US3706632A - Manufacture of lube oil containing overbased sulfurized calcium alkylphenolate - Google Patents

Abstract

METHOD OF PREPARING A LUBRICATING OIL COMPOSITION CONTAINING A PARTIALLY HYDROLYZED OVERBASED SULFURIZED CALCIUM ALKYLPHENOLATE DETERGENT OF ANTIOXIDANT AND SKIN FORMING RESISTANT PROPERTIES AND OF REDUCED VISCOSITY AND IMPROVED FLTERABILITY COMPROSING FIRST CONTACTING A SULFURIZED NORMAL CALCIUM ALKYLPHENOLATE WITH A CALCIUM ALKOXYALKOXIDE WHILE SIMULTANEOUSLY BLOWING THE REACTION MIXTURE WITH NITROGEN GAS AT A RATE OF BETWEEN ABOUT 0.25 AND 0.6 S.C.F.H/GALLON OF REACTION MIXTURE, SUBSEQUENTLY STRIPPING THE REACTION MIXTURE WITH SAID GAS AT A RATE OF BETWEEN ABOUT 0.25 AND 0.6 S.C.F.H./GALLON OF RESULTANT MIXTURE AND THEN SECOND CONTACTING THE STRIPPED MIXTURE WITH WATER WHILE SIMULTANEOUSLY BLOWING DURING SAID SECOND CONTACTING THE STRIPPED MIXTURE WITH SAID GAS AT A RATE OF BETWEEN ABOUT 0.1 AND 0.2 S.C.F.H./GALLON OF STRIPPED MIXTURE.

Description

United States Patent O 3,706,632 MANUFACTURE OF LUBE 01L CONTAINING OVERBASED SULFURIZED CALCIUM ALKYL- PHENOLATE Frederic F. Day and George E. Emery, Port Arthur, Tex., and James G. Dadura, Fishkill, N.Y., assignors to Texaco Inc., New York, NY. No Drawing. Filed Oct. 19, 1970, Ser. No. 82,190 Int. Cl. C10m 1/38, 1/54 U.S. Cl. 25242.7 5 Claims ABSTRACT OF THE DISCLOSURE Method of preparing a lubricating oil composition containing a partially hydrolyzed overbased sulfurized calcium alkylphenolate detergent of antioxidant and skin forming resistant properties and of reduced viscosity and improved filterability comprising first contacting a sulfurized normal calcium alkylphenolate with a calcium alkoxyalkoxide while simultaneously blowing the reaction mixture with nitrogen gas at a rate of between about 0.25 and 0.6 s.c.f.h./gallon of reaction mixture, subsequently stripping the reaction mixture with said gas at a rate of between about 0.25 and 0.6 s.c.f.h./gallon of resultant mixture and then second contacting the stripped mixture with water while simultaneously blowing during said second contacting the stripped mixture with said gas at a rate of between about 0.1 and 0.2 s.c.f.h./gallon of stripped mixture.

BACKGROUND OF THE INVENTION It is well known that lubricating oils tend to deteriorate under the conditions of use in present day diesel and automotive engines with attendant formations of sludge, lacquer and resinous materials which adhere to the engine parts, particularly the engine rings, grooves and skirt, thereby lowering the operating efiiciency of the engine. To counteract the formation of these deposits, certain chemical additives have been found which when added to lubricating oils have the ability to keep the deposit forming materials suspended in oil so the engine is kept clean and in efiicient operating condition for extended periods of time. These agents are known in the art as detergents or dispersants. Metal organic compounds are particularly useful in this respect. These metal organic compounds are considered to be effective because they provide alkalinity to neutralize strong organic and inorganic acids and are capable of dispersing deposits and deposit precursors into the oil phase. Overbased sulfurized metal alkylphenolates have been found to be particularly effective dispersants in lubricating oils.

Hereinbefore and hereinafter, by the term overbased it is meant that the ratio of the number of equivalents of calcium moiety to the number of equivalents of phenol moiety is greater than 1, that is, the calcium metal ratio is greater than 1. In contrast, the equivalent ratio of calcium to phenol moiety in normal sulfurized calcium alkylphenolate is about 1:1, i.e., a calcium metal ratio of 1.

