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

Abstract

The present invention provides a laser-welded product containing a semi-aromatic polyamide resin, characterized by high welding strength between the permeable resin member and the absorbent resin member, and suppressed burr formation, as well as a method for manufacturing a laser-welded product. [Solution] The laser-welded product according to this disclosure is a laser-welded product of a transparent resin member and an absorbent resin member, having a joint portion formed by laser welding of the transparent resin member and the absorbent resin member, wherein at least one of the transparent resin member and the absorbent resin member comprises a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2), and in a cross section including the normal to the transparent resin member and perpendicular to the scanning direction of the laser beam, a molten pool is observed in the joint portion, and the area of ​​the molten pool is 1.00 mm². 2 Ultra 3.01mm 2 The following applies:

Description

[Technical Field]

[0001] The present invention relates to a laser-welded article and a method for producing a laser-welded article. In particular, the present invention relates to a resin composition for laser welding containing a polyamide resin as a main component. [Background Art]

[0002] Polyamide resin, which is a typical engineering plastic, is easy to process and is excellent in mechanical properties, electrical properties, heat resistance, and other physical and chemical properties. For this reason, it is widely used in vehicle parts, electrical and electronic equipment parts, other precision equipment parts, and the like. Recently, parts with complex shapes have also been produced from polyamide resin. For example, various welding techniques are used for bonding parts having hollow portions such as intake manifolds, including adhesive welding, vibration welding, ultrasonic welding, hot plate welding, injection welding, and laser welding techniques.

[0003] However, welding using an adhesive has problems such as environmental load such as surrounding contamination in addition to time loss until curing. Problems such as damage to products caused by vibration and heat, and the need for post-treatment due to generation of abrasion powder and burrs have been pointed out for ultrasonic welding, hot plate welding, and the like. In addition, injection welding often requires special molds and molding machines, and further has problems such as being unusable if the material does not have good fluidity.

[0004] On the other hand, laser welding is a method for joining two resin members by bringing a resin member having transmittance (also referred to as non-absorbability or weak absorbability) to laser light in a specific wavelength range (hereinafter referred to as "transmissive resin member") into contact with and welding to a resin member having absorbability to laser light (hereinafter referred to as "absorptive resin member"), thereby joining the two resin members together. Specifically, it is a method in which a laser beam of a specific wavelength is irradiated onto the joint surface from the transmissive resin member side, and the absorptive resin member forming the joint surface is melted by the energy of the laser beam and then joined. Laser welding does not generate abrasion powder and produces few burrs, thus causing less damage to products. Furthermore, since polyamide resin itself is a material with relatively high laser transmittance, processing of polyamide resin molded products by laser welding technology has attracted attention recently. For a polyamide resin composition for laser welding, for example, there is a description in Patent Document 1.

Prior Art Literature

Patent Literature

[0005]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0006] Here, for a laser-welded product containing a semi-aromatic polyamide resin in at least one of the transmissive resin member and the absorptive resin member, higher mechanical strength can be expected than that of a laser-welded product formed from an aliphatic polyamide resin. However, as a result of studies conducted by the present inventors, it has been found that in laser-welded products containing a semi-aromatic polyamide resin, the welding strength between the transmissive resin member and the absorptive resin member may be low in some cases. It has also been found that burrs may occur in laser-welded products in some cases. The present invention aims to solve the above problems and to provide a laser-welded product containing a semi-aromatic polyamide resin, wherein the welding strength between the permeable resin member and the absorbent resin member is high and the generation of burrs is suppressed, as well as a method for manufacturing a laser-welded product. [Means for solving the problem]

[0007] Under the above problems, the inventors conducted studies and found that at least one of the permeable resin member and the absorbent resin member should be a member containing a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2), and the area of ​​the molten pools of both should be 1.00 mm². 2 Ultra 3.01mm 2 We found that the above problem can be solved by doing the following. Specifically, the above problem was solved by the following means. [1] A laser-welded product of a transparent resin member and an absorbent resin member, having a joint portion formed by laser welding between the transparent resin member and the absorbent resin member, At least one of the permeable resin member and the absorbent resin member comprises a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2), In a cross-section that includes the normal to the transparent resin member and is perpendicular to the scanning direction of the laser beam, a molten pool is observed in the joint portion. The area of ​​the molten pool is 1.00 mm². 2 Ultra 3.01mm 2 The following are laser-welded products. [2] The laser-welded product according to [1], wherein the cooling crystallization temperature (Tc) of at least one of the transparent resin member and the absorbent resin member is 170 to 230°C. [3] The laser-welded product according to [1] or [2], wherein at least one of the permeable resin member and the absorbent resin member contains aliphatic polyamide resin (A2) in a ratio of 5 parts by mass or more and less than 50 parts by mass per 100 parts by mass of the total of semi-aromatic polyamide resin (A1) and aliphatic polyamide resin (A2). [4] The value obtained by dividing the welding strength (unit: N) of the transparent resin member and the absorbing resin member of the laser welded product by the melt pool area (welding strength / melt pool area) is 500 N / mm 2 2 or more and 1000 N / mm 2 2 or less, the laser welded product according to any one of [1] to [3]. [5] The laser welded product according to any one of [1] to [4], wherein at least one of the transparent resin member and the absorbing resin member contains a filler (B). [6] The crystallization temperature (Tc) during cooling of at least one of the transparent resin member and the absorbing resin member is 170 to 230°C, At least one of the transparent resin member and the absorbing resin member contains the aliphatic polyamide resin (A2) in a proportion of 5 parts by mass or more and less than 50 parts by mass based on 100 parts by mass in total of the semi-aromatic polyamide resin (A1) and the aliphatic polyamide resin (A2), The value obtained by dividing the welding strength (unit: N) of the transparent resin member and the absorbing resin member of the laser welded product by the melt pool area (welding strength / melt pool area) is 500 N / mm 2 2 or more and 1000 N / mm 2 2 or less, The laser welded product according to any one of [1] to [5], wherein at least one of the transparent resin member and the absorbing resin member contains a filler (B). [7] A welding method for laser welding a transparent resin member and an absorbing resin member, wherein At least one of the transparent resin member and the absorbing resin member comprises a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2), By laser welding the transparent resin member and the absorbing resin member, a melt pool is observed at the joint portion in a cross section that includes the normal line of the transparent resin member and is orthogonal to the scanning direction of the laser beam, The area of the melt pool is more than 1.00 mm 2 2 and 3.01 mm 2 2 or less, a method for manufacturing a laser welded product, comprising the welding method for obtaining the laser welded product. [8] The method for manufacturing a laser-welded product according to [7], wherein the laser-welded product is a laser-welded product according to any one of [1] to [6]. [Effects of the Invention]

[0008] The present invention provides a laser-welded product containing a semi-aromatic polyamide resin, which exhibits high welding strength between the permeable resin member and the absorbent resin member, and suppresses the generation of burrs, as well as a method for manufacturing a laser-welded product. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram illustrating a method for obtaining a cross-section of a laser-welded product. [Figure 2] This is a schematic diagram illustrating the molten pool area of ​​laser-welded products. [Modes for carrying out the invention]

[0010] 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 numerical values ​​before and after it are included as the lower and upper limits. Furthermore, the upper and lower limits of the numerical values ​​in this specification are given as examples of this embodiment, regardless of the combination of upper and lower limits. In this specification, a preferred combination of embodiments is a more preferred embodiment. In this specification, all physical properties and characteristic values ​​shall be those at 23°C unless otherwise specified.

[0011] In this specification, unless otherwise specified, the number-average molecular weight may be measured in accordance with paragraph 0047 of Japanese Patent Application Publication No. 2018-165298, which is incorporated herein by reference.

