FIELD OF THE INVENTION This invention relates to compositions useful as additives for lubricants and functional fluids, and to additive concentrates, lubricants and functional fluids containing said additives. More particularly, this invention relates to compositions comprising a major amount of an oil of lubricating viscosity, (A) a metal salt selected from the group consisting of sulfonates, phenates, carboxylates and mixtures thereof, (B) an aliphatic carboxylic acid or anhydride, or carboxylic acid containing derivative thereof, wherein the aliphatic group contains at least about 20 carbon atoms and optionally (C) a metal salt of (C) (I) at least one organic phosphorus acid or a mixture of (C) (I) at least one organic phosphorus acid and (C) (II) at least one carboxylic acid. Also disclosed are lubricants and functional fluids containing these additives and methods for improving the wet filterability of lubricants and functional fluids. This invention also relates to the retention of zinc when compositions containing zinc-containing additives are exposed to water.

BACKGROUND OF THE INVENTION Depending upon their intended use, lubricants are required to meet a variety of performance requirements. It is known in the art to add various chemical additives

to a lubricating oil basestock in order to provide or reinforce needed properties.

For very mild applications, the lubricant may contain nothing more than the lubricating base stock, although even in this case, additives such as oxidation and corrosion inhibitors and antifoam agents are often included.

More often, especially when lubricating machinery such as engines, gears, transmissions, hydraulic systems and the like, it is necessary that the lubricant provides some degree of antiwear and extreme pressure performance. Chemical additives to provide extreme pressure and antiwear performance are known. These include, but are not limited to, phosphorus-containing additives, sulfur-containing additives and others. Phosphorus additives include metal-free and metal-containing derivatives of phosphorus acids.

Adams et al, U.S. 4,938,884, describes phosphorus-containing coupled amides as lubricating oil additives.

Hoke (U. S. Patents 4,032,461; 4,208,357; and 4,282,171, refers to various phosphorus and sulfur-containing amides and thioamides.

Metal salts of phosphorodithioic acids are known lubricant additives. See, for example, Le Suer et al, U.S. 3,390,082 and Chamberlin, U.S. 4,326,974.

Metals salts of mixtures of carboxylic and phosphorus acids are also known, as are post-treated metal salts of phosphorus acids. See, for example, Clason et al, U.S. 4,308,154, Schroeck, U.S. 4,289,635, Schroeck, U.S. 4,507,215 and Schroeck, U.S. 4,263,150.

Metals salts of organic acids, and particularly overbased metal salts of organic acids are also well-known lubricating oil additives.

Grover, in U.S. 4,466,894, describes lubricants having, inter alia, improved hydrolytic stability.

For many applications, lubricating oils described in the aforementioned patents provide exemplary performance. However, in several applications, it has been found to be desirable, and sometimes necessary, that the lubricant possess even further enhanced performance characteristics.

Many lubricating oil compositions such as functional fluids, and especially hydraulic fluids, are used in equipment designed to very close tolerances. For example, a hydraulic fluid which is employed as the lubricant and power transmitting fluid in hydraulic pumps must provide extreme pressure, antiwear and oxidation performance. Because of the close operating tolerances, it is usually necessary that hydraulic fluids be kept meticulously clean. To accomplish this end, very fine filters are employed to remove solid contaminants from the circulating hydraulic fluid. The filter must remove abrasive contaminants, but still must allow free fluid flow through the system. ,

It has been recently observed that lubricating oil compositions, including hydraulic fluids, containing metal salts of organic acids, and particularly those containing overbased metal salts, when exposed to mois¬ ture, may clog filters. Such moisture may arise from, for example, environmental contamination or condensation of atmospheric moisture. When the filters become clogged, fluid flow is reduced, or in extreme cases, essentially stops. Filterability of moisture (water) containing lubricating compositions is referred to herein as wet filterability.

The nature of the moisture-contaminated lubricating oil is not understood, that is, it is not known with certainty whether, for example, the moisture (water) is simply dispersed within the oil composition, whether a chemical reaction has taken place or if the moisture is incorporated in some other fashion. What is known is that when the oil composition is contaminated with

moisture, filterability, especially filterability through fine filters, ^" is impaired.

In general, moisture contamination contributing to filterability difficulties is present in the oil composi¬ tion in amounts ranging up to about 1% by weight of the oil composition, although more than 1% by weight of water may be present as a contaminant and may contribute to filterability di iculties.

It has also been observed with zinc-containing lubricating oil compositions that, when the oil composi¬ tion is exposed to water, loss of zinc from the lubri¬ cating oil composition may take place. In some cases as much as 50% or even more of the zinc originally present may be lost. Since zinc compounds are frequently used to provide enhanced antiwear and/or antioxidancy, loss of zinc may result in reduced performance.

Accordingly, it would be beneficial to provide a lubricant or functional fluid that does not tend to generate materials that clog filters when the fluid is exposed to moisture. Likewise, it would be beneficial if a zinc-containing lubricating oil composition resisted loss of zinc when the oil is exposed to water.

SUMMARY OF THE INVENTION

The present invention provides compositions useful as additives for lubricants and additive concentrates and lubricants containing these additives. Lubricants and functional fluids containing these additives have a reduced tendency to clog filters when the lubricants are exposed to moisture and resist depletion of zinc when exposed to water.

The present invention provides a composition com¬ prising a major amount of an oil of lubricating viscos¬ ity, and minor amounts of (A) a metal salt selected from the group consisting of sulfonates, phenates, carbox- ylates and mixtures thereof, (B) an aliphatic carboxylic acid or anhydride, or carboxylic-acid group containing

derivative thereof, wherein the aliphatic group contains at least about 20 carbon atoms and optionally (C) a metal salt of (C) (I) at least one organic phosphorus acid or mixture of (C) (I) at least one organic phosphorus acid and (C) (II) at least one carboxylic acid. Component (B) is present in an effective amount to improve wet filter- ability of the composition. In another embodiment, the composition may comprise a phosphite. These compositions are useful as lubricating compositions, and functional fluids, such as hydraulic fluids.

Further, the present invention provides a method for improving the wet filterability of lubricants and func¬ tional fluid compositions. Also provided is a method for imparting to lubricating oil compositions the ability to resist depletion of zinc when the compositions are exposed to water.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The term "hydrocarbon based group" is used throughout this specification and in the appended claims to denote a group having a carbon atom directly attached to the remainder of the molecule and having a predominantly hydrocarbon character within the context of this invention. Thus, the term "hydrocarbon based group" includes hydrocarbon, as well as substantially hydrocarbon, groups. Substantially hydrocarbon describes groups may contain non-hydrocarbon substituents, or non-carbon atoms in a ring or chain, which do not alter the predominantly hydrocarbon nature of the group.

Hydrocarbon based groups can contain up to three, preferably up to one, non-hydrocarbon substituent, or non-carbon heteroatom in a ring or chain, for every ten carbon atoms, provided this non-hydrocarbon substituent or non-carbon heteroatom does not significantly alter the predominantly hydrocarbon character of the group. Preferably, hydrocarbon-based groups are purely hydrocarbon, that is, they are substantially free of

non-hydrocarbon substituents or heteroatoms. Those skilled in the art will be aware of such heteroatoms, such as oxygen, sulfur and nitrogen, or substituents, which include, for example, hydroxyl, halo (especially chloro and fluoro) , alkoxyl, alkyl mercapto, alkyl sulfoxy, etc.

Examples of hydrocarbon based groups include, but are not necessarily limited to, the following:

(1) hydrocarbon groups, that is, aliphatic (e.g., alkyl or alkenyl) , alicyclic (e.g., cycloalkyl, cycloalkenyl) groups, aromatic-, aliphatic- and alicyclic-substituted aromatic groups and the like as well as cyclic groups wherein the ring is completed through another portion of the molecule (that is, for example, any two indicated substituents may together form an alicyclic radical) ;

(2) substituted hydrocarbon groups, that is, those groups containing non-hydrocarbon groups or atoms which, in the context of this invention, do not alter the predominantly hydrocarbon character of the group; those skilled in the art will be aware of such groups (e.g., halo (especially chloro and fluoro) , hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, sulfoxy, etc.);

(3) hetero groups, that is, groups which will, while having a predominantly hydrocarbon character within the context of this invention, contain atoms other than carbon present in a ring or chain otherwise composed of carbon atoms. Suitable heteroatoms will be apparent to those of ordinary skill in the art and include, for example, sulfur, oxygen, nitrogen and such substituents as, e.g., pyridyl, furyl, thienyl, imidazolyl, etc. In general, no more than about 2, preferably no more than one, non-hydrocarbon substituent or non-carbon atom in a ring moiety, will be present for every ten carbon atoms in the hydrocarbyl group. More preferred, however, the hydrocarbyl groups are purely hydrocarbon and contain

substantially no such non-hydrocarbon groups or substituents. fA) The Metal Sulfonate. Phenate or Carboxylate

Component (A) is a metal salt selected from the group consisting of sulfonateε, phenates or carboxylates. These salts may be normal salts or they may be overbased salts. Overbased salts are preferred.

The metals may be alkali or alkaline earth metals, copper or zinc. In a preferred embodiment the metals are alkali or alkaline earth metals, more preferably, sodium, potassium, calcium or magnesium. The Normal Metal Salt

Component (A) may be a normal metal salt, that is, a salt wherein the metal content is substantially that which is present according to the stoichiometry of the metal and the particular organic compound reacted with the metal. These salts are sometimes referred to as "neutral" salts despite the fact that, depending upon the nature of the anion and cation, the salt may ,display basic properties, i.e., may display basic character as opposed to neutral or acidic character, especially in aqueous media. For the purposes of this invention, metal salts of sulfonic acids, phenols and carboxylic acids are preferred. Preferred metals are alkali or alkaline earth metals, copper or zinc. Normal metal salts are readily prepared by the reaction of an acid with a metal compound such as a hydroxide or carbonate, double displacement reactions, such as the reaction of a sodium salt with calcium chloride, etc. The skilled worker is aware of numerous means for preparing normal metal salts, and further elaboration here is unnecessary. The Overbased Metal Salt

The terms "overbased," "superbased," and "hyperbased," are terms of art which are generic to well-known classes of metal-containing materials which have generally been employed as detergents and/or dispersants in lubricating oil compositions. Overbased

materials are characterized by a metal content in excess of that which would be present according to the stoichiometry of the metal and the particular organic compound reacted with the metal, e.g., a carboxylic or sulfonic acid or phenol. Thus, if a monocarboxylic acid,

0 Ii R c OH

is neutralized with a basic metal compound, e.g., calcium hydroxide, the "normal" metal salt produced will contain one equivalent of calcium for each equivalent of acid, i.e.,

0 0 II II R C 0 Ca—O C R .

However, as is well known in the art, various processes are are available which result in an inert organic liquid solution of a product containing more than the εtoichiometric amount of metal. The solutions of these products are referred to herein as overbased materials. Following these procedures, the carboxylic acid or an alkali or alkaline earth metal salt thereof can be reacted with a metal base and the product will contain an amount of metal in excess of that necessary to neutralize the acid, for example, 4.5 times as much metal as present in the normal salt or a metal excess of 3.5 equivalents.

The actual εtoichiometric excess of metal can vary considerably, for example, from about 0.1 equivalent to about 50 or more equivalents depending on the reactions, the process conditions, and the like. The overbased materials useful in accordance with the present invention contain from about 1.1 to about 40 or more equivalents of metal, more preferably from about 1.5 to about 30 and most preferably from about 2 to about 25 equivalents of metal for each equivalent of material which is overbased.

In the present specification and claims the term "overbased" is used to designate materials containing a stoichiometric excess of metal and is, therefore, inclusive of those materials which have been referred to in the art as overbased, superbased, hyperbased, etc. , as discussed supra, and hereinbelow.

It is recognized herein that in many chemical reactions, slightly more or slightly less of a component may be incorporated into the resulting product. In the present case, it is recognized that very small amounts of excess metal may be incorporated into what is otherwise a substantially neutral product. For the purposes of this invention, such products are not considered "overbased".

The terminology "metal ratio" is used in the prior art and herein to designate the ratio of the total chemical equivalents of the metal in the overbased material (e.g., a metal sulfonate or carboxylate) to the chemical equivalents of the metal in the product which would be expected to result in the reaction between the organic material to be overbased (e.g., sulfonic or carboxylic acid) and the metal-containing reactant (e.g., calcium hydroxide, barium oxide, etc.) according to the known chemical reactivity and stoichiometry of the two reactants.

