JP2000109872A - Lubricating oil composition for nonstep variable speed gear of metal belt type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain novel lubricating oil compsn. which, when used for nonstep variable speed gears of a metal belt type, can realize a high between-metal friction coefficient between a belt and a pulley. SOLUTION: This compsn. is prepd. by compounding a lube base oil with, based on the compsn., (A) 0.005-0.2 mass % (in terms of phosphorus) at least one phosphorous compd. or its deriv. represented by the formula (wherein R1 and R2 are each independently a 1-6C alkyl, phenyl, or cresyl; R3 is H, a 1-6C alkyl, phenyl, or cresyl; and X1, X2, and X3 are each independently O or S) and (B) 0.05-10.0 mass % ashless dispersant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil composition for a metal belt type continuously variable transmission, and more particularly to a metal belt type continuously variable transmission having excellent friction characteristics between a belt and a pulley in a metal belt type continuously variable transmission. The present invention relates to a lubricating oil composition for a step transmission.

[0002]

2. Description of the Related Art In a metal belt type continuously variable transmission, torque is transmitted by friction between a belt made of metal and a pulley, and transmission is performed by changing a radius ratio of the pulley. In recent years, the transmission has been in the limelight as a transmission for automobiles in view of the fact that energy loss due to shifting is small. As the lubricating oil used in this metal belt type continuously variable transmission, it is extremely important to have excellent friction characteristics and lubrication characteristics between the metal belt and the metal pulley, as well as lubricating oil for gears that extract torque and bearings that support them. The performance as oil and the performance as a hydraulic control medium for determining a gear ratio, that is, the performance as a hydraulic oil are also required. Further, when the continuously variable transmission includes a forward / reverse switching wet clutch or a lockup system for a torque converter, in addition to the above-described performance, a performance for controlling friction characteristics of the wet clutch is also required. As described above, since various performances are required for the lubricating oil for the metal belt type continuously variable transmission, automatic transmission oil (ATF) is generally used. However, when ATF is used as a lubricating oil for a metal belt type continuously variable transmission, although the performance as a hydraulic oil and the function of controlling the friction characteristics of a wet clutch are excellent, the friction coefficient between the metal of the belt and the pulley is increased. Is not enough. Therefore, the conventional metal belt-type continuously variable transmission using the ATF has a problem in that the transmission torque capacity is limited and can be mounted only on a small car. Therefore,
The present invention has been made in view of such circumstances,
Its purpose is to use it in a metal belt type continuously variable transmission,
An object of the present invention is to provide a novel lubricating oil composition for a continuously variable transmission of a metal belt, which can exhibit a high coefficient of friction between metals between a belt and a pulley.

[0003]

In order to achieve the above object, a lubricating oil composition for a metal belt type continuously variable transmission according to the present invention is represented by the following general formula (1) in a lubricating base oil. At least one phosphorus compound or a derivative of at least one phosphorus compound represented by the following general formula (1)
It is called "(A) component". ) Is 0.005 to 0.2 mass% as a phosphorus element amount based on the total amount of the composition;

Embedded image (In the formula (1), R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms, a phenyl group or a cresyl group, R ³ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, A phenyl group or a cresyl group, and X ¹ , X ² and X ³ each independently represent an oxygen atom or a sulfur atom) and an ashless dispersant (hereinafter, referred to as “component (B) component”); It is contained in an amount of 0.05 to 10.0% by mass based on the total amount. Further, the lubricating oil composition for a metal belt-type continuously variable transmission according to the present invention further comprises a total base number of 20 to 500 mg KOH in addition to the components (A) and (B) in the amounts specified above.
/ G of alkaline earth metal sulfonate (hereinafter, referred to as
It is called “(C) component”. ) Is contained in an amount of 0.01 to 0.5% by mass as an alkaline earth metal element based on the total amount of the composition. Further, the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention has a total base number of 20 to 50 in addition to the components (A) and (B) in the specified amounts.
0 mg KOH / g of calcium phenate (hereinafter, referred to as calcium phenate)
It is called “(D) component”. ) Is contained in an amount of 0.01 to 0.5% by mass as a calcium element amount based on the total amount of the composition. Further, the lubricating oil composition for a continuously variable transmission of a metal belt type according to the present invention comprises the components (A) and (B) in the amounts specified above.
In addition to the component and the component (C), the composition further comprises the above specified amount of the component (D). Further, the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention contains the components (A) and (B) in the amounts specified above, and
It does not substantially contain zinc dithiophosphate (hereinafter, referred to as “component (E)”). Further, the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention contains the above specified amounts of the components (A), (B) and (C), and substantially contains the component (E). Is not contained. Further, the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention contains the above specified amounts of the components (A), (B) and (D), and substantially contains the component (E). Is not contained. Further, the lubricating oil composition for a metal belt type continuously variable transmission of the present invention contains the components (A), (B), (C) and (D) in the above-specified amounts, and (E) ) Components are substantially free of components.
It is preferable that all or a part of the component (B) is boron-modified succinimide. Thereby, the lubricating oil composition for a metal belt type continuously variable transmission of the present invention can transmit high torque between the belt and the pulley,
It can also be mounted on large vehicles.

