Lubricating oil composition

Abstract

The present invention relates to: a lubricating oil composition; a motorcycle having a manual transmission filled with said lubricating oil composition; and a method for using said lubricating oil composition. There is a need to improve the gear shift feeling for motorcycle users (riders). The gear shift feeling for motorcycle users (riders) can be improved by using this lubricating oil composition which contains a base oil (A) and a molybdenum compound (B) (excluding compounds having a dithiocarbamate structure (-N-C(=S)-S-) or a dithiophosphate structure (-P(=S)-S-) in the molecule), and in which the content of the molybdenum compound (B) is not less than 100 ppm by mass and less than 500 ppm by mass in terms of molybdenum atoms relative to the total amount of the lubricating oil composition.

Description

lubricating oil composition

[0001] The present invention relates to a lubricating oil composition, a motorcycle filled with said lubricating oil composition, and a method for using said lubricating oil composition.

[0002] Motorcycles equipped with a manual transmission system require gear changes while traveling by operating a transmission, which is generally referred to as a "shift change." Shift changes require the user (driver) to operate a transmission inside a gearbox with their hands or feet, and the characteristics experienced by the user, such as the smoothness of the shift change (shift feeling), affect the riding comfort of the motorcycle (see, for example, Patent Document 1).

[0003] JP 2008-232028 A

[0004] Given this background, there is a demand for improving the shift feeling for motorcycle users (drivers).

[0005] The present invention provides the following aspects [1] to [8]. [1] A lubricating oil composition comprising a base oil (A) and a molybdenum compound (B) (excluding compounds having a dithiocarbamate structure (-N-C(=S)-S-) or a dithiophosphate structure (-P(=S)-S-) in the molecule), wherein the content of the molybdenum compound (B) is 100 ppm by mass or more and less than 500 ppm by mass, calculated as molybdenum atoms, based on the total amount of the lubricating oil composition. [2] The lubricating oil composition according to [1], wherein the molybdenum compound (B) comprises a mononuclear molybdenum compound. [3] The lubricating oil composition according to [2], wherein the mononuclear molybdenum compound comprises one or more compounds selected from the group consisting of a mononuclear molybdenum compound (B1) represented by the following formula (1) and a molybdenum compound (b2) represented by the following formula (2): an amine salt of molybdic acid (B2); molybdenum trioxide (B3); and a molybdenum succinimide complex (B4). (In the above formulas (1) and (2), R represents a fatty oil residue.) [4] The lubricating oil composition according to any one of [1] to [3], wherein the content of a molybdenum compound having a dithiocarbamate structure (-N-C(=S)-S-)) in the molecule is less than 0.01 mass% based on the total amount of the lubricating oil composition. [5] The lubricating oil composition according to any one of [1] to [4], wherein the content of a molybdenum compound having a dithiophosphate structure (-P(=S)-S-)) in the molecule is less than 0.01 mass% based on the total amount of the lubricating oil composition. [6] The lubricating oil composition according to any one of [1] to [5], which is used for lubricating a two-wheeled vehicle having a manual transmission. [7] A two-wheeled vehicle having a manual transmission, which is filled with the lubricating oil composition according to any one of [1] to [5]. [8] A method for using the lubricating oil composition according to any one of [1] to [5], which comprises applying the lubricating oil composition to a two-wheeled vehicle having a manual transmission.

[0006] A preferred embodiment of the present invention provides a lubricating oil composition that can improve the shift feeling for motorcycle users. Another preferred embodiment of the present invention provides a lubricating oil composition that can improve the shift feeling for motorcycle users while maintaining good clutch friction characteristics. Because the lubricating oil composition of a preferred embodiment of the present invention exhibits the above-mentioned effects, it can be suitably used for lubricating motorcycles with manual transmissions that require the user to perform shift changes themselves.

[0007] Regarding the numerical ranges described herein, the upper and lower limits can be arbitrarily combined. For example, when a numerical range is described as "preferably 30 to 100, more preferably 40 to 80," the ranges "30 to 80" and "40 to 100" are also included in the numerical ranges described herein. Furthermore, when a numerical range is described as "preferably 30 or more, more preferably 40 or more, and preferably 100 or less, more preferably 80 or less," the ranges "30 to 80" and "40 to 100" are also included in the numerical ranges described herein. Furthermore, as a numerical range described herein, for example, "60 to 100" means a range of "60 or more (60 or more) and 100 or less (100 or less)." Furthermore, when specifying the upper and lower limits described herein, the numerical range from the lower limit to the upper limit can be specified by appropriately selecting from the respective options and combining them arbitrarily. In addition, multiple combinations of the various requirements described as preferred aspects of the present specification can be used.

[0008] [Constitution of Lubricating Oil Composition] The present invention provides a lubricating oil composition comprising a base oil (A) (hereinafter also referred to as "component (A)") and a molybdenum compound (B) (excluding those having a dithiocarbamate structure (-N-C(=S)-S-)) or a dithiophosphate structure (-P(=S)-S-)) in the molecule (hereinafter also referred to as "component (B)"), wherein the content of the molybdenum compound (B) is 100 ppm by mass or more, calculated as molybdenum atoms, based on the total amount of the lubricating oil composition. As described above, motorcycles with manual transmissions require the user to perform gear changes themselves, and improved shift feel is required to achieve a more comfortable ride. In response to this, the present inventors have found that the use of a lubricating oil composition containing a certain molybdenum compound improves shift feel, leading to the completion of the present invention. Note that the lubricating oil composition of one embodiment of the present invention may further contain other lubricating oil additives other than component (B) as necessary, within a range that does not impair the effects of the present invention.

[0009] In the lubricating oil composition of one embodiment of the present invention, the total content of components (A) and (B) is, based on the total amount (100 mass%) of the lubricating oil composition, preferably 70 mass% or more, more preferably 75 mass% or more, even more preferably 80 mass% or more, and is preferably less than 90 mass%, more preferably 95 mass% or less, even more preferably 90 mass% or less.

[0010] Hereinafter, each component contained in the lubricating oil composition of one embodiment of the present invention will be described in detail.

