I UR 1CANTS WITH IMPROVFO RUST INHIBITION

5 RAC fiROUND OF THE INVENTION

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

0 The use of amine phosphates in lubricating oils is known in the art

(see, for example. U.S. Patent 3,197.405). Similarly, the use of pπmary amines in lubricating oils has also been disclosed (see. for example, U.S. Patent 4,089,792) In addition, the use of amine phosphates and primary amines in lubπcating oils has been described (see, for example. U.S. Patents

15 3.974,815; 5.354.485: and 5.403,501 ). However, none of these references describe lubπcants having enhanced rust inhibition due to the presence of the amme phosphates and the particular primary amines claimed herein.

0 «» IMMARY OF THE INVENTION

This invention concerns a lubricant having improved rust inhibition which compnses a major amount of lubricating oil and a minor rust inhibiting amount of an additive combination compπsing

-> ς

(a) an amine phosphate, and

(b) an alkyl primary amme

This invention also concerns an additive concentrate 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.

JJ RFTAII ED DESCRIPTION OF THE INVENTION

The lubricant of this invention requires a lubricating oil. an amme phosphate, and an alkyl primary amme.

1 .ihriπatmα Oils

Lubricating oils useful in this invention are derived from natural lubricating oils, synthetic lubricating oiis. and mixtures thereof. In general, both the natural and synthetic lubricating oii will each have a kinematic viscosity ranging from about 1 to about 40 mm ² /s (cSt) at 100°C, although typical applications will require each oil to have a viscosity ranging from about

2 to about 35 mm ² /s (cSt) at 100°C. Particularly preferred are viscosities from 10 to 35 mm ² /s (cSt) at 100°C .

Natural lubricating oiis include animal oils, vegetable oils (e.g., castor oil and lard oil), petroleum oiis. mineral oils, and oils derived from coai or shale. The preferred natural lubricating oil is mineral oil.

Suitable mineral oiis include ail common mineral oil basestocks. This includes oils that are naphthenic or paraffinic in chemical structure. Oils that are refined by conventional methodology using acid, alkali, and clay or other agents such as aluminum chloride, or they may be extracted oils produced, 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 isomenzed wax materials or residues of other refining processes.

Synthetic lubricating oils include hydrocarbon oiis and halo-substituted hydrocarbon oiis such as oligomenzed. polymerized, and interpoiymerized olefins [e.g., polybutyienes, polypropylenes, propylene, isobutylene copolymers. chlorinated polytactenes. poly(l-hexenes), poly(l-octenes), poly- (1-decenes), etc.. and mixtures thereof]; aikylbenzenes [e.g., dodecyl- benzenes _, tetradecylbenzenes, dinonyl-benzenes. di(2-ethylhexyl)benzene, etc.]; polyphenyls [e.g.. biphenyls. terphenyls. alkylated polyphenyls. etc.]; and alkylated diphenyl ethers, alkyiated diphenyl sulfides. as well as their derivatives, analogs, and homologs thereof, and the like. The preferred oils from this class of synthetic oils are oligomers of α-olefins, particularly oligomers of 1-decene.

Synthetic lubricating oils also include alkylene oxide polymers, interpolymers copoiymers. and derivatives thereof where the terminal hydroxyl grouD _S have been modifieα by esterification. etheπfication. etc This class of synthetic oiis is exemplified by polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide: the alkyl and aryl ethers of these polyoxyalkylene polymers (e.g., methyl-polyisopropylene glycol ether having an average molecular weight of 1000. diphenyl ether of polypropylene glycol having a molecular weight of 1000 - 1500); and mono- and poly-carboxylic esters thereof (e.g., the acetic acid esters, mixed C3-C8 fatty acid esters, and C12 ^{oxo acιd} diester of tetraethyiene glycol)

Another suitable class of synthetic lubricating oils comprises the esters of dicarboxy _l ic acids (e.g., phthaπc acid, succ ic acid, alkyl succinic acids and alkenyl succmic acids, maleic acid, azelaic acid, suberic acid, sebasic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyimalonic acids _, alkenyl malonic acids, etc.) with a variety of alcohols (e.g., butyl alcohol _, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoethers, propylene glycol, etc.). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-π-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl isothalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebasic acid with two motes of tetraethyiene glycol and two moles of 2-ethyl- hexanoic acid, and the like. A preferred type of oil from this class of synthetic oils are adipates of C4 to C12 alcohols.

Esters useful as synthetic lubricating oils also include those made from C5 to C12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, tπmethylolpropane pentaerythritol dtpentaerythπtol, tnpentaerythπtot, and the like.

Silicon-based oils (such as the polyalkyl-, polyaryl-, polyalkoxy-, or poiyaryloxy-siloxane oils and silicate oils) comprise another useful class of synthetic lubricating oils. These oils include tetra-ethyl siiicate, tetraisopropyl silicate _, tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-2-ethylhexyl) silicate, tetra-(p-tert-butylphenyl) silicate. hexa-(4-methyl-2-pentoxy)-disιioxane.

poly(methyl)-siloxanes and poly(methylphenyl) siioxanes. and the iike. Other synthetic lubricating oils include liquid esters of phosDnorus-containing acids (e.g., tricresyi phosphate, tπoctyl phosphate, and diethyl ester of decylphosphonic acid), polymeric tetra-hydrofurans. poly-α-olefins. and the like.

