JP2008115267A - Sliding member having low friction and lubricating oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding member having low friction, improved in friction characteristics by applying to a space between a sliding surface having a diamond-like carbon film and an organic material and a lubricating oil composition used for the member. <P>SOLUTION: The sliding member having low friction is obtained by interposing a lubricating oil composition containing one kind of ash-free friction regulating agent selected from a heterocyclic compound derived from a compound selected from pyridines, pyrroles, pyrimidines, pyrazoles, pyridazines, indazoles, pyrazines, triazines, triazoles, tetrazoles, oxazoles, oxadiazoles, thiadiazoles, furans, dioxanes, pyrans and thiphens, and acid amides, aliphatic esters and aliphatic amines, and base oil on a sliding surface between a sliding part having a diamond-like carbon film and an organic material. The lubricating oil composition is used for the sliding member having low friction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a low friction sliding member having a lubricating oil composition containing an ashless friction modifier composed of a heterocyclic compound having a specific chemical structure on a sliding surface made of a combination of specific materials, and the like. The present invention relates to a lubricating oil composition used in the above. More specifically, the present invention relates to a low-friction sliding member in which the lubricating oil composition is interposed on a sliding surface between a sliding portion having a diamond-like carbon film at least partially and an organic material, and a lubricating oil composition used therefor .

  Sealing devices such as hydraulic cylinders and lip seals are required to have low frictional resistance, excellent adhesion, and no leakage of lubricating oil. In the case of a rubber material such as nitrile butadiene rubber (NBR), the frictional resistance is large. On the other hand, in the case of a fluororesin, although the frictional resistance is reduced, it is difficult to ensure sufficient adhesion between the seal members.

  In order to reduce the frictional resistance in the sealing device, there is one in which the rubber material of the seal portion is coated with diamond-like carbon (DLC) (Patent Document 1). However, when the rubber material is coated with DLC, peeling and cracking are likely to occur and there is a problem in durability.

JP 2003-343632 A

  This invention makes it a subject to provide the low-friction sliding member for sealing devices, and the lubricating oil composition used for this.

The inventors of the present invention have studied to improve the frictional characteristics of the sliding portion between the DLC-coated sliding portion and the organic material, and as a result, the sliding surface between the sliding surface coated with the DLC coating on the metal material and the organic material. As a ashless friction reducer for surfaces, the present inventors have found that a low friction sliding member can be obtained by interposing a lubricating oil composition containing a heterocyclic compound having a specific chemical structure, etc., and completed the present invention. .
That is, the present invention provides the following (1) to (11).
(1) Between the sliding surface having a diamond-like carbon film at least in part and the organic material, the following general formula (I)

[In the general formula (I), X ¹ , X ² and X ³ represent at least one element selected from N or NH (N is nitrogen), O (oxygen), S (sulfur), each of which is different These elements may be used. (C) x, (C) y and (C) v each represents an alkylene group or an alkylene group residue in which R ¹ , R ² or Y ¹ and Y ² are substituted. x and y are 0 to 2, v is an integer of 0 to 5 (when p is 1, as described later, v is an integer of 0 to 3), m and n are 0 or 1, m, n, v Are not 0 at the same time. R ¹ and R ² are each a hydrogen atom or an alkyl group having 6 to 30 carbon atoms, alkenyl group, alkyl and alkenylamino group, alkyl and alkenylamide group, alkyl and alkenyl ether group, alkyl and alkenyl carboxyl group, cycloalkyl R ¹ and R ² may be the same or different, and when p is 0, R ¹ and R ² are not hydrogen atoms at the same time. Y ¹ and Y ² include a functional group or the same functional group selected from a hydrogen atom or hydrocarbon residue, amino group, amide group, hydroxyl group, carbonyl group, aldehyde group, carboxyl group, ester group, ether group, halogen atom A hydrocarbon residue or a group obtained by adding a hydrocarbon residue containing the same functional group to the same functional group. Z is the following structural unit (II)

