US2619460A

US2619460A - Lubricating oil composition

Info

Publication number: US2619460A
Application number: US83779A
Authority: US
Inventors: Loren L Neff
Original assignee: Union Oil Company of California
Current assignee: Union Oil Company of California
Priority date: 1949-03-26
Filing date: 1949-03-26
Publication date: 1952-11-25
Anticipated expiration: 1969-11-25

Description

Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE LUBRICATING OIL COMPOSITION No Drawing. Application March 26, 1949, Serial No. 83,779

14 Claims.

This invention relates to mineral lubricating oils which have been modified by the addition of constituents which impart to the oils special characteristics, adapting them to use in high output diesel engines and particularly to use in supercharged diesel engines where conditions of use are so severe that ordinary mineral lubricating oils, and even mineral lubricating oils containing the ordinary detergency and anticorrosion agents in the usual amounts, are not satisfactory. The invention relates, also, to the addition agents themselves, to methods for preparing the agents and to concentrated oil solutions or oil concentrates of said agents, which agents or oil concentrates may be used in preparing the final lubricating oil compositions.

The present trend in internal combustion engines, particularly of the diesel engine type, is in the direction of higher compression ratios, higher operating temperatures and thus higher horse power output per unit Weight of the engine. Moreover, it is the trend to operate engines of this type for longer periods without oil change so that oils which are satisfactory for use in the present-day hi h output diesel engines, for example, must have not only an initially high detergency and initially high anticorrosion characteristics but these properties must be retained under severe conditions of use for relativel long periods of use in an engine. To further complicate the preparation of a satisfactory oil for the lubrication of such engines the fuels available often contain higher proportions of sulfur than those which have been used in the past and it is well recognized that high sulfur fuels tend to produce corrosive conditions in an engine which must be overcome by the lubricating oil employed, otherwise not Only does corrosion take place in the engine but wear rates are sufficiently high that frequent overhaul and replacement of parts becomes necessary, thereby unduly increasing engine operation cost.

In order to prepare oils which may be used in engines of the character described it has been the practice to merely increase the percentage of additive materials which have been used in the past in ordinar diesel engines, automotive engines and the like, hoping to gain the extra protection necessary by the use of these larger proportions. In such oils it is general practice to employ two or more different additive materials. One of these additive materials which is considered to be a detergent additive, as for example, a metal sulfonate, is employed to impart to the oil sufficient detergency to prevent deposition of varnish and lacquer-like deposits in the engine.

Another additive which is generally employed is referred to as an anticorrosion agent which is employed for the purpose of preventing corrosion to engine parts, particularly corrosion-sensitive bearings. Sometimes an antioxidant is employed and sometimes antiwear agents may also be included in the composition. Some of the anticorrosion agents employed also appear to impart antioxidant and/or antiwear properties to the oil. Using combinations of the various additive materials which have been employed in the past in oils where the various requirements are not as great as those of the supercharged diesel engine, for example, it is found that even with extremely high percentages of these additive materials sufficient protection is still not obtained. The failure of these larger quantities of two or more ad ditives to give the desired protection is due in part at least to the fact that although the additives may co-operate to give improved detergency and anticorrosion effects, for example when used in small amounts they do not co-operate when present in the oil in the larger amounts. Thus, in using the larger percentages of additive the anticorrosion agent tends to reduce the effectiveness of the detergency additive and the detergent tends to reduce the effectiveness of the anticorrosion agent. Moreover, it is found that with the usual agents, whether used in relatively small or large amounts, excessive wear of engine parts occurs. This wear effect is aggravated by the use of high sulfur fuels such as diesel fuels containing up to 0.5% or 1% of sulfur.

It is an object of this invention to prepare a lubricating oil containing a single additive material which will impart sufficient detergency, anticorrosion characteristics and antiwear characteristics to an oil to permit its use under the severe service conditions existing in the presentday high output diesel engines over relatively long periods of service. It is another object of this invention to prepare a lubricating oil containing a single additive material which imparts to the oil these characteristics and which has the ability to protect high output diesel engines over long periods of service from deposition of carbonaceous and lacquer-like deposits, from corrosion such as bearing corrosion and from wear of bearings, pistons, rings and other moving parts within the engine. It is a further object of this invention to prepare a lubricating oil which will protect an engine of the type described operating under severe conditions even While using a fuel containing as high as 1% or more of sulfur.

It is found that these and other objects can be obtained by reacting a mixture of sulfonic acids and phenolic material, preferably a hydrocarbon substituted phenol, with a low molecular weight aldehyde, as for example formaldehyde, neutralizing the resulting acidic product with a metal base to produce an oil-soluble metal salt of the reaction product and complexing the resulting metal salt with a basically reacting metal compound, which may be a metal base or a metal salt of a weak organic or inorganic acid. The resulting complex is oil-soluble and may be dissolved in mineral lubricating oil to produce oils having exceptional detergency, anticorr sion and antiwear characteristics. Moreover, not only do these oils have initially high detergency, anticorrosion and antiwear characteristics but these characteristics are retained over relatively long periods of use in an engine under severe service conditions. Apparently the inclusion in the composition of basically reacting metal compound is of extreme importance. The complex, even though containing large amounts of base or basically reacting material, is not in itself in any way corrosive or deleterious in an engine but is capable of reacting with and preventing corrosion produced by acids or acidic bodies of various sorts which are produced under the severe conditions encountered in internal combustion engines. An oil containing the complex described herein thus has a large amount of reserve alkalinity and apparently this reserve alkalinity is instrumental in providing antioorrosion and antiwear properties which are retained by the oil over long periods of service.

