JPH08104803A - Resin composition - Google Patents

Abstract

PURPOSE: To obtain a mass-producible resin composition excellent in durability and wear resistance, having low coefficient of friction, causing no damage to a partner material as a light metal and no offensive noise generation in sliding, comprising a polyethernitrile, fluororesin and zinc oxide whisker. CONSTITUTION: This composition comprises (A) 70-30wt.% of polyethernitrile (a homopolymer containing >=90mol% of recurring unit of the formula), (B) 20-35wt.% of a fluororesin (polytetrafluoroethylene: PTFE), and (C) 20-35wt.% of zinc oxide whisker. The component A is prepared by reaction between equimolar amounts of a dihalogenobenzonitrile and resorcin in the presence of an alkali metal carbonate in an aprotic polar solvent in an inert gas atmosphere.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition.
More specifically, the present invention relates to a resin composition that is preferably used as a material for sliding parts in the fields of electric and electronic devices and machines.

[0002]

2. Description of the Related Art Various sliding parts are used in the fields of electric and electronic devices and machines. In recent years, mass production and weight reduction have been attempted by using resin as a material for such sliding parts. Further, as for a material to be slid with such as a shaft, the weight is further reduced by using a heavy metal such as iron and a light metal such as an aluminum alloy. Therefore, the resin as a material for the sliding parts has further sliding characteristics (a small friction coefficient, wear resistance, no damage to the mating material, no abnormal noise, and mass production by injection molding). Etc.) is desired. From this point of view, various techniques have been disclosed.
That is, a resin composition in which zinc oxide whiskers are mixed with a resin (JP-A-1-225663, JP-A-5-247351, JP-A-4-210123, etc.), polyether nitrile (PEN), PTFE and graphite, two Resin composition containing fillers such as molybdenum sulfide and potassium titanate whiskers (special opening and closing 1-233626)
No. 9, No. 3-88844, and No. 3-91.
No. 559, etc.)

[0003]

However, the resin composition (1) and (2) have a large friction coefficient with respect to a soft metal such as an aluminum alloy, have insufficient wear resistance, and may damage the mating material. Also, the durability was not always sufficiently satisfactory. The present invention has been made in view of the above problems, and has excellent durability,
It has excellent friction characteristics such as low friction coefficient, excellent wear resistance, less damage to the mating material made of light metal, no abnormal noise during sliding, and mass production by injection molding. It aims at providing the resin composition which has.

[0004]

To achieve the above object, according to the present invention, there is provided a resin composition containing the following components as main components. (A) Polyether nitrile 70 to 30 wt% (B) Fluororesin 20 to 35 wt% (C) Zinc oxide whiskers 20 to 35 wt%

In a preferred embodiment, the above-mentioned polyether nitrile (A) is a homopolymer containing 90% by weight or more of a repeating unit represented by the following general formula (I). To be done.

[0006]

[Chemical 1]

Further, there is provided a resin composition characterized in that the fluororesin (B) is polytetrafluoroethylene (PTFE).

The present invention will be specifically described below. The resin composition of the present invention has a predetermined ratio of polyether nitrile (A).
And fluororesin (B) and zinc oxide whiskers (C) as main components.

1. Constituent component (1) Polyether nitrile (A) In the present invention, the use of polyether nitrile (A) as a constituent component has excellent sliding characteristics and a high melting point of 340 to 350 ° C. and sufficient heat resistance. This is because it is a resin having properties. Examples of the polyether nitrile used in the present invention include those having a repeating unit represented by the general formula (I) as a main constituent component. That is,

## STR00001 ## The specific ratio varies depending on the type and the like and cannot always be uniquely determined, but in general, it is preferable that the repeating unit of the formula (I) is 90% by weight or more, A homopolymer composed of this repeating unit is preferred. In addition, if the amount is small, preferably less than 10% by weight, the following general formula (II)

[0010]

Embedded image (Where Ar is

[0011]

Embedded image Etc. ) Or the following general formula (III)

[0012]

[Chemical 4] (Where Ar 'is

[0013]

Embedded image

Etc. are shown. ) It may contain a repeating unit represented by.

However, when the content of the repeating units of the general formulas (II) and (III) is 10% by weight or more, the properties of the polyether nitrile may be impaired.

The above-mentioned polyether nitrile is, for example,
The following general formula (IV)

[0017]

[Chemical 6] (In the formula, X and X'represent a halogen atom.) Dihalogenobenzonitrile and resorcinol are present in an approximately equimolar ratio in the presence of an alkali metal carbonate and in an aprotic polar solvent. It is manufactured by reacting under an inert gas atmosphere.

Here, as the alkali metal carbonate, for example, carbonates such as sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, rubidium carbonate and the like and hydrogen carbonates corresponding thereto can be used. The amount of these alkali metal carbonates used may be appropriately selected depending on the situation, and is generally 1.0 to 1.3 with respect to resorcin.
It is preferable to use a double equivalent amount, particularly a slight excess amount.