[0011] <Component (A): Base Oil> The base oil contained in the lubricating oil composition of one embodiment of the present invention may be a mineral oil, a synthetic oil, or a mixture of a mineral oil and a synthetic oil. Examples of mineral oils include atmospheric residues obtained by atmospheric distillation of crude oils such as paraffinic crude oil, intermediate crude oil, and naphthenic crude oil; distillates obtained by vacuum distillation of these atmospheric residues; and refined oils obtained by subjecting the distillates to one or more refining treatments such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, and hydrorefining.

[0012] Examples of synthetic oils include poly-α-olefins such as α-olefins, homopolymers thereof, and α-olefin copolymers (for example, α-olefin copolymers having 8 to 14 carbon atoms, such as ethylene-α-olefin copolymers); isoparaffins; polyalkylene glycols; ester oils such as polyol esters, dibasic acid esters, monoesters, and phosphate esters; ether oils such as polyphenyl ethers; alkylbenzenes; alkylnaphthalenes; synthetic oils (GTL) obtained by isomerizing wax produced from natural gas by the Fischer-Tropsch process or the like (GTL wax (Gas To Liquids WAX)); synthetic oils (CTL) obtained by isomerizing wax produced from coal by the Fischer-Tropsch process or the like (CTL wax (Coal To Liquids WAX)); and wax produced from biomass by the Fischer-Tropsch process or the like (BTL wax (Biomass To Liquids WAX)). Examples of suitable oils include synthetic oils (BTL) obtained by isomerizing waxes and waxes.

[0013] Among these, the base oil used in one embodiment of the present invention preferably contains at least one selected from mineral oils classified in API (American Petroleum Institute) base oil categories Group 2 and Group 3, and synthetic oils classified in API base oil categories Group 4 and Group 5. In one embodiment of the present invention, these base oils may be used alone or in combination of two or more.

[0014] The kinematic viscosity at 100°C of the base oil (A) used in one embodiment of the present invention is 12.00 mmHg, from the viewpoint of providing a lubricating oil composition with improved cooling properties. ２ / s or less, 11.50mm ２ / s or less, 11.00mm ２ / s or less, 10.50mm ２ / s or less, 10.00mm ２ / s or less, 9.50mm ２ / s or less, 9.00mm ２ / s or less, 8.50mm ２ / s or less, 8.00mm ２ / s or less, 7.50mm ２ / s or less, or 7.00 mm ２ On the other hand, from the viewpoint of obtaining a lubricating oil composition having good oil film retention and improved component protection by enhancing lubricating performance, the kinematic viscosity of the base oil (A) at 100°C is preferably 3.00 mm / s or less. ２ / s or more, 3.50mm ２ / s or more, 4.00mm ２ / s or more, 4.50mm ２ / s or more, 5.00mm ２ / s or more, 5.50mm ２ / s or more, 6.00mm ２ / s or more, 6.50mm ２ / s or more, 7.00mm ２ / s or more, 7.50mm ２ / s or more, or 8.00 mm ２ / s or more is preferable.

[0015] The kinematic viscosity at 40°C of the base oil (A) used in one embodiment of the present invention is 100.00 mmHg from the viewpoint of providing a lubricating oil composition with improved cooling properties. ２ / s or less, 90.00mm２ / s or less, 80.00mm ２ / s or less, 75.00mm ２ / s or less, 70.00mm ２ / s or less, 65.00mm ２ / s or less, 60.00mm ２ / s or less, 55.00mm ２ / s or less, 50.00mm ２ / s or less, 45.00mm ２ / s or less, or 40.00 mm ２ On the other hand, from the viewpoint of obtaining a lubricating oil composition having good oil film retention and improved component protection by enhancing lubricating performance, the kinematic viscosity of the base oil (A) at 40°C is preferably 10.00 mm / s or less. ２ / s or more, 15.00mm ２ / s or more, 20.00mm ２ / s or more, 25.00mm ２ / s or more, 30.00mm ２ / s or more, 35.00mm ２ / s or more, 40.00mm ２ / s or more, 45.00mm ２ / s or more, or 50.00 mm ２ / s or more is preferable.

[0016] The viscosity index of the base oil (A) used in one embodiment of the present invention is set appropriately depending on the application of the lubricating oil composition, but is preferably 90 or more, more preferably 110 or more, even more preferably 130 or more, and particularly preferably 150 or more. In one embodiment of the present invention, when a mixed oil combining two or more base oils is used as component (A), the kinematic viscosity and viscosity index of the mixed oil are preferably within the above-mentioned ranges. Therefore, the mixed oil may be prepared by combining a low-viscosity base oil and a high-viscosity base oil so that the mixed oil has a kinematic viscosity and viscosity index within the above-mentioned ranges. The mixed oil may be a mixed oil combining two or more base oils whose kinematic viscosity and viscosity index at 100 ° C. fall within the above-mentioned ranges, or a mixed oil combining a base oil whose kinematic viscosity and viscosity index at 100 ° C. fall within the above-mentioned ranges with a base oil that does not fall within the above-mentioned ranges. It may also be a mixed oil adjusted to fall within the above-mentioned ranges by combining a low-viscosity base oil and a high-viscosity base oil whose kinematic viscosity and viscosity index at 100 ° C. do not fall within the above-mentioned ranges. In this specification, the kinematic viscosity and viscosity index refer to values ​​measured or calculated in accordance with JIS K2283:2000.

[0017] In the lubricating oil composition of one embodiment of the present invention, the content of base oil (A) is preferably 70.00 mass% or more, more preferably 75.00 mass% or more, even more preferably 80.00 mass% or more, based on the total amount (100 mass%) of the lubricating oil composition, from the viewpoint of providing a lubricating oil composition with an improved shift feeling, and is preferably 99.00 mass% or less, more preferably 95.00 mass% or less, even more preferably 90.00 mass% or less.

[0018] <Component (B): Molybdenum Compound> The lubricating oil composition of the present invention contains a molybdenum compound (B). However, molybdenum compounds having a dithiocarbamate structure (-N-C(=S)-S-) or a dithiophosphate structure (-P(=S)-S-) in the molecule are not included in the molybdenum compound (B) of the present invention. Molybdenum compounds having these specific structures are generally blended into lubricating oil compositions as friction modifiers or the like. However, in the present invention, by blending a molybdenum compound (B) that does not have these specific structures, a lubricating oil composition that can improve shift feeling can be obtained.

