JP2007137983A - Polyarylene sulfide resin composition for molded article having cylindrical part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyarylene sulfide resin composition excellent in fluidity and mechanical strength, and suitably used for a molded article having a cylindrical part that is excellent in roundness. <P>SOLUTION: The polyarylene sulfide resin composition comprises (A) a polyarylene sulfide resin having melt viscosity at a resin temperature of 310°C and at a shear rate of 1,200 sec<SP>-1</SP>of 10-50 Pa s, (B) a fibrous filler having an average fiber diameter of 15 μm or less and (C) a non-fibrous filler, so that the amount Wf (wt.%) of the fibrous filler (B) and the amount Wm (wt.%) of the non-fibrous filler (C) in the composition satisfy formula (1): -Wf+45≤Wm≤-Wf+70 and formula (2): 0.4Wf≤Wm≤2.5Wf at the same time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyarylene sulfide resin composition for a molded article having a cylindrical portion that is excellent in fluidity and mechanical strength and excellent in roundness. According to the JIS standard (B0621), the roundness is defined as “when the interval between two concentric circles is minimized when the circular shape (c) is sandwiched between two concentric geometric circles,” It is defined by a difference (f) in the radius of the circle and is expressed as roundness mm or roundness μm ”, and the roundness referred to in this specification is also synonymous.

  Polyarylene sulfide (hereinafter sometimes abbreviated as PAS) resin, represented by polyphenylene sulfide (hereinafter sometimes abbreviated as PPS) resin, has high heat resistance, mechanical properties, chemical resistance, dimensional stability and flame retardancy. Therefore, it is used in a wide range of fields such as various automobile parts and electrical / electronic equipment parts mainly for injection molding applications. Because of these characteristics, PAS resin is often used as a metal substitute material. In such a metal substitute material application, in addition to material properties, high dimensional stability of a metal is often required, and among them, a material having high roundness may be required. The PAS resin is generally widely used as a material to which a fibrous filler such as glass fiber is added. However, such a material has dimensions such as roundness due to the orientation of the fibrous filler. Accuracy is reduced.

Patent Document 1 discloses a PAS resin composition in which a fibrous filler and a non-fibrous filler are blended at the same time, and a non-fibrous filler is blended more than the fibrous filler. Property and mechanical strength and roundness cannot be satisfied at the same time.
JP 2003-301108 A

  The present invention provides a PAS resin composition that solves the above-described problems of the prior art and is suitably used for a molded article having a cylindrical portion that is excellent in fluidity and mechanical strength and excellent in roundness. It is intended.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above object is achieved by combining and blending a specific amount of fibrous filler and non-fibrous filler with a specific PAS resin. The inventors have found that a resin composition can be obtained, and have completed the present invention.

That is, the present invention comprises (A) a polyarylene sulfide resin having a melt temperature of 10 to 50 Pa · s at a resin temperature of 310 ° C. and a shear rate of 1200 sec ⁻¹ , (B) a fibrous filler having an average fiber diameter of 15 μm or less, and (C) It consists of non-fibrous filler, and (B) Fibrous filler amount Wf (% by weight) and (C) Non-fibrous filler amount Wm (% by weight) in the composition are the following formulas (1) (2) is a polyarylene sulfide resin composition for cylindrical part-containing molded articles characterized by satisfying the above (2) simultaneously.

−Wf + 45 ≦ Wm ≦ −Wf + 70 (1)
0.4Wf ≦ Wm ≦ 2.5Wf (2)

  ADVANTAGE OF THE INVENTION According to this invention, the PAS resin composition for molded articles which is excellent in fluidity | liquidity and mechanical strength, and was excellent in roundness and which has a cylindrical shape part can be provided.

  Hereinafter, the constituent components of the present invention will be described in detail. The PAS resin as the component (A) used in the present invention is a polymer compound composed mainly of-(Ar-S)-(where Ar is an arylene group) as a repeating unit, and is generally known in the present invention. A PAS resin having a molecular structure can be used.

  Examples of the arylene group include a p-phenylene group, m-phenylene group, o-phenylene group, substituted phenylene group, p, p′-diphenylene sulfone group, p, p′-biphenylene group, p, p′-. A diphenylene ether group, p, p′-diphenylenecarbonyl group, naphthalene group and the like can be mentioned. The PAS resin may be a homopolymer consisting only of the above repeating units, or a copolymer containing the following different types of repeating units may be preferable from the viewpoint of processability and the like.

  As the homopolymer, PPS using a p-phenylene sulfide group as an arylene group and a p-phenylene sulfide group as a repeating unit is preferably used. As the copolymer, among the arylene sulfide groups comprising the above-mentioned arylene groups, two or more different combinations can be used, and among them, a combination containing a p-phenylene sulfide group and an m-phenylene sulfide group is particularly preferably used. It is done. Among these, those containing 70 mol% or more, preferably 80 mol% or more of p-phenylene sulfide groups are suitable from the viewpoint of physical properties such as heat resistance, moldability and mechanical properties.

