US3277004A - Additives for lubricants - Google Patents

Description

United States Patent 3,277,004 ADDITIVES FOR LUBRICANTS Sidney Schifi, Barflesville, 0kla., assignor to Phillips Petroleum Company, a corporation of Delaware 7 No Drawing. Filed Nov. 30, 1964, Ser. No. 414,855 16 Claims. (Cl. 25233) This invention relates to improved additives for lubricants. In one aspect this invention relates to methods of preparing said improved additives. In another aspect this invention relates to lubricant compositions containing said improved additives.

At the present time it is common practice to enhance or modify certain of the properties of lubricating oils through the use of various additives or improvement agents. The lubricating oils employed in internal combustion engines, such as automotive, light aircraft, and diesel engines in particular, require the use of additive agents to render them serviceable under the adverse environmental conditions encountered in these engines. Among the various additives employed in modern engine oils, one of the most important is the type which acts to prevent accumulation of sludge in the crankcase and on the cylinder walls, thereby preventing sticking of the piston rings, and the formation of varnish-like coating on the pistons and cylinder walls. Because of their general function of maintaining a clean engine, additives of this nature are termed detergents, although it is now understood that they have little utility in cleaning a dirty engine but by virtue of dispersant activity preventor greatly retard engine fouling.

Metal petroleum sulfonates have been widely used as detergent additives for lubricating oils. Various methods have been employed for the preparation of said metal petroleum sulfonates. Many of these processes are quite complex involving a large number of treating steps. Generally speaking, said methods comprise the sulfonation of a petroleum fraction to obtain a mixture of sulfonic acids and unsulfonated oils, and neutralizing the reaction mixture with the carbonate, oxide, or hydroxide of a metal to obtain a mixture of the corresponding metal petroleum sulfonate and unsulfonated oils. Metals which have been used in such processes include the alkaline earth metals, such as calcium, and other metals, including lead, nickel, cobalt, tin, zinc, etc.

In addition to detergent properties, it would be highly desirable for such detergent additives to have good rust inhibiting properties. I have now discovered that a superior lead petroleum sulfonate having excellent rust inhibiting properties as well as good detergent properties can be prepared by neutralizing the acid oil obtained in the sulfonation step with both lead oxide and lead acetate. The lead petroleum sulfonate prepared in this manner is superior to lead petroleum sulfonates which are prepared by using either lead oxide or lead acetate alone.

Thus, broadly speaking, the present invention resides in a superior lead petroleum sulfonate which has been prepared by neutralizing the acid oil obtained in the sulfonation step with both lead oxide and lead acetate; methods of preparing said improved lead petroleum sulfonates; and lubricant compositions containing said-superior lead petroleum sulfonates. 7

An object of this invention is to provide an improved or superior lead petroleum sulfonate which is useful as an additive in lubricant compositions. Another object of this invention is to provide a process for preparing said 3 ,Z77,004 Patented Oct; 4, 1966 improved or superior lead petroleum sulfonates. Still another object of this invention is to provide an improved lubricant composition containing said superior lead petroleum sulfonate. Other aspects, objects, and advantages of the invention will be apparent to those skilled in the art in view of this disclosure. 1

Thus, according to the invention, there is provided a process for producing a superior lead petroleum sulfonate, useful as an additive for lubricants, which process comprises: sulfonating a petroleum hydrocarbon fraction having a viscosity within the range of 90 to 720 SUS at 210 F. and a viscosity index of at least about 85; neutralizing the reaction product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount suflicient to supply from 12 to 90 weight percent and said. lead acetate being present in said mixture inan amount'sufiicient to supply from 88 to 10 weight tralizinng the reaction product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount sufiicient to supply from 12 to 90 Weight percent and said lead acetate being present in said mixture in an amount suflicient to supply from 88 to 10 weight percent of the total amount of lead milliequivalents present; and recovering a mixture of said lead petroleum sulfonate and unsulfonated oil from said neutralized reaction product as said additive.

' Still further according to the invention, there is pro vided a lubricating oil composition comprising a lubricating oil base stock containing from 0.2 to about 30 weight percent of a lead petroleum sulfonate obtained by: sulfonating a petroleum hydrocarbon fraction having a viscosity within the range of 90 to 720 SUS at 210 F. and

in an amount sufiicient to supply from 88 to 10 weight percent of. the total amount of lead milliequivalents present; and recovering the resulting lead petroleum sulfonate.

