JP2018188530A - Resin composition for slide member and slide bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for slide member using an aliphatic polyketone resin which is excellent in heat resistance and chemical resistance and is inexpensive compared to other resin composition for slide member made from a synthetic resin.SOLUTION: Graphs 3-1 to 3-4 and 4-1 to 4-4 show coefficients of friction and abrasion mark depths of test pieces 1-1 to 1-4 of an aliphatic polyketone resin blended with jojoba oil, polyethylene and carbon particles, graphs 3-5 to 4-5 show coefficients of friction and abrasion mark depths of test piece 1-5 blended with jojoba oil and polyethylene 1, graphs 3-7 to 4-7 show coefficients of friction and abrasion mark depths of comparative example 1-7 of an aliphatic polyketone resin blended with PTFE powder, and graphs 3-8 and 4-8 show coefficients of friction and abrasion mark depths of comparative examples 1-8 of a single aliphatic polyketone resin. It can be expected from these measurement results, slide performance can be improved using an aliphatic polyketone resin blended with jojoba oil and polyethylene.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a resin composition for sliding members, and more particularly to a resin composition for sliding members suitable for sliding bearings.

  Conventionally, resin compositions for sliding members are known. For example, in Patent Document 1, as a resin composition for a sliding member suitable for a sliding bearing, polyacetal resin, polyamide resin, polybutylene terephthalate resin, polyphenylene sulfide resin, polyetherimide resin, polyethersulfone resin, polycyanoaryl A filler selected from polytetrafluoroethylene resin, carbonate, copper powder, zinc powder, and copper oxide powder is added to a base resin selected from ether resin, polyether ketone resin, polyamideimide resin, and polyimide resin. A resin composition for a sliding member formed by doing so is disclosed.

JP 2001-139777 A

  In recent years, aliphatic polyketone resins have been attracting attention because the raw material monomers are cheaper than other synthetic resins having equivalent heat resistance. However, although the aliphatic polyketone resin is excellent in heat resistance and chemical resistance, the aliphatic polyketone resin alone is not suitable as a resin composition for a sliding member because it has a high friction coefficient and a large amount of wear.

  The present invention has been made in view of the above circumstances, and its purpose is to make a slide using an aliphatic polyketone resin that is excellent in heat resistance and chemical resistance and is less expensive than other resin compositions for sliding members. It is providing the resin composition for moving members.

  The present inventor has found that sliding performance can be improved by blending an oily agent with an olefin resin such as polyethylene into an aliphatic polyketone resin. Here, the oil-based agent preferably contains a higher fatty acid, a higher fatty acid ester, or a higher alcohol in the aliphatic polyketone resin. Further, in order to prevent the oily agent blended in the aliphatic polyketone resin from being vigorously vaporized at a high temperature during molding of the resin composition for the sliding member, the oily agent blended in the aliphatic polyketone resin is aliphatic. Those having a boiling point higher than the molding temperature of the polyketone resin are used. For example, jojoba oil can be used.

  According to the present invention, by adding an oily agent to an aliphatic polyketone resin together with an olefinic resin, the oily agent is evenly dispersed in the aliphatic polyketone resin, and the sliding performance of the aliphatic polyketone resin can be improved. it can. Therefore, it is possible to provide a resin composition for a sliding member using an aliphatic polyketone resin which is excellent in heat resistance and chemical resistance and is less expensive than other resin compositions for sliding members.

FIG. 1 is a diagram for explaining a sliding performance test of a test piece 1 made of a resin composition for a sliding member according to an embodiment of the present invention. FIG. 2 shows the sliding performance test under the room temperature environment performed on the test pieces 1-1 to 1-5 shown in Table 1 and Comparative Examples 1-7 and 1-8 under the conditions shown in Table 3. It is a figure which shows a measurement result. FIG. 3 is a diagram showing a measurement result of a sliding performance test in a high temperature environment (120 ° C.) performed on the test pieces 1-1 to 1-5 shown in Table 1 under the conditions shown in Table 3. is there.

