Laser welding ink coating tool, laser welding method, and method for manufacturing a welded body.

Abstract

The present invention provides a laser welding ink application tool that allows for the relatively thin, uniform, and easy application of laser welding ink to desired locations. [Solution] A laser welding ink coating tool 1 comprising an ink 5 containing a near-infrared absorbing dye and a solvent, a container 2 containing the ink 5, and a core material 3 from which the ink 5 contained in the container 2 is supplied, wherein the ink 5 can be coated from the core material 3.

Description

[Technical Field]

[0001] This disclosure relates to a laser welding ink coating tool, a laser welding method, and a method for manufacturing a welded body. [Background technology]

[0002] Laser welding is a joining method that uses laser light to weld components together. Typically, laser welding involves layering a laser-transmitting material and a laser-absorbing material, and then irradiating the laser light from the laser-transmitting material side to join the transparent and absorbing materials. In this method, the absorbing material absorbs the laser light and generates heat, causing it to melt and weld at the interface with the transparent material, thus joining the transparent and absorbing materials. On the other hand, there is also a known method of welding two components together by placing a laser-absorbing material between them and irradiating it with laser light. For example, Patent Documents 1 to 3 describe the use of adhesives, films, toners, paints, etc., as the laser-absorbing material. In this method, the laser-absorbing material absorbs the laser light and generates heat, causing the interface of two adjacent components to melt and weld them together. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-155402 [Patent Document 2] Japanese Patent Publication No. 2003-181931 [Patent Document 3] Japanese Patent Publication No. 2004-1071 [Overview of the project] [Problems that the invention aims to solve]

[0004] When laser welding components together using laser-absorbing materials, a simple method is to use a liquid laser-absorbing material, i.e., laser welding ink, and apply it to the components to be welded before laser welding. For example, spin coating is a method for applying a thin, uniform layer of laser welding ink to the components to be welded. However, spin coating can only be applied to flat surfaces, limiting its applicability to components with complex shapes such as curved or uneven surfaces. For components with complex shapes, dipping is a possible method for applying the ink. However, dipping results in a relatively thick layer of ink, which can lead to long drying times and reduced production and work efficiency. Furthermore, in areas where the laser welding ink is thickly applied, excessive heat generation may occur when irradiated with laser light, potentially causing welding problems. Dripping is also a concern.

[0005] The problem to be solved by this disclosure is to provide a laser welding ink coating tool that can easily and relatively thinly and uniformly coat a laser welding ink onto a desired location. This disclosure also provides a laser welding method and a method for manufacturing a welded body using the laser welding ink coating tool of this disclosure. [Means for solving the problem]

[0006] The laser welding ink coating tool according to this disclosure, which has been able to solve the aforementioned problems, is as follows. [1] A laser welding ink coating tool comprising an ink containing a near-infrared absorbing dye and a solvent, a container containing the ink, and a core material from which the ink contained in the container is supplied, wherein the ink can be applied from the core material. [2] The laser welding ink coating tool according to [1], wherein the near-infrared absorbing dye has a weight loss rate of 5.0% or less when heated from 25°C to 200°C by thermogravimetric differential thermal analysis (TG-DTA). [3] The laser welding ink coating tool according to [1] or [2], wherein the content of the near-infrared absorbing dye in the ink is 1% by mass or less. [4] A laser welding ink coating tool according to any one of [1] to [3], wherein the viscosity of the ink at 25°C is 1 mPa·s or more and 1000 mPa·s or less. [5] The ink is a laser welding ink coating tool according to any one of [1] to [4], wherein the minimum transmittance in the wavelength range of 300 nm to 1300 nm is 10%, and the average transmittance in the wavelength range of 380 nm to 700 nm is 80% or more. [6] The near-infrared absorbing dye has an absorption maximum wavelength in the range of 750 nm to 1300 nm. [1] to [5] The laser welding ink coating tool. [7] The laser welding ink coating tool according to any one of [1] to [6], wherein the near-infrared absorbing dye is at least one selected from cyanine dyes, diimmonium dyes and phthalocyanine dyes. [8] The laser welding ink coating tool according to [7], wherein the cyanine-based dye or the diimmonium-based dye has an anion with a conjugate acid pKa of -8.0 or less. [9] The laser welding ink coating tool according to [7] or [8], having a cyanine-based dye or a diimmonium-based dye.

[10] The laser welding ink coating tool according to any one of [1] to [9], further comprising a resin in the ink.

[11] The laser welding ink coating tool according to any one of [1] to

[10] , wherein the ink has a solid content concentration of 0.1% by mass or more and 40% by mass or less.

[12] A pen-type ink coating tool, as described in any of [1] to

[11] , for laser welding.

[0007] This disclosure also provides the following laser welding method and method for manufacturing a welded body.

[13] A laser welding method comprising the steps of: applying the ink to a first resin material using a laser welding ink application tool described in any of [1] to

[12] ; and welding the first resin material and the second resin material by overlapping the portion of the first resin material to which the ink has been applied and irradiating the ink with laser light.

[14] In the step of coating the first resin material with the ink, the coating area of ​​the ink on the first resin material per application is 100 cm². 2 The laser welding method described below

[13] .

[15] In the step of coating the first resin material with the ink, the dry weight of the ink per coated area is 0.1 μg / cm². 2 More than 1000μg / cm 2 The laser welding method described below

[13] or

[14] . A method for manufacturing a welded body, comprising the steps of: applying the ink to a first resin material using a laser welding ink application tool described in any of [1] to

[12] ; and welding the first resin material and the second resin material together by overlapping the portion of the first resin material to which the ink has been applied and irradiating the ink with laser light. [Effects of the Invention]

[0008] According to the laser welding ink coating tool, laser welding method, and manufacturing method for welded bodies described herein, laser welding ink can be applied relatively thinly, uniformly, and easily to desired locations. Therefore, the drying time of the ink can be shortened, and the efficiency of the work can be improved. In addition, because the ink is applied relatively thinly and uniformly, excessive heat generation during laser welding can be suppressed, making it easier to prevent charring at the welded location. [Brief explanation of the drawing]

[0009] [Figure 1] This is an example of the configuration of a laser welding ink coating tool, and shows a schematic cross-sectional view along the longitudinal axis of a pen-type ink coating tool. [Figure 2] This diagram shows another example of a laser welding ink coating tool configuration, specifically a schematic cross-sectional view of an ink coating tool where the core material is separate from the container. [Modes for carrying out the invention]

[0010] This disclosure relates to a laser welding ink coating tool, more specifically, to a coating tool that holds laser welding ink and can suitably coat the ink onto a member to be laser-welded. The ink is used to weld members together by irradiating them with laser light. When irradiated with laser light, the ink absorbs the laser light and generates heat, thereby welding the members together.

[0011] The ink contains at least a near-infrared absorbing dye and a solvent. In laser welding, for example, laser light having a wavelength of 800 nm to 1300 nm is used, and the near-infrared absorbing dye can suitably absorb light in this wavelength range and function as a heat source. By coating the components to be laser-welded with the ink, a laser light absorption layer can be formed on the surface of the components, and by placing another component on top and irradiating the absorption layer with laser light, the components can be welded together. Hereinafter, the components to be laser-welded will be referred to as "welded components," the laser welding ink will be simply referred to as "ink," and the laser welding ink application tool will be simply referred to as "ink application tool."

[0012] The laser welding ink coating tool according to this disclosure comprises an ink containing a near-infrared absorbing dye and a solvent, a container holding the ink, and a core material from which the ink contained in the container is supplied, and is configured to allow ink to be applied from the core material. By bringing the core material into contact with the welding member, the ink can be applied to the welding member. Using such an ink coating tool, the ink can be easily applied to desired locations on the welding member. For example, even with welding members that have a container shape with a rim or a complex shape with irregularities, the ink can be easily applied to desired locations. Furthermore, the minimum amount of ink required for welding can be applied precisely to the desired location, making it easy to weld without damaging the color or appearance of the product after welding. Moreover, with the laser welding ink coating tool according to this disclosure, it is easy to apply the ink relatively thinly and uniformly without dripping. Therefore, the drying time of the ink can be shortened, and the efficiency of the work can be improved. In addition, even when laser welding welding members with low solvent resistance, for example, the deterioration of the welding member can be suppressed because the solvent dries quickly, making it possible to apply to various materials. Furthermore, by applying the ink relatively thinly and evenly, excessive heat generation during laser welding can be suppressed, making it easier to prevent charring at the welded area.

[0013] In one embodiment, the ink application tool can be configured so that the container and core material can be handled as a single unit. In this case, the ink application tool can be configured as, for example, a pen-type ink application tool. This improves the portability, handling, and application efficiency of the ink application tool. An example of the configuration of a pen-type ink application tool will be explained with reference to Figure 1.

[0014] The ink application tool 1 shown in Figure 1 comprises a container 2 and a core material 3. The container 2 contains ink 5, the core material 3 is held in a holder 4, and the holder 4 covers the opening of the container 2. One end of the core material 3 in the longitudinal direction is positioned facing the outside of the ink application tool 1, and the other end is located inside the ink application tool 1, so that the ink 5 contained in the container 2 is supplied to the core material 3. The core material 3 functions as a pen tip. With this configuration, the ink application tool 1 can be held by hand and ink 5 can be easily applied to the welding member.

[0015] The core material 3 may or may not extend into the interior of the container 2, as long as it is configured so that the ink 5 contained in the container 2 is supplied to the core material 3. In Figure 1, the ink 5 is contained in bulk liquid form inside the container 2, and the core material 3 is installed extending into the interior of the container 2. The other end of the core material 3 in the longitudinal axis direction is installed so as to be immersed in the bulk liquid ink 5.

[0016] Although not shown in the drawings, the ink application tool 1 may be configured such that a cotton swab soaked in ink 5 is placed inside the container 2, and the other end of the core material 3 in the longitudinal direction is in contact with this cotton swab. Alternatively, the inside of the container 2 may be divided into a space where the ink 5 exists and a space where the other end of the core material 3 in the longitudinal direction exists, and these two spaces may be connected via a valve or a connecting tube, so that the supply of ink 5 to the core material 3 is regulated by the valve or the connecting tube. The ink application tool 1 may have the container 2 and holder 4 integrally formed. The ink application tool 1 may be equipped with a cap. The ink application tool 1 may have core materials 3 provided on both sides of the container 2 in the longitudinal direction.

[0017] In another embodiment, the ink application tool may be configured so that the core material can be operated independently of the container. An example of such a configuration for an ink application tool is shown in Figure 2.

[0018] The ink application tool 1 shown in Figure 2 comprises a container 2 containing ink 5, a holder 4 for holding a core material 3, and a tube 6 connecting the container 2 and the holder 4. The ink 5 contained in the container 2 is supplied to the core material 3 through the tube 6. This configuration of the ink application tool 1 allows for a larger container 2, enabling it to hold a large amount of ink 5. When using the ink application tool 1, the ink 5 can be applied to the welding member by moving the holder 4 holding the core material 3 without moving the container 2, thereby bringing the core material 3 into contact with the welding member. In the ink application tool 1 shown in Figure 2, the ink 5 may be applied by holding the holder 4 by hand, or the holder 4 may be moved by machine. In the latter case, the ink application tool 1 can be automated.

[0019] The materials used to construct the container are not particularly limited and can be made of, for example, resin or metal. The container may be transparent, opaque, or semi-transparent. The shape of the container is also not particularly limited; for example, if it is a pen-type ink application tool, a long, slender shape is preferable.

[0020] The core material can be formed, for example, from a fiber bundle. The fiber bundle of the core material can be composed of synthetic fibers such as polyester fibers, polyamide fibers, acrylic fibers, polyurethane fibers, polycarbonate fibers, polyether fibers, polyvinyl fibers, and polyacetal fibers, or natural fibers such as cellulose fibers. From the viewpoint of the durability of the core material, it is preferable to use synthetic fibers. The thickness of the core material is not particularly limited and may be, for example, 0.25 mm or more or 0.5 mm or more, or 50 mm or less, 30 mm or less, or 20 mm or less.

[0021] The types of near-infrared absorbing dyes contained in the ink are not particularly limited and include, for example, cyanine dyes, diimmonium dyes, squarylium dyes, crokonium dyes, cyclic tetrapyrrole dyes (porphyrins, chlorines, phthalocyanines, naphthalocyanines, cholines, etc.) which may have copper (e.g., Cu(II)), zinc (e.g., Zn(II)), or vanadium oxide as the central metal ion, azo dyes, quinone dyes, xanthene dyes, indoline dyes, arylmethane dyes, quaterylene dyes, perylene dyes, quinacdrin dyes, oxazine dyes, dipyromethene dyes, nickel complex dyes, copper ion dyes, etc. These dyes may be used individually or in combination of two or more.

