CA2225646A1 - Lubricants with improved rust inhibition - Google Patents

Abstract

The rust inhibition of lubricant compositions, such as power transmitting fluids, is improved by an additive combination comprising an amine phosphate and an alkyl primary amine.

Description

LUBRICANTS WIT~ IMP~OVFD RllST tNHlBlTlON

BACKGROUND OF THF INVENTION

This invention relates to lubricants having improved rust inhibition due to the presence of an amine phosphate and an alkyl primary amine.

The use of amine phosphates in lubricating oils is known in the art (se~, for example. U.S. Patent 3,197,405). Similarly, the use of primary amines in lubricatin~ oils has also been disclosPd (see, for example, U.S.
Patent 4,089,792). In addition, the use of amine phosphates and primary amines in lubricating oils has been described (see, for example. U.S. Patents 3,974,815; 5,3~448~: and ~.403,501). However, none of these references describe lubricants having enhanced rust inhibition due to the presence of the amine pt-os~ s and the particuiar primary amines cl~imed herein.

SUMMARY OF THF INVFNTION

~ his invention CG~cel-l5 a lu~r;-,~"t having improved rust inhibition which cc,."~,iaes a major amount of lubricating oil and a minor rust inhibiting amount of an additive combination comprising __ (a) an amine phosphate, and (b) an alkyl primary amine This invention also collce-ll5 an additive concenL~dLe comprising (a) 30 and (b~, a lubricant formed from the mixture of (a) and (b), and a method of improving the rust inhibition of a lubricant. particularly a power transmitting fluid.

;5 DF~AII Fr) DFSCRIPTION OF TH F INVFNTION

The lubricanL of this invention re~uires a lu6ricaLi"g oil. an amine phosphate. and an alkyl primar,v amine.

CA 0222~646 1998-02-06 Lubricating Oils Lubricating oiis useful in this invention are derived from natural 5 lubricating oils, synthetic lubricating oils. and mixtures thereof. In general, both the natural and synthetic lubricating oil will each have a kinematjc viscosity ranging from about 1 to about 40 mm2/s (cSt) at 100~C, although typical applications will require each oii to have a viscosity ranging from about 2 to about 35 mm2Js (cSt) at 100~C. Particularly preferred are viscositieS
from 10 to 3~ mm2Js (cSt) at 100~C.

Natural lubricating oils include animal oils. vegetable oils (e.g., castor oil and lard oil), petroieum oils. mineral oils, and oils derived from coal or shale. The preferred natural lubricating oil is mineral oil.
Suitable mineral oils include all common mineral oil basestocks. This includes oils that are naphthenic or paraffinic in chemicai structure. Oils thatare refined by conventional methodology using acid, alkali, and clay or other agents such as aluminum chioride, or they may be extracted oils produced, 20 for example, by solvent extraction with solvents such as phenol, sulfur dioxide, furfural, dichlordiethyl ether, etc. They may be hydrotreated or hydrofined, dewaxed by chilling or catalytic dewaxing processes, or hydrocracked. The mineral oil may be produced from natural crude sources or be composed of isomerized wax materials or residues of other refining ~5 processes.

Synthetic lubricating oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as oligomerized. polymerized, and interpolymerized olefins le.g., polybutylenes, polypropylenes, propylene, isobutylene 30 copolymers, chlorinated polylactenes. poly(1-hexenes), poly(1-octenes), poly- (1-decenes), etc., and mixtures thereofi; alkylbenzenes [e.g., dodecyl-benzenes, tetradecyibenzenes. dinonyl-benzenes. di(2-ethylhexyl)benzene, etc.~; polyphenyls [e.g., biphenyls. terphenyls, alkylated polyphenyls, etc.'i;
and alkylated diphenyl ethers, alkylated diphenyl sulfides. as well as their ;5 derivatives, analogs, and homologs thereof. and the like. The preferred oils from this class of synthetic oils are oligomers of a-olefins, particularly oligomers of 1-decene.

CA 0222~646 1998-02-06 W O 97/12949 PCT~US96/15804 Synthe~ic lubricating oils also include alkylene oxide polymer5 interpolymers. copoiymers. and derivatives thereof where the terminal hydroxyl groups have beeri rnobifie~ by esterifi~ation. ~therification. etc. This class of synthelic oils is exemplified by: polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide: the alkyl and aryl ethers of these polyoxyaikylene polymers (e.g., methyi-polyisopropylene glycol ether having an average molecuiar weight of 1000, diphenyl ether of polypropylene glycol having a molecular weight of 1000 - 1500); and mono-10 and poly-carboxylic esters thereof (e.g., the acetic acid esters, mixed C3-C8 fatty acid esters, and C12 oxo acid diester of tetraethyiene glycol).

Another suitable class of synthetic lubricating oils comprises the esterS
of dicarboxyiic acids (e.g., phthaiic acid, succinic acid. alkyl succinic acids 15 and aikenyl succinic acids. maleic acid, azelaic acid, suberic acid, sebasjc acid, fumaric acid, adipic acid. Iinoleic acid dimer, malonic acid. alkylmalonicacids, alkenyl malonic acids, etc.) with a variety of aicohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoethers. propylene glycol, etc.). Specific examples of ~0 these esters include dibutyl ~clir~t~, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl seb~c~t~. diisooctyl ~7~1~te, diisodecyl ~ t~, dioctyl isothalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the compiex ester formed by reacting one mole of sebasic acid with two moles of tetraethylene glycol and two moles of 2-ethyl-~5 hexanoic acid. and the like. A preferred type of oil from this class of syntheticoils are adipates of C4 to C12 alcohols.

Esters useful as synthetic lubricating oils also include those made from Cs to C 12 monocarboxylic acids and polyols and polyol ethers such as 30 neopentyl glycol, Ll i" ,ell ,ylolpropane pentaerythritol, dipentaerythritol, tripentaerythritol, and the like.

Silicon-based oils (such as the polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and silicate oils) comprise another useful class of 'S synthetic lubricating oils. These oils include tetra-ethyl silicate, tetraisopropyl silicate, tetra-(2-ethyihexyl) silicate, tetra-(4-methyl-2-ethylhexyl) silicate,tetra-(p-tert-butylphenyl) silicate. hexa-(4-methyl-2-pentoxy)-disiloxane, CA 0222~646 1998-02-06 poly(methyl)-siloxanes and poly(methylphenyl) siioxanes. and the like. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate. trioctyl phosphate. and diethyl ester of decylphosphonic acid), polymeric tetra-hydrofurans. poly-a-olefin5. and the like.

The lubricating oils may be derived from refined. rerefined oils, or mixtures thereof. Unrefined oils are obtained directly from a natural source or synthetic source (e.g., coal, shale, or tar sands bitumen) without further 10 p~-lir,c~Lion or treatment. Examples of unrefined oils include a shale oil obtained directly from a retorting operation, a petroleum oil obtained directly from distillation, or an ester oil obtained directly from an esterificat;On process. each of which is then used without further treatment. Refined oils are similar to the unrefined oils except that refined oils have been treated in 15 one or more purification steps to improve one or more properties. Suitable pul ir,cdlion techniques include distillation, hydrotreating, dewaxing, solvent extraction, acid or base extraction, filtration, and percolation, all of which are known to those skilled in the art. Rerefined oils are obtained by treating used oils in ptocesses similar to those used to obtain the refined oils. These 20 rerefined oils are also known as reclaimed or reprocessed oils and are often a.ldilio"ally process~o~ by techniques for remoYal of spent additives and oil breakdown products.

