US2355106A - Lubricating composition - Google Patents

Description

Patented Aug. 8, 1944 wnarcarmc comrosrrrou Carl F. Prutton, East Cleveland, Ohio, assig'nor,

by mesne assignments, to The Lubri -Zol Development Corporation, Cleveland, Ohio, at corporation of Delaware No Drawing. Application September 11, 1949, Serial No. 356,357

11 Claims.

This invention relates, as indicated, to lubricents and more particularly to lubricating compositions capable of providing efllcient lubrication under extreme pressure conditions, that is, of satisfactorily maintaining a lubricating film between hearing or other metallic surfaces oper ating under such extremely high pressures as would ordinarily cause seizing or scoring of such surfaces if a plain mineral lubricating oil, for example, were employed. These, lubricating compositions are characterized by the fact that they are generally more effective and at the same time more stable than those used heretofore.

This application is a continuation in part of my copending application Serial No. 755,987, filed December 4, 1934, now Patent No. 2,320,984; dated June 1, 1943, and of my copending application Serial No. 121,827, filed Jan. 22, 1937, now Patent No. 2,242,260, dated May 20, 1941.

This invention further relates to a method ofpreventing seizing or scoring of relatively moving bearing surfaces and of reducing the wear or friction between such surfaces. The addition of certain agents to lubricating compositions generally for the purpose of improving their extreme pressure characteristics is not new. It is generally recognized that the degree of efiectiveness of extreme pressure addition agents is usually directly proportional to their chemical or physico-chemical action on the bearing surfaces in producing a film which usually has an anti-fiuxing function in preventing actual metal to metal contact, and in addition, sometimes the function of producing. a film which is more strongly attached to the metal surfaces than plain lubricating oils. Also, the action of the addition agents is to provide a film characterized by the fact that the coefficient of friction between the surfaces where such film is maintained is generally lower than when ordinary lubricants are employed.-

While a certain amount of chemical or physicochemical action by the addition agent upon the bearing surfaces is necessary and desirable in order that an extreme pressure film may be produced, the addition agent must, ne ertheless, be

sufficiently stable and relatively inactive so that its activity along this line remains dormant under ordinary conditions and is only activated under the conditions of extreme pressure where its effectiveness is required for the stated purpose.

In certain types .of use, such as in crankcases of internal combustion engines, and in lubricants added to motor fuels and thus introduced into the apparatus to be lubricated through the combustion zone, such relatively high temperatures are encountered that the resultant conditions tend to either decompose or render undesirably active many types of addition agents which are accordingly not usable in such an environment.

It is also generally accepted that many plain lubricating compositions such as refined mineral 011, due either to naturally occurring constituents in the base material or constituents in the finished product produced by refining processes, are relatively corrosive, particularly when used in conjunction with certain sensitive metals or alloys.

It is a principal object of this invention to provide a lubricating compositioncharacterized by the fact that it contains an addition agent which may be effective not only for the purpose of imparting extreme pressure characteristics to the lubricant, but at the same time likewise effective as a corrosion inhibitor for certain active constituents which may either be originally present oradded to the composition for certain specific results and which will otherwise be detrimentally active.

It is a further object of this invention to pro-- vide a lubricating composition which may be characterized by the fact that all of the above named desirable characteristics are imparted thereto by means of a single addition agent.

Other objects of this invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then, consists of the features hereinafter fully described, and particularly pointed out in the claims, the following description setting forth in detail certain embodiments of the invention, these being illustrative, however, of but a few of the various ways in which the principle of the invention may be employed.

Broadly stated, this invention comprises the use as and in lubricants of organic compositions containing phosphorus and sulphur. These compositions are generally of the type which may be produced by reacting organic compositions with phosphorus and sulphur-containing reagents.

More specifically, this invention contemplates the use for the above purposes of organic compositions which (before reacting with the above referred to reagents) may desirably contain an organic oxygen compound and preferably a compound including a hydroxyl group which may advantageously be attached to a benzenoid ring structure.

