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

Abstract

A polyarylene sulfide resin composition for laser welding, said composition containing a polyarylene sulfide resin (A), an alkoxysilane compound (B), and a fibrous inorganic filler (C), wherein the carboxyl group content of the polyarylene sulfide resin (A) is in the range of 5-100 µmol / g, and 0.05-3 parts by mass of the alkoxysilane compound (B) is included per 100 parts by mass of the polyarylene sulfide resin (A).

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 resins, such as polyphenylene sulfide resin, are widely used in electrical and electronic equipment components, automotive parts, and chemical equipment components due to their excellent heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame retardancy. However, because polyarylene sulfide resins have a high refractive index, their laser light transmittance is lower compared to other resins. Furthermore, because there is a large difference in refractive index between polyarylene sulfide resins 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 comprising a polyarylene sulfide resin (A), an alkoxysilane compound (B), and a fibrous inorganic filler (C), wherein the carboxyl group content of the polyarylene sulfide resin (A) is in the range of 5 to 100 μmol / g, and the alkoxysilane compound (B) is contained in an amount of 0.05 to 3 parts by mass per 100 parts by mass of the polyarylene sulfide resin (A).

[0008] Another embodiment relates to a laser-weldable polyarylene sulfide resin composition comprising a polyarylene sulfide resin (D), an alkoxysilane compound (B), and a fibrous inorganic filler (C), wherein the polyarylene sulfide resin (D) contains a carboxyl group, and the area ratio of the polyarylene sulfide resin component with a molecular weight of 520,000 or more in the GPC measurement of the molten kneaded product is in the range of 0.5 to 12 area%.

[0009] This disclosure makes it possible to provide laser-weldable polyarylene sulfide resin compositions, molded articles, and composite molded articles with high laser light transmittance.

[0010] 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 (hereinafter also referred to as "PAS resin composition (1)") comprising a polyarylene sulfide resin (A) (hereinafter also referred to as "PAS resin (A)"), an alkoxysilane compound (B) and a fibrous inorganic filler (C), wherein the carboxyl group content of the PAS resin (A) is in the range of 5 to 100 μmol / g, and the alkoxysilane compound (B) is contained in an amount of 0.05 to 3 parts by mass per 100 parts by mass of the PAS resin (A).

[0011] PAS resin (A) is a resin whose main structure consists of repeating units represented by -(Ar-S)- (Ar represents an arylene group), similar to general PAS resins. PAS resin (A) may be used alone or in combination of two or more types. The specific structure of the arylene group contained in PAS resin (A) 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. PAS resin (A) may be a homopolymer in which the resin contains one type of arylene group, or it may be a copolymer in which the resin contains two or more types of arylene groups.

[0012] When the PAS resin (A) 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 (A) 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 the PAS resins (A), 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 (A) may be substantially linear with no branching or crosslinking structure, or may have 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, since the laser light transmittance is improved by using a PAS resin (A) having a specific carboxyl group content in combination with an alkoxysilane compound (B), the PAS resin is not limited to substantially linear, and a PAS resin having at least one of branching and crosslinking can also be suitably used.

[0014] PAS resin (A) contains a carboxyl group. A PAS resin containing a carboxyl group can be produced, for example, by washing a PAS resin made using monomers that can constitute the above-mentioned structural units with an acidic aqueous solution of appropriate acidity. In this case, examples of acids used as the acidic aqueous solution include inorganic acids such as hydrochloric acid, sulfuric acid, and ammonium chloride; saturated fatty acids such as acetic acid, formic acid, propionic acid, butyric acid, valeric acid, and caproic acid; unsaturated fatty acids such as acrylic acid, crotonic acid, and oleic acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, and salicylic acid; dicarboxylic acids such as oxalic acid, maleic acid, and fumaric acid; and methanesulfonic acid and p-toluenesulfonic acid. One type of acid may be used alone, or two or more types may be used in combination. Among these, hydrochloric acid, acetic acid, ammonium chloride, and combinations thereof are preferred. Furthermore, a washing step with an organic solvent such as acetone, water, etc. may be provided before and after washing with the acidic aqueous solution, if necessary.

[0015] Another method for producing PAS resin containing carboxyl groups is to polymerize a monomer having a carboxyl group as a monomer that can constitute the above-mentioned structural units. In this case as well, it is preferable to wash with an acidic aqueous solution of appropriate acidity after polymerization.