When the lubricating oil is a mixture of natural and synthetic lubricating 25 oils (i.e., partially synthetic~, the oil typically will contain 1 to 80, prererably from about 10 to 75, most preferably from about 10 to 50 weight percent synthetic lubricating oil. While the choice of the partial synthetic oil components may widely vary, particularly useful combinations are ~o""u,iaed of mineral oils and poly-a-olefins (PAO), particularly oligomers of 1-decene.
Amine Phosphates The amine phosphates useful in this invention are the neutr~ii7~tion or partial neutralization products of acidic phosphorus-containing intermediates 35 and amines. The acidic intermediates are preferably formed from a hydroxy-substituted triester of a phosphorothioic acid with an inorganic phosphorus reagent sele~cted from the group consisting of phosphorus acids, phosphorus CA 0222~646 1998-02-06 W O 97/12949 PCTrUS96/15804 _ ~ _ oxides. and phosphorus halides. Generally, these phosphates perform an extreme pressure or antiwear function in the lubricant.

The hydroxy-substituted triesters of phosphorothioic acids include principally those having the struc-ural formula R-X X
\ 11 I \
R-X X-R

15 wherein R is selected from the ctass consisting of substantially hydrocarbon,functionally substituted hydrocarbon and hydroxy-substituted hydrocarbon radicals, at least one of the R radicals being a hydroxy-substituted suhst~r,Lially hydrocarbon radical, and X is selected from the class consisting of sulfur and oxygen. The substantially hydrocarbon radicals include ?0 aliphatic, arur"dLic, alkyl substituted aromatic, cycloaliphatic and heterocyciic radicals such as alkyl, aryl, aralkyl, alkaryl, cycloalkyl and heterocycioalkyl radicals. The functionally substituted hydrocarbon radicals may contain a substituent such as fluoro, chloro. bromo. iodo. alkoxy, polyalkyioxy, aryloxy, aikylthio, alkylpolythio. arylthio. alkylamino. nitro. keto, thioketo carboalkoxy, '5 amido, imido, aldehydo. or thioaldehydo group. Although there may be more than one functional suhstih~ent in each hydrocarbon radical it is generally preferred that there be no more than one.

Some specific examples of the substantially hydrocarbon and ,0 functionally substituted hydrocarbon radicals are: methyl, ethyl, isopropyl, secondary-butyl, isobutyl, n-pentyl, n-hexyl 1.3-dimethylbutyl, 2-ethylhexyl, isodecyl, dodecyl, tetrapropenyl, isotridecyl, oleyi. polyisobutenyl, polybutenyl, cyclohexyl, cyclopentyl, 2-heptyl-cyclohexyl, pnenyl, naphthyl, xenyl, p-heptylphenyl, 2,6-di-tertiary-butylphenyl, benzyl, phenylethyl, 3,5-35 dodecylphenyl, octylthioethyl. dodecylthioethyl, hydroxylethylthioeth chlorophenyl, alpha-methoxy-beta-naphthyl, p-nitrophenyl, p-phenoxyphenyll 2-bromomethyl, 3-chlorocyclohexyl, polypropylene (molecular weight of 300)-CA 0222~646 l998-02-06 W O97/12949 PCT~US96/15804 substituted phenyl, polyisobutenyisuccinimidoethyl. 2-furanyimethyl~ 2-thiofuranylmethyl .

The hydroxy-substituted substantially hydrocarbon and funclionally substituted hydrocarbon radicais include principally the above~ ustrated substantially hydrocarbon. and functionally substituted hydrocarbon~ radicals containing a hydroxy group. Examples of such radicals are hydroxymethyl~
hydroxyethyl, 2-hydroxypropyl. 3-hydroxypropyl. 2-hydroxycyclohexyl~ 2-hydroxycyclopentyl, 2-hydroxy-1-octyl. 1-hydroxy-3-octyl, 1-hydroxy-2 2-hydroxy-3-phenyl-cyclohexyl, 1-hydroxy-2-phenylethyl, 2-hydroxy-1 phenylethyl, 2-hydroxy-1-p-tolylethyl, 2-hydroxy-3-butyl, 2-(2-hydroxyethylthio~-ethyl, 2-(2-hydroxyethoxyl)-ethyl, and.2-(2-(2-hydroxylethoxy)-ethoxy)-ethyl radicals. Other hydroxy-substituted substantially hydrocarbon radicals are exemplified by 2.5-dihydroxyphen l ~ aipha-hydroxy-beta-naphthyl, 3-hydroxy4-dodecyl, 3-hydroxy-6-octadecyll and p-(p-hydroxyphenyl)-phenyl radicals. Those having less than about 8 carbon atoms are preferred because of the convenience in preparing such hydroxy-substituted triesters.

20 A more preferred class of hydroxy-substitl It~d triesters of phophorothioic acids include those having the structural formula R-O X
\ 11 ~5 P
I
R-O X-R

wherein R is selected from the class consisting of substantially hydrocarbon, 30 functionally substituted hydrocarbon. and hydroxy-substituted substantially hydrocarbon radicais as described above, with at least one of the R radicals being a hydroxy-substituted substantially hydrocarbon radical, and X is selected from the class consisting of sulfur and oxygen with at least one of the X radicals being sulfur.
3~
A most preferred class of the hydroxy-substituted triesters comprises those having the structural forrnula CA 0222~646 1998-02-06 WO 97112949 PCT~US96/15804 R"O\ S
P~
R"C~ S~ OH

where R" is a substantially hydrocarbon radical illustrated above and R~ is a bivalent substantially hydrocarbon radical such as alkylene or arylene radicals derived from the previously illustrated substantially hydrocarbon radicals A
convenient method for preparing such esters involves the reaction of a phosphorodithioic acid with an epoxide or a glycol- Such reaction is known in the art. The following equations are illustrative of the reaction.

\ p~ ~R~ ~ P~

R"O\ ~,S + HO - R' - OH R"O\ ~S

R"G~/ SH R"~ S - R' - OH

where ~ is an epoxide and HO - R' - OH is a glycol.

Especially useful epoxides are exemplified by ethylene oxide, propylene oxide, styrene oxide, alpha-methylstyrene oxide, p-methylstyrene oxide, cyclohexene oxide, cyciopentene oxide. dodecene oxide, octadecene ~0 oxide, 2,3-butene oxide~ 1,2-butene oxide. 1.2-octene oxide, 3.4-pentene oxide, and 4-phenyl-1,2-cyclohexene oxide. For reasons of economy, aliphatic epoxides having less than about 8 carbon atoms and styrene oxides are preferred for use in the above process. Glycots include both aliphatic and ~ aromatic di-hydroxy compounds. The iatter are exemplified by hydroquinone, '~ catechol, resorcinol. and 1,2-dihydroxynaphthalene Aliphatic glycols are especially useful such as ethylene glycol. propylene glycol, hexylene glycol, trimethylene glycol. tetramethylene glycol. decamethylene glycol. di-ethylene CA 0222~646 1998-02-06 glycol, dipropylene glycol. triethylene giycol, and pentaethylene glycol. The glycols may also contain he~eroatoms such as 2-(2-hydroxylethylthioj ethanol.

