Laser-welded body, and method for manufacturing a laser-welded body.

Abstract

The present invention provides a laser-welded body having a three-dimensional cavity as a component, which is sufficiently laser-welded even with a small applied pressure, and a method for manufacturing a laser-welded body. [Solution] The laser welded body according to the present disclosure is a laser welded body having a transparent resin member and an absorbing resin member, wherein the absorbing resin member is a three-dimensional body having a cavity formed from an absorbing resin composition containing a thermoplastic polyester resin, an amorphous resin, and a dye that absorbs laser light.

Description

Technical Field

[0001] The present invention relates to a laser welded body and a method for manufacturing a laser welded body. In particular, it relates to a laser welded body of a member having a cavity formed from a thermoplastic polyester resin.

Background Art

[0002] Thermoplastic polyester resins such as polybutylene terephthalate resin are excellent in mechanical strength, chemical resistance, electrical insulation properties, etc., and also have excellent heat resistance, moldability, and recyclability, so they are widely used in various equipment parts.

[0003] Recently, the example of performing welding processing for productivity improvement has been increasing, and among them, laser welding that has little influence on electronic components has been frequently used. Laser welding is a technique in which a transmissive resin member made of a laser transmissive material and an absorptive resin member made of a laser light absorptive material are overlapped, laser light is irradiated from the side of the transmissive resin member, and heat is generated at the interface with the absorptive resin member to perform welding. Regarding the method for manufacturing a laser welded body, for example, it is described in Patent Document 1 and Patent Document 2.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] When laser welding, in order to laser-weld a transmissive resin member and an absorptive resin member, it is necessary for the members to be in close contact with each other. This is because heat can be generated at the interface between the members due to their close contact, enabling welding. Here, thermoplastic polyester resins typified by polybutylene terephthalate resin are known to be prone to warping. Therefore, when laser-welding a transmissive resin member and an absorptive resin member made of a thermoplastic polyester resin, it is common to apply pressure to both members to bring them into close contact. However, if the applied pressure is too high, large stresses will occur within the members, making it easy to damage the resulting laser-welded body. Therefore, it is desirable to minimize the applied pressure as much as possible. On the other hand, it has been found that the close contact between a transmissive resin member and an absorptive resin member made of a thermoplastic polyester resin also varies greatly depending on the shape of the members. That is, when both the transmissive resin member and the absorptive resin member are thin and flat, even if there is warping, it is easy to reduce the applied pressure for correcting the warping. However, when one of them is a three-dimensional shape with a cavity such as a box shape or a cylindrical shape, the balance of force equilibrium is poor, and strong warping is likely to occur. Also, depending on the application, a member with a greater thickness may be required, but a member with a greater thickness tends to have even stronger warping. Therefore, in order to achieve sufficient laser welding, it is necessary to increase the applied pressure. An object of the present invention is to solve the above problems, and to provide a laser-welded body having a three-dimensional shape with a cavity as a member, which can be sufficiently laser-welded even with a small applied pressure, and a method for manufacturing the laser-welded body.

Means for Solving the Problems

[0006] As a result of the inventor's examination under the above problems, the above problems have been solved by the following means. [1] A laser-welded body having a transmissive resin member and an absorptive resin member, where the absorptive resin member is a three-dimensional shape with a cavity formed from an absorptive resin composition containing a thermoplastic polyester resin, an amorphous resin, and a dye that absorbs laser light. Laser-welded body. [2] The laser welded body according to [1], wherein the thermoplastic polyester resin contained in the absorbent resin composition comprises a polybutylene terephthalate resin. [3] The laser welded body according to [1] or [2], wherein the amorphous resin contained in the absorbent resin composition contains a styrene-based resin. [4] The laser welded body according to any one of [1] to [3], wherein the dye that absorbs the laser light contains carbon black. [5] The laser welded body according to any one of [1] to [4], wherein the transparent resin member is formed from a transparent resin composition containing a thermoplastic polyester resin and a dye that transmits laser light. [6] The laser welded body according to [5], wherein the permeable resin composition comprises an amorphous resin. [7] The laser welded body according to any one of [1] to [6], wherein the transparent resin member is a flat plate-shaped member. [8] The thermoplastic polyester resin contained in the absorbent resin composition includes a polybutylene terephthalate resin, The amorphous resin contained in the absorbent resin composition includes a styrene-based resin, The dye that absorbs the laser light contains carbon black, The aforementioned transparent resin member is a member formed from a transparent resin composition containing a thermoplastic polyester resin and a dye that transmits laser light. The permeable resin composition comprises an amorphous resin, The laser-welded body according to any one of [1] to [7], wherein the transparent resin member is a flat plate-shaped member. [9] This includes laser welding between a transparent resin member and an absorbent resin member while applying a force of 2.7 N / mm or less per unit distance, The absorbent resin member is a three-dimensional structure having a cavity, formed from an absorbent resin composition containing a thermoplastic polyester resin, an amorphous resin, and a dye that absorbs laser light. A method for manufacturing laser-welded bodies.

[10] The method for producing a laser welded body according to [9], wherein the permeable resin composition is the permeable resin composition according to any one of [1] to [8]. [Effects of the Invention]

[0007] The present invention provides a laser-welded body having a three-dimensional cavity as a component, which is sufficiently laser-welded even with a small applied pressure, and a method for manufacturing a laser-welded body. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram (1) showing the shape of the box (absorbent resin member) used in the example. [Figure 2] This is a schematic diagram (2) showing the shape of the box (absorbent resin component) used in the example. [Figure 3] This is a schematic diagram (3) showing the shape of the box (absorbent resin component) used in the example. [Figure 4] This is a schematic diagram (1) showing the shape of the permeable cover (permeable resin member) used in the embodiment. [Figure 5] This is a schematic diagram (2) showing the shape of the permeable cover (permeable resin member) used in the example. [Figure 6] This is a schematic diagram showing the method for measuring the welding strength used in the example, where (a) shows the state before laser welding and (b) shows the state after laser welding. [Modes for carrying out the invention]

[0009] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). Note that the following embodiment is illustrative for explaining the present invention, and the present invention is not limited to this embodiment. In this specification, "~" is used to mean that the numbers before and after it are included as the lower and upper limits, respectively. In this specification, all physical properties and characteristic values ​​shall be those at 23°C unless otherwise specified. In this specification, unless otherwise specified, the weight-average molecular weight is the polystyrene equivalent value measured by GPC (gel permeation chromatography) using a Tosoh HLC-8320GPC EcoSEC, tetrahydrofuran as the solvent, Shodex KF-G, KF-805L×3, and KF-800D columns, at a column temperature of 40°C and a flow rate of 1.2 mL / min, detected at a detection wavelength of 254 nm. If the measurement methods, etc., described in the standards shown in this specification differ from year to year, unless otherwise specified, the standards as of January 1, 2024 shall apply. If the measurement methods, etc., described in the standards shown in this specification have been discontinued as of January 1, 2024, the standards in effect at the time of discontinuation shall apply. Figures 1-6 may not be consistent with the actual scale.

[0010] The laser-welded body of this embodiment is a laser-welded body having a transparent resin member and an absorbing resin member, wherein the absorbing resin member is a three-dimensional structure having a cavity formed from an absorbing resin composition containing a thermoplastic polyester resin, an amorphous resin, and a dye that absorbs laser light. With this configuration, a laser-welded body can be made that is a three-dimensional structure having a cavity and is sufficiently laser-welded even with a small applied pressure. As mentioned above, resin components formed from thermoplastic polyester resins tend to warp. This tendency is particularly pronounced in three-dimensional resin components with cavities. This is because three-dimensional components with cavities have poorer overall balance compared to flat components, making them inherently more prone to warping. Furthermore, three-dimensional components with cavities are relatively difficult to make into thin-walled components, further increasing their susceptibility to warping. In this embodiment, an amorphous resin is blended into the resin member formed from a thermoplastic polyester resin that has a three-dimensional cavity. This is because the blending of the amorphous resin makes it easier to suppress warping. Furthermore, in this embodiment, the absorbent resin member is made of a thermoplastic polyester resin that has a three-dimensional cavity. By adopting this configuration, the shape of the permeable resin member can be made relatively thinner than that of the absorbent resin member, and it is presumed that laser welding will be easier.

[0011] The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is merely one example of an embodiment of the present invention and is not limited to these.