The lubricating oiis may be derived from refined, rerefined oils, or mixtures thereof. Unrefined oiis are obtained directly from a natural source or synthetic source (e.g., coal, shate, or tar sands bitumen) without further purification 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 esterification process, each of which is then used without further treatment. Refined oils are similar to the unrefined oiis except that refined oiis have been treated in one or more purification steps to improve one or more properties. Suitable purification 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 processes similar to those used to obtain the refined oils. These rerefined oils are also known as reclaimed or reprocessed oiis and are often additionally processed by techniques for removal of spent additives and oil breakdown products.

When the lubricating oil is a mixture of natural and synthetic iubπcating oils (i.e., partially synthetic), the oil typically will contain 1 to 80, preferably from about 10 to 75, most preferably from about 10 to 50 weight percent synthetic lubricating oil. While the choice of the partial synthetic oii components may widely vary, particularly useful combinations are comprised of mineral oiis and poly-α-olefins (PAO), particularly oligomers of 1-decene.

AminP Phosphates

The amme phosphates useful in this invention are the neutralization or partial neutralization products of acidic phosphorus-containing intermediates and amines. The acidic intermediates are preferably formed from a hydroxy- substituted triester of a phosphorothioic acid with an inorganic phosphorus reagent selected from the group consisting of phosphorus acids, phosphorus

oxides. and phosphorus haiides. Generally, these phosohates perform an extreme pressure or antiwear function in the lubricant

The hydroxy-substituted tπesters of phosDnorothioic acids include principally those having the structural formula

R - X X

\ //

P

/ \ R - X X - R

wherein R is selected from the class consisting of substantially hydrocarbon, functionally substituted hydrocarbon and hydroxy-substituted hydrocarbon radicals, at least one of the R radicals bemg a hydroxy-substituted substantially hydrocarbon radical, and X is selected from the class consisting of sulfur and oxygen. The substantially hydrocarbon radicals include aliphatic, aromatic, alkyl substituted aromatic, cycloaliphatic and heterocyclic radicals such as alkyl, aryl, aralkyl, alkaryl, cycloalkyl and heterocycloalkyl radicals. The functionally substituted hydrocarbon radicals may contain a substituent such as fluoro, chloro. bromo. iodo. alkoxy, polyalkyioxy, aryloxy, alkylthio. alkyipolythio, arylthio. alkylamino. nitro. keto, thioketo. carboaikoxy, amido, imido. aldehydo. or thioaldehydo group. Although there may be more than one functional substituent in each hydrocarbon radical it is generally preferred that there be no more than one.

Some specific examples of the substantially hydrocarbon and functionally substituted hydrocarbon radicals are: methyl, ethyl, isopropyl, secondary-butyl, isobutyl, n-pentyl, n-hexyl 1 3-dιmethylbutyl, 2-ethylhexyl, isodecyl, dodecyl, tetrapropenyl, isotridecyl, oieyi. polyisobutenyl, polybutenyi, cyclohexyl _, cyclopentyl, 2-heptyl-cyclohexyl, Dnenyl, naphthyl, xenyl, p- heptylphenyl _, 2,6-di-tertιary-butytphenyl, benzyl, phenylethyl, 3,5- dodecylphenyl _, octylthioethyl. dodecyithioethyl, hydroxylethylthioethyl, chlorophenyl _, alpha-methoxy-beta-naphthyl, p-nitrophenyl, p-phenoxyphenyl, 2-bromomethyl, 3-chlorocyclohexyl, polypropylene (molecular weight of 300)-

substituted phenyl, polyisobutenyisuccinimidoethyl. 2-furanyimethyl. 2- thiofuranylmethyl.

The hyαroxy-substituted substantially hyαrocarbon. and functionally substituted hydrocarbon radicals iπciude principally the above-iilustrated 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- hydroxycyciopentyl, 2-hydroxy-1 -octyl, 1-hydroxy-3-octyl, 1-hydroxy-2-octyl _, 2-hydroxy-3-phenyl-cyclohexyl, 1-hydroxy-2-pheπylethyl, 2-hyαroxy-l- 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-dihydroxypnenyl _, aipha-hydroxy-beta-naphthyl, 3-hydroxy-4-dodecyl, 3-hydroxy-6-octadecyl, and p-(p-hydroxyphenyi)-phenyl radicals. Those having less than about 8 carbon atoms are preferred because of the convenience in preparing such hydroxy-substituted triesters.

A more preferred class of hydroxy-substituted triesters of phophorothioic acids include those having the structural formula

R - 0 X

\ // P

/ \

R - 0 X - R

wherein R is selected from the class consisting of substantially hydrocarbon, functionally substituted hydrocarbon, and hydroxy-substituted substantially hydrocarbon radicals 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.

