Molded article, method for manufacturing a molded article subjected to laser marking, and laser marking method

Abstract

A molded article obtained by molding a resin composition containing a thermoplastic resin (A), the molded article having a foam identification portion, wherein the unfolded area ratio Sdr of the interface of the foam identification portion as specified by ISO 25178 is 0.10 or more and 1.00 or less, and the bulge height of the foam identification portion is 6.6 μm or more and 100.0 μm or less.

Description

Technical Field

[0001] This invention relates to molded articles, a method for manufacturing molded articles that have undergone laser marking, and a laser marking method.

[0002] This application claims priority based on Japanese Patent Application No. 2021-040597 filed in Japan on March 12, 2021, the contents of which are incorporated herein by reference. Background Technology

[0003] In the past, the method of recording product names, manufacturing numbers, precautions, etc. on resin molded products was to use methods such as pasting seals with this information printed on them, or various printing methods such as pad printing and screen printing.

[0004] The aforementioned recording methods suffer from problems such as printing defects caused by recording fluid splatter, printing onto uneven surfaces, and difficulty in printing tiny characters. Furthermore, the method of affixing seals has limitations, such as requiring a smooth surface on the molded product. Therefore, in recent years, laser marking technology (hereinafter referred to as "laser marking") has been used as a means to solve these problems. Laser marking is a technology with good reproducibility and high-speed marking capabilities, and it is an extremely useful method that avoids the aforementioned defects.

[0005] However, laser marking is not necessarily a technology applicable to all resin monomers. Research is usually conducted to improve laser marking performance by modifying the resin itself and various additives.

[0006] For example, Patent Document 1 proposes a scheme to improve the marking properties of transparent polyamide.

[0007] In addition, a polyamide resin composition with excellent laser marking properties is proposed in Patent Document 2.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2009-149896

[0011] Patent Document 2: Japanese Patent Application Publication No. 2009-035656 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] However, the technology in Patent Document 1 cannot improve the clarity of marking on opaque items that are used in large quantities. Furthermore, laser marking often involves printing not only large amounts of text information on seals, but also complex graphics such as QR codes (registered trademarks) that provide extensive traceability information. Therefore, the technology in Patent Document 2 has room for improvement in marking clarity.

[0014] In addition, fillers, collectively referred to as fillers, are often added to polyamides to enhance their performance, suppress shrinkage, impart mechanical properties such as flame retardancy, and provide functionality. It is generally known that these fillers tend to be exposed on the surface of polyamides. When the filler is exposed, the color tone changes compared to the case without filler. Therefore, polyamides with added fillers suffer from a further reduction in the clarity of laser marking.

[0015] The present invention was made in view of the above circumstances, and provides a molded article with clear marking formed by laser marking, a method for manufacturing the molded article, and a laser marking method capable of obtaining clear marking.

[0016] means for solving problems

[0017] That is, the present invention includes the following methods.

[0018] (1) A molded article obtained by molding a resin composition containing a thermoplastic resin (A),

[0019] The molded article has a foam identification part.

[0020] The unfolded area ratio (Sdr) of the interface of the foaming identification part, as specified by ISO 25178, is 0.10 or higher and 1.00 or lower.

[0021] The height of the foam recognition part is 6.6 μm or more and 100.0 μm or less.

[0022] (2) The molded article as described in (1), wherein the thermoplastic resin (A) comprises a polyamide resin (A1).

[0023] (3) The molded article as described in (2), wherein,

[0024] The polyamide resin (A1) is a semi-aromatic polyamide (A1-2) containing an aromatic ring in its backbone; or

[0025] The polyamide resin (A1) is an alloy of the semi-aromatic polyamide (A1-2) and the aliphatic polyamide (A1-1).

[0026] (4) The molded article as described in (3), wherein the semi-aromatic polyamide (A1-2) contains more than 10 mol% isophthalic acid units relative to 100 mol% of all dicarboxylic acid units constituting the semi-aromatic polyamide (A1-2).

[0027] (5) The molded article as described in any one of (1) to (4), wherein the glass transition temperature of the resin composition is 75°C or higher.

[0028] (6) The molded article as described in any one of (1) to (5), wherein the crystallization peak temperature of the resin composition is below 240°C.

[0029] (7) The molded article as described in any one of (1) to (6), wherein the resin composition further contains filler (B).

[0030] (8) The molded article as described in (7), wherein the resin composition contains more than 0 parts by weight and less than or equal to 150.0 parts by weight of the filler (B) relative to 100 parts by weight of the thermoplastic resin (A).

[0031] (9) The molded article as described in (7) or (8), wherein the filler (B) is one or more selected from the group consisting of glass fiber, calcium carbonate, talc, mica, wollastonite and ground fiber.

[0032] (10) A molded article as described in any one of (1) to (9), wherein the resin composition further contains a flame retardant (C).

[0033] (11) The molded article as described in (10), wherein the flame retardant (C) is one or more selected from the group consisting of phosphonates and diphosphonates.

[0034] (12) The molded article as described in (11), wherein the phosphonate is a compound represented by the following general formula (I),

[0035] The secondary phosphonate is a compound represented by the following general formula (II).

[0036]

[0037] (In general formula (1), R) 11 and R 12 Each is independently an alkyl group having 1 or more but 6 or fewer carbon atoms, or an aryl group having 6 or more but 10 or fewer carbon atoms. M n11+ A metal ion with a valence of n11. M is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum. n11 is 2 or 3. Multiple Rs exist. 11 and multiple R 12They can be the same or different.

[0038] In general formula (2), R 21 and R 22 Each is independently an alkyl group having 1 or more but 6 or fewer carbon atoms, or an aryl group having 6 or more but 10 or fewer carbon atoms. 21 It is an alkylene group having 1 or more but less than 10 carbon atoms, or an arylene group having 6 or more but less than 10 carbon atoms. M' m21+ A metal ion with a valence of m21. M' is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum. n21 is an integer greater than or equal to 1 and less than or equal to 3. When n21 is 2 or 3, multiple R's exist. 21 Multiple R 22 and multiple Y 21 Each can be the same or different. m21 is 2 or 3. x is 1 or 2. When x is 2, there are multiple M's that can be the same or different. n21, x, and m21 are integers that satisfy the relation 2 × n21 = m21 × x.

[0039] (13) The molded article as described in any one of (1) to (12), wherein the resin composition further contains a colorant (D) that is black, gray or orange (color).

[0040] (14) The molded article as described in (13), wherein the colorant (D) contains carbon black (D1), and

[0041] The content of carbon black (D1) is 0.001 parts by mass or more and 5.00 parts by mass or less relative to 100 parts by mass of the thermoplastic resin (A).

[0042] (15) The molded article as described in any one of (1) to (14), wherein the molded article is a magnetic switch housing, a circuit breaker housing or a connector molded article.

[0043] (16) A method for manufacturing a molded article with laser marking, wherein the method includes a step of laser marking the molded article obtained by molding a resin composition containing a thermoplastic resin (A).

[0044] In the process described above, laser marking is performed such that the unfolded area ratio Sdr of the laser-marked portion of the molded article, as specified by ISO 25178, is 0.10 or more and 1.00 or less, and the raised height of the laser-marked portion of the molded article is 6.6 μm or more and 100.0 μm or less.

[0045] (17) A laser marking method, wherein the laser marking method includes a step of laser marking a molded article obtained by molding a resin composition containing a thermoplastic resin (A).

[0046] In the laser marking, the laser marking is performed such that the unfolded area ratio Sdr of the laser-marked portion of the molded article, as specified by ISO 25178, is 0.10 or higher and 1.00 or lower.

