JP2018021097A - Sliding member, and method for producing sliding member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sliding member excellent in a physical deterioration suppression effect during sliding by suppression of rise of a temperature during sliding, and to provide a method for producing the same.SOLUTION: There is provided a sliding member which is obtained by crosslinking a resin composition containing polyamide and a crosslinking assistant. In the sliding member, an abrasion loss in a pin-on-disk abrasion test in which three pins with a diameter of 4.7 mm are slid at a load of 4 MPa and a speed of 30 m/min for 30 minutes is 100 mg or less. A method for producing the sliding member includes: an injection molding step of injection-molding a resin composition containing the polyamide and the crosslinking assistant; and an ionization radiation irradiation step of irradiating a molded body obtained in the injection molding step with ionization radiation. In the method for producing the sliding member, an abrasion loss of the sliding member obtained in a pin-on-disk type abrasion test in which three pins with a diameter of 4.7 mm are slid at a load of 4 MPa and a speed of 30 m/min for 30 minutes is 100 mg or less.SELECTED DRAWING: None

Description

  The present invention relates to a sliding member and a method for manufacturing the sliding member.

  Polyamides are widely used for sliding members in the industrial machinery field because they are excellent in mechanical properties, friction wear resistance, chemical resistance, and the like. For example, gears, cams, washers, bearings, and the like obtained by molding polyamide are widely used for automobile parts, machine parts, electrical and electronic parts, and the like.

  Further, from the viewpoint of improving the sliding effect, a resin composition containing polyamide 66 and a sliding agent has been proposed as a resin composition used for molding a molded body (for example, JP-A-5-93129 and JP-A-2003-93129). 2013-64420 gazette).

JP-A-5-93129 JP 2013-64420 A

  A sliding member such as a gear obtained from a conventional resin composition containing polyamide and a sliding agent has a relatively small coefficient of dynamic friction. However, in order to suppress physical deterioration (deterioration, etc.) during sliding in the sliding member, it is necessary to prevent the sliding member during sliding from becoming high temperature. The obtained gear becomes a high temperature of 80 ° C. or higher during sliding, and physical deterioration during sliding cannot be said to be sufficient.

  The present invention has been made based on the above-described circumstances, and includes a sliding member that includes polyamide and is excellent in the effect of suppressing physical deterioration during sliding due to suppression of temperature rise during sliding, and such It aims at providing the manufacturing method of a sliding member.

  The sliding member according to one aspect of the present invention made to solve the above problems is a sliding member obtained by crosslinking a resin composition containing polyamide and a crosslinking aid, and has three diameters of 4.7 mm. The amount of wear in a pin-on-disk wear test in which the pin is slid for 30 minutes at a load of 4 MPa and a speed of 30 m / min is 100 mg or less.

  The manufacturing method of the sliding member which concerns on another one aspect | mode of this invention made | formed in order to solve the said subject is the injection molding process which injection-molds the resin composition containing polyamide and a crosslinking adjuvant, and the said injection molding process And an ionizing radiation irradiating step for irradiating an ionizing radiation to the molded body obtained in Step 1, wherein three pins having a diameter of 4.7 mm are slid for 30 minutes at a load of 4 MPa and a speed of 30 m / min. In the pin-on-disk wear test to be moved, the wear amount of the obtained sliding member is 100 mg or less.

  The sliding member of the present invention contains polyamide and is excellent in the effect of suppressing physical deterioration during sliding due to suppression of temperature rise during sliding. The manufacturing method of the sliding member of the present invention can relatively easily manufacture a sliding member that includes polyamide and is excellent in the effect of suppressing physical deterioration during sliding by suppressing temperature rise during sliding.

[Description of Embodiment of the Present Invention]
A sliding member according to an aspect of the present invention is a sliding member obtained by crosslinking a resin composition containing polyamide and a crosslinking aid, and includes three pins having a diameter of 4.7 mm, a load of 4 MPa, and a speed of 30 m / min. The amount of wear in a pin-on-disk wear test that is slid for 30 minutes is 100 mg or less.