  Further, among these PAS resins, a high molecular weight polymer having a substantially linear structure obtained by condensation polymerization from a monomer mainly composed of a bifunctional halogen aromatic compound can be preferably used. In addition to the PAS resin, a polymer in which a branched structure or a crosslinked structure is partially formed by using a small amount of a monomer such as a polyhaloaromatic compound having three or more halogen functional groups when polycondensation can be used, Low molecular weight linear structure polymers can be used at high temperatures in the presence of oxygen or oxidants to increase melt viscosity by oxidative crosslinking or thermal crosslinking to improve molding processability, or mixtures thereof. is there.

The PAS resin used in the present invention is mainly composed of the linear PAS resin, and a part thereof (1 to 30% by weight, preferably 2 to 25% by weight) has a relatively high viscosity (resin temperature 310 ° C., A mixed system with a branched or crosslinked PAS resin having a melt viscosity of 300 to 3000 Pa · s, preferably 500 to 2000 Pa · s at a shear rate of 1200 sec ⁻¹ may be used. In addition, the PAS resin used in the present invention is preferably a PAS resin that has been subjected to acid cleaning, hot water cleaning, organic solvent cleaning (or a combination thereof) and the like to remove by-product impurities and the like after polymerization.

In addition, the PAS resin as the component (A) used in the present invention needs to have a melt viscosity of 10 to 50 Pa · s at a resin temperature of 310 ° C. and a shear rate of 1200 sec ⁻¹ . If the melt viscosity is higher than 50 Pa · s, the fluidity is insufficient, and if it is less than 10 Pa · s, problems occur during molding.

  Next, as the component (B) used in the present invention, the fibrous filler is glass fiber, asbestos fiber, carbon fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, boron fiber, potassium titanate fiber, Furthermore, inorganic fibrous substances, such as metal fibrous substances, such as stainless steel, aluminum, titanium, copper, and brass, are mentioned. Particularly typical fibrous fillers are glass fibers or carbon fibers. High melting point organic fiber materials such as polyamide, fluororesin and acrylic resin can also be used.

  Further, the fibrous filler as the component (B) used in the present invention needs to have an average fiber diameter of 15 μm or less. When the average fiber diameter is larger than 15 μm, the mechanical strength is insufficient.

  Next, as the component (C) used in the present invention, the non-fibrous filler is a granular filler or a plate-like filler. As granular fillers, carbon black, silica, quartz powder, glass beads, glass powder, calcium oxalate, aluminum oxalate, kaolin, talc, clay, diatomaceous earth, oxalate such as wollastonite, iron oxide, Metal oxides such as titanium oxide, zinc oxide and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, other silicon carbide, silicon nitride, boron nitride, various metals A powder is mentioned. Examples of the plate-like filler include mica, glass flakes, and various metal foils. These fillers can be used alone or in combination of two or more.

  In using these fillers, it is desirable to use a sizing agent or a surface treatment agent if necessary. Examples of this are functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds. These compounds may be used after being subjected to surface treatment or convergence treatment in advance, or may be added at the same time as material preparation.

  The feature of the present invention resides in that (B) a fibrous filler and (C) a non-fibrous filler are used in combination, and the blending ratio thereof is restricted to a specific range. That is, (B) fibrous filler amount Wf (% by weight) and (C) non-fibrous filler amount Wm (% by weight) in the composition satisfy the following equations (1) and (2) at the same time. is necessary.

−Wf + 45 ≦ Wm ≦ −Wf + 70 (1)
0.4Wf ≦ Wm ≦ 2.5Wf (2)
When Wm> −Wf + 70, the melt viscosity of the material is high, and when −Wf + 45> Wm, mechanical properties such as strength and rigidity are low. Further, when Wm> 2.5 Wf, the mechanical properties are low, and when 0.4 Wf> Wm, the roundness is poor.

An example of satisfying and not satisfying the above formulas (1) and (2) is as follows. (B) When the fibrous filler amount Wf is 10 (% by weight), the formulas (1) and (2) In
35 ≦ Wm ≦ 60 (1)
4 ≦ Wm ≦ 25 (2)
Therefore, the requirements of the present invention are not satisfied.

When (B) the fibrous filler amount Wf is 30 (% by weight), in the formulas (1) and (2):
15 ≦ Wm ≦ 40 (1)
12 ≦ Wm ≦ 75 (2)
(C) The non-fibrous filler amount Wm is limited to 15 to 40 (% by weight).

When (B) the fibrous filler amount Wf is 40 (% by weight), in the formulas (1) and (2):
5 ≦ Wm ≦ 30 (1)
16 ≦ Wm ≦ 100 (2)
(C) The non-fibrous filler amount Wm is limited to 16 to 30 (% by weight).

