JPH05117677A - Sliding member made from thermoplastic resin - Google Patents

Abstract

PURPOSE:To provide an improved sliding member such as a gear, a cam; a bearing or a roll used in an electric household appliance, a business machine, an automobile component or the like. CONSTITUTION:A sliding member made from a polybutylene naphthalenedicarboxylate resin or a composition prepared by adding at least one slidability improver selected from among graphite, molybudenum sulfide, polytetrafluoroethylene and a lubricating oil thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding part made of a thermoplastic resin made of polybutylene naphthalene dicarboxylate resin (hereinafter abbreviated as PBN).

[0002]

2. Description of the Related Art Today, many resins are used as sliding parts for electric and electronic products such as OA equipment and AV equipment, and automobiles and mechanical parts. The reason why resin is used for sliding members is that, in addition to its excellent slidability, the weight of parts can be reduced, the degree of freedom in shape is great, the corrosion resistance is excellent, and the quietness is excellent. And the like. Among the resins, thermoplastic resins are widely used because they can be mass-produced by injection molding.

Among thermoplastic resins, crystalline resins are preferred from the viewpoint of slidability. Typical crystalline resins for this application include polyacetal (hereinafter abbreviated as POM), polybutylene terephthalate (hereinafter abbreviated as PBT), and polyamide (hereinafter abbreviated as PA).
However, these resins have not a few drawbacks, and it has become difficult to meet the demands of the expanding market. For example, although POM has excellent slidability, it requires a strict control of molding conditions because it has a large dimensional shrinkage factor during molding and a large change in dimensions due to molding conditions. In addition, since it is difficult to make flame-retardant, there is a drawback that the parts used are limited. Further, PBT may have a low glass transition temperature (about 23 ° C.), so that sliding characteristics (friction coefficient et
The temperature dependency of c) is large. Further, since PA has a large water absorption property, it has a drawback that sliding characteristics change depending on ambient conditions (temperature, humidity).

The present inventor has accomplished the present invention as a result of extensive studies on the development of an excellent sliding component based on such a background.

[0005]

The present invention is a sliding part made of a thermoplastic resin made of PBN resin. In the present invention, PBN is naphthalene dicarboxylic acid, preferably naphthalene-2,6-dicarboxylic acid as a main acid component,
A polyester having 1,4-butanediol as a main glycol component, that is, a polyester in which all or most of repeating units (usually 90 mol% or more, preferably 95 mol% or more) are butylene naphthalene dicarboxylate.

Further, this polyester can be copolymerized with the following components within a range not impairing the physical properties. That is, as the acid component, an aromatic dicarboxylic acid other than naphthalenedicarboxylic acid, for example, phthalic acid, isophthalic acid, terephthalic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylmethanedicarboxylic acid, diphenylketonedicarboxylic acid, Examples thereof include diphenyl sulfide dicarboxylic acid, diphenyl sulfone dicarboxylic acid, aliphatic dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, tetralindicarboxylic acid and decalindicarboxylic acid.

As the glycol component, ethylene glycol, propylene glycol, trimethylene glycol,
Pentamethylene glycol, hexamethylene glycol, octamethylene glycol, neopentyl glycol, cyclohexanedimethanol, xylylene glycol, diethylene glycol, polyethylene glycol,
Examples thereof include bisphenol A, catechol, resorcinol, hydroquinone, dihydroxydiphenyl, dihydroxydiphenyl ether, dihydroxydiphenylmethane, dihydroxydiphenylketone, dihydroxydiphenylsulfide, dihydroxydiphenylsulfone and the like.

Examples of the oxycarboxylic acid component include oxybenzoic acid, hydroxynaphthoic acid, hydroxydiphenylcarboxylic acid and ω-hydroxycaproic acid.

Further, trifunctional or higher functional compounds such as glycerin, trimethylpropane, pentaerythritol, trimellitic acid and pyromellitic acid may be copolymerized within a range in which the polyester does not substantially lose molding performance.