[0012] 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, 2025 shall apply. If the measurement methods, etc., described in the standards shown in this specification are obsolete as of January 1, 2025, the standards in effect at the time of obsolete shall apply. Figures 1 and 2 may not accurately reflect reality in terms of scale and other factors.

[0013] The laser-welded product of this embodiment is a laser-welded product of a transparent resin member and an absorbent resin member, having a joint portion formed by laser welding of the transparent resin member and the absorbent resin member, wherein at least one of the transparent resin member and the absorbent resin member comprises a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2), and in a cross-section that includes the normal to the transparent resin member and is perpendicular to the scanning direction of the laser beam, a molten pool is observed in the joint portion, and the area of ​​the molten pool is 1.00 mm². 2 Ultra 3.01mm 2 The following characteristics apply: By adopting this configuration, it becomes possible to provide laser-welded products containing semi-aromatic polyamide resin, which have high welding strength between the permeable resin member and the absorbent resin member, and suppress the generation of burrs. Laser-welded products containing semi-aromatic polyamide resins can be expected to have higher mechanical strength than laser-welded products containing aliphatic polyamide resins. However, in the case of laser-welded products containing semi-aromatic polyamide resins, the laser welding strength of the transparent resin component and the absorbing resin component may be inferior. Here, by increasing the molten pool area at the joint between the permeable resin member and the absorbent resin member, the joint surface area increases, and therefore, the welding strength is expected to increase. However, the inventors' investigations revealed that if the molten pool area at the joint is large, burrs may be generated. In this embodiment, we discovered that by adjusting the molten pool area, we could achieve high welding strength and suppress the generation of burrs, thus completing the present invention.

[0014] The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is just one example of an embodiment of the present invention and is not limited to these.

[0015] <Laser-welded products> This embodiment is a laser-welded product in which a transparent resin member and an absorbent resin member are laser-welded together. The laser-welded product of this embodiment has a joint formed by laser welding. In this specification, the term "jointed portion" refers to the portion where a transparent resin member and an absorbent resin member are joined by laser welding, where the absorbent resin member melts, the transparent resin member melts upon receiving heat from the melted portion, and these molten regions solidify in contact with each other, thereby joining the transparent resin member and the absorbent resin member.

[0016] The aforementioned "joint portion" may be present in one or more locations within the laser-welded product. Having a joint portion is expected to have effects such as joining parts together to form a composite structure, or creating a sealed structure.

[0017] The laser irradiation path is not particularly limited, but for example, when joining parts, it can be an open path with a start point and an end point that are far apart, and when producing a laser-welded product with a sealed structure, it can be a closed path where the end point coincides with any point on the path (including the start point). The shape of the open path is not particularly limited and may be a straight line, a curve, or a combination thereof. The shape of the closed path is not particularly limited and can be appropriately adjusted depending on the shape of the laser-welded product with a sealed structure.

[0018] The laser-welded product of this embodiment only needs to have at least a transparent resin member and an absorbent resin member joined together, and the transparent resin member and the absorbent resin member to be joined may each be at two or more points.

[0019] A transparent resin component is a component through which laser light passes. The transmission of laser light may be selective. In particular, by incorporating a light-transmitting dye (also called a photoselective dye), it is possible to selectively transmit laser light while maintaining aesthetic appeal. An absorbent resin component is a component that absorbs laser light, generates heat, and melts.

[0020] In this embodiment, the laser-welded product includes the normal to the transparent resin member, and a molten pool is observed at the joint in a cross-section perpendicular to the scanning direction of the laser beam. As shown in Figure 1, the normal N of the transparent resin member 1 is defined. The normal N is a line perpendicular to the tangent plane. If the transparent resin member or the absorbent resin part is a curved surface, the normal N is a line perpendicular to the tangent to the curved surface. In Figure 1, 2 is the absorbent resin member. The normal to the absorbent resin member also usually coincides with the normal N. In this specification, the optical axis of a laser beam refers to the axis that coincides with the direction of propagation of the laser beam. In a flat-head type laser where the laser irradiation port itself moves, the direction of movement of the laser irradiation port is defined as the scanning direction of the laser beam. In a galvanometer-type laser, where the laser is controlled by the angle of a mirror installed at a fixed irradiation port, the direction of propagation of the laser beam reflected by the mirror is defined as the scanning direction of the laser beam. In Figure 1, La1 and La2 are the optical axes of the laser beam, and La is the scanning direction of the laser beam. In this embodiment, the laser-welded product includes the normal N of the transparent resin member or the absorbent resin member, and a molten pool is observed in a cross-section S perpendicular to the scanning direction La of the laser beam. The molten pool refers to the region where the absorbent resin member has melted, the adjacent transparent resin member has also melted, and they have re-solidified.

[0021] The area of ​​the molten pool is 1.00 mm². 2 Ultra 3.01mm 2 The following is 1.05 mm 2 Preferably, it is 1.16 mm or more. 2 It is more preferable that the amount be greater than or equal to 1.20 mm 2 It is even more preferable that the amount be greater than or equal to 1.45 mm 2It is even more preferable that the amount be greater than or equal to 1.60 mm 2 It is even more preferable that the above be the case, and 1.70 mm 2 It is even more preferable that the above is true, and also 2.80 mm 2 Preferably, the following: 2.50 mm 2 The following is more preferable: 2.30 mm 2 It is even more preferable that the following be the case: 2.10 mm 2 It is even more preferable that the following be the case: 2.05 mm 2 It is even more preferable that the following conditions are met. Setting the value above the lower limit tends to further improve the laser welding strength. Setting the value below the upper limit tends to effectively suppress the generation of burrs. Methods for adjusting the molten pool area to the above range include using a resin composition containing a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2) as the permeable resin member and / or absorbing resin member; using a resin composition with a cooling crystallization temperature (Tc) of 170-230°C; and adjusting the total energy input during laser welding, among other combinations. Of course, it goes without saying that adjustments can also be made by other methods.

[0022] The area of ​​the molten pool in a laser-welded product is calculated by first obtaining a cross-section of the laser-welded product using the following method, and then calculating the area of ​​the molten pool using the following method.

[0023] • How to obtain a cross-section First, the laser-welded product is cut to expose the cross-section including the joint. At this time, the laser-welded product is cut in a direction that includes the normal to the transparent resin component and is perpendicular to the scanning direction of the laser beam. The exposed cross-section is observed with an optical microscope to obtain an optical microscope image. For example, a VHX6000 manufactured by Keyence Corporation can be used as the optical microscope. The magnification at this time is 50x.

[0024] • Method for calculating the area of ​​the melting pool The optical microscope image of the cross-section of the laser-welded product obtained by the method described above can be measured using the function of the device to calculate the area of ​​a specified region. For specifying the region to measure the area of ​​the molten pool, for example, the outer perimeter of the molten pool is specified so as to pass through both ends of the maximum diameter length x shown in Figure 2 and both ends of the maximum diameter y perpendicular to x. An example of region specification is shown by a dashed line in Figure 2.

[0025] To clearly observe the molten pool, you may perform polishing work on the laser-welded area before cutting it with a band saw or other cutting tool and then observing it.

[0026] The polishing method is not particularly limited, but using a rotary polishing device is preferable because it allows for uniform polishing of the observation area.

[0027] Furthermore, etching may be performed on the observation area to allow for clearer observation of the molten pool. The etching method is not particularly limited, but chemical etching that damages the object is preferred.

