphenols are also obtained by chlorination, preferably controlled to replace nuclear hydrogen by a chloro group. This may be accomplished by chlorinating the phenol before alkylation. In such a manner, for example, 2-chloro-4-tert amyl phenol can be produced. Nitro substituents are introduced readily into the aromatic nucleus by direct nitration, and nitro substituents can be reduced to amino groups. It is to be understood, however, that the preparation of substituted phenolic compounds which have been described does not form part of this invention and that any of the well-known methods-for their production may be used.

A variety of metal salts of alkyl phenol sulfides may also be prepared by substituting polysulfldes or polymers such as the dimers, trimers, and tetramers, of the alkyl phenol thioethers, disulfides, and the like, in place of the alkyl phenol thioethers mentioned above. Also, the metal salts of alkyl phenol selenides and tellurides may be prepared, although the sulfur compounds are generally preferred.

The various products obtained may be purified, if desired, by fractional crystallization, extrac-. tion, selective precipitation, etc. Also, impurities may be removed by treatment with suitable adsorptive agents such as clay.

If desired, one can use compounds having mixed radicals such as, for instance, those of octadecyl alcohol and amyl phenol sulfide, presumably having the formula: v

or mixed metals as, for instance, a mixed sodium and cobalt salt of the formula:

Na(OCsHaCsHn)S(C5H11CaHsO)Co(OCisI-Is1) Generally, the amount of metal compound to be used should be between the approximate limits of 0.02 to 2.0%, and preferably from 0.1 to 1.0%, the exact amount to be used depending to a certain extent upon the particular compound, the amount of higher alcohol used. the character of the mineral oil base and the operating conditions of the engine in which the lubricant is to be used.

The lubricating oil base stock for this invention in its broadest aspect may oil distillate or blend and may contain a residual oil, or it may be a fraction resulting from various physical and chemical refinery treatments such as solvent extraction, precipitation, etc. For best results, however, the base stock chosen should usually be that oil which, without the additives present, gives the optimum performance in the service contemplated. Since the advantage of the additives is that their use also make feasible the employment of less satisfactory mineral oils, no strict rule can be laid-down for the choice of the base stock. Certain essentials must, of course, be observed. The oil must-possess the viscosity and volatility characteristics known to be required for the service contemplated. The 011 must also be a satisfactory solvent for the additives. For lubrication of medium and high speed Diesel engine: it is general practice to use a lubricating 011 base stock, prepared from naphthenic or aromatic crudes to have-a Baybolt viscosity at 210' I". of 45 to seconds and a viscosity index of 0-50. However, preference is often expressed for oils of higher viscosity index and such products, particularly as prepared by extraction. may also be used. Where the additives are to be employed in gasoline engine (spark ignition) service, they will probably find most widespread application to motor oils of '75 viscosity index and over.

The higher alcohols to be used in conjunction with the metal compounds are preferably those having 8 carbon atoms or more, though in general alcohols falling in the Cu to C20 range are preferred. The alcohols may be saturated straight and branched chain aliphatic alcohols such as octyl alcohol, CsHnOH, lauryl alcohol. CisHrsOH, cetyl alcohol, CisHnOH, stearyl alcohol, sometimes referred to as octadecyl alcohol. CISHMOH, and the like; the corresponding olefinic alcohols such as oleyl alcohol; cyclic alcohols, such as naphthenic alcohols; and aryl substituted alkyl alcohols, for instance, phenyl octyl alcohol, or octadecyl benzyl alcohol or mixtures of these various alcohols, which may be pure or substantially pure syntheticalcohols. One may also use mixed naturally occurring alcohols such as those found in wool fat (which is known to contain a substantial percentage of alcohols having about 16 to 18 carbon atoms) and in sperm oil (which contains a high percentage of cetyl alcohol) and although it is preferable to isolate the alcohols from those materials, for some purposes, the wool fat, sperm oil or other natural products rich in alcohols may be used per se. Products prepared synthetically by chemical processes may also .be used such as alcohols prepared by the oxidation of petroleum hydrocarbons, e. g. paraffin wax; petrolatum, etc.