A most preferred class of the hydroxy-substituted triesters comprises those having the structural formula

where R" is a substantially hydrocarbon raαicat 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 giycol. Such reaction is known in the art. The following equations are illustrative of the reaction.

where

\ ^R > O is an epoxide and HO - R' - OH is a glycol.

Especially useful epoxides are exemplified by ethyiene oxide, propylene oxide, styrene oxide, alpha-methylstyrene oxide, p-methylstyrene oxide, cyclohexene oxide, cyclopenteπe oxide, dodecene oxide, octadecene 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. Glycols include both aliphatic and aromatic di-hydroxy compounds. The iatter are exemplified by hydroquinone. catechol, resorcinol. and 1 ,2-dihydroxynaphthalene. Aliphatic giycols are especially useful such as ethylene giycol. propylene glycol, hexylene glycol, tnmethylene glycol. tetramethylene glycol. decamethylene glycol. di-ethylene

glycol, dipropylene glycol triethylene glycol, and pentaethylene glycol The glycols may also contain heteroatoms such as 2-(2-hydroxyiethytthιoj- ethanol

5 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 alcohol, or oleyl alcohol such as is described in U.S Patent 2.528 723 Still another method involves the reaction of a metal phosphorothiate with a hatogen-substituted alcohol 0 described in U.S Reissue Patent 20,411

The phosphorodithioic acids from which the hydroxy-substituted tπesters can be derived are likewise well-known They may be prepared by the reaction of phosphorus pentasulfide with an alcohot. a phenoi mixtures of 5 two or more alcohols, or mixtures of two or more phenols The reaction involves at least 4 moles of the alcohol or phenol per mole of phosphorus pentasulfide and may be carried out within the temperature range from about 25°C to about 200°C. Thus, the preparation of 0,O'-dι-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 aiong with whatever excess alcohol was added to drive the reaction to completion In practice, this small amount of excess alcohol may either be left in or removed before the acid is used Also in practice, commercially 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 preparation of phosphoromonothioic acid however may be better effected by treatment of corresponding phosphorodithioic acid with steam 0 Phosphorotπthioic acids and phosphorotetrathioic acids can be obtamed by the reaction of phosphorus pentasulfide with mercaptans. thiophenols, mixtures of mercaptans and thiophenols, mixtures of mercaptans and alcohols, mixtures of thiophenols and alcohois. mixtures of mecaptans and phenols, and mixtures of thiophenols and phenols.

J .5

The reaction of phosphorus pentasulfide with a mixture of phenols or alcohols (e.g , isobutanol ana n-hexanol in 2.1 weight ratio) results in a

m _i xture of various phospnoroαithioic acids in wnich the r.vo crganic radicals are present _. Such acids iikewise are useful herein

The -πorαanic pnosphorus reagent useful in tne reac::cn with the hydroxy-su _DS tituted triesters cf pnosDnorothioic acids mciuαes cnosphorus oxides sucn as. phosphorus pentoxide. phospnorus trioxide ana cnosDhorus tetroxide; phos _D horus acids such as. phosohoπc acid. pyroDnosDnoπc acid, metaphospnoπc acid. hypoDnospnoπc acid. phosonorous acid, pyrophosphorous acid, metaDnosphorous acid. hypoDhosDhorous acid: phosphorus haiides such as phosohorus trichloride ^, phosphorus tribromide. phosphorus pentachlor.de, monobromophosphorus tetrachloride. phosphorus oxychloride. and phosphorus tπiodide: and phosphorus suifides such as phosphorus oentasulfide and cnosDhorus oxysuifide. The most preferred inorganic pπosonorus reagent is Dnosohorus pentoxide.

The reaction of the hyαroxy-substituteα tπesters of phosDhorothioic acids with the inorganic phosphorus reagent results in an acidic product. The chemical constitution 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 complex mixture the precise composition of which is not known. It is known _, however, that the reaction of the hydroxy-substituted triesters of phosphorothioic acids with phosDhorus pentoxide involves the hydroxy radical of the triester with the inorganic phosphorus reagent. In this respect the reaction may be likened to that of an alcohol cr a phenol with the inorganic phosphorus reagent Thus, the reaction of tne hydroxy-substituteα triester with phosphorus pentoxide is believed to result principally in acidic phosphates _, i _. e.. mono- or di-esters of phosDnoπc acid in which the ester radical is the residue obtained by the removal of the hydroxy radical of the phosphorothioic triester reactant. The product may also contain phosphonic acids and pnosphinic acids in which one or two direct carboπ-to-phosphorus linkages are present. The reaction product may aiso contain small amounts of pyrophosphates depending UDOΠ the reaction conditions such as the _i nadvertent contamination of the pnosphorus pentoxide with small amounts of water. Sma _l l amounts of these oyrophosphates may be left in the Droduct.

The acidic product of the reaction between the hyαroxy-substituted tr _i ester with _D nosphorus oxyhatide or phosphoric acid is Deiieved to resuit in

simiiar mixtures of acidic phosDnates. phosphonic acids, and/or Dhosphinic acids. On the other hand, the reaction of the hydroxy-substituted triester with phosphorus trichloride or phospnorus acid is believed to result Dπncipally in acidic organic pnosphites. Still other products may be obtained from the use 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 moies of the triester is used for each mole of the inorganic phosphorus reagent. The preferred proportion of the triester is about 3-4 moies 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 phosDhorus pentoxide. the preferred inorganic phosphorus reagent. 3 moies of triester are used per mole of phosphorus pentoxide.

