WO2016158071A1

WO2016158071A1 - Lubricating grease composition

Info

Publication number: WO2016158071A1
Application number: PCT/JP2016/054892
Authority: WO
Inventors: 渉澤口; 基之井内; 晃篠崎
Original assignee: Ｎｏｋクリューバー株式会社
Priority date: 2015-03-27
Filing date: 2016-02-19
Publication date: 2016-10-06
Also published as: US20180016517A1; CN107406792B; CN107406792A; MX2017012178A; CA2980989C; JP6683196B2; CA2980989A1; JPWO2016158071A1

Abstract

The present invention provides a lubricating grease composition that suppresses the degradation of a polyamide resin member particularly in a high-temperature usage environment while maintaining excellent low-temperature characteristics, and that can maintain breaking elongation at a high level with almost no reduction thereof. This lubricating grease composition for polyamide resin members is a lubricating grease composition for polyamide resin members that is used by being supplied as a lubricant to a surface of at least a sliding part of a polyamide resin member wherein said sliding part slides against another member, the lubricating grease composition comprising: a base oil which is a synthetic hydrocarbon oil; and a thickener which is a metal composite soap comprising a barium composite soap and/or a lithium composite soap. The base oil has a kinematic viscosity within the range of from 30 to 200 mm²/s at 40°C, and the thickener has a dropping point of 270°C or higher.

Description

Lubricating grease composition

The present invention supplies, as a lubricant, at least the surface of a polyamide resin member having a sliding portion on which another member made of a resin member or a metal material slides or slides on another member. The present invention relates to a lubricating grease composition for a polyamide resin member used for the production.

Conventionally, grease has been used as a lubricant composition in various industrial fields such as steel, automobiles, general machinery, and precision machinery. In recent years, polyamide resins have been frequently used for members such as sliding parts such as automobile parts for the purpose of improving heat resistance from the viewpoint of being used in a high temperature environment in addition to weight reduction and cost reduction. .

Lubricating grease used for the sliding portion of the polyamide resin member is required to have properties that do not deteriorate (embrittle) the polyamide resin member in addition to lubricity, low temperature property, and heat resistance. However, when a commonly used lithium soap grease or urea grease is used as a lubricating grease for polyamide resin members, it exhibits aggressiveness against polyamide resin members used in high temperature (eg 150 ° C) environments. Thus, there is a tendency that the polyamide resin member is deteriorated and the performance of the machine parts made of polyamide resin is impaired. That is, lithium soap grease has a tendency to oxidize and deteriorate the polyamide resin member. Urea grease has high heat resistance, but if it is immersed in a resin in the above high temperature environment, There is a tendency that a part of the amine inside is desorbed, and the desorbed amine develops aggressiveness against the polyamide resin member and degrades the polyamide resin.

For example, Patent Document 1 includes a synthetic hydrocarbon oil, a urea-based thickener, and zinc stearate for the purpose of suppressing deterioration of a polyamide resin member in a high temperature (140 ° C. in the embodiment) environment. A lubricant composition is described that contains at least one compound selected from the group consisting of merit acid esters, aromatic sulfonamides, phthalate esters and hindered phenols.

However, in the lubricant composition containing the urea-based thickener described in Patent Document 1, as described above, the polyamide resin member is deteriorated by exhibiting aggressiveness against the polyamide resin member in a high-temperature environment, There was a problem that the performance of the machine parts made of polyamide resin, particularly the elongation at break, was lowered.

JP 2012-102191 A

Therefore, an object of the present invention is to optimize the base oil and the thickener to suppress deterioration of the polyamide resin member particularly under high temperature use environment while having good low temperature characteristics, and to achieve elongation at break. An object of the present invention is to provide a lubricating grease composition for a polyamide resin member that can be maintained at a high level with almost no decrease in the viscosity.

In order to solve the above problems, the gist of the present invention is as follows.

(1) A lubricating grease composition for a polyamide resin member used to be supplied as a lubricant to at least the surface of the sliding portion of a polyamide resin member having a sliding portion with another member. A base oil which is a hydrocarbon oil and a thickener which is a metal composite soap of at least one of barium composite soap and lithium composite soap, and the base oil has a kinematic viscosity at 40 ° C. of 30 to 200 mm ² / s. A lubricating grease composition for polyamide resin members, wherein the dropping point of the thickener is 270 ° C. or higher.

