Masterbatch, resin composition, pellet, method for producing resin composition, molded article, and method for producing molded article

Abstract

To provide a master batch capable of achieving light transmittance equal to that in the case of compounding pigment powder when compounded in a resin composition and capable of providing a resin composition excellent in mold releasability, and to provide a resin composition, a pellet, a method for producing a resin composition, a molded article and a method for producing a molded article.SOLUTION: The masterbatch according to the present disclosure contains an amorphous resin, a pigment, and a metal salt of a fatty acid having an aliphatic chain having 10 to 35 carbon atoms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a masterbatch, a resin composition, pellets, a method for producing a resin composition, a molded article, and a method for producing a molded article. [Background technology]

[0002] Conventionally, when blending pigments with thermoplastic resins, the use of masterbatching has been considered. Masterbatching allows for avoiding the direct blending of pigment powder into thermoplastic resins. In other words, masterbatching pigments can eliminate problems such as deterioration in product quality due to the difficulty of cleaning the extruder production machine, the spread of contamination to other production machines, and safety and hygiene concerns due to the dispersion of pigment powder in the air. A method for making a pigment into a masterbatch is described in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2023 / 182121 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, there are cases where high light transmittance is required for resin compositions containing pigments, such as resin compositions for laser welding. Laser welding is a method of joining two resin members (hereinafter sometimes referred to as "light-selectively transparent resin member") that are transparent (also referred to as non-absorbent or weakly absorbent) to laser light in a specific wavelength range to one another by contacting and welding them with one another and a resin member (hereinafter sometimes referred to as "absorbent resin member") that is absorptive of laser light. Specifically, this method involves irradiating the joining surface with laser light of a specific wavelength from the light-selectively transparent resin member side, and melting and joining the absorptive resin member that forms the joining surface with the energy of the laser light. Laser welding does not produce abrasion powder or burrs and causes little damage to the product, so laser welding technology for processing resin molded products has recently been attracting attention. Here, a pigment may also be blended into the light selectively transmitting resin member, mainly from the viewpoint of design, such as matching the color with the light absorbing resin member. However, when a pigment is blended into a resin composition, the light transmittance of the resulting molded article tends to be poor. In particular, as described above, when the pigment is made into a masterbatch, a light transmittance equivalent to or higher than that obtained when the pigment powder is blended directly into the resin composition is required. Furthermore, since resin compositions such as molded articles used for laser welding are generally molded using a mold, they require mold releasability. The present invention aims to solve these problems, and to provide a masterbatch that, when blended into a resin composition, can achieve light transmittance equivalent to that achieved when a pigment powder is blended and can provide a resin composition with excellent mold releasability, as well as a resin composition, pellets, a method for producing a resin composition, a molded article, and a method for producing a molded article. [Means for solving the problem]

[0005] In light of the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using an amorphous resin as the resin used for masterbatching when preparing a pigment into a masterbatch and by blending a predetermined fatty acid metal salt therein. Specifically, the above problems were solved by the following means. [1] A masterbatch containing an amorphous resin, a pigment, and a metal salt of a fatty acid having an aliphatic chain having 10 to 35 carbon atoms. [2] The masterbatch according to [1], wherein the masterbatch is molded into a test piece with a thickness of 1 mm and has a light transmittance of 0.1 to 10% at a wavelength of 1,100 nm as measured in accordance with ISO-13468-2. [3] The masterbatch according to [1] or [2], wherein the metal salt of a fatty acid having a fatty chain containing 10 to 35 carbon atoms comprises a metal stearate and / or a metal montanate. [4] The masterbatch according to any one of [1] to [3], wherein the metal salt of a fatty acid having a fatty chain with 10 to 35 carbon atoms includes a metal salt of montanic acid. [5] The masterbatch according to any one of [1] to [4], wherein the metal salt of a fatty acid having a fatty chain with 10 to 35 carbon atoms contains calcium salt of a fatty acid having a fatty chain with 10 to 35 carbon atoms. [6] The masterbatch according to any one of [1] to [5], wherein the proportion of the fatty acid metal salt having an aliphatic chain with 10 to 35 carbon atoms in the masterbatch is 5 to 20 mass %. [7] The masterbatch according to any one of [1] to [6], wherein the amorphous resin contains an acrylonitrile-styrene copolymer resin. [8] The masterbatch according to any one of [1] to [7], wherein the pigment is a black pigment composition. [9] The pigment comprises copper phthalocyanine halide and / or perylene; The masterbatch according to any one of [1] to [8].

[10] The masterbatch is molded into a test piece with a thickness of 1 mm, and the light transmittance at a wavelength of 1100 nm measured in accordance with ISO-13468-2 is 0.1 to 10%, the metal salt of a fatty acid having a fatty chain having 10 to 35 carbon atoms includes calcium montanate, the ratio of the fatty acid metal salt having a fatty chain having 10 to 35 carbon atoms in the masterbatch is 5 to 20 mass %, the amorphous resin includes an acrylonitrile-styrene copolymer resin, the pigment is a black pigment composition, The pigment comprises copper phthalocyanine halide and / or perylene; [1] The masterbatch according to the present invention.

[11] A resin composition comprising 1 to 10 parts by mass of the masterbatch according to any one of [1] to

[10] , per 100 parts by mass of a thermoplastic resin.

[12] The resin composition according to

[11] , wherein the thermoplastic resin comprises a polyamide resin.

[13] The resin composition according to

[11] or

[12] , wherein when the resin composition is molded into a test piece having a thickness of 1 mm, the light transmittance at a wavelength of 940 nm is 50 to 100%.

[14] The thermoplastic resin includes a polyamide resin, The resin composition according to any one of

[11] to

[13] , wherein when the resin composition is molded into a test piece having a thickness of 1 mm, the light transmittance at a wavelength of 940 nm is 50 to 100%.

[15] Pellets of the resin composition according to

[11] .

[16] A method for producing a resin composition, comprising melt-kneading a thermoplastic resin and the masterbatch according to any one of [1] to

[10] .

[17] A molded article formed from the resin composition according to any one of

[11] to

[14] .

[18] A method for producing a molded article, comprising obtaining a resin composition by the production method according to

[16] and injection molding the resin composition. [Effects of the Invention]

[0006] The present invention makes it possible to provide a masterbatch that, when blended into a resin composition, can achieve light transmittance equivalent to that achieved when a pigment powder is blended and can provide a resin composition with excellent mold releasability, as well as a resin composition, pellets, a method for producing a resin composition, a molded article, and a method for producing a molded article. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only this embodiment. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as upper and lower limits. "A to B" means that the range is A or more and B or less. In addition, any combination of the upper and lower limit values ​​of the numerical values ​​in this specification is an example of this embodiment. In this specification, various physical properties and characteristic values ​​are those at 23°C unless otherwise specified. In this specification, unless otherwise specified, the weight average molecular weight and number average molecular weight can be measured according to the description in paragraph 0047 of JP 2018-165298 A, the contents of which are incorporated herein by reference. In this specification, unless otherwise specified, the melting point (Tm) and glass transition temperature (Tg, also referred to as glass transition temperature) are values ​​measured by differential scanning calorimetry (DSC) in accordance with ISO 11357. Specifically, they can be measured as described in paragraph 0036 of WO 2016 / 084475, the contents of which are incorporated herein by reference. If the measurement methods, etc. described in the standards shown in this specification change from year to year, they will be based on the standards in effect as of January 1, 2024, unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification are abolished as of January 1, 2024, they will be based on the standards in effect at the time of abolition.