[0004]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described in more detail. As the lubricating base oil in the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention, any mineral oil and / or synthetic oil used as a base oil for ordinary lubricating oils can be used. As the mineral oil, specifically, for example, a lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil, solvent dewatering, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing,
Paraffin-based, naphthene-based oils, normal paraffins, and the like can be used, which are appropriately combined with purification treatments such as hydrorefining, sulfuric acid washing, and clay treatment. The synthetic oil is not particularly limited, but specifically, for example, poly-α
-Olefins (1-octene oligomer, 1-decene oligomer, ethylene-propylene oligomer, etc.) and hydrides thereof, isobutene oligomers and hydrides thereof,
Isoparaffin, alkylbenzene, alkylnaphthalene, diester (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc.), polyol ester (trimethylolpropane caprylate, trimethylolpropaneperargonate) Pentaerythritol 2-ethylhexanoate,
Pentaerythritol pelargonate), polyoxyalkylene glycol, dialkyl diphenyl ether, polyphenyl ether, and the like. The kinematic viscosities of these lubricating base oils are not particularly limited and are arbitrary. Usually, the kinematic viscosities at 100 ° C. are preferably 1 to 10 mm ² / s, more preferably ² to 8 mm ² / s.

The component (A) in the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention comprises at least one phosphorus compound represented by the following general formula (1) or general formula (1):
Is a derivative of a phosphorus compound represented by

Embedded image (1) In the formula, R ¹ and R ² each independently have 1 carbon atom.
To 6, alkyl, phenyl, or cresyl groups. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like (these alkyl groups may be linear or branched). Examples of the cresyl group include an o-cresyl group, an m-cresyl group, and a p-cresyl group. (1) In the formula, R ³ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a cresyl group, preferably a hydrogen atom. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like (these alkyl groups may be linear or branched). Examples of the cresyl group include an o-cresyl group, an m-cresyl group, and a p-cresyl group. (1) In the formula, X ¹ , X ² and X ³ are
Each represents an oxygen atom or a sulfur atom, preferably an oxygen atom. As the component (A) of the present invention, R
It is important that R ¹ , R ² and R ³ are groups having a limited structure as described above. If R ¹ , R ² or R ³ is a group other than the specified groups, the metal between the belt and the pulley It is not preferable because the friction characteristics deteriorate. As the derivative of the phosphorus compound represented by the formula (1), specifically, for example, a hydrogenated phosphite (hydrogen phosphite) wherein R ³ is a hydrogen atom in the above formula (1) or Phosphorus-based compounds such as hydrogenated thiophosphites (hydrogen thiophosphites) include ammonia and nitrogen-containing compounds such as amine compounds containing only a hydrocarbon group having 1 to 8 carbon atoms or a hydroxyl group-containing hydrocarbon group in the molecule. Salts obtained by reacting a compound to neutralize a part or all of the remaining acidic hydrogen are exemplified. As the nitrogen-containing compound, specifically, for example,
Ammonia; monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, monohexylamine, monoheptylamine, monooctylamine, dimethylamine, methylethylamine, diethylamine, methylpropylamine, ethylpropylamine, dipropylamine Alkylamines such as methylbutylamine, ethylbutylamine, propylbutylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine and dioctylamine (the alkyl group may be linear or branched); monomethanolamine, monoethanolamine Amine, monopropanolamine, monobutanolamine, monopentanolamine, monohexanolamine, monoheptanolamine, monooctanol Min, mono nonanol amine,
Dimethanolamine, methanolethanolamine, diethanolamine, methanolpropanolamine, ethanolpropanolamine, dipropanolamine,
Methanol butanolamine, ethanolbutanolamine, propanolbutanolamine, dibutanolamine, dipentanolamine, dihexanolamine,
Alkanolamines such as diheptanolamine and dioctanolamine (alkanol groups may be linear or branched); and mixtures thereof.

As the component (A), hydrogen phosphite (hydrogen phosphite) in which R ³ is hydrogen in the above formula (1) or hydrogen hydride Thiophosphites or amine salts and alkanolamine salts of these phosphorus compounds as described above are more preferably used. Specific examples of the component (A) include dimethyl hydrogen phosphite, diethyl hydrogen phosphite, dipropyl hydrogen phosphite, dibutyl hydrogen phosphite, dipentyl hydrogen phosphite, and dihexyl hydrogen phosphite. Dialkyl hydrogen phosphite (these alkyl groups may be linear or branched), diphenyl hydrogen phosphite, dicresyl hydrogen phosphite (the cresyl group may be o-, m- or p-); Dimethyl hydrogen thiophosphite, diethyl hydrogen thio phosphite, dipropyl hydrogen thio phosphite, dibutyl hydrogen thio phosphite, dipentyl hydrogen thio phosphite, Dialkyl hydrogen thiophosphites such as hexyl hydrogen thio phosphite (these alkyl groups may be linear or branched), diphenyl hydrogen thio phosphite, dicresyl hydrogen thio phosphite (cresyl groups are either o- or m- Or p-), trialkyl phosphites such as trimethyl phosphite, triethyl phosphite, tripropyl phosphite, tributyl phosphite, tripentyl phosphite, and trihexyl phosphite (these alkyl groups may be linear or (Branched), triphenyl phosphite, tricresyl phosphite (cresyl group may be o-, m- or p-), trimethylthiophosphite, triethylthiophosphite, tripropylthiophosphite , Tributyl trithiophosphite, tri pentylthio phosphite,
Trialkylthiophosphites such as trihexylthiophosphite (these alkyl groups may be linear or branched), triphenylthiophosphite, tricresylthiophosphite (cresyl groups are either o- or m-
-Or the above-mentioned amine salts, alkanolamine salts, or a mixture of these phosphorus compounds. Of these, dimethyl dimethyl is preferred because of its excellent metal-to-metal friction characteristics of the belt-pulley. Dialkyl hydrogen phosphites such as hydrogen phosphite, diethyl hydrogen phosphite, dipropyl hydrogen phosphite, dibutyl hydrogen phosphite, dipentyl hydrogen phosphite, dihexyl hydrogen phosphite, etc. Or phenyl, and dicresyl hydrogen phosphite (the cresyl group may be o-, m-, or p-), or a mixture thereof. In the lubricating oil composition for a metal belt type continuously variable transmission of the present invention, the lower limit of the content of one or more arbitrarily selected component (A) is determined based on the total amount of phosphorus element based on the total amount of the lubricating oil composition. 0.005% by mass as an amount,
More preferably, it is 0.01% by mass, while its upper limit is 0.2% as the phosphorus element amount based on the total amount of the lubricating oil composition.
% By mass, preferably 0.1% by mass. The content of the component (A) is 0.1 as phosphorus element amount based on the total amount of the lubricating oil composition.
When the content is less than 005% by mass, the effect of improving the friction coefficient between metals between the belt and the pulley is poor. On the other hand, when the content exceeds 0.2% by mass as the phosphorus element amount based on the total amount of the lubricating oil composition, The oxidation stability of the lubricating oil composition may be reduced, and the durability of the sealing material, the resin material, and the like may be adversely affected.

