US2325597A - Compounded mineral oil - Google Patents

Description

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Francisco, (Calilt, a corporation of vlllelaware No lltrawing. Application .lanuary 13, 1941.

Serial No. 374,243

lid Claims.

This invention relates to a new and useful composition of matter and involves a' composition comprising a viscous hydrocarbon oil and a polyvalent metal salt of certain substituted acids of phosphorus.

This application is a continuation-in-part of our parent application Serial No. 241,648, filed November 21, 1938, issued as Batent No. 2,228,659 on January 14, 1941, and is directed to a divisional aspect of the invention disclosed in the parent case. V

The production of improved hydrocarbon oils and particularly of lubricating oils having desired characteristics has been the subject of extensive faces over which the hydrocarbon oil may flow. lltis important that resistance t6 such deterioration be imparted to hydrocarbon oils, particularly to lubricating oils, in order that suchcompositions maybe relatively free from the tendency 30 to term such deposits even under high temperation engines is subjected to extremely severe operating'conditions and in engine of the Diesel zone temperatures of from approximately 425 to 650 F. and pressures from the oxidizing combustion gases as high as 750 to 1150 lbs. per sq. in. Addition agents'which-render hydrocarbon oils resistant to deterioration by heat at high temperature levels in the order of those above-mentioned usually impart to the oil the ability to inhibit piston ring sticking in internal combustion engines and permit longer periods of operation of such engines without the necessity of major overhauls heretofore occasioned by stuck piston rings.

It should be noted that stabilizing agents which are efiective at low temperatures to impart increased stability to hydrocarbon oils, or which research and investigation in recent years. v Gen- 15 are effective at temperatures even as high as 200 erally speaking, the compounding of hydrocaror 250 F'., are often inefiective under the more bon oils to obtain desired characteristics involves severe operating conditions and higher temperaeinpirical phenomena and the action of untested ture levels to which lubricating oils are subjected tyes of compounding agents cannot bepredicted. in Diesel engines. Thus the operativeness of a p A characteristic which has been the subject o 2 stabilizer at atmospheric temperatures, or even extensive investigation is the tendency of hydrotemperatures as high as 200 to 300 F., gives no c rbon oil o deteriorate r p r ially decomp e adequate basis for predicting the action of the and omdize when subjected to hightemperasame stabilizing agent at materially higher temtures. This deterioration is evidenced by the peratures and under more severe operating condeposition of adhesive deposits on hot metal surditions. The disclosures in theprior art relative to such stabilizers therefore cannot serve as a guide for one seeking stabilizing agents or oxidation inhibitors effective at higher temperature levels. The phenomena involved are catalytic in nature, are highly empirical and require extensive experimentation to determine the action of a that dispersion of polyvalent metal salts of sub- 7 stituted oxyacids of phosphorus in hydrocarbon oils such as mineral lubricating oil imparts new, unpredictable and highly desirable properties to the composition. These new properties reader the compounded oil particularly useful for varitype the lubricant encounters in the piston ring 40 0118 P rp ses. Although increased resistance to deterioration at high temperature levels comprises one of the principal advantages of the compounded oils of this invention, it is to be understood that the invention is not limited to this feature, that different compounds of the general type herein involved vary in their degree of effectiveness and may impart one or more other desirable properties to the lubricating composi tion. For example, certain of the compounds reduce the amount of wear produced as compared with a straight uncompounded mineral on. 'The same or other compounds inhibit the corrosion of copper-lead or cadmium-silver bearing metals, etc. In general, however, it has been discovered that the new compositions herein disclosed are more stable to heat than is a hydrocarbon oil with which the compositions are compounded. The new compositions of this invention are therefore useful where resistance to deterioration by heat is important. An example of such utility, other than as a lubricating oil, comprises use as a heat transfer fluid Where it may be desirable to inhibit or prevent the formation of a deposit on the metal surfaces from or to which heat is being conveyed. Likewise, the increased resistance to oxidation imparted to the oil by the compounds of this invention will find various applications as, for instance, in an insulating, switch or transformer oil.

