JP2961311B1 - Polyphenylene sulfide resin composition and molded article thereof - Google Patents

Abstract

The present invention relates to polyphenylene sulfide (P)
PS) PPS resin composition with excellent lubricity (sliding properties) and abrasion resistance under high load and high speed without deteriorating characteristics such as excellent processability, heat resistance and chemical resistance inherent in resin. The task is to provide things. SOLUTION: The PPS resin composition of the present invention comprises: (a) a powdery polymer solid lubricant; (b) potassium titanate fiber, wollastonite, zonotolite, aluminum borate fiber, and magnesium borate. A resin composition comprising at least one inorganic fibrous material selected from the group consisting of fibers and (c) potassium sulfate,
The amount of component (a) in the resin composition is 5 to 20% by weight, the amount of component (b) is 10 to 40% by weight, and (c)
The compounding amount of the component is 3 to 30% by weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyphenylene sulfide resin composition and a molded product thereof.

[0002]

2. Description of the Related Art Polyphenylene sulfide (PPS)
BACKGROUND ART In recent years, resin has been increasing in demand as an engineering plastic that can withstand long-term use at a high temperature of around 200 ° C., and is widely used for mechanical parts such as gears, cams, and bearings.

[0003] However, PPS resin itself is a brittle resin, and thus has a major drawback of poor wear resistance and mechanical strength, and glass fiber or carbon fiber is used as a reinforcing material for improvement. That is the fact.

However, when such a PPS resin composition reinforced with glass fiber or carbon fiber is molded, the surface of the molded product becomes rough, causing a problem in dimensional accuracy, and
Since the Mohs' hardness is reinforced with a hard material of 6 to 7, even when a relatively hard material such as a soft metal material or carbon steel (S45C) is used as a mating material, the wear amount of the mating material is reduced. It is unavoidable that a fatal disadvantage as a material for the sliding portion occurs. Further, the effect of improving the wear resistance is not sufficient.

[0005] In order to solve such a drawback, molybdenum disulfide or tungsten disulfide and bismuth trisulfide as a solid lubricant are added to a PPS resin composition reinforced with glass fiber or carbon fiber at a predetermined ratio. Technology (US
P-3882030, JP-A-52-11039
No. 9) and a technique of adding a fluororesin, graphite and a lubricating oil which is liquid at ordinary temperature (Japanese Patent Publication No. 56-50124).

However, these techniques cannot solve the problem of dimensional accuracy because glass fiber or carbon fiber is used as a reinforcing material. Furthermore, the former technique has a small effect of imparting lubricating properties, and does not lead to the elimination of the above-mentioned disadvantages. In the latter technology, the use of liquid lubricating oil greatly reduces the mechanical properties of the molded product, and when used at high temperatures, the lubricating oil may scatter and contaminate other parts. Becomes

Further, there is known a technique for improving the surface properties and lubricity of a PPS resin molded product by blending a potassium titanate fiber or a mixture thereof with a carbon fiber in a PPS resin (JP-A-4-25562). And JP-B-5-43751).

However, although the techniques described in the above publications can improve the lubricity of the PPS resin molded article to some extent, it cannot be used under a high load and a high speed as required when used as a material for a sliding member. The lubricity is still insufficient.

[0009]

SUMMARY OF THE INVENTION The present invention provides a molded article obtained by molding without impairing the excellent characteristics of PPS resin such as excellent workability, heat resistance, and chemical resistance. An object of the present invention is to provide a PPS resin composition capable of imparting excellent lubricity (sliding characteristics) and abrasion resistance at a high speed and further improved mechanical properties.

[0010]

The PPS resin composition of the present invention comprises: (a) a powdery polymer solid lubricant;
(B) a resin composition containing at least one inorganic fibrous material selected from the group consisting of potassium titanate fiber, wollastonite, zonotolite, aluminum borate fiber and magnesium borate fiber, and (c) potassium sulfate The amount of component (a) in the resin composition is 5 to 20% by weight, the amount of component (b) is 10 to 40% by weight, and the amount of component (c) is 3 to 30% in the resin composition. % Of the PPS resin composition.