[0007] The component (B) in the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention is an ashless dispersant. The nitrogen content of the component (B) is optional, but the lower limit of the nitrogen content is preferably 0.2% by mass, more preferably 0.8% by mass, while the upper limit of the nitrogen content is value is,
Preferably it is 10.0% by mass, more preferably 5.0% by mass. When the nitrogen content of the component (B) is less than 0.2% by mass, the lubricating oil composition may be insufficiently clean and dispersible. On the other hand, when the nitrogen content exceeds 10.0% by mass, the lubricating oil It may adversely affect the abrasion resistance and oxidation stability of the composition. Specific examples of the ashless dispersant (B) include a nitrogen-containing compound having at least one alkyl group or alkenyl group having 40 to 400 carbon atoms in a molecule or a derivative thereof. One or two or more arbitrarily selected from the above can be blended. The alkyl group or alkenyl group may be linear or branched, but is preferably, for example, propylene, 1-butene, an oligomer of an olefin such as isobutylene or a co-oligomer of ethylene and propylene. Derived branched alkyl groups and branched alkenyl groups are exemplified. The alkyl group or alkenyl group may have any number of carbon atoms, but preferably has 40 to 400, more preferably 60 to 350. When the number of carbon atoms of the alkyl group or the alkenyl group is less than 40, the solubility of the compound in a lubricating base oil may decrease. On the other hand, when the number of carbon atoms of the alkyl group or the alkenyl group exceeds 400, the lubricating oil composition It is not preferable because the low-temperature fluidity of the material may be deteriorated.

Specific examples of the nitrogen-containing compound or its derivative include (B-1) succinimide having at least one alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule, or a derivative thereof ( B-2) Benzylamine having at least one alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule, or a derivative thereof (B-3) At least one alkyl group or alkenyl group having 40 to 400 carbon atoms in the molecule One or two or more compounds selected from polyamines having one or derivatives thereof. More specifically, examples of the succinimide (B-1) include compounds represented by the following general formula (2) or (3).

Embedded image (In the formula (2), R ⁴ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms;
Represents an integer of 1 to 5, preferably 2 to 4. )

Embedded image (In the formula (3), R ³ and R ⁴ each independently have 4 carbon atoms.
It represents an alkyl or alkenyl group of 0 to 400, preferably 60 to 350, and b represents an integer of 0 to 4, preferably 1 to 3. In addition, as succinimide, upon imidization,
A so-called mono-type succinimide having a succinic anhydride added to one end of a polyamine and a so-called bis-type such as a general formula (3) having succinic anhydride added to both ends of a polyamine. There is a succinimide of any one of the (B-1) component,
Also, a mixture of these can be used. (B-
2) As benzylamine, more specifically, for example,
Examples include compounds represented by the general formula (4).

Embedded image (In the formula (4), R ⁷ represents an alkyl group or alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms;
Represents an integer of 1 to 5, preferably 2 to 4. The method for producing this benzylamine is not limited at all. For example, a polyolefin such as a propylene oligomer, polybutene, or ethylene-α-olefin copolymer is reacted with phenol to form an alkylphenol, which is then reacted with formaldehyde. It can be obtained by reacting a polyamine such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine by a Mannich reaction. More specifically, the (B-3) polyamine includes, for example, a compound represented by the general formula (5).

