Classifications

• • 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
  • 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
  • C10M169/045—Mixtures of base-materials and additives the additives being a mixture of compounds of unknown or incompletely defined constitution and non-macromolecular compounds
• • 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
  • C10M129/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen
  • C10M129/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen having a carbon chain of less than 30 atoms
  • C10M129/04—Hydroxy compounds
  • C10M129/10—Hydroxy compounds having hydroxy groups bound to a carbon atom of a six-membered aromatic ring
• • 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
  • C10M129/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen
  • C10M129/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen having a carbon chain of less than 30 atoms
  • C10M129/26—Carboxylic acids; Salts thereof
  • C10M129/48—Carboxylic acids; Salts thereof having carboxyl groups bound to a carbon atom of a six-membered aromatic ring
  • C10M129/54—Carboxylic acids; Salts thereof having carboxyl groups bound to a carbon atom of a six-membered aromatic ring containing hydroxy groups
• • 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
  • C10M135/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing sulfur, selenium or tellurium
  • C10M135/08—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing sulfur, selenium or tellurium containing a sulfur-to-oxygen bond
  • C10M135/10—Sulfonic acids or derivatives 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
  • C10M135/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing sulfur, selenium or tellurium
  • C10M135/20—Thiols; Sulfides; Polysulfides
  • C10M135/22—Thiols; Sulfides; Polysulfides containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms
  • C10M135/26—Thiols; Sulfides; Polysulfides containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms containing carboxyl groups; Derivatives 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
  • C10M159/00—Lubricating compositions characterised by the additive being of unknown or incompletely defined constitution
  • C10M159/12—Reaction products
  • C10M159/20—Reaction mixtures having an excess of neutralising base, e.g. so-called overbasic or highly basic products
  • C10M159/22—Reaction mixtures having an excess of neutralising base, e.g. so-called overbasic or highly basic products containing phenol radicals
• • 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
  • C10M159/00—Lubricating compositions characterised by the additive being of unknown or incompletely defined constitution
  • C10M159/12—Reaction products
  • C10M159/20—Reaction mixtures having an excess of neutralising base, e.g. so-called overbasic or highly basic products
  • C10M159/24—Reaction mixtures having an excess of neutralising base, e.g. so-called overbasic or highly basic products containing sulfonic radicals
• • 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
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/02—Hydroxy compounds
  • C10M2207/023—Hydroxy compounds having hydroxy groups bound to carbon atoms of six-membered aromatic rings
• • 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
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/02—Hydroxy compounds
  • C10M2207/023—Hydroxy compounds having hydroxy groups bound to carbon atoms of six-membered aromatic rings
  • C10M2207/028—Overbased 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
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/04—Ethers; Acetals; Ortho-esters; Ortho-carbonates
  • C10M2207/044—Cyclic ethers having four or more ring atoms, e.g. furans, dioxolanes
• • 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
  • C10M2219/04—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions containing sulfur-to-oxygen bonds, i.e. sulfones, sulfoxides
  • C10M2219/044—Sulfonic acids, Derivatives thereof, e.g. neutral 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
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/04—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions containing sulfur-to-oxygen bonds, i.e. sulfones, sulfoxides
  • C10M2219/046—Overbased sulfonic acid 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
  • 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
  • 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
  • C10M2219/085—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms containing carboxyl groups; Derivatives thereof
• • 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
  • C10N2010/00—Metal present as such or in compounds
  • C10N2010/02—Groups 1 or 11
• • 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
  • C10N2010/00—Metal present as such or in compounds
  • C10N2010/04—Groups 2 or 12
• • 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
  • C10N2030/08—Resistance to extreme temperature
• • 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
  • C10N2030/40—Low content or no content compositions
  • C10N2030/42—Phosphor free or low phosphor content compositions
• • 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
  • C10N2030/40—Low content or no content compositions
  • C10N2030/43—Sulfur free or low sulfur content compositions
• • 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
  • C10N2030/40—Low content or no content compositions
  • C10N2030/45—Ash-less or low ash content
• • 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
  • C10N2030/72—Extended drain
• • 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
• • 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
  • C10N2040/08—Hydraulic fluids, e.g. brake-fluids
• • 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
  • C10N2040/20—Metal working
  • C10N2040/24—Metal working without essential removal of material, e.g. forming, gorging, drawing, pressing, stamping, rolling or extruding; Punching metal
• • 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
  • C10N2040/25—Internal-combustion engines