[0022] The near-infrared absorbing dye preferably has an absorption maximum wavelength in the range of 750 nm to 1300 nm. Specifically, the near-infrared absorbing dye preferably has an absorption peak in the absorption spectrum in the range of 600 nm to 1300 nm, with an absorption maximum in the range of 750 nm to 1300 nm, and the absorption maximum of this absorption peak preferably takes its maximum value in the range of 600 nm to 1300 nm. This allows the near-infrared absorbing dye to efficiently generate heat by absorbing light in the wavelength range used for laser welding when the ink is applied to the welding member and irradiated with laser light, enabling suitable laser welding. The absorption maximum wavelength of the near-infrared absorbing dye may be 780 nm or higher, 800 nm or higher, 850 nm or higher, 900 nm or higher, or 1000 nm or higher, and may also be 1280 nm or lower, 1200 nm or lower, 1150 nm or lower, or 1100 nm or lower.

[0023] The near-infrared absorbing dye preferably has an average transmittance of 80% or more in the wavelength range of 380nm to 700nm when the transmittance at the wavelength of maximum absorption is 10% in the wavelength range of 300nm to 1300nm. This allows the near-infrared absorbing dye to transmit light in the visible light region with high transmittance, and the ink can be made substantially free of coloration originating from the near-infrared absorbing dye. The average transmittance of the near-infrared absorbing dye in the wavelength range of 380nm to 700nm is more preferably 83% or more, even more preferably 85% or more, even more preferably 88% or more, and particularly preferably 90% or more.

[0024] The near-infrared absorbing dye preferably has a full width at half maximum (FWHM) of the absorption peak that gives the absorption maximum wavelength of 40 nm or more, more preferably 45 nm or more, and even more preferably 50 nm or more. This allows the near-infrared absorbing dye to absorb laser light over a wide wavelength range, enabling the use of various laser light sources in laser welding. On the other hand, the near-infrared absorbing dye preferably has a FWHM of 100 nm or less, more preferably 80 nm or less, and even more preferably 60 nm or less. This makes it easier to increase the transmittance of light in the visible light region.

[0025] The absorption spectra of near-infrared absorbing dyes described above refer to the absorption spectra of near-infrared absorbing dyes in chloroform. The absorption spectrum is determined by measuring the absorbance at 1 nm intervals in the wavelength range of 300 nm to 1300 nm. The full width at half maximum (FWHM) refers to the width of the absorption peak at 50% transmittance when the transmittance at the absorption maximum wavelength is 10%.

[0026] The solvent contained in the ink is preferably capable of dissolving near-infrared absorption dyes, and is preferably an organic solvent. This makes it easier for the ink to dry quickly when it is applied to the welding material. Suitable solvents include, for example, alcohols such as methanol, ethanol, and isopropyl alcohol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; glycol derivatives such as PGMEA (2-acetoxy-1-methoxypropane), ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, and ethylene glycol ethyl ether acetate (ether compounds, ester compounds, ether ester compounds, etc.); amides such as N,N-dimethylacetamide and N,N-dimethylformamide; and ethyl acetate, propyl acetate, and butyl acetate. Examples of solvents include tellures; pyrrolidones such as N-methylpyrrolidone (specifically, 1-methyl-2-pyrrolidone, etc.); aromatic hydrocarbons such as toluene, xylene, and 1,2,4-trimethylbenzene; aliphatic hydrocarbons such as cyclohexane and heptane; aliphatic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 4-methyltetrahydropyran, dioxane, diethyl ether, and dibutyl ether; aromatic ethers such as anisole, phenyl ether, and benzyl methyl ether; halogenated hydrocarbons such as chloroform, dichloromethane, and 1,2-dichloroethane; and lactones such as γ-butyrolactone. These solvents may be used individually or in combination of two or more.

[0027] The content of near-infrared absorbing pigment in the ink is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more. This makes it easier for the near-infrared absorbing pigment contained in the ink to generate sufficient heat when the ink is applied to the welding members and irradiated with laser light, thus facilitating the welding of the welding members together. On the other hand, the content of near-infrared absorbing pigment in the ink may be 10% by mass or less, 5% by mass or less, or 3% by mass or less, but is preferably 1% by mass or less, more preferably less than 0.8% by mass, and even more preferably less than 0.5% by mass. Even with a near-infrared absorbing pigment content in the ink within these ranges, laser welding can be suitably performed by applying the ink to the welding members and irradiating them with laser light. Such pigment content is a very low value compared to ordinary ink.

[0028] The solvent content in the ink is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, preferably less than 100% by mass, more preferably 99.9% by mass or less, and even more preferably 99.8% by mass or less. In other words, the solid content concentration of the ink (i.e., the content of components other than the solvent in the ink) should be greater than 0% by mass, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. By adjusting the solvent content and solid content concentration of the ink within these ranges, the handling properties of the ink can be easily improved.

[0029] The ink preferably has a viscosity of 1 mPa·s or more and 1000 mPa·s or less at 25°C. If the ink viscosity is 1 mPa·s or more, it is easier to suppress dripping when applying the ink. If the ink viscosity is 1000 mPa·s or less, it is easier to ensure the paintability of the ink. From the viewpoint of shortening the drying time of the ink after application, the ink viscosity may be 500 mPa·s or less, 300 mPa·s or less, 200 mPa·s or less, 100 mPa·s or less, 70 mPa·s or less, or 35 mPa·s or less. The ink viscosity is determined using an E-type viscometer (Toki Sangyo Co., Ltd., TV-20, rotor: 1°34′×R24) at a rotation speed of 3 to 60 rpm, a temperature of 25°C, and a measurement time of 1 minute.

[0030] The ink preferably has an average transmittance of 80% or more in the wavelength range of 380nm to 700nm when the minimum transmittance in the wavelength range of 300nm to 1300nm is 10%. This can improve the transparency of the ink. The average transmittance of the ink in the wavelength range of 380nm to 780nm is more preferably 83% or more, and even more preferably 85% or more. The transmission spectrum is determined by measuring the transmittance at measurement pitches of 1nm in the wavelength range of 300nm to 1300nm. The pigment concentration in the ink is adjusted by removing the solvent from the ink or diluting the ink with a solvent so that the minimum transmittance in the wavelength range of 300nm to 1300nm is 10%.

[0031] The near-infrared absorbing dye preferably has a weight loss rate of 5.0% or less when heated from 25°C to 200°C, as determined by thermogravimetric differential thermal analysis (TG-DTA). This suppresses thermal degradation or decomposition of the near-infrared absorbing dye before it generates heat when the ink is irradiated with laser light, making it easier to more firmly weld the welded members together. The weight loss rate of the near-infrared absorbing dye when heated from 25°C to 200°C is more preferably 4.0% or less, and even more preferably 3.0% or less.

[0032] The near-infrared absorbing dye is preferably at a temperature higher than 200°C at which the weight loss rate when heated from 25°C is 5.0%, and may be 210°C or higher, 215°C or higher, 220°C or higher, 225°C or higher, or 230°C or higher. On the other hand, the near-infrared absorbing dye is preferably at a temperature of 500°C or lower at which the weight loss rate when heated from 25°C is 5.0%, and may be 450°C or lower or 400°C or lower. This makes it possible to suppress discoloration originating from the near-infrared absorbing dye in the welded member, i.e., the welded body, after laser welding. Thermogravimetric differential thermal analysis (TG-DTA) is performed by heating in air at a heating rate of 10°C / min.

[0033] The near-infrared absorbing dye is preferably an organic dye, meaning it is preferably free of metal elements. This makes it easier to increase the transmittance of the near-infrared absorbing dye in the visible light region, thereby suppressing ink discoloration. Examples of metal elements include group 1 to 12 elements (excluding hydrogen) and group 13 to 14 elements such as Al, Ga, In, Tl, Sn, and Pb. Examples of organic dyes that do not contain metal elements include cyanine dyes, diimmonium dyes, squarylium dyes, crokonium dyes, cyazo dyes, quinone dyes, xanthene dyes, indoline dyes, arylmethane dyes, quaterylene dyes, perylene dyes, quinacridone dyes, oxazine dyes, and dipyromethene dyes. Furthermore, by using such dyes, when laser welding is applied to medical containers or food packaging containers, no metal components remain in the ink-coated areas, thus reducing concerns about the leaching of metal components that could affect safety. When laser welding is applied to containers for trace analysis, the amount of metal detected can be measured more accurately because the containers do not contain metal components, thereby improving analytical accuracy.

[0034] The near-infrared absorbing dye is preferably a cyanine-based dye and / or a diimmonium-based dye. Cyanine-based dyes and diimmonium-based dyes suitably absorb laser light in the wavelength range of 800 nm to 1300 nm, which is commonly used in laser welding, and also have high transmittance in the visible light region, resulting in excellent invisibility. Therefore, by using cyanine-based dyes and / or diimmonium-based dyes as near-infrared absorbing dyes, laser welding can be performed suitably, and coloration of the ink derived from these dyes can be suppressed, thereby expanding the range of applications for the ink. In addition, the appearance of the welded member to which the ink is coated can be preserved.

[0035] The cyanine-based dye is preferably a compound represented by the following formula (1). In formula (1), L represents a methine chain having 3 or more carbon atoms, and each methine group contained in the methine chain may independently have substituents, and these substituents may be linked to each other, A + And A represents a group bonded to the methine chain L, and X - represents a monovalent anion. The cyanine dyes in formula (1) also include compounds that are in resonance relationships.

[0036] [ka]

[0037] In formula (1), the methine chain L having 3 or more carbon atoms means a connected methine chain in which 3 or more methine groups (-CH=) form conjugated double bonds. The upper limit of the number of carbon atoms in the methine chain L is not particularly limited, but it is preferably 15 or less, more preferably 13 or less, even more preferably 11 or less, and particularly preferably 9 or less.

[0038] Each methine group (i.e., hydrogen atom on the methine group) in the methine chain L may independently have substituents, and these substituents may be linked to each other. Examples of substituents that the methine group may have (hereinafter sometimes referred to as "substituents P") include halogen groups (halogen atoms) and organic groups. Note that the number of carbon atoms in the methine chain L refers to the number of carbon atoms excluding substituents if the methine groups in the methine chain have substituents.

[0039] The methine chain L is preferably composed of an odd number of methine groups. For example, if the number of carbon atoms in the methine chain L is between 3 and 9, it is preferable that the methine chain L consists of 3, 5, 7, or 9 methine groups. In this case, the compound represented by formula (1) will be represented by the following formulas (1A) to (1D). In formulas (1A) to (1D), R 41 ~R 49 Each of these independently represents a hydrogen atom, a halogen atom, or an organic group.

[0040] [ka]

[0041] Examples of organic substituents P that the methine group may have include alkyl groups, alkoxy groups, alkylthio groups, alkoxycarbonyl groups, alkylsulfonyl groups, alkylsulfinyl groups, aryl groups, aralkyl groups, aryloxy groups, arylthio groups, aryloxycarbonyl groups, arylsulfonyl groups, arylsulfinyl groups, heteroaryl groups, amino groups, amide groups, sulfonamide groups, carboxyl groups (carboxylic acid groups), cyano groups, and the like.

[0042] Examples of alkyl groups of substituent P include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl groups; and cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl groups. Alkyl groups may have substituents, and examples of substituents on alkyl groups include aryl, heteroaryl, halogeno, hydroxyl, carboxyl, alkoxy, cyano, nitro, amino, and sulfo groups. Examples of alkyl groups having a halogen group include monohalogenoalkyl groups, dihalogenoalkyl groups, alkyl groups having a trihalomethyl unit, and perhalogenoalkyl groups. Preferred halogen groups are fluorine atoms, chlorine atoms, and bromine atoms, with fluorine atoms being particularly preferred. The number of carbon atoms (excluding substituents) of the alkyl group is preferably 1 to 20. Specifically, for linear or branched alkyl groups, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. For cyclic alkyl groups, the number of carbon atoms is preferably 4 to 10, and more preferably 5 to 8.

[0043] For specific examples of alkyl groups included in the alkoxy, alkylthio, alkoxycarbonyl, alkylsulfonyl, and alkylsulfinyl groups of substituent P, please refer to the explanation of alkyl groups above.

[0044] Examples of the aryl group of substituent P include phenyl, biphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, and indenyl groups. The aryl group may have substituents, and examples of substituents on the aryl group include alkyl, alkoxy, heteroaryl, halogeno, halogenoalkyl, hydroxyl, cyano, nitro, amino, thiocyanate, acyl, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, sulfo, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, and sulfamoyl groups. The number of carbon atoms in the aryl group (excluding substituents) is preferably 6 to 20, and more preferably 6 to 12.

[0045] Examples of the aralkyl group of substituent P include benzyl group, phenethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, naphthylmethyl group, etc. The aralkyl group may have substituents, and examples of substituents on the aralkyl group include alkyl group, alkoxy group, halogeno group, halogenoalkyl group, cyano group, nitro group, thiocyanate group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, sulfo group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group, etc. The number of carbon atoms (number of carbon atoms excluding substituents) of the aralkyl group is preferably 7 to 25, and more preferably 7 to 15.