[0019] In the present invention, the content of the molybdenum compound (B) is 100 ppm by mass or more, calculated as molybdenum atoms, based on the total amount of the lubricating oil composition, from the viewpoint of preparing a lubricating oil composition that can improve shift feeling. From the above viewpoint, the content of the molybdenum compound (B) calculated as molybdenum atoms may be 110 ppm by mass or more, 115 ppm by mass or more, 120 ppm by mass or more, 125 ppm by mass or more, 130 ppm by mass or more, 135 ppm by mass or more, 140 ppm by mass or more, 145 ppm by mass or more, or 150 ppm by mass or more. Furthermore, from the viewpoint of suppressing the occurrence of precipitation in the lubricating oil composition, the content of the molybdenum compound (B) in terms of molybdenum atoms may be less than 500 ppm by mass, 450 ppm by mass or less, 400 ppm by mass or less, 350 ppm by mass or less, 300 ppm by mass or less, 250 ppm by mass or less, 200 ppm by mass or less, 190 ppm by mass or less, 180 ppm by mass or less, 170 ppm by mass or less, or 160 ppm by mass or less, based on the total amount of the lubricating oil composition.

[0020] In one embodiment of the present invention, from the viewpoint of preparing a lubricating oil composition that can improve shift feeling, the content of the molybdenum compound (B) is preferably 0.01 mass% or more, 0.05 mass% or more, 0.10 mass% or more, or 0.15 mass% or more, based on the total amount of the lubricating oil composition, and may also be 0.20 mass% or more, 0.25 mass% or more, 0.30 mass% or more, 0.35 mass% or more, 0.40 mass% or more, 0.45 mass% or more, or 0.50 mass% or more. Furthermore, from the viewpoint of suppressing the occurrence of precipitation in the lubricating oil composition, the content of the molybdenum compound (B) is preferably 1.00 mass% or less, 0.75 mass% or less, 0.50 mass% or less, 0.40 mass% or less, 0.30 mass% or less, or 0.20 mass% or less, based on the total amount of the lubricating oil composition.

[0021] In the lubricating oil composition of one embodiment of the present invention, the molybdenum compound (B) is preferably a mononuclear molybdenum compound (a compound having one molybdenum atom per molecule). In the lubricating oil composition of one embodiment of the present invention, the mononuclear molybdenum compound may contain a mononuclear molybdenum compound (B1) containing one or more compounds selected from the group consisting of molybdenum compounds (b1) represented by the following formula (1) and molybdenum compounds (b2) represented by the following formula (2):

[0022] In the above formulas (1) and (2), R represents a fatty oil residue, which is a glycerol ester of a higher fatty acid containing at least 12 carbon atoms and may contain 22 or more carbon atoms. Such esters are commonly known as vegetable and animal oils. Examples of useful vegetable oils are derived from coconut, corn, cottonseed, linseed, peanut, soybean, and sunflower seed. Similarly, animal oils such as tallow may also be used. The molybdenum source may be an oxygen-containing molybdenum compound capable of reacting with the intermediate reaction product of the fatty oil and diethanolamine to form an ester-type molybdenum complex. Specific examples of the molybdenum source include amine salts of molybdic acid, molybdenum trioxide, and mixtures thereof. The mixture of the molybdenum compound (b1) represented by formula (1) and the molybdenum compound (b2) represented by formula (2) can be obtained, for example, by successively reacting a fatty oil, diethanolamine, and a molybdenum source by the condensation method described in JP-A-62-108891.

[0023] In another embodiment of the lubricating oil composition of the present invention, the mononuclear molybdenum compound may contain one or more compounds selected from the group consisting of an amine salt of molybdic acid (B2) and molybdenum trioxide (B3). In one embodiment of the present invention, the amine salt of molybdic acid (B2) may be a compound obtained by reacting molybdenum trioxide and / or molybdic acid with an amine compound.

[0024] Examples of the amine compound include monoalkyl or monoalkenyl amines such as hexylamine, secondary hexylamine, octylamine, secondary octylamine, 2-ethylhexylamine, decylamine, secondary decylamine, dodecylamine, secondary dodecylamine, tetradecylamine, secondary tetradecylamine, hexadecylamine, secondary hexadecylamine, octadecylamine, secondary octadecylamine, and oleylamine; N-hexylmethylamine, N-secondary hexylmethylamine, N-cyclohexylmethylamine, N-2-ethylhexylmethylamine, N-secondary octylmethylamine, N-decylmethylamine, N-secondary decylmethylamine, and N-dodecyl Secondary amines such as methylamine, N-secondary dodecylmethylamine, N-tetradecylmethylamine, N-hexadecylmethylamine, N-stearylmethylamine, N-oleylmethylamine, dibutylamine, di-secondary butylamine, dihexylamine, di-secondary hexylamine, dibenzylamine, dioctylamine, bis(2-ethylhexyl)amine, di-secondary octylamine, didecylamine, di-secondary decylamine, didodecylamine, di-secondary dodecylamine, ditetradecylamine, dihexadecylamine, distearylamine, dioleylamine, bis(2-hexyldecyl)amine, bis(2-octyldodecyl)amine, and bis(2-decyltetradecyl)amine;

[0025] N-butylethylenediamine, N-octylethylenediamine, N-(2-ethylhexyl)ethylenediamine, N-dodecylethylenediamine, N-octadecylethylenediamine, N-butyl-1,3-propanediamine, N-octyl-1,3-propanediamine, N-(2-ethylhexyl)-1,3-propanediamine, N-decyl-1,3-propanediamine, N-dodecyl-1,3-propanediamine, N-tetradecyl-1,3-propanediamine, N-hexyl N-alkyl or alkenyl diamines such as dodecyl-1,3-propanediamine, N-octadecyl-1,3-propanediamine, N-oleyl-1,3-propanediamine, N-butyl-1,6-hexylenediamine, N-octyl-1,6-hexylenediamine, N-(2-ethylhexyl)-1,6-hexylenediamine, N-dodecyl-1,6-hexylenediamine, N-octadecyl-1,6-hexylenediamine, and N-oleyl-1,6-hexylenediamine;