In preparing the complex of this invention mixture of a phenol, sulfonic acids and a low molecular weight aldehyde, with or without a diluent such as lubricating oil or petroleum thinner, and preferably with a small amount of water, is heated to a temperature between about 150 F. and 300 F. and preferably be veen about 175 F. and 210 F. or 220 F. for a period of 2 to 3 hours sufficient to effect reaction. The product, which may be referred to as a sulfonic acid-phenol-aldehyde condensation product or a sulfonic acid-modified phenol-aldehyde resin, is acidic and capable of reaction with metal bases to form salts. This acid reaction product, which will be referred to herein as a modified phenol resin or simply as a modified resin, is converted into its metal salt by treatment with a base of the desired metal, as for example an oxide, hydrated oxide, hydroxide or carbonate of a metal. This salt formation is desirably efiected at elevated temperatures within the range indicated above for the condensation reaction. The resulting metal salt is further heated within the temperature range of about 156 F. to 450 F. or 500 F. with additional quantities of metal base or with a basically reacting metal. salt of a weak acid for a time sufricient to effect solubilization of the added base or salt. The resulting product, which is r ferred to herein as a complex, is preferably filtered while hot to remove residual insoluble materials and subsequently heated to remove petroleum thinner if such was employed in its preparation. The complex is oil-soluble and constitutes 1e additive of this invention. if ll is used in th pre aration of the modified resin or in the e tration of the complex or both the product will be an oil solution of the complex.

In preparing the lubricating oils of this invention the complex or oil solution of th complex is dissolved in mineral lubricating oil in amounts between about 1% and 20% by weight of the oil-free complex, based on the finished lubricating oil. The amount to be employed in any given case will depend upon the severity of the service in which the oil is to be used. If it is to be employed in automotive engines, generally between about 1% and S or 4% of the additive will suffice to give adequate protection to the engine. However, if the oil is to be used in high output supercharged diesel engines, larger amounts will generally be required, and when such engines are to be operated with high sulfur fuels amounts of the additive up to 20 9b are sometimes desirable. In this connection it is to b noted that the complex does not unduly thicken an oil even in the amounts indicated and does not tend to impart a greaselike structure to the oil such as would normally be obtained in using like amounts of soaps.

By the term complex or complex of the modified resin salt and a basically reacting metal compound it is meant to include those oil-soluble products obtained by heating a sulfonic acid-modified phenol-aldehyde -esin salt with an inorganic base or a basically reacting metal salt of a weak inorganic acid as described herein. During such heating the base or weak acid salt is solubilized by the modified phenol-aldehyde resin salt and the reaction product is soluble in mineral oil. Apparently the normally oilinsoluble basically reacting metal compound is solubilized by the modified phenol-aldehyde salt by reason of some sort of complex formation. However, regardless of whether true complex formation takes place or not the product, which is oil-soluble and which contains the modified resin salt and solubilized metal compound, will be referred to herein as a complex. This complex is relatively stable, as indicated by the fact that oil solutions are found to remain clear and not to precipitate insoluble materials, even after long periods of storage and/or use. That complex formation and not merely basic salt formation occurs during the treatment is indicated by the fact that the complexes may be produced, not only with polyvalent metal bases, but with monovalent metal bases and also with mono and polyvalent salts of weak acids. The phenomenon is not one, therefore, of basic salt formation as might be expected if the solubilization effect were obtainabl only with polyvalent metal bases and not with the other basically reacting metal compounds described.

The relative proportions of sulfonic acids and phenolic materials to be employed in the preparation of the additive may be varied over rather Wide limits. It is-found that as little as 0.05 moles of sulfonic acids and as much as about 3 moles of sulfonic acids per mole of phenol may be employed. Generally, as the proportion of sulfonic acids is increased the detergency characteristics of oils containing the resulting additive will increase in relation to the anticorrosion characteristics of the oil and thus it is possible, by controlling the ratio of sulfonic acids to phenol used in the preparation of the additive, to control the relative detergency and anticorrosion characteristics of the lubricating oils containing the resulting additives. Generally between about 1.25 and 2 equivalents of aldehyde will be employed per equivalent of phenol. Smaller amounts tend to produce reaction products containing unreacted phenolic molecules and larger amounts appear to be unnecessary to produce the desired reaction.

In preparing the metal salt of the reaction prodnot of the phenol, sulfonic acids and aldehyde sufiicient metal base is added to neutralize the acidity of the product. Generally the reaction product has slightly less than the theoretical acidity, indicating that some of the phenolic groups and/or some of the sulfonic acid groups are destroyed during the condensation reaction.

In preparing the complex, generally between about 0.1 and 3 or 4 equivalents of basically reacting metal compound will be employed with 1 equivalent, based on the metal content, of the metal salt of the modified condensation product. This corresponds to an amount of basically reacting metal compound between about 5% and 60% by weight of the metal salt of the condensation product. The basically reacting metal compound may be added as a water slurry or water solution. However, under any circumstance it is usually desirable that a certain amount of water be present, at least during the initial stages of the complexing reaction. Sometimes it is desirable to add a small amount of glycerol which appears to aid the complex formation and, in fact, it is possible to operate in the complete absence of water if sufiicient glycerol is employed. The effect of water or glycerol is not understood; however, it is observed that the rate of complexing, as indicated by the rate at which basically reacting metal compound is solubilized, is appreciably greater when water and/ or glycerol is present. Amounts of glycerol between about 0.1 and 5%, based on the total materials being complexed, are found to be particularly efiective.

Sulfonic acids which may be used in the preparation of the additives of this invention are preferably mahogany sulfonic acids. These are the oil-soluble sulfonic acids prepared by sulfonating fractions of petroleum, preferably lubricating oil fractions, with sulfuric, chlorosulfonic acid and the like. Green sulfonic acids or mixtures of green and mahogany sulfonic acids may be employed, however, and in some instances are the full equivalents of the mahogany acids. Particularly this applies to mixtures of green acids and mahogany acids. Since both green sulfonic acids and mahogany acids and their method of preparation are well known further description of these materials is not believed to be necessary.