[0046] For specific examples of aryl groups included in the aryloxy, arylthio, aryloxycarbonyl, arylsulfonyl, and arylsulfinyl groups of substituent P, please refer to the explanation of aryl groups above.

[0047] Examples of the heteroaryl group of the substituent P include, for example, thienyl group, thiopyranyl group, isothiochromenyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, pyrralidinyl group, pyrimidinyl group, pyridazinyl group, thiazolyl group, isothiazolyl group, furanyl group, pyranyl group and the like. The heteroaryl group may have a substituent, and examples of the substituent of the heteroaryl group include alkyl group, alkoxy group, aryl group, halogeno group, halogenoalkyl group, hydroxyl group, cyano group, amino group, nitro group, thiocyanate group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, sulfo group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group and the like. The number of carbon atoms of the heteroaryl group (the number of carbon atoms excluding the substituent) is preferably 2 to 20, more preferably 3 to 15.

[0048] Examples of the amino group of the substituent P include the formula: -NR a1 R a2 represented by, and R a1 and R a2 are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a heteroaryl group and the like. Specific examples of the alkyl group, aryl group, aralkyl group, heteroaryl group are referred to the descriptions of these groups above, and examples of the alkenyl group and alkynyl group include groups in which a part of the carbon-carbon single bond of the alkyl group exemplified above is replaced by a double bond or a triple bond. R a1 and R a2 may be linked to each other to form a ring. The number of ring members of the ring formed by the linkage of R a1 and R a2 is preferably 5 or 6, and the constituent atoms of the ring are preferably carbon atoms, oxygen atoms, sulfur atoms other than nitrogen atoms.

[0049] Examples of the amide group of the substituent P include the formula: -NH-C(=O)-R a3 represented by, and R a3Examples include alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups. For specific examples of alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups, please refer to the descriptions of these groups above.

[0050] The sulfonamide group of substituent P is given by formula: -NH-SO2-R a4 It is represented as R a4 Examples include alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups. For specific examples of alkyl groups, aryl groups, aralkyl groups, and heteroaryl groups, please refer to the descriptions of these groups above.

[0051] The substituent P is preferably a halogeno group, alkyl group, alkoxy group, aryl group, aralkyl group, or amino group, and more preferably a halogeno group, alkyl group, aryl group, or amino group. In this case, the alkyl group and alkoxy group have 1 to 8 carbon atoms, more preferably 1 to 5, and even more preferably 1 to 3. The aryl group has 6 to 12 carbon atoms, more preferably 6 to 10, and the aralkyl group has 7 to 13 carbon atoms, more preferably 7 to 11. The amino group is of the formula: -NR a1 R a2 It is represented as R a1 and R a2 Each of these is preferably independently a hydrogen atom, an alkyl group, or an aryl group, wherein the alkyl group has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and the aryl group has 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms.

[0052] When substituents P on a methine group are linked to each other, it is preferable that substituents attached to two adjacent methine groups are linked to each other to form a ring. In formulas (1A) to (1D), R 41 and R 43 , R 42 and R 44 , R 43 and R 45 , R 44 and R 46 , R 45 and R 47 , R 46 and R48 or R 47 and R 49 It is preferable that they are connected to each other to form a ring.

[0053] The ring formed by the linkage of substituents P on the methine group is preferably a 5- to 8-membered ring, more preferably a 5- to 7-membered ring, and even more preferably a 5 or 6-membered ring. The ring formed by the linkage of substituents P on the methine group is formed in partial co-existence with the methine chain, but may or may not have unsaturated bonds in the portion other than the portion shared with the methine chain. Preferably, the ring formed by the linkage of substituents P on the methine group does not have unsaturated bonds in the portion other than the portion shared with the methine chain.

[0054] The ring formed by the linking of substituents P on the methine group may have substituents, and such substituents include organic groups and polar functional groups. For details of organic groups, refer to the description of the organic group of substituent P above. Examples of polar functional groups include halogen groups, hydroxyl groups, nitro groups, sulfo groups (sulfonic acid groups), etc., with halogen groups being preferred. Among these, halogen groups, alkyl groups, alkoxy groups, aryl groups, and amino groups are preferred substituents on the ring formed by the linking of substituents P. In this case, the number of carbon atoms of alkyl groups and alkoxy groups is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2, and the number of carbon atoms of aryl groups is preferably 6 to 12.

[0055] The substituent P that may be present on the methine group is preferably bonded to the meso position (center) or an adjacent methine group, and it is preferable that the other methine groups do not have substituents. In formula (1A), R 41 ~R 43 R may be a hydrogen atom, an organic group, or a polar functional group. In formula (1B), R 42 ~R 44 R may be a hydrogen atom, an organic group, or a polar functional group. 41 and R 45 It is preferable that R is a hydrogen atom. In formula (1C), 43 ~R 45R may be a hydrogen atom, an organic group, or a polar functional group. 41 , R 42 , R 46 , R 47 It is preferable that R is a hydrogen atom. In formula (1D), 44 ~R 46 R may be a hydrogen atom, an organic group, or a polar functional group. 41 ~R 43 , R 47 ~R 49 Preferably, the substituent is a hydrogen atom. More preferably, substituents that do not link to form a ring are bonded to the methine group at the meso position, and substituents that link to form a ring are bonded to the methine group adjacent to the meso position, and are linked to each other. The methine chain L may also preferably have no substituents.

[0056] In equation (1), A + And A represents a group bonded to the methine chain L. The compound represented by formula (1) has A from the methine chain L. + It is preferable that the π electron system extends to A, and A + And A is preferably a group that forms such a π-electron system. + And as A, the groups represented by the following formulas (2) to (4) are preferred.

[0057] [ka]

[0058] In formula (2), R 11 represents an organic group, R 12 ~R 17 Each of these independently represents a hydrogen atom, a halogen atom, or an organic group, and * represents the bonding site with the methine chain L in formula (1).

[0059] [ka]

[0060] In formula (3), R 21The symbol represents an organic group, ring S represents a hydrocarbon ring having a fused ring structure which may have substituents, or a heterocycle having a fused ring structure which may have substituents, and is spirobonded to an adjacent pyrrole ring, ring T represents an aromatic hydrocarbon ring which may have substituents, an aromatic heterocycle which may have substituents, or a fused ring containing these ring structures which may have substituents, and * represents the bonding site to the methine chain L of formula (1).

[0061] [ka]

[0062] In formula (4), R 31 represents an organic group, R 32 ~R 35 Each of these independently represents a hydrogen atom, a halogen atom, or an organic group, or R 32 and R 33 , R 33 and R 34 , R 34 and R 35 They may be connected to each other to form a ring, Y 1 These are oxygen atoms, sulfur atoms, -CH=CH- or -C(R 36 )(R 37 )- represents R 36 and R 37 Each represents an organic group, and * represents the binding site to the methine chain L in formula (1).

[0063] In equations (2) to (4), R 12 ~R 17 , R 32 ~R 35 Examples of halogen atoms (halogeno groups) include fluorine atoms (fluoro groups), chlorine atoms (chloro groups), bromine atoms (bromo groups), and iodine atoms (iodine groups). 11 ~R 17 , R 21 , R 31 ~R 35 For details of the organic group, please refer to the description of the organic group of substituent P above.

[0064] In equation (2), R11 is preferably an alkyl group, an aryl group or an aralkyl group, more preferably an alkyl group. Examples of the alkyl group include linear or branched alkyl groups, and linear alkyl groups are more preferable. R 11 The alkyl group of is preferably 3 or more carbon atoms, more preferably 4 or more carbon atoms, and preferably 12 or less carbon atoms, more preferably 10 or less carbon atoms, and even more preferably 8 or less carbon atoms.

[0065] In formula (2), R 12 ~R 17 is preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an aralkyl group or an amino group, more preferably a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and even more preferably a hydrogen atom, an alkyl group or an alkoxy group. The alkyl group and the alkoxy group preferably have 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. The aryl group and the aryloxy group preferably have 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms. The aralkyl group preferably has 7 to 13 carbon atoms, more preferably 7 to 11 carbon atoms.

[0066] In formula (3), R 21 is preferably an alkyl group, an aryl group or an aralkyl group, more preferably an alkyl group. Examples of the alkyl group include linear or branched alkyl groups, and linear alkyl groups are more preferable. R 21 The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms, and is particularly preferably a methyl group or an ethyl group.

[0067] In formula (3), ring S represents a hydrocarbon ring or heterocycle having a fused ring structure. The hydrocarbon ring and heterocycle of ring S may or may not be aromatic. The number of members of ring S is not particularly limited, but the number of members of the hydrocarbon ring or heterocycle spirobonded to the adjacent pyrrole ring is preferably 5 to 8, more preferably 5 to 7, and even more preferably 5 or 6. Examples of hydrocarbon rings or heterocycles having a fused ring structure of ring S include indene rings, naphthalene rings, anthracene rings, fluorene rings, benzofluorene rings, indole rings, isoindole rings, benzimidazole rings, quinoline rings, benzopyran rings, acridine rings, xanthene rings, carbazole rings, purine rings, pteridine rings, and the like.

[0068] Base A represented by formula (3) + In compounds containing group A, ring S is spirobonded to the adjacent pyrrole ring, resulting in a twisted bond between ring S and the pyrrole ring. This creates molecular distortion, affecting the band gap and allowing for the extension of the absorption wavelength. Furthermore, molecular association and aggregation are suppressed, improving solubility in organic solvents and resins.

[0069] The hydrocarbon ring or heterocycle of ring S may have substituents, such as organic groups and polar functional groups. Details of these organic groups and polar functional groups are described in the above descriptions of the organic groups and polar functional groups of substituent P. Preferred substituents of ring S are alkyl groups, alkoxy groups, alkylthio groups, alkoxycarbonyl groups, aryl groups, aryloxycarbonyl groups, and halogen groups; more preferably alkyl groups, alkoxy groups, alkylthio groups, halogen groups, and aryl groups; and more preferably alkyl groups, alkoxy groups, and halogen groups.

[0070] Ring S preferably has a π bond. Specifically, it is preferable that the hydrocarbon ring or heterocyclic ring spiro-bonded to the pyrrole ring has a π bond. This makes it easier for the whole of ring S to adopt a twisted configuration with respect to the pyrrole ring, and the molecular strain can be increased. In this case, it is preferable that the atom adjacent to one and the atom adjacent to two of the carbons spiro-bonded to the pyrrole ring are connected by a π bond. Examples of the π bond include a double bond, such as a double bond between carbon atoms, a double bond between a carbon atom and a nitrogen atom, and a double bond between nitrogen atoms. The π bond of the hydrocarbon ring or heterocyclic ring spiro-bonded to the adjacent pyrrole ring of ring S may partially share a condensed ring.

[0071] In ring S, the condensed ring is preferably formed so as to share the bond between the atom adjacent to one and the atom adjacent to two of the carbons spiro-bonded to the pyrrole ring. Thereby, ring S is formed in a bulky and twisted state with respect to the pyrrole ring, and the molecular strain can be increased.

[0072] Ring S is particularly preferably a hydrocarbon ring having a condensed ring structure represented by the following formulas (5-1) to (5-4) or a heterocyclic ring having a condensed ring structure. In the following formulas (5-1) to (5-4), ring U 1 ~ring U 6 each independently represents a hydrocarbon ring which may have a substituent, and Y 11 represents -CH2-, -NH-, -O- or -S-, and Y 12 ~Y 15 each independently represents -CH2-, -CH=, -NH-, -N=, -O- or -S-, and * represents the site spiro-bonded to the adjacent pyrrole ring. The substituent that ring U 1 ~ring U 6 may have is referred to the description of the substituent that ring S may have above.

[0073]

Chemical formula

[0074] Ring U 1 ~CircleU 6 Examples of hydrocarbon rings include aromatic hydrocarbon rings and aliphatic hydrocarbon rings. Examples of aromatic hydrocarbon rings include benzene rings, naphthalene rings, phenanthrene rings, anthracene rings, fluorantene rings, etc. Aromatic hydrocarbon rings may have only one ring structure or may be formed by the condensation of two or more ring structures. Examples of aliphatic hydrocarbon rings include monocyclic cycloalkanes with 3 to 10 carbon atoms such as cyclopentane, cyclohexane, and cycloheptane; and monocyclic cycloalkenes with 3 to 10 carbon atoms such as cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene (e.g., 1,3-cyclohexadiene), cycloheptene, and cycloheptadiene. Ring U 1 ~CircleU 6 It is preferably a monocyclic ring, more preferably a monocyclic cycloalkene or benzene ring having 3 to 10 carbon atoms (preferably 5 to 8 carbon atoms), and more preferably a benzene ring (specifically, a benzene ring fused with a 5-membered or 6-membered ring spirobonded at the * position).

