JP2011111475A - Lubricant composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant composition such as a lubricant and grease which can prevent seizing or the like caused when used in automotive parts such as a door lock mechanism, a window regulator, a seat rail, and electric power steering and in a sliding part constituting a moving part such as a tip, an intermeshing part, a lock part, and an engaging part in various devices, has long-term durability, and improves sliding properties. <P>SOLUTION: The lubricant composition includes resin fine particles to be added which are composed of a polyamide, polyarylene ether, polyarylene sulfide, polyether sulfone, polysulfone, polyether ketone, polyether ether ketone, polycarbonate, polyarylate, polyamide-imide, polyimide, polyetherimide resin or the like having a glass transition temperature of not lower than 150°C and have an average particle diameter of 0.1-50 μm and a particle size distribution index of 1-1.5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lubricant composition typified by lubricating oil or grease used for smoothly operating a sliding member, rotating shaft or gear device of a machine for a long time.

  Lubricants such as lubricating oil and grease are used for sliding members, rotating shafts, and gear devices of machines in order to reduce friction caused by direct contact of mechanical elements that move relative to each other.

  These lubricants form an oil film on the contact surface between the mechanical elements that move relative to each other, and if the pressure applied to the contact surface is too large, the lubricant is expelled from the contact surface, the oil film disappears, and a so-called oil-out condition occurs. The purpose cannot be achieved.

  Therefore, by adding a small amount to the lubricant, the additive intervenes on the contact surface of the machine element that contacts while sliding under high surface pressure, preventing the direct contact of the element and exhibiting the reduction of friction or wear. It is known to add.

The necessary conditions for these additives are:
1) Fine particles are well dispersed in lubricating oil or grease and can easily enter the gaps between machine elements,
2) The additive has low friction with the machine element and does not damage the machine element,
3) The additive does not aggregate due to friction,
4) Effective when added in a small amount and does not cause physical or chemical changes in the lubricating oil or grease.
5) The additive does not precipitate in the lubricating oil or grease even if left for a long time. From the above conditions, molybdenum disulfide, polyethylene tetrafluoride, and the like are often used.

  However, additives used in lubricating oils or greases, especially when used at high loads and high speed rotation, are extremely high in extreme pressure at the contact area between machine elements and generate high heat locally. In some cases, gas may be generated. For example, in the case of molybdenum disulfide, there has been a problem such as the generation of a fluorine compound-containing gas in the case of a gas containing sulfur or in the case of tetrafluoropolyethylene.

  In addition, when an inorganic substance such as molybdenum disulfide is added, if a lubricant composed of a hydrocarbon-based organic substance and an inorganic substance are mixed, precipitation will occur after mixing due to the difference in specific gravity, resulting in a non-uniform state. It is known that there are problems such as inconvenience in actual use.

  In order to solve these problems, it has been proposed to use resin fine powder as an additive having a small specific gravity difference from the lubricant and having high heat resistance. If it illustrates concretely, the method (patent documents 1-5) using aromatic resin fine powder and the method (patent document 6) using nylon fine powder will be mentioned.

  The technology using aromatic resin fine powder maintains reliable lubricity even under high temperature and high load by adding resin fine particles of wholly aromatic polyether resins and wholly aromatic polyester resins with an average particle size of 20 μm or less. Further, it is disclosed that, in the technology using nylon fine powder, high lubrication performance can be obtained by using fine powder of nylon 6 or nylon 12 of 20 μm or less.

  However, these resin fine powders are all obtained by, for example, low-temperature pulverization of the resin, and it is presumed that the shape is close to an indeterminate shape and the particle size distribution becomes wide.

  When these added resin fine powders function in the lubricant, it is essential to improve the sliding characteristics by entering the surface interval between the opposing mechanical elements, but actually function effectively. Of the particles to be added, particles on the high particle size side of the particle size distribution often work effectively, and the resin fine powder on the low particle size side does not affect the sliding characteristics. In other words, from the viewpoint of function, adding the fine resin particles on the low particle side means adding unnecessary components.

  In addition, additives with small particle diameters that do not contribute to sliding properties tend to increase the viscosity of the lubricant and tend to be difficult to handle in actual use. It is considered desirable to do so.

Japanese Patent Laid-Open No. 63-135396 JP-A-63-23994 JP 63-17296 A Japanese Patent Laid-Open No. 63-172797 JP 63-172794 A JP 7-252490 A

  The present invention is used for sliding parts constituting moving parts such as a tooth lock part, a meshing part, a locking part, and a locking part in automobile parts such as a door lock mechanism, a window regulator, a seat rail, and an electric power steering, and various devices. It is an object of the present invention to provide a lubricant composition such as a lubricating oil and grease that can prevent seizure or the like that occurs during the process, has long-term durability, and has good sliding characteristics.

  As a result of intensive studies, the present inventors have been able to use resin fine particles that can be used even at high temperature generation under extreme pressure conditions, and that are effective even when the addition amount is small, and a lubricant composition utilizing the same. Was completed.

That is, the present invention
(1) A lubricant comprising resin fine particles having a glass transition temperature of 150 ° C. or higher, an average particle size of 0.1 μm to 50 μm, and a particle size distribution index of 1 to 1.5. Composition,
(2) The resin fine particles are polyamide, polyarylene ether, polyarylene sulfide, polyethersulfone, polysulfone, polyetherketone, polyetheretherketone, polycarbonate, polyarylate, polyamideimide, polyimide, polyetherimide. The lubricant composition as described in (1),
(3) The lubricant composition according to (1) or (2), wherein the content of the resin fine particles is 1% by mass to 50% by mass,
(4) The lubricant composition according to any one of (1) to (3), wherein the lubricant composition is a lubricating oil or a grease.

  According to the present invention, it is used for sliding parts constituting moving parts such as a tooth lock part, a meshing part, a locking part, a locking part, etc. in automobile parts such as a door lock mechanism, a window regulator, a seat rail, and an electric power steering, and various devices. Thus, lubricant compositions such as lubricating oils and greases can be obtained, which can prevent seizure and the like that occur at the time, have long-term durability and good sliding characteristics.

  Hereinafter, embodiments of the present invention will be described in detail.

  The lubricant composition in the present invention can be obtained by mixing a lubricant such as liquid lubricant or semi-solid grease with resin fine particles having a controlled particle size and particle size distribution.

  As the lubricating oil used in the lubricant composition of the present invention, synthetic hydrocarbon oil (for example, poly α olefin oil PAO), synthetic oil such as silicone oil, fluorine oil, ester oil, ether oil, mineral oil, or the like is used. be able to. These lubricating oils can be used alone or in combination of two or more.