U.S. Pat. No. 3,474,035 describes a lubricating composition comprising a hydrocarbon oil of lubricating viscosity containing between about 0.1 and 90 wt. percent of a high temperature alkaline dispersant consisting of a novel partially hydrolyzed overbased sulfurized calcium alkylphenolate having antioxidant and resistant skin formation properties and which is not required to be in the carbonated form in order to promote a high degree of overbasing. Further, the procedure therefor is also set forth. Although the product of the patent is a superior lube oil additive, problems arose in its manufacture on a large scale (tons) commercial basis. Specifically, the patents procedure frequently produced a product of somewhat higher viscosity than desired for the particular run thus requiring cutting back the product with a low viscosity oil. Further, the filterability and solubility of the product was frequently less than satisfactory. Therefore, there was a need to produce a product of the type set forth in U.S. 3,474,035 but of a reduced viscosity and improved filterability and solubility.

SUMMARY OF INVENTION We have discovered and this constitutes our invention, a method of preparing a lubricating oil concentrate of partially hydrolyzed overbased sulfurized calcium alkylphenolate as described in U.S. 3,474,035 of reduced viscosity and improved filterability. More specifically, our method broadly comprises first contacting in hydrocarbon lube oil medium a sulfurized normal calcium alkylphenolate with a calcium alkoxyalkoxide while simultaneously blowing the reaction mixture with nitrogen gas at a rate of between about 0.25 and 0.6 s.c.f.h./gallon to form overbased sulfurized calcium alkylphenolate, stripping the overbased sulfurized calcium alkylphenolate reaction mixture with nitrogen gas at a rate of between about 0.25 and 0.6 s.c.f.h./gallon overbased mixture, subsequently contacting said stripped overbased calcium alkylphenolate with water while simultaneously blowing the resultant reaction mixture with said gas at a rate of between about 0.1 and 0.2 s.c.f.h./gallon of stripped mixture and recovering a lube oil concentrate of hydrolyzed sulfurized calcium alkylphenolate from the reaction mixture. A material aspect of the invention is the discovery that in order to obtain a product of reduced viscosity, nitrogen gas introduction is essential during overbasing, stripping and hydrolysis, and further, the introduction must be with in the prescribed gas rates. Operation outside said rates results in products'of substantially and undesirably increased viscosity.

DETAILED DESCRIPTION OF THE INVENTION Specifically, the lubricant composition of the method of the invention comprises first contacting in the presence of a lubricating oil, a sulfurized normal calcium alkylphenolate having a sulfur content between about 0.1 and 10 wt. percent which is characterized by the theoretical formula:

( -l-y/ Ca In the above formula R is a monovalent saturated aliphatic hydrocarbon radical (alkyl) of from 4 to 100 carbons, x is an average integer of from 1 to 4 and y is an average integer from to 10. It is to be noted x and y are defined as average integers since sulfurized normal calcium alkylphenolate is in essence a complex mixture of monosulfide and polysulfide or a mixture of polysulfides as theoretically defined. In any case, the R group is mainly in the para position with the sulfur mainly in the ortho position. Further, there is probably also a significant amount of covalent character to the calcium-oxygen bond.

The first contacting is conducted at a temperature between about 10 and 200 0., preferably between about 150 and 200 C. for a period of time, e.g., 0.001 to 10 or more hours, preferably between about 1 and hours, utilizing a mole ratio of normal sulfurized calcium alkylphenolate to alkoxide reactant between about 1:01 and 1:25, preferably between about 1:1 and 1:2.

The lubricating oil medium, advantageously constitutes between about and 90 wt. percent of the first reaction mixture, preferably between about 30 and 70 wt. percent, resulting in final lubricating oil concentrate product containing an overbased calcium concentrate of between about 10 and 90 wt. percent, preferably between about 30 and 70 wt. percent.

The nitrogen flow is introduced directly into the reaction mixture liquid, preferably by introducing into the bottom area of the reactor and passing through the liquid in upward flow and continually removing said gas from the upper region of the reactor system. Normally, the nitrogen exerts a positive pressure in the reactor system of between about 1 and 4 p.s.i.g.