Examples of aprotic polar solvents that can be used include N-2-methylpyrrolidone, 1,3-dimethylimidazolidinone, dimethylsulfoxide, dimethylformamide, dimethylacetamide, and the like. The amount may be sufficient to dissolve the compound of general formula (IV) and resorcin.

Furthermore, before or during the polymerization reaction, a chain extender or a terminal terminator, such as fluorobenzonitrile, can be appropriately added.

Other reaction conditions differ depending on various situations and cannot be unambiguously determined, but the reaction temperature is usually 20.
The temperature is 0 ° C or higher, preferably 200 to 210 ° C, and the reaction time is 2 to 6 hours.

There are various kinds of polyether nitriles thus obtained, and these can be used alone or in combination of two or more kinds.

The mixing ratio of the polyether nitrile (A) is 70 to 30% by weight. Above all, 60 to 35% by weight is preferable. When it exceeds 70% by weight and when it is less than 30% by weight, wear increases.

(2) Fluororesin (B) In the present invention, the fluororesin (B) is used as a constituent component because the polyether nitrile simple substance showing excellent sliding characteristics is further added with the fluororesin. This is to reduce the coefficient.

The fluororesin (B) used in the present invention is not particularly limited, and examples thereof include homopolymers or copolymers of tetrafluoroethylene, copolymers of tetrafluoroethylene and hexafluoropropylene, and chlorotrifluoro. Examples thereof include polymers of ethylene and polymers of vinylidene fluoride. Of these, polytetrafluoroethylene (PTFE) is particularly preferable because it has a high melting point and is easily molded. In addition, these may be used individually by 1 type and may use 2 or more types together. In the present invention, the fluororesin (B) is usually available and has an average particle size of about 0.5 to 50 μm, preferably 1
Those in the range of about 30 μm can be blended.

The mixing ratio of this fluororesin is 20 to 35.
Weight% Above all, 25 to 30% by weight is preferable. Two
If it is less than 0% by weight, the lubricity, which is a characteristic peculiar to the fluororesin, is not sufficiently expressed, and if it exceeds 35% by weight, the abrasion resistance which is a peculiar property to the fluororesin is reduced.

(3) Zinc Oxide Whiskers The zinc oxide whiskers used in the present invention are not particularly limited, and may have a simple oblique shape or a tetrapot shape. The surface may be treated with a coupling agent such as a silane coupling agent, a chromium coupling agent, a silyl peroxide coupling agent, an organic phosphorus coupling agent, a titanate coupling agent, or the like.

The compounding ratio of this zinc oxide whisker is 2
0 to 30% by weight is preferable, and 25 to 30% by weight is more preferable. If it is less than 20% by weight, the wear reducing effect does not appear, and if it exceeds 35% by weight, for example, the metal counterpart material is damaged and metal abrasion powder is generated. Will increase.

(4) Additives In the composition of the present invention, various additives generally added to thermoplastic resins, that is, stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, dyes Colorants such as or pigments,
Lubricants, mold release agents and the like can be appropriately added as necessary.

2. Method for producing the composition The method for producing the resin composition of the present invention is not particularly limited, and the above three components as main constituents are melt-mixed by, for example, an extruder to obtain a pelletized composition. be able to.

[0031]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the examples and comparative examples,
The following components were used. The compounding ratios are shown together in Table 1 and Table 2. Polyether nitrile (PEN): Idemitsu Material Co., Ltd. (Idemitsu PEN) Polytetrafluoroethylene (PTFE): Daikin Industries, Ltd. (Lubron L2 average particle size 5 μm) Zinc oxide whiskers: Matsushita Amtec Co., Ltd. (Panatetra fiber length 3 to 200 μm) Graphite: Nippon Graphite Industry Co., Ltd. (ACP1000) Molybdenum disulfide: Nippon Graphite Industry Co., Ltd. (Mori Powder A) Potassium titanate whiskers: Otsuka Chemical Co., Ltd. (Tismo N) The resin compositions of Examples and Comparative Examples were evaluated by the following methods. The results are summarized in Tables 1 and 2.

[0032]

[Table 1]

[0033]

[Table 2]

Friction Coefficient and Wear Depth The friction coefficient and wear depth (μm) of the test piece were measured by the following sliding test and used as a scale of wear resistance. Device: Suzuki type thrust type sliding tester (EFM-III-F type manufactured by Orientec Co.) Surface pressure: 20 kg / cm ² Speed: 15 m / min Sliding time: 50 hr Counterpart material: AL5056H34 Outer diameter 25.6 mm, inner diameter 20 mm cylindrical ring test piece: 40 mm x 40 mm x 3.2 mm flat plate test piece

Damage to Counterpart Material The surface roughness of the counterpart material was used as a measure of damage to the counterpart material. Device: Surface roughness measuring device (Surftest 501 manufactured by Mitutoyo Co., Ltd.) Evaluation method: A sliding test was conducted using the sliding tester, and the surface of the mating material after sliding was measured by the surface roughness measuring device. Was used to evaluate the surface roughness parameter Ra. The mating material before sliding was adjusted to Ra = 0.2 (# 800 emery paper polishing)
did.

