JPWO2018124079A1 - Method of improving corona resistance of polyarylene sulfide resin molded article - Google Patents

Abstract

A method for improving the corona resistance of a polyarylene sulfide resin molded article, wherein the corona resistance can be further improved by using a silicone polymer with respect to a molded article formed by molding a resin composition containing a polyarylene sulfide resin I will provide a. An island portion formed by molding a resin composition containing a polyarylene sulfide resin, a specific silicone-based polymer, and a nonconductive inorganic filler, and made of particles of the silicone-based polymer, and a sea portion composed of a polyarylene sulfide resin A method for improving the corona resistance of a resin molded article having a sea-island structure, comprising: a resin composition such that the average value of the distance between the particles closest to each particle of the silicone-based polymer is 0.25 μm or less It is a method for improving the corona resistance of a polyarylene sulfide resin molded article, characterized in that an article is prepared to form a resin molded article.

Description

  The present invention relates to a method for improving the corona resistance of a molded article obtained by molding a resin composition containing a polyarylene sulfide resin.

  In recent years, in electrical devices, various resin molded articles are used for housings and internal electrical system components. Examples of the electric devices include not only general household appliances and industrial electric appliances but also devices controlling an electric system in a vehicle such as an automobile, a motorcycle, or a truck, for example. Resin moldings are widely used as well. As an electric apparatus in a vehicle, in particular, a resin molded product used for an apparatus disposed in an engine room is required to be able to withstand corona discharge caused by an ignition coil or the like. That is, when the resin molded product is exposed to corona discharge, the dendritic local destruction called electrical tree proceeds to shorten the life of the resin molded product, which is to prevent this.

  On the other hand, as resin used for electric equipment in vehicles, since heat resistance, a flame retardance, etc. are required, polyarylene sulfide resin (It is also called "PAS resin" hereafter) which possesses the required performance. Is preferably used. However, with the PAS resin alone, the corona resistance is insufficient, and various proposals have been made to provide the resin molded article (composition) with the corona resistance (for example, see Patent Documents 1 to 3).

In Patent Document 1, a material (biaxially stretched film) made of polyphenylene sulfide (hereinafter also referred to as "PPS resin") whose corona resistance is improved by setting the content of sodium chloride to 0.5% by weight or less. Is disclosed.
Further, in Patent Documents 2 and 3, molded articles comprising a PAS resin, a conductive carbon black, a graphite, and a resin composition containing an epoxy group-containing α-olefin copolymer (components for cables, snow-settling rings) Is disclosed. This is to pursue various properties such as heat resistance, weather resistance, flame retardancy, waterproofness, airtightness, toughness, as well as corona resistance etc. by setting the volume resistivity of the resin composition to an appropriate value. is there.

  On the other hand, in order to improve various performances of the resin composition containing PAS resin, the resin composition which used together silicone type polymers, such as polysiloxane, is known (for example, refer to patent documents 4-5). The resin composition described in Patent Document 4 is for obtaining excellent water repellency, and the resin composition described in Patent Document 5 is for obtaining excellent mechanical strength and chemical resistance. None of the documents mentions corona resistance.

  Further, Patent Document 6 describes a corona resistant resin composition obtained by melt-kneading a silicone polymer with a resin component such as PAS resin. The document states that the corona resistance can be exhibited by adding a predetermined amount of silicone polymer to the resin component.

Japanese Patent Application Laid-Open No. 59-79903 Japanese Patent Application Laid-Open No. 11-53943 Unexamined-Japanese-Patent No. 11-150848 gazette JP-A-8-231852 JP, 2011-111468, A International Publication No. 2015/064499

  The corona resistant resin composition described in Patent Document 6 exerts corona resistance by adding a silicone-based polymer, and the silicone-based polymer is examined with respect to the addition amount and the average dispersion diameter in the resin component. ing. However, no study was made as to how to make the silicone polymer present in the resin component, leaving room for improvement.

  The present invention has been made in view of the above-mentioned conventional problems, and its object is to use a silicone-based polymer for a molded article obtained by molding a resin composition containing a polyarylene sulfide resin. It is an object of the present invention to provide a method for improving the corona resistance of a polyarylene sulfide resin molded article which can be further improved.

One aspect of the present invention for solving the above-mentioned problems is as follows.
(1) A resin composition containing a polyarylene sulfide resin, a silicone-based polymer, and a nonconductive inorganic filler is molded, and the silicone-based polymer is a silicone-acrylic copolymer, silicone-based core-shell rubber, One or two or more selected from the group consisting of silicone composite powders, and resistance to a resin molded article having a sea-island structure including islands consisting of particles of the silicone-based polymer, and seas consisting of the polyarylene sulfide resin It is a corona property improvement method, and
A polyarylene sulfide, wherein the resin composition is prepared and the resin molded article is formed such that the average value of the distance between the wall and the particles closest to each particle of the silicone polymer is 0.25 μm or less It is a corona-resistance improvement method of a resin molded product.

(2) The content of the silicone-based polymer in the resin molded product is 30.0% by volume or more based on the total of the content of the polyarylene sulfide resin and the silicone-based polymer, and the silicone The total of the content of the base polymer and the nonconductive inorganic filler is 70 parts by volume or more with respect to 100 parts by volume of the polyarylene sulfide resin. It is a corona property improvement method.

(3) In (1) or (2), in the observation with a scanning electron microscope, the average dispersion diameter of the silicone-based polymer in the sea portion of the polyarylene sulfide resin is 0.1 μm or more and less than 4.0 μm. It is a corona-resistance improvement method of the polyarylene sulfide resin molded article as described.

(4) Any one of the above (1) to (3), wherein the nonconductive inorganic filler is one or more selected from the group consisting of glass fibers, glass flakes, glass beads, mica and silica. It is a corona-resistance improvement method of the polyarylene sulfide resin molded article as described in these.

(5) The poly according to any one of (1) to (4) above, wherein the silicone-based polymer contains one or more selected from the group consisting of silicone-acrylic copolymers and silicone-based core-shell rubbers. It is the corona-resistance improvement method of an arylene sulfide resin molded article.