Embedded image (In the formula (5), R ⁸ represents an alkyl group or an alkenyl group having 40 to 400 carbon atoms, preferably 60 to 350 carbon atoms;
Represents an integer of 1 to 5, preferably 2 to 4. The method for producing the polyamine is not limited at all. For example, after chlorinating a polyolefin such as propylene oligomer, polybutene, and ethylene-α-olefin copolymer, the polyamine is added to ammonia, ethylenediamine, diethylenetriamine, and triethylene. It can be obtained by reacting a polyamine such as tetramine, tetraethylenepentamine and pentaethylenehexamine. As the derivative of the nitrogen-containing compound, specifically, for example, a monocarboxylic acid having 2 to 30 carbon atoms (eg, fatty acid), oxalic acid, phthalic acid, trimellitic acid, A so-called carboxylic acid-modified compound obtained by reacting a polycarboxylic acid having 2 to 30 carbon atoms such as merit acid to neutralize or amidate a part or all of the remaining amino group and / or imino group; A sulfur-modified compound obtained by allowing a sulfur compound to act on such a nitrogen-containing compound;
So-called boron-modified compounds in which the above-mentioned nitrogen-containing compounds or their carboxylic acid-modified or sulfur-modified compounds are modified with boron compounds can be exemplified. The method of modification with the boron compound is not limited at all, and any method is possible.For example, the above-described nitrogen-containing compound or a derivative thereof may be added to boric acid, a borate, or a borate ester. Examples of the method include a method of reacting a boron compound to neutralize or amidate a part or all of amino groups and / or imino groups remaining in a nitrogen-containing compound or a derivative thereof. The boric acid mentioned here specifically includes, for example, orthoboric acid, metaboric acid and tetraboric acid. Specific examples of the borate include alkali metal salts, alkaline earth metal salts and ammonium salts of boric acid, and more specifically, for example, lithium metaborate, lithium tetraborate, Lithium borate such as lithium borate and lithium perborate; sodium borate such as sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, and sodium octaborate; metaborate Potassium borate such as potassium, potassium tetraborate, potassium pentaborate, potassium hexaborate, potassium octaborate; calcium metaborate, calcium diborate, tricalcium tetraborate, pentacalcium tetraborate, hexaborate Calcium borate such as calcium phosphate; magnesium metaborate, magnesium diborate, tetraborate Trimagnesium pentoxide magnesium tetraborate, hexaborate magnesium such as magnesium borate; and ammonium metaborate, ammonium tetraborate, ammonium pentaborate, and ammonium borate, such as eight ammonium borate and the like. Examples of the borate ester include an ester of boric acid and preferably an alkyl alcohol having 1 to 6 carbon atoms, and more specifically, for example, monomethyl borate, dimethyl borate, trimethyl borate, monoethyl borate And diethyl borate, triethyl borate, monopropyl borate, dipropyl borate, tripropyl borate, monobutyl borate, dibutyl borate, tributyl borate and the like.

As the component (B) of the present invention, any of the above-mentioned nitrogen-containing compounds or their derivatives can be used, but when used in combination with the component (A), the metal belt type continuously variable transmission can be used. From the viewpoint that the effect of improving the friction coefficient between metals between the belt and the pulley is excellent, the above-mentioned (B-1) carbon number of 40 to 4 is used.
Succinimide having at least one alkyl group or alkenyl group of 00 in the molecule, or a boron-modified product thereof is preferably used. Further, as the component (B) of the present invention, when used in combination with the component (A), the boron-modified succinic acid is more excellent in the effect of improving the friction coefficient between metals between the belt and the pulley of the metal belt type continuously variable transmission. It is desirable to use an imide or a mixture of boron-modified succinimide and boron-free succinimide. The boron content of the boron-modified succinimide is also optional,
The lower limit of the content is preferably 0.1% by mass, from the viewpoint of improving the friction coefficient between metals between the belt and the pulley of the metal belt-type continuously variable transmission, and having excellent wear resistance and oxidation stability. It is preferably 0.4% by mass, while the upper limit of the content is preferably 4.0% by mass, more preferably 2.5% by mass. In the lubricating oil composition for a metal belt type continuously variable transmission of the present invention, the lower limit of the content of one or more arbitrarily selected components (B) is 0 based on the total amount of the lubricating oil composition. It is 0.05 mass%, preferably 0.1 mass%, while the upper limit of the content is 10.0 mass%, preferably 7.0 mass%, based on the total amount of the lubricating oil composition. When the content of the component (B) is less than 0.05% by mass based on the total amount of the lubricating oil composition, the effect of improving the friction coefficient between the belt and the pulley by using the component (A) in combination is poor. (B) The content of the component is 10.
If the amount exceeds 0% by mass, the low-temperature fluidity of the lubricating oil composition is significantly deteriorated, which is not preferable.