  A semi-solid grease can be obtained by adding a thickener to the lubricating oil. Examples of the thickener include conventionally known thickeners such as a soap-based thickener, a urea-based thickener, an organic thickener, and an inorganic thickener. As soap-type thickeners, aluminum soap, calcium soap, lithium soap, metal soap-type thickeners such as sodium soap, lithium-calcium soap, mixed soap-type thickeners such as sodium-calcium soap, aluminum complex, calcium Complex-type thickeners such as complex, lithium complex and sodium complex are listed. Examples of the urea thickener include polyurea, and examples of the organic thickener include polytetrafluoroethylene (PTFE) and sodium terephthalate. Further, examples of the inorganic thickener include organic bentonite, graphite, silica gel and the like.

  For liquid lubricants, solid lubricants such as fluororesins (PTFE, etc.), molybdenum disulfide, graphite, polyolefin waxes (including amides, etc.), phosphorus-based and sulfur-based extreme pressure additives as required Antioxidants such as butylphenol and methylphenol, rust inhibitors, metal deactivators, viscosity index improvers, oiliness agents, antifoaming agents and the like may be added.

  The resin fine particles in the present invention are fine particles made of a resin and have high heat resistance. As an index of heat resistance, in order to maintain the shape in the sliding portion when used as a lubricant composition, the glass transition temperature is 150 ° C. or higher, more preferably 160 ° C. or higher. It is preferably 180 ° C., particularly preferably 200 ° C. or higher, and particularly preferably 220 ° C. or higher. A preferable upper limit is 500 ° C. or less.

  The glass transition temperature can be determined by differential scanning calorimetry (DSC method). That is, in DSC measurement, when the polymer has a melting point, the temperature range from 30 ° C. to 30 ° C. above the melting point, and if not, the temperature range up to 300 ° C. is 20 ° C./min. Glass measured at the rate of temperature rise once, held for 1 minute, then cooled to 0 ° C. at 20 ° C./minute, held for 1 minute, and then heated again at 20 ° C./minute Refers to the transition temperature.

  Specific examples of such resins include polyamide, polyarylene ether, polyarylene sulfide, polyethersulfone, polysulfone, polyetherketone, polyetheretherketone, polycarbonate, polyarylate, polyamideimide, polyimide, polyetherimide. And copolymers thereof.

  Examples of the polyamide include polyamides obtained by polycondensation of a lactam having three or more members, a polymerizable aminocarboxylic acid, a dibasic acid and a diamine or a salt thereof, or a mixture thereof.

  Examples of such polyamides include copolymers of 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, isophthalic acid and 12-aminododecanoic acid (for example, “Grillamide®”). TR55, manufactured by Mzavelke), a copolymer of 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane and dodecadioic acid (for example, “Grillamide (registered trademark)” TR90, manufactured by Mzavelke), A copolymer of 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, isophthalic acid and 12-aminododecanoic acid, and a copolymer of 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane and dodecanedioic acid Mixture with polymer (for example, 'Grillamide (registered trademark)' TR70LX, manufactured by Mzavelke), 4,4'-di (By way of example, 'TROGAMID (TM)' CX7323, manufactured by Degussa) amino copolymer of dicyclohexylmethane and dodeca diacid and the like.

  Among the above, from the viewpoint of ease of dissolution of the polyamide in the solvent, amorphous polyamide is particularly preferable, and among these, non-fully aromatic polyamide is preferable, specifically, aliphatic polyamide, semi-aromatic polyamide, fat Examples include cyclic polyamides.

  The polyarylene ether is a polymer in which aryl groups are connected by an ether bond, and examples thereof include those represented by the general formula (1) and having a structure.

  In this case, the aromatic ring may or may not have a substituent R, and the number m of the substituents is 1 or more and 4 or less. Substituents include saturated hydrocarbon groups having 1 to 6 carbon atoms such as methyl, ethyl and propyl groups, unsaturated hydrocarbon groups such as vinyl and allyl groups, halogens such as fluorine, chlorine and bromine atoms. Preferred examples include a group, an amino group, a hydroxyl group, a thiol group, a carboxyl group, and a carboxy aliphatic hydrocarbon ester group.

  Specific examples of polyarylene ether include poly (2,6-dimethylphenylene ether).

  The polyarylene sulfide is a polymer in which aryl groups are connected by a sulfide bond, and includes a polymer having a structure represented by the general formula (2).

  At this time, the aromatic ring may or may not have a substituent R, and the number m of the substituents is 1 or more and 4 or less. Substituents include saturated hydrocarbon groups such as methyl, ethyl and propyl groups, unsaturated hydrocarbon groups such as vinyl and allyl groups, halogen groups such as fluorine, chlorine and bromine, amino groups and hydroxyl groups. Thiol group, carboxyl group, carboxy aliphatic hydrocarbon ester group and the like. Further, instead of the paraphenylene sulfide unit of the general formula (2), a metaphenylene unit or an orthophenylene unit may be used, or a copolymer thereof may be used.

  Specific examples of the polyarylene sulfide include polyphenylene sulfide.

  As polyether sulfone, what has a structure represented by general formula (a-1) and / or general formula (a-2) is mentioned.

(R in the formula may be the same or different and represents any one selected from an alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 8 carbon atoms, and m is an integer of 0 to 3) Y represents any one selected from a direct bond, oxygen, sulfur, SO ₂ , CO, C (CH ₃ ) _2, CH (CH ₃ ), and CH ₂ )

  Such a polyethersulfone can be produced by a commonly used method. Further, as commercially available polyethersulfone, for example, “ULTRASON E” series manufactured by BSF, “Sumika Excel” series manufactured by Sumitomo Chemical Co., Ltd. and the like can be used.

  Polyarylate is a polyester composed of an aromatic polyhydric alcohol and an aromatic carboxylic acid.

  Specific examples of the polyarylate include bisphenol A / terephthalic acid, bisphenol A / isophthalic acid, and bisphenol A / terephthalic acid / isophthalic acid.

  Such polyarylate can be produced by a generally known method. In addition, as polyarylate produced by a known method, for example, “U polymer” manufactured by Unitika Ltd. can be used.

  As polysulfone, what has a structure represented by General formula (3) is mentioned preferably.

  (R in the formula represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 8 carbon atoms, and m represents an integer of 0 to 3)

  Polyether ketone is a polymer having an ether bond and a carbonyl group. Specifically, what has a structure represented by General formula (4) is mentioned preferably.

  (R in the formula represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 8 carbon atoms, and m represents an integer of 0 to 3)

  Among the polyether ketones, those having a structure represented by the general formula (5) are particularly referred to as polyether ether ketones.

  (R in the formula represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 8 carbon atoms, and m represents an integer of 0 to 3)

  The polycarbonate is a polymer having a carbonate group, and preferably has a structure represented by the general formula (6).

  (R in the formula represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 8 carbon atoms, and m represents an integer of 0 to 3)

  As a specific example, there may be mentioned a polymer in which bisphenol A is polycondensed with a carbonate ester bond and does not have an Rm substituent. Moreover, what copolymerized the polycarbonate and the said polyester may be used.