[0008] The masterbatch of this embodiment is characterized by containing an amorphous resin, a pigment, and a metal salt of a fatty acid having an aliphatic chain with 10 to 35 carbon atoms. By adopting such a configuration, when blended into a resin composition, it is possible to achieve a light transmittance equivalent to that achieved when a pigment powder is blended, and it is also possible to provide a resin composition with excellent releasability. As described above, the use of pigment powders has several issues, and it would be beneficial to avoid the use of pigment powders. However, it has been found that masterbatching pigments tends to cause the pigments to aggregate in the resin composition, resulting in poor transmittance of the resulting molded article. Under these circumstances, in this embodiment, an amorphous resin and a metal salt of a fatty acid having a specific fatty chain are used to masterbatch the pigment, thereby successfully maintaining high light transmittance of molded articles obtained from resin compositions containing such masterbatch.

[0009] Hereinafter, the embodiments of the present invention will be described in detail. However, the explanation of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to these contents.

[0010] <Amorphous resin> The masterbatch of this embodiment contains an amorphous resin. By including an amorphous resin, the light transmittance of the resulting resin composition tends to be further improved on the long wavelength side of about 900 to 1200 nm. The amorphous resin used in this embodiment is not particularly limited in type, but examples include acrylonitrile-styrene copolymer resin (AS resin), polyvinyl chloride resin, polystyrene resin, polymethyl methacrylate resin, acrylonitrile-butadiene-styrene resin, polycarbonate resin, polyphenylene ether resin, polyethersulfone-polyetherimide resin, and polyamideimide resin. Acrylonitrile-styrene copolymer resin (AS resin), polystyrene resin, acrylonitrile-butadiene-styrene resin, polycarbonate resin, and modified polyphenylene ether resin are preferred, and acrylonitrile-styrene copolymer resin (AS resin) is more preferred. For details of these resins, please refer to the description of the thermoplastic resin that can be contained in the resin composition described below.

[0011] The content of the amorphous resin in the masterbatch of this embodiment is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, even more preferably 50 parts by mass or more, and even more preferably 65 parts by mass or more, per 100 parts by mass of the masterbatch, and is preferably 99 parts by mass or less, and more preferably 97 parts by mass or less. By setting the content at or above the lower limit, the light transmittance of the masterbatch on the long wavelength side tends to be further improved, and the production stability of the masterbatch tends to be further improved. On the other hand, by setting the content at or below the upper limit, the light transmittance of the masterbatch on the long wavelength side tends to be further improved. The masterbatch of the present embodiment may contain only one type of amorphous resin, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0012] <Pigments> The masterbatch of this embodiment contains a pigment. The color of the pigment can be determined as appropriate, but a black pigment composition is preferred. The black pigment composition refers to a composition that is recognized as approximately black by the human eye, and may consist of a black pigment or may be a blend of two or more chromatic pigments. In this embodiment, the pigment preferably contains copper phthalocyanine halide and / or perylene, more preferably contains copper phthalocyanine halide and perylene, and even more preferably contains Pigment Violet 29 and Pigment Green 36. By containing such pigments, a molded article can be obtained that has high blackness, excellent laser weldability, and suppresses the occurrence of sink marks. In particular, in this embodiment, when the total amount of Pigment Violet 29 and Pigment Green 36 is 100 parts by mass, the mass ratio of Pigment Violet 29 to Pigment Green 36 is preferably 10-90:90-10. This configuration results in a molded article that exhibits significantly excellent blackness, more effectively suppresses the occurrence of sink marks, and has high light transmittance over a wavelength range of 900 to 1100 nm. The mass ratio of Pigment Violet 29 to Pigment Green 36 is preferably 10-80:90-20, more preferably 10-50:90-50, and even more preferably 10-40:90-60. It may also be 15-40:85-60 or 20-35:80-65.

[0013] The total amount of pigments in the masterbatch of this embodiment is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more, relative to 100 parts by mass of the amorphous resin. It is also preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 18 parts by mass or less, and may be less than 13 parts by mass. By setting the amount at or above the lower limit, the light transmittance of a molded article containing the masterbatch tends to be improved, and the light blocking properties in the low wavelength region tend to be further improved. Furthermore, by setting the amount at or below the upper limit, the light transmittance of a molded article containing the masterbatch in the long wavelength region tends to be improved, and the production stability of the masterbatch tends to be further improved. The masterbatch of this embodiment may contain only one type of pigment, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0014] <Metal salts of fatty acids with fatty chains containing 10 to 35 carbon atoms> The masterbatch of this embodiment contains a metal salt of a fatty acid having an aliphatic chain containing 10 to 35 carbon atoms (sometimes referred to as a "dispersant" in this specification). By containing such a dispersant, the pigment can be sufficiently dispersed in a molded article formed from a resin composition using the obtained masterbatch. As a result, the light transmittance of the obtained molded article can be improved.

[0015] The fatty chain having 10 to 35 carbon atoms is a fatty chain consisting of straight or branched carbon atoms and hydrogen atoms. In other words, calcium 12-hydroxystearate, etc., used in the examples described later, does not correspond to the dispersant in this embodiment. In this embodiment, the fatty chain having 10 to 35 carbon atoms is more preferably a fatty chain consisting of straight carbon atoms and hydrogen atoms, and is more preferably CH3(CH2) 9~29 It is more preferred that the fatty chain is -. The number of carbon atoms in the fatty chain is preferably 12 or more, more preferably 14 or more, even more preferably 20 or more, and even more preferably 22 or more, and is preferably 30 or less, and more preferably 28 or less. By adjusting the number of carbon atoms to be equal to or greater than the above lower limit or equal to or less than the above upper limit, the dispersibility of the pigment in the masterbatch tends to be further improved.

[0016] The dispersant used in this embodiment preferably contains a metal stearate and / or a metal montanate, and more preferably contains a metal montanate. The metal constituting the metal salt of fatty acid serving as a dispersant is preferably an alkali metal salt and / or an alkaline earth metal salt, more preferably an alkaline earth metal salt, further preferably calcium, magnesium, or barium, still more preferably calcium or barium, and still more preferably calcium. That is, a preferred example of the dispersant of this embodiment is fatty acid calcium, and more preferably calcium montanate.

[0017] The content of the dispersant in the masterbatch of this embodiment is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, even more preferably 4 parts by mass or more, and even more preferably 5 parts by mass or more, relative to 100 parts by mass of the amorphous resin. It is also preferably 50 parts by mass or less, more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, even more preferably 35 parts by mass or less, even more preferably 30 parts by mass or less, even more preferably 19 parts by mass or less, and particularly preferably 15 parts by mass or less. By setting the content at or above the lower limit, the pigment dispersibility in the masterbatch is improved, and the mold releasability of molded articles formed from resin compositions containing the masterbatch tends to be further improved. Furthermore, by setting the content at or below the upper limit, the production stability of the masterbatch tends to be further improved.

