US2302703A - Organic phosphorus compoundbearing lubricant - Google Patents

Description

Patented Nov. 24, 1942 oncmc PHOSPHORUS comron'rmnmmo LUBRICANT Bert n. Lincoln and Gordon D. Byrkit, Ponca City,

Okla., assignors to Continental Oil Company,

Ponca City, Okla., a corporation of Delaware No, Drawing. Application March 14, 1940,

Serial No. 323,959

9 Claims.

This invention relates to improvements in lubricants. More specifically, this invention relates to improved materials which, when added to lubricants, greatly increase their resistance to oxidation and formation of corrosive products during use and often improves other characteristics as well. This application is a continuation-inpart of our copending application, Serial No. 231,362, filed September23, 1938.

Present-day mechanical devices require lubriyeating oils of high film strength, of high oiliness characteristics, and of low tendency to oxidize during use. It has been found that the presentday hydrocarbon lubricants of the very highest quality are deficient in these very important characteristics. These three properties are of vital importance under conditions of thin time in which the rubbing surfaces must operate under conditions of dry friction if ordinary hydrocarbon lubricants are used. With dry friction, the wear on friction surfaces is extreme; and during cold weather when the lubricant is sluggish or during periods when the lubricating system is not functioning properly for one reason or another, rubbing surfaces may not only suffer considerable wear but may be damaged to the point where they must be replaced. The product of our invention has a very important property of reacting with the metal surfaces, penetrating or adsorbing on film lubrication where the lubricant has been squeezed from between the friction surfaces because of high pressure, slow speeds, and other causes. It is readily seen that the viscosity or the body of the lubricant plays no part in this type of lubrication and that the remaining film of oil must have a very high film strength and be of high oiliness value to prevent rupture of the film of the lubricant, which would cause seizure. The oil film must tend to keep the coeficient of friction as low as possible. The oil must resist oxidation when these thin films are heated in the presence of oxygen as they are in use.

Mechanical devices are being designed for higher pressure operation, and the film strength of the best quality straight hydrocarbon lubricant has been found to-be too low. It will be obvious that an invention which provides a means of improving the film' strength of these lubricants is of The sludge is not a lubricant in any sense of the word, and the soluble acid is particularly corrosive to bearing metals such as cadmium-silver, copperlead, and the like.

In starting idle mechanical equipment which is lubricated from a sump by pumping or circulating the lubricant, there is always a short period of terious under conditions of thin film lubricationlj the metal surfaces, and leaving a film of lubricant with high oiliness character, which remains on the metal surface irrespective of the length of time the machine has been idle.

This high oiliness film gives very even and smooth operation, which may be easily discerned by the experienced operator or lubricating engineer.

When the hydrocarbon lubricants are diluted with unburned fuel or with other light hydrocarbons, the small degree of oiliness of the original hydrocarbon lubricant is greatly decreased. We have found that the addition of the products of our invention to hydrocarbon lubricants more than compensates for the loss in oiliness and loadcarrying ability from dilution.

It is well known that, in order to obtain lubricants which are preeminently satisfactory from the standpoint of oxidation in use, it is necessary to refine the oil thoroughly and then to add an inhibitor of oxidation. The thorough refining may consist of more and heavier acid treatments or solvent treating so as to remove a considerable part of the oil and leave only the most stable portion. Such drastic refining is necessary in order to obtain stability with respect to sludge formation, but the oil is then subject to easy oxidation to form soluble acids and other corrosive materials. This can be prevented by the addition to the refined oil of small amounts of materials which either prevent the formation of these corrosive products or by some action render them inert. Furthermore, such well refined oils are susceptible to the formation during use of lacquerlike materials which tend to stick rings. This results in blow-by and hence loss of power, failure of lubrication, scratching, scoring, overheating, and. eventually replacement of parts. It

" r is practically impossible to refine a. lubricant in such a manner as to avoid all three of these dimculties, namely, sludge, soluble corrosive products,

' and lacquer.

It is considerably more advantageous to add the materials of our invention and avoid these difliculties by this method.

