US2412903A - Compounded lubricating oil - Google Patents

Description

Patented Dec. 17, 1946 COMPOUNDED LUBRICATING OIL Robert J. Miller and John T. Rutherford, Berkeley,. Calif., assignors, by mesne assignments,

to California Research Corporation, San Franciso, Califi, a corporation of Delaware No Drawing. Application February 1, 1944, Q H J 'Serial No. 520,686 i This invention relates t6 hydrocarbon lubricating oils containing a new and useful combination 7 of addition agents.

This application is a continuation-in-part of our copending application Serial No. 441,964, filed May 6, 1942, now United States Patent No.

I 2,363,012, issued November 21, 1944.

manifests itself in a fouling of the piston by.

gummy deposits, in the tightening and sticking of piston rings, in wear of moving parts and corrosion of copper-lead and other similar alloy bearings, and, eventually, in engine failure.

It is an object'achieved by this inventionto provide a hydrocarbon lubricating oil which will resist deterioration caused by heat and oxidation.

It is a further object achieved by this invention to provide a petroleum lubricating oil compounded with such addition agents that it will give more satisfactory performance as a, crankcase lubricant for heavy duty service than theuncompounded oil. i

It is a particular object achieved by thisin vention to provide a simple type ofcompounding for mineral lubricating oils which Will provide a marked improvement of the quality of the oil for heavy duty service yet which is' more simple and less expensive than many types of compoundin used today. i

It is a further particular object achieved by the present invention to provide a type of compounding for mineral oil lubricants that is superior to most of the present day compoundings yet which is relatively inexpensive.

These and further objects achieved by the invention will be apparent from the following description and the appended claims. 7 9

We have found that a mark'ed'improvement in hydrocarbon oils of lubricating viscosity canbe effected by incorporating in the oil a small amount ot a metal salt of a phenol and of a metal salt of a thiocarbamic acidj i The compounding thus used has been found to produce exceptionally good improvement of mineral lubricating oils and the preferred metal salts used as the compounding areamong the least expensive of lubricant addition agents.

10 Claims. (01. ass- 33.6) E 5 vli'olyvalent 'metal salts of alkyl phenol and 'cresols containing 4 to 20 carbon atoms in one or more akyl groups, and more es-'. pecially the polyvalent metal salts of bis-(alkyl phenol) sulfides and disulfides and sulfurized' polyvalent metal alkyl phenates containing 4' to 20 carbon atoms in one or more alkyl roups, are preferred in the compounding of the present invention. Metal salts of naphthols may 'also be used... Metal salts of phenols such asdisclosedin ReifL'iUnit'ed States, Patent 2,197,833; Gardiner e't'ali, UnitedStat'es Patent 2,211,972; Denisonjet al., United States Patent 2,228,654; Mikeska et 2.1., United States Patent 2,195,539 and Meinert et a1., United States. Patent 2,230,542 may be used in the combination of this invention. 1 The: metal salts ofthiocarbamic acids; which form the second component of'the combination of addition agents of thisinvention, may be rep resented by the formula wherein R1 and Rz are hydrogen or oil-solubiliz; ing organic groups, at least one R being an oil; solubilizing organic group X 1 and Xz are oxygen orsulfur, at least one Xbeing sulfur; and M isa m a ef ably h se nd component p the o b t of; a d ti n, a e .v s a p r enli metal dithiocarbamatej (i. e., M is apolyvalent m a an X nl:. .a .e b th. fur s-wbfl b bot -Brand B; a enas o hy ro bm Sims-,- ture, $29 as po rvale t e a di ut di h ecari e s. lyv me al; p n d h o ari bamates gand polyvalent metal dithiocarbamates derived from cyclic amines such as piperidine and its homologues; e. g., the polyvalent metalpea troleum nitrogen base dithiocarbamates pro-, duced as described in detail in copending United States Patent application Serial No. 441,964, filed May 6, 1942, now United States Patent #2363,- 012. These polyvalent metal petroleum nitrogen base dithiocarbamates are preparedby extracting p ridine as from cra ked. p e in the extracted bases to the piperidine bases, reacting the piperidine bases with carbon disulfide in aqueous or alcoholic caustic soda or-caustic potash and adding a water-soluble polyvalent-metal salt to an aqueous solution lof. v.the alkali metal petroleum nitrogen base dithiocarbamate to pros duce double decomposition and precipitation of the polyvalent metal petroleum nitrogen base di thiocarbamate. The pclyvalent metal dithiocarbamate may be purified by crystallization from a suitab-lesolvent, such as a light hydrocarbon substituted thinner. The aforesaid polyvalent metal petroleum nitrogen base dithiocarbamates are the preferred dithiocarbamates of the invention.

