US2926140A - Chlorinated hydrocarbon ashless detergent and lubricating oil compositions containing same - Google Patents

Description

United SW6 Pflt CHLORINATED HYDROCARBON ASHLESS DETER- GENT AND LUBRICATING OIL COMPOSITIONS CONTAINING SAME Albert N. De Vault, Bartlesville, kla., assignor to Phillips Petroleum Company, a corporation of Delaware No Drawing. Application December 31, 1954 Serial No.'479,218

16 Claims. (Cl. 252-58) This invention relates to a lubricating oil additive. In one of its aspects this invention relates to a method of preparing lubricating oil additives. In another of its aspects this invention relates to an ashless lubricant additive having detergent and/or dispersant properties and being suitable for use in lubricating compositions.

As the speed and output of internal combustion engines have been gradually increased to higher and higher values, the ability of non-additive oils to adequately take care of the lubrication and to maintain an engine free from lacquer, sludge and carbon deposits has containued to decrease. Metal-containing detergents such as barium or calcium sulfonates or phenates have been extensively used. These have served satisfactorily in many cases as the concentrations used were lower only moderately high. As cleanliness requirements called for still greater concentration of detergent additive, the problem of ash deposition in the combustion chamber became more serious. Especially is this a problem in certain engines which tend to develop violent preignition troubles in the presence of metallic ash. Also, in high-output aircraft engines, oils containing detergent additives have never been permitted for the same reason.

The requirements desirable in a satisfactory detergent additive are: (1) compatibilitywith lubricating oil and other types of additives which may be present;-(2) maintenance of satisfactory cleanliness of the engine parts, principally in the ring belt zone of the piston; (3) chemical inertness with respect to supplemental additives and metal engine parts. Additional desirable characteristics include: (1) ease of handling, either as such or as an oil concentrate; (2) minimum effect on oil properties such as viscosity, color and odor; (3) inexpensive overall cost; (4) independence with respect to critically limited or expensive raw materials.

An ashless detergent is one which shows substantially no ash when tested by the standard ASTM procedure D-482. The only possible source of metal in such an additive is that of corrosion products and trace quantities present in some crude oils. It can be generally stated that metal-containing depositions in an engine 1) contribute to valve burning, (2) contribute to pre-ignition, (3) tend to foul and short-out spark plugs and (4) tend to increase octane requirements. Use of conventional detergents contribute to the deposit of metalcontaining materials in the combustion chamber. Metalcontaining deposits do not form from ashless detergents. Use of such a detergent therefore materially reducesthe problems normally encountered in internal combustion engines in connection with metal-containing deposits.

The use of additives in lubricating compositions as corrosion inhibitors, oxidation inhibitors, viscosity index improvers, dispersing agents, pour-point depressants, extreme pressure agents, lubricity improvers and ash forming detergents, is well known. The need for additives to improve various specific properties of lubricating oils is all the more acute and necessary in view of the service conditions which lubricating oils undergo and must withice stand. In internal combustion engines such as automotive, aviation and diesel engines it is desirable that the lubricating compositions be resistant to sludge and varnish formation and in the event of such formation, to prevent the deposition of those materials on metallic parts of the engine.

I have discovered that an ashless additive having detergent and corrosion inhibiting properties, can be easily prepared from a selected hydrocarbon fraction by treating said fraction with a halogenating agent such as chlorine, bromine or a reactive halogen-containing organic compound. Thus, broadly speaking, my invention comprises an ashless additive prepared as described, a method for preparing said additive and a lubricating composition having said additive incorporated therein.

An object of this invention is to provide an ashless additive for lubricants.

Another object of this invention is to provide a method for the preparation of an ashless additive for lubricating oils.

Another object of this invention "is to provide an improved lubricating composition utilizing the ashless additive of the invention.

Another object of this invention is to provide a method for the preparation of an improved lubricating oil composition, possessing excellent detergent properties, utilizing the ashless additiveof the invention.

Other aspects, objects and advantages of the invention will be apparent to those skilled in the art upon studying this disclosure.

