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Title:
LUBRICANT AND FUNCTIONAL FLUID COMPOSITIONS EXHIBITING IMPROVED DEMULSIBILITY
Document Type and Number:
WIPO Patent Application WO/1990/004626
Kind Code:
A2
Abstract:
A lubricating composition is described which comprises a mixture of (A) a major amount of an oil of lubricating viscosity, (B) a dispersant effective amount of at least one ashless dispersant, and (C) a minor, effective amount of at least one demulsifier characterized by formula (I), wherein R is a hydrocarbyl group, R2, R3, R4 and R5 are each independently H or hydrocarbyl groups, and X is O or NR' wherein R' is hydrogen or a hydrocarbyl group. In one embodiment, the ashless dispersant is a carboxylic dispersant, and the demulsifier is a derivative of imidazoline. The lubricating compositions of the invention are characterized as having improved dispersancy, demulsibility, rust-inhibition and anti-wear properties.

Inventors:
Schwind, James J.
Vinci, James N.
Application Number:
PCT/US1989/003628
Publication Date:
May 03, 1990
Filing Date:
August 23, 1989
Export Citation:
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Assignee:
THE LUBRIZOL CORPORATION.
International Classes:
C10M133/44; C10M133/46; C10M133/48; C10M133/58; C10M141/06; C10M141/12; C10M159/12; C10M161/00; C10M163/00; C10N30/00; C10N30/04; C10N30/06; C10N40/04; C10N40/25; (IPC1-7): C10M141/06; C10M133/46; C10M141/12; C10M163/00
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Claims:
Clai s
1. A lubricating composition comprising a mixture of (A) a major amount of an oil of lubricating viscosity, (B) a dispersant effective amount of at least one ashless dispersant, and (C) a minor, effective amount of at least one demulsifier characterized by the formula wherein R is a hydrocarbyl group, R2, R3, R4 and R5 are each independently H or hydrocarbyl groups, and X is 0 or NR' wherein R' is hydrogen or a hydrocarbyl group.
2. The composition of claim 1 wherein the ash¬ less dispersant (B) is selected from the group consist¬ ing of carboxylic dispersants, amine dispersants, Man¬ nich dispersants, polymeric dispersants, carboxylic, amine or Mannich dispersants posttreated with urea, thiourea, carbon disulfide, aldehydes, ketones, carbox¬ ylic acids, hydrocarbonsubstituted succinic anhydrides, nitriles, epoxides, boron compounds or phosphorus com¬ pounds, or mixtures thereof.
3. The composition of claim 1 wherein the ash¬ less dispersant (B) is a carboxylic dispersant compris¬ ing reaction product of at least one carboxylic acylat ing agent with a reactant selected from the group con¬ sisting of (a) amines characterized by the presence with¬ in their structure of at least one >NH group, (b) alcohols or phenols, (c) reactive metal or reactive metal com¬ pounds, and (d) mixtures of two or more of (a) through (c).
4. The composition of claim 3 wherein the carboxylic dispersant comprises the reaction product of a carboxylic acylating agent with (a) an amine character¬ ized by the presence within its structure of at least one >NH group.
5. The composition of claim 3 wherein the car¬ boxylic dispersant comprises the reaction product of a carboxylic acylating agent with (a) or (b) , or mixtures thereof which is posttreated with at least one reagent selected from the group consisting of boron trioxides, boron anhydrides, boron halides, boron acids, boron amides, esters of boric acid and mixtures thereof.
6. The composition of claim 3 wherein the carboxylic acylating agent is a substituted succinic acylating agent consisting of substituent groups and succinic groups wherein the substituent groups are derived from polyalkene.
7. The composition of claim 6 wherein the polyalkene is characterized as having an Mn value of at least about 700.
8. The composition of claim 1 wherein the ashless dispersant is an alkenyl succinimide dispersant wherein the alkenyl group is derived from a polyalkene having an Mn value of from about 700 to about 5000.
9. The composition of claim 1 wherein the ashless dispersant is a borated alkenyl succinimide dis¬ persant wherein the alkenyl group is derived from a poly¬ alkene having an ϊϊn value of from about 700 to about 5000.
10. The composition of claim 8 wherein the polyalkene is a polybutene in which at least about 50% of the total units derived from butene are derived from isobutene.
11. The composition of claim 1 wherein X is 0, R is an aliphatic or alicyclic hydrocarbon group contain¬ ing from about 5 to about 40 carbon atoms, and R4 and R5 are each H.
12. The composition of claim 1 wherein X is NR' wherein R' is hydrogen or an aliphatic hydrocarbon based group containing from 1 to about 8 carbon atoms and at least one OH or >NH group.
13. The composition of claim 1 wherein X is NR', R' is a hydroxy alkylene group containing 1 to about 8 carbon atoms, and R2 and R3 are H.
14. A lubricating composition comprising a mixture of (A) a major amount of an oil of lubricating viscosity, (B) a dispersant effective amount of at least one nitrogen and boroncontaining composition prepared by reacting (B1) a boron compound selected from the group consisting of boron trioxide, boron anhydrides, boron halides, boron acids, boron amides, esters of boric acid and mixtures thereof with (B2) at least one acylated nitrogen inter¬ mediate prepared by the reaction of (B2a) at least one substituted succinic acylating agent with (B2b) at least about onehalf equivalent, per equivalent of acylating agent, of an amine characterized by the presence within its structure of at least one >NH group wherein said substituted suc¬ cinic acylating agent consists of substituent groups and succinic groups, and the substituent groups are derived from polyalkene characterized as having an Mn value of at least about 700, and (C) a minor, effective amount of at least one demulsifier characterized by the formula wherein R is an alkyl or alkenyl group containing from about 5 to about 30 carbon atoms, and R1 is hydrogen or a hydrocarbyl group containing from 1 to about 8 carbon atoms.
15. The lubricating composition of claim 14 wherein the boron compound (B1) is boric acid.
16. The lubricating composition of claim 14 wherein the boron compound (B1) and acylated nitrogen intermediate (B2) are reacted in amounts to provide up to about 10 atomic proportions of boron for each atomic proportion of nitrogen in said acylated nitrogen inter¬ mediate.
17. The lubricating composition of claim 14 wherein the substituent group in the substituted suc¬ cinic acylating agent is derived from a polyalkene having an average Mn value within the range of from about 700 to about 5000.
18. The lubricating composition of claim 14 wherein the polyalkene is a polybutene in which at least about 50% of the total units derived from butene are derived from isobutene.
19. The lubricating composition of claim 14 wherein the substituent group of the acylated nitrogen intermediate is derived from a polyalkene having a number average molecular weight in the range of from about 700 to about 1500.
20. The lubricating composition of claim 14 wherein the amine (B2b) is an aliphatic, cycloalipha tic or aromatic polyamine.
21. The lubricating composition of claim 14 wherein the amine (B2b) is a hydroxysubstituted mono amine, polyamine, or mixtures thereof.
22. The lubricating composition of claim 14 wherein the amine (B2b) is characterized by the gener¬ al formula R3N(UN)nR3 R3 R3 wherein n is an integer of from 1 to about 10, each R3 is independently a hydrogen atom, a hydrocarbyl group or a hydroxysubstituted or aminosubstituted hydrocarbyl group having up to about 30 carbon atoms, or two R3 groups on different nitrogen atoms can be joined toge¬ ther to form a U group with the proviso that at least one R3 group is a hydrogen atom, and U is an alkylene group of about 2 to about 10 carbon atoms.
23. The lubricating composition of claim 14 wherein the amine (B2b) is a polyalkylene polyamine.
24. The lubricating composition of claim 14 wherein R* in demulsifier (C) is hydrogen.
25. The lubricating composition of claim 14 wherein R in demulsifier (C) is an alkenyl group con¬ taining from 9 to about 25 carbon atoms.
26. The lubricating composition of claim 14 wherein R' in demulsifier (C) is a hydrocarbyl group containing at least one >NH or OH group.
27. The lubricating composition of claim 14 wherein the demulsifier (C) is characterized by the formula wherein R is a hydrocarbyl group containing about 5 to about 30 carbon atoms and R" is H or a hydrocarbyl group containing from 1 to about 6 carbon atoms.
28. The lubricating composition of claim 14 containing from about 0.1 to about 10% by weight of the nitrogen and boroncontaining composition (B) and from about 0.01 to about 1% by weight of the demulsifier (C) .
29. The lubricating composition of claim 14 also containing (D) from about 0.01 to about 1% by weight of at least one polyglycol demulsifier.
30. A lubricating composition comprising a mixture of (A) a major amount of an oil of lubricating viscosity, (B) from about 0.1 to about 5% by weight of at least one nitrogen and boroncontaining composition prepared by reacting (B1) a boron compound selected from the group consisting of boron trioxide, boron anhydrides, boron halides, boron acids, boron amides, esters of boric acid, and mixtures thereof with (B2) at least one acylated nitrogen intermediate prepared by reacting (B2a) at least one substituted succinic acylating agent with (B2b) from about onehalf equiva¬ lent up to about 2 moles, per equivalent of acylating agent, of at least one polyamine compound characterized by the presence within its structure of at least one >NH group, wherein said substituted succinic acylating agent consists of substituent groups and succinic groups, and the substituent groups are derived from polyalkenes characterized as having an Mn value of from about 700 to about 5000, and (C) from about 0.01 to about 0.5% by weight of at least one demulsifier characterized by the formula wherein R is an alkyl or alkenyl group containing from about 9 to about 25 carbon atoms, and R* is hydrogen or an alkyl group containing from 1 to about 6 carbon atoms.
31. The lubricating composition of claim 30 wherein the amounts of boron compound (B1) and acylated nitrogen intermediate (B2) reacted are sufficient to provide from about 0.1 atomic proportion of boron for each mole of said acylated nitrogen intermediate to about 10 atomic proportions of boron for each atomic proportion of nitrogen in said intermediate.
32. The lubricating composition of claim 30 wherein the boron compound is boric acid.
33. The lubricating composition of claim 30 wherein the value of Mn in (B2a) is from about 700 to about 1500.
34. The lubricating composition of claim 30 wherein the substituent groups in (B2a) are derived from a polybutene in which at least about 50% of the total units derived from butene are derived from isobu¬ tene.
35. The lubricating composition of claim 30 wherein the polyamine (B2b) is characterized by the formula R3N(UN)nR3 R3 R3 wherein n is an integer of from 1 to about 10, each R3 is independently a hydrogen atom, a hydrocarbyl group or a hydroxysubstituted or aminosubstituted hydrocarbyl group having up to about 30 carbon atoms, or two R3 groups on different nitrogen atoms can be joined toge¬ ther to form a U group with the proviso that at least one R3 group is a hydrogen atom, and U is an alkylene group of about 2 to about 10 carbon atoms.
36. The lubricating composition of claim 30 wherein the polyamine (B2b) is a polyalkylene poly¬ amine.
37. The lubricating composition of claim 30 wherein R in demulsifier (C) is an alkenyl group contain¬ ing from 9 to about 25 carbon atoms.
38. The lubricating composition of claim 30 wherein R' in demulsifier (C) is hydrogen.
39. The lubricating composition of claim 30 also containing from about 0.02 to about 0.5% by weight of at least one polyglycol demulsifier.
40. A lubricating composition comprising the mixture of (A) a major amount of an oil of lubricating viscosity, (B) from about 0.1 to about 5% by weight of at least one nitrogen and boroncontaining composition prepared by reacting (B1) boric acid with (B2) at least one acylated nitrogen inter¬ mediate prepared by the reaction of (B2a) at least one substituted succinic acylating agent with from about onehalf equiva¬ lent up to about two moles per equivalent of acylating agent, of (B2b) at least one polyamine char¬ acterized by the presence within its structure of at least one >NH group, and wherein said substituted succin¬ ic acylating agent consists of substituent groups and succinic groups, the substituent groups are derived from a polyalkene having an Mn value of from about 700 to about 5000, and the amounts of (B1) and (B2) are suffi¬ cient to provide from about 0.1 atomic proportion of boron for each mole of said acylated nitrogen intermedi¬ ate up to about 10 atomic proportions of boron for each atomic proportion of nitrogen of said acylated nitrogen intermediate, and (C) from about 0.02 to about 0.5% by weight of at least one demulsifier selected from 1(2hydroxy¬ ethyl)2alkenyl imidazolines wherein the alkenyl group contains from about 9 to about 25 carbon atoms.
41. The lubricating composition of claim 40 wherein the polyamine (B2b) is a polyalkylene poly¬ amine.
42. The lubricating composition of claim 40 wherein the value of Mn in (B2a) is from about 700 to about 1500.
43. The lubricating composition of claim 40 wherein the polyalkene is a polybutene in which at least about 50% of the total units derived from butenes are derived from isobutene.
44. The lubricating composition of claim 40 wherein the acylated nitrogen intermediate is prepared by the reaction of about one equivalent of the substi¬ tuted succinic acylating agent (B2a) with about one equivalent of the polyamine (B2b) .
45. The lubricating composition of claim 40 wherein the alkenyl group in demulsifier (C) is hepta decenyl1.
46. The lubricating composition of claim 40 also containing (D) from about 0.02 to about 0.5% by weight of at least one polyglycol demulsifier.
47. A concentrate for formulating lubricating oil compositions comprising (A) from about 20 to about 90% by weight of a normally liquid, substantially inert organic diluent/ solvent, (B) from about 0.1 to about 50% by weight of at least one ashless dispersant, and (C) from about 0.01 to about 15% by weight of at least one demulsifier characterized by the formula wherein R is a hydrocarbyl group, R2, R3, R4 and R5 are each independently H or hydrocarbyl groups, and X is 0 or NR' wherein R' is hydrogen or a hydrocarbyl group.
48. A concentrate for formulating lubricating oil compositions comprising (A) from about 20 to about 90% by weight of a normally liquid, substantially inert organic diluent/ solvent, (B) from about 0.1 to about 50% by weight of at least one nitrogen and boroncontaining composition prepared by reacting (B1) a boron compound selected from the group consisting of boron trioxide, boron anhydrides, boron halides, boron acids, boron amides, esters of boric acid and mixtures thereof with (B2) at least one acylated nitrogen inter¬ mediate prepared by the reaction of (B2a) at least one substituted succinic acylating agent with (B2b) at least about onehalf equivalent, per equivalent of acylating agent, of an amine characterized by the presence within its structure of at least one >NH group wherein said substituted suc¬ cinic acylating agent consists of substituent groups and succinic groups, and the substituent groups are derived from polyalkene characterized as having an Mn value of at least about 700, and (C) from about 0.01 to about 15% by weight of at least one demulsifier characterized by the formula wherein R is an alkyl or alkenyl group containing from about 5 to about 30 carbon atoms, and R' is hydrogen or a hydrocarbyl group containing from 1 to about 8 carbon atoms.
49. The concentrate of claim 48 also contain¬ ing from about 0.01 to about 15% by weight of at least one polyglycol demulsifier.
Description:
Title: LUBRICANT AND FUNCTIONAL FLUID COMPOSITIONS EXHIBITING IMPROVED DEMULSIBILITY

