JP2021127403A - Polyarylene sulfide resin composition - Google Patents

Abstract

To provide a polyarylene sulfide resin composition that has insulating properties and reduced occurrence of burrs.SOLUTION: A polyarylene sulfide resin composition has insulating properties and contains 0.05 to 0.5 pt.mass of carbon nanotubes that have a length of more than 10,000 nm and at most 500,000 nm and an aspect ratio of more than 2,000 and at most 3,000,000 relative to 100 pts.mass of a polyarylene sulfide resin that has a melt viscosity of 5 to 500 Pa s as determined at a temperature of 310°C at a shear rate of 1,200 sec-1.SELECTED DRAWING: None

Description

The present invention relates to a polyarylene sulfide resin composition.

Polyphenylene sulfide resin (hereinafter sometimes referred to as "PAS resin") represented by polyphenylene sulfide resin (hereinafter sometimes referred to as "PPS resin") has high heat resistance, mechanical properties, and chemical resistance. Since it has dimensional stability and flame retardancy, it is widely used in electrical and electronic equipment parts materials, automobile equipment parts materials, chemical equipment parts materials, and the like. However, the PAS resin has a problem that the crystallization rate is slow, so that the cycle time at the time of molding is long, and that burrs are frequently generated at the time of molding.

As a method for reducing the generation of burrs, it is known to add various alkoxysilane compounds (see Patent Documents 1 and 2). Various alkoxysilane compounds and PAS resins have high reactivity, and are recognized to have the effects of improving mechanical properties and suppressing the occurrence of burrs. However, there is a limit to the effect of suppressing the occurrence of burrs, and the effect of suppressing the occurrence of burrs has not been sufficiently satisfied, and the effect of increasing the crystallization rate has not been achieved at the same time.

In order to solve the above problems, a resin composition in which a specific PAS resin is mixed with a specific amount of a specific carbon nanotube and, if necessary, an inorganic filler has been proposed (see Patent Document 3).

Special Fair 6-21169 Gazette Japanese Unexamined Patent Publication No. 1-1469555 Japanese Unexamined Patent Publication No. 2006-143827

However, in the resin composition described in Patent Document 3, it is necessary to add a relatively large amount of carbon nanotubes in order to sufficiently suppress the generation of burrs. Then, due to the conductivity of the carbon nanotubes, the resin composition becomes conductive. Then, such a resin composition could not be used for a molded product that requires insulating properties.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a polyarylene sulfide resin composition having insulating properties and less generation of burrs.

One aspect of the present invention that solves the above problems is as follows.
(1) The length is more than 10,000 nm and less than 3,000,000 nm, and the aspect ratio is more than 2000 with respect to 100 parts by mass of the polyarylene sulfide resin having a melt viscosity of 5 to 500 Pa · s measured at a temperature of 310 ° C. and a shear rate of 1200 sec ^-1. A polyarylene sulfide resin composition containing 0.05 to 0.5 parts by mass of carbon nanotubes of 500,000 or less and having insulating properties.

(2) The polyarylene sulfide resin composition according to (1) above, further comprising 5 to 250 parts by mass of a non-conductive inorganic filler with respect to 100 parts by mass of the polyarylene sulfide resin.

(3) The polyarylene sulfide according to (2) above, wherein the non-conductive inorganic filler is one or more selected from the group consisting of glass fibers, glass beads, glass flakes, calcium carbonate and talc. Resin composition.

According to the present invention, it is possible to provide a polyarylene sulfide resin composition having insulating properties and less generation of burrs.

The polyarylene sulfide resin composition of the present embodiment (hereinafter, also referred to as “PAS resin composition”) is a polyarylene sulfide resin having a melt viscosity of 5 to 500 Pa · s measured at a ^{temperature of 310 ° C. and a shear rate of 1200 sec -1.} It contains 0.05 to 0.5 parts by mass of carbon nanotube (CNT) having a length of more than 10,000 nm and less than 3,000,000 nm and an aspect ratio of more than 2,000 and not more than 500,000 with respect to 100 parts by mass, and has insulating properties. It is characterized by that.
In the present embodiment, "insulating property" means that the volume resistivity at room temperature (23 ° C.), which is measured in accordance with IEC60093, is 10 ¹⁴ Ω. It refers to the property of cm or more.