[0026] N-Alkyl or alkenyl monoethanolamines such as N-hexyl monoethanolamine, N-octyl monoethanolamine, N-decyl monoethanolamine, N-dodecyl monoethanolamine, N-tetradecyl monoethanolamine, N-hexadecyl monoethanolamine, N-octadecyl monoethanolamine, and N-oleyl monoethanolamine; 2-hydroxyalkyl primary amines such as 2-hydroxyhexylamine, 2-hydroxyoctylamine, 2-hydroxydecylamine, 2-hydroxydodecylamine, 2-hydroxytetradecylamine, 2-hydroxyhexadecylamine, and 2-hydroxyoctadecylamine; N-2-hydroxyhexylmethylamine, N-2-hydroxyoctylmethylamine , N-2-hydroxydecylmethylamine, N-2-hydroxytetradecylmethylamine, N-2-hydroxyhexadecylmethylamine, N-2-hydroxyoctadecylmethylamine, N-2-hydroxyhexylethylamine, N-2-hydroxyoctylethylamine, N-2-hydroxydecylethylamine, N-2-hydroxytetradecylethylamine, N-2-hydroxyhexadecylethylamine, N-2-hydroxyoctadecylethylamine, N-2-hydroxyhexylbutylamine, N-2-hydroxyoctylbutylamine, N-2-hydroxydecylbutylamine, N-2-hydroxytetradecylbutylamine, N-2-hydroxyhexadecylbutylamine, N-2-hydroxyoctadecylbutylamine;

[0027] Examples of N-hydroxyalkyl secondary amines include N-2-hydroxyhexyl monoethanolamine, N-2-hydroxyoctyl monoethanolamine, N-2-hydroxydecyl monoethanolamine, N-2-hydroxytetradecyl monoethanolamine, N-2-hydroxyhexadecyl monoethanolamine, N-2-hydroxyoctadecyl monoethanolamine, bis(2-hydroxyoctyl)amine, bis(2-hydroxydecyl)amine, bis(2-hydroxydodecyl)amine, bis(2-hydroxytetradecyl)amine, bis(2-hydroxyhexadecyl)amine, and bis(2-hydroxyoctadecyl)amine.

[0028] These amine compounds may be used alone or in combination of two or more. The reaction ratio of molybdenum trioxide and / or molybdic acid to the amine compound is preferably 0.7 to 5, more preferably 0.8 to 4, and even more preferably 1 to 2.5, in terms of the molar ratio of molybdenum atoms in molybdenum trioxide and / or molybdic acid to 1 mole of the amine compound. The reaction method is not particularly limited, and the method described in JP-A-2003-252887, for example, can be employed.

[0029] In a lubricating oil composition according to yet another embodiment of the present invention, the mononuclear molybdenum compound may contain a molybdenum-containing succinimide complex (B4) produced by a process comprising the steps of reacting an alkyl or alkenyl succinimide of a polyamine of the following formula (A) with an ethylenically unsaturated carboxylic acid or anhydride, and reacting the succinimide product of the above step with an acidic molybdenum compound: In the above formula, R is an alkyl group or alkenyl group having 12 to 30 carbon atoms, a and b each independently represent 2 or 3, and x represents 0 to 10. The molybdenum succinimide composite (B4) can be obtained by the method described in JP-A-2011-526959.

[0030] In the lubricating oil composition of one embodiment of the present invention, the molybdenum compound (B) may be any of the mononuclear molybdenum compound (B1), the amine salt of molybdic acid (B2), molybdenum trioxide (B3), and the molybdenum succinimide complex (B4) described above, which may be used alone or in combination of two or more thereof.

[0031] Furthermore, the lubricating oil composition of one embodiment of the present invention may contain a dinuclear molybdenum compound (a compound having two molybdenum atoms in one molecule) and / or a trinuclear molybdenum compound (a compound having three molybdenum atoms in one molecule), as long as the compound does not have a dithiocarbamate structure (-N-C(=S)-S-)) or a dithiophosphate structure (-P(=S)-S-)) in the molecule, within a range in which the effects of the present invention can be exhibited.

[0032] When the lubricating oil composition of one embodiment of the present invention contains a dinuclear molybdenum compound, the content thereof may be 10 ppm by mass or more, 30 ppm by mass or more, 50 ppm by mass or more, 70 ppm by mass or more, or 100 ppm by mass or more, calculated as molybdenum atoms, based on the total amount of the lubricating oil composition. The content of the dinuclear molybdenum compound, calculated as molybdenum atoms, may be less than 500 ppm by mass, 450 ppm by mass or less, 400 ppm by mass or less, 350 ppm by mass or less, 300 ppm by mass or less, 250 ppm by mass or less, 200 ppm by mass or less, 150 ppm by mass or less, 125 ppm by mass or less, or 100 ppm by mass or less, based on the total amount of the lubricating oil composition.

[0033] When the lubricating oil composition of one embodiment of the present invention contains a dinuclear molybdenum compound, the content thereof may be 0.001 mass% or more, 0.01 mass% or more, 0.05 mass% or more, or 0.10 mass% or more, based on the total amount of the lubricating oil composition, or 0.50 mass% or less, 0.40 mass% or less, 0.30 mass% or less, or 0.20 mass% or less, based on the total amount of the lubricating oil composition.

[0034] When the lubricating oil composition of one embodiment of the present invention contains a trinuclear molybdenum compound, the content thereof may be 10 ppm by mass or more, 30 ppm by mass or more, 50 ppm by mass or more, 70 ppm by mass or more, or 100 ppm by mass or more, calculated as molybdenum atoms, based on the total amount of the lubricating oil composition. The content of the trinuclear molybdenum compound, calculated as molybdenum atoms, may be less than 500 ppm by mass, 450 ppm by mass or less, 400 ppm by mass or less, 350 ppm by mass or less, 300 ppm by mass or less, 250 ppm by mass or less, 200 ppm by mass or less, 150 ppm by mass or less, 125 ppm by mass or less, or 100 ppm by mass or less, based on the total amount of the lubricating oil composition.

[0035] When the lubricating oil composition of one embodiment of the present invention contains a trinuclear molybdenum compound, the content thereof may be 0.001 mass% or more, 0.01 mass% or more, 0.05 mass% or more, or 0.10 mass% or more, based on the total amount of the lubricating oil composition, or 0.50 mass% or less, 0.40 mass% or less, 0.30 mass% or less, or 0.20 mass% or less, based on the total amount of the lubricating oil composition.