[0018] Furthermore, the content of the dispersant in the masterbatch of this embodiment is preferably 5% by mass or more and 20% by mass or less, based on 100% by mass of the masterbatch. By making the content equal to or greater than the lower limit, the pigment dispersibility in the masterbatch is improved, and the molded article formed from the resin composition containing the masterbatch tends to have better releasability. By making the content equal to or less than the upper limit, the production stability of the masterbatch tends to be improved. The masterbatch of this embodiment may contain only one type of metal salt (dispersant) of a fatty acid having an aliphatic chain with 10 to 35 carbon atoms, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range. The masterbatch of this embodiment preferably does not substantially contain any dispersants other than the metal salt (dispersant) of a fatty acid having an aliphatic chain containing 10 to 35 carbon atoms. "Substantially free" means that the content of dispersants other than the metal salt (dispersant) of a fatty acid having an aliphatic chain containing 10 to 35 carbon atoms is less than 10% by mass of the content of the metal salt (dispersant) of a fatty acid having an aliphatic chain containing 10 to 35 carbon atoms, preferably less than 5% by mass, more preferably less than 3% by mass, even more preferably less than 1% by mass, and even more preferably less than 0.1% by mass.

[0019] The masterbatch of this embodiment preferably has a light transmittance of 0.1 to 10% at a wavelength of 1,100 nm, measured according to ISO-13468-2 on a 1 mm thick test piece. By ensuring that the light transmittance is equal to or greater than the lower limit, the light transmittance in the long wavelength region of a molded article formed from a resin composition containing the masterbatch tends to be improved. By ensuring that the light transmittance is equal to or less than the upper limit, the light blocking ability in the short wavelength region of a molded article formed from a resin composition containing the masterbatch tends to be improved. The light transmittance is preferably 0.3% or more, more preferably 0.5% or more, even more preferably 1.0% or more, even more preferably 2.0% or more, and even more preferably 3.5% or more. It is also preferably 8% or less, and more preferably 6% or less.

[0020] The masterbatch of the present embodiment may or may not contain components other than the amorphous resin, pigment, and dispersant. In the masterbatch of this embodiment, the total of the amorphous resin, pigment, and dispersant preferably accounts for 90% by mass or more of the masterbatch, more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more, and may even be 100% by mass.

[0021] Next, the resin composition of this embodiment will be described. The resin composition of this embodiment contains 1 to 10 parts by mass of the masterbatch of this embodiment per 100 parts by mass of the thermoplastic resin. By blending a pigment as a masterbatch in this manner, it is possible to eliminate concerns about deterioration in product quality due to difficulty in cleaning production machines such as extruders when producing the resin composition, the spread of contamination to other production machines, and safety and hygiene concerns due to the dispersion of pigment powder in the air. The content of the masterbatch in the resin composition of this embodiment is preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and preferably 8 parts by mass or less, more preferably 7 parts by mass or less, even more preferably 6 parts by mass or less, and even more preferably 5 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin. By setting the content at or above the lower limit, the light-blocking properties in the low wavelength region of a molded article formed from a resin composition containing the masterbatch tend to be further improved. Meanwhile, by setting the content at or below the upper limit, the light transmittance of a molded article formed from a resin composition containing such a masterbatch tends to be further improved. The resin composition of the present embodiment may contain only one type of masterbatch, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0022] <Thermoplastic resin> The resin composition of the present embodiment contains a thermoplastic resin. The thermoplastic resin may be a crystalline resin, an amorphous resin, or a blend of both. Thermoplastic resins include polyolefin resins (polyethylene resin, polypropylene resin, etc.), polyamide resin, polyacetal resin, polyester resin (polyethylene terephthalate resin, polybutylene terephthalate resin), polyphenylene sulfide resin, polyether ether ketone resin, liquid crystal polymer, polytetrafluoroethylene resin, acrylonitrile-styrene copolymer resin (AS resin), polyvinyl chloride resin, polystyrene resin, polymethyl methacrylate resin, acrylonitrile-butadiene-styrene resin, polycarbonate resin, and polyphenylene ether. Examples of the resin include a resin, a polyethersulfone-polyetherimide resin, and a polyamideimide resin, and the resin preferably contains at least one selected from the group consisting of a polyolefin resin, a polyamide resin, a polyacetal resin, a polyester resin, an acrylonitrile-styrene copolymer resin (AS resin), a polystyrene resin, a polymethyl methacrylate resin, an acrylonitrile-butadiene-styrene resin, a polycarbonate resin, and a polyphenylene ether resin, and more preferably contains a polyamide resin and / or an acrylonitrile-styrene copolymer resin (AS resin). In a first embodiment, the thermoplastic resin in this embodiment includes a polyamide resin. A second embodiment of the thermoplastic resin in this embodiment includes a polyamide resin and an acrylonitrile-styrene copolymer resin.

[0023] The thermoplastic resin used in this embodiment may be a recycled thermoplastic resin (including recovered products, material recycled products, chemical recycled products, etc.), a rejected product, or scrap material generated when molding a molded product from a resin composition. The thermoplastic resin used in this embodiment may be a biomass resin produced using biomass raw materials. Using biomass resin can reduce the environmental impact. Mass balance certified (ISCC PLUS) raw materials can also be used for the biomass resin. Mass balance certification means that the amount of renewable raw materials or bio-based raw materials used in each factory or production facility and the amount of products produced or shipped are quantified and guaranteed along with their quality.

[0024] <<Polyamide resin>> The polyamide resin is a polymer having, as a constituent unit, an acid amide obtained by ring-opening polymerization of lactam, polycondensation of aminocarboxylic acid, or polycondensation of diamine and dibasic acid, and may be an aliphatic polyamide resin, an alicyclic polyamide resin, a semi-aromatic polyamide resin, or a blend of two or more of these. Specific examples of polyamide resins include polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 6I, polyamide 6 / 66, polyamide 6T / 6I, polyamide 6 / 6T, polyamide 66 / 6T, polyamide 66 / 6T / 6I, polytrimethylhexamethylene terephthalamide, polybis(4-aminocyclohexyl)methanedodecamide, polybis(3-methyl-4-aminocyclohexyl)methanedodecamide, polyundecamethylenehexahydroterephthalamide, and xylylenediamine-based polyamide resins, which will be described in detail below. The "I" in the above table represents an isophthalic acid component, and the "T" represents a terephthalic acid component. Regarding polyamide resins, the description in paragraphs 0011 to 0013 of JP-A No. 2011-132550 can be referred to, the contents of which are incorporated herein by reference.

[0025] The polyamide resin used in this embodiment is preferably a xylylenediamine-based polyamide resin that is composed of diamine-derived structural units and dicarboxylic acid-derived structural units, and in which 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine. The diamine-derived structural units of the xylylenediamine-based polyamide resin are more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 99 mol% or more, derived from xylylenediamine (preferably paraxylylenediamine and / or metaxylylenediamine).