The PAS resin composition of the present embodiment suppresses the generation of burrs by containing carbon nanotubes (hereinafter, also referred to as “CNT”) having a predetermined length and a predetermined aspect ratio. Insulation is ensured by minimizing the content of the CNTs. In other words, the CNT according to the present embodiment can suppress the occurrence of burrs even if the content is so small that it does not exhibit conductivity. It is presumed that the mechanism by which burrs are suppressed by the addition of CNTs is contributed by the increase in melt viscosity in the low shear rate region and the improvement in crystallization rate (improvement in solidification rate due to the nuclear agent effect). Further, the mold release resistance can be reduced by increasing the melt viscosity in the low shear rate region, and the molding cycle can be shortened by improving the crystallization rate.
Hereinafter, each component of the PAS resin composition of the present embodiment will be described.

[Polyarylene sulfide resin]
The PAS resin is characterized by being excellent in mechanical properties, electrical properties, heat resistance and other physical and chemical properties, and also having good processability.
The PAS resin is a polymer compound mainly composed of-(Ar-S)-(where Ar is an arylene group) as a repeating unit, and in this embodiment, a PAS resin having a molecular structure generally known is used. Can be used.

Examples of the arylene group include a p-phenylene group, an m-phenylene group, an o-phenylene group, a substituted phenylene group, a p, p'-diphenylene sulphon group, a p, p'-biphenylene group, p, p'-. Examples thereof include a diphenylene ether group, a p, p'-diphenylene carbonyl group and a naphthalene group. The PAS resin may be a homopolymer composed of only the above-mentioned repeating units, or a copolymer containing the following different kinds of repeating units may be preferable from the viewpoint of processability and the like.

As the homopolymer, a polyphenylene sulfide resin using a p-phenylene group as an arylene group and having a p-phenylene sulfide group as a repeating unit is preferably used. Further, as the copolymer, two or more different combinations can be used among the allylene sulfide groups composed of the allylene groups, and among them, the combination containing the p-phenylene sulfide group and the m-phenylene sulfide group is particularly preferably used. Be done. Among these, those containing 70 mol% or more, preferably 80 mol% or more of the p-phenylene sulfide group 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 polycondensation from a monomer mainly composed of a bifunctional halogen aromatic compound can be particularly preferably used. The PAS resin used in this embodiment may be a mixture of two or more different molecular weight PAS resins.

In addition to the linear structure PAS resin, a small amount of a monomer such as a polyhalo aromatic compound having three or more halogen substituents is used at the time of polycondensation to partially form a branched structure or a crosslinked structure. Examples thereof include a polymer obtained by heating a low molecular weight linear structure polymer in the presence of oxygen or the like at a high temperature to increase the melt viscosity by oxidative cross-linking or thermal cross-linking to improve molding processability.

The melt viscosity (310 ° C., shear rate 1200 sec ^-1 ) of the PAS resin as the substrate resin used in this embodiment is 5 to 500 Pa from the viewpoint of the balance between mechanical physical properties and fluidity, including the case of the above mixed system. -Use the one of s. The melt viscosity of the PAS resin is preferably 7 to 300 Pa · s, more preferably 10 to 250 Pa · s, and particularly preferably 13 to 200 Pa · s.