[0047] Invention Effects

[0048] According to the molding and manufacturing method described above, a molded product with clear markings formed by laser marking can be obtained. According to the laser marking method described above, a molded product with clear markings can be obtained. Detailed Implementation

[0049] Hereinafter, a method for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail. This embodiment is merely an example for illustrating the present invention and is not intended to limit the present invention to its contents. The present invention can be implemented with appropriate modifications within its scope.

[0050] It should be noted that, in this specification, "polyamide" refers to a polymer having an amide (-NHCO-) ​​group in its main chain.

[0051] Molded Products

[0052] The molded article of this embodiment is a molded article obtained by molding a resin composition containing thermoplastic resin (A).

[0053] The molded article of this embodiment has a foam identification section. It should be noted that the "foam identification section" in this specification refers to the following processed part: by using laser, heat, or the like to foam the surface of the molded article made of resin composition, a color difference is produced between it and other parts, making it clearly distinguishable.

[0054] In this embodiment, the foam identification part of the molded article is preferably a marking part formed by laser marking.

[0055] In the molded article of this embodiment, the unfolded area ratio Sdr of the interface of the foam identification part as specified by ISO25178 is 0.10 or more and 1.00 or less, preferably 0.15 or more and 0.90 or less, more preferably 0.20 or more and 0.80 or less, and even more preferably 0.30 or more and 0.70 or less.

[0056] By ensuring the unfolded area ratio Sdr is within the aforementioned range, the light scattering efficiency is improved, resulting in superior clarity of the laser-marked markings on the molded product.

[0057] The aforementioned unfolded area ratio Sdr is one of the parameters defined by ISO 25178 that defines the surface roughness of an object.

[0058] The aforementioned unfolded area ratio Sdr can be measured according to ISO 25178. For example, it can be measured using a non-contact method with a laser.

[0059] More specifically, measurements can be performed using a laser microscope (measurement unit: VK-X210, controller: VK-X200) manufactured by Keyence Corporation. By setting the objective lens to 20x magnification, moving the measuring instrument to the observation area, and starting the measurement in measurement mode "expert", the aforementioned unfolded area ratio Sdr as defined by ISO 25178 can be measured.

[0060] In the molded article of this embodiment, the raised height of the foam identification portion is 6.6 μm or more and 100.0 μm or less, preferably 10.0 μm or more and 90.0 μm or less, more preferably 14.0 μm or more and 80.0 μm or less, and even more preferably 17.0 μm or more and 70.0 μm or less.

[0061] By ensuring the raised height is within the aforementioned range, the base portion of the foam identification part can be concealed, and the loss of the foam identification part can be suppressed during scratching. Therefore, the clarity of the mark formed by laser marking on the molded product is excellent.

[0062] The aforementioned bulge height is calculated from the difference in average height between the foam identification section and the surrounding unprocessed portion. For example, it can be measured using a non-contact method employing lasers.

[0063] More specifically, measurements can be performed using a laser microscope (measurement unit: VK-X210, controller: VK-X200) manufactured by Keyence Corporation. By setting the objective lens to 20x magnification, moving the measuring instrument to the observation area, and starting the measurement in the "expert" measurement mode, the height of the aforementioned bulge can be measured according to the "average height difference".

[0064] The molded article of this embodiment, by having the above-described structure, enables the marking formed by laser marking to have excellent clarity.

[0065] Next, the resin composition constituting the molded article of this embodiment will be described.

[0066] <Resin Composition>

[0067] The resin composition contains a thermoplastic resin (A).

[0068] [Thermoplastic Resin (A)]

[0069] Examples of thermoplastic resins (A) include: polyamide resins, polyester resins, polyacetal resins, polycarbonate resins, polyacrylic acid resins, polyphenylene ether resins (including modified polyphenylene ethers obtained by blending or grafting polyphenylene ethers with other resins), polyarylate resins, polysulfone resins, polyphenylene sulfide resins, polyethersulfone resins, polyketide resins, polyphenylene ether ketone resins, polyimide resins, polyamide-imide resins, polyether-imide resins, polyurethane resins, polyolefin resins (e.g., α-olefin polymers (copolymers)), and various ionomers.

[0070] The thermoplastic resin (A) is preferably a crystalline resin having a melting point in the range of 100°C or higher and 350°C or lower, an amorphous resin having a glass transition temperature in the range of 50°C or higher and 250°C or lower, or a combination thereof.

[0071] The melting point of the crystalline resin referred to herein is the peak temperature of the endothermic peak that appears when the temperature is increased from 23°C at a heating rate of 10°C / min using a differential scanning calorimeter (DSC). When two or more endothermic peaks appear, the melting point of the crystalline resin refers to the peak temperature of the endothermic peak at the highest temperature. The enthalpy of this endothermic peak is preferably 10 J / g or more, more preferably 20 J / g or more. Furthermore, in the determination, it is preferable to use a sample obtained by temporarily heating the sample to a temperature of melting point +20°C or more to melt the resin, and then cooling it to 23°C at a cooling rate of 10°C / min.

[0072] Furthermore, the glass transition temperature (Tg) of the amorphous resin mentioned here refers to the temperature at which the storage modulus decreases significantly and the loss modulus reaches its maximum when measured using a dynamic viscoelasticity measuring device at a heating rate of 2°C / min from 23°C and an applied frequency of 10Hz. In the case of two or more loss modulus peaks, the glass transition temperature (Tg) of the amorphous resin refers to the peak temperature of the highest temperature peak. To improve measurement accuracy, the measurement frequency is set to at least once every 20 seconds. There are no particular restrictions on the sample preparation method, but from the viewpoint of eliminating the influence of molding strain, it is preferable to use slices of thermoformed articles. Furthermore, from the viewpoint of heat conduction, it is preferable that the size (width and thickness) of the slices be as small as possible.

[0073] The thermoplastic resin (A) can be a homopolymer or a copolymer.

[0074] The thermoplastic resin (A) can be used alone or in combination with two or more of the above-mentioned resins. In addition, as the thermoplastic resin (A), a resin obtained by modifying the above-mentioned resin with at least one compound selected from unsaturated carboxylic acids, their anhydrides and their derivatives can also be used.

[0075] As the thermoplastic resin (A), considering heat resistance, moldability, appearance design and mechanical properties, it is preferred to select one or more resins from the group consisting of polyolefin resins, polyamide resins, polyester resins, polyacetal resins, polyacrylic resins, polyphenylene ether resins and polyphenylene sulfide resins.

[0076] Furthermore, as the thermoplastic resin (A), it is more preferable to contain a polyamide resin (A1). This makes the markings formed by laser marking clearer. It should be noted that the polyamide resin (A1) can be used alone or in combination with other thermoplastic resins.

[0077] (Polyamide resin (A1))

[0078] The polyamide resin (A1) is preferably an alloy of a semi-aromatic polyamide (A1-2) or an aliphatic polyamide (A1-1) with a semi-aromatic polyamide (A1-2) having an aromatic ring in the backbone. This allows for clearer markings formed by laser marking. It should be noted that, for the thermoplastic resin (A), when the polyamide resin (A1) is an alloy, the polyamide resin (A1) can be an alloy of three or more other thermoplastic resins.

[0079] When the polyamide resin (A1) is the above alloy, there are no particular restrictions on the content of aliphatic polyamide (A1-1) and semi-aromatic polyamide (A1-2) in the polyamide resin (A1).

