JP2009533528A - Low SAP engine lubricant additives and compositions comprising non-corrosive sulfur and organic borates - Google Patents

Abstract

The present invention relates to a lubricating oil composition, the composition comprising a lubricating oil base, and at least 0.1 wt% and less than 8.0 wt% boron-free additive, ashless sulfur additive, relative to the composition At least 0.1 wt% and less than 4.0 wt%, dispersant-detergent-antioxidant system less than 15 wt%, zinc dithiophosphate additive at least 0.2 wt% and less than 2.0 wt%. The elements in the formulated oil composition have phosphorus at least 100 and less than 630 PPM, at least 1,000 PPM and less than 3,000 PPM, phosphorus at least 100 PPM and less than 630 PPM, and zinc at least 105 PPM and less than 710 PPM. In a second embodiment, an additive composition for a lubricating oil is disclosed. In a third embodiment, a method for obtaining advantageous lubricating oil properties is disclosed.
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Description

  The present invention relates to a lubricating oil composition suitable for use in an internal combustion engine. More particularly, the present invention relates to low ash, low sulfur, and low phosphorus lubricating oil compositions.

  Many means for reducing overall wear and friction, as well as controlling oxidation / cleanability, are used in modern engines, particularly automotive engines. The main methods include extending engine life by reducing engine wear and increasing oxidation resistance by reducing engine sludge / deposit accumulated through oil degradation. Some of the solutions to reduce wear were strictly mechanical, including engine construction with wear resistant alloys or ceramic parts, improved contact structure, and the addition of specific coating materials. Solutions that improve cleanliness also include oil improvements including the use of metal-containing detergents. Recently, a lot of research has also been done on lubricating oils, and their wear / oxidation resistance properties have been enhanced by modifying them with ashless antioxidants and antiwear components.

  Modern lubricating oils, such as engine oils, incorporate a number of performance benefits using a mixture of additive components. Examples of additive components include antiwear and extreme pressure components, fuel economy enhancing components, friction reducers, dispersants, detergents, corrosion inhibitors, and viscosity index improvers. These additives provide energy savings, engine cleanliness, and durability, and high performance levels for lubricants under a wide range of engine operating conditions, including temperature, pressure, and lubricant service life.

  Worldwide, regulations aimed at reducing automotive emissions have pushed fuel sulfur levels down. Recently, lubricating oil has been the subject of monitoring as a source of air pollution and emission catalyst degradation. Phosphorus is known to poison automobile ternary HC conversion catalysts.

  Conventional engine oil technology remarkably relies on zinc (dialkyl) dithiophosphate (“ZnDTP” or “ZDDP”). ZnDDP is a multifunctional antiwear / oxidation resistant component that significantly reduces cam and lifter wear and advantageously prevents oxidation under harsh conditions. ZnDTP has drawbacks, especially at a high processing rate. Because they carry three unfavorable components: Zn, S, P, until the reduction of phosphorus and zinc levels can replace or eliminate the new additive technology for zinc dithiophosphate Because it cannot be realized. Sulfur is known to be toxic to de-Nox catalysts and zinc phosphate causes exhaust particulate filter plugging. The sulfur, ash, and phosphorus components in the oil are commonly referred to in the art as “SAP”.

  The main problem with ZnDTP is the poisoning effect on the post-treatment device. This exacerbates the emission problem. In addition, ZnDTP has a strong interaction with dispersants, detergents, other anti-wear components, and MoDTP. This causes antagonizing effects of friction, sludge, and deposits when inappropriate concentrations are used. The anti-wear requirements for today's engines are remarkably high, and the substitution of ZnDTP additives is not a straightforward effort because it imposes very severe chemical limits on any reduction in ZnDTP processing levels.

  Engine lubricants are often used in high temperature applications where extreme temperatures can significantly reduce the useful life of the lubricant. At high temperatures, lubricating oils can be oxidized early unless a strong antioxidant system is used in the oil to prevent this degradation process. Good anti-wearing of pistons, rings, cams and lifters is also an important property of today's engine oils. In addition, many engine oils are often required to work well in the presence of water and thus prevent rust formation. Conventionally, ZnDTP is used to provide the appropriate preventive properties described above. Engine designers are now seeking greater wear resistance and more stringent testing techniques have been set up to ensure that lubricants meet these more stringent standards. However, strict emission regulations have caused the lubricant prescribers to pull from ZnDTP for the reasons described above.

  Accordingly, there is a need for an engine oil additive or additive system that has the ability to improve both rust and wear protection while substantially enhancing oxidative stability while meeting stringent emission requirements. .

