LUBRICATING COMPOSITIONS CONTAINING PHOSPHORUS COMPOUNDS FOR LUBRICA- TION OF SILVER BEARINGS Richard G. Cunningham, Edwardsville, and Theodore W. Havely and James R. Price, Alton, Ill., assignors to Shell Oil Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Feb. 17,1956, Ser. No. 566,106
5 Claims. (Cl. 25233.4)
This invention relates to new and improved lubricating compositions. More particularly, it relates to highly detergent mineral oil lubricating compositions which are non-corrosive and wear-resistant to metals, such as silver and alloys of silver and the'like. i
It has been observed that one of the best additive combinations for imparting detergency to lubricants is the combination of a particular class of oil-soluble metal sulfonates and oil-soluble metal phenates. The supplemental use of conventional anti-oxidants friction reducers and corrosionand Wear-inhibitors, such as nitrogenand sulfur-containing compounds, such as thiocarbamates or organic thiophosphates (e.g. zinc or calcium dialkyl dithiophosphates and the like), although effective in inhibiting oxidation, corrosion and/ or wear of conventional metal surfaces, such as steel, steel alloys, babbitt surfaces, cadmium and the like, have been found to be ineffective for oils which contact silver metal bearing surfaces, such as are used in certain railroad diesel engines, for instance the silver wrist pin bushings, or in aircraft engines which have silver bearing surfaces.
It has now been discovered that these detergent lubricants containing this particular oil-soluble sulfonate phenate additive combination can be rendered non-corrosive and wear resistant toward silver surfaces when supplemented with minor amounts of a particular class phenates reduces the coeflicient of friction of the com-' position making them better lubricants, particularly when employed in the lubrication of contacting silver-steel surfaces.
The sulfonates are oil-soluble neutral and/or basic polyvalent metal petroleum sulfonates, of which petroleum sulfonates of the metals of group H of the periodic table having an atomic number of from 12 to 56, inclusive, are preferred, and especially of the alkaline earth metals. Suitable sulfonates include the neutral and/or basic calcium, barium and magnesium petroleum sulfonates of oil-soluble petroleum sulfonic acids. The acids can range in molecular weight from about 350 to 550 and preferably are in the range of from 400 to 500. By basic petroleum sulfonates is meant that the amount of neutralizing agent, such as calcium carbonate and/or calcium hydroxide, which is used to neutralize the petroleum sulfonic acid, is in excess of that which is normally required to neutralize the acid. The excess should be from to 100 and preferably between 20 to 60 percent that normally required to neutralize the acid.
The phenates used in compositions of this invention are oil-soluble neutral and/or basic polyvalent metal polyphenates. By polyphenates is meant to include a plurality of phenolic radicals linked together through a carbon, such as where a plurality of simple phenates are condensed at positions ortho and/ or para to the phenolic hydroxy group through alkylidene (methylene) radicals. The cationic portion of the phenate can be the same as chloride.
that in the sulfonate and usually will be, but different i cations may be used. The alkaline earth metal salts of.
the condensation product of an alkylphenol (e.g. p-octylphenol) with formaldehyde, acetaldehyde or benzaldehyde, e.g. calcium or barium salts of octylphenol-form ing a P-C linkage and the halogen may be (I) directlyor (II) indirectly connected to the phosphorus atom in the molecule.
Compounds of group I are characterized by the follow ing structure:
RP=S
- wherein R is an aromatic radical directly bonded to phosphorus, X is a halogen and preferably a middle halo-' gen, such as chlorine and/orbromine. Compounds of this class can be prepared by the methods described by G. M. Kosolapofi in *Organo Phosphorus Compounds,- John Wiley and Sons or by any other suitable means.
