EP0179814B1

EP0179814B1 - Additives for lubricants and functional fluids which exhibit improved performance and method for preparing same

Info

Publication number: EP0179814B1
Application number: EP85901882A
Authority: EP
Inventors: Thomas Robert Steckel; Thomas Robert Hopkins
Original assignee: Lubrizol Corp
Current assignee: Lubrizol Corp
Priority date: 1984-04-16
Filing date: 1985-04-04
Publication date: 1993-10-13
Anticipated expiration: 2005-04-04
Also published as: AU4212085A; ES542252A0; MX168665B; JPS61501925A; IN163735B; ZA852833B; WO1985004896A1; DE3587624D1; EP0179814A1; FI854920A0; BR8506703A; AU577116B2; CA1276004C; ES8609442A1; FI854920A; DE3587624T2

Abstract

Sulfur-based additives, which are essentially labile-sulfur free, are employed in lubricants and functional fluids to substantially eliminate the problem of metal corrosivity and elastomer degradation generally exhibited by sulfur-based additives.

Description

This invention relates to a sulfur-based additive exhibiting improved performance for use in lubricants and functional fluids. More specifically, substantially labile-sulfur free additives for lubricants and functional fluids are obtained by treatment with copper, or copper and another material reactive with labile-sulfur in order to substantially eliminate the detrimental metal corrosivity and the detrimental degradation of elastomer materials which are exhibited by labile-sulfur containing additives.
Sulfur-based additives have been widely used in various lubricants, e.g., crankcase lubricating oils, gear lubricants, metal-working lubricants and the like, and in various functional fluids, e.g., hydraulic fluids, automatic transmission fluids, heat transfer fluids and the like. The most common of such sulfur-based additives are phenolsulfides, disulfides, polysulfides, salts thereof, overbased salts thereof, and mixtures thereof. These additives function as oxidation inhibitors, antiwear additives and load carrying additives for these different categories of fluids.
While these sulfur-based additives have been found to be quite effective for the above-mentioned functions, they have generally been found to be corrosive to metals such as copper and copper alloys which are widely used as bearings and bearing liners and have been found to cause the degradation of elastomer materials which are used as seals or sealant devices.
To overcome this problem, various co-additives such as aryltriazoles and various thiadiazoles have been included with these sulfur-based additives in lubricants and functional fluids. However, aside from their expense, these co-additives create further complications in lubricant formulation, e.g., additional solubilizers may be required as well as additional blending steps are necessary.
In U.S. Patent 4,309,293, it is disclosed that phenolsulfides, disulfides or polysulfides, oligomers thereof or mixtures of same when treated with alkylvinyl ethers reduce metal corrosivity when incorporated into lubricants and like fluids. The alkylvinyl ethers of this patent are reactive with the phenolic hydroxyl groups which are generally treated in successive steps where the reaction product is not removed from the additive. This particular treatment or process has the problem, aside from the expense of alkylvinyl ethers, of not eliminating corrosive labile-sulfur contained in these types of additives and, in addition, they require special handling because of their high volatility.
US Patent No. 4228022 describes a lubricating oil additive formed from the reaction of (a) an alkylphenol, (b) sulfur, (c) an alkaline earth metal, and (d) an olefin. The reaction may be carried out in two steps with a sulfurized alkylphenol being formed in a first step followed by reaction of the sulfurized phenol with the olefin in the second step.
EP-A-0076376 describes a method for improving the odour of dialkyl polysulfides which contain sulfur-bearing odoriferous impurities wherein the polysulfide is contacted with an inorganic or monocarboxylic acid salt of a metal selected from manganese, iron, cobalt, nickel, copper, zinc, silver, lead, cadmium and mercury.
British Patent No. 1209500 describes a process for improving the oxidative stability of a polyphenyl thioether functional fluid by treating the thioether with a Group Ib or IIb metal or oxide thereof.
While a number of approaches have been attempted to solve the corrosion problem associated with sulfur-based additives for lubricants and functional fluids, the prior art has not disclosed any which are entirely successful or are not without other problems, e.g., creating formulation problems, inhibiting the desired effects of these additives, and the like.
We have now found it possible to provide a highly effective and a relatively economic method for eliminating the metal corrosion and elastomer degradation problem associated with certain sulfur-based additives for lubricants and functional fluids.
Thus in accordance with the invention, there is provided a use of a sulfur-based additive selected from phenol sulfides, disulfides or polysulfides and salts thereof or overbased salts thereof, which has been treated with a) copper in its elemental state or as a salt, or with b) copper and an optional material reactive with labile-sulfur selected from olefins, unsaturated natural oils, a Diels-Alder reaction product of butadiene and esters of acrylic acid, metallic basic salts, amines, organic phosphites and combinations thereof, at an elevated temperature to remove labile-sulfur from said additive, as an additive for lubricants or functional fluids to substantially eliminate the detrimental degradation of elastomer materials contacted by said lubricant or functional fluid.
It has been found that treating sulfur-based additives selected from phenolsulfides, disulfides, polysulfides, salts thereof, overbased salts thereof, and mixtures thereof with copper metal, copper salts or copper metal or salts and an optional additional reactive material, a substantially labile-sulfur free additive is obtained which will not corrode metals, particularly copper or copper-alloys, and will not degrade elastomer sealant materials.
Still further in accordance with the present invention, labile-sulfur free additives exhibiting improved performance, labile-sulfur free additive concentrates, lubricant and functional fluid compositions containing such additives and a method for lubricating copper and copper-alloy bearings by applying lubricant and functional fluid compositions containing such additives thereto are contemplated and within the scope of the present invention.
These and other aspects of the invention will become clear to those skilled in the art upon the reading and understanding of the specification.
Preferred embodiments of the invention are described hereinafter.
