US2197832A - Mineral oil composition - Google Patents

Description

"r OFFlC RQL OIL COMPOSITION No Drawing. Application May 7, 1938,

- Serial No. 206,682

31 Claims.

This invention has to do in a general way with mineral oil compositions and is more particularly related to compositions comprised of mineral oil and a minor proportion of an added ingredient 5 which will improve the oil in one or more important respects.

It is well known to those familiar with the art that mineral oil fractions refined for their various uses are in and of themselves usually de- 10 ficient in one or more respects, so that their practical utility is limited even in the particular field for which they have been refined. For example, mineral oil fractions refined for use as lubricants have a tendency to om'dize un'der con- 15 dltions of use with the formation of sludge or acidic oxidation products; also the lighter fractions such as gasoline and kerosene tend to oxidize with the formation of color bodies, gum, etc. In order to prevent the formation of these. prod- 2o ucts and thereby extend the useful life of the oil fraction, it is common practice to blend with such oil fractions an additive ingredient which will have the efiect of inhibiting oxidation, such ingredients being generally known to the trade- 25 as oxidation inhibitors or sludge inhibitors, gum

inhibitors, etc.

It is also the practice to add other ingredients to mineral oil fractions for the purpose of improving oiliness characteristics and the 30 wear-reducing action of such mineral oils when they are used as lubricants, particularly when the oils are used for the purpose of lubricating metal surfaces which are engaged under extremely high pressures and at high rubbing 35 speeds.

Other ingredients have been developed for the purpose of I depressing the pour point of mineral oil fractions which have been refined for use as lubricants, such refinement leaving a certain -l amount of wax, in the oil, which, without the added ingredient, would tend to crystallize at temperatures which would render the oil impracticable for use under low temperature conditions. Additive agents have also been de- 45 veloped for improving the viscosity index of lubricating oil fractions; In the case of internal com bustion engines, particularly those operating with high cylinder pressures, there is a decided tendency for the ordinary lubricating oil frac- 50 tions to form, under such conditions of use, carbonaceous deposits which cause the piston rings to become stuck in their slots and which fill the slots in the oil ring or rings, thus materially reducing theemciency of the engine. Ingredients have therefore been developed which, when added 5 to the oil, will reduce the natural tendency of the oil to form deposits which interfere with the function of the piston rlngs.

Aside from the corrosive action which attends the formation of acidic products of oxidation in mineral oil fractions of the lubricant range, it has been discovered that certain types of recently developed hard metal alloy bearing metals, such as cadmium-silveralloy bearings, are attacked by ingredients in certain types of oils, particularly oils of high viscosity index obtained by various methods of solvent refining. This corrosive action on alloys of the above type has led to the development of corrosion inhibitors which may be used in solvent-refined oils to protect such bearing metals against this corrosive action.

In the lighter mineral oil fractions, such as those used for fuel purposes, particularly in internal combustion engines, it has been found that the combustion characteristics of the fuel may be controlled and. improved by adding minor proportions of various improving agents thereto.

The various ingredients which have been developed for use in mineral oil fractions to improve such fractions inthe various respects enumerated above are largely specific to their particular applications, and it has therefore been the'pr'actice to add a separate ingredient for each of the improvements which is to be effected.

It is a primary object of the present inventionto provide a mineral oil composition which has been improved in one or more of the various properties enumerated above by the incorporation therein 01' a small quantity of a multifunctional compound selected from that group or class of metalorganic compounds which is herein' referred to as the oil-soluble or oil-miscible metal salts of alkyl-substituted hydroxyaromatic carboxylic acids. I have discovered that metal salts of the general class above referred to may be added in small quantities to mineral oil fractions to form mineral oil compositions or blends superior to the unblended fractions in one or 0 more important respects, and the present invention, therefore, is broadly directed to a mineral oil composition containing a compound falling into the general class referred to.

The oil-improving agents contemplated by this invention are all characterized by the presence of an aromatic nucleus in which at least one nuclear hydrogen is substituted with an hydroxyl group and another nuclear hydrogen is substituted with a carboxyl group in which the carboxyl hydrogen has been replaced with its equivalent weight of metal. This characterizing group may be represented by the formula: T(OH)COOM in which T represents an aromatic nucleus; (OH) represents at least one hydroxyl group; and COOM represents at least one carboxyl group in which the hydrogen is replaced with its equivalent weight of a metal, M, both the (OH) group and the (COOM) group being attached to the nucleus T.

The metal salts of hydroxyaromatic carboxylic acids corresponding to the group represented by the above formula which are otherwise unsubstituted *are not miscible with mineral oil, and it is therefore important that the improving agents containing the above characterizing group have additional nuclear hydrogen replaced with substituents of a solubilizing nature. In other words, it is important that the aryl nucleus carry a substituent or substituents which will render the composition as a whole miscible withmineral oil fractions. By the terms oil-miscible" or oilsoluble" as they are used herein I have reference to that property of remaining uniformly dispersed in the mineral oil fraction either as a true solution or as a colloidal suspension during normal conditions of handling and use.

The improving agents contemplated by this invention are characterized by the presence of alkyl substituents in the aryl nucleus, and -the improving agents preferred for use in viscous mineral oils are further characterized by the presence of alkyl or aliphatic substituents in the aryl nucleus which will give other properties to the composition as a whole in addition to oilmiscibility. I have found, for example, that where the aryl nucleus is substituted with one or more aliphatic groups corresponding to certain aliphatic hydrocarbon compounds of relatively high molecular weight (herein referred to asheavy alkyl groups), a compound or composition can be obtained which will effect marked improvement in the viscosity index and the pour point as well as other important properties of viscous mineral oils.

As a general proposition, therefore, it may be said that the improving agents contemplated by this invention are metal salts of hydroxyaromatic carboxylic acid having the characterizing group T(OH)COOM described above, in which additional nuclear hydrogen is replaced with an oilsolubilizing substituent such as a predominantly aliphatic material, such substituent comprising a sufficient proportion of the composition as a whole to render the same miscible with mineral oil fractions under normal conditions of handling and use. As a further generalization it may be said that at least one point on the aromatic nucleus T, and preferably two or more points on such nucleus, aresubstituted with aliphatic hydrocarbon radicals or groups, such aliphatic radicals or groups preferably being high molecular weight derivatives or heavy alkyl groups. a

The simplest type of compound satisfying the above requisites may be represented by the formula: I. R(T(OH) (COOM)) in which R represents at least one aliphatic II. R(T (OH) (COOM) Y) in which R, T, (H), and (COOM) have the same significance indicated above and in which Y represents residual hydrogen which may be replaced by a radical from the group consisting of chlorine, alkoxy, aroxy, aralkyl, alkaryl, aryl, nitro and amino radicals or groups. Compounds of the above general formula-type having'mono, di, and tri cyclic nuclei are illustrated by the following specific formulae:

R OH R OH R on R COOM n' COOM R COOM R R 'R' R R, B

in which at least one R represents an aliphatic radical or group, preferably a heavy alkyl group,

and in which the remaining Rs represent resid- Y ual hydrogen which may be replaced with hydroxy, chlorine, 'alkoxy, aroxy, aralkyl, alkaryl, aryl nitro and amino radicals or groups.

In the foregoing examples it will be observed that the aliphatic or alkyl substituent is a monovalent aliphatic hydrocarbon group, but, as will appear from the hereinafter described synthesis of our oil-improving agent, part or all of the aliphatic hydrocarbon material may be comprised of polyvalent aliphatic hydrocarbon radicals or groups in which the several valences are attached to separate aromatic nuclear groups. Compounds of this type are included under the following general formula representation:

III. R (T(OH) (COOM) Yb) n in which T, (OH), and (COOM) have the same significance indicated above; R represents at least one aliphatic or alkyl radical or group, such alkyl group or groups being attached by one valence only to at least one aromatic nucleus T, 1; representing the valence of the aliphatic radical R", which may be one to four; Yb represents a monovalent element or group selected from the class identified above in connection with Y; b represents the number of Y's and is equal to zero or a whole number corresponding to the valences on the nucleus T not satisfied with R", (OH), or (COOM); and n represents a whole number from one to four and indicates the total number of groups (T(OH) (COOM)Y1 present in the molecule represented by the formula which are attached to the aliphatic group or groups represented by B through the valences 17.