Such a polyester can be obtained by polycondensing naphthalenedicarboxylic acid and / or a functional derivative thereof and butylene glycol and / or a functional derivative thereof by a conventionally known aromatic polyester production method. The concentration of the terminal carboxyl group of PBN used in the present invention is not particularly limited, but it is desirable that the concentration is low.
The PBN resin used in the present invention itself has excellent sliding properties. However, when further improved sliding properties are required depending on the application, various sliding property improvers can be used as in the case of improving other resins. It is desirable to add. Examples of the slidability improver include graphite, molybdenum sulfide, polytetrafluoroethylene, and lubricating oil. These slidability improving agents can be used in combination of two or more kinds. Usually, these slidability improvers are added to the resin in the range of 0.5 to 30 wt%, preferably 1 to 20 wt%.

Further, the PBN resin used in the present invention further has other additives such as glass fiber, carbon fiber, potassium titanium fiber, etc. within a range that does not significantly impair the physical properties thereof in order to impart desired characteristics according to the purpose. Fibrous reinforcing material, carbon black, silica, glass beads, glass powder, calcium silicate, kaolin, talc, calcium carbonate and other powder fillers, mica, glass flakes and other plate fillers,
A flame retardant, a flame retardant aid, a stabilizer, a colorant, an ultraviolet absorber, a release agent, an antistatic agent, a crystallization accelerator, an impact modifier and the like can be added.

The sliding parts of the present invention are not particularly limited, but typical parts are various home electric appliances,
Gears, cams, bearings, rolls, etc. used in office equipment and automobile parts can be mentioned.

The sliding parts made of the PBN resin of the present invention not only have excellent slidability but also have good electric insulation, chemical resistance and heat resistance.

[0014]

EXAMPLES The present invention will be further described with reference to examples.

[0015]

[Example 1 and Comparative Examples 1 to 3] P having an intrinsic viscosity of 0.80
BN and POM (Polyplastics Co., Ltd .; Duracon M90), PBT (Teijin Co., Ltd .; PBT C700)
0), nylon (NY) 66 (Asahi Kasei Corp .; Leona 1)
300S) was used to injection-mold a test piece for evaluating sliding characteristics, and the friction coefficient and the amount of wear were measured under the conditions shown below. The results are shown in Table 1.

The sliding property evaluation method is as follows. Measuring instrument; Toyo Sokki Co., Ltd. EFM-III type (thrust type tester) Counterpart material: Steel Surface pressure: 10 kg / cm ² Sliding linear velocity: 10 cm / sec Ambient temperature: 23 ° C Ambient humidity: 50%

[0017]

[Table 1]

[0018]

Examples 2-3 and Comparative Examples 4-5 In addition to the unreinforced PBN and PBT resins used in Example 1 as materials, GF30-PBN and CF3 reinforced with 30 wt% of glass fiber.
The coefficient of friction and the amount of wear were measured using 0-PBT under the following conditions. The results are shown in Table 2.

The measurement conditions are as follows. Counterpart material: Steel Surface pressure ； 5kg / cm ² Slip linear velocity ； 50cm / sec Ambient temperature ； 23 ℃ Ambient humidity ； 50%

[0020]

[Table 2]

[0021]

[Example 4] Using PBN reinforced with 20 wt% of graphite as a material, the friction coefficient and the abrasion amount were measured under the same conditions as in Example 2. As a result, the friction coefficient was 0.35, and the abrasion amount was 0.33 mg / 1000 m ( Was running).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location F16C 33/20 A 6814-3J // C10N 10:12 40:02 50:08 (72) Inventor Ken Kojima 3-37-19 Oyama, Sagamihara-shi, Kanagawa Teijin Limited Sagamihara Research Center

Claims (2)

[Claims] 1. A thermoplastic resin sliding component comprising a polybutylene naphthalene dicarboxylate resin. 2. A thermoplastic resin in which the polybutylene naphthalene dicarboxylate resin according to claim 1 contains at least one slidability improver selected from the group consisting of graphite, molybdenum sulfide, polytetrafluoroethylene and lubricating oil. Made sliding parts.