Definitions

• the present invention relates to a lubricating oil composition for an internal combustion, particularly to a lubricating oil composition suitable for use in an internal combustion engine such as a gasoline engine, a diesel engine or a gas engine. More specifically, the present invention is directed to a lubricating oil composition which, despite its low ash content, low phosphorus content and low sulfur content, can maintain excellent wear resistance, exhibits excellent heat resistance, can extend the lubricating oil change interval and has a long service life.
• a lubricating oil for an internal combustion engine mainly functions to lubricate various sliding portions such as piston rings, cylinder liners, crankshafts, connecting rods and a valve-operating mechanism including a cam and a valve-lifter.
• the lubricating oil functions to cool the inside of the engine and to disperse sludge and uncombusted residues of the fuel.
• lubricating oils for internal combustion engines are required to have various properties. Further, in recent years, lubricating oils are required to exhibit high performance, since internal combustion engines have been improved in their performance and output and since the operation conditions thereof have become more severe. In order to satisfy the required performance, various additives such as an wear inhibitor, a metal detergent, an ashless dispersant and an antioxidant are compounded in the lubricating oils.
• ZnDTP zinc alkyldithiophosphate
• Patent Document 1 discloses a lubricating oil composition which contains a metal salt or amine salt of a thiophosphate or of a phosphate and which is alleged to have a reduced sulfur content and excellent properties to maintain its base number. Though the composition can reduce the sulfur content as a replacement for ZnDTP, reduction of a phosphorus component and a zinc (ash) component is not achieved. Thus, problems of catalyst poisoning and clogging of DPF remain unsolved. Namely, the composition is still unsatisfactory as a lubricating oil composition.
• sulfur-based antioxidant mainly known is one which has a monosulfide structure.
• Sulfur-based compounds having a polysulfide (tri- or higher polysulfide) structure has a problem that it is highly corrosive to non-iron metals.
• an object of the present invention is to provide a lubricating oil composition which, despite its low ash content, low phosphorus content and low sulfur content, can maintain excellent wear resistance, exhibits excellent heat resistance, can extend the lubricating oil change interval and has a long service life.
• the present inventors have made an earnest study with a view toward developing a lubricating oil composition for internal combustion engines having the above-described suitable properties and have found that a combination of a disulfide compound having a specific structure with a specific amount of a detergent can accomplish the above object.
• the present invention has been completed based on the above finding.
• the present invention provides:
• a lubricating oil composition for an internal combustion engine including a base oil; (A) at least one member selected from the group consisting of disulfide compounds represented by the general formula (I):
• R 1 and R 2 each independently represent a C 1 to C 30 hydrocarbyl group which may contain an oxygen atom, a sulfur atom or a nitrogen atom, and A 1 and A 2 each independently represent a group expressed by CR 3 R 4 CR 3 R 4 —CR 5 R 6 where R 3 to R 6 each independently represent a hydrogen atom or a C 1 to C 20 hydrocarbyl group
• R 7 , R 8 , R 12 and R 13 each independently represent a C 1 to C 30 hydrocarbyl group which may contain an oxygen atom, a sulfur atom or a nitrogen atom and R 9 to R 11 and R 14 to R 14 each independently represent a hydrogen atom or C 1 to C 5 hydrocarbyl group
• B at least one member selected from the group consisting of alkali metal-based detergents and alkaline earth metal-based detergents, the component (B) being present in an amount of 10 to 2,000 ppm by mass in terms of metal content
• (3) The lubricating oil composition for an internal combustion engine as defined in above (1) or (2), wherein the alkali metal-based or alkaline earth metal-based detergent of the component (B) is a salicylate and/or
• a lubricating oil composition for internal combustion engines which, despite its low ash content, low phosphorus content and low sulfur content, can maintain excellent wear resistance, exhibits excellent heat resistance, can extend the lubricating oil change interval and has long service life can be provided.
