JP4943399B2 - Polyarylene sulfide resin composition - Google Patents

Description

  The present invention relates to a polyarylene sulfide resin composition having excellent fluidity during injection molding.

  Polyarylene sulfide (hereinafter abbreviated as PAS) typified by polyphenylene sulfide (hereinafter abbreviated as PPS) resin has high heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame retardancy. Widely used in electrical / electronic equipment parts materials, automotive equipment parts materials, chemical equipment parts materials, etc.

  Since PAS resin is excellent in compatibility with an inorganic filler, it is generally used as a composite material to which an inorganic filler is added. By blending the inorganic filler, various properties including mechanical properties are improved, or there is an advantage that the cost can be reduced by applying an inexpensive inorganic filler, while the melt viscosity of the resin composition increases. However, there is a problem that fluidity is lowered and it becomes difficult to form a thin molded product.

  As a technique for improving the fluidity of the PAS resin composition, for example, a method of using a molecular weight modifier in a polymerization system has been proposed (Patent Document 1). However, the polymerization conditions must be controlled more precisely in consideration of the production stability, yield, and quality of the PAS resin, and it is difficult to actually carry out.

If any PAS resin with good productivity and quality is used as a raw material and the melt viscosity of the PAS resin composition can be easily controlled by devising additives and compounding technology, a highly fluid PAS resin composition can be obtained. It can be designed freely and produced stably.
JP-A-5-239 211

  As described above, a high fluidization method and a PAS resin composition obtained therefrom are desired from the market, but no PAS resin composition satisfying all these requirements has been known so far.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a high-fluidity PAS resin composition can be obtained by mixing and kneading a sulfur-based inorganic compound with a specific PAS resin. The invention has been completed.

That is, the present invention
(A) 100 parts by weight of a polyarylene sulfide resin having a substantially linear structure
(B) 0.05-2 parts by weight of a sulfur-based inorganic compound (however, when an aqueous solution or hydrate is used, the water content is excluded)
Is a polyarylene sulfide resin composition having a melt viscosity of 80 to 350 Pa · s (temperature: 310 ° C., shear rate: 1200 / sec) obtained by blending and melt kneading.

  The (A) PAS resin is mainly composed of — (Ar—S) — (wherein Ar is an arylene group) as a repeating unit. Examples of the arylene group include p-phenylene group, m-phenylene group, o-phenylene group, substituted phenylene group, p, p′-diphenylene sulfone group, p, p′-biphenylene group, and p, p′-di. A phenylene ether group, p, p′-diphenylenecarbonyl group, naphthalene group, and the like can be used.

  In this case, in addition to the polymer using the same repeating unit in the arylene sulfide group composed of the arylene group, that is, a homopolymer, a copolymer containing a different repeating unit is used from the viewpoint of processability of the composition. It may be preferable.

  As the homopolymer, polyphenylene sulfide using p-phenylene group as an arylene group and having 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.

  The PAS resin used in the present invention is 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. In addition, 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 at the time of condensation polymerization can also 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.

  (A) The melt viscosity of the PAS resin is preferably 5 to 400 Pa · s, particularly 50 to 250 Pa · s. If the melt viscosity is too low, it becomes very difficult to obtain a PAS resin having an effective mechanical strength. If the melt viscosity is too high, a PAS resin composition having a melt viscosity of 80 to 350 Pa · s can be obtained. Since it becomes difficult, it is not preferable.

  In addition, as the (A) PAS resin, a resin that has been acid-treated in a post-treatment step after polymerization is used to react with an alkoxysilane that is added to reduce the occurrence of burrs during injection molding. The pH is preferably 4-7. If the resin pH is excessive, the reaction with the alkoxysilane is insufficient, so that the ability to suppress burrs becomes insufficient. Further, even if the resin pH is too small, the reaction with alkoxysilane becomes unstable, which is not suitable.

  The amount of chlorine in the PAS resin is not particularly limited, but is preferably 1000 to 2000 ppm in order to obtain a PAS resin composition having a chlorine content of 950 ppm or less. If the chlorine content is 1000 to 2000 ppm, the production method of the PAS resin is not particularly limited.

  Filling with inorganic filler reduces the chlorine content in the PAS resin composition, but if the chlorine concentration in the PAS resin exceeds 2000 ppm, it is difficult to achieve the target chlorine content of 950 ppm or less in the PAS resin composition. It becomes. Moreover, it is difficult to obtain a PAS resin of less than 1000 ppm by a normal production method.

  In the present invention, the sulfur-based inorganic compound (B) is preferably one or a mixture of two or more selected from sulfur, alkali metal sulfides and alkali metal hydrosulfides.