The amount of the higher alcohols to be used may vary between the approximate limits of 0.01 and 5.0%, though generally from 0.1 to 1.0% and frequently from 0.1 to 0.5%, the exact amount to be used depending upon the severity of the oper-- ating conditions and upon the type of lubricating oil base stock used.

ing the effect of the metal compounds in reducing the pour point and cloud point of a be any mineral lubricating oil blend containing a small amount or higher alcohol:

TABLE 1 Metal compound I Test Cloud Pour No. Per Alcohol point point out Metal added present 0. 5 Ba--. 0. 5 ML 1. Mg..- 1. 0 00-..-

0.5 0. 3a.-.- 0. 5 L 0 00.-.- 0. 5 0. 5 Mg--- 0. 5 l. 0 Mg- 0. 5 1.0 Ba 0. 5 0. 5 1. 0 Mg- 0. 5 1. 0 Mg- 0. 4 l. 0 Mg--- 0. 25 1. 0 Mg--. 0. 6 l. 0 Mg. 0; 25

0. 25 cet +22 25 1.8 lfig.-- gb gl auryl x -2 -20 1. gaury 0. 25 stearyL. +2) 20 1 N aphthenic base oil, vis. 55 sec. Saybolt/2l0" F.

tsglt oi tertiary amyl phenol sulfide in all cases except where Barium diisobutyl phenolate.

This table shows (in tests 1-5) that the barium, magnesium and cobalt salts of tertiary amyl phenol sulfide did not affect the --10 F. pour point of the naphthenic base oil by more than :5 F. which is almost within experimental error, but (in tests 6-10) these same metal compounds, when added to a +45 F. pour point blend of 0.5% of stearyl alcohol in the same base oil, reduces the pour point at least to F. and in some cases to -15 F., thus efiecting a pour point reduction of to 60 degrees. This is an unexpected and obviously valuable phenomenon.

Table 1 also shows that a barium diisobutyl phenolate. (test 11) had an effect substantially similar to that of the metal alkyl phenol sulfide in reducing the pour point of a mineral oil blend containing some stearyl alcohol.

Tests 12 to 19 in Table 1 show that cetyl alcohol (test 16) and lauryl alcohol (test 18) or mixtures thereof (such as in test 17) are even better than plain stearyl alcohol in the blend containing 1% of magnesium tertiary amyl phenol sulfide, in regard to the feature of having a low cloud point and pour point.

To show the efiectiveness of t e lubricants ofthis invention in commercial use, the following tests are described in which various internal combustion engines were operated under a variety or conditions using a lubricating oil alone and the same lubricating oil containing a small amount of a meta1 phenolate and, in some cases, a higher alcohol.

Although the lubricants of this invention show definite and unexpected improvement in the operation of ordinary automobile engines( i. e. the spark ignition type) and in the standard C. F. R. (Cooperative Fuel Research) engine, they are particularly superior to prior art lubricants in auto-ignition engines, especially high speed Diesel engines. However, owing to their particularly efiicient cleansing action in internal combustion engines discussed hereinabove, as well as more particularly to the sludge-dispersing action which will be described more in detail under Examples 9 and 10, the compositions of this invention can also be used for a number of other purposes, for example as flushing compositions for cleaning a crankcase of an internal combustion engine (for which purpose an oil base stock should be used which has a lower viscosity than that of the lubricating oils discussed hereinabove. e. 8. gas oil, mineral seal oil or even kerosene).

, EXAMPLE 2 A naphthenic base stock having the following viscosity characteristics: 55.? seconds (Saybolt) at 210 F., 514.0 seconds at F., viscosity index 39, S. A. E. grade 30, was tested for a total period of 539 hours in a Caterpillar Diesel engine. At intervals during the test the engine was dismantled and the engine parts rated by a numerical system on the basis of the amount of deposits occurring on them. The demerit ratings are recorded 'in Table II.

