Polyphenylene sulfide resin composition for waveguide antenna, molded article for waveguide antenna, and waveguide antenna

Abstract

The present invention addresses the problem of providing: a molded article for a waveguide antenna, the molded article having excellent dimensional stability and low warpage, and having excellent coating processability and adhesion to a metal thin film; and a waveguide antenna comprising the molded article. In order to solve the problem, provided is a polyphenylene sulfide resin composition which is for a waveguide antenna and which contains 60-200 parts by weight of a fibrous filler and 0.1-120 parts by weight of a non-fibrous filler with respect to 100 parts by weight of a polyphenylene sulfide resin, the composition being characterized in that a linear expansion coefficient (LEC(MD)) in the MD direction and a linear expansion coefficient (LEC(TD)) in the TD direction are each at most 25 ppm / K, and the ratio (LEC(MD) / LEC(TD)) of LEC (MD) to LEC (TD) is 0.8-1.1.

Description

Polyphenylene sulfide resin composition for waveguide antenna, molded article for waveguide antenna, and waveguide antenna

[0001] The present invention relates to a waveguide antenna for communications used in radar for base stations and automobiles.

[0002] In recent years, there has been a demand for improved radar functionality to accommodate the increased speed and capacity of wireless communications in the lead-up to Beyond 5G (6G), ADAS (Advanced Driver Assistance Systems), and AD (Autonomous Driving). Microstrip antennas have traditionally been used for radar antennas. However, currently, complex shapes are required for antennas to accommodate the improved radar functionality, and waveguide antennas, which allow for three-dimensional wiring design, are being used. The microstrip antenna referred to here refers to a planar antenna consisting of a dielectric substrate, a radiating element printed on its surface, and a ground plane printed on its back. The radiating element can be wired two-dimensionally on the substrate, forming various waveguides. A waveguide antenna is an antenna comprising a waveguide having a waveguide extending in the axial direction and a plurality of radiation slots arranged at predetermined intervals along the axial direction of the waveguide, the waveguide being composed of a combination of first and second waveguide-forming members each having a cross section with an end shape at each end along the waveguide's extension direction. By stacking the waveguide-forming members, three-dimensional wiring is possible, enabling high performance. While this waveguide antenna allows for complex designs, it is mainly made of metal because it requires dimensional stability of the waveguide width and electrical conductivity under thermal changes in order to transmit radio waves stably. However, metal waveguide antennas have issues such as heavy weight and poor mass productivity, so alternatives are sought, such as resin-molded waveguide antennas coated with a thin metal film.

[0003] Patent Document 1 describes a waveguide antenna with excellent radio wave radiation efficiency, which uses an injection-molded product of a resin composition based on a thermoplastic resin such as liquid crystal polymer (LCP), polyphenylene sulfide (PPS), or polyacetal (POM) to which a filler such as glass fiber (GF) or carbon fiber (CF) has been added, and which is then coated with a thin metal film such as copper, silver, or gold that has excellent conductivity.

[0004] JP 2017-85311 A

[0005] Waveguide antennas made of resin molded products require dimensional stability of the waveguide width against temperature changes and low warpage (minimal warpage of the molded product) because radio waves pass through the waveguide while interfering with one another. Furthermore, electrical conductivity is necessary for radio wave transmission, and the insulating resin needs to be easy to process when a metal thin film is applied and to have good adhesion to the metal thin film. For waveguide antenna applications, resin compositions with improved properties are required. However, Patent Document 1 describes that a molded product made of an injection-molded resin composition based on a thermoplastic resin such as liquid crystal polymer (LCP), polyphenylene sulfide (PPS), or polyacetal (POM) and containing a filler such as glass fiber (GF) or carbon fiber (CF), and to which a highly conductive metal thin film such as copper, silver, or gold is applied, is preferred as a waveguide antenna. However, it does not describe any means for improving the dimensional stability against temperature changes, low warpage, and the easy to process when a metal thin film is applied and the adhesion to the metal thin film, which are required for waveguide antennas made of resin molded products.

[0006] Therefore, an object of the present invention is to provide a molded article for a waveguide antenna that has excellent dimensional stability and low warpage against temperature changes, and that has excellent processability when a metal thin film is applied and excellent adhesion to the metal thin film, and a waveguide antenna made of such a molded article.

[0007] As a result of extensive research aimed at solving the above problems, the present inventors have found that a PPS resin composition containing a PPS resin, a fibrous filler, and a non-fibrous filler satisfies certain properties, thereby providing good processability when a metal thin film is applied, good adhesion to the metal thin film, and excellent dimensional stability against temperature changes and low warpage, and have also found that a molded article made from such a resin composition is suitable for a waveguide antenna part for communication.

[0008] [1] A polyphenylene sulfide resin composition for a waveguide antenna, comprising a polyphenylene sulfide (component (A)) resin, a fibrous filler (component (B)), and a non-fibrous filler (component (C)), wherein the content of component (B) is 60 to 200 parts by weight and the content of component (C) is 0.1 to 120 parts by weight, relative to 100 parts by weight of component (A), and wherein, when molded under the following conditions, a molded product has a linear expansion coefficient in the machine direction (LEC(MD)) and a linear expansion coefficient in the transverse direction (LEC(TD)), each of which is 25 ppm / K or less, and a ratio of LEC(MD) to LEC(TD), (LEC(MD) / LEC(TD)), of 0.8 to 1.1. <Molding conditions for molded product> A mold (see Figure 1) was prepared, which had a rectangular parallelepiped space of 80 mm x 80 mm x 3 mm, a slit-shaped discharge hole (slit width 1.5 mm, slit length 78 mm) corresponding to one side of the 80 mm square of the rectangular parallelepiped, and an injection hole on a perpendicular line to the side passing through the midpoint of the side (see Figure 1). The resin composition was discharged and injection molded using an injection molding machine NEX-1000-9E manufactured by Nissei Plastic Industrial Co., Ltd. under the following conditions: cylinder temperature: 320°C, injection pressure: lower limit molding pressure + 12.8 MPa, injection time: 15 seconds, and cooling time: 15 seconds.

[0009] A rectangular test piece measuring 10 mm in length, 5 mm in width, and 3 mm in thickness was cut out so that the center of gravity of the test piece coincided with the center of gravity of the square, with the direction from the slit edge to the opposite edge defined as MD and the direction perpendicular to MD defined as TD (see Figure 2). A test piece for LEC (MD) measurement had its long side aligned with MD, and a test piece for LEC (TD) measurement had its long side aligned with TD. [2] The polyphenylene sulfide resin composition for a waveguide antenna according to [1] above, characterized in that all or part of component (B) is a fibrous filler having a modified cross section. [3] The polyphenylene sulfide resin composition for a waveguide antenna according to [1] or [2] above, characterized in that it further contains 0.1 to 12 parts by weight of an elastomer per 100 parts by weight of component (A). [4] A molded article for a waveguide antenna obtained by molding the polyphenylene sulfide resin composition for a waveguide antenna according to any one of [1] to [3]. [5] The molded article for a waveguide antenna according to [4], wherein the thermal expansion coefficients in a direction parallel to the surface of the molded article and in which the component (B) is oriented (thermal expansion coefficient A) and in a direction parallel to the surface of the molded article and perpendicular to the direction in which the component (B) is oriented (thermal expansion coefficient B) are both 25 ppm / K or less, and the value obtained by dividing the thermal expansion coefficient A by the thermal expansion coefficient B is 0.8 to 1.1. [6] The molded article for a waveguide antenna according to [4] or [5], wherein a metal thin film is formed on at least a portion of the surface of the molded article, and the arithmetic mean roughness of the portion of the surface of the molded article where the metal thin film is formed is 10 μm or less. [7] The molded article for a waveguide antenna according to [6], wherein the metal thin film is composed of at least one material selected from the group consisting of silver, copper, and aluminum. [8] A waveguide antenna comprising the molded article for a waveguide antenna according to any one of [4] to [7] above.

[0010] According to the present invention, a molded article for a waveguide antenna having excellent dimensional stability and low warpage during thermal changes can be provided as an alternative to conventional metallic waveguide antennas. In addition, a resin composition for a waveguide antenna having excellent coating processability and adhesion to a metal thin film sufficient for a waveguide antenna can be provided.