It has also been discovered that certain metal salts of substituted oxyphosphoric acids have a combination of properties heretofore unknown and particularly desirable in compounded mineral oil, namely, the ability to inhibit oxidation and impart to lubricating oils increased resistance to deterioration by heat, the ability to inhibit piston ring sticking, freedom from the production of increased wear on,cylinder walls and piston rings as compared with uncompounded mineral oils, and low corrosivity as respects the chemical action of the compounded oil on bearing metals such as cadmium-silver and copperlead alloys. Although various compounded mineral oils are known which are capable of inhibiting piston ring sticking, the discovery of specific compounding agents capable of imparting the above combination of properties to hydrocarbon oils represents an unobvious and important contribution.

Metal salts of substituted oxyacids of phosphorus which may be added to hydrocarbon lubricatlng oils to provide a new composition of matter of the type herein involved comprise the salts of metals selected from groups 11, III, IV

and VI of Mendeleefi's Periodic Table of the Elements. Specific examples of such metals are aluminum, calcium, barium, strontium, chromium and magnesium. Salts of iron, cobalt, nickel, zinc, tin and lead comprise additional examples of compounds falling within the broader aspects of the invention.

The metal salts of this invention are preferably formed from substituted oxyacids of pentahere R and B may be alkyl, aryl, alkaryl, ar-

'alkyl or cyclic nonbenzeneoid radicals. Substi tutedphosphoric acids containing at least twelve carbon atoms are preferred. Examples of preferred type acids are alkyl or alkaryl substituted phosphoric acids having at least twelve carbon atoms in the molecule. However, it is to be understood that the broader aspects of the invention include the use of other types of substituted oxyacids of phosphorus containing more than twelve carbon atoms. Additional examples of substituted oxyacids of phosphorus which may be used in forming the metal salts of the present invention are as follows:

phosphonic acid monoester of phosphonic acid phosphinic acid In all of the. above formulae R and R may b4. alkyl, aryl, alkaryl, aralkyl or cyclic non-benzenoid groups.

In general, polyvalent metal salts of substituted derivatives of oxyacids of phosphorus such phosphorous acid, hypophosphoric acid, H2PO3; orthophosphoric acid, H.1P04; pyrophosphoric acid, H4P2Ov; fall within the broadest aspects of the invention. By substituted or sub-.

stituted derivatives of acids of phosphorus whenever used herein, it is intended to designate acids containing an organic group of the type previously listed, i. e., alkyl, aryl, alkaryl, aralkyl, or cyclic non-benzenoid groups. The organic groups may be either directly attached to the phosphorus atom of the compound or attached thereto through an intervening atom such as oxygen. The term oxyacids of phosphorus is intended to designate throughout the specification and claims acids of phosphorus in which one oxygen atom may intervene between the hydrogen and phosphorus atoms of the ester.

The preferred acids are substituted orthophosphoric acldsand the preferred salts comprise the aluminum, calciim, barium .and chromium salts of these acids. Examples of such salts are alu minum lauryl phosphate, aluminum cetyl phosphate, aluminum octadecyl phosphate, aluminum spermol" phosphate, aluminum oleyl phosphate, aluminum spermenyl" phosphate, aluminum cetyl phenyl phosphate, aluminum di-(amylphenyl) phosphate, aluminum naphthenyl phosphate, calcium lauryl phosphate, calcium cetyl phosphate, calcium octadecyl phosphate, calcium "spermol phosphate, calcium oleyl phosphate, calcium spermenyl phosphate, calcium cetyl phenyl phosphate, calcium di-(amylphenyl) phosphate, calcium naphthenyl phosphate, chromium lauryl phosphate, chromium cetyl phosphate, chromium octadecyl phosphate, chromium spermol" phosphate, chromium oleyl phosphate, chromium "spermeny phosphate, chromium cetyl phenyl phosphate, chromium di-(amylphenyl) phosphate, chromium naphthenyl phos-- phate, barium lauryl phosphate, barium cetyl phosphate, barium octadecyl phosphate, barium spermol phosphate, barium oleyl phosphate, barium spermenyl phosphate, barium cetyl phenyl phosphate, barium di-(amylphenyl) phosphate, and barium naphthenyl phosphate.

