Classifications

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  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
  • C10M169/04—Mixtures of base-materials and additives
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  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M141/00—Lubricating compositions characterised by the additive being a mixture of two or more compounds covered by more than one of the main groups C10M125/00 - C10M139/00, each of these compounds being essential
  • C10M141/10—Lubricating compositions characterised by the additive being a mixture of two or more compounds covered by more than one of the main groups C10M125/00 - C10M139/00, each of these compounds being essential at least one of them being an organic phosphorus-containing compound
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  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M107/00—Lubricating compositions characterised by the base-material being a macromolecular compound
  • C10M107/02—Hydrocarbon polymers; Hydrocarbon polymers modified by oxidation
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  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M135/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing sulfur, selenium or tellurium
  • C10M135/02—Sulfurised compounds
  • C10M135/04—Hydrocarbons
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  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M137/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing phosphorus
  • C10M137/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing phosphorus having no phosphorus-to-carbon bond
  • C10M137/04—Phosphate esters
  • C10M137/08—Ammonium or amine salts
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M137/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing phosphorus
  • C10M137/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing phosphorus having no phosphorus-to-carbon bond
  • C10M137/04—Phosphate esters
  • C10M137/10—Thio derivatives
  • C10M137/105—Thio derivatives not containing metal
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M105/00—Lubricating compositions characterised by the base-material being a non-macromolecular organic compound
  • C10M105/02—Well-defined hydrocarbons
  • C10M105/04—Well-defined hydrocarbons aliphatic
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M137/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing phosphorus
  • C10M137/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing phosphorus having no phosphorus-to-carbon bond
  • C10M137/04—Phosphate esters
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M137/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing phosphorus
  • C10M137/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing phosphorus having no phosphorus-to-carbon bond
  • C10M137/04—Phosphate esters
  • C10M137/10—Thio derivatives
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
  • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
  • C10M2205/0206—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers used as base material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
  • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
  • C10M2205/028—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms
  • C10M2205/0285—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms used as base material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
  • C10M2205/17—Fisher Tropsch reaction products
  • C10M2205/173—Fisher Tropsch reaction products used as base material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/02—Sulfur-containing compounds obtained by sulfurisation with sulfur or sulfur-containing compounds
  • C10M2219/022—Sulfur-containing compounds obtained by sulfurisation with sulfur or sulfur-containing compounds of hydrocarbons, e.g. olefines
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/02—Sulfur-containing compounds obtained by sulfurisation with sulfur or sulfur-containing compounds
  • C10M2219/024—Sulfur-containing compounds obtained by sulfurisation with sulfur or sulfur-containing compounds of esters, e.g. fats
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/08—Thiols; Sulfides; Polysulfides; Mercaptals
  • C10M2219/082—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2223/00—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
  • C10M2223/02—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
  • C10M2223/04—Phosphate esters
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2223/00—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
  • C10M2223/02—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
  • C10M2223/04—Phosphate esters
  • C10M2223/043—Ammonium or amine salts thereof
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2223/00—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
  • C10M2223/02—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
  • C10M2223/04—Phosphate esters
  • C10M2223/047—Thioderivatives not containing metallic elements
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2223/00—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
  • C10M2223/02—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
  • C10M2223/049—Phosphite
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
  • C10N2020/01—Physico-chemical properties
  • C10N2020/02—Viscosity; Viscosity index
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/02—Pour-point; Viscosity index
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/06—Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/10—Inhibition of oxidation, e.g. anti-oxidants
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/04—Oil-bath; Gear-boxes; Automatic transmissions; Traction drives

Definitions

• the present invention relates to a lubricating oil composition.
• the present invention relates to an automobile lubricating oil composition having a reduced viscosity, which can be applied to differential gears.
• Lubricating oil compositions are used in a wide variety of applications including automobiles and machines. In recent years, from the standpoint of improving fuel efficiency, a reduction in viscosity is demanded in automobile lubricating oil compositions. However, a reduction in the viscosity of a lubricating oil composition affects the oil film-forming capability. Particularly in the field of automobile gear oils, more particularly in those lubricating oils used for differential gears, a reduction in the viscosity of a lubricating oil causes problems, such as occurrence of wear of bearings and the like and occurrence of scoring on gear tooth surfaces, and it is thus difficult to implement a reduction in viscosity. Therefore, it is desired to develop an automobile gear oil composition, particularly a differential gear oil composition, which is capable of, even at a low viscosity, suppressing wear of bearings and the like under high-temperature conditions where formation of an oil film is difficult.