The equivalent weight of the acidic organic compound is its molecular weight divided by the number of acidic groups (i.e., sulfonic acid, carboxy or acidic hydroxy groups) present per molecule. In many cases the acidic organic compound contains a diluent such as oil or unreacted alkylate. Often the acidic organic compound is not a pure single species. In these and in other situations as appropriate, the equivalent weight of the acidic organic compound can be determined by a suitable analytical technique such as acid number (e.g. ASTM procedures D-664 and/or D-974) . Thus, in the normal calcium carboxylate discussed above, the metal ratio is one, and in the overbased carboxylate, the metal ratio

may be 4.5. Obviously, if there is present in the material to be overbased more than one compound capable of reacting with the metal, the "metal ratio" of the product will depend upon whether the number of equivalents of metal in the overbased product is compared to the number of equivalents expected to be present for a given single component or a combination of all such components.

The metal ratio may be expressed in terms of percentages. For a normal metal salt, the percentage is 100%; for overbased materials, the percentage is greater than 100. For the overbased calcium carboxylate example above, the percentage is 450.

Generally, overbased materials are prepared by treating a reaction mixture compriεing the organic material to be overbased, a reaction medium consisting esεentially of at leaεt one inert, organic εolvent for said organic material, a stoichiometric excess of a metal base, and a promoter with an acidic material. .Methods for preparing the overbased materials for use in the present invention, as well as an extremely diverse group of overbased materials, are well known in the art and are disclosed for example in the following U.S. Patent Nos.

2,616,904; 2,616,905 2,616,906, 2,616,911 2,616,924; 2,616,925; 2,617,049 2,695,910 2,723,234 2,723,235; 2,723,236; 2,760,970 2,767,164 2,767,209 2,777,874; 2,798,852; 2,839,470 2,856,359 2,859,360 2,856,361; 2,861,951; 2,883,340 2,915,517 2,959,551 2,968,642; 2,971,014; 2,989,463 3,001,981 3,027,325 3,070,581; 3,108,960; 3,147,232 3,133,019 3,146,201 3,152,991; 3,155,616; 3,170,880 3,170,881 3,172,855 3,194,823; 3,223,630; 3,232,883 3,242,079 3,242,080 3,250,710;

3,256,186; 3,274,135; 3,492,231; 4,230,586 and 4,466,894. These patents disclose processes, materials which can be overbased, suitable metal bases, promoters, and acidic materials, as well as a variety of specific overbased

products useful in this invention and are, accordingly, incorporated herein by reference.

An important characteristic of the organic materials which are overbased is their solubility in the particular reaction medium utilized in the overbasing process. As the reaction medium used frequently comprises petroleum fractions, particularly mineral oils, these organic materials have generally been oil-soluble. However, if another reaction medium is employed (e.g., aromatic hydrocarbons, aliphatic hydrocarbons, kerosene, etc.) it is not essential that the organic material be soluble in mineral oil as long as it is soluble in the given reaction medium. Obviously, many organic materials which are soluble in mineral oils will be soluble in many of the other indicated suitable reaction media.

Materials which can be overbased are generally oil-soluble organic acids including sulfonic acids, phosphorus acids, thiophosphorus acids, sulfur acids, alkylphenols, coupled alkylphenols, carboxylic, acids, thiocarboxylic acids, and the like, as well as the corresponding - alkali and alkaline earth metal salts thereof. Representative examples of each of these classes of organic acids, as well as other organic acids, e.g., nitrogen acids, arsenic acids, etc., are disclosed along with methods of preparing overbased products therefrom in the above-cited patents and are, accordingly, incorporated herein by reference. U.S. Patent No. 2,777,874 identifies organic acids suitable for preparing overbased materials. Similarly, U.S. Patent NOS. 2,616,904; 2,695,910; 2,767,164; 2,767,209; 3,147,232; 3,274,135; etc., disclose a variety of organic acids suitable for preparing overbased materials as well as representative examples of overbased products prepared from such acids. Overbased acids wherein the acid is a phosphorus acid, a thiophosphorus acid, phosphorus acid-sulfur acid combination, and sulfur acid prepared from polyolefins are disclosed in U.S. Patent Nos.

2,883,340; 2,915,517; 3,001,981; 3,108,960 and 3,232,883. Overbased phenateε are disclosed in U.S. Patent No. 2,959,551, while overbased ketones are found in U.S. Patent No. 2,798,852. A variety of overbased materials derived from oil-soluble metal-free, non-tautomeric neutral and basic organic polar compounds εuch as ester, amines, amides, alcohols, ethers, sulfides, sulfoxides, and the like are disclosed in U.S. Patent Nos. 2,968,642; 2,971,014 and 2,989,463. Another class of materials which can be overbased are the oil-soluble, nitro-substituted aliphatic hydrocarbons, particularly nitro-substituted polyolefins such as polyethylene, polypropylene, polyisobutylene, etc. Materials of this type are illustrated in U.S. Patent No. 2,959,551. Likewise, mixtures of alkylated phenols and the oil-soluble reaction product of alkylene polyamines such as propylene diamine or N-alkylated propylene diamine with formaldehyde or formaldehyde producing compound (e.g., paraformaldehyde) can be overbased. The .process and products obtained thereby are disclosed in U.S. 3,372,118. Other compounds suitable for overbasing are disclosed in the above-cited patents or are otherwise well-known in the art. For the purposeε of this invention, overbased sulfonic acids, phenols and carboxylic acids are preferred.

The metal compounds used in preparing the overbased materials are normally the basic salts, oxides and hydroxides of alkali and alkaline earth metals, although corresponding metal compounds such as lead, zinc, manganese, copper, etc. , can be used in the preparation of overbased materials. Mixtureε of different metal compounds can be used to prepare mixed metal overbased products. The anionic portion of the metal compound can be hydroxyl, oxide, carbonate, hydrogen carbonate, acetate, hydrogen εulfite, halide, amide, borate, etc., as disclosed in the above-cited patents. For purposes of this invention the preferred overbased materials are

prepared from alkali and alkaline earth metal oxides, hydroxides, and alcoholates such as the alkaline earth metal lower alkoxides. The more preferred metals are calcium, magnesium, sodium, lithium, and/or barium. The most preferred alkali metal is sodium, and calciτun is the most preferred alkaline earth metal. As mentioned hereinabove, mixed metal overbased products are also useful.

The promoters, that is, the materials which permit the incorporation of the excess metal into the overbased material, are also quite diverse and well known in the art as evidenced by the cited patents. A particularly comprehensive discussion of suitable promoters is found in U.S. Patent Nos. 2,777,874; 2,695,910 and 2,616,904. These include the alcoholic and phenolic promoters which are preferred. The alcoholic promoters include the alkanols of one to about eighteen carbon atoms, preferably one to about twelve carbon atoms, and more preferably one to about five carbon atoms, εuch as methanol, ethanol, n-butanol, amyl alcohol, octanol, isopropanol, isobutanol, and mixtures of these and the like. Polyols are also useful promoters. A particularly preferred polyol is ethylene glycol. Phenolic promoters include a variety of hydroxy- substituted benzenes and naphthalenes. A particularly useful class of phenols are the alkylated phenols of the type listed in U.S. Patent No. 2,777,874, e.g., heptylphenols, octylphenols, and nonylphenols. Mixtures of various promoters are sometimes used.

Suitable acidic materials are also disclosed in the above-cited patents, for example, U.S. Patent No. 2,616,904. Included within the known group of useful acidic materials are liquid acids such as formic acid, acetic acid, nitric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, carbamic acid, substituted carbamic acids, etc. Acetic acid is a very useful acidic material, although inorganic acidic materials such as

boric acid, HCI, SO., SO,, ^C0 ₂ r ^H 2 ^S ' ^N 2° ₃ ' ^etc *' ^are ordinarily employed as the acidic materials. The most preferred acidic materials are carbon dioxide and acetic acid, with carbon dioxide being especially preferred.

When the metal reactant used in the overbasing process is an oxide or alkoxide, H_0 can be used as the acidic material. Examples include overbasing with MgO or aluminum isopropoxide.

In preparing overbaεed materials, the material to be overbased, an inert, non-polar, organic solvent therefor, the metal base, the promoter and the acidic material are brought together and a chemical reaction ensues. The exact nature of the resulting overbased product is not known. However, it can be adequately described for purposes of the present specification as a single phase homogeneous mixture of the solvent and (1) either a metal complex formed from the metal base, the acidic material, and the material being overbased and/or (2) an amorphous metal salt formed from the reaction of the. acidic material with the metal base and the material which is said to be overbased. Thus, if mineral oil is used as the reaction medium, carboxylic acid as the material which is overbased, Ca(OH). as the metal base, and carbon dioxide as the acidic material, the resulting overbased material can be described for purposes of this invention as an oil solution of either a metal-containing complex of the acidic material, the metal base, and the carboxylic acid or as an oil solution of amorphous calcium carbonate and calcium carboxylate.

The temperature at which the acidic material is contacted with the remainder of the reaction mass depends to a large measure upon the promoting agent used. With a phenolic promoter, the temperature usually ranges from about 80*C to 300"C, and preferably from about 100'C to about 200 ^* C. When an alcohol or mercaptan is used as the promoting agent, the temperature usually will not exceed

the reflux temperature of the reaction mixture and preferably will not exceed about 100*C.

In view of the foregoing, it should be apparent that the overbased materials may retain all or a portion of the promoter. That is, if the promoter is not volatile (e.g., an alkyl phenol) or otherwise readily removable from the overbased material, at least some promoter remains in the overbased product. The presence or absence of the promoter in the overbased material does not represent a critical aspect of the invention. Obviously, it is within the skill of the art to select a volatile promoter such as a lower alkanol, e.g., methanol, ethanol, etc., so that the promoter can be readily removed prior to incorporation within the compositions of the present invention.

One preferred class of overbased materials is the metal-overbased water-insoluble organic acids, preferably those containing at least eight aliphatic carbons, although the acids may contain as few as six aliphatic carbon atoms if the acid molecule includes an aromatic ring such as phenyl, naphthyl, etc. Representative organic acids suitable for preparing these overbased materials are discussed and identified in detail in the above-cited patents. In particular, U.S. Patent Nos. 2,616,904 and 2,777,874 discloεe a variety of very suitable organic acids. Overbased carboxylic and sulfonic acids and phenols are particularly suitable.

Suitable carboxylic acids include aliphatic, cycloaliphatic and aromatic mono- and polybasic carboxylic acids free from acetylenic unsaturation, including naphthenic acids, alkyl- or alkenyl-substituted cyclopentanoic acids, alkyl- or alkenyl-substituted cyclohexanoic acids, and alkyl- or alkenyl-substituted aromatic carboxylic acids. The aliphatic acids generally contain from about 8 to about 50, and preferably from about 12 to about 25, carbon atoms. The cycloaliphatic and aliphatic carboxylic acids can be saturated or

unsaturated. Specific examples include 2-ethylhexanoic acid, linolenic acid, propylene tetramer-εubstituted maleic acid, behenic acid, isostearic acid, pelargonic acid, capric acid, palmitoleic acid, linoleic acid, lauric acid, oleic acid, ricinoleic acid, undecylic acid, dioctylcyclopentanecarboxylic acid, myristic acid, dilauryldecahydronaphthalene-carboxylic acid, εtearyl-octahydroindenecarboxylic acid, palmitic acid, alkyl- and alkenylsuccinic acids, acids formed by oxidation of petrolatum or of hydrocarbon waxes, and commercially available mixtures of two or more carboxylic acids, such as tall oil acids, rosin acids, and the like. Other carboxylic acids include propenyl- substituted glutaric acid, polybutenyl-substituted succinic acids derived from a polybutene (Mn equals about 200-1500, preferably about 300-1500), propenyl-substituted succinic acids derived from polypropylenes (Mn equals 200-1000) , acids, acids formed by oxidation of petrolatum or of hydrocarbon waxes, available mixtures of two or more carboxylic acids and mixtures of these acids, their metal salts, and/or their anhydrides.