In the foregoing general formula representation III it will be seen that the compounds represented thereby include those materials in which all of the aliphatic substituent is monovalent (11:1 and n=1) or in which all of the aliphatic substituent is polvvalent (v and n being equal to two, three, or four); or since It" is defined as being at least one aliphatic radical or group and may therefore include several such groups, it will be seen that this general Formula III is inclusive of compounds having aliphatic groups or radicals of different valences (from one to four) in the same molecule. Also it will be observed that since it may be any whole number from one to four, the number of aromatic nuclei T in the molecule may likewise vary from one to four; It will be seen therefore, that the relationship between n and v in Formula III, in its broadest aspect, is such that when n is equal to one, 17 is equal to one; and when n is greater than one, the valence v of at least one of the R's is equal-to n (in order to tie the several nuclei or T's together, the valence of any remaining R"s being any whole number equal to or less than n.

As stated above and as will appear more fully later from the description of their. synthesis, these materials represented by general Formula 111 may contain both monovalent and polyvalent aliphatic substituents. Both the polyvalent aliphatic substituent and the monovalent substituent, if both are present, may be introduced in the nucleus as part of an alkylation reaction, or allor part of the monovalent aliphatic substituent/may be present in the nucleus of a hydroxyaromatic starting material as low molecular weight aliphatic groups, such as methyl, ethyl,

propyl groups, etc.

, the monovalent and the polyvalent aliphatic substituents, are included; under the subgeneric formula representation:

IV. R"'(T(OH) (COOM) Yb'Rc) n' in which T, (OH), and (COOM) have the same significance as indicated above; R represents at least one polyvalent aliphatic radical or group having a valence v of two, three, or four; Yb

indicates the same group of sustituents as described above for Y; Rc represents monovalent aliphatic radicals or groups; 17' represents the number of Ybs and is equal to zero or a whole number corresponding to the valences on the nucleus T not satisfied with R (OH), (COOM) and Re; c indicates the number of Rc's and is equal to zero or a whole number corresponding to the valences on the nucleus T not satisfied with R (OH), (COOM), and Yb; and n represents a whole number from two to four and indicates the total number of the groups (T(0H) (Co0M)Yb'Rc) present in the molecule represented by the formula which are attached} to the aliphatic group or groups represented by R through the valences o.

In the above general Formulae HI and IV it will be understood that since R and R are aliphatic hydrocarbon radicals of the chain type and are each attached by one valence only to each corresponding aromatic nucleus, the valence v or v of such radical or radicals is of necessity never greater than the number n, which indicates the number of aromatic nuclei in the molecule and in Formula III is always equal to one when n equals one. Otherwise an R or and R having a valence greater than the number (n or n) of aromatic nuclei would either have some of its valences unsatisfied or else would form a condensed ring or rings by attachment at,

two or more points to one and the same aro-' matic nucleus. Such latter compounds, as already indicated from the definition of R' or R are not considered as characterizing the product of the present invention although probably formed in some instances in minor amounts as unobjectionable by-products by certain of the methods of preparation herein disclosed.

A simple type of compound coming under general Formula III in which 0 and n is each equal to one and in which there is only one oil-solubilizing aliphatic group l=t may be illustrated by the following formula showing T for purposes of illustration as a monocyclic nucleus:

A. 0K 00 0M H H J C -CH In theabove formula the chain represents the oil-solubilizing alkyl substituent (R and Yb, (OH), and (COOM) have the same significance as has been heretofore given to these groups.

Since group R has been defined as "at least one, it will be apparent that there may be more than one heavy alkyl substituent attached to the nucleus T. Such a compound, where v and n are each one and in which there are two such monovalent 11. groups, may be represented by the following formula:

B. 0H 000M H H H H no ------c |C-------CH H H v H H in which the chains and the substituent'characters have the same significance defined above.

Compounds of the type satisfying the general Formula III and the subgeneric Formula IV in which R. (or R') is polyvalent and v (or v) and n (or n) are more than one and in which there is only one such polyvalent R group may be illustrated by the following formula, in which the aryl nucleus T is again indicated for illu'stration asbeing monocyclic:

O, OH COOM OH COOM OH COOM Yi$ R Yt-QR, Ya R, H v B B0 c ----c on H H H H H In the above Formula C, Rx: is a monovalent alkyl group as defined above under Formula IV and is the same as monovalent R in Formula III.

Under this same type of compound indicated by Formula C there may also be more than one polyvalent R group (represented by the chain), such a compound in which there are, for example, two polyvalent R groups being illustrated by the following formula; in which the characterizing groups have the same significance described above under Formula C.

The possible molecular structure of compounds in which the aryl nucleus T is polycyclic will be obvious from the foregoing exemplary'Formulae Ato D inclusive, and the possible molecular structure of compounds in which '0 and n are equal to two and four will be readily understood from the exemplary Formulae C and D.

Another possible molecular structure of compounds coming under general Formula III is a compound having more than one polyvalent R', at least .two of which have different valences. Such a compound may be typified by the followin formula in which the symbols have the same significance as in Formula C:

H H H 11% c I o OH 0001 OH 000M OH b R: Yb---R= H He J H H as the nucleus is mono or poly cyclic and also as the nucleus is otherwise substituted. It will also be apparent that available valences on the nuclei may all be attached to polyvalent aliphatic substituents.

It will be understood that the oil-improving agents contemplated by this invention may be pure compounds satisfying the general Formula III described above with any one of the various mono and poly cyclic aromatic nuclei as T and the various substituents R" (or R and Y) described, the only requisites being that at least one nuclear hydrogen be substituted with a hydroxyl group, at least one nuclear hydrogen be substituted with a (COOM) group, and at least one nuclear hydrogen be substituted with an oilsolubilizing aliphatic radical or group. However, in manufacturing the preferred oil-improving product of the present invention by the preferred method of procedure, as will appear more fully.

later on, the final oil-improving product obtained is normally or usually a mixture of different compounds corresponding to difierent values of n and v and to diiferent numbers of aliphatic groups R'.

In compounds of the type represented by the subgeneric Formula IV it will be seen that since R is polyvalent, each of the aromatic nuclei attached to one or more such polyvalent aliphatic groups carries a carboxyl group in which the carboxyl hydrogen is substituted with its equivalent weight or metal. My present invention also contemplates as modifications of the improving agents represented by Formula IV compounds in 'which some of the carboxyl hydrogen is not so substituted. Compounds of this general character may be termed broadly acid metal salts of aliphatic-substituted hydroxyaromatic carboxylic mono cyclic nucleus (11) may be represented by the formula:

V. OH

' COOM OOOH sented by general Formulae III and IV have nuclear hydrogen in the aromatic'nucleus T substituted with predominantly aliphatic 'material which comprises a suflicient proportion of the composition as a whole to render the same miscible with the mineral oil fraction in which the improving agent is used under normal conditions of handling and use. It appears from the results of my research that there is a critical range in the degree of alkylation of these improving agents below which the product oragent will not satisfy the requirements for oil-miscibility. Expressing this in another way, it appears that the hydroxyarornatic constituent should not exceed a certain percentage of the alkylated composition as a whole. This critical range of alkylation may be roughly expressed as the ratio by weight of (T(OH) )n to R"(T(OH) )n.

The degree of alkylation and the critical range within which operative compounds can be obtained may also be expressed as the number oi: carbon atoms contained in the aliphatic substituents for each aryl nucleus in a given molecule or molecular structure.