Many'of these additive materials are effective an added to poorly refined or even wholly unned lubricants. The addends may thus be stituted in. whole or in part for the usual ning processes. 11 the prior art of applying these principles to manufacture of lubricants, many diverse es of materials have been suggested to be led to obtain improvement in various chareristics. It has been found that the addition various organic esters of the oxygen and sulacids of phosphorus frequently improves film ength, oxidation resistance, non-corrosiveness, :1 other characteristics. Nitrogen compounds ve been found to inhibit oxidation of oils. Our ,terials combine both of these properties. )ne object of our invention is to provide imived inhibitors of oxidation and corrosion for clition to lubricants. Another object of our invention is to provide n strength improving addition agents suitable use in lubricants and especially in crankcase iricants. Other and further objects of our invention i1 appear in the course of the following de- -iption. in general, our invention consists of the ad- .ion of certain organic phosphorus compounds staining at least one phosphorus-nitrogen uble bond to hydrocarbon fuels and lubricants. lese materials combine the advantages of the osphorus compounds and of the nitrogen mpounds, particularly in preventing the delopment of corrosive materials during use. mpounds having a double bond between a iosphorus and a nitrogen atom have outstandg anti-oxidant properties. Why this is so is it clear, but the fact remains that it is so. We lieve that the anti-oxidant activity is a relt of the augmented chemical reactivity at the 'int of the double bond, which is instrumental reducing to an unusual degree the oxidation .te and oxidation tendencies of the fuels and bricants w th which these compounds are ended. With a double bond between the nitron and phosphorus atoms, there is a likelihood at these may react with primary valence bonds an oxidation reaction, thus showing more iemical activity than when all of the valences the n trogen and phosphorus atoms are satis- .d by primary valence bonds. Obviously we do at wish to be bound by these theories but only v the appended claims interpreted as broadly the prior art permits.

Besides the unexpected and unusual oxidation mibiting effects produced by this class of comounds, there is increased film strength and inreased oiliness. Some of these materials which re suitable for use in accordance with our inention are shown in the following outline. A11 nd each of these are to be considered as exmples of our invention when blended in an oil f lubricating viscosity.

i. Phosphazo halides, R.-N:PX (R is an aromatic radical; X is a halogen) l. Phosphazobenzene chloride, CsHsNzPcl 2. Phosphazoxylene chloride,

(CH3) zcsHaNzPcl 3. Phosphazochlorobenzene chloride,

C1CeH4N2PC1 4. Phosphazophenylbenzene chloride,

. C6H5C6H4NIPC1 Phosphazonitrobenzene bromide,

O2NCsH4N:PBr

B. Aryloxy-Phosphazo-aromatics RNzPOR' (R and R are aromatic radicals) 1. Phenoxy-phosphazobenzene,

CsHsN Z POCoHs 2. p-Amyloxyphenoxy-phosphazobenzene.

CcHsN I POCsH4OC5H11 3. p-Amylphenoxy-phosphazobenzene,

CeH-sNzPoCsHicsHu 4. p-Amylphenoxy-phosphazotoluene,

CH3CcH4N 2 POCsH4C5H11 C. Anilides of phosphazo-aromatics RNzRNHR' (R and R are aromatic radicals) 1. Phosphazobenzene anilide,

C6H5N2P.NHC6H5 2. Phosphazotoluene mesidide,

CH3CsI-I4N I P.NHCeH2 (CH3) 3 3. Phosphazochlorobenzene chloroanilide,

CICGH4NZRNHCBH4C1 D. Oxyphosphazo-aryl anilides, RNHPOENR' (R and R are aromatic radicals) 1. Oxyphosphazobenzanilide,

CsHsNHPOZNCaHs 1 2. Oxyphosphazobenzophenylanilide,

CsHsNHPO: NCsH4CuH5 3. Oxyphosphazochlorobenzotoluidide,

CH3CsH4NH.PO I NCeH4Cl 4. Oxyphosphazobenzochloroanilide,

C1CsH4NH.PO I NCoHs E. Trichlorophosphanils, RN:PC13 (R is an aromatic radical) 1. Trichlorophosphanil, csHsNzPCla 2. Trichlorophosphochloranil,