In the specification and in the claims, where a is employed, wherein M represents the metal and the residue represents the acid radical, it is to be understood, where M is a polyvalent metal, that the other valences of the metal besides the single valence shown in the formula will be satisfied by the same or other acid radicals, or by an hydroxyl group or groups as in the basic salts. But where a complete formula is given, such as R2 I 4: wherein the subscript a is designated as the valence of M, all the valences of M are accounted for in the formula.

The following specific examples will serve-to illustrate the practice and advantages of the pres ent invention.

Example 1.-Various uncompounded and compounded petroleum lubricating oils were subjected to test in a single cylinder Lauson gasoline engine. This engine, having a-2%" bore, 2 stroke, was operated under severe conditions to develop any tendency of the oil to cause piston discoloration, 40 ring sticking and the like: 1200 revolutions per minute, jacket temperature of 375 F., sump oil temperature of 300 F. The engine was inspected after 30 hours and again after 60 hours of operation. The engine inspection included observation of the condition of the piston rings (whether stuck or not) and of the amount of lacquer and gum deposits on the piston skirt. The lacquer and. gum deposits on the piston skirt were determined visually and expressed as Piston Discoloration No. (PD No.). The PD No. rating was accomplished by a widely used method, as follows: The piston skirt surface is divided into the thrust surface and the anti-thrust surface, which are of equal area. Each area is inspected to determine the percentage which is black, percentage dark brown, percentage brown and percentage light brown. Since the darker areas are more serious and represent thicker deposits of gum and lacquer, they are weighted. The 60 weights assigned the black, dark brown, brown and light brown areas are 4, 3, 2 and 1, respectively. The calculation of PD No. is as follows:

w. Ul

65 Thrust Anti-thrust surface surface Percentag'e'of area 'blaekX4. c A A Percentage of area dark brownXB B B Percentage of area brown 2 C 0' Percentage of area light brownXl D D 70 Total E E n: No.=E+E'.

Thus a completely black piston skirt gives a PD 75 No. of 800 and a completely clean piston skirt gives a PD No. of zero.

Table I Piston discoloration number Base oil Compounding hrs. 60 hrs.

S. E. 30 blended Nil 700 Do Commercial compoundingA 80 270 Do 1% sulfurized Ga cetyl phe- 150 nate+l% Zn petroleum nitrogen base dithiocarbamate. Do 2.2% Paranox 56"+1% Zn 7O petroleum nitrogen base dithiocarbamate. Do 1% sulfurized Ca cetyl phe- 35 55 nate+1% Zn dibutyl dithiocarbamate. D0 1% sulfurized Ca cetyl phe- 135 300 nate+l% Cd petroleum nitrogen base dithiocarbamate.

The S. A. E. 30 blended oil was a blend consisting of 70% solvent treated California naphthenic oil (viscosity index= 25 and 30% California paraffinic oil (V. 1:85). the blend was 57.

In the above table, the hour piston discoloration N0. of the base oil was obtained by extrapolation; actually, under the severe conditions of operation, the engine could not be run safely for 60 hours with the uncompounded oil since ring sticking and engine failure would have occurred. With all of the compounded oils, no ring sticking occurred in 60 hours operation. Commercialcompounding A consisted of a phenate, a phosphate and a sulfide and is a compounding which is in wide commercial use in heavy duty oils. The various other compounding agents were as follows: I

butene polymer (average molecular weight about i 194 and boiling range about 375 to,500 F.) are slowly added 140 cc. of 94% sulfuric acid with stirring of the mixture and cooling to maintain,

the temperature below F. The mixture is agitated for two hours after addition of the acid,

cooled to room temperature, diluted with an equal volume of water and heated in an autoclave at 350 F. one hour with agitation. Water is separated and the nonaqueous phase washed with 5% sodium carbonate solution to free it from sulfuric acid, sulfonic acids and unreacted phenol. The product recovered was a high molecular weight, Water-insoluble alkyl phenol having an acetyl number of 181.