Following said first contacting, the resultant mixture is stripped by continuing said nitrogen flow at a rate between about 0.25 and 0.6 s.c.f.h./gallon at a temperature between about 150 and 200 C. and permitting the volatile materials to be removed. The stripped first reaction mixture is then second contacted with water for a period of time, e.g., between about 0.1 and 10 hours, preferably between about 2 and 4 hours, at a temperature between about 10 and 250 C., preferably between about 150 and 200 C. utilizing a mole ratio of water to calcium alkoxide reactant of between about 100:1 and 0.211 while simultaneously blowing the reaction mixture with nitrogen gas at a rate of between about 0.1 and 0.2 s.c.f.h./ gallon, preferably between about 0.15 and 0.16 s.c.f.h./ gallon. The Water in the contacting may be either in its liquid or vapor form or mixtures thereof, and the contacting with water is continued until the overbased sulfurized calcium alkylphenolate is between about and 70% hydrolyzed.

The water introduction into the liquid reaction mixture is preferably introduced at the bottom of the reactor as steam and passed therethrough. At the completion of the hydrolysis step the residual unreacted water is desirably substantially removed from the final reaction mixture, e.g., by stripping with nitrogen gas, e.g., at a temperature between about 150 and 200 C. and at a rate of between about 0.25 and 0.60 s.c.f.h./gallon. The term at least a substantial removal of water is intended to denote removal of water to the extent that less than about 1 wt. percent water exists in the final reaction mixture.

The crude product may be further purified by standard means such as distilling any diluent and by-product such as alkoxyalkanol which is not removed during the excess water removal step and filtering the residue through a standard pressure filter plate at about 20 to 200 C. under between about 0.1 to 100 p.s.i. pressure utilizing a diatomaceous earth filter aid.

It is to be noted the extent of hydrolysis is dependent on time, temperature and reactant ratios, therefore, periodic sampling and analysis of the overhead and/or reaction mixture is necessary to determine the extent of hydrolysis. As a practical matter once the amount of hy- 4 drolysis is decided upon, the particular set of conditions to produce the desired degree of hydrolysis for a given reactor can be determined. After such a determination the need for periodic sampling becomes unnecessary.

In the foregoing procedure, it is theorized the calcium alkoxyalkoxide complexes with, or is dispersed by, the sulfurized normal calcium alkylphenolate and the water hydrolyzes a portion of the complex calcium alkoxyalkoxide moiety with about 50% hydrolysis of said moiety being optimum in respect to stability of the product at high metal ratios.

The following theoretical equations further describe the preparation of the hydrolyzed overbased sulfurized calcium alkylpheuolate component of the compositions of the invention. It is to be noted Q below is theorized as sulfurized normal calcium alkylpheuolate as heretofore defined.

In the foregoing equations R' and A are as heretofore defined, n is an average integer from about 0.2 to 1.4 and m is an average integer from 0.1 to 2.5. Under preferred circumstances It is an average integer between about 0.8 and 1.2.

In the foregoing procedure as herefore stated a material aspect in respect to obtaining a product of reduced viscosity is the rate of blowing with inert gas during overbasing, stripping of the overbased mixture and during hydrolysis. Rates employed outside these ranges result in a product of substantially increased viscosity. In regard to the unexpected importance of the use of nitrogen and the rate of introduction thereof, it is theorized that the nitrogen gas coupled with its rate of introduction has a direct effect on particle size of the formed hydrolyzed overbased sulfurized calcium alkylpheuolate. One explanation is a rate higher than the maximum allowed produces particles so fine that they are inadequately coated and they agglomerate resulting in a too viscous product of reduced filterability and also a product which has poor solubility even upon filtration and oil dilution. It is further theorized when the nitrogen gas rate is below the minimum set forth, particles are formed that are so large as to also result in a too viscous product and also a product having poor solubility even upon oil dilution. To summarize, we have unexpectedly discovered that the nitrogen gas introduction during overbasing, stripping and hydrolysis affects particle size which in turn affects viscosity, filterability and solubility of the final product. To obtain minimum viscosity and maximum filterability and solubility, a particular set of conditions, ingredients and amounts coupled with a defined rate range of nitrogen gas blowing in the overbasing, stripping and hydrolysis phases are required.

The nitrogen gas employed preferably has an impurity content (oxygen and carbon dioxide) of less than about 0.5 wt. percent. Impurities such as carbon dioxide and oxygen undesirably degrade the calcium alkoxyalkoxide reactant.