• a lubricating oil composition for internal combustion engines of the present invention contains a base oil which may be a mineral oil or a synthetic oil.
• a base oil which may be a mineral oil or a synthetic oil.
• mineral oils and synthetic oils are available, and a suitable oil can be suitably selected in accordance with the intended use.
• the mineral oil include paraffinic mineral oils, naphthenic mineral oils and intermediate mineral oils.
• Specific examples of the mineral oil include light neutral oil, intermediate neutral oil, heavy neutral oil and bright stock. which are obtained by solvent refining or purification by hydrorefining.
• Examples of the synthetic oil include poly- ⁇ -olefins, ⁇ -olefin copolymers, polybutene, alkylbenzenes, polyol esters, esters of dibasic acids, polyhydric alcohol esters, polyoxyalkylene glycols, polyoxyalkylene glycol esters, polyoxyalkylene glycol ethers and cycloalkane compounds.
• These lube base oils may be used singly or in combination of two or more thereof.
• a combination of a mineral oil with a synthetic oil may be also used.
• the compound of the general formula (I) used as the component (A) of the lubricating oil of the present invention has the following structure:
• R 1 and R 2 each independently represent a C 1 to C 30 hydrocarbyl group (which may contain an oxygen atom, a sulfur atom or a nitrogen atom), preferably a C 1 to C 20 , more preferably C 2 to C 18 , particularly preferably C 3 to C 18 hydrocarbyl group.
• the hydrocarbyl group may be straight chained, branched or cyclic.
• R 1 and R 2 may be the same or different but are preferably the same for reasons of easy production.
• a 1 and A 2 each independently represent a group expressed by CR 3 R 4 or CR 3 R 4 —CR 5 R 6 where R 3 to R 6 each independently represent a hydrogen atom or a C 1 to C 20 hydrocarbyl group.
• the hydrocarbyl group is preferably a C 1 to C 12 , more preferably C 1 to C 8 hydrocarbyl group.
• a 1 and A 2 may be the same or different but are preferably the same for reasons of easy production.
• the content of tri- or higher poly-sulfides in the general formula (I) be 30% by mass or less based on a total amount of the disulfide compound.
• the polysulfide content is 30% by mass or less, corrosiveness to non-iron metals may be suppressed.
• the content of tri- or higher poly-sulfide is more preferably 10% by mass or less, particularly preferably 5% by mass or less.
• the disulfide compound represented by the above general formula (I) should be produced by a method in which the amount of tri- or higher poly-sulfide compounds by-produced is within the above range.
• the disulfide compound may be preferably produced by the following method.
• R 1 , R 2 , A 1 and A 2 are as defined above.
• tri- or higher poly-sulfide compounds are substantially not by-produced. Specifically produced are R 1 OOC-A 1 -S—S-A 2 -COOR 2 , R 1 OOC-A 1 -S—S-A 1 -COOR 1 and R 2 OOC-A 2 -S—S-A 2 -COOR 2 .
• an oxidizing agent for oxidizing an ⁇ -mercaptocarboxylic acid ester for the production of the corresponding disulfide there may be used an oxidizing agent used for producing a disulfide from mercaptan.
• an oxidizing agent include oxygen, hydrogen peroxide, a halogen (such as iodine or bromine), a hypohalous acid and a salt thereof, a sulfoxide (such as dimethyl sulfoxide or diisopropyl sulfoxide) and manganese (IV) oxide.
• oxygen, hydrogen peroxide and dimethyl sulfoxide are preferred because they are inexpensive and make it easy to produce a disulfide.
• disulfide compound represented by the general formula (I) include bis(methoxycarbonylmethyl) disulfide, bis(ethoxycarbonylmethyl)disulfide, bis(n-propoxycarbonylmethyl) disulfide, bis(isopropoxy-carbonylmethyl) disulfide, bis(n-butoxycarbonylmethyl) disulfide, bis(n-octoxycarbonylmethyl)disulfide, bis(n-dodecyloxycarbonylmethyl) disulfide, bis(cyclopropoxycarbonylmethyl)disulfide, 1,1-bis(1-methoxycarbonylethyl)disulfide, 1,1-bis(1-methoxycarbonyl-n-propyl) disulfide, 1,1-bis(1-methoxycarbonyl-n-butyl) disulfide, 1,1-bis(1-methoxycarbonyl-n-hexyl)disulfide,
• the compound of the general formula (II) used as the component (A) of the lubricating oil composition of the present invention has the following structure:
• R 7 , R 8 , R 12 and R 13 each independently represent a C 1 to C 30 hydrocarbyl group (which may contain an oxygen atom, a sulfur atom or a nitrogen atom), preferably a C 1 to C 20 , more preferably C 2 to C 18 , particularly preferably C 3 to C 18 hydrocarbyl group.