[0036] <Molybdenum Compounds Other than Component (B)> As described above, the molybdenum compound (MoDTC) having a dithiocarbamate structure (-N-C(=S)-S-) in the molecule and the molybdenum compound (MoDTP) having a dithiophosphate structure (-P(=S)-S-) in the molecule are not included in the molybdenum compound (B) of the present invention. Examples of molybdenum compounds having a dithiocarbamate structure (-N-C(=S)-S-) or a dithiophosphate structure (-P(=S)-S-) in the molecule include molybdenum dithiocarbamate (MoDTC) and molybdenum dithiophosphate (MoDTP), respectively.

[0037] More specifically, molybdenum dithiocarbamate (MoDTC) includes binuclear molybdenum dithiocarbamate containing two molybdenum atoms in the molecule, and trinuclear molybdenum dithiocarbamate containing three molybdenum atoms in the molecule.

[0038] The dinuclear molybdenum dithiocarbamate may be, for example, a compound represented by the following formula (3):

[0039] In the above formula (3), R １１ ~R １４ each independently represents a hydrocarbon group; X １１ ~X １４ each independently represents an oxygen atom or a sulfur atom.

[0040] The trinuclear molybdenum dithiocarbamate may be, for example, a compound represented by the following formula (3-1).

[0041] In the above formula (3-1), k is an integer of 1 or more, m is an integer of 0 or more, and k + m is an integer of 4 or more and 10 or less. n is an integer of 1 or more and 4 or less, and p is an integer of 0 or more. z is an integer of 0 or more and 5 or less, including non-stoichiometric values. Mo is a molybdenum atom, and S is a sulfur atom. Each E is independently an oxygen atom or a selenium atom, and is capable of substituting sulfur in the core. Each L is independently an anionic ligand having an organic group containing a carbon atom, and the total number of carbon atoms in the organic group in each ligand is 14 or more. Each U is independently an anion other than L. Each Q is independently a compound that donates a neutral electron, and is present to fill a vacant coordination position on the trinuclear molybdenum compound.

[0042] The molybdenum dithiophosphate may be, for example, a compound represented by the following formula (4):

[0043] In formula (4), R ２１ ~R ２４ each independently represents a hydrocarbon group; X ２１ ~X ２４ each independently represents an oxygen atom or a sulfur atom.

[0044] In one embodiment of the present invention, the content of the various molybdenum compounds having a dithiocarbamate structure (—N—C(═S)—S—) in the molecule (for example, compounds represented by the above formula (3) or formula (3-1)) is less than 0.01 mass %, less than 0.005 mass %, less than 0.001 mass %, or less than 0.0001 mass %, and preferably 0 mass %, based on the total amount of the lubricating oil composition, from the viewpoint of preparing a lubricating oil composition that can improve shift feeling.

[0045] Furthermore, from the viewpoint of preparing a lubricating oil composition that can improve shift feeling, the content of the various molybdenum compounds described above having a dithiocarbamate structure (—N—C(═S)—S—) in the molecule (for example, compounds represented by the above formula (3) or formula (3-1)) in terms of molybdenum atoms is less than 2 ppm by mass, less than 1 ppm by mass, less than 0.1 ppm by mass, less than 0.05 ppm by mass, less than 0.01 ppm by mass, and preferably 0 ppm by mass, based on the total amount of the lubricating oil composition.

[0046] In one embodiment of the present invention, the content of the various molybdenum compounds having a dithiophosphate structure (-P(=S)-S-) in the molecule (for example, the compound represented by formula (4)) is less than 0.01 mass %, less than 0.005 mass %, less than 0.001 mass %, or less than 0.0001 mass %, and preferably 0 mass %, based on the total amount of the lubricating oil composition, from the viewpoint of preparing a lubricating oil composition that can improve shift feeling.

[0047] Furthermore, from the viewpoint of preparing a lubricating oil composition that can improve shift feeling, the content of the various molybdenum compounds having a dithiophosphate structure (-P(=S)-S-) in the molecule (for example, the compound represented by the above formula (4)) in terms of molybdenum atoms is less than 2 ppm by mass, less than 1 ppm by mass, less than 0.1 ppm by mass, less than 0.05 ppm by mass, less than 0.01 ppm by mass, and preferably 0 ppm by mass, based on the total amount of the lubricating oil composition.

[0048] <Lubricating Oil Additives> The lubricating oil composition of one embodiment of the present invention may contain other lubricating oil additives besides component (B) as needed, as long as the effects of the present invention are not impaired. Examples of such lubricating oil additives include pour point depressants, viscosity index improvers, antioxidants, metal-based detergents, friction modifiers, anti-wear agents, metal deactivators, ashless dispersants, and anti-foaming agents. These lubricating oil additives may be used alone or in combination of two or more.

[0049] The content of each of the above lubricating oil additives can be adjusted as appropriate within a range that does not impair the effects of the present invention, but is typically 0.001 to 15 mass %, preferably 0.005 to 10 mass %, and more preferably 0.01 to 5 mass %, for each additive independently, based on the total amount (100 mass %) of the lubricating oil composition.

[0050] Furthermore, the lubricating oil composition of one embodiment of the present invention may have limited contents of the lubricating oil additives, and the content of each of the lubricating oil additives may be less than 5.0 mass%, less than 2.0 mass%, less than 1.0 mass%, less than 0.1 mass%, less than 0.01 mass%, less than 0.001 mass%, less than 0.0001 mass%, or less than 0.00001 mass%, based on the total amount (100 mass%) of the lubricating oil composition.

[0051] [Viscosity Index Improver] The lubricating oil composition of one embodiment of the present invention may contain a viscosity index improver. The viscosity index improver may be used alone or in combination of two or more types. Examples of viscosity index improvers used in one embodiment of the present invention include polymers such as non-dispersant polymethacrylate, dispersant polymethacrylate, olefin copolymers (e.g., ethylene-propylene copolymer, etc.), dispersant olefin copolymers, and styrene copolymers (e.g., styrene-diene copolymer, styrene-isoprene copolymer, etc.). When the lubricating oil composition of one embodiment of the present invention contains a viscosity index improver, the content of the viscosity index improver is 0.1 to 10.0 mass%, preferably 1.0 to 8.0 mass%, and more preferably 3.0 to 6.0 mass%, based on the total amount (100 mass%) of the lubricating oil composition.