The reaction of the hydroxy-substituted triester with the inorganic phosphorus reagent to produce the acidic intermediate can be effected simply by mixing the two reactant at a temperature above about room temperature, preferably above about 50°C. A higher temperature such as 100°C or 150°C may be used but ordinarily is unnecessary.

The amines useful for neutralizing the acidic intermediate may be 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

Rl - N - R3

R2

where R- _j , R2 and R3 are for selected for example from the group consisting of hydrogen, substantially hydrocarbon, functionally substituted hydrocarbon, and hydroxy-substituted substantially hydrocarbon radicals as described above. Examples of useful aiiDhatic amines include tert-octyl, tert-dodecyl,

tert-tetraαecyi, tert-octadecyl. cetyl, n-tetradecyl. coco ^, behenyl, stearyl. eicosyl _, docosyl _, tetracosyl, hexatπacontanyl, and pentahexacontanyl. Examples of other aliphatic amines include cyclohexyl amine. n-hexylamme. dodecylam _i ne _, di-dodecytamine, tridodecylamine. N-methyl-octylamine. butylamine. behenylamine. stearyl amine. oleyl amme. myπstyl amme. N- dodecyi tπmethyleπe diamine. menthaπe diamine. cyclopentyl amme. ethyiene diamine _, hexamethylene tetramiπe, octamethylene diamine. isononyioxypropylamine, isodecyioxyipropylamine. isotridecyioxypropylamine, and tallowdiamine. Examples of aromatic amines include aniline, o-toluidine. benzidine, phenylene diamine, N,N'-di-sec-butylphenylene diamine, N,N'- dibutyl-phenylene diamine, beta-naphthylamine, and atpha-naphthylamine. Examples of heterocyclic amines include morpholine. and piperazine. and Also useful are hydroxy-substituted amines such as ethanolamine, diethanolamine _, triethanolamine. isopropanolamine. para-am ophenol, 4- amιno-naphthol-1 _, 8-amιno-naphthol-1 , beta-aminoalizaπn, 2-amιno-2-ethyl- 1 ,3-propandiol _, 4-amino-4'-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 amines _, particularly those which conform for the most part to the formula

Q / R - N

\ (AO)χH

wherein R is as previously defined; A is a lower alkylene radical such as methylene _, ethylene, propylene-1 ,2, tπ-methylene, butylene-1.2. tetramethylene, amy lene- 1.3. pentamethylene, etc.; x is 1-10. inclusive; and Q is hydrogen, (AO) _x H, or R The use of such hydroxy-substituted aliphatic am _i nes 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-4- hydroxybutyl-dodecyl amme. N-2-hydroxyethyl-n-octylamine. N-2- hydroxypropyl dinonylamme. N,N-di-(3-hydroxypropyi)-tert-dodecyl amme. N- hydroxytriethoxyethyl-tert-tetradecyl amine. N-2-hydroxyethyl-tert-dodecyl

amme. N-hydroxyhexaproDoxypropyi-teπ-octadecyi amine. N-5-hyαroxypentyl di-n-decyl amine. N,N-diethoxycccoamιne, N j\ _| . diethoxyisodecyioxylpropylamine. etc. A convenient and economical method for the preparation of sucn hyαroxy-substituted alipnatic amines involves the known reaction of an aliphatic primary or secondary amme with at least about an equimoiecular amount of an epoxide, preferady in the presence of a suitable catalyst such as sodium methoxide, sodamiαe. sodium metal _, etc.

Q /

RNH2 + XAO > R - N

\ (AO)χH

R2NH + XAO > R2N - (A0) _X H

In the above formulae, R, x and A are as previously defined. A preference is expressed for N-monohydroxyalkyl substituted mono-tertiary-alkyl ammes of the formula tert-R - NHAOH. wherein tert-R is a tertiary-alky I 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 an epoxide such as ethylene oxide, propylene oxide, or butylene oxide with a commercial mixture of tertiary-alkyl pnmary amines such as C-] 1-C14 tertiary- alkyl primary amines, C13-C22 tertiary-alkyl primary amines, etc.

Other useful amines are the primary ether ammes R"OR'NH2 wherein R ^* is a divalent alkylene grouD 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 preoared 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 efficiency and economy, the alcohol is a linear or branched aliphatic alcohol with R" having up to about 50 carbon atoms, preferably up to 26 carbon atoms and most preferably R" has from 6 to 20 carbon atoms. The nitrile

reactant can have from 2 to 6 caroon atoms with acrylon ⁱ tr ⁱ le ce ⁱ ng most preferred. Ether amines are known commercial products wh ⁱ ch are ava ⁱ lable under the name SURFAM" proαuceα ana marneted by Mars Chemical Company _, Atlanta. Ga. Typical of sucn amines are those nav ⁱ ng from aDout 150 to about 400 molecular weight Preferreα etheram ⁱ nes are exemDiified by those _i dent _i fied as SURFAM P14B (decyioxyprooyiam ⁱ ne ^{) ,} SURFAM P16A (linear Ci _β ), SURFAM P17B (tπdecyioxyproDyiamme ⁾ The carbon chain lengths ( _i .e.'. C . etc.) of the SURFAMS αescr ⁱ bed above and used here _i nafter are approximate and include the oxygen ether linkage. For example _, C ₁₄ SURFAM would have the following general formula