  According to the present invention, a polyarylene sulfide resin molded article capable of further improving the corona resistance by using a silicone polymer with respect to a molded article formed by molding a resin composition containing a polyarylene sulfide resin It is possible to provide a method for improving the corona resistance of

(A) is a SEM image after removing the silicone-based polymer of the test piece of the PAS resin molded product of the present embodiment, and (B) is a SEM in which the portion where the removed silicone-based polymer particles were present is blacked out. It is an image. It is a figure which shows typically a mode that a voltage application is carried out to the PAS molded article containing a plate-shaped inorganic filler. It is a figure which shows typically a mode that a voltage application is carried out to the PAS molded article containing a plate-shaped inorganic filler. It is a figure which shows notionally about arrangement | positioning of a test piece and each electrode in a corona-resistance test. It is a figure in the example 1 and 2 and comparative example 1 and comparative example 2 showing the relation of the average value of the shortest distance between particle walls to the amount of addition of silicone type polymer with a graph. It is a figure which shows notionally the arrangement configuration of a test piece and an electrode at the time of measurement of dielectric breakdown strength.

  The corona resistance improvement method of the PAS resin molded product of the present embodiment is formed by molding a resin composition containing a PAS resin, a silicone-based polymer, and a nonconductive inorganic filler, and the silicone-based polymer is silicone acrylic. A sea-island structure including one or more selected from the group consisting of a copolymer, a silicone-based core-shell rubber, and a silicone composite powder, and an island composed of particles of a silicone-based polymer and a sea composed of a PAS resin A method for improving the corona resistance of a resin molded article having the resin composition, wherein the resin composition is prepared such that the average value of the distance between the particles closest to each particle of the silicone polymer and the wall is 0.25 .mu.m or less And molding the resin molded article.

In the method for improving the corona resistance of a PAS resin molded product according to the present embodiment, the silicone resin molded product has a structure including a sea-island structure including an island portion made of particles of silicone polymer and a sea portion made of PAS resin. The corona resistance is improved by setting the average value of the distance between the particles closest to each particle of the base polymer and the wall to 0.25 μm or less. In the present specification, “volume%” and “volume part” of each component are values calculated by calculation based on the mass and specific gravity of each component. In the present specification, the specific gravity means a specific gravity of 23/4 ° C. measured in accordance with JIS Z 8807 solid specific gravity measurement method.
The resin composition (corona resistant resin composition) used for shaping | molding of a PAS resin molded article is demonstrated first below.

<Corona resistant resin composition>
The corona resistant resin composition of the present embodiment (hereinafter referred to as "resin composition") contains a PAS resin, a specific silicone-based polymer, and a nonconductive inorganic filler, and as required, other resins. Contains ingredients. Each component will be described below.

[Polyarylene sulfide resin]
PAS resin is characterized by having excellent mechanical properties, electrical properties, heat resistance and other physical and chemical properties, and 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 generally known molecular structure is used. It can be used.

  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, p, p'- A diphenylene ether group, p, p'-diphenylene carbonyl group, a naphthalene group etc. are mentioned. The PAS resin may be a homopolymer consisting only of the above repeating units, or a copolymer containing the following different repeating units may be preferable from the viewpoint of processability and the like.

  As a homopolymer, a polyphenylene sulfide resin having a p-phenylene sulfide group as a repeating unit, which uses a p-phenylene group as an arylene group, is preferably used. As the copolymer, a combination of two or more different arylene sulfide groups consisting of arylene groups described above can be used, and among them, a combination containing p-phenylene sulfide group and m-phenylene sulfide group is particularly preferably used. Be Among them, one containing 70 mol% or more, preferably 80 mol% or more of p-phenylene sulfide group is suitable in terms 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 composed mainly of a difunctional halogen aromatic compound can be particularly preferably used. The PAS resin used in the present embodiment may be a mixture of PAS resins of two or more different molecular weights.

  In addition to the PAS resin having a linear structure, a partial branched structure or a crosslinked structure is formed by using a small amount of a monomer such as a polyhaloaromatic compound having three or more halogen substituents when condensation polymerization is performed. And polymers obtained by heating the low molecular weight linear structural polymer at a high temperature in the presence of oxygen or the like to increase the melt viscosity by oxidative crosslinking or thermal crosslinking to improve the molding processability.

The melt viscosity (310 ° C., shear rate 1216 sec ⁻¹ ) of the PAS resin as the base resin used in the present embodiment is preferably 600 Pa · s or less, including in the case of the above mixed system, and in particular in the range of 8 to 300 Pa · s. Some are particularly preferable because they have an excellent balance of mechanical properties and fluidity.

  The resin composition of the present embodiment may contain other resin components as resin components in addition to the above-described PAS resin and silicone-based polymer as long as the effects of the present invention are not impaired. The other resin components are not particularly limited, and, 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, polyamideimide Resin, polyether imide resin, poly sulfone resin, polyether sulfone resin, polyether ketone resin, polyether ether ketone resin, liquid crystal resin, fluorine resin, cyclic olefin resin (cyclic olefin polymer, cyclic olefin copolymer, etc.), thermoplasticity Elastomers, silicone polymers other than the above-mentioned silicone polymers, various biodegradable resins, and the like can be mentioned. In addition, two or more types of resin components may be used in combination. Among them, polybutylene terephthalate resin, polyacetal resin, liquid crystal resin and the like are preferably used from the viewpoints of mechanical properties, electrical properties, physical and chemical properties, processability and the like.

[Silicone-based polymer]
As the silicone-based polymer, one or more silicone-based polymers selected from the group consisting of silicone-acrylic copolymers, silicone-based core-shell rubbers, and silicone composite powders are used. These silicone polymers are excellent in the effect of improving corona resistance.

(Silicone-acrylic copolymer)
The silicone-acrylic copolymer is a copolymer containing an acrylic structural unit (acrylic component) and a Si-containing structural unit (silicon component). The acrylic component is derived from an acrylic monomer such as (meth) acrylic acid ester. As a (meth) acrylic acid ester, _C1-12 alkyl acrylate is mentioned, for example. Examples of the Si-containing structural unit include, but are not limited to, monomethyl siloxane unit, dimethylsiloxane unit, monophenyl siloxane unit, diphenyl siloxane unit, and methyl phenyl siloxane unit. In addition, part of these structural units may be modified with a hydroxyl group, an amino group, a carboxyl group, an epoxy group, a methacryloxy group, a mercapto group or the like.

