JP2009179715A - Lubricant composition and lubrication system using the same - Google Patents

Abstract

In order to solve various problems in sliding members that are becoming more severe due to miniaturization and higher speed, specific oxides that have not been used in conventional lubricants are included to significantly reduce wear. And a lubricant composition that stably exhibits a low coefficient of friction.
The present invention relates to a liquid or semi-solid lubricant composition containing a mineral base oil, synthetic oil base and / or animal and vegetable base oil, and a zinc oxide having an average particle size of 100 nm or less ( ZnO), aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cobalt oxide (CoO), tin oxide (SnO ₂ ), titanium oxide (TiO ₂ ), copper oxide (CuO), and manganese oxide (Mn) ₃ O ₄ ) is a lubricant composition containing 1 to 30% by mass of at least one oxide selected from the group consisting of ₃ O ₄ ), and a lubrication system using the lubricant composition.
[Selection figure] None

Description

  The present invention relates to a lubricant composition containing a specific oxide having a specific particle size and a lubrication system using the same, greatly reducing wear in a sliding portion, improving poor lubrication, It improves the reliability of the lubrication system.

  A wide variety of mechanical systems such as precision machines, industrial machines, transport machines, measuring instruments, and the like are in an environment where wear is unavoidably repeated due to repeated friction. If poor lubrication occurs in these sliding parts, the lubrication system or a mechanical system including the lubrication system cannot perform a desired function. For this reason, various lubricants are used for the sliding portion depending on the environment, materials having excellent lubricity are used for the members constituting the sliding portion, or excellent lubricity is achieved. Various measures such as performing surface treatment are given.

Commonly used lubricants include liquid lubricants, semi-solid greases, and recently developed thermoreversible gel lubricants at normal temperatures. Among them, especially in the case of grease, there is a case where a solid lubricant is mixed to improve wear resistance, and a certain effect is obtained. As the solid lubricant, molybdenum disulfide, graphite, PTFE (polytetrafluoroethylene), and BN (boron nitride) are generally used, and recently MCA (melamine cyanurate) has begun to be used. In both cases, a relatively soft solid is used as a lubricant.
However, recently, the load on the sliding portion has increased due to the reduction in size and speed of the mechanical system, and there is a demand for a lubricant that is more excellent in lubricity such as wear resistance.

The ideal characteristics of the lubricant are that there is little friction loss at high speeds and low speeds, and there is little wear such as fretting wear. That is, the lubricant needs to reduce friction loss and reduce wear. Therefore, it is desired that the friction loss is small and the wear is small even when the contact surface speed is high, such as when rotating at high speed, or when high torque is applied at low speed.
To reduce the friction loss at high speed, it is necessary to reduce the viscosity of the base oil itself. However, when the viscosity of the base oil is lowered, it becomes weak against wear such as fretting, that is, the contact between base materials such as sliding metals occurs and the risk of causing wear increases.

  An object of the present invention is to solve various problems in the sliding member that is more severe due to the above-described miniaturization and high speed. That is, the present invention aims to provide a lubricant composition that contains a specific oxide that has not been used in conventional lubricants, greatly reduces wear, and stably exhibits a low coefficient of friction. And Another object of the present invention is to provide a lubrication system using such a lubricant composition.

  As a result of investigating and studying various materials (oxides) and their forms in order to improve the performance of the lubricant and solve the above-mentioned problems, the present inventor has lubricated hard oxides having a fine particle size. It has been found that lubricity can be greatly improved by adding to oil or semi-solid lubricant. In other words, fine oxide particles enter the irregularities due to the surface roughness of the base material surface, filling the surface roughness of the sliding surface state, forming a mirror-like state, well known for mirror surfaces Like the phenomenon, wear is suppressed. Furthermore, since the lubricating component is retained around the particles that have entered the irregularities due to the surface roughness, contact between the base materials such as the sliding metal is avoided, and as a result, the lubricity can be greatly improved. It is thought that it was made. The present invention has been completed based on such findings.