[0075] In formula (3), ring T represents an aromatic hydrocarbon ring, an aromatic heterocycle, or a fused ring containing these ring structures, and these ring structures may have substituents. By having ring T, the cyanine dye compound has a wide π-electron system extending from the methine chain L through the pyrrole ring to ring T, which allows for the extension of the absorption wavelength to longer wavelengths.

[0076] The aromatic hydrocarbon ring of ring T is composed of carbon atoms and hydrogen atoms and is not particularly limited as long as it has an aromatic ring structure, for example, a benzene ring, naphthalene ring, phenanthrene ring, anthracene ring, fluorantene ring, etc. The aromatic hydrocarbon ring may have only one ring structure or may be a fused ring of two or more ring structures. The aromatic heterocycle of ring T is not particularly limited as long as it contains one or more atoms selected from N (nitrogen atom), O (oxygen atom), and S (sulfur atom) in its ring structure and has aromaticity, for example, a furan ring, thiophene ring, pyrrole ring, pyrazole ring, oxazole ring, thiazole ring, imidazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, purine ring, pteridine ring, etc. The aromatic heterocycle may have only one ring structure or may be a fused ring of two or more ring structures. These fused rings, which include these ring structures, have a structure in which an aromatic hydrocarbon ring and an aromatic heterocycle are fused together. Examples include indole rings, isoindole rings, benzimidazole rings, quinoline rings, benzopyran rings, acridine rings, xanthene rings, and carbazole rings.

[0077] Ring T may have substituents, such as organic groups and polar functional groups. For details of these organic groups and polar functional groups, refer to the descriptions of the organic groups and polar functional groups of substituent P above. Preferred substituents that ring T may have are alkyl groups, alkoxy groups, alkylthio groups, alkoxycarbonyl groups, aryl groups, aryloxycarbonyl groups, amino groups, cyano groups, halogeno groups, nitro groups, and more preferably alkyl groups, alkoxy groups, alkylthio groups, halogeno groups, and aryl groups. If ring T has substituents, the number is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 to 2. If ring T has multiple substituents, the substituents may be the same or different. Ring T may not have substituents.

[0078] The number of π electrons in ring T, that is, the number of π electrons in the aromatic hydrocarbon ring, aromatic heterocycle, or fused ring containing these ring structures, is not particularly limited and may be, for example, 4 or more, or 6 or more. There is no particular upper limit to the number of π electrons in ring T, but it is preferably 18 or less, more preferably 14 or less, and even more preferably 10 or less. Note that the number of π electrons in ring T refers to the number of π electrons in the carbon-carbon bond shared by ring T and the pyrrole ring. From the viewpoint of ease of compound production, ring T is preferably an aromatic hydrocarbon ring, and particularly preferably a benzene ring or a naphthalene ring.

[0079] In equation (4), R 31 The alkyl group is preferably an alkyl group, an aryl group, or an aralkyl group, with alkyl groups being more preferred. Examples of the alkyl group include linear or branched alkyl groups, with linear alkyl groups being more preferred. 31 The alkyl group preferably has 3 or more carbon atoms, more preferably 4 or more, preferably 12 or less, more preferably 10 or less, and even more preferably 8 or less.

[0080] In equation (4), R 32 ~R 35 If R is an independent group, 32 ~R 35 Each of these groups is preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an aralkyl group, or an amino group, more preferably a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group, and even more preferably a hydrogen atom, an alkyl group, or an alkoxy group. The alkyl group or alkoxy group has 1 to 8 carbon atoms, more preferably 1 to 5, and even more preferably 1 to 3. The aryl group or aryloxy group has 6 to 12 carbon atoms, more preferably 6 to 10, and the aralkyl group has 7 to 13 carbon atoms, and even more preferably 7 to 11.

[0081] In equation (4), R 32 and R 33 , R 33 and R 34 , R34 and R 35 Each ring formed by the linkage of these elements (hereinafter referred to as "ring R") can be a hydrocarbon ring or a heterocycle, and these ring structures may or may not be aromatic. Examples of ring R include aromatic hydrocarbon rings, aromatic heterocycles, non-aromatic hydrocarbon rings, and non-aromatic heterocycles. The number of members in ring R is preferably 5 to 8, more preferably 5 to 7, and even more preferably 5 or 6.

[0082] For aromatic hydrocarbons and aromatic heterocycles of ring R, refer to the description of ring T above. Examples of non-aromatic hydrocarbon rings of ring R include aliphatic hydrocarbon rings, such as monocyclic cycloalkanes with 3 to 10 carbon atoms, such as cyclopentane, cyclohexane, and cycloheptane; and monocyclic cycloalkenes with 3 to 10 carbon atoms, such as cyclopentene, cyclopentadiene, cyclohexene, cyclohexadiene (e.g., 1,3-cyclohexadiene), cycloheptene, and cycloheptadiene. Examples of non-aromatic heterocycles of ring R include rings in which one or more carbon atoms constituting the aliphatic hydrocarbon ring are replaced by at least one atom selected from N (nitrogen atom), S (sulfur atom), and O (oxygen atom). Examples of non-aromatic heterocycles include pyrrolidine rings, tetrahydrofuran rings, tetrahydrothiophene rings, piperidine rings, tetrahydropyran rings, tetrahydrothiopyran rings, morpholine rings, hexamethyleneimine rings, hexamethylene oxide rings, hexamethylene sulfide rings, and heptamethyleneimine rings. Ring R may have a fused ring structure formed by fusion with other rings. Examples of such ring structures include indene rings, fluorene rings, benzofluorene rings, indole rings, isoindole rings, benzimidazole rings, quinoline rings, benzopyran rings, acridine rings, xanthene rings, carbazole rings, purine rings, and pteridine rings.

[0083] Ring R may have substituents, such as organic groups and polar functional groups. For details on these organic groups and polar functional groups, refer to the descriptions of the organic group and polar functional group of substituent P above. A halogen group is preferred as the polar functional group. If ring R has multiple substituents, the substituents may be the same or different. Ring R may not have substituents.

[0084] In equation (4), Y 1 When -CH=CH- represents the base A + And group A will have a quinoline skeleton. 1 -C(R 36 )(R 37 )- When representing R 36 and R 37 For details of the organic group, refer to the description of the organic group of substituent P above. 36 and R 37 Each of these is preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or an amino group, and more preferably a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. The alkyl group or alkoxy group has 1 to 8 carbon atoms, more preferably 1 to 5, and even more preferably 1 to 3. The aryl group has 6 to 12 carbon atoms, more preferably 6 to 10, and the aralkyl group has 7 to 13 carbon atoms, and more preferably 7 to 11.

[0085] The diinmonium dye is preferably a compound represented by the following formula (6). In formula (6), R 51 ~R 58 Each of these independently represents a hydrogen atom, a halogen atom, or an organic group, and X - represents a monovalent anion. The diimmonium dyes in formula (6) also include compounds that are in resonance relationships.

[0086] [ka]

[0087] In equation (6), R 51 ~R58 Examples of halogen atoms (halogeno groups) include fluorine atoms (fluoro groups), chlorine atoms (chloro groups), bromine atoms (bromo groups), and iodine atoms (iodine groups). 51 ~R 58 For details of the organic group, refer to the description of the organic group of substituent P above. In formula (2), R 51 ~R 58 The alkyl group is preferably an alkyl group, an aryl group, or an aralkyl group, with alkyl groups being more preferred. Linear or branched alkyl groups are preferred. 51 ~R 58 The alkyl group preferably has 2 to 12 carbon atoms, more preferably 10 or fewer, and even more preferably 8 or fewer.

[0088] In equations (1) and (6), X - Examples of anions include halogen ions and BF4. - PF6 - ClO4 - These are some examples. Note that X - The conjugate acid is preferably an anion with a pKa of -8.0 or less; that is, cyanine-based dyes and / or diinmonium-based dyes preferably have an anion with a conjugate acid pKa of -8.0 or less. This can improve the heat resistance of cyanine-based dyes and diinmonium-based dyes.

[0089] Acids with a pKa of -8.0 or less include, for example, those listed in Table 1 of Agnes Kutt et al., “Equilibrium Acidities of Super acids”, J.Org.Chem., 76, 391-395 (2011). If the pKa is publicly known from literature, that value should be cited; otherwise, a calculated value obtained using Advanced Chemistry Development (ACD / Labs) Software can be used. - The pKa of the conjugate acid of the anion is preferably -10.0 or less, more preferably -11.0 or less, and even more preferably -18.0 or less. -The anion is preferably a low nucleophilic anion, and is generally preferred to be an anion formed when a low pKa acid, commonly known as a super acid, dissociates a proton.

[0090] X - Examples of anions include those represented by the following equations (7-1) to (7-3). In equations (7-1) to (7-3), R 61 ~R 67 Each of these independently represents a fluorine atom, a fluoroalkyl group, a fluoroaryl group, or a cyano group, and R 68 and R 69 Each of these is independently a fluorine atom, a fluoroalkyl group, a fluoroaryl group, a cyano group, or -SO2-R 70 Represents R 70 This represents a fluorine atom, a fluoroalkyl group, a fluoroaryl group, or a cyano group.

[0091] [ka]

[0092] X - In addition to the anions of formulas (7-1) to (7-3), the anions may also be perchlorate ions, fluorosulfonate ions, fluoroalkyl sulfonate ions, cyanoalkyl sulfonate ions, 2,4,6-trinitrobenzenesulfonate ions, 1,1,3,3-tetracyanoallyl ions, fluorophosphate ions, fluoroantimonate ions, etc.

[0093] In formulas (7-1) to (7-3), R 61 ~R 70 The fluoroalkyl group can be linear, branched, or cyclic fluoroalkyl groups, with linear or branched being preferred and more preferably linear. The fluoroalkyl group preferably has 1 to 8 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 4 carbon atoms, and is preferably a perfluoroalkyl group. 61 ~R 70The number of carbon atoms in the fluoroaryl group is preferably 6 to 12, more preferably 6 to 10, and preferably a perfluoroaryl group. Furthermore, the fluoroalkyl sulfonate ion, fluorophosphate ion, and fluoroantimonate ion listed above as anions other than the anions of formulas (7-1) to (7-3) are preferably perfluoroalkyl sulfonate ion, hexafluorophosphate ion, and hexafluoroantimonate ion, respectively. The number of carbon atoms in the alkyl group of the fluoroalkyl sulfonate ion is preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4.

[0094] X - The anion is preferably an anion represented by formula (7-1), i.e., a borate ion, and therefore it is preferable that cyanine-based dyes and / or diimmonium-based dyes have a borate ion. This can further enhance the heat resistance of cyanine-based dyes and diimmonium-based dyes. In this case, R 61 ~R 64 It is more preferably a fluoroalkyl group, a fluoroaryl group, or a cyano group, even more preferably a fluoroalkyl group or a fluoroaryl group, and particularly preferably a fluoroaryl group. Examples of borate ions having a fluoroaryl group and a conjugate acid pKa of -8.0 or less include tetrakis(pentafluorophenyl)borate anion (conjugate acid pKa is approximately -30).

[0095] The near-infrared absorbing dye is preferably a phthalocyanine-based dye. Phthalocyanine-based dyes can suitably absorb laser light with wavelengths of 800 nm to 1300 nm, which are commonly used in laser welding. However, since phthalocyanine-based dyes have slightly lower transmittance in the visible light region compared to cyanine-based dyes and diimmonium-based dyes, it is preferable to use cyanine-based dyes or diimmonium-based dyes rather than phthalocyanine-based dyes if you want to increase visible light transmittance.

[0096] As the phthalocyanine compound, it is preferable to use a compound represented by the following formula (8). In formula (8), M represents a metal atom, a metal oxide, or a metal halide, and R 71 ~R 86 Each of these is independently a hydrogen atom, a halogen atom, and -OR 87 , -SR 88 or -NH-R 89 Represents R 87 ~R 89 Each of these independently represents an optionally substituted aryl group, an optionally substituted aralkyl group, an optionally substituted heteroaryl group, or an optionally substituted alkyl group. The metal element constituting M may be bonded to or coordinated with other elements such as oxygen or halogens.

[0097] [ka]

[0098] In formula (8), examples of metal elements constituting M include copper, zinc, indium, cobalt, vanadium, iron, nickel, tin, silver, magnesium, sodium, lithium, and lead. Among these metal elements, copper, vanadium, and zinc are preferred in terms of visible light transmittance and light resistance.

[0099] In formula (8), R 71 ~R 86 Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., with fluorine atoms and chlorine atoms being preferred. 71 ~R 86 ga-OR 87 , -SR 88 or -NH-R 89 When representing R, 87 ~R 89 For details on the aryl, aralkyl, heteroaryl, and alkyl groups, refer to the descriptions of these groups in substituent P above.

