Polyarylene sulfide resin composition for laser welding, molded body, and composite molded body

Abstract

A polyarylene sulfide resin composition for laser welding, said composition having a chlorine content of 3,000 ppm or less.

Description

Laser-weldable polyarylene sulfide resin composition, molded article, and composite molded article

[0001] This disclosure relates to laser-weldable polyarylene sulfide resin compositions, molded articles, and composite molded articles.

[0002] Laser welding is a well-known technique for joining resin molded parts together. In laser welding, a transparent molded part that transmits laser light emitted from a light source and an absorbing molded part that absorbs laser light are placed on top of each other so that the surfaces to be joined are in contact, and laser light is shone from the transparent molded part towards the absorbing molded part. The laser light shone on the interface between the two parts, causing it to heat up, melt, and join together. The higher the laser light transmittance of the resin composition used in the transparent molded part, the lower the power of the laser required for welding.

[0003] Polyarylene sulfide resin is widely used in electrical and electronic equipment components, automotive parts, and chemical equipment components due to its excellent heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame retardancy. However, because polyarylene sulfide resin has a high refractive index, its laser light transmittance is lower compared to other resins. Furthermore, because there is a large difference in refractive index between polyarylene sulfide resin and inorganic fillers (e.g., glass fibers), the transmittance of molded resin compositions containing inorganic fillers is further reduced.

[0004] Patent Document 1 describes a transparent material consisting of a resin molded member that transmits laser light, which is made of a polyphenylene sulfide resin having a predetermined weight-average molecular weight.

[0005] Japanese Patent Publication No. 2006-168221

[0006] One of the objectives of this disclosure is to provide a laser-weldable polyarylene sulfide resin composition, molded article, and composite molded article with high laser light transmittance.

[0007] This disclosure includes, but is not limited to, the following embodiments. One embodiment relates to a laser-weldable polyarylene sulfide resin composition having a chlorine content of 3,000 ppm or less.

[0008] This disclosure makes it possible to provide laser-weldable polyarylene sulfide resin compositions, molded articles, and composite molded articles with high laser light transmittance.

[0009] Embodiments of the present disclosure will be described in detail below. The present disclosure is not limited to the following embodiments. One embodiment of the present disclosure is a laser-weldable polyarylene sulfide resin composition having a chlorine content of 3,000 ppm or less. The laser-weldable polyarylene sulfide resin composition (hereinafter also referred to as "PAS resin composition") includes a polyarylene sulfide resin (hereinafter also referred to as "PAS resin"), and the chlorine content of the PAS resin composition as a whole is 3,000 ppm or less, and the specific structure of the PAS resin, the presence or absence of other components, etc., are not particularly limited. A chlorine content of 3,000 ppm or less results in a PAS resin composition with high laser light transmittance. The chlorine content of the PAS resin composition may be 2,000 ppm or less, or 1,000 ppm or less.

[0010] The method for measuring the chlorine content of a PAS resin composition is not particularly limited, but for example, it can be measured by combustion ion chromatography under the following conditions: Ion chromatography analyzer: Thermo Fisher Scientific "ICS1600" Combustion pretreatment device: Nitto Seiko Analytech Co., Ltd. "AQF-5000H" Sample: 10 mg Heater: InletTemp / 900℃, OutletTemp / 1000℃ Absorption solution: H ２ O ２ 900ppm, internal standard PO ４ ３－ 25 ppm

[0011] PAS resin is a resin whose main structure consists of repeating units represented by -(Ar-S)-(Ar represents an arylene group). One type of PAS resin may be used alone, or two or more types may be used in combination. The specific structure of the arylene group contained in the PAS resin is not particularly limited, but examples include phenylene groups such as p-phenylene group, m-phenylene group, and o-phenylene group, p,p'-biphenylene group, p,p'-diphenylene ether group, p,p'-diphenylene carbonyl group, p,p'-diphenylene sulfone group, and naphthylene group. The PAS resin may be a homopolymer in which there is one type of arylene group in the resin, or a copolymer in which there are two or more types of arylene groups in the resin.

[0012] When the PAS resin is a homopolymer, it is preferable that the arylene groups are p-phenylene groups, as this provides extremely high heat resistance, high strength, high rigidity, and high dimensional stability over a wide temperature range. When the PAS resin is a copolymer, the specific structure and number of types of arylene groups contained in the resin are not particularly limited. The copolymer may be random or block-type. As a specific example of the copolymer, a combination containing p-phenylene sulfide groups and m-phenylene sulfide groups is preferable, as this provides molded articles with high physical properties such as heat resistance, moldability, and mechanical properties. The ratio of p-phenylene sulfide groups to the total number of arylene groups in the resin is preferably 70 mol% or more, and more preferably 80 mol% or more. Among PAS resins, those in which the arylene groups are phenylene groups are generally called polyphenylene sulfide resins (hereinafter also referred to as "PPS resins").