• the hydrocarbyl group may be straight chained, branched or cyclic.
• R 7 , R 8 , R 12 and R 13 may be the same or different but are preferably the same for reasons of easy production.
• R 9 to R 11 and R 14 to R 16 each independently represent a hydrogen atom or C 1 to C 5 hydrocarbyl group. For reasons of easy material availability, a hydrogen atom is preferred.
• the above disulfide compound is preferably produced by, for example, the following two methods.
• a diester of a mercaptoalkanedicarboxylic acid represented by the following general formula (V) and/or general formula (VI) as a raw material is subjected to oxidative coupling:
• R 7 to R 16 are as defined above.
• R 12 OOC—CR 15 R 14 —CR 16 (COOR 13 )—S—S—CR 6 (COOR 13 )—CR 14 CR 15 —COOR 12 Specifically produced are R 7 OOC—CR 9 R 10 —CR 11 (COOR 8 )—S—S—CR 16 (COOR 13 )—CR 14 CR 15 —COR 12
• oxygen As an oxidizing agent, there may be mentioned oxygen, hydrogen peroxide, a halogen (such as iodine or bromine), a hypohalous acid and a salt thereof, a sulfoxide (such as dimethyl sulfoxide or diisopropyl sulfoxide) and manganese (IV) oxide.
• a halogen such as iodine or bromine
• a hypohalous acid such as iodine or bromine
• a hypohalous acid such as iodine or bromine
• a hypohalous acid such as iodine or bromine
• a hypohalous acid such as iodine or bromine
• a hypohalous acid such as iodine or bromine
• a hypohalous acid such as iodine or bromine
• a hypohalous acid such as iodine or bromine
• a hypohalous acid such as iodine or bromine
• a mercaptoalkanedicarboxylic acid represented by the following general formula (VII) and/or general formula (VIII) as a raw material is subjected to oxidative coupling:
• R 9 to R 11 and R 14 to R 16 are as defined above.
• the product is then esterified with a monohydric alcohol having a C 1 to C 30 hydrocarbyl group which may contain an oxygen atom, a sulfur atom or a nitrogen atom.
• a monohydric alcohol having a C 1 to C 30 hydrocarbyl group which may contain an oxygen atom, a sulfur atom or a nitrogen atom.
• an oxidizing agent there may be used the above-described oxidizing agent.
• R 17 is the same as the above R 7 .
• the esterification may be carried out by an ordinary method using an acid catalyst.
• disulfide compound represented by the general formula (II) examples include tetramethyl dithiomalate, tetraethyl dithiomalate, tetra-1-propyl dithiomalate, tetra-2-propyl dithiomalate, tetra-1-butyl dithiomalate, tetra-2-butyl dithiomalate, tetraisobutyl dithiomalate, tetra-1-hexyl dithiomalate, tetra-1-octyl dithiomalate, tetra-1-(2-ethyl)hexyl dithiomalate, tetra-1-(3,5,5-trimethyl)hexyl dithiomalate, tetra-1-decyl dithiomalate, tetra-1-dodecyl dithiomalate, tetra-1-hexadecyl dithiomalate, tetramethyl
• the disulfide compounds represented by the above general formulas (I) and (II) have excellent load-carrying capacity and wear resistance as a sulfur-based extreme-pressure additive and is used as an additive for the lubricating oil composition.
• one of or two or more of the disulfide compounds represented by the above general formula (I) may be used as the component (A).
• one of or two or more of the disulfide compounds represented by the above general formula (II) may be used as the component (A).
• the content of the component (A), the disulfide compound, in the lubricating oil composition of the present invention may be suitably determined in view of the intended use and using conditions of the composition but is generally preferably 0.01 to 0.50% by mass, more preferably 0.01 to 0.30% by mass, in terms of sulfur content.
• the lubricating oil composition of the present invention should contain 10 to 2,000 ppm by mass, in terms of metal, of at least one member selected from alkali metal-based detergents and alkaline earth metal-based detergents, as component (B).
• the content of the component (B) is preferably 100 to 2,000 ppm by mass, more preferably 200 to 2,000 ppm by mass.
• the content, in terms of metal, of the component (B) is within the above range, an increase of the ash content can be prevented without reducing the acid neutralization power, so that the clogging of OPF can be prevented. Additionally, formation of deposits can be prevented, and lubricating oil change interval can be extended.
• the alkali metal-based or alkaline earth metal-based detergent of the component (B) (hereinafter occasionally referred to as “metal-based detergent” for brevity) is preferably used to improve the acid neutralization power, high-temperature detergency, wear preventing property, etc.