(2) The polyamide resin member according to (1), wherein the base oil is a poly-α-olefin single oil or a mixed oil of the poly-α-olefin and an ethylene-α-olefin copolymer. Lubricating grease composition.

(3) The lubricating grease composition for polyamide resin members according to (1) or (2), wherein the other member is a metal member.

According to the present invention, it contains a base oil that is a synthetic hydrocarbon oil and a thickener that is a metal composite soap of at least one of barium composite soap and lithium composite soap, and the base oil has a kinematic viscosity at 40 ° C. By setting the drop point of the thickener to 270 ° C. or higher within the range of 30 to 200 mm ² / s, it is possible to suppress deterioration of the polyamide resin member particularly in a high temperature use environment while having good low temperature characteristics. Thus, it has become possible to provide a lubricating grease composition for polyamide resin members which can be maintained at a high level with almost no decrease in elongation at break.

Next, an embodiment of the present invention will be described below.

The lubricating grease composition for a polyamide resin member according to the present invention is used to be supplied as a lubricant to at least the surface of the sliding portion of a polyamide resin member having a sliding portion with another member. It has both properties and excellent mechanical properties (especially elongation at break) especially under high temperature use environment.

Other members include, for example, resin materials or metal materials. The resin material may be a resin material having the same composition as the polyamide resin member, or may be a resin material having a different composition. In addition, when the other member is a metal member, the lubricating grease composition of the present invention is preferably used as a lubricant on the surface of the polyamide resin member because it has a particularly remarkable effect.

Here, “high temperature (use) environment” means an environment where the ambient temperature is in the range of 130 to 150 ° C.

The lubricating grease composition of the present invention contains a base oil and a thickener.

(Base oil)
In the present invention, the base oil is a synthetic hydrocarbon oil, and the kinematic viscosity of the base oil at 40 ° C. needs to be in the range of 30 to 200 mm ² / s. When the kinematic viscosity at 40 ° C. of the synthetic hydrocarbon oil is lower than 30 mm ² / s, the deterioration of the polyamide resin member is promoted, and when it is higher than 200 mm ² / s, the torque at low temperature (low temperature torque) increases. Because. In addition, since base oil may have a bad influence with respect to a resin member when using, for example, ester type synthetic oil or ether type synthetic oil other than synthetic hydrocarbon oil, it may be composed only of synthetic hydrocarbon oil. preferable. Synthetic hydrocarbon oils include poly-α-olefins, ethylene-α-olefin copolymers, and polybutenes. As a specific example in which the base oil is composed of a synthetic hydrocarbon oil, it is particularly preferable that the base oil is a single oil composed of poly-α-olefin, or a poly-α-olefin and an ethylene-α-olefin copolymer. And a mixed oil.

In the present invention, the poly-α-olefin refers to a polymer obtained by homopolymerizing or copolymerizing one or more monomers of α-olefin having 3 or more carbon atoms.

Here, the α-olefin is not particularly limited, but is preferably a linear terminal olefin having 3 to 30 carbon atoms, more preferably 4 to 20 carbon atoms, and further preferably 6 to 16 carbon atoms. . More specifically, propylene, 1-butene, 1-pentene, 1-hexene and the like can be mentioned.

The blending ratio of poly-α-olefin with respect to the entire lubricating grease composition is preferably in the range of 67 to 91% by mass. In addition, when the synthetic hydrocarbon oil is a mixed oil of poly-α-olefin and ethylene-α-olefin copolymer, the blending ratio of the poly-α-olefin to the entire lubricating grease composition is 69 to 86 mass. % Is preferable.

In addition, the polymerization degree of poly-α-olefin is not particularly limited, and includes what is usually called an oligomer. Poly-α-olefins may be used alone or in combination of two or more.

In the present invention, the ethylene-α-olefin copolymer refers to a copolymer containing ethylene and one or more α-olefins having 3 or more carbon atoms as constituent monomers.