In a preferred embodiment the sulfurized normal calcium alkylpheuolate reactant is prepared in the following manner:

The first stage comprises contacting, preferably in a hydrocarbon lubricating oil medium advantageously constituting between about 15 and 70 wt. percent of the final reaction mixture, an alkylphenol of the formula:

where R is as heretofore defined with a calcium alkoxyalkoxide of the formula:

where A and R are as heretofore defined, at a temperature between about and 150 C., utilizing a mole ratio of alkylphenol to calcium alkoxyalkoxide of about 2 to form a normal calcium alkylphenolate characterized by the formula:

Prior to the next stage of the reaction the alkoxyalkanol solvent (if used) and by-product is preferably removed from the reaction mixture by standard means such as stripping with an inert gas (e.g., nitrogen) at the temperature of distillation for said alcohol. The purpose of the stripping is to prevent sulfur contamination of the alkoxyalkanol by-product which unless removed would take place in the next stage.

To the stripped or unstripped reaction mixture in the first stage there is charged at a temperature between about 75 and 250 C., sulfur in a mole ratio of sulfur to normal calcium alkylphenolate of between about 0.15:1 and 8:1, preferably between about 0.5 :1 and 3:1. The sulfur is desirably introduced as a slurry in mineral oil in between about 10 and wt. percent concentration. At the end of the sulfur charge the temperature is maintained for a period of time, e.g., between about 1 and 25 hours, preferably under gas stripping conditions to remove volatile sulfur by-products. The resultant product is sulfurized normal calcium alkylphenolate having a sulfur content between about 0.1 and 10 wt. percent and a calcium metal ratio of about 1.

Under preferred conditions, stripping of the normal sulfurized calcium alkylphenolate with carbon dioxide which is bracketed by nitrogen gas stripping is most desirable since carbon dioxide facilitates removal of volatile, odorous, sulfurous by-products. In addition, the carbon dioxide deodorization treatment of the sulfurized normal calcium alkylphenolate appears to somewhat improve the filterability and stability of the final hydrolyzed overbased product. The inert and 00 stripping rate generally employed is between about 0.1 and 10 s.c.f.h./ gallon of reaction mixture at between about 10 and 250 C.

Alternative means for manufacture of the sulfurized normal calcium alkylphenolate reactant contemplated herein call for reacting alkylphenol with sulfur dichloride with continuous removal of hydrochloric acid by-products and reacting the resultant alkylphenol sulfide with calcium oxide to form a normal sulfurized calcium alkylphenolate as heretofore defined. This alternative procedure although producing the desired product has the undesirable feature of producing hydrochloric acid by-products which require relatively costly apparatus and handling techniques for removal, and also generally results in the incomplete neutralization of the phenol.

Another alternative procedure for forming the sulfurized normal calcium alkylphenolate reactant is contacting an alkylphenol with calcium oxide or calcium hydroxide in the presence of a glycol such as ethylene glycol to form the calcium alkylphenolate with simultaneous sulfurization. The process has the disadvantage of usually requiring reduced pressure to remove the solvent glycol, thus increasing equipment requirements. Also, the normal sulfurized calcium alkylphenolate prepared in this way retains residual glycol decomposition products which tend to degrade the high temperature dispersant properties of the product.

In a still further preferred embodiment the calcium alkoxyalkoxide reactant as heretofore defined utilized in the preparation of the sulfurized normal calcium alkylphenolate reactant and overbased product is prepared by contacting an alkoxyalkanol of the formula where R and A are as heretofore defined with calcium carbide preferably in the presence of a filter aid such as diatomaceous earth utilizing a mole ratio of alcohol to calcium carbide of between about 5:1 and 8:1 and filter aid when employed of between about 0.5 and 2.0 wt. percent of the reaction mixture. The presence of filter aid facilitates the purification of the product via filtration, the product being recovered as the purified filtrate. The reaction is conducted at a temperature between about 60 and 130 C., and the product is isolated as heretofore described via filtration to remove insolubles and purging to remove the acetylene by-product.

In all stages of the manufacturing procedure the reaction ingredients are preferably stirred.