  Polyamideimide is a polymer having an imide bond and an amide bond, and includes a polymer having a structure represented by the general formula (7).

(Wherein R ₁ and R ₂ represent an aromatic or aliphatic hydrocarbon, and may have a structural group having an ether bond, a thioether bond, a carboquinyl group, a halogen bond, or an amide bond therein. )

  The polyimide is a polymer having an imide bond, and typically includes a polymer having a structure represented by the general formula (8).

(Wherein R ₁ and R ₂ represent an aromatic or aliphatic hydrocarbon, and may have a structural group having an ether bond, a thioether bond, a carboquinyl group, a halogen bond, or an amide bond inside. )

  Particularly in this system, a thermoplastic polyimide is preferable. Specifically, a polycondensate of 1,2,4,5-benzenetetracarboxylic anhydride and 4,4′-bis (3-aminophenyloxy) biphenyl, Examples include polycondensates of 3,3 ′, 4,4′-biphenyltetracarboxylic anhydride and 1,3-bis (4-aminophenyloxy) benzene.

  Polyetherimide is a polymer having an ether bond and an imide bond in the molecule. Specifically, 4,4 ′-[isopropylidenebis (p-phenyleneoxy)] diphthalic dianhydride And a polymer obtained by the condensation of and metaphenylenediamine.

  The molecular weight of the resin in the present invention is preferably 1,000 to 100,000,000, more preferably 1,000 to 10,000,000, still more preferably 5,000 to 1, in terms of weight average molecular weight. 000,000, particularly preferably in the range of 10,000 to 500,000, and most preferably in the range of 10,000 to 100,000.

  The weight average molecular weight here refers to a weight average molecular weight measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent and converted to polystyrene.

  When it cannot be measured with dimethylformamide, tetrahydrofuran is used. When it cannot be measured, hexafluoroisopropanol is used. When it cannot be measured with hexafluoroisopropanol, measurement is performed using 2-chloronaphthalene.

  The particle size of the resin fine particles in the present invention is 50 μm or less in terms of average particle size, and according to a more preferred embodiment, it is 30 μm or less, more preferably 20 μm or less, and particularly preferably 10 μm or less. As a minimum, it is 0.1 micrometer or more, Preferably it is 0.2 micrometer or more, More preferably, it is 0.5 micrometer or more, More preferably, it is 1 micrometer or more.

  The particle size distribution is a particle size distribution index, which is 1.5 or less, preferably 1.2 or less, and particularly preferably 1.1 or less. The preferred lower limit is 1.

  The average particle diameter of the fine particles can be calculated by specifying an arbitrary 100 particle diameters from a scanning electron micrograph and calculating the arithmetic average thereof. In the above photograph, when the shape is not a perfect circle, that is, when it is oval, the maximum diameter of the particle is taken as the particle diameter. In order to accurately measure the particle diameter, it is measured at a magnification of at least 1000 times, and when further accuracy is required, it is at a magnification of 5000 times or more.

  The particle size distribution index is determined based on the value of the particle diameter obtained above based on the following numerical conversion formula.

  Here, Di: particle size of each particle, n: number of measurement 100, Dn: number average particle size, Dv: volume average particle size, PDI: particle size distribution index.

  The shape of the resin fine particles is preferably a true sphere, but may be an oval sphere.

  At this time, the index representing the degree of true sphere can be represented by the ratio of the major axis to the minor axis of the resin fine particles, preferably the ratio is 2 or less, more preferably 1.8 or less, still more preferably Is 1.5 or less, particularly preferably 1.2 or less.

  In addition, this sphericity is obtained by specifying an arbitrary 100 particles from a scanning electron micrograph, measuring the ratio of the major axis to the minor axis, calculating the sphericity, and using an arithmetic average. . The preferred lower limit is 1.

  In order to accurately measure the particle diameter, the measurement is performed at a magnification of at least 1000 times, and when further accuracy is required, at a magnification of 5000 times or more.

  Such resin fine particles are obtained by, for example, dissolving and mixing a polymer to be micronized (hereinafter referred to as polymer A), a polymer B dissolved in a poor solvent of the polymer A, and an organic solvent, and a solution phase (mainly polymer A) ( Hereinafter, an emulsion is formed in a system that phase-separates into two phases, which may be referred to as a polymer A solution phase) and a solution phase mainly composed of polymer B (hereinafter also referred to as polymer B solution phase). After that, the polymer A can be obtained by a method of precipitating the polymer A by contacting with a poor solvent of the polymer A.

  The above method will be described more specifically.

  In the above, “a system in which polymer A, polymer B, and an organic solvent are dissolved and mixed and phase-separated into two phases of a solution phase mainly composed of polymer A and a solution phase mainly composed of polymer B” means a polymer When A, polymer B, and an organic solvent are mixed, the system is divided into two phases, a solution phase mainly containing polymer A and a solution phase mainly containing polymer B.

  By using such a phase-separating system, it is possible to mix and emulsify under the phase-separating conditions to form an emulsion.

  In the above, whether or not the polymer is dissolved is more than 1% by mass with respect to the organic solvent at the temperature at which this method is carried out, that is, the temperature at which the polymer A and the polymer B are dissolved and mixed to separate into two phases. Judged by whether or not to dissolve.

  This emulsion has a polymer A solution phase in the dispersed phase, a polymer B solution phase in the continuous phase, and a polymer A solution in contact with the polymer A poor solvent by contacting the emulsion with the polymer A poor solvent. A precipitates, and polymer fine particles composed of the polymer A can be obtained.

  In this method, polymer A, polymer B, an organic solvent for dissolving them, and a poor solvent for polymer A are used, and the combination thereof is not particularly limited as long as the polymer fine particles of this method can be obtained. A refers to a high molecular weight polymer, preferably a synthetic polymer that does not exist in nature, and more preferably a water-insoluble polymer.

  In the present method, the polymer A is preferably insoluble in the poor solvent, since the present method is intended to precipitate fine particles when contacting with the poor solvent, and a polymer that does not dissolve in the poor solvent described later is used. A water-insoluble polymer is particularly preferable.

  Here, the water-insoluble polymer is a polymer having a solubility in water of 1% by mass or less, preferably 0.5% by mass or less, and more preferably 0.1% by mass or less.

  Examples of the polymer B include thermoplastic resins and thermosetting resins, but those that are soluble in an organic solvent that dissolves the polymer A used in the present method and a poor solvent for the polymer A are preferable. And what dissolve | melts in an alcohol solvent or water is more preferable at the point which is excellent in industrial handleability, and also what melt | dissolves in an organic solvent and melt | dissolves in methanol, ethanol, or water is especially preferable.