[0016] The carboxyl group content of PAS resin (A) is in the range of 5 to 100 μmol / g. When PAS resin composition (1) contains multiple PAS resins (A), the carboxyl group content in the mixture is in the range of 5 to 100 μmol / g. In this case, all of the PAS resins (A) may have carboxyl groups, or a combination of those with carboxyl groups and those without may be used. The carboxyl group content of PAS resin (A) may be 10 μmol / g or more, or 15 μmol / g or more. It may also be 80 μmol / g or less, or 60 μmol / g or less.

[0017] The carboxyl group content of PAS resin (A) was measured by the following method: (1) FT-IR measurement of benzoic acid was performed to determine the absorption peak of the C-H bond of the benzene ring at 3065 cm⁻¹. －１ Peak height (α0) and absorption peak of carboxyl group at 1704 cm⁻¹ －１ The peak height (β0) was measured, and the relative intensity of the absorption peak of the carboxyl group relative to one C-H bond of the benzene ring was calculated as (β0) / {(α0) / 5}. (2) The PAS resin was measured at 3065 cm in FT-IR. －１ and 1704cm －１ The material was press-molded to a thickness such that the transmittance was 70% or less, and the absorption peak of the C-H bond of the benzene ring was determined by FT-IR measurement at 3065 cm⁻¹. －１ Peak height (α1) and absorption peak of carboxyl group at 1704 cm⁻¹ －１ The peak height (β1) was measured. Based on the relative intensity of the absorption peak of the carboxyl group relative to one C-H bond of the benzene ring in benzoic acid, the ratio of carboxyl groups relative to one C-H bond of the benzene ring in PAS resin was calculated from the value of [(β1) / {(α1) / 4}] / [(β0) / {(α0) / 5}] × 100 [%]. (3) The amount of repeating units -(Ar-S)-(Ar is a benzene ring) contained in 1 g of PAS resin is 9.3 × 10 －３ Since the concentration is expressed in mol / g, the carboxyl content of the PAS resin was calculated by multiplying this value by the ratio of carboxyl groups to one C-H bond in the benzene ring of the PAS resin.

[0018] The cooling crystallization temperature (Tc) of PAS resin (A) is preferably 215°C or higher, more preferably 216°C or higher, even more preferably 220°C or higher, and particularly preferably 230°C or higher, in order to obtain a PAS resin composition (1) with even higher laser light transmittance. Furthermore, it is preferably 260°C or lower, more preferably 250°C or lower, and particularly preferably 240°C or lower. The cooling crystallization temperature (Tc) of PAS resin (A) is preferably in the range of 215 to 260°C. When two or more types of PAS resin (A) are used in combination, the cooling crystallization temperature (Tc) of the mixture is in the range of 215 to 260°C.

[0019] In this disclosure, the cooling crystallization temperature (Tc) of PAS resin (A) is a value measured by the following method: 5 mg of PAS resin (A) was weighed, and the temperature was raised to 340°C at a heating rate of 10°C / min using a PerkinElmer differential scanning calorimeter "DSC-8500". After holding at 340°C for 5 minutes, the temperature was cooled at a rate of 10°C / min, and the crystallization peak (exothermic peak) temperature was read from the obtained DSC chart, and this temperature was defined as the cooling crystallization temperature (Tc).

[0020] The melt viscosity of PAS resin (A) 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 (A) are used in combination, the melt viscosity of the mixture may be in the range of 80 to 250 Pa·s.

[0021] The molecular weight of PAS resin (A) is not particularly limited, but for example, the weight-average molecular weight (Mw) may be in the range of 1,000 to 100,000. Furthermore, when two or more types of PAS resin (A) are used in combination, the weight-average molecular weight (Mw) of the mixture may be in the range of 1,000 to 100,000.

[0022] In this disclosure, the weight-average molecular weight (Mw) of PAS resin (A) is a value measured by the following method. First, 1-chloronaphthalene is used as the solvent, and the PAS resin (A) to be measured is added and heated in a block bath at 230°C for 6 minutes to dissolve. If necessary, the solution 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. For 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.

[0023] In the PAS resin composition (1), the laser light transmittance is improved by using a PAS resin (A) having a specific carboxyl group content in combination with an alkoxysilane compound (B), so the melt viscosity and molecular weight of the PAS resin (A) are not relevant.