[0011] 1 shows the shape of an injection-molded product for measuring the linear expansion coefficient, where (a) is a plan view and (b) is a side view. It is a diagram showing the cutting position of a test piece for measuring the linear expansion coefficient, where (a) shows the cutting position of a test piece for measuring LEC (MD), and (b) shows the cutting position of a test piece for measuring LEC (TD). It is a diagram for explaining the sampling position of a test piece for measuring peel strength.

[0012] The present invention relates to a polyphenylene sulfide resin composition containing a polyphenylene sulfide resin (hereinafter sometimes referred to as "component (A)"), a fibrous filler (hereinafter sometimes referred to as "component (B)"), and a non-fibrous filler (hereinafter sometimes referred to as "component (C)"). When molded under the conditions described below, the polyphenylene sulfide resin composition has a linear expansion coefficient in the machine direction (LEC(MD)) and a linear expansion coefficient in the transverse direction (LEC(TD)), each of which is 25 ppm / K or less, and a ratio of LEC(MD) to LEC(TD) (LEC(MD) / LEC(TD)) of 0.8 to 1.1. Molded articles made from such polyphenylene sulfide resin compositions exhibit excellent processability when a metal thin film is applied, excellent adhesion to the metal thin film, and excellent dimensional stability and low warpage against temperature changes, making them suitable for waveguide antenna components.

[0013] Hereinafter, an embodiment of the present invention will be described.

[0014] Polyphenylene Sulfide Resin (Component (A)) The component (A) used in the present invention is a polymer having a repeating unit represented by the following structural formula.

[0015]

[0016] From the viewpoint of heat resistance, component (A) preferably contains 70 mol % or more, and more preferably 90 mol % or more, of repeating units represented by the above structural formula. Component (A) may contain repeating units having the following structure in an amount of less than 30 mol %:

[0017]

[0018] Next, a method for obtaining component (A) will be described. PPS resin can be produced by a known method including a pre-process, a polymerization reaction process, a recovery process, and a post-treatment process. It is preferable that the raw materials and pre-process used in the production of PPS resin conform to the method described in JP 2017-155221 A. The polymerization reaction process, recovery process, and post-treatment process will be described below.

[0019] [Polymerization Reaction Step] A sulfidizing agent and a polyhalogenated aromatic compound are reacted in an organic polar solvent at a temperature ranging from 200°C to 290°C to produce a powdery PPS resin.

[0020] To start the polymerization reaction, the sulfidizing agent and the polyhalogenated aromatic compound are added to an organic polar solvent, preferably in an inert gas atmosphere, at a temperature ranging from room temperature to 215°C, and preferably from 100 to 215°C. A polymerization aid may also be added at this stage. These raw materials may be added in any order, or simultaneously.

[0021] The mixture is usually heated to a temperature in the range of 200° C. to 290° C. There are no particular restrictions on the rate of temperature increase, but a rate of 0.01 to 5° C. / min is usually selected, and a range of 0.1 to 3° C. / min is more preferred.

[0022] In general, the temperature is finally raised to 250 to 290° C., and the reaction is carried out at that temperature for usually 0.25 to 50 hours, preferably 0.5 to 20 hours.

[0023] A method in which, before reaching the final temperature, the reaction is carried out for a certain period of time at, for example, 200° C. to 245° C., and then the temperature is raised to 270° C. to 290° C. is effective in obtaining a higher degree of polymerization. In this case, the reaction time at 200° C. to 245° C. is usually selected from the range of 0.25 to 20 hours, preferably 0.25 to 10 hours.

[0024] In order to obtain a polymer with a higher degree of polymerization, it is effective to carry out the polymerization in multiple stages. When carrying out the polymerization in multiple stages, it is effective to raise the temperature to the next stage when the conversion of the polyhalogenated aromatic compound in the system at 245°C reaches 40 mol% or more, preferably 60 mol%.

[0025] [Recovery Step] After the polymerization is completed, solid matter is recovered from the polymerization reaction product containing the polymer, solvent, etc.

[0026] The most preferred method for recovering PPS resin is to perform the recovery under rapid cooling conditions, and one preferred method for this recovery method is the flash method. The flash method is a method of subjecting the polymerization reaction product to high temperature and high pressure (usually 250°C or higher, 8 kg / cm ２ In this method, the polymer is flashed from a state of above (above) into an atmosphere of normal pressure or reduced pressure, and the polymer is recovered in powder form at the same time as the solvent is recovered. The "flashing" here means that the polymerization reaction product is ejected from a nozzle. Specific examples of the flashing atmosphere include nitrogen or water vapor at normal pressure, and the temperature is usually selected in the range of 150°C to 250°C.

[0027] The flash method is an economical method because it allows the recovery of solids simultaneously with the recovery of solvents and the recovery time can be relatively short. In this recovery method, ionic compounds such as sodium and organic low-molecular-weight polymers (oligomers) tend to be incorporated into the polymer during the solidification process.

[0028] However, the method for recovering the PPS resin used in the production method of the present invention is not limited to the flash method, and any method that satisfies the requirements of the present invention, in which a polymerization reaction product containing a polymer, a solvent, etc. is slowly cooled to recover a particulate polymer (quench method), may be used. However, from the viewpoint of economy, it is more preferable to use PPS resin recovered by the flash method.

[0029] [Post-treatment process] In the production process of PPS resin, a thermal oxidation treatment can be carried out after the above-mentioned polymerization reaction process and recovery process. A hot water treatment process and an acid treatment process can also be carried out before the thermal oxidation treatment process. A washing process with an organic solvent can also be included before the acid treatment process or the hot water treatment process. The acid treatment process, the hot water treatment process, and the washing with an organic solvent can also be carried out in an appropriate combination.

[0030] [Post-treatment step (thermal oxidation treatment)] The PPS resin used in the present invention is preferably subjected to a thermal oxidation treatment after an acid treatment, a hot water treatment, or washing with an organic solvent. The thermal oxidation treatment is a treatment in which the PPS resin is heated in an oxygen atmosphere or heated with the addition of a peroxide such as hydrogen peroxide or a vulcanizing agent such as sulfur, and heating in an oxygen atmosphere is particularly preferred because of the simplicity of the treatment.

[0031] The melt flow rate (measured in accordance with ASTM D-1238-70 at a temperature of 315.5°C and a load of 5000 g) of the PPS resin preferably used in the present invention preferably has a lower limit of 100 g / 10 min or more, more preferably 300 g / 10 min or more. The upper limit is preferably 5000 g / 10 min or less, more preferably 3000 g / 10 min or less. A melt flow rate of 100 g / 10 min or more allows for the production of a PPS resin with excellent moldability, and a melt flow rate of 5000 g / 10 min or less allows for the production of a PPS resin with excellent mechanical strength, which are preferred.

[0032] Fibrous Filler (Component (B)) The polyphenylene sulfide resin composition of the present invention contains component (B). Examples of component (B) include glass fiber, milled glass fiber, carbon fiber, modified cross-section glass fiber, cut glass fiber, stainless steel fiber, metal fibers such as aluminum fiber and brass fiber, organic fibers such as aromatic polyamide fiber and Kevlar (registered trademark) fibril, gypsum fiber, ceramic fiber, asbestos fiber, zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, carbon nanotube, carbon nanohorn, and cellulose nanofiber.

[0033] Here, whether a filler is a fibrous filler or a non-fibrous filler can be determined as follows. That is, after baking the resin composition in an electric furnace to evaporate component (A), the residual filler can be observed with a scanning electron microscope to determine whether the filler is a fibrous filler or a non-fibrous filler. The fibrous filler referred to here refers to a filler having a constant cross-sectional diameter and a length to diameter (L / D) ratio of the cross-section of the filler (the cross-section with the smallest cross-sectional area) of 3 or more. Note that the cross-section may be circular or non-circular (including irregular cross-sections), and the diameter in the case of irregular cross-sections is taken as the circle-equivalent diameter. Furthermore, since the cross-sectional diameter is constant, so-called needle-like shapes do not fall under component (B).