It has surprisingly been discovered that an additive, free of labile-sulfur useful in lubricants and functional fluids may be obtained by a highly effective and relatively economic method. This method gives a labile-sulfur free additive for lubricants and functional fluids which does not corrode metals, or only to a minor, insignificant extent and will not degrade elastomer materials or only to a minor, insignificant extent.
The method of the present invention involves contacting certain sulfur-based additives for lubricants and functional fluids with copper or copper and another material reactive with labile-sulfur at an elevated temperature conveniently followed by filtering off copper sulfide and other particulate material from the thus treated additive to give an essentially labile-sulfur free additive. By this method, to be further described in detail, essentially all labile-sulfur is removed from these additives where the resulting treated additive contains at most about 0.4% by weight of labile-sulfur. Employing thus treated additives in lubricants and functional fluids substantially eliminates the problem of metal corrosion and elastomer degradation previously exhibited by sulfur-based additives. Moreover, the method of the present invention does not have some of the other inherent problems associated with previous approaches to overcome the metal corrosion and elastomer degradation problem such as various formulating problems, inhibition of the properties of these additives and the like.
It was found in accordance with the present invention that sulfur-based additives may be treated with copper or copper and another labile-sulfur reactive material. As used herein, copper includes metallic copper as well as copper salts. The physical form of metallic copper used in the method of the invention is not particularly critical and may include turnings, granules and powder. For the purposes of the present invention, copper powder has been found to be particularly useful. Copper salts that may be useful within the scope of the present invention there may be mentioned oxides, oleates and halides, preferably chlorides. The amount of copper used to treat various sulfur-based additives should be sufficient to essentially remove all labile-sulfur contained by the additive. More specifically, the amount of copper generally utilized in the method of the present invention ranges from about 5% by weight based on the additive to about 0.01% by weight and preferably in the range of about 1.0% to about 0.1% by weight of the additive.
As other reactive materials that may be used in combination with copper to treat various sulfur-based additives there may be mentioned unsaturated natural oils including vegetable and animal oils such as soybean oil, lard and the like: various olefins, particularly alpha-olefins which preferably have 4 to 30 carbon atoms and most preferably 10 to 20 carbon atoms: the Diels-Alder reaction products of butadiene and esters of acrylic acid, preferably butylacrylate: organic phosphites such as triphenol phosphite: basic metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate and the like: and various amines, including primary and secondary amines. The amount of these other reactive materials used with copper in the method of the present invention is not particularly critical wherein the amount of labile-sulfur present in the, particular additive to be treated and economics will be determinative of the actual amount used. The amount used within the practice of the present invention may range from about 1 part of other reactive material to about 10 parts copper to 10 parts other reactive material to about 1 part copper.
The method of the present invention is generally conducted at atmospheric pressure, however, higher pressures may be utilized. The contacting of the sulfur-based additives with the treating agents of the present invention is conducted at temperatures sufficient to react essentially all the labile-sulfur present in the particular additive which is usually at an elevated temperature, preferably in the temperature range of from about 100°C to about 250°C and most preferably from about 130°C to about 160°C. However, it is pointed out that the temperature range may vary widely depending upon the particular treating agent and/or the presence of a catalyst.
The additives that may be treated according to the method of the present invention are selected from phenolsulfides, disulfides, polysulfides, salts thereof and overbased salts thereof. These "sulfurized" phenols include alkyl and dialkyl phenols wherein the alkyl group may range from about 6 to about 100 carbon atoms. Many of these sulfurized phenols are commercially available or may be prepared by initially reacting a phenol or alkylphenol with a sulfur monohalide (e.g., sulfurmonochloride). This reaction may be conducted in the presence of excess base to result in the salts of the mixture of sulfides, disulfides or polysulfides that may be produced depending upon the reaction conditions. It is the resulting product of this reaction which is then treated in accordance with the method of the present invention. However, the overbased salts may be prepared after the treatment in accordance with the present invention. U.S. Patents 2,971,940 and 4,309,293 disclose various sulfurized phenols which are illustrative of sulfur-based additives that may be treated according to the method of the present invention.
One particular class of phenates for use in this invention are the basic (i.e., overbased, etc.) Group IIA metal sulfurized phenates made by sulfurizing a phenol as described hereinabove with a sulfurizing agent such as sulfur, a sulfur halide, or sulfide or hydrosulfide salt. Techniques for making these sulfurized phenates are described in U.S. Patents 2,680,096: 3,036,971 and 3,775,321.
As previously indicated, the additives of the present invention, which are essentially labile-sulfur free, find use in a wide range of lubricants and functional fluids. Such additives may be employed in a variety of lubricants based on diverse oils of lubricating viscosity, including natural and synthetic lubricating oils and mixtures thereof. The lubricants include crankcase lubricating oils for spark-ignited and compression-ignited internal combustion engines, including automobile and truck engines, 2-cycle engines, aviation piston engines, marine and railroad diesel engines and the like. Also contemplated are lubricants for gas engines, stationary power engines and turbines and the like. Transaxle lubricants, gear lubricants, metal-working lubricants and other lubricating oil and grease compositions are within the scope of the present invention. Various functional fluids to which the additives of the present invention may be added include hydraulic fluids, heat transfer fluids, automatic transmission fluids and the like.