[0028] <Welding strength / molten pool area> Furthermore, in this embodiment, the welding strength (unit: N) of the laser-welded product between the transparent resin member and the absorbent resin member is divided by the molten pool area (welding strength / molten pool area), and this value is 500 N / mm². 2 It is preferable that the value be above the above lower limit. By setting it above the lower limit, warping can be suppressed more effectively. The aforementioned welding strength / molten pool area is 600 N / mm². 2 Preferably, it is 1000 N / mm² or higher, and also 1000 N / mm². 2 Preferably, the following: 700 N / mm 2 It is more preferable that the value be less than the above upper limit. By keeping it below the upper limit, the welding strength can be increased.

[0029] <Permeable resin members and absorbent resin members> In this embodiment, at least one of the permeable resin member and the absorbent resin member includes a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2). In this embodiment, the remaining of the permeable resin member and the absorbent resin member includes a thermoplastic resin. Examples of thermoplastic resins include polyamide resins, olefin resins, vinyl resins, styrene resins, acrylic resins, polyphenylene ether resins, polyester resins, polycarbonate resins, and polyacetal resins, with polyamide resins and / or polyphenylene ether resins being preferred. The first form of the thermoplastic resin in this embodiment is one in which a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2) are included, and the total amount of the semi-aromatic polyamide resin (A1) and the aliphatic polyamide resin (A2) is 90% by mass or more (preferably 95% by mass or more, more preferably 97% by mass or more) of the thermoplastic resin. The second form of the thermoplastic resin in this embodiment is one that includes a semi-aromatic polyamide resin (A1), an aliphatic polyamide resin (A2), and a polyphenylene ether resin, wherein the total amount of the semi-aromatic polyamide resin (A1), aliphatic polyamide resin (A2), and polyphenylene ether resin is 90% by mass or more (preferably 95% by mass or more, more preferably 97% by mass or more) of the thermoplastic resin.

[0030] In this embodiment, at least one of the permeable resin member and the absorbent resin member preferably contains 5 parts by mass or more, more preferably 10 parts by mass or more, and preferably less than 50 parts by mass of aliphatic polyamide resin (A2) per 100 parts by mass of the total of semi-aromatic polyamide resin (A1) and aliphatic polyamide resin (A2). With this configuration, the molten pool area can be more easily set to 1.00 mm². 2 Ultra 3.01mm 2 The following adjustments will be possible. In this embodiment, the permeable resin member is composed of, excluding the filler (B) which is added as needed, preferably 90% by mass or more, more preferably 95% by mass or more, a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2), as well as a polyphenylene ether resin which is added as needed. In this embodiment, the absorbent resin member is composed of, preferably 90% by mass or more, more preferably 95% by mass or more, of the components excluding the filler (B) which is added as needed, a semi-aromatic polyamide resin (A1), an aliphatic polyamide resin (A2), and a polyphenylene ether resin which is added as needed.

[0031] In this embodiment, it is preferable that at least one of the permeable resin member and the absorbent resin member, preferably both, independently has a cooling crystallization temperature (Tc) of 170°C or higher, more preferably 180°C or higher, even more preferably 190°C or higher, even more preferably 195°C or higher, and also preferably 240°C or lower, more preferably 230°C or lower, even more preferably 220°C or lower, even more preferably 215°C or lower, and may also be 210°C or lower. Furthermore, it is preferable that the crystallization temperature (Tc) during cooling is within the range of the resin composition (e.g., pellets) used to form the permeable resin member and / or absorbent resin member described later. The crystallization temperature (Tc) during cooling is measured according to the description in the examples below. Such components and resin compositions that satisfy Tc are achieved by adjusting the composition of the resin composition, including the blending ratio of semi-aromatic polyamide resin (A1) and aliphatic polyamide resin (A2), and additives, which will be described in detail later.

[0032] In this embodiment, it is preferable that the permeable resin member and the absorbent resin member are each formed independently from a resin composition. In this embodiment, the permeable resin member is preferably formed from a resin composition comprising a semi-aromatic polyamide resin (A1), an aliphatic polyamide resin (A2), and a filler (B), and may further, as necessary, contain at least one selected from maleic anhydride-modified polyphenylene ether resin, a flame retardant, a flame retardant additive, a light-transmitting dye, and other components (details of which will be described later). In this embodiment, the permeable resin member is preferably a resin composition comprising a semi-aromatic polyamide resin (A1), an aliphatic polyamide resin (A2), and a filler (B), and further blended as needed, a maleic anhydride-modified polyphenylene ether resin, a light-permeable dye, a flame retardant, a flame retardant aid, a nucleating agent, and a mold release agent, with the total amount being 90% by mass or more (preferably 95% by mass or more, more preferably 97% by mass or more).

[0033] In this embodiment, the absorbent resin member is preferably formed from a resin composition comprising a semi-aromatic polyamide resin (A1), an aliphatic polyamide resin (A2), and a filler (B), and may further contain, as necessary, at least one selected from maleic anhydride-modified polyphenylene ether resin, a flame retardant, a flame retardant additive, a light-absorbing dye, and other components (details of which will be described later). In this embodiment, the absorbent resin member is preferably a resin composition comprising a semi-aromatic polyamide resin (A1), an aliphatic polyamide resin (A2), and a filler (B), and further blended as needed, a maleic anhydride-modified polyphenylene ether resin, a light-absorbing dye, a flame retardant, a flame retardant aid, a nucleating agent, and a mold release agent, with the total amount accounting for 90% by mass or more (preferably 95% by mass or more, more preferably 97% by mass or more).

[0034] In this embodiment, it is preferable that the permeable resin member and the absorbent resin member have 80% or more of their composition in common by mass, more preferably 85% or more by mass, even more preferably 90% or more by mass, and even more preferably 95% or more by mass.

[0035] The following describes each component of the above resin composition.

[0036] <Semi-aromatic polyamide resin (A1)> Examples of semi-aromatic polyamide resins (A1) include polyamide resins containing diamine-derived structural units and dicarboxylic acid-derived structural units, wherein 20 to 80 mol% (preferably 30 to 80 mol%, more preferably 40 to 70 mol%) of the total structural units of the diamine-derived and dicarboxylic acid-derived structural units are structural units containing aromatic rings. By using such a semi-aromatic polyamide resin, the mechanical strength of the resulting laser-welded product can be increased. Examples of semi-aromatic polyamide resins (A1) include terephthalic acid-based polyamide resins (polyamide 6T, polyamide 6T / 6I, polyamide 9T, polyamide 10T), and xylylenediamine-based polyamide resins, which will be described later.

[0037] In this embodiment, a polyamide resin containing diamine-derived structural units and dicarboxylic acid-derived structural units is preferred, wherein 50 mol% or more of the diamine-derived structural units are derived from xylylenediamine, and 50 mol% or more of the dicarboxylic acid-derived structural units are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms (hereinafter sometimes referred to as "xylylenediamine-based polyamide resin").

[0038] The diamine-derived structural units of the xylylenediamine-based polyamide resin are more preferably derived from xylylenediamine (preferably para-xylylenediamine and / or meta-xylylenediamine, more preferably meta-xylylenediamine) in amounts of 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and especially most preferably 99 mol% or more.

[0039] The xylylenediamine is preferably para-xylylenediamine and / or meta-xylylenediamine. The xylylenediamine preferably contains 0 to 100 mol% meta-xylylenediamine and 100 to 0 mol% para-xylylenediamine (provided that the sum of meta-xylylenediamine and para-xylylenediamine does not exceed 100 mol%), more preferably 10 to 100 mol% meta-xylylenediamine and 90 to 0 mol% para-xylylenediamine, even more preferably 30 to 100 mol% meta-xylylenediamine and 70 to 0 mol% para-xylylenediamine, even more preferably 60 to 100 mol% meta-xylylenediamine and 40 to 0 mol% para-xylylenediamine, and even more preferably 90 to 100 mol% meta-xylylenediamine and 10 to 0 mol% para-xylylenediamine. In xylylenediamine-based polyamide resins, it is preferable that the total of constituent units derived from para-xylylenediamine and meta-xylylenediamine constitutes preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, even more preferably 98 mol% or more, and even more preferably 99 mol% or more of the constituent units derived from diamine. The upper limit of the total of the constituent units derived from para-xylylenediamine and meta-xylylenediamine is 100 mol%.