It will be appreciated that the lower the demerit ratings the better is the condition of the engine parts. In a second test the naphthenic base oil was compounded with 0.5% of the cobalt derivative of tertiary amyl phenol sulfide. This blend was then tested for 515 hours in a Caterpillar Diesel engine. From the demerit ratings assigned to engine parts (see Table 11) at intervals during this test the marked superiority of the compounded oil is readily apparent. In a further experiment, the naphthenic base oil was compounded with 0.5% of the cobalt derivative of tertiary amyl phenol sulfide and 0.5% of stearyl alcohol. This blend was tested in 9. Caterpillar Diesel engine for a total period of 546 hours. The superiority of this compounded oil over the base oil is again apparent from the demerit-ratings. It will be observed further that the condition of the oil filter in particular was markedly improved by the addition of the stearyl alcohol to the cobalt tertiary amyl phenol sulfide blend, the condition of the filter after 546 hours of operation on the cobalt tertiary amyl phenol sulfide+stearyl alcohol blend being superior to that obtained after only 113 hours of operation with the straight cobalt tertiary amyl phenol sulfide blend.

The inspection record of these three samples is EXAMPLE 3 blended with 1.0% magnesium tertiary amyl phen01 sulfide and a second blend 0! the same comfi fiflgi fffif fg gfi flm 25 53: pound with 0.5% stearyl alcohol were tested for 60 and a second blend of the same compound to hours. Both compounded oils proved outstanding which 0.5% oi a stem] al hol wa added were in maintaining engine parts in a clean condition tested for 60 hours in a Caterpillar Diesel engine. under the Severe Operation- Aanin the pro- The marked improvement efl'ected by the ad nounced eflect of the added stearyl alcohol in stearyl alcohol is readily observed from thedeimproving the perform n q li e of th m merit ratings of engine parts at the conclusion of nesium tertiary amyl phenol sulfide blend is the tests on the above blends. (See Table III.)

Teen III Caterpillar Diesel engine tests Individual demerits Ring grooves Overall Oil Hours and sides Heat Skirt on groove varnish filter I1 and M and I2 #5 Na htbenie base oil 1. barium tertiary u ly! phenol lulfldi- 60 1. 03 7. 5 ll. 60 28. 1.25 2.00 Ditto+0. 5% stearyl alcohol 0. 96 4. 0 7. 60 9. 00 0. 12 0. 76

mm 4 readily apparent from the engine test data A naphthenic oil blended with 1 .0% of the recordedinTable V.

Tenn: V

Caterpillar Diesel engine tests under high temperature conditions Individual demerits Ring grooves Overall Oil Hours and aid merit Heat Skirth on groove vsrpis to #1 end #4 and r Na hthenic base oil 1.0 m esium tert ry amyl phenol s i ilfl ufi i 60 l. 00 5. 0 8. 00 5. 0.00 1 00 Ditto-[05% stearyleloohol 00 0.77 5.0 6.60 3.70 0.12 1 00 magnesium derivative of tertiary amyl phenol EXAMPLE 6 sulfide and a second blend of the same compound The outstanding performance qualities of a to which 0.5% stearyl alcohol was added were naphthemc base on blended with tested. for hours in a Caterpillar Diesel ennesium phenol sulfide and sine- Aga n the supe i it of the compounded stearyl alcohol are shown by the data of Table oil to which the stearyl alcohol w added is VI, in which demerit ratings from a 539-hour apparent from the demerit ratings recorded in base oil and from a 995-hour Caterpillar test Table IV. on the compounded naphthenic oil are recorded.

