KR960014934B1 - Low phosphorus and zinc lubricants - Google Patents

Abstract

Lubricants having antiwear, corrosion inhibition and antioxidant performance appropriate to modern oil requirements with reduced or zero amounts of zinc and phosphorous and without the need for large amounts and/or expensive forms of antioxidant comprise 5 to 500 parts per million by weight (ppm) of added copper present in oil-soluble form, one or more added oil-soluble sulphur-containing compounds and a bearing corrosion inhibitor.

Description

Low phosphorus and zinc content lubricants

The present invention relates to lubricating oil compositions, in particular crankcase lubricating oils of automobiles which contain no zinc and phosphorus or are 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 dithio phosphate (ZDDP) and other phosphorus-containing additives have been widely used as anti-wear and / or antioxidant additives. Will fall.

The present invention provides lubricating oil compositions and concentrates that include notable copper, sulfur and bearing corrosion inhibitors and exhibit remarkable engine performance with little or no zinc and phosphorus.

U. S. Application No. 2666666 1 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. A lubricating oil comprising a compound.

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% have been described and above 0.5 wt% have been described as very harmful. In US application 25552580 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% of phosphorus as ZDDP and sulfided ethyl ester of tall oil acid are described, among other things, copper salts of acylated nitrogen compounds, hexene oxides. Lubricating oils containing other copper contain more phosphorus or no sulfur at all. All transition metal compound groups as anti-oxidant stabilizers with amines, selenides, phosphines or phosphites have been described in US Application No. 422033 and can be used in many cases, such as additives for lubricating oils. None of the preceding applications relate to fully formulated lubricants with the features required for state of the art lubricants, and in particular, do not record lowering phosphorus levels while maintaining anti-wear, anti-oxidation and corrosion inhibiting performance.

Dispersants and / or polymerizable dispersants which improve the viscosity index, lubricant compositions containing copper in the form of dithiocarbamate but require zinc and 0.01-0.5 wt% phosphorus have been described in European Patent Application No. 24146. . Thiadiazole polysulfide may be included as an optional component.

Oils with reduced phosphorus content (up to 0.05% P) using mixtures of dialkyldiphenylamines and sulfided polyolefins to aid in reducing the amount of ZDDP have been described in US application 4330420. The use of copper or thiadiazole polysulfides is not described.

4, 4-ethylene-bis (2, 6-di -t- butynyl phenol) and tri -sec-C ₄ -12 lubricant to reduce the amount of the reaction product and the ZDDP alkyl ortho to the borate 0.05-0.11wt% P The use of this product in is described in European patent application no.

Heterocyclics containing bis (dithio benzyl) metal derivatives as 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 hindered bisphenol crosslinked with copper or sulfur Lubricants composed of compounds have been described in US Patent Application No. 4490265. There is no need to reduce or eliminate all phosphorus and in all embodiments the lubricant contains 0.05 wt% phosphorus. 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 polysulfide and carboxylic acid copper have been described. Although the boron-containing heterocyclic compounds were described without phosphorus, no fully formulated oils containing less than 0.05 wt% P were described. Similarly described US Patent Application No. 462958. Boron and metal-boron derivatives, antiwear additives and friction reducing additives for lubricating oils, compositions containing no ZDDP, etc., for use under extreme pressure, are described in US Application No. 4,569,579 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-860462, WO-A-8606092.

The present invention provides lubricating oils with moderate antiwear, corrosion inhibiting and antioxidative performance as modern oils with low or no phosphorus content and without the need to use large amounts of antioxidants in the form of 1 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 engine, longer life and higher operating temperatures all contribute to the improved performance required for lubricants. The present invention relates in particular to automotive lubricating oils, which meet or exceed the SF API requirements of general automotive oils and / or the CD API requirements for commercial outbound / diesel engines as formulated by API, SAE, ASTM.