• the present inventors previously discovered that, by using a low-viscosity base oil and a high-viscosity base oil in combination, the viscosity of a lubricating oil can be reduced and, particularly, an improvement in the bearing fatigue life characteristics affected by the oil film-forming capability and an improvement in fuel efficiency can be achieved at the same time, thereby completing the invention disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2007-039480 (PLT 1).
• PLT 1 Japanese Unexamined Patent Publication
• Japanese Unexamined Patent Publication (Kokai) No. 2014-012855 discloses a lubricating oil composition that includes: a specific acid alkyl phosphate; a dialkylamine and/or a trialkylamine; a specific sulfur compound containing no poly-sulfur bond that is equal to or longer than -S-S-S-; and, depending on the case, a specific trihydrocarbyl thiophosphate.
• the lubricating oil composition disclosed in PLT 2 however, relates to a step-up gear oil composition for wind power generation, for which seizure resistance and fatigue resistance are required, and PLT2 offers no description at all with regard to scoring.
• the present inventors aim at providing a lubricating oil composition that is capable of suppressing wear of bearings and the like, as well as scoring on gear tooth surfaces and the like even at a reduced viscosity.
• the present inventors discovered that the above-described object can be achieved by incorporating a combination of a specific amount of an extreme pressure agent having a specific active sulfur content and a specific amount of a phosphorus-based extreme pressure agent into a lubricating oil composition, thereby completing the present invention.
• the present invention provides a lubricating oil composition
• a lubricating oil composition comprising: (A) a lubricating base oil; (B) a sulfur-based extreme pressure agent; and (C) a phosphorus-based extreme pressure agent, wherein the sulfur-based extreme pressure agent (B) has an active sulfur content of 5 to 30% by weight; the sulfur-based extreme pressure agent (B) is contained in the composition in an amount of 5 to 15% by weight based on a total weight of the lubricating oil composition; and the phosphorus-based extreme pressure agent (C) is contained in the composition in an amount of 1.5 to 8% by weight based on the total weight of the lubricating oil composition.
• Preferred embodiments of the present invention include at least one of following characteristic features (1) to (9):
• the lubricating oil composition of the present invention can suppress wear of bearings and the like as well as scoring on gear tooth surfaces and the like even at a reduced viscosity.
• the lubricating oil composition of the present invention can be preferably used as a lubricating oil for automobiles, and is also suitable as a transmission gear oil and as a differential gear oil.
• the lubricating base oil is not particularly restricted, and any conventionally known lubricating base oil can be used.
• the lubricating base oil may be, for example, a mineral base oil, a synthetic base oil or a mixed base oil thereof.
• the mineral base oil is preferably a highly refined paraffinic mineral oil (high-viscosity-index mineral oil-based lubricating base oil) obtained by performing a treatment, such as solvent dewaxing or hydrodewaxing, on a hydrorefined oil, a catalytically isomerized oil or the like.
• mineral base oils other than the above-described one include raffinates obtained by solvent refining of a lubricating oil raw material with an aromatic extraction solvent, such as phenol or furfural; and hydrotreated oils obtained by hydrotreatment using a hydrotreatment catalyst, such as cobalt or molybdenum supported on a silica-alumina carrier. Examples thereof include 100 neutral oil, 150 neutral oil, and 500 neutral oil.
• the synthetic base oil examples include base oils (so-called GTL-derived base oils) that are obtained by hydrocracking and hydroisomerization of a raw material (e.g., a wax) obtained from a natural gas (e.g., methane) by Fischer-Tropsch synthesis; PAO base oils, polybutenes, alkylbenzenes, polyol esters, polyglycol esters, dibasic acid esters, fatty acid esters, phosphoric acid esters, and silicon oils. Thereamong, GTL-derived base oils and PAO base oils are preferred.
• the lubricating base oil may be any one of, or any combination of two or more of the above-described base oils, as long as it is selected from the above-described mineral base oils, the above-described synthetic base oils, and combinations thereof.
• two or more lubricating base oils may be a combination of mineral base oils, a combination of synthetic base oils, or a combination of a mineral base oil and a synthetic base oil, and the mode thereof is not restricted.