[0026] The xylylenediamine is preferably paraxylylenediamine and / or metaxylylenediamine. The xylylenediamine preferably contains 0 to 100 mol% metaxylylenediamine and 100 to 0 mol% paraxylylenediamine (however, the total of metaxylylenediamine and paraxylylenediamine does not exceed 100 mol%), more preferably 10 to 90 mol% metaxylylenediamine and 90 to 10 mol% paraxylylenediamine, even more preferably 30 to 80 mol% metaxylylenediamine and 70 to 20 mol% paraxylylenediamine, and even more preferably 40 to 80 mol% metaxylylenediamine and 60 to 20 mol% paraxylylenediamine. As will be shown in the examples described later, when a xylylenediamine-based polyamide resin using metaxylylenediamine and paraxylylenediamine as diamine components is mixed with a xylylenediamine-based polyamide resin using a paraxylylenediamine component as the diamine component, it is preferable that the ratio of the diamine components contained in the mixed xylylenediamine-based polyamide resin be within the above range. In the xylylenediamine-based polyamide resin, the total of the constitutional units derived from paraxylylenediamine and the constitutional units derived from metaxylylenediamine preferably accounts for 80 mol % or more, more preferably 85 mol % or more, even more preferably 90 mol % or more, still more preferably 95 mol % or more, still more preferably 98 mol % or more, and still more preferably 99 mol % or more of the constitutional units derived from diamine. The upper limit of the total of the constitutional units derived from paraxylylenediamine and the constitutional units derived from metaxylylenediamine is 100 mol %.

[0027] Diamines other than metaxylylenediamine and paraxylylenediamine that can be used as raw diamine components for xylylenediamine-based polyamide resins include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine; 1,3-bis( Examples of the diamine include alicyclic diamines such as bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane; and diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. These diamines can be used alone or in combination of two or more.

[0028] On the other hand, the dicarboxylic acid-derived structural units of the xylylenediamine-based polyamide resin are preferably 70 mol% or more, more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 99 mol% or more, of which the structural units are derived from an α,ω-linear aliphatic dicarboxylic acid preferably having 4 to 20 carbon atoms (preferably sebacic acid).

[0029] Examples of α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms that are suitable for use as the raw dicarboxylic acid component of xylylenediamine-based polyamide resins include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, undecanedioic acid, and 1,12-dodecanedioic acid. These can be used alone or in combination of two or more. Among these, at least one of adipic acid, sebacic acid, and 1,12-dodecanedioic acid is preferred, as the melting point of the polyamide resin falls within a range suitable for molding and processing. Adipic acid and / or sebacic acid is more preferred, and sebacic acid is even more preferred.

[0030] Examples of dicarboxylic acid components other than those mentioned above include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acid such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid, and these can be used alone or in combination of two or more.

[0031] In this embodiment, the polyamide resin preferably contains diamine-derived structural units and dicarboxylic acid-derived structural units, with at least 70 mol% of the diamine-derived structural units being derived from xylylenediamine and at least 70 mol% of the dicarboxylic acid-derived structural units being derived from sebacic acid. More preferably, the xylylenediamine-based polyamide resin contains at least 90 mol% of the diamine-derived structural units being derived from xylylenediamine and at least 90 mol% of the dicarboxylic acid-derived structural units being derived from sebacic acid. Such xylylenediamine-based polyamide resins are preferred because they have a high degree of crystallization, a high melting point, and excellent dimensional stability.

[0032] Although the xylylenediamine-based polyamide resin is primarily composed of diamine-derived structural units and dicarboxylic acid-derived structural units, other structural units are not completely excluded, and it goes without saying that it may contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, "major component" refers to the structural units constituting the xylylenediamine-based polyamide resin in which the total number of diamine-derived structural units and dicarboxylic acid-derived structural units is the largest among all structural units. In this embodiment, the total of the diamine-derived structural units and dicarboxylic acid-derived structural units in the xylylenediamine-based polyamide resin preferably accounts for 90% by mass or more of all structural units, more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0033] The melting point of the polyamide resin is preferably 150°C or higher, more preferably 250°C or higher, and even more preferably 280°C or higher, and is preferably 350°C or lower, more preferably 330°C or lower, and even more preferably 300°C or lower.

[0034] The lower limit of the number average molecular weight (Mn) of the polyamide resin is preferably 6,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more, and is preferably 100,000 or less, more preferably 50,000 or less. Within such ranges, the heat resistance, elastic modulus, dimensional stability, and moldability are improved.

[0035] <<Polycarbonate resin>> The polycarbonate resin is not particularly limited, and any of aromatic polycarbonate, aliphatic polycarbonate, and aromatic-aliphatic polycarbonate can be used. Among them, aromatic polycarbonate is preferred, and further, thermoplastic aromatic polycarbonate polymers or copolymers obtained by reacting an aromatic dihydroxy compound with phosgene or a diester of carbonic acid are more preferred.

[0036] Examples of aromatic dihydroxy compounds include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, and 4,4-dihydroxydiphenyl, with bisphenol A being preferred. Furthermore, for the purpose of preparing a highly flame-retardant composition, compounds in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compounds, or polymers or oligomers having a siloxane structure and containing phenolic OH groups at both ends, can be used.

[0037] Preferred examples of the polycarbonate resin used in this embodiment include polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane; and polycarbonate copolymers derived from 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy compounds.

[0038] The method for producing the polycarbonate resin is not particularly limited, and in this embodiment, polycarbonate resins produced by any method, such as a phosgene method (interfacial polymerization method) or a melting method (ester interchange method), can be used. In addition, in this embodiment, polycarbonate resins produced by a general melting method production process followed by a process of adjusting the amount of OH groups in the terminal groups may also be used.

[0039] Furthermore, the polycarbonate resin used in this embodiment may be not only a polycarbonate resin as a virgin raw material, but also a polycarbonate resin regenerated from used products, that is, a so-called material-recycled polycarbonate resin.

[0040] For further details regarding the polycarbonate resin used in this embodiment, see, for example, the descriptions in paragraphs 0018 to 0066 of JP-A No. 2012-072338 and paragraphs 0011 to 0018 of JP-A No. 2015-166460, the contents of which are incorporated herein by reference.

[0041] <<Polyester resin>> Examples of polyester resins include polyethylene terephthalate resins and polybutylene terephthalate resins. As is well known, polyethylene terephthalate resins and polybutylene terephthalate resins are produced on a large scale by reacting terephthalic acid or ester with ethylene glycol or 1,4-butanediol, and are distributed on the market. In this embodiment, these commercially available resins can be used. Some commercially available resins contain copolymer components other than the terephthalic acid component and the ethylene glycol component or 1,4-butanediol component. In this embodiment, resins containing a small amount of copolymer component, typically 10% by mass or less, preferably 5% by mass or less, can also be used. The intrinsic viscosity of polyethylene terephthalate resin is usually 0.4 to 1.0 dL / g, and preferably 0.5 to 1.0 dL / g. When the intrinsic viscosity is equal to or greater than the lower limit, the mechanical properties of the resin composition are less likely to deteriorate, and when it is equal to or less than the upper limit, fluidity is easily maintained. Note that all intrinsic viscosities are measured at 30°C in a phenol / tetrachloroethane (1 / 1 mass ratio) mixed solvent. The intrinsic viscosity of the polybutylene terephthalate resin is usually 0.5 to 1.5 dL / g, and preferably 0.6 to 1.3 dL / g. If the intrinsic viscosity is equal to or greater than the lower limit, it is easy to obtain a resin composition with excellent mechanical strength. If the intrinsic viscosity is equal to or less than the upper limit, the resin composition does not lose its fluidity, and tends to have excellent moldability. In addition, the amount of terminal carboxyl groups is preferably 30 meq / g or less.