In one aspect of the invention, most lubricating oils, added copper present in a fat-soluble form of 5-500 ppm, at least one fat soluble added to a total sulfur content of at least 0.5-2.0 wt%, preferably 0.5-1.0 wt% Comprising a sulfur-containing compound and an effective amount of a bearing corrosion inhibitor, it is desirable to provide a lubricant composition that contains less than 0.05 wt% phosphorus and less than 0.01 wt% zinc and is substantially free of zinc and phosphorus.

In particularly preferred embodiments of the present invention, the lubricant oil composition may also contain one or more ashless dispersants and / or one or more viscosity index improving dispersants and / or antacids such as overbased calcium or magnesium sulfonates or phenates, over salts that act as rust inhibitors. It contains a ready-made additive.

The copper used in the present invention, which is made of a low phosphorus oil that can control oxidation and meets the required performance of state-of-the-art oils that are economically obtainable, is a special oxidation catalyst used by the metals accumulated in the oil due to corrosion or abrasion with iron. It is catalyzed in the engine. If the concentration of copper is excessively low, in some cases, the anti-acid effect is insufficient. If the copper concentration is excessively high, the ash content of the oil will increase and the bearing tendency to increase corrosion will noticeably increase. The amount of copper added to the composition is generally between 10-400 ppm and 10-300 ppm is representative, preferably between 10-200 ppm, such as 60-200 ppm, for example.

The performance of the compositions of the present invention consisting 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. European Patent Application No. 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 acidic activity.

If the copper compound is free of phosphorus, the copper compound used as an antioxidant in the present invention may be selected from those described in European Patent Application No. 2414 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 paltic acid, unsaturated acids such as oleic acid, branched carboxylic acids such as naphthenic acid having a molecular weight of 200-500, neo decanoic acid or 2-ethylhexanoic acid such as octadekenylsuccinic acid Alkyl or alkale substituted dicarboxylic acids such as polydekene substituted succinic acid, dodecaneyl succinic acid, polyisobutenyl succinic acid, and the like.

Copper can be mixed into oil, as are 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, isle, arylalkyl, alkaryl and cycloalkyl radicals Hydrocarbyl radical. Other compounds including 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 lubricating oil composition is in the form of a fat-soluble compound, the inserted copper 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 compounds is preferably dithiocarbamates 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.

Sulfur is also a mercaptide, in particular a mercaptide of fatty mercaptans (including copper mercaptide as described above), sulfide olefins (eg US-A-4119549, US-A-4119550, US-A-4191659, US-A- 4147640) sulfided unsaturated organic compounds, including sulfided Diels-Alder adducts (such as US-A03632566, US-A-3498915, US-E-27331) and sulfurized unsaturated alcohols and esters, in particular such as organic oil substituents; Sulfides and benzothiazoles, including di- and polysulfides, thioethers, thiophenols, thioxates (including copper thioxate as described above), sulfided esters, thioesters, thioamides and the like, in particular Thiazoles such as captobenzothiazole and sulfides such as thiadiazole.

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 0.5-1.0wt%. 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 a fat-soluble sulfur-containing compound added in the form of most preferably sulfided esters.

Bearing corrosion inhibitors are effective in suppressing corrosion problems such as mass loss, such as copper stains 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 include B (OR) ₃ , (OR) ₂ BOB (OR) ₂ , (ROBO) ₃ (RO) ₂ BOR ¹ 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 ¹ is a substituted or unsubstituted alkylene group) and such materials are for example alkoxyalkanols (US Alcohols such as all short-chain alkanols and long-chain alcohols), polyetheralkanols as in -A-4440656; Mono such as, for example, 2-ethylhexanol, 2-ethyl hexane-1,3-diol, butane-1,2-diol, butane-1,3-diol, glasol and acyl acid polyols in US-A-2866811; Oxazolines derived from di- and trihydroxy alkanols such as oleic acid and tris (hydroxymethyl) -aminomethane; Hydroxy esters such as glyceryl mono-oleate; Sulfur-containing alcohols obtained by reacting an epoxide with mercaptans such as t-dodecyl-mecaptoethanol; Primary amines (such as oleylamines) or secondary amines may be derived from amino alcohols 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 epoxyethanol.