Field of the Invention

This invention relates to lubricating and func¬ tional fluid compositions, and to additive concentrates useful in preparing such compositions. More particular- ly f the lubricating compositions of the present inven¬ tion comprise an oil of lubricating viscosity, an ash¬ less dispersant, and a minor effective amount of a demul¬ sifier. The compositions are useful in automotive as well as industrial applications.

Background of the Invention

The problems associated with the lubrication of gears such as utilized in automotive transmissions and axles are well known to those skilled in the art. In the lubrication of automatic transmissions, proper fluid viscosity at both low and high temperatures is essential to successful operation. Good low temperature fluidity eases cold weather starting and insures that the hydraul¬ ic control system will properly "shift gears". High viscosity at elevated temperatures insures pumpability and the satisfactory operation of converters, valves, clutches, gears and bearings.

It also is well known that the high pressure which occurs in certain types of gears and bearings may cause rupture of lubricant films with consequent damage to the machinery. Because of the severe conditions under which they are used, industrial and automotive

gear lubricants ordinarily must contain additives which maximize their capability of functioning under extreme pressure conditions. It has been suggested that certain compounds of metal-reactive elements, such as compounds of chlorine, sulfur, phosphorus and lead impart extreme pressure properties to various lubricants. Among the various compositions known to serve this purpose are various phosphorus- and sulfur-containing compositions, chiefly salts and esters of dialkylphosphorodithioic acids, and sulfurization products of various aliphatic olefinic compounds. These two types of compositions have been used in combination in lubricants of this type, and they serve to increase the effectiveness of the lubricant under conditions of extreme pressure.

In addition to extreme pressure agents, lubri¬ cating compositions useful as gear lubricants generally will contain one or more of the following: dispersants, detergents, pour point depressants, oxidation inhibit¬ ors, corrosion inhibitors, foam inhibitors, friction modifiers and viscosity improvers.

Lubricating and industrial oil compositions con¬ tain dispersants which are capable of dispersing sludge and other deposits formed in the oil compositions in use. Unless maintained in fine suspension (i.e., dis¬ persed in the lubricating or industrial oil) the sludge deposits on gears, bearings and seals where it eventual¬ ly interferes with equipment operation. Dispersants which have been used extensively in lubricants and func¬ tional fluids include the so-called ashless dispersants. These dispersants are referred to as being ashless be¬ cause they do not ordinarily contain metal and therefore do not yield a metal-containing ash on combustion. Many types of ashless dispersants are known in the art, and they are described more fully below.

It is well known that water is an undesirable contaminant in lubricants and functional fluids. Water not only reduces the effectiveness of the lubricant or fluid, it tends to form deleterious by-products, parti¬ cularly in relation to the metal parts in contact with or utilizing the lubricant or functional fluid. For example, water present in a lubricant is responsible for the formation of objectionable mayonnaise-like sludge which in turn promotes the formation of hard-to-remove deposits from various parts of the machinery being lubri¬ cated. Presumably, the formation of the sludge is pre¬ ceded by the water forming an emulsion with the lubri¬ cant oil. While water should be separable from an oil or functional fluid due to immiscibility, some of the additives in the lubricants or functional fluids may have water-solubility sufficient to form emulsions which are difficult to remove. Also, the presence of additives such as ashless dispersants and detergents facilitate the formation and increase the stability of emulsions thereby making it difficult to separate the water from the oil or functional fluid. Therefore, it is important to minimize the presence of water in lubricating composi¬ tions and functional fluids to reduce or eliminate the formation of such emulsions.

Obviously, lubricants having minimum contact with water will not present serious problems of water- oil emulsions. However, it is difficult to eliminate contact with water, particularly during storage, handl¬ ing, and/or use (e.g., in a steel mill environment).

Demulsifiers have been suggested and used in the prior art. Primarily, these demulsifiers have comprised compositions such as polyoxyalkylene glycols and polyoxypolyamines. It has been observed, however.

that these glycols and polyamines have not been entirely satisfactory because of their limited use and inability to function except in specific lubricants or functional fluids.

U.S. Patent 4,129,508 describes a demulsifier additive composition for lubricants and fuels which com¬ prises (A) one or more reaction products of a hydrocar¬ bon-substituted succinic acid or anhydride with one or more polyalkylene glycols or monoethers thereof, (B) one or more organic basic metal salts, and (C) one or more alkoxylated amines.

The use of various derivatives of imidazolines as friction-reducing additives in lubricating composi¬ tions is described in U.S. Patents 4,406,802; 4,298,486; and 4,273,665. The *802 patent describes the use of mixed borated alcohol-amines, alcohol-amides, alcohol- ethoxylated amines, alcohol-ethoxylated amides, alcohol- hydroxy esters, alcohol-imidazolines and alcohol-hydro- lyzed imidazolines and mixtures thereof as friction-modi¬ fying agents in various organic media. The borated derivatives include those derived from hydroxy alkyl or hydroxy alkenyl alkyl or alkenyl imidazolines and/or the hydrolysis products of the imidazolines. The '486 patent describes boric acid salts and borate esters of hydroxy- ethyl alkyl imidazolines whereas U.S. Patent 4,273,665 describes the use of hydrolysis products of l-(2-hydroxy- alkyl)-2-alkyl or alkenyl imidazolines and borated adducts of hydrolyzed l-(2-hydroxyethyl)-2-alkyl imidazo¬ lines as friction modifiers for lubricating oils. In addition to exhibiting friction-reducing properties, the imidazoline derivatives described in the above patents are reported to provide the lubricant with copper anti- corrosion and antioxidant properties.

Summary of the Invention A lubricating composition is described which comprises a mixture of

(A) a major amount of an oil of lubricating viscosity,

(B) a dispersant effective amount of at least one ashless dispersant, and

(C) a minor, effective amount of at least one demulsifier characterized by the formula

wherein R is a hydrocarbyl group, R2, R3, R4 and R5 are each independently H or hydrocarbyl groups, and X is 0 or NR' wherein R' is hydrogen or a hydrocarbyl group.

In one embodiment, the ashless dispersant is a carboxylic dispersant, and the demulsifier is a deriva¬ tive of imidazoline. The lubricating compositions of the invention are characterized as having improved dis- persancy, demulsibility, rust-inhibition and anti-wear properties.

Description of the Preferred Embodiments Throughout the specification and claims, refer¬ ences to percentages by weight of the various compon¬ ents, except for component (A) which is oil, or on a chemical basis unless otherwise indicated. For example, when the oil compositions of the invention are described

as containing 1% by weight of (B) , the oil composition comprises 1% by weight of (B) on a chemical basis. Thus, if component (B) is available as a 50% by weight oil solution, 2% by weight of the oil solution would be included in the oil composition of the invention.

As used in this specification and in the append¬ ed claims, the term "hydrocarbyl" denotes a group having a carbon atom directly attached to the remainder of the molecule and having a hydrocarbon or predominantly hydro¬ carbon character within the context of this invention. Such groups include the following:

(1) Hydrocarbon groups; that is, aliphatic, (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl or cycloalkenyl) , aromatic, aliphatic- and alicyclic-substi- tuted aromatic, aromatic-substituted aliphatic and alicy¬ clic groups, and the like, as well as cyclic groups wherein the ring is completed through another portion of the molecule (that is, any two indicated substituents may together form an alicyclic group) . Such groups are known to those skilled in the art. Examples include methyl, ethyl, octyl, decyl, octadecyl, cyclohexyl, phenyl, etc.

(2) Substituted hydrocarbon groups; that is, groups containing non-hydrocarbon substituents which, in the context of this invention, do not alter the predom¬ inantly hydrocarbon character of the group. Those skilled in the art will be aware of suitable substitu¬ ents. Examples include halo, hydroxy, nitro, cyano, alkoxy, acyl, etc.

(3) Hetero groups; that is, groups which, while predominantly hydrocarbon in character within the context of this invention, contain atoms other than carbon in a chain or ring otherwise composed of carbon atoms. Suitable hetero atoms will be apparent to those

skilled in the art and include, for example, nitrogen, oxygen and sulfur.

In general, no more than about three substitu¬ ents or hetero atoms, and preferably no more than one, will be present for each 10 carbon atoms in the hydrocar¬ byl group.

Terms such as "alkyl-based", "aryl-based", and the like have meanings analogous to the above with respect to alkyl groups, aryl groups and the like.

The term "hydrocarbon-based" has the same meaning and can be used interchangeably with the term hydrocarbyl when referring to molecular groups having a carbon atom attached directly to the remainder of a molecule.

The term "lower" as used herein in conjunction with terms such as hydrocarbyl, alkyl, alkenyl, alkoxy, and the like, is intended to describe such groups which contain a total of up to 7 carbon atoms.

The term "oil-soluble" refers to a material that is soluble in mineral oil or the lubricating oil or functional fluid compositions of this invention to the extent of at least about one gram per liter at 25°C.

Throughout the specification and claims, unless otherwise specifically stated, all parts and percentages are by weight, temperatures are in degrees centigrade, and pressures are atmospheric. (A) Oil of Lubricating Viscosity.

The oil which is utilized in the preparation of the lubricants of the invention may be based on natural oils, synthetic oils, or mixtures thereof.

Natural oils include animal oils and vegetable oils (e.g., castor oil, lard oil) as well as mineral lubricating oils such as liquid petroleum oils and sol¬ vent treated or acid treated mineral lubricating oils of

the paraffinic, naphthenic or mixed paraffinic-naphthen- ic types. Oils of lubricating viscosity derived from coal or shale are also useful. Synthetic lubricating oils include hydrocarbon oils and halosubstituted hydro¬ carbon oils such as polymerized and interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene- isobutylene copolymers, chlorinated polybutylenes, etc.); poly(l-hexenes) , poly(l-octenes) , poly(l-dec- enes) , etc. and mixtures thereof; alkylbenzenes (e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes, etc.); polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls, etc.); alkylated diphenyl ethers and alkylated diphenyl sulf- ides and the derivatives, analogs and homologs thereof and the like.

Alkylene oxide polymers and interpolymers and derivatives thereof where the terminal hydroxyl groups have been modified by esterification, etherification, etc., constitute another class of known synthetic lub¬ ricating oils that can be used. These are exemplified by the oils prepared through polymerization of ethylene oxide or propylene oxide, the alkyl and aryl ethers of these polyoxyalkylene polymers (e.g., methylpolyiso- propylene glycol ether having an average molecular weight of about 1000, diphenyl ether of polyethylene glycol having a molecular weight of about 500-1000, di- ethyl ether of polypropylene glycol having a molecular weight of about 1000-1500, etc.) or mono- and polycar- boxylic esters thereof, for example, the acetic acid esters, mixed C3-C8 fatty acid esters, or the C13 Oxo acid diester of tetraethylene glycol.

Another suitable class of synthetic lubricating oils that can be used comprises the esters of dicarbox- ylic acids (e.g., phthalic acid, succinic acid, alkyl

succinic acids, alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic acids, etc.) with a var¬ iety of alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc.) Specific examples of these esters include dibutyl adi- pate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azel- ate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid and the like.

Esters useful as synthetic oils also include those made from C5 to C12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, tri- methylol propane, pentaerythritol, dipentaerythritol, tripentaerythritol, etc.