Natural oils include animal oils and vegetable oils (e.g., castor, lard oil) liquid petroleum oils and hydrorefined, solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic and mixed paraffinic-naphthenic types. Oils of lubricating viscosity derived from coal or shale are also useful base oils.
Synthetic lubricating oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized and interpolymerized olefins [e.g.. polybutylenes, polypropylenes, propylene-isobutylene copolymers, chlorinated polybutylenes, poly(1-hexenes), poly(1-octenes), poly(1-decenes)]: alkylbenzenes (e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di(Z-ethylhexyl)benzenes]: polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenols): and alkylated diphenyl ethers and alkylated diphenyl sulfides and the derivatives, analogs and homologs thereof.
Alkylene oxide polymers and interpolymers and derivatives thereof where the terminal hydroxyl groups have been modified by esterification, etherification, etc., constitute another class of known synthetic lubricating oils. These are exemplified by polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide, the alkyl and aryl ethers of these polyoxyalkylene polymers (e.g., methyl-polyisopropylene glycol ether having an average molecular weight of 1000, diphenyl ether of poly-ethylene glycol having a molecular weight of 500-1000, diethyl ether of polypropylene glycol having a molecular weight of 1000-1500): and mono- and polycarboxylic esters thereof, for example, the acetic acid esters, mixed C₃-C₈ fatty acid esters and C₁₃ Oxo acid diester of tetraethylene glycol.
Another suitable class of synthetic lubricating oils comprises the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acids, alkenyl malonic acids) with a variety of alcohols (e.g., butyl alcohol. hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid.
Esters useful as synthetic oils also include those made from C₅ to C₁₂ monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and tripentaerythritol.
Silicon-based oils such as the polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxysiloxane oils and silicate oils comprise another useful class of synthetic lubricants: they include tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate, tetra-(4-methyl-2-ethylhexyl) silicate, tetra-(p-tert-butylphenyl) silicate, hexa-(4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes and poly(methylphenyl) siloxanes. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decylphosphonic acid) and polymeric tetrahydrofurans.
Unrefined, refined and rerefined oils can be used in the lubricants of the present invention. Unrefined oils are those obtained directly from a natural or synthetic source without further purification treatment. For example, a shale oil obtained directly from retorting operations, a petroleum oil obtained directly from distillation or ester oil obtained directly from an esterification process and used without further treatment would be an unrefined oil. Refined oils are similar to the unrefined oils except they have been further treated in one or more purification steps to improve one or more properties. Many such purification techniques, such as distillation, solvent extraction, acid or base extraction, filtration and percolation are known to those skilled in the art. Rerefined oils are obtained by processes similar to those used to obtain refined oils applied to refined oils which have been already used in service. Such rerefined oils are also known as reclaimed or reprocessed oils and often are additionally processed by techniques for removal of spent additives and oil breakdown products.
Generally the lubricants of the present invention contain a performance and lubricating improving amount of one or more of the treated sulfur-based additives of this invention which do not corrode metals or only to a minor, insignificant extent and do not degrade elastomer materials or only to a minor, insignificant extent. Normally the amount employed will be about 0.05% to about 20%, preferably about 0.1% to about 10% of the total weight of the lubricating composition. This amount is exclusive of solvent/diluent medium. In lubricating compositions operated under extremely adverse conditions. such as lubricating compositions for marine diesel engines, the sulfur based additives of this invention may be present in amounts of up to about 30% by weight, or more, of the total weight of the lubricating composition.
The invention also contemplates the use of other additives in combination with the treated additives of this invention. Such additives include, for example, detergents and dispersants of the ash-producing or ashless type, and other oxidation-inhibiting agents, pour point depressing agents, extreme pressure agents, antiwear agents, color stabilizers and anti-foam agents.
The ash-producing detergents are exemplified by oil-soluble neutral and basic salts of alkali or alkaline earth metals with sulfonic acids, carboxylic acids, or organic phosphorus acids characterized by at least one direct carbon-to-phosphorus linkage such as those prepared by the treatment of an olefin polymer (e.g., polyisobutene having a molecular weight of 1000) with a phosphorizing agent such as phosphorus trichloride, phosphorus heptasulfide, phosphorus pentasulfide, phosphorus trichloride and sulfur, white phosphorus and a sulfur halide, or phosphorothioic chloride. The most commonly used salts of such acids are those of sodium, potassium, lithium, calcium, magnesium, strontium and barium.
The term "basic salt" is used to designate metal salts wherein the metal is present in stoichiometrically larger amounts than the organic acid radical. The commonly employed methods for preparing the basic salts involve heating a mineral oil solution of an acid with a stoichiometric excess of a metal neutralizing agent such as the metal oxide, hydroxide, carbonate, bicarbonate, or sulfide at a temperature of about 50°C. and filtering the resulting mass. The use of a "promoter" in the neutraliziation step to aid the incorporation of a large excess of metal likewise is known. Examples of compound useful as the promoter include phenolic substances such as phenol, naphthol, alkylphenol, thiophenol, sulfurized alkylphenol, and condensation products of formaldehyde with a phenolic substance: alcohols such as methanol, 2-propanol, octyl alcohol, cellosolve, carbitol, ethylene glycol, stearyl alcohol, and cyclohexyl alcohol: and amines such as aniline, phenylenediamine, phenothiazine, phenyl-β-naphthylamine, and dodecylamine. A particularly effective method for preparing the basic salts comprises mixing an acid with an excess of a basic alkaline earth metal neutralizing agent and at least one alcohol promoter, and carbonating the mixture at an elevated temperature such as 60-200°C.