According to the invention thereis provided an ashless additive for lubricating oils, which additive is pre pared by subjecting a selected hydrocarbon fraction to the action of a halogenating agent, under halogenating and dehydrohalogenating conditions, in an amount and for a period. of time sufiicient to increase the viscosity of said hydrocarbon fraction at least 1.25 fold; and a lubricating composition having said additive incorporated therein.

Examples of suitable halogenating agents for the preparation of the additive of the invention are chlorine, bromine and reactive halogen-containing organic compounds such as carbon tetrachloride, carbon tetrabromide, chloroform andbromoform.

The additives of this invention can be prepared from selected hydrocarbon fractions having a viscosity at 210 F., measured in Saybolt Universal seconds, within the range of to 230. The presently preferred raw material for the ashless additive of the invention is a refined lubricating oil stock prepared by solvent extraction and propane fractionation. I

Petroleum fractions which contain substantially no asphalt, either in a natural state or when deasphalted, and which have been treated to reduce the content of aromatic type hydrocarbons therein are suitable materials for the preparation of the additive of the invention. These include lubricating oils produced from Pennsylvania, Mid-Continent, California, East Texas, West Texas, Gulf Coast, Venzuela, Borneo and Arabian crudes. The source of the crude oil from which the petroleum fraction is derived does not significantly influence the preparation orproperties of the ashless detergent material of this invention provided the petroleum fractionhas been prepared by subjecting the crude to certain necessary treatments to exclude undesired materials therefrom.

In the preparation of the preferred petroleum fraction from which the detergent material of this invention is produced, a crude oil is topped, i.e., distilled to remove thereforrn the more volatile, lower molecular weight hydrocarbons such as gasoline and light gas oil, and then vacuum reduced to remove heavy gas oil and light lubricating oil of the SAE 10 and 20 viscosity grade. The

vacuum reduced crude is then propane fractionated to remove an overhead fraction of about 100 SUS at 210 F. viscosity and the residual material is subjected to a second propane fractionation to remove another overhead fraction of about 200 SUS at 210 F. viscosity. The residue from the second fractionation can be subjected to a third propane fractionation to remove still another overhead fraction of about 575 SUS at 210 F. viscosity. Propane fractionation can be modified by the presence of butane, ethane or methane to the extent desired.

Following the propane fractionation step the overhead oil fraction is solvent extracted with a selective solvent which will separate the parafiinic hydrocarbons from the more aromatic-type hydrocarbons. Suitable selective solvents for aromatic hydrocarbons include among others the various phenols, sulfur dioxide, furfural and [3, 3'-dichlorodiethyl ether. This solvent extraction step for the removal of themore highly aromatic compounds can be carried out in accordance with the well-known concurrent or countercurrent solvent extraction techniques as well as by the well-known Duo-Sol technique.

Each of the solvent extracted, propane-fractionated oils can be used in preparing the detergent material of this invention with good results but the overhead fraction from the second propane fractionation is preferred. It will be recognized by those skilled in the art that propane fractionated oils differing from those described can be used or a single broad viscosity cut can be used. The residual material from the final propane fractionation contains the rejected asphalt and more aromatic oils.

Although the preferred method for preparation of feed stock is as above described, other methods can be used to secure a similar type hydrocarbon fraction. Thus, .a vacuum reduced crude which has essentially no asphalt, such as a Pennsylvania oil, can be used directly or after a light acid treatment. Another method, while not feasible commercially at the present time, is ultra high vacuum (molecular) distillation to obtain the desired fraction.

The reaction can be carried out at temperatures within the range of 375 to 700 F., preferably within the range of 400 to 600 F. Cracking temperatures should be avoided. Ambient pressures are generally used although the range of to 200 pounds per square inch absolute can be set forth as suitable.

The amount of halogenating agent used is generally within the range of 10 to 200 percent by weight based on the material treated. Generally speaking, the amount of halogenating agent used will be in the lower portion of said range.

When the halogenating agent is in the vapor phaseit is preferred, for economic reasons, to add the vapor at such a rate that none is lost by bubbling through the material being treated. Faster rates can be used. When the halogenating agent is a liquid having a boiling point below the treating temperature, a convenient method for effecting the reaction is to add the halogenating agent in relatively small increments to the hot oil in a reaction vessel equipped with a reflux condenser.