C1CsH4N=PC13 F. Sulfophosphazoaryl chlorides, RNzPSCl (R is an aromatic radical) 1. Sulfophosphazobenzene chloride,

C6H5NIPSC1 2. Sulfophosphazomethylbenzoate ride CHaO.CO.CsH4NtPSC1 3. Sulfophosphazochloronaphthalene chloride, ClCmHsNZPSCl G. Triaryl phosphazines, RzC:N.N:PR'a (R is aliphatic; R is aromatic or aliphatic) 1. Tribenzyl phosphazine,

CH2 N.N:P(CH2CaH5) a 2. Tri-o-chlorobenzyl dimethylphosphazine (CH3) 2C N.N:P (CHzCuHiCl) a 3. Tricyclohexyl phosphazine,

CH2:N.NIP(CsHn)3 H. Aryl phosphin-imines, R3P=NR' (R' is aromatic, R's may be aromatic or aliphatic) 1. Phenyl diethyl phenylphosphin-imine,

(CsHs) (C2H5)2PINC6H5 2. Triamyl phenylphosphin-imine, v (CsH11)3P:NCsH5 3. Tribenzyl o-chlorophenylphosphinimine (CsHsCI-Ia) 3PZNC6H4C1 Any of these compounds or other members of the classes represented or their derivatives within the limitations set forth above may be used within the scope of our invention.

It is to be understood that in practicing our invention, oil-soluble phosphorus-nitrogen compounds of the type described are to be selected. Some of the examples described have only limited solubility in hydrocarbon oils. It is to be remembered, however, that, because of their great efiiciency, extremely small amounts are often effective. Thus we may use as little as 0.001 per cent of some of these compounds, and it will be chloseen that a fairly insoluble material may dissolve to a sufllcient extent to be satisfactory for our purpose. In general, more than 0.001 per cent of our addition agents are used, and we may add 7 manent suspens n.

. .stearate, aluminum stearate, calcium: soaps of" Many of the more difilcultly soluble materials are rendered more soluble by the introduction of alkyl groups, particularly those containing four or more carbon atoms. The isoamyl, octyl, lauryl, and octadecyl radicals and radicals from paraffln wax greatly increase the solubility of organic compounds in oil. One or more of such groups may be introduced as required into the previously described compounds or their derivatives. For example, phosphazobenzanilide is not very soluble in hydrocarbon lubricating oils but phosphazooctadecyl-benzenexylidide is much more soluble.

The selection of a particular compound or com-- pounds to be used as an addition agent to the hydrocarbon oil is to be made considering the use to which the blend is put. Thus, if water is likely to be present during use, a phosphorus compound or combination of compounds is selected which is not aflected by water. In general, we prefer to use compounds having boiling points over 250 F. It is sometimes advantageous 'to combine more than one of these compounds in a blend to obtain particular properties. We accomplish this by mixing two or more of these compounds together and blending the mixture with the hydrocarbon oil or by blending one in the hydrocarbon oil, blending the second into this mixture, and so on until the composition is complete.

The various phosphorus-nitrogen compounds usually improve both the film strength and oxidation characteristics of the hydrocarbon oil. For example, th sludging tendencies may be decreased by as little as 0.001 per cent of our phosphorus-nitrogen compounds. The oxidation characteristics of lubricants are very important, and these are markedly improved by our compounds. The ability to reduce friction is another feature contributed to lubricants by our phosphorus-nitrogen compounds.

It may be desirable to include in one and the same blend based on a hydrocarbon oil, in addition to the iaddends here described, other addends for specific purposes. Thus, we may add a pour point depressor such as a naphthalenechlor wax condensation product and a viscosity index improver such as certain resins or polymerized hydrocarbons in addition to our organo-phosphorus compounds. Furthermore. various metallic compounds may be added to the blend without interfering with the action of our ingredients. Indeed, in some cases it is advantageous to combine with our organic phosphorus-nitrogen compounds in a h dro arbon oil blend such materials as calcium d chlorostearate, chromium oleate, tin octadecyl phthalate, aluminum stearate, and other metallic soaps.