Ashless detergents and dispersants are so called despite the fact that, depending on its constitution, the dispersant may upon combustion yield a non-volatile material such as boric oxide or phosphorus pentoxide: however, it does not ordinarily contain metal and therefore does not yield a metal-containing ash on combustion. Many types are known in the art, and any of them are suitable for use in the lubricant compositions of this invention. The following are illustrative:
(1) Reaction products of carboxylic acids (or derivatives thereof) containing at least about 34 and preferably at least about 54 carbon atoms with nitrogen containing compounds such as amine, organic hydroxy compounds such as phenols and alcohols, and/or basic inorganic materials. Examples of these "carboxylic dispersants" are described in British patent 1,306,529 and in many U.S. patents including the following:

3,163,603	3,351,552	3,541,012
3,184,474	3,381,022	3,543,678
3,215,707	3,399,141	3,542,680
3,219,666	3,415,750	3,567,637
3,271,310	3,433,744	3,574,101
3,272,746	3,444,170	3,576,743
3,281,357	3,448,048	3,630,904
3.306,908	3,448,049	3,632,510
3,311,558	3,451,933	3,632,511
3,316,177	3,454,607	3,697,428
3,340,281	3,467,668	3,725,441
3,341,542	3,501,405	4,234,435
3,346,493	3,522,179	Re 26,433

(2) Reaction products of relatively high molecular weight aliphatic or alicyclic halides with amines, preferably polyalkylene polyamines. These may be characterized as "amine dispersants" and examples thereof are described for example, in the following U.S. patents:

3,275,554	3,454,555
3,438,757	3,565,804

(3) Reaction products of alkyl phenols in which the alkyl group contains at least about 30 carbon atoms with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines), which may be characterized as "Mannich dispersants". The materials described in the following U.S. patents are illustrative:

2,459,112	3,442,808	3,591,598
2,962,442	3,448,047	3,600,372
2,984,550	3,454,497	3,634,515
3,036,003	3,459,661	3,649,229
3,166,516	3,461,172	3,697,574
3,236,770	3,493,520	3,725,277
3,355,270	3,539,633	3,725,480
3,368,972	3,558,743	3,726,882
3,413,347	3,586,629	3,980,569

(4) Products obtained by post-treating the carboxylic, amine or Mannich dispersants with such reagents as urea, thiourea, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, nitriles, epoxides, boron compounds, phosphorus compounds or the like. Exemplary materials of this kind are described in the following U.S. patents:

3,036,003	3,282,955	3,493,520	3,639,242
3,087,936	3,312,619	3,502,677	3,649,229
3,200,107	3,366,569	3,513,093	3,649,659
3,216,936	3,367,943	3,533,945	3,658,836
3,254,025	3,373,111	3,539,633	3,697,574
3,256,185	3,403,102	3,573,010	3,702,757
3,278,550	3,442,808	3,579,450	3,703,536
3,280,234	3,455,831	3,591,598	3,704,308
3,281,428	3,455,832	3,600,372	3,708,422

(5) Interpolymers of oil-solubilizing monomers such as decyl methacrylate, vinyl decyl ether and high molecular weight olefins with monomers containing polar substituents, e.g., aminoalkyl acrylates or acrylamides and poly-(oxyethylene)-subsituted acrylates. These may be characterized as "polymeric dispersants" and examples thereof are disclosed in the following U.S. patents:

3,329,658	3,666,730
3,449,250	3,687,849
3,519,565	3,702,300

Extreme pressure agents and corrosion- and oxidation-inhibiting agents are exemplified by chlorinated aliphatic hydrocarbons such as chlorinated wax; phosphosulfurized hydrocarbons such as the reaction product of a phosphorus sulfide with turpentine or methyl oleate,phosphorus esters including principally dihydrocarbon and trihydrocarbon phosphites such as dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite, dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite, dimethyl napthyl phosphite, oleyl 4-pentylphenyl phosphite, polypropylene (molecular weight 500)-substituted phenyl phosphite, diisobutyl-substituted phenyl phosphite; metal thiocarbamates, such as zinc dioctyldithiocarbamate, and barium heptylphenyl dithiocarbamate; Group II metal phosphorodithioates such as zinc dicyclohexylphosphorodithioate, zinc dioctylphosphorodithioate, barium di(heptylphenyl)-phosphorodithioate, cadmium dinonylphosphorodithioate, and the zinc salt of a phosphorodithioic acid produced by the reaction of phosphorus pentasulfide with an equimolar mixture of isopropyl alcohol and n-hexyl alcohol.
Many of the above-mentioned extreme pressure agents and corrosion- oxidation inhibitors also serve as antiwear agents. Zinc dialkylphosphorodithioates are a well known example.
Pour point depressants are a particularly useful type of additive often included in the lubricating oils described herein. The use of such pour point depressants in oil-based compositions to improve low temperature properties of oil-based compositions is well known in the art. See, for example, page 8 of "Lubricant Additives" by C.V. Smalheer and R. Kennedy Smith (Lezius-Hiles Co. publishers, Cleveland, Ohio, 1967).
Examples of useful pour point depressants are polymethacrylates, polyacrylates; polyacrylamides; condensation products of haloparaffin waxes and aromatic compounds; vinyl carboxylate polymers: and terpolymers of dialkylfumarates, vinylesters of fatty acids and alkylvinylethers. Pour point depressants useful for the purposes of this invention, techniques for their preparation and their uses are described in U.S. Patents 2,387,501; 2,015,748; 2,655,479; 1,815,022; 2,191,498; 2,666,746; 2,721,877; 2,721,878; and 3,250,715.
Anti-foam agents are used to reduce or prevent the formation of stable foam. Typical anti-foam agents include silicones or organic polymers. Additional anti-foam compositions are described in "Foam Control Agents". by Henry T. Kerner (Noyes Data Corporation, 1976), pages 125-162.
The labile-sulfur free additive compositions of this invention can be added directly to the lubricant. Preferably, however, they are diluted with a substantially inert, normally liquid organic diluent such as mineral oil, naphtha, benzene, toluene or xylene, to form an additive concentrate. These concentrates usually contain from about 5% to 90% by weight of the additive of this invention and may contain, in addition, one or more other additives known in the art or described hereinabove. The remainder of the concentrate is the substantially inert normally liquid diluent.
The following non-limiting examples are afforded in order that those skilled in the art may more readily understand the present invention and specified preferred embodiments thereof with respect to the method of the present invention in accordance with the foregoing description.

EXAMPLE 1

While maintaining a temperature of 55° 1000 parts phenol and 68 parts sulfonated polystyrene catalyst (marketed as Amberlyst-15 by Rohm and Haas Company) are charged to a reactor equipped with a stirrer, condenser, thermometer and subsurface gas inlet tube. The reactor contents are then heated to 120° while nitrogen blowing for 2 hours. 1232 parts propylene tetramer is charged, and the reaction mixture is stirred at 120° for 4 hours. Agitation is stopped, and the batch is allowed to settle for 0.5 hour. The crude supernatant reaction mixture is filtered and vacuum stripped until a maximum of 0.5 percent residual propylene tetramer remains.

EXAMPLE 2

Benzene (217 parts) is added to phenol (324 parts, 3.45 moles) at 38°C and the mixture is heated to 47°C. Boron trifluoride (8.8 parts, 0.13 mole) is blown into the mixture over a one-half hour period at 38-52°C. Polyisobutene (1000 parts, 1.0 mole) derived from the polymerization of C₄ monomers predominating in isobutylene is added to the mixture at 52-58°C over a 3.5 hour period. The mixture is held at 52°C for one additional hour. A 26% solution of aqueous ammonia (15 parts) is added and the mixture heated to 70°C over a two-hour period. The mixture is then filtered and the filtrate is the desired crude polyisobutene-substituted phenol. This intermediate is stripped by heating 1465 parts to 167°C and the pressure is reduced to 10mm as the material is heated to 218°C in a 6-hour period. A 64% yield of stripped polyisobutene-substituted phenol (Mn=885) is obtained as the residue.

EXAMPLE 3

A commercial mixture of ethylene polyamines (41 parts, 1.0 equivalent) corresponding in empirical formula to penta(ethylene)hexamine is added to a mixture of the substituted phenol (400 parts, 0.38 equivalent) described in Example 2 and diluent oil (181 parts) at 65°C. The mixture is heated to 93°C and paraformaldehyde (12 parts, 0.4 equivalent) added. The mixture is heated from 93-140°C over a 5-hour period and then held at 140°C for 4 hours under nitrogen. The mixture is cooled to 93°C and additional paraformaldehyde (12 parts, 0.4 equivalent) is added. The mixture is heated from 93-160°C for a total of 12 hours. The total amount of distillate collected is 13.2 parts. An additional amount of diluent oil (119 parts) is added to the mixture which is then filtered. The filtrate is a 40% oil solution of the desired Mannich condensation product containing 1.87% nitrogen.