Heating of the hydrocarbon fraction in the presence of the halogenating agent is continued until a noticeable increase in viscosity, measured in Saybolt Universal seconds, is obtained. This viscosity increase should be at least 1.25 fold and can go as high as 50 fold. The viscosity increase is generally in the range of 1.25 to 10 fold and the range of 2 to 4 fold has been found to be preferred for some stocks.

The time required for this viscosity increase is somewhat dependent upon the temperature at which the reaction is carried out. In general the reaction time can vary from 2 to 40 hours. Shorter reaction times are associated with higher temperatures and vice versa.

Following completion of the rea t on h e genating agent the reaction mixture is heated to at least 500 F. and an inert gas, such as carbon dioxide or natural gas, is bubbled through the product for several hours to strip off any relatively light product formed, such as hydrogen chloride, and to decompose any relatively unstable halogenated compounds. Further condensation, as evidenced by further increase in viscosity, usually occurs during this step. Cracking temperatures should be avoided during this step.

Following removal of any light products formed during the reaction, the reaction mixture containing the additive of the invention can be used per se as the additive of the invention without additional concentration or purification. However, if a product of improved quality and purity is desired,the reaction mixture containing the additive can be reated with a suitable solvent which is a solvent for the unreacted portion of the hydrocarbon fraction treated, but which is not a solvent for the additive contained therein. Hydrocarbon solvents are preferred. A presently preferred method is to treat the reaction mixture with propane under propane fractionating conditions such that a propane-insoluble fraction is obtained as the bottom fraction and a propane-soluble fraction is obtained as the overhead fraction. The propane-insoluble material obtained as the bottom fraction is the additive concentrate of the invention.

The additive contains a small amount of halogen which is firmly bound in the molecule and is stable in lubricating oils under all operating conditions. The halogen in the additive can range from 1 to 5 weight percent.

It appears that the reaction by which the additive of the invention is prepared can be described as halogenation and simultaneous dehydrohalogenation with concomitant condensation. Thus the hydrocarbon fraction is halogenated but simultaneously with said halogenation, dehydrohalogenation is occurring, and concomitantly with said dehydrohalogenation, condensation is occurring.

In compounding the improved oil compositions provided by this invention, the additive is added to the desired oil base in an amount sufficient to obtain the desired degree of improvement in service characteristics of-the'oil. This amount will accordingly depend upon thecharacteristics of the lubricating oil itself as well as the conditions to which the composition is subjected in use. Ordinarily, the additive is employed in an amount representing between 0.1 and 20 weight percent of the entire composition and preferably about 0.3 to 10 weight percent. The base oil may be any oil of suitable grade and viscosity obtained by any of the modern refining methods. 5

The additive of this invention functions independently of other types of additives without adversely altering the physical characteristics of the oil. Accordingly, there may also be added to the lubricating oil compositions including the detergent of this invention, other oil additives which are usually present in lubricating oil compositions. These additives may include corrosion inhibitors, oxidation inhibitors, viscosity index improvers, pour point depressants, extreme pressure additives, peptizing or dispersing agents, lubricity agents and the like. However, since the material of this invention when employed in lubricating oil compositions is an ashless detergent, it would obviously be appropriate to employ only those other additives which are also ashless. However, even when the other additives present in the lubricating oil composition are not ashless, the use of the subject ashless detergent additive would yield an oil of lower ash content than otherwise if a detergent other than an ashless detergent were employed.

The following'examples are illustrative of the subject invention and of the advantages to be obtained in the practice thereof. These following examples are merely illustrative of the invention and are in -no sense 'limitive thereof.

The carbon spot test referred to hereinafter in the examples comprises the steps of utilizing a standard mixture of oil and corrosion inhibitor in normal concentration plus 0.4 weight percent carbon black. For one measured drop of this mixture the carbon black spreads to a circle of 16 millimeters in diameter on a flat polished steel plate which is maintained at 482 F. The test mixture which is utilized in the examples is the above identified standard mixture plus a designated percent of detergent product. Any increase in diameter over 16 millimeters of the carbon spot resulting on the flat polished steel plate is an indication of improvement provided by the detergent action of the detergent additives.

