JP6657740B2 - Sliding material, molded product thereof, and sliding member - Google Patents

Description

  The present invention relates to a sliding material, a molded product thereof, and a sliding member.

  As components having a sliding portion such as a bearing, a seal ring, and a blade, sliding members made of various materials are used. For example, a carbon sintered body (for example, see Patent Literature 1) and a thermosetting resin containing a solid lubricant (for example, see Patent Literature 2) make use of the properties of a low friction coefficient and excellent wear resistance. It is used as a sliding member that can be used in a non-lubricated environment.

JP 2008-249129 A JP 2008-001883 A

  The carbon sintered body as described in Patent Literature 1 has a low coefficient of friction and excellent wear resistance, but may be damaged due to insufficient strength depending on the use environment. On the other hand, a thermosetting resin containing a solid lubricant as described in Patent Literature 2 is superior in strength as compared with a carbon sintered body, but is generally used as a material of a mating material such as an iron alloy or an aluminum alloy. The coefficient of thermal expansion is larger than that of the first embodiment, and the volume may expand due to a rise in temperature during driving, and the coefficient of friction may increase.

  In view of the above circumstances, an object of the present invention is to provide a sliding material which can be used in a non-lubricated environment, has sufficient strength, is excellent in dimensional stability, a molded product thereof, and a sliding member. I do.

Means for solving the above problems include the following embodiments.
<1> A thermosetting resin containing a phenol resin and a carbon material, wherein the content of the thermosetting resin is 15% by mass to 30% by mass of the total mass of the thermosetting resin and the carbon material. There is a sliding material.
<2> The sliding material according to <1>, further including a film adjusting material.
<3> The sliding material according to <2>, wherein the film adjusting material includes at least one selected from the group consisting of aluminosilicate, carbonate, phosphate, titanate, and hydroxide.
<4> The carbon material includes a carbonaceous material and a graphite material, and the mass ratio of the carbonaceous material to the graphite material (carbonaceous material / graphite material) is 0.1 to 3.0. The sliding material according to any one of <1> to <3>.
<5> A molded article of the sliding material according to any one of <1> to <4>.
<6> The molded article of the sliding material according to <5>, wherein the bulk density is 1700 kgf / m ^{3 to} 1900 kgf / m ³ .
<7> A sliding member including a molded article of the sliding material according to <5> or <6>.

  ADVANTAGE OF THE INVENTION According to this invention, the sliding material which can be used in a lubrication-free environment, has sufficient intensity | strength, and can form a sliding member excellent in dimensional stability, its molded object, and a sliding member are provided. Is done.

Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the components (including the element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and their ranges, and does not limit the present invention.
In this specification, the term "step" includes, in addition to a step independent of other steps, even if the purpose of the step is achieved even if it cannot be clearly distinguished from the other steps, the step is also included. It is.
In the present specification, the numerical value range indicated by using “to” includes the numerical value described before and after “to” as the minimum value and the maximum value, respectively.
In the present specification, the content of each component in the composition, if there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, the total of the plurality of substances present in the composition Means the content of
In the present specification, the particle diameter of each component in the composition, when there are a plurality of particles corresponding to each component in the composition, unless otherwise specified, a mixture of the plurality of particles present in the composition Means the value of

<Sliding material and molded product thereof>
The sliding material of the present embodiment includes a thermosetting resin containing a phenolic resin and a carbon material, and the content of the thermosetting resin is 15% of the total mass of the thermosetting resin and the carbon material. % By mass to 30% by mass.

  The molded body of the sliding material of the present embodiment can be used in a non-lubricated environment when used as a sliding member. That is, the surface of the molded body can be used as it is, without using a lubricant, by directly contacting the surface of the molded body. It is considered that a molded body containing a carbon material develops good wear resistance by forming a film by abrasion powder generated when worn and attached to a contact surface of a sliding material and a mating material. .

Furthermore, the molded article of the sliding material according to the present embodiment has excellent strength and excellent dimensional stability by containing a thermosetting resin containing a phenolic resin in addition to the carbon material at a specific ratio. Low expansion coefficient).
The method for obtaining the molded body of the sliding material is not particularly limited. For example, there is a method in which heating and pressing are performed so that the sliding material has a desired shape (heat molding). The method of heating and pressurizing is not particularly limited, and can be performed by a known method.

