CN114302916A

CN114302916A - Polyamide resin composition for sliding member and sliding member

Info

Publication number: CN114302916A
Application number: CN202080059795.7A
Authority: CN
Inventors: 岩村和树; 吉村信宏
Original assignee: Toyobo Co Ltd
Current assignee: Dongyang Textile Mc Co ltd
Priority date: 2019-09-27
Filing date: 2020-09-11
Publication date: 2022-04-08
Anticipated expiration: 2040-09-11
Also published as: JP6872155B1; CN114302916B; TW202118830A; JPWO2021060030A1; WO2021060030A1; TWI845760B

Abstract

The present invention aims to provide a polyamide resin composition suitable for molding of sliding parts which are required to have excellent moldability and heat resistance stability and excellent sliding characteristics, particularly excellent abrasion resistance and sliding stability with particles having high hardness (hereinafter, also referred to as dust) interposed therebetween. The polyamide resin composition for a sliding member of the present invention contains: a crystalline polyamide resin (A); a modified polyolefin resin (B) having a reactive functional group capable of reacting with the terminal group and/or the main chain amide group of the polyamide resin (a); a thermoplastic elastomer (C) having a reactive functional group capable of reacting with the terminal group and/or the main chain amide group of the polyamide resin (a); an antioxidant (D); and a release agent (E) in which the modified polyolefin resin (B) and the thermoplastic elastomer (C) are dispersed in a matrix of the polyamide resin (A) in a region having a particle diameter of 5 μm or less.

Description

Polyamide resin composition for sliding member and sliding member

Technical Field

The present invention relates to a polyamide resin composition, and more particularly to a polyamide resin composition suitable for molding a sliding member.

Background

Polyamide resins are crystalline and therefore have excellent sliding properties, but solid lubricants such as molybdenum disulfide, graphite, and fluorine resins, various lubricating oils, and liquid lubricants such as silicone oils are known to be blended in order to obtain more excellent sliding properties.

These sliding improvers have a drawback that a large amount of solid lubricant needs to be mixed, and the toughness of the polyamide resin as a base material is significantly reduced. Although the liquid lubricant can impart a high sliding property in a relatively small amount, in many cases, the liquid lubricant has poor compatibility with a resin as a base material, and the surface of a molded article is easily contaminated with the liquid lubricant, which has a drawback that the use is limited.

As a method for improving the disadvantages caused by the mixing of various lubricants as described above, a method of mixing a modified ethylene polymer and a modified high-density polyethylene having a molecular weight within a specific range has been proposed (patent document 1); a method of mixing a modified polyolefin resin while using a crystalline polyamide resin having a high viscosity (patent document 2), and the like.

According to the polyamide resin composition, a molded article having excellent sliding properties can be provided without the above-mentioned disadvantages. However, in recent years, higher-level properties such as improvement in moldability, improvement in heat resistance stability, and improvement in sliding properties have been required due to a tendency toward weight reduction of molded articles, complication of the shape of molded articles, and the like.

Documents of the prior art

Patent document

Patent document 1 Japanese patent application laid-open No. Hei 8-157714

Patent document 2 WO2008/075699 publication

Disclosure of Invention

Problems to be solved by the invention

An object of the present invention is to provide a polyamide resin composition suitable for molding of a sliding member which is required to have excellent moldability and heat resistance stability and also excellent sliding characteristics, particularly excellent wear resistance and sliding stability with particles having high hardness (hereinafter, also referred to as dust (dust)) interposed therebetween.

Technical scheme for solving problems

The present inventors have conducted intensive studies to achieve the above-mentioned object, and as a result, have found that an antioxidant and a release agent added to improve moldability and heat resistance can improve sliding properties, and have completed the present invention.

That is, the present invention has the following configuration.

[1]

A polyamide resin composition for a sliding member, comprising: a crystalline polyamide resin (A); a modified polyolefin resin (B) having a reactive functional group capable of reacting with the terminal group and/or the main chain amide group of the polyamide resin (a); a thermoplastic elastomer (C) having a reactive functional group capable of reacting with the terminal group and/or the main chain amide group of the polyamide resin (a); an antioxidant (D); and a release agent (E) in which the modified polyolefin resin (B) and the thermoplastic elastomer (C) are dispersed in a matrix of the polyamide resin (A) in a region having a particle diameter of 5 μm or less.

