US3223630A

US3223630A - Increasing the base number of calcium petroleum sulfonate

Info

Publication number: US3223630A
Application number: US143783A
Authority: US
Inventors: James T Gragson
Original assignee: Phillips Petroleum Co
Current assignee: Phillips Petroleum Co
Priority date: 1961-10-09
Filing date: 1961-10-09
Publication date: 1965-12-14
Anticipated expiration: 1982-12-14

Description

Dec. 14, 1965 J. T. GRAGSON 3,223,530

INCREASING THE BASE NUMBER OF CALCIUM PETROLEUM SULFONATE Filed Oct. 9, 1961 2 Sheets-Sheet 1 NEUTRALIZATION 25 22 23 26 4 -|STABILIZATION DRYING FILTRATIoN]- LIME METHANOL Mlxmcq-fi BLOWING I FLASH FILTRATION HIGH VISCOSITY so- 3 GEL I PREFERRED l l l l l l l l 1 I I20 I40 I50 CH3 OH F /6. 2 INVENTOR.

J.T. GRAGSON RW M A 7'7'ORNE VS Dec. 14, 1965 J. T. GRAGSON INCREASING THE BASE NUMBER OF CALCIUM PETROLEUM SULFONATE 2 Sheets-Sheet 2 Filed Oct. 9. 1961 310V u o u ioimmomzh mo 52;

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ATTORNEYS United States Patent G ice 3,223,630 INCREASING THE BASE NUMBER OF CALCIUM PETRULEUM SULFONATE James T. Gragson, Bartiesville, kla., assignor to Phillips Petroleum Company, a corporation of Delaware Filed Oct. 9, 1961, Ser. No. 143,783 3 Claims. (Cl. 252-33) This invention relates to increasing the base number of a calcium petroleum sulfonate. In one aspect the invention relates to a process for increasing the base number of a calcium sulfonate of a high viscosity paraffinic petroleum lubricating stock by contacting with a calcium compound produced by passing carbon dioxide through a mixture comprising methanol and calcium oxide or calcium hydroxide. In another aspect, this invention relates to an improved lubricant additive comprising an overbased calcium petroleum sulfonate produced by this process. In another aspect this invention relates to an improved lubricant containing this novel additive. In another aspect, this invention relates to means for producing an overbased calcium petroleum sulfonate.

Calcium petroleum sulfonates are widely used in the manufacture of additives for lubricating oil used in combustion engines. These materials impart detergency to lubricating oils and thus assist in keeping internal engine parts clean and reducing sludge formation in the oil. By increasing the alkaline reserve of the additive, equivalent detergency is obtained with a lower concentration of additive in the lubricating oil. Also, higher alkaline reserve neutralizes larger quantities of acidic combustion products which accumulate in the oil.

A recently developed detergent additive is produced by the novel process described in copending application Serial No. 665,985, Whitney et al., filed June 17, 1957. This additive, which comprises a calcium petroleum sulfonate, not only gives excellent results in increasing the detergency of lubricating oils and reducing sludge formation, but also has quite adequate alkaline reserve for many applications. However, for some uses, for example under conditions such that large quantities of acids are formed, as in diesel engines burning high sulfur fuels, it is desirable to increase the alkaline reserve of this detergent additive. Previously known processes for overbasing lubricating oil additives, specifically those processes for overbasing metal sulfonates of mahogany acids, have not proved to be applicable to the Whitney et al. developed additives.

It is an object of this invention to increase the base number of a calcium petroleum sulfonate.

Another object of this invention is to provide novel overbased calcium petroleum sulfonates.

Another object of this invention is to provide improved lubricants containing novel overbased calcium petroleum sulfonates.

Another object of this invention is to provide means for producing overbased calcium petroleum sulfonates.

Other aspects, objects and the advanatges of my invention are apparent in the written description, the drawing and the claims.

Alkaline reserve can be measured by base number, which is the number of milligrams of potassium hydroxide equivalent to the amount of acid required to neutralize the alkaline constituents present in one gram of sample. A compound having a base number higher than can be obtained from the calcium petroleum sulfonate alone is said to be overbased sometimes superbasic.

Petroleum sulfonic acid which is neutralized to form petroleum sulfonates normally includes appreciable amounts of various hydrocarbons not having the acid group so that when the sulfonate is formed, the resulting 3,223,630 Patented Dec. 14, 1965 product is a mixture of hydrocarbons and petroleum sulfonates. When the sulfonic acid is neutralized with an excess of CaO or Ca(OH) to form the sulfonate, the resulting product has a relatively small alkaline reserve. Addition of a large excess of neutralizing material normally does not materially increase the alkaline reserve beyond this point, since the excess material is removed, for example by filtration, prior to the use of the sulfonate in a lubricant.