That is, the present invention is the following lubricant composition and a lubrication system using the same.
(1) In a liquid or semi-solid lubricant composition containing a mineral base oil, synthetic oil base and / or animal and vegetable base oil, zinc oxide (ZnO), aluminum oxide having an average particle size of 100 nm or less From (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cobalt oxide (CoO), tin oxide (SnO ₂ ), titanium oxide (TiO ₂ ), copper oxide (CuO), and manganese oxide (Mn ₃ O ₄ ) A lubricant composition comprising 1 to 30% by mass of at least one oxide selected from the group consisting of:

(2) The lubricant composition according to the above (1), wherein the oxide is zinc oxide (ZnO) and the average particle size is 50 nm or less.
(3) The lubricant composition according to the above (1) or (2), wherein the kinematic viscosity at 40 ° C. of the lubricant base oil is 100 mm ² / s or less.
(4) The lubricant composition according to any one of the above (1) to (3), which contains an amide compound and is semi-solid.
(5) The lubricating oil composition according to any one of the above (1) to (4), which is a semisolid having a consistency of 90 to 400.

(6) A lubricating system using the lubricant composition according to any one of (1) to (5) above.

  According to the lubricant composition of the present invention, since it contains an oxide having a fine particle size, the wear is remarkably reduced and the friction coefficient is low and stable. Therefore, the lubricant composition of the present invention is suitable for long-term use, and can be expected to exhibit a special effect in terms of energy saving due to the low and stable characteristics of the friction coefficient.

The lubricant composition of the present invention is a liquid or semi-solid lubricant composition containing a mineral base oil, a synthetic oil base and / or an animal or vegetable base oil, and has an average particle size of 100 nm or less. (ZnO), aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cobalt oxide (CoO), tin oxide (SnO ₂ ), titanium oxide (TiO ₂ ), copper oxide (CuO), and manganese oxide ( 1 to 30% by mass of at least one oxide selected from the group consisting of (Mn ₃ O ₄ ). By containing fine powder having an average particle size of 100 nm or less, the effect of wear resistance of the lubricant is remarkably improved.

〔lubricant〕
As the liquid or semi-solid lubricant to be the subject of the present invention, if it is a lubricant used to bring about a lubricating action by dropping, applying, spraying, spraying or sprinkling on the sliding part, It can be applied to any kind of lubricant. Specifically, a so-called gel grease at normal temperature, a thermoreversible gel lubricant, and a general lubricating oil that is liquid at room temperature can be used. In particular, when applied to a lubricant using a low-viscosity base oil, the energy saving effect is increased, which is preferable.

[Liquid lubricant]
The liquid lubricant used in the present invention is represented by so-called lubricating oil. Lubricating oil is a liquid used to lubricate sliding parts to prevent friction surface wear and seizure, as well as to cool and wash away foreign materials. Mineral oils and synthetic base oils are the main constituents. There are oil and animal and vegetable oils. Generally, mineral-based lubricating oils made from a fraction having a relatively high boiling point of petroleum are widely used because they are inexpensive. Synthetic oil-based lubricating base oils include poly-α-olefins, alkylbenzenes, esters, ethers, silicones, fluorinated oils, and the like. Examples of animal and vegetable oil-based lubricating base oils include rapeseed oil and soybean oil. Usually, these base oils are appropriately combined depending on the application, and are produced by appropriately blending various additives in order to further impart various performances required for each application.

Preferred physical property values of the liquid lubricant that can be used effectively in the present invention include a basic kinematic viscosity of 8 to 500 mm ² / s at 40 ° C., a low temperature pour point of −10 ° C. or less, and safety. From the surface, the flash point is preferably 70 ° C. or higher.
Lubricating oils are used throughout the sliding parts of machines and instruments, and lubricating oils such as engine oils, gear oils, hydraulic oils, turbine oils, compressor oils, and bearing oils are widely used depending on the application. Although the suitable kinematic viscosity differs depending on the target device, generally, a low viscosity having a low resistance and a small power loss is preferable from the viewpoint of energy saving. However, when the viscosity is low, the oil film becomes thin and the risk of wear increases.
Therefore, it can be said that energy saving can be achieved if the lubricating oil has low viscosity and little wear. In particular, by making it possible to use a wide range of base oils having a kinematic viscosity at 40 ° C. of 100 mm ² / s or less, the effect of reducing the energy loss at the sliding portion is extremely large.