[2]

The polyamide resin composition for sliding parts according to [1], wherein the antioxidant (D) and the release agent (E) are compounds that inhibit deactivation of the reactive functional groups of the modified polyolefin resin (B) and the thermoplastic elastomer (C). [3]

The polyamide resin composition for sliding parts according to [1] or [2], wherein the reactive functional group is an acid anhydride.

[4]

The polyamide resin composition for sliding parts according to any one of [1] to [3], wherein the antioxidant (D) is a hindered phenol antioxidant.

[5]

The polyamide resin composition for a sliding member according to any one of [1] to [4], wherein the release agent (E) is a higher fatty acid ester compound.

[6]

The polyamide resin composition for sliding members according to any one of [1] to [5], wherein the thermoplastic elastomer (C) is a styrene-based and/or olefin-based thermoplastic elastomer.

[7]

A sliding member obtained from the polyamide resin composition for sliding members according to any one of [1] to [6 ].

ADVANTAGEOUS EFFECTS OF INVENTION

The polyamide resin composition of the present invention is excellent in moldability and heat resistance stability, and is also recognized to improve sliding characteristics such as improvement in abrasion resistance and less change in friction coefficient.

Drawings

Fig. 1 is an image obtained by observing a cross section of the evaluation sample prepared in example 1 with a differential interference microscope.

Fig. 2 is an image obtained by observing a cross section of the evaluation sample prepared in comparative example 6 with a differential interference microscope.

Detailed Description

The present invention will be described in detail below. The polyamide resin composition for a sliding member of the present invention contains: a crystalline polyamide resin (A); a modified polyolefin resin (B) having a reactive functional group capable of reacting with the terminal group and/or the main chain amide group of the polyamide resin (a) (hereinafter, also referred to as modified polyolefin resin (B)); a thermoplastic elastomer (C) having a reactive functional group capable of reacting with the terminal group and/or the main chain amide group of the polyamide resin (a) (hereinafter, also referred to as a thermoplastic elastomer (C)); an antioxidant (D); and a release agent (E).

The amount of each component is represented by mass parts assuming that the total amount of the crystalline polyamide resin (a), the modified polyolefin resin (B), and the thermoplastic elastomer (C) is 100 mass parts. In the polyamide resin composition of the present invention, the blending amount may be set as it is to the content in the polyamide resin composition.

The crystalline polyamide resin (A) is not particularly limited as long as it is a crystalline polymer having an amide bond (-NHCO-) in the main chain, and examples thereof include polyamide 6(NY6), polyamide 66(NY66), polyamide 46(NY46), polyamide 11(NY11), polyamide 12(NY12), polyamide 610(NY610), polyamide 612(NY612), polymetaxylylene adipamide (MXD6), hexamethylenediamine-terephthalic acid polymer (6T), hexamethylenediamine-terephthalic acid and adipic acid polymer (66T), hexamethylenediamine-terephthalic acid and epsilon-caprolactam copolymer (6T/6), trimethylhexamethylenediamine-terephthalic acid polymer (TMD-T), isophthalic acid and adipic acid-isophthalic acid copolymer (MXD-6/I), trimethylhexamethylenediamine and copolymers of terephthalic acid with epsilon-caprolactam (TMD-T/6), diaminodicyclohexylmethane (CA), and copolymers of isophthalic acid with laurolactam, and the like. These may be used in a mixture of 1 or more than 2 kinds. Among them, polyamide 6(NY6) and polyamide 66(NY66) are preferably used.

The relative viscosity of the crystalline polyamide resin (A) is not particularly limited, but is preferably 2.0 to 5.0, more preferably 2.0 to 3.5, as measured in a 96% sulfuric acid solution (polyamide resin concentration: 1g/dl, temperature: 25 ℃).

The modified polyolefin resin (B) is a resin obtained by modifying a polyolefin resin. Examples of the polyolefin resin include high-density polyethylene, low-density polyethylene, ultrahigh-molecular-weight polyethylene, linear low-density polyethylene, polypropylene, poly (1-butene), poly (4-methylpentene), and the like. These may be used in a mixture of 1 or more than 2 kinds. Among them, high density polyethylene is preferably used.

In order to improve the compatibility with the crystalline polyamide resin (a), the modified polyolefin resin (B) has a reactive functional group capable of reacting with the terminal group (amino group or carboxyl group) and/or the main chain amide group of the polyamide resin (a). Examples of the reactive functional group include a carboxyl group, an acid anhydride group, an epoxy group, an oxazoline group, an amino group, and an isocyanate group. Among them, an acid anhydride group is preferable from the viewpoint of high reactivity with the polyamide resin (a).