According to my invention, the alkaline reserve of the Whitney et al. additives is increased by contacting either the unneutralized sulfonic acid or the calcium petroleum sulfonate with a calcium containing material produced by passing carbon dioxide through a mixture comprising methanol and lime (CaO and/or Ca(OH) either by adding the previously produced calcium material to the sulfonated petroleum material, or by producing the calcium material in the presence of the sulfonated petroleum material.

In the drawing, FIGURE 1 is a schematic representation of the process steps and apparatus.

FIGURE 2 is a curve illustrating the relationship of the amounts of Ca(OH) and CH OH to various characteristics of the product.

FIGURE 3 is a curve illustrating the effect of water.

In producing the sulfonated petroleum material of this invention, the base stock is selected from highly paraflinic, deasphalted and solvent-refined petroleum fractions having a viscosity of about 180 to 230 SUS at 210 F. and having a viscosity index of at least about 85. A preferred material is a propane fractionated, solvent-extracted and dewaxed Midcontinent oil of about 200 to 215 SUS at 210 F. and having a viscosity index of about to 100 or higher. The residual material from the propane fractionation contains the rejected asphalt and aromatic oils. Following the propane fractionation step the overhead oil fraction is solvent-extracted to remove additional aromatic hydrocarbons.

These oils are contacted with sulfonating agents such as fuming sulfuric acid, chlorosulfonic acid and sulfur trioxide, a particularly preferred sulfonating agent being a solution of sulfur trioxide in liquid sulfur dioxide. The petroleum stocks are contacted with the sulfonating agents at a temperature of from about 50 to 200 F., preferably from 80 to 150 F., for about 1 to minutes. The ratio of sulfonating agent to oil can vary considerably, but generally is within the range of from about 0.1:1 to 1:1 on a weight basis, the sulfonating agent being calculated as 20 percent fuming sulfuric acid or equivalent.

The eflluent from the sulfonation step is a petroleum sulfonic acid and this material is converted to an overbased calcium petroleum sulfonate. In one method, the petroleum sulfonic acid is contacted with an aqueous slurry of lime. Preferably, the petroleum sulfonic acid mixture has been flashed to remove S0 which can be recycled, and also diluted with a hydrocarbon such as naphtha. Sufficient lime is employed to neutralize the sulfonic acid present. The resulting solution of calcium petroleum sulfonate is then stabilized by heating under pressure, as for example 350 to 400 F. at 150 to 250 p.s.i.g. The water is removed from the stabilized solution by such methods as evaporation. The solution of calcium petroleum sulfonate can be overbased by contact with a previously prepared carbonated calcium compound or by carbonation in situ.

When the calcium material is prepared prior to contacting the sulfonated material, the process comprises slurrying either calcium oxide or calcium hydroxide in methanol. The amount of calcium compound which is employed is within the range between 2 and 20 grams of the calcium compound per milliliters of methanol. This slurry is then treated with carbon dioxide in an amount sufiicient to furnish from about 0.5 to about 5.0 grams of carbon dioxide per gram of calcium compound present in the slurry. A most convenient way for treating the slurry is to bubble CO into it. The slurry treating step can be conveniently carried out at temperatures ranging from to 125 F. Higher temperatures cause excessive loss of methanol by evaporation, so if it is desired to employ higher temperatures, supenatmospheric pressure should be used. The amount of calcium compound which is added to the solution of calcium petroleum sulfonate can vary considerably but generally is within the range suflicient to supply calcium in an amount equal to that present in from 0.02 to 0.8 gram of calcium oxide per gram of calcium petroleum sulfonate present. The treatment of the calcium petroleum sulfonate solution with the slurry can be carried out under such conditions that small amounts of Water are present. Following the contacting of the sulfonate solution with the calcium compound slurry, the methanol is removed by flashing or equivalent procedure. At this point, it is preferred to have the mixture diluted with a diluent such as naphtha, following which the entire stream is filtered to remove solids. The resulting solution is then subjected to fractionation to remove naphtha diluent, thus yielding as a final product an over-based calcium petroleum sulfonate. The excess of base present in this over-based sulfonate apparently is in the form of very finely divided solid calcium compound, particles sufliciently fine that they pass through a one micron filter, and are not visible to the naked eye. Photomicrographs of the over-based sulfonate indicate that the particle size of the suspended calcium compound is in the order of 100 A. The suspension is stable and does not change on standing.

It is also within the scope of this invention to treat the filtered calcium petroleum sulfon'ate product with a slurry of calcium compound in methanol, and when such a process is employed, methanol is tripped from the final product.

In a further embodiment of this invention, the slurry of calcium compound in methanol is used to supply all of the calcium to the process. Thus, the amount of calcium compound in methanol should be suflicient to neutralize the sulfonic acid product from the sulfonation step and to supply the over-base in amounts previously set forth hereinabove.

