US2377955A - Lubricant - Google Patents

Description

Patented June 12, 1945 UNITED STATE v 2,377,955 s PATENTS orrics LUBRICANT Lawson W. Mixon and Clarence Morrison Lo ane, Hammond, Ind., 'assignors to Standard Oil ana No Drawing.

Company, Chicago, 111., a corporation of indi- Application September 30, 1942, Serial No. 469,282

14 Glaims. (El. 252-48) This invention relates to a new composition of matter suitable for use as a. lubricant additive and more particularly suitable for use in lubria eating oil compositions intended for use in inter- Y nal combustion engines such as spark-ignition engines and compression-ignition engines under severe conditions wherein corrosion, piston ringsticking, cylinder wear, carbon, and varnish for mation may be encountered.

Straight petroleum lubricating oils are effective lubricants within certain deflned'limits of operating conditions, but when these limits are exceeded such lubricants frequently fail to give-the tive which effectively inhibits the formation of varnish and/or carbon and/or corrosion in engines in which lubricants containing such additives are employed. Other objects and inventions mentioned will become apparent as the description thereof proceeds.

In copending applications of one ofus, namely Serial No. 384,938 and No. 384,941 filed March 24, 1 941, which issued respectively as Patents Nos.

, 2,316,080 and 2,316,082 on April 6, 1943, there are described certain types of lubricant additives resulting from the neutralization of the reaction products of phosphorus sulfides and certain hydrocarbons. The neutralization of the reaction product described in said applications is accom- 'plished by means of basic reagents such as the hydroxides, oxides or carbonates of metals of the alkali metal group and the alkalineea'rth metal group. While these neutralized reactionprodnets are very effective in inhibiting carbon and/or varnish formation, under certain conditions they sometimes do not exhibit inhibiting effect. v

We have now discovered that a product having the desired carbonand/o'r varnish formation inthe desired corrosion .tions, etc. I While the basic metallic sulfide-treated phoslubricyants alone or in combination with the alkali hydroxide-neutralized phosphorus sulfide-hydrocarbon reaction product. Improved lubricants are obtained by employing a small amount, for

example, from about .001% to about 10% and preferably from about .5% to about of the sulfide treated reaction product.

The phosphorus sulfide-hydrocarbon reaction products normally show a titratable acidity ranging from about to about 50 milligrams KQH per gram of product. In accordance with the present invention these acidic products are treated 'with a metallic sulfide to effect the neutralization of at least about 1% of the titratable acidity. The term "neutralized, as used herein means a product having at least about 1% of its .titratable acidity reduced by reaction or treatment with a metallic sulfide on the type described.

The hydrocarbon reactant is preferably a, hy-

drocarbon compound having a molecular weight I greater than about 150 and preferably a molecular weight greater than about 300. The hydrocarbons may be paraflins, oleflns or olefin polymers, aromatics, or alkyl aromatics, cyclic aliphatics, petroleum fractions such as lubricating oil fractionspetrolatums, waxes, cracked cycle stocks, or condensation products of petroleum fractions, solvent extracts of petroleumv fracphorus sulfide-hydrocarbon reaction products all impart to a definite degree improved and desired properties to mineral oils to which they are added, all are notnecessarily exactly equivalent in their effectiveness. Most effective and therefore preferred are the basic metallic sulfide-treated reaction products of a phosphorus sulfide and an olefin having at least carbon atoms in the molecule. Such olefins can be obtained by the polymerization of oleflns. by the dehydrogenation of parafilns, such as by the cracking of paraflin waxesjor by the dehalogenation of alkyl halides,

preferably long chain alkyl halides, particularly halogenated paraflln waxes.