[0034] Among the (B) components, it is preferable to use at least one selected from glass fiber, milled glass fiber, flat glass fiber, and irregular cross-section glass fiber from the viewpoints of mechanical properties and dimensional properties (dimensional stability against temperature changes and low warpage of molded articles). The polyphenylene sulfide resin composition of the present invention is suitable for use in melt molding methods such as injection molding, and the (B) component is often oriented during molding. While the (B) component contributes significantly to the reinforcing effect of molded articles, it may cause anisotropy in the physical properties of the molded articles. In order to reduce the linear expansion coefficients in the MD and TD directions and the ratio of the linear expansion coefficients in the MD and TD directions when molded under the molding conditions described below, it is preferable to use a fibrous filler with an irregular cross-section, and it is particularly preferable to use a glass fiber with an irregular cross-section. Glass fibers having a modified cross section are, for example, glass fibers having a flat cross section or plate-like glass fibers. A flat cross section means that, in a cross section perpendicular to the longitudinal direction of the glass fiber, the ratio of the major axis (the distance between two points on the periphery of the cross section that is the longest distance between the two points) to the minor axis (the distance between two points on the periphery of the cross section that is the longest line segment among the line segments connecting the two points on the periphery of the cross section that is perpendicular to the line segment connecting the two points forming the major axis) (major axis / minor axis, hereinafter sometimes referred to as "flatness") is preferably 1.3 or more and 10 or less. The flatness is preferably 1.5 or more and 7 or less, more preferably 1.5 or more and 6 or less. When the flatness is 1.3 or more, when the resin composition is molded, a molded article with good low anisotropy can be obtained, and dimensional stability against temperature changes can be further improved. When the flatness is 10 or less, when the resin composition is molded, a molded article with good mechanical strength can be obtained. The flattening ratio is a value obtained by observing 50 randomly selected glass fibers with a scanning electron microscope, measuring the major axis and minor axis of the cross section of the fibers, calculating the ratio, and then calculating the number average.

[0035] The average fiber length of the glass fibers is preferably 50 μm or more, and desirably 500 μm or less. If the average fiber length of the glass fibers is less than 50 μm, the bending strength is significantly reduced, and if the average fiber length exceeds 500 μm, the weld tensile strength is significantly reduced, and dimensional stability and warpage resistance are reduced. The average fiber length was determined by heating the polyphenylene sulfide resin composition in air to remove the resin. The remaining glass fibers were observed using an optical microscope at 120x magnification, and the fiber lengths of 1,000 or more randomly selected glass fibers were measured and calculated as the arithmetic average.

[0036] Component (B), particularly when component (B) is an inorganic fiber, is preferably treated with a sizing agent or surface treatment agent. Examples of the sizing agent or surface treatment agent include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds, and epoxy compounds with a high epoxy content are particularly preferred from the viewpoint of improving the reactivity of the reinforcing fiber.

[0037] The content of component (B) in the polyphenylene sulfide resin composition of the present invention is, from the viewpoints of mechanical properties and dimensional properties, a lower limit of 60 parts by weight or more, preferably 80 parts by weight or more, and more preferably 100 parts by weight or more, per 100 parts by weight of component (A). If the content is less than 60 parts by weight per 100 parts by weight of component (A), mechanical properties are lost and the linear expansion coefficient increases. On the other hand, from the viewpoints of fluidity, rigidity, and dielectric properties during molding, the upper limit is 200 parts by weight or less, preferably 150 parts by weight or less, and more preferably 130 parts by weight or less, per 100 parts by weight of component (A). If the content exceeds 200 parts by weight per 100 parts by weight of component (A), excessive surface roughening occurs, and adhesion to metal thin films is likely to deteriorate.

[0038] Non-fibrous Filler (Component (C)) The polyphenylene sulfide resin composition of the present invention contains component (C). Examples of component (C) include fullerene, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, silicates such as alumina silicate, metal compounds such as silicon oxide, magnesium oxide, alumina, zirconium oxide, titanium oxide, and iron oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black, silica, and graphite. These may be hollow, and two or more types may be used in combination. These may also be pre-treated with a coupling agent such as an isocyanate compound, an organosilane compound, an organotitanate compound, an organoborane compound, or an epoxy compound before use.

[0039] Among these, it is preferable to use one or more materials selected from calcium carbonate, glass beads, and glass flakes from the viewpoint of mechanical properties and dimensional properties.

[0040] The content of component (C) in the polyphenylene sulfide resin composition of the present invention is, from the viewpoint of dimensional stability against temperature changes, a lower limit of 0.1 parts by weight or more, preferably 35 parts by weight or more, and more preferably 45 parts by weight or more, per 100 parts by weight of component (A). If it is less than 0.1 part by weight, appropriate dimensional properties cannot be obtained when the molded product is formed. On the other hand, from the viewpoint of mechanical properties and dimensional properties, the upper limit is preferably 120 parts by weight or less, more preferably 115 parts by weight or less, per 100 parts by weight of component (A). If it exceeds 120 parts by weight, fluidity during molding is impaired, affecting moldability.

[0041] To further improve dimensional properties, the ratio of the weight of component (C) to the weight of component (B) (hereinafter referred to as "(C) / (B)") is preferably 0.6 or more and 1.2 or less. By making (C) / (B) 0.6 or more, the ratio (LEC(MD) / LEC(TD)) described below can approach 1.0. Furthermore, by making (C) / (B) 1.2 or less, a decrease in strength can be suppressed.

[0042] Elastomer (Component (D)) The polyphenylene sulfide resin composition of the present invention preferably contains an elastomer (hereinafter, sometimes referred to as “component (D)”). Component (D) is present as dispersed in component (A). The content of component (D) in the polyphenylene sulfide resin composition of the present invention is, from the viewpoints of coating processability and adhesion to a metal thin film, preferably 0.1 part by weight or more, more preferably 5 parts by weight or more, and most preferably 8 parts by weight or more, per 100 parts by weight of component (A). On the other hand, from the viewpoints of an increase in the linear expansion coefficient, a decrease in fluidity during molding, and coating processability and adhesion to a metal thin film, the upper limit is preferably 12 parts by weight or less, more preferably 11 parts by weight or less, and most preferably 10 parts by weight or less, per 100 parts by weight of component (A).

[0043] Examples of the component (D) that can be used in the present invention include (co)polymers obtained by polymerizing α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-octene, 4-methyl-1-pentene, and isobutylene, either alone or in combination; copolymers of α-olefins with α,β-unsaturated acids and alkyl esters thereof, such as acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, and butyl methacrylate; and copolymers of α-olefins with α,β-unsaturated acids and alkyl esters thereof, such as ethylene / propylene copolymers (" / " indicates copolymerization, the same applies hereinafter), ethylene / 1-butene copolymers, ethylene / 1-hexene, ethylene / 1-octene, ethylene / methyl acrylate copolymers, ethylene / ethyl acrylate copolymers, ethylene / butyl acrylate copolymers, ethylene / methyl methacrylate copolymers, ethylene / ethyl methacrylate copolymers, and ethylene / butyl methacrylate copolymers. These may also have functional groups such as epoxy groups, isocyanate groups, carbodiimide groups, and amino groups in their molecular structures, and it is preferable to use those having such functional groups from the viewpoint of improving dispersibility in component (A).

[0044] Of these, component (D) is preferably an α-olefin copolymer having an epoxy group.

[0045] An α-olefin copolymer having an epoxy group can be obtained by introducing an epoxy group-containing component, such as a glycidyl ester of an α,β-unsaturated acid, into an olefin elastomer. Examples of glycidyl esters of α,β-unsaturated acids include epoxy group-containing monomers such as glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, and glycidyl citraconate. There are no particular restrictions on the method for introducing these epoxy group-containing components, and they can be introduced by copolymerization during copolymerization of an olefin (co)polymer, or by graft polymerization using a radical initiator onto an olefin (co)polymer.

[0046] The amount of the epoxy group-containing component introduced is suitably within the range of 0.001 to 40 mol %, preferably 0.01 to 35 mol %, when the total amount of repeating units derived from olefin is taken as 100 mol %.

[0047] Specific examples of particularly useful α-olefin copolymers having epoxy groups include ethylene / propylene-g-glycidyl methacrylate copolymer ("g" represents graft, the same applies hereinafter), ethylene / 1-butene-g-glycidyl methacrylate copolymer, ethylene / glycidyl acrylate copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / methyl acrylate / glycidyl methacrylate copolymer, ethylene / methyl methacrylate / glycidyl methacrylate copolymer, and epoxy group-containing olefin copolymers obtained by copolymerizing an α-olefin such as ethylene or propylene with a glycidyl ester of an α,β-unsaturated acid and a monomer having an aliphatic carbon-carbon unsaturated bond other than the above-mentioned monomers.