  An embodiment of the present invention will be described below.

  The sliding member resin composition according to the present embodiment is formed of an aliphatic polyketone resin in which an oily agent and an olefinic resin are blended, and is used for, for example, a sliding bearing. Here, the oily agent blended with the aliphatic polyketone resin is used to prevent the oily agent blended with the aliphatic polyketone resin from being vigorously vaporized and dissipated during the molding of the resin composition for the sliding member. Those having a boiling point higher than the molding temperature of the resin are used.

  Oiliness agents to be mixed with aliphatic polyketone resins include higher fatty acids (such as stearic acid), higher fatty acid esters (such as butyl stearate), higher alcohols (such as cetyl alcohol), amines (such as octadecylamine), and metal soaps (stearic acid). Lithium, etc.), phosphate esters (tricresyl phosphate, etc.) are preferably used, and those containing higher fatty acids, higher fatty acid esters, or higher alcohols are more preferred. For example, jojoba oil can be used. Moreover, it is preferable that the compounding quantity of an oil-based agent shall be 1-6 mass%. When the blending amount of the oily agent is less than 1% by mass, there is no significant difference in sliding performance as compared with the case of 100% by mass of the aliphatic polyketone resin. On the other hand, as the blending amount of the oily agent increases, the oily agent may not be evenly dispersed in the aliphatic polyketone resin.

  The present inventor separates the oily agent from the aliphatic polyketone resin by holding the oily agent in the olefinic resin by blending the olefinic resin having a high affinity with the oily agent together with the oily agent into the aliphatic polyketone resin. It has been found that it can be dispersed more evenly within the aliphatic polyketone resin.

  Here, the olefin-based resin is preferably polyethylene, and the polyethylene may be high-density polyethylene, ultrahigh molecular weight polyethylene, or high-sliding special polyethylene, but high-density polyethylene is particularly preferable. In addition to polyethylene, an olefin resin having a structure in which hydrocarbon groups are polymerized can be expected to have an effect as a retaining agent for an oily agent as in the case of polyethylene. Moreover, it is preferable to set it as 0.5-15 mass%, and, as for the compounding quantity of olefin resin, it is more preferable to set it as 1-10 mass%. Moreover, it is preferable that the compounding quantity of an oiliness agent shall be less than 4 mass parts with respect to 1 mass part of olefin resin.

  This inventor performed various tests using the plate-shaped test piece 1 (dimensions: length 30mm, width 30mm, thickness 3mm) which consists of the resin composition for sliding members which concerns on this Embodiment.

  First, as shown in Table 1 below, as test pieces 1, test pieces 1-1 to 1-5 having five kinds of blending ratios are prepared, and as comparative examples, three kinds of comparative examples 1-6 to 1-6 are prepared. 1-8 was prepared. These test pieces 1-1 to 1-5 and Comparative Examples 1-6 to 1-8 were produced by injection-molding pellets having the blending ratios shown in Table 1 into a plate shape. Specifically, the material is put into a biaxial vent type extrusion molding machine, melted and kneaded, and molded to produce a string-shaped molded product, and then the string-shaped molded product is cut to mix pellets. Produced. Then, this mixed pellet was put into a screw type injection molding machine to form a test piece 1.

  In addition, as a material of the test piece 1, “M330A (trade name)” manufactured by Hyosung is used for the aliphatic polyketone resin, and jojoba oil “jojoba golden (trade name)” imported from Mitsuba Trading Co., Ltd. is used for the oily agent. High-density polyethylene “Hi-Zex (registered trademark) 2100JP (trade name)” manufactured by Prime Polymer Co., Ltd. is used as the olefin resin, and “Bell Pearl (registered trademark) C2000 (trade name)” manufactured by Air Water Velpearl Co. And “KTL620 (trade name)” manufactured by Kitamura Co., Ltd. was used as the PTFE (polytetrafluoroethylene) powder.