We prefer to employ as the hydrocarbon re-' a-ctant olefin polymers, preferably mono-olefin polymers having molecular weights above 150 and referably above 300. As starting materials for hibiting properties as well as much improved corrosion inhibiting properties, can be obtained by neutralizing or treating the reaction product of a phosphorus sulfide and a hydrocarbon with a basic metallic sulfide, preferably an alkali metal.

sulfide or an alkaline earth metal sulfide, such as, for example, sodium sulfide, sodium polysuliide, potassium sulfide, calcium sulfide, etc. Ammonium sulfide can also be used. These metallic sulfide treated reaction products can be used in mally gaseous oleflns.

the roduction of suitable polymers as the hydrocarbon reactant, we can employ the individual olefins themselves. mixtures of olefins or mixtures of olefinsand non-olefinic compounds. For example, the olefinlc starting'material can be propylene. butylenes, amylenes, refinery gases 'containinggnormally gaseous olefins and cracked distillates or other relatively low-boiling hydrocarbon mixtures containing normally liquid? oleflns and mixtures of normally liquid olefins, containing substantial amounts of dissolved nor- The polymers can be those obtained by polymerizing olefinic hydrocarbons in the presence of catalysts such as sulfuric acid, phosphoric acid, or aluminum chloride, zinc chloride, boron fluoride and other catalysts of the Friedel-Crafts type. For example, we may employ the polymers resulting from the treatment of mono-ole fins, .preferably iso-mono-olefins such as isobutylene and isoamylene, and/or the copolymers obtained by the polymerization of hydrocarbon mixtures containing low molecular weight isooleflns and normal olefins, preferably those of less than six carbon atoms.

The polymers employed are preferably mono olefin polymers, in which the molecular weight ranges from about 150 to about 50,000 or more, and preferably from about 500 to about 10,000. These polymers can be obtained. for example, by the polymerization in the liquid phase of an isoolefin, such as isobutylene, or hydrocarbon mixtures containing the same at atemperature of from about 80 F. to about 100 F. in the presence' of a metal halide catalyst of the Friedel- Crafts type, such as boro'n fluoride. In the preparation of these polymers we may employ, for example, .liquid isobutylene or a hydrocarbon mixture containing isobutylene, butane, and butylene, recovered from petroleum gases, especially those gases produced in the cracking of petroleum oils in the manufacture of gasoline. This light fraction may contain from about to about 25% isobutylene, the remainder being principally butanes and normal butylene.

The preparation of low molecular weight polymers having molecular weight ranging from about .300 to about 2000 from the butane-butylenein which n is a whole number, preferably 20 or more, and X is an halogen. We prefer to employ as the alkyl'hydrocarbon to be halogenated paraffin waxes having at least about 20 carbon atoms per molecule, and melting points upwards from about 90 F. and preferably within the range of from about 120 F. to about 140 F.

To obtain the halogenated paraffin wax, for example, chlorinated paraflln wax, we introduce chlorine into the wax, maintained in a molten state, until the wax has a chlorine content of from about 8% to about 15%. The chlorinated wax product is a mixture of unchlorinated wax, monochlor wax and polychlor wax. This chlorinated product may be used as such, but it is advantageous to use the substantially monochlor wax fraction. The monochlor wax fraction can be segregated from the unchlorinated wax and the polychlor wax fractions by taking advantage of the differences in the melting points of the various fractions, since the melting point of the wax varies with the extent of chlorination; i. e. the melting point of the unchlorinated wax is greater than that of the monochlor wax, and the melting point of the latter is greater than that of the polychlor wax. Thus, the monochlor paraffin wax can beseparated from the unchlorinated and the polychlor wax fractions by means such as sweating, fractional distillation, solvent extraction, solvent precipitation, and

' fractional crystallization.

0 F. to about 100 F., and preferably from about 0 F. to about 32 F., and from about'0.1% to about 2% boron fluoride, based upon the isobutylene content of the material treated, is added with vigorous agitation. Excessive rise in the temperature due to the heat of reaction may-be avoided by eflici'ent cooling. After the polymerization of the isobutylene together with a relatively minor amount of the normal oleflns present, the reaction mass is neutralized, washed free of acidic substances arising from the catalyst, the oily layer separated, and the polymer subsequently separated from the unreacted hydrocarbons by distillation. The polymer mixture so obtained, depending upon the temperature of reaction, varies in consistency from a light liquid to a viscous oily material and contains polymers having-molecular weights ranging from about 300' to 2000 or more. The polymers so obtained may be treated with a phosphorus sulfide or the polymer may-be fractionated under reduced pressure into fractions of increasing molecular weights and the various fractions reacted with a phosphorus sulfide and the reaction product treated with the basicmetallic sulfide. I