68 5 grams of alkylated phenol prepared as described above are agitated six hours at 500-540 F. with grams of calcium carbide, yielding the calcium alkyl phenate. This is sulfurized by being dissolved in hydrocarbon lubricating oil to form a 50%solution, adding gram atom of sulfur per gram mol of calcium alkyl phenate and heating the mixture at 300 to 320 F. for one hour. The reaction mixture is then blown with air until it no longer darkens a copper strip immersed in the hot mixture. The oil solution is then added to the oil which it is desired to compound. i

The zinc and. cadmium petroleum nitrogen base dithiocarbamates were prepared as described in Example 1 of the aforesaid copending application Serial No. 441,964. They are each Viscosity index of a mixture of compounds which may be represented by the formula I in which the six membered rings containing nitrogen are piperidine rings, each containing one or more alkyl groups (indicated by R and R), and in which M represents zinc or cadmium.

Paranox 56 is the trade name of a lubricant addition agent sold by Paraflow Sales Division of Stanco Distributors, Inc. It is the barium salt of a bis-(alkyl phenol) -disulfide.

Zinc dibutyl dithiocar-bamate is a compound of the formula and is commercially available under the trade name of Dibutyl Zimate.

It is apparent from Table I that the compounding of the present invention not only greatly improves the base oil but that the compounded In Table II, figures in parentheseswere obtained by interpolation and extrapolation. The Zn Salt is the same salt as the Zn petroleum nitrogen base dithiocarbamate of Table I. The calcium cetyl phenate is the unsulfurized calcium phenate described above in connection with the manufacture of sulfurized calcium cetyl phenatej i. e., it is the unsulfurized calcium salt of the alkylated phenol described above. 10"

The oxygen absorption test from which the figures of Table II are taken was carried out as follows: Samples of grams each of base oil and compounded oil were taken and oxygen was bub-. bled through each sample, the temperature of the oil being maintained at 340 F. and all other conditions, such as oxygen pressure and rate and. duration of bubbling, being maintained the same for each sample. Part of the oxygen was absorbed by the oil, the amount absorbed being determined by calculating the difference between unabsorbed oxygen and the oxygen fed to the sample of oil.

The Ca cetyl phenate and Zn dithiocarbamate of Table III were the same as the Ca cetyl phenate and Zn salt, respectively, of Table II.

The corrosion test from which the figures of Table III were taken is the test described in United States Patent No. 2,228,658 to Farrington et al. at page 3, right-hand column, lines 2'7 to 65. Briefly, the test comprises bubbling air through an oil maintained at 300 F. and at 24 hour intervals weighing strips of copper-lead and cadmium-silver bearing-type alloys which are kept immersed in th oil, to determine the loss in weight of the strips. This loss in weight is a measure of the amount of corrosion, being greater the greater the corrosion.

The addition agents of this invention may be used in a Wide variety of oils, such as paraffinic, naphthenic and mixed base lubricating oils, oils produced by polymerization of olefin, synthetic lubricating oils, etc. Oils of widely varying viscosity, e. g. 50 S. S. U. at 100 F. to 300 S. S. U.

Table II Cubic centimeters of oxygen absorbed aiter' Oil 0.5 hour 0.92 hour 1.0 hour 1.42 hours 1.5 hours 2.0 hours 2.42 hours 2.5 hours 8. A. E. 30 Pennsylvania (paraflinic) oil 68 130 178 254 302 Same+0.5% of Zn salt (25) 38 (39) 45' (49) 57 69 (70) Same+0.5% of Zn salt+0.5% Ca cetyl 1uhenate. (55) 66 (68) (83) 90 (91) Same+0.25% of Zn salt+0.5% Ca cety phenata- (60) (82) 94 (96) 112 224 (350) Same+0.l% of Zn salt+0.5% Ca cetyl phenate (60) 82 (99) (113) (200) Table III Weight loss of strip in milligrams Base oil Additives Cu-Pb alloy Cd-Ag alloy 24 hours 48 hours 72 hours 24 hours 48 hours 72 hours California paraffinic base oil 0.6% Ca cetyl phenate 4. 5 19. 5 27. 4 0 0 0 Do 0.5% Ca cetyl phenate+0.25% Zn dithio-' 1.2 5.3 24.4 0 0 0 carbainate. D0 0.5% Ca cetyl phenate+0.5% Zn dithio- 0.8 1.0 1.9 0.1 0.1 0. carbamate. Pennsylvania araiiinic base oil. None 1. 6 4. 5 11. 2 0.1 0.1 0. Do 0.5 Zn dithiocarbamata". 0. 9 1. 3 l. 9 0.1 0. 2 0. 0.75% Ga cetyl phenate 18. 5 107. 3 166. 6 5. 9 111.9 21-5. 0.5% Ca cetyl phenate+0.25% Zn dithio- 1.0 17. 2 51. 9 0.1 8.5 31.