[0012] In this embodiment, the absorbent resin member is a three-dimensional object having a cavity. The cavity in the three-dimensional object having a cavity may be a cavity with an opening or a closed cavity. Examples of three-dimensional objects having a cavity include box-shaped and cylindrical shapes. Examples of three-dimensional objects having a cavity with an opening include the box used in the embodiment described later, a box-shaped object with one side open, and a cup. An example of a box-shaped object with one side open is the member indicated by reference numeral 1 in Figure 1 of International Publication No. 2019 / 088058, and the details of this specification are incorporated herein by reference. An example of a cup is the member indicated by reference numeral 1 in Figure 1 of Japanese Patent Application Publication No. 2019-081365, and the details of this specification are incorporated herein by reference. On the other hand, an example of a closed cavity is a closed space that is isolated from the outside. Such a three-dimensional object having a closed cavity may be a laser-welded body. Absorbing resin components are typically shaped to have at least surface contact points (flat or curved surfaces) because they are joined together by laser welding. In laser welding, laser light that passes through the transparent resin component is absorbed by the absorbing resin component, causing it to melt and the two components to be welded together.

[0013] In this embodiment, the absorbent resin member is preferably an injection-molded product having a cavity. The absorbent resin component has a thickness of, for example, 0.2 mm or more at its thinnest point, more specifically, 0.5 mm or more, and also, for example, 10 mm or less, and more specifically, 5 mm or less. The absorbent resin member has a thickness of, for example, 1.0 mm or more at its thickest point, more specifically, 1.5 mm or more, and also, for example, 50 mm or less, and more specifically, 30 mm or less. The absorbent resin member has a difference between the thickness of its thinnest part and the thickness of its thickest part that is, for example, 0.1 mm or more, more specifically 0.2 mm or more, and also, for example, 49.8 mm or less, and more specifically 30 mm or less.

[0014] The absorbent resin member in this embodiment is formed from an absorbent resin composition containing a thermoplastic polyester resin, an amorphous resin, and a dye that absorbs laser light. The absorbent resin composition will be described below.

[0015] <Thermoplastic polyester resin> The absorbent resin composition in this embodiment includes a thermoplastic polyester resin. Thermoplastic polyester resins are polyesters obtained by polycondensation of dicarboxylic acid compounds and dihydroxy compounds, polycondensation of oxycarboxylic acid compounds, or polycondensation of these compounds, and may be either homopolyesters or copolyesters. The thermoplastic polyester resin used in this embodiment is preferably a polyalkylene terephthalate resin, more preferably a polyethylene terephthalate resin and / or a polybutylene terephthalate resin, and even more preferably a polybutylene terephthalate resin. The thermoplastic polyester resin used in this embodiment is a crystalline resin.

[0016] As the dicarboxylic acid compound constituting the thermoplastic polyester resin, aromatic dicarboxylic acids or their ester-forming derivatives are preferably used. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenylisopropylidene-4,4'-dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, anthracene-2,5-dicarboxylic acid, anthracene-2,6-dicarboxylic acid, p-tert-phenylene-4,4'-dicarboxylic acid, pyridine-2,5-dicarboxylic acid, etc., with terephthalic acid being preferred.

[0017] These aromatic dicarboxylic acids may be used in combination of two or more types. As is well known, they can be used in polycondensation reactions not only as free acids but also as ester-forming derivatives such as dimethyl esters. Furthermore, in small amounts, these aromatic dicarboxylic acids can be used in combination with one or more aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedionic acid, and sebacic acid, or alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.

[0018] Examples of dihydroxy compounds constituting thermoplastic polyester resins include aliphatic diols such as ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, and triethylene glycol, as well as alicyclic diols such as cyclohexane-1,4-dimethanol, and mixtures thereof. In small amounts, one or more long-chain diols with molecular weights of 400 to 6,000, such as polyethylene glycol, poly-1,3-propylene glycol, and polytetramethylene glycol, may be copolymerized. In addition, aromatic diols such as hydroquinone, resorcinol, naphthalenediol, dihydroxydiphenyl ether, and 2,2-bis(4-hydroxyphenyl)propane can also be used.

[0019] In addition to the difunctional monomers mentioned above, small amounts of trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane can also be used to introduce branched structures, as well as monofunctional compounds such as fatty acids to adjust molecular weight. The thermoplastic polyester resin typically consists mainly of a polycondensation of a dicarboxylic acid and a diol; that is, 50% by mass, preferably 70% by mass or more, of the total thermoplastic polyester resin consists of this polycondensate. Aromatic carboxylic acids are preferred as the dicarboxylic acid, and aliphatic diols are preferred as the diol.

[0020] Of these, polyalkylene terephthalate resins are preferred, in which 95 mol% or more of the acid component is terephthalic acid and 95% by mass or more of the alcohol component is an aliphatic diol. Typical examples include polybutylene terephthalate resin and polyethylene terephthalate resin, with polybutylene terephthalate resin being preferred. These are preferably close to homopolyesters, that is, in which 95% by mass or more of the total resin consists of the terephthalic acid component and the 1,4-butanediol or ethylene glycol component.

[0021] Thermoplastic polyester resins are also preferably copolymerized with isophthalic acid, dimer acid, polyalkylene glycols such as polytetramethylene glycol (PTMG), and more preferably copolymerized with isophthalic acid. Examples of these copolymers include those with a copolymerization amount of 1 mol% or more and less than 50 mol% of the total segments of polyalkylene terephthalate, preferably less than 40 mol%, more preferably less than 30 mol%, and may be less than 20 mol%.

[0022] The thermoplastic polyester resin used in this embodiment may include recycled materials. Examples of recycled thermoplastic polyester resins include those obtained through material recycling, which involves crushing and washing used thermoplastic polyester resin molded products such as leftover or unsuitable molded parts, and those obtained through chemical recycling (chemical decomposition).

[0023] An example of a blend form of the thermoplastic polyester resin in this embodiment is that it contains at least polybutylene terephthalate resin. The mass ratio of polybutylene terephthalate resin in this blend form is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 52% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and may also be 95% by mass or more, based on 100% by mass of the thermoplastic polyester resin. Setting it above the lower limit tends to result in a higher load deflection temperature of the resulting member and improved moldability of the resin composition. In the first embodiment, the mass ratio of polybutylene terephthalate resin may be 100% by mass of 100% by mass of the thermoplastic polyester resin contained in the resin composition, or, depending on the application, it may be 90% by mass or less, 70% by mass or less, or 60% by mass or less.

[0024] The polybutylene terephthalate resin used in this embodiment may be a homopolymer of polybutylene terephthalate, or a copolymer of a portion with isophthalic acid, dimer acid, polytetramethylene glycol (PTMG), or other polyalkylene glycols. Preferably, 1 to 30 mol% (preferably 5 to 25 mol%) of the terephthalic acid component in the polybutylene terephthalate resin may be isophthalic acid modified. Using such an isophthalic acid modified polybutylene terephthalate resin tends to improve toughness, fluidity, tracking resistance, and laser welding strength.

[0025] In the above blend configuration, polyethylene terephthalate resin is preferred as the resin other than polybutylene terephthalate resin. In the above blend form, it is particularly preferable that the blend contains 30% by mass or more (preferably 50% by mass or more) of polybutylene terephthalate resin in 100% by mass of thermoplastic polyester resin, and that the total of polybutylene terephthalate resin and polyethylene terephthalate resin (the content of polyethylene terephthalate resin may be 0% by mass) accounts for 90% by mass or more (preferably 95% by mass or more) of 100% by mass of thermoplastic polyester resin. By incorporating polyethylene terephthalate resin, the warping of the resulting member tends to be suppressed more effectively.

[0026] The concentration of terminal carboxyl groups in the thermoplastic polyester resin is preferably 1 eq / ton or more, more preferably 7 eq / ton or more, preferably 23 eq / ton or less, and more preferably 22 eq / ton or less. By setting the concentration within this range, the fluidity of the absorbent resin composition tends to improve. In this embodiment, if the absorbent resin composition contains two or more thermoplastic polyester resins, the concentration of terminal carboxyl groups of the thermoplastic polyester resins shall be the same as the concentration of terminal carboxyl groups of the mixture. The amount of terminal carboxyl groups can be determined by dissolving 0.5 g of thermoplastic polyester resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide.

[0027] The thermoplastic polyester resin used in this embodiment preferably has an intrinsic viscosity of 0.40 dL / g or higher, and more preferably 2.00 dL / g or lower. Setting the intrinsic viscosity below the upper limit tends to improve the moldability of the resulting component. Conversely, setting the intrinsic viscosity above the lower limit tends to improve mechanical properties such as tensile strength and flexural strength. The intrinsic viscosity of the thermoplastic polyester resin is preferably 0.50 dL / g or more, more preferably 0.65 dL / g or more, even more preferably 0.70 dL / g or more, and even more preferably 0.75 dL / g or more. The intrinsic viscosity is preferably 1.50 dL / g or less, and more preferably 1.00 dL / g or less.