P is 0 or 1. X ⁴ represents any element selected from N or NH (N is nitrogen), O (oxygen), and S (sulfur). (C) w, (C) u and (C) t each represent an alkylene group or a residue of an alkylene group substituted with R ³ , R ⁴ or Y ³ . w is 0 to 2, u is 0 to 4, k is 0 to 2, t is an integer of 0 to 3, and when p is 1, v is an integer of 0 to 3. R ³ and R ⁴ may be the same or different, but R ¹ , R ² , R ³ and R ⁴ are not simultaneously hydrogen atoms. Y ³ is a hydrogen atom or a hydrocarbon residue, an amino group, an amide group, a hydroxyl group, a carbonyl group, an aldehyde group, a carboxyl group, an ester group, an ether group, a functional group selected from a halogen atom or a hydrocarbon residue containing the same functional group. It is a group. The cyclic part in the general formula (I) and the structural unit (II) may have a double bond]
And a low-friction friction comprising a lubricating oil composition containing a base oil and at least one ashless friction modifier selected from acid amides, aliphatic esters, and aliphatic amines. Moving members,
(2) Low in the above (1), wherein p in the general formula (I) is 0, and X ¹ , X ² and X ³ are any elements selected from N (nitrogen) or O (oxygen) Friction sliding member,
(3) In the above (1), p in the general formula (I) is 1, and X ¹ , X ² , X ³ and X ⁴ are any elements selected from N (nitrogen) or O (oxygen) Low friction sliding member as described,
(4) The general formula (I) is a pyridine, pyrrole, pyrimidine, pyrazole, pyridazine, indazole, pyrazine, triazine, triazole, tetrazole, oxazole, oxadiazole, thiazole, The low friction sliding member according to any one of the above (1) to (3), which has a heterocyclic skeleton derived from a compound selected from thiadiazoles, furans, dioxanes, pyrans, and thiophenes,
(5) The low friction sliding member according to any one of (1) to (4), which is used under wet conditions,
(6) The low friction sliding member according to any one of (1) to (5), wherein the diamond-like carbon film is an amorphous carbon-based material having a hydrogen content of 5 atomic% or less,
(7) The organic material according to any one of (1) to (6), wherein the organic material is any material selected from nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, fluorine rubber, acrylic rubber, urethane rubber, and silicone rubber. Low friction sliding member,
(8) The low friction sliding member according to any one of (1) or (5) to (7), wherein the acid amide is oleic acid amide,
(9) The low friction sliding member according to any one of (1) or (5) to (7), wherein the aliphatic ester is glycerin monooleate,
(10) The low friction sliding member according to the above (1) or any one of (5) to (7), wherein the aliphatic amine is N, N-dipolyoxyethylene-N-oleylamine, and (11) the above 1 The lubricating oil composition for a low friction sliding member according to any one of 10 to 10, wherein the addition amount of the ashless friction modifier is 0.1 to 3.0% by mass based on the total amount of the composition A lubricating oil composition characterized by the above is provided.

  According to the present invention, for example, the friction characteristics of the sliding portion in a hydraulic cylinder, a lip seal, a shock absorber, and the like are improved, and an excellent wear reduction effect can be achieved.

Hereinafter, the present invention will be described in detail.
First, the heterocyclic compound represented by the general formula (I) among the ashless friction modifiers used in the present invention will be described.
In the general formula (I), Z represents the structural unit (II), and p is 0 or 1.

When p is 0 and any or all of X ^{1 to} X ³ are N, one of the two bonds of each N may be a double bond. In the case where both are single bonds, R ¹ , R ² , and ^one of Y ¹ and Y ² are bonded, or one hydrogen is bonded.
C all represents a carbon element, and one of the two bonds of each C may be a double bond. When p is 0, the remaining one or two single bond bonds are omitted even if one bond of C is a double bond or no double bond. The two single bond bonds are not shown, and a group selected from R ¹ , R ² , Y ¹ and Y ² is bonded to the omitted bond. When p is 1, the conditions for X ^{1 to} X ³ are the same as when p is 0. When X ⁴ is N, one of the two bonds of N is a double bond. There is. When both are single bonds, a state in which one group selected from R ³ , R ⁴ , Y ³ , and hydrogen is bonded is shown. When p is 1, C in the general formula (I) is under the same conditions as when p is 0, and all C in the structural unit (II) represents a carbon element, and two bonds of each C Either one of the bonds may be a double bond. Whether one is a double bond or no double bond, the remaining one or two single bond bonds are omitted, and R ³ , R ⁴ , Y are not shown in the omitted bond bonds. ³ shows a state in which two groups selected from hydrogen are bonded. R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom or an alkyl group having 6 to 30 carbon atoms, an alkenyl group, an alkyl and alkenylamino group, an alkyl and alkenylamide group, an alkyl and alkenyl ether group, an alkyl and R ¹ , R ² , R ³ and R ⁴ may be the same or different, and R ¹ and R ² and R ³ and R ⁴ are groups selected from an alkenyl carboxyl group, a cycloalkyl group and an aryl group. At the same time, it does not become a hydrogen atom. Y ¹ , Y ² and Y ³ are a functional group selected from a hydrogen atom or a hydrocarbon residue, an amino group, an amide group, a hydroxyl group, a carbonyl group, an aldehyde group, a carboxyl group, an ester group, an ether group, a halogen atom, or the same A hydrocarbon residue containing a functional group, or a group obtained by adding a hydrocarbon residue containing the same functional group to the same functional group, which may be the same or different.