Phenols which may be employed in the preparation of the additives of this invention include phenols with at least one substituent having at least 3 and preferably 4 or more carbon atoms. The substituent may be an alkyl group, such as butyl, isobutyl, amyl, tert. amyl as well as the normal and iso, hexyl, heptyl, octyl, nonyl, decyl, lauryl, stearyl, oleyl and the like groups; cycloalkyl groups such as cyclopentyl, cyclohexyl, alkyl substituted cyclopentyl and cyclohexyl such as methylcyclohexyl, ethylcyclohexyl, dicyclohexyl and the like; an aryl group such as ethylphenyl, dimethylphenyl and aralkyl groups, as for example benzyl, and the like. In place of the single aromatic ring as in phenol, the arcmatic nucleus of the phenol may be mono or dicyclic and, therefore, may be a naphthalene nucleus. Naphthalene itself may be employed although generally better oil solubility of the resulting resins are obtained with substituted naphthalene Where the substituents may be any of those indicated above for phenol.

The aldehyde which is referred to herein as a lower molecular weight aldehyde is preferably formaldehyde, although aldehydes containing up to 4 or 5 carbon atoms may be employed. Thus, acetaldehyde, propionaldehyde, butyraldehyde,

furfuraldehyde may be employed to produce the phenol-aldehyde resins which are usable in the preparation of the complexes of this invention. Formaldehyde is generally used as a 40% by volume aqueous solution, however other forms may be employed. Paraformaldehyde or polymethylene oxide may be employed or trioxane, which is a trimer of formaldehyde, may be used with satisfactory results.

Inorganic bases which may be used to prepare the metal salts of the sulfonic acid-modified phenol-aldehyde resins of this invention include the basic compounds, particularly the hydroxides, hydrated oxides or oxides and, in some cases, the carbonates, of the alkaline earth metals, as for example, calcium, strontium, barium and magnesium, the alkali metals sodium, potassium and lithium and the polyvalent metals lead, tin, zinc, aluminum, copper, cadmium, mercury, vanadium, chromium, molybdenum, manganese, iron, cobalt and nickel. Generally the salts are produced by direct neutralization of the acid product as indicated hereinabove. Preferably the inorganic base is added as a water solution or at least Water is added along with the inorganic base to aid the neutralization reaction. When neutralization is complete the product is preferably heated to expel the water. This neutralization may be effected in the presence of naphtha or other petroleum thinner where such naphtha or petroleum thinner was employed in the preparation of the acid resin, and, following neutralization, the water and petroleum thinner is volatilized from the product. In some instances it may be desirable to prepare a particular metal salt, such as a polyvalent metal salt, by first preparing an alkali metal salt, e. g., the sodium salt, and converting this salt to the desired polyvalent metal salt by metathesis. This metathesis reaction can be carried out in alcoholic solution, thus preventing hydrolysis which would occur in aqueous solution because the modified phenol-aldehyde resins are relatively weak acids. Methods of metathesis of Weak acid salts are well known in the art and, therefore, need no further description here.

The basically reacting metal compound to be used in the preparation of the complex may be a metal base and will include all of the metal compounds referred to in the preceding paragraph. When a metal base is to be complexed with the metal salt of the modified condensation product it may be the same or different from the metal base used in the preparation of the salt. Thus, the calcium salt of a modified condensation product may be complexed with calcium hydroxide or it may be complexed with any of the other bases mentioned above, as for example, barium hydroxide, lead oxide, sodium hydroxide or the like.

The basically reacting metal compound may be a basically reacting metal salt of a weak acid. By the term weak acid it is meant to include both organic and inorganic acids having ionization constants less than 1 10 In the case of diand tribasic acids, the primary hydrogen will have a dissociation constant less than 1 l0 By the term basically reacting is meant having a basic reaction as might be indicated by chemical indicators. By the term basically reacting metal salt of a Weak acid is meant a salt of a weak acid, as defined, in which the metal component of the salt forms a base Which is more strongly basic, 1. e., more highly 7 dissociated in aqueous solution than the acid of the weak-acidcom p'onent ofthe salt is acid as indicated by its dissociation in-aqueous solution.

Weak acid 'salts' as defined herein include the borates such aszinc'borate, 3Z1'1O2B2O3, lead metaborate, Pb(BO2)2, calcium metaborate, Ca(BO2)2 and sodium tetraborate, NazBrOv; aluminates such as sodiumaluminate, NaAlOz; thiosulfates such as calcium thiosulfate, CaSzOs, sodium thiosulfate and the like; trithionates such as calcium trithionate, CaSsOe, sodium trithionate or other metal trithionates; tetrathionates such as calcium tetrathionata'CaSlOa; arsenates such as sodium arsenate, NasAsoi; arsenites such as sodium arsenite, Na2AsO3; thioarsenates'such as calcium thioarsenate, Ca(AsSs)2; thiccyanates such as zinc thiocyanate, Zn(SCN) 2, calcium thiocyanate, Ca(SCN) 2 and barium thiocyanate, -Ba(SCN)2; antimonates such as calcium antimonate, Ca3(SbO4)z; antimonitcs such as sodium antimonite, NaSbOz; thioantimonites such as calcium thioantimonite, Ca(SbS2)2; cyanides such as nickel cyanide, Ni(CN)2; cyanates such as lead cyanate, Pb(CNO)2; sulfides, as for example sodium sulfide and-calcium sulfide, sulfites such as sodium sulfite; stannates-such as sodium stannataNazSnOs; piumbites such as sodium plumbite and calcium plumbite; phosphates such as sodium phosphate and the like.

Organic acid salts which may be employed include the metal salts of lower molecular weight fatty acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid and the like. calcium acetate, sodium propionate, barium propionate, and strontium butyrate are typical of these salts. Other salts include phenates such as sodium phenate, calcium phenate, lead phenate, and the like; salicylates such as barium salicylate, potassium salicylate and zinc salicylate; thiophenates such as sodium thiophenate, strontium thiophenate and lead thiophenate;' thioglycolates such as potassium thioglycolate, nickel thioglycolate and magnesium thioglycolate. Metal salts of dibasic carboxylic acids, particularly the lower molecular weight dibasic carboxylic acids, may be employed. Such salts include sodium succinate, potassium succinate, sodium malonate and the like.