  Examples of the alkali metal sulfide include lithium sulfide, sodium sulfide, potassium sulfide, magnesium sulfide, calcium sulfide, aluminum sulfide, and the like, preferably lithium sulfide and sodium sulfide.

  Examples of the alkali metal hydrosulfide include lithium hydrosulfide, sodium hydrosulfide, potassium hydrosulfide, magnesium hydrosulfide, calcium hydrosulfide and the like, preferably lithium hydrosulfide and sodium hydrosulfide.

  The amount of (B) sulfur-based inorganic compound added is 0.05 to 2 parts by weight, preferably 0.1 to 1.5 parts by weight, per 100 parts by weight of (A) PAS resin. Alkali metal sulfides are usually often used as hydrates, and alkali metal hydrosulfides are often used as aqueous solutions. (B) When such an aqueous solution or hydrate is used as the sulfur-based inorganic compound, the amount added is excluding the water content.

  If the addition amount is too small, the resulting PAS resin composition has insufficient fluidity, and if the addition amount is too large, gas generation during melt-kneading increases, which is not preferable.

  In the present invention, (C) alkoxysilane is not essential, but is preferably used for reducing the generation of burrs during injection molding. (C) Although the kind of alkoxysilane is not specifically limited, Epoxy alkoxysilane, amino alkoxysilane, vinyl alkoxysilane, mercapto alkoxysilane, etc. are mentioned, These 1 type (s) or 2 or more types are used. In addition, carbon number of an alkoxy group is 1-10, Preferably it is 1-4.

  Examples of the epoxyalkoxysilane include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and the like.

  Examples of aminoalkoxysilane include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N- (β-aminoethyl)- Examples thereof include γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-diallylaminopropyltrimethoxysilane, and γ-diallylaminopropyltriethoxysilane.

  Examples of vinylalkoxysilane include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, and the like.

  Examples of mercaptoalkoxysilanes include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and the like.

  The alkoxysilane to be used is preferably an epoxyalkoxysilane and an aminoalkoxysilane, and particularly preferably γ-aminopropyltriethoxysilane.

  The usage-amount of an alkoxysilane compound is 0.1-3 weight part with respect to 100 weight part of (A) PAS resin, Preferably it is 0.4-2 weight part. If the use amount of the alkoxysilane compound is too small, a sufficient burr suppression effect cannot be obtained, and if the use amount of the alkoxysilane compound is excessive, problems such as an increase in the amount of generated gas occur. Absent.

  In the present invention, the (D) inorganic filler is not particularly essential, but is essential for making the chlorine content of the composition 950 ppm or less and for obtaining sufficient mechanical strength. The inorganic filler is not particularly limited, and for example, calcium carbonate powder such as light calcium carbonate, heavy or finely divided calcium carbonate, special calcium-based filler; calcination of nepheline feldspar fine powder, montmorillonite, bentonite, etc. Clay (aluminum silicate powder) such as clay and silane modified clay; Talc; Silica (silicon dioxide) powder such as fused silica and crystalline silica; Silicate-containing compounds such as diatomaceous earth and silica sand; Pumice powder, Pumice Natural mineral pulverized products such as balloons, slate powder, mica powder; alumina-containing compounds such as alumina, colloidal alumina (alumina sol), alumina white, aluminum sulfate; barium sulfate, lithopone, calcium sulfate, molybdenum disulfide, graphite (graphite) ) Minerals such as glass fiber, glass beads, glass Glass fillers such as flakes and foamed glass beads; fly ash sphere, volcanic glass hollow body, synthetic inorganic hollow body, single crystal potassium titanate, carbon fiber, carbon nanotube, carbon hollow sphere, carbon 64 fullerene, anthracite powder, artificial ice Examples thereof include crystallite (cryolite), titanium oxide, magnesium oxide, basic magnesium carbonate, dolomite, potassium titanate, calcium sulfite, mica, calcium silicate, aluminum powder, molybdenum sulfide, boron fiber, and silicon carbide fiber.

  Among these, fibrous inorganic fillers are preferable, and examples thereof include glass fiber, asbestos fiber, carbon fiber, silica fiber, silica / alumina fiber, potassium titanate fiber, and polyaramid fiber.

  The amount of component (B) is 10 to 250 parts by weight, preferably 30 to 150 parts by weight, based on 100 parts by weight of (A) PAS resin. If the amount of component (B) is too small, sufficient mechanical strength cannot be obtained, and if too large, moldability and mechanical strength are lowered, which is not preferable.

  The melt viscosity of the obtained PAS resin composition is 80 to 350 Pa · s, preferably 150 to 330 Pa · s, particularly preferably 180 to 330 Pa · s. An excessively low melt viscosity is not preferable because not only the moldability becomes unstable but also the occurrence of burrs deteriorates. On the other hand, if the melt viscosity is excessive, the fluidity is insufficient and the molding stability is deteriorated, or it is difficult to mold a thin molded product.