[0013] Furthermore, the PAS resin may be substantially linear with no branching or crosslinking structure, or with at least one of branching and crosslinking. Generally, substantially linear PAS resins are preferred from the viewpoint of improving laser light transmittance, but in this disclosure, the laser light transmittance is improved by specifying the chlorine content of the PAS resin composition, so PAS resins having at least one of branching and crosslinking can also be suitably used, not just substantially linear PAS resins.

[0014] The melt viscosity of the PAS resin is not particularly limited, but for example, at a temperature of 310°C and a shear rate of 1200 sec. －１ The value measured under these conditions may be in the range of 80 to 250 Pa·s. Furthermore, when two or more types of PAS resin are used in combination, the melt viscosity of the mixture may be in the range of 80 to 250 Pa·s.

[0015] The molecular weight of the PAS resin is not particularly limited, but for example, the weight-average molecular weight (Mw) may be in the range of 1,000 to 100,000. In this disclosure, the laser light transmittance is improved by specifying the chlorine content of the PAS resin composition, so any PAS resin can be suitably used regardless of its molecular weight. When two or more types of PAS resin are used in combination, the weight-average molecular weight (Mw) of the mixture may be in the range of 1,000 to 100,000.

[0016] In this disclosure, the weight-average molecular weight (Mw) of the PAS resin is a value measured by the following method. First, 1-chloronaphthalene is used as the solvent, the PAS resin to be measured is added, and it is heated and dissolved in a block bath at 230°C for 6 minutes. If necessary, it is purified by high-temperature filtration to prepare a 0.075% by mass PAS resin 1-chloronaphthalene solution. High-temperature gel permeation chromatography is performed to calculate the weight-average molecular weight (Mw) of the PAS resin on a standard polystyrene basis. As the measuring device, for example, the "SSC-7000" manufactured by Senshu Kagaku Co., Ltd. (now Kitahama Seisakusho Co., Ltd.) and a UV detector (detection wavelength: 360 nm) can be used.

[0017] The chlorine content of the PAS resin is not particularly limited, and the chlorine content of the entire PAS resin composition should be 3,000 ppm or less. For example, the chlorine content of the PAS resin may be 4,000 ppm or less, or 2,000 ppm or less. Furthermore, the lower limit is not particularly limited, but it may be 500 ppm or more. The chlorine content of the PAS resin may be in the range of 500 to 4,000 ppm. The chlorine content of the PAS resin can be measured by the same method as the chlorine content of the PAS resin composition. When two or more types of PAS resin are used in combination, the chlorine content of the mixture may be in the range of 500 to 4,000 ppm.

[0018] The method for producing PAS resin is not particularly limited and can be produced by conventionally known production methods. When producing high molecular weight PAS resin, it can also be produced by first producing low molecular weight PAS resin and then polymerizing it under high temperature conditions using a known polymerization aid to increase its molecular weight.

[0019] The PAS resin composition may contain other thermoplastic resins in addition to PAS resin, depending on the application and desired performance. The other thermoplastic resins may be used individually or in combination of two or more. Specific examples of other thermoplastic resins include, for example, olefin resins such as polyethylene resin, polypropylene resin, and poly-4-methylpentene-1 resin; cyclic olefin resins such as norbornene resin; polystyrene resin; polyester resins such as polyethylene terephthalate resin, polybutylene terephthalate, polyethylene naphthalate resin, and polyarylate resin; polyacetal resin, polyamide resin, polyimide resin, polyamide-imide resin, polyetherimide resin, polyphenylene ether resin, polysulfone resin, polyethersulfone resin, polyetherketone resin, polyetheretherketone resin, liquid crystal resin, fluororesin, and silicone resin. The proportion of PAS resin to the total resin components in the PAS resin composition may be 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass. Specifically, the resin components in a PAS resin composition refer to PAS resin and other thermoplastic resins.

[0020] The PAS resin composition may contain fillers depending on the application and desired performance. When using the PAS resin composition as a laser light transmitting material, it is preferable to use a filler with high laser light transmittance. As mentioned above, because the refractive index of PAS resin is large compared to inorganic fillers such as glass fibers, the transmittance of laser light tends to decrease further when inorganic fillers are added. However, in this disclosure, the laser light transmittance is improved by specifying the chlorine content of the PAS resin composition, so it can be suitably used as a transmitting material in laser welding even when fillers are added.