Silicon-based oils such as the polyalkyl-, poly- aryl-, polyalkoxy-, or polyaryloxy-siloxane oils and sil¬ icate oils comprise another useful class of synthetic lu¬ bricants (e.g., tetraethyl silicate, tetraisopropyl sili¬ cate, tetra-(2-ethylhexyl)silicate, tetra-(4-methylhex- yl)silicate, tetra-(p-tert-butylphenyl)silicate, hexyl- (4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes, poly(methylphenyl)siloxanes, etc.). Other synthetic lub¬ ricating oils include liquid esters of phosphorus-con¬ taining acids (e.g., tricresyl phosphate, trioctyl phos¬ phate, diethyl ester of decane phosphonic acid, etc.), polymeric tetrahydrofurans and the like.

-10-

Unrefined, refined and rerefined oils, either natural or synthetic (as well as mixtures of two or more of any of these) of the type disclosed hereinabove can be used in the concentrates of the present invention. Unrefined oils are those obtained directly from a natur¬ al or synthetic source without further purification treatment. For example, a shale oil obtained directly from retorting operations, a petroleum oil obtained directly from primary distillation or ester oil obtained directly from an esterification process and used without further treatment would be an unrefined oil. Refined oils are similar to the unrefined oils except they have been further treated in one or more purification steps to improve one or more properties. Many such purifica¬ tion techniques are known to those skilled in the art such as solvent extraction, hydrotreating, secondary dis¬ tillation, acid or base extraction, filtration, percola¬ tion, etc. Rerefined oils are obtained by processes similar to those used to obtain refined oils applied to refined oils which have been already used in service. Such rerefined oils are also known as reclaimed, recycl¬ ed or reprocessed oils and often are additionally proces¬ sed by techniques directed to removal of spent additives and oil breakdown products. (B) Ashless Dispersant.

The lubricating compositions of the present invention contain a dispersant effective amount of at least one ashless dispersant. Ashless dispersants are referred to as being ashless despite the fact that, depending on their constitution the dispersants may upon combustion yield a non-volatile material such as boric oxide or phosphorus pentoxide. However, the ashless dispersants do not ordinarily contain metal, and there-

fore do not yield a metal-containing ash upon combus¬ tion. Many types of ashless dispersants are known in the prior art, and any of these is suitable for use in the lubricating compositions of the present invention. The ashless dispersants which can be utilized in the lubricating compositions of the present invention include the following: carboxylic dispersants; amine dispersants; Mannich dispersants; polymeric dispersants; and carboxylic, amine or Mannich dispersants post-treat¬ ed with such reagents as urea, thiourea, carbon disulf- ide, aldehydes, ketones, carboxylic acids, hydrocarbon- substituted succinic anhydrides, nitriles, epoxides, boron compounds, phosphorus compounds, etc.

The amine dispersants are reaction products of relatively high molecular weight aliphatic or alicyclic halides with amines, preferably polyalkylene polyamines. Amine dispersants are known and have been described in the prior art such as in U.S. Patents 3,275,554; 3,438,757; 3,454,555; and 3,565,804. Mannich dispersants are reaction products of alkyl phenols in which the alkyl group contains at least about 30 carbon atoms with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines). The mater¬ ials described in the following patents are illustrative of Mannich dispersants: U.S. Patents 3,413,347; 3,697,574; 3,725,277; 3,725,480; and 3,726,882.

Products obtained by post-treating the carbox¬ ylic, amine or Mannich dispersants with such reagents as urea, thiourea, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhy¬ drides, nitriles, epoxides, boron compounds, phosphorus compounds or the like are useful ashless dispersants. Exemplary materials of this kind are described in the

foilowing U.S. Patents 3,036,003; 3,200,107; 3,254,025 3,278,550 3,281,428; 3,282,955; 3,366,569; 3,373,111 3,442,808 3,455,832; 3,493,520; 3,513,093; 3,539,633 3,579,450 3,600,372; 3,639,242; 3,649,659; 3,703,536 and 3,708,522. Polymeric dispersants are interpolymers of oil-solubilizing monomers such as decyl methacrylate, vinyl decyl ether and high molecular weight olefins with monomers containing polar substituents, e.g., aminoalkyl acrylates or acrylamides and poly-(oxyethylene)-substi¬ tuted acrylates. Polymeric dispersants are disclosed in the following U.S. Patents 3,329,658; 3,449,250; 3,519,565; 3,666,730; 3,687,849; and 3,702,300. All of the above-noted patents are incorporated by reference herein for their disclosures of ashless dispersants.

The carboxylic dispersants generally are reac¬ tion products of substituted carboxylic acylating agents such as substituted carboxylic acids or derivatives thereof with (a) amines characterized by the presence within their structure of at least one >NH group, (b) organic hydroxy compounds such as phenols and alcohols, (c) basic inorganic materials such as reactive metal or reactive metal compounds, and (d) mixtures of two or more of (a) through (c) . The dispersants which are obtained by the reaction of a substituted carboxylic acylating agent with an amine compound often are refer¬ red to as "acylated amine dispersants" or "carboxylic imide dispersants" such as succini ide dispersants. The ashless dispersants obtained by the reaction of a substi¬ tuted carboxylic acylating agent with an alcohol or phenol generally are referred to as carboxylic ester dispersants.

The substituted carboxylic acylating agent may be derived from a monocarboxylic acid or a polycarboxyl- ic acid. Polycarboxylic acids generally are preferred. The acylating agents may be a carboxylic acid or deriva¬ tives of the carboxylic acid such as the halides, esters, anhydrides, etc. The free carboxylic acids or the anhydrides of polycarboxylic acids are preferred acylating agents.

In one preferred embodiment, the ashless dis¬ persants utilized in the lubricating oil compositions of the present invention are the acylated amines or dispers¬ ants obtained by reaction of a carboxylic acylating agent with at least one amine containing at least one hydrogen attached to a nitrogen group. In one preferred embodiment, the acylating agent is a hydrocarbon-substi¬ tuted succinic acid acylating agent.

The nitrogen-containing carboxylic dispersants particularly useful as component (B) in the lubricating compositions of the present invention are known in the art and have been described in many U.S. patents including

3,172,892 3,341,542 3,630,904

3,215,707 3,444,170 3,632,511

3,219,666 3,454,607 3,787,374

3,316,177 3,541,012 4,234,435

The above U.S. patents are expressly incorporated herein by reference for their teaching of the preparation of nitrogen-containing carboxylic dispersants useful as component (B) .

In general, the nitrogen-containing carboxylic dispersants are produced by reacting (B-2-a) at least one substituted succinic acylating agent with (B-2-b) at least one amine compound containing at least one >HN

group, and wherein said acylating agent consists of sub- stituent groups and succinic groups wherein the substi- tuent groups are derived from a polyalkene characterized by an Mn value of at least about 700, and more generally from about 700 to about 5000. Generally, the reaction involves from about 0.5 equivalent to about 2 moles of the amine compound per equivalent of acylating agent.

Similarly, the carboxylic ester dispersants are prepared by reacting the carboxylic acylating agents described above with one or more alcohols or phenols in ratios of from about 0.5 equivalent to about 2 moles of hydroxy compound per equivalent of acylating agent. The preparation of carboxylic ester dispersant is described in the prior art such as U.S. Patents 3,522,179 and 4,234,435.

The number of equivalents of the acylating a- gent depends on the total number of carboxylic functions present. In determining the number of equivalents for the acylating agents, those carboxyl functions which are not capable of reacting as a carboxylic acid acylating agent are excluded. In general, however, there is one equivalent of acylating agent for each carboxy group in these acylating agents. For example, there are two equivalents in an anhydride derived from the reaction of one mole of olefin polymer and one mole of maleic anhy¬ dride. Conventional techniques are readily available for determining the number of carboxyl functions (e.g., acid number, saponification number) and, thus, the number of equivalents of the acylating agent can be readily deter¬ mined by one skilled in the art.

An equivalent weight of an amine or a polyamine is the molecular weight of the amine or polyamine divid¬ ed by the total number of nitrogens (or >NH groups)

present in the molecule. Thus, ethylene diamine has an equivalent weight equal to one-half of its molecular weight; diethylene triamine has an equivalent weight equal to one-third its molecular weight. The equivalent weight of a commercially available mixture of polyalkyl¬ ene polyamine can be determined by dividing the atomic weight of nitrogen (14) by the %N contained in the poly¬ amine and multiplying by 100; thus, a polyamine mixture containing 34% nitrogen would have an equivalent weight of 41.2. An equivalent weight of ammonia or a monoamine is the molecular weight.

An equivalent weight of a hydroxyl-substituted amine to be reacted with the acylating agents to form the carboxylic derivative (B) is its molecular weight divided by the total number of >NH and -OH groups pres¬ ent in the molecule. Thus, ethanolamine would have an equivalent weight equal to one-half of its molecular weight, and diethanolamine has an equivalent weight equal to one-third of its molecular weight.

The terms "substituent", "acylating agent" and "substituted succinic acylating agent" are to be given their normal meanings. For example, a substituent is an atom or group of atoms that has replaced another atom or group in a molecule as a result of a reaction. The terms acylating agent or substituted succinic acylating agent refer to the compound per se and does not include unreacted reactants used to form the acylating agent or substituted succinic acylating agent.

The acylated nitrogen compounds and carboxylic esters can be used directly as ashless dispersants in the compositions of the invention or they can be used as intermediates and post-treated with certain reagents as described more fully below.

The substituted succinic acylating agent (B-2-a) utilized the preparation of the carboxylic dis¬ persant (B) can be characterized by the presence within its structure of two groups or moieties. The first group or moiety is referred to hereinafter, for convenience, as the "substituent group(s)" and is derived from a poly- alkene. The polyalkene from which the substituted groups are derived is characterized by an Mn (number average molecular weight) value of at least about 700. In one embodiment, the polyalkene is characterized by an Mn value of about 700 to about 5000, and in another embodi¬ ment Mn varies between about 700 to about 1200 or 1300.

In another embodiment the value of Mn is gener¬ ally higher and between 1300 to about 5000 with an Mn value in the range of from about 1500 to about 5000 also being preferred. A more preferred Mn value in this embodiment is one in the range of from about 1500 to about 2800. A most preferred range of Mn values is from about 1500 to about 2400.

In yet another embodiment the substituent groups are derived from polyalkenes having an Mn value of at least about 1300 up to about 5000, and the ~ Mw/Mn value is from about 1.5 to about 4. The preparation and use of substituted succinic acylating agents wherein the substituent is derived from such polyolefins are describ¬ ed in U.S. Patent 4,234,435, the disclosure of which is hereby incorporated by reference.

Gel permeation chromatography (GPC) is a method which provides both weight average and number average molecular weights as well as the entire molecular weight distribution of the polymers. For purpose of this inven¬ tion a series of fractionated polymers of isobutene, polyisobutene, is used as the calibration standard in the GPC.

The techniques for determining Mn and Mw values of polymers are well known and are described in numerous books and articles. For example, methods for the deter¬ mination of Mn and molecular weight distribution of poly¬ mers is described in W.W. Yan, J.J. Kirkland and D.D. Bly, "Modern Size Exclusion Liquid Chromatographs", J. Wiley & Sons, Inc., 1979.

The second group or moiety in the acylating agent is referred to herein as the "carboxylic group" or "succinic group(s) π . The succinic groups are those groups characterized by the structure

0 I _ ° X-C-C-C-C-X' (I)

wherein X and X' are the same or different provided at least one of X and X' is such that the substituted succinic acylating agent can function as carboxylic acylating agents. That is, at least one of X and X' must be such that the substituted acylating agent can form amides or amine salts with amino compounds, and otherwise function as a conventional carboxylic acid acylating agents. Transesterification and transamida- tion reactions are considered, for purposes of this invention, as conventional acylating reactions.

Thus, X and/or X' is usually -OH, -0-hydrocar- byl, -0-M+ where M+ represents one equivalent of a metal, ammonium or amine cation, -NH2, -Cl, -Br, and together, X and X' can be -0- so as to form the anhy¬ dride. The specific identity of any X or X* group which is not one of the above is not critical so long as its presence does not prevent the remaining group from enter¬ ing into acylation reactions. Preferably, however, X

and X' are each such that both carboxyl functions of the succinic group (i.e., both -C(0)X and -C(0)X' can enter into acylation reactions.

One of the unsatisfied valences in the grouping

I I -C-C-

I I of Formula I forms a carbon carbon bond with a carbon atom in the substituent group. While other such unsatis¬ fied valence may be satisfied by a similar bond with the same or different substituent group, all but the said one such valence is usually satisfied by hydrogen; i.e., -H.

In one preferred embodiment, the succinic groups will normally correspond to the formula

-CH- -C(0)R I

CH2—C(0)R « (ID

wherein R and R' are each independently selected from the group consisting of -OH, -Cl, -O-lower alkyl, and when taken together, R and R* are -0-. In the latter case, the succinic group is a succinic anhydride group. All the succinic groups in a particular succinic acylat¬ ing agent need not be the same, but they can be the same. Preferably, the succinic groups will correspond to

(A) (B)

and mixtures of (111(A)) and (111(B)). Providing substi¬ tuted succinic acylating agents wherein the succinic groups are the same or different is within the ordinary skill of the art and can be accomplished through conven¬ tional procedures such as treating the substituted suc¬ cinic acylating agents themselves (for example, hydrolyz- ing the anhydride to the free acid or converting the free acid to an acid chloride with thionyl chloride) and/or selecting the appropriate maleic or fumaric react- ants.