Another convenient method for preparing the hydroxy-substituted triesters comprises the addition of a phosphorodithioic acid to an unsaturated alcohol such as allyl alcohol, cinnamyl aicohol. or oieyl alcohol such as is described in U.S. Patent 2.528.723. Still another method involve5 the reaction of a metal phosphorothiate with a halosen-substituted alcohol described in U.S. Reissue Patent20,411.

The phosphorodithioic acids from which the hydroxy-substituted triesters can be derived are likewise well-known. They may be prepared by the reaction of phosphorus pentasulfide with an aicohol, a phenol. mixtureS of 15 two or more alcohols, or mixtures of two or more phenols. The reaction involves at least 4 moles of the alcohol or phenol per moie of phosphorus pentasulfide and may be carried out within the temperature range from about 25~C to about 200~C. Thus, the preparation of O,O'-di-n-hexylphosphorodithioic acid involves the reaction of phosphorus pentasulfide ~0 with at least 4 moles of n-hexyl alcohol at about 100~C for about 2 hours.
Hydrogen sulfide is liberated and the residue is the defined acid along with whatever ~xcess alcohol was added to drive the reaction to completion. In practice, this small amount of excess aicohol may either be left in or removed before the acid is used. Also in practice. colllrllercially available phosphorus'5 pentasulfide may contain small amounts of phosphorus-oxygen species which lead to the formation of small amounts of phosphoromonthioic acids These are not usually removed but may be left in the phosphorodithioic acid.
The ptepdr~lion of phosphoromonothioic acid howeYer may be better effected by treatment of corresponding phosphorodithioic acid with steam.
30 Phosphorotrithioic acids and phosphoroteLI~lhioic acids can be obtained by the reaction of phosphorus pentasulfide with mercaptans, thiophenols, mixtures of mercaptans and thiophenols, mixtures of mercaptans and alcohols, mixtures of thiophenois and alcohols. mixtures of mecaptans and phenols, and mixtures of thiophenols and phenols.
The reaction of phosphorus pentasulfide with a mixture of phenols or alcohols (e.g., isobutanol and n-hexanol in 2:1 weight ratio) results in a CA 0222~646 1998-02-06 WO 97/12949 PCT~US96/lS804 _ 9 _ mixture of vanous phosphorociithioic acids ;n wnich the r.Yo crganlc radicals are present. Such acids iikewise are useful here!n.

The !norganic phosphorus reagent useful in the reac::-n with the hydroxy-substituted triesters of ?hosphorothioic acids include5 .pnosphOrus oxid~s such as~ phosphorus pentoxide. phospnorus trioxide anc phosphoru5 tetroxide: phosphorus acids such as. phosphoric acid. pyrophosDhoric acid.
metaphosphoric acid, hypophosphoric acid. phosphorous acid.
pyrophosphorous acid, metapnosphorous acid, hypophosphorous acid phosphorus halides such as phosphorus trichioride. phosphorus tribrom;de~
phosphorus pentachloride. monobromophosphorus tetrachloride. phosphoru5 oxychloride, and phosphorus triiodide: and phosphorus sulfides such as phosphorus pentasulfide and ?hcsphorus oxysulfide. rhe most preferred inorganic pnosphorus reagent is Dnosr?horus pentoxide.
The reaction of the hydroxy-substituted triesters of phosphorothioic acids with the inorganic phosphorus reagent resuits in an acidic product. The chemical constih~tion of the acidic product depends to a large measure on the nature of the inorganic phosphorus reagent used. In most instances the product is a compiex mixture the precise composition of which is not known.
It is known, however. that the reaction of the hydroxy-substituted triesters of phosphorulhioic acids with phosphorus pentoxide involves the hydroxy radicat of the triester with the inorganic phosphorus reagent In this respect the reaction may be likened to that of an aicohol or a phenoi with the inorganic '~ phosphorus reagent. Thus, the reaction of the hydroxy-substituted triester with phosphorus pentoxide is believed to result principally in acidic phosphates. i.e., mono- or di-esters of phosphoric acid in which the ester radical is the residue obtained by the removai of the hydroxy radical of the phosphorothioic triester reactant. The product may also contain phosphonic '0 acids and phosphinic acids in which one or two direct carbon-to-phosphorus linkages are present. The reaction product may also contain small amounts ? of pyrophosphates depending upon the reaction conditions such as the inadvertent contamination of the phosphorus Fentoxide with small amounts of water. Smaii amounts of these pyrophosphates may be left in the product.
~5 The acidic product of the reaction ber~een the hydrcxy-substituted triester with phosphorus oxyhalide or phosphoric acid is beiieved to result in CA 0222~646 1998-02-06 W O 97/12949 PCTnUS96/15804 simiiar mixtures of acidic phosphates. phosphonic acids. andlor phosphjnjc acids. On the other hand. the reaction of the hydroxy-substituted triester with phosphorus trichloride or phosphorus acid is believed to result principally in acidic organic pnosphites. Still other products may be obtained from the use 5 of other inorganic phosphorus reagents illustrated previously. In any event the product is acidic and as such is useful as the intermediate for the preparation of the neutralized products useful in invention.

Usually, from about 2 moles to about 5 moles of the triester is used for 10 each mole of the inorganic phosphorus reagent. The preferred proportiOn of the triester is about 34 moles for each mole of the phosphorus reagent. The use of amounts of either reactant outside the limits indicated here results in excessive unused amounts of the reactant and is ordinarily not preferred Thus for the reaction of the triester with phosphorus pentoxide, the preferred 15 inorganic phosphorus reagent. 3 moles of triester are used per mole of phosphorus pentoxide.

The reaction of the hydroxy-substituted triester with the inorgani phosphorus reagent to produce the acidic intermediate can be effected simply 20 by mixing the two reactant at a temperature above about room temperature, preferabiy above about 50~C. A higher temperature such as 1 00~C or 1 50~C
may be used but ordinarily is unnecess~ry.