In cases where the desired weak'acidsalt is substantially insoluble in water, provided its acidic constituent is adequately stable, it is convenient to form the salt in situ. For example, in solubilizing sodium arsenate an oil solution of the calcium'salt of modified resin isheated to a temperature of about 350 F. with anaqueous solution of sodium hydroxide and to the resulting sodium hydroxide complex is added an aqueous solution of arsenic acid and the resulting mixture is dehydrated and filtered.

In preparing complexes in which the metal Thus, sodium acetate, potassium acetate,

salt of the sulfonic acid-phenol-aldehyde reaction product is to be complexed with a carbonate or a. bicarbonate the desired metal carbonate or bicarbonate may be directly complexedis blown with carbon dioxide will bewithin the range of 275 to 375 F. Usually- 2 to 4'hours is sufiicient to convert the hydroxide to the corresponding carbonate and somewhat longer times are required to convert the hydroxide into the bicarbonate. Thus, in preparing a complex consisting of the calcium salt of sulfonic acidmodified phenol-aldehyde resin and sodium carbonate the calcium resin salt is first heated with sodium hydroxide and the resulting mixture is carbonated by blowing with carbondioxide.

The complexes of this invention maybe employed to improve the lubricating characteristics of substantially any type of lubricating oil. Preferably the mineral oil to be employed will be a lubricating oil'having a viscosity index as defined by Dean and Davis, Chemical and Metallurgical Engineering, volume 36, page 618 (1929). above about '70 such as those produced by solvent treating paraffinic base stocks. An ideal oil to be used in connection with the additives of this invention is a highly solvent treated parafiinic Western lubricating oil having a viscosity index of to 95. Forsome purposes the lower viscosity index oils such as those having viscosity indices of below '70, such as in the range of 0 to 50, produce high quality oils when-the additive is dissolved in them in amounts indicated herein.

Lubricating oils containing the oil-soluble complexes described herein-have been evaluated in Lauson singlecylinder test engines operated in such a manner that the oil-is subjected to severe service conditions. This test is employed to determine the corrosion tendencies of the -oil and to determine the tendency for the oil to deposit resinous and lacquer-like materials in the engine. In carrying out the Lauson engine test the engine is operated for a. total of 60 hours under a load of about 3.5 horsepower, with a coolant temperature of about 295 F; and an oil temperature of about 280 F. At the end of-the test the cleanliness of the engine is observed and the oil is given a numerical detergency rating between 0% and where 100% indicates a. perfectly clean engine. Thus, a detergency rating of 100% would indicate that during the test with a given oil there were substantially no lacquer or varnish-like deposits within the engine. The corrosivity of the oil is measured by determining the loss in weight of corrosionsensitive copper-lead bearings during the period of test. Generally, the bearings are removed and weighed after 20, 40 and 60 hours'of operation.

In those cases in which corrosion is extremely severe and there appears to be danger of engine failure due to excessive corrosion-of the bearings as indicated by an examination made at the 40- hour period, the copper-lead bearings are replaced with babbitt bearings in order to complete the 60-hour test. The results of such engine tests are shown in connection with some of the examples presented hereinbelow.

The experimental determination of wear in an engine is somewhat more difficult than the determination of detergency and anticorrosion characteristics. However, an indication of the amount of Wear is obtained by either of two methods. One is to determine theamount of iron contained in an oil after agiven period of use. Thus an iron determination made'onused oil samples gives a fair indication of wear rates which can be correlated to wear rates in actual service. The oils of this inventionappear to reduce engine wear, as indicated by the above method of testing, over the amount of Wear observed with ordinary mineral lubricating oil or oils containing the ordinary lubricating oil addition agents. Apparently the reserve alkalinity imparted to the oils of this invention by reason of the complexes which contain inorganic bases or basically reacting metal salts is responsible, in part at least, for this improved wear resistance.

In the following examples the proportion of additive material is referred to in many instances on the basis of the sulfate ash content of the product or of the resulting mineral lubricating oil. The sulfate ash is a measure of the metal content of the material being tested. The term sul-' fate ash or S04 ash may be defined as the percentage of residue obtained when a weighed portion of a material is ashed or burned in the presence of sulfuric acid. Thus, if a sulfate ash determination is carried out on a composition consisting of the calcium salt of a modified phenolaldehyde resin and oil, the sulfate ash of the composition is the amount of dry residue expressed in percentage obtained from a weighed amount of the composition after being ashed or burned in the presence of sulfuric acid. Generally the amount of oil-soluble complex of metal salt of the modified resin and basically reacting metal compound to be employed in preparing the final lubricating oil composition, indicated hereinabove as being between about 0.5% and 20% by weight, will be such that the sulfate ash of the final oil will be between about 0.1% and 6%. It is to be pointed out; however, that this value varies greatly with the proportion of basically reacting inorganic compound present in the complex, with the particular metal employed in the preparation of the complex and With the ratio of phenol to sulfonic acids used in the preparation of the modified resin. In the case of heavy metals such as lead and where the proportion of basically reacting compound is high, the sulfate ash of the final lubricating oil may be as high as 10 or even The following examples will serve to illustrate further my invention but are not to be taken as in any way limiting the broader aspects of the invention.

Example I A complex of the calcium salt of the reaction product of octyl phenol, mahogany sulfonic acids and formaldehyde with calcium hydroxide is prepared in the following manner. Mahogany sulfonic acids are prepared from a commercial calcium sulfonate containing about 62% by volume of oil by treatment with aqueous HCl solution. The sulfonic acids are washed free from inorganic salts produced during the acidification and 500 g. of the sulfonic acids in oil (0.67 equivalents) are mixed with 500 g. (2.42

equivalents) of octyl phenol and 2580 g. of an SAE 10 solvent treated Western mineral lubricating oil having a viscosity index of 90. This mixture is heated with vigorous stirring to 175 F.

10 oil solution and analysis shows it to have a sulfate ash of 4.98%.