[Formability confirmation test]
The inventor conducted a test for confirming moldability using a screw-type injection molding machine for test pieces 1-1 to 1-5 and comparative example 1-6, with the cylinder temperature set to 240 degrees. In the injection molding by the screw type injection molding machine, when the pressure inside the mold cannot be kept constant in the pressure holding process performed after the injection filling process in which the molten resin (mixed pellet) in the cylinder is injected and filled into the mold, It is considered that jojoba oil is separated from the molten resin injected and filled in the mold and flows back into the cylinder, and the molten resin cannot maintain a desired shape in the mold. Therefore, the present inventor monitors the pressure-holding state in the pressure-holding process up to the 10th molding, and if the pressure inside the mold in the pressure-holding process is kept constant at the 10th molding, When moldability is judged as “good moldability” and the pressure inside the mold in the pressure holding process falls slightly in the second half, the moldability is judged as “moldable” and the pressure inside the mold in the pressure holding process When the pressure did not reach the target pressure from the beginning, the moldability was judged as “difficult to mold”.

  Table 2 below shows the results of the moldability confirmation test. Here, the symbol “◎” indicates “good moldability”, the symbol “◯” indicates “moldable”, and the symbol “×” indicates “difficult to mold”.

  As shown in Table 2, in the case of 1% by mass of polyethylene and 1% by mass of carbon particles, up to 4% by mass of jojoba oil (test pieces 1-1 and 1-2), gold in the pressure-holding step of the 10th molding was performed. The pressure inside the mold is kept constant and the moldability is “good moldability”, but with 6% by mass of jojoba oil (test piece 1-3), the pressure inside the mold in the pressure holding process of the 10th molding is The moldability fell slightly in the second half, and the moldability was “moldable”. However, when the mass of jojoba oil is 6% and the carbon particles are 1% by mass and the polyethylene is 2% by mass (test piece 1-4), the pressure in the mold in the pressure-holding step of the 10th molding is kept constant. The moldability was “good moldability”. Further, in the case of 3% by weight of jojoba oil and 1% by weight of polyethylene (test piece 1-5), the pressure inside the mold in the pressure-holding step of the 10th molding was kept constant, 3% by weight of jojoba oil, polyethylene 1 As in the case of 1% by mass and 1% by mass of carbon particles (test piece 1-1), the moldability was “good moldability”. In addition, when 3% by mass of jojoba oil was blended without blending polyethylene and carbon particles (Comparative Example 1-6), the pressure inside the mold in the pressure-holding process of the 10th molding was the target pressure from the beginning. The moldability was “difficult to mold”. As a result, from the viewpoint of moldability, it should be blended with polyethylene together with jojoba oil, preferably within 4 parts by mass of jojoba oil with respect to 1 part by mass of polyethylene, and the influence of the presence or absence of carbon particles is ignored. I understood that I could do it.

[Sliding performance test]
This inventor performed the sliding performance test about test piece 1-1 to 1-5 and comparative examples 1-7 and 1-8.

  FIG. 1 is a diagram for explaining a sliding performance test of a test piece 1 made of a resin composition for a sliding member according to the present embodiment.

  As shown in the figure, a cylindrical mating member 2 is placed on the sliding surface (surface) 10 of the test piece 1, and the load N in the direction of the axis O is set to the value of the test piece 1 under the conditions shown in Table 3 below. In addition to the back surface 11, the mating member 2 was rotated in the rotation direction R around the axis O while the sliding surface 10 of the test piece 1 was pressed against the support target surface (end surface) 20 of the mating member 2. Then, the torque in the rotational direction R of the sliding member 2 at that time was detected by a load cell (not shown), and the friction coefficient between the sliding surface 10 and the support target surface 20 was measured from the detected torque. Further, after measurement of the friction coefficient, the wear scar depth (abrasion trace cross-sectional curve) at the arrow A of the sliding surface 10 was measured. The support target surface 20 of the counterpart material 2 was ground, then handler-wrapped with water-resistant abrasive paper # 400 and the like, and further washed with acetone.

