JP2726580B2 - Sliding property improved polyarylene sulfide resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyarylene sulfide resin composition having improved slidability. More specifically, the present invention particularly relates to a polyarylene sulfide resin composition having improved slidability and excellent mechanical properties, moldability, adhesiveness, and the like.

[0002]

2. Description of the Related Art In recent years,
Electrical and electronic equipment parts materials, automobile equipment parts materials, and chemical equipment parts materials are required to have high heat resistance, chemical resistance, and flame-retardant thermoplastic resin materials. Polyarylene sulfide resins represented by polyphenylene sulfide are also one of the resins that meet this demand, and demand is growing due to their good cost-performance ratio. However, this resin generally has poor slidability and insufficient friction and wear resistance. In particular, the tendency is remarkable in a resin composition containing a fibrous reinforcing agent, and there is a problem when used as a sliding part. Conventionally, techniques for solving this problem include the addition of carbon fillers such as carbon fiber and graphite, the addition of molybdenum disulfide, the addition of silicone oil and silicone resin, the addition of liquid lubricants such as mineral oil, and the like. It is known to mix fluorine resins such as tetrafluoroethylene (hereinafter PTFE) and to use these additives in combination. However, although these methods improve the slidability for the time being, they each have problems and can be applied only to limited uses. That is, carbon fiber and graphite improve the slidability but also impart conductivity, and are unsuitable for application to the electric field as an insulating material. Further, the blending of graphite or molybdenum disulfide tends to impair the mechanical properties and is not preferred. Furthermore, the composition of these substances becomes black, and it is impossible to obtain a color tone other than black. In addition, silicone-based substances and liquid lubricants have poor affinity for polyarylene sulfide resin, and precipitate and adhere to the mold during molding, or exude to the surface when molded products are used at high temperatures, and viscous substances adhere. Causes inconvenience in practical use. Although the blending of the fluororesin has few problems as described above, the lubricating effect is relatively low, and unless a large amount is used, a sufficient improvement in the sliding properties cannot be obtained, and an affinity for the polyarylene sulfide resin is obtained. It is not preferable for a part which is poor in properties and impairs mechanical properties, and further has poor adhesiveness in a part which is used by bonding and molding a molded article with another material such as a metal or another plastic. An object of the present invention is to solve such problems and to develop a sliding material with further improved sliding characteristics and mechanical properties.

[0003]

In order to improve the slidability of polyarylene sulfide (PAS) resin, the present inventors have studied the mechanical properties, heat resistance and electrical insulation inherent in polyarylene sulfide. As a result of diligent research to obtain excellent slidability, excellent in moldability, moldability, adhesiveness, etc., PAS resin was simply polytetrafluoroethylene.
Only emissions resin not to Blend is further a particular sliding characteristics by combining using polymer further the problems caused by the addition of significantly improved and polytetrafluoroethylene resin is improved, its The inventors have found that the object has been achieved, and have completed the present invention. That is, the present invention relates to (A) 100 parts by weight of a polyarylene sulfide resin, (B) 3 to 70 parts by weight of a polytetrafluoroethylene resin, (C) an olefin polymer or copolymer (a), and One or two or more of the polymer or copolymer (b) composed of the repeating units represented by 1) or (2) is a graft copolymer in which 0.5 to 50 parts by weight of a branched or crosslinked structure is chemically bonded. ,

[0004]

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(D) A polyarylene sulfide resin composition having improved slidability, comprising at least one of fibrous, powdery and plate-like fillers in an amount of 0 to 400 parts by weight.