To the above calcium salt in oil solution is added 50 g. of calcium hydroxide, 30 g. of glycerol and 250 g. of water and the mixture is heated to a temperature of 300 F. for a period of 4 hours with constant agitation. At this time the calcium hydroxide appears to be completely solubilized. The product, after filtration through clay, has a sulfate ash of 7.0%, indicating that approximately 0.5 equivalents of calcium hydroxide have been solubilized per equivalent of calcium salt.

A lubricating oil is prepared by dissolving 15 parts by Weight of the oil concentrate of the complex in parts by weight of an SAE 30 solvent treated Western mineral lubricating oil having a viscosity index of 90. This oil, having a sulfate ash of 1.0%, is found to have a detergency of 82% and a bearing Weight loss at 60 hours of 14 mgs. in the Lauson test engine.

As a modification of the method of preparation of the complex described above it is equally feasible to add all of the calcium hydroxide to be used in the preparation of the complex to the acidic product of condensation. Thus, the acid resin is reacted with an amount of calcium hydroxide sufficient to neutralize the resin plus that amount which it is desired to complex with the calcium salt of the resin and the resulting mixture heated to a temperature such as 300 F. for about 4 hours to effect neutralization and complexing. A calcium hydroxide-calcium resin salt complex prepared in this manner, when dissolved in mineral lubricating oil in the amounts indicated in the preceding paragraph, gives an oil of similar properties.

Example II An acid resin for use in complexing with various basically reacting metal compounds is prepared in the following manner. A mixture of 5000 g. (30.5 equivalents) of tort. amyl phenol, 10 kg. of an oil solution of sulfonic acids containing about 62% acids (13.5 equivalents) and 20 kg. of an SAE 10 solvent treated Western mineral lubricating oil having a viscosity index of is heated with vigorous stirring to 180 F. and 3000 ml. of 40% formalin solution is added slowly. The resulting mixture is heated to a temperature between 180 and 210 F. for about 5 hours with continued stirring. This product consists of an oil solution of a sulfonic acidmodified phenol-aldehyde resin containing approximately 35% by weight of the acid resin and about 65% by weight of mineral oil.

A 500 g. portion of the oil concentrate above produced is converted into a complex by adding to the concentrate 172 g. of barium hydroxide (2.0 equivalents) and 250 g. of water. This mixture is heated to about 175 F. for 3 hours and the temperature is then gradually increased to 350 F. over a period of 2 hours. The resulting product is filtered to remove residual insoluble materials. This product has a sulfate ash of 35% and contains a ratio of equivalents of barium hydroxide per equivalent of barium resin salt of 2.1.

A lubricating oil is prepared by dissolving 30 parts by weight of the above oil concentrate of the complex in 70 parts by weight of an SAE 30 mineral lubricating oil having a viscosity index of about 90. This oil has a detergency of 97% and a bearing weight loss at 60 hours of 13 mgs. in the Lauson engine test.

example.

Example III A 500 g. portion of the oil concentrate of acid resin produced in Example II is converted into a complex by adding 14:3 g. of lead oxide 30 g. of glycerol and 200 g. of water and heating and agitating the mixture at a temperature of 200 F. for 4 hours then gradually increasing the temperature to 400 R, which temperature is maintained for a period of 4 hours. At this time the lead oxide is substantially completely dissolved and the product is filtered. This-product, which is an oil concentrate of a lead oxide-lead. modified resin salt, has a sulfate ash content of 30.2%.

A lubricating oil is prepared by dissolving parts by weight of the oil concentrate of the lead oxide complex in an SAE 30 mineral lubricating oil of the character described in the preceding This oil has a detergency of 81% and a bearing weight loss at 60 hours of 6 mgs.

Example IV A 500 g. portion of the oil concentrate of acid resin produced in Example II is converted into itscalcium salt by treatment with 24 g. of calcium hydroxide and 50 g. of water. This mixture is heated to effect reaction and the resulting product filtered to remove residual insoluble materials.

Theresulting oil solution of the calcium salt is separated into two portions. To one portion is added 13 g. of sodium hydroxide and themixture heated to 300 F. for a period of 2 hours. The product, which will be referred to as a sodium hydroxide complex, contains a-ratio of equi-- valents of sodium to calcium of 1 to l.

The second portion of the calcium resin salt is heated with 80 g. of lead oxide. Heating is continued at a temperature of about 350 F. for 4 hours and the product is filtered. This product, which will be referred to as a lead oxide complex, contains a ratio of equivalents of lead to calcium of 2.2 to 1.

Lubricating oils prepared by dissolving 25% by weight of the sodium hydroxide complex and the lead oxide complex, respectively, in an SAE Western mineral lubricating oil having a viscosity-index of about show exceptional deter- V gency, anticorrosion and antiwear properties.

Example V A 500 g. portion of the oil concentrate of the acid resin produced in Example II is converted into a complex by treatment with 38 g. of sodium hydroxide. Complexing is efiected by heating the mixture to a temperature of 300 F. for 2 hours. The resulting product,. after filtration, is found to have a sulfate ash of 12.7%.

. A portion of the complex so produced isdissolved in mineral oil in theratio of 5 parts of the concentrate to 95 parts of mineral oil. 'This oil has a .detergency rating of 80, and a bearing weight loss at 60 hours of 52 mgs.

.A secondportion of the sodium hydroxide complex is heated to 300 F. and blown with carbon dioxide for a periodrof 3 hours. The resulting product will be referred. to, as a sodium carbonate complex.

A lubricating oil is prepared by dissolving 15 parts by weight of the above carbonate complex in oil in'85 parts by weight of an SAE 30, 90 V. I. mineral'lubricating oil. This oil has a detergency greater than 97 and a bearing weight loss of 27 mgs. at 60 hours in the Lauson engine test.