Our addends are admirably adapted for use Example 1 Per cent Mid-Continent paraffin-base SAE 30 99. 0 p-Amylphenoxyphosphazobenzene 1.0

Example 2 Per cent California naphthenic base SAE 30 99. 5 Phosphazo-p-tert.-butylbenzene anilide 0. 5

Example 3 Per cent Mid-Continent mixed base SAE 50 98. 4 Aluminum naphthenate 1. 3 Tribenzyl phosphazine 0. 3

Example 4 Per cent Mid-Continent paraiiin base SAE 40 93. 8 Voltolized corn oil 5. 0 Chlorodiphenylene oxide 1.0 Triamyl phenylphosphin-imine 0. 2

Example 5 In making a grease containing our addends. we may use:

Per cent Oleic acid 8. 1 Lime 1. 2 Water 0. 3 Dichlorosteari'c acid 1. 1 Bright stock 13. 1 Distillate (440 seconds at 100 F.) 76. 0 Phosphazobenzene chloride 0.2

Example 6 In making a lubricating gasoline, we blend 0.5 per cent of the product of Example 1 with gasoin lubricating oils of all types including those designed for use in automotive crankcases, Diesel oils, and any other oils of lubricating viscosity such as castor oil, cottonseed oil, lard oil, sperm oil, shale oil. Furthermore, .our addends are advantageously blended in gasoline and other petroleum fuels either directly or after being blended first in a lubricating oil and then added to the fuel. Soap-thickened mineral oils of all types ranging from those showing only a slight increase in viscosity over that of the mineral oil alone to the semisolid and solid greases containing fiftyper cent or more of soap are amenable to treatment according to our invention. In making these greases, the usual soaps such as sodium beta fat and the like may be used. Various other thickening ingredients or materials for other purposes may be added. These include yarn, hair graphite, glycerol, water, lamp black, mica, zinc dust, litharge, and .the like.

The following examples of blends of our additon agents are given as illustrations but not as limitations:

line. The product has the composition:

Per cent Gasoline 99.5 Oil 0.495 p-Amlyphenoxyphosphazobenzene 0.005

It is to be understood, however, that the hydrocarbon oil in the treated fuels may be of a viscosity of from about 35 seconds at F. S. S. U. to 350 seconds'or more; and the amount of oil blended with the phosphorus-nitrogen compound to form the fuel addend may vary between 0 per cent and 99.5 per cent. In some cases the fuel may be prepared without adding any hydrocarbon oil. Th quantity of phosphorous-nitroen compound in the final blended fuel may ary from 0.0001 to 1.0 per cent or slightly more.

It will be understood that certain features and ubcomblnations may be employed without reirence to other species or combinations. This s contemplated by and is within the scope of ur claims. It is further obvious that various :hanges may be made in details within the scope it our claims without departing from the spirit )1 our invention. It is therefore to be under- ;tood that our invention is not to be limited ;6 the details described.

Having thus described our invention,.we claim:

1. A lubricant comprising in combination a najor proportion of oil of lubricating viscosity and a minof proportion of an organic phosphorus sompound containing at least one nitrogenphosphorus double bond.

2. A lubricant comprising in combination a majo proportion of oil of lubricating viscosity and a minor proportion of an organic compound containing phosphorus and nitrogen connected by a double bond.

- 3. A lubricant comprising in combination oil of lubricating viscosity and from 0.001 to 5 per cent of an organic phosphorus compound containing at least one nitrogen-phosphorus double bond.

4. A lubricant comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of a phosphazine.

5. A lubricant comprising in combination a major proportion of oil of lubricating. viscosity and a minor proportion of a phosphazo-aromatic anilide.

6. A lubricant comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of an aryloxyphosphazoaromatic.

7. A lubricant comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of p-Amylphenoxy-phosor phazotoluene.

8. A lubricant comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of phosphazobenzene anilide.

9. A lubricant comprising in combination a major proportion of oil of lubricating viscosity and a minor proportion of tribenzyl phosphazine.

BERT H. LINCOLN. GORDON D. BYRKIT.