  Specific examples of the polymer B include poly (vinyl alcohol) (which may be fully saponified or partially saponified poly (vinyl alcohol)), poly (vinyl alcohol-ethylene) copolymer ( Fully saponified or partially saponified poly (vinyl alcohol-ethylene) copolymer), polyvinylpyrrolidone, poly (ethylene glycol), sucrose fatty acid ester, poly (oxyethylene fatty acid ester), poly (Oxyethylene laurin fatty acid ester), poly (oxyethylene glycol monofatty acid ester), poly (oxyethylene alkylphenyl ether), poly (oxyalkyl ether), polyacrylic acid, sodium polyacrylate, polymethacrylic acid, polymethacrylic acid Sodium, polystyrenesulfonic acid, poly Sodium styrenesulfonate, polyvinylpyrrolidinium chloride, poly (styrene-maleic acid) copolymer, aminopoly (acrylamide), poly (paravinylphenol), polyallylamine, polyvinyl ether, polyvinyl formal, poly (acrylamide), poly ( Methacrylamide), poly (oxyethyleneamine), poly (vinyl pyrrolidone), poly (vinyl pyridine), polyaminosulfone, polyethyleneimine, and other synthetic resins, disaccharides such as maltose, cellobiose, lactose, sucrose, cellulose, chitosan, hydroxy Ethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl cellulose, ethyl hydroxy cellulose, carboxymethyl ethyl cellulose, carboxymethyl cell Cellulose, cellulose derivatives such as sodium carboxymethylcellulose, cellulose ester, amylose and derivatives thereof, starch and derivatives thereof, polysaccharides or derivatives thereof such as dextrin, cyclodextrin, sodium alginate and derivatives thereof, gelatin, casein, collagen, albumin, Examples include fibroin, keratin, fibrin, carrageenan, chondroitin sulfate, gum arabic, agar, protein, etc., preferably poly (vinyl alcohol) (fully saponified or partially saponified poly (vinyl alcohol)) Good), poly (vinyl alcohol-ethylene) copolymer (may be fully or partially saponified poly (vinyl alcohol-ethylene) copolymer), polyethylene glycol, sucrose fatty acid Ester, poly (oxyethylene alkylphenyl ether), poly (oxyalkyl ether), poly (acrylic acid), poly (methacrylic acid), carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, ethylhydroxycellulose, carboxymethyl Cellulose derivatives such as ethyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, cellulose ester, and polyvinyl pyrrolidone, and more preferably poly (vinyl alcohol) (fully saponified or partially saponified poly (vinyl alcohol)). ), Poly (vinyl alcohol-ethylene) copolymer (fully saponified or partially saponified poly (vinyl alcohol-ethylene) Polymer), polyethylene glycol, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, ethylhydroxycellulose, carboxymethylethylcellulose, carboxymethylcellulose, carboxymethylcellulose sodium, cellulose ester, and the like, and polyvinylpyrrolidone, particularly preferred Is poly (vinyl alcohol) (may be fully saponified or partially saponified poly (vinyl alcohol)), poly (ethylene glycol), carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, ethyl Cellulose derivatives such as hydroxycellulose, poly Is Nirupiroridon.

  The molecular weight of the polymer B is preferably 1,000 to 100,000,000, more preferably 1,000 to 10,000,000, and still more preferably 5,000 to 1,000,000 in terms of weight average molecular weight. 000, particularly preferably in the range of 10,000 to 500,000, and most preferably in the range of 10,000 to 100,000.

  The weight average molecular weight here refers to a weight average molecular weight measured by gel permeation chromatography (GPC) using water as a solvent and converted into polyethylene glycol.

  Use dimethylformamide when it cannot be measured with water, use tetrahydrofuran when it cannot be measured with water, and use hexafluoroisopropanol when it cannot be measured with water.

  The organic solvent that dissolves the polymer A and the polymer B is an organic solvent that can dissolve the polymer A and the polymer B to be used, and is selected according to the type of each polymer.

  Specific examples include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, n-decane, n-dodecane, n-tridecane, tetradecane, cyclohexane, cyclopentane, benzene, toluene, xylene, 2- Aromatic hydrocarbon solvents such as methylnaphthalene, ester solvents such as ethyl acetate, methyl acetate, butyl acetate, butyl propionate, butyl butyrate, chloroform, bromoform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, 1 , 1,1-trichloroethane, chlorobenzene, 2,6-dichlorotoluene, halogenated hydrocarbon solvents such as hexafluoroisopropanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl butyl ketone, methanol, ethanol, 1 − Alcohol solvents such as propanol, 2-propanol, N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), propylene carbonate , Aprotic polar solvents such as trimethyl phosphoric acid, 1,3-dimethyl-2-imidazolidinone, sulfolane, carboxylic acid solvents such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid, anisole, diethyl ether, tetrahydrofuran, diisopropyl Ether solvents such as ether, dioxane, diglyme, dimethoxyethane, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium hydrogen sulfate, 1-ethyl-3-imidazolium acetate Ionic liquids or mixtures thereof, such as 1-ethyl-3-methylimidazolium thiocyanate, and the like. Preferred are aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, halogenated hydrocarbon solvents, alcohol solvents, ether solvents, aprotic polar solvents, carboxylic acid solvents, and more preferred are: Alcohol-based solvents, aprotic polar solvents, and carboxylic acid solvents that are water-soluble solvents are preferred, and aprotic polar solvents and carboxylic acid solvents are particularly preferable. Most preferred is N-methyl-2-, because it has a wide range of application to polymer A because it can be dissolved, and can be uniformly mixed with a solvent that can be preferably used as a poor solvent described later, such as water or an alcohol solvent. Pyrrolidone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, propylene carbonate, formic acid, It is an acid.

  These organic solvents may be used in a plurality of types, or may be used in combination. However, particles having a relatively small particle size and a small particle size distribution can be obtained, and when used solvents are recycled. From the standpoint of reducing the process load in manufacturing, avoiding the troublesome separation step, it is preferable to use a single organic solvent, and it should be a single organic solvent that dissolves both polymer A and polymer B. Is preferred.

  The poor solvent for polymer A in this method refers to a solvent that does not dissolve polymer A. When the solvent is not dissolved, the solubility of the polymer A in the poor solvent is 1% by mass or less, more preferably 0.5% by mass or less, and further preferably 0.1% by mass or less.

  In this method, a poor solvent for polymer A is used, and the poor solvent is preferably a poor solvent for polymer A and a solvent that dissolves polymer B. Thereby, the polymer fine particle comprised with the polymer A can be precipitated efficiently. Moreover, it is preferable that the solvent for dissolving the polymer A and the polymer B and the poor solvent for the polymer A are solvents that are uniformly mixed.