• a combination of a mineral base oil and a synthetic base oil is preferred.
• a combination of a mineral base oil, a GTL-derived base oil and a PAO base oil is particularly preferred.
• the mineral base oil is not restricted to be one produced by the above-described production method; however, it is appropriate that the mineral base oil have a kinematic viscosity at 100°C of preferably 2 to 35 mm 2 /s, more preferably 2 to 20 mm 2 /s, still more preferably 3 to 10 mm 2 /s.
• the GTL-derived base oil is not particularly restricted; however, it is appropriate that the GTL-derived base oil have a kinematic viscosity at 100°C of preferably 2 to 40 mm 2 /s, more preferably 2 to 20 mm 2 /s, still more preferably 2 to 10 mm 2 /s.
• the PAO base oil is also not particularly restricted and, for example, a 1-octene oligomer, a 1-decene oligomer, an ethylene- ⁇ -olefin oligomer, an ethylene-propylene oligomer, an isobutene oligomer, or a hydrogenated product thereof can be used. It is appropriate that the PAO base oil have a kinematic viscosity at 100°C of preferably 2 to 200 mm 2 /s, more preferably 2 to 150 mm 2 /s, still more preferably 4 to 50 mm 2 /s.
• the kinematic viscosity of the lubricating base oil is not restricted as long as the gist of the present invention is not impaired.
• the whole lubricating base oil have a kinematic viscosity at 100°C of preferably 3 to 40 mm 2 /s, more preferably 4 to 20 mm 2 /s, still more preferably 5 to 15 mm 2 /s, particularly preferably 6 to 12 mm 2 /s.
• the kinematic viscosity at 100°C of the lubricating base oil is higher than the above-described upper limit value, it is difficult to reduce the viscosity of the lubricating oil composition, and this can make it difficult to achieve an improvement in fuel efficiency. Meanwhile, when the kinematic viscosity at 100°C is less than the above-described lower limit value, an improvement in fuel efficiency can be achieved; however, it may be difficult to ensure anti-wear performance and anti-scoring performance.
• the lubricating oil composition of the present invention comprises a sulfur-based extreme pressure agent as an indispensable component.
• the sulfur-based extreme pressure agent used in the present invention is required to have an active sulfur content of 5 to 30% by weight, and the active sulfur content is preferably 5 to 20% by weight, more preferably 5 to 15% by weight, particularly preferably 8 to 12% by weight.
• the active sulfur content is higher than the above-described upper limit value, not only the sulfur-based extreme pressure agent causes metal corrosion but also it is difficult to ensure anti-wear performance. Meanwhile, when the active sulfur content is less than the above-described lower limit value, it is difficult to ensure anti-scoring performance.
• the active sulfur content is determined by the method prescribed in ASTM D1662. More specifically, the active sulfur content based on ASTM D1662 can be determined by the following procedures.
• the active sulfur content (% by weight) is calculated based on "Amount (% by weight) of sulfur contained in the original sample (Procedure (1)) - Amount (% by weight) of sulfur contained in the filtrate (Procedure (4)) after the reaction with copper powder.”
• the sulfur-based extreme pressure agent may be any sulfur-based extreme pressure agent as long as it has the above-described specific active sulfur content, and the sulfur-based extreme pressure agent can be selected from known sulfur-based extreme pressure agents.
• the sulfur-based extreme pressure agent is preferably at least one selected from sulfide compounds that are represented by sulfurized olefins and sulfurized esters that are represented by sulfurized oils and fats, and the sulfur-based extreme pressure agent is particularly preferably a sulfurized olefin.
• extreme pressure agents containing sulfur and phosphorus such as thiophosphate esters
• phosphorus-based extreme pressure agent (C) is included in the below-described phosphorus-based extreme pressure agent (C), and are thus not included in the sulfur-based extreme pressure agent (B).
• sulfur-based extreme pressure agent of the present invention does not encompass zinc dithiophosphate.
• the sulfur-based extreme pressure agent used in the present invention is represented by, for example, following Formula (1): R 1 -(-S-) x -R 2 (1).
• R 1 and R 2 each independently represent a monovalent substituent that contains at least one element of carbon, hydrogen, oxygen and sulfur. Specific examples thereof include saturated or unsaturated hydrocarbon groups that have 1 to 40 carbon atoms and a linear or branched structure, and the monovalent substituent may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an aromatic group-containing aliphatic hydrocarbon group. An oxygen atom and/or a sulfur atom may also be contained therein.