(1) When p is 0
m and n are 0 or 1, v is 0 to 5, and x and y are integers of 0 to 2. From the viewpoint of stability of the compound, preferably, when m = n = 0, v is 4 or 5, when either m or n is 0, v is 2 or 3, and when m = n = 1, v is 0 or 1. More preferably, when m = n = 0, v is 4 or 5, m = 1, n = 0, and when v is 2 or 3, x is 1 or 2, m = 0, and n = 1. When v is 2 or 3, y is 1 or 2, and when m = n = 1 and v is 0, x = y = 1 or x = 1, y = 2 or x = 2, y = 1. When m = n = 1 and v is 1, x = 0, y = 1 or 2, or x = 1 or 2, y = 0 or x = y = 1.
X ¹ , X ² , and X ³ represent at least one element selected from N (nitrogen), O (oxygen), and S (sulfur), but the stability of the compound and the deterioration resistance of the product containing the compound X ¹ , X ² , and X ³ are preferably any element selected from N or O (oxygen) from the viewpoint of the property and prevention of catalyst poisoning.
When any or all of X ¹ , X ² , and X ³ are N, one of the two bonds of each N may be a double bond. When both are single bonds, ^one of R ¹ , R ² and Y ¹ is bonded, or one group selected from hydrogen is bonded.
C all represents a carbon element, and one of the two bonds of each C may be a double bond. Even when one of them is a double bond and when there is no double bond, the remaining one or two single bond bonds are not shown, and R ¹ , R ² , and Y ² represents a state in which one group selected from hydrogen is bonded.
R ¹ and R ² are each a hydrogen atom or an alkyl group having 6 to 30 carbon atoms, alkenyl group, alkyl and alkenylamino group, alkyl and alkenylamide group, alkyl and alkenyl ether group, alkyl and alkenyl carboxyl group, cycloalkyl And R ¹ and R ² may be the same or different, but R ¹ and R ² are not hydrogen atoms at the same time.
In an alkyl group or the like, by setting the number of carbon atoms to 6 or more, the compound has sufficient solubility in a lubricating base oil and has an excellent friction reducing effect, and by setting the carbon number to 30 or less, It becomes the compound which has the outstanding friction reduction effect.
R ¹ and R ² are preferably a hydrogen atom or a 12-24 hydrocarbon group, specifically, an octyl group, octenyl group, decyl group, decenyl group, dodecyl group, dodecenyl group, tetradecene group, tetradecenyl group , A hexadecene group, a hexadecenyl group, an octadecyl group, an octadecenyl group, an oleyl group, a stearyl group, an isostearyl group and the like, which are alkyl groups or alkenyl groups having up to 24 carbon atoms, which may be linear or branched.
Y ¹ and Y ² are hydrogen atoms or hydrocarbon residues, amino groups, amide groups, hydroxyl groups,
A functional group selected from a carbonyl group, an aldehyde group, a carboxyl group, an ester group, an ether group and a halogen atom, or a hydrocarbon residue containing the same functional group, which may be the same or different.

(2) When p is 1 X ¹ , X ² and X ³ are the same as when p is 0. X ⁴ also represents at least one element selected from N (nitrogen), O (oxygen), and S (sulfur) in the same manner as X ^{1 to} X ³ , but the stability of the compound and the resistance of the product containing the compound From the viewpoint of degradability and catalyst poisoning prevention, X ^{1 to} X ⁴ are preferably any compounds selected from N and O.
R ¹ and R ² have the same conditions as when p is 0, and R ³ and R ⁴ have the same conditions as R ¹ and R ² .
R ^{1 to} R ⁴ may be the same or different, but R ¹ and R ^2, and R ³ and R ⁴ are not simultaneously hydrogen atoms.
Y ¹ and Y ² are the same conditions as when p is 0. Y ³ has the same conditions as Y ¹ and Y ² .
m, n, x, y, and v are the same conditions as when p is 0. w is an integer of 0 to 3, but from the viewpoint of stability of the compound, preferably, when m = n = 0, w is 1 or 2, and either m or n is 1 and the other is 0 , W is 0.
k is an integer of 0 to 3, u is 0 to 4, and t is an integer of 0 to 3. From the viewpoint of stability of the compound, preferably, when k = 0, u is 3 or 4, and k = 1. In the case, u is 0, 1, 2, or u, if k = 2, u is 0, more preferably, if k = 0, u is 3 or 4, and if k = 1 and u = 0 , T is 2 or 3, k = 1 and u = 1, t is 1 or 2, k = 1 and u = 2, t is 0 or 1, and k = 2 u When = 0, t is 1.
X ^{1 to} X ³ have the same conditions as when p is 0. When X ⁴ is N, one of the two bonds of N may be a double bond. When one of them is a single bond or both are single bonds, a state in which one group selected from R ³ , R ⁴ , Y ² and hydrogen is bonded to the bond is shown.
When p is 1, C in the general formula (I) is the same as when p is 0, and all C in the structural unit (II) represents a carbon element, and in which of the two bonds of each C, One of the bonds may be a double bond. In the case where one is a double bond and the case where there is no double bond, the remaining one or two bond bonds are not shown, and R ³ , R ⁴ , and Y ³ represents a state in which two groups selected from hydrogen are bonded.

The heterocyclic compound represented by the general formula (I) is, for example, a compound such as pyridine, which is a basic skeleton of a heterocyclic ring, or a derivative thereof (a), an alkyl group having 6 to 30 carbon atoms, an alkenyl group, an amide group. And a compound having a cycloalkyl group and an aryl group (b) in a molar ratio (a) :( b) of 1: 5 to 5: 1, preferably 1: 2 to 2: 1. Reaction product.
By setting the molar ratio (a) :( b) to 1: 5 or more and 5: 1 or less, the amount of the active ingredient of the additive of the present invention is prevented from being reduced, and a large amount is added to show the wear reduction effect. Prevent need.
The reaction of (a) and (b) is performed at room temperature to 200 ° C, preferably about 50 to 150 ° C. The reaction may be performed without a catalyst or in the presence of a catalyst.
Moreover, when performing reaction, organic solvents, such as a solvent, for example, hexane, toluene, xylene, THF, DMF, can also be used.