An illustrative substance, phenyl phosphorus thiodichloride, can be prepared by reacting, in a suitable reaction vessel, 0.3 mole of benzene, 0.9 mole of phos-- phorus trichloride and 0.3 mole of anhydrous aluminum The mixture is then cooled to about 30 C. and 0.31 mole of flowers of sulfur is added while stirring. The reaction is exothermic increasing the temperature to about 60 C. After the temperature begins to de-- crease, the mixture is heated briefly to about C. Excess phosphorus trichloride is distilled off at reduced pressure and the remainder poured into ice. The resulting mixture is extracted with naphtha, the solvent extracts combined, washed with water and filtered. The naphtha is removed by distillation, leaving behind the desired 'end product phenyl phosphorus thiodichloride, C H PSCl Other suitable compounds include, butylphenyl phosphorus thiodichloride, octylphenyl phosphorus thiodichloride, butoxyphenyl phosphorus thiodichloride, naphthyl phosphorus thiodichloride, phenyl phosphorus thiodibromide and mixtures thereof. I
"The phosphorus compounds of group H are essentially halo-containing esters of alkenephosphonic acids, which compounds can be represented by the formula:
(RO)r-PR wherein R' is an alkene radical directly bonded to phosphorus, preferably a vinyl radical, R" is a halogen-cone taining hydrocarbyl radical, such as haloalkylor haloaryl radicals. Compounds of this type can be prepared by the emthod described by M. I. Kabachnick et al., Bull. Acad. Sci. USSR Classe Sci. Chem, 1947, pages 233-34. Examples of such compounds include bis(betachloroethyl)vinyl phosphonate, bis(beta-bromoethyl)vinyl phosphonate, bis(chlorophenyl)vinyl phosphonate, bis- (chlorocyclohexyl)vinyl phosphonate and mixtures thereof.
The addition of minor amounts of arylamines to compositions of this invention may at ti'me be beneficial. Such arylamines preferably have at least two aromatic rings. Preferred compounds are, for example, the naphthylamines: primary, secondary or tertiary alkyl, aryl aralkyl radicals are attached directly to a nuclear carbon atom of the aromatic nucleus or preferbly to the nitro- Patented Nov. 22, 1960.
gen atom, such as phenyl-alphaor phenyl-beta-naphthylamine, tetralin naphthylamine, aJpha,alpha-, a lpha,beta-, or beta-beta-dinaphthylamines, various phenanthryl-, anthry1-naphthylamines, .xenyl naphthylamines benzyl phenyl naphthylamines, diphenyl naphthylamines, phenyl xenyl naphthylamines, dixenyl naphthylamines; also vanous phenanthryl, anthryl or picyl phenyl amines, etc. The N-aryl substituted naphthylamines are in general more useful for the present purpose. 1
The base for additives of this invention can be any natural or synthetic oil material having lubricating properties. Thus, the base may be a hydrocarbon oil obtained from a paratfinic, naphthenic, asphaltic sto'ck and/or mixtures thereof. The viscosity of these oils may vary over a wide range, such as from 45 SUS at 100 F. to 100 SUS at 210 F. The hydrocarbon oils may be blended with fixed oils, such as castor oil, lard oil and the like and/or with synthetic lubricants, such as polytmerized olefins, copolymers of alkylene glycols and alkylene oxides, organic esters, e.g., di-2-ethylhexyl sebacate, dioctyl phthalate, trioctyl phosphate; polymeric tetrahydrofuran, polyalkyl silicones, e.g., dimethyl silicone and the like. If desired, the synthetic lubricants may be used as the sole base lubricant or admixed with fixed oils and derivatives thereof.