The high temperature Lauson engine test or the simulated L1 Lauson engine test referred to in the following examples was carried out as follows. The ashless detergent of the invention, in the selected amount, was added to the base oil and 920 grams of the resulting composition was placed in the crankcase of a standard single cylinder Lauson engine. The engine was operated under a 1.2 horse power load at 1600:20 r.p.m., maintaining a cooling jacket temperature of 300 R, an oil temperature of 225 R, an air-to-fuel ratio of 13.5 :1, carburetor air at room temperature, spark advance of 25 BTDC, and crankcase vacuum of 1.0 inch of mercury. At the end of 60 hours engine operation under these conditions the engine was stopped, dis-assembled, and the piston, crankcase and bearings were examined. The piston varnish was rated on an arbitrary scale of to with 10 representing a clean or perfect condition and 0 representing the dirtiest condition.

The Lauson cold engine sludge test referred to in the following examples was carried out as follows. 920 gramsof the composition to be tested was placed in the crankcase of a standard Lauson engine. The engine was operated under fan load under the following conditions:

TEST CYCLE Test Cooling Oil Period, R.p.m. Jacket; Sump Hrs. Temp, Temp,

1 Total hrs.

Example I The reaction was carried out in a closed vessel open to the atmosphere. The oil charge which consisted of 20.75 pounds of an SAE 250 stock having a viscosity of chloride was evolved until near the end of the reaction period. The viscosity of the chlorine treated material was 600 SUS at 210 F.

After introduction of the chlorine was complete, the oil was heated to 520 F. and natural gas was bubbled through the liquid for six to eight hours to strip ofi any relatively light products formed and to decompose any relatively unstable chlorine compounds. The viscosity of the oil at the conclusion of his treatment was 738 SUS at 210 F.

The product resulting from the stripping operation was propane fractionated at 7/1 propane-to-oil ratio in the usual manner to recover the detergent as propane-insoluble material. The yield of propane-insoluble material was 30.8 weight percent.

The propane-insoluble material was tested in a Lauson cold engine sludge test. For comparison, a test was also run on Paranox 64. The results were as follows:

1 1.25 wt. percent; inhibitor (Lubrizol 309) added. No inhibitor was added to Paranox 64, as this additive is a package unit with inhibiting properties. N 0 inhibitor was added to the base oil. Said base oil had essentially the same physical properties as that used in Example 11.

A comparison of the above data shows that the product additive prepared from an SAE 250 stock is an excellent: detergent and that excellent cold engine characteristics are imparted to the base oil by the said product additive.

Example II A sample of 235 g. of an SAE 250 oil, having a viscosity of 207 SUS at 210 F., oil .was refluxed with carbon tetrachloride at 400 F. for 10 hours. Hydrogen chloride was noted to be evolved beginning at 380 F. After refluxing for ten hours, the temperature was increased to 510 to 520 F. for 5 hours to decompose relative unstable organic chlorides. The viscosity of this additive was 545 SUS at 210 F.

This additive in a base oil was tested in a high temperature Lauson engine test. The oil used as a base oil was a solvent-refined Mid-Continent oil of lubricating grade having the following characteristics:

Results of this test are presented in the following table together with comparative data for the base oil and base oil plus the commercial oxidation inhibitor Santolube 395x.

Piston varnish Base oil 6.0

Base oil+0.82 wt. percent 395x 6.0 Base oil+0.82 wt. percent 395x+ 3.5 wt. percent this additive 8.3

The above results show that the additive of Example II is also an excellent detergent.

Example III A carbon spot test of a lubricating composition, an SAE 30 stock, containing the additive oil-Example H These re Oil Spot Diameter, mm.

Carbon Spot Diameter, mm.

Standard lVIlxture Standard Mixture plus of additive of Example II Example IV Carbon Spot Oil Spot Diameter, Diameter, mm. min.

Standard 16 Standard plus 6% of additive 49 51 When detergent' additives are used in lubricating oils employed in internal combustion engines there is an increase in the required octane number of the fuel burned in the engine. This is commonly referred to by those skilled in the art as the octane requirement increase (ORI).

Tests have shown that the ashless additive of this invention has an ORI of approximately 10. This compares very favorably with the ORI values on present commercially available detergents which range from about 9 to about 13.

As will be evident to those skilled in the art, various modifications of this invention can be made, or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the claims.