Next, although not essential, the effect of the present invention is further increased by adding and using a crystal nucleating agent. As the crystal nucleating agent used for this purpose, any of known organic nucleating agents and inorganic nucleating agents can be used. Examples of inorganic substances include simple substances such as Zn powder, Al powder, graphite, and carbon black, metal oxides such as ZnO, MgO, Al ₂ O ₃ , TiO ₂ , MnO ₂ , SiO ₂ , and Fe ₃ O ₄ , and boronite. Nitrides such as rides, inorganic salts such as Na ₂ CO ₃ , CaCO ₃ , MgCO ₃ , CaSO ₄ , CaSiO ₃ , BaSO ₄ , Ca ₃ (PO ₄ ) ₃ , silica, talc, kaolin, clay, clay, etc. It is done. As organic substances, use is made of organic salts such as calcium oxalate, sodium oxalate, calcium benzoate, calcium phthalate, calcium tartrate, magnesium stearate, heat-resistant polymers, cross-linked products of heat-resistant polymers, etc. be able to. Particularly preferred are boron nitride; or clays such as talc, kaolin, clay and clay; polymer compounds having a crosslinked or branched structure, and the like. Here, the polymer compound having a crosslinked or branched structure is, for example, a polymer compound having a branched or crosslinked structure generated by polycondensation of a monomer having three or more functional units, or an existing polymer. Any of those obtained by adding a cross-linked or branched structure to the substance later may be used.

  In addition, some of the above crystal nucleating agents overlap with (D) inorganic filler, and these substances can fulfill both functions, but the amount used as a crystal nucleating agent is 100 parts by weight of component (A). 0.01 to 3 parts by weight per unit is sufficient, and preferably 0.1 to 2 parts by weight.

  In the present invention, a thermoplastic elastomer can be used in combination as appropriate in order to further improve the high and low temperature impact characteristics. Thermoplastic elastomers include polyolefin-based elastomers, polyester-based elastomers, fluorine-based elastomers, silicone-based elastomers, butadiene-based elastomers, polyamide-based elastomers, polystyrene-based elastomers, urethane-based elastomers, and various particle-based elastomers with a cross-linked structure at the center. 1 type or 2 types or more can be used.

  As the thermoplastic elastomer, an olefin-based elastomer is preferable, and an olefin-based copolymer mainly containing an α-olefin and a glycidyl ester of an α, β-unsaturated acid is used. Further, an olefin elastomer obtained by copolymerizing various graft copolymers with main components of α-olefin and glycidyl ester of α, β-unsaturated acid can also be preferably used.

  As a compounding quantity of a thermoplastic elastomer, 1-25 weight part is mix | blended with respect to 100 weight part of (A) component, Preferably it is 1-15 weight part, More preferably, 1-8 weight part is mix | blended. When the amount is less than 1 part by weight, the effect of improving the high and low temperature impact characteristics is not sufficient. When the amount is more than 25 parts by weight, there is a problem that the mold deposit attached to the mold during molding increases.

  The PAS 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. The other thermoplastic resin used here may be any thermoplastic resin that is stable at high temperatures.

  Further, the PAS resin composition used in 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 dye / pigment. Such coloring agents, lubricants, and the like can be appropriately added according to the required performance.

  The resin molding method used in the present invention is not particularly limited, and can be molded using generally known thermoplastic resin molding methods such as injection molding, extrusion molding, vacuum molding, compression molding, etc., but is most preferable. Is injection molding.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
・ Raw material (A) PAS resin
A-1: Fortron KPS W214A, manufactured by Kureha Corporation
(Linear PPS, 310 ° C, Viscosity 130Pa · s at shear rate 1200sec ^-1 , Cl content 1200ppm, Resin pH = 6.0)
A-2: Fortron KPS W220A, manufactured by Kureha Corporation
(Linear PPS, 310 ° C, Viscosity 210Pa · s at shear rate 1200sec ^-1 , Cl content 1700ppm, Resin pH = 6.0)
A-3: Kureha Co., Ltd., Fortron KPS W203A
(Linear PPS, 310 ° C, Viscosity 28Pa · s at shear rate 1200sec ^-1 , Cl amount 3800ppm, Resin pH = 6.0)
A-4: Kureha Co., Ltd., Fortron KPS W312
(Linear PPS, 310 ° C, Viscosity 170Pa · s at shear rate 1200sec ^-1 , Cl content 1500ppm, Resin pH = 10.8)
(B) Sulfur-based inorganic compounds · B-1: Sulfur (manufactured by Kanto Chemical Co., Inc.)
・ B-2: Sodium sulfide nonahydrate (manufactured by Kanto Chemical Co., Inc.)
・ B-3: Sodium hydrosulfide solution (manufactured by Kanto Chemical Co., Inc.)
(C) Alkoxysilane / C-1: γ-aminopropyltriethoxysilane
(D) Fibrous inorganic filler D-1: Glass fiber (manufactured by Nippon Electric Glass Co., Ltd., 13 μmφ chopped strand (ECS03T-717))