It is to be noted that both lead oxide and lead acetate are used in the neutralization step of the invention. As clearly shown by data given in the examples hereinafter, lead petroleum sulfonates prepared by using both lead oxide andlead acetate to neutralize the acid oil obtained in the sulfouation step are markedly superior to lead petroleum sulfonates produced when either lead oxide or lead acetate is used alone to neutralize said acid oil. Said data clearly show that when both lead oxide and lead acetate are used there is obtained a synergistic effect with respect to rust inhibition properties as compared to using either lead oxideor lead acetate alone, the same total mi-lliequivalents of lead being used in all instances.

In" the practice of the invention, said lead oxide and said lead acetate are used in amounts, with respect to each other, whereby of the total amount of lead milliequivalents present, lead oxide is present in an amount sufl'icient to supply from 12 to 90 weight percent and lead acetate is present in an amount sufiicient to supply from 88 to weight percent of said total amount of lead. Preferably, the lead oxide is present in an amount sufiicient to supply from 20 to 88 weight percent and said lead acetate is present in an amount sufiicient to supply from 80 to 12 weight percent of said total amount of lead present. Still more preferably, the lead oxide is present in an amount suflicient to supply from 50 to 87 weight percent and said lead acetate is present in an amount suflicient to supply from 50 to 13 weight percent of said total amount of lead present.

Said total amount of lead oxide and lead acetate which is used in the practice of the invention is an amount which is at least sufiicient to essentially neutralize the total acidity of the reaction product from the sulfonation step, i.e., an amount which is stoichiometrically equivalent to said total acidity. Preferably, said total amount of said lead compounds. Will be an amount which is sufiicient to supply at least about 1.13, preferably at least about 1.3, and more preferably at least about 1.4 milliequivalents of lead per milliequivalent of said total acidity. Usually not more than 2.5, more usually not more than 2 or less, total milliequivalents of lead per milliequivalent of total acidity are use-d in the neutralization step. However, it is within the scope of the invention to use more than 2.5, e.g., up to aboutS or more, milliequivalents of lead per milliequivalent of total acidity. When the milliequivalents of lead used per milliequivalent of total acidity is in the order of 2 or more, the product obtained is sometimes a gel which presents ditficulties in dispersing same in the base lubricating oil. However, this difiiculty (when it occurs) can be readily avoided by blending the base lubricating oil into the, hydrocarbon diluted product after the filtration step and before removal of said hydrocar bon diluent. Said filtration step is described hereinafter.

As used herein and in the claims, unless otherwise spephalt, or both paraflin and asphalt'are present in the residue after distillation of the lighter components.

Mexican and Mid-Continent petroleums respectively.

The residual material discarded from the propane fractionation step contains the rejected asphalt and more aromatic oils. The lube oil fraction, recovered in a propane fractionation step after removal of the SAE 50 lube stock,

I sulfuric acid can vary from 10 weight percent to 40 weight cified, the term total acidity refers to the titratable acidity, reported as H 80 and determined as follows. Two grams of the acid oil obtained in the sulfonation step are weighed into a 250 ml. flask and 15 ml. of benzene, 15 ml. of isopropyl alcohol, and ml. of water are added. The mixture is shaken well and three drops of phenolphthalein indicator are added. The mixture is then titrated with standard 0.1 N NaOH until a permanent pink color remains in the water layer. From the above, total acidity as weight percent where V=ml. of NaOH, N=norma1i ty of NaOH, and W=grams of sample.

A wide variety of oils can be used in the practice of the invention as the charge oil in preparing the lead petroleum sulfonates of the invention. Said charge oil is selected from the more viscous bright stock fractions of petroleum. A petroleum fraction having a viscosity of at least 90 SUS at 210. Fqwill produce a lead petroleum sulfonate which is satisfactory for many purposes. The deasphalted and solvent refined petroleum fractions having a viscosity of about 140 to about 720 SUS at 210 F; are preferred. A presently more preferred sulfonation charge stock is a propane fractionated, solvent extracted, and dewaxed Mid-Continent oil of about 200 to about 230 SUS at 210 F. and having a viscosity index of about 85 to 100, or even higher.

A Mid-Continent oil is more precisely defined as a mixed base or intermediate base oil in The Science of Petroleum, volume 1, page 7, Oxford University Press, London,- New York and Toronto, 1938. The base of a crude petroleum is defined therein as follows:

The base of a crude petroleum is descriptive of the chemical nature of its main constituents. A petroleum may be described as parafiin base, asphalt base, or mixed base (intermediate base), according as paraffin wax, as-

percent excess S0 However, it is usually preferred to use commercial fuming sulfuric acid which contains about 20 weight percent excess S0 Liquid S0 i.e., liquid 50;; in liquid S0 is the presently preferred sulfonatingagent for use in the practice of the invention. Such liquid S0 is commercially available.