The silicone-acrylic copolymer may be a polymer obtained by copolymerizing a comonomer component in addition to the above-mentioned acrylic component and silicone component. Examples of the comonomer component include unsaturated bond-containing monomers other than acrylic monomers. Examples of unsaturated bond-containing monomers other than acrylic monomers include nitrile monomers such as (meth) acrylonitrile; aromatic vinyl monomers such as styrene; and diene monomers such as butadiene and isoprene. Also, the silicone-acrylic copolymer may be a polymer obtained by copolymerizing a crosslinkable monomer. Examples of the crosslinkable monomer include esters of polyol and acrylic acid, vinyl compounds, allyl compounds and the like.
The polymerization form of the silicone-acrylic copolymer is not particularly limited, and examples thereof include block copolymers, random copolymers, and graft copolymers.

(Silicone core shell rubber)
Examples of silicone-based core-shell rubbers include particulate ones composed of a core layer and one or more shell layers covering the core layer, and at least one layer of the core layer or shell layer contains a rubber elastic material. . The rubber elastic body is not particularly limited, but a rubber obtained by polymerizing one or more selected from an acrylic component, a silicone component, a styrene component, a nitrile component, a conjugated diene component and the like, or a crosslinked rubber thereof is preferable. Further, it is more preferable that at least one layer of the core layer or the shell layer is a rubber elastic body containing the above-described Si-containing structural unit as a main component. The core layer and the shell layer may be bonded by graft copolymerization. In one embodiment, the core layer preferably comprises a rubber elastic material.

  Examples of silicone-based core-shell rubbers include, for example, a core layer containing a rubber component such as silicone rubber and the above-mentioned silicone / acrylic copolymer, and polymerization with the (meth) acrylic ester and / or (meth) acrylonitrile as a main component Or particles of core-shell structure having a shell layer containing a polymer obtained by copolymerization, but not limited thereto. The polymer contained in the shell layer is more preferably a polymer obtained by polymerizing or copolymerizing a (meth) acrylic acid ester as a main component from the viewpoint of environmental protection and safety. Examples of silicone rubbers include polyorganosiloxanes such as polydimethylsiloxane containing the above-mentioned Si-containing structural unit as a main component, polymethylphenylsiloxane, dimethylsiloxane-diphenylsiloxane copolymer, and modified polyorganosiloxanes.

(Silicone composite powder)
Examples of silicone composite powders include, but are not limited to, spherical powders in which the surface of spherical silicone rubber is coated with a silicone resin.

  Among them, silicone-acrylic copolymer and silicone-based core-shell rubber are preferable from the viewpoint of improving corona resistance, and silicone-based core-shell rubber is preferable from the viewpoint that the corona resistance effect is higher.

  In the present specification, the term "(meth) acrylic acid" is used to mean that it includes both acrylic acid and methacrylic acid unless it is specified that either one is referred to. Similarly, the term "(meth) acrylonitrile" is used in a sense encompassing both acrylonitrile and methacrylonitrile.

  There is no restriction | limiting in particular as a silicone acryl copolymer, silicone type core shell rubber, and silicone composite powder, For example, a commercially available thing can be used. Examples of commercially available products include, as silicone-based core-shell rubber, KANE ACE MR-01 etc. manufactured by Kaneka Co., Ltd .; as silicone composite powder, KMP-600 etc. manufactured by Shin-Etsu Chemical Factory Co., Ltd .; silicone-acrylic copolymer And Nisshin Chemical Industry Co., Ltd., R-181S, etc .; but not limited thereto.

[Non-conductive inorganic filler]
Examples of the nonconductive inorganic filler include fibrous inorganic fillers, plate-like inorganic fillers, particulate inorganic fillers and the like. In addition, in this specification, when it describes as an "inorganic filler", unless it is specified that it is a conductive filler, it means a nonelectroconductive inorganic filler.

(Fibrous inorganic filler)
It will not specifically limit, if an example of a fibrous inorganic filler is a thing with a large specific surface area. For example, glass fibers, whiskers, wollastonite and the like can be mentioned, with glass fibers being preferred. The fibrous inorganic filler preferably has a fiber diameter in the range of 3 to 13 μm, and more preferably in the range of 3 to 11 μm. The fiber diameter of 13 μm or less is more preferable from the viewpoint of mechanical strength improvement. Further, in terms of availability, the fiber diameter is preferably 3 μm or more. It is more preferable that the fiber diameter is in the range of 3 to 11 μm. Moreover, it is preferable that it is a shape with different diameter ratio 1-4, and an aspect ratio of 2-1500. In the present specification, the different diameter ratio is “major axis of the cross section perpendicular to the longitudinal direction (longest linear distance of cross section) / short diameter (longest linear distance perpendicular to the major axis)”, and the aspect ratio Is the “longest linear distance in the longitudinal direction / short diameter of the cross section perpendicular to the longitudinal direction (“ longest linear distance in the cross section ”and the longest linear distance in the orthogonal direction)”.

  Examples of commercial products include Nippon Electric Glass Co., Ltd., chopped glass fiber (ECS03T-790DE, average fiber diameter: 6 μm), Owens Corning Manufacturing Co., Ltd., chopped glass fiber (CS03DE 416A, average fiber 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 (ECS 03 T-747, average fiber diameter: 13 μm) Etc.

(Particulate inorganic filler)
The particulate inorganic filler is not particularly limited as long as it has a large specific surface area and can delay the progress of the electrical tree. Examples of particulate inorganic fillers include glass beads, silica, calcium carbonate, talc (particulate) and the like. From the viewpoint of low water absorption, glass beads and silica are preferable, and from the viewpoint of cost, glass beads are preferable. The shape is more preferably a shape (including a spherical shape) having a different diameter ratio of 1 to 4 and an aspect ratio of 1 to 2. A spherical filler is more preferable in the viewpoint of discharge relaxation by surface smoothness. The particle diameter is preferably in a range that can achieve a preferred mode diameter in the PAS molded product described later.