[0080] Of which, relative to the total of 100.0 parts by weight of aliphatic polyamide (A1-1) and semi-aromatic polyamide (A1-2), the content of semi-aromatic polyamide (A1-2) is preferably 5.0 parts by weight or more and 100.0 parts by weight or less, more preferably 5.0 parts by weight or more and 95.0 parts by weight or less, even more preferably 10.0 parts by weight or more and 80.0 parts by weight or less, and even more preferably 15.0 parts by weight or more and 70.0 parts by weight or less.

[0081] Furthermore, relative to the total of 100.0 parts by weight of aliphatic polyamide (A1-1) and semi-aromatic polyamide (A1-2), the content of aliphatic polyamide (A1-1) is preferably 0.0 parts by weight or more and 95.0 parts by weight or less, more preferably 5.0 parts by weight or more and 95.0 parts by weight or less, even more preferably 7.0 parts by weight or more and 80.0 parts by weight or less, and even more preferably 9.0 parts by weight or more and 70.0 parts by weight or less.

[0082] By ensuring that the content of aliphatic polyamide (A1-1) and semi-aromatic polyamide (A1-2) is within the above-mentioned range, the clarity of the marking formed by laser marking is further improved relative to 100 parts by mass of aliphatic polyamide (A1-1) and semi-aromatic polyamide (A1-2).

[0083] (1) Aliphatic polyamide (A1-1)

[0084] The structural units of the aliphatic polyamide (A1-1) preferably satisfy at least one of the following conditions (1) and (2).

[0085] (1) Contains aliphatic dicarboxylic acid units (A1-1a) and aliphatic diamine units (A1-1b).

[0086] (2) Contains at least one structural unit (A1-1c) selected from the group consisting of lactam units and aminocarboxylic acid units.

[0087] As a structural unit of aliphatic polyamide (A1-1), it can contain one or more structural units that satisfy at least one of the conditions in (1) and (2) above. Among them, the structural unit of aliphatic polyamide (A1-1) preferably satisfies (1) above.

[0088] (1-1) Aliphatic dicarboxylic acid unit (A1-1a)

[0089] Examples of aliphatic dicarboxylic acids that constitute an aliphatic dicarboxylic acid unit (A1-1a) include linear or branched saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms.

[0090] Examples of linear saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms include: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, diethylene glycol, etc., but not limited to these.

[0091] Examples of branched saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms include: dimethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methylhexanoic acid, trimethylhexanoic acid, etc., but not limited to these.

[0092] These aliphatic dicarboxylic acid units (A1-1a) can be used alone or in combination of two or more.

[0093] Among them, the aliphatic dicarboxylic acid constituting the aliphatic dicarboxylic acid unit (A1-1a) is preferably a straight-chain saturated aliphatic dicarboxylic acid with 6 or more carbon atoms, because it tends to have better heat resistance, flowability, toughness, low water absorption and rigidity of the resin composition.

[0094] Preferred linear saturated aliphatic dicarboxylic acids having 6 or more carbon atoms include, for example, adipic acid, sebacic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, etc.

[0095] Among them, adipic acid, sebacic acid, or dodecanoic acid are preferred as straight-chain saturated aliphatic dicarboxylic acids with 6 or more carbon atoms, considering the heat resistance of the resin composition.

[0096] Furthermore, without compromising the effect of the molded article of this embodiment, the aliphatic polyamide (A1-1) may, as needed, also contain units derived from three or more polycarboxylic acids. Examples of three or more polycarboxylic acids include trimellitic acid, pyromellitic acid, and pyromellitic tetroxide. These three or more polycarboxylic acids may be used alone or in combination of two or more.

[0097] (1-2) Aliphatic diamine unit (A1-1b)

[0098] Examples of aliphatic diamines that constitute an aliphatic diamine unit (A1-1b) include linear saturated aliphatic diamines with 2 or more but less than 20 carbon atoms, and branched saturated aliphatic diamines with 3 or more but less than 20 carbon atoms.

[0099] Examples of linear saturated aliphatic diamines with 2 or more but less than 20 carbon atoms include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, etc., but are not limited to these.

[0100] Examples of branched saturated aliphatic diamines with 3 or more but less than 20 carbon atoms include 2-methylpentamethylenediamine (also known as 2-methyl-1,5-diaminopentane), 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyl-1,8-octanediamine (also known as 2-methyloctamethylenediamine), 2,4-dimethyloctamethylenediamine, etc., but are not limited to these.

[0101] These aliphatic diamines that constitute the aliphatic diamine unit (A1-1b) can be used alone or in combination of two or more.

[0102] The aliphatic diamine constituting the aliphatic diamine unit (Al-1b) preferably has 6 or more and 12 or less carbon atoms, more preferably 6 or more and 10 or less. When the number of carbon atoms in the aliphatic diamine constituting the aliphatic diamine unit (Al-1b) is at or above the aforementioned lower limit, the molded article exhibits superior heat resistance. Conversely, when the number of carbon atoms is at or below the aforementioned upper limit, the molded article exhibits superior crystallinity and mold release properties.

[0103] Preferred linear or branched saturated aliphatic diamines having 6 to 12 carbon atoms include, for example, hexamethylenediamine, 2-methylpentamethylenediamine, and 2-methyl-1,8-octanediamine.

[0104] Among them, hexamethylenediamine or 2-methylpentamethylenediamine is preferred as a straight-chain or branched saturated aliphatic diamine with 6 to 12 carbon atoms. By including such aliphatic diamine units (A1-1b), the heat resistance and rigidity of the molded article are superior.

[0105] Furthermore, without impairing the effects of the molded article of this embodiment, the aliphatic polyamide (A1-1) may, as needed, also contain units derived from ternary or higher polyaliphatic amines. Examples of ternary or higher polyaliphatic amines include, for instance, bis(hexamethylenetriamine).

[0106] (1-3) Select at least one structural unit from the group consisting of lactam units and aminocarboxylic acid units (A1-1c).

[0107] Aliphatic polyamides (A1-1) can contain at least one structural unit (A1-1c) selected from the group consisting of lactam units and aminocarboxylic acid units. By including such units, there is a tendency to obtain polyamides with excellent toughness.

[0108] It should be noted that the "lactam unit" and "aminocarboxylic acid unit" mentioned here refer to lactams and aminocarboxylic acids that have undergone polymerization (condensation).

[0109] Examples of lactams that constitute a lactam unit include, but not limited to, butyrolactam, valproic acid lactam, ε-caprolactam, octyl lactam, heptalactam, undecyllactam, laurolactam (dodecyllactam), etc.

[0110] Among these, the lactam constituting the lactam unit is preferably ε-caprolactam or laurolactam, more preferably ε-caprolactam. By including such a lactam, the molded article tends to have better toughness.

[0111] Examples of aminocarboxylic acids that constitute an aminocarboxylic acid unit include, but are not limited to, ω-aminocarboxylic acids, α,ω-amino acids, etc., which are compounds obtained by ring opening of lactams.

[0112] The aminocarboxylic acid constituting the aminocarboxylic acid unit is preferably a straight-chain or branched saturated aliphatic carboxylic acid in which the number of carbon atoms substituted at the ω-position is 4 or more and 14 or less. Examples of such aminocarboxylic acids include, but are not limited to, 6-aminohexanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Other examples of aminocarboxylic acids include p-aminomethylbenzoic acid.

[0113] These lactams and aminocarboxylic acids that constitute the structural unit (A1-1c) can each be used alone or in combination of two or more.