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 (epoxyethyl) orthoborate ester or metaborate ester, or butane-1 And biborate of diols such as, 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-1-2719125, 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 acid numbers, reaction products of aldehydes and amines, reaction mixtures of alcohols or mercaptans, amine salts, dithiocarbamates, hummus dispersants (e.g. US-A-41404643 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.

The lubricant composition is preferably a lubricant composition which contains a small amount of phosphorus, less than 0.05 wt%, preferably less than 0.01 wt%, particularly preferably less than 0.005 wt%, but is virtually free of phosphorus.

As a preferred aspect the present lubricant composition consists of: (A) (i) long-chain hydrocarbon substituted mono and dicarboxylic acids or fat-soluble salts of these anhydrides, amides, imides, oxazolines and esters or mixtures thereof; (ii) long chain aliphatic hydrocarbons directly attached to polyamines; And (iii) Mannich condensation products made by condensation of 1-2.5 moles of formaldehyde substituted long chain hydrocarbon phenols with polyalkylene polyamines in a 0.5-2 molar ratio; 1-10 wt% ashless dispersant compound which is a ashless nitrogen or ester containing dispersant compound preferably selected from (where the long chain hydrocarbon group is a polymer of C ₂ -C ₅ mono olefins and the molecular weight is 700-5000) and / or polymer with unsaturated nitrogen containing monomers having ₂₀ (B) (a) a vinyl alcohol ester of a C _4-24 or an unsaturated C ₃ -C ₁₀ unsaturated mono- or di-carboxylic acids and C _4; (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 which are grafted onto C ₄ -C ₂₀ unsaturated nitrogen-containing monomers or grafted to the polymer backbone of unsaturated acids for further reaction before the carboxylic acid reacts with amines, hydroxyamines or alcohols. Polymer of; Nitrogen or ester comprising a viscosity index improving polymer dispersant 0.3-10wt%.

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. The same is known in the art as a sludge dispersant for crankcase motor oils.

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 aromatics such as phenols and naphthols, for example as prepared in US-A-3522179. Compound.

Hydroxyamines that can react with the aforementioned long-chain hydrocarbon carboxylated carboxylic acid to make dispersants include 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, P- (beta-hydroxyethyl) -Aniline, 2-amino-1-propanol, 3-amino-1-propanol, 2-amino-2-methyl 1,3-propane-diol, 2-amino-2-ethyl-1,3-perphandiol, N- (beta-hydroxy-propyl) -N '-(beta-iminoethyl) -piperazine, tris (hydroxymethyl) -amino-methane (also called tris methylol aminomethane), 2-amino-1 Butanol, ethanolamine, beta- (beta-hydroxyethoxy) -ethylamine, and the like.

Mixtures of these or similar amines may be used.

Preferred dispersants are or are derived from, for example, polyoxyethylene and polyoxypropylene amines such as pentaerythritol, trismethylolamine nomethane, polyoxypropylene diamine, polystyrene amines such as tetraethylene pentaamine and polyisobutenyl succinic anhydride It is a combination of One particularly preferred dispersant combination is (A) polyisobutenyl succinic anhydride and (B) a hydroxy compound such as pentaerythritol, (C) a polyoxyalkylene polyamine such as polyoxypropylene diamine and (D) polyethylenediamine and tetraethylene pentaamine A combination of the same polyalkyrene polyamine was prepared as described in US-A-3894763 (A) about 1 equivalent to about 0.01 to about 2 equivalents of (C) and about 0.01 to about 4 equivalents of (B) and (D) Create using Still other preferred dispersant combinations include (A) polyisobutenyl succinic anhydride and (B) polyalkylene polyamines such as tetraethylene pentaamine and (C) pentaerythritol or tris methylol aminomethane as described in US-A-3632511. Same polyhydroxy-substituted aliphatic primary amine or a combination of polyhydric alcohols.