The amines useful for neutralizing the acidic intermedfate may be '5 primary, secondary or tertiary amines. They may include aliphatic amines aromatic amines, cycloaliphatic amines, heterocyclic amines, or carbocyclic amines. Amines having from about 4 to about 30 aliphatic carbon atoms are preferred. having the formula I

where R1, R2 and R3 are for selected for example from the group consisting 35 of hydrogen. substantially hydrocarbon. functionally substituted hydrocarbon, and hydroxy-substituted substantially hydrocarbon radicals as described above. Examples of useful aliphatic amines include tert-octyl, tert-dodecyl, CA 0222~646 1998-02-06 WO 97/12949 PCT~US96/15804 - 11 -tert-tetradecyl, tert-octadecyi, cetyl. n-tetradecyl coco. behenyl, stearyl, eicosyl, docosyl, tetracosyl, hexatriacontanyl, and pentahexacontanyl.
Examples of other aliphatic amines include cyclohexyl amine. n-hexylamine.
dodecylamine, di-dodecylamine. tridodecylamine. N-methyl-octylamine.
butylamine, behenylamine. stearyi amine. oleyl amine. myristyl amine, N-dodecyl trimethylene diamine. menthane diamine, cyclopentyl amine, ethylene diamine, hexamethylene t~l~ar"ine, octamethylene diamine, isononyloxypropylamine, isodecyloxylpropylamine. isotridecyloxypropylamine~
and tallowdiamine. Examples of aromatic amines include aniline, o-toluidine, 10 benzidine, phenylene diamine, N,N'-di-sec-butylphenylene diamine, N,N'-dibutyl-phenylene diamine, beta-naphthylamine. and aipha-naphthylamine~
Examples of heterocyclic amines include morpholine, and piperazine. and Also useful are hydroxy-substituted amines such as ethanolamine~
diethanolamine, triethanolamine. isopropanolamine. para-arninophen l 5 amino-naphthol-1, 8-amino-naphthol-1 . beta-aminoalizarin, 2-amino-Z-ethy 1,3-propandiol, 4-amino4'-hydroxy-diphenyl ether, 2-amino-resorcinol. etc.

Of the various available hydroxy-substituted amines which can be employed, a preference is expressed for hydroxy-substituted aliphatic ~0 amines, particularly those which conforrn for the most part to the formula Q

R - N
'5 (AO)XH

wherein R is as previously defined; A is a lower alkylene radical such as methylene, ethylene, propylene-1,2. tri-methylene, butylene-1,2, tetramethylene, amylene-1.3. pentamethylene, etc.; x is 1-10, inclusive; and Q is hydrogen, (AO)XH, or R The use of such hydroxy-substituted aliphatic o amines in many instances imparts improved rust-inhibiting characteristics to the phosphorus and nitrogen-containing compositions of this invention.
Examples of such preferred hydroxy-substituted aliphatic amines include N 1-hydroxybutyl-dodecyl amine, N-2-hydroxyethyl-n-octylamine, N-2-hydroxypropyl dinonylamine. N,N-di-(3-hydroxypropyl)-tert-dodecyl amine, N-hydroxytriethoxyethyl-tert-tetradecyl amine. N-2-hydroxyethyl-tert-dodecyl CA 0222~646 l998-02-06 amine. N-hydroxyhexapropoxypropyl-tert-octadecyi amine, N-5-hydroxypentyl di-n-decyl amine. N,N-diethoxycocoamine, N,N-diethoxyisodecyloxylpropylamine. etc. A convenient and economical method for the preparation of such hydroxy-substituted aliphatic amines involves the known reaction of an aliphatic primary or secondary amine with at least about an equimolecular amount of an epoxide, preferably in the presence of a suitabie catalyst such as sodium methoxibe, sodamide. sodium metal, etc.
Q

RNH2 + xAO ~ R - N
\

(AO)XH

R2NH + xAO - - ~ R2N - (AO)XH

In the above formulae, R, x and A are as previously defined. A preference is ~0 expressed for N-monohydroxyalkyl substituted mono-tertiary-alkyl amines of the formula tert-R - NHAOH, wherein tert-R is a tertiary-alkyl radical containing from about 11 to about 24 carbon atoms In lieu of a single compound of the formula tert-R - NHAOH, it is often convenient and desirable to use a mixture of such compounds prepared. for example, by the reaction of ~5 an epoxide such as ethylene oxide, propylene oxide. or butylene oxide with a commercial mixture of tertiary-alkyl primary amines such as C1 1-C14 tertiary-alkyl primary amines, C13-C22 tertiary-alkyl primary amines, etc.

Other useful amines are the primary ether amines R"OR'NH2 wherein 30 R' is a divalent alkylene group having 2 to 6 carbon atoms and R" is a hydrocarbyl group of about 5 to about 150 carbon atoms. These primary ether amines are generally prepared by the reaction of an alcohol R"OH with an unsaturated nitrile. The R" group of the alcohol can be a hydrocarbon-based group having up to about 150 carbon atoms. Typically, and for 35 efficiency and economy, the aicohol is a linear or branched aliphatic alcohol with R" having up to about ~0 carbon atoms. preferably up to 26 carbon atoms and most preferably R" has from 6 to 20 carbon atoms. The nitrile W O 97/12949 PCT~US96/15804 reactant can have from Z to 6 carbon aloms ';/ilh acrylonitrile being most preferred. E~her amines are known commercial products which are available under the name SURF~M" produced ana marketed by Mars Chemical Company, Atlanta. Ga. Typical of such amines are those having from about 15D to about 400 molecuiar weight Pre.;errea ctheramines are exemplified by those identified as SURFAM P14B (decyloxypropylamine), SlJRFAM P16A
(linear C16), SURFAM P17B (tridecyioxypropyiamine) The carbon chain lengths (i.e., C14, etc.) of the SURFAMS described above and used hereinafter are approximate and include the oxygen ether linkage. For example, C~4 SURFAM would have the following general formula C1 oHZ1 0C3H6NH2 The amines used to forrn the ammonium saits may be hydroxyamines lo In one embodiment, these hydroxyamines can ce represented by the formu~a ( R 9O)zH\ [CH~R~1 1)CH(R~1 1)O~XH
R'8~N--R~107LN
~CH(R 1 1)CI l(R 1 1)0~yH

wherein R 8 is a hydrocarbyl group generally containing from about 6 to about 30 carbon atoms, R 9 is an ethylene or propylene ~roup, R 10 is an alkylene group containing up to about 5 carbon atoms. a is zero or one. each R~11 is hydrogen or a lower alkyl grouD. and x. y and z are each independentiy integers from zero to about 10. al !east one of x, y and z being at least 1.
_5 The above hydroxyamines can be prepared by techniques well known in the art, and many such hydroxyamines are commercially available. They may be prepared. for example, by reaction of Drimary amines containing at least 6 carbon atoms with various amounts of alkylene oxides such as v -~O ethylene oxide. propylene oxide. etc. The Frlmary amines may be single amines or mixtures of amines such as obtainea by the hydrolysis of fatty oils such as tallow oils. sperm oiis. coconut oils. e~c Specific examples of fatty acid amines containing from about 6 to about 30 carbon atoms include saturated as well as unsaturated aliphatic amines such as octyl amine. decyl CA 0222~646 1998-02-06 amine, lauryl amine. stearyl amine. oleyl amine. myristyl amlne _almityl amine. dodecyl amine. and octadecyl amine.

The useful hydroxyamines where a in the above formuia s zero inciude 2-hydroxyethylhexylamine. 2-hydroxyethyloctylamine. 2-hydroxyethylpentadecylamine, 2-hydroxyethyloleylamine. 2-hydroxyethylsoyamine, bis(2-hydroxyethyl)hexylamine, bis(2-hydroxyethyl)oleylamine, and mixtures thereof Also included are the comparable members wherein in the above formula at least one of x and y is lO at least 2, as for exampie, 2-hydroxyethoxyethylhexylamine.