[0114] The weight-average molecular weight (MAM) can be used as an indicator of the molecular weight of aliphatic polyamide (A1-1). The MAM of the aliphatic polyamide is preferably 10,000 or more and 50,000 or less, more preferably 17,000 or more and 45,000 or less, further preferably 20,000 or more and 45,000 or less, even more preferably 25,000 or more and 45,000 or less, particularly preferably 30,000 or more and 45,000 or less, and most preferably 35,000 or more and 40,000 or less.

[0115] By ensuring that the weight-average molecular weight is within the above-mentioned range, it is possible to obtain molded products with clearer markings formed by laser marking.

[0116] The weight-average molecular weight of aliphatic polyamide (A1-1) can be determined, for example, using gel permeation chromatography (GPC).

[0117] (2) Semi-aromatic polyamide (A1-2)

[0118] Semi-aromatic polyamides (A1-2) are polyamides that have an aromatic ring in their backbone and contain diamine units and dicarboxylic acid units.

[0119] Relative to all structural units of the semi-aromatic polyamide (A1-2), the semi-aromatic polyamide (A1-2) preferably contains 10 mol% or more and 95 mol% or less of aromatic structural units, more preferably 20 mol% or more and 90 mol% or less of aromatic structural units, and even more preferably 30 mol% or more and 85 mol% or less of aromatic structural units. Here, "aromatic structural units" refers to aromatic diamine units and aromatic dicarboxylic acid units.

[0120] In addition, relative to 100 mol% of all dicarboxylic acid units in the semi-aromatic polyamide (A1-2), the semi-aromatic polyamide (A1-2) preferably contains more than 10 mol% aromatic dicarboxylic acid units, more preferably more than 30 mol% aromatic dicarboxylic acid units, even more preferably more than 50 mol% aromatic dicarboxylic acid units, and particularly preferably more than 70 mol% aromatic dicarboxylic acid units.

[0121] When the content of aromatic dicarboxylic acid units is above the aforementioned lower limit, the marking portion formed by laser marking becomes clearer.

[0122] There are no particular restrictions on the aromatic dicarboxylic acid units in the semi-aromatic polyamide (A1-2), but terephthalic acid units or isophthalic acid units are preferred, and isophthalic acid units are more preferred.

[0123] It should be noted that the specified proportions of the monomer units constituting the semi-aromatic polyamide (A1-2) can be determined by nuclear magnetic resonance spectroscopy. 1 The measurements were performed using methods such as H-NMR.

[0124] Specifically, for example, a semi-aromatic polyamide (Al-2) was heated and dissolved in deuterated hexafluoroisopropanol at a concentration of approximately 5% by mass, and analyzed using a JNM ECA-500 nuclear magnetic resonance analyzer manufactured by NEC Corporation. 1 H-NMR analysis was performed, and the integral ratio was calculated to determine the units constituting the semi-aromatic polyamide (A1-2) composed of aromatic dicarboxylic acids, units composed of dicarboxylic acids other than aromatic dicarboxylic acids, units composed of aromatic diamines, and units composed of diamines other than aromatic diamines.

[0125] (2-1) Dicarboxylic acid unit (A1-2a)

[0126] There are no particular limitations on the dicarboxylic acid unit (A1-2a) that constitutes the semi-aromatic polyamide (A1-2). Examples include aromatic dicarboxylic acid units, aliphatic dicarboxylic acid units, and alicyclic dicarboxylic acid units.

[0127] (2-1-1) Aromatic dicarboxylic acid unit

[0128] Aromatic dicarboxylic acids, which constitute aromatic dicarboxylic acid units other than isophthalic acid units, can be exemplified by, but are not limited to, dicarboxylic acids having aromatic groups such as phenyl or naphthyl groups. The aromatic groups in aromatic dicarboxylic acids can be unsubstituted or substituents.

[0129] There are no particular restrictions on the substituents, and examples include: alkyl groups with 1 or more and 4 or less carbon atoms, aryl groups with 6 or more and 10 or less carbon atoms, aralkyl groups with 7 or more and 10 or less carbon atoms, alkylaryl groups with 7 or more and 10 or less carbon atoms, halogen groups, silyl groups with 1 or more and 6 or less carbon atoms, sulfonic acid groups and their salts (sodium salts, etc.).

[0130] Alkyl groups having 1 or more but less than 4 carbon atoms include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc.

[0131] Aryl groups having 6 or more but less than 10 carbon atoms include, but are not limited to, phenyl and naphthyl groups.

[0132] Aryl groups having 7 or more but less than 10 carbon atoms include, for example, benzyl, etc., but are not limited thereto.

[0133] Examples of alkylaryl groups with 7 or more but less than 10 carbon atoms include tolyl and xylyl, but are not limited to these.

[0134] Examples of halogen groups include, but are not limited to, fluorine, chlorine, bromine, and iodine groups.

[0135] Examples of silyl groups with 1 or more but less than 6 carbon atoms include trimethylsilyl, tert-butyldimethylsilyl, etc., but are not limited to these.

[0136] Among them, the aromatic dicarboxylic acid that constitutes the aromatic dicarboxylic acid unit other than the isophthalic acid unit is preferably an aromatic dicarboxylic acid with 8 or more and 20 or less carbon atoms that are unsubstituted or substituted by a specified substituent.

[0137] Aromatic dicarboxylic acids having 8 or more and 20 carbon atoms, either unsubstituted or substituted with specified substituents. Specifically, examples include, but are not limited to, terephthalic acid, naphthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, sodium isophthalate-5-sulfonate, etc.

[0138] Aromatic dicarboxylic acids that make up an aromatic dicarboxylic acid unit can be used alone or in combination of two or more.

[0139] (2-1-2) Aliphatic dicarboxylic acid unit

[0140] Aliphatic dicarboxylic acids that constitute aliphatic dicarboxylic acid units can be listed as: straight-chain or branched saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms.

[0141] Examples of linear saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms include: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, diethylene glycol, etc., but not limited to these.

[0142] Examples of branched saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms include: dimethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methylhexanoic acid, trimethylhexanoic acid, etc., but not limited to these.

[0143] (2-1-3) Alicyclic dicarboxylic acid units

[0144] Alicyclic dicarboxylic acids that constitute an alicyclic dicarboxylic acid unit (hereinafter sometimes referred to as an "alicyclic dicarboxylic acid unit") include, for example, alicyclic dicarboxylic acids with 3 or more and 10 or less carbon atoms in the alicyclic structure, but are not limited thereto. Among these, alicyclic dicarboxylic acids with 5 or more and 10 or less carbon atoms in the alicyclic structure are preferred.

[0145] Examples of such alicyclic dicarboxylic acids include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid, but they are not limited to these. Among them, 1,4-cyclohexanedicarboxylic acid is preferred as an alicyclic dicarboxylic acid.

[0146] It should be noted that the alicyclic dicarboxylic acid units that make up the alicyclic dicarboxylic acid units can be used alone or in combination of two or more.

[0147] The alicyclic group in alicyclic dicarboxylic acids can be unsubstituted or substituent. Examples of substituents include alkyl groups having 1 or more but less than 4 carbon atoms. Examples of alkyl groups having 1 or more but less than 4 carbon atoms include alkyl groups that are the same as the alkyl groups exemplified in the "Aromatic Dicarboxylic Acid Units" section above.

[0148] As a dicarboxylic acid unit other than isophthalic acid unit, it is preferable to include an aromatic dicarboxylic acid unit, and more preferably to include an aromatic dicarboxylic acid unit having 6 or more carbon atoms.

[0149] By using such a dicarboxylic acid, there is a tendency to obtain resin compositions with superior mechanical properties. Furthermore, molded articles with clearer markings formed by laser marking can be obtained.

