KR960014933B1 - Low phosphorus lubricants - Google Patents

Abstract

None.

Description

Low phosphorus lubricant

The present invention relates to lubricating oil compositions, in particular to crankcase lubricating oils in motor vehicles which are free of phosphorus or contained in small amounts.

Since phosphorus has a detrimental effect on catalysts commonly used in catalytic converters to control emissions, work is underway to reduce the phosphorus content in lubricating oils. In general, the phosphorus content was 0.1%, but the need for lowering or removing all of the phosphorus content was increased to 0.05 wt% or less. However, zinc dialkyl dithiophosphate (ZDDP) and other phosphorus-containing additives have been widely used as anti-wear and / or antioxidant additives and reducing or removing all of these components from the lubricant will result in engine performance. Will fall.

The present invention provides lubricating oil compositions and concentrates that contain remarkable engine performance, including copper, sulfur, bearing corrosion inhibitors, and containing no or small amounts of phosphorus.

U.S. Application No. 26666661 is a fat-soluble organic compound, such as copper dialkyl dithiocarbamate, which contains 50-1000 ppm of copper and a fat-soluble organic sulfur compound, such as thiocarbamate, which contains phosphorus with 0.1-0.5 wt% sulfur in oil. It relates to a lubricant containing.

The addition of copper compounds, including copper containing phosphorus complexed with sulfur compounds, to lubricating oils is described in US application 2343756. Sulfur contents of 0.1-0.5 wt% are described and described as very harmful above 0.5 wt%. In U. S. Application No. 2552580, cuprous thiophosphates were included in the lubricating oil composition at relatively high levels to increase the level of phosphorus in the oil.

In US application 3346493, polymer amine-metal reactants containing various various metals have been used as detergents in lubricating oil compositions. In one embodiment, among others, lubricating oils containing 0.075% as ZDDP reacting with copper salts of acylated nitrogen compounds, hexene oxides and sulfided methyl esters of tall oil acids have been described. It contained more phosphorus or no sulfur than other copper-containing lubricants. All transition metal compound groups as anti-oxidant stabilizers together with amines, selenides, phosphines or phosphites have been described in US Pat. No. 4,202,33 and these can be used in many cases, such as additives for lubricants. None of the preceding applications relate to fully formulated lubricants with the features required for state of the art lubricants, and in particular have not been written about lowering phosphorus levels while maintaining anti-wear, anti-oxidation and anti-corrosion performance.

Ashless dispersants and / or polymeric dispersants that improve the viscosity index, lubricating oil compositions containing copper in the form of dithiocarbamate but require zinc and 0.01-0.5 wt% phosphorus are described in European Patent Application No. 24146 . Thiadiazole polysulfide may be included as an optional component.

An oil with reduced phosphorus content (up to 0.05% P) using a mixture of dialkyldiphenylamines and sulfided polyolefins to compensate for the reduction in ZDDP amounts has been described in US application 4330420. The use of copper or thiadiazole polysulfides is not described.

Reaction product of 4,4'-methylene bis (2,6-di-t-butylphenol) with tri-sec-C _4-12 alkyl orthoborate and lubricant to reduce the amount of ZDDP to 0.05-0.11 wt% P The use of this product in is described in European patent application no.

Heterocyclics containing bis (dithiobenzyl) metal derivatives and boron in the form of metal salts including copper salts, thiadiazole polysulfides and terephthalic acid as oxidation inhibitors, especially where the metal is a steric hindrance bisphenol crosslinked with copper or sulfur Lubricants composed of compounds have been described in US Patent Application No. 4490265. The need to reduce or eliminate all phosphorus is not described and in all embodiments the lubricant contains 0.05 wt. Similar is US Patent Application No. 4463474.

Boron-containing heterocyclic compounds that may be in the form of copper salts and may be sulfided are described in US Pat. Thiadiazole polysulfides and carboxylic acid coppers have been described. Although boron-containing heterocyclic compounds are described without phosphorus, no fully formulated oils containing less than 0.05 wt% P have been described.

Similarly described patent is US application 462958. Boron and metal-boron derivatives for use under extreme pressure, antiwear and antifriction additives for lubricating oils, compositions containing no ZDDP, and the like are described in US Application No. 4629579, but with small amounts of phosphorus in combination with sulfur and copper. There is no description of compositions containing or without.