A number of hydroxyamines wherein a is zero are available from the Armak Chemical Division of Akzona. Inc-, Chicago. Ill., under the general trade designation "Ethomeen" and "Propomeen Specific examples of such 1~ products include "Ethomeen C/15" which is an ethylene oxide ccndensate of a coconut fatty acid containing about 5 moles of ethylene oxide: "Ethomeen C/20" and "C/2~" which also are ethylene oxide condensation products from coconut fatty acid containing about 10 and 15 moles of ethylene oxide respectively; "Ethomeen 0/12" which is an ethylene oxide condensdl~
20 product of oleyl amine containing about 2 moles of ethylene oxide per mole of amine. "Ethomeen S/15" and "S/20" which are ethylene oxide condensation products with stearyl amine containing about 5 and 10 moles of ethylene oxide per mole of amine respectively; and "Ethomeen T/12, T/15" and "T/25"
which are ethyiene oxide condensation products of tailow amlne containing about 2.5 and 15 moles of ethylene oxide per mole of amine respectively "Propomeen 0/12" is the condensation product of one mole of oleyl amine with 2 moles propylene oxide.

Commercially available examples of alkoxylated amines where a is 1 30 include "Ethoduomeen T/13" and "T/ZD' which are ethylene oxide condensation products of N-tallow lli",eihylene diamine containing 3 and 10 moles of ethylene oxide per mole of diamine. respectively.

The fatty polyamine diamines include mono- or dialkyl, symmetrical or '~ asymmetrical ethylene diamines, propane diamines (1,2, or 1,3), and polyamine analogs of the above. Suitable commercial fatty polyamines are "Duomeen C" (N-coco-1.3-diaminopropane), Duomeen S" (N-soya-1,3 CA 0222~646 l998-02-06 diaminopropane), "Duomeen r~ (N-tallow-1~3-diamonopropane)~ or "Duomeen O" (N-oleyl-1.3-diaminopropane~. "Duomeens" are commercially available diamines described in Product Data Bulletin No. /-10R1 of Armak Chemicai Co.. Chicago, Ill. In another embodiment. the secondary amineS
may be cyclic amines such as piperidine. piperazine. morpholine etc.

The neutralization of the acidic intermediate with the amine is in most instances exothermic and can be carried out simply by mixing the reactantS at ordinary temperatures, preferably from about 0~C to about 200~C. The lO chemical constitution of the neutralized product of the reaction depends to alarge extent upon the temperature. Thus, at a relatively low temperature such as less than about 80~C. the product comprises predominantly a salt of the amine with the acid. At a temperature above 100~C, the product may contain amides, amidines, or mixtures thereof. However, the reaction of the 15 acidic intermediate with a tertiary amine results only in a salt.

The relative proportions of the acidic intermediate and the amines used in the reaction are preferably such that a substantial portion of the acidic intermediate is neutralized. The lower iimit as to the amount of amine used in 20 the reaction is based primarily upon a considerable of the utility of the product formed. In most instances. enough amine should be used as to neutralize at least about 50% of the acidity of the intermediate For use as additives in hydrocar~on oils, substantially neutral products such as are obtained by neutralization of at least about 90% of the acidity of the intermediate are ~5 desirable. Thus the amount of the amine used may vary within wide ranges depending upon the acidity desired in the product and aiso upon the acidity of the intermediate as determined by, for example, ASTM procedure designation D-664 or D-974.

A particularly preferred amine phosphate is when the acidic intermediate is derived from the reaction of P2~s with hydroxypropyl O,O-di(4-methyl-2-pentyl) phosphorodithioate. This acidic intermediate may then be neutralized or partially neutralized with a C12 to C14 tertiary aliphatic primary amine. An exampie of such an amine may be commercially purchased under the trade name of Primene 81 R.

Primary Amines CA 0222~646 1998-02-06 W O 97/12949 PCTnUS96/15804 The second component of the lubricant of this invention is a primary amine of the formula RNH2 where R is an alkyl group having at least 4 carbon atoms. Generally, R will have from 4 to 60 carbon atoms, preferably from 6 to 25 carbons. Preferred alkyl primary amines are tallow amine and 2 ethylhexyl amine. Particularly preferred amines are branched alkyl primary amines, especially branched beta alkyl substituted primary amines, with the most preferred primary amine being 2 ethylhexyl amine. The amount of alkyl primary amine can vary broadly, but typically will range from 0.01 to about 2 l0 wt. %, preferably from 0.1 to 0.6 wt. %, although for economic reasons, the most preferred range will be from 0.1 to about 0.3 wt. %.

Other additives known in the art may be added to the lubricating oil.
These additives include corrosion inhibitors. antioxidants. dispersant5~
l5 antiwear agents, metallic detergents. other extreme pressure additives, seal swellants and the like. They are typically disciosed in, for example, "LubricantAdditives" by C. V. Smalheer and R. Kennedy Smith, 1967, pp. 1-11 and U.S. Patent 4,105,571.

Representative amounts of these additives in a fully formulated lubricant are summarized as follows:
Additive (Broad) Wt.% (Preferred) Wt.%
Vl Improvers 1 -12 1 - 8 Corrosion inhibitor 0.01 - 3 0.02 - 1 Antioxidants 0.1 - 5 0.25 - 3 Dispersants 0.10 -10 2 - 8 Al,Lirudn~i"y Agents 0.0 - 1 0.001 - 0.5 Metallic Detergents 0.0 - 6 0.01 - 3 Antiwear Agents 0.0 - 5 0.2 - 3 Pour Point Depressants 0.0 - 2 0.0 - 1.5 Seal Swellants 0.1 - 8 0.5 5 Lubricating Oil Balance Balance Suitable viscosity index improvers include homopoiymers and '5 copolymers of two or more monomers of C2 to C30 olehns. Suitable olefins include both alpha-olefins and internai olefins, which may be straight or branched. aliphatic aromatic. alkyl-aromatic. cyclo-aliphatic, etc. Fre~uently they will be of ethylene with C3 to C30 olefins. particularly preferred being the CA 0222~646 l998-02-06 copolymers of ethylene and propylene. Other polymers can be used such as polyisobutylenes. homopolymers and copolymers of C6 and high alpha-olefins. atactic polypropylene. hydrogenated poiymers and copolymers and terpolymers of styrene. e.g., with isoprene and/or butadiene.

Other suitable viscosity index improvers include polyacrylates and polymethacrylates and their derivatives. Especially preferred are the polymethacrylates .