The content of the reactive functional group in the modified polyolefin resin (B) is preferably 0.05 to 8% by mass, more preferably 0.1 to 5% by mass. The method for producing the modified polyolefin resin (B) having the reactive functional group is not particularly limited, and examples thereof include a method in which a compound having the reactive functional group is reacted in the step of producing a polyolefin resin; a method of mixing pellets of a polyolefin resin with a compound having the above-mentioned reactive functional group, and kneading the mixture by an extruder or the like to react.

The amount of the modified polyolefin resin (B) to be mixed is not particularly limited as long as the modified polyolefin resin (B) can be dispersed in a region having a particle diameter of 5 μm or less in the matrix of the polyamide resin (a), and is usually 0.5 to 10% by mass, preferably 1 to 8% by mass, and more preferably 2 to 6% by mass, based on 100% by mass of the total resin component.

The thermoplastic elastomer (C) is not particularly limited, and examples thereof include styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyurethane-based thermoplastic elastomers. These may be used in a mixture of 1 or more than 2 kinds.

The styrene-based thermoplastic elastomer is not particularly limited, and examples thereof include a styrene/butadiene/styrene block copolymer (SBS), a styrene/ethylene-butylene/styrene block copolymer (SEBS) as a hydrogenated product thereof, a styrene/butadiene copolymer (SBR), a styrene/ethylene/butylene copolymer (HSBR) as a hydrogenated product thereof, a styrene/isoprene/styrene block copolymer (SIS), and a styrene/ethylene-propylene/styrene block copolymer (SEPS) as a hydrogenated product thereof.

The olefinic thermoplastic elastomer is not particularly limited, and examples thereof include rubbers such as ethylene/propylene/diene rubber (EPDM), ethylene/propylene rubber (EPR), and butyl rubber (IIR), dynamically crosslinked olefinic thermoplastic elastomers, and ethylene copolymers having flexibility.

The polyamide-based thermoplastic elastomer is not particularly limited, and examples thereof include polyether ester amides and polyester amides in which a polyamide having high crystalline melting temperature is used as a hard segment and a polyether or polyester having low glass transition temperature is used as a soft segment.

The polyester-based thermoplastic elastomer is not particularly limited, and examples thereof include a block copolymer of a polyether polyester and a polyester, in which a crystalline polyester having a high melting temperature is used as a hard segment and a polyether or polyester having a low glass transition temperature is used as a soft segment.

The polyurethane-based thermoplastic elastomer is not particularly limited, and examples thereof include polyether polyurethane and polyester polyurethane in which a crystalline polyester having a high melting temperature is used as a hard segment and a polyether or polyester having a low glass transition temperature is used as a soft segment.

Among these thermoplastic elastomers, from the viewpoint of a balance between the toughness-improving effect and the elastic modulus, styrene-based and/or olefin-based thermoplastic elastomers are preferred, styrene-based thermoplastic elastomers are more preferred, and SEBS is further preferred.

In order to improve the compatibility with the crystalline polyamide resin (a), the thermoplastic elastomer (C) has a reactive functional group capable of reacting with a terminal group (amino group or carboxyl group) and/or a main chain amide group of the polyamide resin (a). Examples of the reactive functional group include a carboxyl group, an acid anhydride group, an epoxy group, an oxazoline group, an amino group, and an isocyanate group. Among them, an acid anhydride group is preferable from the viewpoint of high reactivity with the polyamide resin (a).

The content of the reactive functional group in the thermoplastic elastomer (C) is preferably 0.05 to 8% by mass, more preferably 0.1 to 5% by mass. The method for producing the thermoplastic elastomer (C) having the reactive functional group is not particularly limited, and examples thereof include a method in which a compound having the reactive functional group is reacted in the step of producing a thermoplastic elastomer; a method of mixing pellets of a thermoplastic elastomer with the compound having the reactive functional group, and kneading the mixture with an extruder or the like to react the mixture.

The amount of the thermoplastic elastomer (C) to be mixed is not particularly limited as long as the thermoplastic elastomer (C) can be dispersed in the matrix of the polyamide resin (a) in the form of a region having a particle diameter of 5 μm or less, and is usually 0.1 to 10% by mass, preferably 1 to 7% by mass, based on 100% by mass of the total resin component.