  Since the amount of wear in the pin-on-disk type wear test is not more than a specific value, the sliding member is excellent in the effect of suppressing physical deterioration during sliding. This is because if the amount of wear is less than a specific value, the sliding member is not easily deformed, and a good sliding state is maintained during sliding, thereby suppressing an increase in temperature during sliding. Guessed. The “pin-on-disk type wear test” means, for example, a test in which revolving sliding is performed while pressing the tip of an iron pin perpendicularly to the sliding surface of the member.

  The crosslinking aid preferably contains triallyl isocyanurate. By including triallyl isocyanurate as a crosslinking aid in this manner, the crosslinking density of the sliding member can be further increased, so that the effect of suppressing physical deterioration during sliding can be further promoted.

  As content of the said crosslinking adjuvant, 1 to 10 mass parts is preferable with respect to 100 mass parts of polyamide. Thus, by making content of a crosslinking adjuvant into the said range, the physical deterioration inhibitory effect during sliding can further be accelerated | stimulated.

  The resin composition may further contain an inorganic filler. Thus, the intensity | strength of a sliding member can be improved because a resin composition contains an inorganic filler.

  The method for producing a sliding member according to still another aspect of the present invention includes an injection molding step of injection molding a resin composition containing polyamide and a crosslinking aid, and ionizing radiation on the molded body obtained in the injection molding step. In a pin-on-disk wear test in which three pins with a diameter of 4.7 mm are slid for 30 minutes at a load of 4 MPa and a speed of 30 m / min. The amount of wear of the resulting sliding member is 100 mg or less.

  The manufacturing method of the said sliding member can obtain the sliding member excellent in the physical deterioration suppression effect during sliding comparatively easily because the abrasion loss in a pin-on-disk type | mold abrasion test is 100 mg or less.

[Details of the embodiment of the present invention]
Hereinafter, the sliding member and the method for manufacturing the sliding member according to the present invention will be described.

  The sliding member is formed by crosslinking a resin composition containing polyamide and a crosslinking aid, and is a pin-on that slides three pins having a diameter of 4.7 mm for 30 minutes at a load of 4 MPa and a speed of 30 m / min. The amount of wear in the disc type wear test is 100 mg or less.

  Since the sliding member has a wear amount in a pin-on-disk type abrasion test that is not more than a specific value, the sliding member is excellent in the effect of suppressing physical deterioration during sliding by suppressing temperature rise during sliding.

(Resin composition)
The sliding member is formed by crosslinking a resin composition containing polyamide and the crosslinking aid.

  The resin composition contains polyamide and a crosslinking aid. The resin composition preferably contains polyamide as a main component. By containing polyamide as a main component, the resin composition can improve mechanical properties, friction wear resistance, chemical resistance, and the like of the sliding member. The “main component” means a component that is contained most, for example, a component that is contained by 50% by mass or more.

  Examples of the polyamide include polyamide 6, polyamide 66, polyamide 46, polyamide 11, polyamide 12, polyamide 610, polyamide 612, polyamide 66 / 6I, polyamide 66 / 6T, polyamide 6T / 66, polyamide 6T / 6I, polyamide 6T / 6I. / 66, polyamide 6T-5MT, polyamide 6T / 6, polyamide MXD-6, polyamide 9T, wholly aromatic polyamide, and the like. Among these, polyamide 66 is particularly preferable from the viewpoint of elastic modulus and mechanical strength.

  70 mass% or more is preferable and, as for content of the polyamide in the said resin composition, 80 mass% or more is more preferable.

  The resin composition may include a resin (other resin) other than polyamide. In addition, other resin can be used individually or in combination of 2 or more types.