[0021] The type of filler is not particularly limited, and any filler used in the field of PAS resin compositions can be used without any particular limitations. One type of filler may be used alone, or two or more types may be used in combination. The filler may be either an inorganic filler or an organic filler. Furthermore, the shape of the filler is not particularly limited, and may be fibrous, plate-shaped, spherical, granular, powder-shaped, etc. In this disclosure, "fibrous" refers to a shape in which the ratio of different diameters is in the range of 1 to 4 and the average fiber length (cut length) is 0.01 to 3 mm. "Plate-shaped" refers to a shape in which the ratio of different diameters is greater than 4 and the aspect ratio is in the range of 1 to 500. "Granular" refers to a shape (including spherical) in which the ratio of different diameters is in the range of 1 to 4 and the aspect ratio is in the range of 1 to 2. All shapes are the initial shapes (shapes before melting and kneading). The diameter ratio is defined as "the longest straight-line distance of the cross-section perpendicular to the longitudinal direction / the longest straight-line distance of the cross-section perpendicular to the longitudinal direction." The aspect ratio is defined as "the longest straight-line distance in the longitudinal direction / the longest straight-line distance perpendicular to the longest straight-line distance in the cross-section perpendicular to the longitudinal direction." Both the diameter ratio and aspect ratio can be calculated using a scanning electron microscope and image processing software. In addition, the average fiber length (cut length) can be the value published by the manufacturer in their catalog, etc.

[0022] Examples of fibrous inorganic fillers include mineral fibers such as glass fibers, carbon fibers, zinc oxide fibers, titanium oxide fibers, wollastonite, silica fibers, silica-alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, and potassium titanate fibers, as well as metallic fibrous materials such as stainless steel fibers, aluminum fibers, titanium fibers, copper fibers, and brass fibers. The fibrous inorganic filler may also be hollow fibers for purposes such as reducing the specific gravity of the PAS resin composition. Furthermore, the fibrous inorganic filler may be surface-treated with a surface treatment agent. Examples of surface treatment agents include epoxy compounds, isocyanate compounds, silane compounds, titanate compounds, and fatty acids.

[0023] The shape of the fibrous inorganic filler may be circular, nearly circular, oblong, elliptical, semicircular, cocoon-shaped, rectangular, or any of these similar shapes in cross-section perpendicular to the longitudinal direction. Milled fibers, obtained by crushing fibrous inorganic fillers, can also be used. Note that "cocoon-shaped" refers to an oblong shape where the area near the center along the longitudinal direction is indented inward.

[0024] From the viewpoint of further enhancing the mechanical properties, the fibrous inorganic filler preferably has a cross-sectional area perpendicular to the longitudinal direction of 15 μm in its initial shape (shape before melting and kneading). ２ ~2000 μm ２ It may be within this range. "Cross-sectional area perpendicular to the longitudinal direction" means the area of ​​the surface perpendicular to the longitudinal direction of the fibrous inorganic filler. "Cross-sectional area" can be measured using a scanning electron microscope and image processing software. If the cross-sectional shape perpendicular to the longitudinal direction is circular, approximately circular, oblong, or elliptical, the longest straight-line distance of the cross-section of the fibrous inorganic filler measured using a scanning electron microscope and image processing software is taken as the major axis, and the shortest straight-line distance is taken as the minor axis. The value obtained by multiplying the value obtained by dividing the major axis by 2 by the value obtained by dividing the minor axis by 2, and then multiplying that by pi (π), can be used.

[0025] The average fiber length of the fibrous inorganic filler is not particularly limited, but from the viewpoint of the mechanical properties and moldability of the molded product, the average fiber length (cut length) in the initial shape may be in the range of 0.01 to 3 mm.

[0026] Examples of marketed glass fiber products include chopped glass fiber (ECS03T-790DE, average fiber diameter 6 μm) manufactured by Nippon Electric Glass Co., Ltd., chopped glass fiber (CS03DE416A, average fiber diameter 6 μm) manufactured by Owens Corning Japan, chopped glass fiber (ECS03T-747H, average fiber diameter 10.5 μm) manufactured by Nippon Electric Glass Co., Ltd., chopped glass fiber (ECS03T-747, average fiber diameter 13 μm) manufactured by Nippon Electric Glass Co., Ltd., irregular cross-section chopped strand (CSG3PA-830, major diameter 28 μm, minor diameter 7 μm) manufactured by Nitto Boseki Co., Ltd., and irregular cross-section chopped strand (CSG3PL-962, major diameter 20 μm, minor diameter 10 μm) manufactured by Nitto Boseki Co., Ltd. Plate-shaped inorganic fillers may be surface-treated in the same manner as fibrous inorganic fillers.