The PPS resin composition of the present invention does not impair the characteristics inherent in the PPS resin such as excellent processability, heat resistance, chemical resistance and the like. Moreover, the molded article of the resin composition of the present invention is excellent in lubricity and abrasion resistance under a high load (for example, 10 kgf / cm ² or more) and a high speed (for example, 300 mm / sec or more). The physical properties such as bending strength and tensile strength are remarkably improved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a PPS resin is
It is a crystalline thermoplastic resin and is conventionally known.
As the PPS resin, for example, a general formula

[0013]

Embedded image And a resin comprising a repeating unit represented by the formula:

Among these PPS resins, particularly typical ones are represented by the general formula

[0015]

Embedded image It is a resin comprising a repeating unit represented by Such a resin is commercially available from Philips Petroleum Corporation in the United States under the trademark "Ryton", and its production method is described, for example, in Japanese Patent Publication No. 45-3368. That is, Ryton is 160-250 ° C. in N-methylpyrrolidone solvent,
It is produced by reacting p-dichlorobenzene with sodium disulfide under pressurized conditions. According to this method,
It is possible to freely produce resins with various degrees of polymerization, from those with no cross-links in the resin to those with partial cross-links, so that those having the desired melt viscosity characteristics can be arbitrarily selected and used. Becomes easier.

Further, in the present invention, P
It is also possible to use a linear PPS resin which is a PS resin and does not have a crosslinked structure.

In the present invention, examples of the powdery polymer solid lubricant used as the component (a) include polytetrafluoroethylene, high-density polyethylene, and ultrahigh-molecular-weight polyethylene.

Polytetrafluoroethylene (PTFE)
Conventionally known ones can be widely used. The PTFE may be a powder for molding or a fine powder for a solid lubricant. As commercially available PTFE,
For example, Teflon 7 manufactured by DuPont Fluorochemicals
J and TLP-10, Fluon G16 manufactured by Asahi Glass Co., Ltd.
3. Polyflon M15 and Lubron L5 manufactured by Daikin Industries, Ltd., and the like. PTFE modified with alkyl vinyl ether can also be used.

Examples of the high-density polyethylene include polyethylene having a density of 0.94 to 0.97 g / cm ³ and a viscosity average molecular weight of about 20,000 to 200,000.

Examples of the ultrahigh molecular weight polyethylene include polyethylene having a viscosity average molecular weight of about 1,000,000 to 5,000,000. Specific examples of such ultrahigh molecular weight polyethylene include HIZEX (manufactured by Mitsui Petrochemical Industries, Ltd.) and Suntech (manufactured by Asahi Kasei Kogyo Co., Ltd.).

Among these powdery polymer solid lubricants,
PTFE is particularly preferred.

The powdery polymer solid lubricant has an average particle diameter of 100 μm or less, preferably 0.1 to 20 μm. In this specification, the average particle diameter is measured using an electron microscope. Specifically, the particle diameters of 50 particles near the center of the visual field of the electron microscope were measured, and the average value was defined as the average particle diameter. When a powdery polymer solid lubricant having an average particle diameter within the above range is used, a PPS resin molded article having excellent surface properties and appearance and excellent dimensional accuracy can be obtained.

In the present invention, the inorganic fibrous material used as the component (b) is at least one selected from the group consisting of potassium titanate fibers, wollastonite, zonotolite, aluminum borate fibers and magnesium borate fibers. It is.

As the potassium titanate fiber, for example, a general formula K ₂ O.nTiO ₂ (where n is an integer of 2 to 8) or a general formula K ₂ O.nTiO ₂ .1 / 2H ₂ O (where n is The same applies to the above). More specifically, examples thereof include 4-potassium titanate fiber, 6-potassium titanate fiber, 8-potassium titanate fiber, and the like, and mixtures thereof. Among these potassium titanate fibers, potassium titanate fibers having an average fiber diameter of 3 μm or less, an average fiber length of 5 to 200 μm, and an average fiber length / average fiber diameter (aspect ratio) of 10 or more are particularly preferable.

As the wollastonite, conventionally known ones can be widely used. For example, “Daiken Fiber Knight” (average fiber diameter 6.0 μm) sold by Sanyo Kogyo Co., Ltd.
m, average fiber length 132 μm), Pantek Mine
RALCOL-10 (average fiber diameter: 4.5 μm, average fiber length: 13 μm).

As the zonotolite, conventionally known zonotolites can be used widely, for example, the formula 6CaO.6SiO ₂ .H ₂ O
And the like. Further, as zonotolite, for example, the average fiber diameter of 0.1 to 0.5μ
m and an average fiber length of 1 to 5 μm are preferably used.