• R 1 and R 2 are optionally bound to each other and, when R 1 and R 2 form a single bond, the sulfur-based extreme pressure agent is represented by, for example, following Formula (2):
• x represents an integer of 1 or larger, preferably an integer of 1 to 12.
• x is preferably an integer of 1 to 6, more preferably an integer of 2 to 5.
• the sulfur-based extreme pressure agent represented by Formula (1) or (2) is usually not a compound having a single x but a mixture of compounds having various numbers of sulfur atoms, and it is believed that, among such compounds, one having a specific number of sulfur atoms functions as active sulfur.
• Sulfurized olefins are obtained by sulfurization of olefins and generally referred to as "sulfide compounds", including those compounds that are obtained by sulfurization of hydrocarbon-based raw materials other than olefins.
• sulfurized olefins include those obtained by sulfurizing olefins, such as polyisobutenes and terpenes, with sulfur or other sulfurizing agent.
• sulfide compounds other than the sulfurized olefins include diisobutyl polysulfides, dioctyl polysulfides, di-tert-butyl polysulfides, diisobutyl polysulfides, dihexyl polysulfides, di- tert -nonyl polysulfides, didecyl polysulfides, didodecyl polysulfides, diisobutene polysulfides, dioctenyl polysulfides, and dibenzyl polysulfides.
• Sulfurized oils and fats are a reaction product of an oil or a fat and sulfur, and examples of the oil or the fat include animal and vegetable oils and fats, such as lard, beef tallow, whale oil, palm oil, coconut oil, and rapeseed oil.
• the reaction product is not composed of a single substance species, but is a mixture of various substances, and its chemical structure itself is not necessarily clear.
• sulfurized esters other than the above-described sulfurized oils and fats include those obtained by sulfurizing, with sulfur or other sulfurizing agent, ester compounds each generated by a reaction between an organic acid (e.g., a saturated fatty acid, an unsaturated fatty acid, a dicarboxylic acid, or an aromatic carboxylic acid) and an alcohol.
• an organic acid e.g., a saturated fatty acid, an unsaturated fatty acid, a dicarboxylic acid, or an aromatic carboxylic acid
• an alcohol e.g., a saturated fatty acid, an unsaturated fatty acid, a dicarboxylic acid, or an aromatic carboxylic acid
• the content of the sulfur-based extreme pressure agent is 5% by weight to 15% by weight, preferably 6% by weight to 12% by weight, based on the weight of the whole lubricating oil composition, and the present invention is also characterized in that the content of the sulfur-based extreme pressure agent is higher as compared to conventional lubricating oil compositions.
• the above-described sulfur-based extreme pressure agents may be used singly, or in combination of two or more thereof as a mixture.
• the lubricating oil composition of the present invention contains a phosphorus-based extreme pressure agent as an indispensable component.
• a phosphorus-based extreme pressure agent as an indispensable component.
• sulfur-based extreme pressure agent By incorporating the below-described amount of the phosphorus-based extreme pressure agent along with the above-described sulfur-based extreme pressure agent, satisfactory anti-wear performance and anti-scoring performance can be attained in a well-balanced manner.
• extreme pressure agents containing sulfur and phosphorus such as thiophosphate esters, are included in the phosphorus-based extreme pressure agent (C), not in the sulfur-based extreme pressure agent (B).
• the phosphorus-based extreme pressure agent of the present invention does not encompass zinc dithiophosphate.
• the phosphorus-based extreme pressure agent is not particularly restricted and may be any conventionally known phosphorus-based extreme pressure agent. It is appropriate that the phosphorus-based extreme pressure agent be, for example, at least one selected from phosphate esters, acid phosphate esters, phosphite esters, acid phosphite esters, thiophosphate esters, acid thiophosphate esters, thiophosphite esters, acid thiophosphite esters, amine salts of acid phosphate esters, amine salts of acid phosphite esters, amine salts of acid thiophosphate esters, and amine salts of acid thiophosphite esters.
• the phosphorus-based extreme pressure agent is preferably at least one selected from amine salts of acid phosphate esters, amine salts of acid phosphite esters, amine salts of acid thiophosphate esters, and amine salts of acid thiophosphite esters.