[0150] In the semi-aromatic polyamide (A1-2), the dicarboxylic acid constituting the dicarboxylic acid unit (A1-2a) is not limited to the compounds described above as dicarboxylic acids, but may also be compounds equivalent to the dicarboxylic acids described above.

[0151] The term "compounds equivalent to dicarboxylic acids" as used herein refers to compounds capable of forming dicarboxylic acid structures identical to those derived from the aforementioned dicarboxylic acids. Examples of such compounds include, but are not limited to, acid anhydrides and acyl halides of dicarboxylic acids.

[0152] In addition, without compromising the effect of the molded article of this embodiment, the semi-aromatic polyamide (A1-2) may, as needed, also contain units derived from ternary or more polycarboxylic acids.

[0153] Examples of polycarboxylic acids with three or more nucleotides include trimellitic acid, pyromellitic acid, and pyromellitic tetracarboxylic acid. These polycarboxylic acids with three or more nucleotides can be used individually or in combination of two or more.

[0154] (2-2) Diamine unit (A1-2b)

[0155] There are no particular limitations on the diamine unit (A1-2b) constituting the semi-aromatic polyamide (A1-2), and examples include aromatic diamine units, aliphatic diamine units, and alicyclic diamine units. Among these, the diamine unit (A1-2b) constituting the semi-aromatic polyamide (A1-2) preferably contains a diamine unit with 4 or more but less than 10 carbon atoms, and more preferably contains a diamine unit with 6 or more but less than 10 carbon atoms.

[0156] (2-2-1) Aliphatic diamine unit

[0157] Examples of aliphatic diamines that constitute aliphatic diamine units include linear saturated aliphatic diamines with 4 or more but less than 20 carbon atoms.

[0158] Examples of linear saturated aliphatic diamines with 4 or more but less than 20 carbon atoms include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, etc., but are not limited to these.

[0159] (2-2-2) Alicyclic diamine unit

[0160] Alicyclic diamines (hereinafter sometimes referred to as "alicyclic diamines") that constitute alicyclic diamine units include, for example, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-cyclopentanediamine, etc., but are not limited thereto.

[0161] (2-2-3) Aromatic diamine unit

[0162] As a constituent unit of aromatic diamines, an aromatic diamine is any diamine containing an aromatic group, and is not limited to the following substances. Specifically, examples of aromatic diamines include m-phenylenediamine.

[0163] It should be noted that the diamines that make up each diamine unit can be used alone or in combination of two or more.

[0164] Among them, the diamine unit (A1-2b) is preferably an aliphatic diamine unit, more preferably a linear saturated aliphatic diamine unit with 4 or more and 10 or less carbon atoms, even more preferably a linear saturated aliphatic diamine unit with 6 or more and 10 or less carbon atoms, and particularly preferably a hexamethylene diamine unit.

[0165] By using such a diamine, there is a tendency to obtain resin compositions with superior mechanical properties. Furthermore, molded articles with clearer markings formed by laser marking can be obtained.

[0166] The weight-average molecular weight (MAM) can be used as an indicator of the molecular weight of the semi-aromatic polyamide (A1-2). The MAM of the semi-aromatic polyamide is preferably 10,000 or more and 50,000 or less, more preferably 15,000 or more and 45,000 or less, further preferably 15,000 or more and 40,000 or less, even more preferably 17,000 or more and 35,000 or less, particularly preferably 17,000 or more and 30,000 or less, and most preferably 18,000 or more and 28,000 or less.

[0167] By ensuring that the weight-average molecular weight is within the above-mentioned range, it is possible to obtain molded products with clearer markings formed by laser marking.

[0168] The weight-average molecular weight of semi-aromatic polyamide (A1-2) can be determined, for example, using GPC.

[0169] (3) End-capping agent

[0170] The ends of polyamide resins (A1) can be capped using known capping agents.

[0171] When polyamides are manufactured from the above-mentioned dicarboxylic acids and diamines, or from at least one of the groups selected from the above-mentioned lactams and aminocarboxylic acids, such end-capping agents can also be added as molecular weight regulators.

[0172] Examples of capping agents include monocarboxylic acids, monoamines, acid anhydrides (such as phthalic anhydride), monoisocyanates, monoesters, and monohydric alcohols, but are not limited to these. A single capping agent can be used alone, or two or more can be used in combination.

[0173] Among these, monocarboxylic acids or monoamines are preferred as end-capping agents. By end-capping the polyamide with an end-capping agent, the molded product tends to have better thermal stability.

[0174] Any monocarboxylic acid that can be used as a capping agent is a monocarboxylic acid that is reactive with an amino group that may be present at the end of the polyamide. Examples of monocarboxylic acids include, but are not limited to, aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids.

[0175] Examples of aliphatic monocarboxylic acids include: formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, tertralic acid, isobutyric acid, etc.

[0176] Examples of alicyclic monocarboxylic acids include cyclohexanecarboxylic acid.

[0177] Examples of aromatic monocarboxylic acids include benzoic acid, methylbenzoic acid, α-naphthoic acid, β-naphthoic acid, methylnaphthoic acid, and phenylacetic acid.

[0178] These monocarboxylic acids can be used alone or in combination of two or more.

[0179] In particular, from the viewpoint of fluidity and mechanical strength, the ends of semi-aromatic polyamides (A1-2) are preferably capped with acetic acid.

[0180] Any monoamine that can be used as a capping agent can be a monoamine that is reactive with the carboxyl group that may be present at the end of the polyamide. Examples of monoamines include, but are not limited to, aliphatic monoamines, alicyclic monoamines, and aromatic monoamines.

[0181] Examples of aliphatic monoamines include: methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, etc.

[0182] Examples of alicyclic monoamines include cyclohexylamine and dicyclohexylamine.

[0183] Examples of aromatic monoamines include aniline, toluidine, diphenylamine, and naphthylamine.

[0184] These monoamines can be used alone or in combination of two or more.

[0185] Resin compositions containing polyamides that have been capped with end-capping agents tend to have superior heat resistance, flowability, toughness, low water absorption, and rigidity.

[0186] (4) Preferred polyamide resin (A1)

[0187] Preferred polyamide resins (A1) are not particularly limited, and examples include: polyamides such as polyamide 6, polyamide 11, and polyamide 12 obtained through the condensation reaction of lactams; and polyamides such as polyamide 66, polyamide 610, polyamide 611, polyamide 612, polyamide 66 / 6I, polyamide 6T, polyamide 6I, polyamide 6I / 6T, polyamide 9T, polyamide 10T, polyamide 2M5T, polyamide MXD6, polyamide 6C, and polyamide 2M5C obtained as copolymers of diamines and dicarboxylic acids.

[0188] Among these, more preferably is one or more aliphatic polyamides selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 611 and polyamide 612, or one or more semi-aromatic polyamides selected from the group consisting of polyamide 66 / 6I, polyamide 6T, polyamide 6I, polyamide 6I / 6T, polyamide 9T and polyamide MXD6.

[0189] (Manufacturing method of polyamide resin (A1))

[0190] When manufacturing polyamide resins (A1) (aliphatic polyamide (A1-1) and semi-aromatic polyamide (A1-2)), the amount of dicarboxylic acid added is preferably about equimolar to the amount of diamine added. Regarding the molar ratio, taking into account the amount of diamine released from the reaction system during polymerization, the molar amount of all diamine relative to the total molar amount of all dicarboxylic acid is preferably 0.9 or more and 1.2 or less, more preferably 0.95 or more and 1.1 or less, and even more preferably 0.98 or more and 1.05 or less.