When '20 percent fuming sulfuric acid is used as the sulfonating agent, the acid-oil ratio can be in the range of from about 0.1 :1 to about 0.7:1, or even 1:1 to produce the petroleum sulfonates of the invention. A preferred range of acid-oil ratios is in the range of about 0.3 to

about 0.6:1. When liquid SO; in liquid S0 is the S111? fonation agent, the 80;, to oil weight ratios are maintained equivalent to those available from the. 20 percent fuming sulfuric acid values given above.

0.2, preferably about 0.06 to about 0.12:1. Said S0 10 oil ratios can be controlled by varying the rate of flow of the oil or of the SO -containing medium, or both. The

above given ratios are weight ratios.

fuming sulfuric acid is utilized as the sulfonating agent in order to provide optimum yield and quality of products. When sulfur trioxide, e.g., sulfur trioxide in sulfur dioxide, is utilized as the sulfonation agent, the reaction rate is greatly accelerated and the reaction has been found to be substantially completed in the time required to. ac-

complish suitable contact of the oil with the sulfur trioxide, usually less than about five minutes.

The sulfonation reaction can be carried out at atmospheric pressure although'pressures greater or less than atmospheric also can be employed,.if desired. When using liquid S0 in liquid S0 as the sulfonating agent,

it is preferred to carry out the reaction at suflicient pressure to maintain the S0 in liquid phase.

The neutralization step in the process of the invention can be carried out-in any suitable manner for contacting the acid oil, obtained from the sulfonation step, and the dual neutralizing agents of the invention. One very satisfactory method simply comprises contacting said acid oil with both lead oxide and lead acetate in any suitable mix ing vessel employing conventional mixing means, at a tem perature above about 100 F., for a period of time suflicient to eifect the neutralization, and recovering a mix-.

ture of lead petroleum sulfonates. and unsulfonated oil.

. In a more specific application of the invention, the oil charge stock is intimately contacted with the sulfonation For example, the contacting can conveniently be' agent. accomplished by mixing the oil and acidstreams, or the oil and liquid 80;, in liquid S0 streams, in a centrifugal pump. When fuming sulfuric acid is'the sulfonation agent, the mixture is passed to a reaction chamber main YP cal representatives of these three classes are Pennsylvanian,

In other words, the to oil ratio can be in the range of about0.02 to tained at reaction temperature, through which the mixture passes with a minimum of mixing overa period of time in the range of about 20 to about 90 minutes. When liquid sulfur trioxide in liquid sulfur dioxide is the sulfonating agent, the reaction chamber can be partly or wholly by-passed, and a suitable soaking vessel providing a few minutes residence time (usually not more than about five minutes) can be employed. The sulfonation step per se forms no part of my invention and any suitable sulfonation technique known to the art can be employed. When liquid S0 in liquid S0 is used as the sulfonating agent, the reactor or soaking zone effluent is passed to a flash tank where the S0 is vaporized and substantially completely removed for reuse.

The reaction product effiuent from the reaction chamher or flash tank (depending upon the sulfonation agent used) is neutralized by running it into an agitated vessel to which there are also added the required amounts of lead oxide and lead acetate, a hydrocarbon diluent, and water. Preferably, said lead oxide and lead acetate are added together as a mixture. However, it is within the scope of the invention to add said oxide and said acetate separately in the required amounts. The temperature of the contents of this neutralizing vessel is not critical with respect to neutralization, but is ordinarily held between about 160 to 200 F. for a period of time suificient to neutralize the reaction mixture because the subsequent filtering step is greatly benefited by neutralizing at the above temperature.

Suitable hydrocarbon diluents for use in the practice of the invention include Stoddard solvent, kerosine, normal heptane, normal octane, benzene, toluene, and others. Said diluent can be employed in a diluent to acid oil ratio of from 0.5 :1 to 3:1, preferably about 0.75:1 to 1.5: 1. Water is usually employed in a water to acid oil ratio of about 0.75 :1 to 1.5 :1. Said ratios are volume ratios and are not critical, the actual amounts used being chosen largely as a matter of convenience.

After the neutralization of the acid oil is complete, the neutralized mixture is then heated to a temperature within the range of about 300 to about 375 F. to remove the water and at least a portion of the hydrocarbon diluent. The remaining product is then cooled, dissolved in additional hydrocarbon diluent, and filtered to remove inor ganic solids. The filtrate from said filtering step is then heated to remove said diluent therefrom so as to recover the product comprising lead petroleum sulfonate and unsulfonated oil. If desired, filtration of said diluted product can be facilitated by the addition thereto of a filter aid.