  Examples of marketed products include, as glass beads, GL-BS (average particle size (50% d): 21 μm), manufactured by Potters Barotini Ltd., EMB-10 (average particle size (manufactured by Potters Barrotini) 50% d): 5 μm); As silica, SC2000-ZD (average particle size (50% d): 0.5 μm) manufactured by Admatex Co., Ltd .; As calcium carbonate; Toyo Fine Chemical Co., Ltd. manufactured by Whiteton P -30 (average particle size (50% d): 5 m) and the like, but not limited thereto.

(Plate-like inorganic filler)
The plate-like inorganic filler is not particularly limited as long as it can delay the progress of the electrical tree. For example, glass flakes, mica, talc (plate-like), kaolin, clay, alumina and the like can be mentioned. From the viewpoint of improving the corona resistance, glass flakes, mica and talc are preferred, and glass flakes and mica are more preferred. As the shape of the plate-like inorganic filler, for example, a shape having a different diameter ratio of greater than 4 and an aspect ratio of 1 to 1,500 is preferable. With regard to the thickness, the smaller the number (for example, the average thickness is 20 μm or less), the more the absolute number of the sheets increases, so the specific surface area is increased, and the labyrinth effect is enhanced. The particle diameter is preferably in a range that can achieve a preferred mode diameter in the PAS molded product described later.

  As an example of the marketed product of glass flakes, Nippon Sheet Glass Co., Ltd. product, REFG-108 (average particle size (50% d): 623 μm), (Nippon Sheet Glass Co., Ltd. product, fine flake (average particle size (50%) d): 169 μm), manufactured by Nippon Sheet Glass Co., Ltd., REFG-301 (average particle size (50% d): 155 μm), manufactured by Nippon Sheet Glass Co., Ltd., REFG-401 (average particle size (50% d): 310 μm) And the like, but is not limited thereto.

As mica, for example, white mica (KAl ₂ (AlSi ₃ O ₁₀ ) (OH) ₂ ), gold mica (KMg ₃ (AlSi ₃ O ₁₀ ) (OH) ₂ ), black mica (K (Mg, Fe) ₃ (AlSi ₃ O ₁₀ ) (OH) ₂ ), mica (KLi ₂ Al (Si ₄ O ₁₀ ) (OH) ₂ ), synthetic mica (KMg ₃ (AlSi ₃ ) O ₁₀ F ₂ ), and the like. It is preferable to use gold mica, white mica or synthetic mica in that it can exert the effect of corona resistance most, and among these, white mica can be maintained in insulation even under severe environments such as constant temperature and humidity. It is more preferable to use synthetic mica.

  As an example of the marketed product of mica, as gold mica, 150-S (average particle size (50% d): 163 μm) and 325-S (average particle size (50% d): 30 μm) manufactured by West Japan Trade Co., Ltd. 60-S (average particle size (50% d): 278 μm), etc .; White mica, manufactured by Yamaguchi Mica Co., Ltd., AB-25S (average particle size (50% d): 24 μm), B- 82 (average particle size (50% d): 137 μm) and the like; Synthetic micas such as PDM-7-80 (average particle size (50% d): 70 μm) etc. may be mentioned, but limited to them I will not.

  Further, examples of commercially available products of talc include, for example, Crown Talc PP manufactured by Matsumura Sangyo Co., Ltd., and Tulcan Powder PKNN manufactured by Hayashi Kasei Co., Ltd.

  In the present specification, the average particle diameter (50% d) means a median diameter of 50% integrated value in particle size distribution measured by a laser diffraction / scattering method.

  More preferably, the resin composition of the present embodiment contains, as the nonconductive inorganic filler, one or more selected from the group consisting of glass fibers, glass beads, glass flakes, mica and silica.

  Among them, the total content of glass fibers, glass beads, glass flakes, mica and silica is preferably 50% by volume or more in the inorganic filler, more preferably 70% by volume or more, 90% by volume or more It is further preferable that (including 100% by volume).

  As the nonconductive inorganic filler, in addition to the above-mentioned fibrous, plate or granular inorganic filler, a filler using a metal oxide having no conductivity; a nitride such as aluminum nitride or boron nitride Filler that has been used; poorly soluble ionic crystal particles such as barium sulfate, calcium fluoride and barium fluoride; semiconductor materials (element semiconductors such as Si, Ge, Se and Te; compound semiconductors such as oxide semiconductors) Can be mentioned.

In the present specification, the nonconductive inorganic filler is a concept including both an inorganic filler mainly composed of an insulating material and an inorganic filler mainly composed of a semiconductor material. As an index of the electrical resistivity of the nonconductive inorganic filler, a test piece of 100 mm in length, 100 mm in width, 3 mm in thickness prepared using a resin composition consisting of 70% by volume of PPS resin and 30% by volume of inorganic filler It is preferable to use an inorganic filler having a volume resistivity of 1 × 10 ⁴ Ω · cm or more measured at 23 ° C. and an applied voltage of 500 V in accordance with IEC 60093. From the viewpoint of insulation, an inorganic filler having a volume resistivity of 1 × 10 ⁵ Ω · cm or more is more preferable, and an inorganic filler having a volume resistivity of 1 × 10 ⁶ Ω · cm or more is further preferable.

  Among them, the nonconductive inorganic filler preferably contains an inorganic filler using an insulating material. In one embodiment, the inorganic filler using the insulating material is preferably 50% by volume or more of the nonconductive filler, more preferably 60% by volume or more, and 70% by volume or more (including 100% by volume) It is further preferred that

[Other ingredients]
The resin composition of the present embodiment is a lubricant, a nucleating agent, a flame retardant, a flame retardant auxiliary, an antioxidant, a metal deactivator, other anti-aging agent, a UV absorber, as long as the effects of the present invention are not impaired. Stabilizers, plasticizers, pigments, dyes, colorants, antistatic agents, foaming agents, organic fillers, conductive fillers and the like may be contained.