[0191] Methods for manufacturing polyamides include, for example, polymerization steps including (1) or (2) below, but are not limited thereto.

[0192] (1) A process of polymerizing a dicarboxylic acid constituting a dicarboxylic acid unit with a diamine constituting a diamine unit to obtain a polymer.

[0193] (2) A process of polymerizing one or more of the group consisting of lactams constituting lactam units and aminocarboxylic acids constituting aminocarboxylic acid units to obtain a polymer.

[0194] Furthermore, as a method for manufacturing polyamide, it is preferable to include an enhancement step after the polymerization step to increase the degree of polymerization of the polyamide. Additionally, an end-capping step, which uses an end-capping agent to end the ends of the obtained polymer, may be included after the polymerization step and the enhancement step, as needed.

[0195] Specific methods for manufacturing polyamides include, for example, the various methods illustrated in 1) to 4) below.

[0196] 1) A method of polymerizing an aqueous solution or aqueous suspension of one or more selected from the group consisting of dicarboxylic acid-diamine salts, mixtures of dicarboxylic acids and diamines, lactams and aminocarboxylic acids by heating and maintaining the solution in a molten state (hereinafter, sometimes referred to as "thermal melt polymerization").

[0197] 2) A method for increasing the degree of polymerization of polyamide obtained by hot melt polymerization at a temperature below its melting point while maintaining it in a solid state (hereinafter, sometimes referred to as "hot melt polymerization / solid phase polymerization").

[0198] 3) A method of polymerizing one or more of the following groups: dicarboxylic acid-diamine salt, mixture of dicarboxylic acid and diamine, lactam and aminocarboxylic acid, in a solid state (hereinafter, sometimes referred to as "solid-state polymerization").

[0199] 4) A method of polymerization using dicarboxylic acid acyl halide components and diamine components that are equivalent to dicarboxylic acids (hereinafter, sometimes referred to as the "solution method").

[0200] Among the specific manufacturing methods for polyamide, a method including hot melt polymerization is preferred. Furthermore, when manufacturing polyamide using hot melt polymerization, it is preferable to maintain the molten state until polymerization is complete. To maintain the molten state, suitable polymerization conditions for the polyamide composition are required. Examples of polymerization conditions include those shown below. Firstly, the polymerization pressure in the hot melt polymerization method is controlled at 14 kg / cm². 2 Above and 25kg / cm 2Set the pressure below the gauge pressure and continue heating. Then, depressurize for at least 30 minutes until the pressure inside the tank reaches atmospheric pressure (gauge pressure 0 kg / cm²). 2 ).

[0201] In the manufacturing process of polyamide, there are no particular restrictions on the polymerization method; it can be either batch or continuous.

[0202] There are no particular restrictions on the polymerization apparatus used in the manufacture of polyamide, and any known apparatus can be used. Specifically, examples of polymerization apparatus include, for instance, autoclave reactors, drum reactors, and extruder-type reactors (kneaders, etc.).

[0203] The following describes a method for manufacturing polyamide using an intermittent hot melt polymerization method, but the method for manufacturing polyamide is not limited to this.

[0204] First, an aqueous solution containing at least 40% by mass and less than 60% by mass of a polyamide raw material (a combination of dicarboxylic acid and diamine, and at least one selected from the group consisting of lactam and aminocarboxylic acid, as needed) is prepared. Next, this aqueous solution is concentrated in a concentration tank operating at a temperature of 110°C to 180°C and a pressure of at least 0.035 MPa to 0.6 MPa (gauge pressure) to approximately 65% ​​by mass and less than 90% by mass, thereby obtaining a concentrated solution.

[0205] Next, the obtained concentrated solution is transferred to an autoclave and heated until the pressure in the autoclave reaches about 1.2 MPa or higher and about 2.2 MPa or lower (gauge pressure).

[0206] Next, in the autoclave, while extracting at least one of the water and gas components, the pressure is maintained at approximately 1.2 MPa or higher and approximately 2.2 MPa or lower (gauge pressure). Then, when the temperature reaches approximately 220°C or higher and approximately 260°C, the pressure is reduced to atmospheric pressure (gauge pressure 0 MPa). After reducing the pressure inside the autoclave to atmospheric pressure, further depressurization is performed as needed, thereby effectively removing the byproduct water.

[0207] Next, the autoclave is pressurized using inert gases such as nitrogen, and the polyamide molten material is extruded from the autoclave in the form of wire. The extruded wire is cooled and cut to obtain polyamide granules.

[0208] [Packaging (B)]

[0209] The resin composition preferably contains filler (B) in addition to the aforementioned thermoplastic resin (A). By including filler (B), a resin composition with superior mechanical properties such as toughness and rigidity can be obtained.

[0210] As filler (B), there are no particular limitations, and examples include: glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, flake glass, calcium carbonate, talc, kaolin, mica, hydrotalcite, zinc carbonate, dicalcium phosphate, wollastonite, zeolite, boehmite, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, Ketjen black, acetylene black, furnace black, carbon nanotubes, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, bentonite, apatite, ground fibers, etc.

[0211] These fillers (B) can be used alone or in combination of two or more.

[0212] Among these, considering rigidity and strength, glass fiber, carbon fiber, flake glass, talc, kaolin, mica, dicalcium phosphate, wollastonite, carbon nanotubes, graphite, calcium fluoride, montmorillonite, bentonite, or apatite are preferred as filler (B). Furthermore, filler (B) is more preferably selected from one or more of the group consisting of glass fiber, calcium carbonate, talc, mica, wollastonite, and ground fibers; glass fiber or carbon fiber is even more preferred; and glass fiber is particularly preferred.

[0213] When the filler (B) is glass fiber or carbon fiber, the number-average fiber diameter (d1) is preferably 3 μm or more and 30 μm or less. Furthermore, the weight-average fiber length (L) is preferably 100 μm or more and 5 mm or less. Additionally, the aspect ratio ((L) / (d1)) of the weight-average fiber length (L) to the number-average fiber diameter (d1) is preferably 3 or more and 100 or less. By using glass fiber or carbon fiber with the above-described configuration, superior properties can be exhibited.

[0214] Furthermore, when the filler (B) is glass fiber, the number-average fiber diameter (d1) is more preferably 3 μm or more and 30 μm or less. The weight-average fiber length (L) is more preferably 103 μm or more and 5 mm or less. In addition, the aspect ratio ((L) / (d1)) is more preferably 10 or more and 100 or less.

[0215] The number-average fiber diameter and weight-average fiber length of filler (B) can be determined using the following methods.

[0216] First, the molded article is dissolved using a solvent such as formic acid that can dissolve the thermoplastic resin (A). Next, at least 100 fillers (B) are arbitrarily selected from the obtained insoluble components. Then, the fillers (B) are observed using an optical microscope, scanning electron microscope, or similar instrument. The number-average fiber diameter can be determined by dividing the total measured fiber diameter by the total number of fillers (B). Alternatively, the weight-average fiber length can be determined by dividing the total measured fiber length by the total measured weight of the fillers (B).

[0217] Relative to 100 parts by weight of thermoplastic resin (A), the resin composition preferably contains more than 0 parts by weight and less than or equal to 150.0 parts by weight of filler (B), more preferably contains more than 10.0 parts by weight and less than 140.0 parts by weight of filler (B), even more preferably contains more than 20.0 parts by weight and less than 135.0 parts by weight of filler (B), particularly preferably contains more than 25.0 parts by weight and less than 130.0 parts by weight of filler (B), and most preferably contains more than 30.0 parts by weight and less than 100.0 parts by weight of filler (B).