In addition to preferred substituted succinic groups where the preference depends on the number and identity of succinic groups for each equivalent weight of substituent groups, still further preferences are based on the identity and characterization of the poly- aikenes from which the substituent groups are derived.

The polyalkenes from which the substituent groups 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 interpoly¬ mers are those in which two or more olefin monomers are interpolymerized according to well-known conventional procedures to form polyalkenes having units within their structure derived from each of said two or more olefin monomers. Thus, "interpolymer(s)" as used herein is inclusive of copolymers, 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 character¬ ized by the presence of one or more ethylenically unsat-

urated groups (i.e., >C=C<); that is, they are monoole- finic monomers such as ethylene, propylene, butene-1, isobutene, and octene-1 or polyolefinic monomers (usual¬ ly diolefinic monomers) such as butadiene-1,3 and iso- prene.

These olefin monomers are usually polymerizable terminal olefins; that is, olefins characterized by the presence in their structure of the group >C=CH2. How¬ ever, polymerizable internal olefin monomers (sometimes referred to in the literature as medial olefins) charac¬ terized by the presence within their structure of the group

I I I I

-C-C=C-C-

I I can also be used to form the polyalkenes. When internal olefin monomers are employed, they normally will be em¬ ployed with terminal olefins to produce polyalkenes which are interpolymers. For purposes of this invention, when a particular polymerized olefin monomer can be classified as both a terminal olefin and an internal olefin, it will be deemed to be a terminal olefin. Thus, 1,3-pentadiene (i.e., piperylene) is deemed to be a terminal olefin for purposes of this invention.

There is a general preference for aliphatic, hydrocarbon polyalkenes free from aromatic and cycloali- phatic groups. Within this general preference, there is a further preference for polyalkenes which are derived from the group consisting of homopolymers and interpoly- mers of terminal hydrocarbon olefins of 2 to about 16 carbon atoms. This further preference is qualified by the proviso that, while interpolymers of terminal ole¬ fins are usually preferred, interpolymers optionally

containing up to about 40% of polymer units derived from internal olefins of up to about 16 carbon atoms are also within a preferred group. A more preferred class of polyalkenes are those selected from the group consisting of homopolymers and interpolymers of terminal olefins of 2 to about 6 carbon atoms, more preferably 2 to 4 carbon atoms. However, another preferred class of polyalkenes are the latter more preferred polyalkenes optionally containing up to about 25% of polymer units derived from internal olefins of up to about 6 carbon atoms. Polybu- tenes in which at least about 50% of the total units derived from butene are derived from isobutylene.

Obviously, preparing polyalkenes as described above which meet the various criteria for ϊϊn and Mw/Mn is within the skill of the art and does not comprise part of the present invention. Techniques readily appar¬ ent to those in the art include controlling polymeriza¬ tion temperatures, regulating the amount and type of polymerization initiator and/or catalyst, employing chain terminating groups in the polymerization proced¬ ure, and the like. Other conventional techniques such as stripping (including vacuum stripping) a very light end and/or oxidatively or mechanically degrading high molecular weight polyalkene to produce lower molecular weight polyalkenes can also be used.

In preparing the substituted succinic acylating agents of this invention, one or more of the above-des¬ cribed polyalkenes is reacted with one or more acidic reactants selected from the group consisting of maleic or fumaric reactants of the general formula

X(0)C-CH=CH-C(0)X' (IV)

wherein X and X* are as defined hereinbefore in Formula I. Preferably the maleic and fumaric reactants will be one or more compounds corresponding to the formula

RC(0)-CH=CH-C(0)R' (V)

wherein R and R' are as previously defined in Formula II herein. Ordinarily, the maleic or fumaric reactants will be maleic acid, fumaric acid, maleic anhydride, or a mixture of two or more of these. The maleic reactants are usually preferred over the fumaric reactants because the former are more readily available and are, in gen¬ eral, more readily reacted with the polyalkenes (or derivatives thereof) to prepare the substituted succinic acylating agents of the present invention. The especial¬ ly preferred reactants are maleic acid, maleic anhy¬ dride, and mixtures of these. Due to availability and ease of reaction, maleic anhydride will usually be em¬ ployed.

The molar ratio of polyalkene to maleic reac- tant preferably is such that there is at least about one mole of maleic reactant for each mole of polyalkene. This is necessary in order that there can be at least 1.0 succinic group per equivalent weight of substituent group in the product. Preferably, however, an excess of maleic reactant is used. Thus, ordinarily about a 5% to about 25% excess of maleic reactant will be used rela¬ tive to that amount necessary to provide the desired number of succinic groups in the product.

In another embodiment, the acylating agents are prepared by reacting the polyalkene with an excess of maleic anhydride to provide substituted succinic acylat¬ ing agents wherein the number of succinic groups for

each equivalent weight of substituent group is at least 1.3. The maximum number will not exceed 4.5. A suitable range is from about 1.4 to 3.5 and more specifically from about 1.4 to about 2.5 succinic groups per equiva¬ lent weight of substituent groups. In this embodiment, the value of Mn is preferably between about 1300 and 5000. A more preferred range for Mn is from about 1500 to about 2800, and a most preferred range of Mn values is from about 1500 to about 2400.

Examples of patents describing various proced¬ ures for preparing useful acylating agents include U.S. Patents 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. The disclosures of these patents are hereby incorporated by reference.

For convenience and brevity, the term "maleic reactant" is often used hereinafter. When used, it should be understood that the term is generic to acidic reactants selected from maleic and fumaric reactants corresponding to Formulae (IV) and (V) above including a mixture of such reactants.

The acylating reagents described above are intermediates in processes for preparing the acylated nitrogen compositions (B-2) which may, per se, be used in the lubricants or may be used as intermediates and post-treated with various reagents as described below to form dispersants useful in the invention. The acylated nitrogen compositions (B-2) are prepared by reacting (B-2-a) one or more acylating reagents with (B-2-b) at least one amino compound characterized by the presence within its structure of at least one >HN group.

The amine (B-2-b) characterized by the presence within its structure of at least one HN< group can be a monoamine or polyamine compound. Mixtures of two or more amino compounds can be used in the reaction with one or more acylating reagents of this invention. Pref¬ erably, the amino compound contains at least one primary amino group (i.e., -NH2) and more preferably the amine is a polyamine, especially a polyamine containing at least two -NH- groups, either or both of which are prim¬ ary or secondary amines. The amines may be aliphatic, cycloaliphatic, aromatic or heterocyclic amines. The polyamines not only result in carboxylic acid derivative compositions which are usually more effective as dispers- ant/detergent additives, relative to derivative composi¬ tions derived from monoamines, but these preferred poly¬ amines result in carboxylic derivative compositions which exhibit more pronounced V.I. improving properties.

Among the preferred amines are the alkylene polyamines, including the polyalkylene polyamines. The alkylene polyamines include those conforming to the formula

R3N-(U-N)n-R 3 (VI) R3 R3

wherein n is from 1 to about 10; each R3 is independ¬ ently a hydrogen atom, a hydrocarbyl group or a hydroxy- substituted or amine-substituted hydrocarbyl group hav¬ ing up to about 30 atoms, or two R3 groups on differ¬ ent nitrogen atoms can be joined together to form a U group, with the proviso that at least one R3 group is a hydrogen atom and U is an alkylene group of about 2 to about 10 carbon atoms. Preferably U is ethylene or pro-

pylene. Especially preferred are the alkylene poly¬ amines where each R3 is hydrogen or an amino-substi- tuted hydrocarbyl group with the ethylene polyamines and mixtures of ethylene polyamines being the most prefer¬ red. Usually n will have an average value of from about 2 to about 7. Such alkylene polyamines include methyl- ene polyamine, ethylene polyamines, butylene polyamines, propylene polyamines, pentylene polyamines, hexylene polyamines, heptylene polyamines, etc. The higher homo- logs of such amines and related amino alkyl-substituted piperazines are also included.

Alkylene polyamines useful in preparing the acylated nitrogen compositions (B-2) include ethylene diamine, triethylene tetramine, propylene diamine, tri- methylene diamine, hexamethylene diamine, decamethylene diamine, hexamethylene diamine, decamethylene diamine, octamethylene diamine, di(heptamethylene) triamine, tri- propylene tetramine, tetraethylene pentamine, trimeth- ylene diamine, pentaethylene hexamine, di(trimethylene)- triamine, N-(2-aminoethyl)piperazine, 1,4-bis (2,aminoeth- yl)piperazine, and the like. Higher homologs as are obtained by condensing two or more of the above-illus¬ trated alkylene amines are useful, as are mixtures of two or more of any of the afore-described polyamines.

Ethylene polyamines, such as those mentioned above, are especially useful for reasons of cost and effectiveness. Such polyamines are described in detail under the heading "Diamines and Higher Amines" in The Encyclopedia of Chemical Technology, Second Edition, Kirk and Othmer, Volume 7, pages 27-39, Interscience Publishers, Division of John Wiley and Sons, 1965, which is hereby incorporated by reference for the disclosure of useful polyamines. Such compounds are prepared most

conveniently by the reaction of an alkylene chloride with ammonia or by reaction of an ethylene imine with a ring-opening reagent such as ammonia, etc. These reac¬ tions result in the production of the somewhat complex mixtures of alkylene polyamines, including cyclic conden¬ sation products such as piperazines. The mixtures are particularly useful in preparing the acylated nitrogen compounds (B-2) useful in this invention. On the other hand, quite satisfactory products can also be obtained by the use of pure alkylene polyamines.

Other useful types of polyamine mixtures are those resulting from stripping of the above-described polyamine mixtures. In this instance, lower molecular weight polyamines and volatile contaminants are removed from an alkylene polyamine mixture to leave as residue what is often termed "polyamine bottoms". In general, alkylene polyamine bottoms can be characterized as having less than two, usually less than 1% (by weight) material boiling below about 200°C. In the instance of ethylene polyamine bottoms, which are readily available and found to be quite useful, the bottoms contain less than about 2% (by weight) total diethylene triamine

(DETA) or triethylene tetramine (TETA) . A typical sample of such ethylene polyamine bottoms obtained from the Dow Chemical Company of Freeport, Texas designated "E-100" showed a specific gravity at 15.6°C of 1.0168, a percent nitrogen by weight of 33.15 and a viscosity at 40°C of 121 centistokes. Gas chromatography analysis of such a sample showed it to contain about 0.93% "Light Ends"

(most probably DETA), 0.72% TETA, 21.74% tetraethylene pentamine and 76.61% pentaethylene hexamine and higher

(by weight) . These alkylene polyamine bottoms include cyclic condensation products such as piperazine and high-

er analogs of diethylenetriamine, triethylenetetramine and the like.

These alkylene polyamine bottoms can be reacted solely with the acylating agent, in which case the amino reactant consists essentially of alkylene polyamine bot¬ toms, or they can be used with other amines and poly¬ amines, or alcohols or mixtures thereof. In these latter cases at least one amino reactant comprises alkylene polyamine bottoms.

Other polyamines which can be reacted with the acylating agents (B-2-a) in accordance with this inven¬ tion are described in, for example, U.S. Patents 3,219,666 and 4,234,435, and these patents are hereby incorporated by reference for their disclosures of amines which can be reacted with the acylating agents described above.

The acylated nitrogen compositions (B-2) produc¬ ed from the acylating reagents (B-2-a) and the amines (B-2-b) described hereinbefore comprise acylated amines which include amine salts, amides, imides, etc., as well as mixtures thereof. To prepare the acylated nitrogen compounds from the acylating reagents and the amines, one or more acylating reagents and one or more amines are heated, optionally in the presence of a normally liquid, substantially inert organic liquid solvent/dilu¬ ent, at temperatures in the range of about 80°C up to the decomposition point (where the decomposition point is as previously defined) but normally at temperatures in the range of about 100°C up to about 300°C provided 300°C does not exceed the decomposition point. Temper¬ atures of about 125°C to about 250°C are normally used. The acylating reagent and the amine are reacted in amounts sufficient to provide from about one-half equiv-

alent up to about 2 moles of amine per equivalent of acylating reagent.

Because the acylating reagents (B-2-a) can be reacted with the amine compounds (B-2-b) in the same manner as the high molecular weight acylating agents of the prior art are reacted with amines, U.S. Patents 3,172,892; 3,219,666; 3,272,746; and 4,234,435 are expressly incorporated herein by reference for their dis¬ closures with respect to the procedures applicable to reacting the acylating reagents with the amines as described above.

The amount of amine compound (B-2-b) within the above ranges that is reacted with the acylating agent (B-2-a) may also depend in part on the number and type of nitrogen atoms present. For example, a smaller amount of a polyamine containing one or more -NH2 groups is required to react with a given acylating agent than a polyamine having the same number of nitrogen atoms and fewer or no -NH2 groups. One -NH2 group can react with two -COOH groups to form an imide. If only second¬ ary nitrogens are present in the amine compound, each >NH group can react with only one -COOH group. Accord¬ ingly, the amount of polyamine within the above ranges to be reacted with the acylating agent to form the car¬ boxylic derivatives of the invention can be readily determined from a consideration of the number and types of nitrogen atoms in the polyamine (i.e., -NH2, >NH, and >N-) .