[0040] Diamines other than meta-xylylenediamine and para-xylylenediamine that can be used as raw material diamine components for xylylenediamine-based polyamide resins include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine, as well as 1,3-bis( Examples include alicyclic diamines such as aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane, as well as aromatic ring-containing diamines such as bis(4-aminophenyl) ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. One or more of these can be used in combination.

[0041] On the other hand, of the dicarboxylic acid-derived constituent units of the xylylenediamine-based polyamide resin, more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and especially most preferably 99 mol% or more, are α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms. The α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms are more preferably derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 12 carbon atoms, even more preferably from α,ω-linear aliphatic dicarboxylic acids having 4 to 9 carbon atoms, and even more preferably from adipic acid.

[0042] Examples of dicarboxylic acid components other than those mentioned above include phthalate compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. One or more of these can be used in combination.

[0043] It should be noted that while xylylenediamine-based polyamide resins are mainly composed of diamine-derived and dicarboxylic acid-derived structural units, they do not completely exclude other structural units, and may also contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, "main component" refers to the structural unit in the xylylenediamine-based polyamide resin in which the total number of diamine-derived and dicarboxylic acid-derived structural units is the largest among all structural units. In this embodiment, it is preferable that the total of diamine-derived and dicarboxylic acid-derived structural units in the xylylenediamine-based polyamide resin accounts for 90% by mass or more of the total structural units, more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0044] The semi-aromatic polyamide resin (A1) used in this embodiment may be recycled products (including recovered products, material recycled products, chemical recycled products, etc.), rejected products, or scraps from thermoplastic resin molding.

[0045] The melting point of the semi-aromatic polyamide resin (A1) is preferably 150°C or higher, more preferably 180°C or higher, even more preferably 200°C or higher, preferably 350°C or lower, more preferably 330°C or lower, even more preferably 300°C or lower, and even more preferably 250°C or lower.

[0046] The semi-aromatic polyamide resin (A1) preferably has a lower limit of number average molecular weight (Mn) of 6,000 or more, more preferably 8,000 or more, even more preferably 10,000 or more, preferably 35,000 or less, more preferably 30,000 or less, even more preferably 25,000 or less, and even more preferably 20,000 or less. Within this range, heat resistance, elastic modulus, dimensional stability, and moldability are improved.

[0047] In this embodiment, the content of the semi-aromatic polyamide resin (A1) in the resin composition is preferably 25% by mass or more, more preferably 30% by mass or more, preferably 50% by mass or less, and more preferably 45% by mass or less. In this embodiment, the resin composition may contain only one type of semi-aromatic polyamide resin (A1), 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.

[0048] <Aliphatic polyamide resin (A2)> Examples of the aliphatic polyamide resin (A2) used in this embodiment include polyamide 4, polyamide 46, polyamide 6, polyamide 66, polyamide 666, polyamide 610, polyamide 11, polyamide 12, and at least one of polyamide 6, polyamide 66, and polyamide 666 is preferred, with polyamide 66 being more preferred.

[0049] The aliphatic polyamide resin (A2) used in this embodiment may be recycled products (including recovered products, material recycled products, chemical recycled products, etc.), rejected products, or scraps from thermoplastic resin molding.

[0050] <Polyphenylene ether resin> Examples of polyphenylene ether resins used in this embodiment include poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, and poly(2-methyl-6-propyl-1,4-phenylene) ether, with poly(2,6-dimethyl-1,4-phenylene) ether being particularly preferred. Preferred polyphenylene ether resins typically have an intrinsic viscosity of 0.2 to 0.6 dL / g, more preferably 0.3 to 0.5 dL / g, as measured in chloroform at 30°C. If the intrinsic viscosity is less than 0.2 dL / g, impact resistance may be insufficient, and if it exceeds 0.6 dL / g, moldability and appearance tend to deteriorate. The intrinsic viscosity within the above range may be adjusted by using two or more polyphenylene ether resins with different intrinsic viscosities in combination.

[0051] The polyphenylene ether resin used in this embodiment may be a maleic anhydride-modified polyphenylene ether resin. A maleic anhydride-modified polyphenylene ether resin is a polyphenylene ether resin that has been modified with maleic anhydride. Furthermore, the amount of maleic anhydride in the maleic anhydride-modified polyphenylene ether resin is preferably 0.01 to 1.0% by mass, and more preferably 0.1 to 0.7% by mass, in terms of maleic acid content. High mechanical strength can be achieved by keeping the amount within this range. Here, the amount of maleic anhydride in the maleic anhydride-modified polyphenylene ether resin refers to the mass obtained by converting the amount of maleic anhydride used to modify the polyphenylene ether resin into maleic acid content.

[0052] If the resin composition used in this embodiment contains a polyphenylene ether resin, its content is preferably 1% by mass or more of the total amount of thermoplastic resin contained in the resin composition, may be 3% by mass or more, 5% by mass or more, and preferably 15% by mass or less, may be 10% by mass or less, and may be 7% by mass or less.

[0053] <Filler (B)> The resin composition used in this embodiment preferably contains 40 to 95 parts by mass of filler (B). By including filler (B), high mechanical strength can be achieved in the resulting laser-welded product. In this embodiment, it is more preferable to use a filler (B) that has been surface-treated with a surface treatment agent such as a coupling agent in the resin composition. A filler (B) with a surface treatment agent attached is preferable because it has excellent durability, resistance to humid heat, resistance to hydrolysis, and resistance to thermal shock.

[0054] Examples of filler (B) include carbon filler and glass filler, with glass filler being preferred. The glass consists of glass compositions such as A glass, C glass, E glass, S glass, R glass, M glass, and D glass, with E glass (alkali-free glass) being particularly preferred.

[0055] The filler (B) used in the resin composition used in this embodiment includes glass fibers, flake glass, plate glass, glass beads, and the like, with glass fibers and flake glass being preferred, and glass fibers being more preferred. Glass fibers may be single fibers or multiple single fibers twisted together. The glass fibers can take any form, including single fibers, "glass roving" made by continuously winding multiple single fibers twisted together, "chopped strands" cut to a length of 1 to 10 mm, or "milled fibers" crushed to a length of 10 to 500 μm. Such glass fibers are readily available, commercially sold by Asahi Fiber Glass Co., Ltd. under the product names "Glasslon Chopped Strand" and "Glasslon Milled Fiber," and by Nippon Electric Glass Co., Ltd. under the product name "E Glass Fiber Chopped Strand." Different forms of glass fibers can also be used in combination.

[0056] Furthermore, the glass fibers used in this embodiment may have a circular or non-circular cross-section. By using glass fibers with a non-circular (especially flat) cross-section, warping of the resulting laser-welded product can be suppressed more effectively. In addition, in this embodiment, even if glass fibers with a circular cross-section are used, warping can be effectively suppressed by using a polyamide resin that crystallizes sufficiently even at low mold temperatures.

[0057] The content of filler (B) in the resin composition used in this embodiment is preferably 1 part by mass or more, more preferably 50 parts by mass or more, even more preferably 80 parts by mass or more, and even more preferably 100 parts by mass or more, per 100 parts by mass of aromatic polyamide resin (A1). Setting the content above the lower limit tends to further improve the mechanical strength of the laser-welded product. The upper limit of the content of filler (B) is preferably 200 parts by mass or less, more preferably 180 parts by mass or less, and more preferably 165 parts by mass or less, per 100 parts by mass of aromatic polyamide resin. Setting the content below the upper limit tends to maintain a better appearance.