Further, the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention further comprises (C) a total base number of 20 to 5;
It is preferable to contain 00 mg KOH / g of alkaline earth metal sulfonate. By using the component (C) in combination, it is possible to improve the metal-to-metal friction characteristic between the belt and the pulley in the metal belt type continuously variable transmission (reduce the slip speed dependence of the friction coefficient). The lower limit of the total base number of the alkaline earth metal sulfonate of the component (C) is 20 mgKOH / g, preferably 100 mgKOH / g.
/ G, more preferably 150 mg KOH / g, while the upper limit is 500 mg KOH / g, more preferably 450 mg KOH / g. 20mg total base number
If it is less than KOH / g, the oxidation stability of the lubricating oil composition may be degraded, while the total base number is 500 mg KOH / g.
If it exceeds / g, the storage stability of the lubricating oil composition may be adversely affected, which is not preferred. The term “total base number” as used herein refers to JIS K2501 “Petroleum products and lubricating oils-Neutralization number test method”. Means the total base number measured by the perchloric acid method in accordance with
As the alkaline earth metal sulfonate of the component (C), more specifically, for example, a molecular weight of 100 to 1500,
Alkaline earth metal salts of alkyl aromatic sulfonic acids obtained by sulfonating alkyl aromatic compounds of preferably 200 to 700 are preferably used,
Specific examples of the alkyl aromatic sulfonic acid include so-called petroleum sulfonic acid and synthetic sulfonic acid. As the petroleum sulfonic acid, generally, a sulfonated alkyl aromatic compound of a lubricating oil fraction of a mineral oil, so-called mahoganic acid, which is a by-product of white oil production, is used. Examples of the synthetic sulfonic acid include, as a raw material, an alkylbenzene having a linear or branched alkyl group, which is obtained as a by-product from an alkylbenzene production plant that is a raw material of a detergent or obtained by alkylating a polyolefin to benzene. A sulfonated product thereof, or a sulfonated product of dinonylnaphthalene is used. The sulfonating agent for sulfonating these alkyl aromatic compounds is not particularly limited, but fuming sulfuric acid or sulfuric acid is usually used. The alkaline earth metal sulfonate of the component (C) can be directly treated with the above-mentioned alkyl aromatic sulfonic acid or the like as long as the base number is in the range of 20 to 500 mgKOH / g. Neutral salt (normal salt) obtained by reacting with an alkaline earth metal base such as sodium or hydroxide, or once replacing an alkali metal salt such as a sodium salt or potassium salt with an alkaline earth metal salt, etc. In the presence of carbon dioxide gas or a basic salt obtained by heating excess alkaline earth metal salt or alkaline earth metal base (hydroxide or oxide of alkaline earth metal) in the presence of water. And overbased salts (ultrabasic salts) obtained by reacting a neutral salt (normal salt) with a base of an alkaline earth metal. These reactions are:
Usually, it is carried out in a solvent (aliphatic hydrocarbon solvent such as hexane, aromatic hydrocarbon solvent such as xylene, light lubricating base oil, etc.). In addition, the metal-based detergent is usually commercially available in a diluted state with a light lubricating base oil or the like, and is available, but generally has an alkaline earth metal content of 1.
It is desirable to use one having 0 to 20% by mass, preferably 2.0 to 16% by mass. Specific examples of the alkaline earth metal include calcium, magnesium, barium and the like, and calcium is particularly preferable because it is more excellent in the frictional property between metals of the belt-pulley. When one or more arbitrarily selected components (C) are used in combination in the lubricating oil composition for a metal belt type continuously variable transmission of the present invention, the lower limit of the content is determined by the lubricating oil composition It is 0.01% by mass, preferably 0.03% by mass, based on the total amount of the alkaline earth metal element, while the upper limit is 0.5%, based on the total amount of the lubricating oil composition. % By mass, preferably 0.2% by mass.
When the content of the component (C) is less than 0.01% by mass as the amount of the alkaline earth metal element based on the total amount of the lubricating oil composition, the metal of the belt-pulley of the lubricating oil composition in combination with the component (C) is used. When the effect of improving the inter-frictional properties is poor, and when the content exceeds 0.5% by mass as the amount of alkaline earth metal element based on the total amount of the lubricating oil composition, the oxidation stability of the lubricating oil composition decreases. It is not preferable because there is a fear.

Further, the lubricating oil composition for a continuously variable transmission of a metal belt type according to the present invention further comprises (D) a total base number of 20 to 5;
Preferably, it contains 00 mg KOH / g calcium phenate. By using the component (D) in combination,
It becomes possible to further improve the friction characteristics between the metal and the belt-pulley in the metal belt type continuously variable transmission (reduce the slip speed dependence of the friction coefficient). The lower limit of the total base number of the calcium phenate of the component (D) is 20 mgK
OH / g, preferably 100 mg KOH / g, more preferably 150 mg KOH / g, while its upper limit is 500 mg KOH / g, more preferably 450 mg KOH / g.
KOH / g. When the total base number is less than 20 mgKOH / g, the oxidation stability of the lubricating oil composition may be deteriorated. On the other hand, when the total base number exceeds 500 mgKOH / g, the storage stability of the lubricating oil composition is adversely affected. Respectively, which is not preferable. The term “total base number” as used herein refers to JIS K2501 “Petroleum products and lubricating oils-Neutralization number test method”. Means the total base number measured by the perchloric acid method in accordance with As the calcium phenate of the component (D), more specifically, for example, an alkylphenol having at least one linear or branched alkyl group having 4 to 30 carbon atoms, preferably 6 to 18 carbon atoms; An alkyl phenol sulfide obtained by reacting an alkyl phenol with elemental sulfur or a calcium salt of methylene bisalkyl phenol obtained by subjecting this alkyl phenol and acetone to a condensation dehydration reaction is preferably used. The calcium phenate of the component (D) has a total base number of 20 to 500 mg KOH.
/ G, the above-mentioned alkylphenol, alkylphenol sulfide, Mannich reaction product of alkylphenol or the like is directly reacted with a calcium base such as calcium oxide or hydroxide, or once sodium salt or potassium. A neutral salt (normal salt) obtained by substituting a calcium salt with an alkali metal salt such as a salt in the presence of excess calcium salt or calcium base (calcium hydroxide or oxide) in the presence of water Basic salts obtained by heating and overbased salts (ultrabasic salts) obtained by reacting a neutral salt (normal salt) with a calcium base in the presence of carbon dioxide gas are included. These reactions are usually performed in a solvent (such as an aliphatic hydrocarbon solvent such as hexane, an aromatic hydrocarbon solvent such as xylene, or a light lubricating base oil). Metal-based detergents are usually marketed in a diluted state with a light lubricating base oil or the like, and are available, but generally have a calcium content of 1.0 to 20% by mass. , Preferably 2.0 to 16% by mass. In the metal belt type continuously variable transmission lubricating oil composition of the present invention,
When one or two or more arbitrarily selected components (D) are used in combination, the content is arbitrary, but usually the lower limit is 0.1% as the calcium element amount based on the total amount of the lubricating oil composition. It is 0.01% by mass, preferably 0.03% by mass, while its upper limit is 0.5% by mass, preferably 0.2% by mass as a calcium element amount based on the total amount of the lubricating oil composition. When the content of the component (D) is less than 0.01% by mass as the calcium element amount based on the total amount of the lubricating oil composition, the frictional property between the metal and the belt-pulley of the lubricating oil composition in combination with the component (D) is used. When the content exceeds 0.5% by mass as the calcium element amount based on the total amount of the lubricating oil composition, the oxidation stability of the lubricating oil composition may be reduced. Not preferred.