In the case where the resin composition of the present embodiment contains a conductive filler, the content of the conductive filler is measured according to the amount that the molded product can exhibit electrical insulation, specifically, in accordance with IEC 60093. Preferably, the volume resistivity of the molded article at room temperature (23.degree. C.) can be maintained at 1 × 10 ⁸ Ω · cm or more. The term "conductive filler" is well known to those skilled in the art, but carbon-based fillers (carbon black, carbon fibers, graphite, etc.), metal-based fillers (SUS fibers, etc.) conductive metal fibers, It means a filler having conductivity such as a metal or metal oxide powder having conductivity, a metal surface-coated filler, etc. In one embodiment, the content of these conductive fillers is, for example, 10% by mass or less, preferably 6% by mass or less, and more preferably 4% by mass or less of the entire resin composition of the present embodiment. In addition, since the addition amount with which a conductive filler can express electroconductivity may differ also with the kind, shape, and electroconductivity of an electroconductive filler, it may be more than said content.

  In the resin composition of the present embodiment, the total content of the above-described PAS resin, silicone-based polymer and nonconductive inorganic filler is preferably 70% by mass or more of the entire resin composition, and more preferably 80% by mass. % Or more, more preferably 90% by mass or more (including 100% by mass).

  The resin composition of the present embodiment can be produced by melt-kneading a mixed component containing at least a PAS resin, a silicone-based polymer, and a nonconductive inorganic filler. The method for producing the resin composition of the present embodiment is not particularly limited, and various methods known in the art can be employed. For example, after mixing each component mentioned above, the method of throwing | throwing-in to an extruder, melt-kneading, and pelletizing is mentioned. In addition, once a pellet of different composition is prepared, the pellet is mixed in a predetermined amount and subjected to molding, and a method of obtaining a molded article of the target composition after molding, a method of directly feeding one or more of each component to a molding machine, etc. You may use.

<Method for improving corona resistance of resin molded products>
In the present embodiment, in order to improve the corona resistance of a PAS resin molded product formed by molding the above resin composition, particles that are closest to each particle of the silicone-based polymer when molding the PAS resin molded product The resin composition is prepared and molded so that the average value of the inter-wall distance (hereinafter also referred to as “the shortest distance between particle walls”) is 0.25 μm or less.

  Here, "the shortest distance between particle walls" means the distance between particle walls with the nearest silicone polymer particle among a plurality of silicone polymer particles adjacent to a certain silicone polymer particle. The “average value of the shortest distance between particle walls” refers to the average value of the shortest distance between particle walls of many silicone-based polymer particles in the PAS resin molded article excluding the overlapping distance. That is, when the particle closest to a certain particle A is particle B, if the particle closest to particle B is also particle A, the shortest distance between particle walls overlaps. In this case, only the shortest distance between one particle wall is counted to calculate an average value. Even if a large number of particles are bound (contacted), they are regarded as one particle.

  On the other hand, the measurement of the shortest distance between particle walls can be performed as follows. First, a molded product to be measured is cut to obtain a plate-like test piece of 3 mm × 3 mm × 1 mm. A portion about 50 μm deep from the outermost surface of the test piece is removed, and the exposed surface is photographed by a scanning electron microscope to obtain a SEM image. Then, the shortest distance between the particle walls as described above is obtained for each particle of each silicone-based polymer from this SEM image, and the average distance is obtained by dividing by the number n of the distance.

  The above operation can be simplified by image analysis software. An example is shown below. First, in order to facilitate image analysis, a portion about 50 μm deep from the outermost surface of the test piece is removed and the exposed surface is etched with sulfuric acid or the like. That is, the particles of the silicone-based polymer are dissolved and removed with sulfuric acid or the like. Next, the etched surface is photographed by a scanning electron microscope to obtain a SEM image (see FIG. 1A). In FIG. 1 (A), the darkened portion is the void formed by removal of the silicone-based polymer. The SEM image is taken into a computer (PC), and the silicone polymer removal portion is blacked out in a computer and displayed in black and white (see FIG. 1 (B)). Then, the average value of the shortest distance between particle walls is obtained by software programmed to match the method of calculating the average value of the shortest distance between particle walls.

  Examples of means for making the average value of the shortest distance between particle walls of the silicone-based polymer to be 0.25 μm or less include, for example, (1) both the particle size and the content of the silicone-based polymer when preparing the PAS resin composition Are suitably adjusted, (2) extrusion conditions of the PAS resin composition are appropriately adjusted, and the like.

  Regarding the above (1), specifically, when the PAS resin composition is molded into a molded article, the particle diameter of the silicone-based polymer is an average dispersion of the PAS resin in the sea part in observation with a scanning electron microscope The diameter is preferably 0.1 μm or more and less than 4.0 μm (for example, 3.9 μm or less), and more preferably 0.1 to 3.5 μm. The lower limit of the content of the silicone-based polymer is also dependent on the content of the nonconductive inorganic filler, although the content of the silicone-based polymer is the sum of the content of the PAS resin and the silicone-based polymer. The total content of the PAS resin and the silicone-based polymer is preferably 30.0% by volume or more. If the total content of the PAS resin and the silicone-based polymer is 30.0% by volume or more, the average value of the shortest distance between particles of the silicone-based polymer can be easily adjusted to 0.25 μm or less. The content of the silicone-based polymer is more preferably 32.5% by volume or more, particularly preferably 35.0% by volume or more.

  Regarding the above (2), it is preferable to adjust the extrusion conditions of the PAS resin composition so as to improve the dispersibility of the silicone-based polymer. For example, adjustment methods such as improving the dispersibility of the silicone-based polymer by screw arrangement, increasing the screw rotation speed, and decreasing the cylinder temperature to increase the melt viscosity of the molten resin and increase the shear force It can be mentioned. The silicone-based polymer is preferably supplied from a hopper (raw material supply unit).

  On the other hand, the upper limit of the content of the silicone-based polymer is preferably 45% by volume or less. It is preferable in the viewpoint which suppresses the fall of mechanical physical properties that content of a silicone type polymer is 45 volume% or less. The content of the silicone-based polymer is more preferably 40% by volume or less.

  In addition, the total content of one or more silicone polymers selected from silicone / acrylic copolymer, silicone core shell rubber, and silicone composite powder and nonconductive inorganic filler is 100 parts by volume of PAS resin, It is preferably 70 parts by volume or more. When the total content of the silicone-based polymer and the nonconductive inorganic filler is 70 parts by volume or more, the corona resistance is easily improved significantly. The upper limit is not particularly limited, but is preferably 230 parts by volume or less in terms of extrudability, moldability, and the like.