Suitable corrosion inhibitors which can be used in the practice of this invention are comprised of thiazoles. triazoles. and thiadiazoles Examptes include ben~otlia~ole and its substituted derivatives (e-g, tolyltriazole) as well as mercapto- and hydrocarbylthio-disubstituted derivatives of 1,3,4_ thiadiazole, e.g., C2 to C30; alkyl. aryl, cycloalkyl, aralkyl and aikaryl-mono-~
15 di-, tri, or tetra- or thio-disubstituted derivatives thereof. Examples of such thiadiazole derivatives include 2,~-bis(octylthio) 1,3,4-thiadiazole; 2.5-bis(octyldithio)-1,3,4-thiadiazole; 2,5-bis(octyltrithio)-1,3,4-thiadiazole; 2,5-bis(oct~llel,dll,io)-1,3,4,-lhiaciia ole; 2,5-bis(nonylthio)- 1l3l4-thiadiazole; 2,~-bis(dodecyldithio)-1,3,4-thiadiazole; 2-5-bis(cyclohexyldithio)-1,3,4-20 thi~ 7nle: and mixtures thereof.

Preferred thiadiazoles are derivatives of 1,3,4-thiadiazoies such as those described in U.S. Patent Nos. 2,719,125. 2,719,126 and 3,087,932.
Especially preferred are the compounds 2,5-bis(t-octyldithio)- 1,3,4-'5 thiadiazole commercially avaiiable as Amoco 150, 2,5-bis(t- nonyldithio1,3,4-thiadiazole, commercially available as Amoco 158, Z- nonyldisulfide-5 mercapto- 1,3,4-thiadiazole, and their mixtures. with 2~5-bis(t-nonyldithio) 1,3,4-thi~di~ole being particuariy preferred. Tolyltriazole is a preferred triazole derivative.
iO
Suitable seal swellants include mineral oils of the type that provoke swelling, including aiiphatic alcohols of 8 to 13 carbon atoms such as tridecyi alcohol. A preferred seal swellant is an oil-soluble. saturated. aliphatic or aromatic hydrocarbon ester of from 10 to 60 carbon atoms and 2 to 4 35 linkages, e.g., dihexyl phthalate. as are described in U.S. Patent No.
3,974,081.

CA 0222~646 1998-02-06 W O 97/12949 PCT~US96/15804 Useful antioxidants are the ashiess antioxidants sucn as arylamjne5 and phenols, and the metal-containing antioxidants such as zinc dialkyldithiophosphates.

o The ashless antioxidants useful with this invention are either aryl amines or phenols. The amine type antioxidants include phenyl-zlpha naphthylamine. diphenylamine, phenothiazine. p-phenylene diamine, alkylated diphenylamines (e.g., p,p'-bis(alkylphenyl) amines wherein the alkyl groups contain from 8 to 12 carbons atoms each; such a material is Naugalube~) 438L). Phenolic antioxidants include sterically hindered phenols (e.g., 2,6-di-t-butyl phenol, 4-methyl-2,6-di-t-butyl-phenol) and bis-phenols (4,4'-methylenebis(2,6-di-t-but~lphenol); such a material is Ethyl~ 702~.
Another class of phenoiic anlioxidants are the 4-substituted 2,6-di-t-buty phenols. these would inciude materials such as 3.5-di-t-butyl~
lS hydroxyhydrocinnamic acid. C7-Cg ester. (Such a material is Irganox~ L
1 3~).

The metal-containing zinc dithiodiphosphates antioxidants are produced by reaction of alcohols with P2S~ to produce dialkylthiophosphoric acids, which are then neutralized with zinc oxide- The preparation of zinc dithiodiphosphate is well known and discucsed in much published literature.
See for example the books, "Lubricant AdditiYes, by C-V Smaiheer and R.
K. Smith, published by Le~ius-Hiles Co., Cleveland, Ohio (1967) and "Lubricant Additives," by M. W. Ranney, published by Noyes Data Corp., Park '5 Ridge, N. J. (1973). Exampies of such materiais are zinc (di-isooctyldithiophosphric acid) and zinc (di-2-ethylhexyldithiophosphoric acid).

Other suitable antioxidants include P2S~ treated terpenes and their derivatives. Examples of suitable terpenes include isomeric terpene hydrocarbons having the formula C10H6 such as contained in turpentine, pine oil and dipentenes, and the various synthetic and naturally occurring oxygen-containing derivatives. A particularly preferred terpene compound is a-pinene. Thus a preferred antioxidant in the P2S~ treated a-pinene reacted with a polyisobutenyl succinimide dispersant.
3~
Suitable a"Liroalll agents for use in the compositions of this invention include silicones and organic polymers such as acrylate polymers. Various CA 0222~646 l998-02-06 W O 97/12949 PCT~US96/15804 _ 19 _ antifoam agents are descr~bed in Foam Control Agents by H. T. Kerner (Noyes Data Corporation. 1976. pages 12~-176). Mixtures of silicone-type - antifoam agents such as the iiquid dialkyi silicone Dolymers with various other substances are also effective. Typical of such mixtures are silicones mixed with an acryiate polymer, silicones mixed with one or more amines and silicones mixed with one or more amine carboxylates. Other such mixtureS
include combinations of a dimethyl silicone oil with (i) a partial fatty acid ester of a polyhydric alcohol (U.S. Pat. No. 3,235, 498); (ii) an alkoxylated partial fatty acid ester of a polyhydric alcohol (U.S. Pat. No. 3,235,499); (iii) a polyalkoxyiated aliphatic amine (U.S. Pat. No. 3,235.501); and (iv) an alkoxylated aliphatic acid (U.S. Pat. No. 3.235,502).

Suitable dispersants include hydrocarbyl succinimides, hydrocarb succinamides. mixed esterlamides of hydrocarbyl-substituted succinic acid.
hydroxyesters of hydrocarbyl-substituted succinic acid, and Mannich condensation products of hydrocarbyl-substituted phenols, formaldehyde and polyamines. Mixtures of such dispersants can also be used.

The preferred dispersants are the alkenyl succinimides. These include acyclic hydrocarbyl substituted succi~ llides forrned with various amines or amine derivatives such as are widely disciosed in the patent literature. Use of alkenyl succiui" ,ides which have been treated with an inorganic acid of phosphorus (or an anhydride thereofl and a boronating agent are also suitable for use in the compositions of this invention as they are much more ~5 co~ atiL,le with elastomeric seals made from such substances as fluoro-elastomers and silicon-containing elastomers. Polyisobutenyl succinimides formed from polyisobutenyl succinic anhydride and an alkylene polyamine such as triethylene tetramine or tetraethylene pentamine wherein the poiyisobutenyl substituent is derived from poiyisobutene having a number average molecular weight in the range of 500 to 5000 (preferably 800 to 2500) are particularly suitable. Dispersants may be post-treated with many reagents known tG those skilled in the art. (see. e.g., U.S. Pat. Nos.
3,254,025, 3,502,677 and4.857,214).