In the present invention, the lubricating base oil may contain only a specific amount of each of the components (A) and (B), and further, if necessary, the components (C) and / or (D). A lubricating oil composition for a metal belt type continuously variable transmission excellent in the effect of improving the friction coefficient between metals between the belt and the pulley can be obtained only by using one or two or more compounds selected from among them. However, for the purpose of further improving its performance, if necessary, extreme pressure additives, friction modifiers, viscosity index improvers, pour point depressants, antioxidants, corrosion inhibitors, rubber swelling agents, defoamers Various additives typified by agents, coloring agents, etc. may be contained alone or in combination of several types.

Examples of extreme pressure additives include zinc dithiophosphates, disulfides, sulfurized olefins, sulfurized oils and fats, phosphates and phosphites other than the component (A) of the present invention, and phosphorus-based compounds thereof. And phosphorus-based compounds such as derivatives of the above. One or more compounds arbitrarily selected from these are
Any amount can be contained, but usually, the content is 0.01 to 5.0% by mass based on the total amount of the lubricating oil composition.
It is desirable that However, it is desirable that the lubricating oil composition for a metal belt type continuously variable transmission of the present invention does not substantially contain (E) zinc dithiophosphate. Here, "substantially does not contain the component (E)" means that the component (E) is not contained at all, or
Even if contained, it means that the content of the component (E) is 0.03% by mass or less as a zinc element amount based on the total amount of the lubricating oil composition, and in the present invention, the component (E) is More preferably, it is not contained at all. In the lubricating oil composition for a metal belt type continuously variable transmission of the present invention, when (E) zinc dithiophosphate is contained in an amount of more than 0.03% by mass as a zinc element amount based on the total amount of the lubricating oil composition, the belt -The durability of the friction coefficient between metals between the pulleys is deteriorated, and the friction coefficient is likely to be reduced during oil deterioration. In addition, as the component (E), specifically,
Examples include zinc dithiophosphate represented by the following general formula (6).

Embedded image In the above formula, R ⁹ , R ¹⁰ , R ¹¹ and R ¹² each independently represent an alkyl group having 1 to 18 carbon atoms, an aryl group or an alkylaryl group having 7 to 18 carbon atoms. As the alkyl group, specifically, a methyl group, an ethyl group, a propyl group,
Butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl,
Examples thereof include a hexadecyl group, a heptadecyl group, and an octadecyl group. Particularly, an alkyl group having 3 to 8 carbon atoms is generally used. These alkyl groups include both linear and branched ones. They also include primary (primary) and secondary (secondary) alkyl groups. R ⁹ ,
When introducing R ¹⁰ , R ¹¹ and R ¹² , a mixture of α-olefins may be used as a raw material. In this case, as the compound represented by the formula (6), a dialkyldithioline having an alkyl group having a different structure as the compound represented by the formula (6) It becomes a mixture of zinc acid. Specific examples of the aryl group include a phenyl group and a naphthyl group. Specific examples of the alkylaryl group include a tolyl group, a xylyl group, an ethylphenyl group, a propylphenyl group, a butylphenyl group, a pentylphenyl group, a hexylphenyl group, a heptylphenyl group, an octylphenyl group, a nonylphenyl group, and a decyl group. Phenyl group,
And an undecylphenyl group, a dodecylphenyl group, and the like (these alkyl groups include both linear and branched ones, and all substituted isomers).

As the friction modifier which can be used in combination with the lubricating oil composition for a metal belt type continuously variable transmission of the present invention, any compound usually used as a friction modifier for lubricating oils can be used. An amine compound, a fatty acid amide, a fatty acid metal salt, a phosphoric acid ester, having at least one linear alkyl group or linear alkenyl group having 8 to 24 carbon atoms, particularly a linear alkyl group or linear alkenyl group having 8 to 24 carbon atoms, Phosphite and the like. As the amine compound, an aliphatic monoamine having a straight-chain or branched alkyl group or alkenyl group having 6 to 30 carbon atoms, preferably a straight-chain alkyl group or alkenyl group having 8 to 24 carbon atoms, Aliphatic polyamines having 6 to 30 linear or branched alkyl or alkenyl groups, preferably having 8 to 24 carbon atoms, or aliphatic (poly) amines having these aliphatic (poly) amines; Examples thereof include alkylene oxide adducts. Examples of the fatty acid amide include a fatty acid having a linear or branched alkyl or alkenyl group having 6 to 30 carbon atoms, preferably a linear alkyl or alkenyl group having 8 to 24 carbon atoms, and an aliphatic monoamine. Alternatively, an amide with an aliphatic polyamine can be exemplified. Examples of the fatty acid metal salt include alkaline earth salts of fatty acids having a straight-chain or branched alkyl group or alkenyl group having 6 to 30 carbon atoms, preferably a straight-chain alkyl group or alkenyl group having 8 to 24 carbon atoms. Metal salts (such as magnesium salts and calcium salts) and zinc salts can be exemplified. As the phosphate ester, a linear or branched alkyl or alkenyl group having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms.
Phosphoric acid triesters having three linear alkyl or alkenyl groups in one molecule, acid phosphates (acid phosphates) having one or two alkyl or alkenyl groups in one molecule, etc. Can be illustrated.
As the phosphite, a straight-chain or branched alkyl or alkenyl group having 6 to 30 carbon atoms, preferably a straight-chain alkyl or alkenyl group having 8 to 24 carbon atoms, is contained in one molecule. Phosphite triester having one or one such alkyl group or alkenyl group in one molecule.
Or a hydrogenated phosphite (hydrogen phosphite) having two or the like can be exemplified. In the present invention,
One or two or more compounds arbitrarily selected from these friction modifiers can be contained in an arbitrary amount. Usually, the content is 0.1% based on the total amount of the lubricating oil composition. 01 to 5.0 mass%, preferably 0.03 to
It is desirably 3.0% by mass.