[0028] The intrinsic viscosity of thermoplastic polyester resins is measured by the following method. Polybutylene terephthalate resin pellets are dissolved in a phenol / 1,1,2,2-tetrachloroethane (mass ratio 1 / 1) mixed solvent by stirring at 110°C for 1 hour to a concentration of 1.00 g / dL. The mixture is then cooled to 30°C. Using a fully automated solution viscometer, the drop time of the sample solution and the drop time of the solvent alone are measured at 30°C, and the intrinsic viscosity is calculated using the formula. Intrinsic viscosity=((1+4K H η sp ) 0.5 -1) / (2K H C) Here, η sp =η / η0-1, where η is the number of seconds for the sample solution to fall, η0 is the number of seconds for the solvent only to fall, C is the concentration of the sample solution (g / dL), and K is the concentration of the sample solution (g / dL). H K is Huggins' constant. H 0.33 was adopted. In this embodiment, if the absorbent resin composition contains two or more thermoplastic polyester resins, the intrinsic viscosity of the thermoplastic polyester resins shall be the intrinsic viscosity of the mixture.

[0029] In this embodiment, the absorbent resin composition preferably contains thermoplastic polyester resin in an amount of 20% by mass or more, more preferably 25% by mass or more, depending on the application, it is even more preferably 30% by mass or more, even more preferably 32% by mass or more, and also preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 70% by mass or less, preferably 55% by mass or less, depending on the application, it is even more preferably 50% by mass or less, even more preferably 45% by mass or less, and may also be 40% by mass or 30% by mass or less. The absorbent resin composition in this embodiment may contain only one type of thermoplastic polyester resin, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0030] <Amorphous resin> The absorbent resin composition in this embodiment includes an amorphous resin. By including an amorphous resin, warping of the absorbent resin member can be effectively suppressed. While there are no specific requirements regarding the type of amorphous resin, it is usually an amorphous thermoplastic resin, with examples including styrene resins, polycarbonate resins, acrylic resins, and modified polyphenylene ether resins. Styrene resins and / or polycarbonate resins are preferred, and styrene resins are more preferred.

[0031] The amorphous resin used in this embodiment may be a virgin amorphous resin or a recycled amorphous resin. Examples of recycled amorphous resins include those obtained through material recycling, which involves crushing and washing recovered used amorphous resin molded products for reuse, and those obtained through chemical recycling (chemical decomposition method).

[0032] <<Styrene resin>> The styrene resin used in this embodiment may be a virgin styrene resin or a recycled amorphous styrene resin, but a recycled styrene resin is preferred. Examples of polystyrene resins include homopolymers of styrene monomers and copolymers of styrene monomers and monomers copolymerizable with styrene monomers. In copolymers of styrene monomers and copolymerizable monomers, it is preferable that 50% by mass or more of the total monomer is styrene monomer, more preferably 60% by mass or more is styrene monomer, and preferably 100% by mass or less is styrene monomer.

[0033] Styrene monomers refer to styrene and styrene having substituents, and include styrene, α-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromstyrene, dibromstyrene, fluorostyrene, and tribromstyrene, with styrene and α-methylstyrene being more preferred, and styrene being particularly preferred. Furthermore, among the monomers that make up styrene-based resins, monomers other than styrene-based monomers include (meth)acrylic acid ester monomers, maleimide monomers such as maleimide, N-methylmaleimide, and N-phenylmaleimide, α,β-unsaturated carboxylic acids and their anhydrides such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, phthalic acid, and itaconic acid, and rubbers such as butadiene.

[0034] The polystyrene resin used in this embodiment may include rubber-reinforced polystyrene resin. Specific examples of rubber-reinforced polystyrene resins include acrylonitrile-styrene copolymer (AS resin), high-impact polystyrene resin (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylene propylene-rubber-styrene copolymer (AES resin), styrene-IPN type rubber copolymer, and other resins.

[0035] In this embodiment, it is also preferable that a portion of the polystyrene resin used is a styrene-maleic acid polymer (preferably a styrene-maleic anhydride polymer). The styrene-maleic acid polymer acts as a compatibilizer between the polybutylene terephthalate resin and the polystyrene resin and / or rubber-reinforced polystyrene resin. As a result, the strength of the resulting component can be increased.

[0036] In this embodiment, the polystyrene resin preferably includes at least one selected from polystyrene resin (GPPS), acrylonitrile-styrene copolymer (AS resin), high-impact polystyrene resin (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), and acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin), and more preferably high-impact polystyrene resin (HIPS). Furthermore, from the viewpoint of heat resistance, polystyrene resin (GPPS) and acrylonitrile-styrene copolymer (AS resin) are more preferred, and AS resin is even more preferred.

[0037] <<Polycarbonate resin>> The polycarbonate resin used in this embodiment is a branched thermoplastic polymer or copolymer obtained by reacting a dihydroxy compound or a small amount thereof with a polyhydroxy compound with phosgene or a diester carbonate.

[0038] The dihydroxy compounds used as raw materials are substantially free of bromine atoms, and aromatic dihydroxy compounds are preferred. Specifically, examples include 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc., with bisphenol A being preferred. In addition, compounds in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compounds can also be used.

[0039] Among the polycarbonate resins mentioned above, aromatic polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane, or aromatic polycarbonate copolymers derived from 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy compounds are preferred. Alternatively, copolymers mainly composed of aromatic polycarbonate resins, such as copolymers with polymers or oligomers having a siloxane structure, may also be used. Furthermore, two or more of the above-mentioned polycarbonate resins may be mixed and used.

[0040] To adjust the molecular weight of polycarbonate resin, monovalent aromatic hydroxy compounds can be used, such as m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, and p-long-chain alkyl-substituted phenols.

[0041] The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or more, more preferably 12,000 or more, still more preferably 13,000 or more, and particularly preferably more than 14,000. When a polycarbonate resin having a viscosity average molecular weight lower than 10,000 is used, the resulting resin composition tends to have low mechanical strength such as impact resistance. Also, Mv is preferably 60,000 or less, more preferably 40,000 or less, still more preferably 35,000 or less, even more preferably 30,000 or less, and may be 25,000 or less or 20,000 or less. When it is more than 60,000, the fluidity of the resin composition may deteriorate and the moldability may deteriorate.

[0042] In the present invention, the viscosity average molecular weight (Mv) of the polycarbonate resin is a value calculated from the following Schnell viscosity formula by measuring the viscosity of a methylene chloride solution of the polycarbonate resin at 25 °C using an Ubbelohde viscometer to obtain the intrinsic viscosity ([η]). [[ID=X]]<000008> [η]=1.23×10 -4 Mv 0.83

[0043] The melt flow rate (MFR) of the polycarbonate resin measured in accordance with JIS K7210 (temperature 300 °C, load 1.20 kgf) is preferably 3 g / 10 min or more, more preferably 6 g / 10 min or more, and preferably 100 g / 10 min or less, more preferably 70 g / 10 min or less. When the MFR is within the above range, the effects of the present invention tend to be more effectively exhibited. The melt volume rate (MVR) of the polycarbonate resin measured in accordance with JIS K7210 (temperature 300 °C, load 1.20 kgf) is preferably 0.5 to 80 cm 3 g / 10 min, more preferably 40 to 70 cm 3 / 10 min. When the MVR is within the above range, the effects of the present invention tend to be more effectively exhibited.

[0044] The method for producing the polycarbonate resin is not particularly limited, and polycarbonate resin produced by either the phosgene method (interfacial polymerization method) or the melting method (transesterification method) can be used. Furthermore, polycarbonate resin produced by the melting method and then subjected to post-treatment to adjust the amount of terminal OH groups is also preferred.

[0045] In this embodiment, the amorphous resin content in the absorbent resin composition is preferably 25 parts by mass or more, more preferably 30 parts by mass or more, even more preferably 35 parts by mass or more, even more preferably 40 parts by mass or more, even more preferably 45 parts by mass or more, and also preferably 75 parts by mass or less, more preferably 69 parts by mass or less, even more preferably 65 parts by mass or less, even more preferably 60 parts by mass or less, and even more preferably 55 parts by mass or less. Setting the content above the lower limit tends to further improve the low warpage of the resulting molded product. Also, setting the content below the upper limit tends to further improve the heat resistance and basic physical properties of the resin composition.