  FIG. 2 shows the measurement results of the sliding performance test under the room temperature environment performed on the test pieces 1-1 to 1-5 and Comparative Examples 1-7 and 1-8 under the conditions shown in Table 3. FIG.

  Here, the left vertical axis indicates the friction coefficient, and the right vertical axis indicates the wear scar depth (the average value of the wear scar depth in the arrow A of the sliding surface 10). Graphs 3-1 to 3-5 show the measurement results of the friction coefficients of the test pieces 1-1 to 1-5, and graphs 3-7 and 3-8 show the results of Comparative Examples 1-7 and 1-8. The measurement results of the friction coefficient are shown, and the graphs 4-1 to 4-5 show the measurement results of the wear scar depths of the test pieces 1-1 to 1-5, and the graphs 4-7 and 4- 8 shows the measurement results of the wear scar depths of Comparative Examples 1-7 and 1-8.

  As shown in FIG. 2, in a room temperature environment, the friction coefficient of Comparative Example 1-8 of 100% by mass of aliphatic polyketone resin is 0.54 (Graph 3-8). On the other hand, the friction coefficient of the test piece 1-1 containing 3% by weight of jojoba oil, 1% by weight of polyethylene, and 1% by weight of carbon particles is 0.11 (graph 3-1), 4% by weight of jojoba oil, and 1% by weight of polyethylene. %, The friction coefficient of the test piece 1-2 containing 1% by mass of carbon particles is 0.10 (Graph 3-2), 6% by mass of jojoba oil, 1% by mass of polyethylene, and 1% by mass of carbon particles. The friction coefficient of 1-3 is 0.10 (graph 3-3), and the friction coefficient of test piece 1-4 containing 6% by mass of jojoba oil, 2% by mass of polyethylene, and 1% by mass of carbon particles is 0.12. Yes (graph 3-4), and the friction coefficient of test piece 1-5 containing 3% by weight of jojoba oil and 1% by weight of polyethylene is 0.07 (graph 3-5). Each of the test pieces 1-1 to 1-5 has a friction coefficient that is overwhelmingly smaller than that of Comparative Example 1-8 using only aliphatic polyketone resin 100, and Comparative Example 1-7 containing 15% by mass of PTFE powder. It is sufficiently smaller than the friction coefficient 0.25 (Graph 3-7). Here, when the test piece 1-1 and the test piece 1-5 are compared, the test piece 1-1 is common in that it contains 3% by weight of jojoba oil and 1% by weight of polyethylene. The test piece 1-1 has 1% by weight of carbon particles. On the other hand, the test piece 1-5 is different in that it does not contain carbon particles. Since there was no significant difference in the friction coefficient between the two, it was found that the blending of carbon particles did not affect the friction coefficient.

  Further, the wear scar depth of Comparative Example 1-8 with 100% by mass of aliphatic polyketone resin is 229.5 μm (Graph 4-8). On the other hand, the wear scar depth of the test piece 1-1 containing 3% by weight of jojoba oil, 1% by weight of polyethylene and 1% by weight of carbon particles is 1.3 μm (graph 4-1), 4% by weight of jojoba oil, polyethylene The wear depth of the test piece 1-2 containing 1% by mass and 1% by mass of carbon particles is 1.6 μm (graph 4-2), 6% by mass of jojoba oil, 1% by mass of polyethylene, and 1% by mass of carbon particles. The wear scar depth of the test piece 1-3 is 1.8 μm (graph 4-3), and the wear trace of the test piece 1-4 containing 6% by weight of jojoba oil, 2% by weight of polyethylene, and 1% by weight of carbon particles. The depth is 2.7 μm (Graph 4-4), and the wear scar depth of the test piece 1-5 containing 3% by weight of jojoba oil and 1% by weight of polyethylene is 1.8 μm (Graph 4). -5). The wear scar depth of any of the test pieces 1-1 to 1-5 was sufficiently smaller than the wear scar depth of Comparative Example 1-8 of 100% by mass of the aliphatic polyketone resin, and 15% by mass of PTFE powder was blended. It is smaller than the wear scar depth of Comparative Example 1-7 of 42.5 μm (Graph 4-7). Here, when the test piece 1-1 and the test piece 1-5 are compared, the test piece 1-1 is common in that it contains 3% by weight of jojoba oil and 1% by weight of polyethylene. The test piece 1-1 has 1% by weight of carbon particles. On the other hand, the test piece 1-5 is different in that it does not contain carbon particles. Since there was no significant difference in the wear scar depth between the two, it was found that the blending of the carbon particles did not affect the wear scar depth.