[0100] The ink may also contain a resin in addition to a near-infrared absorbing dye and a solvent. This makes it easier to improve the coating properties of the ink. The resin used in the ink is preferably one that melts when irradiated with laser light and can weld components together, and is preferably a thermoplastic resin. This makes it easier for the resin in the ink to melt and weld components together when irradiated with laser light. The resin may be not only a completed polymer, but also a resin raw material (including resin precursors, raw materials for the precursors, monomers that make up the resin, etc.) that undergoes a polymerization or crosslinking reaction to be incorporated into the resin during use. The ink may not contain resin, in which case it becomes easier to improve the quick-drying properties of the ink or to apply the ink more thinly.

[0101] Resins used in inks include, for example, (meth)acrylic resins, (meth)acrylic urethane resins, polyacrylic acid and its salts, polyacrylamide, polyvinyl chloride resins, polyvinylidene chloride resins, polyvinylpyrrolidone, polyolefin resins (e.g., polyethylene resin, polypropylene resin), cycloolefin resins, polyethyleneimine, melamine resin, polyurethane resin, polystyrene resin, polyvinyl acetate, polyamide resin (e.g., nylon), aramid resin, polyimide resin, polyamideimide resin, alkyd resin, phenolic resin, epoxy resin, polyester resin (e.g., polybutylene terephthalate (PBT) resin, polyethylene terephthalate (PET) resin, polyarylate resin, etc.), polysulfone resin, polyethersulfone resin, polysulfonamide and its salts, butyral resin, polycarbonate Examples of suitable resins include polyimide resins, polyacetal resins, polyether resins, polyphenylene sulfide resins, ABS resins (acrylonitrile butadiene styrene resins), AS resins (acrylonitrile-styrene copolymers), styrene-maleic anhydride copolymers, silicone resins, modified silicone resins (e.g., (meth)acrylic silicone resins, alkylpolysiloxane resins, silicone urethane resins, silicone polyester resins, silicone acrylic resins, etc.), fluororesins (e.g., fluorinated aromatic polymers, polytetrafluoroethylene (PTFE), perfluoroalkoxy fluororesins (PFA), fluorinated polyaryl ether ketones (FPEK), fluorinated polyimide (FPI), fluorinated polyamic acid (FPAA), fluorinated polyethernitrile (FPEN), etc.), carboxymethylcellulose, polyethylene glycol, etc. Among these, polyimide resins, polyamide-imide resins, (meth)acrylic resins, cycloolefin resins, epoxy resins, polyester resins, polyarylate resins, polyamide resins, polycarbonate resins, polysulfone resins, and fluorinated aromatic polymers are preferred. These resins are highly transparent, which allows for a good appearance when components are welded together using ink.

[0102] Polyimide resins are polymers that contain imide bonds in the repeating units of their main chain. For example, they can be produced by condensation polymerization of tetracarboxylic acid 2-anhydride and a diamine to obtain polyamic acid, which is then dehydrated and cyclized (imidized). As the polyimide resin, it is preferable to use aromatic polyimides in which aromatic rings are linked by imide bonds. Examples of polyimide resins that can be used include Neoprim® from Mitsubishi Gas Chemical Company, Kapton® from DuPont, Aurum® from Mitsui Chemicals, Meldin® from Saint-Gobain, and the TPS® TI3000 series from Toray Plastics Precision Co., Ltd.

[0103] Polyamide-imide resins are polymers that contain amide and imide bonds in the repeating units of their main chain. Examples of polyamide-imide resins that can be used include Tolon® from Solvay Advanced Polymers, Byromax® from Toyobo Co., Ltd., and the TPS® TI5000 series from Toray Plastics Precision Co., Ltd.

[0104] (Meth)acrylic resins are polymers having repeating units derived from (meth)acrylic acid or its derivatives. For example, resins having repeating units derived from (meth)acrylic acid esters, such as poly(meth)acrylic acid ester resins, are preferably used. (Meth)acrylic resins with a ring structure in the main chain are also preferred. Examples include carbonyl group-containing ring structures such as lactone ring structures, glutaric acid anhydride structures, glutarimide structures, maleic acid anhydride structures, and maleimide ring structures; and carbonyl group-free ring structures such as oxetane ring structures, azetidine ring structures, tetrahydrofuran ring structures, pyrrolidine ring structures, tetrahydropyran ring structures, and piperidine ring structures. Note that carbonyl group-containing ring structures also include structures containing carbonyl group derivative groups such as imide groups. (Meth)acrylic resins having a carbonyl group-containing ring structure can be those described in, for example, Japanese Patent Publication No. 2004-168882, Japanese Patent Publication No. 2008-179677, International Publication No. 2005 / 54311, Japanese Patent Publication No. 2007-31537, etc.

[0105] Cycloolefin resins are polymers obtained by polymerizing cycloolefins as at least a portion of their monomer components, and are not particularly limited as long as they have an alicyclic structure in part of their main chain. Examples of cycloolefin resins that can be used include Topas® manufactured by Polyplastics, Inc., Appel® manufactured by Mitsui Chemicals, Inc., Zeonex® and Zeonor® manufactured by Nippon Zeon Corporation, and Arton® manufactured by JSR Corporation.

[0106] Epoxy resins are resins that can be cured by crosslinking epoxy compounds (prepolymers) in the presence of a curing agent or curing catalyst. Examples of epoxy compounds include aromatic epoxy compounds, aliphatic epoxy compounds, alicyclic epoxy compounds, and hydrogenated epoxy compounds. For example, fluorene epoxy (Ogusol® PG-100) manufactured by Osaka Gas Chemical Co., Ltd., bisphenol A type epoxy compound (JER® 828EL) and hydrogenated bisphenol A type epoxy compound (JER® YX8000) manufactured by Mitsubishi Chemical Corporation, and alicyclic liquid epoxy compound (Celoxide® 2021P) manufactured by Daicel Corporation can be used.

[0107] Polyester resins are polymers that contain ester bonds in the repeating units of their main chain, and can be obtained, for example, by condensation polymerization of a polycarboxylic acid (dicarboxylic acid) and a polyalcohol (diol). Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. For example, the OKP series from Osaka Gas Chemical Co., Ltd., the TRN series from Teijin Ltd., Theonex®, Lynite® from DuPont, Novapex® from Mitsubishi Chemical Corporation, Novaduran® from Mitsubishi Engineering Plastics Corporation, Lumirror® and Trecon® from Toray Industries, Inc., and Elitel® from Unitika Ltd. can be used.

[0108] Polyarylate resins are polymers obtained by polycondensation of a divalent phenol compound and a dibasic acid (for example, an aromatic dicarboxylic acid such as phthalic acid), and the repeating units of the main chain contain aromatic rings and ester bonds. Examples of polyarylate resins that can be used include Vectran® from Kuraray Co., Ltd., and U Polymer® and Unifiner® from Unitika Corporation.

[0109] Polyamide resins are polymers that contain amide bonds in the repeating units of their main chain, and can be obtained, for example, by condensation polymerization of a diamine and a dicarboxylic acid. Polyamide resins may also have an aliphatic skeleton in their main chain, and nylon can be used as such an amide resin. Polyamide resins may also have an aromatic skeleton, and aramid resins are known as such polyamide resins. Aramid resins are preferred because they have excellent heat resistance and high mechanical strength, and examples of aramid resins that can be used include Twaron® and Conex® from Teijin Corporation, and Kevlar® and Nomex® from DuPont.

[0110] Polycarbonate resin is a polymer that contains carbonate groups (-O-(C=O)-O-) in the repeating units of its main chain. Examples of polycarbonate resins that can be used include Panlite® and Multilon® manufactured by Teijin Corporation, Yupiron® manufactured by Mitsubishi Engineering Plastics Corporation, Yupizeta®, Novalex®, and Zanter® manufactured by Mitsubishi Gas Chemical Company, SD Polyca® manufactured by Sumika Styron Polycarbonate Co., Ltd., and Toughlon® manufactured by Idemitsu Kosan Co., Ltd.

[0111] Polysulfone resins are polymers having repeating units containing an aromatic ring, a sulfonyl group (-SO2-), and an oxygen atom. Examples of polysulfone resins that can be used include Sumika Excel® PES3600P and PES4100P manufactured by Sumitomo Chemical Co., Ltd., and UDEL® P-1700 manufactured by Solvay Specialty Polymers Ltd.

[0112] Fluorinated aromatic polymers are polymers having repeating units comprising an aromatic ring having one or more fluorine atoms and at least one bond selected from the group consisting of ether bonds, ketone bonds, sulfone bonds, amide bonds, imide bonds, and ester bonds. Among these, polymers that essentially include repeating units comprising an aromatic ring having one or more fluorine atoms and an ether bond are preferred. For example, fluorinated aromatic polymers described in Japanese Patent Application Publication No. 2008-181121 can be used.

[0113] The resin may be transparent to visible light or opaque to visible light, but it is preferable that the resin be highly transparent in order to improve the appearance of the welded body formed by laser welding and to broaden the range of ink application. The resin is preferably 75% or more in total light transmittance when it is made into a 0.1 mm thick plate, more preferably 80% or more, and even more preferably 85% or more. There is no particular upper limit to the total light transmittance of the resin; it is sufficient if the total light transmittance is 100% or less, but it may be, for example, 95% or less. The total light transmittance is measured in accordance with JIS K 7105.

[0114] The glass transition temperature (Tg) of the resin is not particularly limited, but from the viewpoint of improving the heat resistance of the welded body formed by welding components together with ink, it is preferably 110°C or higher, more preferably 120°C or higher, and even more preferably 130°C or higher. The upper limit of the glass transition temperature of the resin is not particularly limited, but from the viewpoint of facilitating laser welding, it is preferably 380°C or lower, more preferably 300°C or lower, and even more preferably 250°C or lower.

[0115] The ink may contain dyes other than near-infrared absorbing dyes, as long as the desired performance is ensured. For example, it may contain visible light absorbing dyes and / or ultraviolet absorbing dyes. The visible light absorbing dye may be a pigment or a dye. The ink may contain various additives as needed, such as dispersants, plasticizers, surfactants, viscosity modifiers, defoamers, preservatives, and resistivity modifiers.

[0116] The ink coating tool of this disclosure can weld a first welding member and a second welding member by coating them with ink and irradiating them with laser light. The ink only needs to be coated on at least one of the first welding member and the second welding member. Preferably, at least one of the first welding member and the second welding member is transparent to laser light. On the other hand, the other of the first welding member and the second welding member may be transparent to laser light or not. The first welding member and the second welding member can be welded together by irradiating the area coated with ink from the side of the first welding member and the second welding member that is transparent to laser light. Furthermore, from the perspective of laser welding the first and second welding members with ink applied using an ink application tool, it is desirable that the first and second welding members themselves do not generate heat when irradiated with laser light. Therefore, it is preferable that both the first and second welding members are transparent materials that transmit laser light.

[0117] The shapes of the first and second welded members are not particularly limited and include, for example, plate-shaped, sheet-shaped, columnar, rod-shaped, case-shaped, granular, cloth-shaped, fibrous, convex lens-shaped, concave lens-shaped, irregular shape, etc.

[0118] The constituent materials of the welded members are not particularly limited, but it is preferable that at least one of the first welded member and the second welded member is made of resin. This allows the near-infrared absorbing dye contained in the ink to generate heat when irradiated with laser light, causing at least one of the first welded member and the second welded member to melt and firmly weld the first and second welded members together. More preferably, both the first and second welded members are made of resin. Hereinafter, the first and second welded members made of resin will be referred to as the "first resin material" and the "second resin material," respectively.

[0119] If the ink contains resin, the resin contained in the ink may be the same type as or different from the resin constituting the first resin material and / or the second resin material. However, it is preferable that the resin contained in the ink is the same type as the first resin material and the second resin material, as this makes it easier to bond the first resin material and the second resin material more firmly and to make the joint between the first resin material and the second resin material less noticeable. It is also preferable that the first resin material and / or the second resin material be composed of thermoplastic resin.

[0120] Examples of laser light include solid-state lasers, fiber lasers, semiconductor lasers, gas lasers, and liquid lasers. For example, YAG lasers (wavelengths 1064 nm, 1070 nm) and semiconductor lasers (wavelengths 808 nm, 840 nm, 940 nm, 980 nm) can be preferably used. The wavelength of the laser light is preferably in the range of 800 nm to 1300 nm, more preferably 850 nm to 1200 nm, and even more preferably 900 nm to 1100 nm. Among these, laser light with wavelengths of 940 nm, 980 nm, or 1070 nm is particularly preferred.

[0121] The wavelength of the laser light is preferably close to the absorption maximum wavelength of the near-infrared absorbing dye contained in the ink. For example, the difference between the wavelength of the laser light and the absorption maximum wavelength of the near-infrared absorbing dye contained in the ink is preferably 150 nm or less, and may be 100 nm or less, 50 nm or less, or 30 nm or less. This allows the laser light to be efficiently absorbed by the near-infrared absorbing dye contained in the ink. As a result, the laser output during laser welding can be set low, which reduces damage to the welded material and makes it easier to maintain a good appearance of the welded material.