The ratio of succinic groups to the equivalent weight of substituent group present in the acylating agent can be determined from the saponification number of the reacted mixture corrected to account for unreact- ed polyalkene present in the reaction mixture at the end

of the reaction (generally referred to as filtrate or residue in the following examples) . Saponification num¬ ber is determined using the ASTM D-94 procedure. The formula for calculating the ratio from the saponifica¬ tion number is as follows:

Ratio = (Mn) (Sap No. ,corrected)

112,200-98(Sap No. ,corrected)

The corrected saponification number is obtained by dividing the saponification number by the percent of the polyalkene that has reacted. For example, if 10% of the polyalkene did not react and the saponification number of the filtrate or residue is 95, the corrected saponification number is 95 divided by 0.90 or 105.5.

The carboxylic dispersants (B) may be a carbox¬ ylic ester derivative compositions produced by reacting at least one substituted succinic acylating agent (B-2-a) with at least one alcohol or phenol of the general formula

R4(OH) m (VII)

wherein R4 is a monovalent or polyvalent organic group joined to the -OH groups through a carbon bond, and m is an integer of from 1 to about 10.

The carboxylic ester dispersants are those of the above-described succinic acylating agents with hydroxy compounds which may be aliphatic compounds such as monohydric and polyhydric alcohols or aromatic com¬ pounds such as phenols and naphthols. The aromatic hydroxy compounds from which the esters may be derived are illustrated by the following specific examples: phenol, beta-naphthol, alpha-naphthol, cresol, resorcin-

ol, catechol, p,p'-dihydroxybiphenyl, 2-chlorophenol, 2,4-dibutylphenol, etc.

The alcohols from which the esters may be derived preferably contain up to about 40 aliphatic car¬ bon atoms and more often from 2 to about 30 carbon atoms. They may be monohydric alcohols such as methanol, ethanol, isooctanol, dodecanol, cyclohexanol, etc. The polyhydric alcohols preferably contain from 2 to about 10 hydroxy groups. They are illustrated by, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, dibutylene glycol, tributylene glycol, and other alkylene glycols in which the alkylene group contains from 2 to about 8 carbon atoms.

An especially preferred class of polyhydric alcohols are those having at least three hydroxy groups, some of which have been esterified with a monocarboxylic acid having from about 8 to about 30 carbon atoms such as octanoic acid, oleic acid, stearic acid, linoleic acid, dodecanoic acid, or tall oil acid. Examples of such partially esterified polyhydric alcohols are the monooleate of sorbitol, distearate of sorbitol, mono- oleate of glycerol, monostearate of glycerol, di-dodecan- oate of erythritol.

The carboxylic ester dispersants (B) may be prepared by one of several known methods. The method which is preferred because of convenience and the super¬ ior properties of the esters it produces, involves the reaction of a suitable alcohol or phenol with a substan¬ tially hydrocarbon-substituted succinic anhydride. The esterification is usually carried out at a temperature above about 100°C, preferably between 150°C and 300°C. The water formed as a by-product is removed by distilla¬ tion as the esterification proceeds.

The relative proportions of the succinic react¬ ant and the hydroxy reactant which are to be used depend to a large measure upon the type of the product desired and the number of hydroxyl groups present in the mole¬ cule of the hydroxy reactant. For instance, the forma¬ tion of a half ester of a succinic acid, i.e., one in which only one of the two acid groups is esterified, involves the use of one mole of a monohydric alcohol for each mole of the substituted succinic acid reactant, whereas the formation of a diester of a succinic acid involves the use of two moles of the alcohol for each mole of the acid. On the other hand, one mole of a hexa- hydric alcohol may combine with as many as six moles of a succinic acid to form an ester in which each of the six hydroxyl groups of the alcohol is esterified with one of the two acid groups of the succinic acid. Thus, the maximum proportion of the succinic acid to be used with a polyhydric alcohol is determined by the number of hydroxyl groups present in the molecule of the hydroxy reactant. In one embodiment, esters obtained by the reaction of equimolar amounts of the succinic acid react¬ ant and hydroxy reactant are preferred.

Methods of preparing the carboxylic ester dis¬ persants (B) are well known in the art and need not be illustrated in further detail here. For example, see U.S. Patent 3,522,179 which is hereby incorporated by reference for its disclosures of the preparation of carboxylic ester compositions useful as component (B) . The preparation of carboxylic ester derivative composi¬ tions from acylating agents wherein the substituent groups are derived from polyalkenes characterized by an ¥n of at least about 1300 up to about 5000 and an Mw/Mn ratio of from 1.5 to about 4 is described in U.S. Patent

4,234,435 which was incorporated by reference earlier. As noted above, the acylating agents described in the •435 patent are also characterized as having within their structure an average of at least 1.3 succinic groups for each equivalent weight of substituent groups.

The carboxylic ester derivatives which are des¬ cribed above resulting from the reaction of an acylating agent with a hydroxy containing compound such as an alco¬ hol or a phenol may be further reacted with an amine, and particularly polyamines in the manner described pre¬ viously for the reaction of the acylating agent (B-2-a) with amines (B-2-b) in preparing dispersant (B) . In one embodiment, the amount of amine which is reacted with the ester is an amount such that there is at least about 0.01 equivalent of the amine for each equivalent of acylating agent initially employed in the reaction with the alcohol. Where the acylating agent has been reacted with the alcohol in an amount such that there is at least one equivalent of alcohol for each equivalent of acylating agent, this small amount of amine is suffi¬ cient to react with minor amounts of non-esterified carboxyl groups which may be present. In one preferred embodiment, the amine-modified carboxylic acid ester dispersants are prepared by reacting about 1.0 to 2.0 equivalents, preferably about 1.0 to 1.8 equivalents of hydroxy compounds, and up to about 0.3 equivalent, pref¬ erably about 0.02 to about 0.25 equivalent of polyamine per equivalent of acylating agent.

In another embodiment, the carboxylic acid acylating agent may be reacted simultaneously with both the alcohol and the amine. There is generally at least about 0.01 equivalent of the alcohol and at least 0.01 equivalent of the amine although the total amount of

equivalents of the combination should be at least about 0.5 equivalent per equivalent of acylating agent. These carboxylic ester dispersant compositions (B) are known in the art, and the preparation of a number of these derivatives is described in, for example, U.S. Patents 3,957,854 and 4,234,435 which have been incorporated by reference previously.

The above-described acylated amines and carbox¬ ylic esters are effective dispersants in the lubricating compositions of the invention. In another embodiment, these compositions may be considered as intermediates and post-treated with one or more post-treating reagents selected from the group consisting of boron trioxide, boron anhydrides, boron halides, boron acids, boron amides, esters of boric acids, carbon disulfide, hydro¬ gen sulfide, sulfur, sulfur chlorides, alkenyl cyanides, carboxylic acid acylating agents, aldehydes, ketones, urea, thiourea, guanidine, dicyanodiamide, hydrocarbyl phosphates, hydrocarbyl phosphites, hydrocarbyl thiophos- phates, hydrocarbyl thiophosphites, phosphorus sulfides, phosphorus oxides, phosphoric acid, hydrocarbyl thiocyan- ates, hydrocarbyl isocyanates, hydrocarbyl isothiocyan- ates, epoxides, episulfides, formaldehyde or formalde¬ hyde-producing compounds with phenols, and sulfur with phenols. These post-treating reagents can be used with carboxylic derivative compositions prepared from the acylating reagents and a combination of amines and alco¬ hols as described above.

Since processes involving the use of these post-treating reagents is known insofar as application to reaction products of high molecular weight carboxylic acid acylating agents and amines and/or alcohols, a detailed description of these processes herein is believ-

ed unnecessary. The following U.S. Patents are express¬ ly incorporated herein by reference for their disclosure of post-treating processes and post-treating reagents applicable to the carboxylic derivative compositions of this invention: U.S. Patent Nos. 3,087,936; 3,254,025 3,256,185; 3,278,550; 3,282,955; 3,284,410; 3,338,832 3,533,945; 3,639,242; 3,708,522; 3,859,318; 3,865,813 etc. U.K. Patent Nos. 1,085,903 and 1,162,436 also describe such processes.

Particularly useful as ashless dispersants in the lubricating compositions of the present invention are boron-containing compositions prepared from the acylated nitrogen compounds described above. Thus, preferred dispersants contained nitrogen and boron and are prepared by reacting

(B-l) a boron compound selected from the group consisting of boron trioxide, boron anhydrides, boron halides, boron acids, boron amides, esters of boric acid and mixtures thereof with

(B-2) at least one acylated nitrogen inter¬ mediate prepared by the reaction of

(B-2-a) at least one substituted succin¬ ic acylating agent with

(B-2-b) at least about one-half equiva¬ lent, per equivalent of acylating agent, of an amine characterized by the presence within its structure of at least one >NH group wherein said substituted succinic acylating agent consists of substituent groups and suc¬ cinic groups, and the substituent groups are derived from polyalkene characterized as having an Mn value of at least about 700.

The acylated nitrogen intermediate (B-2) described above is identical to the acylated nitrogen compositions (B-2)

also described above which have not been reacted with a boron compound. The amount of boron compound reacted with the acylated nitrogen intermediate (B-2) generally is sufficient to provide from about 0.1 atomic propor¬ tion of boron for each mole of the acylated nitrogen composition up to about 10 atomic proportions of boron for each atomic proportion of nitrogen of said acylated nitrogen composition. More generally the amount of boron compound present is sufficient to provide from about 0.5 atomic proportion of boron for each mole of the acylated nitrogen composition to about 2 atomic proportions of boron for each atomic proportion of nitrogen used.

The boron compounds (B-l) useful in the present invention include boron oxide, boron oxide hydrate, boron trioxide, boron trifluoride, boron tribromide, boron trichloride, boron acids such as boronic acid (i.e., alkyl-B(OH)2 or aryl-B(OH)2) > boric acid (i.e., H3BO3), tetraboric acid (i.e., H2B4O7) , metaboric acid (i.e., HBO2) , boron anhydrides, boron amides and various esters of such boron acids. The use of complexes of boron trihalide with ethers, organic acids, inorganic acids, or hydrocarbons is a convenient means of introducing the boron reactant into the reac¬ tion mixture. Such complexes are known and are exempli¬ fied by boron-trifluoride-triethyl ester, boron trifluor- ide-phosphoric acid, boron trichloride-chloroacetic acid, boron tribromide-dioxane, and boron trifluoride- methyl ethyl ether.

Specific examples of boronic acids include methyl boronic acid, phenyl-boronic acid, cyclohexyl boronic acid, p-heptylphenyl boronic acid and dodecyl boronic acid.

The boron acid esters include especially mono-, di-, and tri-organic esters of boric acid with alcohols or phenols such as, e.g., methanol, ethanol, isopropan- ol, cyclohexanol, cyclopentanol, 1-octanol, 2-octanol, dodecanol, behenyl alcohol, oleyl alcohol, stearyl alco¬ hol, benzyl alcohol, 2-butyl cyclohexanol, ethylene gly¬ col, propylene glycol, trimethylene glycol, 1,3-butane- diol, 2,4-hexanediol, 1,2-cyclohexanediol, 1,3-octane- diol, glycerol, pentaerythritol diethylene glycol, carbi- tol, Cellosolve, triethylene glycol, tripropylene gly¬ col, phenol, naphthol, p-butylphenol, o,p-diheptylphen- ol, n-cyclohexylphenol, 2,2-bis-(p-hydroxyphenyl) pro¬ pane, polyisobutene (molecular weight of 1500)-substi¬ tuted phenol, ethylene chlorohydrin, o-chlorophenol, m- nitrophenol, 6-bromo-octanol, and 7-keto-decanol. Lower alcohols, 1,2-glycols, and 1-3-glycols, i.e., those hav¬ ing less than about 8 carbon atoms are especially useful for preparing the boric acid esters for the purpose of this invention.

Methods for preparing the esters of boron acid are known and disclosed in the art (such as "Chemical Reviews," pp. 959-1064, Vol. 56). Thus, one method involves the reaction of boron trichloride with 3 moles of an alcohol or a phenol to result in a tri-organic borate. Another method involves the reaction of boric oxide with an alcohol or a phenol. Another method involves the direct esterification of tetra boric acid with 3 moles of an alcohol or a phenol. Still another method involves the direct esterification of boric acid with a glycol to form, e.g., a cyclic alkylene borate.

The reaction of the acylated nitrogen inter¬ mediate (B-2) with the boron compounds (B-1) can be effected simply by mixing the reactants at the desired

temperature. The use of an inert solvent is optional although it is often desirable, especially when a highly viscous or solid reactant is present in the reaction mixture. The inert solvent may be a hydrocarbon such as benzene, toluene, naphtha, cyclohexane, n-hexane, or mineral oil. The temperature of the reaction may be varied within wide ranges. Ordinarily it is preferably between about 50°C and about 250°C. In some instances it may be 25°C or even lower. The upper limit of the temperature is the decomposition point of the particular reaction mixture and/or product.