Examples 1-9 and Comparative Examples 1-2
Each raw material component shown in Table 1 is mixed with a Henschel mixer for 5 minutes, and this is put into a twin screw extruder with a cylinder temperature of 320 ° C (glass fiber is added separately from the side feed part of the extruder), and the resin temperature is 350 ° C. And kneaded to prepare pellets of the resin composition.

  The obtained resin composition pellets were put into an injection molding machine having a cylinder temperature of 320 ° C. and molded to prepare a target molded product (test piece) for evaluation. The results are shown in Table 1.

  In Table 1, the blending amount of (B) sulfur-based inorganic compound is a value excluding the water content when an aqueous solution or hydrate is used.

Moreover, the evaluation method in an Example and a comparative example is as follows.
<Method for measuring resin pH>
At room temperature (15-25 ° C), 6 g of sample, 15 ml of acetone, and 30 ml of purified water (manufactured by Kanto Chemical Co., Inc.) are placed in a flask, shaken for 30 minutes using a shaker, and then separated with a separating funnel. Filtered. The pH of the supernatant was measured with a pH meter.
<< Evaluation of tensile strength >>
A test piece (width: 10 mm, thickness 4 mm) according to ISO 3167 was molded and measured according to ISO 527-1,2.
<Measurement method of chlorine content>
It was measured by combustion ion chromatography.
(Measurement condition)
Ion chromatograph: DX320 made by DIONEX
Combustion pretreatment equipment: Mitsubishi Chemical AQF-100, ABC, WS-100, GA-100
Sample: 10mg
Heater: Inlet Temp / 900 ℃, Outlet Temp / 1000 ℃
Absorbing solution: H ₂ O ₂ 900ppm, internal standard PO ₄ ^3- 25 ppm
<Measuring method of melt viscosity>
The melt viscosity was measured at 310 ° C. and a shear rate of 1200 (1 / second) using a capillograph equipped with a nozzle having an inner diameter of 1.0 mmφ and a length of 20.0 mm.
・ Measuring device: Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd.
<Evaluation of burrs>
Using a disk-shaped cavity mold with a burr measuring part with a mold gap of 20 μm on the outer periphery, injection molding is performed at the minimum pressure necessary to completely fill the cavity, and the burr length generated at that part Was measured.
(Cylinder temperature 320 ° C, mold temperature 150 ° C)

Claims (7)

(A) 100 parts by weight of a polyarylene sulfide resin having a substantially linear structure
(B) 0.05-2 parts by weight of a sulfur-based inorganic compound (however, when an aqueous solution or hydrate is used, the water content is excluded)
A polyarylene sulfide resin composition having a melt viscosity of 80 to 350 Pa · s (temperature of 310 ° C., shear rate of 1200 / sec) obtained by blending and melt kneading.   (B) The polyarylene sulfide resin composition according to claim 1, wherein the sulfur-based inorganic compound is one or a mixture of two or more selected from sulfur, alkali metal sulfides and alkali metal hydrosulfides.   The polyarylene sulfide resin composition according to claim 2, wherein the alkali metal sulfide is lithium sulfide or sodium sulfide.   The polyarylene sulfide resin composition according to claim 2, wherein the alkali metal hydrosulfide is lithium hydrosulfide or sodium hydrosulfide.   (A) The polyarylene sulfide resin composition according to any one of claims 1 to 4, wherein the polyarylene sulfide resin has a melt viscosity of 5 to 400 Pa · s (temperature: 310 ° C., shear rate: 1200 / sec).   The pH of the (A) polyarylene sulfide resin is 4 to 7, and 0.1 to 3 parts by weight of (C) an alkoxysilane compound is blended and melt-kneaded per 100 parts by weight of the (A) polyarylene sulfide resin. The polyarylene sulfide resin composition according to any one of 1 to 5.   (A) The amount of chlorine in the polyarylene sulfide resin is 1000 to 2000 ppm, and (A) per 100 parts by weight of the polyarylene sulfide resin, (D) 10 to 250 parts by weight of the inorganic filler is blended and melt-kneaded. The polyarylene sulfide resin composition whose chlorine content in any one of 1-6 is 950 ppm or less.