In a preferred embodiment of my invention the methanol and calcium oxide or calcium hydroxide are added to the neutralized sulfonated petroleum material prior to treatment with carbon dioxide. In this system atmospheric pressure and room temperature have proven to be entirely satisfactory. No apparent benefit with respect to base number is obtained by operating at elevated temperature and pressure. However, there are indications that higher temperatures during carbonation improves the filter rates of the superbased products. From an operating standpoint, some pressure above atmospheric often is desirable. In this respect pressures from 0500 p.s.i.g. or higher are suitable. Similarly temperature from 50 to 200 F. give satisfactory results.'

This embodiment is illustrated in the drawing wherein the selected petroleum stock is introduced to sulfonation zone through conduit 11. A sulfonating agent such as sulfur trioxide dissolved in sulfur dioxide is introduced to sulfonation zone 10 through conduit 12. The reaction products are transported through conduit 13 to dash zone 14 wherein sulfur dioxide is removed through conduit 15. The remaining reaction product passes through conduit 16 to neutralization zone 17 wherein it is diluted with a hydrocarbon solvent such as naphtha introduced through conduit 18 and is neutralized by a slurry of metal hydroxide such as an aqueous slurry of lime, introduced through conduit 19. The resulting substantially neutralized slurry of calcium sulfate and calcium hydroxide in water and of diluted sulfonation reaction efiluent is passed through conduit 20 to stabilization zone 21 wherein the reaction product is maintained in the presence of the metal hydroxide at elevated temperature and elevated pressure so that the base number of the sulfonate is raised as high as possible by this action. The stabilized material then proceeds through conduit 22 into drying zone 23, in which step substantially all of the water is removed through conduit 24. The stabilized and dehydrated reaction product is passed through conduit 26.

In a preferred process, filtration zone 27 is eliminated and this is illustrated in the drawing by the inclusion of conduit 44 having a valve 43 therein. Conduit 44 connects conduit 26 with conduit 29 thus bypassing the filtration zone 27. In this manner excess lime present in the effiuent from drying zone 23 is retained whereby the amount of lime introduced through conduit 31 can be reduced or, in some cases, eliminated entirely.

When it is desired to include a filtration step at this point the product is passed through conduit 26 to filtration zone 27, valve 43 being closed and valve 45 open. It is desirable in most instances to add a solvent such as naphtha to conduit 26 to facilitate the filtration step. A solids-containing stream is removed through conduit 28 while the filtrate comprising the metal petroleum sulfonate continues through conduit 29 into mixing zone 30 wherein any needed lime is added through conduit 31 while methanol is added in conduit 32. The mixture then passes through conduit 33 into blowing zone 34 where it is cont-acted with carbon dioxide which is introduced through conduit 35 and bubbled through the mixture. The CO treated material is passed to flash zone 37 from which methanol is removed through conduit 3.8. The residue is conducted through conduit 39 to filtration zone 40 from Which a solids-containing stream is removed through conduit 41 while the product continues for further treatment through conduit 42.

One substantial advantage of a process wherein the lime and methanol are contacted with carbon dioxide in the presence of the sulfonated material is that a major portion of the methanol required for the preparation of the slurry for prior carbon dioxide treatment can be eliminated. The limiting factor on the amount of methanol used in a process utilizing prior treatment is th amount necessary to form the slurry of the lime and is a considerably greater amount than that required to produce the desired alkaline reserve increase. Conversely, when the carbon dioxide treatment is carried out in the presence of the sulfonated material only that amount of methanol necessary to produce the desired alkaline reserve increase need be used.

In this process, the minimum amount of lime used is limited by the amount necessary to give the desired base number. Expressed as equivalent CaO, the minimum amount which will generally be used in the practice of my invention is about two parts by weight per 100 parts by weight of calcium petroleum sulfonate (about 2.6 parts expressed as Ca(OH) The maximum amount of lime is limited by the formation of a gel which makes further processing of the material impossible. This occurs when the .amount of lime expressed as Oa(OH) reaches a value determined by the equation Oa(OH) and CH OH being expressed as parts by weight per 100 parts of calcium petroleum sulfonate and hydrocarbon solvent mixture. The maximum amount of lime also is limited by the viscosity of the mixture, an amount greater than parts by weight of Ca(OH) per parts by weight of calcium petroleum sulfonate and hydrocarbon solvent mixture increasing the viscosity to a point at which further processing is not practical. When the material-being treated is a petroleum sulfonic acid,

the above amount of lime is in addition to the amount necessary for neutralization.