  Examples of the resin other than the polyamide include polyolefin, polyurethane, acrylic resin, methacrylic resin, polyester, epoxy resin, fluorine resin, natural or synthetic rubber, silicone resin, ABS (styrene-acrylonitrile-butadiene copolymer) resin, polycarbonate, poly Examples include lactic acid and polyacetal.

  When the resin composition contains polyamide and the other resin as a resin component, the upper limit of the proportion of the other resin in the total resin component of the resin composition is preferably 20% by mass, and 10% by mass. More preferred is 5% by mass.

  The resin composition preferably contains only polyamide as the resin component, and more preferably contains only polyamide 66.

  The resin composition contains a crosslinking aid. For this reason, the said resin composition can raise the crosslinking density of the said sliding member, and can form the sliding member excellent in the physical deterioration suppression effect in sliding.

  Examples of the crosslinking aid include oxime compounds, acrylate or methacrylate compounds, vinyl compounds, allyl compounds, maleimide compounds, and the like. In addition, a crosslinking adjuvant can be used individually or in combination of 2 or more types.

  Examples of the oxime compound include p-quinone dioxime, p, p′-dibenzoylquinone dioxime, and the like.

  Examples of the acrylate or methacrylate compound include diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, and acrylic acid / zinc oxide. A mixture, allyl acrylate, allyl methacrylate, trimethacryl isocyanurate, etc. are mentioned.

  Examples of the vinyl compound include divinylbenzene, vinyltoluene, vinylpyridine, and the like.

  Examples of the allyl compound include hexamethylene diallyl nadiimide, diallyl itaconate, diallyl phthalate, diallyl isophthalate, diallyl monoglycidyl isocyanurate, triallyl cyanurate, triallyl isocyanurate and the like.

  Examples of the maleimide compound include N, N′-m-phenylenebismaleimide, N, N ′-(4,4′-methylenediphenylene) dimaleimide, and the like.

  Among them, as the crosslinking aid, an allyl compound is preferable and triallyl isocyanurate is more preferable because the crosslinking density of the sliding member can be further increased.

  As a minimum of content of the above-mentioned crosslinking auxiliary agent in the above-mentioned resin composition, 1 mass part is preferred to 1.5 mass parts of polyamide, 1.5 mass parts is more preferred, and 2 mass parts is still more preferred. On the other hand, the upper limit of the content is preferably 10 parts by mass, more preferably 9 parts by mass, and still more preferably 8 parts by mass with respect to 100 parts by mass of the polyamide. When the said content is less than the said minimum, the crosslinking density of the said sliding member cannot fully be enlarged, and there exists a possibility that the physical deterioration suppression effect in sliding may become inadequate. Moreover, when the said content exceeds the said upper limit, there exists a possibility that the moldability of the said resin composition may fall.

  Moreover, it is preferable that the said resin composition contains an inorganic filler. The mechanical strength of the said sliding member can be improved because the said resin composition contains an inorganic filler. From this viewpoint, an acicular filler is preferable as the inorganic filler.

  The lower limit of the average aspect ratio of the acicular filler is preferably 2, more preferably 10, and still more preferably 20. On the other hand, the upper limit of the average aspect ratio of the acicular filler is preferably 100, more preferably 90, and still more preferably 80. When the average aspect ratio of the acicular filler is less than the above lower limit, the effect of improving the mechanical strength may be insufficient. Conversely, when the average aspect ratio of the needle filler exceeds the upper limit, the inorganic filler may be easily damaged during kneading.

  In addition, as a minimum of the average diameter (average short diameter) of an acicular filler, 0.1 micrometer is preferable and 0.3 micrometer is more preferable. On the other hand, the upper limit of the average diameter of the acicular filler is preferably 1 μm and more preferably 0.6 μm. Moreover, as a minimum of the average length (average major axis) of an acicular filler, 5 micrometers is preferable and 10 micrometers is more preferable. On the other hand, the upper limit of the average length of the acicular filler is preferably 40 μm and more preferably 20 μm.