[0046] In this embodiment, the total content of thermoplastic polyester resin and amorphous resin in the absorbent resin composition is more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 50% by mass or more, and also preferably 99% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, based on 100% by mass of the resin composition. The absorbent resin composition in this embodiment may contain only one type of amorphous resin, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0047] <Dyes that absorb laser light> The absorbing resin composition in this embodiment contains a dye that absorbs laser light. Examples of dyes that absorb laser light include dyes that have maximum absorption between wavelengths of 700 and 1200 nm. Carbon black is a specific example of a dye that absorbs laser light. There are no restrictions on the type, raw material, or manufacturing method of carbon black; furnace black, channel black, acetylene black, Ketjen black, etc., can all be used. Of these, furnace black is preferred. The number-average particle size of carbon black is preferably 5 to 60 nm. The upper limit is preferably 60 nm or less, more preferably 40 nm or less, even more preferably 30 nm or less, and even more preferably 25 nm or less. The lower limit is preferably 10 nm or more, more preferably 13 nm or more, even more preferably 16 nm or more, and even more preferably 19 nm or more. By keeping the number-average particle size within the above upper and lower limits, the appearance and laser weldability of the component tend to improve. The number-average particle size can be determined by obtaining an aggregate magnified image according to the procedure described in ASTM D3849 standard (Standard Test Methods for Carbon Black - Morphological Characterization by Electron Microscopy), measuring the particle size of 3,000 unit constituent particles from this aggregate image, and taking the arithmetic mean.

[0048] DBP oil absorption capacity of carbon black (unit: cm) 3 (100g) is 40-300cm 3 It is preferable that it be / 100g. The upper limit is 300cm 3 It is preferable that the amount be 100g or less, and 200cm 3 It is more preferable that the weight be 100g or less, and 150cm 3 It is even more preferable that the amount be 100g or less, and 100cm 3 It may be less than 100g. Also, the lower limit is 40cm. 3 / 100g or more is preferable, 50cm 3 / 100g or more is more preferable, 60cm 3A value of 100g or more is even more preferable. By keeping the value within the above upper and lower limits, the appearance of the component and the laser welding strength tend to improve. Note that DBP oil absorption (unit: cm 3 The amount (per 100g) can be measured in accordance with JIS K6217.

[0049] It is preferable to form a masterbatch with carbon black and then knead it with a thermoplastic polyester resin. A polyester resin is preferably used for the masterbatch, and a polybutylene terephthalate resin is more preferably used.

[0050] The content of the laser light-absorbing dye in the absorbent resin composition is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.15 parts by mass or more, even more preferably 0.20 parts by mass or more, and also 1.0 part by mass or less, more preferably 0.8 parts by mass or less, and even more preferably 0.5 parts by mass or less. Setting the content above the lower limit tends to further improve the laser welding strength. Setting the content below the upper limit tends to further improve the mechanical strength and laser welding strength of the resulting member. The absorbent resin composition may contain only one type of dye that absorbs laser light, or it may contain two or more types. If it contains two or more types, it is preferable that the total amount is within the above range.

[0051] <Fibrous filler> The absorbent resin composition in this embodiment preferably further contains a fibrous filler. Including a fibrous filler tends to improve the mechanical strength.

[0052] The fibrous filler that can be used in the absorbent resin composition in this embodiment is one that has the effect of improving the mechanical properties of the resin composition obtained by blending it with the resin, and any commonly used fibrous filler for plastics can be used. Preferably, fibrous fillers such as glass fibers, carbon fibers, basalt fibers, wollastonite, and potassium titanate fibers can be used, with glass fibers and / or carbon fibers being preferred, and glass fibers being more preferred. It is more preferable to use fibrous fillers that have been surface-treated with a surface treatment agent such as a coupling agent. Glass fibers to which a surface treatment agent has been applied are preferable because they have excellent durability, resistance to humid heat, resistance to hydrolysis, and resistance to thermal shock.

[0053] Any conventionally known surface treatment agent can be used, and specifically, silane coupling agents such as aminosilane, epoxysilane, allylsilane, and vinylsilane are preferred. Among these, aminosilane surface treatment agents are preferred, and specifically, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ-(2-aminoethyl)aminopropyltrimethoxysilane are preferred examples.

[0054] In addition, other preferred surface treatment agents include epoxy resin-based surface treatment agents such as novolac-type and bisphenol A-type epoxy resin-based surface treatment agents, with treatment using a novolac-type epoxy resin-based surface treatment agent being particularly preferred. Silane-based surface treatment agents and epoxy resin-based surface treatment agents may be used individually or in combination, and it is also preferable to use both in combination. In this embodiment, glass fibers refer to fibrous glass material, and more specifically, chopped glass fibers, which are bundled together in a manner of 1,000 to 10,000 strands and cut to a predetermined length, are preferred.

[0055] In this embodiment, the glass fibers have a number-average fiber length of 0.5 to 10 mm, and more preferably 1 to 5 mm. By using glass fibers with such a number-average fiber length, the mechanical strength can be further improved. The number-average fiber length is calculated by randomly selecting glass fibers to be measured from an image obtained by observation with an optical microscope, measuring their longest side, and then calculating the number-average fiber length from the obtained measurement values. The observation magnification is 20x, and the number of measurements is 1,000 or more. This roughly corresponds to the cut length. Furthermore, the cross-section of the glass fiber may be circular, elliptical, oblong, rectangular, a rectangle with semicircles attached to both short sides, or cocoon-shaped, but a circular shape is preferred. Here, "circular" includes not only a circular shape in the geometric sense, but also what is commonly referred to as circular in the technical field of this embodiment. The number-average fiber diameter of glass fibers is preferably 4.0 μm or more at the lower limit, more preferably 4.5 μm or more, and even more preferably 5.0 μm or more. The upper limit of the number-average fiber diameter of glass fibers is preferably 15.0 μm or less, and more preferably 14.0 μm or less. Using glass fibers having a number-average fiber diameter within this range tends to yield components with superior mechanical strength. The number-average fiber diameter of glass fibers is calculated by randomly selecting glass fibers to be measured from an image obtained by observing with an electron microscope, measuring the fiber diameter near the center, and obtaining the measured values. The observation magnification is 1,000x, and the number of measurements is 1,000 or more. For glass fibers with a cross-section other than circular, the number-average fiber diameter is calculated as the number-average fiber diameter when converted to a circle with the same area as the cross-sectional area.

[0056] Glass fibers are generally obtained by melt-spinning supplied glass such as E glass (Electrical glass), C glass (Chemical glass), A glass (Alkali glass), S glass (High strength glass), D glass, R glass, and alkali-resistant glass, but any material that can be made into glass fibers can be used and is not particularly limited. In this embodiment, it is preferable to include E glass.

[0057] The glass fibers used in this embodiment are preferably surface-treated with a surface treatment agent such as a silane coupling agent, such as γ-methacrylateoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, or γ-aminopropyltriethoxysilane. The amount of surface treatment agent applied is preferably 0.01 to 1% by mass of the glass fibers. Furthermore, if necessary, glass fibers may be surface-treated with a lubricant such as a fatty acid amide compound or silicone oil, an antistatic agent such as a quaternary ammonium salt, a resin with film-forming ability such as epoxy resin or urethane resin, or a mixture of a resin with film-forming ability and a heat stabilizer.

[0058] Glass fibers are available commercially. Examples of commercially available products include T-286H, T-756H, T-127, T-289H from Nippon Electric Glass Co., Ltd., DEFT2A from Owens Corning, HP3540 from PPG, and CSG3PA820 from Nitto Boseki Co., Ltd.

[0059] In this embodiment, the content of fibrous filler (preferably glass fiber) in the absorbent resin composition is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and even more preferably 35 parts by mass or more, based on 100 parts by mass of the total of the thermoplastic polyester resin and amorphous resin contained in the absorbent resin composition in this embodiment. Setting it above the lower limit tends to increase the mechanical strength of the resulting member. Furthermore, the upper limit of the content of fibrous filler is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 45 parts by mass or less, based on 100 parts by mass of the total of the thermoplastic polyester resin and amorphous resin. Setting it below the upper limit tends to increase the welding strength of the interface.

[0060] Furthermore, the content of fibrous filler (preferably glass fiber) in the absorbent resin composition in this embodiment is preferably 20% by mass or more, and more preferably 25% by mass or more. Moreover, the content of the fibrous filler (preferably glass fiber) is preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 32% by mass or less. The absorbent resin composition in this embodiment may contain only one type of fibrous filler (preferably glass fiber), or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0061] <Stabilizer> The absorbent resin composition in this embodiment may contain stabilizers (light stabilizers and / or heat stabilizers). The stabilizer preferably contains one or more compounds selected from the group consisting of thioether compounds, phosphorus compounds, hindered phenol compounds, and phosphite compounds, with phosphorus compounds and / or hindered phenol compounds being more preferred. Furthermore, in this embodiment, it is also preferable to use two or more thioether compounds, hindered phenol compounds, and phosphite compounds in combination as needed.