The lead petroleum sulfonates can be'separated from the residual unsulfonated oil associated therewith by means of extraction with propane and/ or butanes under appropriate conditions of temperature and pressure. The light hydrocarbons, propane, isobutane, and normal butane, have been found to have a unique and unexpected selectivity for this separation, producing under appropriate conditions, substantially ash-free oil and oil-free sulfonates. Using propane as the solvent, extraction temperatures of about 150 to about 200 F. are required at pressures of about 640 p.s.i.g. Lower temperatures result in excessive inclusion of sulfonate in the extract. With normal butane, lower pressures of about 400 to 500 p.s.i.g. are adequate, but to achieve selectivity, the temperature range must be held between about 290 and about 305 F. The conditions required when isobutane is required are intermediate those for propane and for normal butane.

The products of this invention can be incorporated into lubricating oil compositions in several combinations depending upon specific service requirements. For example, if desired, in the case of heavy duty oils, such as those used in trucks, buses, and general diesel applications, the oil-free lead petroleum sulfonate can beblended with suitable base stocks. In many general duty crank- 6 case oils, the unfractionated combination of lead petroleurn sulfonate and unsulfonated' product oil can be blended with appropriate base oils. In the case of other general duty crankcase oils, there can be added to the base oils, suificient oil-free lead petroleum sulfonate to provide adequate detergency, and'unsulfonated product oil substantially in excess of that normally present in the unfractionated total product of the sulfonation process. In these variations of blending, the lead petroleum sulfonate components will provide high quality oils as required in various ordnance and other qualification tests and other specifications, and outstanding performance with respect to sludge formation in stop-and-go engine operation as well as superior performance with respect to rust inhibition.

Generally speaking, the, product of the invention comprising lead petroleum sulfonates and unsulfonated oil can be added to the base oil in anamount suflicient to obtain the desired degree of improvement characteristics of the base oil. Said product can be added to said base oil in amounts of about 0.2 to about 30 weight percent of the finished oil. The concentration of lead petroleum sulfonate alone in the base oil is normally in the range of about 0.1 to about 15 weight percent of the finished oil and a presently preferred concentration of said'product comprising lead petroleum sulfonate and .unsulfonated oil is in the range of about 2 to 20 weight percent of the finished oil. A presently preferred concentration of lead petroleum sulfonate in the finished oil is in the range of about 1 to about 10 weight percent of the finished oil.

The following examples will serve to further illustrate the invention.

EXAMPLE'I A lead petroleum sulfonate was prepared from a solvent-refined, dewaxed lubricating oil fraction derived from Mid-Continent petroleum and having the following properties: Viscosity of 4222 SUS at 100 F., viscosity of 212.4 SUS at 210 F., and viscosity index of 97.3. The charge stock, identified as finished 250 stock, was sulfonated with a 10 percent SO percent S0 mixture in a continuous operation. The S0 to oil weight ratio was 0.08 and the temperature of the reaction was controlled at about 115 F. The total' reaction time was 5 minutes, including the mixing and soaking periods. The system was maintained in liquid phase at a pressure of -120 p.s.i.g. -Efiluent from the sulfonation unit was subjected to a two-stage flash for 50 -80 removal.

Eight l'00-gram portions of the acid oil resulting from the SO -S0 flashing step were each dissolved in 80 ml. of toluene and 50 ml. of water was added to each of the resulting solutions. Leadoxide and/or lead acetate (in amounts togive 116 total milliequivalents of lead) was added, the-mixtures were stirred, and heated to 360 F. to strip the toluene and water. The productwas cooled, redissolved in toluene, filtered, and the filtrate heated to strip the toluene and yield eight product additives of lead petroleum sulfonate and unsulfonated oil.

Said eight product additives were tested for .pH and TBN (total base number) as described hereinafter.

Said eight product additives were each blended at a 4 weight percent concentration into eight individual samples of a commercial SAE 10 lubricating oil stock con-.

taining 0.9 weight percent of Lubrizol 1360 (zinc alkyl dithiophosphate). The eight resulting lubricating oil compositions were then tested for rust in hibiting properties in accordance with a modified version of ASTM D665-60, Procedure A. In said modified version, 30 ml. of 1 percent'acetic acid was used instead of 30 ml. of distilled water, and-stirring of the oil-acid mixture was for 16 hours instead of 24 hours. A control test (Run No. 9) was also run on said base SAE 10 lubricating oil stock which did not contain any additive of the invention. The results of the above tests are set forth in Table I below.