In one embodiment, the carboxylic acids are aromatic carboxylic acids. A group of useful aromatic carboxylic acids are those of the formula

wherein R. is an aliphatic hydrocarbon based group preferably derived from polyalkenes, a is a number in the range of 1 to about 4, usually 1 or 2, Ar is an aromatic group, each X is independently sulfur or oxygen, preferably oxygen, b is a number in the range of from 1 to about 4, uεually 1 or 2, c is a number in the range of

zero to about 4, usually 1 to 2, with the proviso that the sum of a, b and c does not exceed the number of valences of Ar. Examples of aromatic carboxylic acids include substituted benzoic, phthalic and salicylic acids.

The R. group is a hydrocarbon based group that is directly bonded to the aromatic group Ar. Examples of R groups include substituents derived from polymerized olefins such as polyethylenes, polypropylenes, polybutylenes, ethylene-propylene copolymers, chlorinated olefin polymers and oxidized ethylene-propylene copolymers.

The aromatic group Ar may have the same structure as any of the aromatic groups Ar discussed below. Examples of the aromatic groups that are useful herein include the polyvalent aromatic groups derived from benzene, naphthalene, anthracene, etc., preferably benzene. Specific examples of Ar groups include phenylenes and naphthylene, e.g., methylphenyleneε, ethoxyphenylenes, isopropylphenylenes, hydroxyphenylenes> dipropoxynaphthylenes, etc.

Within this group of aromatic acids, a useful class of carboxylic acids are those of the formula

wherein R. is defined above, a is a number in the range of from 1 to about 4, preferably 1 to about 3; b is a number in the range of 1 to about 4, preferably 1 to about 2, c is a number in the range of zero to about 4, preferably 1 to about 2, and more preferably 1; with the proviso that the sum of a, b and c does not exceed 6.

Preferably, b and c are each one and the carboxylic acid is a salicylic acid.

Overbased salts prepared from salicylic acids wherein the aliphatic hydrocarbon based substituentε (R.) are derived from polyalkenes, particularly polymerized lower 1-mono-olefins such as polyethylene, polypropylene, polyisobutylene, ethylene/propylene copolymerε and the like and having average carbon contents of about 50 to about 400 carbon atoms are particularly useful.

The above aromatic carboxylic acidε are well known or can be prepared according to procedureε known in the art. Carboxylic acidε of the type illuεtrated by theεe formulae and processes for preparing their neutral and basic metal saltε are well known and disclosed, for example, in U.S. Patents 2,197,832; 2,197,835; 2,252,662; 2,252,664; 2,714,092; 3,410,798; and 3,595,791. These patents are incorporated by reference for discloεure of carboxylic acidε, their basic salts and processes of making the εame.

Zinc, calcium and magnesium saltε of the aromatic carboxylic acids, and especially the salicylic acids, are preferred.

The εulfonic acids for use in the preparation of component (A) include those represented by the formulas R ^a (SO- •<•)H)i and (R ^b )_r_>T(S0O,H)y. In these formulas, R ^a is an aliphatic or aliphatic-subεtituted cycloaliphatic hydrocarbon or eεεentially hydrocarbon radical free from acetylenic unεaturation and containing up to about 60 carbon atoms. When R is aliphatic, it usually contains at least about 15 carbon atoms; when it is an aliphatic-substituted cycloaliphatic radical, the aliphatic substituentε usually contain a total of at least about 12 carbon atoms. Exampleε of R ^a are alkyl, alkenyl and alkoxyalkyl radicals, and aliphatic-εubεtituted cycloaliphatic radicals wherein the aliphatic εubεtituents are alkyl, alkenyl, alkoxy, alkoxyalkyl, carboxyalkyl and the like. Generally, the

cycloaliphatic nucleuε iε derived from a cycloalkane or a cycloalkene such aε cyclopentane, cyclohexane, cyclohexene or cyclopentene. Specific exampleε of R ^a are cetylcyclohexyl, laurylcyclohexyl, cetyloxyethyl, octadecenyl, and radicalε derived from petroleum, εaturated and unεaturated paraffin wax, and olefin polymers including polymerized monoolefinε and diolefinε containing about 2-8 carbon atomε per olefinic monomer unit. R ^a can also contain other substituents such as phenyl, cycloalkyl, hydroxy, mercapto, halo, nitro, amino, nitroso, lower alkoxy, lower alkylmercapto, carboxy, carbalkoxy, oxo or thio, or interrupting groups such as -NH-, -O- or -S-, as long as the essentially hydrocarbon character thereof is not destroyed.

R is generally a hydrocarbon or substantially hydrocarbon radical free from acetylenic unsaturation and containing from about 4 to about 60 aliphatic carbon atomε, preferably an aliphatic hydrocarbon radical εuch aε alkyl or alkenyl. It may also, however, _* contain substituentε or interrupting groupε such as those enumerated above provided the esεentially hydrocarbon character thereof is retained. In general, any non-hydrocarbon atoms preεent in R ^a or R do not account for more than 10% of the total weight thereof. Preferably, R ^a and R are substantially free of non-hydrocarbon atoms.

The radical T is a cyclic nucleus which may be derived from an aromatic hydrocarbon such aε benzene, naphthalene, anthracene or biphenyl, or from a heterocyclic compound such aε pyridine, indole or iεoindole. Ordinarily, T iε an aromatic hydrocarbon nucleuε, especially a benzene or naphthalene nucleuε.

The εubscript x is at least 1 and is generally 1-3. The subεcriptε r and y have an average value of about 1-4 per molecule, more often about 1.

Illustrative sulfonic acids useful in the preparation of component A are mahogany sulfonic acids,

petrolatum εulfonic acidε, mono- and polywax-εubεtituted naphthalene εulfonic acidε, cetylchlorobenzene εulfonic acids, cetylphenol εulfonic acidε, cetylphenol diεulfide sulfonic acidε, cetoxycapryl benzene εulfonic acidε, dicetyl thianthrene sulfonic acidε, dilauryl beta-naphthol εulfonic acids, dicapryl nitronaphthalene sulfonic acids, saturated paraffin wax εulfonic acidε, unεaturated paraffin wax sulfonic acidε, hydroxy-εubεtituted paraffin wax sulfonic acids, tetraiεobutylene sulfonic acids, tetra-amylene εulfonic acidε, chloro-εubεtituted paraffin wax εulfonic acidε, petroleum naphthene εulfonic acidε, cetylcyclopentyl fulεonic acidε, lauryl cyclohexyl εulfonic acidε, mono- and polywax-εubεtituted cyclohexyl εulfonic acidε, poεtdedecylbenzene εulfonic acidε, "dimer alkylate" εulfonic acidε, and the like. Theεe εulfonic acidε are well-known in the art and require no further diεcuεεion herein.

It iε deεirable that the overbaεed materialε, have a metal ratio of at leaεt about 1.1, preferably at leaεt about 1.5, and more preferably at leaεt 2 to about 4. An especially suitable group of the preferred sulfonic acid and carboxylic acid overbaεed materialε has a metal ratio of at leaεt about 7.0. While overbaεed materialε having a metal ratio of 75 have been prepared, normally the maximum metal ratio will not exceed about 50 and, in moεt caεes, not more than about 40. Especially preferred are those having a metal ratio from about 7 to about 20, except for overbased phenols, wherein the metal ratio generally ranges up to about 10, more often up to about 5.

The overbased materialε utilized in the compoεitionε of the invention uεually contain from about 10% to about 70% by weight of metal-containing componentε. The exact nature of theεe metal-containing componentε iε not known. The remainder of the overbased materials comprise the inert organic reaction medium and any promoter which iε

not removed from the overbased product. For purposes of this application, the organic material which is subjected to overbasing iε considered a part of the metal-containing components. Normally, the liquid reaction medium constitutes at least about 30% by weight of the reaction mixture utilized to prepare the overbased materials.

In one particularly preferred embodiment, component A is prepared from phenols; that is, compounds containing a hydroxy radical bound directly to an aromatic ring. The term "phenol" as used herein includeε compounds having more than one hydroxy group bound to an aromatic ring, such as catechol, resorcinol and hydroquinone. It also includes alkylphenols such as the creεolε and ethylphenolε, and alkenylphenolε. Preferred are phenolε containing at leaεt one alkyl or alkenyl substituent containing about 3-100 and especially about 6-50 carbon atomε, εuch aε heptylphenol, octylphenol, dodecylphenol, tetrapropenealkylated phenol, octadecylphenol and polybutenylphenolε. Phenolε containing more than one εubstituent may also be used, but the monoalkylphenols are preferred becauεe of their availability and eaεe of production.

Also useful are condenεation products of the above-described phenols with at least one lower aldehyde, the term "lower" denoting aldehydes containing not more than 7 carbon atoms. Suitable aldehydes include formaldehyde, acetaldehyde, propionaldehyde, the butyraldehydes, the valeraldehydeε and benzaldehyde. Alεo suitable are aldehyde-yielding reagents such as parafor aldehyde, trioxane, methylol, Methyl Formcel and paraldehyde. Formaldehyde and the formaldehyde-yielding reagents are especially preferred.

In a particularly preferred embodiment, the metal phenates are overbased metal phenateε, more preferably overbaεed εulfurized metal phenateε, preferably alkaline earth metal phenateε, and eεpecially calcium phenateε.

The phenol group of the phenateε includeε an aromatic moiety with at leaεt one hydrocarbon-baεed radical and an oxygen atom attached to such aromatic moiety, aε indicated in Formula I, below. The phenol group may be sulfurized and reacted with a metal, as discussed below, to form component (A) . Aε uεed herein, the term "normal" metal phenateε iε uεed to refer to those phenates wherein the ratio of equivalents of metal to the phenolic 0 group is about 1:1, in accordance with Formula I

(R _a - Ar - 0 -) _χ M I wherein (R C_L - Ar - 0-) is the phenol group; M iε a metal; x iε the valence of M. Ar iε an aromatic moiety which iε preferably benzene; R iε a hydrocarbon-baεed radical; and a iε an integer of from 1 up to the number of unsatisfied valences in Ar, preferably 1 or 2. As used herein, the term overbased metal phenates refers to metal phenates wherein the ratio of metal to the phenol group iε greater than that of normal metal phenateε. Such phenateε are εometimeε referred to interchangeably aε "baεic" or "overbaεed". Component (A) generally containε up to about 1000%, preferably up to about 500%, of the metal preεent in the corresponding normal metal phenate. Advantageously, component (A) contains from about 250% to about 450%, preferably up to about 350%, of the metal preεent in the corresponding normal metal phenate.

Any of alkali or alkaline earth metalε, copper or zinc may be uεed in the phenate of component (A) ; however, alkaline earth metal compounds are preferred, and calcium iε especially preferred.

As mentioned hereinabove, component (A) preferably comprises a sulfurized metal phenate and the metal contents referred to hereinabove apply equally to this preferred embodiment. When component (A) is a sulfurized phenate it has a phenol to sulfur group molar ratio of from about 2:1 to about 1:2, preferably about 2:1 to about 1:1, and advantageously about 4:3.

The term "basic" iε uεed herein the εame way in which it waε uεed in the definition of other componentε above, that iε, it referε to εaltε having a metal ratio in excess of 1. The neutral and baεic saltε of phenol εulfideε provide antioxidant and detergent properties to the oil compositions of the invention.

In a particularly preferred embodiment, component (A) includeε, for example, baεic sulfurized tetrapropenyl phenate with, for example, about 230% or 380% of the calcium present in the corresponding normal calcium phenate, and a phenol to sulfur group molar ratio of about 4:3.

The alkylphenols from which the neutral and overbased saltε are prepared generally compriεe phenolε containing hydrocarbon substituents with at least about 6 carbon atoms; the subεtituentε may contain up to about 700 aliphatic carbon atomε. Also included are substantially hydrocarbon substituents, as defined hereinabove. The preferred hydrocarbon subεtituentε are derived from the polymerization of olefins such as ethylene, propene, etc.