[0024] The PAS resin composition (1) may contain other thermoplastic resins other than PAS resin (A) depending on the desired application, performance, etc. One type of other thermoplastic resin may be used alone, or two or more types may be used in combination. 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, polyamideimide resin, polyetherimide resin, polyphenylene ether resin, polysulfone resin, polyethersulfone resin, polyetherketone resin, polyetheretherketone resin, liquid crystal resin, fluororesin, silicone resin, etc.

[0025] The proportion of PAS resin (A) to the total resin components in the PAS resin composition (1) 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 the PAS resin composition (1) refer to PAS resin (A) and other thermoplastic resins.

[0026] The type of alkoxysilane compound (B) is not particularly limited, and any compound used in the field of PAS resin compositions can be used without any particular limitations. One type of alkoxysilane compound (B) may be used alone, or two or more types may be used in combination. Examples of alkoxysilane compounds (B) include epoxyalkoxysilane, aminoalkoxysilane, vinylalkoxysilane, mercaptoalkoxysilane, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 10, and particularly preferably 1 to 4.

[0027] Specific examples of epoxyalkoxysilanes include γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and γ-glycidoxypropyltriethoxysilane.

[0028] Specific examples of aminoalkoxysilanes include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-diallylaminopropyltrimethoxysilane, and γ-diallylaminopropyltriethoxysilane.

[0029] Specific examples of vinylalkoxysilanes include vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(β-methoxyethoxy)silane.

[0030] Specific examples of mercaptoalkoxysilanes include γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

[0031] In the PAS resin composition (1), the content of alkoxysilane compound (B) is preferably 0.05 parts by mass or more, more preferably 0.08 parts by mass or more, and particularly preferably 0.1 parts by mass or more, per 100 parts by mass of PAS resin (A). Furthermore, it is preferably 3 parts by mass or less, more preferably 2.5 parts by mass or less, and particularly preferably 2 parts by mass or less. The content of alkoxysilane compound (B) is preferably in the range of 0.05 to 3 parts by mass per 100 parts by mass of PAS resin (A).

[0032] The type of fibrous inorganic filler (C) is not particularly limited, and any type used in the field of PAS resin compositions can be used without any particular limitation. One type of fibrous inorganic filler (C) may be used alone, or two or more types may be used in combination. In this disclosure, "fibrous" refers to a shape in which the diameter ratio is in the range of 1 to 4 in the initial shape (shape before melting and kneading), and the average fiber length (cut length) is 0.01 to 3 mm. The diameter ratio is defined as "the major axis of the cross section perpendicular to the longitudinal direction (the longest straight distance of the cross section) / the minor axis of the cross section (the longest straight distance in the direction perpendicular to the major axis)." The diameter 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.

[0033] Specific examples of fibrous inorganic fillers (C) 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 (C) 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.

[0034] The shape of the fibrous inorganic filler (C) may be any of circular, substantially circular, oval, elliptical, semicircular, comma-shaped, rectangular, or similar shapes in a cross-sectional shape perpendicular to the longitudinal direction. Also, milled fibers obtained by pulverizing the fibrous inorganic filler can be used. The "comma shape" is a shape in which the vicinity of the center in the longitudinal direction of the oval is recessed inward.

[0035] From the viewpoint of further enhancing the mechanical properties, the cross-sectional area perpendicular to the longitudinal direction of the fibrous inorganic filler (C) is preferably 15 μm ２ to 2000 μm ２ in the initial shape (the shape before melt-kneading). The "cross-sectional area perpendicular to the longitudinal direction" means the area of the surface perpendicular to the longitudinal direction of the fibrous inorganic filler (C). The "cross-sectional area" can be measured using a scanning electron microscope and image processing software. When the cross-sectional shape perpendicular to the longitudinal direction is circular, substantially circular, oval, or elliptical, the value obtained by multiplying the value obtained by dividing the longest straight-line distance of the cross-section of the fibrous inorganic filler (C) measured using a scanning electron microscope and image processing software by 2 as the major axis and the value obtained by dividing the shortest straight-line distance by 2 as the minor axis, and then multiplying by the value of the pi π can be used.

[0036] The average fiber length of the fibrous inorganic filler (C) is not particularly limited, but from the viewpoints of the mechanical properties of the molded body, molding processability, etc., the average fiber length (cut length) in the initial shape may be in the range of 0.01 to 3 mm.