Hereinafter, each component will be described. In the present invention, the resin serving as the base is (A) a polyarylene sulfide resin, which is a polymer containing at least 70 mol% of a repeating unit represented by-(Ar-S)-(where Ar is an arylene group) (hereinafter, referred to as A typical substance is polyphenylene sulfide having a repeating unit represented by the structural formula-(Ph-S)-(where Ph is a phenylene group) of 70 mol% or more (hereinafter, abbreviated as PPS). ). Among them, those having a melt viscosity measured at a temperature of 310 ° C. and a shear rate of 1200 / sec in the range of 10 to 20000 poise, particularly 100 to 5000 poise are suitable. In general, PAS resins are known to have a substantially linear, molecular structure having no branched and cross-linked structure, and a structure having branched and cross-linked structures, according to the present invention. It is also effective for things. However, a linear structure having substantially no branch is particularly effective. Preferred PAS resin for use in the present invention is a polymer containing at least 70 mol%, more preferably at least 80 mol%, of a paraphenylene sulfide unit-(Ph-S)-as a repeating unit. If this repeating unit is less than 70 mol%, the crystallinity, which is a characteristic of the crystalline polymer, tends to be low, so that sufficient strength tends not to be obtained, and toughness tends to be poor. or,
The PAS resin used in the present invention may contain less than 30 mol% of other copolymerized structural units, for example, metaphenylene sulfide units, orthophenylene sulfide units,
p, p'-diphenylene ketone sulfide unit, p,
p′-diphenylene sulfone sulfide unit, p, p ′
-Biphenylene sulfide unit, p, p'-diphenylene ether sulfide unit, and 2,6-naphthalene sulfide unit. In particular, the PAS resin used in the present invention includes a substantially linear PPS homopolymer having a repeating unit composed of paraphenylene sulfide, and a repeating unit composed of 70 to 95 mol% of a repeating unit composed of paraphenylene sulfide and a repeating unit composed of metaphenylene sulfide of 70 to 95 mol%.
PPS copolymers having a substantially linear structure consisting of mol% are preferred. Further, as the polyarylene sulfide resin of the present invention, in addition to the above-mentioned substantially linear polymer, a branched or cross-linked polyarylene sulfide resin polymerized by using a small amount of a monomer having three or more functional groups as a part of the monomer is used. Can be used, or a blended resin obtained by blending this with the linear polymer can also be used, which is preferable. Further, as the PAS resin as the component (A) used in the present invention, a polymer obtained by increasing the melt viscosity of a linear polymer having a relatively low molecular weight by oxidative crosslinking or thermal crosslinking and improving moldability can be used.

Next , as the component (B) , polytetrafluoroethylene (PTFE) or a copolymer containing this as a main component is used . In general, the finer the PTFE resin, the more preferable it is, and the particle size is 100 μm or less, preferably 50 μm
Hereinafter, it is particularly preferably 10 μm or less, but a fibrous material may be used. Further, the amount of that is 3 to 70 parts by weight per 100 parts by weight of the PAS resin, preferably 5 to 50 parts by weight. If the amount is too small, the improvement of the frictional properties and slidability aimed at by the present invention cannot be obtained. If the amount is too large, the original characteristics of the PAS resin are lost, and the mechanical properties and moldability also cause problems. Absent.

Next, the graft copolymer used as the component (C) in the present invention is an olefin polymer or a copolymer (a).
And a graft copolymer in which one or more of polymers or copolymers (b) composed of repeating units represented by the following general formula (1) or (2) are chemically bonded in a branched or crosslinked structure: It is united.

[0009]

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Here, the segment constituting the portion (a) may be an α-olefin polymer or copolymer such as ethylene, propylene, butene-1, etc., but polyethylene or a copolymer mainly composed of ethylene. Is preferred. Examples of the copolymer include a copolymer of an α-olefin such as ethylene, propylene, and butene-1, and a glycidyl ester of an α, β-unsaturated acid such as glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and glycidyl itaconate. Copolymers, copolymers with acrylates such as ethyl acrylate, copolymers with vinyl acetate, especially copolymers of ethylene and glycidyl methacrylate, are preferred. It may be a copolymer. Such an olefin polymer or copolymer (a) can be (co) polymerized by a well-known radical polymerization reaction to obtain the (co) polymer of (a). In that case, the composition of the segment (a) is such that the α-olefin is 50% by weight or more, and the other copolymer component is
50% by weight or less is preferred. Next, the polymer or copolymer (b) to be graft-polymerized to the polymer or copolymer (a) as a branched or cross-linked chain is composed of the repeating unit represented by the general formula (1) or (2). Polymers or copolymers obtained by copolymerizing two or more kinds, for example, polymethyl methacrylate, polyethyl acrylate, polybutyl acrylate, poly (2-ethylhexyl acrylate), polystyrene, polyacrylonitrile, polyacrylonitrile-
A styrene copolymer, a copolymer of butyl acrylate and methyl methacrylic acid, a copolymer of butyl acrylate and styrene, and the like can be given. The component (C) in the present invention is as described above.
The (co) polymer of (a) and the (co) polymer of (b) are not used alone, but at least the (co) polymer of (a) and the (co) polymer of (b) It is characterized in that it contains a graft copolymer having a branched or cross-linked structure chemically bonded at one point. By having such a graft structure, it is possible to simply mix (a) and (b) (co) polymers. The remarkable effect which cannot be obtained by is obtained. The method for preparing the graft copolymer comprising the (a) segment and the (b) segment is not particularly limited, but can also be easily prepared by a radical reaction. That is, for example, in the presence of an olefin (co) polymer (a), the vinyl monomer constituting at least one component (b) and a specific radical (co)
The polymerizable organic peroxide is copolymerized to form a peroxide group-containing copolymer, which is heated and kneaded, and graft polymerization is performed by bonding both polymers by the reaction of the peroxide group in the vinyl copolymer. A coalescence is prepared. Where (a) and
The ratio of (b) is suitably from 95: 3 to 40:60. Preferred examples of such a graft copolymer include a multiphase structure prepared by a preparation method described in JP-A-63-313313 and the like. Such a graft copolymer is also available as a commercial product (for example, "Modeler A" series, manufactured by NOF Corporation).