As noted above, when the overbasing is accomplished by adding a lime-methanol slurry to the calcium petroleum sulfonate with subsequent carbonation, sufficient alcohol is necessary to form a slurry which can be handled practically. This is somewhat less than the amount required when carbonation is accomplished prior to addition but is a very large amount as compared with the amount required when the separate ingredients are added to the calcium petroleum sulfonate-hydrocarbon solvent mixture. In this type of operation, the minimum amount is determined by the amount required in conjunction with the lime to give the desired base number. The minimum generally used is about parts by weight per 100 parts by weight of calcium petroleum. sulfonate. Within practical operating limits, the maximum amount of methanol permissible is limited by the formation of a gel, as described above in the discussion of the amount of calcium compound. The same equation expressed as an amount of methanol is The upper limit for methanol is determined by practical, economic consideraitons. Generally I prefer not to exceed about 150 parts by weight per 100 parts by weight of calcium petroleum sulfonate, hydrocarbon solvent mixture.

The preferred range for the lime is from 3 parts by weight of CaO (4 parts by weight Ca(OI-I) per 100 parts by weight of calcium petroleum sulfonate to 70 parts by weight of CaO per 100 parts by weight of calcium petroleum sulfonate. The preferred range for methanol is from 12 parts by weight of methanol per 100 parts by weight of calcium petroleum sulfonate to 100 parts by weight of methanol per 100 parts of calcium petroleum sulfonate.

The over-based calcium petroleum sulfonates of this invention have wide utility. It is advantageous to employ these materials in the preparation of lubricating oils for internal combustion engines, particularly engines which are operating under conditions which produce high quantities of acids and sludge.

EXAMPLES The following specific examples illustrate the advantages of the process and products of this invention. In all instances the oil which was sulfonated was a propane fractionated, phenol extracted and dewaxed Mid-Continent lubricating oil fraction of about 203 SUS viscosity at 210 F. and a viscosity index of about 93. This charge stock was sulfonated with a solution of about 10 weight percent S0 in liquid S0 at 110 F. for about 10 minutes. The S0 to oil weight ratio was about 0.08 to 1. The sulfonation efiluent was flashed to remove S0 leaving a solution of about 48 weight percent petroleum sulfonic acid in unsulfonated oil. This mixture was then diluted with Stoddard solvent, a petroleum naphtha, and neutralized by addition of an aqueous slurry of calcium hydroxide more than chemically equivalent to the sulfonic acid present. This mixture was stabilized by heating, followed by drying in a flash tower. The product recovered at this point is termed dryer tower bottoms and contains 19-20 weight percent each of calcium petroleum sulfonate and unsulfonated oil, and about 0.76 weight percent Ca(OH) about 0.24 weight percent water; and the remainder is Stoddard solvent. The dryer tower bottoms are diluted wtih additional Stoddard solvent and filtered to remove the solids. The Stoddard solvent is then removed to produce a concentrate which is substantially 50 weight percent calcium petroleum sulfonate and 50 weight percent unsulfonated oil, this product being referred to as the additive concentrate in the subsequent examples, and has a base number of about 7 .5.

6 EXAMPLE 1 A series of runs were carried out in which the additive concentrate was treated with a slurry of a calcium compound in methanol.

In the run 1, a slurry of 15 grams of calcium oxide in 125 grams of methanol was warmed slightly and blown with an excess of carbon dioxide, the resulting slurry was diluted with additional methanol and added to 51.5 grams of additive concentrate and a hydrocarbon. The mixture contained 50.8 percent by weight of the concentrate, while the hydrocarbon diluent which was used was a 32- 33 API gravity hydrocarbon which had been solvent refined and dewaxed. This hydrocarbon, a lubricating oil fraction, had an SUS viscosity at 100 F. of about 96-98, an SUS viscosity at 210 F. of approximately 39 and a viscosity index of about 105. The mixture was heated to expel the methanol, following which 10 ml. of water was added. This resulting mixture was then heated to 260 F. to drive off the water, diluted with benzene and filtered through Celite (diatomaceous earth). The filtrate was then heated to strip off the benzene. The base number of the product mixture was 112, and the sulfated ash was 14.42 percent by weight, The base number of the concentrate in the blend was 221, and the ash of this product was 28.4 weight percent.

In run 2, a slurry of 5.0 grams of calcium oxide in 40 ml. of isopropyl alcohol was warmed gently and blown with an excess of carbon dioxide. This material was added to 30.8 grams of a 1:1 mixture of the additive concentrate with the hydrocarbon described in run 1. The mixture was heated to 300 F., diluted with benzene and filtered through diatomaceous earth. After stripping the benzene from the filtrate, the product had a base number of 3.9. This is essentially no increase over the approximately 3.75 base number of the starting concentrate, and demonstrates that isopropyl alcohol is inoperable in my invention.

In run 3, a slurry of 5.0 grams of calcium oxide in 40 ml. methanol was warmed gently and blown with excess carbon dioxide. The resulting gel was thinned with methanol and mixed with 13.3 grams of the petroleum sulfonic acid solution from the sulfonation step described above, which had not been neutralized with lime. The methanol was stripped off by heating, and benzene added, the mixture filtered, and the benzene stripped oif. The product had a base number of 90.4. This run shows that the slurry of calcium compound in methanol can be employed both for neutralization and supply of overbase to the sulfonate.