Bulk density of the molded body of sliding material according to the present embodiment ^is preferably ^{1700kgf / m 3 ~1900kgf / m 3} , more preferably ^{1750kgf / m 3 ~1900kgf / m 3} . If the bulk density of the molded body of the sliding material is 1700 kgf / m ³ or more, sufficient strength tends to be obtained, and if it is 1900 kgf / m ³ or less, the weight as the sliding member tends to be light. is there. In the present embodiment, the bulk density is a value measured according to JIS R 7212: 1995 using a test piece of 10 mm × 10 mm × 50 mm.

  The bulk density of the molded body of the sliding material changes depending on the composition of the raw material and the manufacturing conditions. In particular, it greatly depends on molding conditions such as molding temperature and molding pressure. Therefore, a molded body having a desired bulk density can be obtained by changing these conditions.

(A) Thermosetting resin The sliding material of the present embodiment contains a phenol resin as the thermosetting resin. The molded body of the sliding material of the present embodiment may be used as a sliding member in a high-temperature environment. Further, even in a usage environment where the temperature is not high, the sliding member itself becomes high temperature due to the generation of frictional heat due to friction during driving. Therefore, the molded body of the sliding material is required to have heat resistance that can withstand a high temperature environment. From the above, it is necessary that the resin used is a thermosetting resin having excellent heat resistance. Among thermosetting resins, phenolic resins have a three-dimensional network structure and are therefore excellent in electrical and mechanical properties, and particularly excellent in heat resistance and flame retardancy. Therefore, the sliding material of the present embodiment contains a phenol resin as the thermosetting resin.
The content of the phenol resin in the thermosetting resin is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The sliding material may include a thermosetting resin other than the phenol resin, and examples of such a resin include an epoxy resin, a urea resin, a melamine resin, an unsaturated polyester resin, and a diallyl phthalate resin.

  Examples of the phenol resin include a novolak-type phenol resin and a resol-type phenol resin, and either one of them may be used or both may be used in combination.

  The content of the thermosetting resin containing the phenolic resin is 15% by mass to 30% by mass of the total mass of the thermosetting resin and the carbon material contained in the sliding material. When the content of the thermosetting resin including the phenol resin is 15% by mass, a sufficient strength can be imparted to the molded body of the sliding material. When the content of the thermosetting resin including the phenol resin is 30% by mass or less, sufficient dimensional stability can be imparted to the molded body of the sliding material. From the viewpoint of the strength of the molded body of the sliding material, it is preferably from 23% by mass to 30% by mass of the total mass of the thermosetting resin and the carbon material. It is preferably 15% by mass to 27% by mass of the total mass of the carbon material. Therefore, from the viewpoint of both improvement in strength and dimensional stability of the molded body of the sliding material, the content of the thermosetting resin including the phenol resin is 23% by mass of the total mass of the thermosetting resin and the carbon material. It is more preferable that the content be 27% by mass.

(B) Carbon material In this embodiment, the carbon material means a substance (carbonized substance) obtained by carbonizing an organic substance. Carbon materials are roughly divided into carbonaceous materials having a low degree of crystallinity and graphitic materials having a high degree of crystallinity. Specific examples of the carbonaceous material include coke, carbon black, activated carbon, coal, and charcoal. Specific examples of the graphite material include graphite. As the graphite, either natural graphite or artificial graphite can be used. One type of carbon material may be used alone, or two or more types may be used in combination. As a case where two or more kinds of carbon materials are used in combination, a case where two or more kinds of carbon materials having different types, average particle diameters, particle shapes and the like of the carbon materials are used in combination is exemplified.

  From the viewpoint of the dimensional stability of the molded body of the sliding material, the content of the carbon material may be 73% by mass to 85% by mass of the total mass of the thermosetting resin and the carbon material included in the sliding material. Preferably, from the viewpoints of strength and fluidity during molding, it is preferably 70% by mass to 77% by mass of the total mass of the thermosetting resin and the carbon material. Therefore, from the viewpoints of dimensional stability, strength and fluidity during molding of the molded body of the sliding material, the content of the carbon material is 73% by mass to 77% by mass of the total mass of the thermosetting resin and the carbon material. Is more preferable.

  From the viewpoint of the strength of the molded body of the sliding material, the carbon material preferably contains a carbonaceous material. On the other hand, from the viewpoint of wear resistance, the carbon material preferably contains a graphitic material. Therefore, from the viewpoint of the strength and wear resistance of the molded body of the sliding material, the carbon material preferably includes a carbonaceous material and a graphite material. From the viewpoint of price and quality stability, the carbon material preferably contains coke as the carbonaceous material and artificial graphite as the graphite material.