[0052] [Antioxidant] The lubricating oil composition of one embodiment of the present invention may contain an antioxidant. The antioxidants may be used alone or in combination of two or more. Examples of antioxidants used in one embodiment of the present invention include amine-based antioxidants such as alkylated diphenylamine, phenylnaphthylamine, and alkylated phenylnaphthylamine; phenol-based antioxidants such as 2,6-di-t-butylphenol, 4,4'-methylenebis(2,6-di-t-butylphenol), isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, and n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; and sulfur-based antioxidants such as phenothiazine, dioctadecyl sulfide, dilauryl-3,3'-thiodipropionate, and 2-mercaptobenzimidazole.

[0053] [Metallic Detergent] The lubricating oil composition of one embodiment of the present invention may contain a metallic detergent. The metallic detergent may be used alone or in combination of two or more. Examples of the metallic detergent used in one embodiment of the present invention include metal salts such as metal sulfonates, metal salicylates, and metal phenates. Furthermore, the metal atom constituting the metal salt is preferably a metal atom selected from alkali metals and alkaline earth metals, more preferably sodium, calcium, magnesium, or barium, and even more preferably calcium or magnesium.

[0054] The lubricating oil composition of one embodiment of the present invention may contain calcium phenate as a metallic detergent. Examples of the calcium phenate used in one embodiment of the present invention include compounds represented by the following general formula (m-1):

[0055] In the above general formula (m-1), each R is independently a hydrocarbon group having 8 to 30 carbon atoms, and y is an integer of 0 or greater. Examples of hydrocarbon groups that can be selected as R include alkyl groups having 8 to 30 carbon atoms. When the lubricating oil composition of one embodiment of the present invention contains calcium phenate, the content of calcium phenate is 0.1 to 5.0 mass%, preferably 1.0 to 4.0 mass%, and more preferably 2.0 to 3.0 mass%, based on the total amount (100 mass%) of the lubricating oil composition.

[0056] The lubricating oil composition of one embodiment of the present invention may contain calcium salicylate as a metallic detergent. Examples of calcium salicylate used in one embodiment of the present invention include compounds represented by the following general formula (m-2):

[0057] In the above general formula (m-2), each R is independently a hydrocarbon group having 8 to 30 carbon atoms. Examples of hydrocarbon groups that can be selected as R include alkyl groups having 8 to 30 carbon atoms. When the lubricating oil composition of one embodiment of the present invention contains calcium phenate, the content of calcium phenate is 0.1 to 5.0 mass %, preferably 1.0 to 4.0 mass %, and more preferably 2.0 to 3.0 mass %, based on the total amount (100 mass %) of the lubricating oil composition.

[0058] The lubricating oil composition of one embodiment of the present invention may contain a calcium sulfonate as a metal-based detergent. Examples of the calcium sulfonate used in one embodiment of the present invention include compounds represented by the following general formula (m-3):

[0059] In the above general formula (m-3), each R is independently a hydrocarbon group having 8 to 30 carbon atoms. Examples of hydrocarbon groups that can be selected as R include alkyl groups having 8 to 30 carbon atoms. When the lubricating oil composition of one embodiment of the present invention contains calcium phenate, the content of calcium phenate is 0.1 to 5.0 mass %, preferably 1.0 to 4.0 mass %, and more preferably 2.0 to 3.0 mass %, based on the total amount (100 mass %) of the lubricating oil composition.

[0060] The lubricating oil composition of one embodiment of the present invention may contain a magnesium phenate as a metallic detergent. Examples of the magnesium phenate used in one embodiment of the present invention include compounds represented by the following general formula (n-1):

[0061] In the above general formula (n-1), each R is independently a hydrocarbon group having 8 to 30 carbon atoms, and y is an integer of 0 or greater. Examples of hydrocarbon groups that can be selected as R include alkyl groups having 8 to 30 carbon atoms. When the lubricating oil composition of one embodiment of the present invention contains magnesium phenate, the content of magnesium phenate is 0.1 to 5.0 mass%, preferably 0.5 to 4.0 mass%, and more preferably 1.0 to 3.0 mass%, based on the total amount (100 mass%) of the lubricating oil composition.

[0062] The lubricating oil composition of one embodiment of the present invention may contain magnesium salicylate as a metallic detergent. Examples of the magnesium salicylate used in one embodiment of the present invention include compounds represented by the following general formula (n-2):

[0063] In the above general formula (n-2), each R is independently a hydrocarbon group having 8 to 30 carbon atoms. Examples of hydrocarbon groups that can be selected as R include alkyl groups having 8 to 30 carbon atoms. When the lubricating oil composition of one embodiment of the present invention contains magnesium phenate, the content of magnesium phenate is 0.1 to 5.0 mass%, preferably 0.5 to 4.0 mass%, and more preferably 1.0 to 3.0 mass%, based on the total amount (100 mass%) of the lubricating oil composition.

[0064] The lubricating oil composition of one embodiment of the present invention may contain a magnesium sulfonate as a metallic detergent. Examples of the magnesium sulfonate used in one embodiment of the present invention include compounds represented by the following general formula (n-3):

[0065] In the above general formula (n-3), each R is independently a hydrocarbon group having 8 to 30 carbon atoms. Examples of hydrocarbon groups that can be selected as R include alkyl groups having 8 to 30 carbon atoms. When the lubricating oil composition of one embodiment of the present invention contains magnesium phenate, the content of magnesium phenate is 0.1 to 5.0 mass%, preferably 0.5 to 4.0 mass%, and more preferably 1.0 to 3.0 mass%, based on the total amount (100 mass%) of the lubricating oil composition.

[0066] [Friction modifiers and anti-wear agents] The lubricating oil composition of one embodiment of the present invention may contain a friction modifier or an anti-wear agent. The friction modifier or anti-wear agent may be used alone or in combination of two or more. Examples of the friction modifier and anti-wear agent used in one embodiment of the present invention include sulfur-based compounds such as sulfurized olefins, dialkyl polysulfides, diaryl alkyl polysulfides, and diaryl polysulfides; phosphorus-based compounds such as phosphate esters, thiophosphate esters, phosphites, alkyl hydrogen phosphites, phosphate ester amine salts, and phosphites ester amine salts; ashless friction modifiers such as amine compounds, fatty acid esters, fatty acid amides, fatty acids, aliphatic alcohols, aliphatic ethers, urea-based compounds, and hydrazide-based compounds.