carbamate. I 0.5% Ca cetyl phenate+0.5% Zn dithio- 0.7 '2.6 16.2 0.1 0.2 0.

carbamate. 1 I None 0.2 0.0 +0. 6 +0. 2 +0. 2 +0. 1% Zn dithiooarbamate 0. 0 0.0 +2. 2 '+0. 1 +0. 1 0. 0.5% Ca cetyl phenate 17.0 44.0 81.5 3.7 36.4 Er. 0.5% Ca cetyl phenate+0.5% Zn dithio- 0.7 7.6 34.7 0.1 0.4 0. carbamate.

at 210 F. may be compounded with the addition agents of the invention. Amounts of addition agents used will vary with the base oil and the type of service. In general, amounts ranging from about 0.1 to per cent each of phenate and thiocarbamate will be used, preferably about 0.25 to 2 percent each. (All percentages throughout the specification and claims are percentages by weight based on finished oil unless otherwise indicated.) Concentrates of the addition agents in hydrocarbon lubricating oil, such as petroleum lubricating oil, may be prepared for later blending with more oil to produce the finished oil. For example, concentrates containing up to phenate, up to 25% thiocarbamate and or more hydrocarbon. lubricating oil; concentrates containing up to 50% phenate, up to 25% thiocarbamate and 25% or more of hydrocarbon lubricating oil; and concentrates containing up to 25% phenate, up to 50% thiocarbamate and 25% or more hydrocarbon oil, all percentages being by weight based on concentrate, may be prepared. v

As stated, polyvalent metal phenates and polyvalent metal thiocarbamates are preferred.

Sodium, potassium and lithium phenates and/0r dithiocarbamates are preferred. Monothiocarbamates may be of two types: (1) thiolcarbamates and (2) thionocarbamates (almN-r -oau) s tives of primary and secondary amines:

Amine residue CXIXBM wherein both of the HS are hydrocarbon or substituted hydrocarbon groups or one B, is a hydrocarbon or substituted hydrocarbon group and the other R is hydrogen. In the first case the thiocarbamate may be looked upon as a derivative of a secondary amine and in the second case, as a derivative of a primary amine. Both types of thiocarbamates may be used in the combination of addition agents of this invention, but the first calcium,

Thiocarbamates may be looked upon as derivatheir oil solubility may be improved by substitu tion of alkyl groups on the phenyl groups.

Examples of phenates and thiocarbamates that may be used in combination with each other according to the invention are as follows:

Phenates.-Calcium p-tert. amyl phenate; barium 2,4-di-tert. butyl phenate; lithium, magnesium, aluminum and basic barium hexadecyl phenates; calcium parafl'in phenate (i. e., the normal calcium salt of the product of nuclear condensation of chlorinated parafiln wax with phenol, in the presence of a Friedel-Crafts catalyst); barium o-cyclo-hexyl phenate; cal cium o-phenyl phenate; chlorophenate; normal barium salt of bis-(ditert. amyl phenol) -sulfide; normal barium salt of bis-(4,6-di-tert. butyl-m-cresol)-disulfide; sulfurized calcium 4,6-di-tert. butyl-ni-cresylate; calcium hexadecyl amino, nitro and thiophenates; and calcium cetyl hydroxy thiophenate.

Thz'ocarbama'tera-Calcium, lead, zinc and cadmium dibutyl dithiocarbamates; zinc methyl octyl dithiocarbamate; zinc dicetyl dithiocarbamate; zinc diamyl thiolcarbamate; zinc diamyl thioncarbamate; zinc monocetyl dithioarbamate; zinc butyl amylphenyl dithiocarbamate; calcium di-cyclohexylphenyl dithiocarbamate; calcium, zinc, cadmium and potassium petroleum nitrogen base dithiocarbamates (produced as described in Example 1 of said copending application serial #441,964, new United States Patent #2,363,012; zinc dibenzyl dithiocarbamate; zinc di-cetylphenyl dithiocarbamate; and zinc diamylpiperidyl dithiocarbamate.