EXAMPLE 4

To 1850 parts (1.0 equivalent) of the Mannich condensate described in Example 3 is added sulfur flowers (64 parts, 2.0 equivalents) at 80°C. The mixture is heated to 160°C over a 10-hour period removing the hydrogen sulfide evolved (35 grams). The mixture is then filtered. The filtrate is a 40% oil solution of the desired sulfurized product containing 1.79% nitrogen and 1.43% sulfur.

EXAMPLE 5

A reactor equipped with a stirrer, condenser, thermometer and subsurface addition tube is charged with 1000 parts of the reaction product of Example 1. The temperature is adjusted to 48-49° and 319 parts sulfur dichloride is added while the temperature is kept below 60°. The batch is then heated to 88-93° while nitrogen blowing until the acid number (using bromphenol blue indicator) is less than 4.0. 400 parts diluent oil is then added, and the mixture is mixed thoroughly.

EXAMPLE 6

Following the procedure of Example 5, 1000 parts of the reaction product of Example 1 is reacted with 175 parts of sulfur dichloride. The reaction product is diluted with 400 parts diluent oil.

EXAMPLE 7

Following the procedure of Example 5, 1000 parts of the reaction product of Example 1 is reacted with 319 parts of sulfur dichloride. 788 parts diluent oil is added to the reaction product, and the materials are mixed thoroughly.

EXAMPLE 8

Following the procedure of Example 6, 1000 parts of the reaction product of Example 2 are reacted with 44 parts of sulfur dichloride to produce the sulfurized phenol.

EXAMPLE 9

Following the procedure of Example 7, 1000 parts of the reaction product of Example 2 are reacted with 80 parts of sulfur dichloride.

EXAMPLE 10

A reactor equipped with a stirrer, condenser, thermometer and subsurface gas inlet tube is charged with 1000 parts phenol, 38.4 parts SuperFiltrol (a sulfuric acid treated clay supplied by Filtrol Corporation) and 845 parts of a mixture of isomeric heptenes. The reactants are heated to 120° while nitrogen blowing. The reaction is then continued at 120° for 4 hours. The reaction mixture is filtered, and vacuum stripped to remove water, unreacted heptenes, and excess phenol. The residue after stripping is the product.

EXAMPLE 11

Following the procedure of Example 10, 1000 parts of a C₂₄₋₂₈ alpha-olefin, 903 parts phenol and 46 parts SuperFiltrol are reacted to prepare an alkylated phenol.

EXAMPLE 12

Following the procedure of Example 10, 1090 parts phenol, 585 parts isomeric nonenes, and 200 parts of a slurry of 10 pacts Amberlyst 15 in 190 parts nonenes are reacted to form the substituted phenol.

EXAMPLE 13

To a 1-liter, 4-necked flask equipped with a stirrer, nitrogen inlet, subsurface tube, thermowell and Dean-Stark trap with condenser was charged with 500 parts of the reaction mixture of Example 7. With fast stirring, 7.5 parts cuprous oxide is charged followed by heating to 180° with nitrogen blowing. Heating was continued at 180° for 3 hours, while a small amount of yellow-colored distillate was removed in the Dean-Stark trap. The mixture was then cooled to 150° and held at 150° for an additional 3 hours. The reaction mixture was then filtered using a diatomaceous earth filter aid. The reaction product contained 0.06 percent copper.

EXAMPLE 14

To a reactor equipped as described in Example 13, is charged 406 parts of the reaction product of Example 4. With fast stirring, 2.4 parts cupric oxide and 1.2 parts copper metal powder is charged, followed by heating to 155° with a slight nitrogen purge. The mixture was heated at 155° for 5 hours. The materials were then filtered using a diatomaceous earth filter aid.

EXAMPLE 15

A 1-liter, 4-necked flask equipped with a stirrer, thermowell, and reflux condenser is charged with 600 parts of the reaction product of Example 7. With fast stirring, 3 parts copper metal powder is added, the mixture is heated to 120° and is held at 120° for 5 hours. The reaction mixture is filtered using a diatomaceous earth filter aid.

EXAMPLE 16

Following the procedure of Example 15, 2400 parts of the reaction product of Example 8 are treated with 3 parts of copper metal powder.

EXAMPLE 17

Following the procedure of Example 15, 1000 parts of the reaction product of Example 7 is heated at 150° with 5 parts copper metal powder. The filtered product contains 0.005 percent copper.

EXAMPLE 18

A 1-liter, 4-necked flask equipped with a stirrer, thermometer, below surface gas inlet and a Dean-Stark trap is charged with 475 parts of the reaction product of Example 7. The material is heated to 80°C, 25 parts copper metal powder is added and the reaction mixture is heated to 155° over 0.5 hour followed by heating at 155-160° for 5 hours. The material is filtered at 140° using a diatomaceous earth filter aid. The product contains 0.0032 percent copper.