Lubricating oil compositions with little or no phosphorus and no copper are described in WO-A-8604601, WO-A-8604602 and WO-A-8606092.

The present invention provides lubricating oils with moderate antiwear, corrosion inhibiting, and antioxidative performance as modern oils with little or no phosphorus content and without the need to use large amounts of antioxidants in the form of large and / or expensive forms.

As used herein, the term 'latest oil' refers to a car's crankcase lubricant, an oil that meets the requirements for crankcase lubricants in major industrial countries. Due to the longer oil change time, the required high performance engines, longer life and higher operating temperatures all contribute to the improved performance required for lubricating oils. The present invention relates in particular to automotive crankcase lubricating oils that meet or exceed the SF API requirements of general automotive oils and / or the CD API requirements for commercial oils / diesel engines as formulated by the API, SAE, ASTM association.

In one aspect of the invention, most of the lubricating oil, added copper present in a fat-soluble form of 5-500 ppm, at least one fat-soluble sulfur added such that the total sulfur content is at least 0.5-2.0 wt% and preferably 0.5-1.0 wt%. A lubricant composition comprising a compound containing an effective amount of bearing corrosion inhibitor and containing less than 0.01 wt% phosphorus and substantially free of phosphorus provides a preferred lubricating oil composition.

In a particularly preferred embodiment of the invention the lubricating oil composition is also one or more ashless dispersants and / or one or more viscosity index improving dispersants and / or overbased to act as antacids, anti-rust agents such as overbased calcium or magnesium sulfonates or phenates. Contains additives.

The copper used in the present invention, which is made of low phosphorus oils that can control oxidation and meets the performance requirements of state-of-the-art oils that can be economically obtained, is used by metals accumulated in the oil due to corrosion or wear with a special oxidation catalyst, iron. Catalyzed in the engine.

If the concentration of copper is too low, in some cases the antioxidant effect is insufficient. If the copper concentration is excessively high, the oil will increase ash and increase the bearing tendency to increase significantly. The amount of copper added to the composition is generally between 10-400 ppm and 10-300 ppm is representative and preferably between 10-200 ppm, such as 60-200 ppm, for example.

The performance of the compositions of the present invention composed of small amounts or no phosphorus and small amounts of fat-soluble copper compounds to provide adequate anti-oxidation and anti-wear performance to the specification conditions of modern engine tests is surprising. In many cases, similar metals such as copper and cobalt, chromium, which act as oxidation promoters or catalysts, are not effective lubricant antioxidants. EP 24146 describes at least 0.01 wt% of phosphorus and zinc present.

Surprisingly, the function of copper compounds is effective in compositions containing zinc and other metal compounds, such as overbased additives of calcium or magnesium, which have inherently oxidizing activity.

If the copper compound is free of phosphorus at all, the copper compound used as the antioxidant in the present invention may be selected from those described in European Patent Application No. 24146 suitable for lubricating oil.

Therefore, copper can be mixed into oil as a fat-soluble copper salt of synthetic or natural carboxylic acids. Examples of suitable carboxylic acids are C ₁₀ -C ₁₈ fatty acids such as stearic acid or palmitic acid, unsaturated acids such as oleic acid, branched carboxylic acids such as naphthenic acid having a molecular weight of 200-500, neodecanoic acid or 2-ethylhexanoic acid such as octadekenyl Alkyl or alkenyl substituted dicarboxylic acids such as polyalkene substituted succinic acid which is succinic acid, dodecanyl succinic acid, polyisobutenyl succinic acid, and the like.

Copper may be mixed into the oil as fat soluble copper dithiocarbamates of the general formula (RR'NCSS) _n Cu. Wherein n is 1 or 2, and R and R 'contain the same or different C _1-18 , preferably C _2-12 , such as alkyl, alkenyl, aryl, aralyl, alkaryl and cycloalkyl radicals It is hydrocarby radical. Compounds comprising copper and sulfur, such as copper mercaptide, disulfide and thioxanthates, are suitable for use in the present invention. Copper sulfonates, phenates, acetylacetonates can be used.

Alternatively, if the copper in the finished lubricant composition is in the form of a fat-soluble compound, the copper to be inserted may be insoluble in oil. "Added copper" does not include copper that has accumulated in the oil during use, such as when the copper-containing component is worn or corroded.