[0048] Furthermore, it is preferable to use, as component (D), an α-olefin copolymer having an epoxy group in combination with an olefin polymer having no polar functional group, in order to obtain excellent moldability and excellent coating processability and adhesion to a metal thin film.

[0049] Examples of the olefin polymer having no polar functional group include polymers or copolymers obtained by polymerizing α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-octene, 4-methyl-1-pentene, and isobutylene, either alone or in combination, such as ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, and ethylene / 1-octene copolymer.

[0050] When an α-olefin copolymer having an epoxy group and an olefin polymer having no polar functional group are used in combination as component (D), there are no particular restrictions on the ratio thereof. However, from the viewpoints of moldability and adhesion to a metal thin film, a weight ratio of (α-olefin copolymer having an epoxy group) / (olefin (co)polymer having no polar functional group) is preferably 5 / 95 to 95 / 5, and more preferably 10 / 90 to 90 / 10.

[0051] The polyphenylene sulfide resin composition of the present invention may contain a silane compound for the purpose of improving mechanical strength, toughness, etc., within a range that does not impair the effects of the present invention. Examples of silane compounds include isocyanate group-containing alkoxysilane compounds such as γ-isocyanate propyl triethoxysilane, γ-isocyanate propyl trimethoxysilane, γ-isocyanate propyl methyl dimethoxysilane, γ-isocyanate propyl methyl diethoxysilane, γ-isocyanate propyl ethyl dimethoxysilane, γ-isocyanate propyl ethyl diethoxysilane, and γ-isocyanate propyl trichlorosilane; epoxy group-containing alkoxysilane compounds such as γ-glycidoxypropyl trimethoxysilane, γ-glycidoxypropyl triethoxysilane, and β-(3,4-epoxycyclohexyl)ethyl trimethoxysilane; amino group-containing alkoxysilane compounds such as γ-(2-aminoethyl)aminopropyl methyl dimethoxysilane, γ-(2-aminoethyl)aminopropyl trimethoxysilane, and γ-aminopropyl trimethoxysilane; and silane compounds such as modified silicone oils having epoxy groups, amino groups, isocyanate groups, and hydroxyl groups. Among these, alkoxysilanes having an epoxy group, an amino group, an isocyanate group, or a hydroxyl group are particularly suitable for achieving excellent mechanical strength and thermal shock resistance. The preferred content of such silane-based compounds in the polyphenylene sulfide resin composition is in the range of 0.05 to 3 parts by weight per 100 parts by weight of component (A). The content of such silane-based compounds in the polyphenylene sulfide resin composition can be determined by fluorescent X-ray analysis of polyphenylene sulfide resin composition pellets.

[0052] Furthermore, the polyphenylene sulfide resin composition of the present invention may be blended with other resins as long as the effects of the present invention are not impaired. There are no particular restrictions on the resins that can be blended, and specific examples include polyamide, polyethylene terephthalate, polyether ether ketone resin, and vinyl aromatic compound-based block copolymers.

[0053] Furthermore, the polyphenylene sulfide resin composition of the present invention can contain one or more antioxidants selected from phenolic compounds and phosphorus-based compounds to maintain heat resistance and thermal stability, as long as the effects of the present invention are not impaired. The content of such antioxidants in the polyphenylene sulfide resin composition is preferably 0.01 part by weight or more, and more preferably 0.02 part by weight or more, per 100 parts by weight of the component (A) resin, from the viewpoint of improving heat resistance. From the viewpoint of reducing gas components generated during molding, the content is preferably 5 parts by weight or less, and more preferably 1 part by weight or less. Furthermore, using a phenolic antioxidant and a phosphorus-based antioxidant in combination is particularly effective in maintaining heat resistance and thermal stability, and is therefore preferred.

[0054] There are no particular limitations on the method for preparing the polyphenylene sulfide resin composition of the present invention, but a representative example is a method in which the raw materials are fed into a conventional melt mixer such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll, and kneaded at a temperature of 280 to 380°C. The order in which the raw materials are mixed is also not particularly limited, and any of the following methods may be used: a method in which all raw materials are blended and then melt-kneaded by the above-mentioned method; a method in which some raw materials are blended and then melt-kneaded by the above-mentioned method, and then the remaining raw materials are blended and melt-kneaded; or a method in which some raw materials are blended and then the remaining raw materials are mixed using a side feeder while melt-kneading in a single-screw or twin-screw extruder. Furthermore, minor additive components can also be added before molding after other components have been blended and pelletized by the above-mentioned method or the like.

[0055] The polyphenylene sulfide resin composition of the present invention thus obtained can be subjected to various molding processes such as injection molding, extrusion molding, blow molding and transfer molding, but is particularly suitable for injection molding.

[0056] The polyphenylene sulfide resin composition of the present invention is molded under the following molding conditions. The linear expansion coefficient in the machine direction (LEC(MD)) and the linear expansion coefficient in the transverse direction (LEC(TD)) of a molded article are both 25 ppm / K or less, and the ratio of these (LEC(MD) / LEC(TD)) is 0.8 to 1.1. This results in excellent dimensional stability and low warpage during thermal changes, making it applicable to products with complex shapes, such as waveguide antenna components, that require dimensional stability during thermal changes. The molding conditions for measuring the linear expansion coefficient are as follows. The linear expansion coefficient is measured in the range of -40 to 150°C in accordance with ISO 11359-2 (2021). The specific measurement method is as described in the Examples section. Furthermore, assuming melt molding, the MD direction generally coincides with the direction in which the resin flows and the direction in which component (B) is oriented.

[0057] <Molding conditions for molded product> A mold (see Figure 1) was prepared, which had a rectangular parallelepiped space of 80 mm x 80 mm x 3 mm, a slit-shaped discharge hole (slit width 1.5 mm, slit length 78 mm) corresponding to one side of the 80 mm square of the rectangular parallelepiped, and an injection hole on a perpendicular line to the side passing through the midpoint of the side (see Figure 1). The resin composition was discharged and injection molded using an injection molding machine NEX-1000-9E manufactured by Nissei Plastic Industrial Co., Ltd. under the following conditions: cylinder temperature: 320°C, injection pressure: lower limit molding pressure + 12.8 MPa, injection time: 15 seconds, and cooling time: 15 seconds.

[0058] The direction perpendicular to the slit side and parallel to the surface of the square was defined as MD, and the direction perpendicular to MD was defined as TD. A rectangular test piece measuring 10 mm in length, 5 mm in width, and 3 mm in thickness was cut out so that the center of gravity of the test piece coincided with the center of gravity of the square (see Figure 2). A test piece for LEC (MD) measurement was obtained whose long side was in the same direction as MD (corresponding to reference numeral 5 in Figure 2), and a test piece for LEC (TD) measurement was obtained whose long side was in the same direction as TD (corresponding to reference numeral 6 in Figure 2). These test pieces were used for the measurements.

[0059] Although FIG. 1 shows the shape of the injection-molded resin composition, it can be considered to be equal to the internal dimensions of the space within the mold.

[0060] The lower limits of LEC(MD) and LEC(TD) are preferably 10 ppm / K or more, more preferably 15 ppm / K or more, from the viewpoint of conformity with the metal thin film coating during expansion and contraction due to changes in environmental temperature, while the upper limits are preferably 23 ppm / K or less, from the viewpoint of conformity with the metal thin film coating and dimensional stability.

[0061] In order to reduce the linear expansion coefficient of the molded product of the polyphenylene sulfide resin composition of the present invention to 25 ppm / K or less when molded under the above-mentioned molding conditions, it is convenient to use glass fibers having a flat cross section or plate-like glass fibers as component (B), or to set the ratio (C) / (B) to 0.6 or more and 1.2 or less.

[0062] Furthermore, in terms of compatibility with the metal thin film coating, the lower limit of LEC(MD) / LEC(TD) is preferably 0.9 or more, and the upper limit is preferably 1.05 or less, and most preferably 1.0, i.e., the values ​​of LEC(MD) and LEC(TD) are equal.

[0063] As described above, a simple way to adjust the LEC(MD) / LEC(TD) to 0.8 to 1.1 is to include in the PPS resin composition any one selected from glass fiber, modified cross-section glass fiber, and glass flake, which are highly effective in increasing low anisotropy.