The antioxidant (D) is preferably a compound that suppresses deactivation of the reactive functional groups of the modified polyolefin resin (B) and the thermoplastic elastomer (C). By "inhibiting the deactivation of the reactive functional group" is meant "not reacting with the reactive functional group". That is, the antioxidant (D) is a compound which does not inhibit the fine dispersion of the modified polyolefin resin (B) and the thermoplastic elastomer (C) in the matrix of the polyamide resin (A).

The antioxidant (D) is not particularly limited, and examples thereof include organic antioxidants such as hindered phenol antioxidants, sulfur antioxidants and phosphorus antioxidants, and heat stabilizers which do not have a functional group reactive with an acid anhydride group when the reactive functional group of the modified polyolefin resin (B) and the thermoplastic elastomer (C) is an acid anhydride group, and hindered phenol antioxidants are preferable. These may be used in a mixture of 1 or more than 2 kinds. Examples of the functional group reactive with an acid anhydride group include an amino group and a hydroxyl group. The phenolic hydroxyl group of the hindered phenol structure does not belong to the functional group that reacts with the acid anhydride group. Amine antioxidants are not preferred because they react with the reactive functional groups to deactivate them.

The amount of the antioxidant (D) is preferably 0.01 to 1 part by mass, more preferably 0.1 to 0.5 part by mass, per 100 parts by mass of the total resin component. The amount of the antioxidant (D) is within the above range, and not only contributes to improvement of the sliding property and toughness of the polyamide resin composition, but also prevents oxidation degradation with time as a formulation amount corresponding to the amount of the polyamide resin composition.

The release agent (E) is preferably a compound that suppresses deactivation of the reactive functional groups of the modified polyolefin resin (B) and the thermoplastic elastomer (C). By "inhibiting the deactivation of the reactive functional group" is meant "not reacting with the reactive functional group". That is, the release agent (E) is a compound which does not inhibit the fine dispersion of the modified polyolefin resin (B) and the thermoplastic elastomer (C) in the matrix of the polyamide resin (a).

The release agent (E) is not particularly limited, and examples thereof include higher fatty acid ester compounds, amide compounds, polyethylene wax, silicone, polyethylene oxide, and the like. These may be used in a mixture of 1 or more than 2 kinds. When the reactive functional group of the modified polyolefin resin (B) and the thermoplastic elastomer (C) is an acid anhydride group, the release agent (E) is preferably a higher fatty acid ester compound. The higher fatty acid is a fatty acid having more than 10 carbon atoms, and preferably a fatty acid having 11 to 30 carbon atoms. The metal salt compound is not preferable because it reacts with the reactive functional group to deactivate the compound.

The amount of the release agent (E) to be mixed is preferably 0.05 to 1 part by mass, more preferably 0.1 to 0.8 part by mass, per 100 parts by mass of the total resin components. If the amount of the release agent (E) is within the above range, the composition can not only contribute to improvement of the sliding property and toughness of the polyamide resin composition, but also ensure appropriate releasability.

The antioxidant (D) and the release agent (E) do not inhibit the fine dispersion of the modified polyolefin resin (B) and the thermoplastic elastomer (C) in the matrix of the polyamide resin (A). Therefore, the modified polyolefin resin (B) and the thermoplastic elastomer (C) are efficiently reacted with the polyamide resin (A) to finely disperse the polyamide resin (A) in the matrix thereof in the region having a particle diameter of 5 μm or less. As a result, it is considered that the effect of improving the sliding property by the modified polyolefin resin (B) and the effect of improving the toughness by the thermoplastic elastomer (C) effectively act, and the specific effects of the present invention are exhibited. The particle diameter is preferably 4 μm or less, more preferably 3.5 μm or less. The lower limit of the particle size is not particularly limited, but is preferably 1 μm or more, more preferably 2 μm or more, from the viewpoint of fluidity.

In the polyamide resin composition of the present invention, in addition to the components (a) to (E), additives such as carbon black or copper oxide, alkali metal halide, light stabilizer or heat stabilizer, crystal nucleus agent, lubricant, antistatic agent, pigment, dye, coupling agent, etc., which have been conventionally mixed in polyamide resin compositions, may be mixed in the range not to inhibit the fine dispersion of the modified polyolefin resin (B) and the thermoplastic elastomer (C) in the matrix of the polyamide resin (a). Further, the strength and rigidity of the molded article can be greatly improved by mixing the filler. Examples of the filler include glass fiber, carbon fiber, metal fiber, aramid fiber, asbestos, potassium titanate whisker, wollastonite, glass flake, glass bead, talc, mica, clay, calcium carbonate, barium sulfate, titanium oxide, and alumina. The total amount of the components (a) to (E) in the polyamide resin composition of the present invention is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more.