The content of the aforedescribed hydrolyzed overbased sulfurized calcium alkylphenolate in the lubricating composition of this invention may range anywhere from 0.1 to wt. percent. The higher concentration, e.g., between about 30 and 90 wt. percent are normally found in compositions directly from the manufacture of the hydrolyzed overbased calcium alkylphenolate whereas the preferred concentration in final lubricating oil compositions of the hydrolyzed overbased phenolate additive for automotive use is between about 0.1 and 5 wt. percent. In any event in the entire range, the additive in the lubricating oil composition will function as an alkaline dispersant.

In the finished lubricating oil compositions other additives may be included. These other additives may be any of the standard suitable pour depressants, heat thickening sulfurized fatty oils, additional sludge dispersants (e.g., petroleum sulfonates), antioxidants, silver corrosion inhibitors, viscosity index improvers and oiliness agents. Exactly what additional additives are included in the finished oils and the particular amounts will, of course, depend on the particular use and conditions desired for the finished oil product.

Suitable base oils useful in the compositions of the invention as well as diluent in the manufacture of the hydrolyzed overbased sulfurized calcium alkylphenolate component include a wide variety of hydrocarbon lubricating oils such as naphthenic base, paraflinic base and mixed base mineral oils or other hydrocarbon lubricants, e.g., lubricating oils derived from coal products and synthetic oils, e.g., alkylene polymers such as polypropylene and polyisobutylene of a molecular weight between about 250 and 2500. Advantageously, lubricating oils having an SUS viscosity at F. between about 50 and 2000 are employed.

Examples of the alkylphenol reactants contemplated herein are 4-octylphenol, 4-tertiary octylphenol, Z-decylphenol, 2-dodecylphenol, 4-hexadecylphenol, 2,4-didodecylphenyl, 2-nonylphenol, 4-tricontylphenol, 4-eicosylphenol, a mixture of a decylphenol and dodecylphenol (C -C alkylphenol) and mixtures of 2 and 4 positioned monoalkyl and dialkylphenol. It is to be noted the alkylphenol employed will normally have the alkyl groups in the para position. However, 2,4-substituted dialkylphenols may also be employed. The only restriction is one ortho or para position of the alkylphenol reactant is desirably available for sulfurization.

Examples of the calcium alkoxyalkoxide reactants contemplated herein are calcium 2-methoxyethoxide, calcium l-methoxypropoxide, calcium 3-methoxybutoxide, calcium ethoxy-Z-ethoxide and calcium 4-dodecoxyhexoxide. In order to facilitate reactant contact, the calcium alkoxyalkoxide reactant is preferably employed in conjunction with volatile solvent such as the corresponding alkoxyalkanols, 2-methoxyethanol, l-methoxypropanol, 3-methoxybutanol etc. The calcium alkoxyalkoxide reactant concentration in the solvent solution is normally between about 20 and 60 wt. percent although higher and lower amounts may be employed. The calcium alkoxyalkoxide reactant is prepared by standard means such as reacting calcium metal, calcium hydride or calcium carbide with the corresponding alkoxyalkanol desirably at a temperature between about and 150 C. Of the inorganic calcium reactants, calcium carbide is preferred for economic reasons.

Examples of the sulfurized normal calcium alkylphenolate reactants based on the theoretical formula:

are where R is 4-octyl, x is 1 and y is 0; R is 4-dodecyl, x is 1 and y is 1; R is 4-eicosyl, x is 3 and y is R is 2,4-didecyl, x is 2 and y is 3; and mixtures thereof. It is to be noted x and y are defined as average integers.

The following examples further illustrate the method of the invention but are not to be construed as limitations thereof.

EXAMPLE I This example illustrates the preferred preparation of calcium alkoxide reactant.

To a 3,000 gallon reactor fitted with a variable speed stirrer and means for heating, collecting volatile overhead, and purging with gases, there were charged at ambient temperature (72 F.) 18,000 lbs. of Z-methoxyethanol, 3,000 lbs. calcium carbide and 250 lbs. diatomaceous earth, and the reactor was purged with nitrogen to produce a nitrogen atmosphere. The reaction mixture was heated with stirring to 60 C. whereupon the temperature rose to about 100 C. due to the heat of reaction. After about one hour, the mixture was heated to about 120 C. for a period of 4 hours with high speed mixing and nitrogen purging. While continuing to mix at high speed the product is pumped by means of a centrifugal slurry pump through a plate and frame type filter and back to the reactor. When the bulk of the solids have been transferred to the filter, the filtrate is diverted to storage as a clear solution of calcium Z-methoxyethoxide in Z-methoxyethanol.