[0027] Examples of plate-shaped inorganic fillers include glass flakes, talc (plate-shaped), mica, kaolin, clay, alumina (plate-shaped), and various metal foils. The average particle size (volume-based cumulative 50% diameter D50) of the plate-shaped inorganic filler is preferably 10 μm to 1000 μm, and more preferably 30 μm to 800 μm, in its initial shape (shape before melting and kneading). The average particle size (volume-based cumulative 50% diameter D50) can be measured by laser diffraction scattering.

[0028] Examples of marketed glass flakes include REFG-108 (average particle size (50%d): 623 μm), Fine Flake (average particle size (50%d): 169 μm), REFG-301 (average particle size (50%d): 155 μm), and REFG-401 (average particle size (50%d): 310 μm), all manufactured by Nippon Sheet Glass Co., Ltd. Examples of marketed talc products include Crown Talc PP, manufactured by Matsumura Sangyo Co., Ltd., and Talc Powder PKNN, manufactured by Hayashi Kasei Co., Ltd.

[0029] Examples of granular or powdered inorganic fillers (hereinafter also referred to as "granular / powdered inorganic fillers") include talc (granular), carbon black, silica, quartz powder, glass beads, glass powder, silicates such as calcium silicate, aluminum silicate, and diatomaceous earth, metal oxides such as iron oxide, titanium oxide, zinc oxide, and alumina (granular), metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, and other materials such as silicon carbide, silicon nitride, boron nitride, and various metal powders. Granular / powdered inorganic fillers may be surface-treated in the same manner as fibrous inorganic fillers.

[0030] The average particle size (volume-based cumulative 50% diameter D50) of granular / powdered inorganic fillers may be in the range of 0.1 μm to 50 μm in their initial form (form before melting and kneading). The average particle size (volume-based cumulative 50% diameter D50) can be measured by laser diffraction scattering.

[0031] Examples of commercially available glass beads include EGB731A (average particle size (50%d): 20 μm) and EMB-10 (average particle size (50%d): 5 μm) manufactured by Potters Barotini Co., Ltd. Examples of commercially available calcium carbonate include Whiteon P-30 (average particle size (50%d): 5 μm) manufactured by Toyo Fine Chemical Co., Ltd.

[0032] Among fillers, fibrous inorganic fillers are preferred from the viewpoint of laser light transmittance, and glass fibers are more preferred. Fillers are optional components in PAS resin compositions, and the composition may not contain any fillers. If the PAS resin composition contains fibrous inorganic fillers, the inorganic filler content is preferably 40% by mass or less of the total mass of the PAS resin composition. Furthermore, it may be 30% by mass or less, or 25% by mass or less.

[0033] The PAS resin composition may contain a PAS resin, other thermoplastic resins, and other components other than fillers. Examples of other components include, for example, alkoxysilane compounds, lubricants, barium inhibitors, mold release agents, plasticizers, flame retardants, colorants such as dyes and pigments, crystallization accelerators, crystal nucleating agents, various antioxidants, heat stabilizers, weather resistance stabilizers, and corrosion inhibitors. These may be used individually or in combination of two or more. Further, the content of these other components is not particularly limited and is appropriately adjusted according to the use of the PAS resin, desired performance, etc. For example, for each component, it may be 5% by mass or less based on the total mass of the PAS resin composition.

[0034] The type of alkoxysilane compound is not particularly limited, and those used in the field of PAS resin compositions can be widely used without particular limitation. Examples of alkoxysilane compounds include epoxyalkoxysilane, aminoalkoxysilane, vinylalkoxysilane, mercaptoalkoxysilane, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 10, particularly preferably 1 to 4.

[0035] Specific examples of epoxyalkoxysilane include γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, etc.

[0036] Specific examples of aminoalkoxysilane include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-diallylaminopropyltrimethoxysilane, γ-diallylaminopropyltriethoxysilane, etc.

[0037] Specific examples of vinylalkoxysilane include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, etc.

[0038] Specific examples of the mercaptoalkoxysilane include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and the like.

[0039] Examples of the lubricant include polyethylene wax, fatty acid ester, fatty acid amide, and the like.

[0040] The method for producing the polyarylene sulfide resin composition is not particularly limited, and it can be obtained by mixing each raw material. In one method, the PAS resin and other optional components can be melt-kneaded to obtain the polyarylene sulfide resin composition. In the melt-kneading, each raw material may be charged all at once or dividedly. For example, the PAS resin and the alkoxysilane compound may be melt-kneaded, and then the fibrous inorganic filler may be added and melt-kneaded additionally. The polyarylene sulfide resin composition is not limited in its shape, such as pellet form, lump form, powder form, powdery form, etc.