  When the carbon material includes a carbonaceous material and a graphite material, the mass ratio of the carbonaceous material and the graphite material (carbonaceous material / graphite material) is preferably 0.1 to 3.0. When the ratio is 0.1 or more, the strength of the molded body of the sliding material tends to be sufficiently obtained. In addition, when the molded body is used as a sliding member, the amount of the graphite material is not too large, and excessive adhesion of wear powder to a film formed on the surface of the molded body is suppressed, and the thickness of the film is appropriate. , And excellent abrasion resistance tends to be maintained. When the ratio is 3.0 or less, a film having a sufficient thickness is formed on the surface of the molded body, and excellent wear resistance tends to be maintained. From the above comprehensive viewpoint, the mass ratio between the carbonaceous material and the graphite material (carbonaceous material / graphite material) is more preferably 0.4 to 1.5, and 0.6 to 1. More preferably, it is 5.

  It is preferable that the state of the carbon material when it is a raw material is particulate. For example, the average particle diameter is preferably from 5 μm to 100 μm, more preferably from 10 μm to 50 μm, even more preferably from 15 μm to 40 μm. The shape of the particles is not particularly limited, and may be spherical, scaly, massive, and the like. The average particle diameter here is a value measured by a laser diffraction method according to JIS Z 8825: 2013.

(C) Film adjusting material The sliding material preferably further includes a film adjusting material. In the present embodiment, the film adjusting material means a substance (excluding a carbon material) having a Mohs hardness of 2 to 6. When a molded body of a sliding material is used as a sliding member, the film adjusting material is used to cut off the film formed on the surface of the molded body and the mating material by wear powder, and to appropriately maintain the thickness of the film (film). Adjustment effect).
Mohs hardness can be determined using a Mohs hardness meter using talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, jade, steel ball and diamond as standard substances.

  From the viewpoint of obtaining a sufficient effect of adjusting the film, the content of the film adjusting material is preferably 0.3% by mass or more of the total mass of the sliding material. From the viewpoint of suppressing excessive polishing of the film, The content of the adjusting material is preferably 5% by mass or less of the total mass of the sliding material. Therefore, the content of the film adjusting material is more preferably 0.5% by mass to 3% by mass of the total mass of the sliding material, and further preferably 1% by mass to 2% by mass.

  From the viewpoint of obtaining a sufficient film adjusting effect, the Mohs hardness of the film adjusting material is preferably 3 or more, more preferably 4 or more. From the viewpoint of suppressing excessive polishing of the film, the Mohs hardness of the film adjusting material is more preferably 5 or less.

  It is preferable that the film adjusting material contains, for example, at least one selected from the group consisting of aluminosilicate, carbonate, phosphate, titanate, and hydroxide. Specifically, feldspar, zeolite (zeolite), clay mineral, calcium carbonate, potassium carbonate, barium carbonate, magnesium carbonate, lithium carbonate, calcium phosphate, calcium hydrogen phosphate, calcium dihydrogen phosphate, calcium diphosphate (calcium pyrophosphate), Monomagnesium phosphate, dimagnesium phosphate, trimagnesium phosphate, magnesium diphosphate (magnesium pyrophosphate), magnesium metaphosphate, zinc phosphate, zinc diphosphate (zinc pyrophosphate), potassium titanate, lithium titanate Potassium, magnesium titanate, potassium magnesium titanate, calcium titanate, calcium hydroxide, aluminum hydroxide, zinc hydroxide and the like can be mentioned. One kind of the film adjusting material may be used alone, or two or more kinds may be used in combination.

(D) Inorganic substance having Mohs hardness of less than 2 The sliding material may include an inorganic substance having Mohs hardness of less than 2. An inorganic substance having a Mohs hardness of less than 2 acts as a solid lubricant. Examples of the inorganic substance having a Mohs hardness of less than 2 include talc, molybdenum disulfide, tungsten disulfide, boron nitride, mica, cesium, sodium, potassium, phosphorus, lithium, indium, silver chloride, calcium, and gallium. One substance having a Mohs hardness of less than 2 may be used alone or in combination of two or more. When the sliding material contains a substance having a Mohs hardness of less than 2, the content is not particularly limited. For example, it can be 0.1% by mass to 10% by mass of the total mass of the sliding material.