EXAMPLE II This example illustrates the preparation of the lube oil concentrate of the sulfurized normal calcium alkylphenolate reactant.

To a 3,000 gallon stainless steel reactor fitted with a variable speed stirrer and means for heating, collecting volatile overhead, purging with gases, introduction of reactants and removal of product, there was charged 1,042 gallons of a parafi'inic oil having an SUS viscosity of about 100 at 100 F. and 472 gallons of C -C alkylphenol. Stirring and nitrogen blowing through a sparger placed in the bottom of the reactor at a rate of 250 s.c.f.h./ gallon were initiated and the reactor contents were heated to a temperature of about 165 C. With continued heating and stirring at this temperature, 372 gallons of 36 Wt. percent calcium 2-methoxyethoxide in 2-methoxyethanol were added at a rate of 4.5 gallons/minute and upon completion the nitrogen rate was increased to 900 s.c.f.h. The temperature was then increased to about 175 C. for a 3 'hour period and removing during said period excess 2-methoxyethanol. At the end of the 3 /2 hour period the nitrogen rate was reduced to 500 s.c.f.h. and a slurry of 495 lbs. of sulfur in 208 gallons of paraffinic lubricating oil of an SUS viscosity of about 100 at 100 F. was introduced into the reactor system and the temperature of about 175 C. and nitrogen blowing at 500 s.c.f.h. was continued for a period of 5.5 hours. At the end of the 5.5 hour period nitrogen blowing was ceased and the mixture was blown with carbon dioxide at a rate of 1000 s.c.f.h. for a period of 1 hour while maintaining the 175 C. temperature and at the end of the 1 hour period nitrogen blowing was resumed with the ceasing of carbon dioxide blowing for an additional 1 hour period to strip out excess C0 The resultant product was analyzed and determined to be sulfurized normal calcium alkylphenolate lube oil concentrate of the following analysis:

TABLE I Test: Results Calcium, wt. percent 2.0 Sulfur, wt. percent 2.0 TBN (HClO titration) 56 Specific gravity, 60/60 0.96 Viscosity, SUS at 210 F Flash point, F. 360 Sulfated ash, wt. percent 6.8

The product was determined to be a lubricating oil solution containing 32 wt. percent sulfurized normal calcium 4-C -C alkylphenolate having a metal ratio of about 1.

EXAMPLE III This example illustrates the preparation of the lube oil concentrate of overbased sulfurized calcium alkylphenolate of reduced viscosity and further illustrates the criticality of inert gas rate in respect to obtaining a product of reduced viscosity.

The apparatus and sulfurized normal calcium alkylphenolate product described in Example II were utilized.

To 12,900 lbs. of oil concentratecontaining about 32 wt. percent sulfurized normal calcium alkylphenolate produced in Example II maintained at a temperature of about 175 C. there was charged 1 pint of silicone polymer (1,000,000 M.W.) antifoamant and 744 gallons of 36 wt. percent calcium-Z-methoxyethoxide in Z-methoxyethanol produced in Example I at a rate of 4.5 gallons/minute while nitrogen blowing the reaction mixture at a rate of 900 s.c.f.h. (within the 0.250.6 s.c.f.h./gallon range). This overbasing step was followed by a 3-hour stripping period to strip out excess 2-methoxyethanol maintaining nitrogen rate at 900 s.c.f.h. (within the 0.250.6 s.c.f.h./ gallon range). At the end of this first stripping step and still maintaining the temperature at 175 C., lbs./ hour of steam was introduced into the reaction mixture at 175 C. for a period of 2.25 hours for a total amount of 225 lbs. introduction of water (as steam) while continuing to blow at a decreased rate of 250 s.c.f.h. (within 0.1-0.2 s.c.f.h./gallon range) with nitrogen during this hydrolysis step. At the end of the hydrolysis period nitrogen blowing was increased to a rate of 900 s.c.f.h. (within 0.25-0.6 s.c.f.h./gallon range) for a period of 6 hours to strip volatile materials therefrom. At the end of the second stripping there was introduced into the reaction mixture lbs. of diatomaceous silica and the resultant mixture was passed through a precoated filter of diatomaceous earth at about 150 C. at a nominal pressure of about 100 p.s.i.g. The resultant product was then analyzed and determined to be a lube oil concentrate of overbased sulfurized calcium 4-C -C alkylphenolate which is about 50% hydrolyzed. Eight runs Were made. Runs A, B, C, D, E and F represent the procedure of the invention. Runs G and H are comparative runs, wherein the nitrogen rates are outside the range contemplated herein. A comparison of the representative runs with the comparative runs demonstrate that the representative runs have a substantially lower viscosity than the comparative runs. The test data and results are reported below in Tables II-A and II-B.