[0037] When using the PAS resin composition as a laser light transmissive material, the fibrous inorganic filler (C) is preferably glass fiber. Examples of commercially available glass fibers 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., chopped strands with a modified cross-section (CSG3PA-830, major axis 28 μm, minor axis 7 μm) manufactured by Nitto Boseki Co., Ltd., chopped strands with a modified cross-section (CSG3PL-962, major axis 20 μm, minor axis 10 μm) manufactured by Nitto Boseki Co., Ltd., and the like.

[0038] In the PAS resin composition (1), the content of the fibrous inorganic filler (C) is not particularly limited and is appropriately adjusted according to the desired use, performance, etc. The content of the fibrous inorganic filler (C) in the PAS resin composition (1) may be, for example, 40% by mass or less, and may also be 35% by mass or less.

[0039] The PAS resin composition (1) may contain other fillers other than the fibrous inorganic filler (C) depending on the desired application, performance, etc. The other fillers may be used individually or in combination of two or more types. Examples of other fillers include organic fillers and non-fibrous inorganic fillers. Examples of non-fibrous inorganic fillers include plate-shaped inorganic fillers, granular inorganic fillers, and powdered inorganic fillers. In this disclosure, "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 in the initial shape (shape before melting and kneading). "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 in the initial shape (shape before melting and kneading). The ratio of diameter differences is as described above, and the aspect ratio is "the longest straight-line distance in the longitudinal direction / the minor axis of the cross section perpendicular to the longitudinal direction (the longest straight-line distance in the direction perpendicular to the longest straight-line distance in that cross section)." Both the ratio of diameter differences and the aspect ratio can be calculated using a scanning electron microscope and image processing software.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The proportion of fibrous inorganic filler (C) to the total amount of fillers in the PAS resin composition (1) may be 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass.

[0046] The PAS resin composition (1) may contain PAS resin (A), other thermoplastic resins, alkoxysilane compounds (B), fibrous inorganic fillers (C), and other components other than fillers. Examples of other components include lubricants, burr inhibitors, mold release agents, plasticizers, flame retardants, colorants such as dyes and pigments, crystallization accelerators, crystal nucleating agents, various antioxidants, heat stabilizers, weather stabilizers, and corrosion inhibitors. Each of these may be used individually or in combination of two or more. Furthermore, the content of these other components is not particularly limited and is adjusted as appropriate according to the application of the PAS resin composition (1), desired performance, etc., but for example, each component may be 5% by mass or less of the total mass of the PAS resin composition (1).

[0047] Examples of lubricants include polyethylene wax, fatty acid esters, and fatty acid amides.

[0048] The PAS resin composition (1) can be used for molded articles in the same manner as general PAS resin compositions. Specifically, it can be melt-kneaded and then pelletized, and used in the manufacture of molded articles. Melt-kneading can be carried out, for example, by blending PAS resin (A), alkoxysilane compound (B), fibrous inorganic filler (C), and other optional components using a single-screw or twin-screw extruder.

[0049] One embodiment of the present disclosure is a laser-weldable polyarylene sulfide resin composition comprising a polyarylene sulfide resin (D), an alkoxysilane compound (B), and a fibrous inorganic filler (C), wherein the polyarylene sulfide resin (D) contains a carboxyl group, and the area ratio of polyarylene sulfide resin components with a molecular weight of 520,000 or more in the GPC measurement of the molten compound is in the range of 0.5 to 12 area%. This is a laser-weldable polyarylene sulfide resin composition (hereinafter also referred to as "PAS resin composition (2)").

[0050] PAS resin (D), like general PAS resins, is a resin whose main structure consists of repeating units represented by -(Ar-S)-(Ar represents an arylene group). PAS resin (D) may be used alone or in combination of two or more types. Details of PAS resin (D) are the same as those of PAS resin (A) described above.

