JPH06116495A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PURPOSE:To obtain a lightweight resin composition excellent in wear and impact resistances by mixing a polyphenylene sulfide resin with aramid fibers and stainless steel flakes. CONSTITUTION:The composition is obtained by mixing 50-98 pts.wt. polyphenylene sulfide resin with 1-20 pts.wt. aramid fibers and 1-30 pts.wt. (the total being 100 pts.wt.) stainless steel flakes. Although a polyphenylene sulfide resin is excellent in heat and chemical resistances, it is brittle when used alone. Therefore, it is reinforced with a reinforcing fiber or the like. In this case, the mechanical strengths, dimensional stability and rigidity can be improved without detriment to the inherent properties, but it is effective only in the wear occurring when the surface of the composition and that of the mating material perform relative motion in a state in which both surfaces are in direct contact with each other and no abrasive grains are present between them. On the contrary, this composition has markedly improved resistance to the wear due to abrasion, is lightweight, has excellent impact resistance, and can be used even when sand, dust or the like is present on the sliding surfaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyphenylene sulfide resin composition having excellent wear resistance, light weight, and excellent impact resistance.

[0002]

2. Description of the Related Art Polyphenylene sulfide resin is an engineering plastic excellent in heat resistance and chemical resistance. However, since the resin alone is very brittle, it is reinforced with reinforcing fibers or the like. The polyphenylene sulfide resin thus obtained has improved mechanical strength, dimensional stability, and rigidity in addition to conventional performance, and is applied to the fields of automobiles, electric / electronic fields, and the like.

In recent years, polyphenylene sulfide resins have also attracted attention in sliding applications such as bearings and gears. For the purpose of reducing the wear characteristics of the polyphenylene sulfide resin itself and the wear of the mating material, aramids have been added to the polyphenylene sulfide resin. A resin composition obtained by melt-blending fibers (JP-A-63-162727) and a resin composition obtained by melt-blending aramid fibers, a lubricant, etc. (JP-A-2-202548) are known.

[0004]

However, the resin compositions disclosed in the above-mentioned conventional examples have a relative movement while the both surfaces of the polyphenylene sulfide resin and the mating material are in direct contact with each other without abrasive grains. It is effective only in the case of abrasion, and it cannot be said that it is effective in the case of wear of abrasive grains between the contact surfaces. To elaborate,
The former is sliding wear, which is mainly caused by the cohesive shear movement of the material, and the latter is rough wear, which is mainly caused by abrasion or cutting, and both have greatly different wear mechanisms. From this, the polyphenylene sulfide resin as a wear-resistant material known to date is as the former anti-slip wear material,
At present, no rough wear resistant material has been developed.

Accordingly, it is an object of the present invention to provide a polyphenylene sulfide resin composition having a significantly improved roughness and abrasion resistance and excellent mechanical properties.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above objects, the present inventors have found that a polyphenylene sulfide resin composition that meets the above objects can be obtained by blending a polyphenylene sulfide resin with aramid fibers and stainless flakes. They have found that a product can be obtained and have reached the present invention.

That is, the present invention is a polyphenylene sulfide resin composition comprising 50 to 98% by weight of polyphenylene sulfide resin, 1 to 20% by weight of aramid fiber and 1 to 30% by weight of stainless flakes.

The polyphenylene sulfide resin used in the present invention has the following structural formula

[0009]

[Chemical 1]

It is a resin having a basic skeleton. In the present invention, the polyphenylene sulfide resin is not particularly limited, but has a melt viscosity of 100 to 3000 pois.
A material having a degree of "e" is desirable because it has a good balance of physical properties and workability. As the melt viscosity increases, the fluidity decreases, but the strength increases. Those having a low melt viscosity are suitable for parts in which fluidity is more important than strength. As described above, a wide range of polyphenylene sulfide resins can be selected depending on the shape of the molded body, the use conditions, and the like. Further, the polyphenylene sulfide resin may be either a straight-chain type or a cross-linking type. If it does not impair the physical properties, it may be a graft type, a block type, a random type, a copolymer with other resins, or a blend. It does not matter if there is.

The aramid fiber used in the present invention is a fiber composed of a polymer synthesized by polycondensation of an aromatic diamine and an aromatic dicarboxylic acid or its derivative. Among them, copolyparaphenylene-3,4′-oxydiphenylene terephthalamide fiber and the like are preferably used. The average fiber length of the aramid fibers used is not particularly limited, but is preferably in the range of 0.5 to 10.0 mm.
The content of aramid fiber is 1 to 20% by weight, preferably 3
Is selected in the range of ˜15% by weight. If the blending amount is less than 1% by weight, the abrasion reducing effect of the polyphenylene sulfide resin is small, and if it exceeds 20% by weight, the dispersibility of the aramid fiber is lowered and the mechanical strength is remarkably lowered, which is not preferable.