TABLE IV Caterpillar Diesel engine tests Individual demerits Ring grooves Overall Hours and sides on Beat em on groove varnish filter #1 and i4 and :2 #5

Na hthenic base oil 1.07 m esium ter tiar amyl phenol inning? 60 1.14 5 :s 8.00 9.50 0.38 1.50 Ditto+0.5% stearyl alcohol 60 0.87 4.5 9.00 4.75 0.06 0.75

EXAMPLE 5 It will be seen from these data that the engine Caterpillar engine test on the straight naphthenic In a further series of tests a Caterpillar engine parts after 995 hours of operation on t magwas operated under very severe conditions nesium tertiary amyl phenol sulnde+stearyl al- F. atmospheric temperature). A naphthenic oil 76 cohol blend were in as good an overall condition 2,040,000 '7 as that observed after only 110 hours of operation tormance as was obtained with the stearyl aicoon the straight naphthenlc base 011.. hol blend.

Tsau: VI

Caterpillar Diesel engine tests Individual demerits Bing grooves Overall Oil Hours and rides Heat Skirt 011 groove varnish iilter I1 and I4 and n 110 1.40 4.0 0.00 10. 00 1. 00 2.0 Nephthenie on 242 1.00 0.0 12.20 10.00 2.00 4.0 000 2.40 1.0 1000 1000 0.00 7.0 N 11011 1 11+107 1 tertiary 222 3'7 1103 1'03 11% 3'12 8 en 0 0 ru es 11m 1 1 11111 0 phenol 111111e+o$faa1y1 alcohol. 010 1.00 4.0 0.00 1. 00 0.00 1.20 700 1. 21 4.0 10.00 10.00 0.12 2.00 000 1.47 00 12.00 0.00 0.00 2.00

EXAMPLE 7 EXAMPLE 0 Another series of caterpillar Diesel engine 25 Some tests were made on a Hercules DRXB tests was made to compare the eilect on the engine performance of the use of blends of barium gisz ig g fi g 1:35: 528 3;: diisobutyl phenol sulfide alone as well as with e a small amount of a higher alcohol. The results results of 84-hour tests with a reference oil and of these tests are shown in Table m. a blend of said reference oil with a small amount Teens VII 60 hour Caterpillar engine tests Individual demerits Hours Overall Ring grooves E11 0 Test Oil gin demerit Heat and sides skin on groove varnish filter #1 and and 1 Highly extracted base oil+1% barium salt 1 60 0. 72 4. 0 6. 00 a. 0. 00 0 20 v 2 Dltto+0.25 o stear l 31001101 0 0- 63 3. 0 5. 50 1. 50 0.00 0 12 3 Naphthen 0 base o +1% arium salt +0.5% stearyl alcohol" 60 0. B7 4. 5 6. 50 4. 75 0. 00 o 75 4 Naphthenlc base o1l+17 barium salt +0.5 oleyl alcohoL-.. 60 0.88 5. 5 6. 50 5. 25 0. l2- 0 75 5 Naphthenc base oil+l a barium salt +0.15 0 lauryl alcohol... m 0, 91 4. 5 6. 0o 5, 75 0. 06 1 25 l Salt of diisobutyl phenol sulfide. 1a

A comparison of the results of tests 1 and 2, of one of the addition agents or this invention which were both run on engine #1, indicates that were as follows: TABLE the blend containing 0.25% of stearyl alcohol Um in addition to the 1% of the barium salt eilect- Hercules DRXB engine tests ed a substantial improvement in the 'englnepers4 norms or CONTINUOUS OPERATION .1'1; 1000 n. P. M. formame. as indicated b the lower. demem on. ranramronnneoor 210 r.

ratings- I 1 1 11101111011111 demerits, In tests 3, 4 and 5, which were run in engine #2, which, was at this particular time affecting Test 18mm, mug g H has lubricating oils very. severely, and which are, sludseYFiltq f therefore, not. comparable to the tests run. inr 1 engine #1, 3blends containing 1% of the barium 3 g .3-03 .01 9.03 1100 10 salt of diisobutyl ph'enol sulfideare compared. Ba m In tests 4 and 5, blends containing a small gfiW Us L92 2m 6 amount of oleyl and lauryl alcohols, respectively, I

are compared with a blend containing stearyl 7 g fi gggg f gufi g gfggf base Stock having a c i y o alcohol (test 3). The results show that the use 11111111111 salt of dilsobutyl phenol sulfide.