US Pat. No. 6,080,301 US Pat. No. 6,090,989 US Pat. No. 6,165,949 API Technical Document No. 1509 (www.API.org)

  In a first embodiment, a lubricating oil composition is disclosed. The composition comprises a lubricating oil base, a boron-containing additive present in an amount of at least 0.1% by weight and less than 8.0% by weight of the composition, at least 0.1% by weight of the composition and Non-corrosive sulfur additive present in an amount of less than 4.0% by weight, less than 15% by weight dispersant-detergent-antioxidant system for the composition, at least 0.2% by weight for the composition And a zinc dithiophosphate additive present in an amount up to 2.0% by weight relative to the composition, wherein the weight percent is relative to the active ingredient of the composition. The formulated oil composition has phosphorus at least 100 and less than 630 PPM, sulfur at least 1,000 PPM and less than 3,000 PPM, zinc at least 105 PPM and less than 710 PPM, boron at least 80 PPM and less than 450 PPM.

  In a second embodiment, an additive composition for a lubricating oil is disclosed. The composition comprises at least 0.4 wt.% And less than 32 wt.% Organoboron-containing additive relative to the additive, less than 60 wt.% Detergent-dispersant system relative to the additive, and additive. At least 0.8 wt% and less than 8.0 wt% zinc dithiophosphate additive, and at least 0.4 and less than 16.0 wt% non-corrosive ashless sulfur additive relative to the additive.

  In a third embodiment, a method for obtaining advantageous lubricating properties is disclosed. This method comprises a lubricating oil base, at least 0.1 and less than 8 wt.% Organic boron-containing additive for the composition, less than 15 wt.% Dispersant-detergent-antioxidant system for the composition. Zinc dithiophosphate additive at least 0.2% by weight of the composition and not more than 2.0% by weight of the composition, at least 0.1 and less than 4.0% non-corrosive by weight of the composition A step of obtaining a composition comprising a reactive ashless sulfur additive. The formulated oil composition has phosphorus at least 100 and less than 630 PPM, sulfur at least 1,000 PPM and less than 3,000 PPM, zinc at least 105 PPM and less than 710 PPM, boron at least 80 PPM and less than 450 PPM.

  The present invention relates to engine lubricants formulated with unique functional fluids and / or additives to achieve improved performance. One embodiment is a low SAP engine lubricating oil composition comprising a combination of an organic borate, a non-corrosive sulfur compound, any high level of ashless antioxidant, and a low level of ZnDTP, wherein the high level of ZnDTP is A high level of performance equivalent to or better than that used alone is achieved. In one embodiment, the synergistic effects of the components are built for various functions to achieve sufficiently stable performance characteristics. In a preferred embodiment, these performance characteristics advantageously exceed engine oils formulated with high levels of zinc dithiophosphate and metallic detergents.

  In the second embodiment, the lubricating oil retains the low friction properties of the film under various operating conditions. This embodiment advantageously maintains a sufficiently high film thickness at high operating temperatures to provide a minimal lubricant film and prevent wear at various temperatures.

  In a third embodiment, the lubricant maintains cleanliness over the full range of operating conditions while reducing wear to a minimum. In a fourth embodiment, the lubricating oil advantageously suppresses oxidation and corrosion under the most severe operating conditions.

  It has been discovered that non-corrosive organosulfur compounds provide considerable property advantages when mixed with high levels of organoborate and low levels of zinc dithiophosphate. In preferred embodiments, high levels of ashless antioxidants are added to the compound to achieve even more advantageous property advantages. These benefits include, without limitation, wear, reduced corrosion, and increased oil-induced temperature or time (OIT) in oxidizing conditions. This potentially provides a substantial improvement in the service life and durability of the engine oil, along with excellent overall performance benefits. In further embodiments, these benefits can be achieved without deleterious effects (instability, undesirably high viscosity, deposits, etc.) when the additive is added to the lubricating oil. This new engine oil technology is a combination of several typical recent dispersants, ashless antioxidants, detergents, antifoams, and other additives (including recent DI additive packages) Based on advanced wear, anti-friction, and antioxidant systems. These additives enhance wear resistance, oxidation resistance, and corrosion resistance performance.

  Those skilled in the art having the benefit of the present disclosure will include additives that advantageously enhance lubrication performance (including anti-friction, anti-oxidation, and anti-wear performance), while severe wear, oxidation, and cleaning in modern engines You will understand the ability to successfully meet sexual performance requirements. Examples of suitable additives include, but are not limited to, low levels of recent zinc dithiophosphates, borated or non-borated dispersants, phenol and amine ashless antioxidants, high and low levels of metal detergents , Molybdenum or organic friction modifiers, antifoaming agents, seal swelling additives, pour point depressants (including recent DDI additive packages), and any combination thereof.

Preferred organic borates are borated hydroxyl esters. Boronated glycerol mono-oleate (GMO), Boronated glycerol di-oleate (GDO), Boronated glycerol tri-oleate (GTO), Boronated glycerol mono-cocoate (GMC), Boronated mono-tallowate (GMT), Boron glycerol mono - Sorubiteto (GMS), (such as borated pentaerythritol -C ₈ ester) borated polyol esters having pendant hydroxyl groups, and the like in any combination thereof. Short chain tri-hydroxyorthoborates are undesirable but may be used due to their relatively poor thermal / oxidative stability when compared to borated hydroxyl esters. Boronated dispersants and boronated detergents can be used as a source of boron. However, certain organic borates (such as boronated hydroxyl esters) are more preferred to achieve the best overall performance.

