US2501991A - Phenate compounded oils - Google Patents

Description

Patented Mar. 28, 1950 UNITED STATES PATENT OFFICE PHENATE COMPOUNDED QILS No Drawing. Application October 28, 1946, Serial No. 706,083

11 Claims.

This invention relates to mineral lubricating oils and the like; more particularly, it relates to mineral lubricating oils containing a small amount of a metal salt of a phenol havin as a nuclear substituent, an alkoxyl radical in which the alkyl radical is of sufficiently high molecular weight to render the compound soluble in the mineral base oil.

It is a common expedient in the art of motor lubricating oils to incorporate in the oil a small amount of a detergent to inhibit piston ring sticking and promote cleanliness of the piston, piston rings, etc. Among the most advantageous detergents, and perhaps the best detergents currently used, are metal salts of phenols. Examples of these are calcium cetyl phenate, calcium and barium salts of wax-substituted phenols, calcium and barium salts of dialkyl diphenol monosulfides and disulfides and sulfurized calcium cetyl phenate. See, for example, the following United States Patents: Dension et al. No. 2,228,661, Reifi No. 2,197,833, Mikeska No. 2,362,289, Etzler et al. No. 2,360,302.

It is an object of the present invention to improve upon the use of phenates as additives for mineral lubricating oils and the like.

It is a further object of the invention to provide a new and useful class of phenates which are capable of producing a greater improvement in motor lubricating oils than phenates presently in use.

It is a particular object of the invention to provide motor lubricating oils compounded with phenates, which are capable of longer service than phenate-compounded oils currently in use.

These and other objects of the invention will be apparent from the following description and the appended claims.

In accordance with the invention, there is incorporated in an oil of lubricating viscosity a small amount of a compound of the following formula:

in which A is an aromatic nucleus, M is a saltforming atom or radical, and R is an oil-solubilizing aliphatic group containing not less than carbon atoms.

By aliphatic group as thus used is meant a group attached to the oxygen through a nonbenzenoid carbon, and it includes alkyl, alkylene, cycloaliphatic and aralkyl groups.

Preferably, this additive compound is a derivative of a dihydric phenol in which the hydrogen of one hydroxyl group is substituted by a metal to form a metaloxy group and the hydrogen of the other hydroxyl group is substituted by an oil-solubilizing alkyl radical containing not less than 5 carbon atoms. Preferably, the group R contains 10 to 30 carbon atoms.

Specific examples of additive compounds of the invention are as follows: lithium, sodium, potassium, calcium, strontium, barium, zinc and aluminum salts of ortho, meta and para pentoxy, octoxy and decoxy phenol, and the same metal salts of ortho, meta and para dodecoxy, cetoxy, octadecoxy, eicosoxy, paraffinoxy, amylcyclohexoxy and phenylmethoxy phenols. These par ticular salts have the generic formula in which M is lithium, sodium, potassium, calcium, barium, zinc or aluminum; R is an amyl, octyl, decyl, dodecyl, cetyl, octadecyl, eicosyl, paraffin wax, amylcyclohexyl or benzyl group, and the group -0R is in the ortho, meta or para position with respect to the -0M group. The other valence (or valences in the case of aluminum) of the metal M may be satisfied by another similar radical (as in the normal salts) or by a diiierent radical (as in mixed salts and basic salts).

Other metals, for example, cadmium and nickel, may be used in place of those specifically illustrated above; other aliphatic radicals may be used in place of those illustrated above and the nucleus to which the ether and metaloxy radicals are attached may be a, polycyclic nucleus such as the naphthalene nucleus. Also, the aromatic nucleus may contain other substituents such as alkyl, nitro and chloro substituents.

The preferred metals are the alkaline earth metals and the normal salts are preferred to the basic salts.

The base oil to which the additives of the present invention are added may be any hydrocarbon oil of lubricating viscosity, for example, paraffinic, naphthenic and mixed base mineral lubricating oils, polypropylenes, polybutenes and synthetic hydrocarbon lubricating oils derived from coal and oxides of carbon. The additives may also be used in non-hydrocarbon lubricating oils, such as, polypropylene oxides. Preferably, the base oil is a petroleum lubricating oil of 150 to 3000 S. S. U. at F.