• This formula represents an acid thiophosphate ester when one or two of R 3 , R 4 and R 5 is/are a hydrogen atom(s), or thiophosphoric acid when all three of R 3 , R 4 and R 5 are hydrogen atoms.
• X 1 , X 2 , X 3 and X 4 each independently represent an oxygen atom or a sulfur atom, with a proviso that at least one of X 1 , X 2 , X 3 and X 4 is a sulfur atom.
• This formula represents an acid thiophosphite ester when one of R 6 and R 7 is a hydrogen atom, or thiophosphorous acid when both of R 6 and R 7 are hydrogen atoms.
• X 5 , X 6 and X 7 each independently represent an oxygen atom or a sulfur atom, with a proviso that at least one of X 5 , X 6 and X 7 is a sulfur atom.
• the term "monovalent hydrocarbon group having 1 to 30 carbon atoms" used above specifically refers to, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a tridecyl group, an octadecyl group, an eicosyl group, an isobutyl group, an isohexyl group, an isodecyl group, an isooctadecyl group, a neopentyl group, a 2-ethylhexyl group, or an oleyl group, preferably a monovalent hydrocarbon group having 4 to 20 carbon atoms.
• the phosphate esters and the acid phosphate esters are preferably, but not limited to, monoalkyl phosphates, dialkyl phosphates, and trialkyl phosphates.
• the phosphite esters and the acid phosphite esters are preferably, but not limited to, monoalkyl phosphites and dialkyl phosphites.
• the thiophosphate esters and the acid thiophosphate esters are preferably, but not limited to, monoalkyl thiophosphates, dialkyl thiophosphates, and trialkyl thiophosphates.
• the thiophosphite esters and the acid thiophosphite esters are preferably, but not limited to, monoalkyl thiophosphites and dialkyl thiophosphites.
• phosphate esters, phosphite esters, thiophosphate esters and thiophosphite esters include, but not limited to, monooctyl phosphate, dioctyl phosphate, trioctyl phosphate, monooctyl phosphite, dioctyl phosphite, monooctyl thiophosphate, dioctyl thiophosphate, trioctyl thiophosphate, monooctyl thiophosphite, dioctyl thiophosphite, monododecyl phosphate, didodecyl phosphate, tridodecyl phosphate, monododecyl phosphite, didodecyl phosphite, monododecyl thiophosphate, tridodecyl phosphate, monododecyl phosphi
• alkylamine salts and alkenylamine salts of the above-described compounds that are partially esterified can also be preferably used.
• amine salts of the above-described acid phosphate esters, amine salts of the above-described acid phosphite esters, amine salts of the above-described acid thiophosphate esters, and amine salts of the above-described acid thiophosphite esters can be used; however, the phosphorus-based extreme pressure agent is not restricted thereto.
• More specific examples thereof include amine salts of monooctyl phosphate, amine salts of dioctyl phosphate, amine salts of monooctyl phosphite, amine salts of monooctyl thiophosphate, amine salts of dioctyl thiophosphate, amine salts of monooctyl thiophosphite, amine salts of monododecyl phosphate, amine salts of didodecyl phosphate, amine salts of monododecyl phosphite, amine salts of monododecyl thiophosphate, amine salts of didodecyl thiophosphate, amine salts of monooctadecenyl phosphate, amine salts of dioctadecenyl phosphate, amine salts of monooctadecenyl phosphite, amine
• Amines of the above-described amine salts are represented by R 8 R 9 R 10 N, wherein R 8 , R 9 and R 10 each independently represent a hydrogen atom, or a saturated or unsaturated aliphatic, aromatic or aromatic-aliphatic hydrocarbon group that has 1 to 20 carbon atoms and a linear structure or a branched chain. More particularly, examples of R 8 , R 9 and R 10 include a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a nonyl group, a dodecyl group, a stearyl group, and an oleyl group.
• the above-described phosphorus-based extreme pressure agents may be used singly, or in combination of two or more thereof.
• examples of a mode thereof include, but not limited to, the following:
• the amount of the phosphorus-based extreme pressure agent(s) to be added is 1.5 to 8% by weight, preferably 1.8 to 7% by weight, more preferably 2 to 6% by weight, based on the total weight of the lubricating oil composition.