The critical range in the degree of alkylation of the aryl nucleus in the improving agents contemplated herein may vary with: (a) the mineral oil fraction in which the improving agent is to be used; (b) the aryl nucleus T (mono or poly cyclic); (c) the hydroxyl content of the aryl nucleus (mono or poly hydric) (d) the character of aliphatic material comprising the substituent (straight or branched chain); (e) mono or poly substitution of the aryl nucleus; and (f) other substituents on the nucleus T, which may be of positive or negative or of neutral solubilizing activity.

In general it may be said that a polycyclic nucleus appears ,to require a higher degree of alkylation than a monocyclic nucleus; that a polyhydric'nucleus requires a higher degree of alkylation than a monohydric nucleus; and that branched chain aliphatic substituents have a somewhat greater solubilizing action than straight chain solubilizing substituents.

In view of the foregoing variables it would be impracticable and probably misleading to attempt to give an expression and figure which would indicate accurately the proper ratio ofhydroxyaromatic constituent to the alkylated hydroxyaromatic constituent which would express a degree of aliphatic substitution that would satisfy all cases taking these variables into account. As a guide for preparing these improving agents, however, my research indicates that for I a product having pour depressing and V. 1. im-

proving properties in addition to other valuable properties the ratio, expressed as:

should not be greater than .20 when the weight VII.

amaesa of the hydroxyarcmatic nucleus or component (T(OH))1, is expressed in terms of its chemically equivalent weight of phenol (CsHsOH). However, for mere oil-solubility with inhibition of oxidation I have found that this ratio may be raised as high as .60 by substituting the nucleus with branched chain aliphatic groups. In general it may be said that in the preferred improving agents contemplated herein the ratio by-weight of the hydroxyaromatic component in the product to the corresponding alkylated hydroxyaromatic' nucleus or component therein should not be greater than about twenty parts by weight of the former to about 100 parts by weight of the letter, or about twenty per cent, when the weight of the hydroxyaromatic nucleus or component is expressed in terms of its chemically equivalent weight of phenol. It will be observed that the ratio as represented by the Formula VII above does not take into account any other substituent in the nucleus than the aliphatic substituents ferred multifunctional materials.

As stated above, the degree of alkylation may also be expressed by the number of carbon atoms contained in the aliphatic substituent for a given hydroxyaromatic nucleus T. As a general guide here it may be said that the aliphatic substituents represented by It' in the above general Formula III should, for the preferred materials contemplated herein, contain at least twenty-five carbon atoms for each aromatic nucleus T.

The ratio of twenty per cent, which I may term the phenolic ratio, represents what I consider a maximum figure for the preferred products contemplated herein, and in general it will be found that this figure will be lower, the actual ratio, of course, being dependent upon the variable factors enumerated above. For example, as

. will later appear, an improving agent of the preferred type in which the'aliphatic substituent is derived from petroleum wax (a predominantly straight chain aliphatic hydrocarbon of at least twenty carbon atoms) and in which the aromatic nucleus was derived from phenol otherwise unsubstituted should have aphenolic ratio, as expressed above, not substantially greater than about sixteen per cent.

A further general guide for the synthesis of improving agents for viscous oils is to alhlate the aromatic nucleus so that it is polysubstltuted with aliphatic hydrocarbon radicals or groups preferably of relatively high molecular weight.

As has been previously indicated, it is one of the primary objects of the invention toprovide an oil-improving agent which will have multifunctional improving activity in a mineral oil. My research indicates that compounds satisfying the requisites of general Formula 1H above may be blended in minor proportions with mineral oil fractions, particularly of the viscousor lubricating oil type, to efiectmarked improvement in several important properties. The improvement efiected may be varied somewhat with the allphatic substituent, petroleum wax and aliphatic hydrocarbons of similar characteristics such as ester wax, for example, giving products which effect a marked improvement in Viscosity Index and pour point in addition to other properties to be hereinafter pointed out. The effectiveness specific examplw, have shown an allwlated may also be varied with other substituents in the aryl nucleus-for example, alkoxy groups may contribute to 'solubilityand the properties of the agents may also be varied with the character of the metal substituent in the carboxyl group. In general it appears that the, salt of any metal satisfying the requisites of Formula III above will act to inhibit oxidation in mineral oils and reduce the formation of harmful oxidation products. Certain of the metals, such, for example, as lead and zinc, may serve to increase the loadcarrying capacity of lubricating oils.

The procedure whereby the oil-improving agents contemplated herein can be prepared may be broadly described as involving the steps of first substituting the hydroxyl hydrogen in an alkylateslhydroxyaromatic compound with an alkali or alkaline earth metal to form an alkylated or aliphatic substituted aryl metal oxide of-the corresponding alkali or alkaline earth metal. Such alkali or alkaline earth metal oxide is then carboxylated to form the alkali or alkaline earth metal salt of the aliphatic-substituted-hydroxyaromatic carbomlic acid, such reactions being indicated by thefollowing general equation:

R'(T(OH)(COOM)YL)! in which M? indicates an alkali or alkaline earth metal, and the remaining characters have the same significance described above in connection with general Formula III.

These alkali and alkaline earth metal salts constitute part of the oil-improving agents contemplated herein and they may also be used as an intermediate product for forming the salts of the other metals by a process of double decomposi-- tion, such reaction being indicated by the fol lowing general equation:

of the metal may replace a nuclear hydrogen in the aromatic ring; but if such compounds form, they are in the minority and, in any event, are not considered harmful to the product.

The metal substituents in the carboxyl group of the improving agents described herein may be broadly classified as the metals belonging to the silver, copper, tin, aluminum, iron, alkali and alkaline earth analytical groups, which include: silver, mercury, lead, and thallium; bismuth, copper, and cadmium; arsenic, antimony, and tin; iron, cobalt, nickel and manganese; barium, calcium, strontium, and magnesium; and sodium potassium, and lithium, respectively. other desirable metals include: titanium, cerium, thorium, vanadium, molybdenum, tungsten, uranium, and platinum.

The acid-salt type of product typified by Formula V- can be formed by partial neutralization 1 acted with an alcohol-soluble inorganic or fatty acidsalt of the desired metal to form the acid salt by double decomposition. r V i The reactions described and illustrated above, the details of which will be further in or an pound as the starting material.

aliphatic-substituted hydroxy-aromatic com- Compounds of this nature, which satisfy the requirements of high alkylation for the preferred improving agents discussed above, or mixtures of such compounds can be readily prepared by alkylating a a er-(on) Yb) 1:,

in which Yb, if present, is residual hydrogen, may

be a mono or poly cyclic hydroxyaromatic compound otherwise unsubstituted; or such com pounds containing alkyl substituents; or in certain special cases (to be hereinafter described) the starting material may be an alkyl-aryl ether or an aralkyl-aryl ether. For obtaining an alkylated hydroxyaromatic product containing a Y" substituent, in addition to or in place of residual hydrogen, the starting material for the hydroxyaromatic constituent may be a mono or poly cyclic hydroxyaromatic compound in which part of the nuclear hydrogen is substituted with a member or members of the group consisting of chlorine, hydroxy, alkoxy. aroxy, aryl, alkaryl, and aralkyl groups.

Examples of the hydroxyaromatic compounds which may be used as starting material for the alkylation reaction are: phenol, resorcinol, hydroquinone, catechol. cresol, xylenol, hydroxydiphenyl, benzylphenol, phenyl-ethyl-phenol, phenol resins, methyl-hydroxydiphenyl, guiacol, alpha and beta naphthol, alpha and beta methyl naphthol, tolyl naphthol, xylyl naphthol, benzyl naphthol, anthronol, phenyl methyl naphthol, phenanthrol, monomethyl ether of catechol, methoxy phenol, phenoxy phenol, anisole,'beta naphthyl methyl ether, chlorphenol, and the like. Preference in general is to the mono-hydroxy phenols otherwise unsubstituted, particular preference beinggiven to phenol and alpha and beta a convenient means of controlling the degree of alkylation and obtaining the desired phenolic ratio" for use in the preferred mineral oil compositions contemplated by this invention.