a Long chain olefines obtained by the dehalogenation of alkyl halides having at least about 20 -carbon atoms in the molecule of which at least The high molecular weight olefins are obtained by removing the halogen as hydrogen halide from the halogenated paraffln wax. For example, the corresponding olefin is obtained from the monochlor paraflin wax by removing the chlorine from the latter as hydrogen chloride. The monochlor wax can be dechlorinated by heating to a temperature of from about 200 F. to about 600 F. in the presence of a dechlorinating agent such as an alkali metal hydroxide or an alkaline earth metal hydroxide or oxide. Other alkaline inorganic or organic materials can also be used. The

- chlorine can also be removed from the chlorowax by heating the same for a prolonged period in the absence of any dechlorinating agent. After the dehalogenation has been completed the olefin so obtained can be further purified by removing the dehalogenating agent by means of filtration or by other suitable means.

Examples of other high molecular weight oleflnic hydrocarbons which we may employ as reactants are cetene (Cm), cerotene (C20), melene (C30) and mixed high molecular weight alkenes' obtained by cracking petroleum oils. Although additives prepared with starting mastarting material the polymer or synthetic lubrieating oil obtained by polymerizing unsaturated hydrocarbons resulting from the vapor phasecracking of paraiiin waxes in the' presence of aluminum chloride which is fully described in United States Patents Nos. 1,995,260, 1,970,002,

and 2,091,398. Still another type of olefin polymer which maybe employed is the polymer resulting from the treatment of vapor phase cracked gasoline and/or gasoline fractionswith sulfuric acid or 'solid' absorbents such as fullers earth whereby unsaturated polymerized hydrocarbons are removed. Also contemplated within the scope of our invention is the treatment with 7 2,877,966 phosphorus sulfide of the polymers resulting from the voltolization of hydrocarbons as described,

for example, in United States Patents Nos.

2,197,768 and 2,19l,78'7.

Another suitable polymer is a fraction of the polymer obtained in the treatment of a gaseous hydrocarbon mixture containing isobutylene and 1 normal butylene in the presence of a phosphoric acid catalyst in the synthesis of isooctane.

Essentially parafiinic hydrocarbons such as bright stock residuums, lubricating oil distillates,

petrolatums, or paraffin-waxes may be used. We 1 may also employ the condensation'products of i any of the foregoing hydrocarbons in the presence of anhydrous inorganic halides, such as aluminum chloride, zinc chloride, boron fluoride and the like.

Also contemplated within the scope of the present invention are the basic metallic sulfide-treated reaction products of a phosphorus sulfide with an aromatic hydrocarbon such as. for example, benzene, naphthalene, toluene, xylene, diphenyl and the like, or with an alkylated aromatic hydrocarbon, such as, for example, benzene having an alkyl substituent having at least four carbon atoms and preferably at least eight carbon atoms such as a long chain parafiin wax.

The phosphorus sulfide reaction product may be obtained by reacting a phosphorus sulfide such as P283, P481, P4S3,, or preferably Pass with a hydrocarbon at a temperature of from about 200 F. to about 500 F., and preferably from about 300 F. to about400 F. It is advantageous to maintain a,non-oxidizing atmosphere, such as, for example, an atmosphere of nitrogen above the reaction mixture. From about 1% to about 50% and preferably from about 5% to about 25% of the phosphorus sulfide can be used. Any excess phosphorus sulfide can be separated from the reaction product after the reaction is completed by filtration or by diluting the reaction mixture with a suitable oil or with solvent, such as hexane,

filtering, and subsequently distilling off the solvent. The reaction mixture can be further treated by blowing with nitrogen'or other inert gases'at an elevated temperature to improve the odor thereof.