As the aluminum borate fiber, conventionally known ones can be widely used. For example, the aluminum borate fiber of the formula 9Al ₂ O ₃ .2B ₂
O ₃ and the like can be mentioned. As such an aluminum borate fiber, for example, "Albolex G" (average fiber diameter 0.5
-1 μm, average fiber length 10-30 μm).

As the magnesium borate fiber, conventionally known ones can be widely used. For example, the following formula 2MgO.B ₂ O ₃
And the like. As the magnesium borate fiber, for example, an average fiber diameter of 0.05
It is preferable to use one having an average fiber length of 2 to 100 μm.

Among the above various inorganic fibrous materials, potassium titanate fiber and wollastonite are preferable, and potassium titanate fiber is particularly preferable.

Further, the inorganic fibrous material may be surface-treated with a coupling agent in order to enhance wettability with the PPS resin. Examples of the coupling agent used here include a silane coupling agent and a titanate coupling agent.

Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ
-(Methacryloxypropyl) trimethoxysilane, γ
-Chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane and the like.

Specific examples of the titanate-based coupling agent include isopropyl triisostearoyl titanate and tetraoctylbis (ditridecyl phosphite).
Titanate and the like can be exemplified.

The surface treatment with such a coupling agent comprises:
For example, while the inorganic fibrous material used as the component (b) was stirred using a mixer such as a Henschel mixer or a super mixer, the coupling agent was dissolved as such or in a solvent such as toluene, xylene, or various alcohols. It can be performed by dropping or spraying the liquid.

In the present invention, potassium sulfate is used as the component (c). By using potassium sulfate as the component (c), a PPS resin composition excellent in lubricity and abrasion resistance under high load and high speed can be provided. With inorganic salts other than potassium sulfate, for example, barium sulfate, potassium carbonate, sodium carbonate, calcium carbonate, etc., the intended effects of the present invention cannot be exhibited at all.

The average particle size of potassium sulfate as the component (c) is usually 300 μm or less, preferably 0.1 to 100 μm.
A thickness of about μm is preferred. When potassium sulfate having an average particle diameter within the above range is used, a PPS resin molded article having excellent surface properties and appearance and excellent dimensional accuracy can be obtained.

The amounts of the components (a), (b) and (c) to be blended in the PPS resin composition of the present invention are not particularly limited, but the component (a) is added to the resin composition. Usually 5
-20% by weight, preferably 10-20% by weight, component (b) is usually 10-40% by weight, preferably 10-30% by weight, and component (c) is usually 3-30% by weight, preferably 5-5% by weight.
It is good to mix 15% by weight. By setting the blending amounts of the components (a), (b) and (c) in the above ranges, excellent characteristics such as excellent workability, heat resistance, and chemical resistance inherent in the PPS resin can be achieved. It is possible to obtain a PPS resin composition which is excellent in lubricity (sliding characteristics) and abrasion resistance under a high load and a high speed, and can impart excellent mechanical properties to a molded article. In particular, when the component (b) is blended in the above range, the mechanical properties (for example, bending strength, tensile strength, and the like) of the PPS resin molded article can be further improved.

The resin composition of the present invention may further comprise a non-polymeric solid lubricant such as graphite, talc,
A filler such as calcium carbonate, a pigment, a flame retardant, an antistatic agent, an inorganic fibrous substance (eg, glass fiber or the like) other than the component (b), a liquid lubricant such as mineral oil, or the like can be appropriately compounded.

The resin composition of the present invention can be prepared by a conventionally known method,
For example, a molded product can be formed according to injection molding, extrusion molding, or the like. More specifically, the resin composition of the present invention is usually melt-mixed at 280 to 350 ° C. by an extruder, pelletized, and then molded into a desired shape by a known molding means such as injection molding.

The PPS resin composition of the present invention has good recyclability, has little damage to processing machines, and has great practical value as a resource-saving and energy-saving molding material.

As sliding parts made from the resin composition of the present invention, for example, pushing, bearing, sleeve,
Slip links, guide rails, switch parts, gears,
And cams.

The PPS resin composition of the present invention can be used under high load and high speed without impairing the characteristics of the PPS resin such as excellent processability, heat resistance and chemical resistance. It has excellent lubricating properties (sliding properties) and abrasion resistance, and has good mechanical properties, so that it can be used as a high heat-resistant, precision sliding part that could not be applied with conventional plastic materials.

[0042]

The present invention will be further clarified with reference to the following examples. Examples 1 to 4 and Comparative Examples 1 to 4 The components shown in Table 1 below were mixed in a blender at a ratio (parts by weight) shown in Table 1 to obtain a PPS resin composition.