The stainless flakes used in the present invention are
It is in the form of flakes made of stainless steel. Stainless steel is roughly classified into martensitic, ferritic and austenitic types, but any type may be used.
The shape of the flakes is not particularly limited, but preferably the thickness is 20 μm or less, and the length × width = 1000 μm or less × 1000 μm.
m isotropic or less, more preferably 5 μm or less in thickness, length × width = 100 to 700 μm × 100 to 7
It is isotropic with a size of 00 μm. The compounding amount of the stainless flakes is selected in the range of 1 to 30% by weight, preferably 2 to 20% by weight. When the content is less than 1% by weight, the effect of improving the wear reduction of the polyphenylene sulfide resin is small, and when it exceeds 30% by weight, the specific gravity of the composition becomes large and the flowability of the polyphenylene sulfide resin decreases, resulting in poor moldability. Is not preferable.

The polyphenylene sulfide resin composition of the present invention contains, for the purpose of improving the characteristics of molded articles or reducing the cost thereof, for example, fibrous reinforcing materials composed of potassium titanate, asbestos and silicon nitride, calcium carbonate, calcium silicate, carbonic acid. Inorganic fillers such as magnesium, magnesium oxide, zinc oxide, titanium oxide, clay, zeolite, mica, talc, wollastonite, ferrite, gypsum, quartz powder, glass beads, and glass balloons are used within the range that does not impair the physical properties of polyphenylene sulfide resin. It may be mixed.

If necessary, the resin composition of the present invention may further include, for example, polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polysulfone,
Other resins such as polyether sulfone, polyphenylene oxide, polyimide, polyamideimide, polycarbonate, polyurethane, polymethacrylate, epoxy resin and silicone resin can be added within a range that does not deteriorate the characteristics of the molded product.

[0015]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the examples.

The characteristic evaluations in this example were carried out according to the following methods.

Izod impact strength: ASTM-D256 Roughness wear characteristics: ASTM-D1044 (Taber wear test) Load: 1 kg Speed: 60 revolutions / minute Wear wheel: H-22 Example 1 Polyphenylene sulfide resin (hereinafter abbreviated as PPS)
80% by weight, 10% by weight of aramid fiber and 10% by weight of stainless flakes were mixed with a tumbler mixer, and pellets were produced with a twin-screw extruder. Izod impact test pieces and wear test pieces were molded using an injection molding machine. Next, the mechanical properties and wear characteristics of the above resin composition were evaluated.

Example 2 70% by weight of PPS, 10% by weight of aramid fiber and 20% by weight of stainless flakes were processed and molded in the same manner as in Example 1 and then evaluated.

Example 3 85% by weight of PPS, 10% by weight of aramid fiber and 5% by weight of stainless flakes were processed and molded in the same manner as in Example 1 and then evaluated.

Example 4 85% by weight of PPS, 5% by weight of aramid fiber and 10% by weight of stainless flakes were processed and molded in the same manner as in Example 1 and then evaluated.

Comparative Example 1 90% by weight of PPS and 10% by weight of aramid fiber were used in Example 1
After processing and molding in the same manner as described above, evaluation was performed.

Comparative Example 2 80% by weight of PPS and 20% by weight of stainless flakes were processed and molded in the same manner as in Example 1 and then evaluated.

Comparative Example 3 50% by weight of PPS, 10% by weight of aramid fiber and 40% by weight of stainless flakes were processed and molded in the same manner as in Example 1 and then evaluated.

Comparative Example 4 70% by weight of PPS and 30% by weight of glass fiber were processed and molded in the same manner as in Example 1 and then evaluated.

Comparative Example 5 75% by weight of PPS, 20% by weight of glass fiber and 5% by weight of stainless flakes were processed and molded in the same manner as in Example 1 and then evaluated.

The results of Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 1.
Shown in.

[0027]

[Table 1]

[0028]

The PPS composition of the present invention can be formed into a molded product by ordinary injection molding, compression molding or extrusion molding. The molding conditions are not particularly limited, and the molding is performed under normal conditions. The composition of the present invention can be used for molded products which have been limited in use due to lack of abrasion resistance in a severe environment where sand, dust and the like are present on the sliding surface, and the application is expected to expand. It is what is done.

Claims (1)

[Claims] 1. Polyphenylene sulfide resin 50-9
A polyphenylene sulfide resin composition comprising 8% by weight, 1 to 20% by weight of aramid fiber, and 1 to 30% by weight of stainless flakes.