• the metal-based detergent is not specifically limited, i.e. any metal-based detergent commonly used for lubricating oils may be used.
• Specific examples of the metal-based detergent include at least one metal-based detergent selected from alkali metal sulfonates, alkaline earth metal sulfonates, alkali metal phenates, alkaline earth metal phenates, alkali metal salicylates and alkaline earth metal salicylates.
• the alkali metal there may be mentioned sodium and potassium.
• As the alkaline earth metal there may be mentioned magnesium, calcium and barium. Especially preferably used is magnesium or calcium of an alkaline earth metal.
• an alkali metal sulfonate and/or an alkaline earth metal salicylate be used for reasons of obtaining a composition having improved base number maintaining property, high-temperature detergency and wear preventing property.
• the metal-based detergent preferably has a total base number of 20 to 600 mg KOH/g (JIS K2501; perchloric acid method). A total base number of the above range can ensure the ability to neutralize acidic components formed by oxidation, can suppress an increase of ash in the lubricating oil and can prevent the formation of a large amount of deposits during a long-term use.
• the alkaline earth metal sulfonate which is an alkaline earth metal salt of any of various sulfonic acids, may be generally obtained by carbonating an alkaline earth metal salt of any of various sulfonic acids.
• the sulfonic acid there may be mentioned an aromatic petroleum sulfonic acid alkylsulfonic acid, an arylsulfonic acid and an alkylarylsulfonic acid.
• dodecylbenzenesulfonic acid dilaurylcetylbenzenesulfonic acid, paraffin wax-substituted benzenesulfonic acid, polyolefin-substituted benzenesulfonic acid, polyisobutylene-substituted benzenesulfonic acid and naphthalenesulfonic acid,
• the alkaline earth metal salicylate which is an alkaline earth metal salt of an alkylsalicylic acid
• alkylsalicylic acid examples include dodecylsalicylic acid, dodecylmethylsalicylic acid, tetradecylsalicylic acid, hexadecylsalicylic acid, octadecylsalicylic acid and dioctylsalicylic acid.
• the lubricating oil composition of the present invention may contain, depending upon its intended use, a variety of additives such as a friction modifier other than the above-mentioned, an antiwear agent, an ashless dispersant, a viscosity index improver, a pour-point depressant, a rust preventive agent, a metal corrosion inhibitor, an antifoaming agent, a surfactant and an antioxidant.
• a friction modifier other than the above-mentioned
• an antiwear agent such as a ashless dispersant, a viscosity index improver, a pour-point depressant, a rust preventive agent, a metal corrosion inhibitor, an antifoaming agent, a surfactant and an antioxidant.
• sulfur-based compounds such as sulfurized olefins, dialkyl polysulfides, diarylalkyl polysulfides and diaryl polysulfides
• phosphorus-based compounds such as esters of phosphoric acid, esters of thiophosphoric acid, esters of phosphorous acid, alkyl hydrogenphosphites, amine salts of esters of phosphoric acid and amine salts of esters of phosphorous acid
• chlorine-based compounds such as chlorinated fats and oils, chlorinated paraffins, chlorinated fatty acid esters and chlorinated fatty acids
• ester-based compounds such as esters of alkylmaleic acids and alkenylmaleic acids and esters of alkylsuccinic acids and alkenylsuccinic acids
• organic acid-based compounds such as alkylmaleic acids, alkenylmaleic acids, alkylsuccinic acids and alkenylsuccinic acids; and
• succinimides for example, succinimides, succinimides containing boron, benzylamines, benzylamines containing boron, esters of succinic acid and amides of monobasic or dibasic carboxylic acids typically examples, which include fatty acids and succinic acid.
• polymethacrylates As the viscosity index improver, there may be mentioned polymethacrylates, dispersion type polymethacrylates, olefin-based copolymers such as ethylene-propylene copolymers, dispersion type olefin-based copolymers and styrene-based copolymer such as styrene-diene copolymers.
• the pour point depressant there may be mentioned, for example, polymethacrylates.
• rust preventive agent there may be mentioned, for example, alkenylsuccinic acid and partial esters thereof.
• metal corrosion inhibitor there may be mentioned, for example, benzotriazole-based agents, benzimidazole-based agents, benzothiazole-based agents and thiadiazole-based agents.
• defoaming agent there may be mentioned, for example, dimethylpolysiloxane and polyacrylates.