TABLE II-A Run A B C Nitrogen rates s.c.f.h.:

Overbasing 900 900 900 Stri ping- 900 900 900 Hy olysis 250 250 250 Tests on finished products:

Specific gravity 60/60. 0. 9778 Flash COO, F 365 Viscosity SUS at 210 F 215 Total base No. (TBN)- 147 Calcium, wt. percent. 9 5. 4 5. 3 Sulfur, wt. percent 2. 1. 7 1.8 Sediment, vol. percent. 0. 04 0. 01 0. 04 00 wt. percent 0. 6 0. 11 0. 06 Lumetron, 6 hrs. after blending:

vol. percent in oil X 3. 5 5. 0 2. 5 5 vol. percent in oil Y 4. 5 8.0 5. 0

See footnotes at end of Table II-C.

TABLE II-B Run D E F Nitrogen rate s.c.t'.h.:

Overbasing. 900 900 900 Stripping... 900 900 900 Hydrolysis 250 250 250 Tests on finished product Specific gravity, 60/60--- 0.9722 0. 970 0. 972 Flash COC, F 350 370 360 Viscosity SUS at 210 F 209 222 200 Total base No. (TBN) 151 134 136 Calcium, wt. percent-.- 5.4 4. 8 4. 8 Sulfur wt. percent.. 1. 6 1. 9 1. 6 Sediment, vol percen 0.01 0.01 0.02 00 wt. percent- 0. 20 0. 25 0. 41

Lmnetron, 6 hrs. alter blending:

5 vol. percent in oil X 2. 5 2. 5 5. 0 5 vol. percent in oil Y 7. 0 3. 5 16. 0

See footnotes at end of Table 11-0.

TABLE IIC Run G G 1 e H d en rates s.c.i.h.:

gierbasing 250 250 1, 000 Stripping 250 250 1, 000 Hydrolysi 0 0 250 Tests on finished product Specific gravity 60/60. 0. 0677 Flash 000 37 F Viscosity SUS at 210 F.- Total base No. (TBN) Calcium, wt. percent Suliur, wt. percent Sediment, vol. percent.

5 vol. percent in oil X 5 vol. percent in oil Y 5 Oil X is a mineral oil of 130 SUS viscosity at 100 F.

b Oil Y is a. mineral oil of 340 SUS viscosity at 100 F.

0 Run G product diluted with 12 vol. percent of a mineral oil of an SUS viscosity of 100 at 100 F.

d Final product diluted with 20 vol. percent of a mineral oil of an SUS viscosity of 100 at 100 F.

We claim:

1. A method of preparing a hydrolyzed overbased sulfurized calcium alkylphenolate hydrocarbon lubricating oil composition comprising first contacting in a hydrocarbon lubricating oil medium a sulfurized normal calcium alkylphenolate having a sulfur content of between about 0.1 and wt. percent and a calcium metal ratio of about 1 wherein said alkyl group is from 4 to 100 carbons with calcium alkoxyalkoxide of the formula:

where A is alkanediyl of 1 to 6 carbons and R is alkyl of 1 to 25 carbons, at a temperature between about 10 and 200 C. while simultaneously introducing into the reaction mixture during said first contacting nitrogen gas at a rate of between about 0.25 and 0.6 s.c.f.h./gallon utilizing a mole ratio of calcium alkoxyalkoxide to said sulfurized normal alkylphenolate of between about 0.121 and 25:1, said hydrocarbon oil being present in said first contacting in an amount of between about 10 and 90 wt. percent, stripping the resultant reaction mixture with nitrogen gas at a gas rate of between about 0.25 and 0.6 s.c.f.h./ gallon resultant mixture and at a temperature between about 10 and 200 C., subsequently second contacting said overbased sulfurized calcium alkylphenolate with water at a temperature between about 10 and 250 C. while simul- .taneously introducing into said stripped mixture nitrogen gas at between about 0.1 and 0.2 s.c.f.h./gallon stripped mixture utilizing a mole ratio of water to calcium alkoxyalkoxide of between about 100:1 and 02:1, said water contacting continuing until between 20 to 70 wt. percent of said overbased sulfurized calcium alkylphenolate is hydrolyzed, subsequently removing residual water and recovering said hydrocarbon oil composition, said nitrogen gas being continually introduced during said first contacting, said stripping and said second contacting.