  Preferred non-corrosive sulfur compounds are ashless derivatives of thiadiazole, ashless derivatives of benzothiazole, ashless alkyl or aryl sulfides and polysulfides such as disulfides and trisulfides (including thianthrene and its alkylates), diphenyl sulfides and disulfides and Their alkylates, dinonyl sulfides or disulfides, dipyridyl sulfides or disulfides and their alkylates, ashless dithiocarbamates, and thioesters / sulfurized esters (including thioglycolates, dialkylthiodipropionates, dialkyldithiopropionates) Selected from the group consisting of Examples of ashless thiadiazole are Vanlube 871 (TM), Cuvan 826 (TM), and Cuvan 484 (TM). Examples of ashless dithiocarbamates are Vanlube 7723 ™ and Vanlube 981. A prerequisite for the selection of sulfur additives is that they all have to meet the copper corrosion requirements according to ASTM (D130) and low temperature storage affinity tests.

  Corrosion resistance can be determined by the copper corrosion test ASTDM D130 under normal conditions. For ASTDM test D130-6, normal conditions are 250 ° F./3 hours. For ASTDM test D130-8, the normal conditions are set at 210 ° F / 6 hours in the presence of% water, and the more severe conditions are set at 250 ° F / 24 hours. For purposes of the present invention, non-corrosive sulfur will be defined as any sulfur that results in a performance rating of 2B or better in the ASTM D-130 copper corrosion test.

  Dibenzyl disulfide was insufficient in a severe copper corrosion test for 24 hours at Fahrenheit temperature. 2,2'-dipridyl disulfide has insufficient low temperature affinity in engine oils. Therefore, any additive is considered less favorable, regardless of their strong EP performance. Sulfur additives containing a small portion of polysulfides (trisulfide / tetrasulfide, and higher order polysulfides) are still acceptable if they can meet copper corrosion requirements.

  Preferred ashless antioxidants are hindered phenols and arylamines. Typical examples are butylated / octylated / styrenated / nonylated / dodecylated diphenylamine, 4,4 ′ methylenebis- (2,6-di-tert-butylphenol), 2,6-di-tert-butyl- p-cresol, octylated phenyl-alpha-naphthylamine, alkyl esters of 3,5-di-tert-butyl-4-hydroxy-phenylpropionic acid, and many others. Sulfur-containing antioxidants (such as sulfur cross-linked hindered phenols and thiol esters) can also be used.

  Suitable dispersants include boronated and non-borated succinimides, succinic acid-esters and amides, alkylphenol-polyamine conjugated Mannich adducts, other related ingredients, and any combination thereof. In some embodiments, it can often be advantageous to use a mixture of these above-mentioned dispersants and other related dispersants. Examples include boronated additives, predominantly of higher molecular weight, predominantly mono-succinimide, bis-succinimide, or mixtures of the above, made with different amines, end-capped , Dispersants derived from polymers of branched olefins such as polyisobutylene, or other polyolefins other than polyisobutylene (ethylene, propylene, butene), similar dispersants, and any combinations thereof Is included. The average molecular weight of the hydrocarbon backbone of most dispersants (including polyisobutylene) is 1000 to 6000, preferably 1500 to 3000, and most preferably about 2200.

  Suitable detergents include, but are not limited to, calcium phenate, calcium sulfonate, calcium salicylate, magnesium phenate, magnesium sulfonate, magnesium salicylate, metal carbonate, related ingredients including boronated detergents, and Any combination thereof is included. The detergent can be neutral, mildly overbased, or highly overbased. The amount of detergent typically provides a total base number (TBN) in the range of 1-9 for the formulated lubricating oil composition. The metal detergent is selected from alkali or alkaline earth calcium or magnesium phenates, sulfonates, salicylates, carbonates, and similar components.

  Antioxidants are selected from hindered phenols, arylamines, dihydroquinolines, phosphates, thiol / thiol ester / disulfide / trisulfide, low sulfur peroxide decomposers, and other related components. These additives are rich in sulfur, phosphorus, and / or ash content because they form a strong chemical film on the metal surface, thus in lubricants with reduced sulfur, ash, and phosphorus. Requires to be used in limited amounts.

  Antioxidants and rust inhibitors may be used as necessary. Seal swelling inhibiting components and antifoaming agents may be used with the mixtures of the present invention. Various friction modifiers may also be used. Examples include, without limitation, amines, alcohols, esters, diols, triols, polyols, aliphatic amides, various molybdenum phosphorodithioates (MoDTP), molybdenum dithiocarbamates (MoDTC), sulfur / phosphorous. An organic molybdenum component, a molybdenum trinuclear component, and any combination thereof are included.