Additives of the invention may be incorporated in the base oil in amounts ranging from about 0.1% to 2.5%, preferably about 0.3 to 1.5%, proportions being by weight based on finished oil. Greater proportions may be used if desired; for example, to produce concentrates or stock solutions which are useful for later blending with more oil to produce the finished product. Thus, a concentrate containing to 70% of additive may be employed.

The following specific examples will serve to illustrate a mode of preparation of the additive compounds of the invention and use of these compounds in oils.

EXAMPLE 1.PREPARATION OF BARIUM META CETOXY PHENATE Equimolar proportions of resorcinol and cetyl chloride were dissolved in Cellosolve (trade-name of a product of Carbide and Carbon Chemicals Corp being the mono-ethyl ether of ethylene glycol) and the solution was heated to reflux. To the refluxing mixture was slowly added solid potassium hydroxide and the refluxing was continned until all of the cetyl chloride had reacted. The Cellosolve was then removed by distillation and the reaction mixture was washed out of the flask with a petroleum thinner. Unreacted resorcinol and potassium chloride were washed out of the solution, first with water and then with 50% aqueous alcohol. The resorcinol monocetyl ether was recovered from the thinner solution as the potassium salt by washing with potassium hydroxide in 50% aqueous alcohol. The alkaline alcoholic solution was acidified and the liberated resorcinol monocetyl ether was extracted with petroleum ether and freed of petroleum ether by heating to 250 F. The normal barium salt was prepared by reacting the resorcinol monocetyl ether with barium oxide and the final product was recovered by extraction with lubricating oil to produce a concentrate.

The starting material need not be a pure polyhydric phenol, such as resorcinol, but may be a crude mixture of polyhydroxy benzenes or homologues of the same. In general, however, meta dihydroxy benzene and homologues of the same are preferred and where a crude mixture is used as the starting material, it is preferred to use a mixture in which the meta compounds predominate.

In alkylating the polyhydrie phenol, it is not necessary to use a pure aliphatic chloride such as cetyl chloride, but crude mixtures such as chlorinated kerosene and chlorinated paraifin wax having an average molecular weight of 175 to 455, and preferably containing about one gram atom of chlorine per average gram molecular weight of mixture, may be used to alkylate the polyhydric phenol.

A further improvement in the preparation of the additive materiais of the invention is the employment of an excess of the polyhydric phenol. Such excess decreases the yield of diether and increases the yield of the desired monoether.

EXAMPLE 2.ENGINE TESTS Oils compounded with additive agents of the invention and also, for comparison, a reference oil, were tested in a Lauson engine. This engine is a single cylinder gasoline engine, 2% inch bore and 2 inch stroke. Except as otherwise indicated, the engine was operated at 375 F. jacket,

4 300 F. oil temperature and 1200 R. P. M. Results obtained are given in Table I below:

Basc oil was SAE 50 California paraihnic oil. Jacket temperature was 460 F., oil temperature was 375 F. All other base oils were SAE 30 blends of paralfinic and naphthenic oils.

Piston discoloration numbers (PD Nos.) as given in the table were determined by dis-assemcling the test engine at the end of 30 hours, and again after 60 and hours, and inspecting the piston. A compl tely clean piston is rated as showing a PD No. of zero, a completely fouled piston as having a PD No. of 809. Further refinements were employed in arriving at PD Nos. but, for comparative purposes and since the same method was used in all cases, need not be given here.

As a basis of comparison, a reference oil (a commercially available, heavy duty motor oil compounded from the same base oilan SAE 30 blend of solvent refined parafiinic and naphthenic oils and a sulfurized calcium 1 phenate, a phosphate and a sulfide-type oxidati inhibitor) was similarly te-ted at repeated intervals interspersed among the tests on the oils of Table I. At 90 hours, this oil gave a PD No. of 395, at 60 hours the PD NO. averaged about 300 and at 30 hours the PD No. averaged about 90.

The barium m-, oand p-cetoxy phenates of Table i were the normal barium salts of the monocetyl ethers of m-, oand p-dihydroxy benzenes, respectively; the barium salt of the 50-50 mixture was likewise a normal salt; and the barium tert.butyl-o-cetoxy phenate was the normal barium salt of a monocetyl ether of an ortho dihydroxy benzene containing a nuclear tert.-butyl substituent.