The term "alkylphenol sulfides" is meant to include di-(alkylphenol)monosulfides, disulfides, polysulfideε, and other productε obtained by the reaction of the alkylphenol with sulfur monochloride, sulfur dichloride or elemental sulfur. The molar ratio of the phenol to the εulfur compound can be, depending on the εulfur compound, from about 1:0.5 to about 1:1.5, or higher. For example, phenol εulfides are readily obtained by mixing, at a temperature above about 60*C, one mole of an alkylphenol and about 0.5-1 mole of sulfur dichloride. The reaction mixture is usually maintained at about 100 ^β C for about 2-5 hours, after which time the resulting sulfide is stripped of volatiles and filtered. When elemental sulfur is uεed, temperatures of about 200 ^β C or higher are sometimes desirable. It iε alεo deεirable

that the drying operation be conducted under nitrogen or a εimilar inert gas.

A commonly employed method for preparing the basic (or overbased) saltε of theεe phenolε comprises heating the phenol with a stoichiometric excess of a metal neutralizing agent such as a metal oxide, hydroxide, carbonate, bicarbonate, sulfide, etc., at temperatures above about 50 ^β C. Various promoterε may be uεed in the overbasing procesε to aid in the incorporation of the excess metal. Promoterε include such compoundε aε phenolic substances including phenol; alcohols εuch aε methanol, 2-propanol, octyl alcohol, etc.; amines such as aniline and dodecyl amine, etc. Preferably, the basic salt iε treated with carbon dioxide after it haε been formed. The techniqueε of overbaεing various phenols are described in the prior art and can be utilized as procesεeε for preparing the basic or overbaεed phenolε uεed in the preεent invention.

The preparation of εulfurized metal phenateε iε also well known to those skilled in the art. Neutral saltε are prepared by mixing and heating a baεic metal compound with the deεired phenol compound.

The preparation of baεic (overbaεed) phenateε can be accomplished by any of the standard techniqueε known to those skilled in the art for producing basic sulfurized metal phenates. These techniques include, for example, one-step procesεeε wherein εulfurization and baεing (or overbasing) with the metal are effected εimultaneouεly, and two-εtep proceεεeε wherein the phenol iε firεt εulfurized, forming an alkylphenol sulfide, then based. Each of theεe techniqueε is well known to those skilled in the art and, accordingly, need not be further discuεεed herein. The source of εulfur iε generally elemental sulfur, or εulfur halide, for example, SC1_ or S-C1-. Patentε diεcloεing εuitable procedureε for preparing component (B) include U.S. Pat. Noε. 2,680,096;

3,036,971; 3,178,368; 3,437,595; and Re 29,661, these patents being ^' incorporated herein by reference.

Suitable basic alkyl phenol sulfides are disclosed, for example, in U.S. Pat. Nos. 3,372,116, 3,410,798 and 3,562,159, 4,021,419 and 4,740,321 which are hereby incorporated by reference.

The metal salts, component (A), are generally employed in the compositionε of thiε invention in amounts ranging from about 0.1 to about 10% by weight of the total lubricating oil composition. More often, they are uεed in amounts ranging from about 0.02 to about 5%, frequently up to about 2% and preferably from about 0.04% to about 1% by weight of the lubricating compositions.

The following examples illustrate the preparation of metal salts useful as component (A) . All temperatures are in degrees Celεiuε, all partε are partε by weight unless indicated otherwise. Theεe examples are intended to be illustrative only, and are not intended to be construed as limiting the scope of this invention.

Examples A-l through A-10 are non-limiting examples of the preparation of metal carboxylates, sulfonates and mixtures thereof.

Example A-l To 790 parts of an oil solution containing 1 equivalent based on neutralization number of an alkylated benzenesulfonic acid and 71 partε of polybutenyl succinic anhydride (equivalent weight about 560) containing predominantly iεobutene units in 176 parts of mineral oil is added 320 parts (8 equivalents) of sodium hydroxide and 640 parts (20 equivalents) of methanol. The temperature of the mixture inσreaseε to 89*C (reflux) over 10 minuteε due to exother ing. During thiε period, the mixture iε blown with carbon dioxide at 4 cfh (cubic feet per hour) . Carbonation iε continued for about 30 minuteε aε the temperature gradually decreases to 74 ^β C. The methanol and other volatile materials are stripped

from the carbonated mixture by blowing nitrogen through it at 2 cfh while the temperature iε slowly increaεed to 150 'C over 90 minuteε. After εtripping is completed, the remaining mixture is held at lSS'C-lβS'C for about 30 minutes and filtered to yield an oil solution of the desired basic sodium sulfonate having a metal ratio of about 7.75.

Example A-2 Following the procedure of Example A-l, a εolution of 780 partε (1 equivalent) of an alkylated benzeneεulfonic acid (57% by weight 100 neutral mineral oil and unreacted alkylated benzene) and 119 partε of the polybutenyl εuccinic anhydride in 442 partε of mineral oil iε mixed with 800 partε (20 equivalents) of sodium hydroxide and 704 parts (22 equivalents) of methanol. The mixture is blown with carbon dioxide at 7 cfh for 11 minutes as the temperature slowly increaseε to 97*C. The rate of carbon dioxide flow is reduced to 6 cfh and the temperature decreases slowly to 88"C over about 40 minutes. The rate of carbon dioxide flow is reduced to 5 cfh for about 35 minutes and the temperature slowly decreases to 73*C. The volatile materialε are εtripped by blowing nitrogen through the carbonated mixture at 2 cfh for 105 minuteε aε the temperature iε εlowly increaεed to 160*C. After stripping iε completed, the mixture iε held at 160*C for an additional 45 minuteε and then filtered to yield an oil solution of the deεired baεic εodium εulfonate having a metal ratio of about 19.75.

Example A-3 A mixture of 906 partε of an oil solution of an alkyl phenyl εulfonic acid (having a molecular weight of 450), 564 partε mineral oil, 600 parts toluene, 98.7 partε magnesium oxide and 120 parts water is blown with carbon dioxide at a ^" temperature of 78 ^, -85*C for 7 hours at a rate of about 3 cubic feet of carbon dioxide per

hour. The reaction mixture iε conεtantly agitated throughout the carbonation. After carbonation, the reaction mixture iε εtripped to 165"C/20 torr and the reεidue filtered. The filtrate iε an oil solution (34% oil) of the desired overbaεed magnesium εulfonate having a metal ratio of about 3.

Example A-4 A polybutenyl εuccinic anhydride iε prepared by reacting a chlorinated polybutene (having an average chlorine content of 4.3% and derived from a polybutene conεiεting predominantly of iεobutene unitε having a number average molecular weight of about 1150) with maleic anhydride at about 200'C. To a mixture of 1246 parts of thiε succinic anhydride and 1000 parts of toluene there is added at 25*C, 76.6 parts of barium oxide. The mixture iε heated to 115*C and 125 partε of water iε added drop-wise over a period of one hour. The mixture is then allowed to reflux at 150*C until.all the barium oxide is reacted. Stripping and filtration provides a filtrate containing the desired product.

Example A-5 A basic calcium sulfonate having a metal ratio of about 15 iε prepared by carbonation, in incrementε, of a mixture of calcium hydroxide, a neutral εodium petroleum sulfonate, calcium chloride, methanol and an alkyl phenol, followed by removal of volatile materialε and filtration of the reεidue.

Example -6 A mixture of 323 partε of mineral oil, 4.8 partε of water, 0.74 partε of calcium chloride, 79 partε of lime, and 128 partε of methyl alcohol iε prepared, and warmed to a temperature of about 50*C. To thiε mixture there is added 1000 parts of an alkyl phenyl sulfonic acid having a molecular weight of 500 with mixing. The mixture then

iε blown with carbon dioxide at a temperature of about 5 'C at a rate of about 5.4 pounds per hour for about 2.5 hours. After carbonation, 102 additional parts of oil are added and the mixture is εtripped of volatile materialε at a temperature of about 150-155*C at 55 mm. presεure. The reεidue iε filtered and the filtrate iε the desired oil solution of the overbased calcium εulfonate having calcium content of about 3.7% and a metal ratio of about 1.7.

Example A-7 A mixture of 490 partε (by weight) of a mineral oil, 110 partε of water, 61 parts of heptylphenol, 340 parts of barium mahogany sulfonate, and 227 parts of barium oxide is heated at 100*C for 0.5 hour and then to 150 ^* C. Carbon dioxide is then bubbled into the mixture until the mixture is substantially neutral. The mixture is filtered and the filtrate found to have a sulfate ash content of 25%.

Example A-8 Add to a flask about 512 parts by weight of a mineral oil solution containing about 0.5 equivalent of a subεtantially neutral magneεium salt of an alkylated salicylic acid wherein the alkyl group has an average of about 18 aliphatic carbon atoms, about 30 parts by weight of an oil mixture containing about 0.037 equivalent of an alkylated benzenesulfonic acid together with about 15 partε by weight (0.65 equivalents) of magnesium oxide and about 250 parts by weight of xylene. Heat to a temperature of about 60*C to 70*C. Increase the heat to about 85*C and add approximately 60 parts by weight of water. Hold the reaction masε at a reflux temperature of about 95"C to 100*C for about 1 1/2 hourε and εubεequently εtrip at a temperature of 155-160"C, under a vacuum, and filter. The filtrate will compriεe the baεic

carboxylic magnesium salt containing 200% of the εtoichiometrically equivalent amount of magnesium.

Example A-9 Prepare a substantially neutral magnesium salt of an alkylated salicylic acid wherein the alkyl groups have from 16 to 24 aliphatic carbon atoms by reacting approximately stoichiometric amounts of magnesium chloride with a substantially neutral potassium salt of the alkylated salicylic acid. Charge a flask with a reaction maεε comprising approximately 6580 parts by weight of a mineral oil solution containing about 6.50 equivalents of the substantially neutral magnesium salt of the alkylated salicylic acid and about 388 parts by weight of an oil mixture containing about 0.48 equivalent of an alkylated benzenesulfonic acid together with approximately 285 parts by weight (14 equivalents) of magnesium oxide and approximately 3252 parts by weight of xylene. Heat to a temperature of about 55'C to 75*C. Increase the temperature to about 82"C and add approximately 780 parts by weight of water to the reaction and then heat to the reflux temperature. Hold the reaction masε at the reflux temperature of about 95-100"C for about one hour and subsequently strip at a temperature of about 170'C, under 50 torr and filter. The filtrate will comprise the basic carboxylic magnesium saltε and have a εulfated aεh content of 15.7% (εulfated aεh) corresponding to 276% of the stoichiometrically equivalent amount.

Example A-10 A reaction mixture comprising 2900 grams (3 equivalents) of an oil solution of the magnesium salt of polyisobutylene (average molecular weight—480)- εubεtituted salicyclic acids, 624 grams of mineral oil, 277 grams (l equivalent) of a commercial mixture of tall oil acids, 1800 grams of xylene, 195 grams (9

equivalents) of magnesium oxide, and 480 grams of water are carbonated at the reflux temperature (about 95"C) for one hour. The carbonated mixture iε then stripped by first heating to 160"C with nitrogen blowing (3 cubic feet per hour) and thereafter heating to 165*C at a pressure of 30 mm. (Hg) . This stripped carbonated product is filtered, the filtrate being an oil solution of the desired basic magnesium salt. The salt is characterized by a metal ratio of 2.7.

The following examples A-ll through A-15 illustrate the preparation of phenol salts.

Example A-ll A phenol sulfide is prepared by reacting sulfur dichloride with a polyisobutenyl phenol in which the polyisobutenyl substituent has an average of 23.8 carbon atoms, in the presence of sodium acetate (an acid acceptor used to avoid discoloration of the product) . A mixture of 1755 parts of this phenol sulfide, 500 partε of mineral oil, 335 partε of calcium hydroxide and 407 partε of methanol iε heated to about 43-50*C and carbon dioxide iε bubbled through the mixture for about 7.5 hourε. The mixture iε then heated to drive off volatile matter, an additional 422.5 parts of oil are added to provide a 60% solution in oil. This solution contains 5.6% calcium and 1.59% sulfur.