Table I Weight Percent Pb Run Lead Lead Rust No. Oxide Acetate pH TBN 1 Ratmg Meq. Meq. as as PbO Pb(Ac)z 100 0 3. 8 3 10. 90. 9 9. 1 4. 7 17. 0 5 16 86. 2 13. 8 4. 9 15. 1 8. 5 29 1 75. 0 25. 0 4. 4 13. 4 8 58 50.0 50. 0 4. 3 14. 4 7. 5 93 19. 8 80. 2 4. 3 16. 2 7 105. 5 9. 1 90. 9 5. 2 16. 5 5 8 116 0 100 4. 5 17. 5 5. 5 9 (control) 4. 25

1 TBN=total base number 2 10 is a perfect rating The above data show conclusively that a synergistic effect is obtained when both lead oxide and lead acetate are used asneutralizing agents, i.e., when using both lead oxide and lead acetate the lead petroleum sulfonate product obtained has better rust inhibiting properties than the lead petroleum sulfonate productobtained when using either lead oxide or lea-d acetate alone. A plot of the above data plotting rust ratings vs. total lead in weight percent of lead as lead oxide and weight percent as lead acetate shows that when the neutralizing mixture contains from about 12 to about 90 weight percent of lead oxide and from about 88 to about 10 weight percent lead acetate the rust rating of the lead petroleum sulfonate product will be above 5.5.

EXAMPLE H Another series of runs was carried out -to determine the eflect of the quantity of the neutralizing mixture of the invention on the quality of the lead petroleum sulfonate product.

A lead petroleum sulfonate was prepared from a solvent refined, dewaxed lubricating oil fraction essentially like that used in Example I and having a SUS viscosity at 100 F. of 4028, a SUS viscosity at 210 F. of 205.4, and a viscosity index of 97.1. Said lubricating oil fraction was sulfonated and the acid oil product recovered in essentially the same manner as described in Example I.

Five product additives were prepared in the manner described in Example I except that varying amounts of a neutralizing mixture containing 79 weight percent lead,

oxide and 21 weight percent lead acetate were used to neutralize the 100-gram portions of acid oil. The five product additives thus obtained were used to prepare five lubricating oilcompositions in the same manner and using the same base lubricating oil stock as in Example I. Rust rating tests were then run on said five lubricating oil compositions as described in Example I. The results of these tests are set forth as Runs 2 to 6 in Table H below. Run 1 in Table H presents comparable data for volume the product additive of Run 3 from Table 'I. 55' gjgi iggg f P it SAE stock 64: 5 Table II SAE 50 stock 24 0 Lead petroleum sulinnate g Total Grams Neutral- Total Meq. or Lubr1zol1360 0.8 Run No. Acidity of izing Mixture Pb per meq. of Rust santopour C 0. 1'

Acid Oil per 100 grams total acidity Rating 2 wt. percent of Acid on 60 100.0

a. 6 14. 2 1. 59 8.5 Engine Rust Ratings 1 4.8 10.6 0.89 3.5 4.8 14.2 1.18 6.0 4. s 16. 2 1. 36 7. 5 Ratmgs b a ned 4. 3 13, 9 1, 59 9 5 65 Rating Items Ratings on Reference 4. s 23. 0 1. 9a 9.8 GMR 063 1 Product was a gel Cylinder Walls 8.0 7. 5 i I 10 1s a perfect rating igter glunglgrm 8. 0 7. 0

. 't p A graph of the above data plotting rust rating ,vs. f. 38 lg meq. of total Pb/meq. of total acidity shows it is desirable 70 32 52 3 3 afigfifis 3-3 g-g to use at least about 1.13 meq. of total Pb/meq. of total Push 11:11:: acidity to obtaina product having a rust rating above 1 A R 5.5, at least about 1.3 meq. of total Pb/meq. of total vemge Rust 3mg 7 9 6 3 acidity to obtain a product having a rust rating of at x Rust ratio s made in d least 7, and at least about 1.4 meq. of total Pb/meq. of 75 cu (CRO) acgepted if ifg g Cmrdmatmg Resemh 8. total acidity to obtain a producthaving a rust rating of at least 7.5.

EXAMPLE HI A carbon spot dispersancy test was carried out on the lead petroleum sulfonate product additive of Run No. 3 of Table I blended at a 4 percent concentration in a commercial SAE 10 lubricating oil stock. The results of said tests showed the lead petroleum sulfonate additive products of the invention possess excellent detergent properties. In.

EXAMPLE .IV

A 1960 Oldsmobile Sequence H test was carried out on a lubricating oil containing a lead petroleum sulfonate additive of the invention prepared essentially. as described above for Run No. 5 in Example II. Said lead petroleum. sulfonate product additive was blended into a commercial- SAE 30 lubricating oil at a concentration of 4.8 volume.

percent.

The 1960 Sequence II test is an integral part of the.