In this reaction an appropriate mono or poly chlorine-substituted aliphatic compound or material is reacted with the desired hydroxyaromatic compound in the presence of a catalytic amount of aluminum chloride. Pure or substantially'pure mono or poly chlorine-substituted aliphatic compounds may be used. However, as will be readily understood by those skilled in the art, since it is usually very diflicult to prepare or obtain high molecular weight aliphatic hydrocarbons in a pure or substantially pure state andsince it is equally difilcult to prepare the chlorine (or other halogen) substitution products of such hydrocarbons in a pure or substantially pure state, I prefer to employ amixture of such hydrocarbons, such as a suitable petroleum fraction, as the starting material, converting it into a mixture of different chlorine (or other halide) substitution products by any suitable method for use in the alkylation step. In general it may be said that the high molecular weight aliphatic hydrocarbons contemplated by this invention as preferred sources for the alkyl or aliphatic substituent R. in For mula III above may be pure or mixed compounds typified by those which characterize the heavier products of petroleum, such as heavy petroleum oils of the lubricant type, petro'latum and crystalline petroleum wax or other compounds or materials which will result in relatively long aliphatic substituents. Special preference is given to petroleum wax of melting point not substantially less than about 120 F. Such specially preferred aliphatic hydrocarbon materials commonly have molecular weights of about 250 and have at least twenty carbon atoms in their molecules.

As stated above, the Friedel-Crafts synthesis ailords a convenient means of controlling the degree of alkylation" of the product. This is accomplished by controlling: (a) the chlorination of the aliphatic hydrocarbon and (b) the reacting proportions of the chlorinated aliphatic hydrocarbon and the hydroxyaromatic compound used in the Friedel-Crafts reaction. As is well known to those skilled in the art, the replacement of nuclear hydrogen in the hydroxyaromatic compound with an aliphatic group is, in the Friedel- Crafts synthesis, effected by reaction of such nuclear hydrogen with chlorine in the chlorinated aliphatic compound, the substitution being effected with evolution of HCl. It will thus be seen that the number of chlorine substituents in a chlorinated aliphatic compound corresponds to the number of valences (v in general Formula III) which will be satisfied by or attached to hydroxy aromatic nuclei in the product of the reaction. For example, in a reaction where a quantity of pure monochloraliphatic hydrocarbon containing say three atomic proportions of chlorine is reacted with one molecular proportion of hydroxyaromatic compound, the resulting alkylated product, R (T(OH)Yb)n, is one in which 12 and n are equal to one and there are three aliphatic groups R." attached to one nucleus T. On the other hand, assuming a reaction in which a quantity of pure trichlor-aliphatic hydrocarbon containing three atomic proportions of chlorine is reacted with one molecular proportion of hydroxyaromatic compound, the product would be one in which 1) and n of general Formula III are each equal. to three, and the solubilizing action of a single aliphatic group would be distributed among three nuclear hydroxyaromatic groups. It is due to this latter condition that I consider it preferable that the number of valences v (in R of Formula III, etc.) be maintained within the range of from one to four hereinabove specified. In other words, it appears that the required oilsolubilizing and oil-improving action of the aliphatic substituent R particularly where the agent is to be used for, multifunctional activity in viscous oils, is not obtained with materials predominantly comprised of a compound or compounds R"(T(OH) (COOM)Yb),. (Formula III) in which and n are greater than four. Hence, for use in the Friedel-Crafts reaction the chlorinated high molecular weight aliphatic material should be a compound, or should be predominantly com- .to the monoor poly-valent aliphatic groups, a

prised of compounds, in which the chlorine content is not greaterthan a tetrachlor compound.

As will be readily apparent to those skilled in the art, the chlorination of an aliphatic material 5 suchas a liquid petroleum fraction or a. crystall5 to the reaction of Equation 1) above will likewise be a mixture of compounds corresponding to diiferent values of n and v in the formula R (T(OH) (COOM)Yb)n (general Formula III). It will be understood, therefore, that the specific values for vand n in the above formula, as well as the formula itself, relate to the different specific compounds present in such a mixture which characterize it as a product of the present invention.

55 However, in the case of a pure compound corresponding to general Formula III or in mixtures thereof, I have, as previously stated, discovered that for a satisfactory product, the ratio by weight of hydroxyaromatic component (T(OH) to the corresponding alkylated hydroxyaromatic nucleus or component (RI (T(OH) )n) should not be greater than a certain critical maximum ratio which varies with constituents and conditions of use, as discussed in detail hereinabove.

lb The above-mentioned ratio of hydroxyaromatic component to the corresponding alkylated hydroxyaromatic component 0 in which the hydroxvaromatic component is calculated as phenol and which is therefore herein referred to as the phenol content or phenolic ratio, is usually calculated from the weight of the hydroxyaromatic compound used up in the alkyll5 ation reaction and from the total weight of alkylated compound resulting from such alkylation reaction, as will be readily understood by those skilled in the art.

For example, when the Friedel-Crafts synthesis is used for alkylation, the aliphatic hydrocarbon material is first chlorinated until the weight of chlorine absorbed indicates that the average composition of the chlorinated product corresponds roughly to say a dichlor-aliphatic hydrocarbon.

5 Such a product will, of course; contain some monoand tri-chlor compounds and probably some tetrachlor compounds. The reacting proportions (based on atomic proportions of chlorine to one mole of hydroxyaromatic compound) are then selected so that the theoretical product of the Friedel-Crafts reaction will give the approximate phenolic ratio desired. After the Friedel-Crafts reaction and purification of the product the weight of aliphatic material in the chlorinated 5 aliphatic starting material is subtracted from the weight of the alkylated or aliphatic-substituted product to obtain the weight of hydroxyaromatic material ((T(OH))n) actually combined or used up in the almlation synthesis. From this value 0 and the weight of the almlated product the phenolic ratio or phenol content can be readlly If there are other substituents 5' (Yb) on the .1 'maromatlc nucleus in addition deduction should be made for them before calculating the phenolic ratio, an operation which will be apparent to those shlled in the art.

In the foregoing description of the Friedel- Cra-fts alkylation reaction Ihave referred to a hydroxyaromatic compound as a starting material. This same reaction may be used with an alkyl-aryl ether or an aralkyl-aryl ether which undergoes a substantial rearrangement during Friedel-Crafts alkylatlon to form an alkylated hydroxyaromatic compound in which the alkyl group of the ether replaces one of the nuclear hydrogen atoms.

In the event it is desired to obtain a product R (T(OH) (COOM) Yb) 1: which contains an alkoxy group as the substituent Yb, it is preferable that the alkylation be effected with a hydroxyaromatic compound containing such alkoxy or aroxy group as a substituent and a high molecular weight unsaturated aliphatic hydrocarbon (such as polymerized isobutylene, dodecylene, tetradecdroxyaromatic ether can be alnlated without substantial rearrangement taking place. As an alternative procedure, polyhydric phenols can be alkylated by reaction with alcohols o'r unsaturates "or by Friedel-Crafts reaction followed by substitution of one hydroxy with. a low molecular weight alkyl group. In carrying out this latter procedure, the alkylated polyhydric phenol is treated with an alkali 'alcoholate to introduce alkali metal into the OH group followed by treating with the desired alkyl halide, whereby the substitution is efiected.

, When it is desired to, obtain a nitro or amino group as the substituent Yt" in general Formula III, the hydroxyaromatic, compounds are allwlated when free of nitro or amino groups, andsuch alkylation is followed by nitration of the alkylated compound to introduce the nitro substituent. The amino group can be obtained by reduction of the nitro group.

I amaware of the fact that certain polyvalent metal salts of salicylic acid monosubstituted with an alkyl group of relatively low molecular weight (such as octyl salicylic acid) have been pro for use as siccatives in paints. My present invention in its broadest aspect clearly distinguishes from such proposal in that my invention is directed to mineral oil compositions and is based upon the discovery that numerous properties of mineral oil fractions attending their normal uses as lubricants, dielectrics, etc., can be improved through the use of the mineral oil soluble metal salts of alkylated or aliphatic substituted hydroxyaromatic carboxylic acids.