The am _i nes used to form tne ammonium salts may De nyαroxyamines In one embod _i ment _, these hyαroxyammes can ce represented by the formula

1)0] _X H

1)0]yH

where _i n R* ⁸ is a hydrocarbyl group generally containing from about 6 to about 30 carbon atoms, R ^*9 is an ethylene or propylene group, R ^{* i} s an alkylene group containing up to about 5 carooπ atoms ^, a ⁱ s zero or one. each R _* 11 _i s hydrogen or a lower alkyl grouD. and x y and z are each independentiy integers from zero to about 10 at least one of x y and z be ⁱ ng at least 1

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 Dπmary amines containing at least 6 carbon atoms with various amounts of aikylene ox ⁱ des such as ethylene oxide _, propylene oxide, etc. The cπmary am ⁱ nes may be s ⁱ ngle ammes or m _i xtures of amines such as obtaineα by the hydrolysis of fatty o ⁱ ls such as tallow oils _, sperm oils, coconut oils etc Specific examples of fatty ac _i d am _i nes containing from about 6 to aDout 30 carbon atoms ⁱ nclude saturated as well as unsaturated aliphatic amines such as octyl am ⁱ ne. decyl

amine, lauryl amme. stearyl amme. oleyl amine. myπstyl amine. almityl amine. dodecyl amine. and octadecyl amme.

The useful hydroxyamines where a in the above formula :s zero include 2-hydroxyethylhexylamine. 2-hyαroxyethyloctylamιne. 2- hydroxyethyipentadecylamine, 2-hyαroxyethyloleylamιπe. 2- hydroxyethylsoyamine, bis(2-hydroxyethyl)hexylamine, bis(2- hydroxyethyl)oleylamιne, and mixtures thereof. Also incluαed are the comparable members wherein in the above formula at least one of x and y is at least 2, as for example, 2-hydroxyethoxyethylhexylamine.

A number of hydroxyamines wherein a is zero are available from the Armak Chemical Division of Akzona. Inc., Chicago. III., under the general traαe designation "Ethomeen" and "Propomeen" Specific examDles of such products include "Ethomeen C/15" which is an ethylene oxide condensate of a coconut fatty acid containing about 5 moles of ethylene oxide: "Ethomeen C/20" and "C/25" which also are ethyiene 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 condensation product of oleyl amine containing about 2 moies 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 moies of ethylene oxide per mole of amme respectively; and "Ethomeen T/12, T/15" and "T/25" which are ethylene oxide condensation proαucts of tallow amine 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 amme with 2 moles propylene oxide.

Commercially available examples of alkoxylated amines where a is 1 include "Ethoduomeen T/13" and "T/20" which are ethylene oxide condensation products of N-tallow trimethylene diamine containing 3 and 10 moies of ethylene oxide per moie of diamine. respectively.

The fatty polyamine diamines include mono- or dialkyi, 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-diamiπopropane), "Duomeen S" (N-soya-1 ,3-

diam opropane) _, "Duomeen T ιN-tallow-1.3-dιamonopropane), or "Duomeen O" (N-oleyl-1.3-dιamιnoproDane) "Duomeens" are commercially available diamines descriDeα in Proαuct Data Bulletin No. 7-10R1 of Armak Chemical Co.. Chicago, III In another embodiment ^, the secondary amines may be cyclic amines such as Dipeπdine. piperazine. morpholine. etc.

The neutralization of the acidic intermediate with the amme 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 chemical constitution of the neutralized product of the reaction depends to a large 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 am e with the acid. At a temperature above 100°C. the product may contain amides, amidines, or mixtures thereof. However, the reaction of the acidic intermediate with a tertiary amme results oniy 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 limit as to the amount of amine used in the reaction is based primarily upon a considerable of the utility of the product formed. In most instances, enough amme should be used as to neutralize at least about 50% of the acidity of the intermediate. For use as additives in hydrocarbon oils, substantially neutral products such as are obtained by neutralization of at least about 90% of the acidity of the intermediate are desirable. Thus the amount of the amine used may vary within wide ranges depending upon the acidity desired in the product and also upon the acidity of the intermediate as determined by, for example, ASTM procedure designation D-664 or D-974

A particularly preferred amme phosphate is when the acidic intermediate is derived from the reaction of P2O5 with hydroxypropyl 0,0- di(4-methyl-2-pentyl) phosphorodithioate. This acidic intermediate may then be neutralized or partially neutralized with a C-12 to C-14 tertiary aliphatic primary amine. An example of such an amme may be commercially purchased under the trade name of Pπmene 81 R.