Suitable metat-containing detergents are exemplified by oil-soluble neutral or overbased salts of alkali or atkaline earth metals with one or more of the following acidic substances (or mixtures thereof): (1) sulfonic acids. (2) CA 0222~646 1998-02-06 carboxylic acids, (3) saiicylic acids. (4) alkyl phenols, (5) sulfurized alkyl phenols. (6~ organic phosphorus acids characterized by at least one direct carbon-to-phosphorus linkage. Such organic phosphorus acids include those prepared by the treatment of an olefin po~ymer (e.g., polyisobutylene having a S molecuiar weight of 1,000) with a phosphorizing agent such as phosphorus trichloride, phosphorus heptasulfide. phosphorus pentasulfide. phosphoruS
trichloride and sulfur, white phosphorus and a sulfur halide, or phospho~uLhioic chloride. The preferred salts of such acids from the cost-e~,fectiveness, toxicologicai, and environmental standpoints are the salts of 10 sodium, potassium, lithium, calcium and magnesium The preferred salts useful with this invention are either neutral or overbased salts of caicium or magnesium.

Oil-soluble neutrai metal-containing detergents are those detergent5 1~ that co--lai" stoichio-"et~ically equivatent amounts of metal in retation to the amount of acidic moieties present in the detergent. Thus, in general the neutral detergents wiil have a low basicity when compared to their oYerbased co~ dll~. The acidic materials utilized in forming such detergents include carboxylic acids, salicylic acids, alkylphenols. sulfonic acids, sulfurized 2~ alkylphenols and the like.

The terrn "over~ased" in connection with metallic detergents is used to designate metal salts wherein the metal is present in stoichiometrically larger amounts than the organic radical. The co"""oniy empioyed methods for preparing the over-based salts involve heating a mineral oil solution of an acid with a stoichiometric excess of a metal neutralizing agent such as the metal oxide, hydroxide. carbonate. bicarbonate. of sulfide at a temperature of about 5~~C, and filtering the resuitant product.

~0 ~xamples of suitable metal-containing detergents include, but are not limited to, neutral and overbased salts of such substances as lithium phenates, sodium phenates, potassium phenates, calcium phenates, magnesium phenates. sulfurized lithium phenates, sulfurized sodium phenates, sulfurized potassium phenates. sulfurized calcium phenates, and iS sulfurized magnesium phenates wherein each aromatic group has one or more aliphatic groups to impart hydrocarbon solubility; lithium sulfonates, sodium slJlrollates. potassium sulfonates~ calcium sulfonates, and CA 0222~646 1998-02-06 W O 97112949 PCTAUS96/1~804 magnesium sulfonates wherein eaoh sulfonic acid moiety is attached to an aromatic nucleus which in turn usuaily contains one or more aliphatic substituents to impart hydrocarbon soiubility; lithium salicyclates sodium salicylates, potassium salicylates. calcium salicylates and magnesium salicylates wherein the aromatic moiety is usually substituted by one or more aliphatic substituents to impart hydrocarbon solubiiity; the lithium sodium potassium, calcium and magnesium salts of hydrolyzed phosphosulfurized olefins having 10 to 2,000 carbon atoms or of hydroiyzed phospho5ulfurized alcohols andlor aliphatic-substituted phenolic compounds having 10 to 2.000 lO carbon atoms; lithium, sodium, potassium, caicium and magnesium salts of aliphatic carboxylic acids and aliphatic substituted cycloaliphatic carboxyl;c acids; and many other similar alkali and alkaline earth metal salts of oil-soiuble organic acids. Mixtures of neutral or over-based salts of tv~o or more different alkali andJor alkaline earth metals can be used Likewise. neutral 15 and/or overbased salts of mixtures of two or more different acids (e.g. one or more overbased calcium phenates with one or more overbased calcium suliun~les) can also be used.

As is well known, overbased metal detergents are generally regarded 20 as contai"i,.g overbasing quantities or inorganic bases, probably in the formof micro dispersions or colloid~l suspensions. Thus the terrn "oil soluble" as appiied to metallic detergents is intended to include metal detergents wherein inorganic bases are present that are not necessarily completely or truly oil-soluble in the~ strict sense of the term. inasmucn as such detergents when ~5 mixed into base oils behave much the same way as if they were fully and totally dissolved in the oil.

Collectively. the various metallic detergents referred to herein above, have sometimes been called, simply, neutral. basic or overbased alkali metal iO or alkaline earth metal-containing organic acid salts.

Methods for the production of oil-soluble neutral and overbased metallic detergents and alkaline earth metal-containing detergents are well known to those skilled in the art, and extensiveiy reported in the patent 35 literature. See for example, the disclosures of U.S. Patent Nos. 2.001,108;
2,081,075; 2,09~.~38; 2,144,078; 2,163.622; 2,270,183; 2,292,205;
2,335,017; 2,399.877; 2,416,281; 2,451,345: 2,451,346; 2,485.861;

CA 0222~646 l998-02-06 W O 97/12949 PCT~US96tl5804 2,~01,731; 2,~01,732; 2,58~.~20; 2,671,7~8: 2.616.904 2.616,905;
2,616,906; 2,616.911; 2,616.924; 2,616.925; 2,617,049: 2.695.910;
3,178,368: 3,367,867; 3,496.105; 3,629.109; 3,865.737: 3.907 691;

4,100,085: 4,129,~89; 4,137.184; 4,184.740; 4,212,752: 4.617,13~;
4,647,387; 4,880.550.

The metallic detergents utilized in this invention can, if desired, be oil-soluble boronated neutral andlor overbased alkali of alkaline earth metal-containing detergents. Methods for preparing boronated metallic detergentS
are described in, for example, U.S. Pat. Nos. 3,480,548: 3,679,~84;
3,829,381;3,909,691;4,965,003;4,965,004.

Preferred metallic detergents for use with this invention are neutral and overbased calcium or magnesium sulphurized phenates and neutral and overbased calcium or magnesium sulphonates.

The additive combinations of this invention may be combined with other desired lubricating oil additives to form a concentrate. Typically the active ingredient (a.i.) level of the concentrate wili range from 30 to 99, preferably 40 to 9~, most preferably 50 to 90 weight percent of the concentrate. The balance of the concentrate is a diluent typically comprised of a lubricating oil or solvent.

While the benefits of this invention are applicable to a wide variety of '5 lubricants, they are particularly suitable to power transmission fluids such as automatic transmission fluids, gear oils, hydraulic fluids, heavy duty hydraulicfluids, industrial oil, power steering fluids. pump oils, tractor fluids. universal tractor fluids and the like. These power transmitting fluids can be formulated with a variety of performance additives and in a variety of base oils.
This invention will be better understood by referring to the examples shown beiow.

Fxample 1 - Preparation of Amine Phosphate Used in Oils 3-9 i5 Phosphorus pentasulfide (450 grams) is added to 4-methyl-2-pentanol (870 grams~ at 80~C over a period of about 11/2 hours. The reaction mixture is CA 0222~646 1998-02-06 W O 97/12949 PCT~US96/15804 then allowed to stir at temperature until substantialiy all of the phosphoruS
pentasulfide reacts. The reaction product is stripped under reduced pressure to remove excess 4-methyl-2-pentanol then propylene oxide (247 grams) is added at ~02C over a period of about 4 hours The reaction mixture is again allowed to stir at reaction temperature until substantially all of the propyleneoxide has reacted at which point it is again stripped under vaccum to remove volatile material. The residue which is obtained constitutes O~o-di(4-me pentyl)phosphorodithioate.