PREPARATION or man SALTS or'waxsoes'rrro'rnn PHENOL capo: 0 new f 1) Arxrumon or Pnznor.

A paramn wax melting at approximately 120 F. and predominantly comprised of compounds having at least twenty carbon atoms in their molecules is melted and heated to about 206 FL, after which chlorine is bubbled therethrough until the wax has absorbed from sixteen per cent to twenty per cent of chlorine, such product hav-' ing an average composition between a monochlor wax and a dichlor wax; or corresponding roughly to a dichlor wax. Preferably the chlorination is continued until about one-filth the weight of the chlorine content of the chlor-aliphatic material.

chlorwax" formed is chlorine. A quantity of chlorwax thus obtained, containing three atomic proportions of chlorine, is heated to a temperature varying from just above its melting point to not over 150 F., and one mole oi phenol (CeHaOH) is admixed therewith. The mixture is heated to about 150 F., and a quantity of anhydrous aluminum chloride corresponding to about three per cent of the weight of chlorwax in the mixture is slowly added to the mixture with active stirring. The rate of addition of the aluminum chloride should be suiiflciently slow to avoid violent foaming, and during such addition the temperature should be held at about 150 F. After the aluminum chloride has been added, the temperature of the mixture may be increased slowly over a period of from fifteento twenty-five minutes to a temperature of about 250 F. and then should be more slowly increased to about 350 F. To control the evolution of HCl gas the temperature of the mixture is preferably raised from 250 F. to 350 F. at a rate of approximately one degree per minute, the whole heating operation occupying approximately two hours from the time of adding the aluminum chloride. I1 the emission of HCl gas has not ceased when the final temperature is reached the mixture may be held at 350 F. for a short time to allow completion of the reaction. But, to avoid possible cracking of the wax, the mixture should not be heated appreciably above 350 F., nor should it be held at that temperature for any extended length of time. 4

It is important that all unreacted or non-alkylated hydroxyaromatic material (phenol) remaining after the alkylation reaction be removed. Such removal can be efiected generally by water-washing, but it is preferable to treat the water-washed product with super-heated steam, thereby insuring complete removal of the unreacted material and accomplishing the drying of the product in the same operation.

The wax-substituted phenol thus obtained may be characterized by the general formula R"(T(OH) Yb) 1;, in which R represents at least one aliphatic group or radical characteristic of paraflin wax having a valence v of from one to four; T represents a monocyclic aromatic nucleus; Yb represents residual hydrogen, "1) being a number corresponding to the number of valences on the nucleus T not satisfied by R' and (OH); and n is a numberfrom one to four corresponding to the valences v on the aliphatic group or groups R which are satisfied by the nuclear group or groups T(OH)Yb. process, b in the above general formula should always be at least one, since residual hydrogen in the nucleus is important to the carboxylation step to be hereinafter described.

A wax-substituted phenol prepared according to the above procedure, in which a'quantity of chlorwax containing three atomic proportions of chlorine (twenty per cent chlorine in the chlorwax) is reacted with one mole of phenol, may, for brevity herein, be designated as wax-phenol (3-20). Parenthetical expressions of this type (A-B) will be used hereinafter in connection with thealkyla-ted hydroxyaromatic compounds to designate (A) the number atomic proportions of chlorine in chlor-aliphatic material reacted with one mole of hydroxyaromatic compound in the Friedel-Crafts reaction, and (B) the At this step of the.

ratio of about sixteen per cent. 'My research 1 indicates that this phenolic ratio of sixteen per cent may be considered as representing about the maximum for satisfactory miscibility in viscous oils of the metal salts of "alkylated hydroxyaromatic carboxylic acid in which the alkyl substituent is derived from wax and the hydroxyaromatic constituent is derived from phenol (CBH5OH). Effective oil-improving agents can, however, be obtained from wax-phenol (3-46) in which the phenol content or phenolic ratio is in the neighborhood of thirteen per cent.

The lower phenol content obtained from waxphenol (346) in which the chlorine content of the wax was sixteen per cent instead of twenty per cent is due to the lower proportions of poly- .chlor-substituted compounds in the chlorwax resulting in a smaller proportion of compounds R (T(oH)Yb)n in which 12 is greater than one (l t polyvalent) or a larger proportion of such compounds'in which E. is polyvalent but c is one or more. Also, as the chlorine content of the chlorwax is decreased, the Friedel-Craits reaction undoubtedly results in the formation of an increased proportion of compounds in which R is more than one monovalent wax group (12 and n=1).

(2) FORMATION or Wax-Sunsrrrnrno ALKALI 0a ALKALINE EARTH METAL Pnmu'rn As an example 01 this step in the preparation of my oil-improving agents, wax-substituted sodium phenate can 'be prepared by the reaction of wax-phenol with metallic sodium in the presence of a non-oxidizing gas. The reaction mixture is heated at 500 F. during a two-hour period with rapid stirring to produce finely divided sodium and thereby accelerate the reaction. The

proportions of reactants which were used in preparing a wax-substituted alkali metal phenate according to the above procedure. were:

500 grams wax-phenol (13.2% combined phenol content) 16 grams sodium or equivalent amount of potassium 1 Wax-substituted phenates of the alkali and alkali earth metals may also be prepared by reacting a wax-phenol with the desired alcoholate or alkyl metal oxide of an alkali or alkaline earth metal. Forthis purpose anhydrous methyl and ethyl alcohols are usually most suitable for use in preparing the alkyl metal oxides. As an example, 500 grams of wax-phenol (3-16) of 13.2 per cent combined-phenol content was reacted with sixteen grams of sodium in the form of the ethyl sodium oxide by heating the mixture to about 300 F. during a one-hour period and allowing the alcohol released in the reaction to distill oil, thereby obtaining the wax-substituted sodium phenate as the final product.

(3) Qmoxmnon '10 Form. ALKALI on ALKALINE Earn METAL SALT or WAX-PHEKOL Cxa- BOXYLIC Acm ONa By rearrangement the carboxy group is transferred to the rin giving the sodium salt of the phenol carboxylic acid:

OCOONa OH COONa Other carboxylating reactions may be used in this step of the process, such as the reaction of the alkali metal wax-phenate with carbonyl chloride or carbon tetrachloride; but since'the salt formed in the presence of C02 is obtained in high yield and in a pure state, this is the preferred carboxylation procedure.

Because of the high viscosity of the mixture it is advantageous to dilute the wax-substituted phenol initially with one or two parts of mineral oil. When a diluent has been used, carbon dioxide can be introduced at room temperature; and the temperature of the reaction in this case may be regulated ,by the amount of external heating.

The product of this step, where the starting material was wax-substituted sodium phenate, is the sodium salt of wax-substituted phenol carboxylic acid. l

(4) FORMATION on THE SALTS or OTHER Mnrsrs With an alkali or alkaline earth metal salt, such as the sodium salt of the foregoing step, as the starting material, the corresponding salts of the other metals can be prepared by double decomposition of the first-mentioned salt with an alcohol-soluble inorganic or fatty acid salt of the desired metal. The use of alcohol as a solvent for the salt is desirable to insure proper solution and reaction, the reaction being conveniently carried out by heating the mixture at 175 F. during a two-hour period. I

The reaction product-of this double decomposition can be purified by diluting the mixture with a light mineral oil and settling out the insoluble reaction salts, followed by removal of the diluent by distillation to obtain the finished product. Another procedure of purification is to water-wash the reaction mixture to remove the reaction salts, breaking any emulsion that may be formed in the water-washing operation by the use of an alcohol such as amyl alcohol.