Primary Amines

The second component of the lubricant of this invention is a primary am e 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 ethyihexyl 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 amme can vary broadly, but typically wiil range from 0.01 to about 2 0 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. dispersants. 15 antiwear agents, metallic detergents, other extreme pressure additives, seal swellants and the like. They are typically disclosed in, for example. "Lubricant Additives" by C. V. Smalheer and R. Kennedy Smith, 1967, pp. 1-11 and U.S. Patent 4,105,571.

0 Representative amounts of these additives in a fully formulated lubricant are summarized as follows:

Additive (Broad . Wt.% (Preferred . \Λf\

VI 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

Antifoaming 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 homopolymers and

-". copolymers of two or more monomers of C2 to C30 olefins. Suitable olefins include both alpha-olefms and internal olefins, which may be straight or branched, aliphatic aromatic, alkyl-aromatic, cyclo-aliphatic, etc. Frequently they will be of ethylene with C3 to C30 olefins. particularly preferred being the

copoiymers of ethylene and propylene. Other polymers can be used such as polyisobutylenes. homopolymers and copolymers of C5 and high alpha- olefins. atactic polypropylene, hydrogenated polymers and copolymers and terpolymers of styrene. e.g., with isoprene and/or butad ⁱ ene.

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

Suitable corrosion inhibitors which can be used in the practice of this invention are compπsed of thiazoles. triazoles. and thiadiazoies. Examples include benzotriazole and its substituted derivatives (e.g., tolyitriazole) as well as mercapto- and hydrocarbylthio-disubstituted derivatives of 1 ,3,4- thiadiazoie _, e.g., C2 to C30; alkyl. aryl, cycloalkyl, aralkyl and alkaryl-mono- di-, tri _, or tetra- or thio-disubstituted derivatives thereof. Examples of such thiadiazole derivatives include 2,5-bis(octylthio) 1 ,3,4-thiadiazoie; 2.5- bis(octyldithio)-1 _, 3 _, 4-thiadiazole; 2.5-bis(octyltrithio)-1 ,3,4-thiadiazole; 2.5- bis(octyltetrathio)-1 ,3,4 _, -thiadiazole: 2,5-bis(nonylthio)- 1 ,3,4-thiadiazole; 2.5- bis(dodecyldithio)-1 ,3,4-thiadiazole: 2-5-bis(cyclohexyldithio)-1 ,3,4- thiadiazole; and mixtures thereof.

Preferred thiadiazoies 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-bιs(t-octyldithιo)- 1 ,3.4- thiadiazole commercially available as Amoco 150. 2.5-bis(t- nonyldithio)- 1 ,3,4-thiadiazole, commercially available as Amoco 158. 2- nonyldisulfide-5- mercapto- 1 _, 3 _, 4-thiadiazole, and their mixtures, with 2.5-bis(t-nonyldithio)- 1 ,3,4-thiadiazole being particuariy preferred. Tolyitriazole is a preferred triazole derivative.

Suitable seal swellants include mineral oils of the type that provoke swelling, including aliphatic 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 linkages _, e.g., dihexyl phthalate. as are described in U.S. Patent No. 3.974,081.

Useful antioxidants are the ashiess antioxidants such as arylam es and phenols, and the metal-containing antioxidants such as zmc diaikyldithiophosphates.

The ashiess antioxidants useful with this invention are either aryl amines or phenols. The amine type antioxidants include phenyl-alpha- naphthyiamme. diphenylamine, phenothiazine. p-phenylene diamine, alkylated diphenyiamines (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-dι-t-butyl-phenol) and bis-phenols (4,4'-methylenebis(2,6-di-t-butylphenol), such a material is Ethyl® 702). Another class of phenolic antioxidants are the 4-substιtuted 2.6-dι-t-butyl phenols, these would include materials such as 3.5-dι-t-butyl-4- hydroxyhydrocinnamic acid, C7-C9 ester. (Such a material is Irganox® L- 135).

The metal-containing zinc dithiodiphosphates antioxidants are produced by reaction of alcohols with P2S5 to produce dialkylthiophosphoπc acids, which are then neutralized with zmc oxide. The preparation of zinc dithiodiphosphate is well known and discussed in much published literature. See for example the books. "Lubricant Additives," by CV. Smaiheer and R. K. Smith, published by Lezius-Hiles Co., Cleveland, Ohio (1967) and "Lubricant Additives," by M. W. Ranney, published by Noyes Data Corp., Park Ridge, N. J. (1973). Examples of such mateπals are zinc (di- isooctyldithiophosphπc acid) and zinc (di-2-ethylhexyldithiophosphoπc acid).