• the amount of the phosphorus-based extreme pressure agent(s) is greater than the above-described upper limit value, the anti-scoring performance on gear tooth surfaces and the like may be deteriorated; therefore, such a large amount is not preferred.
• the phosphorus-based extreme pressure agent(s) by controlling the amount to be not less than the above-described lower limit value based on the total weight of the lubricating oil composition, the phosphorus-based extreme pressure agent(s) further contribute to an improvement of the anti-wear performance.
• the amount of the phosphorus-based extreme pressure agent(s) is less than the lower limit value, a reaction film is not sufficiently formed, and the anti-wear performance thus deteriorates.
• the lubricating oil composition of the present invention is characterized by containing a combination of the sulfur-based extreme pressure agent (B) and the phosphorus-based extreme pressure agent (C) in the above-described respective specific amounts.
• a total content of the sulfur-based extreme pressure agent (B) and the phosphorus-based extreme pressure agent (C) is preferably 7 to 20% by weight, more preferably 8 to 18% by weight, still more preferably 9 to 16% by weight, based on the total weight of the lubricating oil composition.
• the use ratio (weight ratio) of the sulfur-based extreme pressure agent (B) and the phosphorus-based extreme pressure agent (C), (B)/(C), is preferably 1 to 10, more preferably 1.1 to 8, still more preferably 1.2 to 7, particularly preferably 1.4 to 5.
• the lubricating oil composition of the present invention may further contain an extreme pressure agent other than the sulfur-based extreme pressure agent (B) and the phosphorus-based extreme pressure agent (C), in combination with components (B) and (C).
• an extreme pressure agent other than the sulfur-based extreme pressure agent (B) and the phosphorus-based extreme pressure agent (C), in combination with components (B) and (C).
• zinc dithiophosphate ZnDTP
• the content of ZnDTP is preferably 0.1 to 5% by weight, more preferably 0.2 to 3% by weight, still more preferably 0.3 to 1% by weight, based on the total weight of the lubricating oil composition.
• the lubricating oil composition of the present invention may further contain an ashless dispersant.
• the ashless dispersant any conventionally known ashless dispersant can be used, and the ashless dispersant is not particularly restricted. Examples thereof include nitrogen-containing compounds having at least one linear or branched alkyl or alkenyl group having 40 to 400 carbon atoms, and derivatives thereof; and succinimides and modified products thereof. These ashless dispersants may be used singly, or in combination of two or more thereof.
• a boronated ashless dispersant can also be used.
• the boronated ashless dispersant is obtained by boronation of an arbitrary ashless dispersant used in a lubricating oil. The boronation is generally performed by allowing boric acid to react with an imide compound and neutralizing some or all of residual amino groups and/or imino groups.
• the number of carbon atoms in the above-described alkyl or alkenyl group is preferably 40 to 400, more preferably 60 to 350.
• the alkyl or alkenyl group may have a linear structure or a branched structure.
• Examples of a preferred mode thereof include branched alkyl groups and branched alkenyl groups, which are derived from olefin oligomers, such as propylene, 1-butene and isobutene, and co-oligomers of ethylene and propylene.
• the above-described succinimides encompass so-called mono-type succinimides that are reaction products between one end of a polyamine and succinic anhydride, and so-called bis-type succinimides are reaction products between both ends of a polyamine and succinic anhydride.
• the lubricating oil composition of the present invention may contain either one of, or both of a mono-type succinimide and a bis-type succinimide.
• succinimides modified with a boron compound examples include succinimides modified with a boron compound (hereinafter, may be referred to as "boronated succinimides").
• the phrase "modified with a boron compound” used herein means to perform boronation.
• the boronated succinimides may be used singly, or in combination of two or more thereof. When a combination of boronated succinimides is used, it may be a combination of two or more boronated succinimides.
• the combination may contain both a mono-type succinimide and a bis-type succinimide, or may be a combination of mono-type succinimides or a combination of bis-type succinimides.
• a combination of a boronated succinimide and a non-boronated succinimide may be used as well.
• Examples of a method of producing a boronated succinimide include the methods disclosed in Japanese Examined Patent Publication (Kokoku) No. S42-8013 , Japanese Examined Patent Publication (Kokoku) No. S42-8014 , Japanese Unexamined Patent Publication (Kokai) No. S51-52381 , Japanese Unexamined Patent Publication (Kokai) No. S51-130408 , and the like.