Each component blended in the PPS resin composition is as follows:
It is as follows. PPS resin: trade name Toprene T-4, polytetrafluoroethylene manufactured by Toprene Corporation: trade name Fluon L150
J, average particle size 80 μm, high-density polyethylene manufactured by DuPont-Mitsui Fluorochemicals Co., Ltd .: Hi-Zex, trade name: viscosity average molecular weight of about 200,000, average particle size 70 μm, potassium titanate fiber manufactured by Mitsui Petrochemical Industry Co., Ltd .: Tismo, trade name D-102, average fiber diameter 0.3 μm, average fiber length 15 μm, wollastonite manufactured by Otsuka Chemical Co., Ltd .: trade name Daikenfibanite HG,
Average fiber diameter 6.0 μm, average fiber length 132 μm, sold by Sanyo Kogyo Co., Ltd. Potassium sulfate: average particle diameter 50 μm, Otsuka Chemical Co., Ltd. barium sulfate: average particle diameter 10 μm, Sakai Chemical Co., Ltd. carbon fiber: product Name Kureha Carbon Fiber M-107
T, epoxysilane treated, average fiber diameter 18μ
m, average fiber length 0.7 μm, manufactured by Kureha Chemical Industry Co., Ltd.

Next, pellets were produced from the various PPS resin compositions obtained above using a 60 mm single screw extruder.

Further, the obtained pellets were molded at a molding temperature of 340.
° C, injection pressure (primary pressure) 1200 kgf / cm ² , holding pressure (secondary pressure) 500 kgf / cm ² , injection / holding time 20
Abrasion test pieces (hollow cylinders having an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a height of 15 mm) were prepared by injection molding under the conditions of seconds.

The wear test pieces prepared as described above were subjected to a friction and wear test, and the friction coefficient and specific wear amount (mm ³ / kgf · km) of each test piece, and the mating material (carbon steel, S4
5C) was determined (mm ³ / kgf · km).

The Suzuki type friction and wear test was applied to the friction and wear test. EFM-III-EN manufactured by Toyo Baldwin Co., Ltd. was used as the friction and wear tester. The friction and wear test was performed under the following conditions 1 and 2. Condition 1: load 10 kgf / cm ² , peripheral speed 30 cm /
Second, running distance 10 km Condition 2: load 20 kgf / cm ² , peripheral speed 30 cm /
Seconds, running distance 10km.

Table 1 shows the results.

[0049]

[Table 1] As is clear from Table 1, P containing potassium sulfate was added.
The molded article of the PS resin composition has a small friction coefficient and a small specific wear even under a high load of 20 kgf / cm ² , and also has a small specific wear of a partner material (carbon steel, S45C). Was.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ identification code FI (C08L 81/02 23:06) (58) Investigated field (Int.Cl. ⁶ , DB name) C08L 81/00-81 / 02 C08L 27/12-27/18 C08L 23/00-23/08 C08K 3 / 24,3 / 30

Claims (7)

(57) [Claims] (1) a compound represented by the general formula : The resin comprising a repeating unit represented in, selected from the group consisting of (a) powdery polymer solid lubricant, (b) potassium titanate fiber, wollastonite, xonotlite, aluminum borate fibers and magnesium borate fibers A resin composition containing at least one kind of inorganic fibrous material and (c) potassium sulfate, wherein the amount of the component (a) in the resin composition is 5 to 20% by weight; Is 10 to 40% by weight, and component (c) is 3 to 3% by weight.
0 Tree fat composition you, wherein the percentages by weight. 2. The resin composition according to claim 1, wherein the powdery polymer solid lubricant is at least one selected from the group consisting of polytetrafluoroethylene, high-density polyethylene and ultra-high-molecular-weight polyethylene. 3. The resin composition according to claim 1, wherein the powdery polymer solid lubricant has an average particle size of 100 μm or less. 4. The at least one inorganic fibrous material selected from the group consisting of potassium titanate fibers and wollastonite.
The resin composition according to claim 1, which is a seed. 5. The resin composition according to claim 1, wherein the inorganic fibrous material is a potassium titanate fiber. 6. The amount of component (a) in the resin composition is 10 to 20% by weight, and the amount of component (b) is 10 to 3% by weight.
The resin composition according to claim 1, wherein 0% by weight and a blending amount of the component (c) are 5 to 15% by weight. 7. A molded article obtainable by molding the resin composition according to claim 1.