The viscosity index improver which can be used in combination with the lubricating oil composition for a metal belt type continuously variable transmission of the present invention is, specifically, one or two selected from various methacrylates.
Examples include so-called non-dispersion type viscosity index improvers such as copolymers of two or more kinds of monomers or hydrogenated products thereof, and so-called dispersion type viscosity index improvers obtained by copolymerizing various methacrylates containing nitrogen compounds. . Specific examples of other viscosity index improvers include non-dispersed or dispersed ethylene-α-olefin copolymers (α-olefins include propylene, 1-butene, and 1-pentene).
And its hydride, polyisobutylene and its hydrogenated product,
There are styrene-diene hydrogenated copolymer, styrene-maleic anhydride copolymer and polyalkylstyrene. It is necessary to select the molecular weight of these viscosity index improvers in consideration of shear stability. Specifically, the number average molecular weight of the viscosity index improver is, for example, 5,000 to 15 in the case of a dispersion type and a non-dispersion type polymethacrylate.
000, preferably 5,000 to 35,000 is polyisobutylene or a hydride thereof in the case of polyisobutylene.
If the ethylene-α-olefin copolymer or its hydride is 800 to 150,000, preferably 3, 0 to 5,000, preferably 1,000 to 4,000,
2,000 to 12,000 are preferred. When an ethylene-α-olefin copolymer or a hydride thereof is used among these viscosity index improvers, a lubricating oil composition having particularly excellent shear stability can be obtained. In the present invention, one or two or more compounds arbitrarily selected from these viscosity index improvers can be contained in an optional amount. It is desirably 0.1 to 40.0% by mass based on the total amount of the substance.

Antioxidants which can be used in combination with the lubricating oil composition for a metal belt type continuously variable transmission of the present invention include those generally used in lubricating oils such as phenolic compounds and amine compounds. Can be used. Specifically, 2-
Alkylphenols such as 6-di-tert-butyl-4-methylphenol, bisphenols such as methylene-4,4-bisphenol (2,6-di-tert-butyl-4-methylphenol), phenyl-α-naphthylamine Such as naphthylamines, dialkyldiphenylamines, (3,5-di-tert-butyl-4-hydroxyphenyl) fatty acid (such as propionic acid) and a monohydric or polyhydric alcohol such as methanol, octadecanol, 1,6- Examples include esters with hexadiol, neopentyl glycol, thiodiethylene glycol, triethylene glycol, pentaerythritol, and the like. In the present invention, one or two or more compounds arbitrarily selected from these antioxidants can be contained in an arbitrary amount. It is desirably 0.01 to 5.0% by mass based on the total amount.

Examples of the corrosion inhibitor usable in combination with the lubricating oil composition for a metal belt type continuously variable transmission of the present invention include benzotriazole, thiadiazole and imidazole compounds. In the present invention, one or more compounds arbitrarily selected from these corrosion inhibitors can be contained in an arbitrary amount. 0 based on the total amount.
It is desirably from 0.1 to 3.0% by mass.

Examples of the antifoaming agent which can be used in combination with the lubricating oil composition for a metal belt type continuously variable transmission of the present invention include silicones such as dimethyl silicone and fluorosilicone. In the present invention, one or more compounds arbitrarily selected from these defoamers are
Although it can be contained in any amount, it is generally desirable that the content is 0.001 to 0.05% by mass based on the total amount of the lubricating oil composition.

The colorant that can be used in combination with the lubricating oil composition for a metal belt type continuously variable transmission of the present invention is optional and can be contained in any amount. It is desirable that the content is 0.001 to 1.0% by mass based on the total amount of the composition.

[0020]

EXAMPLES Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Test 1] A lubricating oil composition for a belt type continuously variable transmission according to the present invention having the compositions shown in Examples 1 to 3 of Table 1 was prepared, and Comparative Examples 1 to 3 of Table 2 were prepared. Comparative lubricating oil compositions having the indicated compositions were each prepared.

[0022]

[Table 1]

[0023]

[Table 2]

For each of the adjusted compositions, the "Standard Test Method for Calibration and Operati" specified in ASTM D2714-94 was evaluated in order to evaluate the friction characteristics between the belt and the pulley of the metal belt type continuously variable transmission.
on of Falex Block-on-Ring Friction and Wear Testin
g Machine ", the LFW-1 friction test was performed under the following conditions, and the friction coefficient was determined from the friction force measured at each sliding speed. The results are shown in Fig. 1. Test condition ring: Falex S-10 Test Ring (SAE 4620 Steel) Block: Falex H-60 Test Block (SAE 01 Steel) Oil Temperature: 100 ° C Maximum Hertz Pressure at Contact of Test Specimen: 0.287 GPa Sliding Speed: 0-25 cm / s As is clear from the results, the lubricating oil compositions of Examples 1 to 3 containing the component (A) and the component (B) according to the present invention are the compositions of comparative examples using a phosphorus compound other than the component (A). It can be seen that the coefficient of friction between metals is higher than that of the material.

[Test 2] In the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention, the effect of (C) the use of an alkaline earth metal sulfonate on the intermetallic friction characteristics was evaluated. Lubricating oil compositions having the compositions shown in Examples 4 to 8 were respectively prepared.