The PAS resin composition of the present embodiment may contain other resin components in addition to the PAS resin as a resin component as long as the effect is not impaired. The other resin components are not particularly limited, and are, for example, polyethylene resin, polypropylene resin, polyamide resin, polyacetal resin, modified polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polyimide resin, and polyamideimide. Resins, polyetherimide resins, polysulfone resins, polyether sulfone resins, polyether ketone resins, polyether ether ketone resins, liquid crystal resins, fluororesins, cyclic olefin resins (cyclic olefin polymers, cyclic olefin copolymers, etc.), thermoplastics Examples thereof include elastomers, silicone-based polymers, and various biodegradable resins. Further, two or more kinds of resin components may be used in combination. Among them, polyamide resins, modified polyphenylene ether resins, liquid crystal resins and the like are preferably used from the viewpoints of mechanical properties, electrical properties, physical / chemical properties, processability and the like.

[carbon nanotube]
In this embodiment, CNTs having a length of more than 10,000 nm and not more than 3,000,000 nm and an aspect ratio of more than 2000 and not more than 500,000 are used. By using the CNT, it is possible to suppress the generation of burrs even if a relatively small amount is added, and it is possible to suppress the generation of burrs and impart insulating properties at the same time. The CNT used in this embodiment may be either a single-walled carbon nanotube or a multi-walled carbon nanotube.
Here, the aspect ratio of the CNT is a numerical value obtained by dividing the length of the CNT by the diameter of the CNT, and a manufacturer value (a numerical value published by the manufacturer in a catalog or the like) can be adopted.

In the CNT according to the present embodiment, the length is more than 10,000 nm and 3,000,000 nm or less, and the aspect ratio is more than 2000 and 500,000 or less, so that the occurrence of burrs can be suppressed. The length of the CNT is preferably 11,000 to 1500,000 nm, more preferably 12,000 to 500,000 nm. The aspect ratio of CNT is preferably 2010 to 250,000, more preferably 2030 to 100,000. The diameter of the CNT is preferably 5 to 100 nm, more preferably 7 to 50 nm.

In the present embodiment, 0.05 to 0.5 parts by mass of CNT is contained with respect to 100 parts by mass of PAS resin. If the CNT is less than 0.05 parts by mass, the generation of burrs cannot be suppressed. Further, if the CNT exceeds 0.5 parts by mass, the insulating property cannot be ensured. The content of CNT is preferably 0.1 to 0.5 parts by mass, more preferably 0.2 to 0.5 parts by mass.

Examples of the CNTs on the market according to the present embodiment include LG Chem Co., Ltd., CP1002M, High Pressure Gas Industry Co., Ltd., NTF series and the like.

[Non-conductive inorganic filler]
In the present embodiment, it is preferable to include a non-conductive inorganic filler in the PAS resin composition from the viewpoint of improving the mechanical properties while ensuring the insulating property. Examples of the non-conductive inorganic filler include a fibrous inorganic filler, a plate-like inorganic filler, and a powder-granular inorganic filler, one of which may be used alone or two or more thereof may be used in combination. You may. In addition, in this specification, the term "inorganic filler" means a non-conductive inorganic filler unless it is clearly stated that it is a conductive filler.

Examples of the fibrous inorganic filler include glass fibers, whiskers, wollastonite, zinc oxide fibers, titanium oxide fibers, silica fibers, silica-alumina fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, etc. Examples thereof include metal fibrous substances such as mineral fibers and titanium fibers of the above, and one or more of these can be used. Of these, glass fiber is preferable.

Examples of commercially available glass fibers include chopped glass fibers (ECS03T-790DE, average fiber diameter: 6 μm) manufactured by Nippon Electric Glass Co., Ltd., and chopped glass fibers (CS03DE 416A, average fibers) manufactured by Owens Corning Japan LLC. Diameter: 6 μm), Nippon Electric Glass Co., Ltd., chopped glass fiber (ECS03T-747H, average fiber diameter: 10.5 μm), Nippon Electric Glass Co., Ltd., chopped glass fiber (ECS03T-747, average fiber diameter: 13 μm), Nitto Spinning Co., Ltd., odd-shaped cross-section chopped strand CSG 3PA-830 (major axis 28 μm, minor axis 7 μm), Nitto Spinning Co., Ltd., irregular cross-section chopped strand CSG 3PL-962 (major axis 20 μm, minor axis 10 μm) And so on.