Example A-12 To 6072 parts (22 moles OH) of a tetrapropenyl- substituted phenol (prepared by mixing, at 138"C and in the preεence of a sulfuric acid treated clay, phenol and tetrapropylene) , there are added at 90*-95'C, 1134 parts (11 moles) of εulfur dichloride. The addition is made over a 4-hour period whereupon the mixture is bubbled with nitrogen for 2 hourε, heated to 150*C and filtered. To 861 partε (3 equivalentε) of the above product, 1068 partε of mineral oil, and 90 partε of water, there are

added at 70"C, 122 parts (3.3 equivalents) of calcium hydroxide. The mixture iε maintained at 110°C for 2 hourε, heated to 165"C and maintained at thiε temperature until it iε dry. Thereupon, the mixture iε cooled to 25*C and 180 partε of methanol are added. The mixture iε heated to 50°C and 366 partε (9.9 equivalents) of calcium hydroxide and 50 parts (0.633 equivalent) of calcium acetate are added. The mixture is agitated for 45 minutes and iε then treated at 50-70*C with carbon dioxide at a rate of 2-5 cubic feet per hour for 3 hours. The mixture iε dried at 165*C and the residue is filtered. The filtrate has a calcium content of 3.3%, a neutralization number of 39 (basic) and a metal ratio of 4.4.

Example A-13 To 5880 parts (12 moles OH) of a polyisobutene- substituted phenol (prepared by mixing, at 54'C and in the presence of boron trifluoride, equimolar amounts of phenol and a polyisobutene having a number average molecular weight of about 350) and 2186 partε of mineral oil, there are added over 2.5 hours and at 90-110*C, 618 parts (6 moles) of sulfur dichloride. The mixture is heated to 150*C and bubbled with nitrogen. To 3449 parts (5.25 equivalents) of the above product, 1200 parts of mineral oil, and 130 parts of water, there are added at 70 ^* C, 147 parts (5.25 equivalents) of calcium oxide. The mixture is maintained at 95-110"C for 2 hours, heated to and maintained at 160 'C for one hour and then cooled to 60 ^* C whereupon 920 parts of 1-propanol, 307 parts (10.95 equivalents) of calcium oxide, and 46.3 parts (0.78 equivalent) of acetic acid are added. The mixture is then contacted with carbon dioxide at a rate of 2 cubic feet per hour for 2.5 hours. The mixture is dried at 190"C and the residue is filtered to give the desired product.

Example A-14 A mixture of 485 partε (1 moleε OH) of a polyiεobutene-substituted phenol wherein the substituent has a number average molecular weight of about 400, 32 parts (1 equivalent) of εulfur. 111 partε (3 equivalentε) of calcium hydroxide, 16 parts (0.2 equivalent) of calcium acetate, 485 parts of diethylene glycol monomethyl ether and 414 parts of mineral oil is heated at 120-205 ^• C under nitrogen for 4 hours. Hydrogen sulfide evolution beginε aε the temperature rises above 125*C. The material is allowed to distill and hydrogen sulfide is absorbed in a sodium hydroxide solution. Heating is discontinued when no further hydrogen sulfide absorption is noted; the remaining volatile material is removed by distillation at 95"C/10 mm presεure. The distillation reεidue iε filtered. The product thuε obtained iε a 60% εolution of the desired product in mineral oil.

Example A-15

To a mixture of 3192 partε (12 eguivalentε) of tetrapropenyl-εubεtituted phenol, 2400 partε of mineral oil and 465 partε (6 equivalentε) of 40% aqueouε formaldehyde at 82"C, iε added, over 45 minuteε, 960 partε (12 equivalentε) of 50% aqueouε εodium hydroxide. Volatile materialε are removed by εtripping at 160"C under nitrogen and subsequently under vacuum, and to the residue is added 618 partε (12 equivalentε) of εulfur dichloride over 3 hourε. Toluene, 1000 partε, and 1000 partε of water are added and the mixture is heated under reflux for 2 hours. Volatile materials are then removed at 180"C by blowing with nitrogen and the intermediate is filtered.

To 1950 parts (4 equivalents) of the intermediate thus obtained is added 135 parts of the polybutenyl succinic anhydride wherein the polybutenyl group has a molecular weight of about 1000 and conεiεts primarily of

iεobutene unitε. The mixture iε heated to 51"C, and 78 partε of acetic acid and 431 partε of methanol are added, followed by 325 partε (8.8 equivalentε) of calcium hydroxide. The mixture iε blown with carbon dioxide and iε finally εtripped with nitrogen blowing at 158*C and filtered while hot, using a filter aid. The filtrate iε a 68% solution in mineral oil of the desired product and contains 2.63% sulfur and 22.99% calcium sulfate ash.

The Carboxylic Acid or Anhydride

Component (B) is an aliphatic carboxylic acid or an anhydride thereof, wherein the aliphatic group contains at least about 20 carbon atomε and up to about 500 carbon atomε, preferably from about 30 to about 300 carbon atomε and often from about 30 to about 150 carbon atomε. In another embodiment, component (B) is an aliphatic substituted succinic anhydride or acid containing from about 20 to about 500 carbon atoms in the aliphatic substituent, preferably from about 30 to about 400 carbon atoms, and often from about 50 to about 200 carbon atoms. Patents deεcribing uεeful aliphatic carboxylic acidε or anhydrides and methods for preparing them include, among numerous others, U.S. Pat. Nos. 3,215,707 (Rense) ; 3,219,666 (Norman et al) , 3,231,587 (Rense); 3,912,764 (Palmer); 4,110,349 (Cohen); and 4,234,435 (Meinhardt et al) ; and U.K. 1,440,219.

As indicated in the above-mentioned patents, which are hereby incorporated by reference for their disclosure of compounds uεeful aε component (B) of thiε invention, the carboxylic acidε (or variouε derivatives thereof) are usually derived by the reaction of a carboxylic acid containing compound with a polyalkene or halogenated derivative thereof or a suitable olefin.

The polyalkenes from which the carboxylic acids (B) are derived are homopolymers and interpolymers of polymerizable olefin monomers of 2 to about 16 carbon atoms; usually 2 to about 6 carbon atoms. The

interpolymerε are thoεe in which two or more olefin monomerε are interpolymerized according to well-known conventional procedureε to form polyalkeneε having units within their structure derived from each of said two or more olefin monomers. Thus, interpolymer(ε)" as used herein iε incluεive of copolymerε, terpolymers, tetrapolymers, and the like. As will be apparent to those of ordinary skill in the art, the polyalkenes from which the substituent groups are derived are often conventionally referred to as "polyolefin(s)".

The olefin monomers from which the polyalkenes are derived are polymerizable olefin monomers characterized by the presence of one or more ethylenically unεaturated groupε (i.e., >C=C<) ; that is, they are monolefinic monomerε εuch aε ethylene, propylene, butene-1, iεobutene, and octene-1 or polyolefinic monomerε (uεually diolefinic monomerε) εuch aε butadiene-1,3 and iεoprene.

Theεe olefin monomerε are uεually polymerizable terminal olefins; that iε, olefins characterize' by the preεence in their εtructure of the group >C=CH2-. However, polymerizable internal olefin monomerε (εometimeε referred to in the literature aε medial olefins) characterized by the preεence within their structure of the group

-C-C=C-C- can alεo be uεed to form the polyalkeneε. When internal olefin monomerε are employed, they normally will be employed with terminal olefinε to produce polyalkeneε which are interpolymerε. For purposes of this invention, when a particular polymerized olefin monomer can be claεεified aε both a terminal olefin and an internal olefin, it will be deemed to be a terminal olefin. Thuε, 1,3-pentadiene (i.e., piperylene) iε deemed to be a terminal olefin for purposes of this invention.

Preferred carboxylic acids include polyolefin substituted succinic acids, succinic anhydrides, ester acids or lactone acids.

Component (B) iε generally uεed in the lubricating oil compositions of this invention in amounts ranging from about 0.01% to about 10% by weight of the lubricating oil composition, preferably from about 0.01% to about 5% by weight and often up to about 1% by weight. Most preferably, component (B) iε preεent in amountε ranging from about 0.02% to about 1% by weight.

Non-limiting exampleε of compounds useful as component (B) include those in the following examples:

Example B-l A mixture of 6400 partε (4 oleε) of a polybutene comprising predominantly iεobutene unitε and having a molecular weight of about 1600 and 408 partε (4.16 moles) of maleic anhydride iε heated at 225-240 ^β C for 4 hours. It iε then cooled to 170*C and an additional 102 partε (1.04 moleε) of maleic anhydride iε added, followed by 70 parts (0.99 mole) of chlorine; the latter is added over 3 hours at 170-215'C. The mixture is heated for an additional 3 hours at 215*C and is then vacuum stripped at 220"C and filtered through diatomaceous earth. The product iε the deεired polybutenyl-εubstituted succinic anhydride having a saponification number of 61.8.

Example B-2 A monocarboxylic acid is prepared by chlorinating a polyisobutene having a molecular weight of 750 to a product having a chlorine content of 3.6% by weight, converting the product to the correεponding nitrile by reaction with an equivalent amount of potaεεium cyanide in the preεence of a catalytic amount of cuprouε cyanide and hydrolyzing the reεulting nitrile by treatment with 50% exceεε of a dilute aqueous sulfuric acid at the reflux temperature.

Example B-3

A high molecular weight mono-carboxylic acid is prepared by telomerizing ethylene with carbon tetrachloride to a telomer having an average of 35 ethylene radicalε per molecule and hydrolyzing the telomer to the corresponding acid in according with the procedure described in British Patent No. 581,899.

Example B-4 A polybutenyl εuccinic anhydride iε prepared by the reaction of a chlorinated polybutylene with maleic anhydride at 200'C. The polybutenyl radical haε an average molecular weight of 805 and containε primarily iεobutene unitε. The reεulting alkenyl εuccinic anhydride is found to have an acid number of 113 (corresponding to an equivalent weight of 500) .

Example B-5 A lactone acid is prepared by reacting 2 equivalentε of a polyolefin (Mn about 900) substituted Succinic anhydride with 1.02 equivalents of water at a temperature of about 90*C in the presence of a catalytic amount of concentrated sulfuric acid. Following completion of the reaction, the sulfuric acid catalyst is neutralized with sodium carbonate and the reaction mixture is filtered.

Example B-6 An ester acid is prepared by reacting 2 equivalents of an alkyl εubεtituted εuccinic anhydride having an average of about 35 carbon atomε in the alkyl group with 1 mole of ethanol.

Example B-7 A reactor iε charged with 1000 partε of polybutene having a molecular weight determined by vapor phaεe iεometry of about 950 and which conεiεtε primarily of isobutene units, followed by the addition of 108 parts of moleic anhydride. The mixture iε heated to 110'C

followed by the sub-surface addition of 100 parts Cl ₂ over 6.5 hours at a temperature ranging from 110 to 188'C. The exothermic reaction is controlled as not to exceed 188'C. The batch is blown with nitrogen then stored.

Example B-8 The procedure of Example B-7 is repeated employing 1000 parts of polybutene having a molecular weight determined by vapor phase isometry of about 1650 and conεisting primarily of isobutene units and 106 parts moleic anhydride. Cl, is added beginning at 130 ^* C and added a near continuous rate such that the maximum temperature of 188*C is reached near 1;he end of chlorination. The residue is blown with nitrogen and collected.

(C) The Metal Salts of an Organic Phoεphoruε Acid or Mixture of Organic Phosphorus Acid and Carboxylic Acid

The compositionε of the preεent invention may also contain (C) a metal salt of (C) (I) at leaεt one organic phosphorus acid or mixture of (C) (I) at least one organic phosphorus acid and (C) (II) at least one carboxylic acid.

The phosphorus acid (B) (I) is preferably at least one acid of the general formula

wherein R 1 and R2 is the same or different and each of R1 and R 2 is independently H or a hydrocarbon-based group with the proviso that at least one of R 1 and R2 is a hydrocarbon-based group and each X is independently S or

0.

In a preferred embodiment, the phosphorus acid

(C) (I) has the general formula

wherein R 1 and R2 are as defined hereinabove. Theεe are referred to aε phoεphorodithioic acidε. The hydrocarbon-baεed groups R 1 and R2 may be alkyl, cycloalkyl, aralkyl or alkaryl groups. Illustrative alkyl groups include isopropyl, iεobutyl, n-butyl, sec-butyl, the variouε amyl groupε, n-hexyl, ethyliεobutyl carbinyl, heptyl, 2-ethylhexyl, diiεobutyl, iεooctyl, nonyl, behenyl, decyl, dodecyl, tridecyl, etc.

Illuεtrative alkaryl groups include lower alkylphenyl groupε εuch aε butylphenyl, amylphenyl, heptylphenyl, etc. Cycloalkyl groupε likewiεe are uεeful and theεe include chiefly cyclohexyl and the lower alkyl-cyclohexyl radicalε. Lower alkyl groupε contain from one to about εeven carbon atomε. Many εubεtituted hydrocarbon groupε may also be uεed, e.g., chloropentyl, dichlorophenyl, and dichlorodecyl.