The reaction mixture employed in this double decomposition reaction may, for example, consist of one mole of the sodium salt of wax-substituted phenol carboxylic acid and one mole equivalent of the inorganic or fatty acid salt of the desired metal in alcohol solution. One part by volume of Stoddard Solvent may be employed as a diluent for the mixture.

Theproducts obtained from both steps (2) and (3) discussed above are comprised of compounds which satisfy the special case of general Formula 111 (R"(T( OH) (COOM)Yb)1| in which R' represents an aliphatic group characteristic of pe-.

troleum wax having a valence o of one to four by which it is attached by one valence only to a nucleus T; T is a monocyclic aryl nucleus; (OH) represents one hydroxyl group attached to nucleus T; (COOM) represents one carboxyl group attached to nucleus T, the hydrogen of such carboxyl group being substituted with its equivalent weight of metal M; and Yb represents residual nuclear hydrogen. The'subscripts b and "n have the same significance hereinabove discussed under general Formula Ill.

or Wax-Sonsmumn NAPHTOL CABBOXYLIC ACID In addition to the salts just discussed above I have, by following the same procedure, prepared metal salts of wax-substituted naphtholic acid. A wax-naphthol (3-14) was obtained from the alkylation reaction. This product and the corresponding salts obtained therefrom had a combined naphthol content of sixteen per cent and METAL SALTS an equivalent phenol content or "phenolic ratioof 9.7 per cent.

METAL SALTS or Tnsnsnc Our-Palmtop GAnnoxmo Aom Metal salts of alkylated hydroxyaromatic acids in which the alkyl or aliphatic substituent is a derivative of lower molecular weight hydrocarbons have been made from phenol alkylated in the Friedel-Crafts reaction with Transil oil. This is a highly refined parafiin base white oil having a Saybolt viscosity of eighty-two seconds at 100 F. and corresponds to an aliphatic hydrocarbon compound of about sixteen carbon atoms. Such an oil was chlorinated to a chlorine content of twenty per cent. A quantity of such chlorinated Transil oil containing three atomic proportions of chlorine was reacted with one mole of phenol according to the procedure described above to give Transil oil-phenol (3-20) which had a combined phenol content of seventeen per cent. The metal salts of Transil oilphenol carboxylic acid are prepared from this product according to the same procedure described above for the wax-phenolieacid salts.

As will appear from the foregoing description, the oil-improving agents contemplated by this invention are characterized by thegeneral Formula III (R (T(OH) (CO0M)Ys)a described hereinabove, such chemical compounds or materials may also be characterized'asoil-miscible metal salts of alkylated or alkyl-substituted hydroxyaromatic carboxylic acids or "metal salts of alkylated, carboxylated hydromraromatic compounds, it being understood that the terms alkyl and alkylated are used herein in a broad sense to include polyatomic or polyvalent, as well as monovalent, aliphatic radicals or groups.

To demonstrate the eflectiveness of compounds of the type described above in the mineral oil compositions contemplated by this invention I have conducted several comparative tests with representative mineral oils alone and with the same oils blended'with various metal salts of representative alkyl-substituted hydroxyaromatic acids. These tests, which, with their results, are discussed below, show that mineral oil compositions containing these materials are improved as SLUDGE INHIBITION This series of tests was conducted with a mineral lubricating oil having a Saybolt viscosity of 244 seconds at 130 F. The test involved subjecting the oil and the various oil blends to accelerated oxidizing conditions in the presence of metal at a temperature of 350 F. over a period 7 of. seven days, the amount of sludge formed during such test being expressed as the tar number. The salts used in this test were obtained according to the foregoing exemplary procedures using petroleum wax and Transil oil as the source of the alkyl substituents.

Table I Tar number Improving agent After 7 days Start None Cnpric salt 0: wax phenol carboxylic acid- Aluninnm salt of wax phenol carboxylic 8C1 Zinc salt of wax phenol carboxylic acid. chronic salt of wax phenol carboxylic ac: Ferric salt of wax phenol carboxylic acid- Cobaltous salt of wax phenol carboxylic aci Manganous salt of wax phenol carboxylic 6 Trace am Calcjlm salt of wax phenol carboxylic aci Maggesium salt of wax phenol carboxylic a Potassium salt of wax phenol carbo lie 'iit'twax'piifii 5t3ii5id1 salt of wax beta naphtholic acid silt of transil oil-phenol carboxac:

xxifixxxxxxiixxx ccocoocooooooc The foregoing results demonstrate that the mineral oil compositions containing metal salts of alkyl (wax and Transil oil) substituted hydroxyaromaticacids have been inhibited against the formation of sludge or tar under conditions of oxidation which normally cause substantial sludge formation in the unblended oil. In addition to the foregoing blends, I have also prepared and tested a blend of the same oil with the sodium salt of a tri-alkyl-substituted phenolic acid in which the alkyl substituent was derived from Transil oil. This oil composition also failed to develop tar or sludge precipitation at the end of seven days.

POUR POINT DEPRESSION In addition to the property of inhibiting sludge formation, the metal salts of wax-substituted hydroxyaromatic acids are effective pour point depressants-as indicated by the results tabulated below. These results were obtained from blends of a. mineral lubricating oil having a. -Saybolt Universal viscosity of 244 seconds at 130 F. and

\ salts of'wax-substituted phenol carboxylic acid and wax-substituted naphtholic acids of the same oeoocomw' Table II Concentration by Improving agent weight pour point Percent Degrees F. None Oupric salt of wax phenol carboxylic 801d,

Stannous salt of wax phenol carboxylic ac Aluminum salt of wax ph nol carboxylic Zinc siii 'Jwai'piib'fiic' 'rbii li' Edd. Chromic salt of wax phenol carboxyhc acid Manganous salt of wax phenol carboxylic am Ferric salt of wax phenol carboxylic acid Cobadltous salt of wax phenol carboxylic ac! Calcium salt of wax phenol carboxylic acid. IMaggesium salt of wax phenol earbuxyhc aci s Potatsisium salt of wax phenol carboxylic aci Sodium salt of wax phenol carboxylic acid. Sodium salt of wax beta naphtholic acid- Sodium salt of wax alpha naphthollc acid,

stars 2K $12K 31?; XXX X 3-K VISCOSITY INDEX IMPROVEMENT As has been previously indicated, the

A.s.'r.M. I

droxyaromatic carboxylic acids in which the "tetra-wax-substituted phenol carboxylic acid prepared fromchlorwax of twenty per cent chlorine content (wax phenol carboxylic acid,

(4-20)); and salts of tri-wax-substituted naphtholic acid prepared from chlorwax of. eighteen per cent chlorine content (wax naphtholic acid (3-18) In conducting these. tests the viscosity index was obtained in the conventional manner from the Saybolt viscosity of the oil and the oil blends at 100 F. and 210 F. The oil used was a mineral lubricating oil having a Saybolt viscosity of 244 seconds at 130 F. In the table below giving the results of these tests the parenthetical figures used after the respective salts (2-16) etc., indicate the degree of alkyl substitution of the aryl nucleus (that is, the number of atomic proportions of chlorine in the chlorwax reacted with one mole of hydroxyaromatic material) and the chlorine content of the chlorwax used in the first step of the synthesis described above.

oneness and is recorded as being indicative of the corrosive nature of the oil.

OPERATION TEST In addition to the foregoing tests I have also made tests of an oil and oil blend containing a Table III Saybolt Oon-' vlscodty centraseconds at- We Improving agent tion cosity by index weight 100 210 4 F. F.