[0218] When the content of filler (B) is above the aforementioned lower limit, there is a tendency to further improve the mechanical properties of the molded article, such as strength and rigidity. On the other hand, when the content of filler (B) is below the aforementioned upper limit, there is a tendency to obtain molded articles with better surface appearance and better laser welding strength.

[0219] In particular, by using glass fiber as filler (B) and having the content of filler (B) within the above-mentioned range relative to 100 parts by mass of thermoplastic resin (A), there is a tendency to further improve the mechanical properties of the molded article, such as strength and rigidity.

[0220] [Flame retardant (C)]

[0221] The resin composition preferably contains a flame retardant (C) in addition to the thermoplastic resin (A) described above.

[0222] As a flame retardant (C), there are no particular restrictions. Examples include: halogenated flame retardants containing halogen elements, such as chlorine-containing flame retardants and bromine-containing flame retardants; and phosphorus-containing flame retardants that do not contain halogen elements.

[0223] These flame retardants (C) can be used alone or in combination of two or more. Furthermore, their flame retardancy can be further improved by using them in combination with flame retardant additives.

[0224] As a halogenated flame retardant, from the viewpoint of suppressing the generation of corrosive gases during melt processing such as extrusion and molding, and from the viewpoint of flame retardancy performance, toughness and rigidity and other mechanical properties, brominated polyphenylene ether (including poly(di)bromophenylene ether, etc.) or brominated polystyrene (including polydibromostyrene, polytribromostyrene, cross-linked brominated polystyrene, etc.) is preferred, and brominated polystyrene is even more preferred.

[0225] The bromine content in brominated polystyrene is preferably 5% by mass or more and 75% by mass or less, relative to the total mass of the brominated polystyrene. By setting the bromine content to the lower limit, the required bromine content for flame retardancy can be met with a smaller amount of brominated polystyrene, and molded articles with excellent heat resistance, flowability, toughness, low water absorption, rigidity, and flame retardancy can be obtained without compromising the properties of the polyamide. Furthermore, by setting the bromine content to the upper limit, thermal decomposition is less likely to occur during melt processing such as extrusion and molding, further suppressing gas generation, and resulting in molded articles with superior heat resistance and colorfastness.

[0226] As for phosphorus-containing flame retardants, there are no particular restrictions as long as they contain phosphorus but not halogen elements. Examples of phosphorus-containing flame retardants include: phosphate ester flame retardants, melamine polyphosphate flame retardants, phosphononitrile flame retardants, phosphonic acid flame retardants, and red phosphorus flame retardants.

[0227] Among them, the flame retardant (C) is preferably a phosphate ester flame retardant, a polyphosphate melamine flame retardant, a phosphononitrile flame retardant, or a phosphonic acid flame retardant, and is particularly preferably a phosphonic acid flame retardant.

[0228] As a type of phosphonic acid flame retardant, examples include phosphonates and diphosphonates.

[0229] Examples of hypophosphates include compounds represented by the following general formula (I) (hereinafter sometimes simply referred to as "hypophosphates (I)").

[0230] Examples of secondary phosphonates include those represented by the general formula (II) below (hereinafter, sometimes simply referred to as "secondary phosphonate (II)").

[0231]

[0232] (In general formula (1), R) 11 and R 12 Each is independently an alkyl group having 1 or more but 6 or fewer carbon atoms, or an aryl group having 6 or more but 10 or fewer carbon atoms. M n11+ A metal ion with a valence of n11. M is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum. n11 is 2 or 3. Multiple Rs exist. 11 and multiple R 12 They can be the same or different.

[0233] In general formula (2), R 21 and R 22 Each is independently an alkyl group having 1 or more but 6 or fewer carbon atoms, or an aryl group having 6 or more but 10 or fewer carbon atoms. 21It is an alkylene group having 1 or more but less than 10 carbon atoms, or an arylene group having 6 or more but less than 10 carbon atoms. M' m21+ A metal ion with a valence of m21. M' is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum. n21 is an integer greater than or equal to 1 and less than or equal to 3. When n21 is 2 or 3, multiple R's exist. 21 Multiple R 22 and multiple Y 21 Each can be the same or different. m21 is 2 or 3. x is 1 or 2. When x is 2, there can be multiple M's that are the same or different. n21, x, and m21 are integers that satisfy the relation 2 × n21 = m21 × x.

[0234] (R 11 R 12 R 21 and R 22 )

[0235] R 11 R 12 R 21 and R 22 Each is independently an alkyl group with 1 or more but less than 6 carbon atoms, or an aryl group with 6 or more but less than 10 carbon atoms. Multiple R groups exist. 11 and multiple R 12 They can be the same or different, but from the perspective of ease of manufacture, being the same is preferred. Furthermore, when n21 is 2 or 3, there are multiple R... 21 and multiple R 22 They can be the same or different, but from the perspective of ease of manufacturing, it is preferable to be the same.

[0236] As an alkyl group, it can be chain-like or cyclic, but chain-like is preferred. As a chain-like alkyl group, it can be straight-chain or branched. Examples of straight-chain alkyl groups include: methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, etc. Examples of branched alkyl groups include: 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, etc.

[0237] Examples of aryl groups include phenyl and naphthyl groups.

[0238] Alkyl and aryl groups can have substituents. Examples of substituents for alkyl groups include aryl groups with 6 or more but less than 10 carbon atoms. Examples of substituents for aryl groups include alkyl groups with 1 or more but less than 6 carbon atoms.

[0239] Alkyl groups with substituents, specifically, examples include benzyl and the like.

[0240] Aryl groups with substituents include, for example, tolyl and xylyl.

[0241] Among them, as R 11 R 12 R 21 and R 22 Preferably, it is an alkyl group with 1 or more but less than 6 carbon atoms, and more preferably methyl or ethyl.

[0242] (Y 21 )

[0243] Y 21 It is an alkylene group having 1 or more but less than 10 carbon atoms, or an arylene group having 6 or more but less than 10 carbon atoms. When n21 is 2 or 3, multiple Y atoms exist. 21 They can be the same or different, but from the perspective of ease of manufacturing, it is preferable to be the same.

[0244] The alkylene group can be chain-like or cyclic, but chain-like is preferred. The chain-like alkylene group can be straight-chain or branched. Examples of straight-chain alkylene groups include methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene. Examples of branched alkylene groups include 1-methylethylene and 1-methylpropylene.

[0245] Examples of aryl groups include phenylene and naphthylene.

[0246] Alkylenes and arylenes can have substituents. Examples of substituents for alkylenes include aryl groups with 6 or more but less than 10 carbon atoms. Examples of substituents for arylenes include alkyl groups with 1 or more but less than 6 carbon atoms.

[0247] As alkylene groups with substituents, examples include: phenylmethylene, phenylethylene, phenyltrimethylene, phenyltetramethylene, etc.

[0248] As arylene groups with substituents, examples include: methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene, tert-butylnaphthylene, etc.

[0249] Among them, as Y 21 Preferably, it is an alkylene group with 1 or more but less than 10 carbon atoms, more preferably a methylene or ethylene group.

[0250] (M and M')

[0251] M and M' are each independently an ion belonging to an element in Group 2 or Group 15 of the periodic table, an ion of a transition element, a zinc ion, or an aluminum ion. Examples of ions belonging to Group 2 include calcium ions and magnesium ions. Examples of ions belonging to Group 15 include bismuth ions.

[0252] Furthermore, when x is 2, the multiple M's can be the same or different, but from the perspective of ease of manufacture, it is preferable that they are the same.