The preparation of theεe acidε iε well known in the art and iε described in the patent literature and numerous other textε and publications. See for example the books, "Lubricant Additives," by C. V. Smalheer and

R. K. Smith, published by Lezius-Hileε Co. , Cleveland,

Ohio (1967) and "Lubricant Additiveε," by M. W. Ranney, publiεhed by Noyeε Data Corp., Parkridge, New Jerεey

(1973), and the following U.S. Patentε:

2,261,047 3,211,648 3,402,188

2,540,084 3,211,649 3,413,327

2,838,555 3,213,020 3,446,735

2,861,907 3,213,021 3,502,677

2,862,947 3,213,022 3,573,292

2,952,699 3,305,598 3,859,300

2,987,410 3,328,298 4,002,686

- 39 -

3,004,996 3,335,158 4,089,793

3,089,867 3,376,221 4,123,370

3,151,075 3,390,082 4,308,154

3,190,833 3,401,185 4,466,895

4,507,215

Theεe bookε and patents are hereby incorporated by reference for relevant disclosures contained therein. Preferred acids of the general formula

are readily obtainable from the reaction of phosphorus pentasulfide (-P _H * ³ *) with an alcohol or mixtureε of alcoholε. The reaction involveε mixing at a temperature of about 20'C to about 200'C, 4 moleε of the alcohol with one mole of phoεphorus pentasulfide. Hydrogen εulfide is liberated in this reaction. The oxygen-containing analogs of these acids are conveniently prepared by treating the dithioic acid with water or steam which, in effect, replaces one or both of the sulfur atoms.

The mixed phosphates (RO)xP(0H)y are readily prepared by reacting 3 moles of an alcohol with 1 mole of phosphorus pentoxide (P_0 _g ) .

The expression "hydrocarbon-based group" as uεed herein with reεpect to and R ² iε uεed to define a monovalent radical derived from a hydrocarbon-baεed material by removal of a hydrogen from a carbon atom of the hydrocarbon-based material. Thiε carbon atom is directly bonded to the remainder of the molecule. The hydrocarbon-based groups may be straight chains, e.g., isopropyl-, n-pentyl, εec-butyl-, etc. or branched, e.g., 2-methyl-4-pentyl-, iεooctyl-, etc.

Preferably the groupε R1 and R2 are εubεtantially εaturated. The terminology "εubεtantially εaturated" aε used herein is intended to define radicals free from acetylenic unsaturation (-C C-) in which there iε not more than one ethylenic linkage (-C=C-) for every 10 carbon-to carbon (preferably 20) covalent bondε. The so-called "double bonds" in aromatic rings (e.g., benzene) are not to be considered as contributing to unsaturation with respect to the terminology

"substantially saturated". Usually there will be no more than an average of one ethylenic linkage per substantially saturated monovalent radical as described hereinbefore. Preferably, (with the exception of aromatic rings) all the carbon-to-carbon bonds in a substantially εaturated radical will be εaturated linkages; that is, the radical will be free from acetylenic and ethylenic linkages. For the purposeε of thiε disclosure, aromatic unsaturation is not to be conεidered ethylenic unεaturation.

In general, the hydrocarbon-baεed radical may contain at leaεt 3 carbon atomε and up to about 100 carbon atomε with a preferred range from 3 to about 50 carbon atomε, more preferably from about 3 to about 16 carbon atomε. Other preferred rangeε are from about 6 to about 18 carbonε, more preferably from about 6 to about 8 carbonε. Mixtures wherein R 1 and R2 are different are useful. Typical exampleε of R and R include iεopropyl-, n-butyl-, n-pentyl-, 4-methyl-2-pentyl-, isooctyl-, n-dodecyl-, etc. Mixtures, such as isopropyl- and isooctyl, sec-butyl and n-decyl-, iεopropyl- and 4-methyl-2-pentyl- and the like are useful. Mixtures are often εtatiεtical mixtureε which comprise a mixture wherein some of the moleculeε have both R 1 and R2 alike and additional moleculeε wherein R 1 and R2 are different.

The term "lower" when uεed herein to denote radicalε εuch aε lower alkyl iε intended to deεcribe a radical containing up to about 7 carbon atomε.

Methodε for preparing the metal εaltε (C) are well known and are deεcribed in detail in the patent literature. Moεt frequently, the εaltε are prepared by reacting one or more of the phoεphoruε-containing acids deεcribed hereinabove with a metal base. Suitable metal baseε include the free metals previously enumerated and their oxides, hydroxides, alkoxides and baεic εalts. Examples include sodium hydroxide, calcium hydroxide, zinc oxide, copper oxide, calcium acetate and the like. Other methods include "double-displacement" reactionε wherein one metal εalt of a phosphoruε acid iε reacted with a εalt, εuch as a halide, of another metal. Metal exchange may take place. For example, a sodium dithiophosphate can be reacted with calcium chloride to form a calcium dithiophosphate and sodium chloride. Sodium chloride is then removed by means commonly used in the art, εuch aε filtration, water waεhing, etc. Theεe and other methodε are described in the books and U.S. Patents listed hereinabove which describe the method of preparation of the various phosphoruε acidε. Each of the above-liεted bookε and patentε iε hereby incorporated by reference for diεcloεureε relating to the preparation of the metal salts.

Also contemplated for use in the lubricating compositions of this invention are metal saltε of phoεphorus-containing acidε aε described hereinabove, which have been post-treated with other reagents to improve various properties. Exampleε include poεt-treatmentε with phoεphites, epoxides, amines and the like. Such post-treatmentε and productε εo obtained are described in the following U.S. Patents:

- 42 -

3,004,996 3,213,022

3,151,075 3,213,023

3.211.648 4,263,150

3.211.649 4,289,635 3,213,020 4,507,215 3,213,021

Aε noted hereinabove, the metal εaltε (C) useful in the lubricating compositionε of thiε invention may be metal εaltε of a mixture of (C) (I) at leaεt one organic phoεphoruε acid and (C) (II) at leaεt one carboxylic acid wherein the various elements of the formula are as described hereinabove.

These metal εaltε are εaltε of at leaεt two acidic componentε. The phoεphoruε-containing acidε (C) (I) have been deεcribed hereinabove.

The carboxylic acid reactant (C) (II) may be a monocarboxylic or polycarboxylic acid, uεually containing from 1 to about 3 carboxy groupε and preferably only 1. It may contain from about 2 to about 40, preferably from about 2 to about 20 carbon atomε. The preferred carboxylic acidε are thoεe having the formula R 3COOH,

3 wherein R ιε an aliphatic or alicyclic hydrocarbon-baεed group preferably free from acetylenic unsaturation.

Suitable acidε include acetic, propionic, butanoic, hexanoic, decanoic, dodecanoic, octadecanoic and eicoεanoic acidε, as well aε olefinic acids such as acrylic, oleic, linoleic, and linoleic acid dimer. For

3 the moεt part, R lε a εaturated aliphatic radical and especially a branched alkyl radical such as the isopropyl or 3-heptyl radical. Illuεtrative polycarboxylic acidε are oxalic, malonic, succinic, alkyl- and alkenylsuccinic, glutaric, adipic, pimelic, sebacic, maleic, fumaric and citric acidε.

The εalt of a mixture of (C) (I) and (C) (II) may be prepared by merely blending a metal salt of compoment

(C) (I) with a metal εalt of component (C) (II) in the deεired ratio. Thiε ratio iε between about 0.5:1 and about 500:1 on an equivalent basis. Preferably, the ratio is between about 0.5:1 and about 200:1. Advantageously, the ratio can be from about 0.5:1 to about 100:1, preferably from about 0.5:1 to about 50:1, and more preferably from about 0.5:1 to about 20:1. Further, the ratio can be from about 0.5:1 to about 4.5:1, preferably about 2.5:1 to about 4.25:1. For this purpose, the equivalent weight of a phosphoruε containing acid (C) (I) iε itε molecular weight divided by the number of acidic groups, and that of a carboxylic acid is its molecular weight divided by the number of carboxy groups therein. The information required to determine equivalents can uεually be determined from the εtructural formula of componentε (C) (I) and (C) (II) or empirically through well-known titration procedureε.

A second and preferred method for preparing the metal salts of mixtures of acids (C) (I) and (C) (II) is to prepare a mixture of the acidε in the deεired ratio and to react the acid mixture with a suitable metal base. When thiε method of preparation iε uεed, it iε frequently poεεible to prepare a neutral εalt or a εalt containing an excesε of metal with reεpect to the number of equivalentε of acid preεent; thus, mixed metal εaltε containing aε many aε 2 equivalentε and especially up to about 1.5 equivalents of metal per equivalent of acid may be prepared. The equivalent of a metal for this purpose is its atomic weight divided by its valence.

The term "neutral salt" refers to saltε characterized by metal content equal to that which would be preεent according to the stoichiometry of the metal and the particular organic compound reacted with the metal. Thuε, if a phoεphorodithioic acid, (RO)-PSSH, iε neutralized with a baεic metal compound, e.g., zinc oxide, the neutral metal εalt produced would contain one

equivalent of zinc for each equivalent of acid, i.e., [(R0) ₂ PSS] ₂ Zn.

However, component (C) can contain more or leεε than the εtoichiometric amount of metal. The products containing leεs than the stoichiometric amount of metal are acidic materialε. The productε containing more than the εtoichiometric amount of metal are overbased materials. Component (C) may have about 80% to about 200%, preferably about 100% to about 150%, more preferably about 100% to about 135%, and advantageously about 103% to about 110% of the metal preεent in the correεponding neutral εalt.

Variants of the above-deεcribed methodε may alεo be uεed to prepare the mixed metal εaltε of thiε invention. For example, a metal εalt, component (C) may be blended with the free acid aε component (C) (II) , and the reεulting blend reacted with additional metal base.

Suitable metal bases for the preparations of the metal εaltε (C) of thiε invention include the free metalε previously enumerated and their oxides, hydroxides', alkoxides and basic saltε. Exampleε are εodium hydroxide, εodium methoxide, εodium carbonate, potaεεium hydroxide, potaεεium carbonate, magneεium oxide, magneεium hydroxide, calcium hydroxide, calcium acetate, zinc oxide, zinc acetate, lead oxide, nickel oxide, copper oxide, antimony trioxide and the like.

The temperature at which the metal salts used in this invention are prepared is generally between about 30'C and about 150*C, preferably up to about 125*C. If component (C) is prepared by neutralization of a mixture of acids with a metal base, it is preferred to employ temperatures above about 50"C and especially above about 75 ^* C. It iε frequently advantageouε to conduct the reaction in the preεence of a substantially inert, normally liquid organic diluent such as naphtha, benzene, xylene, mineral oil or the like. If the diluent is mineral oil or is physically and chemically εimilar to

mineral oil, it frequently need not be removed before using component (C) in the compoεitionε of the invention.

Component (C) , when preεent, iε generally uεed in the lubricating oil compoεitionε of thiε invention in amountε ranging up to about 10% of the total weight of the lubricating oil composition. More often, component (C) , when uεed, iε preεent in amountε ranging from about 0.05% to about 5%, preferably from about 0.1 to about 2% and more preferably from about 0.1 to about 1% by weight of the lubricating oil compoεition.

As mentioned hereinabove, and as illustrated by the numerous references incorporated herein which describe the metal saltε of phoεphorus-containing acids, the metal salts and derivatives thereof are well known in the art. The following examples are provided to illustrate several of the metal saltε uεeful aε component (C) in thiε invention. It iε emphaεized that theεe exampleε are provided for illuεtrative purposes and are not to serve as a limitation on the scope of the invention.

Example fC-l) One mole of an 0,0-di(alkyl)phosphorodithioic acid containing 40 mole % isopropyl and 60 mole % 4-methyl-2-pentyl group iε reacted with an oil εlurry of 1.08 eguivalentε (0.54 moleε) of zinc oxide at about 190'F (88 ^* C). H ₂ 0 is evolved. The reaction mixture is steam stripped followed by vacuum stripping. Oil is added if necesεary to adjust the phosphoruε content of the residue to about 9.5%. The oil solution is filtered.