Additional examples of salts within the scope of the invention are: aluminum di-cyclohexanyl phosphate, aluminum di-stearo-glyceryl phosphate, aluminum tetra-chloro-octadecyl phosphate, aluminum di-(6-chloro, 2-phenyl phenyl) phosphate, aluminum di-(3-methyl, l-chloro phenyl) phosphate, aluminum (monochlorocetyl) phosphate; calcium di-cyclohexanyl phosphate, calcium di-stearo-glyceryl phosphate, calspermol phosphate, magnesium oleyl phosphate, magnesium spermenyPphosphate, magnesium cetyl 'phenyl phosphate, magnesium die (amylphenyl) phosphate, magnesium naphthenyl phosphate, magnesium (monochlorooetyl) phosphate; barium di-cyclohexanyl phosphate, barium di-stearo-glyceryl phosphate, barium tetrachloro-octadecyl phosphate, barium di-(6-' chloro, Z-phenyl phenyl) phosphate, barium di- (S-methyl, l-chloro phenyl) phosphate,.and barium (monochlorocetyl) phosphate.

The substituted oxyacids of phosphorus utilized in the present invention may be prepared by methods known in the art. For example, a mixture of a higher alcohol and phosphorus pentoxide in ethyl ether maybe refluxed for several hours. The reactionby which' the substituted phosphoric acid is formed in this operation is believed to be represented bythe following. equation:

where R is an alkyl radical. The alkyl ethyl phosphoric acid is soluble in ether, while the ethyl metaphosphate is not and the'ether solution of the former may be separated from the latter by amples of substituted phosphoric acids suitable for'the purposes of thisinventionand a brief indication as to their method of preparation.

TABLE 1 Acid Method of preparation M no-cet 1 has horic 9.25 lb. cetyl alcohol and 5.61 lb. YD p P205 were refl ed with gal.

ethyl ether for 2 4 hr. Cetylpliosphoric acid solution decanted.

Mono-spermo phosphoric. 112 gms. solid sperm alcohols, 60 gms. P 0 and 400 gms. ethyl ether treated as above.

Acid Method of prepeaation gms. octadecanol and c. c. benzene treated with 56.8 gins. POClz. Product was hydrolyzed to give a free acidic hydrogen.

100 gms. of the phenol and 50 gins.

P205 heated to for 18 hr.

107 gms. oleyl alcohol and 28.5 gms. P 0 were refluxed in ethyl ether for 24 hours.

107 gins. liquid sperm alcohols and Mono-octade cylphosphoric D i-(6-chloro-2-phenylphenyl) phosphoric. Mono-oleylphosphoric 100 gms. amyl phenol and 43 gms.

P205 heated to F. for 15 hr. glns. tetrachloropctadecanol and 28 gins. P20 refluxed with ethyl ether for 17 hr. 644 gms. monocetyl phosphoric acid Dicyclohexanylphosphoric.

(Cetylphenyl) phosphoridu.

Di-(amylphenol) phosphoric.

Mono (tetrachloro) actedecylphosphoric.

Mono (mono'chlorocetyl) phosphoric.

through in sunlight until the weight increased to 7l4 gms.

In preparing the metal salts herein involved,

the ethyl group in the ethyl phosphoric acid above mentioned may be hydrolyzed off to form the metal salt of the mono-alkyl-ortho-phosphoric acid, 1. e. the salt of RH2PO4. This type of operation is not limited to the alkyl derivatives but includes aryl-ethyl-phosphoric acid, alkaryl-ethylphosphoric acid, aralkyl-ethyl-phosphoric acid and ethyl phosphoric. acids containing a cyclic non-benzenoid group. The metal salts of the various substituted oxyacids of phosphorus may be conveniently prepared by reacting the acid with sodium hydroxide or potassium hydroxide and then precipitating the desired metal salt from the solution of the sodium or potassium salt by the addition of the appropriate metal ion. The salt may also'be prepared by the direct neutralization of the acid as, for example, with lime where the calcium salt is to be obtained.