Per cent None 540 66.9 101.6

Sodium salt of wax phenol arboxylic acid -l 2% 603 71.7 104.2 Sodium salt ofwarp no carborvllc acid (3-20) 2% 720 81.7 111.7 Stennous salt of waxphen'ol carboxylic acid (3-20) 2% 687 78. 2 109 1 Zinc salt of war phenol carboxylic 5 acid (a2o 2% 712 73.5 106.3

Aluminum salt of wax boxylio acid (3-20) 2% 688 79 110.4 Sodium salt of wax phenol carboxyllc acid (3-18) 2% 672 75. 8 105.6 Sodium salt of wax phenol carbonvllc acid (4-20) 2% 677 76.1 105. o

to aphtholic acid (34.8) 2% 706 82. 5 114. 8

In addition to the foregoing results showin the comparative effects of various representative 25 salts from the class of oil-improving agents concating oil, I have conducted tests to demonstrate the effectiveness of my novel improving agents upon the viscosity index of different oils. The

improving agent used. in these tests, results of which are tabulated below, was the sodium salt of wax phenol carboxylic acid (3-20)- The physical characteristics of the mineral oils used (designated as oils A, B, C, D and E) are indicated by the viscoslties and viscosity indexes of these The following data demonstrate the efiectiveness of improving agents of the type contemplated by this invention as corrosion inhibitors. To obtain this data an actual motor operation test was employed, the oil used being a solvent-refined Pennsylvania motor oil having an a. P. I. gravity of 31, a flash point of 420 F. and 2. Sayoolt viscosity of 295 at 106 F. The improving agent employed in this test was a sodium salt of wax-substituted phenol carboxylic acid preparedin accordance with the procedure outlined hereinabove.

in conducting this test, a motor oil blank and 2. motor oil blend containing the improving agent ahove referred to were subjected to test in a modified Delco knock test engine equipped with bearings of cadmium-silver alloy on a steel back. @311 each test the engine was operated at a rotative speed equivalent to a road speed of fifty miles per hour. The hearings in the engine were new for each test and were carefully weighed before and after to determine loss of weight. The neutralization number of the used oil was measuredtemplated upon a representative mineral lubrilubricating oil having an A. P. I. gravity of 31.7,

a flash point of 445 F., and a viscosity of 229 seconds at 100 F. The improving agent used was a sodium salt of wax phenol carboxylic acid, the oil blend containing one per cent of the improving agent.

At the end of these tests it was found that when operated with the oil alone, eight of the piston rings were stuokand the slots in the oil control rings were 14.1 per cent filled with carbonaceous residue, whereas with the same 011 containing the improving agent only one ring was stuck and the slots in the oil-control ring were clear. 4

Further improved properties in the oil blend containing my improving agent are indicated by the table below, showing comparative viscosity and neutralization numbers (N. N.) at various stages of the test. and the crankcase condltion after 10o hours operation.

The lubricant fraction used in obtaining the data of Table VI was of the S. A. E. 20 type and was obtained from a certain crude, from which it is extremely dificult to obtain a. satisfactory motor oil of the S. A. 20 type, because of its instability in operation. As will be observed from Table VI. the oil composition containing the improving agent remained substantially stable in the indicated properties throughout the entire test.

As has been previously pointed out I can obtain oil-miscible improving agents of the type contemplated herein (metal salts of alkylated hydroxyaromatic acids) in which the alkyl substituent is a. low molecular weight aliphatic group or oups. Such a compound in which the com- .five miles per hour.

bined phenol content is as high as sixty per cent has been obtained from o-amyl phenol carboxylic acid. -This product (the cobaltous salt) was found to be soluble in gasoline and certain heavy mineral oil-fractions in the lubricating oil range. To demonstrate the efiectiveness of this type of product having a high phenolic ratio or combined phenol content a lubricant composition was prepared by blending per cent of the cobaltous salt of o-amyl phenol carboxylic acid in a lubricating oil of seconds Saybolt viscosity at 210 F. and comparative tests were made with this blend and the oil alone. These tests were carried out in a single cylinder C F R engine cooled with a diethylene glycol-water mixture held at about 390 F. The engine was operated for twenty-eight hours at about 1200 R. P. M., which is equivalent to a. road speed of about twenty- The oil temperature remained in the neighborhood of F. during the test.

At the end of the test the piston was examined for stuck rings and ring slots filled with carbonaceous deposit. The acidity or neutralization number (N. N.) of the used oil and the amount of carbonaceous deposits in the used oil were determined. The comparative results obtained with the oil alone and the oil blend (containing per cent of the cobaltous salt of o-amyl phenol carboxylic acid) are listed below in Table It will be apparent from the foregoing description that I have developed a new class of mineral oil compositions characterized by the presence in a minor proportion of a metal salt of an, alkylsubstituted hydroxyaromatic carboxylic acid as an improving agent. The improved properties obtained and the degree of improvement-effected in a particular property may be varied with the metal substituents and the hydroxyaromatic constituents in the salts; also by the degree of alklation of the aryl nucleus. As to the degree of alkylation, it is important that the aryl, nucleus be sufficiently alkylated to provide a salt which is soluble in the particular mineral oil fraction with which it is to be blended; that is, one which will remain uniformly dispersed in the oil in sufficient amount to efi'ect desired improvement. The amount of improving agent used may be varied, depending upon the mineral oil or the mineral oili'raction with which it is blended and the properties desired in the final oil composition. The salts described herein may be used in amounts ranging from 1 3' per cent to five per cent, and in general compositions of the desired improved properties may be obtained with these improving agents in amounts of from A; per cent to two percent.

with a mineral oil solubilizing substituent and in which the metal is substituted for the carboxyl hydrogen.

2. An improved mineral oil composition comprising a mineraloil having admixed therewith a minor proportion of an oil-miscible metal salt of a hydroxyaromatic acid in which the metal is substituted for the carboxyl hydrogen, and in which part of the nuclear hydrogen has been Substituted with predominantly aliphatic organic material, said last-mentioned substituent comprising a suiilcient proportion of the substituted hydroxyaromatic acid salt to render said salt miscible with said oil under normal conditions of handling and use.

3. An improved mineral oil composition comprising a mineral oil having admixed therewith.

in minor proportion: an oil-miscible Wax-substituted hydroxyaromatic compound having at least one hydrogen atom on the aryl nucleus substituted with a carboxyl group in which the carboxyl hydrogen is replaced with its equivalent weight of metal.-

4. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid in which the metal is substituted for the carboxyl hydrogen.

5. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid in which the alkyl substituent is a high molecular weight aliphatic hydrocarbon derivative.

6. An improved mineral oil composition comprising a mineral oil'having admixed therewith a minor proportion of an oil-miscible metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid in which the alkyl substituent is derived from an aliphatic hydrocarbon having at least twenty carbon atoms.

'7. An improved mineral ofl composition comprising a mineral oil having admixed therewith a minor proportion 01' an oil-miscible metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid in which the alkyl substituent is derived from petroleum wax.

8. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion oi an oil-miscible metal salt of a substituted hydroxyaromatic carboxylic acid in which the subnituent is a high molecular weight aliphatic hydrocarbon group and in which the aryl nucleus is poly-substituted with said substituent.

9. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt 01' a substituted hydroxyaromatlc carboxylic acid in which the substituent is derived from an aliphatic hydrocarbon having at least twentycarbon atoms and in which the aryl nucleus is polysubstituted with said aliphatic derivative.

10. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt or substituted hydroxyaromatic carboxylic acid in which the substituent is derived from petroleum wax and inwhich the aryl nucleus is polysubstituted with said wax derivative.

11. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion otan oil-miscible metal salt of an alkyl-substituted phenol carboxylic acid in which the metal replaces the carboxyl hydrogen.

12. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of an alkyl-substituted naphtholic acid in which the metal replaces the carboxyl hydrogen.

- 13. An improved mineral oil composition comprising a mineral oil having admixed therewith a' minor proportion of an oil-miscible metal salt of an alkyl-substituted phenol carboxylic acid in which the alkvl substituent is a high molecular weight aliphatic hydrocarbon derivative.

14. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of an alkyl-substituted naphtholic acid in which the alkyl substituent is a high molecular weight aliphatic hydrocarbon derivative.

15. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of an alkyl-substituted phenol carboxylic acid in which the alkyl substituent is a high molecular weight aliphatic hydrocarbon derivative andin which the aryl nucleus is poly-substituted with said aliphatic derivative.