Engine Sequence tests used by industry to describe minimum performance requirements of crankcase oi-ls forAPI Service MS. These tests have been approved by ASTM. They are reviewed and updated periodically to maintain.

their significance in terms of contemporary field performance. Detailed descriptions of the Engine Sequence tests are covered in ASTM Special Technical Publication No. 315A, Engine Test Sequences for Evaluating Automotive Lubricants for API Service MS; American Society for Testing Materials, 1916 Race Street, Philadelphia 3, Pa..

The Sequence H test on the experimental lead sulfonate was run in accordance with test conditions prescribed in this publication.

Said Sequence H test measures anti-rust performance of crankcase motor oils. Relative performance of lubricants is determined by the degree to which certain engine components are attacked by rust. This level of engine rust is then compared to rust ratings obtained on a reference 1 lubricant (GMR 6063) evaluated in the same laboratory. This reference lubricant is considered by industry to pro- Kqicegninimum acceptable performance for API Service The results of said Sequence H tests are set forth in Table D1 below.

Table III' 1960 OLDSMOBILE SEQUENCE II TEST RESULTS The data given in the above Table III show that lubricating oils containing the lead petroleum sulfonate additives of the invention provide a higher level of anti-rust protection than that provided by the reference lubricant.

The above pH values and total base number values (TBN) were determined in accordance with a modification of ASTM D664-58. In this modified test 2 grams of the lead petroleum sulfonate product additive are dissolved in 100 milliliters of a 50/50 mixture of benzene and isopropyl alcohol containing 0.5 volume percent water. The mixture is shaken Well and the pH determined using a standard pH meter. If the pH of the said mixture is above 4, the mixture is then titrated to a pH of 4 using standard 0.1 N HCl. From this titration TBN, or total base number, is calculated as follows:

where V=ml. of HCl, N=normality of HCl, and W=grams of sample. TBN is reported as mg. of KOH per gram of oil.

While certain embodiments of the invention have been described for illustrative purposes, the invention obviously is not limited thereto. Various other modifications will be apparent to those skilled in the art in view of this disclosure. Such modifications are within the spirit and scope of the invention.

I claim:

1. A process for producing a superior lead petroleum sulfonate, useful as an additive for lubricants, said additive having superior rust inhibiting properties as well as good detergent properties, which process comprises: sulfonating a petroleum hydrocarbon fraction having a viscosity within the range of 90 to 720 SUS at 210 F. and a viscosity index of at least about 85; neutralizing the reaction product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount suflicient to supply from 12 to 90 weight percent and said lead acetate being present in said mixture in an amount sufiicient to supply from 88 to' weight percent of the total amount of lead milliequivalents prescut; and recovering the resulting lead petroleum sulfonate.

2. A process according to claim 1 wherein said petro:

leum hydrocarbon fraction has a viscosity within the range of from 200 to 230 SUS at 210 F said lead oxide is present in an amount sufficient to supply from 20 to 88 weight percent and said lead acetate is present in an amount suflicient to supply from 80 to 12 weight percent of the total amount of lead milliequivalents present.

3. A process according to claim 2 wherein said lead oxide is present in an amount sufficient to supply from to 87 weight percent and said lead acetate is present in an amount sufiicient to supply from 50 to 13 weight percent of the total amount of lead milliequivalents present, and the total amount ofsaid lead milliequivalents is sufficient to supply at least about 1.13 milliequivalents of lead per milliequivalent of total acidity in said reaction product before neutralization thereof.

4. A process for producing a superior lead petroleum sulfonate additive for lubricants, said additive having superior rust inhibiting properties as well as good detergent properties, which process comprises: sulfonating a petroleum hydrocarbon fraction having a viscosity within the range of about 90 to about 720 SUS at 210 F. and a viscosity index of at least about 85; neutralizing the reaction product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount sufficient to supply from 12 to 90 weight percent and said lead acetate being present in said mixture in an amount sufiicient to supply from 88 to 10 weight percent of the total amount of lead milliequivalents present; and recovering a mixture of lead petroleum sulfonate and unsulfonated oil from said neutralized reaction product as said additive.

5. A process according to claim 4 wherein said petroleum hydrocarbon fraction has a viscosity within the range of from 200 to 230 SUS at 210 F., said lead oxide is present in an amount sufiicient to supply from 20 to 88 weight percent and said lead acetate is present in an amount suflicient to supply from to 12 weight percent of the total amount of lead milliequivalents present.

6. A process according to claim 5 wherein said lead oxide is present in an amount suflicient to supply from 50 to 87 weight percent and said lead acetate is present in an amount suflicient to supply from 50 to 13 weight percent of the total amount of lead milliequivalents present, and the total amount of said lead milliequivalents is suflicient to supply at least about 1.13 milliequivalents of lead per milliequivalent of total acidity in said reaction product before neutralization thereof.