[0051] PAS resin (D) contains carboxyl groups. The carboxyl group content of PAS resin (D) is not particularly limited, and it is sufficient that the area ratio of PAS resin components with a molecular weight of 520,000 or more in the GPC measurement of the molten compound is in the range of 0.5 to 12 area%. In terms of ease of adjusting the area ratio of components with a molecular weight of 520,000 or more in the GPC measurement of the molten compound to this range, the carboxyl group content of PAS resin (D) may be 5 μmol / g or more, 10 μmol / g or more, or 15 μmol / g or more. It may also be 100 μmol / g or less, 80 μmol / g or less, or 60 μmol / g or less. The carboxyl group content of PAS resin (D) may be in the range of 5 to 100 μmol / g. The carboxyl group content of PAS resin (D) is a value measured by the same method as the carboxyl group content of PAS resin (A). Furthermore, if the PAS resin composition (2) contains multiple PAS resins (D), the carboxyl group content in the mixture may be in the range of 5 to 100 μmol / g. In this case, all of the PAS resins (D) may have carboxyl groups, or a combination of those with carboxyl groups and those without may be used.

[0052] The cooling crystallization temperature (Tc) of PAS resin (D) is not particularly limited, but in terms of obtaining a PAS resin composition with even higher laser light transmittance, it may be 215°C or higher, 216°C or higher, 220°C or higher, or 230°C or higher. It may also be 260°C or lower, 250°C or lower, or 240°C or lower. The cooling crystallization temperature (Tc) of PAS resin (D) may be in the range of 215 to 260°C. When two or more types of PAS resin (D) are used in combination, the cooling crystallization temperature (Tc) of the mixture may be in the range of 215 to 260°C. The cooling crystallization temperature (Tc) of PAS resin (D) is a value measured by the same method as the cooling crystallization temperature (Tc) of PAS resin (A).

[0053] The melt viscosity of PAS resin (D) 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 (D) are used in combination, the melt viscosity of the mixture may be in the range of 80 to 250 Pa·s.

[0054] The molecular weight of PAS resin (D) is not particularly limited, but for example, its weight-average molecular weight (Mw) may be in the range of 1,000 to 100,000. Furthermore, when two or more types of PAS resin (D) are used in combination, the weight-average molecular weight (Mw) of the mixture may be in the range of 1,000 to 100,000. The weight-average molecular weight (Mw) of PAS resin (D) is measured using the same method as that used for the weight-average molecular weight (Mw) of PAS resin (A).

[0055] PAS resin composition (2) may contain other thermoplastic resins other than PAS resin (D) depending on the desired application, performance, etc. One type of other thermoplastic resin may be used alone, or two or more types may be used in combination. Specific examples of other thermoplastic resins and their proportions are the same as those for PAS resin composition (1).

[0056] PAS resin composition (2) contains an alkoxysilane compound (B). Specific examples of the alkoxysilane compound (B) are the same as those in PAS resin composition (1). The content of the alkoxysilane compound (B) in PAS resin composition (2) is not particularly limited, and it is sufficient that the area ratio of PAS resin components with a molecular weight of 520,000 or more in the GPC measurement of the molten compound is in the range of 0.5 to 12 area%. In terms of ease of adjusting the area ratio of PAS resin components with a molecular weight of 520,000 or more in the GPC measurement of the molten compound to this range, the content of the alkoxysilane compound (B) per 100 parts by mass of PAS resin (D) may be 0.05 parts by mass or more, 0.08 parts by mass or more, or 0.1 parts by mass or more. It may also be 3 parts by mass or less, 2.5 parts by mass or less, or 2 parts by mass or less. The content of the alkoxysilane compound (B) may be in the range of 0.05 to 3 parts by mass per 100 parts by mass of the PAS resin (D).

[0057] PAS resin composition (2) contains a fibrous inorganic filler (C). Specific examples of the fibrous inorganic filler (C), their content, etc., are the same as those of PAS resin composition (1).

[0058] PAS resin composition (2) may contain other fillers besides fibrous inorganic filler (C) depending on the desired application, performance, etc. One type of other filler may be used alone, or two or more types may be used in combination. Specific examples of other fillers and their amounts are the same as those for PAS resin composition (1).

[0059] The PAS resin composition (2) may contain PAS resin (D), other thermoplastic resins, alkoxysilane compounds (B), fibrous inorganic fillers (C), and other components other than fillers. Examples of other components include lubricants, burr inhibitors, mold release agents, plasticizers, flame retardants, colorants such as dyes and pigments, crystallization accelerators, crystal nucleating agents, various antioxidants, heat stabilizers, weather stabilizers, and corrosion inhibitors. Each of these may be used individually or in combination of two or more. Furthermore, the content of these other components is not particularly limited and is adjusted as appropriate according to the application of the PAS resin composition (2), desired performance, etc., but for example, each component may be 5% by mass or less of the total mass of the PAS resin composition (2).