The general formulations of compositions of this invention may be represented by:
The following compositions are illustrative of preferred compositions of the invention:
Composition A Oil-soluble Ca petroleum sulfonate percent S.A. 2.3 Oil-soluble Ca salt of octylphenol-formaldehyde condensation product (av.-mol. wt. 1000) percent'S.A 2.3 Phenyl phosphorus thiodichloride percent P 0.1 Mineral lubricating oil (SAE 40) Balance Composition B Oil-soluble Ca petroleum sulfonate "percent S.A. 2.3 Oil-soluble Ca salt of octylphenol-formaldehyde condensation product (av.-mol. Wt. 1000) percent S.A 2.3 Bis(beta-chloroethyl)vinyl phosphonate percent P 0.1 Mineral lubricating oil (SAE 40) Balance Com position C Oil-soluble Ca petroleum sulfonate .percent S.A. 2.3 Oil-soluble Ca salt of octylphenol-formaldehyde condensation product (av.-mol. wt. 1000) percent S.A 2.3
Phenyl phosphorus thiodichloride .percent P 0.1
Phenyl-a-naphthylamine --percent wt 0.4
Mineral lubricating oil (SAE 40) Balance Composition D Gil-soluble Ca petroleum sulfonate "percent S.A. 2.3 Oil-soluble Ca salt of octylphenol-formaldehyde condensation product (av.-mol. wt 1000) percent S.A 2.3
Phenyl-n-naphthylamine percent wt..- 0.4 Bis(bcta-ch1oroethyl)vinyl phosphonate percent P-.. 0.1 Mineral lubricating oil (SAE40) Balance 1 S.A.= sulfate ash.
tion product (av.-mol. v/t. 1000); and from about 0.1
to about 0.5% P of phenyl phosphorus thiodichloride, butylphcnyl phosphorus thiodichloride, phenyl phosphorus thiodibromide, bis(beta-chloroethyl)vinyl phosphonate, bis(betabromoethyl)vinyl phosphonate, bis(chlorophenyl)viny1 phosphonate and mixtures thereof.
The beneficial properties which compositions of this invention have when used to lubricate silver surfaces is demonstrated by the data in Table I which were obtained by subjecting test compositions to a modified four-ball machine similar in principle to the Boerlage apparatus described in Engineering, vol. 136, July 13, 1933, using a rotating steel top ball and 3 silver discs, operated at 700 r.p.m. spindle speed, 22.8 Kg load and 300 F. 011 temperature.
TABLE 1 Ca Salt 0! 4-132111 Test Results Ca Petro- Oetylphcnol- Phos- Composlleum Sul- Formaldephorus tion ionate hyde Con- Com- 4 densation pounds 1 f d, m r
Product A 2.3% 2.3% S.A l 0. 015 1.39 0. 64 18.. 2.3% 2.3% S.A 2 0. 014 1. 67 1.21 C 4 2.3% 2.3% S. 1 0. 0000 1. 40 D 2.3% 2.3% S. 2 0. 0105 l. 83 E 2.3% 2.3% S.A 3 0.023 2.14 1.12 F 2.3% 2.3% S.A 4 0. 031 1. 59 5. l6 (3.... 2.3% 2.3% S A.. 5 0. 036 2. 29 1. 41 H- 2.3% 2.3% 8.11.... 6 0.07 1.81 2. 40 I. 2.3% 2.3% S.A 7 0. 000 2. 94 0. 83 1.. 2.3% 2.3% S.A.-.. 8 0.072 2.81 9. 03 K. 2.3% 2.3% 8.6. 9 0. 091 2. 15.7 L 2.3% 2.3% S.A- 10 0. l8 3. 63 14. 4 M- 2.3% 2.3% S. 11 0. 046 4. 0 1.41 N- 2.3% 2.3% S. 12 0.123 4. 5 2. 43 0..-. 2.3% 2.3% S 0.051 2. 40 3.44 P 2.3% 0. 050 2.11 Q" 0. 052 2.71 2.3% 0.051 2. 40 2.3% 0.039 1.38 0. 047 1. 51
1 In Compositions A through T the oil used was a refined SAE 40 mincml lubricating oil, of which compositions A, B, C, and D are illustrative of the present invention, while compositions E through T are used for comparison.