Throughout the ensuing description of this invention. the above described material indicated as usable either by iteli as a lubricant or in minor amounts as an addition agent to other lubricating compositions for the purpose of improving the characteristics of the same will, for convenience, hereinafter be referred to as the addition agent.

As above indicated, the addition agent is of the type produced by reacting an organic composition with certain reagents which contain either separately in combined or elemental form, or in combination, phosphorus and sulphur. The addition agent thus produced may, in most cases, be described as an organic composition containing both the elements, phosphorus and sulphur.

The type of organic base composition contemplated for use in the reaction above described, by which the addition agents are produced, is represented by the following examples:

I. Hydracarbons, preferably containing more than [our (4) carbon a A. Chain type (acyclic) (i) Parsiflns, e. g.

P tane (b b 1 all h tic yc o a e. g.

(a) Nap thenes, e. g. Cycle ntane Cycle exane I Cycle octane Cycle oleilns, e. g. Cyciobuteue Cycle ntene Cycle exene (c) It will be noted that certain oi the above i. e., cyclohexane and cyclohexene, are also by o-aromatic compounds, oiwhich the following are additional examples:

The hydro-diphenyls The hydro-no bthaienes,.e. g.,

Hexa-dz odeca-hydronaphthalsnes Tetra- & decahydronaphthalenes The hydro-anthracenes The hydro-phenantbrenes The hydro-retenes (2) Aromatic, e. g.

Benzene Di-phenyl Naphthalene Anthracene Phenanthrene Bridged ring hydrocarbons. e. g.

Aromatic terpenes such as pinene Homologs oi the above such as aliryiated aromatic hydrocarbons, e. g. methyl, ethyl, propyl and iso-propyl, butyl, amyl, etc. benzenes, diphenyls, naphthalenes, anthraccnes, phenanthrenes-more specific examples are toluene, xylene, ethyl-benzene, cumene, cymene methyl naphthalene, retene Aromatic hydrocarbons with one or more unsaturated side-chains, such as phenyl ethylene s yrene Il. Naturally occurring, or commercially available complex compositions consisting principally of hydrocarbons A. Petroleum and petroleum derivatives, such as crude mineral oils oi paraifinic, naphthcnic, or asphaltic character and from various sources including the Penna, Mid-Cont, and Comtal fields; and products refined from them, e. g. Bright stock Neutral or pale oils Steam refined oils Fuel oils Kerosene Gas oils Gasoliues Psraifin wax (or petroleum wax) Petroiatum Solvent extracted fractions, e. g.

Edeleanu extract Furiural extract B. Hydrocarbon materials of non-mineral origin, e. g. hydrocarbon (products of vegetable origin such as certain oils obtaine from the distillation of wood, etc., o. g.

III. Oxygen-bearing organic compounds (including oxygen-bearing derivatives of hydrocarbons in groups I and II above) may be classified according to the nature 0! attachment oi the oxygen alcohols andother derivatives of carbinol (including phenols, crssols, nsphthoia, etc.)

(3) Compounds containing the carbonyl C=O radiclo,

"anate ahydroxylam lno trate The following are specific examples of suitable oxygen-bearing compounds:

Aurin'ric Anoiu'ric Alcohols Meth lalcohol Benzyl alcohol Etbyl alcohol Phenyl ethyl alcohol Propyl and iso-propyl alcohols Butyl and iso-butyl alcohols Amyl alcohols Laur lalcohci Cety alcohol Polyhydroxy alcohols;

Dih droxy alcohols, e.g.

thylene glycol Di-ethylene glycol 'lri-hydroxy alcohols, e.g.

Glyoerine Phenols Monohydroxy, e.g.

Phenol Alkyl phenols, e.g.

Cresols Xylenols Ethyl henois Propy & iso-propyl phenol Amyl phenols Phenyl phenols P lNarhthols o y roxy, c.g.

Di hydrox ,e.g.

Dih roxy bcnzencs yrocatcchin (Catcchol) Rescrcmol H droquinonc Dihy roxy diphenyls Tri-hydroxy, e.g.

Tri-hydrox benzcncs Pyroga lol Hydroxy-hydroquinone Phlorogluciuol Others, e.g.