[0042] The polybutylene terephthalate resin may be a polybutylene terephthalate resin modified by copolymerization. Specific preferred copolymers include polyester ether resins copolymerized with polyalkylene glycols, particularly polytetramethylene glycol, dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins. These copolymers refer to those in which the copolymerization amount is 1 mol% or more but less than 50 mol% of the total polybutylene terephthalate resin segments. The copolymerization amount is preferably 2 to 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%. Reference is also made to paragraphs 0014 to 0022 of JP 2019-006866 A, which are incorporated herein by reference. In addition to the above, the polyester resin may be found in paragraphs 0013 to 0016 of JP-A-2010-174223, the contents of which are incorporated herein by reference. The resin composition used in the present embodiment may contain only one type of thermoplastic polyester resin, or may contain two or more types.

[0043] <<Styrene-based resin>> The styrene-based resin refers to at least one polymer selected from the group consisting of a styrene-based polymer made of a styrene-based monomer, a copolymer of a styrene-based monomer and another copolymerizable vinyl-based monomer, and a copolymer obtained by polymerizing a styrene-based monomer or a styrene-based monomer and another copolymerizable vinyl-based monomer in the presence of a rubber-based polymer, and among these, a copolymer with a rubber-based polymer is preferred.

[0044] Examples of rubbery polymers copolymerizable with styrene-based monomers include polybutadiene, polyisoprene, styrene-butadiene random copolymers and block copolymers, acrylonitrile-butadiene random copolymers and block copolymers, acrylonitrile-butadiene copolymers, copolymers of acrylic acid alkyl esters or methacrylic acid alkyl esters with butadiene, copolymers of ethylene and α-olefins such as polybutadiene-polyisoprene diene copolymers, ethylene-isoprene random copolymers and block copolymers, and ethylene-butene random copolymers and block copolymers, copolymers of ethylene and α,β-unsaturated carboxylic acid esters such as ethylene-methacrylate copolymers and ethylene-butyl acrylate copolymers, ethylene-propylene-non-conjugated diene terpolymers such as ethylene-vinyl acetate copolymers and ethylene-propylene-hexadiene copolymers, acrylic rubbers, and composite rubbers consisting of polyorganosiloxane rubber and polyalkyl acrylate or methacrylate rubber. For details of styrene-based resins, please refer to the descriptions in paragraphs 0019 to 0029 of JP 2015-166460 A, which are incorporated herein by reference. The resin composition used in the present embodiment may contain only one type of styrene-based resin, or may contain two or more types.

[0045] <<Acrylonitrile-styrene copolymer resin (AS resin)>> AS resin is a copolymer of acrylonitrile and styrene. In AS resin, acrylonitrile units and styrene units usually account for 90% by mass or more, preferably 95% by mass or more, and may account for 99% by mass or more of all structural units.

[0046] <<Other resins, etc.>> For further details about the thermoplastic resin, please refer to paragraphs 0011 to 0028 of JP 2014-074162 A, the contents of which are incorporated herein by reference.

[0047] A first embodiment of the thermoplastic resin of this embodiment is an aspect in which 90% by mass or more (more preferably 95% by mass or more, and even more preferably 99% by mass or more) of the thermoplastic resin is a polyamide resin (preferably a xylylenediamine-based polyamide resin). In one embodiment of the thermoplastic resin of this embodiment, 90% by mass or more (more preferably 95% by mass or more, and even more preferably 99% by mass or more) of the thermoplastic resin is a polyamide resin (preferably a xylylenediamine-based polyamide resin) and an AS resin. The blend ratio of polyamide resin to AS resin is preferably 10 parts by mass or more of AS resin per 100 parts by mass of polyamide resin, more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more, and is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.

[0048] The content of the thermoplastic resin in the resin composition of this embodiment is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, and is preferably 65% ​​by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, and even more preferably 50% by mass or less. The resin composition of the present embodiment may contain only one type of thermoplastic resin, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0049] <Nucleating agent> The resin composition of the present embodiment may contain a nucleating agent. The nucleating agent is not particularly limited as long as it remains unmelted during melt processing and can serve as a nucleus for crystals during the cooling process. Among these, talc and calcium carbonate are preferred, with talc being more preferred. The lower limit of the number average particle size of the nucleating agent is preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 3 μm or more.The upper limit of the number average particle size of the nucleating agent is preferably 40 μm or less, more preferably 30 μm or less, even more preferably 28 μm or less, even more preferably 15 μm or less, and even more preferably 10 μm or less.

[0050] The content of the nucleating agent in the resin composition of this embodiment is preferably 0.01 to 1% by mass, more preferably 0.1% by mass or more, and more preferably 0.5% by mass or less. The resin composition of the present embodiment may contain only one type of nucleating agent, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0051] <Copper iodide, potassium iodide> The resin composition of this embodiment preferably contains copper iodide and / or potassium iodide, and more preferably contains copper iodide and potassium iodide. The inclusion of copper iodide tends to further improve the heat resistance of the resulting molded article. Furthermore, the inclusion of potassium iodide tends to facilitate the formation of a complex in the thermoplastic resin, thereby more effectively suppressing resin decomposition. In other words, blending these components makes it possible to impart performance suited to the application.

[0052] The proportion of copper iodide in the resin composition of this embodiment is preferably 0.01 mass% or more, more preferably 0.02 mass% or more, and is preferably 2 mass% or less, more preferably 1 mass% or less, even more preferably 0.5 mass% or less, and even more preferably 0.3 mass% or less. The resin composition of the present embodiment may contain only one type of copper iodide, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range. The proportion of potassium iodide in the resin composition of this embodiment is preferably 0.01 mass% or more, more preferably 0.02 mass% or more, and is preferably 2 mass% or less, more preferably 1 mass% or less, even more preferably 0.5 mass% or less, and even more preferably 0.3 mass% or less. The resin composition of the present embodiment may contain only one type of potassium iodide, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0053] <Reinforcing filler> The resin composition of this embodiment preferably contains a reinforcing filler. By containing the reinforcing filler in the above proportion, the obtained molded article can achieve high mechanical strength. Note that the reinforcing filler in this embodiment does not include anything equivalent to a nucleating agent. The reinforcing filler that can be contained in the resin composition of this embodiment has the effect of improving the mechanical properties of the resulting resin composition when blended with the resin, and can be a commonly used plastic reinforcing material. The reinforcing filler can be organic or inorganic, with inorganic materials being preferred, and glass filler being more preferred. The reinforcing filler can also be fibrous reinforcing fillers such as glass fiber, carbon fiber, basalt fiber, wollastonite, and potassium titanate fiber. Other reinforcing fillers that can be used include granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organoclay, and glass beads; and scaly reinforcing materials such as flake glass, mica, and graphite. Among these, fibrous fillers, particularly glass fiber, are preferred in terms of mechanical strength, rigidity, and heat resistance. Glass fibers can have either a round or irregular cross-sectional shape. It is more preferable to use a reinforcing filler that has been surface-treated with a surface treatment agent such as a coupling agent. Glass fibers with a surface treatment agent attached thereto are preferred because they have excellent durability, moist heat resistance, hydrolysis resistance, and heat shock resistance.