  The poor solvent in this method varies depending on the type of polymer A to be used, desirably both types of polymers A and B to be used. Specifically, for example, pentane, hexane, heptane, octane, nonane, n -Aliphatic hydrocarbon solvents such as decane, n-dodecane, n-tridecane, tetradecane, cyclohexane, cyclopentane, etc., aromatic hydrocarbon solvents such as benzene, toluene, xylene, 2-methylnaphthalene, ethyl acetate, methyl acetate Ester solvents such as butyl acetate, butyl propionate and butyl butyrate, chloroform, bromoform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, chlorobenzene, 2,6-dichlorotoluene, Halogenated hydrocarbons such as hexafluoroisopropanol Solvent, ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl butyl ketone, alcohol solvent such as methanol, ethanol, 1-propanol, 2-propanol, dimethyl sulfoxide, N, N-dimethylformamide, N, N -Aprotic polar solvents such as dimethylacetamide, trimethylphosphoric acid, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, sulfolane, carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid Examples include acid solvents, ether solvents such as anisole, diethyl ether, tetrahydrofuran, diisopropyl ether, dioxane, diglyme and dimethoxyethane, and a solvent selected from at least one of water.

  From the viewpoint of efficiently atomizing the polymer A, an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, an alcohol solvent, an ether solvent, and water are preferable, and an alcohol solvent, water is most preferable. Particularly preferred is water.

  In this method, polymer A can be efficiently precipitated and polymer fine particles can be obtained by appropriately selecting and combining polymer A, polymer B, an organic solvent for dissolving them, and a poor solvent for polymer A.

  At this time, the liquid obtained by mixing and dissolving the polymers A and B and the organic solvent for dissolving them is phase-separated into two phases, a solution phase mainly composed of the polymer A and a solution phase mainly composed of the polymer B. is required.

  At this time, the solution-phase organic solvent containing polymer A as the main component and the organic solvent containing polymer B as the main component may be the same or different, but are preferably substantially the same solvent.

  Conditions for generating a state of two-phase separation vary depending on the types of polymers A and B, the molecular weights of polymers A and B, the types of organic solvents, the concentrations of polymers A and B, the temperature and pressure at which this method is performed. come.

  In order to obtain conditions that are likely to result in a phase-separated state, it is preferable that the difference between the solubility parameters of the polymer A and the polymer B (hereinafter also referred to as SP values) is separated.

At this time, the difference in SP value is 1 (J / cm ³ ) ^1/2 or more, more preferably 2 (J / cm ³ ) ^1/2 or more, and further preferably 3 (J / cm ³ ) ^1/2 or more. Particularly preferably, it is 5 (J / cm ³ ) ^1/2 or more, and very preferably 8 (J / cm ³ ) ^1/2 or more. When the SP value is within this range, phase separation is easily performed.

There is no particular limitation as long as both polymer A and polymer B can be dissolved in an organic solvent, but the upper limit of the difference in SP value is preferably 20 (J / cm ³ ) ^1/2 or less, more preferably 15 (J / Cm ³ ) ^1/2 or less, more preferably 10 (J / cm ³ ) ^1/2 or less.

  Here, the SP value is calculated based on the Fedor's estimation method, and is calculated based on the cohesive energy density and the molar molecular volume (hereinafter also referred to as a calculation method). ("SP Value Basics / Applications and Calculation Methods" by Hideki Yamamoto, Information Organization Co., Ltd., published on March 31, 2005).

  When the calculation cannot be performed by this estimation method, the SP value is calculated by an experimental method by determining whether or not the solubility parameter is dissolved in a known solvent (hereinafter also referred to as an experimental method). ("Polymer Handbook Fourth Edition" by J. Brand, published in Wiley 1998).

  In order to select the conditions for the phase separation state, a three-component phase diagram can be prepared by a simple preliminary experiment by observing a state in which the ratio of the three components of the polymer A, the polymer B, and the organic solvent in which they are dissolved is changed. Can be distinguished.

  The phase diagram is prepared by mixing and dissolving the polymers A and B and the solvent at an arbitrary ratio and determining whether or not an interface is formed when allowed to stand at least 3 points, preferably 5 points or more. Preferably, the measurement is performed at 10 points or more, and by separating the region that separates into two phases and the region that becomes one phase, the conditions for achieving the phase separation state can be determined.

  At this time, in order to determine whether or not it is in a phase-separated state, the polymers A and B are adjusted to any ratio of the polymers A and B and the solvent at the temperature and pressure at which the present invention is to be carried out. Then, the polymers A and B are completely dissolved, and after the dissolution, the mixture is sufficiently stirred and left for 3 days to confirm whether or not the phase separation is performed macroscopically.

  However, in the case of a sufficiently stable emulsion, macroscopic phase separation may not occur even after standing for 3 days. In that case, an optical microscope, a phase contrast microscope, or the like is used to determine the phase separation based on whether or not the phase separation is microscopically.

  The phase separation is formed by separating into a polymer A solution phase mainly composed of polymer A and a polymer B solution phase mainly composed of polymer B in an organic solvent. At this time, the polymer A solution phase is a phase in which the polymer A is mainly distributed, and the polymer B solution phase is a phase in which the polymer B is mainly distributed. At this time, the polymer A solution phase and the polymer B solution phase seem to have a volume ratio corresponding to the types and amounts of the polymers A and B used.

  The concentration of the polymers A and B with respect to the organic solvent is premised on being within a possible range that can be dissolved in the organic solvent. Is more than 1% by mass to 50% by mass, more preferably more than 1% by mass to 30% by mass, and still more preferably 2% by mass to 20% by mass.

  In this method, since the interfacial tension between the two phases of the polymer A solution phase and the polymer B solution phase is an organic solvent, the interfacial tension is small, and the resulting emulsion can be stably maintained due to its properties. The particle size distribution seems to be smaller. In particular, when the organic solvents of the polymer A phase and the polymer B phase are the same, the effect is remarkable.

Since the interfacial tension between the two phases in this method is too small, it cannot be measured directly by the hanging drop method in which a different kind of solution is added to a commonly used solution. The interfacial tension can be estimated by estimating from the surface tension. When the surface tension of each phase with air is r ₁ and r ₂ , the interfacial tension r ₁₂ can be estimated by an absolute value of r ₁₂ = r ₁ −r ₂ . At this time, a preferable range of r ₁₂ is more than 0 to 10 mN / m, more preferably more than 0 to 5 mN / m, still more preferably more than 0 to 3 mN / m, and particularly preferably 0. Super-2 mN / m.

  The viscosity between the two phases in this method affects the average particle size and particle size distribution, and the smaller the viscosity ratio, the smaller the particle size distribution. In the case where the viscosity ratio is defined as the polymer A solution phase / polymer solution phase B under the temperature conditions for carrying out the present invention, a preferable range is 0.1 or more and 10 or less, and a more preferable range is 0.1. 2 or more and 5 or less, more preferably 0.3 or more and 3 or less, particularly preferably 0.5 or more and 1.5 or less, and remarkably preferable range is 0.8 or more and 1.2 or less. is there.