The reaction is usually complete within a short period such as 0.5 to 6 hours. After the reaction is complete, the product may be dissolved in the solvent and the resulting solution purified by centrifugation or filtration if it appears to be hazy or contain insoluble substances. Ordinarily the product is sufficiently pure so that further purification is unnecessary or optional.

The reaction of the acylated nitrogen composi¬ tions with the boron compounds results in a product containing boron and substantially all of the nitrogen originally present in the nitrogen reactant. It is believed that the reaction results in the formation of a complex between boron and nitrogen. Such complex may involve in some instances more than one atomic propor¬ tion of boron with one atomic proportion of nitrogen and in other instances more than one atomic proportion of nitrogen with one atomic proportion of boron. The nature of the complex is not clearly understood.

Inasmuch as the precise stoichiometry of the complex formation is not known, the relative proportions of the reactants to be used in the process are based pri¬ marily upon the consideration of utility of the products

for the purposes of this invention. In this regard, useful products are obtained from reaction mixtures in which the reactants are present in relative proportions as to provide from about 0.1 atomic proportions of boron for each mole of the acylated nitrogen composition used to about 10 atomic proportions of boron for each atomic proportion of nitrogen of said acylated nitrogen composi¬ tion used. The preferred amounts of reactants are such as to provide from about 0.5 atomic proportion of boron for each mole of the acylated nitrogen composition to about 2 atomic proportions of boron for each atomic pro¬ portion of nitrogen used. To illustrate, the amount of a boron compound having one boron atom per molecule to be used with one mole of an acylated nitrogen composi¬ tion having five nitrogen atoms per molecule is within the range from about 0.1 mole to about 50 moles, prefer¬ ably from about 0.5 mole to about 10 moles.

The following examples are illustrative of the process for preparing the nitrogen-containing and the nitrogen- and boron-containing compositions useful as ashless dispersants (B) in this invention:

Example B-1

A polyisobutenyl succinic anhydride is prepared by the reaction of a chlorinated polyisobutylene with maleic anhydride at 200°C. The polyisobutenyl group has a number average molecular weight of about 850 and the resulting alkenyl succinic anhydride is found to have an acid number of 113 (corresponding to an equivalent weight of 500) . To a mixture of 500 grams (1 equivalent) of this polyisobutenyl succinic anhydride and 160 grams of toluene there is added at room temperature 35 grams (1 equivalent) of diethylene triamine. The addition is made portionwise throughout a period of 15 minutes, and

-39-

an initial exothermic reaction caused the temperature to rise to 50°C. The mixture then is heated and a water- toluene azeotrope distilled from the mixture. When no more water distills, the mixture is heated to 150°C at reduced pressure to remove the toluene. The residue is diluted with 350 grams of mineral oil and this solution is found to have a nitrogen content of 1.6%.

Example B-2

The procedure of Example B-1 is repeated using 31 grams (1 equivalent) of ethylene diamine as the amine reactant. The nitrogen content of the resulting product is 1.4%.

Example B-3

The procedure of Example B-1 is repeated using

55.5 grams (1.5 equivalents) of an ethylene amine mix¬ ture having a composition corresponding to that of tri- ethylene tetramine. The resulting product has a nitrogen content of 1.9%.

Example B-4

The procedure of Example B-1 is repeated using 55.0 grams (1.5 equivalents) of triethylene tetramine as the amine reactant. The resulting product has a nitrogen content of 2.9%.

Example B-5

To a mixture of 140 grams of toluene and 400 grams (0.78 equivalent) of a polyisobutenyl succinic anhydride (having an acid number of 109 and prepared from maleic anhydride and the chlorinated polyisobutyl¬ ene of Example B-1) there is added at room temperature

63.6 grams (1.55 equivalents) of a commercial ethylene amine mixture having an average composition correspond¬ ing to that of tetraethylene pentamine. The mixture is heated to distill the water-toluene azeotrope and then

to 150°C at reduced pressure to remove the remaining toluene. The residual polyamide has a nitrogen content of 4.7%.

Example B-6

A polyisobutenyl succinic anhydride having an acid number of 105 and an equivalent weight of 540 is prepared by the reaction of a chlorinated polyisobutyl¬ ene (having a number average molecular weight of 1050 and a chlorine content of 4.3%) and maleic anhydride. To a mixture of 300 parts by weight of the polyisobu¬ tenyl succinic anhydride and 160 parts by weight of mineral oil there is added at 65-95°C an equivalent amount (25 parts by weight) of the commercial ethylene amine mixture of Example B-5. This mixture then is heated to 150°C to distill all of the water formed in the reaction. Nitrogen is bubbled through the mixture at this temperature to insure removal of the last traces of water. The residue is an oil solution of the desired product.

Example B-7

A polypropylene-substituted succinic anhydride having an acid number of 84 is prepared by the reaction of a chlorinated polypropylene having a chlorine content of 3% and a number average molecular weight of 1200 with maleic anhydride. A mixture of 813 grams of the polypro¬ pylene-substituted succinic anhydride, 50 grams of a com¬ mercial ethylene amine mixture having an average composi¬ tion corresponding to that of tetraethylene pentamine and 566 grams of mineral oil is heated at 150°C for 5 hours. The residue is found to have a nitrogen content of 1.18%.

Example B-8 An acylated nitrogen composition is prepared according to the procedure of Example B-1 except that the reaction mixture consists of 3880 grams of the poly¬ isobutenyl succinic anhydride, 376 grams of a mixture of triethylene tetramine and diethylene triamine (75:25 weight ratio), and 2785 grams of mineral oil. The pro¬ duct is found to have a nitrogen content of 2%.

Example B-9 An acylated nitrogen composition is prepared according to the procedure of Example B-1 except that the reaction mixture consists of 1385 grams of the poly¬ isobutenyl succinic anhydride, 179 grams of a mixture of triethylene tetramine and diethylene triamine (75:25 weight ratio), and 1041 grams of mineral oil. The pro¬ duct is found to have a nitrogen content of 2.55%.

Example B-10 An acylated nitrogen composition is prepared according to the procedure of Example B-7 except that the polyisobutene-substituted succinic anhydride of Example B-1 (1 equivalent for 1.5 equivalents of the amine reactant) is substituted for the polypropylene- substituted succinic anhydride used.

Example B-ll An acylated nitrogen composition is prepared according to the procedure of Example B-7 except that the polyisobutene-substituted succinic anhydride of Example B-1 (1 equivalent for 2 equivalents of the amine reactant) is substituted for the polypropylene-substi¬ tuted succinic anhydride used.

Example B-12 An acylated nitrogen composition is prepared according to the procedure of Example B-4 except that

the commercial ethylene amine mixture (1.5 equivalent per equivalent of the anhydride) of Example B-6 is substituted for the triethylene tetramine used.

Example B-13 An acylated nitrogen composition is prepared according to the procedure of Example B-7 except that the polyisobutene-substituted succinic anhydride of Example B-1 (1 equivalent for 1 equivalent of the amine reactant) is substituted for the polypropylene-substi¬ tuted succinic anhydride. The composition is found to have a nitrogen content of 1.5%.

Example B-14

(a) A mixture of 510 parts (0.28 mole) of poly- isobutene (Mn=1845; Mw=5325) and 59 parts (0.59 mole) of maleic anhydride is heated to 110°C. This mixture is heated to 190°C in 7 hours during which 43 parts (0.6 mole) of gaseous chlorine is added beneath the surface. At 190-192°C an additional 11 parts (0.16 mole) of chlor¬ ine is added over 3.5 hours. The reaction mixture is stripped by heating at 190-193°C with nitrogen blowing for 10 hours. The residue is the desired polyisobutene- substituted succinic acylating agent having a saponifica¬ tion equivalent number of 87 as determined by ASTM proce¬ dure D-94.

(b) A mixture is prepared by the addition of 10.2 parts (0.25 equivalent) of a commercial mixture of ethylene polyamines having from about 3 to about 10 nitrogen atoms per molecule to 113 parts of mineral oil and 161 parts (0.25 equivalent) of the substituted suc¬ cinic acylating agent at 130°C. The reaction mixture is heated to 150°C in 2 hours and stripped by blowing with nitrogen. The reaction mixture is filtered to yield the filtrate as an oil solution of the desired product.

Example B-15

(a) A mixture of 1000 parts (0.495 mole) of polyisobutene (Mn=2020; * Mw=6049) and 115 parts (1.17 moles) of maleic anhydride is heated to 110°C. This mixture is heated to 184°C in 6 hours during which 85 parts (1.2 moles) of gaseous chlorine is added beneath the surface. At 184-189°C, an additional 59 parts (0.83 mole) of chlorine is added over 4 hours. The reaction mixture is stripped by heating at 186-190°C with nitro¬ gen blowing for 26 hours. The residue is the desired polyisobutene-substituted succinic acylating agent hav¬ ing a saponification equivalent number of 87 as deter¬ mined by ASTM procedure D-94.

(b) A mixture is prepared by the addition of 57 parts (1.38 equivalents) of a commercial mixture of ethylene polyamines having from about 3 to 10 nitrogen atoms per molecule to 1067 parts of mineral oil and 893 parts (1.38 equivalents) of the substituted succinic acylating agent at 140-145°C. The reaction mixture is heated to 155°C in 3 hours and stripped by blowing with nitrogen. The reaction mixture is filtered to yield the filtrate as an oil solution of the desired product.

Example B-16 A mixture is prepared by the addition of 18.2 parts (0.433 equivalent) of a commercial mixture of ethylene polyamines having from about 3 to 10 nitrogen atoms per molecule to 392 parts of mineral oil and 348 parts (0.52 equivalent) of the substituted succinic acylating agent prepared in Example B-15 at 140°C. The reaction mixture is heated to 150°C in 1.8 hours and stripped by blowing with nitrogen. The reaction mixture is filtered to yield the filtrate as an oil solution of the desired product.

Example B-17

To 600 grams (1 atomic proportion of nitrogen) of the acylated nitrogen composition prepared according to the process of Example B-13 there is added 45.5 grams (0.5 atomic proportion of boron) of boron trifluoride- diethyl ether complex (1:1 molar ratio) at 60-75°C. The resulting mixture is heated to 103°C and then at 110°C/- 30 mm. to distill off all volatile components. The resi¬ due is found to have a nitrogen content of 1.44% and a boron content of 0.49%.

Example B-18

A mixture of 62 grams (1 atomic proportion of boron) of boric acid and 1645 grams (2.35 atomic propor¬ tions of nitrogen) of the acylated nitrogen composition obtained by the process of Example B-8 is heated at 150°C in nitrogen atmosphere for 6 hours. The mixture is then filtered and the filtrate is found to have a nitrogen content of 1.94% and a boron content of 0.33%.

Example B-19

An oleyl ester of boric acid is prepared by heating an equi-molar mixture of oleyl alcohol and boric acid in toluene at the reflux temperature while water is removed azeotropically. The reaction mixture is then heated to 150°C/20 mm. and the residue is the ester hav¬ ing a boron content of 3.2% and a saponification number of 62. A mixture of 344 grams (1 atomic proportion of boron) of the ester and 1645 grams (2.35 atomic propor¬ tions of nitrogen) of the acylated nitrogen composition obtained by the process of Example B-8 is heated at 150°C for 6 hours and then filtered. The filtrate is found to have a boron content of 0.6% and a nitrogen content of 1.74%.

Example B-20

A mixture of 372 grams (6 atomic proportions of boron) of boric acid and 3111 grams (6 atomic propor¬ tions of nitrogen) of the acylated nitrogen composition obtained by the process of Example B-ll is heated at 150°C for 3 hours and then filtered. The filtrate is found to have a boron content of 1.64% and a nitrogen content of 2.56%.

Example B-21

Boric acid (124 grams, 2 atomic proportions of boron) is added to the acylated nitrogen composition (556 grams, 1 atomic proportion of nitrogen) obtained according to the procedure of Example B-ll. The result¬ ing mixture is heated at 150°C for 3.5 hours and filter¬ ed at that temperature. The filtrate is found to have a boron compound of 3.23% and a nitrogen content of 2.3%.

Example B-22

A mixture of 62 parts of boric acid and 2720 parts of the oil solution of the product prepared in Example B-15 is heated at 150°C under nitrogen for 6 hours. The reaction mixture is filtered to yield the filtrate as an oil solution of the desired boron-con¬ taining product.

Example B-23

An oleyl ester of boric acid is prepared by heating an equimolar mixture of oleyl alcohol and boric acid in toluene at the reflux temperature while water is removed azeotropically. The reaction mixture is then heated to 150°C under vacuum and the residue is the ester having a boron content of 3.2% and a saponifica¬ tion number of 62. A mixture of 344 parts of the heater and 2720 parts of the oil solution of the product prepar¬ ed in Example B-15 is heated at 150°C for 6 hours and

then filtered. The filtrate is an oil solution of the desired boron-containing product.

Example B-24

Boron trifluoride (34 parts) is bubbled into 2190 parts of the oil solution of the product prepared in Example B-16 at 80°C within a period of 3 hours. The resulting mixture is blown with nitrogen at 70-80°C for 2 hours to yield the residue as an oil solution of the desired product.