  In the heterocyclic compound represented by the general formula (I), compounds such as pyridine which are the basic skeleton of the heterocyclic ring and derivatives thereof (a) include pyridine, methylpyridine, dimethylpyridine, ethylpyridine, ethylmethylpyridine. Pyridines such as vinyl pyridine, amino pyridine, oxy pyridine; pyrroles such as pyrrole, methyl pyrrole, ethyl pyrrole, amino pyrrole, pyrrole carboxylic acid; 2-aminouracil, 5-methylcytosine, uracil, thymine Such as benzopyrazole, methylpyrazole, ethylpyrazole, aminopyrazole; pyridazines such as pyridazine, methylpyridazine, ethylpyridazine; indazoles such as 6-aminoindazole, indazole; Pyrazines such as lupyrazine, ethylpyrazine and aminopyrazine; triazines such as 1,2,3-benzotriazine and aminotriazine; 3,5-diamino-1,2,4-triazole, 3-amino-1, Triazoles such as 2,4-triazole; imidazolidines such as 5,5-dimethylhydantoin, methylimidazolidine, ethylimidazolidine, aminoimidazolidine; glycerol formal; methylbenzotriazole, ethylbenzotriazole, aminobenzotriazole Benzotriazoles such as methyltetrazole and aminotetrazole; oxazoles such as methyloxazole and aminooxazole; oxadiazoles such as methyloxadiazole and aminooxadiazole; Chiruchiazoru, thiazoles such as aminothiazole; methyl thiadiazole, thiadiazoles such as amino thiadiazole; furans; dioxanes; pyrans; thiophenes and their derivatives.

In addition, a hydrocarbon group or an amino group, an amide group, a hydroxyl group, a carbonyl group, an aldehyde group, a carboxyl group, an ester group, an ether group, a halogen group, and a hydrocarbon group substituted by them or the same as the substituent in the compound (a) What added the hydrocarbon residue containing the functional group to the functional group may be used.
Examples of the hydrocarbon group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group and the like.

  Examples of the compound (b) include oleic acid chloride, heptylundecanoic acid chloride, tridecanoic acid chloride, isostearic acid chloride, polyisobutane (for example, Mw = 350) acid chloride, higher fatty acid halides such as oleic acid bromide, oleic acid Fatty acid anhydrides such as anhydride, heptyl undecanoic anhydride, tridecanoic anhydride, isostearic anhydride, oleyl bromide, heptyl undecyl bromide, tridecyl bromide, aliphatic halides such as isostearyl bromide, Aliphatic tosylates such as oleyl tosylate, heptyl undecyl tosylate, tridecyl tosylate, isostearyl tosylate, oleyl mesylate, heptyl undecyl mesylate, tridecyl mesylate And aliphatic mesylates such as isostearyl mesylate and the like. These may be used alone or as a mixture of two or more. As another synthesis method, there is a method of obtaining a heterocyclic compound by a reaction between amidines and glyoxals or a reaction between ethylenediamines and carboxylic acids.

In the heterocyclic compound represented by the general formula (I), the cyclic structure moiety when p is 0 or the two cyclic structure moieties when p is 1 is derived from the compound (a). At least one of Y ¹ and Y ² is derived from the compound (b).
In the basic skeleton of the heterocyclic compound represented by the general formula (I), the total number of N (nitrogen) and / or O (oxygen) and / or S (sulfur) in one ring is 1 to 3. Saturated or unsaturated compounds.

Next, acid amide will be described.
An acid amide is a compound obtained by using a 1-4 carboxylic acid and an alkylamine or alkanolamine.
As said monovalent | monohydric carboxylic acid, the carboxylic acid containing a C6-C30 hydrocarbon group is preferable, and especially the carboxylic acid which has a linear or branched saturated or unsaturated hydrocarbon group is preferable.
Examples of the hydrocarbon group constituting such monovalent carboxylic acid include hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, and the like. Group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, penticosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group and triacontyl group, etc., and hexenyl Group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icocenyl group Group, henycosenyl group, dococenyl group, tricocenyl group, tetracocenyl group, pentacocenyl group, hexacocenyl group, heptacocenyl group, octacocenyl group, nonacosenyl group and triaconenyl group, and hydrocarbon groups having two or more double bonds Etc. Examples of the divalent to tetravalent polyvalent carboxylic acid include polyvalent carboxylic acids such as oxalic acid, phthalic acid, trimellitic acid, and pyromellitic acid.