Example (C-2) The procedure of Example B-l is repeated employing 1 mole of di(4-methyl-2-pentyl)dithiophosphoric acid and

1.1 equivalents (0.55 moles) of an oil slurry of zinc oxide. The filtered product contains 8.5% phosphoruε.

Example fC-3) The procedure of Example B-2 iε repeated except no oil diluent iε employed. The filtered product contains 9.25% phosphorus.

Example (C-4) A mixture of 67 parts (1.63 eguivalentε) of zinc oxide and 48 partε of mineral oil iε prepared at room temperature. A mixture of 303 partε (l equivalent) of the 0,0-di(alkyl)phoεphorodithioic acid deεcribed in Example 2 and 36 partε (0.25 equivalents) of 2-ethylhexanoic acid is added over 10 minutes and a slight exotherm is observed. When addition is complete, the temperature is increased to 80*C for 3 hourε. The mixture is vacuum stripped at 100*C and filtered.

Example C-5 Following the procedure of Example C-4, a product is prepared from 383 partε (1.2 equivalentε) of a dialkyl phoεphorodithioic acid containing 65% iεobutyl and 35 % amyl groupε, 43 partε (0.3 equivalent) of 2-ethylhexanoic acid, 71 partε (1.73 equivalentε) of zinc oxide and 47 partε of mineral oil. The reεulting metal εalt, obtained aε a 90% εolution in mineral oil, containε 11.07% zinc.

Example C-6 Following the procedure of Example C-4, a product is prepared from 474 parts (1.2 equivalents) of a dialkylphosphorodithioic acid containing 80% 2-ethylhexyl groupε and 20% isobutyl groupε, 43 partε (0.3 equivalent) of 2-ethylhexanoic acid, 80 partε (1.95 equivalentε) of zinc oxide and 57 parts of mineral oil. The resulting metal εalt is obtained as a 91% solution in mineral oil.

Example C-7 A mixture of 118 partε (2.8 equivalentε) of zinc oxide, 25 partε (0.25 equivalent) of sebacic acid and 72 partε of mineral oil iε εtirred at room temperature and a mixture of 584 parts (2 equivalents) of the dialkylphosphorodithioic acid of Example 2 and 36 parts (0.25 equivalent) of 2-ethyl-hexanoic acid iε added over 30 minutes. The temperature increases to 65"C during the addition. The solution iε heated to 80'C for 3 hourε and vacuum stripped at 180'C. The reεidue iε filtered to yield the desired metal salt (90% solution in mineral oil) containing 11.7% zinc.

Example C-8 A product is prepared by the procedure of Example C-4 except that an equivalent amount of oleic acid iε subεtituted for the 2-ethylhexanoic acid.

Exampleε C-9 to C-ll Triphenyl phoεphite iε heated with a zinc εalt of a mixture of a dialkylphoεphorodithioic acid and a carboxylic acid. The dialkylphosphorodithioic acid uεed in the preparation of the zinc εalt iε itεelf prepared by the reaction of at leaεt one alcohol with phoεphoruε pentaεulfide which contains a εtoichiometric exceεs of εulfur. The reaction conditionε and results are given in Table I. The salts are prepared by reacting zinc oxide with 4 equivalents of the dialkylphosphorodithioic acid and 1 equivalent of the carboxylic acid, a total of 1.3 equivalents of zinc oxide being used per equivalent of acid. The reactions are carried out in a small amount of mineral oil as diluent.

Example C-12 A reaction mixture is prepared by the addition of 3120 parts (24.0 moles) of 2-ethylhexanol and 444 parts (6.0 moles) of isobutyl alcohol. With nitrogen blowing at 1.0 cubic feet per hour, 1540 parts (6.9 moles) of P_S ₅ is added to the mixture over a two-hour period while maintaining the temperature at 60-78 ^β C. The mixture is held at 75"C for one hour and is stirred an additional two hours while cooling. The mixture is filtered through diatomaceous earth. At 25*C, 4745 parts (12.5 moleε) of thiε filtered mixture iε added to a mixture of 590 partε (14.4 moles) of ZnO, 114 parts of a commercially available mixture of C ₁₅ _ ₁₈ alpha-olefinε and 457 partε of diluent oil over a thirty minute period. The exotherm increaεeε the temperature to 70*C. The mixture iε heated to 85*C and maintained at that temperature for three hourε. The mixture is stripped to 110°C at 25 mm. Hg. The mixture is filtered twice through diatomaceouε earth.

Example C-13 A slurry iε prepared by the addition of 486.6 partε (.11.86 eguivalentε) of ZnO and 243.1 partε diluent oil. With medium εpeed εtirring 1204 partε (3.6 equivalents) of 0,0-di(4-methyl-2-pentyl)phoεphorodithioic acid are added to the εlurry and the temperature of the resulting mixture is increased from 56*C to 87'C over a period of 20 minutes. 2407 parts (7.2 equivalents) of 0,0-di-(4-methyl-2-pentyl)phoεphorodithioic acid are added to the mixture. The temperature of the mixture iε maintained at 86 ^β C for 4 hourε. 500 parts of the mixture are poured off. The remaining 3831 partε of mixture are mixed with 156.04 parts of a commercially available mixture of C ₁₅ _ ₁₈ alpha-olefins. The mixture iε εtripped to 105 ^* C at 15 mm. Hg. The temperature of the mixture iε increased from 22'C to 105'C over a 3 1/2 hour period. The mixture iε held at 105*C under a nitrogen flow of 0.5 cubic feet per hour for an additional two hours before

being allowed to cool. The mixture iε cooled and filtered through diatomaceouε earth. The filtrate iε the product.

Example C-14 The process of Example C-l is repeated replacing the zinc oxide with about 1.15 equivalents of cuprouε oxide.

Example C-15 The proceεε of Example C-l iε repeated employing O,O-di(2-ethylhexyl)phoεphorodithioic acid.

Example C-l6 The proceεs of Example C-15 is repeated employing 1 equivalent of copper (I) oxide for each equivalent of zinc oxide.

Examples C-17-20

The procesε of Example C-15 is repeated employing 1 equivalent of:

Example No. Metal Compound

17 Manganese (IV) oxide

18 Nickel (II) oxide

19 Molybdenum (VI) oxide

20 Tin (II) oxide

Additional representative examples of metal salts useful as component (C) in the compositionε of this invention appear in the patents and publications herein incorporated by reference. Other examples will occur to one skilled in the art. (D) The Triazole

The triazole which may be used in this invention may be benzotriazole and alkyl-substituted benzotriazole. The alkyl subεtituent generally containε up to 15 carbon atomε, preferably up to 8 carbon atomε. In addition to the alkyl εubεtituent, the triazoleε may contain other

εubεtituentε on the aromatic ring εuch aε halogens and nitro groups. Exampleε of suitable compounds are benzotiazole and the tolyltriazoles, ethylbenzotriazoles, hexylbenzotriazoles, octylbenzotriazoles, chlorobenzo- triazoleε and nitrobenzotriazoleε. Benzotriazole and tolyltriazole are particularly preferred.

The amount of triazole included in the compoεition generally iε leεε than 5%, more often leεε than 1% by weight. When the compoεition of the invention is to be uεed in a lubricating oil εuch aε a hydraulic fluid, only εmall amounts of the triazole compound are required to obtain improved hydrolytic stability. Generally the composition of the invention will contain an amount of triazole compound which will provide an additive concentrate for lubricants and functional fluid which contains as little as 100 ppm of the triazole and preferably lesε than 50 ppm of the triazole. When formulated into finished lubricants and functional fluids, the compositionε of the invention are prepared to provide the lubricant or functional fluid with a stabilizing amount of the triazole which generally is less than 20 ppm, and may be lesε than 3 ppm of finished lubricant or functional fluid.

It is εometimeε uεeful to incorporate, on an optional, aε-needed baεiε other known additives which include, but are not limited to, disperεantε, detergentε, antioxidantε, anti-wear agentε, extreme preεεure agentε, emulsifiers, demulεifierε, foam inhibitors, friction modifierε, anti-ruεt agents, corrosion inhibitors, viscoεity improverε, pour point depreεεantε, dyes, and solvents to improve handleability which may include alkyl and/or aryl hydrocarbons. These optional additives may be present in various amounts depending on the intended application for the final product or may be excluded therefrom.

Diεpersants include, but are not limited to, hydrocarbon εubεtituted succinimides, εuccinamides, carboxylic esterε, Mannich diεperεantε and mixtureε thereof aε well aε materialε functioning both aε diεperεantε and viεcoεity improverε. The diεperεantε include nitrogen-containing carboxylic diεperεantε, eεter dispersants, Mannich dispersantε or mixtureε thereof. Nitrogen-containing carboxylic diεperεantε are prepared by reacting a hydrocarbyl carboxylic acylating agent (uεually a hydrocarbyl εubεtituted εuccinic anhydride) with an amine (uεually a polyamine) . Eεter diεperεants are prepared by reacting a polyhydroxy compound with a hydrocarbyl carboxylic acylating agent. The ester disperεant may be further treated with an amine. Mannich dispersants are prepared by reacting a hydroxy aromatic compound with an amine and aldehyde. The diεperεantε liεted above may be post-treated with reagents such as urea, thiourea, carbon disulfide, aldehydes, ketoneε, carboxylic acidε, hydrocarbon εubεtituted succinic anhydride, nitrileε, epoxides, boron compounds, phosphoruε compounds and the like. Theεe diεperεantε are generally referred to aε ashless dispersants even though they may contain elementε such as boron or phosphoruε which, on decompoεition, will leave a non-metallic reεidue.

Extreme pressure agentε and corrosion- and oxidation-inhibiting agentε include chlorinated compoundε, εulfurized compoundε, phosphorus containing compounds including, but not limited to, phosphoεulfurized hydrocarbons and phosphoruε esterε, metal containing compounds and boron containing compounds.

Chlorinated compoundε are exemplified by chlorinated aliphatic hydrocarbons εuch aε chlorinated wax.

Exampleε of εulfurized compounds are organic sulfides and polysulfides εuch aε benzyl disulfide, biε(chlorobenzyl)diεulfide, dibutyl tetraεulfide.

εulfurized methyl eεter of oleic acid, εulfurized alkylphenol, ^' εulfurized dipentene, and sulfurized terpene.

Phoεphoεulfurized hydrocarbons include the reaction product of a phosphorus sulfide with turpentine or methyl oleate.

Phoεphoruε eεters include dihydrocarbon and trihydrocarbon phosphiteε, phoεphateε and metal and amine saltε thereof.

Phoεphiteε may be repreεented by the following formulae:

O

H

R ₅ 0 P 0R _r

H

or

(R ₅ o) ₃ P

wherein each R ₅ is independently hydrogen or a hydrocarbon based group, provided at least one R ₅ is a hydrocarbon based group.

Preferably each R ₅ is independently a hydrogen or hydrocarbon based group having from 1 to about 24, more preferably from 1 to about 18, and more preferably from about 2 to about 8 carbon atoms, provided that at least one R ₅ is a hydrocarbon based group. Each R ₅ may be independently alkyl, alkenyl or aryl. When ₅ is aryl it contains at least 6 carbon atoms; preferably 6 to about 18 carbon atomε. Examples of alkyl or alkenyl groupε are propyl, butyl, hexyl, heptyl, octyl, oleyl, linoleyl, εtearyl, etc. Exampleε of aryl groupε are phenyl, naphthyl, heptylphenyl, etc. Preferably each R ₅ is independently propyl, butyl, pentyl, hexyl, heptyl, oleyl or phenyl, more preferably butyl, oleyl or phenyl and more preferably butyl or oleyl.

The R groups may also comprise a mixture of hydrocarbyl groups derived from commercial alcohols.

Examples of preferred monohydric alcohols and alcohol mixtures include commercially available "Alfol" alcohols marketed by Continental Oil Corporation. Alfol 810 is a mixture containing alcohols consiεting eεεentially of εtraight-chain, primary alcoholε having 8 to 10 carbon atomε. Alfol 812 iε a mixture compriεing moεtly C. - fatty alcoholε. Alfol 1218 iε a mixture of εynthetic, primary, εtraight-chain alcoholε having from 12 to 18 carbon atoms. Alfol 20+ alcohols are mixtures of 18-28 primary alcohols having moεtly, on an alcohol baεiε, C_ ₀ alcoholε as determined by GLC (gaε-liguid- chromatography) .