[0026]

[Table 3]

For each of the adjusted compositions (compositions shown in Examples 4 to 8) and the compositions of Example 1 shown in Table 1 and Comparative Example 1 shown in Table 2, a metal belt type continuously variable transmission was used. In order to evaluate the metal-to-metal friction characteristic between the belt and the pulley of the machine, the same conditions as in Test 1 (except that the sliding speed was 0 to 10)
LFW-1 friction test was performed at 0 cm / s), and the friction coefficient was determined from the friction force measured at each sliding speed. The result is shown in FIG. As is clear from the results in FIG. 2, the lubricating oil composition for a metal belt type continuously variable transmission of the present invention significantly improved intermetal friction characteristics by using (C) an alkaline earth metal sulfonate in combination (friction coefficient). It can be seen that the slip speed dependency of the slab can be reduced.

[Test 3] In the lubricating oil composition for a metal belt type continuously variable transmission of the present invention, to evaluate the effect of (D) the use of calcium phenate on the intermetallic friction characteristics,
Lubricating oil compositions having the compositions shown in Examples 9 to 11 in Table 4 were respectively prepared.

[0029]

[Table 4]

For each of the adjusted compositions (compositions shown in Examples 9 to 11) and the compositions of Example 1 shown in Table 1 and Comparative Example 1 shown in Table 2, a metal belt type continuously variable transmission was used. In order to evaluate the frictional property between the metal and the belt-pulley, the same conditions as in Test 1 (except that the sliding speed was 0 to 10)
LFW-1 friction test was performed at 0 cm / s), and the friction coefficient was determined from the friction force measured at each sliding speed. The result is shown in FIG. As is evident from the results of FIG. 3, in the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention, by using (D) calcium phenate together with the metal (C) component, It can be seen that the inter-frictional characteristics can be greatly improved (the slip speed dependence of the friction coefficient can be reduced).

[Test 4] In the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention, (E) the influence of the combined use of zinc dithiophosphate on the intermetallic friction characteristics was investigated. Lubricating oil compositions having compositions shown in Tables 1 to 14 were prepared.

[0032]

[Table 5]

With respect to each of the adjusted compositions (compositions shown in Examples 12 to 14), in order to evaluate the frictional property between metal and the belt-pulley during the deterioration, the test 1 and the new oil were used. Under the same conditions (however, the maximum hertz pressure at the test piece contact portion was 0.574 GPa, and the slip speed was 0 to
LFW-1 friction test was performed at 100 cm / s), and the friction coefficient was determined from the friction force measured at each sliding speed. As for the deteriorated oil, new oil is used according to JIS K25.
Deterioration under conditions of test temperature 150 ° C and test time 144 hours in accordance with “4. Test method of oxidation stability of lubricating oil for internal combustion engine” in “Test method of lubricating oil-oxidation stability” specified in 14-1993. Created by Figure 4 shows the results with new oil
FIG. 5 shows the results for the deteriorated oil. FIG.
As is clear from the results of FIG. 5 and FIG. 5, in the lubricating oil composition for a metal belt type continuously variable transmission according to the present invention, when (E) zinc dithiophosphate is contained in an amount of more than 0.03% by mass of elemental zinc. It can also be seen that the durability of the intermetallic friction coefficient is greatly reduced.

[0034]

As described above, according to the present invention, a lubricating oil composition for a metal belt type continuously variable transmission which can exhibit a high friction coefficient between metals between a belt and a pulley can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a coefficient of friction and a sliding speed.

FIG. 2 is a diagram showing a relationship between a coefficient of friction and a sliding speed.

FIG. 3 is a diagram showing a relationship between a friction coefficient and a slip speed.

FIG. 4 is a diagram showing a relationship between a friction coefficient and a slip speed.

FIG. 5 is a diagram showing a relationship between a coefficient of friction and a sliding speed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) (C10M 163/00 137: 04 139: 00 159: 24 159: 22) C10N 10:04 30:04 30: 06 40:04 60:14 (72) Inventor Shinichi Shirahama 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Pref. Nippon Oil & Oil Co., Ltd. F-term (reference) 4H104 BF03R BH02C BH06C BH07C BJ05C BJ05R DA02A DB06C DB07C EA22C EB02 EB07 FA02 JA18 LA03 PA03 PA50

Claims (5)

[Claims] 1. A lubricating base oil comprising (A) at least one phosphorus compound represented by the following general formula (1) or a derivative thereof as a phosphorus element amount of 0.0
05 to 0.2% by mass, (In the formula (1), R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms, a phenyl group or a cresyl group, R ³ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, A phenyl group or a cresyl group, and X ¹ , X ² and X ³ each independently represent an oxygen atom or a sulfur atom) and (B) an ashless dispersant in an amount of 0.05 to 1 based on the total amount of the composition.
A lubricating oil composition for a metal belt type continuously variable transmission, comprising 0.0% by mass. 2. The lubricating oil composition for a metal belt type continuously variable transmission according to claim 1, wherein all or a part of the component (B) is boron-modified succinimide. 3. The lubricating oil composition for a metal belt type continuously variable transmission according to claim 1, further comprising (C) an alkaline earth metal sulfonate having a total base number of 20 to 500 mgKOH / g. A lubricating oil composition for a metal belt type continuously variable transmission, comprising 0.01 to 0.5% by mass as an alkaline earth metal element on a total amount basis. 4. The lubricating oil composition for a metal belt type continuously variable transmission according to claim 1, further comprising (D) a calcium phenate having a total base number of 20 to 500 mgKOH / g. A lubricating oil composition for a metal belt type continuously variable transmission, characterized by containing 0.01 to 0.5% by mass as a calcium element amount based on the total amount. 5. The lubricating oil composition for a metal belt type continuously variable transmission according to claim 1, wherein (E) zinc dithiophosphate is not substantially contained. Lubricating oil composition for metal belt type continuously variable transmission.