In run 4, a slurry of 10 grams of calcium oxide in 100 ml. methanol was blown with 15 grams of carbon dioxide. The resulting slurry was added to 250 grams of a 20 percent by weight solution of the additive concentrate in the lube oil stock described in Example I. As in the preceding runs, the additive concentrate, before treatment with slurry, had a base number of about 7.5. The methanol was stripped off by heating to 300 F the material diluted with benzene, the mixture filtered'through Celite, and the benzene stripped off. The product had a base number of 70.3.

In run 5, a slurry of 10.0 grams of calcium oxide in 100 ml. of methanol was cooled in an ice bath (approximately 32 F.) and blown with 21 grams of carbon dioxide. The mixture was filtered and added to 100 grams of a 1:1 mixture of the additive concentrate in the lube oil stock of run 1. The methanol was stripped from the resulting mixture, and after filtration, the product had a base number of 14.3. This run demonstrates that the treatment of the slurry of calcium compound in methanol with CO can be carried out at low temperatures.

In run 6, a slurry of 6.0 grams of calcium hydroxide in ml. methanol was blown with 15 grams of carbon dioxide. The resulting mixture was filtered and the filtrate was added to 53 grams of the 1:1 mixture of concentrate and hydrocarbon described in run 5. The methanol was then stripped oif by heating to 310 F. The base number of the mixture was 24.5, This run demonstrates that calcium hydroxide can be used as the calcium compound in the methanol slurry.

In run 7, a slurry of 6.0 grams of calcium oxide in 50 ml. of absolute ethanol was blown with 12 grams of carbon dioxide. This mixture was filtered, and the filtrate added to 42.6 grams of the 1:1 cncentrate:hydr0carbon mixture of runs 5 and 6. After stripping off the ethanol, it was determined that the base number of the product was 4.0. This represents an increase of only approximately 0.25 in base number, and demonstrates that ethanol is inoperable in the process of this invention.

In run 8, a slurry of 6.0 grams of magnesium hydroxide in 60 ml. methanol was blown with 20 grams of carbon dioxide. The material was filtered, and the filtrate was added to 60 grams of the 1:1 mixture of concentrate and hydrocarbon of nms 5, 6 and 7. After stripping off the methanol, it was determined that the product had a base number of 4.3. This represents an increase of only approximately 0.5 in base number and demonstrates that magnesium hydroxide is not operable in the present invention.

EXAMPLE II Three runs were carried out on a pilot plant scale in which the additive concentrate was over-based by treatment with a slurry of calcium compound in methanol. In each of the first two runs, 20 pounds of calcium oxide was slurried in 200 pounds of methyl alcohol, and 11.45 pounds of CO was bubbled into the slurry. Temperature of the slurry rose from approximately 70 F. to 95 F. during the treatment. In each of these two runs, the alcohol slurry was added to 200 pounds of a 50-50 mix ture of a lube stock identical to run 1 of Example I and the additive concentrate which had a base number of 7.5. The resulting mixture was pumped through a drier (feed temperature 104 F., bottom temperature 250 F. and overhead temperature 230 F.). The methanol was thus distilled off overhead. Sufficient naphtha was then added to the mixture to adjust the refractive index at 75 F. to 1.4230, following which the resulting mixture was filtered at about 100 F. through a rotary filter which had been precoated with diatomaceous earth. The naphtha was then stripped off the filtrate by vacuum distillation at 350 to 365 F. at 28 inches vacuum. The properties of the resulting product are tabulated below.

In another run, 10 pounds of calcium oxide was slurried in 100 pounds of methanol and 5 pounds of CO bubbled through the mixture. During the CO addition, the temperature was maintained at 80 F. The resulting slurry was added to a mixture of 100 pounds of the additive concentrate in 100 pounds of naphtha. The mixture was then dried as described in the two runs above, following which it was diluted with naphtha to a refractive index at 75 F. of 1.4370. Filtration and stripping, carried out as described above, and the properties of the product were as follows:

Base number 74.5 Ash Wt. percent 12.6 Solids obtained by centrifuging do 0.03 Flash temperature F. 385

The following examples, III to VI, demonstrate the usefulness of the overbased additive concentrate of my invention as a lubricant additive.

8 EXAMPLE III A test was carried out in which an oil containing overbased additive concentrate was employed for the lubrication of a diesel engine burning a fuel of high sulfur content.

In this run, the oil contained the following ingredients:

Ingredient Weight percent SAE 10 stock 3.8 SAE 20 stock 63.4 SAE 50 stock 28.0 Overbased additive concentrate 3.8 Commercial corrosion inhibitor 0.9 Commercial pourpoint depressant 0.1

lrepared by the method of Example II of the disclosure and having a base number of 67.