  As described above, in the PAS resin molded product of the present embodiment, when the average value of the shortest distance between particle walls of the silicone-based polymer is 0.25 μm or less, the corona resistance can be improved. The smaller the average value of the shortest distance between particle walls, the better.

  There is no limitation in particular as a method to shape | mold the PAS resin molded product of this embodiment, Various methods known in the said technical field are employable. For example, the resin composition described above may be introduced into an extruder and melt-kneaded to form pellets, and the pellets may be introduced into an injection molding machine equipped with a predetermined mold and injection molded.

  The shape of the PAS resin molded product is not particularly limited, and can be appropriately selected according to the application. For example, in addition to a sheet, a plate, a cylinder, a film, etc., it can be molded into a three-dimensional molded body having a desired shape.

  In one embodiment, the mode diameter of the particulate inorganic filler such as glass beads in the PAS resin molded product is preferably 0.1 to 50 μm, more preferably 0.1 to 25 μm, still more preferably 0.1 to 10 μm. . In addition, the mode diameter of a plate-like inorganic filler such as glass flakes or mica in the PAS resin molded product is preferably 1 to 200 μm, more preferably 15 to 150 μm, and still more preferably 40 to 130 μm. It is preferable from the viewpoint of improvement in corona resistance that the mode diameter of the inorganic filler in the PAS resin molded product is within the above range, and the filler can be present more uniformly in the PAS resin molded product, and the labyrinth effect It is preferable from the viewpoint of improvement.

  In addition, the mode diameter of the granular inorganic filler and the plate-like inorganic filler in the PAS resin molded article means the mode diameter in the volume-based particle size distribution measured by the laser diffraction / scattering method, and manufactured by Horiba, Ltd., laser diffraction It can measure using / / particle size distribution analyzer LA-920. There is no restriction | limiting in particular as a means to make the granular inorganic filler and plate-like inorganic filler of a PAS resin molded product into the said mode diameter range. For example, the method of adjusting extrusion conditions etc. appropriately is mentioned using the filler which has a diameter larger than the upper limit of the mode diameter range made into a goal.

  When a plate-like inorganic filler is used as the inorganic filler, in the PAS resin molded product, the plate-like inorganic filler is preferably oriented so as to be orthogonal to the voltage direction caused by corona discharge. Specifically, when a voltage is applied to the PAS resin molded product, the plate-like inorganic filler is oriented to be orthogonal to the voltage application direction, in other words, to be orthogonal to the voltage direction caused by corona discharge, It is preferable that the plate-like inorganic fillers in the molded article be oriented in one direction so as to be parallel to each other. Here, that the orientation direction of the plate-like inorganic filler is orthogonal to the voltage direction due to the corona discharge means that the normal direction of the plate-like inorganic filler matches the voltage direction due to the corona discharge, The normal direction and the voltage direction do not have to completely coincide with each other, and they may be shifted within a range that does not impair the effects of the present embodiment.

Below, the orientation state of the said plate-like inorganic filler is demonstrated with reference to FIG.2 and FIG.3. 2 and 3 schematically show how a high voltage is applied to the PAS resin molded product. In FIG. 2 and FIG. 3, the high voltage side electrode 12 is disposed above the flat plate-like PAS resin molded products 10A and 10B, and the ground side electrode 14 is disposed below, and high voltage and high voltage are applied by both electrodes. Corona discharge occurs near the tip of the side electrode 12, and the surfaces of the PAS resin molded articles 10A and 10B are exposed to corona discharge. Then, in FIG. 2, the plate-like inorganic filler 16 is oriented in the interior of the PAS resin molded product 10A so as to be orthogonal to the voltage application direction, and in FIG. 3 inside the PAS resin molded product 10B. The plate-like inorganic filler 16 is oriented so as to be parallel to the voltage direction. In such a configuration, when high frequency / high voltage is applied to generate corona discharge, in the configuration of FIG. 2, the plate-like inorganic filler 16 is oriented so as to interrupt the progress even if the electrical tree is generated. Can delay its progress. As a result, it can be considered that prolonging the life of the PAS resin molded product 10A can be achieved. On the other hand, in the configuration of FIG. 3, many gaps exist in the traveling direction of the electrical tree, and the effect of blocking the progression of the electrical tree is small.
As described above, the PAS resin molded product in which the plate-like inorganic filler is oriented as shown in FIG. 2 is arranged so that the plate-like inorganic filler inside thereof is orthogonal to the voltage application direction caused by the corona discharge. The corona effect can be more effectively exhibited.

  As described above, in order to orient the plate-like inorganic filler in the PAS resin molded article in the above direction, for example, in injection molding, the desired direction for orienting the plate-like inorganic filler is the flow direction of the resin It can be realized by setting the gate position of the mold so that

In the case where the plate-like inorganic filler in the PAS resin molded product is oriented as described above, the shape of the PAS resin molded product can be, for example, a sheet, a plate, a cylinder, or a film. In this case, when the mica is oriented so as to be orthogonal to the thickness direction in the member of each shape, excellent durability against corona discharge generated due to the voltage applied in the thickness direction of the member is obtained. It can be expressed.
For example, in a sheet-like PAS resin molded product, when high frequency and high voltage are applied in the thickness direction of the sheet, ie, in the direction orthogonal to the sheet surface, the electrical tree proceeds in the thickness direction of the sheet by corona discharge. However, when the plate-like inorganic filler is oriented as described above, the progress of the electric tree can be most effectively prevented, and the life of the sheet-like PAS resin molded product can be extended. The same is true for other shapes.

  The PAS resin molded product of the present embodiment can be used as a member requiring corona resistance. Examples of such a member include an ignition coil case, an insulated wire, and an electrical insulation sheet.

  Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited to the following examples.