  Using the phase-separating system thus obtained, polymer fine particles are produced. The atomization is performed in a normal reaction tank. The temperature suitable for carrying out the present invention is in the range of −50 ° C. to 200 ° C., preferably −20 ° C. to 150 ° C., more preferably 0 ° C. to 120 ° C. from the viewpoint of industrial feasibility. More preferably, it is 10-100 degreeC, Most preferably, it is 20-80 degreeC, Most preferably, it is the range of 20-50 degreeC. From the viewpoint of industrial feasibility, the pressure suitable for carrying out the present invention is in the range of 100 atm from the reduced pressure state, preferably in the range of 1 to 5 atm, and more preferably in the range of 1 to 2 atm. Atmospheric pressure, particularly preferably atmospheric pressure.

  An emulsion is formed by mixing the phase-separated system state under such conditions.

  That is, an emulsion is formed by applying a shearing force to the phase separation solution obtained above.

  In forming the emulsion, the emulsion is formed so that the polymer A solution phase becomes particulate droplets. However, when the volume of the polymer B solution phase is larger than the volume of the polymer A solution phase after phase separation is generally performed. The emulsion in such a form tends to be easily formed, and the volume ratio of the polymer A solution phase is particularly preferably 0.4 or less with respect to the total volume 1 of both phases, 0.4 to 0.1 It is preferable to be between. When preparing the phase diagram, it is possible to set an appropriate range by simultaneously measuring the volume ratio in the concentration of each component.

  The fine particles obtained by this production method are fine particles having a small particle size distribution because a very uniform emulsion can be obtained at the stage of emulsion formation. This tendency is remarkable when a single solvent that dissolves both the polymers A and B is used. For this reason, in order to obtain a sufficient shearing force to form an emulsion, it is sufficient to use stirring by a conventionally known method, such as a liquid phase stirring method using a stirring blade, a stirring method using a continuous biaxial mixer, or a homogenizer. They can be mixed by a generally known method such as a mixing method or ultrasonic irradiation.

  In particular, in the case of stirring with a stirring blade, although depending on the shape of the stirring blade, the stirring speed is preferably 50 rpm to 1200 rpm, more preferably 100 rpm to 1000 rpm, still more preferably 200 rpm to 800 rpm, and particularly preferably 300 rpm to 600 rpm.

  Specific examples of the stirring blade include a propeller type, a paddle type, a flat paddle type, a turbine type, a double cone type, a single cone type, a single ribbon type, a double ribbon type, a screw type, and a helical ribbon type. However, it is not particularly limited as long as a sufficient shearing force can be applied to the system. Moreover, in order to perform efficient stirring, you may install a baffle plate etc. in a tank.

  In order to generate an emulsion, not only a stirrer but also a widely known device such as an emulsifier and a disperser may be used. Specifically, a batch emulsifier such as a homogenizer (manufactured by IKA), polytron (manufactured by Kinematica), TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), Ebara Milder (manufactured by Ebara Seisakusho) , TK fill mix, TK pipeline homomixer (manufactured by Koki Kogyo Co., Ltd.), colloid mill (manufactured by Shinko Pantech Co., Ltd.), slasher, trigonal wet pulverizer (manufactured by Mitsui Miike Chemical Co., Ltd.), ultrasonic homogenizer, static For example, a mixer.

  The emulsion thus obtained is subsequently subjected to a step of precipitating fine particles.

  In order to obtain the fine particles of polymer A, a poor solvent for polymer A is brought into contact with the emulsion produced in the above-described step, thereby precipitating fine particles with a diameter corresponding to the emulsion diameter.

  The contact method of the poor solvent and the emulsion may be a method of putting the emulsion in the poor solvent or a method of putting the poor solvent in the emulsion, but a method of putting the poor solvent in the emulsion is preferable.

  In this case, the method for introducing the poor solvent is not particularly limited as long as the polymer fine particles produced in the present invention are obtained, and any of a continuous dropping method, a divided addition method, and a batch addition method may be used. In order to prevent aggregation of particles, fusion, and coalescence, increase in the particle size distribution, and formation of a mass exceeding 1000 μm, it is preferable to use a continuous dropping method or a divided dropping method, which is industrially efficient. For practical implementation, the continuous dropping method is most preferred.

  The time for adding the poor solvent is from 10 minutes to 50 hours, more preferably from 30 minutes to 10 hours, and even more preferably from 1 hour to 5 hours.

  If the time is shorter than this range, the particle size distribution may increase or a lump may be generated due to the aggregation, fusion and coalescence of the emulsion. Moreover, when it implements in the time longer than this, when industrial implementation is considered, it is unrealistic.

  By carrying out within this time range, aggregation between particles can be suppressed when converting from emulsion to polymer fine particles, and polymer fine particles having a small particle size distribution can be obtained.

  The amount of the poor solvent to be added depends on the state of the emulsion, but is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, and still more preferably, with respect to 1 part by weight of the total emulsion. Is 0.2 to 3 parts by weight, particularly preferably 0.2 to 1 part by weight, and most preferably 0.2 to 0.5 parts by weight.

  The contact time between the poor solvent and the emulsion may be a time sufficient for the fine particles to precipitate, but in order to cause sufficient precipitation and to obtain efficient productivity, 5 minutes to 50 minutes after the addition of the poor solvent is completed. Time, more preferably 5 minutes or more and 10 hours or less, still more preferably 10 minutes or more and 5 hours or less, particularly preferably 20 minutes or more and 4 hours or less, and particularly preferably 30 minutes or more and 3 hours or less. Within hours.

  The polymer fine particle dispersion thus prepared is usually known in the art such as filtration, decantation, vacuum filtration, pressure filtration, centrifugation, centrifugal filtration, spray drying, acid precipitation method, salting out method, freeze coagulation method and the like. By performing solid-liquid separation by the method, the fine particle powder can be recovered.

  The polymer fine particles separated by solid-liquid separation are washed with a solvent or the like, if necessary, to remove impurities attached or contained therein, and then purified. In this case, the preferred solvent is the above poor solvent, and more preferably one or more mixed solvents selected from water, methanol, and ethanol.

  The resulting particles can be dried to remove residual solvent. In this case, examples of the drying method include air drying, heat drying, reduced pressure drying, and freeze drying. The temperature for heating is preferably lower than the glass transition temperature, and specifically 50 to 150 ° C is preferable.

  In the method of the present invention, it is advantageous that the organic solvent and polymer B separated in the solid-liquid separation step performed when obtaining the fine particle powder can be used for recycling.