• surfactant there may be mentioned, for example, polyoxyethylene alkylphenyl ethers.
• antioxidants such as alkylated diphenylamines, phenyl- ⁇ -naphthylamine and alkylated naphthylamines
• phenol-based antioxidants such as 2,6-di-t-butyl-cresol and 4,4′-methylenebis(2,6-di-t-butylphenol).
• the lubricating oil composition of the present invention is, despite its low ash content, low phosphorus content and low sulfur content, excellent in wear resistance and in heat resistance, can extend the lubricating oil change interval and has a long service life.
• the lubricating oil composition is mainly used as the lubricating oil for internal engines.
• the lubricating oil composition is used as automobile lube oils for driving instruments such as automatic transmissions, shock absorbers and power steerings, and for gears; as metal working oils for metal working such as cutting, grinding and deformation processing, and as hydraulic oils, being power transmission fluids, for transmission of power, power control and shock absorbing in hydraulic systems such as hydraulic apparatuses and instruments.
• ICP Inductively Coupled Plasma
• Sulfur concentration was measured in accordance with ASTM D-1552.
• Sulfate ash was determined in accordance with JIS K2272, “Crude Oil and Petroleum Products; Testing Method for Ash and Sulfated Ash”.
• Base number was measured by the potentiometric titration method (base number; hydrochloric acid method) in accordance with JIS K2501 “Petroleum products and lubricants; Testing Method for Neutralization Number”.
• a sample oil and air were allowed to continuously flow at rates of 0.3 ml/hr and 10 ml/min, respectively, for 16 hours, while maintaining the temperature of the glass tube at a predetermined evaluation temperature (280 to 310° C.).
• a predetermined evaluation temperature 280 to 310° C.
• the color of a lacquer deposited onto the glass tube was compared to a color specimen and was rated on the basis of standards in which transparency was rated as 10 points and black as 0 point. The higher the rating is, the better is the performance.
• the friction test was performed using LFW-1 friction tester as a testing machine to measure a width of wear scar on a tested block under the following conditions:
• Block material H-60 Ring material: S-10 Revolution speed: 1,400 rpm Oil temperature: 80° C.
• ISOT test was performed in accordance with JIS K-2514 “Lubricating oil; Oxidation Stability Test”. Thus, an iron-copper plate was immersed in an oil sample while stirring the oil at 165.5° C. for 96 hours. Then, a total base number was measured in accordance with JIS K-2501 (hydrochloric acid method).
• Octyl ester of mercaptoacetic acid was subjected to oxidative coupling according to the production method for the compound represented by the above general formula (I) to obtain bis(n-octoxycarbonylmethyl) disulfide. No tri- or higher polysulfides were detected in the obtained disulfide compound. A sulfur content was found to be 15.8% by mass.
• Composition containing oil-soluble molybdenum Bis-succinimde was synthesized by reacting a mixture of polybutenyl (molecular weight: 1,000) succinic anhydride (PIBSA) and a polyethylene polyamine oligomer (commercially available as Polyethyleneamine E-100 from Huntsman Chemical Company) with a molar ratio of the amine to PIBSA of 0.5:1.
• PIBSA polybutenyl
• polyethylene polyamine oligomer commercially available as Polyethyleneamine E-100 from Huntsman Chemical Company
• the produced bis-succinimde (250 g) and 162.5 g of neutral oil were placed in a glass reactor equipped with a thermoregulator, a mechanical agitator and a water-cooling unit. The mixture was heated to 70° C. being a reaction temperature for forming a molybdic acid salt.
• Lubricating oil compositions having compounding formulations shown in Table 1 were prepared.
• the obtained lubricating oil compositions were each measured for their phosphorus concentrations, sulfur concentrations and sulfated ash and subjected to the hot tube test, LFW-1 friction test and ISOT test, The results of the measurement and evaluation are shown in Table 1.
• Example Example Example 1 2 3 1 100N Mineral oil* 1 % by mass balance balance balance balance 500N Mineral oil* 1 % by mass 15.00 15.00 15.00 15.00 Viscosity index improver* 3 % by mass 6.00 6.00 6.00 6.00 6.00 pour-point depressant* 4 % by mass 0.20 0.20 0.20 ZnDTP: (as P) ppm by mass — — — 740 Disulfide* 5 % by mass 0.13 0.06 0.06 — Ca-based detergent* 6 : (as Ca) ppm by mass 1100 1100 1600 1100 Hindered phenol-based antioxidant* 7 % by mass 0.50 0.50 0.50 0.50 Amine-based antioxidant* 8 % by mass 0.60 0.60 0.60 0.60 Mo-based antioxidant* 9 : (as Mo) ppm by mass 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 Polybutenylsuccinimide* 10 : (as N) ppm by mass 200 200 200 200 200 Boron