[0122] Laser welding machines include Trumpf TruDiode® (laser wavelength: 920-1050nm), Han's Laser WFD series (laser wavelengths: 808nm, 915nm, 980nm), LPKF Laser & Electronics PowerWeld2600 (laser wavelength: 980nm), Coherent ExactWeld230P, Emerson Electric GLX series (laser wavelength: 980nm) or GL-300 (laser wavelength: 1080nm), Amada ML-5120 direct diode laser welding machine - 120W (laser wavelength: 915nm), IPTE Factory Automation laser welding machines, EVLASER SRL TITAN WELD system (laser wavelength: 980nm), and IPG. You can use laser welding machines from Photonics, Panasonic Industries' VL-W1 series (laser wavelength: 1070nm), Mecco's 200W or 300W (laser wavelength: 1064nm), Hamamatsu Photonics' L16490-343 or T-SMILS L15570 series laser heating systems, Fine Devices' FD2330 (laser wavelengths: 808nm, 940nm, 980nm), Nippon Avionics' LW-D30A / LW-D100 semiconductor laser welding machines (laser wavelength: 980nm), TOWA Laser Front's M720A series fiber laser processing machines, Seidensha Electronics Industries' LS-W100 laser resin welding system (laser wavelength: 940nm), Hiroshima's Galweld typeM or typeS (laser wavelength: 1070nm), etc.

[0123] This disclosure also provides a laser welding method using the ink coating tool of this disclosure. The laser welding method according to this disclosure comprises a step of coating ink onto a first resin material using the ink coating tool of this disclosure (hereinafter referred to as the "ink coating step") and a step of welding the first resin material and the second resin material together by overlapping the ink-coated portion of the first resin material with a second resin material and irradiating the ink with laser light.

[0124] In the ink coating process, ink is applied to the first resin material using an ink coating tool. By bringing the core material of the ink coating tool into contact with the first resin material, ink can be applied to the first resin material.

[0125] In the ink coating process, for example, the coating area of ​​the first resin material per application is 100 cm². 2 The following can be achieved: By using the ink application tool of this disclosure, ink can be applied precisely to the areas required for welding, thereby reducing the area to be coated with ink per application. The area to be coated with ink per application is 50 cm². 2 Below, 30cm 2 Below, 10cm 2 Below, 5cm 2 Below, 3cm 2 less than or equal to 1 cm 2 The following is also possible: For example, if the first resin material is in the shape of a container and ink is applied to its rim, the area to which the ink is applied can be reduced.

[0126] In the ink coating process, the dry weight of the ink per unit area coated is 0.1 μg / cm². 2 More than 1000μg / cm 2 The following is preferable. This ensures that when laser light is irradiated onto the ink-coated area during the welding process, the near-infrared absorbing pigment contained in the ink generates heat in an appropriate amount, facilitating suitable laser welding. The dry weight of the ink per coated area is 0.5 μg / cm². 2 1 μg / cm³ or more 2 It may be greater than or equal to 500 μg / cm³. 2 Below 300μg / cm 2 The following or 100 μg / cm³ 2 The following is also acceptable.

[0127] In the welding process, the first resin material and the second resin material are welded together by overlapping the ink-coated area of ​​the first resin material with the second resin material and irradiating the ink with laser light. The laser light can be applied from either the first resin material side or the second resin material side, as long as the laser light reaches the ink. The laser light should be applied from the side of the first and second resin materials that transmits the laser light.

[0128] The laser beam may be irradiated onto the ink only once, or two or more times. The number of laser irradiations, laser scanning speed, irradiation range, etc., should be adjusted as appropriate so that the first resin material and the second resin material are properly welded together.

[0129] In the ink coating process, the second resin material may also be coated with ink. In this case, in the welding process, it is preferable to overlap the second resin material onto the ink-coated areas of the first resin material, and to overlap the first resin material onto the ink-coated areas of the second resin material. Details of the ink, ink coating tool, laser light, first resin material, and second resin material in the laser welding method should be referred to in the above description.

[0130] This disclosure also provides a method for manufacturing a welded body, comprising the steps of: applying ink to a first resin material using the ink application tool of this disclosure; and welding the first resin material and the second resin material together by overlapping the ink-coated portion of the first resin material with a second resin material and irradiating the ink with laser light. A welded body can be obtained by welding the first resin material and the second resin material together. A description of the method for manufacturing a welded body is provided in the description of the laser welding method described above. [Examples]

[0131] The contents of this disclosure will be explained in more detail below with reference to examples, but the contents of this disclosure are not limited by the examples below, and it is possible to implement them with appropriate modifications to the extent that they are in line with the spirit of the preceding and following, and all such modifications are included in the technical scope of this disclosure.

[0132] (1) Synthesis of dye compounds and resins (1-1) Synthesis Example 1: Synthesis of Cyanine Compound 1 In a 500 mL four-necked flask placed in a water bath, 21.9 g (0.195 mol) of potassium tert-butoxide, 98.1 g of super-anhydrous tetrahydrofuran, 10.8 g (0.065 mol) of fluorene, and 11.5 g (0.13 mol) of ethyl acetate were sequentially added under nitrogen flow (10 mL / min), while taking care to avoid exothermic reaction. The mixture was then heated in a water bath under reflux conditions and stirred for 3 hours. After cooling the resulting reaction solution, it was quenched with dilute hydrochloric acid, extracted with ethyl acetate, and washed three times with brine. The resulting organic phase was dehydrated with magnesium sulfate, concentrated using an evaporator, and the resulting solid was purified by silica gel column chromatography (eluent: ethyl acetate) to obtain 12.5 g of 9-acetyl-9H-fluorene.

[0133] In a 500 mL separable flask, 6.2 g (0.026 mol) of 9-acetyl-9H-fluorene, 5.0 g (0.026 mol) of 1-phenylhydrazine hydrochloride, and 112.1 g of tert-amyl alcohol as solvent were charged. The mixture was reacted at 90°C for 4 hours with stirring under a nitrogen flow (10 mL / min). After the reaction was complete, the reaction mixture was cooled to room temperature, quenched with 100 g of water, and extracted with 100 g of ethyl acetate. The resulting organic phase was dehydrated with magnesium sulfate, concentrated using an evaporator, and the resulting solid was purified by silica gel column chromatography (eluent: chloroform) to obtain 5.1 g of indorenine compound 1.

[0134] Next, 2.0 g (0.007 mol) of the indorenine compound 1 obtained above, 11.2 g (0.079 mol) of iodomethane, and 53.3 g of N,N-dimethylformamide were charged into a 100 mL four-necked flask, and the mixture was stirred at 80°C for 6 hours under a nitrogen flow (5 mL / min). After cooling to room temperature, the reaction mixture was precipitated in 300 g of toluene, and the precipitated solid was filtered off to obtain 1.8 g of indorenium salt 1.

[0135] [ka]

[0136] N-((1E)-2-phenyl-3-((E)-(phenylimino)methyl)cyclohexa-2-ene-1-ylidene)methyl)aniline hydrochloride (dianiline salt 1) was synthesized according to the method described in Bioconjugate Chemistry, 29(11), p.3886-3895 (2018). In a 100 mL four-necked flask, 1.0 g (0.0021 mol) of the indorenium salt 1 obtained above, 0.42 g (0.0011 mol) of dianiline salt 1, 0.28 g (0.003 mol) of sodium acetate, 9.9 g of acetic acid, and 10.1 g of acetic anhydride were added and the mixture was stirred at 100 °C for 8 hours. The reaction mixture was cooled to room temperature, 150 g of water was added, and the precipitated solid was filtered off. This solid was purified by silica gel column chromatography (eluent: chloroform) to obtain 0.21 g of the iodide salt of cyanine compound 1.

[0137] [ka]

[0138] 0.50 g (0.50 mmol) of the iodide salt of cyanine compound 1 was dissolved in 20 mL of acetone, and 6.7 g (0.10 mmol) of a 10.5% aqueous solution of sodium tetrakis(pentafluorophenyl)borate (manufactured by Nippon Shokubai Co., Ltd.) was added. The mixture was stirred overnight at room temperature. After concentrating the reaction mixture using an evaporator, it was purified by silica gel column chromatography (developing solvent: chloroform) to obtain 0.57 g of cyanine compound 1 as shown in Table 1. The pKa of the tetrakis(pentafluorophenyl)borate anion of cyanine compound 1 is -8.0 or less.

[0139] [ka]

[0140] (1-2) Synthesis Example 2: Synthesis of Cyanine Compound 2 3-butyl-2-(2-[3-[2-(3-butyl-1,1-dimethyl-1,3-dihydrobenzo[e]indole-2-ylidene)ethylidene]-2-chloro-cyclohexa-1-enyl]vinyl)-1,1-dimethyl-1H-benzo[e]indolium hexafluorophosphate (Few Chemicals, S0712) was used as the starting cyanine compound. 1.00 g (1.2 mmol) of this starting cyanine compound was dissolved in 100 g of acetone, and 9.00 g (1.4 mmol) of a 10.5% sodium tetrakis(pentafluorophenyl)borate aqueous solution heated to 40°C was added, and the mixture was stirred at 50°C for 3 hours. The solvent was then removed by distillation, and the resulting solid was washed with deionized water to obtain 1.47 g of cyanine compound 2 shown in Table 1.

[0141] (1-3) Synthesis Example 3: Synthesis of Cyanine Compound 3 In Synthesis Example 2, 1.23 g of cyanine compound 3, shown in Table 1, was obtained in the same manner as in Synthesis Example 2, except that 6-butoxy-2-[5-(6-butoxy-1-butyl-1H-benzo[cd]indole-2-ylidene)-penta-1,3-dienyl]-1-butyl-benzo[cd]indolium tetrafluoroborate (Few Chemicals, S2437) was used as the starting cyanine compound.

[0142] (1-4) Synthesis Example 4: Synthesis of Cyanine Compound 4 In Synthesis Example 2, 1.12 g of cyanine compound 4, shown in Table 1, was obtained in the same manner as in Synthesis Example 2, except that 1-butyl-2[7-(1-butyl-1H-benzo[cd]indole-2-ylidene)-hepta-1,3,5-trienyl]-benzo[cd]indrolium hexafluorophosphate (Few Chemicals, S2058) was used as the starting cyanine compound.

[0143] (1-5) Synthesis Example 5: Synthesis of Cyanine Compound 5 In Synthesis Example 2, 1.79 g of cyanine compound 5, shown in Table 1, was obtained in the same manner as in Synthesis Example 2, except that 1-butyl-2-(2-[3-(2-[1-butyl-1H-benzo[cd]indole-2-ylidene]ethylidene)-2-chloro-1-cyclohexa-1-enyl]-vinyl)-benzo[cd]indolium tetrafluoroborate (Exciton, IR1014) was used as the starting cyanine compound.

[0144] (1-6) Synthesis Example 6: Synthesis of Cyanine Compound 6 In Synthesis Example 2, 2.12 g of cyanine compound 6, shown in Table 1, was obtained in the same manner as in Synthesis Example 2, except that 1-butyl-2-(2-[3-(2-[1-butyl-1H-benzo[cd]indole-2-ylidene]ethylidene)-2-phenyl-1-cyclopenta-1-enyl]-vinyl)-benzo[cd]indolium tetrafluoroborate (Few Chemicals, S0813) was used as the starting cyanine compound.

[0145] (1-7) Synthesis Example 7: Synthesis of Cyanine Compound 7 In Synthesis Example 1, 1.54 g of the iodide salt of the cyanine compound was obtained by the same procedure as in Synthesis Example 1, except that 4-t-butylphenylhydrazine hydrochloride was used instead of 1-phenylhydrazine hydrochloride, iodobutane was used instead of iodomethane, and dianiline salt 2 shown in Table 2 was used instead of dianiline salt 1. Using the obtained iodide salt of the cyanine compound, 1.01 g of cyanine compound 7 shown in Table 1 was obtained by the same procedure as in the method described in International Publication No. 2014 / 057032

[0220] and Synthesis Example 1.

[0146] (1-8) Synthesis Example 8: Synthesis of Diimmonium Compounds Based on the descriptions in paragraphs

[0059] to

[0069] of Japanese Patent No. 5033632, the diimmonium compounds shown in Table 1 were synthesized.

[0147] [Table 1]

[0148] [Table 2]

[0149] (1-9) Synthesis Example 9: Synthesis of Phthalocyanine Compound 1 Phthalocyanine compound 1, shown in Table 3, was synthesized according to the method described in Example 16 of Japanese Patent No. 4278923.