(E) Release Agent The sliding material may contain a release agent as long as the strength, dimensional stability, and abrasion resistance of the molded body of the sliding material are not significantly reduced. Release agents include liquid paraffin, paraffin wax, synthetic polyethylene wax, stearic acid, zinc stearate, aluminum stearate, calcium stearate, magnesium stearate, stearamide, oleic amide, erucamide, methylene bis stearic acid Examples include amide, ethylene bisstearic acid amide, stearic acid monoglyceride, stearyl stearate, and hydrogenated oil. One release agent may be used alone, or two or more release agents may be used in combination. When the sliding material contains a release agent, the content is not particularly limited, and may be, for example, 0.3% by mass to 1.5% by mass of the total mass of the sliding material.

<Sliding member>
The sliding member of the present embodiment includes a molded body of the above-described sliding material. The sliding member of the present embodiment can be used in a non-lubricated environment, has sufficient strength, and has excellent dimensional stability. The sliding member may be formed only of a molded body of the sliding material, or may be a combination of the molded body of the sliding material and another member. Specific examples of the sliding member include a bearing, a seal ring, a blade, a rotor, and a pulley.

  Hereinafter, the present invention will be described specifically with reference to Examples, but the scope of the present invention is not limited to these Examples.

[Examples 1 to 10 and Comparative Example 1]
The raw materials shown in Table 1 were mixed at the compounding ratio shown in Table 1, charged into a double-arm kneader (Kurimoto Iron Works, Ltd.), and heated and mixed at 50 rpm at 23 rpm for 1 hour. The obtained mixture (sliding material) was pulverized so that the average particle diameter became 25 μm. Next, the pulverized product was placed in a 150 mm × 250 mm × 50 mm mold, and molded under the conditions of a molding surface pressure of 0.2 MPa, a mold temperature of 180 ° C., and a molding time of 10 minutes. The obtained molded body (sliding member) was heat-treated at 250 ° C. for 10 hours.

The details of the raw materials described in Table 1 are as follows.
(A) Thermosetting resin Phenolic resin 1: Hitachi Chemical Co., Ltd., trade name: HP-601UP
Phenol resin 2: Air Water Bell Pearl Co., Ltd., trade name: S890
Phenol resin 3: Showa Denko KK, trade name: BRP-406
Phenol resin 4: Showa Denko Corporation, trade name: BRP-2444

(B) Carbon material coke: Seachem Co., Ltd., trade name: LPC-A, average particle diameter 18 μm, Mohs hardness 4
Artificial graphite 1: Oriental Sangyo Co., Ltd., trade name: AT-No5, average particle diameter 37 μm, Mohs hardness 1
Artificial graphite 2: Oriental Sangyo Co., Ltd., trade name: AT-No10, average particle diameter 18 μm, Mohs hardness 1
Artificial graphite 3: TIMCAL, trade name: T-75, average particle diameter 30 μm, Mohs hardness 1

(C) Film conditioner Film conditioner 1: Onoda Chemical Co., Ltd., calcium diphosphate, Mohs hardness 4
Coating conditioner 2: Daido Pharmaceutical Co., Ltd., zinc diphosphate, Mohs hardness 5

(D) Inorganic talc having Mohs hardness of less than 2: Seiko Sangyo Co., Ltd., trade name: CTA-1, Mohs hardness 1

(E) Release agent Release agent: Sakai Chemical Industry Co., Ltd., zinc stearate, trade name: SZ-P

(Characteristic evaluation)
The following property evaluation was performed using the heat-treated molded bodies produced in Examples 1 to 10 and Comparative Example 1. Table 1 shows the results.

(Bulk density measurement)
The bulk density (unit: kgf / m ³ ) was measured according to JIS R 7212: 1995 using a test piece of 10 mm × 10 mm × 50 mm cut out from the heat-treated molded body.

(Bending strength measurement)
The bending strength (unit: MPa) was measured according to JIS K 6911: 2006 using an Amsler universal testing machine (Shimadzu Corporation) by applying a load in the direction of compression during molding. The measurement was performed using a test piece of 10 mm × 5 mm × 80 mm cut out from the heat-treated molded body.

(Hardness measurement)
The hardness (unit: HsD) was measured using a D-type Shore hardness meter according to JIS-Z 2246: 2000.