• Viscosity index improver polymethacrylate (weight average molecular weight of 90,000) * 4 Pour-point depressant: polyalkyl methacrylate (weight average molecular weight of 69,000) * 5 Disulfide: bis(n-octoxycarbonylmethyl) disulfide, sulfur content of 15.8% by mass (prepared in Preparation Example 1) * 6 Metal-based detergent: calcium sulfonate (base number of 300 mgKOH/g, calcium content of 12% by mass) * 7 Hindered phenol-based antioxidant: 4,4′-methylenebis(2,6-di-t-butylphenol) * 8 Amine-based antioxidant: dialkyldiphenylamine (alkyl group is a mixture of butyl and octyl groups) * 9 Molybdenum-based antioxidant: oil-soluble molybdenum-containing composition prepared in Preparation Example 2 * 10 Ashless dispersant:
• Example 1 The composition of Example 1 is the same as that of Comparative Example except for using a disulfide compound according to the present invention in place of ZnDTP in an amount corresponding to the sulfur content of ZnDTP. It is seen that heat resistance (hot tube test) of Example 1 is superior to that of Comparative Example, while the wear resistance of Example 1 is comparable to that of Comparative Example.
• Example 2 The composition of Example 2 is the same as that of Comparative Example except for using a disulfide compound according to the present invention in place of ZnDTP in a reduced amount relative to the sulfur content of ZnDTP. It is seen that heat resistance of Example 2 is superior to that of Comparative Example, while the wear resistance and base number maintaining property of Example 2 are comparable to those of Comparative Example.
• Example 3 is the same as that of Comparative Example except for using a disulfide compound according to the present invention in place of ZnDTP in a reduced amount relative to the sulfur content of ZnDTP and for adjusting the sulfated ash to 0.6% by mass or less (by increasing the amount of Ca-based detergent). It is seen that heat resistance and base number maintaining property of Example 3 are superior to those of Comparative Example, while the wear resistance of Example 3 is comparable to that of Comparative Example.
• compositions of Examples 1 to 3 do not contain phosphorus that would cause catalyst poisoning. Further, as seen in Examples 2 and 3, it is possible to reduce, without adversely affecting the wear resistance, the content of sulfur which would also cause catalyst poisoning. In general, there is a specified upper limit (API standard, JASO standard, etc.) for sulfated ash which represents a total content of metals which would cause clogging of DPF. From the standpoint of influence on DPF, therefore, the lubricating oil composition of the present invention, in which the disulfide compound is substituted for ZnDTP as shown in Example 3, is of significance in that it can improve the heat resistance (hot tube test) and base number maintaining property after the ISOT test without adversely affecting the wear resistance.
• API standard JASO standard, etc.
• the lubricating oil composition of the present invention can, despite its low ash content, low phosphorus content and low sulfur content, maintain wear resistance and is excellent in heat resistance and has merits that it can extend the lubricating oil change interval.
• the lubricating oil composition is used not only as the lubricating oil for internal engines but also as automobile lube oils for driving instruments such as automatic transmissions, shock absorbers and power steerings, and for gears; as metal working oils for metal working such as cutting, grinding and deformation processing, and as hydraulic oils, being power transmission fluids, for transmission of power, power control and shock absorbing in hydraulic systems such as hydraulic apparatuses and instruments.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=39324514

Family Applications (1)

Country Status (4)

Cited By (8)

Families Citing this family (4)

Citations (5)

Family Cites Families (5)

• 2007
  • 2007-10-22 EP EP07830281A patent/EP2077319A4/fr not_active Withdrawn
  • 2007-10-22 US US12/446,821 patent/US20100009882A1/en not_active Abandoned
  • 2007-10-22 WO PCT/JP2007/070547 patent/WO2008050717A1/fr not_active Ceased
  • 2007-10-22 JP JP2008540978A patent/JP5175739B2/ja not_active Expired - Fee Related

Patent Citations (5)

Also Published As

Similar Documents

Legal Events