[0062] As the thioether compound, any conventionally known sulfur atom-containing compound can be used, with thioethers being particularly preferred. The resin composition of this embodiment tends to have a good appearance and improved thermal stability when it contains a thioether compound. Specifically, examples include didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate], thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, and trilauryl trithiophosphite. Among these, 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate] is preferred. Commercially available products include "C-NOX 412S" manufactured by Cipro Chemical Co., Ltd. and "ADEKA AO-412S" manufactured by ADEKA Corporation.

[0063] Examples of phosphorus-based stabilizers include phosphorous acid, phosphoric acid, phosphorous acid esters (phosphites), trivalent phosphate esters (phosphonites), and pentavalent phosphate esters (phosphates), with organic phosphite compounds, organic phosphonite compounds, and organic phosphate compounds being preferred.

[0064] Preferably, the organic phosphate compound is of the following formula: (R 1 O) 3-n P(=O)OH n (In the formula, R 1 (where n is an alkyl group or an aryl group, which may be the same or different; n is an integer between 0 and 2.) It is a compound represented by . More preferably, R 1 Examples include long-chain alkyl acid phosphate compounds having 8 to 30 carbon atoms. Specific examples of alkyl groups having 8 to 30 carbon atoms include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, and triacontyl group.

[0065] Examples of long-chain alkyl acid phosphates include octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, octadecyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate, cyclohexyl acid phosphate, phenoxyethyl acid phosphate, and alkoxypolyethylene glycol acid phosphate. Examples include octadecyl acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and bisnonylphenyl acid phosphate. Among these, octadecyl acid phosphate is preferred, and this is commercially available under the trade name "ADEKA Stab AX-71" from ADEKA Corporation.

[0066] Preferably, the organophosphite compound is of the following formula: R 2 OP(OR 3 )(OR 4) (In the formula, R 2 , R 3 and R 4 These are a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, respectively. 2 , R 3 and R 4 At least one of them is an aryl group with 6 to 30 carbon atoms. Examples of compounds represented by [the formula shown] are given.

[0067] Examples of organic phosphite compounds include triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono(tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl di(tridecyl) phosphite), and tetra(tridecyl)4,4'-iso Examples include propyridene diphenyl diphosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris(4-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite. Among these, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is preferred.

[0068] The organic phosphonite compound is preferably one of the following formulas: R 5 -P(OR 6 )(OR 7 ) (In the formula, R 5 , R 6 and R7 These are a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, respectively. 5 , R 6 and R 7 At least one of them is an aryl group with 6 to 30 carbon atoms. Examples of compounds represented by [the formula shown] are given.

[0069] Examples of organic phosphonite compounds include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, and tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylenediphosphona Examples include tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, and tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite.

[0070] Examples of hindered phenol compounds include pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), pentaerythritol tetrakis(3-(3,5-di-neopentyl-4-hydroxyphenyl)propionate), and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene. Among these, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Commercially available options include ADEKA products such as "ADEKA Stub AO-60" and "ADEKA Stub AO-330," and BASF products such as "Irganox Knox 1010."

[0071] Preferably, the phosphite compound is of the formula: R 2 OP(OR 3 )(OR 4 ) (In the formula, R 2 , R 3 and R 4 These are a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, respectively. 2 , R 3 and R 4 At least one of them is an aryl group with 6 to 30 carbon atoms. Examples of compounds represented by [the formula shown] are given.

[0072] Phosphite compounds include, for example, triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono(tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl di(tridecyl) phosphite, tetra(tridecyl)4,4'-isopropyl Examples include lopyridene diphenyl diphosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris(4-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite. Among these, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is preferred. A commercially available example is "ADEKA Stab PEP-36" manufactured by ADEKA Corporation.

[0073] In addition, as stabilizers, specific examples can be found in paragraphs 0067-0075 of Japanese Patent Publication No. 2021-063196, paragraphs 0046-0057 of Japanese Patent Publication No. 2018-070722, paragraphs 0030-0037 of Japanese Patent Publication No. 2019-056035, and paragraphs 0066-0078 of International Publication No. 2017 / 038949, the contents of which are incorporated herein by reference.

[0074] The amount of stabilizer in the absorbent resin composition is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of the thermoplastic resin (thermoplastic polyester resin and amorphous resin) contained in the absorbent resin composition. Setting the amount above the lower limit tends to further improve the effect of suppressing thermal degradation and oxidative degradation of the resin during melt mixing, molding, and use as a molded article, and tends to improve heat resistance. Furthermore, the upper limit of the amount of stabilizer is preferably 1.0 part by mass or less, more preferably 0.8 parts by mass or less, more preferably 0.6 parts by mass or less, even more preferably 0.5 parts by mass or less, and even more preferably 0.4 parts by mass or less, per 100 parts by mass of the thermoplastic resin (thermoplastic polyester resin and amorphous resin) contained in the absorbent resin composition. Setting the amount below the upper limit tends to effectively suppress adverse effects on appearance and physical properties due to aggregation of additives such as stabilizers, and tends to suppress discoloration of the resin composition. The resin composition of this embodiment may contain only one stabilizer or two or more stabilizers. When two or more stabilizers are included, it is preferable that the total amount is within the above range.

[0075] <Other ingredients> The absorbent resin composition in this embodiment may contain other components as needed, as long as they do not significantly impair the desired physical properties. The other components may be present as a single component, or as two or more components in any combination and ratio. Other examples of components include resin additives and fillers other than the fibrous fillers mentioned above. Examples of resin additives include nucleating agents, reactive compounds, mold release agents, lubricants, flame retardants, flame retardant aids, transesterification inhibitors, ultraviolet absorbers, antistatic agents, antifogging agents, antiblocking agents, flow improvers, plasticizers, and dispersants. The total amount of these other components is preferably 0% by mass or more and less than 10% by mass, more preferably 0% by mass or more and less than 5% by mass, and even more preferably 0% by mass or more and less than 3% by mass, based on 100% by mass of the resin composition.

[0076] Other fillers besides fibrous fillers include granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organic clay, and glass beads; plate-like fillers such as talc; and flake-like fillers such as glass flakes, mica, and graphite. The total amount of fillers other than fibrous fillers is preferably 0% by mass or more and less than 10% by mass, more preferably 0% by mass or more and less than 5% by mass, and even more preferably 0% by mass or more and less than 3% by mass, based on 100% by mass of the resin composition.

[0077] In this embodiment, the absorbent resin composition preferably contains a total of 90% by mass or more of the thermoplastic polyester resin, amorphous resin, laser light absorbing dye, glass fibers, and resin additives added as needed, more preferably 95% by mass or more, and even more preferably 99% by mass or more.

[0078] <Method for producing absorbent resin composition> The absorbent resin composition in this embodiment can be manufactured by conventional methods for preparing resin compositions (e.g., pellets). Typically, each component and various additives added as desired are thoroughly mixed together and then melt-kneaded in a single-screw or twin-screw extruder. Alternatively, the absorbent resin composition in this embodiment can be prepared by supplying the components to the extruder using a feeder and melt-kneading them without pre-mixing them, or by pre-mixing only a portion of them. For example, it is preferable to supply glass fibers to the extruder using a side feeder and melt-knead them. Alternatively, a masterbatch may be prepared by melt-kneading some of the components with a thermoplastic resin, and then the remaining components may be added to this and melt-kneaded. The thermoplastic resin used to make the masterbatch is preferably polyalkylene terephthalate resin, more preferably polyalkylene terephthalate resin and / or polyethylene terephthalate resin, and even more preferably polyalkylene terephthalate resin.

[0079] On the other hand, the transparent resin member can be a known transparent resin member that can be laser-welded. One example of the shape of a permeable resin member is a flat plate-shaped member. Needless to say, the term "flat plate-shaped" here includes plate-shaped materials that have thickness errors as described later, or that include holes (air holes, screw holes, etc.) or fitting structures with absorbent resin members that are commonly provided in the technical field of the present invention. The permeable resin member has a thickness of, for example, 0.05 mm or more at its thinnest point, more specifically, 0.1 mm or more, and also, for example, 2.0 mm or less, and more specifically, 1.5 mm or less. The permeable resin member has a thickness of, for example, 0.5 mm or more at its thickest point, more specifically, 0.7 mm or more, and also, for example, 5.0 mm or less, and more specifically, 3.0 mm or less. Furthermore, the permeable resin member is preferably a flat plate-shaped member in which the difference (absolute value) between the average thickness and the thickness of the thinnest part, and the difference (absolute value) between the average thickness and the thickness of the thickest part, are both 10% or less of the average thickness, and more preferably 5% or less. In this embodiment, using a flat, thin-walled member tends to more effectively reduce the pressure between the member and the absorbent resin member.