[0011] For such olefinic graft copolymer generally PAS resin formulation, toughness, although it is already known to be effective in improving the impact resistance, PAS resin and P
P particular PTFE resin for a blend of TFE resin
It has the effect of improving the affinity and dispersibility for AS, and is not only particularly effective in improving such physical properties, but also its combined use exerts a synergistic effect particularly on the sliding properties. Furthermore, those having even an effect of improving a defective adhesion of the mating member when using more such PTFE resin containing composition molded article as a composite component which is bonded to another metal or plastic, with such PTFE resin The combined effect is a surprising effect that has never been known before. Component (C) is added in an amount of 0.5 to 100 parts by weight of PAS resin.
5050 parts by weight, preferably 1-30 parts by weight. If the amount is too small, the effect is reduced. If the amount is too large, the original characteristics of the PAS resin are lost, and the viscosity increases, which causes problems in moldability and the like, which is not preferable.

Next, although the composition of the present invention is not an essential component, it has excellent properties such as mechanical strength, rigidity, heat resistance, dimensional stability (deformation resistance, warpage), and electrical properties. In order to obtain a product, it is preferable to blend a filler,
For this purpose, a fibrous, powdery or plate-like filler is used depending on the purpose. Examples of the fibrous filler include glass fiber, asbestos fiber, carbon fiber, silica fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and stainless steel.
Inorganic fibrous materials such as fibrous materials of metals such as aluminum, titanium, copper, and brass can be used. Particularly typical fibrous fillers are glass fibers or potassium titanate fibers.
High-melting organic fibrous substances such as aromatic polyamides and acrylic resins can also be used. On the other hand, as the granular filler, carbon black, silica, quartz powder,
Glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, silicates such as wollastonite, metal oxides such as iron oxide, titanium oxide, zinc oxide, alumina, Calcium carbonate,
Metal carbonates such as magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, and other metal powders such as silicon carbide, silicon nitride, boron nitride, and the like.
Examples of the plate-like filler include mica, glass flake, various metal foils, and the like. These inorganic fillers can be used alone or in combination of two or more. The combined use of a fibrous filler, particularly a glass fiber or a potassium titanate fiber, and a granular and / or plate-like filler is a preferable combination particularly in terms of having both mechanical strength, dimensional accuracy, electrical properties and the like. When using these fillers, it is desirable to use a sizing agent or a surface treatment agent if necessary. This example is a functional compound such as an epoxy compound, an isocyanate compound, a silane compound and a titanate compound. These compounds may be used after being subjected to a surface treatment or a convergence treatment in advance, or may be added simultaneously with the preparation of the material. The amount of the filler used is 0 to 400 parts by weight per 100 parts by weight of the polyarylene sulfide resin of the component (A),
Preferably it is 10 to 200 parts by weight. If the amount is less than 10 parts by weight, the mechanical strength and the composition are slightly inferior.

The composition of the present invention may further contain a small amount of other thermoplastic resin in addition to the above-mentioned components according to the purpose. The other thermoplastic resin used here may be any thermoplastic resin that is stable at high temperatures. For example, aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate and aromatic dicarboxylic acids and diols or oxycarboxylic acids, nylon 66, nylon 6,
Polyamides such as nylon 12, nylon 46, etc., polycarbonate, ABS, polyphenylene oxide, polyalkyl acrylate, polyacetal, polysulfone, polyethersulfone, polyetherimide, polyetherketone, olefin polymers other than the component (C), etc. I can give it. These thermoplastic resins can be used as a mixture of two or more kinds. Further, the composition of the present invention, a known substance generally added to the thermoplastic resin, that is, stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, coloring agents such as dyes and pigments, A lubricant, a crystallization accelerator, a crystal nucleating agent, and the like can be appropriately added according to required performance.