  In a preferred embodiment, this novel synergistic combination significantly improves these important performance parameters while retaining excellent affinity and exhausts the post-processing equipment. This embodiment includes a novel antiwear / friction reduction and antioxidant system consisting of organic borates, non-corrosive sulfur additives, high levels of ashless antioxidant, and low levels of zinc dithiophosphate. More specifically, this formulated engine oil embodiment comprises about 100-630 ppm phosphorus, about 0.1-0.3 wt% sulfur, and about 80-450 ppm boron, and ashless antioxidants (hindered phenols and About 0.5-3.0% by weight).

These components can be used with various substrates (including Groups I, II, III, IV, and V), and gas-to-liquid (“GTL”), and various mixtures thereof. However, due to other performance requirements including volatility, stability, viscosity, and cleanliness characteristics, premium engine oils prefer to use Group II or higher ("Group II ⁺ ") base oils It is ensured that the desired overall performance level is achieved, as well as the maximum potential for unique synergies in the additive is obtained. Further substantial synergies were observed in alkylated aromatics and Group II ⁺ high performance substrates (including Group II, III, IV, V, VI, or GTL substrates).

  Groups I, II, III, IV, and V are a broad class of base stocks developed and defined by the American Petroleum Institute (NPL 1) to develop lube base stock guidelines. Group I substrates generally have a viscosity index of about 80-120 and include greater than about 0.03% sulfur and / or less than about 90% saturation. Group II substrates generally have a viscosity index of about 80-120 and contain no more than about 0.03% sulfur and no less than about 90% saturation. Group III materials generally have a viscosity index greater than about 120, and contain no more than about 0.03% sulfur and more than about 90% saturation. Group IV includes polyalphaolefins (PAO). Group V substrates include substrates not included in Groups I-IV. Table 1 summarizes the characteristics of each of these five groups.

  Substrates having high paraffinic / naphthenic and saturability greater than 90% by weight can often be advantageously used in certain embodiments. These base materials include Group II and / or Group III hydrotreated or hydrocracked base materials, or synthetic equivalents thereof (polyalphaolefin oil, GTL, or similar base oils or mixtures of similar base oils). Etc.).

  In preferred embodiments, at least about 20% of the total composition should consist of these Group II or Group III substrates or GTL, with at least about 30% being preferred, and more than about 80% being most preferred. Gas-to-liquid substrates can also be used preferentially with the components of the present invention as part or all of the substrate used to formulate the finished lubricant. When the components of the present invention are added to a lubrication system primarily comprising Group II, Group III, and / or GTL substrates, a convenient improvement has been found compared to smaller amounts of another fluid. .

  GTL materials can undergo gaseous carbon-containing compounds, hydrogen-containing compounds, and / or components as raw materials (hydrogen, carbon dioxide, carbon dioxide, through one or more of synthesis, combination, transformation, rearrangement, and / or decomposition / disassembly processes. Carbon monoxide, water, methane, ethane, ethylene, acetylene, propane, propylene, propyne, butane, butylene, and butyne). GTL base stocks and base oils are lubricating oil viscosity GTL materials generally derived from hydrocarbons (eg, waxy synthetic hydrocarbons), which are themselves simpler gaseous carbon-containing compounds, hydrogen-containing compounds. And / or derived from raw material elements. The GTL base material includes an oil that boils within the lubricating oil boiling range. This is separated / fractionated from the GTL material, eg, by distillation or thermal diffusion, and subsequently subjected to a well known contact or solvent dewaxing process to reduce / low pour point lubricating oil; Hydrolyzed oils (including hydroisomerized or isomerized dewaxed synthetic hydrocarbons); hydroisomerized or isomerized dewaxed Fischer-Tropsch (“FT”) materials (ie, hydrocarbons, waxy hydrocarbons, Waxes, and possible similar oxygenates); preferably hydroisomerized or / isomerized dewaxed FT hydrocarbons, hydroisomerized or / isomerized dewaxed FT waxes, hydroisomerized or isomerized A dewaxed synthetic wax, or a mixture thereof, is produced.

GTL substrates derived from GTL materials, in particular hydroisomerization / isomerization dewaxing FT material derived substrates, and other hydroisomerization / isomerization dewaxing wax derived substrates are typically Kinematic viscosity (100 ° C.) from about 2 mm ² / second to about 50 mm ² / second, preferably from about 3 mm ² / second to about 50 mm ² / second, more preferably from about 3.5 mm ² / second to about 30 mm ² / second Characterized as a thing. This is illustrated by a GTL substrate (having a kinematic viscosity (100 ° C.) of about 4 mm ² / sec and a viscosity index of about 130 or more) derived by isomerization dewaxing of FT wax. As used herein and in the claims, the terms GTL base oil / base and / or wax isomerate base oil / base are GTL base / base oil or wax isomerate recovered in the manufacturing process. A mixture of two or more individual base / base oil fractions, a GTL base / base oil fraction and / or a wax isomerized oil base / base oil fraction, and a lower viscosity GTL base / base One or more oil fractions and / or wax isomerate base / base oil fraction and higher viscosity GTL base / base oil fraction and / or wax isomerate base / base oil It should be understood that a dumbbell mixture is produced including a mixture of one or more fractions. In so doing, the mixture exhibits a viscosity within the ranges listed above. References to kinematic viscosity in this specification refer to measurements made by ASTM method D445.