[0080] Examples of permeable resin members include the permeable cover used in the embodiments described later, the member labeled reference numeral 2 in Figure 1 of International Publication No. 2019 / 088058, and the member labeled reference numeral 2 in Figure 1 of Japanese Patent Application Publication No. 2019-081365, the contents of which are incorporated herein by reference.

[0081] Since the transparent resin components are joined together by laser welding, they typically have a shape that includes at least surface contact points (flat or curved surfaces).

[0082] In this embodiment, the permeable resin member is preferably a member formed from a permeable resin composition containing a thermoplastic polyester resin, more preferably a member formed from a permeable resin composition containing a thermoplastic polyester resin and a laser light-transmitting dye, and even more preferably a member formed from a permeable resin composition containing a thermoplastic polyester resin, an amorphous resin, and a laser light-transmitting dye. The permeable resin composition will be described below.

[0083] <Thermoplastic polyester resin> The permeable resin composition in this embodiment preferably contains a thermoplastic polyester resin. The details of the thermoplastic polyester resin are the same as those of the thermoplastic polyester resin included in the absorbent resin composition, and the preferred range is also the same.

[0084] In this embodiment, the permeable resin composition preferably contains a thermoplastic polyester resin in an amount of 20% by mass or more, more preferably 25% by mass or more, and depending on the application, it is even more preferably 30% by mass or more, even more preferably 42% by mass or more, and also preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 70% by mass or less, preferably 55% by mass or less, and depending on the application, it is even more preferably 50% by mass or less. The permeable resin composition in this embodiment may contain only one type of thermoplastic polyester resin, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0085] <Amorphous resin> In this embodiment, the permeable resin composition preferably contains an amorphous resin. By including an amorphous resin, warping of the permeable resin member can be effectively suppressed. The details of the amorphous resin are the same as those of the amorphous resin that may be included in the absorbent resin composition, and the preferred range is also the same.

[0086] In this embodiment, the amorphous resin content in the permeable resin composition is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, even more preferably 10 parts by mass or more, and also preferably 75 parts by mass or less, more preferably 50 parts by mass or less, even more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. Setting the content above the lower limit tends to further improve the low warpage of the resin composition. Furthermore, setting the content below the upper limit tends to further improve the heat resistance and basic physical properties of the resin composition.

[0087] In this embodiment, the total content of thermoplastic polyester resin and amorphous resin in the permeable resin composition is more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 50% by mass or more, and also preferably 99% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, based on 100% by mass of the resin composition. The permeable resin composition in this embodiment may contain only one type of amorphous resin, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0088] <Dyes that transmit laser light> In this embodiment, the transparent resin composition preferably contains a dye that transmits laser light. By including a dye that transmits laser light, the color of the transparent resin member and the absorbent resin member can be adjusted, resulting in a laser-welded body with excellent aesthetic appeal. The dye that transmits laser light is not specifically defined as any dye that transmits a certain percentage or more of the laser light used for laser welding; any known dye can be used. The laser light-transmitting dye includes, for example, a dye that, when combined with polybutylene terephthalate resin (e.g., Novaduran® 5008), 30% by mass of glass fiber (e.g., Nippon Electric Glass Co., Ltd., product name: T-127), and 0.2% by mass of a dye (a dye believed to transmit laser light) to a total of 100% by mass, has a transmittance of 5% or more when the light transmittance is measured. Furthermore, by incorporating the laser light-transmitting dye in this embodiment, for example, the transmittance at a wavelength of 1064 nm can be made 5% or more when the laser-transmitting resin composition is molded to a thickness of 1.5 mm. Pigments that transmit laser light are typically dyes. The laser light-transmitting dye can be appropriately selected according to its application, and its color is not particularly specified. In this embodiment, the laser light-transmitting dye is preferably a black dye composition containing a black dye and / or two or more chromatic dyes. A black dye composition means a composition in which two or more chromatic dyes such as red, blue, and green are combined to produce a black color. A first embodiment of the black pigment composition is a form containing a green pigment and a red pigment. A second embodiment of the black pigment composition is a form containing a red pigment, a blue pigment and a yellow pigment. Specific examples of dyes that transmit laser light include nigrosine, naphthalocyanine, aniline black, phthalocyanine, porphyrin, perinone, quaterylene, azo, azomethine, anthraquinone, pyrazolone, squamate derivatives, perylene, chromium complexes, and immonium, with azomethine, anthraquinone, and perinone being preferred, and anthraquinone and perinone being more preferred among them.

[0089] Examples of commercially available products include the colorants e-BIND LTW-8731H and e-BIND LTW-8701H from Orient Chemical Industry Co., Ltd., the colorants Plast Yellow 8000, Plast Red M 8315, Plast Red 8370, and Oil Green 5602 from Arimoto Chemical Co., Ltd., the colorants Macrolex Yellow 3G, Macrolex Red EG, and Macrolex Green 5B from LANXESS, and the colorants KP Plast HK, KP Plast Red HG, KP Plast Red H2G, KP Plast Blue R, KP Plast Blue GR, and KP Plast Green G from Kiwa Chemical Industry Co., Ltd. Furthermore, the dyes described in Japanese Patent Publication No. 4157300 and Japanese Patent Publication No. 4040460 can also be used, and these are incorporated herein by reference.

[0090] The laser-transmitting resin composition used in this embodiment preferably contains 0.001 to 5 parts by mass of a laser light-transmitting dye per 100 parts by mass of the thermoplastic resin (thermoplastic polyester resin and amorphous resin, if necessary) contained in the absorbing resin composition. The lower limit of the content is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and even more preferably 0.2 parts by mass or more. Setting the content above the lower limit results in coloring of the transparent resin member, improving the aesthetic appeal of the laser-welded body. The upper limit of the content is preferably 4 parts by mass or less, more preferably 3.5 parts by mass or less, even more preferably 3.0 parts by mass or less, and even more preferably 2.5 parts by mass or less. Setting the content below the upper limit effectively suppresses the bleed-out of the laser light-transmitting dye. The laser-transmitting resin composition may contain only one type of laser light-transmitting dye, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0091] <Fibrous filler> The permeable resin composition in this embodiment preferably further contains a fibrous filler. Including a fibrous filler tends to improve the mechanical strength.

[0092] The details of the fibrous filler that can be used in the permeable resin composition in this embodiment are the same as those of the fibrous filler that may be included in the absorbent resin composition, and the preferred range is also the same.

[0093] In this embodiment, the content of fibrous filler (preferably glass fiber) in the permeable resin composition is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and even more preferably 35 parts by mass or more, based on 100 parts by mass of the total of the thermoplastic polyester resin and amorphous resin contained in the permeable resin composition in this embodiment. Setting it above the lower limit tends to increase the mechanical strength of the resulting member. Furthermore, the upper limit of the content of fibrous filler is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 45 parts by mass or less, based on 100 parts by mass of the total of the thermoplastic polyester resin and amorphous resin. Setting it below the upper limit tends to increase the welding strength of the interface.

[0094] Furthermore, the content of fibrous filler (preferably glass fiber) in the permeable resin composition in this embodiment is preferably 20% by mass or more, and more preferably 25% by mass or more. Moreover, the content of the fibrous filler (preferably glass fiber) is preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 32% by mass or less. The permeable resin composition in this embodiment may contain only one type of fibrous filler (preferably glass fiber), or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0095] <Other ingredients> The permeable resin composition in this embodiment may contain other components as needed, as long as they do not significantly impair the desired physical properties. The other components may be present as a single component, or as two or more components in any combination and ratio. Other examples of components include resin additives and fillers other than the fibrous fillers mentioned above. Examples of resin additives include nucleating agents, reactive compounds, impact modifiers, stabilizers (thermal stabilizers, light stabilizers), mold release agents, lubricants, flame retardants, flame retardant aids, transesterification inhibitors, ultraviolet absorbers, antistatic agents, antifogging agents, antiblocking agents, fluidity modifiers, plasticizers, and dispersants. The total amount of these other components is preferably 0% by mass or more and less than 10% by mass, more preferably 0% by mass or more and less than 5% by mass, and even more preferably 0% by mass or more and less than 3% by mass, based on 100% by mass of the resin composition.