The polyamide resin composition of the present invention is produced by kneading the components using, for example, a single-screw extruder, a twin-screw extruder, or a pressure kneader. The mixing device is preferably a twin-screw extruder. In one embodiment, the components (a) to (E) and a pigment added according to the use are mixed and added to a twin-screw extruder. The polyamide resin composition having excellent sliding properties can be produced by uniformly kneading the components using a twin-screw extruder. The mixing temperature of the double-screw extruder is preferably 220-300 ℃, and the mixing time is preferably about 2-15 minutes.

The polyamide resin composition of the present invention can be widely used as a raw material for sliding parts such as electric/electronic parts, automobile parts, building parts, and industrial parts, which require slidability. Specific examples of the sliding member include a bearing, a gear, a door, and a chain guide.

[ examples ]

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The physical properties of the polyamide resin molded articles obtained in the following examples were measured by the following test methods.

The raw materials used in the examples and comparative examples are as follows.

The crystalline polyamide resins (a) used were (a1) to (A3).

(A1) Polyamide 66(RV ═ 3.4): EPR34W (manufactured by Shanghai Shenma plastics science and technology Co., Ltd.), melting point of 265 deg.C

(A2) Polyamide 66(RV ═ 2.8): vydyne 21FSR (available from Ascend Co., Ltd.), melting point 265 ℃ C

(A3) Polyamide 66(RV ═ 2.4): EPR24 (manufactured by Shanghai Shenma plastics science and technology Co., Ltd.), melting point of 265 deg.C

As the modified polyolefin resin (B), the resins (B1) and (B2) were used.

(B1) Maleic anhydride-modified polyethylene: modic DH0200 (manufactured by Mitsubishi chemical Co., Ltd.)

(B2) Unmodified polyethylene: HI-ZEX 6203B (manufactured by Priman Polymer Co., Ltd.)

The thermoplastic elastomers (C) used were (C1) and (C2).

(C1) Maleic anhydride-modified SEBS: tuftec M-1943 (manufactured by Asahi Kasei Co., Ltd.)

(C2) Unmodified SEBS: tuftec H-1221 (manufactured by Asahi Kasei Co., Ltd.)

As the antioxidant (D), the antioxidants (D1) and (D2) were used.

(D1) Hindered phenol-based antioxidant: triethylene glycol bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate (SONGWON, SONGNOX 2450)

(D2) Amine-based antioxidant: nonflex DCD (product of Seiko chemical Co., Ltd.)

As the mold release agent (E), the mold release agents (E1) to (E3) were used.

(E1) Aliphatic ester: licolub WE-40 (manufactured by Clariant Japan K.K.)

(E2) Magnesium stearate: N.P.1500-S (manufactured by southern chemical industries Co., Ltd.)

(E3) Calcium montanate: licomont Cav102(Clariant Japan K.K.)

Examples 1 to 7 and comparative examples 1 to 8

Evaluation samples were produced by weighing each raw material in accordance with the mixing ratio of the polyamide resin compositions shown in tables 1 and 2, mixing the raw materials with a tumbler (tubbler), and feeding the mixture to a twin-screw extruder. The set temperature of the double-screw extruder is 250-300 ℃, and the mixing time is 5-10 minutes. The obtained pellets were molded into various evaluation samples by an injection molding machine. The barrel temperature of the extrusion molding machine is 250-290 ℃, and the die temperature is 80 ℃.

Various evaluation methods are described below. The evaluation and measurement results are shown in tables 1 and 2.

1. Relative viscosity of Polyamide resin (96% sulfuric acid solution method)

The measurement was carried out using a Ubbelohde viscosity tube in a 96 mass% sulfuric acid solution at 25 ℃ at a polyamide resin concentration of 1 g/dl.

2. Melting Point of Polyamide resin

The endothermic peak temperature was determined by measuring with a differential scanning calorimeter (SEIKO INSTRUMENTS Co., Ltd., EXSTAR 6000) at a temperature rising rate of 20 ℃ per minute

3. Tensile strength, tensile modulus of elasticity, and tensile elongation

Measured according to ISO 178.

4. Impact resistance

Measured according to ISO 179-1.

