JP3909354B2 - Resin composition - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin composition capable of preparing a molded article having improved surface frictional properties, and a molded article derived from the composition.
[0002]
[Prior art]
Molded bodies with improved surface friction characteristics are used in various applications including sliding members. As such a molded body, a molded body in which a metal base surface is coated with a fluororesin such as polytetrafluoroethylene, and a molded body obtained by mixing a resin with a lubricating powder or fiber are known. For example, a molded product obtained by mixing a powder of viscosity mineral such as graphite or molybdenum disulfide with a thermoplastic resin; a sliding member obtained by mixing carbon fiber or aramid fiber with a thermosetting resin such as epoxy resin (Patent document 1) etc. are utilized. Among the above molded products, in the case of a molded product coated with a fluororesin, since the fluororesin is generally not dissolved in a solvent, a process such as baking coating is required to apply the fluororesin to the substrate surface. To do. Therefore, it cannot be applied to cases other than a metal substrate, and a complicated process is required for manufacturing. In the case of a molded body having the above-mentioned lubricating powder or fiber, the viscosity mineral is exposed on the surface of the molded body and the friction coefficient is lowered, but the degree is still insufficient.
[0003]
[Patent Document 1]
[Patent Document 1] Japanese Patent Laid-Open No. 11-130876
[Problems to be solved by the invention]
The present invention solves the above-described conventional problems, and the object thereof is a composition capable of easily forming a molded article suitably used as a sliding member, a precision part and the like, and a molding derived from the composition To provide a body.
[0005]
[Means for Solving the Problems]
The resin composition of the present invention contains engineering plastic and ultra high molecular weight polyethylene .
[0006]
In the molded article of the present invention, the surface of a base material mainly composed of engineering plastic is coated with ultrahigh molecular weight polyethylene .
[0007]
The above engineering plastics in the preferred embodiment, the polyetherimide, a port Riete Rusuru phone, at least one selected from the group consisting of polyetheretherketone and Po Risarufo down.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The engineering plastic contained in the resin composition of the present invention is a material constituting the main body (base material) portion of a molded article obtained when molding is performed using the composition, Resins known as engineering plastics are used. Such a resin can be molded by injection molding, extrusion molding or the like, and is preferably a resin having a difference in melting point (or softening point) from ultra high molecular weight polyethylene described later of 50 ° C., which is 100 ° C. or higher. A resin is more preferable. The engineering plastics which may be included in the compositions of the present invention, polyetherimide (PEI), Po Riete Rusuru phone (PES), polyether ether ketone (PEEK), and port Risarufon (PSF) can be mentioned.
[0010]
The resin composition of the present invention, ultra-high molecular weight polyethylene is contained. Ultra high molecular weight polyethylene is polyethylene whose viscosity average molecular weight is greater than 1,000,000. The viscosity average molecular weight is preferably 2,000,000 to 7,000,000.
[0011]
This ultra high molecular weight polyethylene is contained in an amount of 10% by weight or less, preferably 0.1 to 5.0% by weight, more preferably 1.0 to 3.0% by weight, based on the weight of the entire composition. . This ultra high molecular weight polyethylene has a melting point of about 130-140 ° C, usually about 136 ° C.
[0012]
The composition of the present invention contains a filler, an additive and the like as necessary. Examples of the filler include carbon fiber. When the filler is contained, it is contained in a proportion of 40 to 60% by weight, preferably about 50% by weight of the whole composition. Examples of the additive include a solid lubricant and an antioxidant, and the additive is contained in a proportion of 10% by weight or less of the entire composition.
[0013]
In order to produce a molded body using the resin composition of the present invention, for example, the above-mentioned engineering plastic, ultra high molecular weight polyethylene and, if necessary, additives such as fillers are blended by a usual method, and heated and kneaded. Perform molding. For example, a desired molded body is manufactured by injection molding, extrusion molding, or the like.
[0014]