  As the main component of the inorganic filler, wollastonite and titanic acid compounds that can improve the mechanical strength while enhancing the wear resistance of the sliding member are preferable. Examples of the titanate compound include potassium titanate and aluminum titanate.

  As a minimum of content of an inorganic filler in the above-mentioned resin composition, 10 mass parts are preferred to 20 mass parts with respect to 100 mass parts of polyamide, and 30 mass parts are still more preferred. On the other hand, as an upper limit of the said content, 60 mass parts is preferable with respect to 100 mass parts of polyamide, 55 mass parts is more preferable, and 50 mass parts is further more preferable. When the said content is less than the said minimum, there exists a possibility that the mechanical strength of the said sliding member cannot fully be enlarged. On the other hand, when the said content exceeds the said upper limit, there exists a possibility that the moldability of the said resin composition may fall.

  Furthermore, the resin composition preferably contains a sliding agent. When the resin composition contains a sliding agent, the dynamic friction coefficient of the sliding member can be reduced, so that the effect of suppressing physical deterioration during sliding can be further increased.

Examples of the sliding agent include polyethylene such as ultra high molecular weight polyethylene, and polyolefin such as polypropylene;
Fluororesin such as polytetrafluoroethylene, polytetrafluoroethylene / perfluoroalkoxyethylene copolymer, polytetrafluoroethylene / polyhexafluoropropylene;
Silicones such as polydimethylsiloxane, polymethylphenylsiloxane, amino-modified polydimethylsiloxane, epoxy-modified polydimethylsiloxane, alcohol-modified polydimethylsiloxane, carboxy-modified polydimethylsiloxane, fluorine-modified polydimethylsiloxane;
Layered inorganic compounds such as graphite;
Inorganic fibers such as glass fiber, potassium titanate whisker, zinc oxide whisker, boronic acid whisker;
Organic fibers such as LCP fiber, aramid fiber, carbon fiber;
Inorganic particles such as alumina, silica, talc;
Phosphates such as metaphosphate, pyrophosphate, calcium hydrogen phosphate, potassium hydrogen phosphate, barium phosphate, lithium phosphate, calcium metaphosphate, zinc pyrophosphate;
Mineral oils such as spindle oil, turbine oil, machine oil, dynamo oil;
Montanates such as calcium montanate;
Examples thereof include molybdenum dioxide. In addition, the said sliding agent can be used individually or in combination of 2 or more types.

  Among these, as the above-mentioned sliding agent, polyolefin is preferable and polyethylene is more preferable from the viewpoint of further improving the wear resistance of the sliding member.

  As a minimum of content of the above-mentioned sliding agent in the above-mentioned resin composition, 1 mass part is preferred to 1.5 mass parts of polyamide, 1.5 mass parts is more preferred, and 2 mass parts is still more preferred. On the other hand, the upper limit of the content is preferably 10 parts by mass, more preferably 9.5 parts by mass, and still more preferably 9 parts by mass with respect to 100 parts by mass of the polyamide. When the content is less than the lower limit, the wear resistance of the sliding member cannot be sufficiently increased, and the effect of suppressing physical deterioration during sliding may be insufficient. Moreover, when the said content exceeds the said upper limit, there exists a possibility that the moldability of the said resin composition may fall.

  The resin composition may contain an additive as necessary. Examples of the additive include a polymerization inhibitor, a filler (excluding the sliding agent), a plasticizer, a pigment, a stabilizer, a lubricant, a softening agent, a sensitizer, an antioxidant, a flame retardant, Examples include release agents, weathering agents, antistatic agents, and silane coupling agents. In addition, an additive can be used individually or in combination of 2 or more types.

  The resin composition can be obtained by mixing each component. Specifically, the resin composition can be obtained, for example, by mixing polyamide and the crosslinking aid. In the mixing, a mixer such as a single screw mixer or a twin screw mixer can be used. Moreover, you may heat in the case of mixing.