  FIG. 3 is a diagram showing measurement results of a sliding performance test under a high temperature environment (120 ° C.) performed on test pieces 1-1 to 1-5 under the conditions shown in Table 3.

  Here, as in FIG. 2, the left vertical axis indicates the friction coefficient, and the right vertical axis indicates the wear scar depth (the average value of the wear scar depth in the arrow A of the sliding surface 10). . Graphs 5-1 to 5-5 show the measurement results of the friction coefficients of the test pieces 1-1 to 1-5, and graphs 6-1 to 6-5 show the test pieces 1-1 to 1-5. The measurement result of the wear scar depth is shown.

  As shown in FIG. 3, in a high temperature environment (120 ° C.), the friction coefficient of the test piece 1-1 containing 3% by mass of jojoba oil, 1% by mass of polyethylene, and 1% by mass of carbon particles is 0.07 (graph) 5-1), the friction coefficient of 4% by mass of jojoba oil, 1% by mass of polyethylene, and 1% by mass of carbon particles is 0.08 (graph 5-2), 6% by mass of jojoba oil, The friction coefficient of the test piece 1-3 containing 1% by mass of polyethylene and 1% by mass of carbon particles is 0.07 (graph 5-3), 6% by mass of jojoba oil, 2% by mass of polyethylene, and 1% by mass of carbon particles. The friction coefficient of the test piece 1-4 is 0.10 (graph 5-4), and the friction coefficient of the test piece 1-5 containing 3% by weight of jojoba oil and 1% by weight of polyethylene is 0.06. (Graph 5-5). Each of the test pieces 1-1 to 1-5 had a lower coefficient of friction under a room temperature environment, and good sliding characteristics were obtained even under a high temperature environment. Moreover, since there was no significant difference in the coefficient of friction between the test piece 1-1 in which the carbon particles were blended and the test piece 1-1 in common with the test piece 1-1 except that the carbon particles were not blended, It was found that the blending of the carbon particles does not affect the friction coefficient even in a high temperature environment.

  Moreover, the wear scar depth of the test piece 1-1 containing 3% by mass of jojoba oil, 1% by mass of polyethylene and 1% by mass of carbon particles is 2.5 μm (graph 6-1), 4% by mass of jojoba oil, polyethylene The wear depth of the test piece 1-2 containing 1% by mass and 1% by mass of carbon particles is 2.8 μm (graph 6-2), 6% by mass of jojoba oil, 1% by mass of polyethylene, and 1% by mass of carbon particles. The wear scar depth of the test piece 1-3 is 4.3 μm (graph 6-3), and the wear trace of the test piece 1-4 containing 6% by weight of jojoba oil, 2% by weight of polyethylene, and 1% by weight of carbon particles. The depth is 3.5 μm (Graph 6-4), and the wear scar depth of the test piece 1-5 containing 3% by weight of jojoba oil and 1% by weight of polyethylene is 3.2 μm (Graph 6). -5). The wear scar depth of any of the test pieces 1-1 to 1-5 is larger in a high temperature environment (120 ° C.) than in a room temperature environment, but sufficient wear resistance can be obtained even in a high temperature environment. I understood.