[0067] [Metal Deactivator] The lubricating oil composition of one embodiment of the present invention may contain a metal deactivator. The metal deactivators may be used alone or in combination of two or more. Examples of the metal deactivator used in one embodiment of the present invention include benzotriazole, triazole derivatives, benzotriazole derivatives, and thiadiazole derivatives.

[0068] [Ashless Dispersant] The lubricating oil composition of one embodiment of the present invention may contain an ashless dispersant from the viewpoint of improving dispersibility. The ashless dispersant may be used alone or in combination of two or more types. The ashless dispersant used in one embodiment of the present invention is preferably an alkenyl succinimide, and examples thereof include alkenyl succinic acid bisimide represented by the following general formula (f-1) and alkenyl succinic acid monoimide represented by the following general formula (f-2).

[0069]

[0070] In the above general formulas (f-1) and (f-2), R ｆ１ , R ｆ２ and R ｆ３ are each independently an alkenyl group having a number average molecular weight (Mn) of 900 to 2500. ｆ１ , R ｆ２ and R ｆ３ Examples of the alkenyl group that can be selected as A include a polybutenyl group and a polyisobutenyl group. ｆ１ , A ｆ２ and A ｆ３ are each independently an alkylene group having 2 to 5 carbon atoms. x1 is an integer of 2 to 6. x2 is an integer of 2 to 6.

[0071] The compound represented by general formula (f-1) or (f-2) may be a modified alkenyl succinimide obtained by reacting it with one or more compounds selected from the group consisting of boron compounds, alcohols, aldehydes, ketones, alkylphenols, cyclic carbonates, epoxy compounds, and organic acids.

[0072] <Method for producing lubricating oil composition> There are no particular limitations on the method for producing the lubricating oil composition of one embodiment of the present invention, but from the viewpoint of productivity, it is preferable that the method comprises a step of blending component (A) with component (B) and, as necessary, various additives.

[0073] [Properties of Lubricating Oil Composition] The kinematic viscosity at 100°C of the lubricating oil composition of one embodiment of the present invention is 20.00 mmHg, from the viewpoint of providing a lubricating oil composition with improved cooling properties. ２ / s or less, 18.00mm ２ / s or less, 16.50mm ２ / s or less, 16.00mm ２ / s or less, 14.00mm ２ / s or less, 12.00mm ２ / s or less, 11.50mm ２ / s or less, 11.00mm ２ / s or less, 10.50mm ２ / s or less, or 10.00 mm ２On the other hand, from the viewpoint of providing a lubricating oil composition that has good oil film retention and improves component protection by enhancing lubricating performance, the kinematic viscosity of the lubricating oil composition at 100°C is preferably 6.00 mm / s or less. ２ / s or more, 6.50mm ２ / s or more, 7.00mm ２ / s or more, 7.50mm ２ / s or more, or 8.00 mm ２ / s or more is preferable.

[0074] The kinematic viscosity at 40°C of the lubricating oil composition of one embodiment of the present invention is 120.0 mm ２ / s or less, 110.0mm ２ / s or less, 105.0mm ２ / s or less, 100.0mm ２ / s or less, 90.00mm ２ / s or less, 80.00mm ２ / s or less, 75.00mm ２ / s or less, 70.00mm ２ / s or less, 65.00mm ２ / s or less, 60.00mm ２ On the other hand, from the viewpoint of providing a lubricating oil composition that has good oil film retention and improves component protection by enhancing lubricating performance, the kinematic viscosity of the lubricating oil composition at 40°C is preferably 40.00 mm / s or less. ２ / s or more, 45.00mm ２ / s or more, or 50.00 mm ２ / s or more is preferable.

[0075] The viscosity index of the lubricating oil composition of one embodiment of the present invention is preferably 90 or greater, more preferably 110 or greater, and even more preferably 130 or greater.

[0076] [Characteristics and Uses of Lubricating Oil Composition] The present invention provides a lubricating oil composition that allows the user to experience an excellent shift feeling when shifting gears in a motorcycle. Therefore, the lubricating oil composition of one embodiment of the present invention can be suitably used to lubricate motorcycles having manual transmissions. Accordingly, the present invention also provides the following motorcycle [I] and the use of the lubricating oil composition [II]. [I] A motorcycle having a manual transmission filled with the lubricating oil composition of one embodiment of the present invention described above. [II] Use of the lubricating oil composition, in which the lubricating oil composition of one embodiment of the present invention described above is applied to a motorcycle having a manual transmission.

[0077] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. The various physical properties of the components used in the examples and comparative examples and the resulting lubricating oil compositions were measured according to the following methods.

[0078] (1) Kinematic viscosity and viscosity index: Measured and calculated in accordance with JIS K2283:2000. (2) Phosphorus atom (P) content: Measured in accordance with JPI-5S-38-92. (3) Calcium atom (Ca) content: Measured in accordance with JPI-5S-38-92. (4) Magnesium atom (Mg) content: Measured in accordance with JPI-5S-38-92. (5) Molybdenum atom (Mo) content: Measured in accordance with JPI-5S-38-92. (6) Clutch friction characteristics: Measured in accordance with JASO T903:2023, and samples with an "SFI" of 1.40 or higher were judged to pass.

[0079] (7) Shift Feeling Test An actual vehicle test was conducted under the following conditions using a motorcycle having a manual transmission filled with the lubricating oil composition of the Examples or Comparative Examples. Test location: Shirosato Test Center, Japan Automobile Research Institute Test conditions: Upshift (1st gear → 6th gear, 7,000 rpm); Downshift (6th gear → 1st gear, 5,000 rpm) Test vehicle: Honda CBR250R Evaluation method: The shift feeling rating in a test run using a motorcycle having a manual transmission filled with a commercially available lubricating oil composition was used as the standard (1.0 points). Thereafter, the engine oil was replaced with the lubricating oil composition of the Examples or Comparative Examples, and four test drivers conducted a test run using the same vehicle. The test drivers conducted the test run without knowing whether the lubricating oil composition filled was the Example or Comparative Example. Note that the lubricating oil composition of Comparative Example 2 was excluded from the shift feeling test due to concerns about the occurrence of clutch slippage. The shift feeling was evaluated by four test drivers based on the smoothness of the shift change operation as perceived by each of them, using a score of 0.5 points in increments of 10.0 points, with the maximum score being 1.0 points, based on the score of a commercially available lubricating oil composition. Tables 1 and 2 show the average scores of the four test drivers. In this test, a vehicle with an average shift feeling score of 5.0 points or more was judged to pass.