Alkenyl succinate polyamine 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.

Alkylene polyamines such as, for example, copolymers of alkyl methacrylate with N-vinyl pyrrolidone or dimethyl aminoalkyl methacrylate, alkylfumarate-vinyl acetate N-vinyl pyrrolidin copolymer, US-A-4149984 Or post-grafted terpolymers of ethylene-propylene with active monomers such as maleic anhydride which will further react with alcohols; Or by adding 0.3-10% of a viscosity index improving polymer dispersant, such as styrene / maleic anhydride polymer, ethoxylated derivative of acylated polymer, as in US-A-3702300, which is subsequently reacted with alcohol and amine. .

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

Highly basic alkaline earth metal alkaline sulfonates such as those shown in US-A-3150088 and 3150089 are common. For the purposes of the present invention, preferred alkaline sulfonates are magnesium alkyl aromatic sulfonates having a total number of bases (TBN, measured in the ASTM D 2896 range) 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 alkyl substituted salicylic or naphthenic acids or mixtures thereof or mixtures thereof with alkylsubstituted phenols This is also included. Basic sulfide salicylates and methods for their preparation are described in SU-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 groups is at least about 9 to achieve proper 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 phenol sulfide in an amount sufficient to impart the desired alkalinity to the sulfided metal phenate.

Sulfurized alkyl phenols are converted by neutralizing the phenols or reacting with metal-containing materials, including oxides, hydroxides, and complexes, in amounts sufficient to photobase to obtain the desired alkalinity of the product by methods known in the art, if desired. do. The 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 calcium sulfonates. Oils containing 500-5000 ppm calcium and / or magnesium from these additives are preferred.

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, azelate and adipate; Complex ester oils such as those formed with dicarboxylic acid glycols and monobasic acids or monohydric alcohols; Silicone oils; 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 base stock oils which are particularly useful for mineral lubricants and which have lower antioxidant properties than are commonly used.

The lubricating oil compositions of the present invention are oleic acid and derivatives thereof, such as N-oleylsarcosine, oleic acid dimers, and trimers, lecithin, sorbitan mono-oleate, dodecyl succinic anhydride or ethoxylation, if none of them are zinc. Green suppressants such as alkylphenols; Pour point depressants, such as copolymers of vinyl acetate and fumaric acid esters of coconut oil alcohols; And typically other lubricant additives 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 dialkaldithiophosphate 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 normal antioxidant added to the oil is 0.1-1.5 wt%. Common antioxidants used include phenols, steric phenols, bis-phenols and sulfided phenols, catechols, alkylated laterols and sulfided alkyl catechols, diphenylamines and alkyl alkyl diphenylamines, phenyl-1 -Naphthylamine and alkylated derivatives thereof.

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 lubricating oils are generally provided in the form of a concentration in the oil to impregnate the bulk lubricant. Therefore, the present invention

(1) less than 0.1 wt% phosphorus and less than 0.1 wt% zinc;

(2) 1-50 wt% of a fat-soluble sulfur containing compound;

(3) 0.005-2 wt% copper; And

(4) 0.1-20 wt% bearing corrosion inhibitor and optionally

(a) 0-60 such as 10-60 wt% ashless dispersant compound

(b) Provides a concentrate consisting of an oil solution containing a dispersant, generally selected from the group consisting of 0-40, such as 3-40 wt% of a viscosity index improving polymer dispersant, even if other viscosity index improvers are added separately.

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 0.1-8 wt% calcium and / or magnesium.