7. A process for producing a superior lead petroleum sulfonate additive for lubricants, said additive having superior rust inhibiting properties as Well as good detergent properties, which process comprises: sulfonating one part by weight of a deasphalted and solvent extracted petroleum fraction having a viscosity within the range of from about 140 to about 720 SUS at 210 F., and a viscosity index of at least 85, with 'from about 0.02 to 0.2 part by weight of liquid S0 as liquid S0 dissolved in liquid S0 neutralizing the reaction product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount sufiicient to supply from 12 to 90 weight percent and said lead acetate being present in said mixture in an amount suflicient to supply from 88 to 10 percent of the total amount of lead milliequivalents present, and said total amount of lead milliequivalents being sufficient to supply at least about 1.13 milliequivalents of lead per milliequivalent of total acidity in said reaction product; and recovering a mixture of lead petroleum sulfonate and unsulfonated oil from said neutralized reaction product as said additive.

. 8. A process according to claim 7 wherein said petroleum fraction has a viscosity within the range of from about 200 to about 230 SUS at 210 F.

9. A process for producing a superior lead petroleum sulfonate additive for lubricants, said additive having superior rust inhibiting properties as well as good de tergent properties, which process comprises: intimately admixing one part by weight of a deasphalted and solvent extracted petroleum fraction having a viscosity within the range of from about to about 720 SUS at 210 F., and a viscosity index of at least about 85, with from about 0.02 to 0.2 part by weight of liquid S0 as liquid S0 dissolved in liquid S0 removing S0 diluent and any excess S0 from the resulting reaction mixture of sulfonic acids and unsulfonated oil; intimately admixing said diluent-free reaction mixture with hydrocarbon diluent, Water, lead oxide and lead acetate to neutralize same, said lead oxide being present in an amount sufiicient to supply from 12 to 90 weight percent and said lead acetate being present in an amount suflicient to supply from 88 to 10 weight percent of the total amount of lead milliequivalents present, and said total amount of lead milliequivalents being suflicient to supply at least about 1.13 milliequivalents of lead per milliequivalent of total acidity in said diluent free reaction mixture; heating said thus neutralized reaction mixture to remove substantially all of said water and at least a portion of said hydrocarbon diluent; diluting said dehydrated and neutralized reaction mixture with another portion of said hydrocarbon diluent and filtering same to remove inorganic solids; and removing hydrocarbon diluent from the resulting filtrate so as to recover a mixture of lead petroleum sulfonate and unsulfonated oil as said additive.

10. A process according to claim 9 wherein said petroleum fraction has a viscosity within the range of from about 200 to about 230 SUS at 210 F.

11. A lubricant additive comprising a mixture of lead petroleum sulfonate and the unsulfonated residual oil as- 11 i sociated therewith, said additive having superior rust inhibiting properties as well as good detergent properties, which mixture is obtained by: sulfonating a petroleum hydrocarbon fraction having a viscosity, within the range of about 90 to about 720 SUS at 210 F. and a viscosity index of at least about 85; neutralizing the reaction product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount sufl'lcient to supply from 12 to 90 weight percent and said lead acetate being present in said mixture inan amount suflicient to supply from 88 to 10 weight percent of the total amount of lead milliequivalents present; and recovering a mixture of lead petroleum sulfonate and unsulfonated oil from said neutralized reaction product as said additive.

12.,A lubricantadditive comprising a mixture of lead petroleum sulfonate and the unsulfonated residual oil associated therewith, which mixture is obtained by: sulfonating one part by weight of a deasphalted and solvent extracted petroleum fraction having a viscosity within the range of from about 140 to about 720 SUS at 210 F., and a viscosity index of, at least 85, with from about 0.02 to 0.2 part by weight of liquid. S as liquid S0 dissolved in liquid 50;; neutralizing the reaction product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount sufiicient to supply frorn'12 to 90 weight percent and said lead acetate being present in said mixture in an amount sufficient to supply from 88 to weight percent of the total amount of lead milliequivalents present, and said total amount of lead milliequivalents being suflicient to supply at least about 1.13 milliequivalents of lead per milliequivalent of total acidity in said reaction product; and recovering a mixture of lead petroleum sulfonate and unsulfonated oil from said neutralized reaction product as said additive.