  From the above sliding performance test results, by blending jojoba oil and polyethylene into the aliphatic polyketone resin, the sliding performance of the aliphatic polyketone resin alone is dramatically improved in both room temperature environment and high temperature environment. It has been found that this can be used for sliding bearings. Also, from the above moldability confirmation test, by blending jojoba oil with polyethylene in an aliphatic polyketone resin, compared to the case where polyethylene is not blended, it is excellent in moldability and suitable for mass production by injection molding. It was found that a resin composition can be realized.

  This is considered to be due to the following reason. That is, the aliphatic polyketone resin is one in which a large number of ketones are linked, and a carbonyl group is arranged in the main chain as shown in Chemical Formula 1 below.

  Here, as shown in the chemical formula 2 below, the carbonyl group is polarized with carbon C and oxygen O charged to + and −, respectively.

  As described above, the aliphatic polyketone resin is considered to be a resin having polarity, and the surface of the aliphatic polyketone resin is considered to be in an active state in which it easily binds to other substances.

Jojoba oil has a fatty acid ester shown in Chemical Formula 3 below. R ₁ and R _{2 in} Chemical formula 3 represent a long-chain hydrocarbon group.

  Higher fatty acid esters are considered to have carbon-oxygen bonds and have polarity. For this reason, it is thought that jojoba oil containing a higher fatty acid ester is retained on the surface of a highly polar aliphatic polyketone resin and exhibits a lubricating effect as an oily agent. The same lubricating effect can be expected with higher fatty acids, higher alcohols, and the like that are also considered to have polarity.

  Polyethylene is a polymer having a structure in which hydrocarbon groups are polymerized, as shown in Chemical Formula 4 below, and has a chemical structure similar to that of a fatty acid ester.

  For this reason, by blending a higher fatty acid ester with polyethylene in an aliphatic polyketone resin, the polyethylene binds to the higher fatty acid ester and functions as a fatty acid ester retention agent. It is thought that it was able to mix | blend with aliphatic polyketone resin, without making it isolate | separate from resin.

  As described above, according to the present embodiment, an aliphatic polyketone resin containing an oily agent containing a higher fatty acid ester, a higher fatty acid, or a higher alcohol, and an olefin resin that functions as a retaining agent for the oily agent. Since the sliding performance can be improved by using, an aliphatic polyketone resin that is excellent in heat resistance and chemical resistance and is less expensive than other sliding member resin compositions having equivalent heat resistance. The resin composition for sliding members using can be provided.

  The resin composition for sliding members of the present invention can be used for various sliding members. In particular, it is suitable for a sliding bearing.

  1: plate-shaped test piece made of resin composition for sliding member, 2: mating material, 10: sliding surface (front surface) of test piece 1, 11: back surface of resin composition 1 for sliding member, 20: Support target surface (end surface) of mating material 2

Claims (7)

An aliphatic polyketone resin;
An oily agent,
And an olefin resin. A resin composition for a sliding member. The resin composition for a sliding member according to claim 1,
The oily agent is
A resin composition for a sliding member, comprising a higher fatty acid, a higher fatty acid ester, or a higher alcohol. The resin composition for a sliding member according to claim 1 or 2,
The oily agent is
The resin composition for a sliding member, which has a boiling point higher than the molding temperature of the aliphatic polyketone. A resin composition for a sliding member according to any one of claims 1 to 3,
The oily agent is jojoba oil. A resin composition for a sliding member. A resin composition for a sliding member according to any one of claims 1 to 4,
The resin composition for a sliding member, wherein the olefin resin is polyethylene. A resin composition for a sliding member according to any one of claims 1 to 5,
The blending amount of the oily agent is 1 to 6% by mass,
The compounding quantity of the said olefin resin is 0.5-15 mass%. The resin composition for sliding members characterized by the above-mentioned.   A sliding bearing formed of the resin composition for a sliding member according to any one of claims 1 to 6.

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