, Examples of finished oils of this invention are as follows:

Example 2.-96-99.5% S. A. E. 30 Pennsylvania oil; 0.25-2% Ba 2,4-di-tert. butyl phenate; 0.25- 2% Zn petroleum nitrogen base dithiocarbamate. Example 3.9699.5% S. A. E. 30 naphthenic oil; 0.25-2% Ca cetyl phenate; 0.25-2% Zn dibutyl dithiocarbamate.

Example 4.96-99.5% S. A. E. 30 mixed base boil; 0.25-2% sulfurized Ca cetyl phenate; 0.25- 2% Cd dibutyl dithiocarbamate.

Example 5.-96-99.5% S. A. E. 30 blended paraffinic-naphthenic oil; 0.25-2% Ba salt of bis-(di-v amyl phenol) -sulfide; 0.25-2% Ca di-cetylphenyl dithiocarbamate.

Besides the ingredients indicated, the finished oils may contain other ingredients, such as extreme pressure agents, blooming agents, pour point inhibitors, etc.

We claim:'

1. A compounded lubricant comprising a major portion of hydrocarbon lubricating oil, from about 0.1 to about 5% by'weight based on the compounded lubricant of an oil-soluble alkaline earth metal phenate and from about 0.1 to 5% by Weight based on the compounded lubricant of an oil-soluble Zinc thiocarbamate.

2. A compounded lubricant as defined in claim 1 wherein the alkaline earth phenate is a sultype (derivatives of secondary amines) is pre ferred.

The more oil-soluble thiocarbamates are precarbamates, such as zinc diphenyl dithiocar bamate, are not as oil-soluble asis -desirable, but.

The diphenyl 1.11101 furized salt of an alkyl phenol.

1 wherein the alkaline earth phenate is a sulfurized calcium salt of an alkyl phenol. 4. A-compounded lubricant as defined in claim 1 wherein the alkaline earth phenate is an alka- .line earth metal salt, of a bis-(alkyl phenol) -sulfide. 1 5. A compounded lubricant as defined inclaim 1 wherein the alkaline earth phenate is a barium salt of a bis-(alkyl phenol) -sulfide.

. .6...A compounded lubricant as 'definedin claim calcium hexalecyl.

3. A compounded lubricant as defined in claim 1 wherein the zinc carbamate is a zinc dithiocarbamate of an aliphatic secondary amine.

'7. A compounded lubricant as defined in claim 1 wherein the zinc carbamate is a zinc dithiocarbamate of a mixture of reduced cyclic petroleum nitrogen bases.

8. A compounded lubricant as defined in claim 1 wherein the zinc carbamate is zinc dibutyl dithiacarbamate.

9. A petroleum lubricating oil comprising a major proportion of petroleum lubricating oil, about 0.25 to 2 per cent by weight based on finished oil of a calcium salt of a phenol alkylated with a butene polymer averaging about 16 carbon atoms per molecule and boiling between about 375 and 500 F., and about 0.25 to 2 per cent by weight based on finished oi1 of mixed zinc dithiocarbamates of reduced cyclic petroleum nitrogen bases.

10. A lubricant additive capable of inhibiting deterioration of lubricating oils which comprises a concentrated hydrocarbon lubricating oil solution containing from about 5 to about 25% by weight based on the solution of an oil-soluble alkaline earth metal phenate and from about 5 to about 25% by weight based on the solution of an oil-soluble zinc dithiocarbamate, said solution being capable of dilution with hydrocarbon lubricating oil to form a homogeneous mixture containing from 0.1 to 5% by weight of said henate and from 0.1 to 5% by weight of said carbamate.

ROBERT J. MILLER. JOHN T. RUTHERFORD.

Certificate of Correction Patent No. 2,412,903. December 17, 1946. ROBERT J. MILLER ET AL.

It is hereby certified that errors appear in the printed specification of the above" numbered patent requiring correction as follows: Column 3, line 27, for that portion of the formula reading CX C read 0X X columns 5 and 6, Table III, line 7 under the heading Additives for 0.5 read 0.5%; column 8, line 14, for hexalecyl read hexadecyl; line 25, for dithioarbamate read dithiocarbamate; column 9, lines 8-9, claim 8, for dithiacarbamate read dith'iocarbamate; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 18th day of February, A. D. 1947. E

LESLIE FRAZER First Assistant Commissioner of Patents.