Other suitable antioxidants include P2S5 treated terpenes and their derivatives. Examples of suitable terpenes include isomeric terpene hydrocarbons having the formula Cιo ^H 6 ^{sucπ as} contained in turpentine, pine oil and dipentenes, and the various synthetic and naturally occurπng oxygen-containing derivatives A particularly preferred terpene compound is α-pmene. Thus a preferred antioxidant in the P2S5 treated α-pineπe reacted with a polyisobutenyl succinimide dispersant

Suitable antifoam agents for use in the compositions of this invention include silicones and organic polymers such as acrylate polymers. Various

ant _i foam agents are described in Foam Control Agents by H ^. T ^. Kerner (Noyes Data Corporation. 1976. pages 125-176). Mixtures of siiicone-type antifoam agents such as the liquid dialkyl silicone oolymers w ⁱ th var ⁱ ous other substances are also effective. Typical of such mixtures are silicones mixed with an acrylate 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 oii 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 polyalkoxylated aliphatic amine (U.S. Pat. No. 3.235.501 ); and (iv) an alkoxylated aliphatic acid (U.S. Pat. No. 3.235,502) ^.

Su _i table dispersants include hydrocarbyl succinimides. hydrocarbyl succmam _i des. m _i xed ester _/ amides of hydrocarbyl-subst.tuted succinic acid. hydroxyesters of hydrocarbyi-substituted succinic acid ^, and Mannich condensation products of hydrocarbyi-substituted phenols ^, formaldehyde and polyamines. Mixtures of such dispersants can also be used.

The preferred dispersants are the alkenyl succinimides. These include acyctic hydrocarbyl substituted succinimides formed with various amines or amine der _i vatives such as are widely disclosed in the patent literature. Use of alkenyl succinimides which have been treated with an inorganic acid of phosphorus (or an anhydride thereof) and a boronating agent are also su _i table for use in the compositions of this invention as they are much more comDat _i bie with elastomeric seals made from such substances as fluoro- elastomers and silicon-containing elastomers. Polyisobutenyl succinimides formed from polyisobutenyl succinic anhydride and an alkylene polyam ⁱ ne such as triethylene tetramine or tetraethyiene peπtamme where ⁱ n the polyisobutenyl substituent is derived from polyisobutene 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 to those skilled in the art. (see. e.g. ^, U.S. Pat. Nos.

3.254 _, 025 _, 3,502,677 and4.857.214).

Suitable metal-containing detergents are exemplified by oil-soluble neutral or overbased salts of alkali or alkaline earth metals with one or more of the follow _i ng acidic substances (or mixtures thereof): (1 ) sulfon ⁱ c acids. (2)

carboxyiic acids. (3) salicylic acids. (4) alkyl pnenois, (5) sulfurized alkyl phenols. (6) organic phosphorus acids cnaracteπzed by at least one direct carbon-to-phosphorus linkage. Such organic phosDhorus acids include those prepared by the treatment of an olefin polymer (e.g., polyisobutylene having a molecular weight of 1 ,000) with a phosDhoπzing agent such as phosphorus trichloride, phosphorus heptasulfide, phosphorus pentasulfide. phosphorus trichloride and sulfur, white phosphorus and a sulfur halide, or phosphorothioic chloride. The preferred salts of such acids from the cost- effectiveness, toxicological, and environmental standpoints are the salts of sodium, potassium, lithium, calcium and magnesium. The preferred salts useful with this invention are either neutral or overbased salts of calcium or magnesium.

Oil-soluble neutral metal-containing detergents are those detergents that contain stoichiometrically equivalent amounts of metal in relation to the amount of acidic moieties present in the detergent. Thus, in general the neutral detergents will have a low basicity when compared to their overbased counteφarts. The acidic materials utilized in forming such detergents include carboxylic acids, salicylic acids, alkylphenols, sulfonic acids, sulfurized alkylphenols and the like.

The term "overbased" 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 commonly employed 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 50 ^β C, and filtering the resultant product.

Examples 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 sulfurized magnesium phenates wherem each aromatic group has one or more aliphatic groups to impart hydrocarbon solubility; lithium sulfonates, sodium sulfonates, potassium sulfonates. calcium sulfonates. and

magnes _i um sulfonates wherein each sulfonic aciα moiety is attacneα to an aromat _i c nucleus which in turn usually contains one or more aiiDhatic subst _i tuents to impart hyαrocarbon solubility; lithium saiicyclates. sodium sal _i cyiates, potassium salicyiates. caiciu saiicylates and magnesium salicyiates wherein the aromatic moiety is usually substituted by one or more aliphat _i c substituents to impart hydrocarbon soiubiiity; the lithium, sodium. potassium _, caicium and magnesium salts of hydrolyzed phosphosulfuπzed olefins having 10 to 2,000 carbon atoms or of hydrolyzed phosphosuifuπzed alcohols and/or aliphatic-substituted phenoiic comDOunds having 10 to 2.000 carbon atoms; lithium, sodium, potassium, caicium and magnesium salts of aliphatic carboxylic acids and aliphatic substituted cycloaliphatic carboxylic ac _i ds; and many other similar alkali and alkaline earth metal salts of oil- soluble organic acids. Mixtures of neutral or over-based satts of two or more different alkali and/or alkaline earth metals can be used. Likewise ^, neutral and/or overbased satts of mixtures of two or more different acids (e.g. one or more overbased caicium phenates with one or more overbased calcium sulfonates) can also be used.

As is well known, overbased metal detergents are generally regarded as containing overbasmg quantities or inorganic bases, probably in the form of micro dispersions or colloidal suspensions. Thus the term "oil soluble" as applied to metallic detergents is intended to include metal detergents wherein _i norganic bases are present that are not necessarily completely or truly oil- soluble in the strict sense of the term, inasmucn as such detergents when 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 or alkaline earth metal-containing organic acid salts.