  GTL substrates and base oils derived from GTL materials, in particular hydroisomerization / isomerization dewaxing FT material derived substrates, and other hydroisomerization / isomerization dewaxing wax derived substrates (wax hydroisomerization) Oils / isomerized dewaxed oils, etc.) can be used as a base component of the present invention, which typically further has a pour point of about −5 ° C. or less, preferably about −10 ° C. Below, more preferably it is characterized as having about −15 ° C. or less, and even more preferably about −20 ° C. or less. Under some conditions, it may have a convenient pour point of about −25 ° C. or less, with a useful pour point being about −30 ° C. to about −40 ° C. or less. If desired, different dewaxing steps may be performed to achieve the desired pour point. Reference to pour point herein refers to measurements made by ASTM D97, and similar automated molds.

  GTL substrates derived from GTL materials, in particular hydroisomerization / isomerization dewaxing FT material derived substrates, and other hydroisomerization / isomerization dewaxing wax derived substrates are used in the present invention. Although it is a substrate component that can be, it is also typically characterized as having a viscosity index of 80 or higher, preferably 100 or higher, more preferably 120 or higher. In addition, in certain cases, the viscosity index of these substrates may preferably be 130 or greater, more preferably 135 or greater, and even more preferably 140 or greater. For example, GTL substrates derived from GTL materials, preferably FT materials, particularly FT waxes, generally have a viscosity index of 130 or higher. Citation of viscosity index herein refers to ASTM method D2270.

  In addition, GTL substrates are typically highly paraffinic (greater than 90 percent saturation) and may include a mixture of monocycloparaffins and multicycloparaffins in combination with acyclic isoparaffins. The ratio of naphthenic (ie cycloparaffin) content in these combinations depends on the catalyst used and the temperature. Furthermore, GTL base stocks and base oils typically have very low sulfur and nitrogen contents. This generally includes less than about 10 ppm, and more typically less than about 5 ppm for each of these elements. The sulfur and nitrogen content of the GTL base stock and base oil obtained by hydroisomerization / isomerization dewaxing of FT materials, in particular FT waxes, is essentially zero.

  In a preferred embodiment, the GTL substrate comprises a paraffinic material consisting primarily of acyclic isoparaffins and only a small amount of cycloparaffins. These GTL substrates are typically greater than 60% acyclic isoparaffin, preferably greater than 80% acyclic isoparaffin, more preferably greater than 85% acyclic isoparaffin, most preferably acyclic. Contains paraffinic material consisting of more than 90% by weight of isoparaffin.

  Useful compositions of GTL substrates, hydroisomerization or isomerization dewaxing FT material-derived substrates, and wax-derived hydroisomerization / isomerization dewaxing substrates (such as wax isomerized oil / isomerized dewaxed oil) Things are listed in, for example, Patent Document 1, Patent Document 2, and Patent Document 3.

  A major advantage of one embodiment of the present invention is the unique synergistic combination of organoborate, non-corrosive sulfur additives in the presence of low levels of zinc dithiophosphate and high levels of ashless antioxidants. . This provides favorable oxidation, corrosion stability, and more importantly wear resistance performance. These advantageous performance levels can be achieved while reducing the levels of sulfur, phosphorus, and zinc in engine oil formulations as compared to typical engine oils used today.

  In one embodiment, a general formulation for low SAP engine oil is summarized in Table 2. In this table, and throughout this application, weight percentages are those that are weight percentages of the active ingredients of the total composition unless otherwise stated.

  Table 3 shows the low temperature stability of the different ashless antiwear additives for a low phosphorus lubricating oil having a phosphorus level of 0.05% by weight based on the composition. Table 3 shows various embodiments for two reference base oil formulations. Both base reference oils A and B are formulated with premium Group III base oils.

  Referring now to Table 3, Comparative Oils 1, 2, 3, and 4 are variants of Reference Oil A. The formulation of reference oil A is disclosed in Table 4.

  Referring to Table 3 again, comparative oil 5 is a variant of reference oil B. The formulation of reference oil B is disclosed in Table 5.

  Table 3 also shows the copper corrosion test according to ASTM D-130 method. Table 6 shows the various classifications according to the ASTM copper corrosion test. As shown in Table 6, grades 1A, 1B, 2A, and 2B are non-corrosive preferred grades, and grades 2C, 2D, 2E, 3A, 3B, 4A, 4B, and 4C are unfavorable grades. It is.