The fibrous inorganic filler may be surface-treated with various surface treatment agents such as generally known epoxy compounds, isocyanate compounds, silane compounds, titanate compounds, and fatty acids. By the surface treatment, the adhesion with the PAS resin can be improved. The surface treatment agent may be applied to the fibrous inorganic filler in advance for surface treatment or convergence treatment before material preparation, or may be added at the same time as material preparation.

The fiber diameter of the fibrous inorganic filler is not particularly limited, but in the initial shape (shape before melt-kneading), it can be, for example, 5 μm or more and 30 μm or less. Here, the fiber diameter of the fibrous inorganic filler means the major axis of the fiber cross section of the fibrous inorganic filler.

Examples of the powdery inorganic filler include talc (granular), silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, silicate such as diatomaceous earth, iron oxide, zinc oxide, alumina (granular) and the like. Non-conductive metal oxides, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, and other nitrides such as silicon carbide, silicon nitride, boron nitride and aluminum nitride, Examples thereof include poorly soluble ion crystal particles such as calcium dioxide and barium fluoride; fillers using semiconductor materials (elemental semiconductors such as Si, Ge, Se and Te; compound semiconductors such as oxide semiconductors), and the like. One type or two or more types can be used. Of these, glass beads and calcium carbonate are preferable.
Examples of the marketed products of calcium carbonate include Whiten P-30 (average particle size (50% d): 5 μm) manufactured by Toyo Fine Chemicals Co., Ltd. Examples of commercially available glass beads include Potters Barotini Co., Ltd., EGB731A (average particle size (50% d): 20 μm), Potters Barotini Co., Ltd., EMB-10 (average particle size). Diameter (50% d): 5 μm) and the like can be mentioned.
The powdery granular inorganic filler may also be surface-treated in the same manner as the fibrous inorganic filler.

Examples of the plate-shaped inorganic filler include glass flakes, talc (plate-shaped), mica, kaolin, clay, alumina (plate-shaped), and the like, and one or more of these can be used. Of these, glass flakes and talc are preferable.
Examples of products on the market of glass flakes are Nippon Sheet Glass Co., Ltd., REFG-108 (average particle size (50% d): 623 μm), (Nippon Sheet Glass Co., Ltd., fine flakes (average particle size (50%)). d): 169 μm), Nippon Sheet Glass Co., Ltd., REFG-301 (average particle size (50% d): 155 μm), Nippon Sheet Glass Co., Ltd., REFG-401 (average particle size (50% d): 310 μm) ) Etc. can be mentioned.
Examples of talc products on the market include Crown Talc PP manufactured by Matsumura Sangyo Co., Ltd. and talcan powder PKNN manufactured by Hayashi Kasei Co., Ltd.
The plate-shaped inorganic filler may be surface-treated in the same manner as the fibrous inorganic filler.

In the present embodiment, among the above inorganic fillers, one or more selected from the group consisting of glass fibers, glass beads, glass flakes, calcium carbonate and talc is preferable. From the viewpoint of improving mechanical properties, the inorganic filler preferably contains 15 to 200 parts by mass, more preferably 25 to 150 parts by mass, and 30 to 110 parts by mass with respect to 100 parts by mass of the PAS resin. It is more preferable to include it.

As described above, the PAS resin composition of the present embodiment preferably contains a non-conductive inorganic filler, but even a conductive inorganic filler is contained within a range that does not interfere with the effects of the present embodiment. May be good. When the PAS resin composition of the present embodiment contains a conductive inorganic filler, the content of the conductive inorganic filler is measured in accordance with an amount at which the molded product can exhibit electrical insulation, specifically, IEC60093. It is preferable to use an amount that can maintain the volume resistivity of the molded product at room temperature (23 ° C.) of 1 × 10 ^{14 Ω · cm or more.} Although the term "conductive inorganic filler" is well known to those skilled in the art, carbon-based fillers (carbon black, carbon fibers, graphite, etc.) and metal-based fillers (SUS fibers, etc.) have conductivity. It means a conductive inorganic filler such as a metal fiber having a metal fiber, a conductive metal or a metal oxide powder, etc.), a metal surface coating filler, and the like. In one embodiment, the content of these conductive inorganic fillers is, for example, 10% by mass or less, preferably 6% by mass or less, and further preferably 4% by mass or less of the total PAS resin composition of the present embodiment. .. The content at which the conductive inorganic filler can exhibit conductivity may differ depending on the type, shape, and conductivity of the conductive inorganic filler, and therefore may be higher than the above content. be.