*Zinc dithiophosphate, purchased under the tradename of Lubrizol 1360.

* Sold under the tradename of Santopour C.

The total base number of the above blend was 2.72.

A diesel engine, burning a fuel containing 1 percent by weight sulfur, was lubricated with the above blend during a total running time of hours. The top groove carbon rating was 97, and the lacquer rating was 99.8.

The above test was a 120 hour diesel L1 test and was carried out according to the procedure described in Example VII on application Serial Number 665,985.

EXAMPLE IV In another test, alubricant was formulated containing a blend of additive concentrate which had not been overbased and additive concentrate which had been overbased by the process of this invention. This lubricant was used in a diesel engine under the L1545 military test conditions, using a fuel containing 1 percent by weigh-t sulfur and was run for 120 hours.

Blend composition Weight percent SAE 10 base oil 4.76 SAE 20 base oil 67.92

SAE 50 base oil 22.0 Additive concentrate 2.16 Overbased additive concentrate 2.16 Lubrizol 1360 0.9 Santopour C 0.1

*This concentrate had a base number of 7.4 and analysis showed 49, 3 Weight percent sulfonate, 001 Weight percent solids obtained by centrifuging, 0 percent water, 4.8 weight percent ash, and had a viscosity of 16 1 1 SUS at 210 F. The PJM- flash point was 490 1*.

**Prepared by method of Example II and having a base number of 98.

At the end of the 120 hour test, the top groove carbon rating was 100, and the lacquer rating was 99.9.

EXAMPLE V In still another 120 hour L-1 diesel test, the following lubricant formulation was used:

' Properties sulfonate content, weight percent Ash, Weight percent Total base number Solids obtained by centrifuging, weight percent 0.02 Water, weight percent Nil SU S viscosity 210 F. 2233 RM. flash point, F. 455

2 Prepared by the method of Example II and having a base number of 98.

Acryloid 703, a clear viscous concentrate of a methacrylic polymer in Mid-Continent solvent refined SU=S/ 100 F. neutral oil. This product is manufactured and sold by Rohm and Haas Company.

4 Lubrizol 1360 (see Example IIII) 9 The above formulated lubricant was an SAE lW30 grade motor oil. The results of the L1 test were: Top groove carbon rating99, lacquer rating-99.9, and no deposits below the top groove.

EXAMPLE VI An SAE l0W-30 motor coil was formulated containing Overbased additive concentrate, prepared by, the method of this invention and tested in a 1959 Cadillac engine for surface ignition count and octane requirement.

Lubricant formulation *Soe footnote 1, Example V.

ee footnote 2, Example V. "-====DC200, a polydimethylsiloxane ta. LG... I. t...

having a viscosity of 100 to 1000 centistokes at 25 C.

The surface ignition counts per hour obtained from -12 second wide open throttle acceleration were 74. The final octane requirement was 97.0.

EXAMPLE VII Example VII illustrates the process for producing an Overbased metal petroleum sulfonate by mixing the sulfonate with a slurry of calcium oxide or calcium hydroxide in methanol, followed by bubbling with CO Two hundred pounds of dryer tower bottoms was mixed with 20 pounds of methanol and pounds of Ca(OH) The resulting mixture was carbonated with CO using an excess of CO over and above that required for stoichiometric reaction with the Ca(OH) This carbonation step was carried out at' room temperature (approximately 75 F.). After carbonation, the mixture was filtered, and an Overbased calcium petroleum sulfonate having a base number of 100 was recovered.

EXAMPLE VIII Example VIII illustrates a preferred process for producing an Overbased metal petroleum sulfonate according to my invention by adding methanol and calcium oxide or hydroxide, to the sulfonate, followed by bubbling with C0 (1) 100 grams of dryer tower bottoms and 10 g. of Ca(OH) were mixed well, 20 g. of CH OH was added and stirred. CO from a Dry Ice generator was passed into the mixture for 20 minutes. After this time the mixwas heated to 280 F. to remove alcohol, diluted with a volume of naphtha, filtered through Celite and the filtrate stripped of naphtha. The base number of the product was 183.

(2) Twenty-five g. of lime [Ca(OH) was mixed with 100 g. of dryer tower bottoms and 10 g. of CH OH and bubbled with C0 The product filtered well and had a base number of 242.

(3) Ten g. of Ca(OH) was mixed in 100 g. dryer tower bottoms and 5 g. of CH OH. The mix was carbonated for 20 minutes, stripped of alcohol, filtered, etc. The material had a base number of 104.

(4) A pilot plant run was made in which 20 lbs. of lime was added to 100 pounds of additive concentrate 10 and pounds of naphtha. Twenty pounds of methanol was added, mixed well and carbonated with a total of 26.5 pounds of C0 The material was stripped of alcohol, diluted, filtered and stripped of naphtha. The product had a base number of (5) Twenty-five g. Ca(OI-I) were added to 100 g. dryer tower bottoms and 40 g. isopropyl alcohol and 2 g. water added. This mixture was bubbled with CO diluted with naphtha, filtered and stripped. The base numher was 22.6.