Ruiigailol Eillers Di-ethyi others Diphenyl ethcrs Propyl and isopropyl others Dixenyl others Butyl and isobutyl ethers Dinaphthyi ethcrs Amyi ethers Mixed rthers Eth l ropyl others Phenyl my lemurs Mei Y yi ethers Phenyl etli yl ethcrs Phcnyl propyi ethcrs Aunu'no Asoinnc Hydrm other: Glycol ether (dlstliylene-gllyool) Mono-methyl others of dihy- Mono-alkyl esters of. di ydrlc droxy ghenols, e. alcohols, e. I; Met oxy pheno s Mono-methyl ester of ethylone glycol Kdoim Acetone Benzophenone Diethyl ketone Naphthyl ketcnes Di-propyl ketones Mind ketonu Methyl-ethyl ketone Aoeto henone Methyl propyl ketones Ethy phenyl ketone Ethyl propyl ketones, etc.

Mixed long chain aryl ketones,

such as Dibenzofuryl heptadecyl keto e Dibenzofuryl undecyl ketone as described in U. 8. Pat. No. 2,033,548

Estersoi an aliphatic alcohol (such as those listed above under Alcohols") and a fatty Esters of a phenol (such as those listed above under Phenols") and a fatty acid (such as those acid (such as those listed listed above under dclds") bove under "Acids" e. e. g. Methyl 8 Phenyl, phenyl-phenyl, and

Ethyl naphthyl: P l Amtam Acetate e31; Pmpionate Propionate Am I Butmte Butyrate L l Lama Laurate 0 Palmitate E h lene steam Stearate Dietl iylene Oleate Glyceryl Esters of an aromatic alcohol (such as those listed above under Aloohols") and a fatty acid (such as those listed above under Acids") e. g. Benzyl and pheuyl-ethyl Acetate Propionate Butyrate Laurate gtalmittate eara e Oleato Esters of an aliphatic alcohol (such as those listed above under Alcohols) and an aromatic acid (such as those listed above under "Acids") e. g. Methyl Ethyl Propyl Butyl Benzoate Amy] Phenyl acetate Lauryl Salieylate Cetyl Phthalate Ethylene Diethylene Glyeeryl Esters of fatty acids derived from naturally occurring fatty oils and waxes, and of the hydrogenated ac1ds derived from like sources, e g.: Methyl, ethyl, butyl, etc. esters of coconut fatty acid, palm fatty acid, or the same after hydrogenation.

Naturally. occurring. or commercially available complex oxygen-bearing organic compositions such as: I

Non-mineral oils and waxes, e. g.

Fatty oils, including:

Animal oils.

Fish oils Lard oil Vegetable oils Cottonseed oil Rape seed oil Corn oil Castor oil Soya bean oil Waxes of animal or vegetable origin:

Carnauba wax Palm wax Beeswax Japan wax Of the foregoing named organic base compositions, the following are among the more suitable:

Hydrocarbon materials Petroleum derivatives, particularly Mineral oil, for example Bright stock a(lp refei'ably Pennsylvania) Neutral or p oils Oxygen-bearing organic compounds henol Cresols Diphenyl ether Stearic acid Benzyl alcohol Lauryl alcohol Oxydized hydrocarbons including oxydizad mineral oils Naphthenic acid Methyl stearate Butyl stearate Methyl salicylate Oleic acid Fatty oils such as lard oil Halogen-bearing organic compounds Mono- 6: dichlor xylene Mono- & dichlor cresol' Para- 6: orthochlorphenol Monochlor pentane (chlor amyl phenol) Chlorinated diphenyl ether, for example Trichlor diphenyl ether and Hexachlor diphenyl ether Mono- & dichlor benzyl alcohol Methyl dichlor steai'ate The reagents which may be employed with the above defined organic base compositions in producing the so-called addition agents, according to this. invention, are, as previously indicated, characterized by their containing free or combined phosphorus and sulphur, either present in the same or different compounds and either in ole mental or combined form. Those containing the above-named elements in combined form may generally be classified as follows:

REAGENTS A. Phosphorus compounds 1. Compounds of phosphorus and haloge Phosphorus chloridePzCl Phosphorus tri-chloride-PC];

Phosphorus pentaohloride-PC]; Phosphorus diclor trifluoride-PChF;

2. Compounds of phosphorus and oxygen Phosphorus trioxide-IHO; (or P103) Phosphorus tetraoxideP:O4 Phosphorus pentOxide-P O; (or P401) 3. Compounds of phosphorus, oxygen and halogen Phosphorus oxychloride-POC]; Phosphorus trioxytetrachloride-P:O;Cl

4. Elemental phosphorus B. Sulphur compounds 1. Sulphur and halogen Sulphur monochloride-SsCl; Sulphur dichloride-SO],

2. Sulphur and oxygen Sulphur dioxide-S0;

Sulphur trioxide-S 0s Sulphur heptoxide-Sz01 3. Sulphur, oxygen and halogen Sulphur monoxytetrachlorideS2OOli Sulphur pentoxydichlorideSi0;Cl: Sulphuric oxychlorideS0-:Clz Sulphurous oxychloride-SOClr 4. Elemental sulphur 0. Phosphorus and sul hur compounds 1. Compounds of p osphorus and sulphur alone Phosphorus di8llllide-Pa$a (or PS) Phosphorus trisulphide-ESa (or P183) Phosphorus sesquisulphide-ES: Phosphorus cntasulphideP:St (or P4810) Phosphorus eptasu]phideP4S1 2. Compounds of phosphorus, sulphur and halogen Phosphorus thiOCl'il0l'ld9--P$0|J Phosphorus thiobromlde-PSBn Phosphorus thiobromide-PzSaBn 3. Compounds of phosphorus, sulphur and oxygen Phosphorus sul hoxide-PsBaOc 4. Compounds of p osphorus, sulphur and elements other than oxygen or halogen Phosphorus thiocyanateP(CN8)s D. Rgagents containing elements equivalent to phosphorus and/or phur.

It will be noted that since the so-called addition agent produced by the above referred to reaction shall contain both phosphorus and sulphur, and advantageously phosphorus, sulphur and oxygen, organic compounds and the reagents selected shall be such as to produce the addition agent of the desired character.

The following is a list of particularly suitable addition agents. Since the addition agents in the list are identified accordmg to the organic compounds and reagents used in their preparation, it includes typical examples of suitable organic compounds and reagents.

AoR'eaction products of the following organic phosphorus pcntasulphido (Pis i oflric acid Lauryl alcohol Benzyl alcohol Phenol Butyl stearate Methyl salicylate Naphthemc acid Dlphenyl other Cresyiic acid (cresol) Mineral oils such as bright stocks and neutrals (preferably Penn.)

Oxidized mineral oils Fatty oils such as lard oil Chlorinated diphenyl ether, particularly Trichlor dighcnyl ether and Hexachlor i henyl ether Mono-6; dichlor nzyl alcohol Para-6: orthochlor phenol Reaction products of the following organic compounds with hosphorus sulphochloride (PSCls) ineral oils such as bright stocks and neutrals (preferably Penn.)

Oxidized mineral oils Naphthenic acid Methyl stearate Fatty oils such as lard oil Methyl salicylate Stearic acid ic acid Diphenyl Dlchlor xylene Dlchlor cresol Orthochlor phenol Monochlor amyl phenol Methyl dichlor stearate Chlordiphenyl The reaction products of thiophenol and chlorinated thlophenol with phosphorus trichloride The reaction products of thio henol and chlorinated thiophenol with phosphorus oxychlori e.

. The reaction products of chlorinated trlcresyl ghosphato (one or more chlorine atoms on one or more met yl groups) with sodium polysul hide.

F. Tlzie 818?? pr need by reacting with phosphorus oxychloride I (a) The reaction product of phenol with phosphorus pentasulphide s.) and (b) The reaction product of orthochlorpbenol with phosphorus pentasulphide.

compounds with A. Organic sulphur compounds with phosphorus-bearing reagents,

( a s (c) PC1 B. Organic phosphorus compounds with sulphur-bearing reagents,

2) Organic compounds containing hosp 3) Any of the foregoing compoun s which contain a halogen.