The additive agents of the invention may be used as the sole compounding agents in lubrica ing oil. However, they are advantageously used in combination with other additive agents, such as, oxidation and corrosion inhibitors; for example, dicetyl sulfide and diparaiiin sulfide (produced by chlorinating paraffin wax and condensing the chlorinated paraffin wax with sodium sulfide or sodium polysulfide). Also phosphates and thiophosphates, such as, calcium cetyl phosphate and calcium and Zinc cetyi thiophosphate and cetylphenyl thiophosphate may be incorporated in lubricating oils along with the additives of the invention. Such sulfides, phosphates and thiophosphates are advantageously used in conjunction with the additive materials of the invention. These materials, like other phenates, have some tendency to corrode hard alloy bearings, such as copper-lead and cadmium-silver bearings, and the sulfides, phosphates and thicphosphates inhibit such corrosion.

We claim:

l. A composition of matter comprising a major proportion of a hydrocarbon oil of lubricating viscosity and about 0.1 to 2.5% by weight based on finished oil, of an alkaline earth metal salt of a phenol containing attached to the aromatic nucleus the group OR,wherein R is an aliphatic group attached to oxygen through carbon and contains 5 to 30 carbon atoms, and wherein the position of the OR group in relation to. the metaloxy group is selected from the class-of meta and para positions.

2. The composition of claim 1, in which the additive material is an alkaline earth metal salt of a dihydric phenol in which the hydrogen of one of the hydroxy groups is substituted by an aliphatic radical containing 5 to 30 carbon atoms.

3. A hydrocarbon lubricating oil containing about 0.1 to 2.5% by weight based on finished oil of an alkaline earth metal salt of ajdihydric phenol in which the hydrogen of one of the hydroxy groups is substituted by an aliphatic radical containing 5 to 30 carbon atoms, said dihydric phenol being selected from the group consisting of meta and para dihydric phenols.

4. The oil of claim 3, in which the aliphatic group is an alkyl radical containing to 30 carbon atoms.

5. A mineral lubricating oil containing about 0.1 to 2.5% by Weight based on finished oil of an alkaline earth metal salt of resorcinol in which the hydrogen of one of the hydroXygroups is substituted by an aliphatic radical containing 5 to 30 carbon atoms.

6. The oil of claim 5, in which the alkaline earth metal is calcium.

7. The oil of claim 5, in which the alkaline earth metal is barium.

8. A mineral lubricating oil containing about 0.1 to 2.5% by weight based on finished oil of an alkaline earth metal salt of resorcinol in which the hydrogen of one of the hydroxy groups is substituted by an aliphatic radical containing 10 to 30 carbon atoms.

9. The oil of claim 8, wherein said salt is barium m-cetoxy phenate.

10. A mineral lubricating oil containing about 0.1 to 2.5% by weight based on finished oil of an alkaline earth metal salt of hydroquinone in which the hydrogen of one of the hydroxy groups is substituted by an aliphatic radical containing 10 to 30 carbon atoms.

11. The oil of claim 8, wherein said salt is barium p-cetoxy phenate.

JAMES o. CLAYTON. WILLIAM H. ALDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,067,960 Werntz Jan. 19, 1937 2,197,833 Reiff Apr. 23, 1940 2,310,710 Rosenwald Feb. 9, 1943 2,344,988 Kavanagh Mar. 28, 1944 2,402,448 Richards June 18, 1946v

Claims (1)

1. A COMPOSITION OF MATTER COMPRISING A MAJOR PROPORTION OF A HYDROCARBON OIL OF LUBRICATING VISCOSITY AND ABOUT 0.1 TO 2.5% BY WEIGHT BASED ON FINISHED OIL, OF AN ALKALINE EARTH METAL SALT OF A PHENOL CONTAINING ATTACHED TO THE AROMATIC NUCLEUS THE GROUP O-R, WHEREIN R IS AN ALIPHATIC GROUP ATTACHED TO OXYGEN THROUGH CARBON AND CONTAINS 5 TO 30 CARBON ATOMS, AND WHEREIN THE POSITION OF THE O-R GROUP IN RELATION TO THE METALOXY GROUP IS SELECTED FROM THE CLASS OF META AND PARA POSITIONS.