  The solvent obtained by solid-liquid separation is a mixture of polymer B, an organic solvent and a poor solvent. By removing the poor solvent from this solvent, it can be reused as a solvent for forming an emulsion. The method for removing the poor solvent is usually performed by a known method, and specific examples include simple distillation, vacuum distillation, precision distillation, thin film distillation, extraction, membrane separation, and the like. This is a method by distillation or precision distillation.

  When performing distillation operations such as simple distillation and vacuum distillation, it is preferable to carry out in a state free from oxygen as much as possible because heat is applied to the system and the thermal decomposition of the polymer B and the organic solvent may be accelerated. Preferably, it is performed under an inert atmosphere. Specifically, it is carried out under nitrogen, helium, argon, carbon dioxide conditions.

  Thus, the resin composition obtained can be added to the lubricating oil, and a desired lubricant composition can be obtained by mixing. The mixing method can be any of general solid-liquid mixing methods such as a kneader, planetary mixer, three rolls, mechanical stirrer, self-revolving mixer, homomixer, homogenizer, ball mill, and bead mill. You may adjust combining these methods. Moreover, you may perform a heating and a minimum pressure as needed.

  The amount of resin fine particles added to the lubricant composition is preferably 50% by mass or less, more preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less. is there.

  A preferable lower limit is 1% by mass or more, more preferably 5% by mass or more, and particularly preferably 10% by mass or more.

  A preferable quantitative ratio when mixing the lubricating oil and resin fine particles is 1/99 to 50/50, preferably 1/99 to 40/60, and more preferably as the ratio of resin fine particles / lubricating oil. Is 1/99 to 30/70, more preferably 1/99 to 20/80, and particularly preferably 1/99 to 10/90.

  Additives other than lubricating oil and resin fine particles may be added as necessary, such as thickeners added when greased. In this case, the amount of additive added is the sum of lubricating oil and resin fine particles. It is 1-100 mass parts with respect to 100 mass parts of quantity, Preferably, it is 1-90 mass parts, More preferably, it is 1-60 mass parts, More preferably, it is 1-50 mass parts.

  Since the lubricant composition in the present invention has high heat resistance and lubricity, it can be used as a lubricant for various sliding members. Specifically, on sliding parts that constitute moving parts such as door lock mechanisms, window regulators, seat rails, electric power steering and other automotive parts, tooth tip parts, meshing parts, locking parts, locking parts, etc. Can be used. Moreover, the effect etc. which suppress the sliding noise in operation of sliding members, such as a gearwheel, can also be anticipated by using resin fine particles.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples.

(1) Measuring method of glass transition temperature of resin fine particles A differential scanning calorimeter (DSC-7 type manufactured by Perkin Elmer) was used and measured at a temperature rising rate of 20 ° C./min in a nitrogen atmosphere.

(2) Average particle size and particle size distribution measuring method The individual particle size of the fine particles was measured by observing the fine particles at 1000 times with a scanning electron microscope (JEOL Ltd. scanning electron microscope JSM-6301NF). It was long. When the particles were not perfect circles, the major axis was measured as the particle diameter.

  The average particle diameter was calculated by measuring an arbitrary 100 particle diameter from a photograph and calculating the arithmetic average thereof.

  The particle size distribution index indicating the particle size distribution was calculated based on the following numerical conversion formula for the individual particle diameter values obtained above.

  Ri: particle diameter of each particle, n: number of measurements 100, Dn: number average particle diameter, Dv: volume average particle diameter, PDI: particle diameter distribution index.

Reference Example 1 Production Method for Resin Fine Particles (Polyethersulfone Fine Particles) In a 100 ml four-necked flask, 2.5 g of polyethersulfone (weight average molecular weight 67,000, Sumika Excel (registered trademark)) 5003P manufactured by Sumitomo Chemical Co., Ltd. ), 45 g of N-methyl-2-pyrrolidone as an organic solvent, 2.5 g of polyvinyl alcohol (“GOHSENOL (registered trademark)” GL-05 manufactured by Nippon Synthetic Chemical Industry Co., Ltd., weight average molecular weight 10,600, SP value 32.8) (J / cm ³ ) ^1/2 ) was added, heated to 80 ° C., and stirred until the polymer was dissolved. After returning the temperature of the system to room temperature, 50 g of ion-exchanged water as a poor solvent was added dropwise at a speed of 0.41 g / min via a liquid feed pump while stirring at 450 rpm. When about 12 g of ion-exchanged water was added, the system turned white. After the addition of the entire amount of water, the mixture was stirred for 30 minutes, and the resulting suspension was filtered, washed with 100 g of ion-exchanged water, and filtered off, followed by vacuum drying at 80 ° C. for 10 hours to obtain a white solid. 2.0 g was obtained. When the obtained powder was observed with a scanning electron microscope, it was a polyethersulfone fine particle having a true spherical fine particle shape, an average particle size of 18.7 μm, and a particle size distribution index of 1.07. The heat of fusion of the polyethersulfone used in this example was not observed, and the SP value of this polymer was determined by an experimental method and was 25.8 (J / cm ³ ) ^1/2 .

  It was 225 degreeC when the glass transition temperature of this resin fine particle was measured.

Reference Example 2 Production Method of Resin Fine Particles (Polyamide Fine Particles) In a 100 ml four-necked flask, 2.5 g of amorphous polyamide (weight average molecular weight 18,000 Emzavelke's “Grillamide (registered trademark)” TR55) as an organic solvent 45 g of N-methyl-2-pyrrolidone and 25 g of polyvinyl alcohol (Nippon Synthetic Chemical Industry Co., Ltd., “GOHSENOL (registered trademark)” GL-05) were added, heated to 80 ° C., and stirred until the polymer was dissolved. After returning the temperature of the system to room temperature, 50 g of ion-exchanged water as a poor solvent was dropped at a speed of 0.41 g / min via a liquid feed pump while stirring at 450 rpl. When 12 g of ion exchange water was added, the system turned white. After all the amount of water had been added, the mixture was stirred for 30 minutes, and the resulting suspension was filtered, washed with 100 g of ion-exchanged water, and vacuum-dried at 80 ° C. for 10 hours to obtain 2.25 g of a white solid. . When the obtained powder was observed with a scanning electron microscope, it was a spherical fine particle, and was an amorphous polyamide fine particle having an average particle size of 24.3 μm and a particle size distribution of 1.13. The heat of fusion of the amorphous polyamide used in this example was not observed, and the SP value of this polymer was 23.3 (J / cm ³ ) ^1/2 from the calculation method.

  It was 160 degreeC when the glass transition temperature of this resin fine particle was measured.