[0054] The glass filler is made of a glass composition such as A-glass, C-glass, E-glass, S-glass, R-glass, M-glass, or D-glass, with E-glass (alkali-free glass) being particularly preferred.

[0055] As described above, the glass filler used in the resin composition of this embodiment is preferably glass fiber. The glass fiber may be a single fiber or a plurality of single fibers twisted together. The glass fiber may be in the form of a "glass roving" which is a continuous winding of a single fiber or a plurality of twisted single fibers, a "chopped strand" which is cut to a length of 1 to 10 mm, or a "milled fiber" which is pulverized to a length of 10 to 500 μm. Such glass fibers are readily available and are commercially available under the trade names "Glaslon Chopped Strand" and "Glaslon Milled Fiber" from Asahi Fiber Glass Co., Ltd. and "E Glass Fiber Chopped Strand" from Nippon Electric Glass Co., Ltd. Glass fibers of different forms can also be used in combination.

[0056] The glass fiber used in this embodiment may have a circular or non-circular cross section. By using glass fiber having a non-circular cross section, warpage of the resulting molded article can be more effectively suppressed. In this embodiment, even when glass fiber having a circular cross section is used, warpage can be effectively suppressed by using a thermoplastic resin (particularly a crystalline resin) that undergoes sufficient crystallization even at a low mold temperature.

[0057] The content of the reinforcing filler in the resin composition of this embodiment is preferably 20% by mass or more, more preferably 25% by mass or more, and is preferably 60% by mass or less, more preferably 55% by mass or less, and may further be 50% by mass or less, 45% by mass or less, 40% by mass or less, or 35% by mass or less. The resin composition of this embodiment may contain only one type of reinforcing filler, or may contain two or more types. When two or more types are contained, the total amount falls within the above range. Note that the content of the reinforcing filler in this embodiment is intended to include the amounts of the sizing agent and the surface treatment agent.

[0058] <Other ingredients> The resin composition of the present embodiment may contain other components within the scope of the present invention, such as a mold release agent, a light stabilizer, an antioxidant, an ultraviolet absorber, a fluorescent brightener, an anti-dripping agent, an antistatic agent, an anti-fogging agent, an anti-blocking agent, a flow improver, a plasticizer, an antibacterial agent, and a flame retardant. In addition, the resin composition of this embodiment can be blended with additives described in paragraphs 0047 to 0103 of WO 2021 / 241471 within the scope of the present invention, the contents of which are incorporated herein by reference. In the resin composition of this embodiment, the contents of the thermoplastic resin, the masterbatch, and other components blended as needed are adjusted so that the total of each component is 100% by mass. In this embodiment, the total of the thermoplastic resin, the masterbatch, and the nucleating agent, copper iodide, potassium iodide, and reinforcing filler blended as needed accounts for 99% by mass or more of the resin composition. The resin composition of this embodiment can also achieve releasability even if it does not substantially contain a release agent. "Substantially" means that the content of the release agent contained in the resin composition (excluding the metal salt of a fatty acid having an aliphatic chain with 10 to 35 carbon atoms, which is blended into the masterbatch) is less than 0.1% by mass of the resin composition, preferably less than 0.01% by mass, more preferably less than 0.003% by mass, and even more preferably less than 0.0001% by mass.

[0059] <Physical properties of resin composition> The resin composition of this embodiment preferably has high light transmittance at wavelengths of 940 to 1100 nm. When the resin composition is molded into a test piece having a thickness of 1 mm, the light transmittance at a wavelength of 940 nm is preferably 50% or more, more preferably 55% or more, even more preferably 60% or more, and still more preferably 65% ​​or more. The upper limit of the light transmittance at a wavelength of 940 nm is preferably 100%, but the required performance is sufficiently satisfied even if the light transmittance is 90% or less or 80% or less. Furthermore, when the resin composition is molded into a test piece having a thickness of 1 mm, the light transmittance at a wavelength of 1,060 nm is preferably 35% or more, more preferably 40% or more, even more preferably 45% or more, and even more preferably 50% or more. The upper limit of the light transmittance at a wavelength of 940 nm is preferably 100%, but the required performance is sufficiently satisfied even if it is 80% or less or 70% or less.

[0060] <Method of manufacturing resin composition> The method for producing the resin composition of this embodiment is not particularly limited, but it is preferable to produce it by melt-kneading a thermoplastic resin and the masterbatch of this embodiment. More specifically, a method using a single-screw or twin-screw extruder equipped with a vent port for volatilization is preferred. The thermoplastic resin, masterbatch, and other additives blended as needed may be fed into the kneader all at once, or the thermoplastic resin component may be fed first, followed by the other blending components. The reinforcing filler is preferably fed midway through the extruder to prevent it from being crushed during blending. Alternatively, two or more components selected from each component may be mixed and blended in advance.

[0061] The method for producing a molded article using the resin composition of this embodiment is not particularly limited, and molding methods commonly used for thermoplastic resins, such as injection molding, blow molding, extrusion molding, and press molding, can be applied. In this case, injection molding is particularly preferred because of its good fluidity. In injection molding, it is preferable to control the cylinder temperature of the molding machine to 250 to 310°C. That is, the method for producing a molded article of the present embodiment preferably includes melt-kneading a thermoplastic resin and the masterbatch of the present embodiment to obtain a resin composition, and injection-molding the resin composition.

[0062] <Application> The resin composition of this embodiment is preferably used for laser welding, particularly as a light-transmitting resin composition for laser welding. One embodiment of the resin composition of the present embodiment is in the form of pellets. In this embodiment, the molded article is preferably formed from a resin composition or pellets.

[0063] <Kit> The resin composition of this embodiment and a light-absorbing resin composition containing a thermoplastic resin and a light-absorbing dye are preferably used as a kit for producing a molded article by laser welding. That is, the resin composition of the present embodiment included in the kit serves as a light-transmitting resin composition, and a molded article formed from such a light-transmitting resin composition becomes a transmissive resin member for laser light during laser welding, whereas a molded article formed from a light-absorbing resin composition becomes an absorptive resin member for laser light during laser welding.