(Abrasion amount)
The upper limit of the amount of wear of the sliding member in a pin-on-disk wear test in which three pins with a diameter of 4.7 mm are slid for 30 minutes at a load of 4 MPa and a speed of 30 m / min is 100 mg, preferably 70 mg. 50 mg is more preferable.

(Mass reduction rate)
The upper limit of the mass reduction rate defined by the following formula (1) when the sliding member is a spur gear A having a fixed shape is preferably 0.5%, more preferably 0.3%, % Is more preferable. “The sliding member is spur gear A” means that the spur gear A is formed under the same conditions as the forming method of the sliding member. In addition, “forming under the same conditions as the sliding member” means using the same resin composition as the resin composition used for forming the sliding member and in the same process (manufacturing method) as the sliding member. This means that the spur gear A and the spur gear B are formed.
Mass reduction rate [%] = (X−Y) / X × 100 (1)
X: initial mass [g] of spur gear A having a tooth width of 5 mm, module 1, number of teeth of 30, and a thickness of 10.7 mm of a continuous tooth, formed under the same conditions as the sliding member
Y: meshing spur gear B and spur gear A having a tooth width of 5 mm, module 1, number of teeth of 31 and a thickness of 10.7 mm between 8 consecutive teeth formed under the same conditions as the sliding member, Mass [g] of spur gear A after a fatigue test in which spur gears are rotated for 100 hours under conditions of a load of 4.5 N / mm and a rotational speed of 616 rpm.

(Decrease rate of straddle thickness)
As the upper limit of the reduction rate of the toothpick thickness defined by the following formula (2) when the sliding member is a spur gear A having a fixed shape, 0.3% is preferable, 0.2% is more preferable, 0.1% is more preferable.
Decrease rate of tooth thickness [%] = (PQ) / P × 100 (2)
P: Thickness [mm] of eight teeth that are continuous with a spur gear A having a tooth width of 5 mm, a module 1, and 30 teeth formed under the same conditions as the sliding member
Q: A spur gear B and a spur gear A having a tooth width of 5 mm, a module 1, a number of teeth of 31 formed under the same conditions as the sliding member, and having a continuous tooth thickness of eight continuous teeth equal to the spur gear A. Thickness [mm] of 8 consecutive teeth of spur gear A after a fatigue test in which gears are rotated for 100 hours under conditions of meshing, tooth load 4.5 N / mm, and rotation speed 616 rpm

  In addition, the said tooth thickness is a value measured based on JIS-B-0102-1 (2013).

(Maximum temperature)
As an upper limit of the maximum temperature in the following sliding test of the said sliding member, 75 degreeC is preferable, 70 degreeC is more preferable, and 50 degreeC is further more preferable. When the maximum temperature is not more than the upper limit, the effect of suppressing physical deterioration during sliding can be promoted. The sliding test is performed under the same conditions as the sliding member, with a tooth width of 5 mm, module 1, the number of teeth of 30, a spur gear A having a thickness of 10.7 mm between 8 consecutive teeth and a tooth width of 5 mm, module 1 A spur gear B having a tooth number of 31 and a spanning tooth thickness of 10.7 mm consisting of eight continuous teeth is produced, and the spur gear A and the spur gear B are engaged with each other, and the tooth surface load is 4.5 N / min in an atmosphere of 25 ° C. This is performed by rotating the gears for 100 hours under the conditions of mm and a rotation number of 616 rpm.

  Examples of the form of the sliding member include a gear, a washer, a cam, a worm, a runner, and a bearing. In particular, the sliding member is preferably used for gears and washers.

  Examples of the form of the gear include a spur gear, a cylindrical gear, a helical gear, a helical gear, a bevel gear, a crown gear, a screw gear, and a worm gear.

  The tooth width of the gear is, for example, 1 mm or more and 20 mm or less. The gear module is, for example, 0.3 to 1.5. Further, the number of teeth of the gear is, for example, 5 or more and 100 or less, and the thickness of the contiguous tooth of 8 teeth is 1 mm or more and 20 mm or less.