Here, the α-olefin in the ethylene-α-olefin copolymer is not particularly limited, but preferably has 3 to 30 carbon atoms, more preferably 4 to 20 carbon atoms, and still more preferably 6 to 16 carbon atoms. The linear terminal olefin of these is mentioned. More specifically, propylene, 1-butene, 1-pentene, 1-hexene and the like can be mentioned. Poly-α-olefins may be used alone or in combination of two or more. The ethylene-α-olefin copolymer may have any structure of a random copolymer, an alternating copolymer, a periodic copolymer, and a block copolymer.

The number average molecular weight of the ethylene-α-olefin copolymer is in the range of 40,000 to 200,000, and the weight average molecular weight is in the range of 40,000 to 200,000.

When the synthetic hydrocarbon oil is a mixed oil of a poly-α-olefin and an ethylene-α-olefin copolymer, the blending ratio of the ethylene-α-olefin copolymer to the entire lubricating grease composition is 1.5 to 3.5. It is preferably in the range of mass%. If the blending ratio of the ethylene-α-olefin copolymer is less than 1.5% by mass, the base oil viscosity may not be increased to a desired value within an appropriate range, and if more than 3.5% by mass, The base oil viscosity may be too higher than the appropriate range.

(Thickener)
In the lubricating grease composition of the present invention, it is necessary that the thickener is limited to at least one metal composite soap of lithium composite soap and barium composite soap from the viewpoint of high heat resistance and not deteriorating the polyamide resin. . Furthermore, the dropping point of the thickener is 270 ° C. or higher from the viewpoint of maintaining high breaking elongation of the polyamide resin member by suppressing deterioration of the polyamide resin member under the high temperature environment (during high temperature durability) of the lubricating grease composition. It is necessary to limit to. When the dropping point of the thickener is less than 270 ° C., the lubricating grease composition may attack and deteriorate the polyamide resin member during high temperature durability.

Here, the lithium composite soap refers to a soap obtained by saponifying a plurality of carboxylic acids or esters with lithium hydroxide. The barium composite soap refers to a soap obtained by saponifying a plurality of carboxylic acids or esters with barium hydroxide.

Specific examples of the lithium composite soap or barium composite soap include fatty acids such as stearic acid, oleic acid, and palmitic acid and / or hydroxy fatty acids having 12 to 24 carbon atoms having one or more hydroxyl groups in the molecule, and aromatics. At least one selected from the group consisting of carboxylic acids, aliphatic dicarboxylic acids having 2 to 20 carbon atoms (more preferably 4 to 12 carbon atoms) and carboxylic acid monoamides, for example, lithium compounds such as lithium hydroxide, Or what is obtained by making it react with barium compounds, such as barium hydroxide, is mentioned.

The hydroxy fatty acid having 12 to 24 carbon atoms is not particularly limited, and examples thereof include 12-hydroxystearic acid, 12-hydroxylauric acid, 16-hydroxypalmitic acid and the like. Among these, 12-hydroxystearic acid is particularly preferable. Acid is preferred.

Examples of the aromatic carboxylic acid include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, salicylic acid, p-hydroxybenzoic acid and the like.

Further, the aliphatic dicarboxylic acid having 2 to 20 carbon atoms is not particularly limited, and for example, oxalic acid, malonic acid, succinic acid, methyl succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid Acid, nonamethylene dicarboxylic acid, decamethylene dicarboxylic acid, undecane dicarboxylic acid, dodecane dicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid, pentadecanedicarboxylic acid, hexadecanedicarboxylic acid, heptadecanedicarboxylic acid, octadecanedicarboxylic acid, etc. Preferably adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonamethylene dicarboxylic acid, decamethylene dicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedi Carboxylic acid, penta decane dicarboxylic acid, hexamethylene decanedicarboxylic acid, hepta-decane dicarboxylic acid, octadecane dicarboxylic acid, or the like is used. Of these, azelaic acid and sebacic acid are preferred.

Furthermore, examples of the carboxylic acid monoamide include those in which one carboxyl group of the dicarboxylic acid is amidated. Preferable examples include those in which one carboxyl group of azelaic acid or sebacic acid is amidated.