[0064] When considering use in a waveguide antenna, a smooth surface is required after the formation of a metal thin film in order to reduce radio wave loss. However, the smoothness of the surface after the formation of the metal thin film is significantly affected by the smoothness of the surface of the molded article before the formation of the metal thin film. Therefore, the arithmetic mean roughness (Ra) of the surface of a molded article made from the polyphenylene sulfide resin composition of the present invention is required to be small, and the surface of the molded article must be smooth. The lower limit is preferably 0.1 μm or more from the surface roughness limit of the mold. The upper limit is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1.0 μm or less.

[0065] The arithmetic mean roughness (Ra) of the surface of a molded article made from the PPS resin composition of the present invention can be reduced to 10 μm or less by adding component (D) to the PPS resin composition.

[0066] The processing method for forming a metal thin film on the surface of a molded article made from the polyphenylene sulfide resin composition of the present invention is not particularly limited. However, in terms of the surface smoothness of the portion where the metal thin film is formed, it is preferable to adopt a processing method that does not roughen the surface of the metal thin film. Specific examples of processing methods that do not roughen the surface include methods of performing an activation treatment on the surface of the molded article, such as UV treatment or plasma treatment, followed by forming a metal thin film by sputtering, vapor deposition, plating, etc. These treatments make it possible to reduce the surface roughness of the portion where the metal thin film is formed to 10 μm or less. Furthermore, as a processing method for improving the adhesion between the molded article and the metal thin film, there is also a processing method in which at least a portion of the surface of the molded article is roughened by etching, blasting, etc., followed by forming the metal thin film. However, since the surface smoothness after forming the metal thin film is significantly affected by the surface roughness of the molded article, methods that only partially process the surface of the molded article are not preferred.

[0067] The metal thin film formed on a molded article made from the polyphenylene sulfide resin composition of the present invention is preferably formed using a metal with high conductivity, particularly one or more metals selected from the group consisting of silver, copper, and aluminum, from the viewpoint of reducing radio wave loss. Furthermore, from the viewpoint of reducing radio wave loss, the film thickness of the metal thin film is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more. The upper limit of the film thickness of the metal thin film is not particularly limited, as a certain thickness is sufficient for the wave-guiding performance when formed into a waveguide, but is preferably about 50 μm.

[0068] Molded articles made from the polyphenylene sulfide resin composition of the present invention exhibit improved coating processability and adhesion between the resin and metal thin film, as well as excellent dimensional stability and low warpage against temperature changes, making them suitable for communication waveguide antenna components used in radars for base stations and automobiles. Furthermore, the composition enables improved coating processability and adhesion between the molded article and metal thin film without sacrificing the various properties inherent to PPS resin. Furthermore, molded articles made from the polyphenylene sulfide resin composition of the present invention are suitable for electrical and electronic components because of the excellent electromagnetic wave shielding properties and surface thermal conductivity provided by the metal thin film. In particular, they are capable of preventing mutual interference caused by electromagnetic waves. Due to these properties, the molded articles of the present invention are excellent for use in housings for sensor components and ECU components.

[0069] Other examples of applications of the polyphenylene sulfide resin composition of the present invention include sensors, capacitors, variable capacitor cases, oscillators, various terminal boards, transformers, plugs, printed circuit boards, small motors, semiconductors, liquid crystal displays, and parabolic antennas. Other examples include machine-related parts such as office computer parts, telephone parts, and facsimile parts; optical instruments and precision machinery parts such as microscopes, binoculars, cameras, and clocks; and automobile and vehicle parts such as valve alternator terminals, alternator connectors, IC regulators, light dimmer potentiometer bases, and exhaust gas valves; various valves such as fuel, exhaust, and intake pipes; intake manifolds, fuel pumps, engine coolant joints, carburetor main bodies, carburetor spacers, water pump housings, engine cooling modules, turbine vanes, wiper motor parts, distributors, starter switches, starter relays, air conditioner panel switch boards, and electrical component insulating plates.

[0070] The present invention will be explained in more detail below by showing examples, but the present invention is not limited to the descriptions of these examples.

[0071] [Methods for evaluating PPS resins produced in each production example] (1) Melt flow rate (MFR) The melt flow rate of the polyphenylene sulfide resin was measured at a temperature of 315.5° C. under a load of 5000 g in accordance with a method in accordance with ASTM-D1238-70.

[0072] However, for polyphenylene sulfide resins with low viscosity, the MFR was calculated by the following method: The flow rate (ER, unit: g / 10 min) of the polyphenylene sulfide resin was measured at a measurement temperature of 315.5°C under a load of 345 g according to a method in accordance with ASTM-D1238-70, and the MFR (unit: g / 10 min) was calculated by the following formula (1).

[0073] MFR = 15.8 × 4.4 × ER Formula (1).

[0074] Production Example 1 Polymerization of PPS (PPS-1) A 70-liter autoclave equipped with a stirrer and a bottom stopper valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.91 kg (69.80 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), and 10.5 kg of ion-exchanged water, and gradually heated to 245°C over about 3 hours under atmospheric pressure while passing nitrogen through. 14.78 kg of water and 0.28 kg of NMP were distilled off, and the reaction vessel was then cooled to 200°C.

[0075] The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 moles, including water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 moles per mole of charged alkali metal sulfide. The mixture was then cooled to 200°C, and 10.48 kg (71.27 moles) of p-dichlorobenzene and 9.37 kg (94.50 moles) of NMP were added. The reaction vessel was sealed under nitrogen gas and heated from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. After reacting for 100 minutes at 270°C, the bottom stopper valve of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen. The contents were then stirred for a while at 250°C to remove most of the NMP.

[0076] The obtained solid and 76 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter. Next, 76 liters of ion-exchanged water heated to 70°C was poured into the glass filter and suction-filtered to obtain a cake.

[0077] The obtained cake and 90 liters of ion-exchanged water were charged into an autoclave equipped with a stirrer, and acetic acid was added to adjust the pH to 7. After the inside of the autoclave was purged with nitrogen, the temperature was raised to 192°C and maintained at that temperature for 30 minutes. Thereafter, the autoclave was cooled, and the contents were removed.

[0078] The contents were filtered under suction using a glass filter, and then 76 liters of ion-exchanged water at 70°C was poured into the filter and filtered under suction to obtain a cake. The resulting cake was dried at 120°C under a nitrogen stream to obtain dried PPS. This was heat-treated at 200°C under an oxygen stream until the MFR value reached 150 g / 10 min, yielding crosslinked PPS-1. The MFR of the resulting polymer was 130 g / 10 min.

[0079] [Production Example 2] Polymerization of PPS (PPS-2) An autoclave equipped with a stirrer and a bottom stop valve was charged with 8267.4 g (70.0 mol) of 47.5% sodium hydrosulfide, 2925.0 g (70.2 mol) of 96% sodium hydroxide, 13860.0 g (140.0 mol) of N-methyl-2-pyrrolidone (NMP), 1894.2 g (23.1 mol) of sodium acetate, and 10500.0 g of ion-exchanged water. The mixture was gradually heated to 240°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. After distilling off 14772.1 g of water and 280.0 g of NMP, the reaction vessel was cooled to 160°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.08 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.023 mole per mole of the charged alkali metal sulfide.

[0080] Next, 10,646.7 g (72.4 mol) of p-dichlorobenzene (p-DCB) and 6,444.9 g (65.1 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. With stirring at 240 rpm, the temperature was raised from 200° C. to 270° C. at a rate of 0.6° C. / min and maintained at 270° C. for 70 minutes. The extraction valve at the bottom of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen, and the contents were stirred for a while at 250° C. to remove most of the NMP.

[0081] The obtained solid and 53 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter having a pore size of 10 to 16 µm. Next, 60 liters of ion-exchanged water heated to 70°C was poured into the glass filter having a pore size of 10 to 16 µm, and suction-filtered to obtain 18,000 g of PPS resin cake (containing 7,550 g of PPS resin).

[0082] 18,000 g of the PPS resin cake, 40 L of ion-exchanged water, and 43 g of acetic acid were charged into an autoclave equipped with a stirrer. After the interior of the autoclave was purged with nitrogen, the temperature was raised to 192°C and maintained for 30 minutes to perform an acid treatment. The pH during the acid treatment was 7. After cooling the autoclave, the contents were filtered through a glass filter with a pore size of 10 to 16 μm. Next, 60 L of ion-exchanged water heated to 70°C was poured into the glass filter and suction filtered to obtain a cake. The resulting cake was dried at 120°C for 4 hours under a nitrogen stream to obtain an acid-treated linear PPS-2. The MFR of the resulting polymer was 6,300 g / 10 min.