Example VI -A.500 g.-portion of the oil concentrate of the acid resin produced in Example II is converted into a complex by treatment with sufficient calcium. hydroxide to neutralize the acid resin. The

..calcium hydroxide and a small amount of water is added. to theresin and the mixture heated to efiectneutralization. To the resulting product is added 52 g. of calcium thiosulfate hexahydrate, 150 g. of water and 20 g. of glycerol. The resulting mixture is heated to 210 F. for 3 hours and the-temperature is then increased to about 400 F. over a period of 2 hours. The resulting prod- I uct is filtered to remove residual insoluble materosion characteristics of the oils of this invention.

Example VII A 500 g. portion of the oil concentrate of the acid resin produced in Example II is converted into its barium'salt by treatment with an equiv- I alent amount of barium hydrate in the presence ofa small amount of water.

- ence of a small amount of water.

, calcium salt is complexed with 20 g. of zinc thio- The resulting barium salt is complexed with 41 g. of barium p'henate in the presence of 20 g. of glycerol and 200 g. of water. This mixture is heated to about 200 F. for 3 hours and then the temperature is increased to 450 F. for 1 hour and the product A lubricating oil prepared by dissolving 20 parts of the above oil concentrate in parts of an SAE 30, V. I. mineral lubricating oil is found to have the desirable characteristics of the oils of this invention.

Example VIII A 500 g. portion of the oil concentrate of the acid resin produced in Example II is converted'into-its sodium salt by treatment with an equivalent amount of sodium hydroxide in the presence of a small amount of water. The resulting sodium salt is complexed with 10 g. of sodium acetate in the presence of 10 g. of glycerol and g. of water. This mixture is heated to about 200 F. for 3 hours and then the temperature is increased to 450 F. for 1 hour and the product filtered.

A lubricating oil prepared by dissolving 8 parts by weight of the above oil concentrate in 92 parts of an SAE 30, 90 V. I. mineral lubricating oil is found to have the desirable characteristics of the oils of this invention.

Example IX A 500 g. portion of the oil concentrate of the acidresin produced in Example II is converted into its calcium salt by treatment with an equivalent amount of calcium hydroxide in the pres- The resulting cyanate in the presence of 10 g. of glycerol and 100 g. of water. This mixture is heated to about 200 F. for 3 hours and then the temperature is increased to 450 F. for 1 hour and the product filtered.

A lubricating oil is prepared by dissolving 4 parts by weight of the above oil concentrate in 96 parts of an SAE 30. 90 V. I. mineral lubricating oil and is found to have the desirable characteristics of the oils of this invention.

Example X An acid resin for use in preparing the complexes of this invention is prepared in the following manner. A mixture of 2060 g. of octyl phenol equivalents), 11.1 kg. of an oil solution of sulf-onic acids containing about 62% acids equivalents) and 10 kg. of an SAE 10, 90 V. I. mineral lubricating oil is heated with vigorous stirring to 175 F. and 1000 ml. of 40% formalin solution is added. The mixture is heated to a temperature of 200 F. for 4 hours with continued stirring and then increased to 350 F. to vaporize water remaining in the mixture. The product consists of an oil solution of a sulfonic acid-modified phenol-aldehyde resin containing approximately 39% by weight of the acid resin and about 61% by weight of mineral oil.

A 500 g. portion of the above oil concentrate of acid resin is converted into a complex by adding 210 g. of lead oxide, 500 1g. of SAE 10 solvent treated mineral lubricating oil and 250 g. of water and heating the mixture to about 210 F. for 3 hours and then at a temperature of about 375 F. for 3 hours. The resulting product, after filtration, has a sulfate ash of 23.5%.

A lubricating oil is prepared by dissolving parts by Weight of the above oil concentrate of the complex in 80 parts by weight of an SAE naphthenic mineral lubricating oil having a viscosity index of about 50. This oil has a detergency greater than 97%, a bearing weight loss at 60 hours of 9 mgs. in the Lauson engine test and appears to have extremely good antiwear characteristics.

Example XI A 500 g. portion of the oil concentrate of the acid resin produced in Example X is complexed with calcium hydroxide by adding 30 g. of calcium hydroxide, 15 g. of glycerol and 100 ml. of water and heating the mixture to a temperature of 300 F. with agitation for a period of 2 hours.

A portion of the above calcium hydroxide complex is converted into a carbonate complex by heating to 300 F. while blowing with carbon dioxide for a period of 2.5 hours. The resulting product is a, calcium carbonate complex of the calcium salt of the acidic reaction product obtained by reacting octyl phenol, sulf-onic acids and formaldehyde.

A lubricating oil is prepared by dissolving 30 parts by Weight of the above oil concentrate of the calcium carbonate complex in 70 parts by weight of an SAE 30 paraflini-c mineral lubricating oil. This oil has a detergency of 95%, a bearing weight loss at 60 hours of 22 mgs. and appears to have extremely good antiwear characteristics as indicated by a low iron content as determined on a sample of the used oil.

Example XII A 500 g. portion of the oil concentrate of the acid resin produced in Example X is converted into a zinc salt-zinc oxide complex by heating the oil concentrate with 54 g. of freshly prepared zinc hydroxide together with 20 g. of glycerol and 50 ml. of water. The mixture is heated to 200 F. for 2 hours and the temperature then increased to 350 F. for 3 hours and the product filter-ed.

f 14 A' lubricating oil is prepared by dissolving 25 parts by Weight of the above oil concentrate in 25 parts by weight of an SAE 30, V. I. mineral lubricating oil. This product has the desirable detergency, anticorrosion and antiwear characteristics.

Example XIII A lubricating oil additive is prepared by heating a mixture of 206 g. of octyl phenol (1 equivalent), 740- g. of an oil solution of mahogany sulfonic acids (1 equivalent), 1000 g. of an SAE 10, 90 V. I. mineral lubricating oil to a temperature of 200 F. and adding to this mixture while stirring vigorously 66 g. of acetaldehyde and g. of water. The aldehyde is added over a period of about 15 minutes and when the addition is complete the temperature is gradually raised to 250 R, where it is maintained for about 4 hours. The resulting acid resin in oil solution is converted into a complex by treatment with 412 g. of strontium hydroxide octahydrate together with 15 g. of glycerol. This mixture is heated to 200 F. for 2 hours and then at about 350 F. for 1 hour to effect salt formation and complexing and then filtered.