The lubricating oil composition of the present invention contains the added fat-soluble sulfur compound. One preferred class of such sulfur compounds is preferably dithiocarbamate of the general formula (RR'NCSS) _n M, wherein R, R 'and n are as described above and M is zinc, molybdenum or Suitable metals such as copper or optionally substituted hydrocarbyl radicals). Preferred dithiocarbamates are dialkyl dithiocarbamates, preferably containing C _2-12 , such as diamyl dithiocarbamates. Particularly preferred compounds are zinc diamyl dithiocarbamate.

Sulfur is also a mercaptide, in particular a mercaptide of an aliphatic mercapdan (including copper mercaptide as described above), sulfide olefins (eg US-A-4119540, US-A-4119550, US-A-4191659, US-E- 4147640) sulfided Diels-Alder adducts (e.g. US-A-3632566, US-A-3498915, US-A-27331) and sulfurized unsaturated alcohols and esters such as, for example, whale oil substitutes such as whale oil, and the like. Sulfides comprising sulfided unsaturated organic compounds, di- and polysulfides, thioethers, thiophenols, thioxates (including copper thioxate as described above), sulfided esters, thioesters, thioamides, and the like; Benzothiazoles and in particular thiazoles such as mercaptobenzothiazoles and sulfides such as thiadiazoles.

Mineral lubricating oils contain sulfur while synthetic lubricating oils are free of sulfur, so the amount of sulfur added as a sulfur-containing compound in the basestock and lubricating oil compositions is such that the total sulfur content is at least 0.5-1.0 wt%. It depends on the sulfur content of the other components present.

The lubricating oil composition of the present invention advantageously contains a total of 0.5-0.7 wt% of S and 0.5 wt% of S as the most preferably added fat-soluble sulfur-containing compound. The composition preferably contains 0.01-0.5 wt% Zn, preferably 0.05-0.2 wt% Zn. Particularly preferred compositions contain 0.5-3 wt% zinc dithiocarbamate.

Bearing corrosion inhibitors are effective in suppressing corrosion problems such as copper stain and high mass loss that can be encountered in bearings such as Cu / Pb bearings. These additives have been found to promote oil's antiwear performance. Preferred bearing corrosion inhibitors are B (OR) ₃ , (RO) ₂ BOB (OR) ₂ , (ROBO) ₃ (RO) ₂ BOR'OB (OR) ₂ and mixtures thereof, wherein R is substituted or unsubstituted alkyl , An aryl or aralkyl group or two groups R form a substituted or unsubstituted alkylene group and R 'is a substituted or unsubstituted alkylene group) and such materials are for example alkoxy alkanols (US Alcohols such as all short-chain alkanols and long-chain alcohols) and polyetheralkanols as in -A-4440656; Mono-, such as, for example, 2-ethylhexanol, 2-ethylhexane-1,3-diol, butane-1,2-diol, butane-1,3-diol, glycerol and acrylic acid polyols in US-A-2866811; Di- and trihydroxy alkanols; Oxazolines derived from, for example, oleic acid and tris (hydroxymethyl) -aminomethane; Hydroxy esters such as glyceryl mono-oleate; Sulfur-containing alcohols obtained by reacting an epoxide with a mocaptan such as t-dodecyl-mecaptoethanol; Primary amines (such as oleylamines) or secondary amines may be derived from aminoalcohols such as hydroxyamines, triethanolamines and alkanolamines which are triisopropanolamines obtained by reacting ethylene or propylene oxide with compounds of US-A-4406802. Can be. Preferred alcohols are 2-methylpentane-1,3-diol, butane-1,2-diol, butane-1,3-diol and similar 1,2 and 1,3 diols and ethoxyethanol.

In a preferred aspect of the invention 0.01-10 wt%, preferably 0.1-5 wt% of borate esters, in particular polyetheralkanols or alkoxyalkanols such as tris (ethoxyethyl) orthoborate ester or metaborate ester, or butane- Biborate of diols such as 1,3-diol.