"of the blends of oleyl alcohol and lauryl alcohol The results of these comparative tests Show the in a Diesel lubricating oil containing a small unquestionable and the remarkable superiority amount of the barium salt of diisobutyl phenol of the blend made according to the present insulflde results in as satisfactory an engine pervention, since the overall demerit rating with this blend was only 1.43 as compared to 3.03 for the plain reference oil (indicating that the condition of the engine was substantially twice as bad with the reference oil as with the blend of this invention).

EXAMPLE 9 An important property possessed by certain compounded lubricating oils is their ability to hold in suspension or disperse carbonaceous or sludge-like deposits formed in the oil during the operation of an internal combustion engine. By preventing the coagulation and deposition of such materials on the surfaces of the engine parts these eflicient compounded oils maintain the engine in a clean condition, free from deposits and stuck rings. In order to evaluate this sludge-dispersing quality of lubricating oils the following laboratory test has been employed: A 450 gram sample of the oil to be tested is heated to 225 F. and agitated in a mixer. 30 grams of carbon black are added gradually to the oil during agitation and the mixture agitated thoroughly for an additional half-hour period. The suspension is then transferred to a graduated 500 cc. cylinder, and allowed to stand for 22 hours in a constant temperature bath at 200 F., and for an additional two-hour period at room temperature. In the absence of certain compounds which.may be referred to as dispersing agents, the carbon black settles from the oil leaving a clear supernatant layer, the volume of which is measured in cubic centimeters. In the presence of an efiective additive, however, the carbon black remains suspended throughout the entire volume of oil in the cylinder.

The effectiveness of a sludge dispersing agent is evaluated by determining the concentration oi carbon black remaining in suspension in a given volume of oil near the top of the cylinder. For this purpose a 10 cc. sample of the suspension is pipetted from a point 25 cc. below the surface of the liquid in the cylinder; diluted to an appropriate volume (usually 250 cc.) with naphtha; and the concentration of carbon black is determined as milligrams per cubic centimeter by colorimetric comparison with a standard suspension. The data recorded below illustrate the influence of stearyl alcohol in improving the sludge dispersing properties of metal containing addition agents in lubricating oils:

Tent: IX Dispersion tests with various metal compounds flCon(cent7a-') on mg.cc. of carbon on m black in on upper layer of suspension Naphthenic base oil 8. A. E. mun"--- 0 Napthenic base oil+0.6% nickel tertiary amyl phenol sulfide 0 9 N aphthenic base oil-+0.15% nickel tertiary amyl phenol sulfide+0.5% stearyl nflrli'iiii base 111w a c o magn um diisobu l phenol sulfide 0 Trace Naphth 0 base oil+1% mamesium diisobugl. phenol su1fide+0.5% stearyl cohol 0 32 Naphthenic base oil+1% barium tertiary amyl phenol sulfide 0 112 Naphthem'c base oil+l% barium tertiary amyl phenol suJfide-l-O.5% stearyl alcohol 0 Naphthenic base oil+1% magnesium tertiary amyl phenol sulfide 65 0 Nzgrlithenic bafepgil-i-llfl', maignisbiur; ary amy eno splfi e .5 o stearyl alcohol 0 EXAMPLElO Another series of sludge dispersion tests (using the same procedure explained in Example 9) was made in order to compare the effect of a number or difierent higher alcohols on the carbon black dispersing properties of a naphthenic base oil' containing 1% of magnesium salt of tertiary amyl phenol sulfide. The results of these tests" are tabulated in Table 2;