[0041] As another example of the polyarylene sulfide resin composition, a mixture of each raw material may be used. The mixture of each raw material may be such that each raw material is in pellet form, lump form, powder form, powdery form, etc. In still another example, a mixture in which some of the raw materials are formed into a molded body such as pellet form may be used, or a mixture of two or more molded bodies such as pellet form having different compositions may be used. In any case, in the overall composition of the mixture, it is preferable to satisfy the conditions of the polyarylene sulfide resin composition described above.

[0042] According to one embodiment, a molded article can be provided using the laser-weldable polyarylene sulfide resin composition of the embodiment described above. As the polyarylene sulfide resin composition, the PAS resin composition described above can be used. Molding methods for forming the molded article include injection molding, extrusion molding, vacuum molding, and compression molding. Before molding the molded article, it is preferable to prepare a polyphenylene sulfide resin composition by melt-kneading PAS resin, an alkoxysilane compound, optionally a fibrous inorganic filler, and other components, and then molding it into pellets or the like. The PAS resin, which is the raw material for the polyphenylene sulfide resin composition, is preferably provided in pellet form, lump form, powder form, or the like, and then melt-kneaded with other raw materials to provide the polyphenylene sulfide resin composition.

[0043] According to one embodiment, a composite molded body can be provided in which a laser light transmitting material and a laser light absorbing material are laser-welded together, wherein the laser light transmitting material is a molded body made using the laser-weldable polyarylene sulfide resin composition of the embodiment described above. The molded body using the polyarylene sulfide resin composition is as described above. In this composite molded body, the laser light transmitting material is preferably formed using a PAS resin composition. The laser light absorbing material may also be formed using a PAS resin composition. When a PAS resin composition is used as the laser light absorbing material, it may further contain light absorbers, colorants, etc. The laser light absorbing material may also be formed using a resin other than a PAS resin composition. In such a composite molded body, because the light transmittance of the laser light transmitting material is high, when laser light is incident on the composite molded body from the laser light transmitting material side, a high-intensity laser reaches the interface between the laser light transmitting material and the laser light absorbing material, thereby increasing the welding strength of the resin. This effect can be obtained even if the molded body contains fillers.

[0044] The manufacturing method for a composite molded body involves overlapping a laser light transmitting material and a laser light absorbing material, irradiating them with laser light from the laser light transmitting material side, and focusing the laser light at the interface between the laser light transmitting material and the laser light absorbing material to weld the two components together.

[0045] The wavelength of the laser light used for laser welding is not particularly limited, but generally, laser light with a wavelength in the range of 800 to 1,200 nm is used. The laser light transmittance of the molded body is preferably 35% or more, as measured by a spectrophotometer under conditions such as an optical path length of 1.0 mm.

[0046] The laser light source used in laser welding is not particularly limited; any laser commonly used in the field of laser welding can be used without any restrictions. Specific examples include dye lasers, gas lasers (excimer lasers, argon lasers, krypton lasers, helium-neon lasers, etc.), solid-state lasers (YAG lasers, etc.), and semiconductor lasers. Pulsed lasers are typically used as the laser light source.

[0047] Such composite molded articles can be used in automotive molded products, electrical equipment components, electronic equipment components, chemical equipment components, and the like. In particular, because they offer excellent high strength and flame retardancy, and can achieve high bonding strength, it is useful to use the composite molded article of one embodiment in automotive molded products.

[0048] PAS resin compositions can be manufactured in the same way as general PAS resin compositions, for example, by melt kneading. Specifically, PAS resin and other optional components are blended and melt-kneaded using a single-screw or twin-screw extruder. When manufacturing molded articles using PAS resin compositions, any of the following methods may be used: preparing pellets by kneading and extruding with an extruder and using these pellets to manufacture the molded article; preparing pellets with different compositions and mixing a predetermined amount of these pellets to use in the manufacture of the molded article; or directly loading one or more of each component into a molding machine.

[0049] The molded article of one embodiment, since it uses the above-described PAS resin composition, has high laser light transmittance and can be suitably used as a laser light transmitting material for laser welding. However, the use of the molded article is not limited to this and can also be used for purposes other than as a laser light transmitting material. For example, a light absorber, a colorant, etc. may be added to the PAS resin composition and used as a laser light absorber.

[0050] The wavelength of the laser light used for laser welding is not particularly limited, but generally, laser light with a wavelength in the range of 800 to 1,200 nm is used. The laser light transmittance of the molded body is preferably 35% or more, as measured by a spectrophotometer under conditions such as an optical path length of 1.0 mm.