Further, when (B) the fibrous filler amount Wf is 55 (% by weight), in the formulas (1) and (2):
−10 ≦ Wm ≦ 15 (1)
22 ≦ Wm ≦ 137.5 (2)
Therefore, the requirements of the present invention are not satisfied.

  Moreover, the silane compound can be mix | blended with the resin composition of this invention in order to improve a burr | flash etc. in the range which does not impair the effect of this invention. The silane compound includes various types such as vinyl silane, methacryloxy silane, epoxy silane, amino silane, mercapto silane, etc., for example, vinyl trichloro silane, γ-methacryloxy propyl trimethoxy silane, γ-glycidoxy propyl trimethoxy silane. , Γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like, but are not limited thereto.

  The resin composition of the present invention can be used in combination with a small amount of other thermoplastic resins in addition to the above components depending on the purpose. As the other thermoplastic resin, any thermoplastic resin that is stable at a high temperature may be used. For example, aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, and aromatic polyesters composed of diol or oxycarboxylic acid, polyamide, polycarbonate, ABS, polyphenylene oxide, polyalkyl acrylate, polysulfone, polyethersulfone, polyetherimide , Polyether ketone, fluororesin, polyarylate and the like. These thermoplastic resins can be used in combination of two or more.

  Further, the resin composition of the present invention is a known substance generally added to a thermoplastic resin within a range not impairing the effects of the present invention, that is, a stabilizer such as an antioxidant, a flame retardant, a coloring of a dye / pigment, etc. An agent, a lubricant, a crystallization accelerator, a crystal nucleating agent, and the like can be appropriately added according to the required performance.

  The resin composition of the present invention can be prepared by facilities and methods generally used for preparing a synthetic resin composition. In general, necessary components can be mixed, melt-kneaded using a single-screw or twin-screw extruder, and extruded to form pellets for molding. It is also a preferred method to melt-extrude the resin component and add and mix an inorganic component such as glass fiber in the middle.

  The material pellets thus obtained can be molded using generally known thermoplastic resin molding methods such as injection molding, extrusion molding, vacuum molding, compression molding, etc., but injection molding is most preferred. .

Next, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these.
Examples 1-6, Comparative Examples 1-5
(A) Components (B) and (C) are added to the polyphenylene sulfide resin in the amounts shown in Table 1, mixed for 5 minutes with a Henschel mixer, and then charged into a twin screw extruder with a cylinder temperature of 320 ° C. Melt-kneading was performed at a resin temperature of 350 ° C. to produce pellets of the resin composition.

Next, a test piece was molded from this pellet, and the following test was performed. The results are shown in Table 1.
[Tensile strength]
A test piece (width 10 mm, thickness 4 mm) according to ISO3167 was molded and measured according to ISO527-1,2.
[Bending elastic modulus]
A test piece (width 10 mm, thickness 4 mm) according to ISO 3167 was molded and measured according to ISO 178.
[Melt viscosity]
Measurement was performed in accordance with ISO11443. A 1 mmφ × 20 mmL / flat die was used as the capillary, and the melt viscosity at a barrel temperature of 310 ° C. and a shear rate of 1000 sec ⁻¹ was measured.
[Roundness]
Measurement was performed in accordance with JIS B0621. A cylindrical test piece (inner diameter 75 mm, wall thickness 2 mm, height 70 mm) was injection-molded, and the roundness of a part 25 mm from the end face of the test piece was measured using a Talirond 300 manufactured by Taylor Bobson.

The specific substances (A) to (C) used in Examples and Comparative Examples are as follows.
(A) Polyphenylene sulfide (PPS) resin, manufactured by Kureha Co., Ltd., Fortron KPS (melting viscosity 30 Pa · s at a resin temperature of 310 ° C. and a shear rate of 1200 sec ⁻¹ )
(B) Fibrous filler ・ (B-1) Glass fiber (E glass), fiber length 3 mm, average fiber diameter 13 μm
・ (B'-1) Glass fiber (E glass), fiber length 3mm, average fiber diameter 17μm
(C) Non-fibrous filler ・ (C-1) Calcium carbonate (heavy calcium carbonate), average particle size 4μm
・ (C-2) Glass beads (E glass), average particle size 20μm

Claims (1)

(A) a polyarylene sulfide resin having a melt temperature of 10 to 50 Pa · s at a resin temperature of 310 ° C. and a shear rate of 1200 sec ⁻¹ , (B) a fibrous filler having an average fiber diameter of 15 μm or less, and (C) a non-fiber (B) Fibrous filler amount Wf (% by weight) and (C) Non-fibrous filler amount Wm (% by weight) in the composition are expressed by the following formulas (1) and (2): A polyarylene sulfide resin composition for a molded part having a cylindrical portion, characterized by being simultaneously filled.
−Wf + 45 ≦ Wm ≦ −Wf + 70 (1)
0.4Wf ≦ Wm ≦ 2.5Wf (2)