To the O~o-di(4-methyl-2-pentyl)phosphorodithioate prepared above is added phosphorus pentoxide (172.5 grams) at 50~C over a period of about 2 hours. After the addition the reaction is stirred at 60-6~~C until substantiallyall of the phosphorus pentoxide has reacted.

The phosphorus pentoxide reaction product prepared above is partially neutralized with a commercially aYaila~le cocoamine (501 grams) added at 60~C over a period of about 4~ minutes. After the addition of the cocod",i"e a hydroc~,~on diluent oil (230 grams) is added to reduce the viscosity and the product is then stripped under vacuum to remove voldliles ~ The final product was found to collL~ill 8.4% phosphorus. 10.6% sulfur and 1.5% nitrogen.

Fxample ~ - Preparation of Amine Phosphate Used in Oils 2-3 Phosphorus pentasulfide (450.~ grams) is added to 4-methyl-2-'5 pentanol (870 grams) at 80~C over a period of about 1~/2 hours. The reactionmixture is then allowed to stir at temperature until substantially all of the phosphorus pentasulfide reacts. The reaction product is stripped under reduced pressure to remove excess 4-methyl-2-pentanol then propylene oxide (247 grams) is added at 50~C over a period of about 4 hours. The reaction mixture is again allowed to stir at reaction temperature until substa"lially all of the propylene oxide has reacted at which point it is again stripped under vaccum to remove volatile material. The residue which is obtained constitutes O O-di(4-methyl-2-pentyl)phosphorodithioate.
.~

CA 0222~646 l998-02-06 To the O,O-di(4-methyl-2-pentyl)PhosPhOrodithioate prepared above is added phosphorus pentoxide (171.5 grams) at 50~C over a period of about 2 hours. After the addition, the reaction is stirred at 60-65~C until substantially all of the phosphorus pentoxide has reacted.
-The phosphorus pentoxide reaction product prepared above is partially A
neutralized with a commercially available amine (473 grams), which consists of a mixture of C11-C14 tertiary alkyl primary amines, added at 60~C over a period of about 45 minutes. After the addition of the C11-C14 tertiary alkyl lOprimary amines, a hydrocarbon diluent oil (228 grams) is added to reduce the viscosity and the product is then stripped under vacuum to remove volatjleS, The final product was found to contain 8.3% phosphorus, 10.~% sulfur and 1.5% nitrogen.

15Fxample 3 - Rust Performance in L 33 Test Several formulated gear oils were tested for rust performance using the L33 test. The L-33 test is described in ASTM ~Speci~l Technical Pubiication 512A, p~lhlic~tion Code Number (PCN): 04-512001-12 available from the ASTM, 1916 Race Street, Philadelphia, PA 19103 It is described as a test procedure for evaluating the rust and corrosion inhibiting properties of a gear lubricant while subjected to water contamination in a bench-mounted hypoid differential housing assembly. The test is usually run for a seven day period. The test procedure utilizes a Dana Corporation Model 30 hypoid '5 differential housing (carrier) assembly, Part No. 27770-1X, 4.10 ratio, standard differential with uncoated drive ~ear and drive pinon. The test consists of a motoring phase and a stora~e phase. The motoring phase utilizes 2.5 pints of the test lubricant and 1 ounce of distilled water and is run at 180 +/- 1~F for four hours as described in the procedure. The storage phase is typically 162 hours at 125 +/- 1~F while the unit is static as described in the procedure. At the end of the storage phase, the differential is disassembled and rated as described in the procedure.

Each oil contained 0.654 wt. % of a conventional lube oil flow improver ;5 and a silicone antifoamant, while oils 2-9 also contained 4.31 wt. % of conventional amounts of ashless dispersant, sulfurized isobutylene, cOI~USjo inhibitor, and acrylate anlifo~l,)d-,t.

CA 02225646 l998-02-06 W O 97/12949 PCT~US96/15804 -2~ -The amine phosphate used in Oils 2-3 was prepared according to the procedure in Examp!e 2. while the phosphate used in Oils 4-9 were prepared according to the procedure of Example 1. The 2 ethylhexylamine was obtained from Hoechst-Celanese. All of the aforementioned additives were blended into a SAE 80W-90 lubricating oil mixture.

The results of performing in the L 33 test on these oils are shown in Table 1.

CA 02225646 l998-02-06 ~ D
c~ ~ u~ ~ tn o o o ~ ~ Q

~ C~
C~
o:~ ~ ~~ ~ o O O O ~ ~ Q, C~ o~ o U~
O O ~ ~ ~L

~1 ~ ~ ~n O ~ o ~
o o ~ o ~1 0 ~ ~ ~ '~ ~ ~ a~
o o c~ o ~ a~
c O O O ~ IOn C
a~ a~
~

. o ~ ~ ~ ~
~ ~ a~
a~
o C~ 0 0 o ~ ~ ~ ~
~ --CD O O O C~
O ~ ~) IL
O
a~ ~
s _o a) c m ~
O-- . _ u~ ~ ," ~E ' -- ''' o -- c s O a) ~

W O 97/12949 PCT~US96/15804 -27-The data in Table 1 show that an oil that does not have the amine phosphate or a primary alkyl amine (Oil 1 ) has a very poor rust rating in the L33 test. The data also show that while an oil having the amine phosphate without any amine (Oil 2~ has an improved rust ratlng, it still fails the L 33 test.

In contrast. Oils 3-~ show that the rust rating is significantly improved when an amine phosphate and an alkyl primary amine are present.

rhe principles, preferred embodiments, and modes of operation of the 10 present invention have been described in the foregoing specificatjOn.
However, the invention which is intended to be protected herein is not to be construed as limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes may be made b,v those skilled in the art without departing from the spirit of the 1 5 invention.

Claims (9)

CLAIMS:

1. A lubricant composition comprising a mayor amount of lubricating oil and a minor rust inhibiting amount of an additive combination comprising:

(a) an amine phosphate, and (b) an alkyl primary amine distinct from the amine source in (a) wherein the additive combination is present in said composition in an amount sufficient to obtain a rust rating that passes the L33 test.

2. The composition of claim 1 where the amine phosphate is a neutralization or partial neutralization product of an aliphatic primary amine and a hydroxy-substituted triester of a phosphorothioic acid treated with an inorganic phosphorus reagent.

3. The composition of claim 2 where the additive combination further comprises an additive selected from the group consisting of a dispersant, an antioxidant, an extreme pressure agent, and mixtures thereof.

4. The composition of claim 3 where the composition is a power transmitting fluid.

5. The composition of claim 1 wherein (b) is a branched beta alkyl primary amine.

6. The composition of claim 1 wherein said composition is the product formed from the mixture of a major amount of lubricating oil and a minor rust inhibiting amount of said additive combination.

7. The composition of claim 5 wherein (b) is tallow amine, 2 ethylhexyl amine, or mixtures thereof.

8. An additive concentrate comprising a major amount of the additive combination of claim 1 and a minor amount of lubricating oil.

9. A method of improving the rust inhibition of a power transmitting fluid by incorporating into the fluid a rust inhibiting amount of the additive concentrate of claim 1.