  As shown in the second and third columns of Table 3, the very low low temperature stability (labeled as soluble appearance) is Aldolthiol-4 (0.2-0.3%), respectively. Observed when added to a low phosphorus reference A base oil formulation (first row). This low oil affinity problem correlates well with the results of the low hot tube deposit test. As shown in the fourth and fifth columns, the oil affinity is improved by adding aldrithiol-2 (0.2-0.3%). However, copper corrosion is unacceptable in the fourth and fifth columns.

  A similar evaluation was made when 0.25% dibenzyl disulfide described in Comparative Oil 5 was added to the Reference Oil B base oil formulation described in Table 3. In this example, the 4-ball wear and EP performance are slightly improved and the average friction and calculated wear scar area (high frequency reciprocating rig (HFRR)) is significantly reduced compared to Reference Oil B compared to Comparative Oil 5. . However, the copper corrosion (250 ° C., 24 hours) test conditions remain low. This is indicated by a rating 4A for comparative oil 5.

  Referring now to Table 6, any rating of grades 2C-2E, 3, and 4 is not preferred because they can result in darkening and discoloration of the copper strip. This exhibits a corrosive or corrosive-like behavior in strength. To achieve the additive synergistic embodiments described in the present invention, a very strict preferred range is established for defining non-corrosive sulfur additives. Thus, dibenzyl disulfide and aldrithiol-2 are not preferred due to their corrosive sulfur species and are therefore not recommended for low SAP engine oils.

  Reference oil B is a blend that does not contain ZnDTP and is developed so that very different amounts of ZnDTP as well as other non-corrosive organic sulfur additives can be added to show comparative performance results. The base formulation is formulated with a Group III base oil. It has a minimum viscosity index of 120, a typical pour point of −15 ° C., a typical Noack of 15, and a typical sulfur of 10 ppm (maximum sulfur content less than 30 ppm). Similarly, formulated base engine oils are also formulated with GTL oil. It has a minimum viscosity index of 135, a typical pour point of -17 ° C, and a typical sulfur of less than 1 ppm.

  Table 7 shows that very good oxidation / corrosion inhibition combines a non-corrosive sulfur additive, a borated dispersant, a high level of ashless antioxidant, and a low level of zinc dithiophosphate in a low phosphorus engine oil. It can be achieved by using. The first and second columns represent reference oils C and D, and the third, fourth, and fifth columns represent comparison oils 6, 7, and 8, respectively. This is a variant of reference oil D. Reference oil C is a low SAP Group III base oil with 0.1 wt% phosphorus. On the other hand, reference oil D and practice comparative oils 6, 7, and 8 are group III low SAP base oils having 0.05 wt% phosphorus. Some variations in formulation are also shown in Table 7.

  The non-corrosive sulfur additive of comparative embodiment oil 6 is an ashless dithiocarbamate (“DTC”) called Vanlube ™ 981. Vanlube ™ 981 is a product of R.A. T.A. Experimental additive available from Vanderbilt Chemical Company. Comparative oils 7 and 8 are specific sulfurized esters / olefins with a low sulfur content, with or without DTC, as in comparative oils 7 and 8. This is labeled RC-2411 and RC-2515, respectively. RC-2411 and RC-2515 are commercially available from Rhein Chemie Chemical Company. Good corrosion inhibition is indicated by the copper corrosion rating 1A-2B under various conditions. The antioxidant performance of oils 6, 7, and 8 is slightly better than that of reference oil D. These properties are shown at higher onset temperatures of about 4-8 ° by pressurized differential scanning calorimetry (“PDSC”). In the PDSC gradient method at 10 ° C./min, the higher the starting temperature, the better the oxidation resistance. In general, the oxidation rate is generally doubled with a temperature increase of about 10 ° C. Thus, these results can be rephrased as about 40% to 80% good by viscosity suppression, acid value increase, or any other comparative measurement to suppress oxidation.

  When non-corrosive sulfur additives are added as in comparative embodiment oils 6, 7, and 8, the results for 4-ball wear and 4-ball EP are quite consistent and better than reference oil D. It is. A slight decrease of 8-14% in the wear scar diameter can be observed for the four ball wear condition of ASTM D4172. This translates into a 29-47% reduction in the calculated wear volume (denoted as K-factor). The final non-seeding load (“LNS”) and load-wear index (“LWI”) are 21-25 for oils 6, 7, and 8 when compared to the performance of Reference 4 in the 4-ball EP test. % Good.