A slightly difierent classification for certain types of the compounds usable as so-called addition agents, in accordance with this invention, is

(1) Esters of phosphorusand sulphur-containing acids, 0. g.

Esters oi tri-thiophosphorus acid and tetrathiophosphoric acid (2) Esters of phosphorus-, sulphurand oxygen-containing acids,

fistersiofigiliigphosphoms, thiophosphoric and tri-thiophosphosphorus and sulphur pho c (3) Any of the previously mentioned compounds which contain a halogen.

Among the specific examples of addition agents contemplated for use in accordance with this invention which have been previously somewhat more generically defined, the following compounds may be mentioned, viz:

'Iri-butyl thiophosphate Triphenyl thiophosphate Tri-benzyl thio hosphate Tri-cresyl thiop osphates, e. g.

Tri-(ortho-cresyl) thiophosphate Tri-butyl tri-thiophosphate Triphenyi trithio h hate Tricresyl trithiop osp ate Tributyl trithiophosphite ..pheny1 trithiofihos bite Tr -cresyl trithiop osp lte Tr chlor ethyl) thiophosphate Tr ort hochlor phenyl) thiophosphate Tr -(o hochlor phenyl) trithiophosphate 'lri-(dic hlor xylyl) thiophosphate Trl-(dichlor cresyl) thiophos hate 'lri-monochlor amyl phenyl thiophosphate Trichlorbenzyl) thiophosphate Tribenzyl tritbiophosphate Trl-lauryl trithioghos hate Tri-(orthochlor p eny) tnthiophosphite As previously indicated, the above named addition agents are usable either by themselves as lubricants or advantageously in small amounts as addition agents to other lubricating compositions. Their particular effectiveness in very small amounts for the purposes previously specified and hereafter explained in greater detail makes the so-called addition agents especially desirable for use in lubricating compositions comprising any of the well known oils usually used as lubricants, such as mineral oil, non-mineral oils such as animal and vegetable oils e. g. rape-seed oil, castor oil, or, for certain uses, desirable combinations of such oils.

It has been found that when a refined mineral lubricating oil base is used, the previously named desirable properties may be imparted thereto by the use of the named addition agents in amounts upwards of 0.10%. The amount of addition agent used in excess of the stated minimum depends of course upon the particular use for which the resultant composition is designed; in preparing a lubricant for use in the crank case of internal combustion engines, the composition will be found to give superior results if it contains from. about 0.10% to about 2% of the addition agents.

It the resultant composition is to be used under orus, sulphur and oxygen conditions of higher pressure where generally temperatures lower than those in a crank case are encountered, for example in lubricating heavily loaded gears'and bearings, the addition agent may be present in greater amounts, 1. e., up to and, in certain cases, desirably up to and 20% may be employed.

The principal advantages resulting from the use of the named addition agents in lubricating compositions of the character described are as follows: The addition agents will be found to impart substantial extreme pressure characteristics to the lubricants. The addition agents containing phosphorus, sulphur, halogen and oxygen will be found, in general, to be more effective than those containing only phosphorus, sulphur and oxygen, and the latter will generally be found to be more effective as extreme pressure addition agents than those which contain only phosphorus and sulphur.

Certain of the addition agents have an inherent property of inhibiting corrosion of metallic surfaces by such constituents as are usually present either by virtue of being contained in the mineral oil, created in the mineral oil during the refining process, or intentionally added thereto for the purpose of producing a particular result. Certain of the addition agents of this invention have the remarkable combination of properties which make it possible to increase the film strength of a mineral lubricating oil by the addition of very small percentages while, at the same time, improving the stability of the lubricant and maintaining it free from harmful corrosive action. This combination of properties is particularly associated with aromatic esters of thiophosphorus acids which contain a halogen, specifically chlorine, in such form that it is directly attached to a carbon atom which is part of an aromatic ring. While halogen in this form. is particularly stable, and ordinarily increases the film strength to only a moderate degree. the addition of halogen in such form with an aromatic ester of thiophosphorus acid increases the film strength to a very great extent much in excess of the degree to be expected from a comparison with other aromatic halogen compounds of the type in which the halogen is directly attached to an aromatic ring.