Bearing corrosion inhibitors on the other hand are thiadiazole polysulfides containing thiadiazole mercaptans, in particular C _5-50 , polymers or derivatives thereof. Preferred materials are 1, 3, 4 thiadiazole polysulfides such as those described in US-A-2719125, 2719126 and 3087932. Particularly preferred compounds are Amoco 150, which is 2, 5-bis (t-octadithio) -1,3,4-thiadiazole or Amoco, which is 2,5-bis (nonyldithio) -1,3,4-thiadiazole 158. Other suitable materials similar to these are those described in US-A-3821236, 3904537, 4097387, 4107059, 4136043, 4188299, 4193882. Derivatives of thiadiazole mercaptans are esters, condensation products of halogenated carboxylic acids, reaction products of aldehydes and amines, reaction mixtures of alcohols or mercaptans, amine salts, dithiocarbamates, ashless dispersants (e.g. US-A- 4140643 and US-A-4136043) and reaction products with sulfur halides and olefins.

Such materials are present in the range of 0.01-10 wt%, preferably 0.1-5.0 wt% of the lubricating oil composition.

Preferred lubricating oil compositions are those which contain small amounts of phosphorus, less than 0.01 wt%, preferably less than 0.005 wt%, but are substantially free of phosphorus.

As a preferable aspect, this lubricating oil composition is further comprised as follows.

(A) (i) long-chain hydrocarbon substituted mono and dicarboxylic acids or fat soluble salts, amides, imides, oxazolines and esters or mixtures thereof; (ii) long-chain aliphatic hydrocarbons directly attached with polyamines; And (iii) Mannich condensation products made by condensation of 1-2.5 moles of formaldehyde substituted long chain hydrocarbon phenols with polyalkylene polyamines at a 0.5-2 molar ratio; 1-10 wt% ashless dispersant compound, wherein the long chain hydrocarbon group is a polymer of C ₂ -C ₅ monoolefins and the molecular weight of the polymer is 700-5000. Or (B) (a) a polymer of C _4-24 unsaturated esters of vinyl alcohols or C ₃ -C ₁₀ unsaturated mono- or di-carboxylic acids with unsaturated nitrogen-containing monomers having C _4-20 ; (b) polymers of unsaturated C ₃ -C ₁₀ mono- or di-carboxylic acids with C ₂ -C ₂₀ olefins neutralized with amines, hydroxyamines or alcohols; And (c) ethylene and C ₃ -C ₂₀ olefins grafted onto C ₄ -C ₂₀ unsaturated nitrogen-containing monomers or further reacted with unsaturated acids to the polymer backbone, whereby the carboxylic acid reacts with amines, hydroxyamines or alcohols. 0.3-10 wt% viscosity index improving polymer dispersant containing nitrogen or ester comprising a polymer.

Dispersant additives containing nitrogen include, for example, those shown in US-A-3275554, US-A-3565804, US-A-3442808, US-A-3442808, GB-A-983040 or BE-A-658236. It is known in the art as a sludge dispersant for crankcase motor oil.

The most widely used dispersants are formed by reacting, for example, polyisobutenyl succinic anhydrides with alkenyl succinic anhydrides such as the amines described in US-A-3202678, 3154560, 3172892, 3024195, 3024237, 3219666, 3216936 and BE-A-662875. .

Ashless dispersants, on the other hand, are esters derived from long-chain hydrocarbon substituted carboxylic acids and esters derived from hydroxy compounds such as monohydric, polyhydric alcohols or aromatic compounds such as phenols and naphthols as prepared, for example, in US-A-3522179. .

Hydroxyamines that can react with the aforementioned long-chain hydrocarbon substituted carboxylic acids to make dispersants include 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, P- (beta-hydroxyethyl) -Aniline, 2-amino-1-propane, 3-amino-1-propanol, 2-amino-2-methyl-1,3-propane-diol, 2-amino-2-ethyl-1,3-propanediol, N- (beta-hydroxy-propyl) -N '-(beta-aminoethyl) -piperazine, tris (hydroxymethyl) amino-methane (also called trismethylolaminomethane), 2-amino-1-butanol , Ethanol amine, beta- (beta-hydroxyethoxy) -ethylamine, and the like.