[0064] <<Light-absorbing resin composition>> The light-absorbing resin composition used in this embodiment contains a thermoplastic resin and a light-absorbing dye, and may further contain other components such as a reinforcing filler. Examples of thermoplastic resins include polyamide resins, polyolefin resins, vinyl resins, styrene resins, acrylic resins, polyphenylene ether resins, polyester resins, polycarbonate resins, polyacetal resins, etc., and polyamide resins, polyester resins, and polycarbonate resins are particularly preferred, with polyamide resins being more preferred, due to their good compatibility with the light-transmitting resin composition (the resin composition of the present embodiment). The thermoplastic resin may be one type or two or more types. The type of polyamide resin used in the light-absorbing resin composition is not particularly limited, but the above-mentioned xylylenediamine polyamide resin is preferred. Examples of reinforcing fillers include glass fillers (preferably glass fiber), carbon fiber, silica, alumina, carbon black, and fillers capable of absorbing laser light, such as inorganic powder coated with a laser-absorbing material, with glass fiber being preferred. The reinforcing filler has the same meaning as the reinforcing filler that may be blended into the resin composition of the present embodiment, and the preferred range is also the same. The content of the reinforcing filler is preferably 20 to 70 mass %, more preferably 25 to 60 mass %, and even more preferably 30 to 55 mass %. The light-absorbing dye includes a dye having an absorption wavelength in the range of the wavelength of the irradiated laser light, for example, in the range of 900 nm to 1100 nm in this embodiment. Furthermore, the light-absorbing dye also includes a dye that, when blended in an amount of 0.3 parts by mass with 100 parts by mass of a xylylenediamine-based polyamide resin and the light transmittance is measured by the measurement method described in the Examples below, exhibits a transmittance of less than 30%, or even 10% or less. Specific examples of light-absorbing dyes include inorganic pigments (black pigments such as carbon black (e.g., acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black, etc.), red pigments such as iron oxide red, orange pigments such as molybdate orange, and white pigments such as titanium oxide), and organic pigments (yellow pigments, orange pigments, red pigments, blue pigments, green pigments, etc.). Among these, inorganic pigments are generally preferred because of their strong hiding power, and black pigments are more preferred. Two or more of these light-absorbing dyes may be used in combination. The content of the light-absorbing dye is preferably 0.01 to 30 parts by mass per 100 parts by mass of the thermoplastic resin.

[0065] In the above kit, it is preferable that 80% by mass or more of the components excluding the pigment and reinforcing filler in the resin composition and the components excluding the light-absorbing dye and reinforcing filler in the light-absorbing resin composition are common, more preferably 90% by mass or more, and even more preferably 95 to 100% by mass.

[0066] <<Laser welding method>> Next, a laser welding method will be described. In this embodiment, a molded article (laser-welded article) can be produced by laser welding a molded article (transmissive resin member) formed from the resin composition of this embodiment and a molded article (absorbent resin member) formed from the light-absorbing resin composition. By laser welding, the transmissive resin member and the absorbent resin member can be firmly welded together without using an adhesive. The shape of the members is not particularly limited, but since the members are used by joining them together by laser welding, they usually have a shape that has at least a surface contact area (flat surface, curved surface). In laser welding, the laser light that passes through the transparent resin member is absorbed by the absorbing resin member, melting it, and welding the two members together. The molded article formed from the resin composition of this embodiment has high laser light transmittance and can be preferably used as a transparent resin member. Here, the thickness of the member through which the laser light passes (the thickness in the laser transmission direction at the portion through which the laser light passes) can be appropriately determined taking into consideration the application, the composition of the resin composition, and other factors, but is, for example, 5 mm or less, preferably 4 mm or less.

[0067] The laser light source used for laser welding can be determined depending on the transmission wavelength of the light of the light-transmitting dye, and a laser with a wavelength in the range of 900 to 1100 nm is preferred, and for example, a semiconductor laser or fiber laser can be used.

[0068] More specifically, for example, when welding a transparent resin member and an absorbing resin member, the portions of the two members to be welded are first brought into contact with each other. At this time, surface contact between the two welded portions is desirable, and they may be flat surfaces, curved surfaces, or a combination of flat and curved surfaces. Next, laser light is irradiated from the transparent resin member side. If necessary, a lens may be used to focus the laser light at the interface between the two members. The focused beam passes through the transparent resin member and is absorbed near the surface of the absorbing resin member, generating heat and melting it. The heat is then transferred by thermal conduction to the transparent resin member, melting it and forming a molten pool at the interface between the two members. After cooling, the two members are joined. The molded product in which the transparent resin member and the absorbing resin member are welded in this manner has high weld strength. Note that the molded product in this embodiment is intended to include not only finished products and parts, but also parts that form part of these.

[0069] Molded articles obtained by laser welding in this embodiment can be used in a variety of applications, such as various storage containers, electrical and electronic equipment parts, office automation (OA) equipment parts, home appliance parts, machine mechanism parts, and vehicle mechanism parts. They are particularly suitable for food containers, pharmaceutical containers, oil and fat product containers, hollow vehicle parts (various tanks, intake manifold parts, camera housings, etc.), vehicle electrical parts (various control units, ignition coil parts, etc.), advanced driver assistance system (ADAS)-related parts, motor parts, various sensor parts, connector parts, switch parts, breaker parts, relay parts, coil parts, transformer parts, and lamp parts. The resin composition or kit of this embodiment is particularly suitable for advanced driver assistance system (ADAS)-related parts (particularly in-vehicle camera parts). Related components used in ADAS (Advanced Driver Assistance Systems) include cameras for image data, LIDAR and millimeter-wave radar components for distance data, GPS and odometer components for position data, and IMU (Inertial Measurement Unit) components for speed, acceleration, and attitude data. [Example]

[0070] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0071] 1.Masterbatch manufacturing The following raw materials were used to prepare the masterbatch: [Table 1]

[0072] <Masterbatch manufacturing (MB1 to MB13)> Of the above raw materials, all components except the dispersant were weighed and dry-blended, and then added to a twin-screw extruder (Shibaura Machine Co., Ltd., TEM26SS) from the main screw base using a twin-screw cassette weighing feeder (Kubota Corporation, CE-W-1-MP). The dispersant was added to the twin-screw extruder from the screw base using a twin-screw cassette weighing feeder (Kubota Corporation, CE-W-1-MP), and melt-kneaded with the resin components to obtain a resin composition masterbatch. The extruder temperature was set to 230°C.

[0073] The light transmittance (unit: %) of the obtained masterbatch at a wavelength of 1100 nm was measured by the following method. The results are shown in Table 2. Specifically, the masterbatch pellets obtained by the above production method were dried at 80°C for 12 hours, and then test pieces for measuring light transmittance (ASTM D638 standard No. 4 dumbbell pieces, 1 mm thick) were produced using an injection molding machine (manufactured by The Japan Steel Works, Ltd., J-50ADS). The cylinder temperature was 220°C, and the mold surface temperature was 80°C. Using the obtained test pieces, light transmittance at a wavelength of 1100 nm was measured in accordance with the ISO-13468-2 standard.

[0074] [Table 2-1] [Table 2-2]

[0075] The units of each component in Table 2 are parts by mass.

[0076] 2. Production of resin composition (pellets) The following raw materials were used to produce the resin composition (pellets). [Table 3]

[0077] <Synthesis Example 1: Synthesis of MP10> Sebacic acid (manufactured by Ito Oil Mills, product name: Sebacic Acid TA) was heated and dissolved in a reactor under a nitrogen atmosphere. Then, while stirring the contents, a mixed diamine of paraxylylenediamine (manufactured by Mitsubishi Gas Chemical Company, Inc.) and metaxylylenediamine (manufactured by Mitsubishi Gas Chemical Company, Inc.) in a molar ratio of 3:7 was gradually added dropwise under pressure (0.35 MPa) so that the molar ratio of diamine to sebacic acid became approximately 1:1, while the temperature was raised to 235°C. After the addition was completed, the reaction was continued for 60 minutes to adjust the amount of components with a molecular weight of 1,000 or less. After the reaction was completed, the contents were removed in the form of strands and pelletized using a pelletizer to obtain a polyamide resin (MP10).