Basic aluminum salts prepared by the precipitation method are preferred by reason of their low corrosivity to alloy bearing metals although the so-called normal salts are not precluded. It

- is also preferred to maintain the amount of codecantation'. Table l gives a number of exminum saltshave properties different from the. .'salts' prepared by precipitation from aqueous solutions. The salts prepared in a non-aqueous environment are soft, low melting solids, while the corresponding saltsprepared by precipitation from aqueous solutions are hard, non-melting solids. Although the former type of salt may be utilized for imparting some desirable. propertiesto hydrocarbon oils, it is preferred to use a salt prepared by precipitation from aqueous solutions where the ability to inhibit piston ringsticking in 27 gms. P905 refluxed in ethyl ether melted and chlorine gas bubbled TABLE 2 Miscellaneous tests En sf gf Strip corrosion Preparation of compound Per Weleks cent mac ine Compound i m 01 ll i t 333% sat ng ean cos y sticking ness Cu Pb Cd Ag increas Acld ggf 0) 9) U) Acid treated Western oil 0 1.0 Poor 1.0 1.0 477 1.0 Aluminum lauryl phosphate. 1.0 5.0 Good 0.1 1.5 546 Oorudmercial lauryl phosphoric Na salt ac Do 0.05 l. 0.1 0 Do. Aluminum cetylphosphate.. 1.0 5.0 Verygood. Do. Do 0.1 4.0 Good 0.2 0.7 Do. Do 0.8 53: o 0.6 0.7 146 0.68 .do Ksalt. Alutrninum octadecyl phos- 0.15 6.0 Verygood. 0.1 1.0 Octadecylalcohol+POCh+CcH.. Na salt a e. Al ulrlninum spermol" phos- 1.0 5.0 do Low 4.0 Solidspermalcohols+P:O +etl1er. Do.

ate. Do 0.7 5.0 do. 1.0 1.0 do Do. Aluminum oleylphosphate 0.7 4.0 Good 0.1 1.0 Oleyl alcohol-i-PrO +ether D0. Aluminum spermenyl 0.3 2.0 Fair 0.1 0.2 Liquid sperm BlCOh0l+P305+ Do.

hosphate. ether. Au ininili u'lt di-cyclohexanyl 0.1 5.0 Verygood. 0yclohexanol+Pr0r+ether Do.

osp a a. Aufinlnlfinidi-(amyl-phenyl) 1.0 3.0 Fair 0.5 2.0 Amy1phenol+PrOr Do.

p can a e. Alufininilllrn di-stearo-glycel'yl 0.7 2.0 Glyceryldistearate-i-P o -l-etheru Do.

as ate. A um num tetra-chloro- 0.1 do 0.2 3.0 Tetra-chloro-octadecanol+P 0r+ Do.

octadecyl phosphate. et er. Calciumlaurylphosphate 1.0 2.0 do 1.0 5.0 Commerciallaurylphosphorlcacld. Do. Calcium oetylphosphate 0.5 5=l= Excellent. Oetylaloohol+Pr0r+ether Ksalt.

o 0.9 4* Verygood. 0.5 1.0 do Do. Chromium cetylphosphate 0.8 0 0.3 0.2 do.-. Nasalt.

Do 1.0 5.0 do do .Do. Magnesiurnlaurylphosphatev 1.0 2.0 Fair .0 .0 Commercial lauryl phosphoric Do.

. ac Aluminum lauryl phosphite.. 0.3 1.0 do .1 Laurylalcohol+POl= Do.

l Expressed as ratio oi time to stick rings of compounded oil to that with an uncompounded Wesg'grn acid refined oil SAE 30.

1 Expressed as ratio of compounded oil corrosion to corrosion with Western acid refined oil SAE a Expressed as ratio of wear of compounded oil to that of Western'acid refined oil SAE 30 The base oil used for testing the addition agent was in all cases an acid refined Western 0 In the above piston ring sticking tests a single cylinder 2% inch bore, 2 /zinch stroke Lauson gasoline engine was operated under extremely severe conditions for the purpose of developing fully piston ring sticking and piston gumming tendencies under circumstances simulating severe operating conditions encountered in the field. Operation of the motor during tests was continuous at 1600 R. P. M. except for shut-downs at fifteen-hour intervals for inspection. The jacket temperature was maintained at 375 F. and the sump oil temperature at 220 F. The wear tests were carried out in a Weeks machine comprising a /2 inch steel ball pressed against a 1% inch steel cylinder with a force of 40 lbs., the cylinder dipping in the oil to be tested and rotating at 600 R. P. M. The duration of the test was sixteen hours and the wear rate determined by measuring the amount of metal removed from the ball. In the above wear tests the lubricant was maintained at approximately 300 F. as indicated. v