5. Slidability of

Using a thrust (scrub) abrasion tester, uniformly coating the surface of the molybdenum disulfide formula on a certain amount of lubricating grease, silica sand and volcanic ash in a mass ratio of 1: 1: 1 with a cylindrical shaped product made of Polyoxymethylene (POM), and under a load of 30kgf/cm²And a speed of 40mm/sec for 30 minutes. Then, the kinetic friction coefficient was calculated from the weight difference before and after wear and the convergence load value at the time of wear test.

6. Particle size

The shaped evaluation sample was cut, and a section was prepared using a microtome equipped with a glass knife. The prepared cross-section was observed with a differential interference microscope to take photographs. In the micrograph of the modified polyolefin resin (B) and the thermoplastic elastomer (C), 10 regions having the largest dispersion diameters were arbitrarily selected, the major axes of the selected regions were measured, and the average value thereof was defined as the particle diameter.

[ Table 1]

[ Table 2]

The Charpy impact strengths of examples 1 to 7 were all 6kJ/m²As described above, a composition having higher toughness than the unmodified polyamide was obtained. Further, the tensile modulus and the tensile elongation were not lost significantly. The abrasion resistance and the coefficient of dynamic friction after the sliding test with dust were also superior to those of comparative examples 1 to 8. In comparative examples 1 and 2, the fracture of the brittle surface during sliding was not suppressed due to insufficient toughness, and the amount of wear was increased. In comparative example 3, although the toughness was sufficient, the effect of the polyolefin resin in the sliding property was hardly exhibited. In comparative example 4, since an unmodified thermoplastic elastomer was mixed, it was difficult to form a finely dispersed region, and it was difficult to obtain a particle diameter exhibiting excellent physical properties, which was not preferable. In comparative examples 5, 6 and 7, since the amine antioxidant and the fatty acid metal salt were used, respectively, and reacted with the reactive functional groups of the modified polyolefin resin or the thermoplastic elastomer to inactivate the reactive functional groups, it was not possible to form finely dispersed regions. In comparative example 8, since the unmodified polyolefin resin was mixed, it was difficult to form a finely dispersed region, and the sliding modification effect was not exhibited on the surface, and the wear amount was increased.

FIG. 1 is an image obtained by observing a cross section of example 1 using a differential interference microscope. It is found that the polyolefin resin and the thermoplastic elastomer are uniformly and finely dispersed in the polyamide resin matrix in the region having a particle diameter of 5 μm or less. On the other hand, fig. 2 is an image obtained by observing the cross section of comparative example 6 using a differential interference microscope. The 2 modifiers were unevenly dispersed in the matrix of the polyamide resin, and a finely dispersed region could not be formed. Further, since the coarse regions exist, stress concentrates during wear, and there is a possibility that the stress may become a starting point of wear.

Industrial applicability

The polyamide resin composition of the present invention is a molding material having both excellent toughness and excellent sliding properties. Particularly, the resin composition is suitable for sliding parts which require excellent wear resistance and sliding stability through particles having high hardness, and is expected to make a great contribution to the industry as an engineering plastic which can be used in a wide range of fields.

Claims

1. A polyamide resin composition for a sliding member, comprising:

a crystalline polyamide resin (A);

a modified polyolefin resin (B) having a reactive functional group capable of reacting with a terminal group and/or a main chain amide group of the polyamide resin (a);

a thermoplastic elastomer (C) having a reactive functional group capable of reacting with an end group and/or a main chain amide group of the polyamide resin (a);

an antioxidant (D); and

a mold release agent (E) for releasing the mold,

the modified polyolefin resin (B) and the thermoplastic elastomer (C) are dispersed in a matrix of the polyamide resin (A) in a region having a particle diameter of 5 μm or less.

2. The polyamide resin composition for sliding parts according to claim 1, wherein the antioxidant (D) and the release agent (E) are compounds that suppress deactivation of the reactive functional groups of the modified polyolefin resin (B) and the thermoplastic elastomer (C).

3. The polyamide resin composition for sliding parts according to claim 1 or 2, wherein the reactive functional group is an acid anhydride.

4. The polyamide resin composition for sliding parts according to any one of claims 1 to 3, wherein the antioxidant (D) is a hindered phenol antioxidant.

5. The polyamide resin composition for sliding parts according to any one of claims 1 to 4, wherein the release agent (E) is a higher fatty acid ester compound.

6. The polyamide resin composition for sliding members according to any one of claims 1 to 5, wherein the thermoplastic elastomer (C) is a styrene-based and/or olefin-based thermoplastic elastomer.

7. A sliding member obtained from the polyamide resin composition for sliding members according to any one of claims 1 to 6.