[0060] In PAS resin composition (2), the area ratio of PAS resin components with a molecular weight of 520,000 or more in the GPC measurement of the molten compound is in the range of 0.5 to 12 area %. Having the area ratio of PAS resin components with a molecular weight of 520,000 or more within this range in the GPC measurement of the molten compound results in a PAS resin composition with high laser light transmittance. The molecular weight of the molten compound is measured under the following conditions: First, PAS resin composition (2) is placed in a twin-screw extruder at a cylinder temperature of 320°C to obtain a molten compound. Next, 1-chloronaphthalene is used as the solvent, the molten compound 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 1-chloronaphthalene solution, which is used as the measurement sample. For example, the measuring device can be the "SSC-7000" manufactured by Senshu Kagaku Co., Ltd. (now Kitahama Seisakusho Co., Ltd.) and a UV detector (detection wavelength: 360 nm).

[0061] The melt-kneading of PAS resin composition (2) can be carried out in the same manner as for general PAS resin compositions. Specifically, PAS resin (D), alkoxysilane compound (B), fibrous inorganic filler (C), and other optional components are blended and melt-kneaded using a single-screw or twin-screw extruder. Furthermore, when manufacturing a molded article using PAS resin composition (2), 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.

[0062] The method for producing PAS resin compositions (1) and (2) is not particularly limited and can be obtained by mixing each raw material. In one method, PAS resin compositions (1) and (2) can be obtained by melt-kneading at least one of PAS resin (A) and PAS resin (D), an alkoxysilane compound (B), a fibrous inorganic filler (C), and other optional components. In melt-kneading, each raw material may be added all at once or in separate portions. For example, at least one of PAS resin (A) and PAS resin (D) may be melt-kneaded with an alkoxysilane compound (B), and then the fibrous inorganic filler (C) may be added and further melt-kneaded. The shape of PAS resin compositions (1) and (2) is not limited and can be pelletized, lumpy, powdered, or otherwise.

[0063] Other examples of PAS resin compositions (1) and (2) include mixtures of each raw material. In a mixture of each raw material, each raw material may be in the form of pellets, lumps, powders, etc. In yet another example, the mixture may be in which some of the raw materials have been molded into pellets or other molded products, or it may be a mixture of two or more pellets or other molded products with different compositions. In any case, it is preferable that the overall composition of the mixture satisfies at least one of the conditions of PAS resin composition (1) and PAS resin composition (2).

[0064] According to one embodiment, a molded article using the laser-weldable polyarylene sulfide resin composition of the embodiment described above can be provided. As the polyarylene sulfide resin composition, the PAS resin composition (1), PAS resin composition (2), or a combination thereof described above can be used. Examples of 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 at least one of PAS resin (A) and PAS resin (D), an alkoxysilane compound (B), a fibrous inorganic filler (C), and optionally other components, and molding it into a pellet or the like. It is preferable that at least one of PAS resin (A) and PAS resin (D), which are raw materials for the polyphenylene sulfide resin composition, be provided in pellet form, lump form, powder form, etc., and then melt-kneaded with other raw materials to provide the polyphenylene sulfide resin composition.

[0065] According to one embodiment, a composite molded article 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 article made using the laser-weldable polyarylene sulfide resin composition of the embodiment described above. The molded article using the polyarylene sulfide resin composition is as described above. In this composite molded article, the laser light transmitting material is preferably formed using at least one of PAS resin composition (1) and PAS resin composition (2). The laser light absorbing material may also be formed using at least one of PAS resin composition (1) and PAS resin composition (2). When at least one of PAS resin composition (1) and PAS resin composition (2) is used as the laser light absorbing material, it may further contain a light absorber, a colorant, etc. The laser light absorbing material may also be formed using a resin other than PAS resin composition (1) and PAS resin composition (2). Because such composite molded articles have high light transmittance of the laser light transmitting material, even when they contain fillers, when laser light is incident on the laser light transmitting material side of the composite molded article, high-intensity laser light can reach the interface between the laser light transmitting material and the laser light absorbing material, thereby increasing the welding strength of the resin.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] The molded article of one embodiment uses at least one of the above-described PAS resin compositions (1) and (2), and therefore has high laser light transmittance, making it suitable for use as a laser light transmitting material for laser welding. However, the use of the molded article is not limited to this, and it can also be used for purposes other than as a laser light transmitting material. For example, a mixture of at least one of the PAS resin compositions (1) and (2) with a light absorber, a colorant, etc., may be used as a laser light absorber.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] The applications of the PAS resin compositions (1) and (2), molded articles using them, 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.