[0058] The content of filler (B) in the resin composition used in this embodiment is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 45% by mass or more, and preferably 60% by mass or less, and more preferably 55% by mass or less, based on 100% by mass of the resin composition. The resin composition used in this embodiment may contain only one type of filler (B), or it may contain two or more types. If it contains two or more types, the total amount will be within the above range. Note that the amount of filler (B) in this embodiment includes the amounts of the sizing agent and the surface treatment agent.

[0059] <Light-transmitting dye> In this embodiment, the resin composition (particularly the resin composition for forming the transparent resin member) may contain a light-transmitting dye (light-selective transparent dye). By including a light-transmitting dye, the resulting laser-welded product can be given a color, improving its appearance. In particular, the color of the light-selective transparent resin member molded from the resin composition and the absorbent resin member (details to be described later) can be unified, improving the appearance of the resulting laser-welded product. The light-transmitting dye used in this embodiment is typically a black dye, and specifically includes dyes having a skeleton selected from nigrosine, naphthalocyanine, aniline black, phthalocyanine, porphyrin, perinone, quaterylene, azo, anthraquinone, pyrazolone, squamate derivative, perylene, chromium complex, and immonium skeleton, with dyes having a perylene skeleton being preferred. Black pigment refers to a pigment that is perceived as black by human vision, and includes mixtures of two or more chromatic pigments that exhibit the color black. A light-transmitting dye is, for example, a dye that, when mixed with polyamide resin, 30% by mass of glass filler, and 0.2% by mass of a dye (a dye thought to be a light-selective transmittance dye) to a total of 100% by mass, and molded into a 1 mm thick body, exhibits a transmittance of 20% or more at a wavelength of 1060 nm as measured by a transmittance measuring instrument without an integrating sphere, as described later. The light-transmitting dye may be a dye or a pigment, but a pigment is preferred. Examples of commercially available products include the colorants (pigments) e-BIND LTW-8731H and e-BIND LTW-8701H from Orient Chemical Industry Co., Ltd., the colorants Plast Yellow 8000, Plast Red M 8315, and Oil Green 5602 from Arimoto Chemical Co., Ltd., the colorants Macrolex Yellow 3G, Macrolex Red EG, and Macrolex Green 3 from LANXESS, and the colorants Spectrasence Black K0087 and K0088 from BASF (all manufactured by Color & Effects Japan Co., Ltd.).

[0060] The content of the light-transmitting dye in the resin composition is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and may be 0.08 parts by mass or more, 0.1 parts by mass or more, or 0.15 parts by mass or more, per 100 parts by mass of the resin composition. Furthermore, the upper limit of the content of the light-transmitting dye is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, even more preferably 1 part by mass or less, even more preferably 0.8 parts by mass or less, and even more preferably 0.5 parts by mass or less, per 100 parts by mass of the resin composition. The light-transmitting dye may contain only one type or two or more types. If two or more types are included, it is preferable that the total amount be within the above range. Furthermore, it is preferable that the resin composition for forming the permeable resin member is substantially free of carbon black. Substantially free means, for example, that the amount of carbon black is 0.0001% by mass or less of the resin composition.

[0061] <Light-absorbing dyes> In this embodiment, the resin composition (particularly the resin composition for forming the absorbent resin member) may contain a light-absorbing dye. The light-absorbing dyes include dyes having absorption wavelengths in the range of the irradiated laser light wavelength, for example, in this embodiment, in the range of 900 nm to 1100 nm. Furthermore, the light-absorbing dyes include dyes that, for example, when 0.3 parts by mass are blended with 100 parts by mass of polyamide resin and a molded article with a thickness of 1 mm is formed, the light transmittance is measured to be less than 30%, and even less than 10%. Specific examples of light-absorbing dyes include inorganic pigments (black pigments such as carbon black (e.g., acetylene black, lamp black, thermal black, furnace black, channel black, Ketjen black, etc.), red pigments such as iron oxide red, orange pigments such as molybdate orange, and white pigments such as titanium dioxide), and organic pigments (yellow pigments, orange pigments, red pigments, blue pigments, green pigments, etc.). Among these, inorganic pigments are generally preferred due to their strong opacity, and black pigments are even more preferred. These light-absorbing dyes may be used in combination of two or more types. The content of the light-absorbing dye is preferably 0.01 to 30 parts by mass per 100 parts by mass of the total of the semi-aromatic polyamide resin (A1) and the aliphatic polyamide resin (A2).

[0062] <Nuclear agent> The resin composition used in this embodiment may contain a nucleating agent. The nucleating agent is not particularly limited as long as it remains unmelted during the melting process and can act as a nucleus for crystals during the cooling process, but talc and calcium carbonate are preferred, with talc being more preferred. The number-average particle diameter of the nucleating agent is preferably 0.1 μm or more at the lower limit, more preferably 1 μm or more, and even more preferably 3 μm or more. The number-average particle diameter of the nucleating agent is preferably 40 μm or less at the upper limit, more preferably 30 μm or less, even more preferably 28 μm or less, even more preferably 15 μm or less, and even more preferably 10 μm or less.

[0063] The proportion of the nucleating agent in the resin composition used in this embodiment is preferably 0.01 to 3% by mass, more preferably 0.1% by mass or more, and even more preferably 2% by mass or less. The resin composition used in this embodiment may contain only one nucleating agent or two or more. When two or more are included, it is preferable that the total amount is within the above range.

[0064] <Release agent> The resin composition used in this embodiment may contain a mold release agent. Examples of release agents include aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds with a number average molecular weight of 200 to 15,000, polysiloxane-based silicone oils, ketone waxes, and fatty acid amides. Aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, and fatty acid amides are preferred, salts of aliphatic carboxylic acids and fatty acid amides are more preferred, and salts of fatty acid carboxylic acids are even more preferred. Details of the release agent can be found in paragraphs 0055 to 0061 of Japanese Patent Publication No. 2018-095706, and these contents are incorporated herein by reference. If the resin composition used in this embodiment contains a release agent, its content is preferably 0.05 to 3% by mass, more preferably 0.1 to 1% by mass, and even more preferably 0.1 to 0.8% by mass. The resin composition used in this embodiment may contain only one type of release agent, 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.

[0065] <Flame retardant> The resin composition used in this embodiment may contain a flame retardant. Examples of flame retardants include halogen-based flame retardants and phosphorus-based flame retardants, with phosphorus-based flame retardants being preferred and phosphazene-based flame retardants being more preferred. By incorporating a phosphazene-based flame retardant, it is possible to enhance the flame retardancy of the resin composition and, compared to brominated polystyrene-based flame retardants, to expect superior coloring power of LTW dyes and excellent compatibility with the resin. The phosphazene-based flame retardant used in this embodiment is an organic compound having a -P=N- bond in its molecule, and is preferably at least one selected from the group consisting of a cyclic phosphazene-based flame retardant represented by formula (1), a chain-like phosphazene-based flame retardant represented by formula (2), and a crosslinked phosphazene-based flame retardant obtained by crosslinking the phosphazene-based flame retardant with a crosslinking group. The crosslinking group is an oxygen atom. The crosslinking group is the R of the cyclic phosphazene-based flame retardant (molecule) represented by formula (1). 1 and / or R 2 R of other molecules (cyclic phosphazene flame retardants represented by formula (1)) 1 and / or R 2 It is more preferable that the molecules are bridged by oxygen atoms.