Preferred dispersants are or are derived from, for example, polyoxyethylene and polyoxypropylene amines such as pentaerythritol, trismethylolaminomethane, polyoxypropylene diamine, polyethylene amines such as tetraethylene pentaamine and polyisobutenylsuccinic anhydride to be. One particularly preferred propellant combination is (A) a polyisobutenyl succinic anhydride and (B) a hydroxy compound such as pentaerythritol, (C) a polyoxyalkylene polyamine such as polyoxypropylene diamine, and (D) a polyethylene diamine and tetra A combination of polyalkylene polyamines, such as ethylene pentaamine, may be prepared from about 0.01-about 2 equivalents of (C) and about 0.01-about 4 equivalents of (B) per equivalent of (A) and as described in US-A-3894763. Make it using (D). Still other preferred dispersant combinations include (A) polyisobutenyl succinic anhydride and (B) polyalkylene polyamines such as tetraethylene pentamine and (C) pentaerythritol or trismethylol aminomethane as described in US-A-3632511. Polyhydroxy-substituted aliphatic primary amines or combinations of polyhydric alcohols.

Alkenyl succinic acid polyamine type dispersants include boron oxide, boron halide, boric acid and boric acid in an amount such that the atomic ratio of boron per mole of acylated nitrogen compound is 0.1-10, as thought in US-A-3087936 and 3254025. It can be further modified with boron compounds such as esters. Mixtures of dispersants may also be used, as described in US-A-4113639.

The oil may contain 1.0-10 wt%, more preferably 2.0-7.0 wt% of this dispersant.

For example, copolymers of alkyl methacrylate with N-vinylpyrrolidone or dimethylaminoalkyl methacrylate, alkylfumarate-vinylacetate, N-vinyl pyrrolidine copolymer, alkylene as in US-A-4149984 Post-grafted interpolymers of ethylene-propylene with active monomers such as maleic anhydride that will further react with polyamines or alcohols; Or 0.3-10% of a viscosity index improving polymer dispersant, such as styrene / maleic anhydride polymer, ethoxylated derivatives of acylated polymers as in US-A-3702300, which are subsequently reacted with alcohols and amines. .

Additives containing magnesium and / or calcium are often used alone in lubricating oil compositions or in combination with alkaline earth metal additives or other alkali metal additives such as those containing sodium. They may also be present in the form of metal salts, such as sulfonic acids, alkylphenols, alkylsulphide sulfides, alkylsalicylates, naphthenates and other fat-soluble mono- and di-carboxylic acids.

High basic alkali earth metal alkali sulfonates are generally shown, for example, in US-A-3150088 and 3150089. For the purposes of the present invention, preferred alkalito sulfonates are magnesium or calcium alkyl aromatic sulfonates with a total number of bases (TBN, measured by the ASTM D 2896 method) in the 300-400 range.

Polyvalent metalalkyl salicylates and naphtonate materials, such as those crosslinked with methylene and sulfur which can be readily derived from alkylsubstituted salicylic or naphthenic acids or mixtures thereof or mixtures of both with alkylsubstituted phenols and the like This is also included. Basic sulfide salicylates and methods for their preparation are described in US-A-3595791.

Sulfurized metal phenates can be thought of as "metal salts of phenol sulfides" which can be discussed in the form of natural or basic compounds represented by the following general formula or polymers of these compounds.

Wherein R is an alkyl radical, n and X are integers from 1 to 4 with each other and the average number of carbon atoms in all R groups is at least about 9 to suitably solubility in oil. x = 1 or 2, n = 0,1 or 2.

Each R group contains 5-40, preferably 8-20 carbon atoms. Metal salts are prepared by reacting a metal containing material with an alkyl phenolsulfide in an amount sufficient to impart the desired alkalinity to the sulfided metal phenate.

Sulfurized alkyl phenols can be reacted with metal-containing materials that contain sufficient amounts of oxides, hydroxides, and complexes to neutralize the phenols or to overbased them if desired to obtain the desired alkalinity of the product by methods known in the art. Is switched. A preferred method is neutralization with a metal solution in glycol ether.

Said magnesium and calcium containing additives, although beneficial in other respects, increase the oxidation of the lubricant. This is especially true for highly basic sulfonates.

Therefore, a preferred embodiment of the present invention provides a crankcase lubricating oil composition containing 2-8000 ppm calcium and / or magnesium.