[0075] Examples of embodiments are given below. The present invention is not limited to the following embodiments. <1> A laser-weldable polyarylene sulfide resin composition comprising a polyarylene sulfide resin (A), an alkoxysilane compound (B), and a fibrous inorganic filler (C), wherein the carboxyl group content of the polyarylene sulfide resin (A) is in the range of 5 to 100 μmol / g, and the alkoxysilane compound (B) is contained in an amount of 0.05 to 3 parts by mass per 100 parts by mass of the polyarylene sulfide resin (A).

[0076] <2> The laser-weldable polyarylene sulfide resin composition according to <1>, wherein the cooling crystallization temperature (Tc) of the polyarylene sulfide resin (A) is in the range of 215 to 260°C.

[0077] <3> A laser-weldable polyarylene sulfide resin composition comprising a polyarylene sulfide resin (D), an alkoxysilane compound (B), and a fibrous inorganic filler (C), wherein the polyarylene sulfide resin (D) contains a carboxyl group, and the area ratio of the polyarylene sulfide resin component with a molecular weight of 520,000 or more in the GPC measurement of the molten compound is in the range of 0.5 to 12 area%.

[0078] <4> A laser-weldable polyarylene sulfide resin composition according to any one of <1> to <3> above, wherein the content of fibrous inorganic filler (C) is 40% by mass or less, or which does not contain fibrous inorganic filler.

[0079] <5> A molded article using the laser-weldable polyarylene sulfide resin composition described in any one of <1> to <3> above.

[0080] <6> A composite molded article 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 article using the laser-weldable polyarylene sulfide resin composition described in any one of <1> to <3> above.

[0081] <7> A composite molded article as described in <6> above, which is a molded product for use in an automobile.

[0082] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0083] In this embodiment, the carboxyl group content of the PAS resin was measured by the following method: (1) FT-IR measurement of benzoic acid was performed at 3065 cm⁻¹, which is the absorption peak of the C-H bond of the benzene ring. －１ Peak height (α0) and absorption peak of carboxyl group at 1704 cm⁻¹ －１ The peak height (β0) was measured, and the relative intensity of the absorption peak of the carboxyl group relative to one C-H bond of the benzene ring was calculated as (β0) / {(α0) / 5}. (2) The PAS resin was measured at 3065 cm in FT-IR. －１and 1704cm －１ The material was press-molded to a thickness such that the transmittance was 70% or less, and the absorption peak of the C-H bond of the benzene ring was determined by FT-IR measurement at 3065 cm⁻¹. －１ Peak height (α1) and absorption peak of carboxyl group at 1704 cm⁻¹ －１ The peak height (β1) was measured. Based on the relative intensity of the absorption peak of the carboxyl group relative to one C-H bond of the benzene ring in benzoic acid, the ratio of carboxyl groups relative to one C-H bond of the benzene ring in PAS resin was calculated from the value of [(β1) / {(α1) / 4}] / [(β0) / {(α0) / 5}] × 100 [%]. (3) The amount of repeating units -(Ar-S)-(Ar is a benzene ring) contained in 1 g of PAS resin is 9.3 × 10 －３ Since the concentration is expressed in mol / g, the carboxyl content of the PAS resin was calculated by multiplying this value by the ratio of carboxyl groups to one C-H bond in the benzene ring of the PAS resin.

[0084] In this embodiment, the cooling crystallization temperature (Tc) of the PAS resin was measured by the following method. 5 mg of PAS resin was weighed and heated to 340°C at a heating rate of 10°C / min using a PerkinElmer differential scanning calorimeter "DSC-8500". After holding at 340°C for 5 minutes, the temperature was cooled at a rate of 10°C / min. The crystallization peak (exothermic peak) temperature was read from the resulting DSC chart and was defined as the cooling crystallization temperature (Tc).