The corrosion tests were carried out in the following manner: Glass tubes 2 inches in diameter and 20 inches long were immersed in an oil bath, the temperature of which was automatically controlled to within 11 F. of the test temperature which was 300 F. Approximately 300 c. c. of oil under the test was placed in each tube and air was bubbled through it at the rate of 10 in sea 30 grade.

liters per hour. Strips of the different types of bearing metals were cut to size and placed in the oils; in most cases the copper-lead mixtures and cadmium-silver bearing alloys were tested simultaneously in the same sample of oil. The weight loss of each strip was recorded. Before weighing, each strip was washed in petroleum ether and carefully wiped with a soft cotton cloth. The duration of the test was-72 hours.

To further illustrate the corrosion inhibiting properties of the compounding agents herein disclosed, the following data obtained in the above type strip corrosion test are given:

On Oxidator test is used for judging the oxidation susceptibility of an oil at elevated temperatures. This test is carried out by placing a weighted amount of oil in an oxygen absorption cell. The oil is completely saturated with oxygen by maintaining a foam with bubbles formed at a perforated glass surface in the cell. Constant temperature is maintained by an oil bath in which the cell and the intake line for the oxygen supply are immersed. Oxygen is circulated by means of a. leakless oil-free pump and is preheated to bath temperature, passed through the oil in intimate contact therewith by means of the perforated glass surface, and certain volatile oxidation products carried out with the gas stream are condensed in a. water-cooled column and returned to the oil. The procedure of taking measurements consists in placing the weighed amount of oil in the cell as previously stated, evacuating the apparatus, filling with oxygen at atmospheric pressure,

and then accurately determining the decrease in the volume ofoxygen caused by its absorption in, the oil by the measurement of the oxygen volume in the system at the stated intervals during the test. In the present test the temperature was maintained at 340 F. and the amount of oxygen absorbed is given in the table of data as cc. of.

omgen gas per 100 gms. of oil oxidized.

TABLE 4 Oxidatdr data Oxygen absorbed at 340 F.

Oil

Acid refined naphthenic base SAE 30 Ditto.-I-0.'5% calcium chlorocetyl phosphate.

The compounding agents herein disclosed may have one or more advantages, depending upon the particular compound selected, the proportion utilized, and the environment which the lubricating oil is to encounter. It should be observed} for example, that even though a compounded oil may be somewhat corrosive to copper-lead or cadmium-silver bearing metals, Babbitt bearings are little if at all aflected by such "corrosive action. Hence, compounded oils which may notbe particularly desirable for lubrication of copper-lead or cadmium-silver bearings may be highly useful and extremely advantageous in conjunction with the operation of internal combustion engines having bearings of babbitt or other corrosive-resistant bearing metals. The present invention in its broader aspects is therefore not limited to the use of a particularcompound having all or the greatest number of advantages, but embraces various of the less advantageous addition agents which will find utility in particular applications where all the possible improvement in properties may not be required or where the standard of performance may not be so high.

Present experience indicates that where the properties desired involve the ability to stabilize lubricating oils under severe operating conditions, such as those encountered in the lubrication of pistons and piston rings of internal combustion engines of the Diesel type, polyvalent metal salts of substituted oxyacids of pentavalent phosphorus containing more than twelve carbon atoms in the molecule and preferably containing an alkyl or alkaryl substituent should be utilized. It is to be understood that by "polyvalent metal salts used in the above connection the alkaline earth metals are included. 6

A moderately acid refined Western naphthenic base oil is the preferred oil stock used as abase.

'for the compounded lubricants involved herein. The compounding ingredients appear to function more efficiently in such a base oil than in a highly paramnic oil stock or a highly refined Western mately 0.25 to approximately 2% of the compound spects the color of the compounded oil after use i ininternal combustion engines. From approximay be added to lubricants where ability to inhibit piston ring sticking comprises the principal property desired. Solutions containing more than 2% of the compounds in mineral oil may be utilized for the purpose of preparing lubricating greases and concentrates capable of dilution with lubricating oils and the like. Such higher concentrations comprise a convenient method of-handlin the compounds and may be used as addition agents for lubricants in general as well. as for other purposes.