[0051] A composite molded article of one embodiment can be obtained using the molded article described above. The molded article may be used as a laser light transmitting material, or, as described above, a light absorber, a colorant, etc. may be added to the PAS resin composition and used as a laser light absorbing material.

[0052] The laser light source used in laser welding is not particularly limited; any laser commonly used in the field of laser welding can be used without any restrictions. Specific examples include dye lasers, gas lasers (excimer lasers, argon lasers, krypton lasers, helium-neon lasers, etc.), solid-state lasers (YAG lasers, etc.), and semiconductor lasers. Pulsed lasers are typically used as the laser light source.

[0053] The applications of the PAS resin composition, molded articles using the same, and composite molded articles are not particularly limited, but they can be widely used, for example, as molded articles for electrical and electronic equipment, in-vehicle molded articles, and chemical equipment.

[0054] Examples of embodiments are given below. The present invention is not limited to the following embodiments. <1> A laser-weldable polyarylene sulfide resin composition having a chlorine content of 3,000 ppm or less.

[0055] <2> The laser-weldable polyarylene sulfide resin composition according to <1>, wherein the content of fibrous inorganic filler is 40% by mass or less, or which does not contain fibrous inorganic filler.

[0056] <3> A molded article comprising the laser-weldable polyarylene sulfide resin composition described in <1> or <2> above.

[0057] <4> A composite body in which a laser light transmissive material and a laser light absorptive material are laser welded, wherein the laser light transmissive material is a molded body using the laser welding polyarylene sulfide resin composition described in <1> or <2>.

[0058] <5> The composite body described in <4>, which is a molded product for vehicle use.

[0059] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.

[0060] In this example, the chlorine content of the PAS resin and the PAS resin composition was measured by combustion ion chromatography under the following conditions. Ion chromatography analyzer: "ICS1600" manufactured by Thermo Fisher Scientific Combustion pretreatment device: "AQF-5000H" manufactured by Nitto Seiko Analytic Co., Ltd. Sample: 10 mg Heater: Inlet Temp / 900 °C, Outlet Temp / 1000 °C Absorbing solution: H ２ O ２ 900 ppm, internal standard PO ４ ３－ 25 ppm

[0061] [Production of PAS resin (1)] 5,700 g of N-methylpyrrolidone (hereinafter also referred to as "NMP") was charged into a 20 L autoclave and replaced with nitrogen gas. While stirring with a stirrer at a rotation speed of 250 rpm, the temperature was raised to 100 °C over about 1 hour. After reaching 100 °C, 1,170 g of a 74.7 wt% aqueous NaOH solution, 1,990 g of an aqueous sulfur source solution (containing 21.8 mol of NaSH and 0.50 mol of Na ２ S), and 1,000 g of NMP were added. The temperature was raised to 200 °C over about 2 hours, and 945 g of water, 1,590 g of NMP, and 0.31 mol of hydrogen sulfide were discharged out of the system.

[0062] The mixture was cooled to 170°C, and 3,427 g of p-dichlorobenzene (hereinafter also referred to as "p-DCB"), 2,800 g of NMP, 133 g of water, and 23 g of 97% by weight of NaOH were added, bringing the system temperature to 130°C. The mixture was then stirred with a stirrer at 250 rpm and heated to 180°C over 30 minutes. The temperature was further increased from 180°C to 220°C over 60 minutes. After reacting at 220°C for 60 minutes, the temperature was increased to 230°C over 30 minutes. The reaction was carried out at 230°C for 90 minutes to perform the preliminary polymerization.

[0063] Immediately after the completion of the first polymerization stage, the stirrer speed was increased to 400 rpm and 340 g of water was injected under pressure. After the injection of water, the temperature was raised to 260°C over 1 hour, and the reaction was carried out at 260°C for 5 hours to perform the second polymerization stage. After the completion of the second polymerization stage, the reaction mixture was cooled to near room temperature, and then the reaction mixture was passed through a 100-mesh screen to sieve off the granular polymer. The granular polymer was washed three times with acetone and three times with water, and then washed with 0.3% acetic acid. Further washing with water was performed four times, and the mixture was dried at 105°C for 13 hours to obtain granular PAS resin (1). The chlorine content of PAS resin (1) was 3,500 ppm.

[0064] [Production of PAS resin (2)] 5,700 g of NMP was placed in a 20 L autoclave and purged with nitrogen gas. The temperature was raised to 100°C over approximately 1 hour while stirring with a stirrer at 250 rpm. After reaching 100°C, 1,170 g of 74.7 wt% NaOH aqueous solution and 1,990 g of sulfur source aqueous solution (NaSH 21.8 mol and Na) were added. ２ (containing 0.50 moles of S) and 1,000 g of NMP were added. The temperature was raised to 200°C over approximately 2 hours, and 945 g of water, 1,590 g of NMP, and 0.31 moles of hydrogen sulfide were discharged from the system.