On the other hand, the alkylamine compound is preferably an alkylamine compound having a linear or branched hydrocarbon group having 6 to 30 carbon atoms, and the hydrocarbon group is exemplified as the hydrocarbon group of the carboxylic acid. Is mentioned.
Furthermore, as said alkanolamine compound, the alkanolamine compound which has a C2-C6 hydroxyalkyl group is preferable.
From the point of friction reduction effect, an acid amide compound is obtained by reaction of an alkanolamine having a hydroxyalkyl group having 2 to 6 carbon atoms and a monovalent carboxylic acid having a linear or branched hydrocarbon group having 6 to 30 carbon atoms. The acid amide compound obtained is preferred. The carbon number of the hydrocarbon group of the monovalent carboxylic acid is more preferably 8 to 24, and particularly preferably 8 to 20.
Examples of the alkanolamine include monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N, N-dimethylethanolamine, N-ethylethanolamine, N, N-diethylethanolamine, N-isopropylethanolamine, N , N-diisopropylethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, N-methylisopropanolamine, N, N-dimethylisopropanolamine, N-ethylisopropanolamine, N, N-diethylisopropanolamine, N-isopropyl Isopropanolamine, N, N-diisopropylisopropanolamine, mono-n-propanolamine, di-n-propanolamine, tri-n Propanolamine, N-methyl n-propanolamine, N, N-dimethyl n-propanolamine, N-ethyl n-propanolamine, N, N-diethyl n-propanolamine, N-isopropyl n-propanolamine, N, N -Diisopropyl n-propanolamine, monobutanolamine, dibutanolamine, tributanolamine, N-methylbutanolamine, N, N-dimethylbutanolamine, N-ethylbutanolamine, N, N-diethylbutanolamine, N-isopropyl Examples include butanolamine and N, N-diisopropylbutanolamine.
As monovalent carboxylic acid having a linear or branched hydrocarbon group having 6 to 30 carbon atoms, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, And saturated carboxylic acids such as lignoceric acid, and unsaturated carboxylic acids such as myristoleic acid, palmitoleic acid, oleic acid, and linolenic acid. Unsaturated carboxylic acids are preferred in terms of their friction reducing effect.
Preferred examples of the acid amide compound obtained by the reaction of the alkanolamine and a monovalent carboxylic acid having a linear or branched hydrocarbon group having 6 to 30 carbon atoms include oleic acid monoethanolamide, oleic acid diethanolamide, Examples include oleic acid monopropanolamide and oleic acid dipropanolamide.

Next, aliphatic esters will be described.
Examples of the aliphatic ester include an aliphatic complete or partial ester composed of a monovalent aliphatic alcohol and / or a polyhydric alcohol, or a complete or partial ester composed of a polyvalent carboxylic acid and an aliphatic alcohol. Partial esters of polyhydric alcohols are used.
The carboxylic acid is preferably a carboxylic acid having a linear or branched hydrocarbon group having 6 to 30 carbon atoms, and the hydrocarbon group preferably has 8 to 24 carbon atoms, particularly preferably 10 to 20 carbon atoms. is there.
Examples of the linear or branched hydrocarbon group having 6 to 30 carbon atoms include those exemplified as the substituent of the (C) acid amide compound, and examples of the carboxylic acid include caproic acid, caprylic acid, capric acid, and lauryl. Saturated carboxylic acids such as acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid, and unsaturated carboxylic acids such as myristoleic acid, palmitoleic acid, oleic acid, and linolenic acid, and friction An unsaturated carboxylic acid is preferable from the viewpoint of the reduction effect.
The aliphatic polyhydric alcohol is a divalent to hexavalent alcohol, and examples thereof include ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, and the like, and glycerin is preferable in terms of a friction reducing effect.
As the carboxylic acid partial ester compound obtained by the reaction of glycerin and the above unsaturated carboxylic acid, monoester such as glycerin monomyristate, glycerin monopalmitate, glycerin monooleate, glycerin dimyristate, glycerin dipalmitate, Examples include diesters such as glycerol diolate, and monoesters are preferred. Specific preferred examples from the viewpoint of the friction reducing effect include glycerin monooleate, glycerin dioleate, sorbitan monooleate and sorbitan dioleate, glycerin monostearate, sorbitan monostearate and the like.

Next, aliphatic amine will be described.
Here, the aliphatic amine includes a primary amine, a secondary amine, and a tertiary amine in which the hydrocarbyl group preferably has 6 or more carbon atoms.
Specifically, hexadecylamine, stearylamine (octadecylamine), eicosylamine, docosylamine, laurylamine, lauryldiethylamine, lauryldiethanolamine, dodecyldipropanolamine, palmitylamine, stearylamine, stearyltetraethylenepentamine, oleylamine , Oleylpropylenediamine, oleyldiethanolamine, and aliphatic amine compounds such as N-hydroxyethyloleylimidazoline, and N, N-dipolyoxyalkylene-N-alkyl (or alkenyl) of these aliphatic amine compounds (having 6 to 6 carbon atoms). And amine alkylene oxide adducts such as 28).
Preferable examples from the viewpoint of the friction reducing effect include N, N-dipolyoxyethylene-N-oleylamine.
The aliphatic amine compound is preferably an amine compound having a linear or branched hydrocarbon group having 6 to 30 carbon atoms, more preferably 8 to 24 carbon atoms, and particularly preferably 10 to 20 carbon atoms. Examples of the linear or branched hydrocarbon group having 6 to 30 carbon atoms include those exemplified as the substituent for the (C) acid amide compound. Examples of the (d2) aliphatic amine compound include an aliphatic monoamine or an alkylene oxide adduct thereof, an alkanolamine, an aliphatic polyamine, an imidazoline compound, and the like. Specifically, laurylamine, lauryldiethylamine, lauryldiethanolamine, dodecyldipropanolamine, palmitylamine, stearylamine, stearyltetraethylenepentamine, oleylamine, oleylpropylenediamine, oleyldiethanolamine, and N-hydroxyethyloleylimidazoline, etc. Examples include aliphatic amine compounds and amine alkylene oxide adducts such as N, N-dipolyoxyalkylene-N-alkyl (or alkenyl) (carbon number 6 to 28) of these aliphatic amine compounds.