[0150] (1-10) Synthesis Example 10: Synthesis of Phthalocyanine Compound 2 In a 500 mL four-neck separable flask, 30.0 g of tetrafluorophthalonitrile, 20.9 g of potassium fluoride, and 67.0 g of acetone were charged and cooled to below 5°C. A mixed solution of 48.9 g of 2,5-dichlorophenol and 44.3 g of acetone was prepared and added dropwise using a dropping funnel. The mixture was heated to 20°C and stirred for 3 hours. Next, 53.5 g of 2,6-diisopropylphenol, 13.1 g of potassium fluoride, and 20.1 g of acetone were added to the flask and stirred at 50°C to 60°C for 8 hours. After cooling, the reaction mixture was filtered, the filtrate was washed with 150.0 g of acetone and filtered, and the filtrates were combined. Acetone was removed from the combined filtrate using a rotary evaporator, and methanol was added to recrystallize the product. The obtained crystals were filtered and vacuum-dried to obtain 67.6 g of (2,5-dichlorophenol)2-(2,6-diisopropylphenol)-fluorophthalonitrile. In a 100 mL four-necked flask, 10 g of (2,5-dichlorophenol)2-(2,6-diisopropylphenol)-fluorophthalonitrile, 0.79 g of vanadium trichloride, 15.0 g of 1,2,4-trimethylbenzene, and 1.6 g of benzonitrile were charged and stirred under reflux for approximately 24 hours. Then, 8.0 g of 1,2,4-trimethylbenzene was added, and after cooling to 40°C, 24.1 g of 2-ethylhexylamine was added and the mixture was stirred at 100°C for 5 hours. After cooling, the reaction mixture was filtered, and methanol was added to the filtrate for recrystallization. The obtained crystals were filtered and vacuum-dried to obtain 6.2 g of phthalocyanine compound 2 shown in Table 3.

[0151] [Table 3]

[0152] (1-11) Synthesis Example 11: Synthesis of Polyarylate Resin In a 2L reaction vessel equipped with a stirring blade, 10.01g (0.044mol) of 2,2'-bis(4-hydroxyphenyl)propane, 3.59g (0.090mol) of sodium hydroxide, and 300g of deionized water were charged and dissolved. Then, 0.89g (0.009mol) of triethylamine was added and dissolved. A solution of 3.57g (0.021mol) of terephthalic acid dichloride and 3.57g (0.021mol) of isophthalic acid dichloride dissolved in 500g of methylene chloride was placed in a dropping funnel and attached to the reaction vessel. The solution in the reaction vessel was stirred while maintaining the temperature at 20°C, and the methylene chloride solution was added dropwise from the dropping funnel over 60 minutes. Then, a solution of 0.71g (0.005mol) of benzoyl chloride dissolved in 10g of methylene chloride was added, and the mixture was stirred for another 60 minutes. The resulting reaction solution was neutralized with an aqueous acetic acid solution to adjust the pH of the aqueous phase to 7, and then the oil phase and aqueous phase were separated using a separatory funnel. The obtained oil phase was added dropwise to methanol under stirring to reprecipitate the polymer, and the precipitate was recovered by filtration. The solution was dried in an oven at 80°C to obtain a white solid polyarylate resin. The yield was 11.5 g. The weight-average molecular weight (Mw) of the obtained polyarylate resin was 33,780, and the number-average molecular weight (Mn) was 8,130. The weight-average molecular weight and number-average molecular weight of the polyarylate resin are polystyrene equivalent values ​​determined by gel permeation chromatography.

[0153] (2) Examples of laser welding ink preparation (2-1) Preparation Example 1: Preparation of Ink 1 0.2 parts by mass of cyanine compound 6 was added to 99.8 parts by mass of cyclohexanone, and the mixture was stirred in a water bath at 40°C to 50°C for 1 hour. The mixture was then filtered through a 0.45 μm pore size filter (GL Sciences Co., Ltd., non-aqueous 25N) to remove impurities and obtain ink 1 with a solid content of 0.2%. The viscosity of ink 1 at 25°C was 2.5 mPa·s.

[0154] (2-2) Preparation Example 2: Preparation of Ink 2 4.8 parts by mass of polyvinylpyrrolidone (K-90, manufactured by Nippon Shokubai, hereinafter referred to as "PVP") were mixed with 47.5 parts by mass of methanol and stirred at room temperature for 1 hour to obtain a resin solution. 0.2 parts by mass of cyanine compound 6 were mixed with 47.5 parts by mass of diethylene glycol monomethyl ether (hereinafter referred to as "DGME") and stirred in a water bath at 50°C to 60°C for 1 hour to obtain a dye solution. The resin solution and dye solution were mixed and stirred at room temperature for 1 hour, and filtered through a 0.45 μm pore size filter (GL Sciences, non-aqueous 25N) to remove impurities, obtaining ink 2 with a solid content of 5.0%. The viscosity of ink 2 at 25°C was 40.3 mPa·s.

[0155] (2-3) Preparation Example 3: Preparation of Ink 3 0.2 parts by mass of cyanine compound 6 was added to 90.0 parts by mass of cyclohexanone and stirred in a water bath at a temperature of 40°C to 50°C for 1 hour. Then, 9.8 parts by mass of polyarylate resin (hereinafter referred to as "PAR") was added and stirred for another hour. The resulting resin solution was filtered through a 0.45 μm pore size filter (GL Sciences Co., Ltd., non-aqueous 25N) to remove impurities and obtain ink 3 with a solid content of 10.0%. The viscosity of ink 3 at 25°C was 62.5 mPa·s.

[0156] (2-4) Preparation Example 4: Preparation of Ink 4 In Preparation Example 3, ink 4 with a solid content of 10.0% was obtained using the same procedure as in Preparation Example 3, except that the polyarylate resin was replaced with polycarbonate resin (manufactured by Mitsubishi Gas Chemical Company, Yupizeta® FPC-8225, hereinafter referred to as "PC"). The viscosity of ink 4 at 25°C was 70.0 mPa·s.

[0157] (2-5) Preparation Example 5: Preparation of Ink 5 In the same procedure as in Preparation Example 1, ink 5 with a solid content of 1.0% was obtained, except that the amount of cyanine compound 6 was changed from 0.2 parts by mass to 1.0 part by mass, and the amount of cyclohexanone was changed from 99.8 parts by mass to 99.0 parts by mass. The viscosity of ink 5 at 25°C was 2.2 mPa·s.

[0158] (2-6) Preparation Example 6: Preparation of Ink 6 In Preparation Example 4, an ink 6 with a solid content of 10.8% was obtained using the same procedure as in Preparation Example 4, except that the amount of cyanine compound 6 was changed from 0.2 parts by mass to 1.0 part by mass, and the amount of cyclohexanone was changed from 90.0 parts by mass to 89.2 parts by mass. The viscosity of ink 6 at 25°C was 72.2 mPa·s.

[0159] (2-7) Preparation Example 7: Preparation of Ink 7 In Preparation Example 5, ink 7 with a solid content of 1.0% was obtained using the same procedure as in Preparation Example 5, except that cyanine compound 6 was replaced with cyanine compound 3. The viscosity of ink 7 at 25°C was 3.0 mPa·s.

[0160] (2-8) Preparation Example 8: Preparation of Ink 8 In Preparation Example 5, ink 8 with a solid content of 1.0% was obtained using the same procedure as in Preparation Example 5, except that cyanine compound 6 was replaced with cyanine compound 4. The viscosity of ink 8 at 25°C was 2.6 mPa·s.

[0161] (2-9) Preparation Example 9: Preparation of Ink 9 In preparation example 5, ink 9 with a solid content of 1.0% was obtained using the same procedure as in preparation example 5, except that cyanine compound 6 was replaced with cyanine compound 7. The viscosity of ink 9 at 25°C was 2.1 mPa·s.

[0162] (2-10) Preparation Example 10: Preparation of Ink 10 In Preparation Example 5, ink 10 with a solid content of 1.0% was obtained using the same procedure as in Preparation Example 5, except that cyanine compound 6 was replaced with a diimmonium compound. The viscosity of ink 10 at 25°C was 1.9 mPa·s.

[0163] (2-11) Preparation Example 11: Preparation of Ink 11 In Preparation Example 10, an ink 11 with a solid content of 1.0% was obtained using the same procedure as in Preparation Example 10, except that the solvent was changed from cyclohexanone to ethylene glycol monomethyl ether. The viscosity of ink 11 at 25°C was 2.0 mPa·s.

[0164] (2-12) Preparation Example 12: Preparation of Ink 12 In Preparation Example 6, an ink 12 with a solid content of 10.8% was obtained using the same procedure as in Preparation Example 6, except that cyanine compound 6 was replaced with phthalocyanine compound 1. The viscosity of ink 12 at 25°C was 69.4 mPa·s.

[0165] (3) Analysis of dye compounds and inks (3-1) Spectroscopic measurement of dye compounds Chloroform solutions of cyanine compounds 1-7, diimmonium compounds, and phthalocyanine compounds 1-2 were prepared, and their transmission spectra were measured at wavelengths of 300 nm to 1300 nm. The concentrations of the chloroform solutions of the cyanine compounds, diimmonium compounds, and phthalocyanine compounds were adjusted so that the transmittance at the absorption maximum wavelength was 10% (±0.05%). Light transmittance was measured using a spectrophotometer (Shimadzu Corporation, UV-3600) at a measurement pitch of 1 nm, and the wavelength at which absorption was maximum (absorption maximum wavelength λmax) in the range of 300 nm to 1300 nm, and the average visible light transmittance in the range of 380 nm to 700 nm were determined. The results are shown in Table 4.

[0166] (3-2) Thermogravimetric Differential Thermal Analysis of Dye Compounds The weight loss temperature was measured using a thermogravimetric differential thermal analyzer (TG-DTA). The temperature was increased from room temperature (25°C) to 400°C at a heating rate of 10°C / min in an air atmosphere. The weight loss rate at 200°C and the 5% weight loss temperature were determined. α-alumina was used as the reference. The results are shown in Table 4.

[0167] [Table 4]

[0168] (3-3) Measuring the viscosity of the ink The viscosity of the ink was measured using an E-type viscometer (Toki Sangyo Co., Ltd., TV-20, rotor: 1°34′×R24) at a rotation speed of 3 to 60 rpm, a temperature of 25°C, and a measurement time of 1 minute. The results are shown in Table 5.

[0169] [Table 5]

[0170] (4) Welding test of case material and plate material (4-1) Test Example A1 Prepare a rectangular polystyrene case (manufactured by AS ONE, rectangular polystyrene case, part number 1-4698-01) with dimensions of 36mm in length, 36mm in width, 14mm in height, and 1mm in thickness, with an open top. Apply the coating to the top edge of the polystyrene case (coating area 1.4cm²). 2 Ink 1 was applied to the polystyrene case using a pen-type ink application tool, and the ink 1 was dried at room temperature. A polystyrene plate (manufactured by Standard Test Piece Co., Ltd.) measuring 40 mm in length, 40 mm in width, and 2 mm in thickness was placed on top of the polystyrene case coated with ink 1 to cover it, and laser welding was performed by irradiating the polystyrene plate side with a laser device (manufactured by Panasonic Industries, Ltd., VL-W1) using a laser (wavelength 1070 nm, beam diameter 2.0 mm, pressing force 750 N, laser output 20-90 W, laser scanning speed 10-1000 mm / sec, number of laser irradiations 1-30 times).

[0171] The pen-type ink application tool used was a pen-type container (model number A1-10) with a coating width of 2 mm, manufactured by Kuretake Co., Ltd. The pen-type ink application tool was prepared by filling the pen-type container with ink, attaching the core material, and allowing the ink to soak into the core material.

[0172] (4-2) Test Examples A2-A10 In Test Example A1, laser welding was performed in the same manner as in Test Example A1, except that one of inks 2-6, 8, or 10-12, as shown in Table 6, was used instead of ink 1.

[0173] (4-3) Test Example A11 Laser welding was performed in the same manner as in Test Example A1, except that instead of using a pen-type ink application tool, a cotton swab was used for coating. Coating with a cotton swab was performed by dipping the cotton tip of the swab in ink and then applying the cotton tip to the upper end of the polystyrene case.

[0174] (4-4) Test Examples A12-A18 In Test Example A11, laser welding was performed in the same manner as in Test Example A11, except that one of inks 2, 5, 6, 8, or 10-12, as shown in Table 6, was used instead of ink 1.

[0175] (4-5) Test Example A19 Laser welding was performed in the same manner as in Test Example A1, except that instead of using a pen-type ink application tool, coating was done by immersion. For immersion coating, approximately 1 mL of ink was placed in a glass container with an inner diameter of 50 mm, and the upper end of the polystyrene case was placed downwards and immersed vertically in the ink in the container for 1 second. Afterwards, the ink was dried at room temperature with the immersed portion of the upper end of the polystyrene case facing downwards.

[0176] (4-6) Test Examples A20~A26 In Test Example A19, laser welding was performed in the same manner as in Test Example A19, except that ink 2, 5, 6, 8, or 10-12 was used instead of ink 1, as shown in Table 6.