(6) Run 5 was repeated using methanol rather than isopropanol. The base number was 203.

EXAMPLE IX The following runs demonstrate the necessity for a minimum amount of alcohol.

In the following run, Ca(OH) was mixed with 100 grams of dryer tower bottoms, methanol added and the mixture bubbled with CO the resultant product diluted with naphtha, filtered and stripped.

Oa(OH) CHsOH, Base grams grams Number Substantially unchanged.

EXAMPLE X CHaOH Gel Grams Ca(0 H) 2 Grams EXAMPLE XI The amount of water which can be used is related to the amount of calcium compound present, an amount too small or too large reducing the base number increase obtained. This is illustrated in FIGURE 3 in which base number is plotted against the amount of free and combined water present in the mixture expressed as a percentage of the water needed to convert an amount of calcium oxide chemically equivalent to the lime present to calcium hydroxide.

1 1 The curves of FIGURE 3 were made from data in the following table.

Runs 1 and 2 were made by charging to a vessel 80 grams of a 50-50 mixture of additive concentrate and an SAE oil, adding grams of CH OH to which was added 0.65 gram water (run 1) and 1.6 gram water (run 2) following which 8 grams of CaO was added.The resulting mixture was carbonated for minutes, the methanol stripped off, the mixture diluted with benzene and filtered. After stripping the benzene diluent, the base numbers were determined and corrected for the amount of SAE 10 oil present. Runs 38 were made with 100 gram samples of dryer tower bottoms. The samples were prepared with 8.15 grams CaO (or corresponding Ca(OH) O), methanol and the amount of water indicated, including both free Water and the chemically combined water in the Ca(OH) in the charge. Following carbonation for 20 minutes, dilution, filtration and stripping, the base numbers were obtained and corrected for the amount of material other than additive concentrate. Run 9 was made by blowing a slurry of 5.0 grams of calcium oxide in ml. methanol with an excess of carbon dioxide and adding it to a mixture of 24.2 grams unneutralized sulfonic acid solution described in Run 3 of Example I and 20 ml. water. The resulting mixture was heated to 420 F., dissolved in benzene, filtered and stripped of benzene. The base number corrected for the amount of material other than additive concentrate was 4.58. From these data it has been determined that the amount of Water should be in the range of 50 to 1000 percent of the theoretical amount to convert CaO to Ca(OH) preferably 100 to 175 percent, but should not exceed about 25 weight percent of the total mixture being treated,

EXAMPLE XII The amount of alcohol required to give a slurry with Ca(OH) was determined as follows: 10 grams Ca(OH) was weighed into a beaker and one gram increment of CH OH added:

3-4 grams CH OHSample pasty 8 grams CH OHSample smooth paste 11 grams CH OH-Sample viscous fluid 12 grams CH OHSample pumpable 115 grams CH OHSample very fluid EXAMPLE XIII Although in all instances, it is necessary that methanol be present to overbase the particular sulfonated petroleum compositions according to my invention, the addition of n-octanol permits even higher base numbers to be obtained. N-octanol alone is inoperative. When n-octanol is used it is ordinarily employed in an amount less than the amount of the methanol but amounts to at least one weight percent of the total of the alcohols. The preferred range for the n-octanol is between two and 50 weight percent, based on the total alcohol present. In the following examples, in all cases, a blend of 25 grams of additive concentrate and 25 grams of refined SAE 10 lubricating oil was mixed with Ca(-OH) and methanol and/ or n-octanol in the amounts indicated, carbonated by bubbling with carbon dioxide, dried, filtered and stripped and the base number determined.

Oa(OII)2, CHaOH, CH;(OH2)u Total grams grams CHzOH, B ase grams Number Octylpheuoxyethanol, 5 grams, added.

Reasonable variation and modification are possible within the scope of my invention which sets forth novel lubricants and lubricant additives and a process for producing overbased calcium petroleum sulfonates from high viscosity paraffinic petroleum lubricating stock.

I claim:

1. A process for producing a lubricant additive which comprises passing carbon dioxide through a mixture consisting essentially of a calcium petroleum sulfonate made from a highly parafi'inic, deasphalted and solvent refined petroleum fraction having a viscosity of 180 to 230 SUS at 210 F. and having a viscosity index of at least about 85, a compound selected from the group consisting of calcium oxide and calcium hydroxide in an amount based on equivalent calcium oxide in the range of 2 g. calcium oxide .per 100 g. sulfonate to g. calcium oxide per g. of mixture, water in the range of 50 to 1,000 percent of r the theoretical amount necessary to convert all of the calcium compound expressed as calcium oxide to calcium hydroxide, methanol in the range of 10 g. per 100 g. of sulfonate to g. per 100 g. of mixture, and n-octanol in the range of 2 to 50 weight percent of the total alcohol present, the maximum amount of calcium compound and methanol being further limited according to the equation 350 OH OH37 wherein the amounts are parts by weight per 100 parts of mixture.