I claim:

1. A process for producing an ashless lubricant additive having detergent and corrosion inhibiting properties which comprises subjecting a selected petroleum hydrocarbon fraction having a viscosity within the range of 185 to 230 SUS at 210 F., to the action of a halogenating agent selected from the group consisting of chlorine, bromine, carbon tetrachloride, carbon tetrabromide, chloroform and bromoform, under halogenating and dehydrohalogenating conditions at a temperature within the range of 375-700 F., in an amount and for a period of time sufiicient to increase the viscosity of said hydrocarbon fraction at least 1.25 fold, heating the thus treated hydrocarbon fraction to a temperature of at least 500 F. to remove hydrogen halide and unstable halogen-containing compounds from the treated hydrocarbon, and recovering said additive from said treated hydrocarbon fraction.

2. A process according to claim 1 wherein said halogenating agent is chlorine.

3. A process according to claim 1 wherein said halogenating agent is bromine.

4. A process according to claim 1 wherein said halogenating agent is carbon tetrachloride.

.5. A process according to claim '1 wherein said halo. genating agent is carbon tetrabromide.

'6. A process according to claim 1 wherein said halogenating agent is chloroform.

7. A process according to claim 1 wherein said halogenating agent is bromoform.

8. A process for producing an ashless lubricant additive having detergent and corrosion inhibiting properties which comprises subjecting a refined petroleum hydrocarbon lubricating oil stock, having a viscosity within the range of to 230 SUS 210 F., to the action of chlorine at a temperature within the range of 400- 600 F., in an amount and for a period of time sulficient to increase the viscosity of said lubricating oil stock within the range of 1.25 to 10 fold, heating the thus treated lubricating oil stock to a temperature of at least 500 F. to remove hydrogen chloride and unstable chlorine-containing compounds, and separating an additive concentrate from said treated lubricating oil stock.

9. A process according to claim 8 wherein said viscosity increase is within the range of 2 to 4 fold, said separation of additive concentrate is effected by a propane fractionation step and said concentrate is recovered as the propane-insoluble fraction from said fractionation step.

10. A process for producing an ashless lubricant additive having detergent and corrosion inhibiting properties which comprises subjecting a refined petroleum hydrocarbon lubricating oil stock having a viscosity within the range of 185 to 230 SUS at 210 F. to the action of refluxing carbon tetrachloride at a temperature of approximately 400 F. for a period of time sufiicient to increase the viscosity of said lubricating oil stock within the range of 2 to 4 fold, heating the thus treated lubricating oil stock to a temperature of at least 500 F. to remove hydrogen chloride and unstable chlorine-containing compounds, and recovering said additive from said treated lubricating oil stock.

11. A lubricant additive having detergent and corrosion inhibiting properties produced by treating a selected petroleum hydrocarbon fraction having a viscosity within the range of 185 to 230 SUS at 210 F. with a halogenating agent selected from the group consisting of chlorine, bromine, carbon tetrachloride, carbon tetrabromide, chloroform and bromoform at a temperature within the range of 375-700" F. in an amount and for a period of time sufiicient to increase the viscosity of said hydrocarbon fraction at least 1.25 fold, heating the thus treated petroleum hydrocarbon fraction to a temperature of at least 500 F. and passing an inert gas therethrough to remove hydrogen halide and unstable halogen-containing compounds from the treated hydrocarbon, solvent treating said treated hydrocarbon, and recovering said additive as the portion insoluble in said solvent.

12. A lubricant additive produced as described in claim 11 wherein, said halogenation agent is chlorine, said viscosity increase is within the range of 2 to 4 fold, said solvent is propane and said additive is recovered as the portion insoluble in propane and contains from 1 to 5 percent chlorine by weight.

13. A lubricant composition comprising a major portion of lubricating oil and at least 0.1 percent by weight oi an additive having detergent and corrosion inhibiting properties produced as described in claim 11.

14. A composition according to claim 13 wherein said additive is present in the amount of 0.3 to 10 percent by weight based on the entire composition.