The following examples merely illustrate the invention and will present 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 additives in the amounts listed in Table 1 in balance with the diluent oil containing 0.3 wt% sulfur, suitable for lubricating oil compositions. The additives used were as follows: A is an oil solution containing 21% of the multifunctional ethylene-propylene copolymer and a dispersant additive containing 0.290 wt% and N. B is a bypass dispersant consisting of a 50 wt% oil solution of boronated polyisobutenyl succinimide having a polyisobutenyl radical and having 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 1.9 wt%. E is an oil solution of copper oleate containing 4 wt% copper. F is a 30 wt% solution of steric hindrance methylene bis-phenolic antioxidant in oil. G is an alkylated diphenylamine antioxidant which is a trademark Irganox L-57 of Ciba-Geigy. H is a zinc diamyl dithiocarbamate 50 wt% oil solution containing 6 wt% zinc and 12 wt% sulfur. J is an orthoborate ester made of ethoxyethanol 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. The maximum and average wear of cams and lifters was measured by IIID engine test. 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 loss (BWL) was measured by CRC-L-39 cleaner 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. As a result, the present invention shows that the phosphorus-free lubricating oil shows excellent anti-oxidation, anti-wear and anti-corrosion bearing. Comparative Examples I, II and III impart inadequate wear performance due to the absence of bearing corrosion inhibitors. Comparative Example IV shows that the addition of olivedenium 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.

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.

P = success

F = fail

* = Failed to complete exam, fails after 4 hours

-= Failed to test

The concentrate may also contain some dilution oil to facilitate manipulation.

Claims (24)

Consists of a large amount of lubricating oil and copper added in fat-soluble form (by weight), one or more fat-soluble sulfur-containing compounds added to achieve a total sulfur content of 0.5-2.0 wt%, and an effective amount of bearing corrosion inhibitor, less than 0.05 wt% A crankcase lubricating oil composition for use in an automobile engine containing phosphorus and less than 0.01 wt% zinc. 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. 2. The method of claim 1, wherein the copper is mixed with oil as a C ₁₀ -C ₁₈ fatty acid, unsaturated carboxylic acid, a copper salt form of narthenic acid having a molecular weight of 200-500 or alkyl or alkenyl substituted dicarboxylic acid, or a general formula (RR ′) NCSS) fat-soluble copperdithiocarbamate, copper sulfonate, copper phenate of _n Cu, wherein n is 1 or 2 and R and R 'are the same or different hydrocarbyl radicals containing C _1-18 Or copper acetylacetonate. The dithiocarbamate or mercaptide, sulfide of claim 1, wherein the fat-soluble sulfur compound is of formula (RR'NCSS) _n M wherein R, R 'and n are as defined in claim 5 and M is a metal. Unsaturated organic compounds, sulfides, thioethers, thiophenols, thioxanthates, sulfided 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 which is substantially free of Zn. The composition of claim 6 containing 0.5-3 wt% of sulfide esters. 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 . B (OR) ₃ , (RO) ₂ BOB (OR) ₂ , (ROBO) ₃ or (OR) ₂ BOR | ¹ OB (OR) ² Wherein R is a substituted or unsubstituted alkyl, aryl or aralkyl group or two groups R combine together to 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) -1,3,4-thiidiazole. 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% of an ashless dispersant compound and / or (B) 0.3-10 wt% of a viscous resin improving polymer dispersant. 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 depressants, additional anti-acid agents, and viscosity index improvers. (1) less than 0.1 wt% phosphorus and less than 0.1 wt% zinc; (2) 1-50 wt% of a fat-soluble sulfur containing compound; (3) 0.005-2 wt% copper; (4) 0.1-20 wt% bearing corrosion inhibitor; And (5) Concentrate consisting of 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 comprising zinc and phosphorus containing lubricants containing fat soluble sulfur compounds, bearing corrosion inhibitors, ashless dispersants and / or viscosity index improving polymer dispersants, and calcium and / or magnesium containing detergents. . Crankcase lubricant compositions for automotive engines containing less than 0.05 wt% phosphorus and less than 0.01 wt% zinc to inhibit oxidation, wear and corrosion and to at least meet the standard specifications SF and / or CD's quality standards for API engine requirements. The use of added copper 5-500 ppm, total 0.5-2.0 wt% sulfur, and bearing corrosion inhibitors, used in fat-soluble form.