Example B-25

A mixture of 1000 parts by weight of a substi¬ tuted succinic acylating agent prepared as in Example B-1 utilizing a polyisobutene having a number average molecular weight of about 950 and 275 parts by weight of mineral oil is prepared and heated to about 110°C where¬ upon nitrogen is blown through the mixture. To this mixture there are added 147 parts of a commercial mix¬ ture of ethylene polyamines containing from about 3 to about 10 nitrogen atoms per molecular (and containing 34% nitrogen) over a period of about one hour. After substantially all of the water has been removed at an elevated temperature, a filter aid is added, and the reaction mixture is filtered at about 150°C. The fil¬ trate is an oil solution of the desired succinic acylat¬ ed amine intermediate.

To 1405 parts by weight of the intermediate there is added a slurry prepared from 239 parts of boric acid and 398 parts of mineral oil. The mixture is heated to about 150°C in a nitrogen atmosphere for about 6 hours. The mixture then is filtered and the filtrate is an oil solution of the desired nitrogen and boron-con¬ taining composition having a nitrogen content of 2.3% and a boron content of 1.8%.

The following examples illustrate the carboxyl¬ ic ester dispersants (B) and the processes for preparing such esters.

Example B-26

A substantially hydrocarbon-substituted succin¬ ic anhydride is prepared by chlorinating a polyisobutene having a number average molecular weight of 1000 to a chlorine content of 4.5% and then heating the chlorin¬ ated polyisobutene with 1.2 molar proportions of maleic anhydride at a temperature of 150-220°C. The succinic anhydride thus obtained has an acid number of 130. A mixture of 874 grams (1 mole) of the succinic anhydride and 104 grams (1 mole) of neopentyl glycol is maintained at 240-250°C/30 mm for 12 hours. The residue is a mix¬ ture of the esters resulting from the esterification of one and both hydroxy groups of the glycol. It has a saponification number of 101 and an alcoholic hydroxyl content of 0.2%.

Example B-27

(a) The dimethyl ester of the substantially hydrocarbon-substituted succinic anhydride of Example B-26 is prepared by heating a mixture of 2185 grams of the anhydride, 480 grams of methanol, and 1000 cc of toluene at 50-65°C while hydrogen chloride is bubbled through the reaction mixture for 3 hours. The mixture is then heated at 60-65°C for 2 hours, dissolved in benzene, washed with water, dried and filtered. The filtrate is heated at 150°C/60 mm to remove volatile components. The residue is the desired dimethyl ester.

(b) A mixture of 334 parts (0.52 equivalent) of the dimethyl ester prepared in (a) , 548 parts of mineral oil, 30 parts (0.88 equivalent) of pentaeryth- ritol and 8.6 parts (0.0057 equivalent) of Polyglycol

112-2 demulsifier from Dow Chemical Company is heated at 150°C for 2.5 hours. The reaction mixture is heated to 210°C in 5 hours and held at 210°C for 3.2 hours. The reaction mixture is cooled to 190°C and 8.5 parts (0.2 equivalent) of a commercial mixture of ethylene poly¬ amines having an average of about 3 to about 10 nitrogen atoms per molecule are added. The reaction mixture is stripped by heating at 205°C with nitrogen blowing for 3 hours, then filtered to yield the filtrate as an oil solution of the desired product.

Example B-28

(a) A mixture of 1000 parts of polyisobutene having a number average molecular weight of about 1000 and 108 parts (1.1 moles) of maleic anhydride is heated to about 190°C and 100 parts (1.43 moles) of chlorine are added beneath the surface over a period of about 4 hours while maintaining the temperature at about 185- 190°C. The mixture then is blown with nitrogen at this temperature for several hours, and the residue is the desired polyisobutene-substituted succinic acylating agent.

(b) A solution of 1000 parts of the above-pre¬ pared acylating agent in 857 parts of mineral oil is heated to about 150°C with stirring, and 109 parts (3.2 equivalents) of pentaerythritol are added with stirring. The mixture is blown with nitrogen and heated to about 200°C over a period of about 14 hours to form an oil solution of the desired carboxylic ester intermediate. To the intermediate, there are added 19.25 parts (0.46 equivalent) of a commercial mixture of ethylene poly¬ amines having an average of about 3 to about 10 nitrogen atoms per molecule. The reaction mixture is stripped by heating at 205°C with nitrogen blowing for 3 hours and

filtered. . The filtrate is an oil solution (45% oil) of the desired amine-modified carboxylic ester which con¬ tains 0.35% nitrogen.

The amount of ashless dispersant utilized in the lubricating compositions of the present invention is an amount which is effective to provide the desired dispersant characteristics. The ashless dispersants, and in particular, the nitrogen and boron-containing dispersants described above also provide rust-inhibiting properties to the lubricating composition. In general from about 0.05 to about 30 parts by weight of the ash¬ less dispersant is included in the lubricating composi¬ tion. More often, from about 0.1 to about 15 parts by weight of the ashless dispersant results in the satis¬ factory lubricant, and in one preferred embodiment, the lubricating compositions contain from about 0.1 to about 10% by weight of the nitrogen- and boron-containing com¬ position (B) . (C) The Demulsifier.

The lubricating compositions of the present invention also contain a minor, effective amount of at least one demulsifier characterized by the formula

wherein R is a hydrocarbyl group, R2, R3, R4 and R5 are each independently H or hydrocarbyl groups, and

X is 0 or NR' wherein R' is hydrogen or a hydrocarbyl group. As can be seen from the formula, the de ulsifi- ers (C) utilized in the present invention may be either oxazoline or imidazoline derivatives. In a preferred embodiment, R and R3 are hydrogen and R is an aliphatic or alicyclic hydrocarbon-based group contain¬ ing from about 5 to about 40 or more carbon atoms. In another preferred embodiment, R is an alkyl or alkenyl group containing from 5 to about 40 or more carbon atoms, more generally from about 5 to about 30 carbon atoms. In one preferred embodiment, R is an alkenyl group containing from about 9 to about 25 carbon atoms.

In one preferred embodiment, the demulsifier is an imidazoline characterized by the formula

wherein R is an alkyl or alkenyl group containing from about 5 to about 30 carbon atoms, and R' is hydrogen or a hydrocarbyl group containing from 1 to about 8 carbon atoms. Generally, the hydrocarbyl group (R') will con¬ tain at least one >NH or -OH group. One type of imidazo¬ line demulsifier which is useful in the present inven¬ tion is characterized by the following formula

wherein R is a hydrocarbyl group containing about 5 to about 30 carbon atoms and R" is H or a hydrocarbyl group containing from 1 to about 6 carbon atoms.

Examples of oxazolines which can be utilized in the present invention include those characterized by formula XI

where R is undecyl, dodecyl, heptadecenyl-1, hexadecen- yl-1, etc. R2 and R3 are hydrogen, hydroxy ethyl, hydroxy methyl, etc.

The preparation of the above and other oxazo¬ lines of the type characterized by Formula VIII is described in the patent literature such as U.S. Patents 2,329,619; 2,905,644; and 4,256,592 and publications such as the chapter by R.H. Wiley and L.L. Bennett, Jr. in Che Reviews, June, 1949, Vol. 44, pp. 447-476.

Non-limiting examples of imidazolines which can be utilized as demulsifiers in the lubricating composi¬ tions of the present invention include l-(5-hydroxypen- tyl)-2-dodecylimidazoline; 1-(2-hydroxyethyl)-2-(3-cyclo- hexylpropyl)imidazoline; 1-(2-hydroxyethyl)-2-dodecylcy- clohexylimidazoline; 1-(4-hydroxybutyl)-2-(1-heptadecen- yl)imidazoline; l-butyl-2-heptadecenylimidazoline; l-(2- aminoethyl)-2-tridecylimidazoline; 1-(2-aminoethyl)-2- (1-heptadecenyl)imidazoline; 1-(2-hydroxyethyl)-2-(1- ethylpentyl)imidazoline; etc.

Imidazolines such as those exemplified above can be prepared by methods such as those disclosed in U.S. Patent Nos. 2,267,965 and 2,214,152. Generally, the imidazolines are readily formed by reacting an

aliphatic or alicyclic carboxylic acid with an appropri¬ ate unsubstituted hydrocarbon-based group substituted ethylene diamine. The reaction involves the condensa¬ tion of the acid with the diamine at a temperature rang¬ ing from about 110°C to about 350°C with the elimination of two moles of water.

The aliphatic or alicyclic carboxylic acid reacted with the amine to form the imidazoline may be saturated or unsaturated and may contain substituents as halo, ether, sulfide, keto, hydroxo, etc., as well as phenyl, tolyl, xylyl, chlorophenyl, hydroxyphenyl, naph- thyl, etc. Representative, but non-limiting examples of acids useful for the preparation of the imidazolines adapted for the purposes of this invention include unde- canoic acid, myristic acid, palmitic, stearic, oleic, linoleic, linolenic, ricinoleic, phenylstearic, xylyl- stearic, chlorostearic, hydroxy phenylstearic, tricosan- oic, and mixtures of any of these acids. The reaction of a carboxylic acid with a diamine to form an imidazo¬ line is illustrated as follows:

RCOOH + H2NCH2CH2-N(H)R' „

where R and R 1 have the same meaning as given previously for Formula IX.

The amount of the demulsifier (C) incorporated into the lubricating composition of the present inven¬ tion is an amount which is effective to demulsify any emulsion which forms when the lubricating oil compo¬ sitions of the present invention are mixed with water as

may occur during use or storage. In one embodiment, the lubricating compositions of the present invention con¬ tain from about 0.01 to about 1% by weight, and more particularly from 0.02 to about 0.2% by weight based on the weight of the lubricating composition, and such amounts are sufficient to provide the desired demulsibil- ity properties. It also has been observed that the incorporation of the imidazoline demulsifiers into the lubricating compositions of the present invention pro¬ vides desirable anti-wear properties to the lubricating composition. In one preferred embodiment, the lubricat¬ ing compositions of the present invention will contain from about 0.4 to about 0.8% by weight of the nitrogen- and boron-containing carboxylic dispersants (B) and about 0.2% by weight of imidazole demulsifier (C) . (D) Supplemental Demulsifiers.

Although the incorporation of the above ashless dispersants (B) and demulsifiers (C) provide lubricating oil compositions of the present invention having desir¬ able characteristics, the incorporation of supplemental demulsifiers (D) into the lubricating compositions re¬ sults in improved demulsibility, and in particular, a reduction in the water separation time. Particularly useful as supplemental demulsifiers are low molecular weight polyoxyalkylene glycols such as polyethylene gly¬ col, polypropylene glycol, low molecular weight polymers containing ethylene and propylene moieties and derived from mixtures of ethylene glycol and propylene glycol, and/or glycols reacted with ethylene oxide and/or propyl¬ ene oxide. A description of various types of polyoxyal¬ kylene glycol and polyol demulsifiers is found in U.S. Patent 4,234,435 beginning at Col. 29, line 51 to Col. 32, line 34, and this disclosure is hereby incorporated

by reference. A non-limiting example of a useful poly- glycol demulsifier is a commercially available polyoxyal¬ kylene glycol in aromatic hydrocarbons which is avail¬ able under the trade designation Tolad 370 from the Tretolite Division of Petrolite. Other examples of com¬ mercially available polyoxyalkylene demulsifiers include the Pluronic and Tetronic polyols from Wyandotte Chemi¬ cals Co.; Polyglycols from Dow Chemical Co.; the Etho- meen, Duomeen, Ethoduomeen, and Ethomids, polyalkoxyl- ated amines from Akzo Chemical, Inc., Chicago, Illinois; and the Tergitols and Ucons available from Union Carbide Corporation.

The supplemental polyglycol demulsifiers may be included in the lubricating compositions of the present invention in amounts of from about 0.001 to about 1% by weight. More generally, from about 0.01 to about 0.5% by weight.

In addition to the above components, the lubri¬ cant compositions of the present invention also may con¬ tain other additives including, for example, fluidity modifiers, auxiliary detergents and dispersants of the ash-producing type, corrosion- and oxidation-inhibiting agents, pour point depressing agents, extreme pressure agents, friction modifiers, color stabilizers, viscosity modifiers, anti-foam agents, etc. One or more of each of these additives may be included in the lubricating compositions of the present invention within the range of from about 0.001 to about 15%, and preferably in amounts of 0.01 to about 10%.

Auxiliary extreme pressure agents and corro¬ sion- and oxidation-inhibiting agents which may be included in the lubricants and functional fluids of the invention are exemplified by chlorinated aliphatic hydro-

carbons such as chlorinated wax; organic sulfides and polysulfides such as benzyl disulfide, bis(chlorobenzyl)- disulfide, dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenol, sulfurized dipen- tene, and sulfurized terpene; phosphosulfurized hydrocar¬ bons such as the reaction product of a phosphorus sul- fide with turpentine or methyl oleate, phosphorus esters including principally dihydrocarbon and trihydrocarbon phosphites such as dibutyl phosphite, diheptyl phos¬ phite, dicyclohexyl phosphite, pentylphenyl phosphite, dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite, dimethyl naphthyl phosphite, oleyl 4-pentyl- phenyl phosphite, polypropylene (molecular weight 500)- substituted phenyl phosphite, diisobutyl-substituted phenyl phosphite; metal thiocarbamates, such as zinc dioctyldithiocarbamate, and barium heptylphenyl dithio- carbamate; Group II metal phosphorodithioates such as zinc dicyclohexylphosphorodithioate, zinc dioctylphos- phorodithioate, barium di(heptylphenyl)-phosphorodithio- ate, cadmium dinonylphosphorodithioate, and the zinc salt of a phosphorodithioic acid produced by the reac¬ tion of phosphorus pentasulfide with an equimolar mix¬ ture of isopropyl alcohol and n-hexyl alcohol.