A lubricating oil is prepared by dissolving 3 parts by weight of the above complex in 97 parts by weight of mineral lubricating oil. This oil has the desirable characteristics of the oils'of this invention.

Example XIV A lubricating oil addition agent is prepared by heating a mixture of 206 g. of octyl phenol (1 equivalent), 300 g. of a mixture of green and mahogany sulfonic acids obtained by a sulfonation treatment of a lubricating oil fraction and consisting of 23% by weight sulfonic acids and 77% by weight of mineral oil to a temperature of 200 F. and adding to this heated mixture, while stirring, g. of 40% by volume formalin. The mixture is then heated to 300 F. for 3 hours. The oil concentrate of the acid reaction product thus obtained is neutralized with an equivalent amount of calcium hydroxide, i. e., an amount suflicient to form the calcium salt, and the calcium salt is then complexed with 40 g. of 50% by weight sodium hydroxide solution. Complexing is efiected by heating the mixture to a temperature of 350 F. for 3 hours.

A portion of the sodium hydroxide-calcium resin salt complex is dissolved in mineral lubricating oil in the ratio of 7 parts by weight of the oil concentrate in 93 parts by weight of oil.

A second portion of the sodium hydroxidecalcium salt complex is converted into the corresponding sodium carbonate complex by heating to 300 F. and blowing carbon dioxide into the mixture for a period of 3.5 hours. This product is filtered and dissolved in mineral lubricating oil in the ratio of 9 parts of the complex concentrate in 91 parts by weight of mineral lubricating oil. This oil has a detergency of 96% and shows a bearing weight loss of 75 mg. in the Lauson engine test.

Example XV Mahogany sulfonic acids ar prepared from a commercial calcium sulfonate solution in oil by the method described in Example I. The sulfonic acids (1000 grams, 1.34 equivalents) are mixed with octylphenol (400 grams, 1.94 equivalents) and an SAE 10 solvent treated Western mineral lubricating oil having a viscosity index of 90 (1000 grams). This mixture is reacted with polymethylene oxide (119 grams) in the presence of 200 grams of water to prepare a sulfonic acid-modified allzylated phenol-aldehyde condensation product.

Example XVI To approximately one-half of the product of Example XV is added 480 grams of lead monoxide and the mixture is heated with stirring at 104 F. for 2 hours. The temperature is then gradually increased to 347 F. during several hours to boil 01f the water present. The product is filtered through filter clay using'vacuum to yield as filtrate a lead salt-lead oxide system analyzing 20.8% sulfate ash. This figure indicates that the product contains approximately 0.8 equivalents of lead oxide per equivalent of lead salt.

A lubricating oil is prepared by dissolving 10.0

parts by weight of the above product in 90 parts by weight of an SAE solvent treated Western mineral lubricating oil having a viscosity index of 90. This oil having a sulfate ash of 2.1% is .found to have a detergency rating of 77% and a bearing weight loss of 12 mgs. after 60 hours of operation in the Lauson test engine as compared to a similar test on the base oil without addition agents which gives a detergency rating of 58% at 60 hours and 400 mgs. bearing weight loss after hours of operation. In this case it is necessary to replace the copper-lead bearing with a babbitt bearing after 40 hours due to excessive corrosion.

Analysis of the used oils from the above tests show, respectively, 0.0016 and greater 0.0039% by weight of iron, thus demonstrating the antiwear characteristics of the products of this invention.

Example XVII To approximately one-half of the product of Example XV is added 366 grams of anhydrous barium hydroxide and the mixture is treated in the same manner as that employed in Example XVI where lead oxide is used. The filtered product, a barium salt-barium hydroxide complex system, has a sulfate ash of 17.1%.

A lubricating oil is prepared by dissolving 10.0 parts by weight of the above product in 90 parts by weight of an SAE 30 solvent treated Western mineral lubricating oil having a viscosity index of 90. This oil having a sulfate ash of 1.7% is found to have a detergency rating of 98% and a bearing weight loss of 2 mgs. after hours of operation in the Lauson test engine as compared to a similar test on the base oil without addition agents which gives a detergency rating of 58% at 60 hours and 400 mgs. bearing weight loss at 40 hours as described in Example XVI.

Analysis of the used oil from the above test with the barium complex of this example shows, respectively, 0.0018 and greater than 0.0039% by weight of iron, thus demonstrating the anti-wear characteristics of the products of this invention.

Lubricating oils containing the additive of this invention, i. e., the complex of an oil-soluble metal salt of the product obtained by reacting sulfonic acids, a hydrocarbon substituted phenol and a low molecular weight aldehyde with a basically reacting metal compound, generally possess the desired detergency, anticorrosion and antiwear characteristics. However, in some instances where it is particularly desirable to obtain extremely high detergency without impairing the antiwear or anticorrosion characteristics of the oil it is found that the inclusion of an oil-soluthan ble metal sulfonate in the lubricating oil containing the additive of this invention produces the desired result. Oil-soluble metal sulfonates which may be employed in conjunction with the additive of this invention and which co-operate to give the improved detergency without affecting other properties of the oil include the mono and polyvalent metal sulfonates. The metal of the metal sulfonate may be any of the metals de scribed as being useful in the form of their inorganic bases to prepare the metal salts of the sulfonic acid-modified phenol aldehyde resins described hereinabove. The sulfonic acids used in preparing the metal sulfonates are preferably mahogany sulfonic acids; however, any oil-soluble sulfonic acid may be employed.