[0096] Other fillers besides fibrous fillers include granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organic clay, and glass beads; plate-like fillers such as talc; and flake-like fillers such as glass flakes, mica, and graphite. The total amount of fillers other than fibrous fillers is preferably 0% by mass or more and less than 10% by mass, more preferably 0% by mass or more and less than 5% by mass, and even more preferably 0% by mass or more and less than 3% by mass, based on 100% by mass of the resin composition.

[0097] In this embodiment, the permeable resin composition preferably contains a total of 90% or more by mass of the thermoplastic polyester resin, amorphous resin, laser light-transmitting dye, glass fibers, and resin additives added as needed, more preferably 95% or more by mass, and even more preferably 99% or more by mass.

[0098] <Method for producing permeable resin composition> The permeable resin composition in this embodiment can be described with reference to the method for producing the absorbent resin composition.

[0099] <Method for manufacturing absorbent resin members and permeable resin members> The manufacturing method for the absorbent resin member and the permeable resin member is not particularly limited, and any molding method commonly used for thermoplastic polyester resin compositions can be arbitrarily employed. Examples include injection molding, ultra-high-speed injection molding, injection compression molding, two-color molding, hollow molding methods such as gas-assisted molding, molding using a heat-insulating mold, molding using a rapidly heated mold, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, etc., with injection molding being preferred among these. Details of injection molding can be found in paragraphs 0113 to 0116 of Japanese Patent No. 6183822, which are incorporated herein by reference.

[0100] <Method for manufacturing laser-welded bodies> Next, the laser welding method will be described. In this embodiment, a transparent resin member and an absorbent resin member can be laser-welded to form a laser-welded body. By laser welding, the transparent resin member and the resin member can be strongly welded together without the use of adhesive. More specifically, the method for manufacturing a laser-welded body according to this embodiment includes laser welding while applying a force of 2.7 N / mm or less per unit distance between a transparent resin member and an absorbing resin member, wherein the absorbing resin member is a three-dimensional structure having a cavity formed from an absorbing resin composition containing a thermoplastic polyester resin, an amorphous resin, and a dye that absorbs laser light. The preferred range for the absorbing resin member here is the same as the matter described in the section on absorbing resin members above, and the preferred range is also the same. The same applies to the transparent resin member.

[0101] Here, the force applied between the permeable resin member and the absorbent resin member is preferably 2.7 N / mm or less per unit distance, more preferably 2.6 N / mm or less, even more preferably 2.5 N / mm or less, even more preferably 2.4 N / mm or less, even more preferably 2.0 N / mm or less, and also preferably 0.1 N / mm or more, and more preferably 0.4 N / mm or more. By setting it below the upper limit, the required laser weldability can be achieved while reducing the pressure on the members. Furthermore, by setting it above the lower limit, the laser weldability tends to improve further.

[0102] Laser welding may be performed using any known laser welding method, but galvanometer scanning laser welding is suitable. Galvanometer scanning laser welding, also known as quasi-simultaneous welding, is a method in which the laser beam is scanned with a built-in galvanometer mirror. By using galvanometer scanning laser welding, the entire welding area is heated almost simultaneously, so the residual stress of the resulting laser-welded body tends to be small.

[0103] The laser light source used for laser welding can be determined according to the absorption wavelength of the light-absorbing dye, with lasers in the wavelength range of 800 to 1100 nm being preferred. Examples of laser light types include solid-state lasers, fiber lasers, semiconductor lasers, gas lasers, and liquid lasers. For example, YAG (yttrium aluminum garnet crystal) lasers (wavelengths 1064 nm, 1070 nm) and LD (laser diode) lasers (wavelengths 808 nm, 840 nm, 940 nm, 980 nm) can be preferably used. Among these, laser light with wavelengths of 940 nm, 980 nm, and 1070 nm is preferred.

[0104] The laser focal diameter is preferably 0.1 mm or larger, more preferably 0.2 mm or larger, and even more preferably 0.5 mm or larger. By keeping it below the upper limit, the welding strength of the laser-welded area can be further increased. The laser irradiation diameter is preferably 5.0 mm or smaller, more preferably 4.0 mm or smaller, and even more preferably 3.0 mm or smaller. By keeping it above the lower limit, the welding width can be controlled more effectively. Furthermore, the focal diameter of the laser beam can be selected to match the width and height of the welding surface. Furthermore, the laser beam may be focused on the bonding surface or defocused, and it is preferable to select this appropriately depending on the desired welded object.

[0105] The laser output is preferably 1W or more, more preferably 10W or more, even more preferably 20W or more, and even more preferably 30W or more. By setting it above the lower limit, sufficient welding strength can be obtained even with a shorter welding time. Furthermore, the laser output is preferably 1000W or less, more preferably 500W or less, even more preferably 400W or less, and even more preferably 300W or less. By setting it below the upper limit, the cost of laser welding equipment can be effectively reduced. The laser irradiation speed is preferably 10 mm / s or more, more preferably 30 mm / s or more, even more preferably 50 mm / s or more, and even more preferably 200 mm / s or more. By setting it above the lower limit, residual stress in the laser-welded body can be reduced more effectively. Furthermore, the laser irradiation speed is preferably 20,000 mm / s or less, more preferably 10,000 mm / s or less, even more preferably 5,000 mm / s or less, and even more preferably 3,000 mm / s or less. By setting it below the upper limit, sufficient welding strength can be obtained for the welded body. In addition, regarding the laser scanning method, it is preferable to adjust the laser output, the planned welding line, the scanning speed, and / or the scanning method according to the shape of the joint surface from the viewpoint of welding efficiency, welding strength, welding appearance, and equipment load.

[0106] More specifically, for example, when welding a transparent resin member and an absorbent resin member, first, the areas to be welded are brought into contact with each other. At this time, surface contact between the two welding areas is desirable, and this may be flat surfaces, curved surfaces, or a combination of flat and curved surfaces. When maintaining the overlapping state, it is preferable to place a transparent plate material such as a glass plate, quartz plate, or acrylic plate on top of the transparent resin member, i.e., on the laser irradiation side, and apply pressure. In particular, when a glass plate or quartz plate is placed, it is suitable for promoting the dissipation of heat generated during laser welding and obtaining a good appearance. Alternatively, pressure may be applied by surrounding the area of ​​the transparent resin member to be welded with a metal plate. Next, a laser beam is irradiated from the transparent resin member side. At this time, if necessary, a lens may be used to focus the laser beam at the interface between the two. The focused beam passes through the transparent resin member and is absorbed near the surface of the absorbent resin member, generating heat and melting it. Then, this heat is transferred to the transparent resin member by thermal conduction, causing it to melt as well, forming a molten pool at the interface between the two. After cooling, the two materials are joined together. In this way, the laser-welded body of the transparent resin member and the absorbent resin member has high welding strength. In this embodiment, the term "laser-welded body" includes not only finished products and parts, but also members that make up a part of them.

[0107] In this embodiment, the laser-welded body typically has a space formed inside by laser welding of a transparent resin member and an absorbent resin member. The volume of this internal space is, for example, 64 x 10 3 mm 3 That's all, and furthermore 125x10 3 mm 3 That's all, and also, for example, 27x10 6 mm 3 The following, and furthermore, 64x10 6 mm 3 The following applies: In this embodiment, the internal space does not necessarily have to be completely sealed off from the outside, but rather refers to a space that serves as a de facto boundary with the outside. Therefore, it goes without saying that it may be provided with air vents or holes for inserting other components.

[0108] The laser-welded body of this embodiment has good mechanical strength, high welding strength, and minimal damage to the resin due to laser irradiation, making it suitable for a variety of applications, such as various storage containers, electrical and electronic equipment components, office automation (OA) equipment components, home appliance components, mechanical mechanism components, and vehicle mechanism components. In particular, it can be suitably used for food containers, pharmaceutical containers, oil and fat product containers, hollow vehicle components (various tanks, intake manifold components, camera housings), vehicle electrical components (various control units, ignition coil components, etc.), in-vehicle electronic components and sensor components (housings for millimeter-wave radar, LiDAR, ECU cases, sonar sensors, etc.), electronically controlled throttle bodies, motor components, various sensor components, connector components, switch components, circuit breaker components, relay components, coil components, transformer components, lamp components, and more. In particular, the laser-welded body of this embodiment is suitable for in-vehicle camera components and in-vehicle camera modules including in-vehicle camera components, millimeter-wave radar modules, sensor modules, and electric parking brake (EPB) components. [Examples]

[0109] The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or other reasons, measurements can be taken using other instruments with equivalent performance.