• a boronated succinimide can be obtained by, for example, mixing an organic solvent (e.g., an alcohol, hexane, or xylene), a light lubricating base oil and the like with a polyamine, succinic anhydride (derivative) and a boron compound (e.g., boric acid, a borate ester, or a borate salt), and heat-treating the resulting mixture under appropriate conditions.
• the boron content in the boronated succinimide obtained in this manner can usually be 0.1 to 4% by weight.
• a boron-modified compound of an alkenylsuccinimide is particularly preferred because of its excellent heat resistance, antioxidation performance and anti-wear performance.
• the boron content in the boronated ashless dispersant is not particularly restricted, and it is usually 0.1 to 3% by weight based on the weight of the ashless dispersant.
• the boron content in the ashless dispersant is preferably not less than 0.2% by weight, more preferably not less than 0.4% by weight, but preferably 2.5% by weight or less, more preferably 2.3% by weight, or less, still more preferably 2.0% by weight or less.
• the boronated ashless dispersant is preferably a boronated succinimide, particularly preferably a boronated bis-succinimide.
• the boronated ashless dispersant has a boron/nitrogen weight ratio (B/N ratio) of 0.1 or higher, preferably 0.2 or higher, but preferably lower than 1.0, more preferably 0.8 or lower.
• the content of the ashless dispersant in the composition may be adjusted as appropriate, and it is, for example, preferably 0.01 to 20% by weight, more preferably 0.1 to 10% by weight, based on the total weight of the lubricating oil composition.
• the content of the ashless dispersant is less than the above-described lower limit value, the sludge dispersibility may be insufficient.
• a content of higher than the above-described upper limit value may cause degradation of a specific rubber material and deteriorate the low-temperature fluidity.
• the lubricating oil composition of the present invention may comprise, as additives other than the above-described components (A) to (D), a viscosity index improver, an antioxidant, a metallic detergent, a friction modifier, a corrosion inhibitor, a rust inhibitor, a demulsifier, a metal deactivator, an antifoaming agent, and a pour-point depressant. It is noted here, however, that the lubricating oil composition of the present invention is not a grease and thus contains no thickening agent.
• the thickening agent is, for example, a metallic soap or a metal salt.
• the viscosity index improver examples include so-called non-dispersion-type viscosity index improvers, such as polymers and copolymers of one or more monomers selected from various methacrylic acid esters, and hydrogenated products thereof; so-called dispersion-type viscosity index improvers obtained by copolymerizing various methacrylic acid esters containing nitrogen compounds; non-dispersion-type or dispersion-type ethylene- ⁇ -olefin copolymers (examples of ⁇ -olefin include propylene, 1-butene, and 1-pentene), and hydrogenated products thereof; polyisobutenes and hydrogenated products thereof; hydrogenated products of styrene-diene copolymers; styrene-maleic anhydride ester copolymers; and polyalkylstyrenes.
• non-dispersion-type viscosity index improvers such as polymers and copolymers of one or more monomers
• the molecular weight of the viscosity index improver is required to be selected taking into consideration the shear stability of the lubricating oil composition.
• the weight-average molecular weight of the viscosity index improve is usually 5,000 to 1,000,000, preferably 100,000 to 900,000, when a dispersion-type or non-dispersion-type polymethacrylate is used; usually 800 to 5,000, preferably 1,000 to 4,000, when a polyisobutene or a hydrogenated product thereof is used; or usually 800 to 500,000, preferably 3,000 to 200,000, when an ethylene- ⁇ -olefin copolymer or a hydrogenated product thereof is used.
• a lubricating oil composition having particularly excellent shear stability when an ethylene- ⁇ -olefin copolymer or a hydrogenated product thereof is used, a lubricating oil composition having particularly excellent shear stability can be obtained. Any one or more compounds selected from the above-described viscosity index improvers can be incorporated in any amount.
• the content of the viscosity index improver(s) in the lubricating oil composition is 0.01 to 20% by weight, preferably 0.02 to 10% by weight, more preferably 0.05 to 5% by weight, based on the total amount of the composition.
• the antioxidant may be any antioxidant that is generally used in lubricating oils, and examples thereof include ashless antioxidants, such as phenolic antioxidants and amine-based antioxidants, and organometallic antioxidants. By adding an antioxidant, the oxidation stability of the lubricating oil composition can be further improved.