Magnesium and / or calcium are generally present as basic or natural detergents such as sulfonates and phenates and preferred additives are basic magnesium or calciumsulfonate. Preferred are oils containing 500-5000 ppm of calcium and / or magnesium from these additives.

These compositions of the present invention may be different and in addition may contain a clean addition agent containing other similar metals such as, for example, containing barium, sodium, potassium or lithium.

The lubricating oil used in the present lubricating oil composition may be a mineral lubricating oil or a synthetic lubricating oil or a mixture thereof. Suitable synthetic oils include diester oils such as di (2-ethyl-hexyl) sebacate, acelate and adipate; Complex ester oils such as those formed with dicarboxylic acid glycols and monobasic acids or monohydric alcohols; Silicone oil; Sulfide esters; Organic carbonates; Hydrocarbon oils and other synthetic oils known in the art. The present invention has the additional advantage that it is possible to use basestock oils which are particularly useful for mineral lubricating oils and which have lower antioxidant properties than are generally used.

The lubricating oil compositions of the present invention can be used if, for example, oleic acid and derivatives thereof, such as N-oleylsarcosine, oleic acid dimers and trimers, lecithin, sorbitan mono-oleate, dodecyl succinic anhydride or ethoxylation Green suppressants such as alkylphenols; Pour point depressants, such as copolymers of fumaric acid esters of vinyl acetate and coconut oil alcohols; And other lubricant additives typical such as viscosity index improvers such as olefin copolymers or polymethacrylates.

In copper free oils it is sometimes necessary to add other antioxidants to the zinc dialkyldithiophosphates in order to increase the oxidative stability of the oil. These supplemental antioxidants are included, especially if the oxidative stability of the basestock is poor and the amount of supplemental antioxidant added to the oil is 0.1-1.5 wt%. Supplementary antioxidants used include phenols, hindered phenols, bis-phenols and sulfided phenols, catechols, alkylated catechols and sulfided alkyl catechols, diphenylamines and alkyldiphenylamines, phenyl-1- Naphthalamine, alkylated derivatives thereof, and the like.

Inclusion of small amounts of copper generally eliminates the need for supplemental antioxidants. In practice, however, if no phosphorus was used at all, such supplemental antioxidants, when present in oil, are included in one aspect of the present invention, especially when operated under extreme conditions.

Additives for lubricants are generally provided in the form of concentrates in oil for incorporation into the bulk lubricant. Therefore, the present invention provides a composition comprising (1) less than 0.1 wt% phosphorus: (2) 1-50 wt% fat-soluble sulfur-containing compound; (3) 0.005-2 wt% copper; And (4) 0.1-20 wt% bearing corrosion inhibitor and optionally (5) (a) 0-60, such as 10-60 wt% ashless dispersant compound (b) 0- although generally other viscosity index improvers are added separately A concentrate consisting of an oil solution containing a dispersant selected from the group consisting of 40, such as 3-40 wt% viscosity index improving polymer dispersant is provided.

This concentrate may also contain other additives such as the viscosity index improver and detergent described above. Particularly preferred concentrates include additives containing magnesium and / or calcium and therefore the present invention provides concentrates further composed of 0.01-8 wt% calcium and / or magnesium.

The following examples merely illustrate the invention and will illustrate a more detailed aspect of the invention.

Comparative Example I-VI and Example 1-4

The formulations in the following comparative examples and examples of the present invention were prepared by combining the amounts of the additives obtained in Table 1 in balance with diluent oils suitable for lubricating oil compositions and containing 0.3 wt% sulfur. The additives used are as follows:

A is an oil solution containing 21% multifunctional ethylene-propylene copolymer and a dispersant V.I. Additive.

B is a ashless dispersant comprising a 50 wt% oil solution of boronated polyisobutenyl succinamide having a polyisobutenyl radical and a molecular weight of about 950 and containing 1.6 wt% of N and 0.35 wt% of B.

C is an oil solution of overbased magnesium sulfonate having a TBN of 400, a magnesium content of 9.2 wt%, and a sulfur content of 1.7 wt%.

D is an oil solution of overbased calcium sulfonate having a TBN of 300, a calcium content of 11.9 wt%, and a sulfur content of .9 wt%.

E is an oil solution of copper oleate containing 4wt% copper.

F is a 30 wt% solution of methylene bis-phenolic antioxidant with steric hindrance in oil.