[0177] (5) Welding test between plates (5-1) Test Example B1 Prepare a polymethyl methacrylate plate (manufactured by Kuraray Co., Ltd., Comoglass® registered trademark, hereinafter referred to as "PMMA plate") measuring 37.5 mm in length, 17.5 mm in width, and 2 mm in thickness. Apply a 17 mm x 15 mm portion (coating area 2.6 cm²) to one side of this PMMA plate. 2 Ink 1 was applied to the PMMA plate using a pen-type ink application tool, and the ink 1 was dried at room temperature. A second PMMA plate measuring 37.5 mm in length, 17 mm in width, and 2 mm in thickness was placed on top of the area of ​​the PMMA plate coated with ink 1, and laser welding was performed by irradiating the second PMMA plate side with a laser (wavelength 1070 nm, beam diameter 2.0 mm, pressing force 900 N, laser output 10-90 W, laser scanning speed 10-300 mm / second, number of laser irradiations 1).

[0178] A pen-type ink application tool was used, specifically a pen-type container (model number C1-10) with a coating width of 15 mm manufactured by Kuretake Co., Ltd. The pen-type ink application tool was prepared by filling the pen-type container with ink, attaching the core material, and allowing the ink to soak into the core material. The core material of the pen-type ink application tool was brought into contact with the PMMA board, and the ink was applied to the PMMA board by moving it in one direction along the lateral side of the PMMA board.

[0179] (5-2) Exam Examples B2-B5 Laser welding was performed in the same manner as in Test Example B1, except that ink 5, 8, 11, or 12 was used instead of ink 1, as shown in Table 7.

[0180] (5-3) Test Example B6 In Test Example B1, laser welding was performed in the same manner as in Test Example B1, except that a polycarbonate sheet (manufactured by Takiron CI Co., Ltd., PC-1600, hereinafter referred to as "PC sheet") with dimensions of 37.5 mm in length, 17 mm in width, and 2 mm in thickness was used instead of the PMMA sheet, and a second PC sheet with dimensions of 37.5 mm in length, 17 mm in width, and 2 mm in thickness was used instead of the second PMMA sheet.

[0181] (5-4) Test Examples B7 to B10 In Test Example B6, laser welding was performed in the same manner as in Test Example B6, except that any one of Inks 5, 8, 11, and 12 was used instead of Ink 1 as shown in Table 7.

[0182] (5-5) Test Example B11 A polypropylene sheet (manufactured by AS ONE Corporation, product number 61-7414-32, hereinafter referred to as "PP sheet") with a length of 30.0 mm, a width of 20.0 mm, and a thickness of 0.75 mm was prepared. Ink 5 was applied to a 20 mm × 15 mm portion (coating area 3.0 cm 2 ) on one side in the longitudinal direction of this PP sheet using the same pen-type ink application tool as in Test Example B1, and Ink 5 was dried at room temperature. A second PP sheet with a length of 30.0 mm, a width of 20.0 mm, and a thickness of 0.75 mm was overlaid on the portion of the PP sheet coated with Ink 5, and laser welding was performed by irradiating a laser under the same conditions as in Test Example B1 from the side of the second PP sheet.

[0183] (5-6) Test Examples B12 to B13 In Test Example B11, laser welding was performed in the same manner as in Test Example B11, except that any one of Inks 8 and 11 was used instead of Ink 5 as shown in Table 7.

[0184] (5-7) Test Example B14 In Test Example B11, an acrylonitrile-butadiene-styrene plate (manufactured by Resonaak Co., hereinafter referred to as "ABS plate") with a length of 30.0 mm, a width of 20.0 mm, and a thickness of 2.0 mm was used instead of the PP sheet, and a second ABS plate with a length of 30.0 mm, a width of 20.0 mm, and a thickness of 2.0 mm was used instead of the second PP sheet. Laser welding was performed in the same manner as in Test Example B11.

[0185] (5-8) Test Examples B15 to B16 In Test Example B14, laser welding was performed in the same manner as in Test Example B14, except that any one of Inks 8 and 11 was used instead of Ink 5 as shown in Table 7.

[0186] (5-9) Test Example B17 Laser welding was performed in the same manner as in Test Example B1, except that a PC board was used instead of a PMMA board and ink 5 was used instead of ink 1.

[0187] (5-10) Test Example B18 In Test Example B17, laser welding was performed in the same manner as in Test Example B17, except that an ABS plate was used instead of a PC plate.

[0188] (5-11) Test Example B19 In Test Example B1, laser welding was performed in the same manner as in Test Example B1, except that a PC plate was used instead of the second PMMA plate and ink 5 was used instead of ink 1.

[0189] (5-12) Test Example B20 Laser welding was performed in the same manner as in Test Example B19, except that an ABS plate was used instead of a PMMA plate.

[0190] (5-13) Test Example B21 Laser welding was performed in the same manner as in Test Example B1, except that an ABS plate was used instead of the second PMMA plate and ink 5 was used instead of ink 1.

[0191] (5-14) Test Example B22 In Test Example B21, laser welding was performed in the same manner as in Test Example B21, except that a PC plate was used instead of a PMMA plate.

[0192] (5-15) Test Example B23 Laser welding was performed in the same manner as in Test Example B1, except that instead of using a pen-type ink application tool, coating was done by immersion. For immersion coating, ink was poured into a glass container with an inner diameter of 50 mm until the liquid depth reached 15 mm. The PMMA plate was then suspended by its top with a clip and immersed vertically in the ink for 1 second. Afterward, the ink was dried at room temperature while the PMMA plate remained suspended by the clip.

[0193] (5-16) Test Examples B24~B27 In Test Example B23, laser welding was performed in the same manner as in Test Example B23, except that one of inks 5, 8, 11, or 12 was used instead of ink 1, as shown in Table 7.

[0194] (5-17) Test Example B28 In Test Example B23, laser welding was performed in the same manner as in Test Example B23, except that a PC plate was used instead of the PMMA plate and the second PMMA plate.

[0195] (5-18) Test Examples B29~B32 Laser welding was performed in the same manner as in Test Example B28, except that ink 5, 8, 11, or 12 was used instead of ink 1, as shown in Table 8.

[0196] (5-19) Test Example B33 In Test Example B23, laser welding was performed in the same manner as in Test Example B23, except that a PP sheet was used instead of the PMMA plate and the second PMMA plate, and ink 5 was used instead of ink 1.

[0197] (5-20) Test Examples B34-B35 In Test Example B33, laser welding was performed in the same manner as in Test Example B33, except that ink 8 or 11 was used instead of ink 5, as shown in Table 8.

[0198] (5-21) Test Example B36 In Test Example B23, laser welding was performed in the same manner as in Test Example B23, except that an ABS plate was used instead of the PMMA plate and the second PMMA plate, and Ink 5 was used instead of Ink 1.

[0199] (5-22) Test Examples B37 - B38 In Test Example B36, laser welding was performed in the same manner as in Test Example B36, except that either Ink 8 or Ink 11 shown in Table 8 was used instead of Ink 5.

[0200] (5-23) Test Example B39 In Test Example B23, laser welding was performed in the same manner as in Test Example B23, except that a PC plate was used instead of the PMMA plate and Ink 5 was used instead of Ink 1.

[0201] (5-24) Test Example B40 In Test Example B39, laser welding was performed in the same manner as in Test Example B39, except that an ABS plate was used instead of the PC plate.

[0202] (5-25) Test Example B41 In Test Example B40, laser welding was performed in the same manner as in Test Example B40, except that a PC plate was used instead of the second PMMA plate.

[0203] (5-26) Test Example B42 In Test Example B23, laser welding was performed in the same manner as in Test Example B23, except that an ABS plate was used instead of the second PMMA plate and Ink 5 was used instead of Ink 1.

[0204] (5-27) Test Example B43 In Test Example B42, laser welding was performed in the same manner as in Test Example B43, except that a PC plate was used instead of the PMMA plate.

[0205] (6) Welding Test Evaluation (6-1) Drying Time After the ink coating was completed, a timer was started to measure the drying time. After a predetermined time had elapsed, the ink-coated area was traced with a cotton swab to check for any remaining ink, thereby determining the drying state. If the ink dried in less than 1 minute after the completion of ink coating, it was evaluated as "A". If the ink dried between 1 minute and 10 minutes after the completion of ink coating, it was evaluated as "B". If the ink dried between 10 minutes and 30 minutes after the completion of ink coating, it was evaluated as "C". If the ink dried 30 minutes or more after the completion of ink coating, it was evaluated as "D".

[0206] (6-2) Appearance after welding For the ink-coated areas, the appearance after laser welding was checked. If neither charring nor whitening was observed, it was evaluated as "A," and if charring or whitening was observed, it was evaluated as "B."

[0207] (6-3) Results The evaluation results are shown in Tables 6 to 8. In test examples A1 to A10 and B1 to B22, where ink was applied using a pen-type ink application tool, the ink dried quickly in less than one minute after application in both cases of laser welding between case material and plate material, and laser welding between plate material, and the appearance of the test specimen (welded body) after laser welding was also good.

[0208] In test examples A11-A18, where ink was applied using a cotton swab, the drying time of the ink was longer compared to when a pen-type ink application tool was used. Drying time was longer when using ink 2 than when using ink 1, taking more than 10 minutes. The appearance of the test specimens after laser welding was good with inks 2, 5, and 6, but charring and whitening were observed with inks 1, 8, and 10-12. When ink was applied with a cotton swab, uneven application occurred, and after drying, the near-infrared absorbing pigment remained unevenly in the ink-coated area, resulting in charring and whitening during laser welding.

[0209] In test examples A19-A26 and B23-B43, where ink was applied by immersion, the drying time of the ink exceeded 30 minutes in all cases. Furthermore, charring and whitening were observed in the ink-coated areas of the test specimens after laser welding. When ink was applied by immersion, uneven ink application occurred significantly, and in particular, when ink was applied to the case material, liquid tended to accumulate in the corners, resulting in charring during laser welding. In welding plate materials together, since there is an absorption layer on the opposite side (back side) from the surface irradiated with the laser (joining interface), if the laser output is high, some of it passes through the joining interface, causing heat generation in the absorption layer on the back side as well, resulting in whitening.

[0210] [Table 6]

[0211] [Table 7]

[0212] [Table 8] [Industrial applicability]

[0213] The laser welding ink coating tool relating to this disclosure can be used for laser welding applications. [Explanation of Symbols]

[0214] 1: Ink application tools 2: Container 3: Core material 4: Holder 5: Ink 6: Tube

Claims

1. An ink containing a near-infrared absorbing dye and a solvent, A container containing the aforementioned ink, The container comprises a core material to which the ink is supplied, A laser welding ink coating tool capable of coating the core material with the aforementioned ink.

2. The laser welding ink coating tool according to claim 1, wherein the near-infrared absorbing dye has a weight loss rate of 5.0% or less when heated from 25°C to 200°C by thermogravimetric differential thermal analysis (TG-DTA).

3. The laser welding ink coating tool according to claim 1, wherein the content of the near-infrared absorbing dye in the ink is 1% by mass or less.

4. The laser welding ink coating tool according to claim 1, wherein the viscosity of the ink at 25°C is 1 mPa·s or more and 1000 mPa·s or less.

5. The laser welding ink coating tool according to claim 1, wherein the ink has a minimum transmittance of 10% in the wavelength range of 300 nm to 1300 nm and an average transmittance of 80% or more in the wavelength range of 380 nm to 700 nm.

6. The laser welding ink coating tool according to claim 1, wherein the near-infrared absorbing dye has an absorption maximum wavelength in the range of 750 nm to 1300 nm.

7. The laser welding ink coating tool according to claim 1, wherein the near-infrared absorbing dye is at least one selected from cyanine-based dyes, diimmonium-based dyes, and phthalocyanine-based dyes.

8. The laser welding ink coating tool according to claim 7, wherein the cyanine-based dye or the diimmonium-based dye has an anion with a conjugate acid pKa of -8.0 or less.

9. The laser welding ink coating tool according to claim 7, wherein the cyanine-based dye or the diimmonium-based dye has a borate ion.

10. The laser welding ink coating tool according to claim 1, further comprising a resin in the ink.

11. The laser welding ink coating tool according to claim 1, wherein the ink has a solid content concentration of 0.1% by mass or more and 40% by mass or less.

12. The laser welding ink application tool according to claim 1, which is a pen-type ink application tool.

13. A step of applying the ink to a first resin material using a laser welding ink application tool described in any one of claims 1 to 12, A laser welding method comprising the steps of: overlapping a second resin material onto a portion of the first resin material coated with the ink, and irradiating the ink with laser light to weld the first resin material and the second resin material together.

14. In the process of coating the first resin material with the ink, the coating area of ​​the first resin material per application of the ink is 100 cm². ２ The laser welding method according to claim 13, which is as follows:

15. In the process of coating the first resin material with the ink, the dry weight of the ink per unit area of ​​coating is 0.1 μg / cm². ２ More than 1000μg / cm ２ The laser welding method according to claim 13, which is as follows:

16. A step of applying the ink to a first resin material using a laser welding ink application tool described in any one of claims 1 to 12, A method for manufacturing a welded body, comprising the steps of: overlapping a second resin material onto a portion of the first resin material coated with the ink, and welding the first resin material and the second resin material together by irradiating the ink with laser light.

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