Examples of amines to be amidated include aliphatic primary amines such as butylamine, amylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, and behenylamine. Aliphatic secondary amines such as dipropylamine, diisopropylamine, dibutylamine, diamylamine, dilaurylamine, monomethyllaurylamine, distearylamine, monomethylstearylamine, dimyristylamine, dipalmitylamine, allylamine, diallylamine, oleylamine Aliphatic unsaturated amines such as dioleylamine, cycloaliphatic amines such as cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, Aromatic amines such as phosphorus, methylaniline, ethylaniline, benzylamine, dibenzylamine, diphenylamine, α-naphthylamine, etc. are mentioned, preferably hexylamine, heptylamine, octylamine, nonylamine, decylamine, laurylamine, myristylamine Palmitylamine, stearylamine, behenylamine, dibutylamine, diamylamine, monomethyllaurylamine, monomethylstearylamine, oleylamine and the like are used.

In blending lithium composite soap or barium composite soap, carboxylic acid and / or its ester and the above metal hydroxide may be added to the base oil and saponified in the base oil.

When preparing lithium complex soap or barium complex soap by saponification reaction in base oil, for example, as carboxylic acid, a combination of stearic acid and / or 12-hydroxystearic acid with azelaic acid or sebacic acid, etc. Is preferably used.

In the saponification reaction in the base oil, a plurality of carboxylic acids and / or esters or acid amides thereof may be saponified simultaneously or sequentially.

When the thickener is lithium composite soap, the blending ratio with respect to the entire lubricating grease composition is preferably 8 to 18% by mass. If the blending amount is less than 8% by mass, the degree of oil separation may increase and the storage stability of the lubricating grease composition may decrease, and if it exceeds 18% by mass, the low-temperature torque at low temperatures may increase. There is.

When the thickener is barium composite soap, the blending ratio with respect to the entire lubricating grease composition is preferably 27 to 33% by mass. If the blending amount is less than 27% by mass, the degree of oil separation may increase and the storage stability of the lubricating grease composition may decrease, and if it exceeds 33% by mass, the low-temperature torque at low temperatures may decrease. There is.

(Other)
In addition to the antioxidants, rust inhibitors, extreme pressure agents, oil agents, viscosity index improvers, and the like that have been added to conventional greases within the range that does not affect the effects of the present invention, These additives can be added as necessary.

Examples of the antioxidant include phenolic antioxidants such as 2,6-ditertiarybutyl-4-methylphenol and 4,4′-methylenebis (2,6-ditertiarybutylphenol), alkyldiphenylamine, Examples include amine-based antioxidants such as phenylamine, phenyl-α-naphthylamine, phenothiazine, alkylated phenyl-α-naphthylamine, and alkylated phenothiazine. In addition, phosphorus antioxidants, sulfur antioxidants, and the like are also used.

Examples of the rust preventive include Ca salt or Na salt of aromatic sulfonic acid or saturated aliphatic dicarboxylic acid, fatty acid, fatty acid amine, alkyl sulfonic acid metal salt, alkyl sulfonic acid amine salt, oxidized paraffin, polyoxyalkyl ether and the like. Can be mentioned.

Examples of extreme pressure agents include phosphorus compounds such as phosphate esters, phosphite esters, phosphate ester amine salts, sulfur compounds such as sulfides and disulfides, dialkyldithiophosphate metal salts (excluding zinc salts), Examples thereof include sulfur compound metal salts such as dialkyldithiocarbamate metal salts, chlorine compounds such as chlorinated paraffin and chlorinated diphenyl, and organometallic compounds such as molybdenum dialkyldithiocarbamate (MoDTP).

Examples of the oily agent include fatty acids or esters thereof, higher alcohols, polyhydric alcohols or esters thereof, aliphatic esters, aliphatic amines, fatty acid monoglycerides, montan wax, amide waxes, and the like.

Examples of the viscosity index improver include polymethacrylate, ethylene-propylene copolymer, polyisobutylene, polyalkylstyrene, styrene-isoprene hydrogenated copolymer, and the like.