G is an alkylated diphenylamine antioxidant which is a trademark Irganox L-57 of Ciba-Geigy.

H is a 50 wt% oil solution of zinc diamyldithiocarbamate containing 6 wt% zinc and 12 wt% sulfur.

J is an orthoborate ester made of ethoxy ethanol composed of 5 wt% boron.

K is 2,5-bis (nonyldithio) -1,3,4-thiadiazole consisting of 33 wt% sulfur under the trademark Amoco 158 of Amoco Chemical Company.

L is an oil solution containing 12wt% molybdenum which is octoate.

M is a sulfurized ester whale oil substituent under the trademark Emery 9844 made by Emery Corporation and consists of 11.5 wt% sulfur.

The formulations were tested according to the following standard assays:

Seq. According to ASTM STP 315M part III. IIID engine tests measured the maximum and average wear of cams and lifters. This test was successful if the maximum wear was greater than 0.02 cm (0.08 in.) And the average wear was greater than 0.01 cm (0.004 in.).

seq. The dynamic viscosity increase in the IID test is measured as an increased percentage within 64 hours at 40 ° C. If the viscosity increased within 64 hours does not exceed 375%, it is successful.

Bearing mass reduction (BWL) was measured by CRC-L-38 screener engine test based on ASTM STP 509A PE IV. If the BWL does not exceed 40 mg, this test is a success.

The results are listed in Table 2. This result shows that the phosphorus-free lubricating oil of the present invention exhibits anti-oxidation, anti-wear and anti-corrosion bearing. Comparative Examples I, II and III show that the wear performance is inadequate due to the absence of bearing corrosion inhibitors. Comparative Example IV shows that the addition of molybdenum additives improves wear performance. Comparative Example V shows that even if a conventional amount of other known antioxidants is added, the performance is poor without copper antioxidants.

Comparing Comparative Example V and Example 2, it can be seen that the use of copper not only improves anti-oxidation performance but also surprisingly improves anti-wear performance. The performance of the formulations in the examples of the present invention does not only aggregate the performance of the individual additives, but contains phosphorus at levels lower than those used in conventional oils, but provides improved antiwear, oxidation and bearing corrosion inhibiting performance. Indicates.

Comparative Example VII-IX and Example 5-7

A major factor in the performance of crankcase lubricants for state-of-the-art engines is to inhibit oxidation, especially to avoid excessive viscosity increase. The effect of the compositions of the present invention on inhibiting viscosity increase was demonstrated in Seq. It was run with IIID engine test. The bench test, ERCOT test, designed to carry out the oxidation and iron contact conditions of the internal combustion engine, was further realized.

In the ERCOT test, less than 300 g of oil composition containing 40 ppm of iron as ferric acetyl acetonate was oxidized by passing air at 1.7 L per minute at 165 ° C. and an increased viscosity difference was measured for 64 hours using a Hakke viscometer. The results are expressed in centipoise (cp).

Comparative Example VII-IX followed Example 11 of WO-A-8604601, Example 13 of WO-A-8604602 and Example IX of WO-A-06092 but used similar materials as defined in this Example. . In Comparative Example, copper was not used, and the following Table 3 indicates that the composition of the present invention in Example 5-7 was in a condition of being oxidized for a long time, up to the time when the engine oil was consumed. Effective for use in modern oils.

The following additives were used as part of the previously defined ingredients:

N is a dispersant similar to dispersant B but the molecular weight of the polyisobutenyl radical is about 1300 and this dispersant contains 1.46 wt% N and 0.32 wt% B.

P is an antiwear additive comprising an oil solution (90% active ingredient) of diisooctyl zinc dithiophosphate containing 7.0 wt% P and 7.7 wt% Zn.

Concentrates-Representative Concentrates to Provide the Formulations

The concentrate may also contain some diluent oil to facilitate manipulation (reduce viscosity).