[0065] The mixture was cooled to 170°C, and 3,283 g of p-DCB, 2,800 g of NMP, 133 g of water, and 23 g of 97% by weight of NaOH were added, bringing the system temperature to 130°C. The mixture was then stirred at 250 rpm and heated to 180°C over 30 minutes. The temperature was further increased from 180°C to 220°C over 60 minutes. After reacting at 220°C for 60 minutes, the temperature was increased to 230°C over 30 minutes. The reaction was carried out at 230°C for 90 minutes to perform the preliminary polymerization.

[0066] Immediately after the completion of the first polymerization stage, the stirrer speed was increased to 400 rpm and 340 g of water was injected under pressure. After the injection of water, the temperature was raised to 260°C over 1 hour, and the reaction was carried out at 260°C for 5 hours to perform the second polymerization stage. After the completion of the second polymerization stage, the reaction mixture was cooled to near room temperature, and then the reaction mixture was sieved through a 100-mesh screen to separate the granular polymer. The granular polymer was washed three times with acetone and three times with water, and then washed with 0.3% acetic acid. Further washing with water was performed four times, and the mixture was dried at 105°C for 13 hours to obtain granular PAS resin (2). The chlorine content of PAS resin (2) was 1,000 ppm.

[0067] [Production of PAS resin (3)] 5,499 g of NMP was placed in a 20 L autoclave and purged with nitrogen gas. The temperature was raised to 100°C over approximately 1 hour while stirring with a stirrer at 250 rpm. After reaching 100°C, 1,071 g of 74.15 wt% NaOH aqueous solution and 1,803 g of sulfur source aqueous solution (NaSH 19.6 mol and Na) were added. ２ (containing 0.50 moles of S) and 1,000 g of NMP were added. The temperature was raised to 200°C over approximately 2 hours, and 851 g of water, 807 g of NMP, and 0.4 moles of hydrogen sulfide were discharged from the system.

[0068] The mixture was cooled to 170°C, and 2,977 g of p-DCB, 3,161 g of NMP, 160 g of water, and 7.9 g of 97% by weight of NaOH were added. The mixture was then heated while stirring with a stirrer at 250 rpm, and the reaction was carried out at 220°C for 4 hours to perform the preliminary polymerization.

[0069] Immediately after the completion of the first polymerization stage, the stirrer speed was increased to 400 rpm and 610 g of water was injected under pressure. After the water injection, the temperature was raised to 260°C. The reaction was carried out at 260°C for 3 hours, then polymerized at 255°C for 3 hours, cooled from 255°C to 245°C over 40 minutes, and the reaction was carried out at 245°C for 7.5 hours for the second polymerization stage. After the completion of the second polymerization stage, the reaction mixture was cooled to near room temperature, and then the reaction mixture was sieved through a 100-mesh screen to separate the granular polymer. The granular polymer was washed three times with acetone and three times with water, and then washed with 0.3% acetic acid. Further washing with water was performed four times, and the mixture was dried at 105°C for 13 hours to obtain granular PAS resin (3). The chlorine content of PAS resin (3) was 800 ppm.

[0070] [Production of PAS resin (4)] Branched PAS resin (4) was obtained by pre-polymerization and post-polymerization of monomers in the same manner as in Synthesis Example 3 described in International Publication No. 2006 / 068161. The chlorine content of PAS resin (4) was 6,500 ppm.

[0071] [Production of PAS resin (5)] 5,700 g of NMP was placed in a 20 L autoclave and purged with nitrogen gas. The temperature was raised to 100°C over approximately 1 hour while stirring with a stirrer at 250 rpm. After reaching 100°C, 1,170 g of 74.7 wt% NaOH aqueous solution and 1,990 g of sulfur source aqueous solution (NaSH 21.8 mol and Na) were added. ２ (containing 0.50 moles of S) and 1,000 g of NMP were added. The temperature was raised to 200°C over approximately 2 hours, and 945 g of water, 1,590 g of NMP, and 0.31 moles of hydrogen sulfide were discharged from the system.

[0072] The mixture was cooled to 170°C, and 3,524 g of p-DCB, 2,800 g of NMP, 133 g of water, and 23 g of 97% by weight of NaOH were added, bringing the system temperature to 130°C. The mixture was then stirred at 250 rpm and heated to 180°C over 30 minutes. The temperature was further increased from 180°C to 220°C over 60 minutes. After reacting at 220°C for 60 minutes, the temperature was increased to 230°C over 30 minutes. The reaction was carried out at 230°C for 90 minutes to perform the preliminary polymerization.