1 An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of an alkyl-substituted naphtholic acid in which the alkyl substituent is a high molecular weight aliphatic hydrocarbon derivative and in which the aryl nucleus is poly-substituted with said aliphatic derivative.

17. An improvedmineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of a wax-substituted phenol carboxylic acid.

18. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of a wax-substituted naphtholic acid.

19. An improved mineral oil composition com prislng a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of an alkyl-substituted hydroxyaromatic carhoxylic acid in which the metal substituent replaces the carboxyl hydrogen, and is selected from the group consisting of copper, tin, aluminum, zinc, chromium, manganese, iron, cobalt. calcium, magnesium, potassium, and sodium.

243. An improved mineral oil composition com,- prising a mineral oil having admixed therewith a minor proportion of a metal salt of an alkyd-- ated, carboxylated phenol in which the alkyl substituent is derived from petroleum wax, the proportion by weight of phenol in the alhylated phenol constituent being in the neighborhood of from about thirteen per cent to'acout sixteen per cent.

21. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of a carboxylated, allrylated hydroxyaromatic compound, the proportion by weight of. the hydroxyaromatic constituent in said alwlatedhydrorwaromatic constituent being chemically equivalent to not more than sixty per cent phenol.

22. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of an oil-miscible metal salt of a carboxylated, almlated hydroxyaromatic compound, the proportion by weight of the hydromaromatic constitumt in said almlated= hydroxyaromatic constituent being chemically equivalent to not more than twenty per cent phenol.

23. An improved mineral oil composition comprising a mineral oil having admixed therewith a minor proportion of a product obtained by: chlorinating petroleum wax until about one-fifth the weight of the reaction product is chlorine;'

24. An improved mineral oil composition comprising a mineral oilhaving admixed therewith a. minor proportion of a product obtained by: chlorinating petroleum wax until about one-fifth the weight of the reaction product is chlorine; reacting the chlorinated wax with a hydroxyaromatic compound in the proportions of one mol of the latter to an amount of the chlorinated wax containing at least/two atomic portions of chlorine to form a wax-substituted hydroxyaromatic compound; substituting the hydroxyl hydrogen with a metal selected from the group consisting, of alkali and alkaline earth metals to form a wax-substituted aryl metal oxide of said metal; carboxylating said metaloxide to form the corresponding metal salt of wax-substituted hydroxyaromatic carboxylicacid; and then substituting the metal of said salt with another metal.

25. An improved mineral oil composition comprising a viscous mineral oil fraction having admixed therewith a minor proportion, from about one-sixteenth per cent to about five per cent of an oil-miscible metal salt of an allrylsubstituted hydroxyaromatic carboxylic acid in which the metal substituent replaces carboxyl hydrogen.

25. An improved mineral oil composition comprising a viscous mineral oil fraction having admixed therewith a minor proportion, from about one-sixteenth per cent to about five per cent of an oil-miscible metal salt of an alkylsubstituted hydroxyaromatic carboxylic acid in which the alkyl substituent is derived from an aliphatic hydrocarbon having at least twenty carbon atoms.

27. An improved mineral oil composition comprising a viscous mineral oil iraction having admixed therewith a minor proportion, from about one-sixteenth per cent to about five per cent of anoil-miscible metal salt of an alkylin which: T represents an aromatic nucleus; (OH) represents at least one hydroxyl group attached to the nucleus T; (000M) is attached to the nucleus T and repres ts at east one carboxyl group the hydrogen or which is replaced by its equivalent weight of a metal M; R represents at least one aliphatic group having a valence v, of onevto four, and attached by one valence only to at least one nucleus T; Y represents a monovalent radical selected from the group consisting of residual hydrogen, and chlorine, alkoxy, aroxy aralkyl, alkaryl, aryl, nitro, and amino radicals; b represents the number of Ys and is equal to zero or a whole number corresponding to the'valences on the nucleus T not satisfied by R', (OH) or (COOM); and n is a whole number from one to four; the substituent R comprising a sufilcient proportion of the metalorganic compound to render same miscible with said oil under normal conditions of handling and use.

29. A composition of matter comprising a mineral oil fraction and in admixture therewith a minor proportion of an oil-miscible metalorganic compound having the general formula R. (T(OH) (COOM) Yb) in which: T represents an aromatic nucleus;

carboxyl group the hydrogen of which is replaced by its equivalent weight 01' a metal M; R represents at least one aliphatic group having a valence v, of one to four, and attached by one valence only to at least one nucleus T; Y represents a monovalent radical selected from the group consisting of residual hydrogen, and chlorine, alkoxy, aroxy aralkyl, alkaryl, aryl, nitro, and amino radicals; 12 represents the number of Y's and is equal to zero or a whole number corresponding to the valences on the nucleus T not satisfied by R", (OH) or (COOM); and n is a whole number from one to four; the total number of carbon atoms in all of the aliphatic groups taken together in said metalorganic compound being not less than about twenty-five for each nucleus T. 30. A composition of matter comprising a mineral oil fraction and in admixture therewith a minor proportion of an oil-miscible metalorganic,

- compound having the general formula 'R' (T(OH) (COOM) Yb) a R represents at least one aliphatic group having a valence v, of one to four, and attached by one valence only to at least one nucleus T; Y represents a monovalent radical selected from the group consisting of residual hydrogen, and chlorine, alkoxy, aroxy aralkyl, alkaryl, aryl, nitro, and amino radicals; b represents the number of Y's and is equal to zero or a whole number corresponding to the valences on the nucleus T not satisfied by R", (OH) or (COOM); and n is a whole number from one to four; the ratio of T(OH) to R'(T(0H) n in said metalorganic compound being not greater than the chemica equivalent of twenty per cent phenol.

31. A composition of matter comprising a min eral oil fraction and in admixture therewith a minor proportion of an oil-miscible metalorganic compound having the general formula R"(T(OH) (COOM) Yb'Re) n in which: T represents an aromatic nucleus; (H) represents at least one hydroxyl group attached to the nucleus T; (COOM) is attached to the nucleus T and represents at least one carboxyl group the hydrogen of which is replaced by its equivalent weight or metal M; R represents at least one polyvalent aliphatic hydrocarbon group of at least twenty carbon atoms having a valence v of from two to four; Yb represents a monovalent radical selected from the group consisting of residual hydrogen, -chlorine, alkoxy, aroxy,;alkaryl, aralkyl, aryl,

nitro, and amino radicals; b represents the number of Yb s and is equal to zero or a whole number corresponding to the valences on the nucleus T not satisfied by R", (OH), (COOM) and Re; Re represents monovalent aliphatic radicals; c represents the number of Rc'S and is equal to zero or a whole number corresponding to the valences on the .nucleus T not satisfied by R (OH), (COOM) and Yb; and n is a whole numher from two to tour.

ORLAND M. REIF'F.

CERTIFICATE OF CORREC TI ON April. 25, 19b0, V

' ORLAND n. REIFF.

It is hereby certified that error appears in the -printed specification of the above numbered patent requiring correction as follows: Page 5', first column, linel9, for "RI )8" read -Rsline 14.9, for ."Y ,s" read Y s--;

' and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the ease in the Patent 01- fi'ce.. i

Signed and sealed this 5th day of November, A. p. 1910.

(Seal) Henry van Arsdale, Acting Commissioner of Patents.

I -CERTIFICA'1E 0F CORRECTION. Patent No. 2 197352. April 25, 191w.

' ORLANDM. REIEF.

It is hereby certified that error 'appears in the -.printed specification of the above numbered patent requiring correction as follows: Page 5', first column, line 19, for "RI :5" read --Rs-- 3 line 149, for FY ,s" read "Y a--;

' and that the said Letters Patent' should be read with this correction therein that the same may oonform to the record of the ease in the Patent 01- fl'ce. Y Sigzed and sealed this 5th day of November, A. n. 1). .O.

Henry van Arsdale (Sean Acting Commissioner of Patents.