13. A lubricating oil composition comprising a petroleum lubricating oil base stock containing from 0.2 to about 30 weight percent of a lead petroleum sulfonate additive having superior rust inhibiting properties as well as good detergent properties, said additive having been obtained by: sulfonating a petroleum hydrocarbon fraction having a viscosity Within the range of 90 to 720 SUS at 210 F. and a viscosity index of at least about 85; neutralizing the reaction product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount suflicient to supply from 12 to 90 weight percent and said lead acetate being present in said mixture in an amount sufiicient to supply from 88 to 10 weight percent of the total amount of lead milliequivalents present; and recovering the resulting lead petroleum sulfonate.

14. A lubricating oil composition comprising a petroleum lubricating oil base stock containing from about 2 to about 20 weight percent of a lead petroleum sulfonate additive having superior'rust inhibiting properties as well as good detergent properties, said additive having been obtained by: sulfonating a petroleum hydrocarbon fraction 12 having a viscosity within the range of about 90 to about 720 SUS at 210 F. and a viscosity index of at least about neutralizing the reaction productwith a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in an amount suflicient to supply from 12 to weight percent and said lead acetate being present in said mixture in an amount suflicient to supply from 88 to 10 weight percent of the total amount of lead milliequivalents present; and recovering a mixture of lead petroleum sultonate and unsulfonated oil from said neutralized reaction product as said additive.

15. 'A lubricating oil composition comprising a petroleum lubricating oil base stock containing from 0.2 to about 30 weight percent of a lead petroleum sulfonate additive having superior rust inhibiting properties as well as good detergent properties, said additive having been obtained by: sulfonating one part by weight of a de-- asphalted and solvent extracted petroleum fraction having a viscosity within the range of from about to about 720 SUS at 210 F., and a viscosity index of at least 85, with from about 0.02 to 0.2 part by weight of liquid S0 as liquid S0 dissolved in liquid S0 neutralizing the re.- action product with a mixture of lead oxide and lead acetate, said lead oxide being present in said mixture in i an amount suflicient to supply from 12 to 90 weight percent and said lead acetate being present in said mixture. in an amount sufficient to supply from 88 to 10 weight percent of the total amount of lead milliequivalents prescut, and said total'amount of lead milliequivalents being sufiicient to supply at least about 1.13 milliequivalents of lead per milliequivalent of total acidity in said reaction product; and recovering a mixture of lead petroleum sulcosity within the range of 90 to 720 SUS at 210 F. and a viscosity index of at least about 85; neutralizing the re-' 1 action product by simultaneously contacting same with both lead oxide and lead acetate, said oxide and said acetate being present during said contacting in amounts sufficient to supply from 12 to 90 and from 88 to 10 weight percent respectively of the total amount of lead milliequivalents present; and recovering the resulting lead petroleum sulfonate.

References Cited by the Examiner UNITED STATES PATENTS I 1,871,941 8/1932 Arveson 25233 2,501,732 3/1950 Mertes 25233 2,865,957 12/1958 Logan 260-435 X DANIEL E. WYMAN, Primary Examiner. C. F. DEES, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patnet N06 3, 277, 004 October 4, 1966 Sidney Schiff It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 10, line 31, before "percent" insert weight column 11, line 18, before "which" insert said additive having superior rust inhibiting properties as well as good detergent properties,

Signed and sealed this 5th day of September 1967.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents

Claims (1)

13. A LUBRICATING OIL COMPOSITION COMPRISING A PETROLEUM LUBRICATING OUL BASE STOCK CONTAINING FROM 0.2 TO ABOUT 30 WEIGHT PERCENT OF A LEAD PETROLEUM, SULFONATE ADDITIVE HAVING SUPERIOR RUST INHIBITING PROPERTIES AS WELL AS GOOD DETERGENT PROPERTIES, SAID ADDITIVE HAVING BEEN OBTAINED BY: SULFONATING A PETROLEUM HYDROCARBON FRACTION HAVING A VISCOSITY WITHIN THE RANGE OF 90 TO 720 SUS AT 210*F. AND A VISCOSITY INDEX OF AT LEAST ABOUT 85; NEUTRALIZING THE REACTION PRODUCT WITH A MIXTURE OF LEAD OXIDE AND LEAD ACETATE, SAID LEAD OXIDE BEING PRESENT IN SAID MIXTURE IN AN AMOUNT SUFFICIENT TO SUPPLY FROM 12 TO 90 WEIGHT PERCENT AND SAID LEAD ACETATE BEING PRESENT IN SAID MIXTURE IN AN AMOUNT SUFFFICIENT TO SUPPLY FROM 88 TO 1 WEIGHT PERCENT OF THE TOTAL AMOUNT OF LEAD MILLIEQUIVA LENTS PRESENT; AND RECOVERING THE RESULTING LEAD PETROLEUM SULFONATE.