[0066] [ka] In equation (1), a is an integer between 3 and 25, and R 1 and R 2 These may be the same or different groups and represent an alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aryloxy group, amino group, hydroxy group, aryl group, or alkylaryl group.

[0067] [ka] In equation (2), b is an integer between 3 and 10000, and R 3 and R 4These may be the same or different groups and represent an alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aryloxy group, amino group, hydroxy group, aryl group, or alkylaryl group. R 5 -N=P(OR 3 )3 units, -N=P(OR 4 )3 units, -N=P(O)OR 3 Base, -N=P(O)OR 4 It shows at least one selected from the elements, R 6 -P(OR 3 ) 4 units, -P(OR 4 ) 4 units, -P(O)(OR 3 )2 units, -P(O)(OR 4 ) Indicates at least one selected from the two units.

[0068] In formulas (1) and (2), examples of alkyl groups include C1-C15 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl, octyl, decyl, and dodecyl groups. C1-C6 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, and hexyl groups are preferred, and C1-C4 alkyl groups such as methyl, ethyl, and propyl groups are particularly preferred.

[0069] Examples of cycloalkyl groups include cyclopentyl groups and cyclohexyl groups, which have 5 to 14 carbon atoms, with cycloalkyl groups having 5 to 8 carbon atoms being preferred.

[0070] Examples of alkenyl groups include C2-C8 alkenyl groups such as vinyl groups and allyl groups. Examples of cycloalkenyl groups include C5-C12 cycloalkenyl groups such as cyclopentyl groups and cyclohexyl groups.

[0071] Examples of alkynyl groups include alkynyl groups with 2 to 8 carbon atoms, such as ethynyl and propynyl groups, and alkynyl groups having aryl groups as substituents, such as ethynylbenzene groups.

[0072] Examples of aryl groups include aryl groups having 6 to 20 carbon atoms, such as phenyl group, methylphenyl (i.e., tolyl) group, dimethylphenyl (i.e., xylyl) group, trimethylphenyl group, and naphthyl group. Among these, aryl groups having 6 to 10 carbon atoms are preferred, and phenyl groups are particularly preferred.

[0073] Examples of alkylaryl groups include aralkyl groups having 6 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups, but aralkyl groups having 7 to 10 carbon atoms are preferred, and benzyl groups are particularly preferred.

[0074] In particular, R in equation (1) 1 and R 2 , R in equation (2) 3 and R 4 However, those that are aryl groups or arylalkyl groups are preferred. By using such aromatic phosphazene-based flame retardants, the thermal stability of the resin composition can be more effectively enhanced. From this viewpoint, the above R 1 , R 2 , R 3 and R 4 It is more preferably an aryl group, and particularly preferably a phenyl group.

[0075] Examples of phosphazene-based flame retardants represented by formula (1) or formula (2) include (poly)tolyloxyphosphazenes such as phenoxyphosphazene, o-tolyloxyphosphazene, m-tolyloxyphosphazene, and p-tolyloxyphosphazene, (poly)xyloxyphosphazenes such as o,m-xylyloxyphosphazene, o,p-xylyloxyphosphazene, and m,p-xylyloxyphosphazene, o,m,p-trimethylphenyloxyphosphazene, and phenoxyphosphazene. Examples include (poly)phenoxytriloxyphosphazenes such as o-tolyloxyphosphazene, phenoxym-tolyloxyphosphazene, and phenoxyp-tolyloxyphosphazene; (poly)phenoxytriloxyxyloxyphosphazenes such as phenoxyo,m-xylyloxyphosphazene, phenoxyo,p-xylyloxyphosphazene, phenoxym,p-xylyloxyphosphazene; and phenoxyo,m,p-trimethylphenyloxyphosphazene.

[0076] As a cyclic phosphazene-based flame retardant represented by formula (1), R 1 and R 2 A cyclic phenoxyphosphazene in which a is a phenyl group is particularly preferred. Examples of such cyclic phenoxyphosphazene-based flame retardants include compounds such as phenoxycyclotriphosphazene, octaphenoxycyclotetraphosphazene, and decaffenoxycyclopentaphosphazene, which are obtained by reacting ammonium chloride and phosphorus pentachloride at a temperature of 120 to 130°C to obtain a mixture of cyclic and linear chlorophosphazene, from which cyclic chlorophosphazene such as hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, and decachlorocyclopentaphosphazene are isolated and then substituted with a phenoxy group. Furthermore, the cyclic phenoxyphosphazene-based flame retardant is preferably a compound in which a in formula (1) is an integer from 3 to 8, and may also be a mixture of compounds with different values ​​of a.

[0077] The average of a above is preferably 3 to 5, and more preferably 3 to 4. In particular, a mixture of compounds in which a=3 accounts for 50% by mass or more, a=4 accounts for 10 to 40% by mass, and a=5 or higher accounts for a total of 30% by mass or less is preferred.

[0078] As a chain-like phosphazene flame retardant represented by formula (2), R 3 and R 4 A linear phenoxyphosphazene flame retardant in which is a phenyl group is particularly preferred. Examples of such linear phenoxyphosphazene flame retardants include compounds obtained by oxidative polymerization of hexachlorocyclotriphosphazene obtained by the above method at a temperature of 220 to 250°C, and substituting the resulting linear dichlorophosphazene with a degree of polymerization of 3 to 10000 with a phenoxy group. In the linear phenoxyphosphazene flame retardant, b in formula (2) is preferably 3 to 1000, more preferably 3 to 100, and even more preferably 3 to 25.

[0079] Examples of crosslinked phosphazene-based flame retardants include compounds having a crosslinked structure of a 4,4'-diphenylene group, such as compounds having a crosslinked structure of a 4,4'-sulfonyldiphenylene (i.e., a bisphenol S residue), compounds having a crosslinked structure of a 2,2-(4,4'-diphenylene)isopropylidene group, compounds having a crosslinked structure of a 4,4'-oxydiphenylene group, and compounds having a crosslinked structure of a 4,4'-thiodiphenylene group.

[0080] Furthermore, as a crosslinked phosphazene-based flame retardant, R in formula (1) 1 , R 2 A cyclic phenoxyphosphazene flame retardant in which is a phenyl group is crosslinked by the above crosslinking group, or a crosslinked phenoxyphosphazene flame retardant in formula (2) where R 3 , R 4A crosslinked phenoxyphosphazene flame retardant, in which a chain-like phenoxyphosphazene flame retardant having a phenyl group is crosslinked by the above crosslinking group, is preferred from the viewpoint of flame retardancy, and a crosslinked phenoxyphosphazene flame retardant, in which a cyclic phenoxyphosphazene flame retardant is crosslinked by the above crosslinking group, is more preferred.

[0081] The flame retardant content in the resin composition used in this embodiment is preferably 1% by mass or more, more preferably 2% by mass or more, may be 3% by mass or more, preferably 20% by mass or less, preferably 15% by mass or less, even more preferably 12% by mass or less, even more preferably 10% by mass or less, and still more preferably 7% by mass or less. By adjusting the amount of flame retardant blended, the laser weldability can be further improved even when the total energy input during laser welding is reduced. The resin composition used in this embodiment may contain only one type of flame retardant, 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.

[0082] <Flame retardant additive> If the resin composition used in this embodiment contains a flame retardant, it may also contain a flame retardant enhancer. As a flame retardant enhancer, an antimony compound is preferred when the flame retardant is a halogen-based flame retardant, and a zinc metal oxide is preferred when the flame retardant is a phosphorus-based flame retardant. The resin composition used in this embodiment particularly includes a phosphazene-based flame retardant as a flame retardant and a zinc metal oxide as a flame retardant aid. By incorporating zinc metal oxide, the flame retardancy of the resin composition can be enhanced while minimizing the impact on the permeability of the thermoplastic resin. Zinc borate is preferred as the zinc metal oxide. Zinc borate can be obtained from zinc oxide and boric acid, and examples include hydrates and anhydrous forms such as ZnO·B2O3·2H2O and 2ZnO·3B2O3·3.5H2O.