[0073] Immediately after the completion of the first polymerization stage, the stirrer speed was increased to 400 rpm and 340 g of water was injected under pressure. After the injection of water, the temperature was raised to 260°C over 1 hour, and the reaction was carried out at 260°C for 5 hours to perform the second polymerization stage. After the completion of the second polymerization stage, the reaction mixture was cooled to near room temperature, and then the reaction mixture was sieved through a 100-mesh screen to separate the granular polymer. The granular polymer was washed three times with acetone and three times with water, and then washed with 0.3% acetic acid. Further washing with water was performed four times, and the mixture was dried at 105°C for 13 hours to obtain granular PAS resin (5). The chlorine content of PAS resin (5) was 4,400 ppm.

[0074] [Examples 1-7 and Comparative Examples 1 and 2] Each component except the fibrous inorganic filler was dry-blended in the proportions shown in Table 1. This was then fed into a twin-screw extruder at a cylinder temperature of 320°C and melt-kneaded to obtain a pellet-shaped PAS resin composition. The fibrous inorganic filler was added separately from the side feed section of the extruder.

[0075] Details of each component listed in Table 1 are as follows: - PAS resin (1): PAS resin (1) obtained earlier - PAS resin (2): PAS resin (2) obtained earlier - PAS resin (3): PAS resin (3) obtained earlier - PAS resin (4): PAS resin (4) obtained earlier - PAS resin (5): PAS resin (5) obtained earlier - Alkoxysilane: γ-aminopropyltriethoxysilane, "KBE-903P" manufactured by Shin-Etsu Chemical Co., Ltd. - Lubricant: Pentaerythritol stearate, "Unistar H476" manufactured by NOF Corporation - Fibrous inorganic filler (1): Chopped strand "ECS 03T-747" manufactured by Nippon Electric Glass Co., Ltd. (fiber diameter 13 μm, length 3 mm) - Fibrous inorganic filler (2): Chopped strand "ECS 03T-747N" manufactured by Nippon Electric Glass Co., Ltd. (fiber diameter 17 μm, length 3 mm)

[0076] [Measurement of Chlorine Content of PAS Resin Composition] The chlorine content of the PAS resin composition was measured by combustion ion chromatography under the above conditions. The results are shown in Table 1.

[0077] [Manufacturing of Molded Body and Measurement of Laser Light Transmittance] Using the pelletized PAS resin composition obtained earlier, a molded body (80 mm long x 80 mm wide x 1.0 mm thick, with a film gate) was manufactured using an injection molding machine (manufactured by FANUC Corporation) with a cylinder temperature of 320°C and a mold temperature of 150°C. A laser beam with a wavelength of 980 nm was perpendicularly irradiated into the center of the molded body, and the laser light transmittance at a path length of 1.0 mm (in the thickness direction of the molded body) was measured using a spectrophotometer with an integrating sphere (JASCO Corporation "V-770"). The measured values ​​were evaluated according to the following criteria. The results are shown in Table 1. A: 40% or more B: 35% or more, less than 40% C: less than 35%

[0078]

[0079] The PAS resin compositions of Examples 1 to 7, which had a chlorine content of 3,000 ppm or less, exhibited high laser light transmittance. Such PAS resin compositions can be suitably used as laser light transmitting materials in laser welding. On the other hand, the PAS resin compositions of Comparative Examples 1 and 2, which had a chlorine content exceeding 3,000 ppm, exhibited lower laser light transmittance compared to the PAS resin compositions of the Examples.

[0080] Although the present invention has been described with reference to several embodiments described above, the present invention is not limited to these embodiments. Various modifications can be made to the structure and details of the present invention within the scope of the invention. This disclosure is related to the subject matter described in Japanese Patent Application No. 2024-228802, filed on 25 December 2024, all of which are incorporated herein by reference.

Claims

1. A laser-weldable polyarylene sulfide resin composition having a chlorine content of 3,000 ppm or less.

2. The laser-weldable polyarylene sulfide resin composition according to claim 1, wherein the content of fibrous inorganic filler is 40% by mass or less.

3. A molded article using the laser-weldable polyarylene sulfide resin composition according to claim 1 or 2.

4. A composite molded article comprising a laser light transmitting material and a laser light absorbing material, wherein the laser light transmitting material is a molded article using the laser-weldable polyarylene sulfide resin composition described in claim 1 or 2.

5. The composite molded article according to claim 4, which is a molded product for use in an automobile.

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