2. A process for producing a lubricant additive which comprises passing carbon dioxide through a mixture consisting essentially of a calcium petroleum sulfonate made from a highly parafiinic, deasphalted and solvent refined petroleum fraction having a viscosity of about 180 to 230 SUS at 210 F. and having a viscosity index of at least about 85, a compound selected from the group consisting of calcium oxide, calcium hydroxide in an amount based on equivalent oxide in the range of 3 g. per 100 g. of sulfonate to 70 g. per 100 g. of sulfonate, water in the range of 100 to percent of the theoretical amount necessary to convert all the calcium compound expressed as equivalent calcium oxide to calcium hydroxide, methanol in the range of 12 g. per 100 g. sulfonate to 100 g. per 100 g. of sulfonate, and n-octanol in the range of 2 to 50 weight percent of the total alcohol present, the maximum amount of calcium compound and methanol being further limited according to the equation 350 CH O H37 wherein the amounts are parts by weight per 100 parts of mixture.

3. A process for producing a lubricant additive which comprises contacting carbon dioxide with a mixture consisting essentially of a calcium petroleum sulfonate made from a highly paraflinic, deasphalted and solvent refined petroleum fraction having a viscosity of 180 to 230 SUS at 210 F. and having a viscosity index of at least about 85, a compound selected from the group consisting of calcium oxide and calcium hydroxide in an amount based on equivalent calcium oxide in the range of 2 g. calcium oxide per 100 g. sulfonate to 80 g. calcium oxide per 100 g. of mixture, water in the range of 50 to 1,000 percent of the theoretical amount necessary to convert all of the calcium compound expressed as calcium oxide to calcium hydroxide, methanol in the range of 10 g. per 100 g. of sulfonate to 150 g. per 100 g. of mixture, an n-octanol in the range of 2 to 50 weight percent of the total alcohol present, the maximum amount of calcium compound and methanol being further limited according to the equation wherein the amounts are parts by Weight per 100 parts of mixture.

References Cited by the Examiner UNITED STATES PATENTS 2,845,393 7/1958 Varvel 25233 2,848,415 8/19158 Logan 25233 2,884,445 4/1959 Axe et a1. 252-33 2,947,694 8/1960 Gragson 252-33 2,956,018 10/1960 Carlyle et a1 25218 3,007,868 11/1961 Eck et al 25233 3,027,325 3/1962 MCMillen et a1 25233 FOREIGN PATENTS 209,175 7/ 1957 Australia.

DANIEL E. WYMAN, Primary Examiner.

JOSEPH R. LIBERMAN, ALPHONSO D. SULLIVAN,

Examiners.

Claims

1. A PROCESS FOR PRODUCING A LUBRICANT ADDITIVE WHICH COMPRISES PASSING CARBON DIOXIDE THROUGH A MIXTURE CONSISTING ESSENTIALLY OF A CALCIUM PETROLEUM SULFONATE MADE FROM A HIGHLY PARAFFINIC, DEASPHALTED AND SOLVENT REFINED PETROLEUM FRACTION HAVING A VISCOSITY OF 180 TO 230 SUS AT 210*F. AND HAVING A VISCOSITY INDEX OF AT LEAST ABOUT 85, A COMPOUND SELECTED FROM THE GROUP CONSISTING OF CALCIUM OXIDE AND CALCIUM HYDROXIDE IN AN AMOUNT BASED ON EQUIVALENT CALCIUM OXIDE IN THE RANGE OF 2 G. CALCIUM OXIDE PER 100 G. SULFONATE TO 80 G. CALCIUM OXIDE PER 100 G. OF MIXTURE, WATER IN THE RANGE OF 50 TO 1,000 PERCENT OF THE THEORETICAL AMOUNT NECESSARY TO CONVERT ALL OF THE CALCIUM COMPOUND EXPRESSED AS CALCIUM OXIDE TO CALCIUM HYDROXIDE, METHANL IN THE RANGE OF 10 G. PER 100 G. OF SULFONATE TO 150 G. PER 100 G. OF MIXTURE, ADN N-OCTANOL IN THE RANGE OF 2 TO 50 WEIGHT PERCENT OF THE TOTAL ALCOHOL PRESENT, THE MAXIMUM AMOUNT OF CALCIUM COMPOUND AND METHANOL BEING FURTHER LIMITED ACCORDING TO THE EQUATION CA(OH)2 = (350/(CH3OH - 37)) + 8 WHEREIN THE AMOUNTS ARE PARTS BY WEIGHT PER 100 PARTS OF MIXTURE.