  The lubricant composition of the present invention contains an oxide having a fine particle size with an average particle size of 100 nm or less uniformly dispersed. When the liquid lubricant composition (lubricating oil) containing an oxide having a fine particle size is applied to the sliding surface, friction and wear on the sliding surface are remarkably reduced. Although this detailed mechanism is not clear, since the fine particles are blended with an oxide having a fine particle diameter and the fine particles are uniformly mixed and dispersed in the base oil, the particles are covered with the sliding surface. The surface of the sliding material gets into the concave part of the surface and fills the concave part, flattening the uneven part of the surface of the sliding part to form a state similar to a mirror surface with low surface roughness, reducing friction and wear It is presumed that this was suppressed.

Low-viscosity base oils generally tend to evaporate, but adhere firmly to the surface together with fine oxide particles and remain on the particle surface and the sliding member surface, and the oxide is chemically Since it is stable and hard, its wear resistance is not lost.
In addition, extremely fine particles having an average particle size of 100 nm or less, once blended uniformly in the lubricating base oil, do not settle, or the particles aggregate to form a non-uniform concentration distribution, The dispersion at a uniform concentration is maintained in the base oil, and the wear resistance effect is not lost over a long period of time.

[Semi-solid lubricant]
Examples of the semi-solid lubricant used in the present invention include a grease composed of a lubricant base oil and a metal soap, a thickener such as a urea compound, and a gel lubricant composed of a lubricant agent such as a lubricant base oil and an amide compound. Is mentioned.

[Grease]
Grease is a semi-solid lubricant composed of a lubricant base oil and a thickener. For example, in a grease using a metal soap as a thickener, a metal soap that is difficult to dissolve in a base oil at room temperature is completely dissolved at a high temperature of 200 ° C. or more, and when this is cooled to room temperature, hundreds to thousands of soap molecules are formed. Aggregates to form soap micelles, which form a network structure intertwined in a fibrous form. Lubricating base oil is held between the network structures to form a semi-solid grease.

As the lubricating base oil, those used for the above liquid lubricant can be used.
As the thickener, metal soaps such as higher fatty acid lithium soaps, calcium soaps, and aluminum soaps are generally used. As a thickener for heat-resistant grease used at high temperatures, a non-soap-based thickener such as a urea compound or an oleophilic bentonite is used. As additives, an antioxidant, a rust inhibitor, an extreme pressure agent, an oily agent, a solid lubricant, and the like are added as necessary, as in general lubricating oils.

  The general properties of grease are defined in JIS K2220. Various types of greases for various uses are manufactured by selecting and setting the types of base oils, the types of thickeners, and their blending amounts. When selecting a grease, the basis is the consistency indicating the hardness of the grease. The performance of grease is largely governed by the type of thickener used in general. Consistency is included in the numerical value in the form of a combination of viscosity and plasticity, and is suitable for comprehensively grasping the flow characteristics, and is defined in 7 of JIS K2220. Generally, a blending penetration of 85 to 475 is used industrially, and the larger the number, the softer. As the grease applied to the present invention, a soft product having a blending degree of 90 or more is preferable from the viewpoint of energy saving.

Grease is used for various types of bearings, such as wheel bearings, constant velocity joints in the automotive field, axle bearings in the railway field, branching machines, various motor bearings in the electrical field, copier bearings, and rolling mill roll neck bearings in the steel field. It is used in a wide range of fields such as continuous casting equipment, roll bearings, and other industrial machine bearings.
The grease prepared according to the present invention, in which an additive having a fine particle size is blended and dispersed, does not separate into the base oil even if it is dissolved by being exposed to a high temperature in the sliding part during use. Good dispersion can be maintained at a uniform concentration. For this reason, wear can be significantly reduced as in the case of lubricating oil.

[Gel lubricant]
A gel lubricant is a semi-solid lubricant consisting of a base oil and a gelling agent such as an amide compound. It becomes liquid when the melting point of the gelling agent is exceeded, and becomes thermoreversible when it is below the melting point. It is a semi-solid lubricant at normal temperature. As the base oil, mineral oil and various synthetic oils can be used in the same manner as grease. As gelling agents corresponding to grease thickeners, amide compounds such as monoamide and bisamide are used. The melting point is often in the range of 40 to 250 ° C., and the melting point of 90 to 210 ° C. is widely studied depending on the application. As additives, the same materials as lubricating oils and greases are used as necessary. As a physical property value, a consistency indicating hardness is basically the same as that of grease, and a softness having a consistency of 175 or more is preferable.