[0110] 1. Raw materials The following ingredients were used. [Table 1]

[0111] 2. Example 1, Example 2, Comparative Example 1 <Manufacturing of resin compositions (pellets)> As shown in Table 2, components other than glass fibers were placed in a stainless steel tumbler and stirred and mixed for 1 hour. The components in Table 2 are expressed in parts by mass. The resulting mixture was fed into the main hopper of a 30 mm vented twin-screw extruder (manufactured by Japan Steel Works, Ltd., "TEX30α"). Glass fibers (GF) were supplied from the hopper through the 7th side feeder. The mixture was kneaded and extruded into strands under the following conditions: extruder barrel temperature C1~C15 260°C, die 250°C, screw rotation speed 200 rpm, discharge rate 40 kg / hour, to obtain pellets of the absorbent resin composition.

[0112] <Manufacturing of permeable resin composition (pellets)> The following materials were used as raw materials for the permeable resin composition. Polybutylene terephthalate resin (Mitsubishi Chemical Corporation, 5008-C): 54 parts by mass Polycarbonate resin (H-4000FN, manufactured by Mitsubishi Engineering Plastics Co., Ltd.): 13 parts by mass Stabilizer (ADEKA AX-71): 0.1 parts by mass Stabilizer (ADEKA AO-60): 0.2 parts by mass Reactive compound (CNE220, manufactured by Changchun Co.): 1.0 part by mass Release agent (Clariant Ricowax E): 0.3 parts by mass Dye 1 (Plast Red 8370, manufactured by Arimoto Chemical Co., Ltd.): 0.42 parts by mass Dye 2 (Kiwa Chemical Industry Co., Ltd. KP Plast Blue R): 0.45 parts by mass Dye 3 (Kiwa Chemical Industry Co., Ltd. KP Plast Yellow HK): 0.38 parts by mass Glass fiber (manufactured by Nippon Electric Glass Co., Ltd., T-127): 30 parts by mass Dyes 1-3 and the inorganic pigment are all dyes that have significantly higher light transmittance at a wavelength of 1070 nm than carbon black.

[0113] Of the above components, all except the glass fiber were placed in a stainless steel tumbler and stirred and mixed for 1 hour. The resulting mixture was fed into the main hopper of a 30 mm vented twin-screw extruder (manufactured by Japan Steel Works, "TEX30α"), and the glass fiber (GF) was supplied from the hopper through the 7th side feeder. The mixture was kneaded and extruded into strands under the following conditions: extruder barrel temperature C1~C15 260°C, die 250°C, screw rotation speed 200 rpm, and discharge rate 40 kg / hour, to produce laser-permeable resin composition (pellets).

[0114] <Fabrication of laser-welded bodies> The laser-absorbing resin composition obtained above was dried at 120°C for 7 hours, and then molded into a box (absorbent resin member) with the shape shown in the design drawings in Figures 1 to 3. The absorbent resin member is a box, and Figure 1 is a schematic diagram viewed from above, with ribs on the frame. Figure 2 is a schematic diagram of the absorbent resin member viewed from the side, with the circled area being an enlarged view of the welded rib section. The arrows indicate the gate positions. Figure 3 is a view of the box from the bottom. Furthermore, the laser-transparent resin composition obtained above was dried at 120°C for 7 hours and then molded into a box (transparent resin member) with the shape shown in the design drawings in Figures 4 and 5. The transparent resin member is flat, with Figure 4 being a top view and Figure 5 being a side view. The arrows in Figure 5 indicate the gate positions. For the molding process, an injection molding machine (Japan Steel Works, Ltd. "J100ADS") was used, and the molds were formed at a cylinder temperature of 265°C and a mold temperature of 60°C to produce each product.

[0115] A transparent resin member and an absorbent resin member were assembled by placing a cover-shaped transparent resin member on top of a box-shaped absorbent resin member, positioning a laser light source vertically above the overlapping portion of the transparent resin member and the absorbent resin member, and applying the pressure shown in Table 3 (welding force, unit: N) from both sides in the thickness direction inward to the overlapping portion of the transparent resin member and the absorbent resin member using a glass plate, while irradiating with a laser under the following conditions to obtain a laser-welded body. The welding equipment is as follows:

[0116] <<Galvanoscanning laser welding>> Laser welding machine: GalWeld TypeS manufactured by Hiroshima Co., Ltd. Wavelength: 1070nm Laser type: Fiber laser Laser output: 33W Galvanometer Scanner: Panasonic Industries, Ltd. Galvanometer Scanner VL-W1A00 Laser beam diameter: 2.0 mm Laser irradiation speed: 300 mm / s Number of laser irradiation cycles: 10 cycles Pressing force: 100~700N Welded area circumference: 242mm

[0117] <Measurement of laser welding strength> For measuring the welding strength, as shown in Figure 6(a), a Φ28 mm hole (not shown) was drilled in the center of the bottom of the absorbent resin member 1 before welding, and a 51 x 61 x 6 mm SUS304 metal plate 3 was then enclosed within the absorbent resin member and set up. As shown in Figure 6(b), after laser welding the absorbent resin member 1 and the transparent resin member 2, the absorbent resin member was placed and fixed in a special jig with the bottom (the side with the hole 4) facing upwards, and a load was applied to the enclosed metal plate 3 using the tip 5 (Φ26 mm) of a rod attached to an IMADA ZTS-5000N digital force gauge, and the maximum welding strength at which the transparent resin member 2 peeled off was measured. In Figures 6(a) and (b), 1 represents the absorbent resin member, 2 represents the permeable resin member, 3 represents the metal plate, 4 represents the hole made in the absorbent resin member, and 5 represents the tip of the rod.

[0118] <Measurement of warpage of absorbent resin components> The absorbent resin component was placed on a surface plate with the non-hollow side facing upwards. Next, thickness gauges were sequentially inserted at eight locations along the outer circumference, and the maximum gap was measured and averaged to obtain the amount of warping. The welding strength retention rate at the applied pressures shown in Table 3 was calculated for a applied pressure of 700 N, and is shown in Table 3. The force per unit distance (unit: N / mm) was calculated as applied pressure (N) / circumference of the welded area (mm).

[0119] [Table 2]

[0120] [Table 3]

[0121] The welding strength retention rate in Table 3 is shown as the ratio (in %) of the welding strength under each applied pressure (600N to 100N) to the welding strength under a applied pressure of 700N. Furthermore, the example showed significantly less warping than the comparative example. As is clear from the results above, the laser-welded body of this embodiment is a laser-welded body made of a three-dimensional material having a cavity, and was sufficiently laser-welded even with a small applied pressure.

[0122] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible without departing from the intent and scope of the invention. [Explanation of Symbols]

[0123] 1 Absorbent resin member 2 Permeable resin member 3 metal plate 4. Holes drilled in the absorbent resin member 5. Rod tip

Claims

1. A laser-welded body having a transparent resin member and an absorbent resin member, The absorbent resin member is a three-dimensional structure having a cavity, formed from an absorbent resin composition containing a thermoplastic polyester resin, an amorphous resin, and a dye that absorbs laser light. Laser-welded body.

2. The laser welded body according to claim 1, wherein the thermoplastic polyester resin contained in the absorbent resin composition includes a polybutylene terephthalate resin.

3. The laser welded body according to claim 1 or 2, wherein the amorphous resin contained in the absorbent resin composition includes a styrene-based resin.

4. The laser-welded body according to claim 1 or 2, wherein the dye that absorbs the laser light includes carbon black.

5. The laser welded body according to claim 1 or 2, wherein the transparent resin member is a member formed from a transparent resin composition containing a thermoplastic polyester resin and a dye that transmits laser light.

6. The laser welded body according to claim 5, wherein the permeable resin composition includes an amorphous resin.

7. The laser-welded body according to claim 1 or 2, wherein the transparent resin member is a flat plate-shaped member.

8. The thermoplastic polyester resin contained in the absorbent resin composition includes a polybutylene terephthalate resin, The amorphous resin contained in the absorbent resin composition includes a styrene-based resin, The dye that absorbs the laser light contains carbon black, The aforementioned transparent resin member is a member formed from a transparent resin composition containing a thermoplastic polyester resin and a dye that transmits laser light. The permeable resin composition comprises an amorphous resin, The laser-welded body according to claim 1, wherein the transparent resin member is a flat plate-shaped member.

9. This includes laser welding between a transparent resin member and an absorbent resin member while applying a force of 2.7 N / mm or less per unit distance, The absorbent resin member is a three-dimensional structure having a cavity, formed from an absorbent resin composition containing a thermoplastic polyester resin, an amorphous resin, and a dye that absorbs laser light. A method for manufacturing laser-welded bodies.

10. The method for producing a laser-welded body according to claim 9, wherein the permeable resin composition is the permeable resin composition according to claim 1, 2, or 8.

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