[Other ingredients]
In the present embodiment, in addition to the above-mentioned components, known additions generally added to thermoplastic resins and thermosetting resins in order to impart desired properties according to the purpose, as long as the effects are not impaired. Agents, that is, elastomers, mold release agents, lubricants, plasticizers, flame retardants, colorants such as dyes and pigments, crystallization accelerators, crystal nucleating agents, various antioxidants, heat stabilizers, weather resistance stabilizers, A corrosion inhibitor or the like may be blended. Although the PAS resin composition of the present embodiment can suppress the generation of burrs, a burr inhibitor such as an alkoxysilane compound may be used in combination if necessary.

The method for producing a molded product using the PAS resin composition of the present embodiment is not particularly limited, and a known method can be adopted. For example, the PAS resin composition of the present embodiment may be put into an extruder, melt-kneaded and pelletized, and the pellets may be put into an injection molding machine equipped with a predetermined mold and injection-molded to produce the pellet. can.

Examples of the molded product obtained by molding the PAS resin composition of the present embodiment include electrical / electronic equipment parts materials, automobile equipment parts materials, chemical equipment parts materials, water-related parts materials, and the like. Specifically, various cooling system parts of automobiles, ignition related parts, distributor parts, various sensor parts, various actuator parts, throttle parts, power module parts, ECU parts, various connector parts, piping joints (pipe fittings), joints. And so on.
Other uses include, for example, LEDs, sensors, sockets, terminal blocks, printed circuit boards, motor parts, electrical and electronic parts such as ECU cases, lighting parts, TV parts, rice cooker parts, microwave parts, iron parts, etc. It can be used for household and office electrical product parts such as copier-related parts, printer-related parts, facsimile-related parts, heaters, and air conditioner-related parts.

Hereinafter, the present embodiment will be described in more detail with reference to Examples, but the present embodiment is not limited to the following Examples. Unless otherwise specified, commercially available raw materials were used.

[Examples 1 to 6 and Comparative Examples 1 to 6] -Containing non-conductive inorganic filler-
In each Example / Comparative Example, after dry-blending each of the raw material components shown in Tables 1 and 2, they are put into a twin-screw extruder having a cylinder temperature of 320 ° C. (glass fibers are separately added from the side feed portion of the extruder). ), Melt-kneaded and pelletized. In Tables 1 and 2, the numerical values of each component indicate parts by mass.
The details of each raw material component used are shown below.

(1) PAS resin / PPS resin: Fortron KPS manufactured by Kureha Corporation (melt viscosity: 30 Pa · s (shear velocity: 1200 sec- ¹ , 310 ° C.))

(Measurement of melt viscosity of PPS resin)
The melt viscosity of the PPS resin was measured as follows.
Using a capillary graph manufactured by Toyo Seiki Seisakusho Co., Ltd., a flat die of 1 mmφ × 20 mmL was used as a capillary, and the melt viscosity was measured at a ^{barrel temperature of 310 ° C. and a shear rate of 1200 sec -1.}

(2) Carbon nanotube (CNT)
CNT1: Made by LG Chem, CP1002M (average diameter: 9 nm, average length: 19000 nm, aspect ratio: 2111)
-CNT2: NC7000 manufactured by NANOCYL (average diameter: 9.5 nm, average length: 1500 nm, aspect ratio: 158)
CNT3: BT1003M manufactured by LG Chem (average diameter: 13.1 nm, average length: 12000 nm, aspect ratio: 916)