The polyarylene sulfide resin composition of the present invention can be prepared by the equipment and method generally used for preparing a synthetic resin composition. That is, a method in which necessary components are mixed, kneaded using a single-screw or twin-screw extruder, and extruded into molding pellets.
In order to improve the dispersion and mixing of each component, any or all of the resin components may be pulverized, mixed and melt-extruded.

[0015]

The PAS resin composition of the present invention is excellent in heat resistance, mechanical properties, moldability, etc., is particularly excellent in friction characteristics, is suitable as a sliding member, and has improved adhesive workability. It is extremely useful as a molded product or functional component material that requires the following.

[0016]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 12 and Comparative Examples 1 to 7 As shown in the table, as a component (A), polyphenylene sulfide A resin (PPS) (trade name "Fortron KPS", manufactured by Kureha Chemical Industry Co., Ltd.) ) tetrafluoroethylene resins as component, various olefin-based graft copolymer as the component (C) were added and premixed for 5 minutes in a Henschel mixer. In some cases, commercially available glass fiber (diameter 13 μm, length 3 mm) and talc (average particle diameter 4 μm) are added in the amounts shown in the table, mixed for 2 minutes, and extruded at a cylinder temperature of 310 ° C. through an extruder for polyphenylene sulfide resin. A pellet of the composition was made. Next, the cylinder temperature was measured with an injection molding machine.
Test specimens were molded at 320 ° C. and a mold temperature of 150 ° C., and the mechanical properties, frictional properties, adhesiveness, etc. were measured. Table 1 shows the results. As a comparative example, a test piece was similarly molded from a composition containing no component (B) or (C), and a test was conducted. Table 2 shows the results.

The items evaluated and the measuring method are as follows.

Izod impact strength: Izod impact values on the notch side and the anti-notch side were measured according to ASTM D-256.

Tensile test: Tensile strength and tensile elongation were measured according to ASTM D-638.

Friction and abrasion test: Using a Suzuki-type friction and abrasion tester, press the molded product under pressure (10 kg), linear velocity 100 mm / sec.
The dynamic friction coefficient and the specific wear were measured with a contact area of 2.0 cm ² and iron (S55C) as the mating material.

Adhesion: A test piece of ASTM D-638 was bisected at the center, and a silicone adhesive (12X-151, manufactured by Three Bond Co., Ltd.)
(Adhesive area: 1 cm × 2 cm), cured at 150 ° C. for 10 minutes, and then subjected to a tensile test to measure the adhesive strength.

[0023]

[Table 1]

[0024]

[Table 2]

(Note 1) LDPE-g-PS: graft copolymer of low density polyethylene and polystyrene LDPE-g-AS: graft copolymer of low density polyethylene and styrene acrylonitrile copolymer E / GMA-g -PS: Graft copolymer of ethylene-glycidyl methacrylate copolymer and polystyrene E / GMA-g-AS: Graft copolymer of ethylene-glycidyl methacrylate copolymer and styrene-acrylonitrile copolymer

Claims (3)

(57) [Claims] (A) Polyarylene sulfide resin 100
(B) 3 to 70 parts by weight of a polytetrafluoroethylene resin, (C) an olefin polymer or copolymer (a), and a repeating unit represented by the following general formula (1) or (2) 0.5 to 50 parts by weight of a graft copolymer in which one or two or more of the obtained polymers or copolymers (b) are chemically bonded in a branched or crosslinked structure; (D) A slidability-improved polyarylene sulfide resin composition comprising 0 to 400 parts by weight of at least one of fibrous, powdery and platy fillers. (A) The polyarylene sulfide resin is represented by the following formula: The polyarylene sulfide resin composition according to claim 1, which is a polyparaphenylene sulfide having a repeating unit represented by the following formula: 70 mol% or more. 3. The filler (D) is a fibrous filler.
3. The composition according to claim 1, wherein the amount is 10 to 200 parts by weight.
A realylene sulfide resin composition.