2. A method in accordance with claim 1 wherein said sulfurized normal calcium alkylphenolate is sulfurized normal calcium 4-C -C alkylphenolate and said calcium alkoxyalkanol is calcium 2-methoxyethoxide.

3. A method of producing a hydrocarbon lubricating oil composition containing between about 0.1 and wt. percent of between about 20 and 70 wt. percent hydrolyzed overbased sulfurized calcium alkylphenolate having a calcium metal ratio of between about 1.1 and 3.5 comprising:

(a) first contacting in a lubricating oil medium an alkylphenol of the formula:

where R is an alkyl of from 4 to carbons with a calcium alkoxyalkoxide of the formula where A is a divalent saturated aliphatic hydrocarbon of from 1 to 6 carbons and R is alkyl of from 1 to 25 carbons in the presence of a hydrocarbon lubricating oil of an SUS viscosity between about 50 and 2000 at 100 F. utilizing a mole ratio of said alkyl- .phenol to said calcium alkoxyalkoxide of about 2:1 at a temperature between about 10 and 250 C. to form a first reaction mixture containing the lube oil concentrate of the corresponding calcium alkylphenolate,

(b) subsequently contacting said formed calcium alklyphenolate with sulfur in a mole ratio of sulfur to said alkylphenol of between about 0.15:1 and 8:1 at a temperature between about 75 and 250 C. to form a second reaction mixture containing sulfurized normal calcium alkylphenolate having a sulfur content of between about 0.1 and 10 wt. percent in a lube oil concentrate,

(c) contacting said lube oil solution of said sulfurized normal calcium alkylphenolate with an additional amount of said calcium alkoxyalkoxide while blowing during said contacting the resultant reaction mixture with nitrogen gas at a rate of between about 0.25 and 0.6 s.c.f.m./gallon said lube oil solution at a temperature between about 10 and 200 C. in a mole ratio of said sulfurized normal calcium alkylphenolate to said additional calcium alkoxyalkoxide of between about 1:0.1 and 1:25 and to form a third reaction mixture containing an overbased sulfurized calcium alkylphenolate having calcium metal ratio of between about 1.1 and 3.5,

(d) stripping the resultant reaction mixture with nitrogen gas at a gas rate of between about 0.25 and 0.6 s.c.f.h./ gallon resultant mixture at a temperature of between about 10 and 250 C. to form a fourth reaction mixture,

(e) subsequently contacting the stripped mixture with water while simultaneously blowing the stripped mixture during said contacting with nitrogen gas at a rate of between about 0.1 and 0.2 s.c.f.h./gallon stripped mixture at a temperature between about 10 and 250 C. in a mole ratio of said water to said additional calcium alkoxyalkoxide of between about 100:1 and 0.2:1 until 20 and 70 wt. percent said overbased sulfurized calcium alkylphenolate is hydrolyzed,

(f) then substantially removing residual water by stripping the final reaction mixture of step (e) with nitrogen gas at a nitrogen gas rate of between about 0.25 and 0.60 s.c.f.h./gallon,

said nitrogen gas being continually introduced during all phases of said steps (0), (d), (e) and (f).

4. A method in accordance with claim 3 wherein the resultant reaction mixture of steps (a), (b) and (f) are stripped with inert gas between about 100 and 250 C. wherein the resultant reaction mixture following said contacting with sulfur is stripped with carbon dioxide, and

wherein the residue of step (t) is filtered and said composition is recovered as filtrate.

5. A method in accordance with claim 4 wherein said alkylphenol is 4-C -C alkylphenol and said calcium a1- koxyalkoxide is calcium Z-methoxyethoxide.

References Cited DANIEL E. WYMAN, Primary Examiner W. H. CANNON, Assistant Examiner US. Cl. X.R.