The metal salts of this invention may be added to hydrocarbon oils containing other compounding ingredients such as pour point depressors,

oiliness agents, extreme pressure addition agents,

blooming agents, compounds for enhancing the viscosity index of the hydrocarbonoil, corrosion inhibitors, color stabilizers, etc. The invention in its broader aspects embraces mineral hydrocarbon oils containing, in addition to metal salts of the substituted acids of phosphorus, thickening agents and/or metal soaps in grease-forming proportions or in amounts insufficient to form greases, as in the case of mineral caster machine oils or other compounded liquid lubricants.

While the character of the invention has been described in detail and numerous examples of the composition given, this has been done by way of illustration only and with the intention that no limitation should be imposed on the invention thereby. It wil1 be apparent to those skilled in the art that numerous modifications and variations of the illustrative examples may be effected in the practice of theinvention which is of the scope of the claims appended hereto.

We claim: t I c '1. A lubricating composition containing a metal salt of an acid of phosphorus having a halogenated organic substituent.

2. A lubricating compositioncontaining an aluminum salt of an acid of phosphorus having a halogenated organic substituent.

3. A lubricating composition containing a chromium salt of an acid of phosphorus having 'a halogenated organic substituent.

4. A lubricating composition containing an alkaline earth metal salt of an acid of phosphorusv having a halogenated organic substituent.

5. A- lubricating composition containing a calcium salt of an acid of phosphorus having a halogenated organic substituent.

6. A lubricant comprising a hydrocarbon'oil and from approximately 0.05% to 2% by weight based on the oil of a metal salt of an acid of phosphorus containing a halogenated organic substituent. I

I; A lubricant comprising a hydrocarbon oil and from approximately'0.05% to 2% by weight based on the oil of an aluminum salt of an acid of phosphorus containing a halogenated organic substituent.

8. A lubricant comprising a hydrocarbon oil and from approximately 0.05% to 2% by weight based on the oil of a chromium salt of an acid of phosphorus containing a halogenated organic substituent.

9. A lubricant comprising a hydrocarbon oil and from approximately 0.05% to 2% by weight based on the oil'of an alkaline earth metal salt 10 of an acid of phosphorus containing a halogenated organic substituent.

10. A lubricant comprising a hydrocarbon oil and from approximately 0.05% to 2% by weight based on the oil of a calcium salt of an acid of phosphorus containing a halogenated organic.

substituent.

11.- A lubricating composition containing a;

polyvalent metal salt of an acid of phosphorus having a chlorinated organic substituent of hydrocarbon structure.

12. A liquid lubricating composition comprising a hydrocarbon oil containing a polyvalent metal salt of a halogenated aryl substituted acid of phosphorus.

13. A liquid lubricating composition comprising a hydrocarbon oil containing a polyvalent metal salt of a halogenated alkaryl substituted acid of phosphorus. v

.14. A liquid lubricating composition comprising a hydrocarbon oil containing a polyvalent metal salt of a halogenated alkyl substituted acid of phosphorus.

BRUCE B. FARRINGTON. JAMES O. CLAYTON. JOHN T. RUTHERFORD.

CERTIFI GATE OF C ORREG TI ON Patent .No. 2,325 597.

BRUCE B. FARRINGTON, ET AL.

A s 5. 191a It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows? Page i, Table 2, third line from the bottom, under the heading "Viscosity; increase 100 F.", for the figure "119 read -199-- and that the said-Letters Patent should be read with this correction therein that the. same may conform. to the record of the case inthe Patent Office.

Signed and sealed this 9th day of November, Air. 1915.

(Seal) Henry Van Aradal e Acting Commissioner of Patents.

CERTIFI GATE OF C ORREG TI ON 'Pate'n't he; 2,325,597. August 5 1915.

BRUCE B. FARRINGTON, ET' AL.

It is hereby certified that error aiapears in the printed specification of the above numbered patent requiring correction as follows!- Page 4 Table 2, third line from the bottom, under the heading viscosityincreas'e 100 -F.", roiche figure "1l9" read --199--;, and that the s'aid Lettera Patent shonld be read with this correction therein that the some new confom; to the record of the case inthe Patent Office.

Signed and sealed this 9th day of November, A31), 1915.

. Henry Van Aradal e, (Seal) Acting Commissioner o'f-Patents.