Preparation of the composition is performed by a method in which a predetermined amount of each of the above components is added and sufficiently kneaded with a three-roll or high-pressure homogenizer.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Examples 1 to 7 and Comparative Examples 1 to 6)
(1) Method for Preparing Lubricating Grease Composition The method for preparing the lubricating grease composition was as follows.
(1-1) When lithium composite soap (Li-Comp) is used as a thickener First, base oil, 12-hydroxystearic acid (thickener component) and lithium hydroxide (thickener component) are mixed. A predetermined amount was blended in a stirring vessel, and saponification reaction was performed by heating and stirring at about 80 to 130 ° C. Add a predetermined amount of azelaic acid (thickener component), heat and stir at about 80-200 ° C, add lithium hydroxide (thickener component) to it, perform saponification reaction, and then cool to gel A substance was produced. Various additives are added to the generated gel substance and stirred, and then passed through a roll mill or a high-pressure homogenizer so that the following components are contained in the blending amounts (% by mass) shown in Table 1 and Table 2. A lubricating grease composition was prepared. In the saponification reaction, the lubricating grease composition containing the thickener A was used for 1 hour or longer, and the lubricating grease composition containing the thickener E was used for less than 30 minutes. The amount of each component constituting the thickeners A and E was 63.5% by mass of 12-hydroxystearic acid, 19% by mass of azelaic acid, lithium hydroxide, based on the total amount of the thickener. Was 17.5% by mass.

(1-2) When barium composite soap (Ba-Comp) is used as a thickener First, a base oil, sebacic acid (thickener component) and carboxylic acid monostearylamide (thickener component) are mixed and stirred. A predetermined amount was blended, heated and stirred at about 80 to 200 ° C., barium hydroxide (a thickener component) was added thereto to carry out a saponification reaction, and then cooled to produce a gel substance. Various additives are added to the generated gel substance and stirred, and then passed through a roll mill or a high-pressure homogenizer so that the following components are contained in the blending amounts (% by mass) shown in Table 1 and Table 2. A lubricating grease composition was prepared. In the saponification reaction, the lubricating grease composition containing Thickener B was used for 30 minutes or longer, and the lubricating grease composition containing Thickener F was used for less than 15 minutes. In addition, the amount of each component constituting the blended thickeners B and F is 27.5% by mass of sebacic acid, 41.5% by mass of carboxylic acid monostearylamide, and barium hydroxide, based on the total amount of the thickener. Was 31% by mass.

(1-3) When lithium soap (Li-OHST) is used as a thickener First, a base oil, 12-hydroxystearic acid (thickener component) and lithium hydroxide (thickener component) are mixed and stirred. A predetermined amount was added to the mixture, and the mixture was heated and stirred at about 80 to 130 ° C. to conduct a saponification reaction. Furthermore, after heating and stirring to the melting temperature, the mixture was cooled to produce a gel substance. Lubricating grease composition containing the following components in the blending amounts (mass%) shown in Table 2 by adding various additives to the resulting gel-like substance, stirring, and passing through a roll mill or high-pressure homogenizer. A product was prepared. The amount of each component constituting the thickener C added was 88% by mass of 12-hydroxystearic acid and 12% by mass of lithium hydroxide with respect to the total amount of the thickener.

(1-4) When urea is used as a thickener First, base oil, diphenylmethane diisocyanate (thickener component) and octylamine (thickener component) are heated and stirred at 70 to 180 ° C. for reaction. Then, the temperature was raised and cooled to produce a gel substance. Lubricating grease composition containing the following components in the blending amounts (mass%) shown in Table 2 by adding various additives to the resulting gel-like substance, stirring, and passing through a roll mill or high-pressure homogenizer. A product was prepared. The amount of each component constituting the thickener D was 50% by mass for diphenylmethane diisocyanate and 50% by mass for octylamine with respect to the total amount of the thickener.