[Examples 1 to 10, Comparative Examples 1 to 4]
As shown in Table 1, each raw material component was pelletized by the following extrusion conditions A, B, or C in each Example and comparative example. Under extrusion conditions A and B, the twin-screw extruder is provided with a side feed section at C7 of C1 part (raw material supply part) to C12 part (die side heater) of cylinder C4 part of kneading block , C6 part, C9 part was a screw arrangement. Under extrusion condition C, the twin-screw extruder is a screw in which the side feed part is installed in C7 of C1 part (raw material supply part) to C12 part (die side heater) of cylinder C and the kneading block is incorporated in C9 part It was an arrangement.
· Extrusion condition A
Raw materials are fed from the raw material feed section (hopper) of a twin screw extruder with a cylinder temperature of 320 ° C (non-conductive inorganic filler is added separately from the side feed section of the extruder), extrusion amount 20 kg / Hr, screw rotation speed 200 rpm The mixture was melt-kneaded under the following conditions and pelletized.
· Extrusion condition B
The raw material is fed from the raw material feed section (hopper) of a twin screw extruder with a cylinder temperature of 320 ° C. (silicone polymer and nonconductive inorganic filler are separately added from the side feed section of the extruder), 20 kg / hr of extrusion amount It melt-kneaded on the conditions of 150 rpm of screw rotation numbers, and pelletized.
· Extrusion condition C
Raw materials are fed from the raw material feed section (hopper) of a twin screw extruder with a cylinder temperature of 320 ° C (non-conductive inorganic filler is added separately from the side feed section of the extruder), extrusion amount 20 kg / Hr, screw rotation speed 200 rpm The mixture was melt-kneaded under the following conditions and pelletized.
The detail of each raw material component shown in Table 1 is described below.

(1) PAS resin component · PPS resin 1: manufactured by Kureha Co., Ltd., Fortron KPS (melt viscosity: 130 Pa · s (shear rate: 1216 sec ^-1 , 310 ° C.)), specific gravity: 1.35 (23/4 ° C.) )

(Measurement of melt viscosity of PPS resin)
The melt viscosity of the PPS resin was measured as follows.
Using a Capirograph manufactured by Toyo Seiki Seisaku-sho, using a flat die of 1 mmφ × 20 mm L as a capillary, the melt viscosity was measured at a barrel temperature of 310 ° C. and a shear rate of 1216 sec ⁻¹ .

(2) Silicone polymer / silicone polymer 1: Kaneka Corporation KANE ACE MR-01 (silicone acrylic core shell rubber), specific gravity: 1.1 (23/4 ° C.)
Silicone-based polymer 2: Toray Dow Corning Co., Ltd. DOW CORNING TORAY DY 33-315 (polyorganosiloxane), specific gravity: 0.98 (23/4 ° C.)

(3) Nonconductive inorganic filler-Glass fiber: Chopped glass fiber, manufactured by Nippon Sheet Glass Co., Ltd., ECS03T-747H Average fiber diameter: 10.5 μm, specific gravity: 2.6 (23/4 ° C)
· Gold mica: 150-S (average particle size (50% d): 163 μm), specific gravity: 2.9 (23/4 ° C.), manufactured by West Japan Trading Co., Ltd.
White Mica: manufactured by Yamaguchi Mica Co., Ltd. B-82 (average particle size (50% d): 137 μm), specific gravity: 2.9 (23/4 ° C.)
· Synthetic mica: manufactured by Topy Industries, Ltd., PDM-7-80 (average particle size (50% d): 70 μm), specific gravity: 2.9 (23/4 ° C)
Glass flakes: Nippon Sheet Glass Co., Ltd. product, REFG-108 (average particle size (50% d): 623 μm), specific gravity: 2.6 (23/4 ° C.)
Fine flakes: Nippon Flat Glass Co., Ltd. product, fine flakes, thickness: 0.7 μm, average particle size (50% d): 169 μm
Glass beads: manufactured by Potters Barotini Ltd., GL-BS (average particle size (50% d): 21 μm), specific gravity: 2.6 (23/4 ° C.)

(Volume resistivity of nonconductive inorganic filler)
Non-conductive inorganic filler, PPS resin 1 and non-conductive inorganic filler, PPS resin 1: non-conductive inorganic filler = 70: 30 (volume ratio) ratio, twin-screw extruder with cylinder temperature 320 ° C. It was charged (inorganic filler was added separately from the side feed part of the extruder), and was melt-kneaded and pelletized. A test piece (flat plate) with a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C. and a length of 100 mm, a width of 100 mm and a thickness of 3 mm was produced from the obtained pellets using an injection molding machine (Sumitomo Heavy Industries, Ltd., SE100D). When the volume resistivity was measured at an applied voltage of 500 V and 23 ° C. in accordance with IEC 60093, it was at least 1 × 10 ¹⁵ Ω · cm.

  In Table 1, the content of the silicone polymer and the inorganic filler is expressed in volume parts relative to 100 parts by volume of the PAS resin, and the content of the silicone polymer in the resin component is {silicone polymer / (PAS resin + silicone) It is represented by volume% as a system polymer)}. The content of each component was calculated based on the mass and the specific gravity (23/4 ° C.) measured according to the JIS Z 8807 solid specific gravity measurement method.

[Measurement of distance between particles and average dispersion diameter]
A flat plate of 80 mm long, 80 mm wide, and 1 mm thick is produced at a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C. from the pellets produced as described above using an injection molding machine (Sumitomo Heavy Industries, Ltd., SE100D). did. The center part of the produced flat plate was cut into a square having a side of 3 mm to obtain a test piece. A portion of about 50 μm in depth was cut from the outermost surface of this test piece, and the exposed surface was etched with sulfuric acid at a concentration of 98%. Next, the etched surface was photographed (magnification: 10,000 times) with a scanning microscope (S-4700, manufactured by Hitachi, Ltd.), and the obtained SEM image was taken into a computer (PC). In a computer, processing was performed to black out the portion where the silicone polymer particles of the SEM image were dropped. The average value and the number average particle diameter of the shortest distance between particle walls were calculated by software for calculating the average value of the shortest distance between particle walls and the number average particle diameter of the SEM image processed in this way. The value of the number average particle diameter was taken as the average dispersion diameter.
The software is programmed to be able to calculate according to the definition of the average value of the shortest distance between particle walls described above and to calculate the number average particle diameter.