Another group of commercially available alcohol mixtureε includes the "Neodol" productε available from

Shell Chemical Company. For example, Neodol 23 iε a mixture of C_ ₂ and C._ alcoholε; Neodol 25 iε a mixture of C- ₂ and C_ ₅ alcoholε; and Neodol 45 iε a mixture of

C1-4. and C1.5 _c linear alcoholε. Neodol 91 iε a mixture of

C _g , C- ₀ and C_ ₁ alcoholε.

Phoεphiteε and their preparation are known and many phoεphites are available commercially. Particularly useful phosphiteε are dibutylhydrogen phosphite, trioleyl phosphite and triphenyl phosphite. Preferred phosphite esterε are generally dialkyl hydrogen phoεphites.

A number of dialkyl hydrogen phosphites are commercially available, such as lower dialkyl hydrogen phosphiteε, which are preferred. Lower dialkyl hydrogen phosphiteε include dimethyl, diethyl, dipropyl, dibutyl, dipenyl and dihexyl hydrogen phoεphiteε.

Phosphate esterε include mono-, di- and trihydrocarbon-based phosphateε of the general formula

(R ₅ O) ₃ PO

wherein R_ is as defined for the phoεphiteε described hereinabove. ^' Exampleε include mono-, di- and trialkyl ; mono-, di and triaryl and mixed alkyl and aryl. Specific, non-limiting exampleε include, tri lower alkyl phosphate, dialkyl phosphates, and the like. Particularly preferred are the reaction products of phosphoruε pentoxide (P ° _c ) with alcoholε in a ratio of 3 hydroxyl groupε to one P ₂ ⁰ ₅ yielding a mixture of mono- and dialkyl phosphates. Also available or readily prepared by known techniques are diheptyl, dicyclohexyl, pentylphenyl, dipentylphenyl, tridecyl, distearyl, dimethyl naphthyl, oleyl 4-pentylphenyl, polypropylene (molecular weight 500)-εubεtituted phenyl, and diiεobutyl-εubstituted phenyl phosphites. Also mixed alkyl hydrogen phosphiteε are uεeful in the preεent invention. Exampleε of mixed alkyl hydrogen phoεphiteε include ethyl, butyl; propyl, pentyl; and methyl, pentyl hydrogen phoεphiteε.

Metal containing compoundε include > metal thiocarbamateε, εuch as zinc dioctyldithiocarbamate, and barium heptylphenyl dithiocarbamate and molybdenum compounds.

Boron containing compounds include borate esters and boron-nitrogen containing compounds prepared, for example, by the reaction of boric acid with a primary or secondary alkyl amine.

Viscosity improvers include, but are not limited to, polyisobuteneε, polymethacrylate acid eεterε, polyacrylate acid eεters, diene polymers, polyalkyl styreneε, alkenyl aryl conjugated diene copolymerε, polyolefinε and multifunctional viεcoεity improverε.

Pour point depreεεantε are a particularly uεeful type of additive often included in the lubricating oils described herein. See for example, page 8 of "Lubricant Additives" by C. V. Smalheer and R. Kennedy Smith (Lesius-Hileε Company Publiεhers, Cleveland, Ohio, 1967) .

Anti-foam agentε uεed to reduce or prevent the formation of εtable foam include εiliconeε or organic polymers. Exampleε of theεe and additional anti-foam compoεitionε are deεcribed in "Foam Control Agentε", by Henry T. Kerner (Noyeε Data Corporation, 1976) , pages 125-162.

These and other additives are deεcribed in greater detail in U.S. Patent 4,582,618 (column 14, line 52 through column 17, line 16, incluεive) , herein incorporated by reference for itε diεcloεure of other additives that may be used in combination with the preεent invention.

The components may be blended together in any suitable manner and then admixed, for example with a diluent to form a concentrate aε discussed below, or with a lubricating oil, aε discussed below. Alternatively, components can be admixed separately with such diluent or lubricating oil. In preparing concentrates, it is preferred that the triazole, if used, be disεolved firεt in the diluent by heating to a temperature of about 80-90*C followed by cooling before the remaining componentε are blended into the diluent. The blending technique for mixing the componentε iε not critical and can be effected uεing any εtandard technique, depending upon the specific nature of the materialε employed. In general, blending can be accompliεhed at room temperature; however, blending can be facilitated by heating the componentε.

Aε previouεly indicated, the compoεitionε of the preεent invention are uεeful aε additiveε for lubricantε and functional fluidε. They can be employed in a variety of lubricantε baεed on diverse oils of lubricating viscoεity, including natural and εynthetic lubricating oilε and mixtureε thereof. The lubricantε include crankcase lubricating oilε for εpark-ignited and compreεsion-ignited internal combuεtion engineε, including automobile and truck engineε, two-cycle

engines, aviation piston engines, marine and railroad diesel engines, and the like. Also contemplated are lubricants for gas engines, stationary power engineε and turbineε and the like. Tranεaxle lubricantε, gear lubricantε, metal-working lubricantε and other lubricating oil and greaεe compoεitionε, aε well aε functional fluids such as hydraulic fluids and automatic transmiεεionε fluidε, benefit from the incorporation therein of the compositions of the present invention. As discuεεed hereinabove, thiε invention provides εpecial benefits when the composition is exposed to water.

The lubricating compositions and methods of thiε invention employ an oil of lubricating viscosity, including natural or synthetic lubricating oils and mixtures thereof. Natural oils include animal oils, vegetable oils, mineral lubricating oils, solvent or acid treated mineral oils, and oils derived from coal or shale. Synthetic lubricating oils include hydrocarbon oils, halo-subεtituted hydrocarbon oilε, alkylene oxide polymerε, eεterε of carboxylic acids and polyols, esters of polycarboxylic acids and alcoholε, esters of phosphorus-containing acids, polymeric tetrahydrofurans, εilicon-baεed oilε and mixtureε thereof.

Specific exampleε of the oilε of lubricating viεcoεity are described in U.S. Patent 4,326,972 and European Patent Publication 107,282, both herein incorporated by reference for their diεclosures relating to lubricating oils. A basic, brief description of lubricant base oils appearε in an article by D. V. Brock, "Lubricant Baεe Oilε", Lubrication Engineering. volume 43, pages 184-185, March, 1987. Thiε article is herein incorporated by reference for itε disclosures relating to lubricating oils. A description of oils of lubricating viscosity occurs in U.S. Patent 4,582,618 (column 2, line 37 through column 3, line 63, inclusive), herein incorporated by reference for its disclosure to oils of lubricating viscoεity.

Component (A) and component (B) are generally uεed in relative amountε of A:B ranging from about 5:1 to about 1:5, more often from about 2:1 to about 1:2, by weight.

When component (C) iε preεent, it iε generally uεed in amountε relative to component (A) ranging from about A:C = 1:40 to 2:1, preferably from about 1:20 to about 1:1, more preferably from about 1:10 to about 1:1.

Component (A) iε uεed in the lubricating oil com¬ poεitionε of thiε invention in amountε ranging from about 0.01 to about 5% by weight, often up to about 2% by weight. A preferred range iε from about 0.01 to about 1% by weight of the total weight of the compoεition.

Components (B) and (C) are utilized in amounts within the above-specified amounts relative to component (A).

The following examples illuεtrate compoεitionε of the preεent invention. The amount of each component in the Exampleε alεo reflectε the amount of oil preεent in the indicated componentε. *

Component

Product of Example C-ll Product of Example C-2 Product of Example C-13 Tolyltriazole Benzotriazole Hexylbenzotriazole Sodium Petroleum Sulfonat Hindered Phenol

Benzotriazole Derived Copper Corrosion Inhibitor 0.55 0.52 0.55 0.49

Product of Example A-15 4.75 Product of Example A-ll 6.18 4.12 Product of Example A-2 72.2 Product of Example A-6 Mineral Oil Diluent 0.39 Polyacrylate Antifoam 2.35 Product of Example B-7 2.06 Product of Example B-2 27.8 Product of Example B-4 7.56

As indicated hereinabove, the compositionε of thiε invention are uεeful aε additiveε for a wide variety of lubricating compoεitionε. Preferred lubricating compoεitionε are functional fluidε, with hydraulic fluidε being particularly preferred. The following are non-limiting exampleε of lubricating compositions of this invention.

Example 6 To a 100 neutral mineral oil baseεtock iε added, with mixing and gentle heating, 1% by weight of the product of Example A-l, 0.3% by weight of the product of Example B-4, and 0.01 percent by weight of a εilicone antifoam.

Example 7 To a mineral oil baεeεtock (250 neutral) iε added 0.85 percent by weight of the additive concentrate of Example 1.

Example 8 Example 7 iε repeated except additive concentrate of Example 1 iε replaced with that of Example 4.

Example 9 To the lubricating oil compoεition of Example 6 iε added 0.05% by weight of the product of Example C-l.

Example 10 To Sun Tulεa ISO 46 baεe oil iε added 0.81 percent by weight of the additive concentrate of Example 3.

Example 11 To Sun Tulεa ISO 46 baεe oil iε added 0.1 percent by weight of the additive concentrate of Example 2.

Example 12 Example 7 iε repeated except the additive concentrate of Example 4 replaceε that of Example 1.

Example 13 To a hydraulic fluid baεeεtock (ISO 46) iε added 0.1 partε of dibutyl hydrogen phoεphite, 0.01 parts of tolyltriazole, 0.1 parts of a magnesium salicylate, 0.05 partε of the reaction product of propylene oxide with tetrapropenyl εuccinic anhydride, 0.2 parts of tricresyl phosphate, 0.25 partε of hindered phenol, 0.25 parts of di(nonylphenyl) amine and 0.05 parts of the product of Example B-7.

Example 14 A hydraulic fluid is prepared according to the procedure of Example 13 replacing 0.05 parts of the product of Example B-7 with 0.03 parts of the product of Example B-6.

Example 15 A compoεition compriεing an oil of lubricating viεcoεity, 0.85 percent by weight of the product of Example A-4, 0.15 partε of the product of Example B-6, 0.2 parts of hindered phenol, 0.002 percent by weight of tolyltriazole and 0.01 percent by weight of an organic polymer antifoam.

Example 16 The composition of Example 7 replacing the product of Example C-ll with that of Example C-16.

The filterability of hydraulic fluids can be determined employing the AFNOR E48-690/1 test published by 1"Association Francaise DeNormaliεation, Tour Europe Cedex 7 92 080 Pariε-La Defense, France. This test

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consists of filtering, under constant pressure, at constant temperature, through a membrane with a determined absolute stopping power, a specified volume of fluid contained in a container of defined dimensions. This test employs an esεentially uncontaminated fluid.

Filterability indiceε of the fluid (IF^ and IF ₂ ) are defined for a given fluid by the ratioε:

IF _χ = and IF ₂ =

² 50 ² < ^T 100 ^{" T} 50>

in which

T_ _0Q iε the passage time, through the membrane, of 300 cm of fluid,

^T ₂₀₀ ^{s tne} P ^assa 9 ^e time, through the membrane, of 200 cm of fluid,

T_ ₀₀ is the pasεage time, through the membrane, of 100 cm of fluid,

T ₅₀ iε the paεεage time, through the membrane, of 50 cm of fluid.

Thiε ratio therefore conεiεtε of comparing the filtration εpeedε of the fluid in the courεe of the test. These ratioε as well as the filtration speedε of the various εegmentε for each εa ple are indicative of the eaεe of filtration of the fluidε.

A modification of thiε teεt entailε the uεe of a water-treated fluid. To the fluid iε added a fixed amount of water, the mixture is agitated, then stored. After the aging period, the water-treated fluid is evaluated as above.

The results of the filtration of the water-free and the water-containing fluids are compared. It has been observed that when the fluids are contaminated with water, filtration of fluidε of the preεent invention iε εignificantly improved compared to similar fluids that do not contain the acidic material, component (B) .

It haε alεo been obεerved that when a fluid contains zinc, usually as a zinc εalt, depletion of zinc may occur when the fluid iε expoεed to ASTM D-943 test conditionε, which are oxidation conditionε including the preεence of water. The compoεitionε of thiε invention reεiεt depletion of zinc under those test conditions.

While this invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the disclosure. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.