Team: X

Dispersion test data with various alcohols eminent/tr) on on. on of ca r on natant bu In clear oil up of map-lien Base oil A 190 0 Base oil A+1% magnesium salt I 0 12 Base oil A+l% magnesium salt +0.5% 0 42 cetyl alcohol Base oil A+l% magnesium salt -I-0.5%

leuryl alcohol 0 115 Base oil A+1% magnesium salt +0.5%

0 alcohols I o 117 Base oil A+1% magnmium salt +0.6%

stearyl alcohol Base oil A+l% magnesium salt +0.15%

oleyl alcohol 152 Base oil A+1% magnesium salt +0.25%

cetyl alcohol 1 Salt of tertiary amyl phenol sulfide. 'Commercially available mixture of primary, secondary and tertiary aliphatic alcohols having 17 carbon atoms.

These results indicate that cetyl, lauryl, stearyl, and oleyl alcohols, as well as the mixture of Cu alcohol when used in small amounts, have a substantial improving effect on the carbon black dispersion properties of the naphthenic lubricating oil base stock containing 1% of magnesium tertiary amyl phenol sulfide. These results are especially significant in view of'the lack of value of the alcohols alone in this dispersion test.

It is not intended that this invention be limited to any particular examples, which have been given for the sake of illustration only, nor to any theories advanced as to the mechanism of the operation of the present invention, but only by the appended claims in which it is intended to claim all novelty inherent in the invention as broadly as the prior art permits.

We claim:

1. A lubricant comprising a major proportion of mineral oil base stock, 0.01% to 5% of an aliphatic alcohol having at least 8 carbon atoms, and 0.02% to 2% of an oil-soluble metal salt of an alkylated phenol.

2. A lubricant comprising a major proportion of mineral oil base stock, about 0.01 to 5.0% of an alcohol having at least 8 carbon atoms, and a small amount of an oil-soluble metal salt of an alkylated phenol sulfide.

3. A lubricant comprising a major proportion of mineral oil base stock, about 0.01% to 5% 0! an alcohol having at least eight carbon atoms and between 0.02% to 2% of an oil soluble metal salt of an alkylated phenol sulfide which has easentially the general formula:

where M is a metal, R represents at least 1 alkylgrcup attached to Ar, Ar is an aromatic nucleus, 1: is 1-2, and n is one half the valence of the metal.

4. Lubricant according to claim 3, in which there are a total of at least 10 carbon atoms in the alkyl portion of the metal compound.

. 2,846,808 5. Lubricant according to claim 3, in which M" is a metal selected from the group consisting of an alkali metal, alkaline earth metal, aluminum, zinc, tin, cadmium, cobalt and nickel.

6. Lubricant according to claim' 3, in which the metal compound used is a divalent metal salt of a phenol sulfide having essentially the general formula:

HO-Ars:

where Ar is a benzene nucleus, R is an alkyl group having at least 5 carbon atoms, and z is 1-2.

I. Lubricant according to claim 3, in which the metal compound used is barium di-isobutyl phenolate sulfide.

8. A lubricant comprising a major proportion of a mineral oil base stock. 0.01% to 5% of an alcohol having at least 8 carbon atoms, and 0.02% to 2% of an alkaline earth metal alkyl phenol sulfide.

9. Lubricant according to claim 8, in which the metal compound is magnesium tertiary amyl phenol sulfide.

l0. Lubricant according to claim 8, in which the metal compound is barium di-isobutyl phenol sulfide.

.11. A lubricant comprising a major proportlon or a mineral oil base stock, 0.01% to 5% of an aliphatic alcohol having 72 to 20 carbon atoms, and 0.02% to 2% of a divalent metal salt of a phenol sulfide having the general formula:

where Ar is a benzene nucleus, R is an alkyl group having at least 5 carbon atoms, and :c

12. A lubricant comprising a major proportion of mineral 011 base stock, 0.01% to "5% of higher alcohol, and 0.02% to 2% of an oil-soluble metal .salt or a reaction product of a sulfur halide with oil-soluble metal salts of alkylated phenols and oil-soluble metal salts of alkylated phenol sulfides.

CARL WINNING. JOHN G. McNAB.