  The characteristics of the gel lubricant compared to grease are that it is thermoreversible and can be used in the semi-solid state after cooling after being liquidized and put into the pores of a sintered bearing. The gelling agent itself is an oily agent. For example, the friction coefficient can be greatly reduced, and the oil film can be maintained for a long time even in a thin film state with strong adhesion. There are also advantages such as low torque at low temperatures and low evaporation. The application is the same as the field where grease is used, but it is considered that it will be used in the future under special equipment, parts and conditions where the properties of grease are not sufficient.

  In the present invention, the addition of MoDTC and an oxide having a fine particle diameter has an effect of lowering the friction coefficient, and the synergistic effect can lower the friction coefficient so far. The gelling agent can maintain a stable coefficient of friction even when water is mixed. Therefore, since the fine particles can be expected to have an effect of covering the base material and suppressing oxidation, etc., the gelling agent is used, and the lubricant containing the fine particles has good characteristics even in a state where water is contained. Can be maintained.

[Oxide having fine particle size]
The lubricant composition of the present invention contains 1 to 30% by mass of a specific oxide which is fine particles having an average particle size of 100 nm or less. In the present invention, oxides include zinc oxide (ZnO), aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cobalt oxide (CoO), tin oxide (SnO ₂ ), and titanium oxide (TiO ₂ ). And at least one selected from the group consisting of copper oxide (CuO) and manganese oxide (Mn ₃ O ₄ ).

  Usually, a lubricant is allowed to act on the sliding portion to avoid contact between the base materials such as metals, but the lubricant composition of the present invention has a particle size that is fine enough to enter the recess in the surface roughness of the base material surface. Therefore, in the case of a mirror surface having a small surface roughness, a situation like a well-known phenomenon is created, and the occurrence of wear is suppressed and friction is reduced. Accordingly, the oxide or the like preferably has an average particle size smaller than the size of the unevenness due to the surface roughness of the base material surface of the sliding portion, more preferably the average particle size is 50 nm or less, and further preferably 30 nm or less. Even in high-speed sliding parts where fretting wear is likely to occur, contact between the base materials such as metals can be avoided by adding a hard substance with a fine particle size enough to enter the irregularities due to the surface roughness of the base material surface. As a result, the wear is suppressed. Accordingly, the viscosity of the lubricant composition applied to the sliding portion can be lowered, and as a result, friction loss can be reduced (energy saving).

In the present invention, the fine-particle oxide is chemically stable, physically hard and does not collapse. Among the oxides exemplified above, zinc oxide (ZnO), aluminum oxide (Al ₂ O ₃ ), and copper oxide (CuO) are preferable because those having a fine particle diameter can be easily obtained at a relatively low cost. In particular, a technique for producing zinc oxide by selecting a particle size of 50 nm or less has been established. Moreover, the thing of shapes, such as spherical shape and a polyhedron, is marketed. Therefore, it is most suitable for this application.
Note that the average particle diameter is assumed to be a perfect circle based on a method obtained from Scherrer's equation using the result of X-ray diffraction measurement, and an image obtained from a transmission electron microscope (TEM). It can be obtained using a method such as In the present invention, the average particle diameter is a value obtained by measuring a constant direction diameter from a TEM image and calculating an arithmetic average.

  Although it is a well-known phenomenon, when the diameter of the powder mixed in the liquid is reduced, a phenomenon that does not settle permanently below a certain particle diameter appears regardless of the specific gravity of the powder. Therefore, when an oxide having a particle size equal to or smaller than that is mixed with the lubricating base oil, the oxide is uniformly dispersed and does not precipitate. This effect, when used in grease, maintains a uniform dispersion without separating, agglomerating or precipitating oxides in the liquid homogeneous mixture of base oil and thickener even when the temperature rises to a level where it cannot exist as a grease. be able to. Naturally, when used as a lubricating oil, the base oil is uniformly dispersed without separation, aggregation or precipitation, and its effect is not lost over a long period of time.

  An oxide is mix | blended so that it may contain 1-30 mass% in a lubricant composition. Preferably, it is 5 to 20% by weight. If the amount is less than 1% by mass, the effect of the oxide cannot be obtained. On the other hand, even if the amount exceeds 30% by mass, the effect of adding the oxide commensurate with the increase cannot be obtained.