[0083] [Production Example 3] Polymerization of PPS (PPS-3) An autoclave equipped with a stirrer and a bottom stop valve was charged with 8,267.4 g (70.0 mol) of 47.5% sodium hydrosulfide, 2,925.0 g (70.2 mol) of 96% sodium hydroxide, 13,860.0 g (140.0 mol) of N-methyl-2-pyrrolidone (NMP), 1894.2 g (23.1 mol) of sodium acetate, and 10,500.0 g of ion-exchanged water. The mixture was gradually heated to 240°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. After distilling off 14,772.1 g of water and 280.0 g of NMP, the reaction vessel was cooled to 160°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.08 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.023 mole per mole of the charged alkali metal sulfide.

[0084] Next, 10,646.7 g (72.4 mol) of p-dichlorobenzene (p-DCB) and 6,444.9 g (65.1 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. With stirring at 240 rpm, the temperature was raised from 200° C. to 270° C. at a rate of 0.6° C. / min and maintained at 270° C. for 70 minutes. The extraction valve at the bottom of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen, and the contents were stirred for a while at 250° C. to remove most of the NMP.

[0085] The obtained solid and 53 L of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered using a glass filter having a pore size of 10 to 16 µm. Next, 60 L of ion-exchanged water heated to 70°C was poured into the glass filter having a pore size of 10 to 16 µm, and suction-filtered to obtain 18,000 g of PPS resin cake (containing 7,550 g of PPS resin).

[0086] 18,000 g of the PPS resin cake, 40 L of ion-exchanged water, and 43 g of acetic acid were charged into an autoclave equipped with a stirrer. The autoclave was then purged with nitrogen, and the temperature was raised to 192°C and maintained for 30 minutes to perform an acid treatment. The pH during the acid treatment was 7. After cooling the autoclave, the contents were filtered through a glass filter with a pore size of 10-16 μm. Next, 60 L of ion-exchanged water heated to 70°C was poured into the glass filter and suction filtered to obtain a cake. The resulting cake was dried at 120°C for 4 hours under a nitrogen stream to obtain an acid-treated PPS resin powder. This PPS resin powder was then placed in a 100 L heater equipped with a stirrer and subjected to thermal oxidation treatment at 220°C and an oxygen concentration of 2% for 2 hours to obtain a crosslinked PPS-3. The MFR of the resulting polymer was 420 g / 10 min.

[0087] [Production Example 4] Polymerization of PPS (PPS-4) An autoclave equipped with a stirrer and a bottom stop valve was charged with 8267.4 g (70.0 mol) of 47.5% sodium hydrosulfide, 2925.0 g (70.2 mol) of 96% sodium hydroxide, 13860.0 g (140.0 mol) of N-methyl-2-pyrrolidone (NMP), 1894.2 g (23.1 mol) of sodium acetate, and 10500.0 g of ion-exchanged water. The mixture was gradually heated to 240°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. After distilling off 14772.1 g of water and 280.0 g of NMP, the reaction vessel was cooled to 160°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.08 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.023 mole per mole of the charged alkali metal sulfide.

[0088] Next, 10,646.7 g (72.4 mol) of p-dichlorobenzene (p-DCB) and 6,444.9 g (65.1 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. With stirring at 240 rpm, the temperature was raised from 200° C. to 270° C. at a rate of 0.6° C. / min and maintained at 270° C. for 70 minutes. The extraction valve at the bottom of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen, and the contents were stirred for a while at 250° C. to remove most of the NMP.

[0089] The obtained solid and 53 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter having a pore size of 10 to 16 µm. Next, 60 liters of ion-exchanged water heated to 70°C was poured into the glass filter having a pore size of 10 to 16 µm, and suction-filtered to obtain 18,000 g of PPS resin cake (containing 7,550 g of PPS resin).

[0090] 18,000 g of the PPS resin cake, 40 L of ion-exchanged water, and 43 g of acetic acid were charged into an autoclave equipped with a stirrer. After the interior of the autoclave was purged with nitrogen, the temperature was raised to 192°C and maintained for 30 minutes to perform an acid treatment. The pH at the time of the acid treatment was 7. After cooling the autoclave, the contents were filtered through a glass filter with a pore size of 10 to 16 μm. Next, 60 L of ion-exchanged water heated to 70°C was poured into the glass filter and suction filtered to obtain a cake. The obtained cake was dried at 120°C for 4 hours under a nitrogen stream to obtain an acid-treated linear PPS.

[0091] The linear PPS was placed in a 100-liter heating device equipped with a stirrer and subjected to thermal oxidation treatment at 220°C and an oxygen concentration of 2% for 2 hours to obtain crosslinked PPS-4. The MFR of the resulting polymer was 5000 g / 10 min.

[0092] [Production Example 5] PPS Polymerization (PPS-5) A 70-liter autoclave equipped with a stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.91 kg (69.80 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), and 10.5 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. After distilling off 14.78 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0093] The mixture was then cooled to 200°C, and 10.48 kg (71.27 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen gas and heated from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. After reacting for 100 minutes at 270°C, the bottom stopper valve of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen, and the contents were stirred for a while at 250°C to remove most of the NMP.

[0094] The obtained solid and 76 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter. Next, 76 liters of ion-exchanged water heated to 70°C was poured into the glass filter and suction-filtered to obtain a cake.

[0095] The obtained cake and 90 liters of ion-exchanged water were charged into an autoclave equipped with a stirrer, and acetic acid was added to adjust the pH to 7. After the inside of the autoclave was purged with nitrogen, the temperature was raised to 192°C and maintained at that temperature for 30 minutes. Thereafter, the autoclave was cooled, and the contents were removed.

[0096] The contents were suction filtered through a glass filter, and then 76 L of ion-exchanged water at 70°C was poured into the filter and suction filtered to obtain a cake. The obtained cake was dried at 120°C under a nitrogen stream to obtain dried PPS-5. The obtained PPS-5 had an ER of 90 g / 10 min, which was converted to an MFR of 6,257 g / 10 min.

[0097] [Production Example 6] Polymerization of PPS (PPS-6) An autoclave equipped with a stirrer and a bottom stop valve was charged with 8267.4 g (70.0 mol) of 47.5% sodium hydrosulfide, 2925.0 g (70.2 mol) of 96% sodium hydroxide, 13860.0 g (140.0 mol) of N-methyl-2-pyrrolidone (NMP), 1894.2 g (23.1 mol) of sodium acetate, and 10500.0 g of ion-exchanged water. The mixture was gradually heated to 240°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. After distilling off 14772.1 g of water and 280.0 g of NMP, the reaction vessel was cooled to 160°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.08 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.023 mole per mole of the charged alkali metal sulfide.

[0098] Next, 10,646.7 g (72.4 mol) of p-dichlorobenzene (p-DCB) and 6,444.9 g (65.1 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. With stirring at 240 rpm, the temperature was raised from 200° C. to 270° C. at a rate of 0.6° C. / min and maintained at 270° C. for 70 minutes. The extraction valve at the bottom of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen, and the contents were stirred for a while at 250° C. to remove most of the NMP.

[0099] The obtained solid and 53 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, washed at 70°C for 30 minutes, and then suction-filtered through a glass filter having a pore size of 10 to 16 µm. Next, 60 liters of ion-exchanged water heated to 70°C was poured into the glass filter having a pore size of 10 to 16 µm, and suction-filtered to obtain 18,000 g of PPS resin cake (containing 7,550 g of PPS resin).

[0100] 18,000 g of the PPS resin cake, 40 L of ion-exchanged water, and 43 g of acetic acid were charged into an autoclave equipped with a stirrer. The autoclave was then purged with nitrogen, and the temperature was raised to 192°C and maintained for 30 minutes to perform an acid treatment. The pH during the acid treatment was 7. After cooling the autoclave, the contents were filtered through a glass filter with a pore size of 10-16 μm. Next, 60 L of ion-exchanged water heated to 70°C was poured into the glass filter and suction filtered to obtain a cake. The resulting cake was dried at 120°C for 4 hours under a nitrogen stream to obtain an acid-treated PPS resin powder. This PPS resin powder was then placed in a 100-L heater equipped with a stirrer and subjected to thermal oxidation treatment at 200°C and an oxygen concentration of 21% for 2 hours. The thermal oxidation treatment was performed in an air atmosphere at 1.96 L / min to obtain a crosslinked PPS-6. The MFR of the resulting polymer was 554 g / 10 min.