(3) Non-conductive inorganic filler / glass fiber: Owens Corning Japan GK, chopped strand, fiber diameter: 10.5 μm, length 3 mm

[evaluation]
The following evaluation was performed using the obtained pellets of each Example / Comparative Example.
(1) Burr length Using a disk-shaped cavity mold provided with a burr measuring part having a mold gap of 20 μm on the outer circumference, the cavity is used at a cylinder temperature of 320 ° C and a mold temperature of 150 ° C. The burrs were injection-molded at the minimum pressure required for complete filling, and the burr length generated in that portion was magnified and measured with a mapping projector. The measurement results are shown in Tables 1 and 2.

(2) Melt Viscosity of Resin Composition Using a capillograph manufactured by Toyo Seiki Seisakusho Co., Ltd., and using a flat die of 1 mmφ × 20 mmL as a capillary, the melt viscosity (MV) ^{at a barrel temperature of 310 ° C. and a shear rate of 1000 sec -1 was obtained.} It was measured. The measurement results are shown in Tables 1 and 2. It can be said that the fluidity is excellent when the melt viscosity is 500 Pa · s or less.

(3) Insulation A test piece (flat plate) having a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C. having a length of 100 mm, a width of 100 mm and a thickness of 3 mm was produced by an injection molding machine (SE100D manufactured by Sumitomo Heavy Industries, Ltd.). , IEC60093, the volume resistivity was measured at an applied voltage of 500 V and 23 ° C. When the volume resistivity was 10 ¹⁴ Ω · cm or more, it ^{was evaluated as 〇, and when it was less than 10 14} Ω · cm, it was evaluated as ×. The evaluation results are shown in Tables 1 and 2.

From Table 1, comparing Example 1 in which the amount of CNT added is the same and Comparative Examples 1 and 2, in Example 1, the burr length is remarkably suppressed as compared with Comparative Examples 1 and 2. I understand. Further, in Examples 3 to 5 in which the same CNTs as in Example 1 are used and the amount of the CNTs added is larger than that in Example 1, the burr length is suppressed as compared with Example 1. Moreover, the larger the amount of CNT added, the more the burr length is suppressed. Moreover, the melt viscosity of the resin composition does not change significantly regardless of the amount of CNT added. Similarly, when Examples 2 and 6 are compared, the burr length of Example 6 having a large amount of CNT added is suppressed as compared with that of Example 2, and the melt viscosities of the resin compositions are almost the same. From these, it can be seen that by adding the predetermined CNT according to the present embodiment, the burr length can be suppressed without significantly changing the melt viscosity of the resin composition.
In Comparative Example 3 in which the same CNTs as in Example 1 were used and the amount of the CNTs added was further increased, the burr length was suppressed as compared with Examples 1 to 6 and Comparative Examples 4 to 5, but insulation was achieved. Has no sex.
From the above, it can be seen that by including CNTs having a predetermined length and a predetermined aspect ratio, insulation can be ensured while suppressing the occurrence of burrs.

Claims (3)

The length is more than 10,000 nm and less than 3,000,000 nm, and the aspect ratio is more than 2000 and less than 500,000 with respect to 100 parts by mass of the polyarylene sulfide resin having a melt viscosity of 5 to 500 Pa · s measured at a temperature of 310 ° C. and a shear rate of 1200 sec ^-1. A polyarylene sulfide resin composition containing 0.05 to 0.5 parts by mass of carbon nanotubes and having insulating properties. The polyarylene sulfide resin composition according to claim 1, further comprising 5 to 250 parts by mass of a non-conductive inorganic filler with respect to 100 parts by mass of the polyarylene sulfide resin. The polyarylene sulfide resin composition according to claim 2, wherein the non-conductive inorganic filler is one or more selected from the group consisting of glass fibers, glass beads, glass flakes, calcium carbonate and talc.