  HFRR data showed that these non-corrosive sulfur additives can help maintain excellent friction properties as well as reduced wear. This is indicated by an average friction coefficient lower by 18-29% and a calculated wear scar area smaller by about 4-15%. In general, the comparison comparative oils 6, 7, and 8 formulated with 0.05% phosphorus and non-corrosive sulfur additives are in 1% by weight reference oil C when compared to typical engine oils. As such, it shows better performance with full filling of ZDDP. This indicates that a strong synergistic effect exists in the various embodiments of Run Oils 6, 7, and 8. All of the additive components of the example oils 6, 7, and 8 are completely compatible with the engine oil. This is indicated by their apparent color appearance in storage over several months. Table 7 shows the sufficient stability of oils containing non-corrosive sulfur additives. Finally, the pin-on V-block shown as a result of the Falex wear test correlates well with the 4-ball wear / EP result. This shows better wear inhibition of the comparative oils 6 and 7 relative to the reference oil D.

  In Table 8, other low SAP oils were also evaluated. Comparative Oil 9 is a low SAP Group III base and the final composition has 0.025 wt% phosphorus.

  Equivalent mean coefficient of friction and calculated wear scar area were observed in the HFRR test. This, however, was found when a substantially improved final non-shearing (LNS) load and load-wear index (LWI) were compared in comparison to reference oil E in the 4-ball EP test. . In fact, the 4-ball EP performance of comparative oil D is approximately equal to that of reference oil F, with twice the amount of ZDDP used as indicated by 0.05% by weight of final phosphorus. Although Reference Oil E has strong 4-ball EP performance, the HFRR data is not as good as Comparative Oil 9 and Reference Oil E. This data clearly shows that too much ZDDP can be antagonistic to friction properties. The base formulation is also shown based on the first column of Table 8, which was also used to mix the oils in Tables 6 and 7. This is fully described in Table 5 for reference.

  Table 9 shows the evaluation of non-corrosive sulfur additives in low SAP commercial vehicle lubricants (“CVL”). Table 9 is formulated with a low SAP base oil that does not contain phosphorus.

  The composition of the base formulation of Table 9 is shown in Table 10. As shown in Table 10 and the third column of Table 9, this base oil does not contain any phosphorus. The base oil system consists of about 50% Group III and about 20% Group I base oil. All oils (Tables 9 and 11) containing ZDDP and other sulfur / boron additives are formulated from the base formulation. Similarly, other base formulations are formulated with GTL base oils. The base oil system consists of more than 50% GTL and less than 20% Group I base oil.

  Referring now to Table 9, in the example oil 10, 0.3 wt% of the non-corrosive sulfur additive (in this example, ashless dithiocarbamate), as indicated by reference oil G, Included in engine oils formulated with 0.03% by weight phosphorus. Four-ball wear performance resulted in a reduction in wear, or a 2-15% increase in wear scar diameter ("WSD"), and an 8-51% increase in calculated wear volume or K-factor. Comparative oils 11 and 12 show the synergistic effect of combining borated GMO with borated dispersant.

  Similarly, Table 11 shows the performance of 4-ball EP and hot tube with a combination of 0.3% ZDDP and 0.3% non-corrosive sulfur additive for Comparative Oil 13 compared to Comparative Oil H (ZDDP 0.6%). It shows. The processing rate of the total AW / EP additive is the same 0.6% and the EP performance is almost the same. However, item 4 hot tubes are much better, indicating a cleaner environment. The 4-ball EP performance of the comparative oil 13 is stronger than the reference oil I with a ZDDP reduced to 0.3% and the third row base oil with a ZDDP of 0%.

  In summary, the new low SAP engine oil system is based on a very unique combination of non-corrosive sulfur additives, low levels of ZDDP, borated components (preferably with high levels of ashless antioxidants) It's been found. This formulation shows significant and unexpected performance for modern engines. One embodiment of this discovery represents an effective way to reduce the amount of ZDDP relative to modern engine oils while retaining excellent wear, oxidation, and corrosion protection. The synergistic concept of this unique component is less than 300 ppm low sulfur base oil, boronated additives (by boronated hydroxy esters such as boronated GMO, and other organic borates such as boronated dispersants), non-corrosive It is believed that it is applicable to similar formulations containing sulfur additives and preferably with ashless antioxidants.

Claims (20)