[0101] [Production Example 7] Polymerization of PPS (PPS-7) A 70-liter autoclave equipped with a stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.94 kg (70.63 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 1.89 kg (23.1 mol) of sodium acetate, and 5.50 kg of ion-exchanged water. The mixture was gradually heated to 245°C over 3 hours under atmospheric pressure while passing nitrogen through it. After distilling off 9.77 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0102] After that, it was cooled to 200 ° C., and 10.42 kg (70.86 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen gas, and the temperature was raised from 200 ° C. to 270 ° C. at a rate of 0.6 ° C. / min while stirring at 240 rpm, and the reaction was carried out at 270 ° C. for 140 minutes. Thereafter, 2.40 kg (133 mol) of water was injected while cooling from 270 ° C. to 250 ° C. over 15 minutes. Next, it was gradually cooled from 250 ° C. to 220 ° C. over 75 minutes, and then rapidly cooled to near room temperature and the contents were removed. The contents were diluted with 35 liters of NMP to form a slurry, which was stirred at 85 ° C. for 30 minutes, and then filtered through an 80-mesh wire net (opening 0.175 mm) to obtain a solid.

[0103] The resulting solid was similarly washed with 35 L of NMP and filtered. The resulting solid was diluted with 70 L of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. This procedure was repeated three times. The resulting solid and 32 g of calcium acetate were diluted with 70 L of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh. The resulting solid was further diluted with 70 L of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid.

[0104] The solid thus obtained was dried at 120° C. under a nitrogen stream to obtain a dried PPS-7, which had an MFR of 600 g / 10 min.

[0105] [Examples 1 to 5, Comparative Examples 1 to 4] Using a twin-screw extruder (TEM-26SS, manufactured by Toshiba Machine Co., Ltd.) with a 26 mm diameter intermediate addition port and a cylinder temperature set to 320°C and a screw rotation speed set to 400 rpm, components (A), (C), and (D) obtained in Production Examples 1 to 7 were added through the raw material supply port in the weight ratios shown in each Example and Comparative Example in Tables 1 and 2 to form a molten state, and component (B) was supplied through the intermediate addition port and melt-kneaded at a discharge rate of 30 kg / hour to obtain pellets. These pellets were used to evaluate various properties. The results are shown in Tables 1 and 2.

[0106] The raw materials used in the present invention are listed below.

[0107] PPS resin (component (A)) PPS-1: PPS resin polymerized by the method described in Production Example 1 PPS-2: PPS resin polymerized by the method described in Production Example 2 PPS-3: PPS resin polymerized by the method described in Production Example 3 PPS-4: PPS resin polymerized by the method described in Production Example 4 PPS-5: PPS resin polymerized by the method described in Production Example 5 PPS-6: PPS resin polymerized by the method described in Production Example 6 PPS-7: PPS resin polymerized by the method described in Production Example 7.

[0108] Fibrous filler (component (B)) B-1: Circular cross section glass fiber (T-760H manufactured by Nippon Electric Glass Co., Ltd., 3 mm length, average fiber diameter 10.5 μm, aspect ratio 1) B-2: Modified cross section glass fiber (T-760FGF manufactured by Nippon Electric Glass Co., Ltd., 3 mm length, minor axis 7 μm, major axis 28 μm, aspect ratio 4) B-3: Chopped strand (T-747GH manufactured by Nippon Electric Glass Co., Ltd., 3 mm length, average fiber diameter 10 μm) B-4: Chopped strand (T-702 manufactured by Nippon Electric Glass Co., Ltd., 3 mm length, average fiber diameter 13 μm).

[0109] Non-fibrous filler (component (C)) C-1: heavy calcium carbonate (KSS1000 manufactured by Kalfin Co., Ltd.) C-2: heavy calcium carbonate (Escalon #800 manufactured by Sankyo Flour Milling Co., Ltd.) C-3: glass flakes: alkali-free glass (REFG-112 manufactured by Nippon Sheet Glass Co., Ltd.).

[0110] Elastomers (component (D)) D-1: ethylene / glycidyl methacrylate / methyl acrylate copolymer (Bondfast E manufactured by Sumitomo Chemical Co., Ltd.) D-2: ethylene / glycidyl methacrylate / methyl acrylate copolymer (Bondfast 7M manufactured by Sumitomo Chemical Co., Ltd., ethylene 67% by mass, glycidyl methacrylate 6% by mass, methyl acrylate 27% by mass) D-3: ethylene / n-butyl acrylate copolymer (Lotryl 35BA40 manufactured by Arkema K.K.) D-4: ethylene / α-olefin copolymer (Tafmer TX650 manufactured by Mitsui Chemicals, Inc.) D-5: olefin copolymer (Engage 8842 manufactured by The Dow Chemical Company).

[0111] [Method for measuring and evaluating molded articles made from resin composition] The method for measuring and evaluating molded articles made from resin compositions is as follows.

[0112] (1) Tensile Strength The tensile strength of the molded product was measured in accordance with ISO 527-1, 2 (2012). Specifically, the measurement was performed as follows. The resin composition pellets as a sample were dried at 130 ° C. for 3 hours using a hot air dryer, and then fed to an injection molding machine (SE-50D) manufactured by Sumitomo Heavy Industries, Ltd., with a cylinder temperature of 310 ° C. and a mold temperature of 145 ° C., and injection molding was performed using a mold with a Type A1 test piece shape (4 mm thick) specified in ISO 20753 (2008) under conditions where the average speed of the molten resin passing through the cross-sectional area of ​​the central parallel part was 400 ± 50 mm / s to obtain a test piece. The test piece was conditioned for 16 hours at 23°C and 50% relative humidity, and then the tensile strength was measured in accordance with ISO 527-1, -2 (2012) under the conditions of 23°C, 50% relative humidity, a gripper distance of 115 mm, and a test speed of 5 mm / min. A tensile strength of 120 MPa or more can be said to be at a product level that presents no practical problems, but the higher this value, the better the mechanical strength and the more preferable it is.

[0113] (2) Flexural Strength Measurement was performed in accordance with ISO 178 (2001). Specifically, the measurement was performed as follows. The resin composition pellets used as samples were fed into an injection molding machine (SE50DUZ-C160) manufactured by Sumitomo Heavy Industries, Ltd., with a cylinder temperature of 310°C and a mold temperature of 145°C. The pellets were filled for a filling time of 0.8 s and injection molded at a holding pressure of 75% of the filling pressure to obtain a Type B2 specimen shape as specified in ISO 20753 (2008). The specimens were conditioned for 16 hours at 23°C and 50% relative humidity, and then measured at a span of 64 mm and a strain rate of 2 mm / min in an atmosphere of 23°C and 50% relative humidity.

[0114] (3) Linear expansion coefficient A mold (see FIG. 1) was prepared having a rectangular parallelepiped space of 80 mm x 80 mm x 3 mm, a slit-shaped discharge hole (corresponding to a gate; slit width 1.5 mm, slit length 78 mm) corresponding to one side of the 80 mm square of the rectangular parallelepiped, and an injection hole (sprue) on a perpendicular line to the side passing through the midpoint of the side. Using an injection molding machine NEX-1000-9E manufactured by Nissei Plastic Industrial Co., Ltd., the resin composition was discharged and injection molded under the following conditions: cylinder temperature: 320 ° C, injection pressure: molding lower limit pressure + 12.8 MPa, injection time: 15 seconds, cooling time: 15 seconds. In FIG. 2, the part corresponding to the sprue is indicated by reference numeral 1, the part corresponding to the runner by reference numeral 2, the part corresponding to the gate by reference numeral 3, and the sampling plate by reference numeral 4. The corners of the runner part of the mold were rounded to 2 mm φ.

[0115] The direction from one side with the slit to the opposite side was defined as MD, and the direction perpendicular to MD was defined as TD, and rectangular test pieces 10 mm long, 5 mm wide, and 3 mm thick were cut out so that the center of gravity of the test piece coincided with the center of gravity of the square (see Figure 2). In this case, test pieces for LEC (MD) measurement whose long sides were in the same direction as MD and test pieces for LEC (TD) measurement whose long sides were in the same direction as TD were obtained.