Many of the above-mentioned auxiliary extreme pressure agents and corrosion-oxidation inhibitors also serve as antiwear agents. Zinc dialkylphosphorodithio- ates are a well known example.

Friction-modifying agents which may be useful in the lubricating compositions of the present invention include: alkyl or alkenyl phosphates or phosphites in which the alkyl or alkenyl group contains from about 10 to about 40 carbon atoms, and metal salts thereof, espe¬ cially zinc salts; C12-20 fatty acid amides; ClO-20

alkyl amines, especially tallow amines and ethoxylated derivatives thereof; salts of the amines with acids such as boric acid or phosphoric acid which have been partial¬ ly esterified as noted above; etc.

Sulfur-containing compositions prepared by the sulfurization of olefins are particularly useful in improving the anti-wear, extreme pressure and antioxi- dant properties of the lubricating oil compositions.. When included in the oil compositions of this invention, the oil composition typically will contain from about 0.01 to about 2% of the sulfurized olefin. The olefins may be any aliphatic, arylaliphatic or alicyclic olefin- ic hydrocarbon containing from about 3 to about 30 carbon atoms. The olefinic hydrocarbons contain at least one olefinic double bond, which is defined as a non-aromatic double bond; that is, one connecting two aliphatic carbon atoms. In its broadest sense, the olefinic hydrocarbon may be defined by the formula

R7R8C=CR9R10

wherein each of R7, R8, R9 and RlO is hydrogen or a hydrocarbon (especially alkyl or alkenyl) radical. Any two of R7, R8, R9, R10 may also together form an alkylene or substituted alkylene group; i.e., the olefinic compound may be alicyclic.

Monoolefinic and diolefinic compounds, particu¬ larly the former, are preferred, and especially terminal monoolefinic hydrocarbons; that is, those compounds in which R9 and RlO are hydrogen and R7 and Rδ are alkyl (that is, the olefin is aliphatic). Olefinic com¬ pounds having about 3-20 carbon atoms are particularly desirable.

Propylene, isobutene and their dimers, trimers and tetramers, and mixtures thereof are especially pre¬ ferred olefinic compounds. Of these compounds, isobut¬ ene and diisobutene are particularly desirable because of their availability and the particularly high sulfur- containing compositions which can be prepared therefrom.

The sulfurizing reagent may be, for example, sulfur, a sulfur halide such as sulfur monochloride or sulfur dichloride, a mixture of hydrogen sulfide and sulfur or sulfur dioxide, or the like. Sulfur-hydrogen sulfide mixtures are often preferred and are frequently referred to hereinafter; however, it will be understood that other sulfurization agents may, when appropriate, be substituted therefor.

The amounts of sulfur and hydrogen sulfide per mole of olefinic compound are, respectively, usually about 0.3-3.0 gram-atoms and about 0.1-1.5 moles. The preferred ranges are about 0.5-2.0 gram-atoms and about 0.5-1.25 moles respectively, and the most desirable ranges are about 1.2-1.8 gram-atoms and about 0.4-0.8 mole respectively.

The temperature range in which the sulfuriza¬ tion reaction is carried out is generally about 50- 350°C. The preferred range is about 100-200°C, with about 125-180°C being especially suitable. The reaction is often preferably conducted under superatmospheric pressure; this may be and usually is autogenous pressure (i.e., the pressure which naturally develops during the course of the reaction) but may also be externally ap¬ plied pressure. The exact pressure developed during the reaction is dependent upon such factors as the design and operation of the system, the reaction temperature and the vapor pressure of the reactants and products and it may vary during the course of the reaction.

It is frequently advantageous to incorporate materials useful as sulfurization catalysts in the reac¬ tion mixture. These materials may be acidic, basic or neutral, but are preferably basic materials, especially nitrogen bases including ammonia and amines, most often alkylamines. The amount of catalyst used is generally about 0.01-2.0% of the weight of the olefinic compound. In the case of the preferred ammonia and amine catal¬ ysts, about 0.0005-0.5 mole per mole of olefin is pre¬ ferred, and about 0.001-0.1 mole is especially desir¬ able.

Following the preparation of the sulfurized mix¬ ture, it is preferred to remove substantially all low boiling materials, typically by venting the reaction vessel or by distillation at atmospheric pressure, vac¬ uum distillation or stripping, or passage of an inert gas such as nitrogen through the mixture at a suitable temperature and pressure.

A further optional step in the preparation of the sulfurized olefins is the treatment of the sulfur¬ ized product, obtained as described hereinabove, to reduce active sulfur. An illustrative method is treat¬ ment with an alkali metal sulfide. Other optional treatments may be employed to remove insoluble by-pro¬ ducts and improve such qualities as the odor, color and staining characteristics of the sulfurized compositions.

U.S. Patent 4,119,549 is incorporated by refer¬ ence herein for its disclosure of suitable sulfurized olefins useful in the lubricating oils of the present invention. Several specific sulfurized compositions are described in the working examples thereof. The follow¬ ing examples illustrate the preparation of two such com¬ positions.

Example S-l Sulfur (629 parts, 19.6 moles) is charged to a jacketed high-pressure reactor which is fitted with agi¬ tator and internal cooling coils. Refrigerated brine is circulated through the coils to cool the reactor prior to the introduction of the gaseous reactants. After seal¬ ing the reactor, evacuating to about 6 torr and cooling, 1100 parts (9.6 moles) of isobutene, 334 parts (9.8 moles) of hydrogen sulfide and 7 parts of n-butylamine are charged to the reactor. The reactor is heated, using steam in the external jacket, to a temperature of about 171°C over about 1.5 hours. A maximum pressure of 720 psig is reached at about 138°C during this heat-up. Prior to reaching the peak reaction temperature, the pressure starts to decrease and continues to decrease steadily as the gaseous reactants are consumed. After about 4.75 hours at about 171°C, the unreacted hydrogen sulfide and isobutene are vented to a recovery system. After the pressure in the reactor has decreased to atmos¬ pheric, the sulfurized product is recovered as a liquid.

Example S-2

Following substantially the procedure of Exam¬ ple S-l, 773 parts of diisobutene are reacted with 428.6 parts of sulfur and 143.6 parts of hydrogen sulfide in the presence of 2.6 parts of n-butylamine, under autogen¬ ous pressure at a temperature of about 150-155°C. Vola¬ tile materials are removed and the sulfurized product is recovered as a liquid.

Pour point depressants are a particularly use¬ ful type of additive often included in the lubricating oils described herein. The use of such pour point depressants in oil-based compositions to improve low temperature properties of oil-based compositions is well

known in the art. See, for example, page 8 of "Lubric¬ ant Additives" by C.V. Smalheer and R. Kennedy Smith (Lezius-Hiles Co. publishers, Cleveland, Ohio, 1967) .

Examples of useful pour point depressants are polymethacrylates; polyacrylates; polyacrylamides; con¬ densation products of- haloparaffin waxes and aromatic compounds; vinyl carboxylate polymers; and terpoly ers of dialkylfumarates, vinyl esters of fatty acids and alkyl vinyl ethers. Pour point depressants useful for the purposes of this invention, techniques for their preparation and their uses are described in U.S. Patents 2,387,501; 2,015,748; 2,655,479; 1,815,022; 2,191,498; 2,666,746; 2,721,877; 2,721,878; and 3,250,715 which are herein incorporated by reference for their relevant dis¬ closures.

Anti-foam agents are used to reduce or prevent the formation of stable foam. Typical anti-foam agents include silicones or organic polymers. Additional anti- foam compositions are described in "Foam Control Agents" by Henry T. Kerner (Noyes Data Corporation, 1976) , pages 125-162.

The lubricating compositions of the present invention may be prepared by dissolving or suspending the various components directly in a base oil* along with any other additives which may be used. More often, one or more of the chemical components used in the present invention are diluted with a substantially inert, normal¬ ly liquid organic diluent/solvent such as mineral oil, to form an additive concentrate. These concentrates usually contain from about 20 to about 90% by weight of the chemical additives, and from about 10 to about 80% by weight of diluent. For example, concentrates in accordance with the present invention may contain from

about 0.1 and more generally from about 10% to about 50% by weight of the ashless dispersant (B) and from about 0.01 to about 15% by weight of demulsifier (C) . The concentrates also may contain any of the other additives described above including, for example, from 1% to about 60% by weight of a sulfurized olefin.

The following examples illustrate concentrates of the present invention.

Parts/Wt. Concentrate I

Product of Ex. B-20 45

1-(5-hydroxypentyl)-2- dodecylimidazoline 10

Mineral Oil 45

Concentrate II

Product of Ex. B-26 50 l-hydroxyethyl-2-(1- heptadecenyl)imidazoline 5

Product of Ex. S-l 30

Mineral Oil 15

Typical lubricating oil compositions according to the present invention are exemplified in the follow¬ ing lubricating oil examples.

Parts/Wt. Lubricant A

Base Oil 98

Product of Ex. B-25 1.6

2-dodecyloxazoline 0.5 Lubricant B

Base Oil 96.75

Product of Ex. B-25 3.00 1-(4-hydroxybutyl)-2-

(1-heptadecenyl)-imidazoline 0.25

0.8

0.02

Amine neutralized phosphate ester of hydroxyalkyl dialkylphosphorodithioate Monoisopropyl amine Oleyl amine

Sulfurized isobutylene Reaction product of alkyl- phenol, formaldehyde and dimercaptothiadiazole 0.054 0.06 0.06 Acrylate terpolymer derived from 2-ethylhexyl acrylate, ethyl acrylate and vinyl acetate 0.026 0.03 0.03

The lubricating compositions of the present invention include crankcase lubricating oils for spark- ignited and compression-ignited internal combustion engines, including automobile and truck engines, two- cycle engines, aviation piston engines, marine and rail-

road diesel engines, etc. They also can be used in gas engines, stationary power engines and turbines. Composi¬ tions prepared in accordance with the present invention also are useful in automatic transmission fluids, trans- axle lubricants, gear lubricants, metal-working lubric¬ ants, hydraulic fluids, etc. The lubricants are particu¬ larly useful as gear lubricants in automotive as well as industrial applications, and particularly where the lub¬ ricating compositions are likely to be contaminated with water either during storage, handling and/or use. The lubricant compositions of the invention are particularly useful as multipurpose gear oil additives for both auto¬ motive and industrial applications. The gear lubricants are thermally stable and provide component cleanliness at elevated temperatures. Gear oil formulations pre¬ pared using the lubricant compositions of this invention are capable of meeting the automotive API GL-5 and the industrial USS224 requirements.

The effectiveness of the demulsifiers (C) util¬ ized in the lubricating compositions of the present invention is demonstrated when the lubricating oil formu¬ lations are subjected to the Demulsibility Test as des¬ cribed in ASTM D-2711. This test provides a method to measure an oil's ability to separate water, and the test is most effective when the test lubricants are medium to high viscosity products such as gear oils, high viscos¬ ity bearing oils or circulation oils.

The test procedure for gear oils uses 90 ml. of water and 360 ml. of oil with stirring at 2500 rpm for 5 minutes in a blender. The mixture then is transferred to a graduated cylinder, and after a 5-hour settling period at 82.2°C, the amount of water separated from the emulsion is determined. Oils showing greater than 80

l. separation in this test are considered to have excellent demulsibility characteristics. The results of this demulsibility test conducted on lubricant Example D and two control examples not containing the demulsifier (C) of the invention are summarized in the following Table I. Control-1 is a lubricating composition similar to Lubricant D except that the imidazoline demulsifier is omitted. Control-2 is a lubricating composition similar to Lubricant D except that the imidazoline

* Average of two runs.

As can be seen from the results of the Demulsibility Test, the lubricant compositions of the present inven¬ tion exhibit improved demulsibility when compared to control lubricants containing no demulsifier and Con¬ trol-2 which contained a known polyglycol demulsifier.

The anti-wear properties of the lubricating com¬ positions of the present invention is evaluated utiliz¬ ing the Shell Four-Ball Wear Test. In this test, four steel balls are arranged in a tetrahedron, the top ball was made to rotate against the three bottom balls, and the points of contact are lubricated by the test lubri¬ cant. During the test, scars are formed on the surfaces

of the three stationary balls. The diameter of the scars depend upon the load, speed, duration of run and type of lubricant. In this test, (ASTM D-2266) , the fourth ball is rotated at 1800 rpm for one hour under a load of 20 Kg. The results of the wear test conducted with Lubricant D and control lubricants identified above as Control-1 and Control-2 are summarized in the follow¬ ing Table II. As can be seen from the results, the lub¬ ricant compositions of the present invention exhibits improved anti-wear properties.

TABLE II Four Ball Wear Oil Sample Scar Diameter (mm)*

Control-1 0.42

Control-2 0.44

Lubricant D 0.30

* Average of two runs.

While the invention has been explained in rela¬ tion to its preferred embodiments, it is to be under¬ stood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. 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.