Reference Example 3 Production Method of Resin Fine Particles (Polyphenylene Ether Fine Particles) In a 100 ml four-necked flask, 2.5 g of poly (2,6-dimethylphenylene ether) (weight average molecular weight 55,000) and N-methyl as an organic solvent 2-Pyrrolidone 45 g and polyvinyl alcohol 2.5 g (Nippon Synthetic Chemical Industry Co., Ltd. 'GOHSENOL (registered trademark)' GL-05) were added, and the mixture was heated to 80 ° C. and stirred until all the polymers were dissolved. After returning the temperature of the system to room temperature, 50 g of ion-exchanged water as a poor solvent was dropped at a speed of 0.41 g / min via a liquid feed pump while stirring at 450 rpm. When 12 g of ion exchange water was added, the system turned white. After all the amount of water had been added, the mixture was stirred for 30 minutes, and the resulting suspension was filtered, washed with 100 g of ion-exchanged water, and vacuum-dried at 80 ° C. for 10 hours to obtain 2.25 g of a white solid. . When the obtained powder was observed with a scanning electron microscope, it was poly (2,6-dimethylphenylene ether) fine particles having an average particle size of 8.6 μm and a particle size distribution of 1.11. The heat of fusion of the polyphenylene ether used in this example was not observed, and the SP value of this polymer was 20.7 (J / cm ³ ) ^1/2 from the calculation method.

  It was 215 degreeC when the glass transition temperature of this resin fine particle was measured.

Reference Example 4 Production Method of Resin Fine Particles (Polyetherimide Fine Particles) In a 100 ml four-necked flask, 2.5 g of polyetherimide (weight average molecular weight 55,000 Ultem 1010 manufactured by GE Plastics) and N-methyl as an organic solvent 2-Pyrrolidone 45 g and polyvinyl alcohol 2.5 g (Nippon Synthetic Chemical Industry Co., Ltd. 'GOHSENOL (registered trademark)' GL-05) were added, and the mixture was heated to 80 ° C. and stirred until all the polymers were dissolved. After returning the temperature of the system to room temperature, 50 g of ion-exchanged water as a poor solvent was added dropwise at a speed of 0.41 g / min via a liquid feed pump while stirring at 450 rpm. When 12 g of ion exchange water was added, the system turned white. After the entire amount of water was added, the mixture was stirred for 30 minutes. Further, 50 g of water was added in a lump, and the resulting suspension was centrifuged at 20,000 times the gravitational acceleration for 20 minutes in a centrifuge to remove the supernatant. The obtained solid content was filtered, washed with 100 g of water, and vacuum-dried at 80 ° C. for 10 hours to obtain 2.1 g of a white solid. When the obtained powder was observed with a scanning electron microscope, it was a spherical shape, and was a polyetherimide fine particle having an average particle size of 0.7 μm and a particle size distribution of 1.13. The heat of fusion of the polyetherimide used in this example was not observed, and the SP value of this polymer was 24.0 (J / cm ³ ) ^1/2 from the experimental method.

  It was 217 degreeC when the glass transition temperature of this resin fine particle was measured.

Reference Example 5 Production method of resin fine particles (polyacrylonitrile fine particles) In a 100 ml four-necked flask, 2.5 g of polyacrylonitrile (weight average molecular weight 610,000, manufactured by Aldrich), 45 g of dimethyl sulfoxide as an organic solvent, polyvinyl alcohol 2 0.5 g (Nippon Synthetic Chemical Industry Co., Ltd. 'GOHSENOL (registered trademark)' GL-05) was added, and the mixture was heated to 80 ° C and stirred until all the polymers were dissolved. After returning the temperature of the system to room temperature, 50 g of ion-exchanged water as a poor solvent was dropped at a speed of 0.41 g / min via a liquid feed pump while stirring at 450 rpm. When 12 g of ion exchange water was added, the system turned white. After the entire amount of water was added, the mixture was stirred for 30 minutes, and the resulting suspension was filtered, washed with 100 g of ion-exchanged water, and vacuum-dried at 80 ° C. for 10 hours to obtain 2.0 g of a white solid. . When the obtained powder was observed with a scanning electron microscope, it was a spherical particle, and was a polyacrylonitrile fine particle having an average particle size of 16.8 μm and a particle size distribution of 1.15. The heat of fusion of the polyacrylonitrile used in this example was not observed, and the SP value of this polymer was 29.5 (J / cm ³ ) ^1/2 from the calculation method.

  It was 101 degreeC when the glass transition temperature of this resin fine particle was measured.

Reference Example 6 Production Method of Resin Fine Particles (Polyamide Fine Particles by Freeze-Crushing Method) Amorphous polyamide (weight average molecular weight: 18,000 MZ Berke's 'Grillamide (registered trademark)' TR55) pellets were freeze-pulverized under liquid nitrogen. Finely pulverized polyamide fine particles were obtained. The average particle size was 30 μm, and the particle size distribution index was 3.3. Observation with a scanning electron microscope revealed that the particles were amorphous.

  It was 160 degreeC when the glass transition temperature of this resin fine particle was measured.

Examples 1-4, Comparative Examples 1-3
<Method for preparing lubricant composition>
10 parts by mass of the resin fine particles prepared in Reference Examples 1 to 6 were added to 90 parts by mass of poly α olefin oil (manufactured by Nippon Steel Chemical Co., Ltd.), and mixed and stirred to prepare a lubricant composition containing resin fine particles. In Comparative Example 3, the same operation was performed except that the resin fine particles were not used.

<Lubrication performance test of lubricant composition containing resin fine particles>
These evaluations were performed using a reciprocating sliding tester.

  The above-mentioned lubricant composition was applied onto a SUS314 substrate that was galvanized with a thickness of 1 μm, and a 3 mmφ hard sphere was applied at a speed of 100 mm / sec, a sliding distance of 50 mm, and a sliding number of 1000 times with a force of 50 g of vertical load. The lubrication performance test was conducted under the conditions, and the sliding characteristics were compared.

  As a result of measuring the dynamic friction coefficient, when the number of sliding is 1000 times, the coefficient of friction is less than 50% with respect to the friction coefficient when the poly α-olefin oil alone is subjected to the sliding test. What was present was Δ, and 100% or more was rated as x.

  Further, after the test, the peeling of the zinc plating applied to the sliding surface is observed with an optical microscope. The plating is not peeled off or 20% or less is ○, less than 50% is Δ, 50% or more What peeled was set as x.

Claims (4)

A lubricant composition comprising resin fine particles having a glass transition temperature of 150 ° C. or higher, an average particle size of 0.1 μm to 50 μm, and a particle size distribution index of 1 to 1.5. One or more types of resin fine particles selected from polyamide, polyarylene ether, polyarylene sulfide, polyethersulfone, polysulfone, polyetherketone, polyetheretherketone, polycarbonate, polyarylate, polyamideimide, polyimide, polyetherimide The lubricant composition according to claim 1, wherein 3. The lubricant composition according to claim 1, wherein the content of the resin fine particles is 1% by mass to 50% by mass. The lubricant composition according to any one of claims 1 to 3, wherein the lubricant composition is a lubricating oil or a grease.