EXAMPLE 19

A 1-liter, 4-necked flask equipped with a stirrer, thermowell, condenser, subsurface tube, nitrogen inlet and Dean-Stark trap was charged with 200 parts of the reaction product of Example 7 and 145 parts of diluent oil. The materials are heated to 80° followed by the addition of 1.7 parts copper metal powder. The mixture is heated to 155° and held at 155° for 5 hours while maintaining a light nitrogen purge. The materials are filtered using a diatomaceous earth filter aid.

EXAMPLE 20

The procedure of Example 19 is followed except 885 parts of the reaction product of Example 7, 641 parts diluent oil and 76 parts copper metal powder are used.

EXAMPLE 21

A 1-liter, 4-necked flask equipped with a stirrer, nitrogen inlet, subsurface tube, thermowell Dean-Stark trap and condenser is charged with 386 parts of the reaction product of Example 5. The material is heated to 150° and 5.8 parts cupric hydroxide is added. The materials are heated to 180° while water is removed. A total of approximately 1 gram water was obtained in the Dean-Stark trap. The total heating time was 2 hours. The product was filtered using a diatomaceous earth filter aid. The filtered product contains 0.36 percent copper.

EXAMPLE 22

A reactor as described in Example 6 is charged with 351 parts of the reaction product of Example 5. The material is heated to 50° and 4.5 parts cupric oxide and 1.1 parts copper metal powder is added. The mixture is heated to 150° and held at 150° for 2 hours. The materials were then heated to 180° over 1 hour and heating at 180° is continued for 4 additional hours. The materials are filtered using a diatomaceous earth filter aid. The filtered product contains 0.43 percent copper.

EXAMPLE 23

To a reactor as described in Example 21 is charged 351 parts of the reaction product of Example 5. The materials is heated to 50° and 5.3 parts cuprous oxide is charged. The mixture is stirred at fast speed for 0.5 hour followed by the addition of 2.2 parts acetic acid. The mixture is heated to 105° over 0.5 hour, heated to 150° over 0.5 hour and held at 150° for 3.5 hours. The temperature is increased to 180° and held at 180° for 3 additional hours. The reaction mixture is filtered using a diatomaceous earth filter aid. The filtered product contains 0.113 percent copper.

EXAMPLE 24

A 2-liter reactor equipped with a stirrer, thermometer, below surface nitrogen inlet and Dean-Stark trap is charged with 990 parts of the reaction product of Example 5. The material is heated to 90° at which time 10 parts of copper metal powder is added. The materials are heated with nitrogen blowing to 150° over 0.35 hour and held at 150-154° for 5.5 hours. 285 parts diluent oil is added, the materials are mixed thoroughly and filtered at 105° using a diatomaceous earth filter aid.

EXAMPLE 25

Cupric chloride dihydrate (51 parts) and 125 parts toluene are charged to a 250 milliliter flask equipped with a subsurface nitrogen inlet and a Dean-Stark trap. The materials are azeotroped for 2 hours to dry. A 2-liter reactor equipped with a stirrer, thermowell, and Dean-Stark trap is charged with 710 parts of the reaction product of Example 5 and 110 parts xylene. 48 parts of a 50 percent aqueous NaOH solution is added at 80°, and the reaction mixture is refluxed at 105-180° for 4.75 hours. The mixture is cooled and 150 parts isopropynol is added. Most of the toluene is decanted from the dried cupric chloride and the solid is added to the solution in the 2-liter flask. Remaining cupric chloride was washed from the 250 milliliter flask using 175 parts methanol. The materials in the 2-liter flask are then held at 55-60° for 0.5 hour then refluxed at 68-70° for 2.5 hours, and stripped to 165^o at 1.1 kPa (8 torr). The residue is filtered at 115° using a diatomaceous earth filter aid. The filtered product contained no sodium and 1.72 percent copper.

EXAMPLE 26

The procedure of Example 25 is repeated employing 312 parts of the reaction product of Example 6, 32 parts of 50 percent aqueous sodium hydroxide, 34 parts of cupric chloride dihydrate, 125 parts toluene, 100 parts xylene, 100 parts methanol, 100 parts of the isobutanol/primary amyl alcohol mixture, and 75 parts isopropanol.

EXAMPLE 27

A 2-liter, 4-necked reactor equipped with a stirrer, addition funnel, subsurface tube, thermowell, and condenser is charged with 800 parts of the reaction product of Example 12. The materials are heated to 50° with a light nitrogen purge. Sulfur dichloride is added dropwise over 5 hours. The materials are heated to 150° and nitrogen blown for 2 hours at 150°. 646 parts diluent oil are added and the materials are stirred at 100° for 1 hour. 1537 parts of the reaction product are transferred to a 3-liter flask and 7.7 parts copper powder is added. The materials are heated to 150° with fast stirring. The materials are then held for 5 hours at 150°, then filtered using a diatomaceous earth filter aid. The filtered product contains 13 parts per million copper.