The prosphorus sulfide-hydrocarbon reaction product obtained in the manner, above described is then treated with a metallic sulfide such as an alkali metal sulfide or an alkali earth metal sulfide to effect the neutralization of the reaction product. From about-3% to about of the metallic sulfide, based on the weight of the phosphorus sulfide hydrocarbon reaction product, is slowly added to the reaction mixture maintained at a temperature of about 200 F. to about 500 F. Treatment with the metallic sulfide is pref- The mixture was stirred and blown with inert gas at 400 F. for 3 hours. At the'end of this time a clear homogenous product was obtained. This material was diluted with an S. A. E.-20

grade oil to a ccncentration'of 65% additive and oil. The mixture was then heated to 400 F. and 5.5% sodium sulfide (60-62%), based on the weight of the polymer-P285 reaction product, was added slowly over a period, of about two hours. Considerable foaming and hydrogen sulfide evolution was obtained. A smallamount of solid material (less than 1%) was removed by filtering the product through a mat of Celite 501.

Exmtx II The isobutylene polymer of Example I was treated at 400 F. with 25% P285 and 2% sulfur as in the preceding example. The product was diluted to 40% additive concentration with an S. A. E. 20 grade oil and neutralized with 14% sodium sulfide and finished as in Example I.

The efiectiveness of our improved additive in inhibiting the corrosion to metals, particularly to alloy metals of the type of copper-lead alloy bearing metals, is illustrated by the data presented.

below, and obtained in the following tests. In this corrosion test about 250 cc. of the lubricant under:

test and containing 1% of powdered iron, 1% of lead oxide, 0.001% of soluble iron and 0.001% of soluble lead as catalysts, ls maintained at a temperature of about 300 F. and stirred with a glass stirrer rotating atabout 1300 R. P. M. A lead test strip and a copper-lead bearing test strip are suspended in the oil. At stated intervals the test strips are removed froin the oil samples, cleaned, dried, and weighed to determine any loss in weight. 4

y The following oils were subjected to the test above described:

I butylene polymer reaction product neutralized Sample A.-A 20 s. A. E.' high-grade motor oil. Sample B.-Sample A plus 1/2'% of a Pass-isowith KOH. I

Sample C.Sample A plus 1 of the product obtained in Example I above.

Sample D.Sample A plus 2% of the product obtained in Example I above.

erably carried .out in a diluted solution of the reaction product, thus the reaction product may be dissolved in a mineral lubricating oil or any other suitable solventor diluent and the dilutedv product treated with the sulfide. Any solid particles remaining in the product after treatment with the sulfide are removed by filtering throug a suitable filtering medium.

As a specific embodiment of our invention the following examples are given by way of illustration and arenot intended aslimitations thereof.

Exmtz I An isobutylene polymer having a Saybolt viscosity at 210 F. of 1000 seconds and an average molecular weight of about 1000 was treated at 400. 1". with 10% by weight of Pass. Two percent by weight of sulfur was added as a catalyst.

p mple A plus il /2% of the product obtained in Example I above.

Sample l".--Sample A plus 3% of the'product obtained in Example I above.

sample G.Sample A plus 1 5% of the product obtained in Example II above.

Sample H.--Sample A plus 2% of the'product The corrosion inhibiting effectiveness of this present invention is well illustrated by the above data. a j

In another test the corrosion inhibiting property of an additive was determined in a standard six cylinder spark ignition engine operated at an oil sump temperature or about 285 F. and the corrosion to copper lead alloy bearings determined. Samples B, C.- and F were subjected to this test with the following results:

Table II Hqurs for rapid corroslon to begin The sludge and varnish inhibiting properties of our new additive are demonstrated by the data presented in Table III which were obtained in thefollowing manner: About 250 cc. of the oil to be tested is heated at about 330 to 332 F. in

a 500 cc. glass beaker in the presence of 5 sq. in. of copper at sq, in. of iron. Four glass rods of about 6 millimeter diameter are suspended in each oil sample which is stirred at about 1300 R. P. M. with-a glass stirrer having a 40 degree light pitch. At stated intervals samples (if the oil are taken and sludge, acidity and viscosity values determined. The glass rods are also inspected for evidence of varnish formation thereon. Varnish values are based on a visual rating in which a glass rod, free of any varnish, is given a rating of 10, while a badly coated rod is given a rating of 1. Rods having appearances between these extremes are given intermediate values.

tests and the data obtained as tabulated in Table III.

Sample 1.S. A. E. high grade motor oil. Sample 2.Sample 1+% PzSs-isobutylene polymer reaction product neutralized with KOH.