Claims (24)

5-500 ppm (by weight) of copper, in which a large amount of lubricant is added in fat-soluble form, one or more fat-soluble sulfur-containing compounds added so that the total sulfur content is 0.5-2.0 wt%, and an effective amount of bearing corrosion inhibitor, less than 0.01 wt% A crankcase lubricating oil composition for use in automobile engines containing phosphorus. The composition of claim 1 wherein the amount of copper added is 10-400 ppm. The composition of claim 2 wherein the amount of copper added is 10-200 ppm. The composition of claim 3 wherein the amount of copper added is 60-200 ppm. 5. The method of claim 1, wherein the copper is mixed with oil or in the form of a copper salt of C ₁₀ -C ₁₈ fatty acids, unsaturated carboxylic acids, naphthenic acids having a molecular weight of 200-500 or alkyl or alkenyl substituted dicarboxylic acids. Fat-soluble copper dithiocarbamate, copper sulfonate of the formula (RR'NCSS) _n Cu [where n is 1 or 2 and R and R 'are the same or different hydrocarbyl radicals containing C _1-18 ] Compositions mixed in oil with copper phenate or copper acetylacetonate. The dithiocarbamate or mercaptite of claim 1, wherein the fat soluble sulfur compound is of the general formula (RR′NCSS) _n M wherein R, R ′ and n are as defined in claim 5 and M is a metal. , Sulfurized unsaturated organic compounds, sulfides, thioethers, thiophenols, thioxanthates, sulfurized esters, thioesters, thioamides, thiazoles or thiadiazoles. The composition of claim 6, wherein the fat soluble compound is dialkyl dithiocarbamate containing C _2-12 . The composition of claim 1 wherein the total sulfur content is 0.5-1.0 wt% including 0.1-0.5 wt% sulfur added to the fat-soluble sulfur containing compound. The composition of claim 1 containing 0.01-0.5 wt% Zn. The composition of claim 6 containing 0.5-3 wt% zinc dithiocarbamate. The composition of claim 1, wherein the bearing corrosion inhibitor consists of thiadiazole polysulfide and derivatives or polymers thereof containing at least one borate and / or C _5-50 of the general formula: B (OR) ₃ , (RO) ₂ BOB (OR) ₂ , (ROBO) ₃ or (RO) ₂ BOR | ¹ OB (OR) ₂ Wherein R is a substituted or unsubstituted alkyl, aryl or aralkyl group or two groups R together form a substituted or unsubstituted alkylene group and R ¹ is a substituted or unsubstituted alkylene group. The composition of claim 11 containing 0.01-10 wt% of borate ester. The composition of claim 11 or 12, wherein the borate ester is tris (ethoxyethyl) orthoborate ester or biborate of butane-1,3-diol. The composition of claim 11 containing 0.01-10 wt% of 2,5-bis (t-nonyldithio) -1,3,3-thiadiazole. The composition of claim 1 containing less than 0.005 wt% phosphorus. The composition of claim 15 which is substantially free of phosphorus. The composition of claim 1 further comprising (A) 1-10 wt% ashless dispersant compound and / or (B) 0.3-10 wt% viscosity index improving polymer dispersant containing nitrogen or ester. The composition of claim 1 comprising 2-8000 ppm calcium and / or magnesium. The composition of claim 18 comprising 500-5000 ppm of calcium and / or magnesium as basic calcium and / or magnesium sulfonate. The composition of claim 1 further comprising one or more antirust agents, pour point depressan ts, additional antioxidants and viscosity index improvers. (1) less than 0-.1 wt% phosphorus; (2) 1-50 wt% of a fat-soluble sulfur-containing compound; (3) 0.005-2 wt% copper; (4) bearing corrosion inhibitor at 0.1-20 wt%; And (5) an oil solution containing 0-60 wt% ashless dispersant and / or viscosity index improving polymer dispersant. The composition of claim 21 further comprising 0.01-8 wt% calcium and / or magnesium. Use of fat-soluble copper as an antioxidant in lubricating oil compositions containing zinc and phosphorus, consisting of fat-soluble sulfur-containing compounds, bearing corrosion inhibitors, ashless dispersants and / or viscosity index improving polymers, dispersants and calcium and / or magnesium containing detergents. . Fat-soluble, used in crankcase lubricating oil compositions for automotive engines containing less than 0.01 wt% phosphorus to inhibit oxidation, abrasion and corrosion and at least meet the quality specifications of the standard SF and / or CD of API engine requirements The use of 5-500 ppm of added copper in total form, 0.5-2.0 wt% total sulfur and bearing corrosion inhibitor combination.