EXAMPLE 28

A 3-liter, 4-necked flask equipped with a stirrer, subsurface cube, addition funnel, thermowell and reflux condenser is charged with 787 parts of the reaction product of Example 10. The material is heated to 50° and sulfurdichloride is added dropwise over 4.25 hours. The materials are heated to 150° with nitrogen blowing and held at 150° with nitrogen blowing for 1.5 hours. 638 parts of diluent oil is added and the materials are stirred for 0.25 hour. The mixture is reheated to 150° and 7.6 parts of copper metal powder is added. The materials are mixed for 5 hours at 150° with a slight nitrogen purge. The materials are filtered using a diatomaceous earth filter aid. The filtered material contains 20 parts per million copper.

Example 29

A 3-liter reactor equipped with a stirrer, thermowell, subsurface gas inlet and reflux condenser is charged with 700 parts of the reaction product as described in Example 17 and 204 parts of diluent oil. The mixture is heated to 55° and 85 parts methanol, 11 parts acetic acid, 58 parts calcium hydroxide and 57 parts toluene are added. The mixture is blown with CO₂ for 0.5 hour at 1.4 x 10⁻²m³ (0.5 cubic feet) per hour at a temperature of 65-70°C. The reaction mixture is stripped to 150° at 4.2 x 10⁻²m³ (1.5 cubic feet) nitrogen purge. The residue is filtered using a diatomaceous earth filter aid.

Example 30

To a 5-liter, 4-necked flask equipped with a stirrer, thermowell, reflux condenser and subsurface tube is charged 3000 parts of the reaction product of Example 7 and 49 parts of C₁₅₋₁₈ alpha-olefin. With rapid stirring, 15 parts copper metal powder is added and the mixture is heated at 150° for 4 hours while nitrogen blowing. The mixture is then filtered using a diatomaceous earth filter aid.

EXAMPLE 31

Following the procedure of Example 30, 3000 parts of the reaction product of Example 9 are reacted with 40 parts of C₁₅₋₁₈ alpha-olefin and 10 parts of copper metal powder.
To further illustrate the efficacy of the treatment method of the present invention, several of the thus reacted sulfur-based additives were tested for labile-sulfur according to the test procedure of ASTM-D 1662. Results from this test are set out in Table I. TABLE I

Ex. No. Amount of Labile-Sulfur¹

13 0.18

14 0.63

15 0.43

17 0.07

20 1.14 (control)

21 0.06

24 Nil

1 - Represents weight percent, of labile-sulfur based on weight of additive.
The additives treated according to the method of the present invention, which showed very little or no labile-sulfur, demonstrated greatly improved performance inthat the detrimental metal corrosivity and elastomer degradation originally exhibited by these additives before treatment had essentially been eliminated.
The following examples illustrate an additive concentrate and a lubricant formulated with a sulfur-based additive treated according to the method of the present invention.

EXAMPLE TO ADDITIVE CONCENTRATE

A sulfur-based concentrate was formulated from the following components:

Product of Ex. 19	12.07
Copper deactivator (Amoco 150)	0.33
Diphenylamine based antioxidant	1.85
Zinc dialkylphosphorodithioate	9.23
Reaction product of pentaerythritol and ethylene polyamine with polyisobutenyl succinic anhydride	13.34
Reaction product of ethylene polyamine with polyisobutenyl succinic anhydride	12.02
Basic magnesium petroleum sulfonate	2.65
Basic calcium petroleum sulfonate	4.62
Silicone antifoam	0.012
Nonylphenoxypoly-(ethyleneoxy)ethanol HLB=8.9 (Surfonic N-40)	0.98
Mineral oil	As needed to bring to 100 parts total

Other additive concentrates employing compositions of the invention in combination with varying amounts of the above additives were also prepared.
A lubrication oil composition is prepared by blending 11.64% by weight of the above-described additive concentrate in a 15W-40 oil which contains polymeric viscosity improvers.

Claims

Use of a sulfur-based additive selected from phenol sulfides, disulfides or polysulfides and salts thereof or overbased salts thereof, which has been treated with a) copper in its elemental state or as a salt, or with b) copper and an optional material reactive with labile-sulfur selected from olefins, unsaturated natural oils, a Diels-Alder reaction product of butadiene and esters of acrylic acid, metallic basic salts, amines, organic phosphites and combinations thereof, at an elevated temperature to remove labile-sulfur from said additive, as an additive for lubricants or functional fluids to substantially eliminate the detrimental degradation of elastomer materials contacted by said lubricant or functional fluid.
Use according to claim 1 wherein said sulfur-based additive has been treated with copper metal powder.
Use according to claim 1 wherein said sulfur-based additive has been treated with a copper salt selected from copper oxides, copper chlorides and copper oleate.
Use according to any preceding claim wherein said optional material is an alpha-olefin.
Use according to claim 4 wherein the alpha-olefin has 4 to 30 carbon atoms.
Use according to any one of the preceding claims wherein the treated sulfur-based additive contains no more than about 0.4% by weight of labile-sulfur.
Use according to claim 6 wherein the treated sulfur-based additive contains less than 0.1% by weight of labile sulfur.