.Sample 3.Samp1e 1+%% PzSs-isobutylene polymer reaction product neutralized with NaaS.

Table 111 Sludge mg./l0 g. oil

Acidity mg. KOH/g Varnish 1 Viscosity oil increase,

Sample No. 48 hrs.

'24 hrs.

48 hrs.

48 hrs.

24 hrs. hrs.

1 Saybolt Universal Viscosity at 100 F. 9 Rating Scale10=no deposit, l=very heavy deposit.

The above data demonstrates that in addition The fol-- lowing samples were subjected to the foregoing to its corrosion inhibiting property, our imor other lubricants to give a finished product of the desired additive content. Thus a concentrate containing more .than 10% by weight of the additive can be diluted with a mineral oil to give a product containing from about 0.01% to bout 1 of the additive.

Whil'ewe' have described the use of our additives inlubricating oils, our'inventi'o'n is not limited to such use, since these reaction products may be employed in other petroleum products such as insulating oils, white oils, greases, waxes, and the like to increase the resistance thereof to oxidation, sludging and to inhibit the tendency thereof to corrode metals. While we have described preferred embodiments of our invention, other modifications thereof may be made without departing from the scope and spirit of the invention, and we do not wish .to limit our invention to the examples set forth herein except insofar as the same is defined by the following claims.

We claim:

1. As a new phosphor-usand sulfur-containing composition of matter the phosphorus sulfideh'ydrocarbon reaction product reacted with a basic metallic sulfide.

2. As a new phosphorusand sulfur-containing composition of matter the phosphorus sulfideolefin reaction product reacted with a basic metallic sulfide.

3. As a new phosphorusand sulfur-containing composition of matter the phosphorus sulfide-.

olefin polymer reaction product reacted with a basic metallic sulfide.

4. As a new phosphorusand sulfur-containin composition .of matter the phosphorus sulfidemono-olefin polymer reaction product reacte with a basic metallic sulfide.

5. A new composition of matter as described in claim 4 in which the basic metallic sulfide is an alkali metal sulfide.

6. A new composition of matter as described in claim 4 in which the basic metallic sulfide is an alkaline earth metal sulfide.

7. An improved lubricant comprising a lubricating oil and a small amount of the phosphorusand sulfur-containing phosphorus sulfide-hydrocarbon reaction product reacted with a basic metallic sulfide.

8. An improved lubricant comprising a lubricating oil and a small amount of the phosphorusand sulfur-containing phosphorus sulfide-olefin reaction product reacted with a basic metallic v sulfide.

9. An improved lubricant comprising a lubricating oil and a small amount of the phosphorusand sulfur-containing phosphorus sulfide-olefin polymer reaction product reacted with a metallic sulfide selected from the class consisting of alkali metal sulfides and alkaline earth metal sulfides.

10. An improved composition of matter comprising mineral oil and a small amount of the phosphorusand sulfur-containing phosphorus sulfide-mono-olefin polymer reaction product reacted with a metallic sulfide selected from the class consisting of alkali metal sulfides and alkaline earth metal sulfides.

11. A new composition of matter as described in claim 9 in which the metal sulfide is sodium sulfide. Y

l2. Anew composition of matter as described in claim 9 in which themetal sulfide is potassium sulfide.

13. An improved composition comprisin a mineral oil and a minor amount of a basic metallic sulfide-neutralized reaction product of a phosphorus sulfide and an olefin hydrocarbon having at least about 20 carbon atoms in the molecule, said basic metallic sulfide neutralized reaction product containing phosphorus and sulfur.

14. An addition agent for mineral oils comprising a concentrated solution in a mineral oil of a phosphorusand sulfur-containing basic metallic sulfide-neutralized reaction product of a phosphorus sulfide and a hydrocarbon, said conof dilution with a mineral oil to form a homogeneous mixture containing from about 0.01% to about 10% by weight of said basic metallic sulfide-neutrallzed reaction product of a phosphorus centrated solution containing more than about 5 sulfide and a hydrocarbon.

10% by weight based on the oil of said neutralized reaction product, said solution being capable LAWSON W. MIXON. CLARENCE M. LOANE.