• the metallic detergent examples include those containing a compound selected from sulfonates, phenates, salicylates and carboxylates of calcium, magnesium, barium and the like, and compounds having different base numbers, such as overbased salts, basic salts and neutral salts, can be selected arbitrarily.
• the metallic detergent is incorporated into the lubricating oil composition usually in an amount of 0.01 to 1% by weight in terms of metal amount.
• friction modifier examples include organic molybdenum compounds, fatty acids, fatty acid esters, alcohols, amines, and amides.
• the friction modifier is incorporated into the lubricating oil composition usually in an amount of 0.01 to 5% by weight.
• the corrosion inhibitor examples include benzotriazole-based, tolyltriazole-based, thiadiazole-based, and imidazole-based compounds.
• the corrosion inhibitor is incorporated into the lubricating oil composition usually in an amount of 0.1 to 5% by weight.
• rust inhibitor examples include petroleum sulfonates, salts of an alkylsulfonic acid, fatty acids, fatty acid soaps, fatty acid amines, alkyl polyoxyalkylenes, alkenylsuccinates, and polyhydric alcohol fatty acid esters.
• the rust inhibitor is incorporated into the lubricating oil composition usually in an amount of 0.01 to 5% by weight.
• the demulsifier examples include polyalkylene glycol-based nonionic surfactants, such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene alkylnaphthyl ethers.
• the demulsifier is incorporated into the lubricating oil composition usually in an amount of 0.01 to 5% by weight.
• metal deactivator examples include pyrroles, imidazoles, pyrazoles, pyrazines, pyrimidines, pyridazines, triazines, triazoles, thiazoles, and thiadiazoles.
• the metal deactivator is incorporated into the lubricating oil composition usually in an amount of 0.01 to 3% by weight.
• antifoaming agent examples include polydimethylsiloxanes and fluorinated derivatives thereof; polyacrylates and fluorinated derivatives thereof; and perfluoropolyethers.
• the antifoaming agent is incorporated into the lubricating oil composition usually in an amount of 0.001 to 1% by weight.
• pour-point depressant for example, a polymethacrylate-based polymer that is compatible with the lubricating base oil to be used can be selected.
• the pour-point depressant is incorporated into the lubricating oil composition usually in an amount of 0.01 to 3% by weight.
• the kinematic viscosity at 40°C of the lubricating oil composition of the present invention is preferably 20 to 120 mm 2 /s, more preferably 30 to 100 mm 2 /s, still more preferably 40 to 80 mm 2 /s.
• the kinematic viscosity at 100°C of the lubricating oil composition of the present invention is preferably 3 to 40 mm 2 /s, more preferably 4 to 20 mm 2 /s, still more preferably 5 to 15 mm 2 /s, particularly preferably 6 to 12 mm 2 /s.
• Lubricating oil compositions were prepared by mixing the following components according to the respective formulations shown in Table 1 below.
• KV40", KV100” and VI mean a kinematic viscosity at 40°C, a kinematic viscosity at 100°C and a viscosity index, respectively.
• the kinematic viscosity at 40°C was measured in accordance with ASTM D445.
• the kinematic viscosity at 100°C was measured in accordance with ASTM D445.
• the viscosity index was measured in accordance with ASTM D2270.
• the composition of Comparative Example 1 having a low content of sulfur-based extreme pressure agent did not have sufficient anti-scoring performance.
• the composition of Comparative Example 2 having an excessively high content of sulfur-based extreme pressure agent exhibited poor oxidation stability.
• the composition of Comparative Example 4 having a low content of phosphorus-based extreme pressure agent had a large width of wear and exhibited poor anti-wear performance.
• the composition of Comparative Example 5 having a high content of phosphorus-based extreme pressure agent did not have sufficient anti-scoring performance.
• the lubricating oil compositions according to the present invention were excellent in all of anti-wear performance, anti-scoring performance, and oxidation stability.
• the lubricating oil composition of the present invention is capable of suppressing wear of bearings and the like as well as scoring on gear tooth surfaces and the like even at a reduced viscosity.
• the lubricating oil composition of the present invention can, therefore, be preferably used as a lubricating oil for automobiles, and is also suitable as a transmission gear oil and as a differential gear oil.

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• 2016
  • 2016-07-28 JP JP2016148523A patent/JP6730122B2/ja active Active
• 2017
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