a. Lubricating oil base;
b. An organoboron-containing additive present in an amount of at least 0.01% by weight and less than 8.0% by weight of the composition;
c. Less than 15% by weight of the dispersant-detergent-antioxidant system relative to the composition;
d. A non-corrosive ashless sulfur additive present in an amount of at least 0.1% by weight and less than 4.0% by weight of the composition; and e. A composition comprising a zinc dithiophosphate additive present in an amount of at least 0.2% by weight of the composition and less than 2.0% by weight of the composition comprising:
f. A composition comprising at least 100 PPM, less than 630 PPM phosphorus, at least 105 PPM, less than 710 PPM zinc, at least 1,000 PPM, less than 3,000 PPM sulfur and at least 80 PPM, less than 450 PPM boron.   At least one performance additive, said performance additive comprising zinc dithiophosphate, boronated or non-borated dispersant, phenol and amine ashless antioxidant, metal detergent, molybdenum or organic friction modifier, Selected from the group comprising antifoams, seal swell additives, pour point depressants and other dispersants including detergent-detergent-antioxidant (DDI) additive packages, and any combination thereof. The composition according to claim 1.   The base material is selected from the group consisting of a group II base material, a group III base material, a group IV base material, a group V base material, a gas-to-liquid base material, and any combination thereof. 2. The composition according to 1.   The dispersant system comprises an additive selected from the group consisting of boronated and non-borated succinimides, succinic acid-esters and amides, alkylphenol-polyamine conjugated Mannich adducts, and any combination thereof. The composition of claim 1.   The composition of claim 1 further comprising an ashless antioxidant additive.   The composition of claim 1 further comprising a metal detergent or detergent system.   7. The composition of claim 6, wherein the detergent system provides the formulated lubricating oil composition with a total base number (TBN) of less than 9, preferably less than 7, and most preferably less than 5.   The composition according to claim 1, further comprising a viscosity modifier additive.   The organic borate includes boronated glycerol mono-oleate, boronated glycerol di-oleate, boronated glycerol tri-oleate, boronated glycerol mono-cocoate, boronated mono-tallowate, boronated glycerol mono-sorbate, boronated polyol ester And a boronated hydroxyl ester selected from the group consisting of any combination thereof.   The non-corrosive sulfur additives include ashless derivatives of thiadiazole, ashless derivatives of benzothiazole, ashless alkyl, aryl sulfide / di-sulfide / tri-sulfide (thianthrene, diphenyl disulfide, dinonyl disulfide, dipyridyl disulfide and the like) ), Ashless dithiocarbamate, thioester / sulfurized ester, thioglycolate, dialkylthiodipropionate, dialkyldithiopropionate and any combination thereof. The composition of claim 1.   11. The composition of claim 10, wherein the non-corrosive organic sulfur additive is a sulfur / nitrogen containing heterocyclic or non-heterocyclic antiwear-antioxidant additive.   12. The composition of claim 11, wherein the non-corrosive organic sulfur additive is an ashless dithiocarbamate additive.   The composition of claim 11, wherein the non-corrosive organic sulfur additive is a thiadiazole derivative antiwear additive. A lubricating oil additive system for a lubricating oil composition comprising:
a. An additive containing at least 0.4 wt.% And less than 32 wt.% Organoboron relative to the additive system;
b. Less than 60% by weight of detergent-dispersant system relative to the additive system;
c. At least 0.8 wt% zinc dithiophosphate additive for the composition and less than 8.0 wt% for the additive system; and d. A lubricating oil additive system comprising at least 0.4 wt.%, Less than 16.0 wt.% Non-corrosive ashless sulfur additive, based on the additive system.   15. Lubricating oil additive system according to claim 14, characterized in that the treatment of all lubricating oil additives is in the range of at least 0.1% to 25% by weight relative to the lubricating oil composition.   15. The lubricating oil additive system of claim 14, further comprising a molybdenum additive.   The lubricating oil additive system of claim 16, wherein the molybdenum additive is an organic molybdenum additive.   15. The lubricating oil additive system of claim 14, wherein the zinc dithiophosphate additive comprises a zinc alkyl thiophosphate derived from a primary alkyl alcohol or a secondary alkyl alcohol, or a combination thereof. a. Obtaining a composition comprising: a lubricating oil base; an organic boron-containing additive present in an amount of at least 0.1% by weight and less than 8% by weight relative to the composition; Less than 15% by weight of dispersant-detergent-antioxidant system, zinc present in an amount of at least 0.2% by weight of said composition and less than 2.0% by weight of said composition A dithiophosphate additive, comprising a non-corrosive ashless sulfur additive present in an amount of at least 0.1% by weight, less than 4.0% by weight relative to the composition, and phosphorus at least 100 PPM, less than 630 PPM, zinc Having 105 PPM, less than 710 PPM, sulfur at least 1,000 PPM, less than 30,000 PPM, boron at least 80 PPM, less than 450 PPM; and b. Lubricating the engine with the composition to achieve favorable wear resistance, oxidation and cleanliness. A method for reducing sulfur in exhaust gas from an internal combustion engine,
a. Obtaining a composition comprising: a lubricating oil base; an organic boron-containing additive present in an amount of at least 0.1% by weight and less than 8% by weight relative to the composition; Less than 15% by weight of dispersant-detergent-antioxidant system, zinc present in an amount of at least 0.2% by weight of said composition and less than 2.0% by weight of said composition A dithiophosphate additive, comprising a non-corrosive ashless sulfur additive present in an amount of at least 0.1 wt.%, Less than 4.0 wt.%, And phosphorus at least 100 PPM, less than 630 PPM, zinc at least Obtaining a composition having 105 PPM, less than 710 PPM, sulfur of at least 1,000 PPM, less than 30,000 PPM, boron of at least 80 PPM, less than 450 PPM; and b. Lubricating the internal combustion engine with the composition.