The oiliness factor of a lubricant, to which cer.

tain of the named addition agents have been added, has been found to be measurably improved over similar untreated lubricating compositions with which they have been compared.

The tendency of the lubricating composition to form sludges resulting either from oxidation on standing or under conditions of use is generally considerably reduced by the presence therein of the addition agent. If any sludge constituents are formed in the lubricating composition containing the addition agents, the latter have a marked tendency to render harmless such constituents so that even so formed, their presence in the composition is not objectionable.

Certain of the named constituents have been found to very materially improve the viscosity index and cold test characteristics of mineral lubricating oils to which they have been added.

The stability and volatility of the addition agents should be such that under conditions encountered in service the concentration of the addition agent in the lubricant will not be substantially reduced because of its loss by evaporation or by decomposition.

For most uses the addition agent should have a vapor pressure less than atmospheric at a temperature of 140 0.; and if the lubricant is to be subjected to elevated temperatures in use, less than atmospheric at C.

The stability 01' the addition agent should be such that decomposition shall be negligiblev at temperatures to which the lubricant will be exposed in service.

By the term non-corrosive" as used herein and in the appended claims is meant such forms of the addition agents as will not react chemically to a substantial and continuing extent with the bearings and other metallic parts exposed to the lubricant .excepting under conditions of extreme pressure and the like, nor cause damaging corrosion of such metallic parts.

The foregoing statements as to non-corrosiveness, stability and volatility of the addition agents applies particularly to compositions made in accordance with this invention and used as lubricants and especially when such lubricants are employed under conditions of extreme stress such as imposed by high temperature, extremely high pressure and the like. There are, however, certain uses such as in metal working, die drawing and the like where relatively more active, i. e., relatively corrosive, addition agents of the character referred to herein may be employed to advantage.

While the lubricating compositions which have been described herein as illustrating one embodiment of the invention have been generally referred to as oils, i.. e., liquids, this invention is, however, also applicable to the solid and semi-solid types of lubricants commonly referred to in the trade as greases, bodied oils, etc. In this connection, it should be noted that certain of the addition agents contemplated for use herein for the purpose of imparting extreme pressure characteristics to the lubricant may be employed for the additional purpose of bodying or thickening the lubricant to which they are added.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the materials employed in carrying out the process, provided the ingredient or ingredients stated in any of the following claims or the equivalent of such stated ingredient or ingredients be employed.

1, therefore, particularly point out and distinctly claim as my invention:

1. A lubricating composition comprising an organic compound containing phosphorus, sulfur and halogen.

2. A lubricating composition comprising an organic compound containing phosphorus, sulfur, oxygen and halogen.

3. A lubricating composition comprising a major proportion of mineral oil and a minor amount of an organic compound containing phosphorus, sulfur and halogen.

4. A lubricating composition comprising a major proportion of mineral oil and a minor amount of an organic compound containing phosphorus, sulfur and chlorine.

5. A lubricating composition comprising a major proportion of mineral oil and a minor amount of an organic compound containing phosphorus, sulfur, oxygen and halogen.

6. A lubricating composition comprising a major proportion of mineral oil and a minor amount of an organic compound containing phosphorus, sulfur, oxygen and chlorine.

'7. A lubricating composition comprising a major proportion ot-mineral oil and a minor amount of a halogenated organic thiophosphate.

8. A lubricating composition comprising a major proportion of mineral oiland a minor amount of a halogenated organic thiophosphite. v

10. A lubricating composition comprising a major proportion of mineral oil and a minor amount of an organic compound containing phosphorus, sulfur and halogen in which all of the halogen is attached to a carbon atom of an aromatic ring.

11. A lubricating composition comprising a major proportion of mineral oil and a minor amount 01' tri-(dichlor xylyl) thiophosphate.

a portion of the halogen is attached to a car- 10 bon atom 01 an aromatic ring.