Poly-α-olefin A: Kinematic viscosity at 40 ° C. 30 mm ² / s (DURASYN 166 manufactured by Ineos Oligomers Japan)
Poly-α-olefin B: Kinematic viscosity at 40 ° C. 46 mm ² / s (DURASYN 168 manufactured by Ineos Oligomers Japan)
Poly-α-olefin C: 40 ° C kinematic viscosity 5 mm ² / s (DURASYN 162, manufactured by Ineos Oligomers Japan)
Poly-α-olefin D: Kinematic viscosity at 40 ° C. 400 mm ² / s (DURASYN 174 manufactured by Ineos Oligomers Japan)
Ethylene-α-olefin copolymer: number average molecular weight 68000, weight average molecular weight 147000 (L6Z-25, Showa Varnish)
Thickener A: Li-Comp with a dropping point of 280 ° C
Thickener B: Ba-Comp (barium complex soap) with a drop point of 270 ° C
Thickener C: Li-OHST with a dropping point of 200 ° C
Thickener D: Urea with a dropping point of 270 ° C
Thickener E: Li-Comp with a dropping point of 255 ° C
Thickener F: Ba-Comp (barium complex soap) with a dropping point of 230 ° C
Antioxidant: Phenylnaphthylamine (VANLUBE 81 manufactured by Sanyo Chemical Industries)
Antirust agent: Neutral calcium sulfonate (NA SUL CA 1089 manufactured by KING)

(2) Evaluation method (2-1) Base oil viscosity The base oil viscosity was measured according to JIS K2283: 2000.

(2-2) Blending penetration The blending penetration was measured according to JIS K2220.7: 2013.

(2-3) Dropping point The dropping point was measured according to JIS K2220.8: 2013.

(2-4) Low temperature characteristics (low temperature torque)
In accordance with JIS K2220.18: 2013, the maximum torque (starting torque) obtained at the start of rotation at −40 ° C. was measured. In the present invention, when the numerical value (index) of the starting torque is 27 or less, it is regarded as an acceptable level, and when it exceeds 27, it is regarded as unacceptable.

(2-5) Compatibility between resin and grease composition under high temperature use environment (elongation at break)
Apply Nylon 66 (registered trademark) grease to the surface of the test piece specified in JIS K7162: 1994 in a thickness of about 1 mm, place it in a thermostatic bath at 150 ° C, leave it for 500 hours, wipe off the lubricant, and wipe off the lubricant. Tensile tests specified in Plastics-Test methods for tensile properties-Part 1: General rules) were performed, and elongation at break was measured. In the present invention, the case where the elongation at break was 30% or more was regarded as an acceptable level, and the case where it was less than 30% was regarded as unacceptable.

(3) Evaluation results Tables 1 and 2 show the evaluation results regarding the low temperature characteristics (low temperature torque) and the high temperature characteristics (breaking elongation) when each lubricating grease composition is applied to the polyamide resin member.

From the evaluation results shown in Table 1, each of Examples 1 to 7 maintains a low starting torque at -40 ° C. of 13 to 27, and has a high elongation at break of 30 to 43%. The compatibility between the resin member and the grease composition was also good.

On the other hand, from the evaluation results shown in Table 2, in Comparative Examples 1 to 6, none of the numerical values of starting torque and breaking elongation at −40 ° C. was at the acceptable level.

According to the present invention, a polyamide resin that has good low-temperature characteristics, can suppress deterioration of a polyamide resin member particularly in a high-temperature use environment, and can be maintained at a high level with almost no decrease in elongation at break. The lubricating grease composition for parts can be provided. The lubricating grease composition of the present invention is suitable for use in sliding parts of various machine parts constituting automobiles, machines, electrical / electronic devices and the like using a resin material such as polyamide resin. Specifically, in automobiles, rolling bearings, sliding bearings or gears that require lubrication of automotive auxiliary equipment such as electric radiator fan motors, fan couplings, electronic control EGR, electronic control throttle valves, alternators, electric power steering, etc. Part and cam part.

Claims

A lubricating grease composition for a polyamide resin member used to be supplied as a lubricant to at least the surface of the sliding portion of a polyamide resin member having a sliding portion with another member,
A base oil that is a synthetic hydrocarbon oil;
A thickening agent which is a metal composite soap of at least one of a barium composite soap and a lithium composite soap,
The kinematic viscosity of the base oil at 40 ° C. is in the range of 30 to 200 mm 2 / s,
A lubricating grease composition for polyamide resin members, wherein the dropping point of the thickener is 270 ° C or higher.
The lubricating grease composition for a polyamide resin member according to claim 1, wherein the base oil is a poly-α-olefin single oil or a mixed oil of the poly-α-olefin and an ethylene-α-olefin copolymer. object.
The lubricating grease composition for polyamide resin members according to claim 1 or 2, wherein the other member is a metal member.