15. A lubricant composition comprising a major portion of lubricating oil and at least 0.1 percent by weight of an additive having detergent and corrosion inhibiting properties produced by subjecting a refined petroleum hydrocarbon lubricating oil stock, having a viscosity within the range of 185 to 230 SUS 210 F., to the action of chlorine at a temperature within the range of 400- 600 F., in an amount and for a period of time sufiicient to increase the viscosity of said lubricating oil stock within the range of 1.25 to 10 fold, heating the thus treated lubricating oil stock to a temperature of at least 500 F. and passing an inert gas therethrough to remove hydrogen chloride and unstable chlorine-containing compounds, mixing said treated lubricating oil stock with propane and recovering said additive as the propane insoluble portion.

16. A composition according to claim 15 wherein said additive is present in the amount of 0.3 to 10 percent by weight based on the entire composition, and said additive contains from 1 to 5 weight percent of chlorine.

References Cited in the file of this patent UNITED STATES PATENTS Lincoln Feb. 6, 1934 Prutton June 7, 1938 Churchill Dec. 12, 1944 Adelson Sept. 25, 1951 Young July 17, 1956 OTHER REFERENCES Ind. and Eng. Chem, March 1936, pp. 333439.

Claims (3)

1. A PROCESS FOR PRODUCING AN ASHLESS LUBRICANT ADDITIVE HAVING DETERGENT AND CORROSION INHIBITING PROPERTIES WHICH COMPRISES SUBJECTING A SELECTED PETROLEUM HYDROCARBON FRACTION HAVING A VISCOSITY WITHIN THE RANGE OF 185 TO 230 SUS AT 210%F., TO THE ACTION OF A HALOGENATING AGENT SELECTED FROM THE GROUP CONSISTING OF CHLORINE, BROMING, CARBON TETRACHLORIDE, CARBON TETRABROMIDE, CHLOROFORM AND BROMOFORM, UNDER HALOGENATING AND DEHYDROHALOGENATING CONDITIONS AT A TEMPERATURE WITHIN THE RANGE OF 375-700* F., IN AN AMOUNT AND FOR A PERIOD OF TIME SUFFICIENT TO INCREASE THE VISCOSITY OF SAID HYDROCARBON FRACTION AT LEAST 1.25 FOLD , HEATING THE THUS TREATED HYDROCARBON FRACTION TO A TEMPERATURE OF AT LEAST 500* F. TO REMOVE HYDROGEN HALIDE AND UNSTABLE HALOGEN-CONTAINING COMPOUNDS, FROM THE TREATED HYDROCARBON, AND RECOVERING SAID ADDITIVE FROM SAID TREATED HYDROCARBON FRACTION.

11. A LUBRICANT ADDITIVE HAVING DETERGENT AND CORROSION INHIBITING PROPERTIES PRODUCED BY TREATING A SELECTED PETROLEUM HYDROCATBON FRACTION HAVING A VISCOSITY WITHIN THE RANGE OF 185 TO 230 SUS AT 210* F. WITH A HALOGENATING AGENT SELECTED FROM THE GROUP CONSISTING OF CHLORING, BROMINE, CARBON TETRACHLORIDE, CARBON TETRABROMIDE, CHLOROFORM AND BROMOFORM AT A TEMPERATURE WITHIN THE RANGE OF 375-700* F. IN AN AMOUNT AND FOR A PERIOD OF TIME SUFFICIENT TO INCREASE THE VISCOSITY OF SAID HYDROCARBON FRACTION AT LEAST 1.25 FOLD, HEATING THE THUS TREATED PETROLEUM HYDROCARBON FRACTION TO A TEMPERATURE OF AT LEAST 500* F. AND PASSING AN INNER GAS THERETHROUGH TO REMOVE HYDROGEN HALIDE AND UNSTABLE HALOGEN-CONTAINING COMPOUNDS FROM THE TREATED HYDROCARBON SOLVENT TREATING SAID TREATED HYDROCARBON, AND RECOVERING SAID ADDITIVE AS THE PORTION INSOLUBLE IN SAID SOLVENT.

13. A LUBRICANT COMPOSITION COMPRISING A MAJOR PROTION OF LUBRICATING OIL AND AT LEAST 0.1 PERCENT BY WEIGHT OF AN ADDITIVE HAVING DETERGENT AND CORROSION INHIBITING PROPERTIES PRODUCED AS DESCRIBED IN CLAIM 11.