(Preparation of lubricant composition)
The lubricant composition of the present invention can be obtained in a state where fine particles of an oxide having an average particle size of 100 nm or less are uniformly dispersed and contained in a lubricant such as lubricating oil, grease and gel lubricant. Any method can be used. For example, in the case of preparing the lubricant composition of the present invention by containing an oxide in a lubricating oil (liquid lubricant), the lubricant of the present invention can be obtained by adding a predetermined amount of fine oxide particles to the lubricating oil and stirring. A composition can be obtained. In addition, when blending fine particles, in the case of lubricating oil, the viscosity may increase, so the base material, additives, etc. of the lubricating oil are appropriately selected and blended so that the desired viscosity can be obtained. It is also important to adjust. Considering this, it is convenient and efficient to blend the lubricating oil base material and the additive, considering the oxide fine particles as one of the additives and blending them at the same time.

  When blended with a semi-solid lubricant such as grease or gel lubricant, it is possible to blend so that the oxide is uniformly contained in the semi-solid form, using a special mixer, Handling is cumbersome and not efficient. Therefore, the lubricant composition of the present invention can be obtained relatively easily once the temperature is raised to a liquid or liquid state and the oxides are blended. Thus, even if it is a semisolid lubricant, the effect of this invention can be enjoyed by disperse | distributing an oxide uniformly. Also, as in the case of lubricating oils, the physical properties may change by blending fine particles such as oxides, so that the lubricating base oil and thickener can be obtained so that the desired physical properties and performance can be obtained. It is preferable to appropriately select a gelling agent and an additive and to adjust the blending amount thereof. Therefore, when preparing a grease or a gel-like lubricant containing an oxide or the like as the lubricant composition of the present invention, at the stage of preparing a normal grease or a gel-like lubricant, as in the case of the above lubricating oil, Fine particles such as oxides are regarded as one type of additive, and once mixed uniformly into the lubricating base oil, and in some cases, other additives are also included in the lubricating base oil, and then a thickener. It is also efficient to mix with a gelling agent at a temperature above these melting points.

〔Additive〕
The lubricant composition of the present invention includes alkaline earth metal detergents and friction modifiers that have been used for greases, gel lubricants, lubricating oils and the like as long as the object of the present invention is not impaired. Additives such as antiwear agents, extreme pressure agents, detergent dispersants, antioxidants, rust inhibitors, metal deactivators, and antifoaming agents can be included to further improve performance.

  The alkaline earth metal detergent contains an alkaline earth metal such as magnesium, calcium, barium, and examples thereof include alkaline earth metal sulfonate, alkaline earth metal phenate, alkaline earth metal salicylate, and the like. . Examples of friction modifiers include aliphatic amines, aliphatic amides, aliphatic imides, alcohols, esters, phosphate ester amine salts, phosphite ester amine salts, and antiwear agents such as phosphate esters and zinc dialkyldithiophosphates. Extreme pressure agents such as sulfurized olefins and sulfurized fats and oils, dispersants such as polyalkenyl succinimides, polyalkenyl succinic acid esters and their respective boric acid modifications, antioxidants such as amine-based and phenol-based antioxidants Examples of the metal deactivator include benzotriazole, examples of the rust preventive include alkenyl succinic acid ester or partial ester, and examples of the antifoaming agent include a silicone compound and an ester-based antifoaming agent.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this Example.

(Preparation of lubricating oil composition)
Lubricating oil compositions (gel lubricants) of Examples and Comparative Examples were prepared using the following lubricating base oil, gelling agent, additive and oxide.
(A) Lubricating base oil: The following highly refined mineral oil was used.
(A1) VG22 [kinematic viscosity (40 ° C.): 20 mm ² / s, viscosity index: 120]
(A2) VG68 [kinematic viscosity (40 ° C.): 68 mm ² / s, viscosity index: 120]
(A3) VG100 [kinematic viscosity (40 ° C.): 100 mm ² / s, viscosity index: 120]
(A4) VG460 [kinematic viscosity (40 ° C.): 460 mm ² / s, viscosity index: 100]
(B) Gelling agent: melting point 150 ° C., bisamide (carbon number 18)
(C) Additive:
(C1) P-based EP agent: orthophosphate (C2) SP-based EP agent: thiophosphate (C3) S-based EP agent: thiadiazole (C4) Extreme pressure agent: MoDTC
(C5) detergent dispersant: overbased Ca sulfonate (D) oxide:
(D1) Zinc oxide: ZnO (average particle size = 20 nm)
(D2) Aluminum oxide: Al ₂ O ₃ (average particle size = 30 nm)
(D3) Copper oxide: CuO (average particle size = 45 nm)
(D4) Iron oxide: Fe ₂ O ₃ (red rust, average particle size = 150 nm)