The relationship between the average value of the shortest distance between particle walls and the addition amount of the silicone-based polymer in Examples 1 and 2 and Comparative Examples 1 and 2 is shown in FIG. In Examples 1 and 2 and Comparative Examples 1 and 2, the type of nonconductive inorganic filler is glass fiber, and the extrusion condition is extrusion condition A. That is, Examples 1 and 2 and Comparative Example 1 and Comparative Example 2 differ only in the silicone-based polymer (type or added amount). As shown in FIG. 5, when the addition amount of the silicone polymer 1 decreases, the shortest distance between the particle walls tends to increase. Therefore, when the silicone polymer 1 is not added in a predetermined amount or more, the average value of the shortest distance between particle walls is 0 It turns out that it can not be less than 25 μm.
Comparative Example 2 was the same as Example 2 except that silicone polymer 2 was used, but no silicone polymer having a specific average dispersion diameter was used, so that the average value of the shortest distance between particle walls was 0. It turns out that it can not be less than 25 μm.

  Next, the following corona resistance test was performed.

(Corona resistance test)
As shown in FIG. 4, the test piece 10 produced in the same manner as the test piece produced in the above-mentioned “Measurement of distance between particles and walls” in each Example and Comparative Example is a high-voltage side electrode 12 (φ 9.5 mm) and the earth side It is fixed between the electrodes 14 (25 mm in diameter), and applied with an withstand voltage of 130 ° C., a frequency of 200 Hz and an applied voltage of 18 kV in air using a withstand voltage tester (YST-243 WS-28 manufactured by Yamayo Test Instruments Co., Ltd.) The time until the occurrence of After the measurement, the presence or absence of whitening in the area (specifically, the area where the electrode was in contact and the area therearound) on which the corona discharge was applied on the test piece was visually confirmed. The measurement results are shown in Table 1.

(Breakdown strength after constant temperature and humidity treatment)
In each of the Examples and Comparative Examples, a test piece prepared in the same manner as the test piece prepared in the above-mentioned "Measurement of distance between particles and walls" was used at a temperature of 85.degree. It was exposed for 100 hours in an environment of humidity 85% RH and subjected to constant temperature and humidity treatment. The dielectric breakdown voltage of the test piece in the thickness direction of the test piece was measured using the dielectric breakdown test apparatus (YST-243-100AD, manufactured by Yamayo Test Instruments Co., Ltd.) according to IEC 60243-1 according to IEC 60243-1 . Specifically, as shown in FIG. 6, in a test tank filled with high-pressure insulating oil, the test piece is fixed between the high-pressure side electrode (cylinder of φ 25 mm) and the low-pressure side electrode (cylinder of φ 25 mm) The dielectric breakdown voltage was measured by boosting an AC voltage of 50 Hz at normal temperature with a voltage increase rate of 2 kV / s. The measurement results are shown in Table 1.

From the results shown in Table 1, in all of the PAS resin molded articles of Examples 1 to 10, in the corona resistance test, long-term durability having a corona destruction life of 2000 hours or more can be obtained, and after the corona resistance test No whitening was observed in the test pieces of No. 1, and excellent corona resistance was obtained. Moreover, in Examples 1-10, the result in which the dielectric breakdown strength after constant temperature and humidity processing was also excellent was obtained. Among them, when various micas and fine flakes are used, the dielectric breakdown strength after the excellent constant temperature and humidity processing of 30 (kV / mm) or more is obtained, and in particular white mica and synthetic mica are excellent. On the other hand, in the PAS resin molded articles of Comparative Examples 1 to 4, the corona destruction life is 1100 hours or less, which is extremely short compared to Examples 1 to 10 and inferior to the corona resistance. I understand that. In particular, the comparison between Example 2 and Comparative Examples 3 and 4 in which the composition of the PAS resin composition is the same and only the shortest distance between the particle walls of the silicone-based polymer is different, the shortest distance between the particles of the silicone-based polymer is resistant It is clear that it contributes to the improvement of the coronal property.
On the other hand, in Examples 1 to 10, although the type and the addition amount of the nonconductive inorganic filler are made different, excellent corona resistance is obtained in any of the examples. From this, it can be seen that the shortest distance between the particle walls of the silicone polymer contributes to the improvement of the corona resistance regardless of the type and the addition amount of the nonconductive inorganic filler.

10 test piece 10A PAS resin molded product 10B PAS resin molded product 12 high voltage side electrode 14 earth side electrode 16 nonconductive inorganic filler

Claims (5)

A resin composition containing a polyarylene sulfide resin, a silicone-based polymer, and a nonconductive inorganic filler is molded, and the silicone-based polymer is a silicone-acrylic copolymer, a silicone-based core-shell rubber, and a silicone composite powder. The corona resistance improvement of a resin molded article having a sea-island structure which is one or more selected from the group consisting of: an island part comprising particles of the silicone-based polymer and a sea part comprising the polyarylene sulfide resin Method,
A polyarylene sulfide, wherein the resin composition is prepared and the resin molded article is formed such that the average value of the distance between the wall and the particles closest to each particle of the silicone polymer is 0.25 μm or less Method for improving corona resistance of resin molded articles.   The content of the silicone-based polymer in the resin molded product is 30.0% by volume or more based on the total of the content of the polyarylene sulfide resin and the silicone-based polymer, and the silicone-based polymer The method for improving corona resistance of a polyarylene sulfide resin molded article according to claim 1, wherein the total content of the nonconductive inorganic filler is 70 parts by volume or more with respect to 100 parts by volume of the polyarylene sulfide resin. .   3. The polyarylene sulfide resin according to claim 1, wherein an average dispersion diameter of the silicone-based polymer in the sea portion of the polyarylene sulfide resin is 0.1 μm or more and less than 4.0 μm in observation with a scanning electron microscope. Method for improving the corona resistance of molded articles.   The poly according to any one of claims 1 to 3, wherein the nonconductive inorganic filler is one or more selected from the group consisting of glass fibers, glass flakes, glass beads, mica and silica. A method for improving the corona resistance of an arylene sulfide resin molded article.   The polyarylene sulfide resin according to any one of claims 1 to 4, wherein the silicone-based polymer contains one or more selected from the group consisting of silicone-acrylic copolymers and silicone-based core-shell rubbers. Method for improving the corona resistance of molded articles.