The engineering plastic is softened to the extent that it can be melted or molded by heat during molding, and the ultrahigh molecular weight polyethylene is melted. A thin film made of the ultra high molecular weight polyethylene is formed on the surface of the formed molded body. The ultra high molecular weight polyethylene is present in a low proportion or substantially absent in the molded body. The thin film made of ultra high molecular weight polyethylene is usually 5 μm or less, preferably 2 μm or less. Since the molded body having such a thin film has a low coefficient of friction on the surface, it is suitable as various members intended for sliding. For example, it is suitably used for video parts such as a cylinder base and a pole base, various bearings, gears and other parts that require low friction characteristics.
[0015]
【Example】
(Example 1)
Epocluster AEI501 (manufactured by Cluster Technology; including polyetherimide, carbon fiber, and clay mineral having a weight average molecular weight of 50,000 to 60,000) and ultrahigh molecular weight polyethylene which are composite materials mainly composed of polyetherimide (Viscosity average molecular weight: 3,500,000) 5 parts by weight were kneaded at 400 ° C. to obtain pellets. Using this pellet, a 20 mm × 20 mm × 3 mm plate-shaped test piece was obtained by injection molding at 400 ° C. (mold temperature: 170 ° C.).
[0016]
Using the above test piece, a high carbon chrome bearing steel (SUJ2) test piece (3/8 inch diameter sphere) was slid back and forth 1000 times to measure the friction coefficient. As the sliding tester, a friction and wear tester manufactured by Shinko Engineering Co., Ltd. was used. The temperature during the test was 22 ° C., the load was 1960 mN, the stroke (amplitude width) was 6 mm, and the frequency was 2.00 Hz (number of reciprocations per second: 2). The result is shown in FIG.
[0017]
Separately, a similar test was performed using a stainless steel (SUS304) test piece instead of the high carbon chromium bearing steel (SUJ2) test piece. The result is shown in FIG.
[0018]
It can be seen from FIGS. 1 and 2 that the friction coefficient of this test piece is about 0.16 to 0.17.
[0019]
(Comparative Example 1)
A test piece was prepared in the same manner as in Example 1 except that ultrahigh molecular weight polyethylene was not used, and a reciprocating sliding test was performed. FIG. 3 shows the results using the high carbon chromium bearing steel (SUJ2) test piece, and FIG. 4 shows the results using the stainless steel (SUS304) test piece.
[0020]
3 and 4, when ultra high molecular weight polyethylene is not used, the friction coefficient is about 0.40 to 0.46, which is 2.5 times higher than that of Example 1.
[0021]
【The invention's effect】
According to the present invention, a resin composition and a molded article derived from the composition that can easily produce a molded article whose surface is coated with ultrahigh molecular weight polyethylene are provided. This molded body is widely used for video parts such as a cylinder base and a pole base, various bearings, gears and other parts that require low friction characteristics.
[Brief description of the drawings]
[1] definitive when performing the sliding test of the molded article of the present invention had use ultra high molecular weight polyethylene is a graph showing the relationship between the number of sliding operations and the coefficient of friction.
[Figure 2] definitive when performing the sliding test of the molded article of the present invention had use ultra high molecular weight polyethylene is a graph showing the relationship between the number of sliding operations and the coefficient of friction.
FIG. 3 is a graph showing the relationship between the number of sliding times and the coefficient of friction when a sliding test is performed on a molded body obtained without using ultrahigh molecular weight polyethylene.
FIG. 4 is a graph showing the relationship between the number of sliding times and the friction coefficient when a sliding test is performed on a molded body obtained without using ultrahigh molecular weight polyethylene.

Claims (4)

A resin composition containing engineering plastic and ultra-high molecular weight polyethylene ,
The engineering plastics, polyetherimide, polyethersulfone, polyether ether ketone, and at least one selected from the group consisting of polysulfone, and the difference in melting points of the engineering plastic and the ultra high molecular weight polyethylene 100 A resin composition that is at or above ° C.   The resin composition according to claim 1, wherein the engineering plastic is a polyetherimide. The surface of the base material mainly composed of engineering plastic is a molded body coated with ultra high molecular weight polyethylene ,
The engineering plastics, polyetherimide, polyethersulfone, polyether ether ketone, and at least one selected from the group consisting of polysulfone, and the difference in melting points of the engineering plastic and the ultra high molecular weight polyethylene 100 A molded body having a temperature of ℃ or higher. The molded article according to claim 3 , wherein the engineering plastic is polyetherimide.

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