(Coefficient of thermal expansion)
The coefficient of thermal expansion (unit: ppm / K) was determined by using a 5 mm × 5 mm × 15 mm test piece cut out from the heat-treated molded body, using a thermal dilatometer (trade name: DL-7000RH, ULVAC, Inc.). The thermal expansion coefficient was calculated from a gradient of 150 ° C. from the temperature rate of 5 ° C./min and the analysis temperature range RT. The coefficient of thermal expansion was calculated based on the dimension in the direction perpendicular to the compression direction (longitudinal direction).

(Friction coefficient and wear amount)
A sliding wear test was performed using a chip-on-disk type wear tester (A & D Co., Ltd.). Specifically, a ring (material: SUS304 (JIS G4303: 2005), outer diameter: 85 mm, inner diameter: 15 mm) was pressed against a test piece of 18 mm × 12 mm × 8 mm cut out of the heat-treated molded body, and the surface was pressed. The measurement was performed for 8 hours under the conditions of pressure: 0.1 MPa, peripheral speed: 10 m / s, and ambient temperature: 100 ° C.
The friction coefficient was a value calculated by (rotational torque load (frictional force) F (N)) / (pressing load P (N)).
The wear amount was defined as a wear depth per hour (μm / hour).

[Comparative Example 2]
20 parts by mass of artificial graphite 2, 21 parts by mass of artificial graphite 3, 54 parts by mass of tar pitch and 5 parts by mass of coal tar were mixed and charged into a double-arm kneader (Kurimoto Iron Works Co., Ltd.) at 23 revolutions / minute. (Rpm) and mixed by heating at 280 ° C. for 8 hours. The obtained mixture was pulverized so that the average particle diameter became 25 μm. The pulverized product was placed in a 150 mm × 250 mm × 50 mm mold and molded under the conditions of a molding surface pressure of 0.2 MPa, a mold temperature of 180 ° C., and a molding time of 10 minutes. The obtained compact is placed in a shuttle kiln firing furnace (Chugai Furnace Industry Co., Ltd.), heated to 900 ° C. in an inert atmosphere over 400 hours, and then cooled to obtain a carbon-graphite sintered material. Was.

The properties of the obtained carbon-graphite sintered material were evaluated in the same manner as in the examples. As a result, the bulk density was 1670 kgf / m ³ , the bending strength was 40 MPa, the hardness was 55 HsD, the thermal expansion coefficient was 4 ppm / K, the friction coefficient was 0.12, and the wear amount was 3. It was 1 μm / hour.

[Consideration of results]
As shown in Table 1, the molded bodies produced in Examples 1 to 10 were superior in strength and abrasion resistance as compared with Comparative Example 2 containing no phenol resin. Although the thermal expansion coefficient was larger than Comparative Example 2, all were 19 ppm / K or less. This is a value close to the friction partner (SUS304: coefficient of thermal expansion 16 ppm / K), and it can be determined that the material has sufficient dimensional stability.
Further, the molded bodies produced in Examples 1 to 10 were superior in strength and dimensional stability as compared with Comparative Example 1 in which the ratio of the phenol resin to the total mass of the phenol resin and the carbon material was 36% by mass.

  Among Examples 1 to 10, Examples 3 to 9 in which the value of the carbonaceous material / graphite material is in the range of 0.6 to 1.5 have a bending strength of 80 MPa or more and a hardness of 72 or more, It had excellent strength and hardness. Further, the abrasion amount was 1.9 mm / hour or less, and the abrasion resistance was excellent.

Claims (7)

And a thermosetting resin containing a phenolic resin, and a carbon material, the content of the thermosetting resin, Ri 15% to 30% by mass of the total mass of the thermosetting resin and the carbon material, A sliding material , wherein the carbon material includes coke and a graphite material, and a mass ratio of the coke to the graphite material (coke / graphite material) is 0.1 to 3.0 .   The sliding material according to claim 1, further comprising a film adjusting material.   The sliding material according to claim 2, wherein the film adjusting material includes at least one selected from the group consisting of aluminosilicate, carbonate, phosphate, titanate, and hydroxide. The sliding material according to any one of claims 1 to 3 , wherein the coke is pitch coke .   A molded article of the sliding material according to any one of claims 1 to 4. Bulk density of ^{1700kgf / m 3 ~1900kgf / m 3} , the molded body of sliding material according to claim 5.   A sliding member comprising a molded article of the sliding material according to claim 5.