<Sliding member manufacturing method>
The sliding member manufacturing method includes an injection molding step of injection molding the resin composition containing polyamide and the crosslinking aid, and ionizing radiation irradiation for irradiating ionized radiation to a molded body obtained in the injection molding step. A process. According to the manufacturing method of the sliding member, the sliding member can be obtained relatively easily.

(Injection molding process)
In the injection molding step, the resin composition is injection molded to obtain a molded body having a desired sliding member shape.

  As a minimum of the temperature of the above-mentioned resin composition of an injection molding process, 200 ° C is preferred and 250 ° C is more preferred. On the other hand, the upper limit of the temperature is preferably 350 ° C, more preferably 320 ° C. When the said temperature is less than the said minimum, the fluidity | liquidity of the said resin composition becomes inadequate, and there exists a possibility that sufficient injection molding speed may not be obtained. Moreover, when the said temperature exceeds the said upper limit, there exists a possibility of producing the thermal decomposition of polyamide.

The lower limit of the injection pressure of the injection molding process, preferably ^{70kg / cm 2, 80kg / cm} 2 is more preferable. On the other hand, the upper limit of the injection pressure, preferably ^{130kg / cm 2, 120kg / cm} 2 is more preferable. When the said injection pressure is less than the said minimum, there exists a possibility that a filling defect may arise and the molded object which has a desired shape and size cannot be obtained. Moreover, when the said injection pressure exceeds the said upper limit, there exists a possibility of producing a burr | flash around a molded object, or causing the fall of productivity.

  As a minimum of mold temperature in an injection molding process, 40 ° C is preferred and 50 ° C is more preferred. On the other hand, the upper limit of the mold temperature is preferably 120 ° C, more preferably 100 ° C. When the mold temperature is less than the lower limit, crystallization occurs due to rapid cooling, which may adversely affect the surface smoothness and dimensional accuracy of the molded body. Moreover, when the said mold temperature exceeds the said upper limit, there exists a possibility of producing a burr | flash around a molded object and having a bad influence on dimensional accuracy.

(Ionizing radiation irradiation process)
In the ionizing radiation irradiation step, the molded body obtained in the injection molding step is irradiated with ionizing radiation to crosslink the molded body. Thereby, a sliding member is obtained.

  Examples of the ionizing radiation include α rays, β rays, γ rays, electron rays, and X rays. Among these, the ionizing radiation is preferably an electron beam from the viewpoints of ease of control and safety.

  The irradiation amount of the ionizing radiation is not particularly limited, but is preferably 1 kGy or more and 1000 kGy or less from the viewpoint of suppressing deterioration of the resin due to irradiation while obtaining a sufficient crosslinking density.

  For example, when an electron beam is irradiated as the ionizing radiation, the lower limit of the irradiation amount is preferably 5 kGy, and more preferably 10 kGy. On the other hand, the upper limit of the irradiation dose is preferably 960 kGy, more preferably 480 kGy. When the irradiation amount of an electron beam is less than the said minimum, there exists a possibility that sufficient crosslinking density may not be obtained in the molded object after electron beam irradiation. Moreover, when the said irradiation amount exceeds the said upper limit, there exists a possibility of producing the decomposition | disassembly and deterioration of a molded object by irradiation of an electron beam.

  The ionizing radiation can be irradiated at room temperature. The ionizing radiation is preferably irradiated in a low oxygen or oxygen-free atmosphere.

[Other Embodiments]
The disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  In manufacturing the sliding member, the resin composition is molded into a desired shape using a molding method other than the injection molding method such as an extrusion molding method, a press molding method, a blow molding method, or a vacuum molding method. May be.

  Moreover, when manufacturing the said sliding member, you may bridge | crosslink the said resin composition by a chemical crosslinking method.

  Furthermore, the sliding member may incorporate a metal part such as a shaft.