  Various lubricating oils to which at least one ashless friction modifier selected from the heterocyclic compound represented by the above general formula (I), acid amide, aliphatic ester, or aliphatic amine is added as necessary A lubricating oil composition is obtained by mixing with a lubricating base oil together with additives.

Examples of various lubricating oil additives include the following. In addition, the preferable content and more preferable content in the lubricating oil composition whole quantity containing the lubricating base oil mentioned later in parenthesis are described.
Viscosity index improver such as polymethacrylate (preferably 1 to 12% by mass, more preferably 1 to 4% by mass), corrosion inhibitor such as benzotriazole (preferably 0.01 to 3% by mass, and more) Preferably 0.01 to 1.5% by mass), antioxidants such as alkylated diphenylamine (preferably 0.01 to 5% by mass, more preferably 0.01 to 1.5% by mass), polybutenyl Dispersing agents such as succinimide (0.1 to 10% by mass, more preferably 0.1 to 5% by mass), lubricant fluidity improver (preferably 0.01 to 2% by mass, more preferably 0) 0.01-1.5% by mass), rust inhibitors such as alkenyl succinic acid derivatives (preferably 0.01-6% by mass, more preferably 0.01-3% by mass), pour points such as polymethacrylate, etc. A depressant (preferably 0.01 1.5% by mass, more preferably 0.01-0.5% by mass), antifoaming agent (preferably 0.001-0.1% by mass, more preferably 0.001-0.01% by mass) , Anti-wear agents such as phosphite esters (preferably 0.001 to 5% by mass, more preferably 0.001 to 1.5% by mass), seal swelling agents (preferably 0.1 to 8% by mass) %, More preferably 0.1 to 4% by mass).
The friction modifier in the present invention is 0.01 to 10% by mass, preferably 0.05 to 5% by mass, and more preferably 0.1 to 2% by mass in the total amount with the lubricating base oil. As used. By setting the content to 0.01% by mass or more, a friction reducing effect is exhibited. By setting the content to 10% by mass or less, an increase in cost is avoided, and deterioration of the original characteristics of the lubricating base oil is prevented. be able to.

The lubricating base oil is not particularly limited, and various mineral and synthetic lubricating base oils can be used.
As the mineral oil base oil, specifically, the lubricating oil fraction obtained by subjecting crude oil to atmospheric distillation and vacuum distillation can be solvent-desorbed, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, Hydrocarbon oil refined by appropriately combining hydrotreating, sulfuric acid washing, refining treatment such as clay treatment, and the like.
Here, as the hydrocarbon oil, for example, any of lubricating oils such as paraffinic mineral oil, naphthenic mineral oil, and aromatic mineral oil can be used.
Further, as a synthetic lubricating base oil, specifically, a poly ether such as a phenyl ether synthetic oil such as polyphenyl ether, polybutene, 1-octene oligomer, 1-decene oligomer, or hydrogenated products thereof. -Polyolefin-based synthetic oils such as olefins, benzene-based synthetic oils such as alkylbenzenes, naphthalene-based synthetic oils such as alkylnaphthalene, ditridecyl glutarate, di-2-ethylhexyl adipate, diisodesia dipate, ditridecia dipate, Esters such as diesters such as di-2-ethylhexyl sebacate and polyol esters such as trimethylolpropane capryate, trimethylolpropane pelargonate, pentaerythritol 2-ethylhexanoate, pentaerythritol pelargonate Oil, glycol-based synthetic oils such as polyoxyalkylene glycol, ether based synthetic oils such as polyphenyl ether, can be used silicone-based synthetic oils such as silicone fluorinated oils. These base oils may be used alone or as a mixture of two or more.
A lubricant base oil comprising at least one selected from the heterocyclic compounds represented by the above general formula (I), acid amides, aliphatic esters and aliphatic amines, which are ashless friction modifiers used in the present invention When the lubricating oil composition added to is applied to the sliding surface between the sliding portion having a diamond-like carbon film and the organic material in a hydraulic cylinder, lip seal, shock absorber, etc., the friction reducing effect is remarkable and the friction is reduced. A low friction sliding member is constituted by acting as a reducing agent and combining them.

A low-friction sliding member in which a lubricating oil composition containing an ashless friction modifier used in the present invention is combined with a friction sliding member having a diamond-like carbon (DLC) film on at least a part of the sliding portion is applicable. Specific examples are as follows. In a lip seal in a rotating shaft portion such as an automobile engine or an automatic transmission, and a shock absorber for a vehicle, a piston rod and a bush, a piston rod and a shoe, and the like can be given.
In a hydraulic system, a piston rod of a hydraulic cylinder, a cylinder packing, etc. are mentioned.

Nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, fluorine rubber, acrylic rubber, urethane rubber, and silicone rubber can be used as the organic material that is the counterpart member of the low friction sliding member having a diamond-like carbon (DLC) film.
The base material of the low friction sliding member having the DLC film is not limited at all, and any material such as a metal, a resin, and a rubber material can be used.
Here, the low-friction sliding member having the DLC film has a DLC film on the surface, the DLC constituting the film is amorphous mainly composed of carbon element, and the bonding form between carbons is a diamond structure (SP3 Bond) and graphite structure (SP2 bond).
Specifically, aC (amorphous carbon) consisting only of carbon elements, aC: H (hydrogen amorphous carbon) containing hydrogen, and some metal elements such as titanium (Ti) and molybdenum (Mo). In the present invention, a low-friction sliding member having a DLC film made of an aC-based material having a hydrogen content of 5 atomic% or less is suitable for the ashless friction modifier. It is.

  Hereinafter, the present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples.

Synthesis example 1
A 500 ml flask was charged with 5.0 g (0.05 mol) of 3,5-diamino-1,2,4-triazole, 5.3 g (0.053 mol) of triethylamine, and 200 ml of THF, and stirred at reflux. To this, 15.0 g (0.05 mol) of oleic acid chloride dissolved in 50 ml of THF was added dropwise and reacted for 4 hours. The reaction mixture was filtered and THF was distilled off, and then dissolved in 200 ml of toluene and washed with water. After drying with magnesium sulfate, toluene was distilled off to obtain a heterocyclic compound. The yield of the obtained heterocyclic compound was 16 g.
The structural formula of the main component of the obtained heterocyclic compound is as follows: p in the general formula (I) is 0, m and n are all 1, X ¹ , X ² and X ³ are all N, x, y and one of v is 0, the other two are 1, one of R ¹ and R ² is an oleamide group, the other is hydrogen, Y ¹ is an amino group, and Y ² is hydrogen. This heterocyclic compound is referred to as “Additive 1”.

Synthesis example 2
The reaction was conducted in the same manner as in Synthesis Example 1 except that 7.1 g (0.05 mol) of kojic acid was used instead of 3,5-diamino-1,2,4-triazole. The yield of the obtained heterocyclic compound was 16 g.
The structure of the main component of the obtained heterocyclic compound is as follows: in general formula (I), p is 0, m and n are 0, X ³ is O, v is 5, and ^one of R ¹ and R ² is oleyl methyl ether A group wherein the other is hydrogen, Y ¹ is a hydroxyl group and Y ² is a carbonyl group, and ^one of R ¹ and R ² is an oleyl ether group, the other is hydrogen, Y ¹ is a hydroxymethyl group, and Y ² is a carbonyl group It is a mixture of compounds. This heterocyclic compound is referred to as “Additive 2”.

Synthesis example 3
A 500 ml flask was charged with 1.3 g (0.055 mol) of NaH and 100 ml of DMF. To this, 4.2 g (0.05 mol) of 3-amino-1,2,4-triazole dissolved in 100 ml of DMF was added dropwise and reacted at 100 ° C. for 2 hours. Next, 16.6 g (0.05 mol) of oleyl bromide was added dropwise to the reaction mixture and reacted at 100 ° C. for 4 hours. After distilling off DMF, it was dissolved in 200 ml of toluene and washed with water. After drying with magnesium sulfate, toluene was distilled off to obtain a heterocyclic compound. The yield of the obtained heterocyclic compound was 15 g.
The structural formula of the main component of the obtained heterocyclic compound is as follows: p in the general formula (I) is 0, m and n are all 1, X ¹ , X ² and X ³ are all N, x, y and One of v is 0, the other two are 1, one of R ¹ and R ² is an oleyl group, the other is hydrogen, Y ¹ is an amino group, and Y ² is hydrogen. This heterocyclic compound is referred to as “Additive 3”.

Examples (reference examples) 1-6
A lubricating oil composition was prepared by blending 0.5 parts by mass of “Additives 1 to 6” with 99.5 parts by mass of mineral oil of a 100 neutral fraction. The coefficient of friction between each lubricating oil composition and the sliding member was evaluated by a Bowden test using the following sliding members for testing. The results of Examples (Reference Examples) 1 to 6 are shown in Table 1. In Table 1, the case where the following sliding member (2) is used using "additives 1-6" is set as reference examples 1-6.

Comparative Example 1
Only mineral oil of 100 neutral fraction was used, and the sliding member was changed and evaluated in the same manner as in the examples. The results are shown in Table 1.

Comparative Example 2
A lubricating oil composition for comparison was prepared by blending 99.1 parts by mass of mineral oil of 100 neutral fraction with 0.4 parts by mass of commercially available MoDTC and 0.5 parts by mass of commercially available ZnDTP, based on the total mass, The sliding member was changed and evaluated in the same manner as in the example. The results are shown in Table 1.