[0083] The content of the flame retardant additive in the resin composition used in this embodiment is preferably 0.5% by mass or more, more preferably 0.1% by mass or more, may be 1% by mass or more, preferably 10% by mass or less, preferably 7% by mass or less, even more preferably 3% by mass or less, and even more preferably 3% by mass or less. The resin composition used in this embodiment may contain only one type of flame retardant additive, 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.

[0084] <Other ingredients> The resin composition used in this embodiment may contain other components without departing from the spirit of the present invention. Examples of such additives include light stabilizers, antioxidants, ultraviolet absorbers, fluorescent whitening agents, anti-dripping agents, antistatic agents, anti-fogging agents, anti-blocking agents, flow improvers, plasticizers, dispersants, and antibacterial agents. The content of these other components is preferably less than 10% by mass, more preferably less than 7% by mass, even more preferably less than 5% by mass, even more preferably less than 3% by mass, and may be less than 1% by mass in the resin composition. Furthermore, the resin composition may contain additives described in paragraphs 0047 to 0103 of International Publication No. 2021 / 241471, without departing from the spirit of the present invention, and this is incorporated herein.

[0085] <Method for producing resin compositions> The method for producing the resin composition used in this embodiment is not particularly limited, but a method using a single-screw or twin-screw extruder equipped with a vent for evaporation is preferred. Each component may be supplied to the kneader all at once, or the polyamide resin component may be supplied first, followed by the other components in sequence. Fillers are preferably supplied from the middle of the extruder to suppress crushing during kneading. In addition, two or more components selected from each component may be mixed and kneaded in advance.

[0086] The method for manufacturing the permeable resin member and the absorbent resin member using the resin composition used in this embodiment is not particularly limited, and molding methods commonly used for thermoplastic resins, such as injection molding, hollow molding, extrusion molding, and press molding, can be applied. In this case, injection molding is a particularly preferred molding method due to its good fluidity. When performing injection molding, it is preferable to control the resin temperature to 250 to 310°C.

[0087] <Laser welding method> Next, the laser welding method will be described. In this embodiment, a laser-welded product can be manufactured by laser welding a transparent resin member and an absorbent resin member. When laser welding, the area of ​​the molten pool described above is 1.00 mm². 2 Ultra 3.01mm 2 The laser welding is performed as follows: The light source used for laser welding is preferably a laser with a wavelength in the range of 800 to 1100 nm.

[0088] As mentioned above, the laser light source used for laser welding is preferably a light source with a wavelength in the range of 800 to 1100 nm, more preferably a laser with a wavelength in the range of 900 to 1100 nm, even more preferably a laser with a wavelength in the range of 1000 to 1100 nm, and even more preferably a laser with a wavelength of 1050 to 1100 nm. The transparent resin member and the absorbent resin member may be laser-welded by 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 welded area is heated almost simultaneously, so the residual stress in the resulting laser-welded product tends to be small. Details of the galvanoscanning laser welding method can be found in Japanese Patent Publication No. 2022-11052, which is incorporated herein by reference.

[0089] For laser welding, the total energy input is preferably 25 J or more, more preferably 30 J or more, even more preferably 35 J or more, even more preferably 40 J or more, preferably 70 J or less, more preferably 65 J or less, even more preferably 60 J or less, even more preferably 55 J or less, and even more preferably 50 J or less.

[0090] The laser-welded products obtained by laser welding in this embodiment can be applied to a variety of uses, such as various storage containers, electrical and electronic equipment components, office automation (OA) equipment components, home appliance components, mechanical components, and vehicle components. In particular, they can be suitably used for food containers, pharmaceutical containers, oil and fat product containers, hollow vehicle components (various tanks, intake manifold components, camera housings, etc.), vehicle electrical components (various control units, ignition coil components, etc.), advanced driver-assistance system (ADAS) related components, motor components, various sensor components, connector components, switch components, circuit breaker components, relay components, coil components, transformer components, lamp components, and the like. In particular, the resin composition or kit used in this embodiment is suitable for advanced driver-assistance system (ADAS) related components (especially in-vehicle camera components). Related components used in ADAS (Advanced Driver-Assistance Systems) include cameras for image data, LiDAR and millimeter-wave radar components for distance data, GPS and odometer components for position data, and IMU (Inertial Measurement Unit) components for speed, acceleration, and attitude data. [Examples]

[0091] 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.

[0092] 1.Raw materials The following ingredients were used. [Table 1]

[0093] <Synthesis Example 1: Synthesis of MXD6> 60.00 mol of accurately weighed adipic acid was placed in a jacketed reaction vessel equipped with a stirrer, partial condenser, condenser, thermometer, dropping tank, and nitrogen gas inlet tube. The vessel was thoroughly purged with nitrogen, and the temperature was raised to 180°C under a small stream of nitrogen gas to dissolve the adipic acid and achieve a uniform fluid state. To this, 60 mol of metaxylylenediamine was added dropwise over 160 minutes with stirring. During this time, the internal pressure of the reaction system was maintained at atmospheric pressure, and the internal temperature was continuously raised to 250°C. Water distilled off with the addition of metaxylylenediamine was removed from the system through the partial condenser and condenser. After the addition of metaxylylenediamine was complete, the reaction was continued for 10 minutes while maintaining the liquid temperature at 250°C. Subsequently, the internal pressure of the reaction system was continuously reduced to 600 Torr over 10 minutes, and the reaction was continued for 20 minutes. During this time, the reaction temperature was continuously raised to 260°C. After the reaction was complete, the reaction vessel was pressurized with nitrogen gas to 0.3 MPa, and the polymer was removed as strands from a nozzle at the bottom of the polymerization tank. After water cooling, the strands were cut into pellets to obtain pellets of the molten polymer product.

[0094] <Manufacturing of flame retardant masterbatches> The polyphenylene ether resin, phosphazene-based flame retardant, zinc borate, and maleic anhydride shown in Table 1 were all added together in the proportions shown in Table 3 to a Henschel mixer (forced agitator with blades) and stirred for 2 minutes to obtain a blend. This blend was fed into an extruder (Shibaura Machinery Co., Ltd., TEM26SS) from the screw base using a twin-screw cassette weighing feeder (Kubota Corporation, CE-W-1-MP) and melt-mixed. The extruder temperature was set to 265°C. The strands exiting the die were cut into pellets using a pelletizer to obtain a flame retardant masterbatch.

[0095] <Examples of resin composition production 1-12> Of the components shown in Table 1, each component other than the resin and glass fibers was weighed in the proportions shown in Table 2 or Table 3 (unit: parts by mass), dry-blended, and then fed into a twin-screw extruder (Shibaura Machine Co., Ltd., TEM26SS) from the screw root using a twin-screw cassette weighing feeder (Kubota Corporation, CE-W-1-MP). The glass fibers were fed into the twin-screw extruder from the side using a vibrating cassette weighing feeder (Kubota Corporation, CE-V-1B-MP), melt-mixed with the resin components, etc., to obtain pellets (resin composition). The extruder temperature was set to 280°C. Furthermore, for manufacturing examples 11 and 12, the polyphenylene ether resin, phosphazene flame retardant, zinc borate, and maleic anhydride were prepared in advance as masterbatches and then fed into the twin-screw extruder (Shibaura Machinery Co., Ltd., TEM26SS) from the screw root using a twin-screw cassette weighing feeder (Kubota Corporation, CE-W-1-MP), similar to the other components, and the rest of the process was carried out in the same manner.