Generation of abnormal noise Whether or not abnormal noise was generated during the sliding test was listened to.

[Example 1] Polyether nitrile (PE
N) 60% by weight, polytetrafluoroethylene (PTF
E) 20 wt% and zinc oxide whiskers 20 wt% were melt-kneaded at a temperature of 350 ° C. by a twin-screw extruder, and then the strand was water-cooled and cut to obtain pellets. The pellets were injection-molded using an injection molding machine at a cylinder temperature of 350 ° C. and a mold temperature of 230 ° C. to obtain 80 × 80 × 3.2 mm.
A flat plate of This flat plate was cut into a size of 40 × 40 × 3.2 mm to prepare a test piece for a sliding test.

[Example 2] The same procedure as in Example 1 was repeated except that PEN was 55% by weight and zinc oxide whiskers were 25% by weight.

[Example 3] The same procedure as in Example 1 was repeated except that PEN was 45% by weight and zinc oxide whiskers were 35% by weight.

[Example 4] The same procedure as in Example 1 was repeated except that PEN was 50% by weight and PTFE was 30% by weight.

[Example 5] The same procedure as in Example 1 was repeated except that PEN was 45% by weight, PTFE was 30% by weight, and zinc oxide whiskers were 25% by weight.

Example 6 The same as Example 1 except that PEN was 35% by weight, PTFE was 30% by weight, and zinc oxide whiskers were 35% by weight.

[Example 7] The same procedure as in Example 1 was repeated except that PEN was 45% by weight and PTFE was 35% by weight.

[Example 8] The same as Example 1 except that PEN was 40% by weight, PTFE was 35% by weight, and zinc oxide whiskers were 25% by weight.

Comparative Example 1 The procedure of Example 1 was repeated except that PEN was 90% by weight, PTFE was 10% by weight, and zinc oxide whiskers were not added.

Comparative Example 2 The procedure of Example 1 was repeated, except that PEN was 70% by weight, PTFE was 30% by weight, and zinc oxide whiskers were not added.

Comparative Example 3 The procedure of Example 1 was repeated, except that PEN was 90% by weight, zinc oxide whiskers was 10% by weight, and that PTFE was not added.

[Comparative Example 4] The procedure of Example 1 was repeated, except that PEN was 70% by weight, zinc oxide whiskers was 30% by weight, and that PTFE was not added.

[Comparative Example 5] The procedure of Example 1 was repeated except that PEN was 80% by weight, PTFE was 10% by weight, and zinc oxide whiskers were 10% by weight.

Comparative Example 6 The procedure of Example 1 was repeated, except that PEN was 40% by weight, PTFE was 10% by weight, and zinc oxide whiskers were 50% by weight.

[Comparative Example 7] The procedure of Example 1 was repeated except that PEN was 50% by weight, PTFE was 40% by weight, and zinc oxide whiskers were 10% by weight.

Comparative Example 8 The procedure of Example 1 was repeated except that PEN was 35% by weight, PTFE was 40% by weight, and zinc oxide whiskers were 25% by weight.

[Comparative Example 9] In Example 1, 2 parts of potassium titanate whiskers were used instead of the zinc oxide whiskers.
Same as Example 1 except that 0% by weight was added.

Comparative Example 10 The procedure of Example 1 was repeated, except that 20% by weight of graphite was added instead of the zinc oxide whiskers.

[Comparative Example 11] In Example 1, 20% by weight of molybdenum disulfide was used instead of the zinc oxide whiskers.
The procedure was the same as in Example 1 except that the addition was made.

[0056]

As described above, according to the present invention,
It has excellent durability, small friction coefficient, excellent wear resistance, less damage to the mating material of light metal, no abnormal noise during sliding, and mass production by injection molding. It is possible to provide a resin composition having excellent sliding properties.

Claims (3)

[Claims] 1. A resin composition comprising the following components as main components. (A) Polyether nitrile 70 to 30 wt% (B) Fluororesin 20 to 35 wt% (C) Zinc oxide whiskers 20 to 35 wt% 2. The polyether nitrile (A) contains 90% by weight of a repeating unit represented by the following general formula (I).
The resin composition according to claim 1, which is a homopolymer containing the above. Embedded image 3. The resin composition according to claim 1 or 2, wherein the fluororesin (B) is polytetrafluoroethylene (PTFE).