5 All phosphorus compounds tested in compositions A through '1 were used in amounts of 0.1% P and they were as follows: I
1. phenyl phosphorus thiodichloride (present invention) bis(beta-chloroethyl) vinyl phosphonate (present invention) diethyl chloro phosphate phenyl phosphorus dichloride 0.0-diethyl chlorothiophosphatc phenyl phosphorus oxydichloride dibutyl chloro phosphate dioctyl phosphitc trimethyl phosphitc 10. tris(2-chloroethyl) phosphite l1. triethyl phosphorotrithioite 12. tripropyl phosphorotrithioite 3 Average three determinations: f=coeiiicient of friction; d=sear diameter in mm.; r=ratio of friction coeifieient of the Ca salt blend to that of the base oil, both containing a phosphorus compound at 0.1% l.
4 1(liompositions C and D also contained 0.4% wt. of phenyl-mnaphthylam e.
From the above data it is apparent that substituting other phosphoruscompounds (compounds 3-12) for the phosphorus-halogen compounds of group I or 11 (compounds 1 and 2) as used in compositionsof this invention or removing either of the two essential salts used in compositions of this invention, results in inferior compositions Which are unsuited for use of lubricating silver surfaces.
In addition to the additives already described lubri eating oil compositions contemplated herein may contain other agents, such as pour-point depressants, oiliness agents, blooming agents, compounds for enhancing the viscosity index of the lubricating oil, peptizing agents, etc.
We claim as our invention:
1. A lubricating oil composition consisting essentially of a major proportion of a mineral lubricating oil from about 0.01% to about 15% of an oil-soluble alkaline earth metal petroleum sulfonate and from about 0.05% to about 15% of an oil-soluble alkaline earth metal salt of an alkylphenol-aldehyde condensation product, which composition causes corrosion and wear of silver and silver alloys and which is rendered non-corrosive and wear-resistant thereto by addition of from about 0.01% to about 5% of a pentavalent phosphorus chlorine containing compound having a P-C linkage selected from the group consisting of phenyl phosphorus thiodichloride and bis(beta-chloroethyl)vinyl phosphonate.
2. A lubricating composition which is non-corrosive and wear-resistant toward silver consisting essentially of a major proportion of mineral lubricating oil containing from 0.01% to 15% of oil-soluble calcium petroleum sulfonate, from 0.05% to 15% of oil-soluble calcium salt of octylphenol-formaldehyde condensation product, and from 0.01% to 5% of phenyl phosphorus thiodichloride.
3. A lubricating composition which is non-corrosive and wear-resistant toward silver consisting essentially of a major proportion of mineral lubricating oil containing from 0.05% to 15% of oil-soluble calcium petroleum sulfonate, from 0.01% to 15% of oil-soluble calcium salt of octylphenol-formaldehyde condensation product, and from 0.01% to 5% of bis(beta-chloroethy1)vinyl phosphonate.
4. A lubricating composition which is non-corrosive and wear-resistant toward silver consisting essentially of a major proportion of mineral lubricating oil containing from 0.05% to 5% of oil-soluble calcium petroleum sulfonate, from 0.1% to 6% of oil-soluble calcium salt of octylphenol-formaldehyde condensation product, and from 0.05% to 2% of phenyl phosphorus thiodichloride.
5. A lubricating composition which is non-corrosive and wear-resistant toward silver consisting essentially of a major proportion of mineral lubricating oil containing from 0.05 to 5% of oil-soluble calcium petroleum sulfonate, from 0.1% to 6% of oil-soluble calcium salt of octylphenol-formaldehyde condensation product, and from 0.05% to 2% of bis(beta-chloroethyl)vinyl phosphonate.
References Cited in the file of this patent UNITED STATES PATENTS 2,223,793 Peery Dec. 3, 1940 2,260,304 Engelize Oct. 28, 1941 2,614,990 Harman et al. Oct. 21, 1952 2,629,693 Barton et al. Feb. 24, 1953 2,708,204 Bell et al. May 10, 1955 2,736,701 Nefl Feb. 28, 1956 2,767,142 Morris et a1. Oct. 16, 1956 2,824,839 Templeman Feb. 25, 1958 FOREIGN PATENTS 151,096 Australia Apr. 27, 1953