The lubricating oil compositions used in Examples and Comparative Examples were prepared by blending the components A to D at the blending ratios shown in Table 1 (addition amounts are mass% based on the total amount of the composition).
Add (B) gelling agent (bisamide) to the stirring mixer (hot plate stirrer) charged with (A) lubricating base oil of VG22, 68, 100 and 460, and raise the temperature to 150 ° C. The mixture was melted and stirred until it was uniformly mixed in a liquid state. The additives (C1) to (C5) and the oxides (D1) to (D4) were added thereto, and the mixture was further stirred for 1 hour. Thereafter, the heating and stirring are stopped, and the temperature is lowered to room temperature, and the semisolid lubricant compositions (gel lubricants) of Examples 1 to 5, 7, 8 and Comparative Examples 1 to 5 are used. Obtained. Further, the additives (C4) and (C5) and the oxide (D1) were added to the (A) lubricating base oil of VG460, stirred at 60 ° C. for 1 hour, and cooled to room temperature. The liquid lubricant composition (lubricating oil) of Example 6 was obtained. In addition, (A) base oil, (B) gelling agent, (C) additive, and (D) oxide were blended in the proportions shown in the upper part of Table 1, respectively.
Commercially available grease A of Comparative Example 7 (JOMO Risonix Grease No. 2) is a commercially available high-grade Li grease, and Grease B of Example 9 is 95 parts by weight of commercially available grease A of Comparative Example 7. This is a semi-solid lubricant composition (oxide-containing grease) obtained by uniformly kneading 5 parts by mass of zinc oxide D1 with a stirring mixer.

  Thus, about the lubricant composition of Examples 1-9 and Comparative Examples 1-7 which were obtained in this way, the performance (wear depth, friction coefficient) as a lubricant composition was evaluated. The obtained measurement / evaluation results are shown in the lower part of Table 1.

[Measurement and evaluation method]
The measurement and evaluation were performed by the following method.
[Consistency]
According to JIS K2220, the immiscible consistency was measured with a ¼ consistency meter.
[Fretting wear test]
Using a cylinder / disk type SRV friction tester, the disk wear depth and the friction coefficient of the lubricant compositions of Examples 1 to 9 and Comparative Examples 1 to 7 were measured.
The wear depth of the disc was determined by applying reciprocating friction to the disc with a cylinder for 1 hour under the conditions of a load of 200 N, a frequency of 300 Hz, a temperature of 25 ° C., and an amplitude of 1.0 mm. Obtained by measuring with a surface roughness meter.
The coefficient of friction is a value measured with a strain gauge provided in advance in the friction tester.

  From the results of the examples shown in Table 1, the wear scar depth can be greatly reduced by blending an oxide having a fine particle diameter of about 20 to 45 nm, particularly zinc oxide, with gelled oil or grease, and It can be seen that the coefficient of friction is low and stable. On the other hand, 150 nm iron oxide, on the other hand, promotes wear and increases the friction coefficient.

Claims (6)

In a liquid or semi-solid lubricant composition containing a mineral base oil, synthetic oil base and / or animal or vegetable base oil, zinc oxide (ZnO) or aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), cobalt oxide (CoO), tin oxide (SnO ₂ ), titanium oxide (TiO ₂ ), copper oxide (CuO), and manganese oxide (Mn ₃ O ₄ ) A lubricant composition comprising 1 to 30% by mass of at least one selected oxide.   The lubricant composition according to claim 1, wherein the oxide is zinc oxide (ZnO), and the average particle size thereof is 50 nm or less. The lubricant composition according to claim 1 or 2, wherein the lubricating base oil has a kinematic viscosity at 40 ° C of 100 mm ² / s or less.   The lubricant composition according to any one of claims 1 to 3, which contains an amide compound and is semi-solid.   The lubricating oil composition according to any one of claims 1 to 4, wherein the lubricating oil composition is a semi-solid having a consistency of 90 to 400. A lubrication system using the lubricant composition according to claim 1.