<Test method and test conditions>
Test method tester: Bowden reciprocating tester test sliding member:
(1) Test material 1
A combination of a 50 × 150 mm flat plate in which a DLC film of less than 5% hydrogen atoms is formed on the surface of SCM420H and NBR, A727 manufactured by NOK.
(2) Test material 2
A combination of a 50 × 150 mm flat plate formed from SCM420H and NOK's NBR, A727.
Test conditions Temperature: 25 ° C
Sliding speed: 3.0mm / sec Load: 10N
Stroke: 10mm

By comparing the friction coefficients in Examples 1 to 6 and Comparative Examples 1 and 2 in Table 1, the ashless friction modifier used in the present invention exhibits a friction reducing effect superior to that of the conventional product. I understand.
Further, by comparing Examples 1 to 6 with Reference Examples 1 to 6, the same ashless friction modifier (additives 1 to 6) was used, and a rubber material and a diamond-like carbon (DLC) film were used. It can be seen that in the case of a combination low friction sliding member with a member having a frictional effect superior to that in the case of a combination of a rubber material and a member not having a DLC film.

  The ashless friction modifier according to the present invention blended with a mineral oil-based hydrocarbon oil, a synthetic-type lubricant base oil or a mixture thereof is used between a sliding portion having a diamond-like carbon film and an organic material. It is suitable as a future environmentally friendly friction modifier because it improves the friction characteristics on the sliding surface and is ashless.

Claims (11)

The following general formula (I) between the sliding surface having a diamond-like carbon film at least partially and the organic material:

[In the general formula (I), X ¹ , X ² and X ³ represent at least one element selected from N or NH (N is nitrogen), O (oxygen), S (sulfur), each of which is different These elements may be used. (C) x, (C) y, and (C) v each represent an alkylene group or an alkylene group residue in which R ¹ , R ^2, or Y ¹ and Y ² are substituted. x and y are 0 to 2, v is an integer of 0 to 5 (when p is 1, as described later, v is an integer of 0 to 3), m and n are 0 or 1, m, n, v Are not 0 at the same time. R ¹ and R ² are each a hydrogen atom or an alkyl group having 6 to 30 carbon atoms, an alkenyl group, an alkyl and alkenylamino group, an alkyl and alkenyl amide group, an alkyl and alkenyl ether group, an alkyl and alkenyl carboxyl group, and a cycloalkyl. R ¹ and R ² may be the same or different, and when p is 0, R ¹ and R ² are not hydrogen atoms at the same time. Y ¹ and Y ² include a functional group selected from a hydrogen atom or hydrocarbon residue, amino group, amide group, hydroxyl group, carbonyl group, aldehyde group, carboxyl group, ester group, ether group, halogen atom or the same functional group A hydrocarbon residue or a group obtained by adding a hydrocarbon residue containing the same functional group to the same functional group. Z is the following structural unit (II)

P is 0 or 1. X ⁴ represents any element selected from N or NH (N is nitrogen), O (oxygen), and S (sulfur). (C) w, (C) u and (C) t each represent an alkylene group or a residue of an alkylene group substituted with R ³ , R ⁴ or Y ³ . w is 0 to 2, u is 0 to 4, k is 0 to 2, t is an integer of 0 to 3, and when p is 1, v is an integer of 0 to 3. R ³ and R ⁴ may be the same or different, but R ¹ , R ² , R ³ , and R ⁴ are not simultaneously hydrogen atoms. Y ³ is a functional group selected from a hydrogen atom or a hydrocarbon residue, an amino group, an amide group, a hydroxyl group, a carbonyl group, an aldehyde group, a carboxyl group, an ester group, an ether group, and a halogen atom, or a hydrocarbon residue containing the same functional group. It is a group. The cyclic part in the general formula (I) and the structural unit (II) may have a double bond]
And a low-friction friction comprising a lubricating oil composition containing a base oil and at least one ashless friction modifier selected from acid amides, aliphatic esters, and aliphatic amines. Moving member. The low friction sliding member according to claim ¹ , wherein p in the general formula (I) is 0, and X ¹ , X ² and X ³ are any elements selected from N (nitrogen) and O (oxygen). . ^2. The low friction according to claim 1, wherein p in the general formula (I) is 1, and X ¹ , X ² , X ³ and X ⁴ are any elements selected from N (nitrogen) and O (oxygen). Sliding member.   General formula (I) is a pyridine, pyrrole, pyrimidine, pyrazole, pyridazine, indazole, pyrazine, triazine, triazole, tetrazole, oxazole, oxadiazole, thiazole, thiadiazole, The low friction sliding member according to any one of claims 1 to 3, which has a heterocyclic skeleton derived from a compound selected from furans, dioxanes, pyrans, and thiophenes.   The low friction sliding member according to any one of claims 1 to 4, which is used under wet conditions.   The low friction sliding member according to claim 1, wherein the diamond-like carbon film is an amorphous carbon material having a hydrogen content of 5 atomic% or less.   The low friction sliding member according to any one of claims 1 to 6, wherein the organic material is any material selected from nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, fluorine rubber, acrylic rubber, urethane rubber, and silicone rubber.   The low friction sliding member according to claim 1, wherein the acid amide is oleic acid amide.   The low friction sliding member according to claim 1, wherein the aliphatic ester is glycerin monooleate.   The low friction sliding member according to claim 1 or 5, wherein the aliphatic amine is N, N-dipolyoxyethylene-N-oleylamine.   It is a lubricating oil composition for low friction sliding members in any one of Claims 1-10, Comprising: The addition amount of an ashless type friction modifier is 0.1-3.0 mass% on the basis of the composition whole quantity A lubricating oil composition characterized in that