Methods for the production of oil-soluble neutral and overbased metall _i c detergents and alkaline earth metal-containing detergents are well known to those skilled in the art, and extensively reported in the patent l _i terature. See for example, the disclosures of U.S. Patent Nos. 2.001.108 2,081 _, 075 _, 2,095.538; 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

2,501 ,731 ; 2.501 ,732; 2.585.520. 2.671 .758. 2.616.904 2.616.905

2.616.906. 2,616.91 1 ; 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 4,129,589; 4,137.184; 4,184.740, 4,212.752. 4.617, 135 4,647,387 4,880.550.

The metallic detergents utilized in this invention can, if desired, be oil- soluble boronated neutral and/or 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. 3,679,584; 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 will range from 30 to 99, preferably 40 to 95, 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 lubricants, they are particulariy suitable to power transmission fluids such as automatic transmission fluids, gear oiis, hydraulic fluids, heavy duty hydraulic fluids, 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 below.

Example 1 - Preparation of Amme Phosphate Used in Oils 3-9

Phosphorus pentasulfide (450 grams) is added to 4-methyl-2-pentanol (870 grams) at 80°C over a period of about VA hours. The reaction mixture is

then allowed to stir at temperature until substantially ail 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 substantially 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 0 ^, 0-di(4-methyl-2- pentyl)phosphorodithioate.

To the 0,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 60-65°C until substantially all of the phosphorus pentoxide has reacted.

The phosphorus pentoxide reaction product prepared above is partially neutralized with a commercially available cocoamine (501 grams) added at 60°C over a period of about 45 minutes. After the addition of the cocoamine, a hydrocarbon diluent oil (230 grams) is added to reduce the viscosity and the product is then stripped under vacuum to remove volatiles . The final product was found to contain 8.4% phosphorus, 10.6% sulfur and 1.5% nitrogen.

Fxamnle 2 - Preparation of Amme Phosphate Used in Oils 2-3

Phosphorus pentasulfide (450.5 grams) is added to 4-methyl-2- pentanol (870 grams) at 80°C over a period of about VA hours. The reaction mixture 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 substantially 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 0 _, O-di(4-methyl-2-pentyl)phosphorodithioate.

To the 0 _, 0-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 neutralized with a commercially available amine (473 grams), which consists of a mixture of C11-C14 tertiary alkyl pπmary amines, added at 60°C over a period of about 45 minutes. After the addition of the C11-C14 tertiary alkyl primary amines, a hydrocarbon diluent oil (228 grams) is added to reduce the viscosity and the product is then stripped under vacuum to remove volatiles. The final product was found to contain 8.3% phosphorus, 10.5% sulfur and 1.5% nitrogen.

Example 3 - Rust Performance in L 33 Test

Several formulated gear oiis were tested for rust performance using the L33 test. The L-33 test is described in ASTM Special Technical Publication 512A, Publication 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 Coφoration Model 30 hypoid differential housing (carrier) assembly, Part No. 27770-1X, 4.10 ratio, standard differential with uncoated drive gear and drive pinon. The test consists of a motoring phase and a storage 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 and a silicone antifoamant, while oils 2-9 also contained 4.31 wt. % of conventional amounts of ashiess dispersant, sulfurized isobutylene. corrosion inhibitor, and acrylate antifoamant.

The am _i ne phosphate useα in Oils 2-3 was preoared accorαing to the procedure _i n Example 2. while the pnosphate used ⁱ n Oils 4-9 were prepared accord _i ng to the procedure of Example 1. The 2 ethylhexylam ⁱ ne was obtained from Hoechst-Cetanese. All of the aforement ⁱ oned 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.

Table 1

Components, wt %( ¹ ) 1 ΛΆ 3 4 5 6 7 8 9

Additives 0.654 4.964 4964 4.964 4964 4964 4.964 4964 4964

Amine Phosphate 0 08 0.8 0856 0856 0.856 0856 0856 0856

2 Ethylhexyl Amine 0 0 015 0.15 03 05 0 0 015

Tallow Amine 0 0 0 0 0 0 03 06 03

Base Oil 99346 94236 94086 94.03 9388 9368 9388 9358 9373

Rust rating 335 35/185/110 10 0.5 00 00 10 10 0

L 33 Test Fail Fail Pass Pass Pass Pass Pass Pass Pass

(1) Based on wt % in finished oil.

(2) The rust ratings for Oil 2 are the results obtained from three tests

The data in Table 1 show that an oii that does not have the amme phosphate or a pπmary alkyl amme (Oil 1 ) has a very poor rust rating in the L 33 test. The data also show that while an oil having the amme phosphate without any amine (Oil 2) has an improveα rust rating, it still fails the L 33 test.

In contrast. Oils 3-9 show that the rust rating is significantiy improved when an amme phosphate and an alkyl primary amine are present.

The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. 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. Vaπations and changes may be made by those skilled in the art without departing from the spirit of the invention.