[0085] [Production of PAS resin (I)] 5,700 g of N-methylpyrrolidone (hereinafter also referred to as "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.

[0086] 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.

[0087] 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 (I). The carboxyl group content of PAS resin (I) was 37 μmol / g, and the cooling crystallization temperature (Tc) was 219°C.

[0088] [Production of PAS resin (II)] 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.

[0089] 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.

[0090] 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 (II). The carboxyl group content of PAS resin (II) was 49 μmol / g, and the cooling crystallization temperature (Tc) was 216°C.

[0091] [Examples 1-8 and Comparative Example 1] Each component except the fibrous inorganic filler was dry-blended in the proportions shown in Table 1. This was 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 re-feed section of the extruder.

[0092] Details of each component listed in Table 1 are as follows: • PAS resin (I): PAS resin (I) obtained previously • PAS resin (II): PAS resin (II) obtained previously • Alkoxysilane: γ-aminopropyltriethoxysilane, "KBE-903P" manufactured by Shin-Etsu Chemical Co., Ltd. • Lubricant: Pentaerythritol stearate, "Unistar H476" manufactured by NOF Corporation • Fibrous inorganic filler: Chopped strand "ECS 03T-747N" manufactured by Nippon Electric Glass Co., Ltd. (fiber diameter 17 μm, length 3 mm)

[0093] [GPC Measurement of Molten Mixture] The pelletized PAS resin composition obtained earlier was added to 1-chloronaphthalene and heated in a block bath at 230°C for 6 minutes to dissolve. The solution was purified by high-temperature filtration to prepare a 0.075% by mass 1-chloronaphthalene solution, which was used as the measurement sample. The area ratio of components with a molecular weight of 520,000 or more was calculated from the chart obtained using the "SSC-7000" and UV detector (detection wavelength: 360 nm) manufactured by Senshu Kagaku Co., Ltd. (now Kitahama Seisakusho Co., Ltd.).

[0094] [Manufacturing of Molded Articles and Measurement of Laser Light Transmittance] Using the pelletized PAS resin composition obtained earlier, a molded article (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 shone perpendicularly onto the center of the molded article, and the laser light transmittance at a path length of 1.0 mm (in the thickness direction of the molded article) was measured using a spectrophotometer with an integrating sphere (JASCO Corporation "V-770"). The results are shown in Table 1.

[0095]

[0096] The PAS resin composition of the example, which contained a PAS resin with a carboxyl group content in the range of 5 to 100 μmol / g and an alkoxysilane compound (B), exhibited high laser light transmittance. Such a PAS resin composition can be suitably used as a laser light transmitting material in laser welding. On the other hand, the PAS resin composition of Comparative Example 1, which did not contain the alkoxysilane compound (B), exhibited lower laser light transmittance compared to the PAS resin composition of the example.

[0097] 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. 2024-228812, filed on 25 December 2024, all of which are incorporated herein by reference.

Claims

1. A laser-weldable polyarylene sulfide resin composition comprising a polyarylene sulfide resin (A), an alkoxysilane compound (B), and a fibrous inorganic filler (C), wherein the carboxyl group content of the polyarylene sulfide resin (A) is in the range of 5 to 100 μmol / g, and the alkoxysilane compound (B) is contained in an amount of 0.05 to 3 parts by mass per 100 parts by mass of the polyarylene sulfide resin (A).

2. The laser-weldable polyarylene sulfide resin composition according to claim 1, wherein the cooling crystallization temperature (Tc) of the polyarylene sulfide resin (A) is in the range of 215 to 260°C.

3. A laser-weldable polyarylene sulfide resin composition comprising a polyarylene sulfide resin (D), an alkoxysilane compound (B), and a fibrous inorganic filler (C), wherein the polyarylene sulfide resin (D) contains a carboxyl group, and the area ratio of the polyarylene sulfide resin component with a molecular weight of 520,000 or more in the GPC measurement of the molten compound is in the range of 0.5 to 12 area%.

4. A laser-weldable polyarylene sulfide resin composition according to any one of claims 1 to 3, wherein the content of fibrous inorganic filler (C) is 40% by mass or less.

5. A molded article using the laser-weldable polyarylene sulfide resin composition according to any one of claims 1 to 3.

6. 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 any one of claims 1 to 3.

7. The composite molded article according to claim 6, which is a molded product for use in an automobile.

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