  The manufacturing method of the said sliding member may be equipped with processes other than the process of injection-molding a resin composition, and the process of irradiating ionizing radiation to a molded object. For example, a drying process for drying the molded body after the injection molding process may be provided, or a heat treatment process may be provided after the ionizing radiation irradiation process.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

The detail of each component used in the Example is as follows.
Polyamide: “Leona 1402S” (Polyamide 66) from Asahi Kasei Corporation
Crosslinking aid: “TAICROS” (triallyl isocyanurate) from Evonik Degussa

[Example 1]
First, 100 parts by mass of polyamide and 1 part by mass of a crosslinking aid were mixed to obtain a resin composition. Next, this resin composition was put into a twin-screw mixer and melt-mixed at 240 ° C. After melt mixing, the resin composition was discharged from a twin-screw mixer, and the discharged material was cooled with water and chopped to obtain a pellet-shaped resin composition. Next, the pellet-shaped resin composition was put into an injection molding machine, and injection molding was performed by the injection molding machine to obtain a plate-like molded body of 40 mm × 40 mm × 2 mm. The injection molding conditions were an injection temperature of 280 ° C., a mold temperature of 80 ° C., an injection pressure of 100 kg / cm ² , and a pressure holding time of 10 seconds.

  Next, the test piece of Example 1 was obtained by irradiating the plate-shaped molded body with an electron beam so that the irradiation dose was 120 kGy.

[Examples 2 and 3 and Comparative Examples 1 to 4]
A plate-like molded body was obtained in the same manner as in Example 1 except that the resin composition was changed to the composition shown in Table 1 below.

  Next, for Examples 2, 3 and Comparative Example 4, the plate-shaped molded body was irradiated with the same electron beam as in Example 1 to obtain test pieces. Moreover, about Comparative Examples 1-3, electron beam irradiation was not performed but the said plate-shaped molded object was made into the test piece as it was.

[Evaluation]
The following evaluation was performed about the said Example and comparative example. These results are shown in Table 1.

(Abrasion amount)
Three iron pins with a diameter of 4.7 mm arranged on one circumference centered on the rotation axis in an atmosphere of 25 ° C. on the surface of each test piece were loaded at 4 MPa and loaded at a speed of 30 m / min. A pin-on-disk type wear test was performed by sliding for minutes, and the amount of wear [mg] was measured. The tip of the pin was flat.

  As shown in Table 1, it is presumed that Examples 1 to 3 having an abrasion amount of 100 mg or less have improved elastic modulus at 80 to 150 ° C., thereby suppressing deformation. That is, Examples 1 to 3 can be evaluated as being excellent in the effect of suppressing physical deterioration during sliding due to suppression of temperature rise during sliding.

  The sliding member according to one embodiment of the present invention is excellent in the effect of suppressing physical deterioration during sliding due to suppression of temperature rise during sliding. This sliding member can be widely used for automobile parts, machine parts, electrical and electronic parts and the like.

Claims (5)

A sliding member obtained by crosslinking a resin composition containing polyamide and a crosslinking aid,
A sliding member having a wear amount of 100 mg or less in a pin-on-disk wear test in which three pins having a diameter of 4.7 mm are slid at a load of 4 MPa and a speed of 30 m / min for 30 minutes.   The sliding member according to claim 1, wherein the crosslinking aid contains triallyl isocyanurate.   The sliding member according to claim 1 or 2, wherein the content of the crosslinking aid is 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polyamide.   The sliding member according to claim 1, wherein the resin composition further contains an inorganic filler. An injection molding step of injection molding a resin composition containing polyamide and a crosslinking aid;
An ionizing radiation irradiating step for irradiating the molded body obtained in the injection molding step with ionizing radiation, comprising:
In a pin-on-disk type wear test in which three pins having a diameter of 4.7 mm are slid at a load of 4 MPa and a speed of 30 m / min for 30 minutes, the resulting sliding member has a wear amount of 100 mg or less. .