[0116] The linear expansion coefficient of the obtained strip-shaped test piece was measured in accordance with ISO 11359-2 (2021) using a TMA-100 manufactured by Seiko Instruments Inc., with a load of 2 g, and the temperature was raised from −50° C. to 200° C. at a rate of 5° C. / min, and the linear expansion coefficient was expressed as a numerical value in the temperature range of −40° C. to 150° C.

[0117] (4) Surface Roughness (Arithmetic Mean Roughness Ra) of Molded Article Before Metal Thin Film Formation The surface roughness of the molded article before metal thin film formation was measured by the following procedure. First, a rectangular parallelepiped of 80 mm × 80 mm × 3 mm was molded using the method described in the section "(3) Linear Expansion Coefficient" above. Next, as shown in FIG. 3, strip test pieces 7 having a width of 15 mm (indicated by L2 in the figure), a length of 80 mm, and a thickness of 3 mm were cut out. The first strip test piece 7 was cut out 10 mm from the edge of the square, with an interval of 7.5 mm between each test piece. The cut strip test pieces 7 were measured using a surface roughness measuring instrument (SV-2100) manufactured by Mito Corporation according to a method conforming to JIS-B-0601, and the arithmetic mean roughness Ra was determined.

[0118] (5) Adhesion strength (peel strength) between resin molded article and metal thin film First, a molded article having a metal thin film layer formed thereon was produced by the following method. A rectangular test piece obtained by the same method as in "(4) Surface roughness of molded article before metal thin film formation (arithmetic mean roughness Ra)" above was irradiated with ultraviolet light having dominant wavelengths of 184.9 nm and 253.7 nm from a height of 30 mm from the surface of the test piece for 60 minutes using a compact ultraviolet irradiation device (Koto Electric, KOL1-300S) equipped with one high-power low-pressure mercury lamp (300 W) having dominant wavelengths of 184.9 nm and 253.7 nm, and then immersed in a 20 wt % potassium hydroxide aqueous solution for 12 minutes to carry out a surface treatment step.

[0119] Next, 0.3 g / dm ３ The catalyst solution was applied to the surface of the molded article, and the concentration of the catalyst solution was 20 g / dm ３ The Pd catalyst on the PPS resin surface was reduced to metal using an aqueous sodium phosphinate solution, forming metal nuclei for smooth deposition of electroless NiP plating (catalysis step and activation step). Next, electroless copper plating was performed on the molded product with the metal palladium deposited on its surface obtained in the above step. Thereafter, electroplating using copper sulfate and nickel plating were performed on the molded product to a plating thickness of 3 μm or more, thereby obtaining a molded product with a metal thin film layer.

[0120] The adhesion strength of the metal thin film layer of the obtained molded article with a metal thin film layer was measured according to the adhesion strength test method in Appendix 1 (regulations) of JIS H8630:2006. A * indicates that no metal thin film was formed, D indicates that the peel strength was less than 0.5 N / cm, C indicates that the peel strength was 0.5 N / cm or more but less than 1 N / cm, B indicates that the peel strength was 1 N / cm or more but less than 10 N / cm, and A indicates that the peel strength was 10 N / cm or more. Grades A to C were evaluated as passing, with A being the best.

[0121] In Examples 1 to 5, by using glass fibers having a flat cross section or plate-shaped glass fibers as component (B), or by setting the ratio (C) / (B) to 0.6 or more and 1.2 or less, excellent results were obtained in terms of low linear expansion and low anisotropy while maintaining high mechanical properties. From the above, it was found that Examples 1 to 5 are suitable for waveguide antenna components that require dimensional stability during thermal changes.

[0122] In Examples 2 to 4, the modified cross section glass fiber was used, which resulted in even lower linear expansion and anisotropy, and it was found that these are more suitable for waveguide antenna parts.

[0123] In Comparative Examples 1 to 4, modified cross section glass fibers were not used and the (C) / (B) ratio was less than 0.6, so the coefficient of linear expansion was large and the anisotropy was poor.

[0124] Furthermore, the results of Examples 1 to 5 showed that a content of 0.1 to 12 parts by weight of component (D) per 100 parts by weight of component (A) was particularly effective in improving the adhesion of the metal thin film.

[0125] From the above, it was found that Examples 1 to 3 are particularly suitable for waveguide antenna parts that require adhesion to a metal thin film and dimensional stability against changes due to heat.

[0126]

[0127]

[0128] According to the present invention, it is possible to provide a resin waveguide antenna that is an alternative to conventional metal waveguide antennas, and that has excellent dimensional stability during thermal changes, low warpage of molded products, and excellent coating processability and adhesion to metal thin films.

[0129] 1 sprue corresponding part 2 runner corresponding part 3 gate corresponding part 4 sampling plate part 5, 6, 7 strip test piece or cutting position of strip test piece

Claims

1. A polyphenylene sulfide resin composition for a waveguide antenna, comprising a polyphenylene sulfide (hereinafter referred to as "component (A)") resin, a fibrous filler (hereinafter referred to as "component (B)"), and a non-fibrous filler (hereinafter referred to as "component (C)"), wherein the content of component (B) is 60 to 200 parts by weight and the content of component (C) is 0.1 to 120 parts by weight per 100 parts by weight of component (A), and wherein, when molded under the following conditions, the molded product has a linear expansion coefficient in the machine direction (LEC(MD)) and a linear expansion coefficient in the transverse direction (LEC(TD)) of 25 ppm / K or less, respectively, and a ratio of LEC(MD) to LEC(TD) (LEC(MD) / LEC(TD)) of 0.8 to 1.

1. <Molding conditions for molded products> A mold (see FIG. 1) having a rectangular parallelepiped space of 80 mm x 80 mm x 3 mm, a slit-shaped discharge hole (slit width 1.5 mm, slit length 78 mm) corresponding to one side of the 80 mm square of the rectangular parallelepiped, and an injection hole on the perpendicular line of one side passing through the midpoint of that side was prepared, and an injection molding machine NEX-1000-9E manufactured by Nissei Plastic Industrial Co., Ltd. was used. The resin composition was discharged and injection molded under the following conditions: cylinder temperature: 320 ° C., injection pressure: molding lower limit pressure + 12.8 MPa, injection time: 15 seconds, cooling time: 15 seconds. The direction from one side where the slit is provided to the opposite side is defined as MD, and the direction perpendicular to MD is defined as TD. A strip-shaped test piece having a length of 10 mm, a width of 5 mm, and a thickness of 3 mm was cut out so that the center of gravity of the test piece coincided with the center of gravity of the square (see FIG. 2). In this case, a test piece for measuring LEC (MD) is obtained whose long side is in the same direction as MD, and a test piece for measuring LEC (TD) is obtained whose long side is in the same direction as TD.

2. A polyphenylene sulfide resin composition for a waveguide antenna according to claim 1, characterized in that all or part of component (B) is a fibrous filler having a modified cross section.

3. A polyphenylene sulfide resin composition for a waveguide antenna according to claim 1 or 2, further comprising 0.1 to 12 parts by weight of an elastomer per 100 parts by weight of component (A).

4. A molded article for a waveguide antenna obtained by molding the polyphenylene sulfide resin composition for a waveguide antenna according to claim 1 or 2.

5. A molded article for a waveguide antenna according to claim 4, wherein the thermal expansion coefficient in the direction parallel to the surface of the molded article and in which component (B) is oriented (thermal expansion coefficient A) and the thermal expansion coefficient in the direction parallel to the surface of the molded article and perpendicular to the direction in which component (B) is oriented (thermal expansion coefficient B) are both 25 ppm / K or less, and the value obtained by dividing thermal expansion coefficient A by thermal expansion coefficient B is 0.8 to 1.

1.

6. A molded product for a waveguide antenna according to claim 4, in which a thin metal film is formed on at least a portion of the surface thereof, and the arithmetic mean roughness of the portion of the surface of the molded product on which the thin metal film is formed is 10 μm or less.

7. The molded article for a waveguide antenna according to claim 6, wherein the metal thin film is made of at least one material selected from the group consisting of silver, copper, and aluminum.

8. A waveguide antenna comprising the molded article for a waveguide antenna according to claim 4.

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