The efiect of oil-soluble metal sulfonates used in conjunction with the additives of this invention is illustrated by tests made on the oil of Example XVI, to which is added 2 parts by weight of calcium mahogany sulfonate. The detergency rating of the oil is increased from 77% to without noticeably changing the bearing weight loss or the iron content of the used oil. A substantially equivalent result is obtained by incorporating 3 parts by Weight of lead sulfonate in the same oil. The amount of sulfonate to be employed, together with the additive of this invention, will depend upon the degree of detergency improvement required but will generally be between about 0.5% and 5% by weight of the finished oil but may be as high as 10%.

The foregoing description and examples of my invention are not to be taken as limiting since many variations may be made by those skilled in the art without departing from the spirit or the scope of the following claims:

I claim:

1. A composition of matter suitable for addition to mineral lubricating oil to impart detergent and anti-corrosion properties to said oil of a complex produced by heating a mixture of 1 mol of phenol, between 0.05 and 3 mole of petroleum sulfonic acids and between 1.25 and 2 equivalents of a low molecular weight aldehyde having 1 to 5 carbon atoms to a temperature between F. and 300 F., thereby producing an oil-soluble acidic condensation product, converting said acidic condensation product into its metal salt and heating a mixture of said metal salt, water and a basically reacting metal compound of the class consisting of metal oxides, metal hydroxides and metal salts of weak acids having an ionization constant less than about 1 x 10 said last-named F metal salts having a basic reaction as indicated by chemical indicators, to a temperature between 150 F. and 500 F. for a time sufiicient to solubilize said basically reacting metal compound, the ratio of equivalents of basically reacting metal compound to equivalents of metal salt of said acidic condensation product being between 0.1 and 4.- to 1.

2. A composition according to claim 1 in which the metal of said basically reacting metal compound is an alkali metal.

3. A composition according to claim 1 in which said basically reacting metal compound is a metal hydroxide.

4. A composition according to claim 1 in which said basically reacting metal compound is a metal carbonate.

5. A mineral lubricating oil consisting essentially of mineral lubricating oil and a minor proportion between about 1% and 20% by weight of an oil-soluble complex of a basically reacting metal compound and an oil-soluble metal salt of an acidic reaction product obtained by condensing at a temperature between 150 F. and 300 F, a mixture of 1 mol of a hydrocarbon substi tuted phenol, between about 0.05 and 3 mois of petroleum sulfonic acids and between about 1.25 and 2 equivalents based on the phenol of a low molecular weight aldehyde having from 1 to 5- carbon atoms per molecule, said basically reacting metal compound being a compound selected from the class consisting of metal oxides, metal hydroxides and metal salts of weak acids having an ionization constant less than about 1 x said last-named metal salts having a basic reaction as indicated by chemical indicators, said oilsoluble complex being formed by heating between 0.1 and 4 equivalents of said basically reacting metal compound with 1 equivalent of said oilsoluble metal salt of the condensation product to a temperature between 150 F. and 450 F. for a time sufilcient to solubilize said inorganic base.

6. An oil according to claim 5 in which the metal of the basically reacting metal compound is an alkali metal.

7. An oil according to claim 5 in which the basically reacting metal compound is a metal hydroxide.

8. An oil according to claim 5 in which said complex is a complex of an alkaline earth metal salt of said acidic reaction product and sodium carbonate.

9. An oil according to claim 5 in which said complex is a complex of a polyvalent metal oxide and an oil-soluble polyvalent metal salt of said acidic reaction product.

10. An oil according to claim 5 in which said complex is a complex of lead oxide and a lead salt of said acidic reaction product.

11. An oil according to claim 5 in which said complex is a complex of an alkaline earth metal hydroxide and an alkaline earth metal salt of said acidic reaction product.

12. An oil according to claim 5 in which said complex is a complex of an alkaline earth metal salt of said acidic reaction product and lead oxide.

13. An oil according to claim 5 in which said complex is a complex of an alkaline earth metal salt of said acidic reaction product and an alkali metal hydroxide.

14. A composition according to claim 1 in which said low molecular Weight aldehyde is formaldehyde.

LOREN L. NEFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,361,804 Wilson Oct. 31, 1944 2,367,470 Neely et a1 Jan. 16, 1945 2,410,652 Grifiin et a1. Nov. 5, 1946 2,467,176 Zimmer et a1. Apr. 12, 1949 2,501,731 Mertes Mar. 28, 1950

Claims

1. A COMPOSITION OF MATTER SUITABLE FOR ADDITION TO MINERAL LUBRICATING OIL TO IMPART DETERGENT AND ANTI-CORROSION PROPERTIES TO SAID OIL OF A COMPLEX PRODUCED BY HEATING A MIXTURE OF 1 MOL OF PHENOL, BETWEEN 0.05 AND 3 MOLS OF PETROLEUM SULFONIC ACIDS AND BETWEEN 1.25 AND 2 EQUIVALENTS OF A LOW MOLECULAR WEIGHT ALDEHYDE HAVING 1 TO 5 CARBON ATOMS TO A TEMPERATURE BETWEEN 150* F. AND 300* F., THERERBY PRODUCING AN OIL-SOLUBLE ACIDIC CONDENSATION PRODUCT, CONVERTING SAID ACIDIC CONDENSATION PRODUCT INTO ITS METAL SALT AND HEATING A MIXTURE OF SAID METAL SALT, WATER AND A BASICALLY REACTING METAL COMPOUND OF THE CLASS CONSISTING OF METAL OXIDES, METAL HYDROXIDES AND METAL SALTS OF WEAK ACIDS HAVING AN IONIZATION CONSTANT LESS THAN ABOUT 1X10-1, SAID LAST-NAMED METAL SALTS HAVING A BASIC REACTION AS INDICATED BY CHEMICAL INDICATORS, TO A TEMPERATURE BETWEEN 150* F. AND 500* F. FOR A TIME SUFFICIENT TO SOLUBILIZE SAID BASICALLY REACTING METAL COMPOUND, THE RATIO OF EQUIVALENTS OF BASICALLY REACTING METAL COMPOUND TO EQUIVALENTS OF METAL SALT OF SAID ACIDIC CONDENSATION PRODUCT BEING BETWEEN 0.1 AND 4 TO 1.