[0096] <Measurement of the crystallization temperature (Tc) of pellets during cooling> After drying the pellets at 120°C for 4 hours, differential scanning calorimetry (DSC) was performed using a Hitachi High-Tech DSC7020 under a nitrogen atmosphere, increasing the temperature from 30°C to 300°C at a rate of 20°C / min, holding at 300°C for 3 minutes, and then cooling at a rate of 20°C / min. The temperature at the peak of the exothermic peak observed during cooling was defined as the cooling crystallization temperature (Tc).

[0097] [Table 2]

[0098] [Table 3]

[0099] Examples 1-11, Comparative Examples 1-7 <Welding strength> The resin composition pellets obtained above were dried at 80°C for 12 hours, and then ASTM D638 standard 1.0 mm thick No. 4 dumbbell pieces (permeable resin component and absorbent resin component) were manufactured using an injection molding machine (manufactured by Japan Steel Works, Ltd., J-50ADS). The cylinder temperature was 280°C and the mold surface temperature was 130°C. The absorbent resin components were stacked on the opposite side of the gate so that they matched the combinations shown in Tables 4 to 7, and then welded using a Fine Devices diode laser welding machine (wavelength 940 nm). The welding conditions were: laser output: 30 W, number of scans: 5, feed rate: 70 (mm / s). The total energy input is shown in Tables 4 to 7. For the obtained laser-welded parts, a tensile testing machine (Instron "5544") was used to measure the breaking strength (in N) of the welded joint. The ends of the permeable resin member and the absorbent resin member opposite the welded joint were grasped, and a load was applied in the tensile direction at a tensile speed of 5 mm / min. The evaluation was as follows: A:1000N or more B: 700N or more, less than 1000N C: 300N or more, less than 700N D: Less than 300N

[0100] <Melting pool area (melting pool)> • How to obtain a cross-section For the laser-welded product described above, a cross-section perpendicular to the scanning direction of the laser beam was created by cutting the short side, including the joint, through the center, thereby exposing the molten pool. In other words, the laser-welded product was cut in a direction that included the normal to the transparent resin component and was perpendicular to the scanning direction of the laser beam.

[0101] Unnecessary portions not related to the observation of the molten pool were cut off, and the observation piece containing the molten pool was embedded in an EPOmount manufactured by Refinetech Co., Ltd. The curing conditions were 12 hours of standing in a 40°C environment. After the embedding chemicals had hardened, the observation surface was polished using a rotary polishing machine (MA-600e, manufactured by Musashino Electronics Co., Ltd.). The abrasive grain sizes used during polishing were progressively 20 μm, 13 μm, 9 μm, 2 μm, and 0.5 μm. Next, etching was performed. The test specimens were immersed in a 15 mol / L formic acid solution for 30 seconds before observation.

[0102] The molten pool was observed using an optical microscope (VHX6000) manufactured by Keyence Corporation. The observation magnification was set to 50x, which is the magnification that allows the entire molten pool to be included in the field of view.

[0103] • Method for calculating the area of ​​the melting pool The optical microscope image of the cross-section of the test specimen obtained by the method described above is used to measure the area of ​​a specified region of the apparatus, thereby determining the molten pool area (unit: mm²). 2 ) was measured.

[0104] <Welding strength / molten pool area (strength / molten pool)> Based on the above, the values ​​for welding strength / molten pool area were calculated (unit: N / mm²). 2 The following categories were used for evaluation. A: 600 N / mm 2 More than 700N / mm 2 less than B-1: 700 N / mm 2 That's all. B-2: 500 N / mm 2 More than 600N / mm 2 less than C: 500N / mm 2 less than

[0105] <curve> The obtained transparent resin components and absorbent resin components were visually inspected for warping before laser welding. The evaluation was conducted by five experts, and the decision was made by majority vote. A: No warping B: It is warped.

[0106] <Bali> The resulting laser-welded products were visually inspected for the presence of burrs. The evaluation was conducted by five experts, and the decision was made by majority vote. A: No burrs B: There is a burr.

[0107] [Table 4]

[0108] [Table 5]

[0109] [Table 6]

[0110] [Table 7]

[0111] As is clear from the results above, the area of ​​the molten pool is 1.00 mm². 2 Ultra 3.01mm 2 The laser-welded products described below exhibited high laser welding strength and effectively suppressed burrs (Examples 1-11). Furthermore, the welding strength / molten pool area was increased to 500 N / mm². 2By making the above adjustments, we were able to effectively suppress warping. On the other hand, the area of ​​the molten pool is 1.00 mm 2 In the following cases, the laser welding strength was inferior (Comparative Examples 1-3). Also, the molten pool area was 3.01 mm². 2 In the case of the ultra-high performance, the burrs were inferior (Comparative Examples 4-7).

[0112] 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]

[0113] 1. Permeable resin member 2 Absorbent resin member

Claims

1. A laser-welded product comprising a transparent resin member and an absorbent resin member, having a joint portion formed by laser welding between the transparent resin member and the absorbent resin member, At least one of the permeable resin member and the absorbent resin member comprises a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2), In a cross-section that includes the normal to the transparent resin member and is perpendicular to the scanning direction of the laser beam, a molten pool is observed in the joint portion. The area of ​​the molten pool is 1.00 mm². ２ Ultra 3.01 mm ２ The following are laser-welded products.

2. The laser-welded product according to claim 1, wherein the cooling crystallization temperature (Tc) of at least one of the transparent resin member and the absorbent resin member is 170 to 230°C.

3. The laser-welded article according to claim 1 or 2, wherein at least one of the permeable resin member and the absorbent resin member contains aliphatic polyamide resin (A2) in a ratio of 5 parts by mass or more and less than 50 parts by mass per 100 parts by mass of the total of semi-aromatic polyamide resin (A1) and aliphatic polyamide resin (A2).

4. The welding strength (in N) of the laser-welded product between the transparent resin member and the absorbent resin member is divided by the molten pool area, and the value obtained (welding strength / molten pool area) is 500 N / mm². ２ More than 1000N / mm ２ The laser-welded product according to claim 1 or 2, which is as follows:

5. The laser-welded article according to claim 1 or 2, wherein at least one of the permeable resin member and the absorbent resin member contains a filler (B).

6. The crystallization temperature (Tc) of at least one of the permeable resin member and the absorbent resin member during cooling is 170 to 230°C. At least one of the permeable resin member and the absorbent resin member contains aliphatic polyamide resin (A2) in a ratio of 5 parts by mass or more and less than 50 parts by mass per 100 parts by mass of the total of semi-aromatic polyamide resin (A1) and aliphatic polyamide resin (A2), The welding strength (in N) of the laser-welded product between the transparent resin member and the absorbent resin member is divided by the molten pool area, and the value obtained (welding strength / molten pool area) is 500 N / mm². ２ More than 1000N / mm ２ The following: The laser-welded product according to claim 1, wherein at least one of the transparent resin member and the absorbent resin member contains filler (B).

7. A welding method for laser welding a transparent resin member and an absorbent resin member, At least one of the permeable resin member and the absorbent resin member comprises a semi-aromatic polyamide resin (A1) and an aliphatic polyamide resin (A2), By laser welding the transparent resin member and the absorbing resin member, a molten pool is observed in the joint portion in a cross-section that includes the normal to the transparent resin member and is perpendicular to the scanning direction of the laser beam. The area of ​​the molten pool is 1.00 mm². ２ Ultra 3.01 mm ２ A method for manufacturing a laser-welded product, including a welding method, which yields a laser-welded product.

8. The method for manufacturing a laser-welded product according to claim 7, wherein the laser-welded product is the laser-welded product according to claim 1, 2, or 6.

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