[0078] <Synthesis Example 2: Synthesis of PXD10> Sebacic acid (manufactured by Ito Oil Mills, product name Sebacic Acid TA) was heated and dissolved in a reaction vessel under a nitrogen atmosphere, and then, while stirring the contents, paraxylylenediamine (manufactured by Mitsubishi Gas Chemical Company, Inc.) was gradually added dropwise under pressure (0.35 MPa) so that the molar ratio of diamine to sebacic acid was approximately 1:1, while the temperature was continuously raised to 293°C. After the dropwise addition was completed, the reaction was continued for 60 minutes, and the amount of components with a molecular weight of 1,000 or less was adjusted. After the reaction was completed, the contents were removed in the form of strands and pelletized in a pelletizer to obtain a polyamide resin (PXD10).

[0079] Examples 1 to 9, Comparative Examples 1 to 5 <Compound> The components other than the glass fiber, such as the thermoplastic resin and masterbatch, were weighed and dry-blended to obtain the compositions shown in Tables 4 to 7 (each component in Tables 4 to 7 is expressed in parts by mass), and then the mixture was added to the base of the screws of a twin-screw extruder (Shibaura Machine Co., Ltd., TEM26SS) using a twin-screw cassette weighing feeder (Kubota Corporation, CE-W-1-MP). The glass fiber was added to the twin-screw extruder from the side using a vibrating cassette weighing feeder (Kubota Corporation, CE-V-1B-MP), and melt-kneaded with the resin components to obtain resin composition pellets. The extruder temperature was set to 280°C.

[0080] <Light transmittance> The resin composition pellets obtained above were dried at 80°C for 12 hours, and then test specimens for measuring light transmittance (ASTM D638 standard No. 4 dumbbell specimens, 1 mm thick) were prepared using an injection molding machine (J-50ADS, manufactured by The Japan Steel Works, Ltd.) The cylinder temperature was 260°C, and the mold surface temperature was 110°C. The light transmittance (unit: %) was measured on the side of the test piece opposite the gate using a transmittance measuring device at wavelengths of 940 nm and 1060 nm. The transmittance measuring device used was UV-3600 manufactured by Shimadzu Corporation.

[0081] <Difference in light transmittance compared to pigment powder formulation (difference in transmittance)> For each of the Examples and Comparative Examples, the difference in light transmittance at a wavelength of 1060 nm from Comparative Example 5 (a formulation containing the same amount of pigment powder) was calculated and shown in Tables 4 to 7.

[0082] <Mold releasability> The resin composition pellets obtained above were dried at 80°C for 12 hours, and then a box-shaped sample for evaluating mold releasability was produced using an injection molding machine (J-50ADS, manufactured by The Japan Steel Works, Ltd.) The cylinder temperature was 260°C, and the mold surface temperature was 110°C. Several engineers visually checked the box-shaped samples for the presence or absence of ejector pin marks, and evaluated the releasability by rating those with no marks as A and those with visible marks as B. The judgment was made by five experts, and the decision was made by majority vote. A: No ejector pin marks B: Ejector pin marks present

[0083] [Table 4]

[0084] [Table 5]

[0085] [Table 6]

[0086] In Tables 4 to 6, the units of transmittance and the difference from transmittance are %. As is clear from the above results, the molded articles obtained using the masterbatch of the present invention had high light transmittance and excellent demolding properties (Examples 1 to 9). In contrast, when no dispersant was blended into the masterbatch (Comparative Example 1), the light transmittance was low and the demolding properties were poor. In particular, when the type of dispersant was outside the range of the present invention, the mold releasability was poor (Comparative Examples 2 to 4).

[0087] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.

Claims

1. A masterbatch comprising an amorphous resin, a pigment, and a metal salt of a fatty acid having an aliphatic chain having 10 to 35 carbon atoms.

2. The masterbatch according to claim 1, wherein the masterbatch is molded into a test piece with a thickness of 1 mm and has a light transmittance at a wavelength of 1,100 nm measured in accordance with ISO-13468-2 standard of 0.1 to 10%.

3. 3. The masterbatch according to claim 1, wherein the metal salt of a fatty acid having a fatty chain containing 10 to 35 carbon atoms comprises a metal stearate and / or a metal montanate.

4. 3. The masterbatch according to claim 1, wherein the metal salt of a fatty acid having a fatty chain containing 10 to 35 carbon atoms comprises a metal salt of montanic acid.

5. 3. The masterbatch according to claim 1, wherein the metal salt of a fatty acid having a fatty chain containing 10 to 35 carbon atoms comprises calcium salt of a fatty acid having a fatty chain containing 10 to 35 carbon atoms.

6. 3. The masterbatch according to claim 1, wherein the proportion of the fatty acid metal salt having a fatty chain containing 10 to 35 carbon atoms in the masterbatch is 5 to 20 mass%.

7. The masterbatch according to claim 1 or 2, wherein the amorphous resin comprises an acrylonitrile-styrene copolymer resin.

8. 3. The masterbatch according to claim 1, wherein the pigment is a black pigment composition.

9. The pigment comprises copper phthalocyanine halide and / or perylene; The masterbatch according to claim 1 or 2.

10. The masterbatch is molded into a test piece with a thickness of 1 mm, and the light transmittance at a wavelength of 1,100 nm measured in accordance with ISO-13468-2 is 0.1 to 10%, the metal salt of a fatty acid having a fatty chain containing 10 to 35 carbon atoms includes calcium montanate, the ratio of the fatty acid metal salt having a fatty chain having 10 to 35 carbon atoms in the masterbatch is 5 to 20 mass %, the amorphous resin includes an acrylonitrile-styrene copolymer resin, the pigment is a black pigment composition, The pigment comprises copper phthalocyanine halide and / or perylene; The masterbatch of claim 1.

11. A resin composition comprising 1 to 10 parts by mass of the masterbatch according to claim 1, 2 or 10 relative to 100 parts by mass of a thermoplastic resin.

12. The resin composition according to claim 11 , wherein the thermoplastic resin comprises a polyamide resin.

13. The resin composition according to claim 11, wherein the resin composition has a light transmittance of 50 to 100% at a wavelength of 940 nm when molded into a test piece having a thickness of 1 mm.

14. the thermoplastic resin comprises a polyamide resin, The resin composition according to claim 11, wherein the resin composition has a light transmittance of 50 to 100% at a wavelength of 940 nm when molded into a test piece having a thickness of 1 mm.

15. Pellets of the resin composition according to claim 11.

16. A method for producing a resin composition, comprising melt-kneading a thermoplastic resin and the masterbatch according to claim 1 .

17. A molded article formed from the resin composition according to claim 11.

18. A method for producing a molded article, comprising obtaining a resin composition by the production method according to claim 16 and injection molding the resin composition.

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