[0080] Lubricating oil compositions were prepared by adding and mixing components (A), (B) and other additives shown in Tables 1 and 2 in the amounts shown in each table. Details of each component used in preparing the lubricating oil compositions are as follows:

[0081] <Component (A): Base oil> - Base oil (a1): 100°C kinematic viscosity = 6.0 mm ２ / s, viscosity index = 132. Mineral oil classified into Group III of the API base oil category. Base oil (a2): kinematic viscosity at 100 ° C = 7.2 mm ２ / s, and a mineral oil classified into Group III of the API base oil category with a viscosity index of 127. In all examples and comparative examples, the kinematic viscosity at 40°C of the mixed base oil obtained by mixing base oil (a1) and base oil (a2) was 38.85 mm２ / s, kinematic viscosity at 100°C is 6.43 mm ２ The viscosity index was 116. <Component (B): Molybdenum Compounds> Molybdenum compound (b1): a mixture of [2,2'-(dodecanoylimino)diethanolato]dioxomolybdenum(VI) and [3-(dodecanoyloxy)-1,2-propanediolate]dioxomolybdenum(VI) (MOLYVAN 855 (manufactured by RT Vanderbilt Company Inc.), Mo content = 7.9 mass%, N content = 2.8 mass%). Molybdenum compound (b2): diisotridecylamine molybdate (SAKURA-LUBE S-710 (manufactured by ADEKA Corporation), Mo content = 10.0 mass%). Molybdenum compound (b4): Oxymolybdenum complex of succinimide (OLOA17502 (manufactured by Chevron Japan Co., Ltd.), Mo content = 5.5 mass%, S content = 0.2 mass%, N content = 1.6 mass%).

[0082] <Component (B'): Molybdenum Compound> Molybdenum dithiocarbamate (MoDTC) (Mo content = 10.0 mass %).

[0083] <Other Additives> Ca Phenate: Overbased calcium phenate with a base number (perchloric acid method) of 258 mg KOH / g, Ca content = 9.5 mass%. Mg Sulfonate (1): Overbased magnesium phenate with a base number (perchloric acid method) of 405 mg KOH / g, Mg content = 9.3 mass%. Mg Sulfonate (2): Overbased magnesium phenate with a base number (perchloric acid method) of 395 mg KOH / g, Mg content = 9.3 mass%. Viscosity index improver: Infineum diblock star polymer (weight average molecular weight = 780,000). Additive package: Additive mixture containing an ashless dispersant, antioxidant, antiwear agent (ZnDTP), pour point depressant, and antifoaming agent. In Examples 3 to 5 and Comparative Examples 4 and 6, the amount of ashless dispersant was greater than in the other samples, and the amount of additive package was therefore greater accordingly.

[0084] For the lubricating oil compositions prepared in the Examples and Comparative Examples, various physical properties were measured and calculated according to the above-mentioned measurement methods. The results are shown in Tables 1 and 2.

[0085] As can be seen from Table 1, when the lubricating oil compositions of Examples 1 and 2, which used a molybdenum compound (B) that did not have a dithiocarbamate structure (-N-C(=S)-S-)) or a dithiophosphate structure (-P(=S)-S-)) in the molecule, were filled, a superior shift feeling could be provided compared to when the lubricating oil composition of Comparative Example 1, which did not contain the molybdenum compound (B), was filled. It should be noted that the lubricating oil composition of Comparative Example 2, which used molybdenum dithiocarbamate (MoDTC), raised concerns about clutch slippage before the shift feeling test. It was also confirmed that the lubricating oil compositions of Examples 1 and 2 had clutch friction characteristics equivalent to those of Comparative Examples 1 and 2. Furthermore, it was confirmed from Table 2 that Examples 3 to 7, which used Mg sulfonate as a metal-based detergent, also had good shift feeling and clutch friction characteristics. On the other hand, Comparative Examples 3 to 6, which had a high content of molybdenum compound (B) in terms of molybdenum atoms, resulted in inferior clutch friction coefficients.

Claims

1. A lubricating oil composition comprising a base oil (A) and a molybdenum compound (B) (excluding compounds having a dithiocarbamate structure (-N-C(=S)-S-) or a dithiophosphate structure (-P(=S)-S-) in the molecule), wherein the content of the molybdenum compound (B) is 100 ppm by mass or more and less than 500 ppm by mass, calculated as molybdenum atoms, based on the total amount of the lubricating oil composition.

2. The lubricating oil composition of claim 1, wherein the molybdenum compound (B) comprises a mononuclear molybdenum compound.

3. The lubricating oil composition according to claim 2, wherein the mononuclear molybdenum compound comprises one or more compounds selected from the group consisting of a mononuclear molybdenum compound (B1) represented by the following formula (1) and a molybdenum compound (b2) represented by the following formula (2): a mononuclear molybdenum compound (B1); an amine salt of molybdic acid (B2); molybdenum trioxide (B3); and a molybdenum succinimide complex (B4). (In the above formulas (1) and (2), R represents a fatty oil residue.) 4. The lubricating oil composition according to any one of claims 1 to 3, wherein the content of the molybdenum compound having a dithiocarbamate structure (-N-C(=S)-S-)) in the molecule is less than 0.01 mass% based on the total amount of the lubricating oil composition.

5. A lubricating oil composition according to any one of claims 1 to 4, wherein the content of a molybdenum compound having a dithiophosphate structure (-P(=S)-S-)) in the molecule is less than 0.01 mass% based on the total amount of the lubricating oil composition.

6. The lubricating oil composition according to any one of claims 1 to 5, which is used to lubricate a two-wheeled vehicle having a manual transmission.

7. A two-wheeled vehicle having a manual transmission, filled with the lubricating oil composition according to any one of claims 1 to 5.

8. A method for using the lubricating oil composition according to any one of claims 1 to 5 in a two-wheeled vehicle having a manual transmission.

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