[0253] Among them, calcium, zinc or aluminum are preferred as M and M', and calcium or aluminum are more preferred.

[0254] (x)

[0255] x represents the number of M's, and is either 1 or 2. x can be appropriately selected based on the type of M' and the amount of secondary phosphonic acid.

[0256] (n11 and n21)

[0257] n11 represents the number of phosphonic acids and the valence of M, and is either 2 or 3. n11 can be appropriately selected based on the type and valence of M.

[0258] n21 represents the number of diphosphonic acids and is an integer greater than 1 and less than 3. n21 can be appropriately selected according to the type and valence of M'.

[0259] (m21)

[0260] m21 represents the valence of M', and is 2 or 3.

[0261] n21, x, and m21 are integers that satisfy the relation 2 × n21 = m21 × x.

[0262] Preferred phosphine salts (I) include, for example, calcium dimethyl phosphine, magnesium dimethyl phosphine, aluminum dimethyl phosphine, zinc dimethyl phosphine, calcium ethyl methyl phosphine, magnesium ethyl methyl phosphine, aluminum ethyl methyl phosphine, zinc ethyl methyl phosphine, calcium diethyl phosphine, magnesium diethyl phosphine, aluminum diethyl phosphine, zinc diethyl phosphine, calcium methyl-n-propyl phosphine, magnesium methyl-n-propyl phosphine, aluminum methyl-n-propyl phosphine, zinc methyl-n-propyl phosphine, calcium methyl phenyl phosphine, magnesium methyl phenyl phosphine, aluminum methyl phenyl phosphine, zinc methyl phenyl phosphine, calcium diphenyl phosphine, magnesium diphenyl phosphine, aluminum diphenyl phosphine, zinc diphenyl phosphine, etc. Among them, as a hypophosphonate (1), considering its excellent flame retardancy, calcium dimethyl phosphonate, aluminum dimethyl phosphonate, calcium diethyl phosphonate or aluminum diethyl phosphonate are preferred, calcium diethyl phosphonate or aluminum diethyl phosphonate are more preferred, and aluminum diethyl phosphonate is particularly preferred.

[0263] Preferred secondary phosphonates (II) include, for example, calcium methanedi(methylphosphonic acid), magnesium methanedi(methylphosphonic acid), aluminum methanedi(methylphosphonic acid), zinc methanedi(methylphosphonic acid), calcium benzene-1,4-di(methylphosphonic acid), magnesium benzene-1,4-di(methylphosphonic acid), aluminum benzene-1,4-di(methylphosphonic acid), zinc benzene-1,4-di(methylphosphonic acid), etc.

[0264] The content of flame retardant (C) relative to 100 parts by weight of thermoplastic resin (A) is preferably 5.0 parts by weight or more and 90.0 parts by weight or less, more preferably 10.0 parts by weight or more and 80.0 parts by weight or less, even more preferably 15.0 parts by weight or more and 70.0 parts by weight or less, and particularly preferably 20.0 parts by weight or more and 60.0 parts by weight or less.

[0265] By setting the content of the flame retardant to the lower limit or above mentioned above, a resin composition with superior flame retardancy can be obtained. On the other hand, by setting the amount of the flame retardant to the upper limit or below mentioned above, a resin composition with superior flame retardancy can be obtained without impairing the properties of the resin composition.

[0266] [Coloring agent (D)]

[0267] In addition to the thermoplastic resin (A) described above, the resin composition may also contain a colorant (D).

[0268] As a colorant (D), it can be combined with commonly used colorants, thereby enabling the resin composition to be colored in any shade from black to light, preferably black, gray, or colored (e.g., orange).

[0269] From the viewpoint of superior clarity of the marked area formed by laser marking, a colorant that absorbs laser light is preferred as the colorant (D). Examples of such colorants include: carbon black (acetylene black, lamp black, thermal cracking carbon black, furnace black, channel black, Ketjen black, natural gas carbon black, petroleum carbon black, etc.), graphite, titanium black, and black iron oxide. Among these, carbon black (D1) is preferred considering dispersibility, color development, and cost. These colorants can be used alone or in combination of two or more.

[0270] Examples of non-black pigments include various inorganic and organic pigments, which will be discussed later. These non-black pigments can be used alone or in combination of two or more.

[0271] As inorganic pigments, examples include: white pigments such as calcium carbonate, titanium dioxide, zinc oxide, and zinc sulfide; yellow pigments such as cadmium yellow, chrome yellow, titanium yellow, zinc chromate, loess, and yellow iron oxide; red pigments such as red pigments (red pigments), brown clay, red iron oxide, and cadmium red; cyan pigments such as Prussian blue, ultramarine, and cobalt blue; and green pigments such as chrome green.

[0272] In addition, as organic pigments, the following can be listed: azo compounds, azomethyl alkaloids, methine compounds, indigo anthraquinones, anthraquinones, teranthrones, flavonoids, benzoanthrones, phthalocyanines, quinophthalones, perylene compounds, violet ketones, and dioxins. Azides, thioindole, isoindolineones, isoindoline, pyrroles, quinacridones, etc.

[0273] The content of colorant (D) relative to 100 parts by weight of thermoplastic resin (A) is preferably 0.001 parts by weight or more and 5.00 parts by weight or less, more preferably 0.005 parts by weight or more and 2.5 parts by weight or less, and even more preferably 0.01 parts by weight or more and 1.00 parts by weight or less. By having the content of colorant (D) at or above the aforementioned lower limit, the heating efficiency using laser is further improved, and the clarity becomes better. On the other hand, by having the content of colorant (D) at or below the aforementioned upper limit, carbonization of the resin caused by heating can be more effectively prevented.

[0274] [Other Additives (E)]

[0275] In addition to the thermoplastic resin (A) described above, the resin composition may also contain other additives (E) commonly used in resin compositions, to a extent that does not impair the effects of the molded article of this embodiment. Examples of other additives (E) include: moldability modifiers, degradation inhibitors, nucleating agents, heat stabilizers, etc.

[0276] The content of other additives (E) in the resin composition varies depending on their type, the intended use of the composition, etc. Therefore, there are no particular limitations as long as they do not impair the effect of the molded article of this embodiment.

[0277] (Molding modifier)

[0278] There are no particular limitations on the use of molding modifiers; examples include: higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides. It should be noted that molding modifiers are also used as "lubricants."

[0279] (1) Higher fatty acids

[0280] Examples of higher fatty acids include linear or branched, saturated or unsaturated aliphatic monocarboxylic acids with 8 or more but less than 40 carbon atoms.

[0281] Examples of linear saturated aliphatic monocarboxylic acids with 8 or more but less than 40 carbon atoms include lauric acid, palmitic acid, stearic acid, behenic acid, and linalic acid.

[0282] Examples of branched saturated aliphatic monocarboxylic acids with 8 or more but less than 40 carbon atoms include isopalmitic acid and isostearic acid.

[0283] Examples of linear unsaturated aliphatic monocarboxylic acids with 8 or more but less than 40 carbon atoms include oleic acid and erucic acid.

[0284] Branched unsaturated aliphatic monocarboxylic acids with 8 or more but less than 40 carbon atoms can be exemplified by isoleic acid, etc.

[0285] Among them, stearic acid or linalic acid are preferred as higher fatty acids.

[0286] (2) Metal salts of higher fatty acids

[0287] Metal salts of higher fatty acids refer to metal salts of higher fatty acids.

[0288] Metallic elements that can be used as metal salts include, for example, elements in Group 1, Group 2 and Group 3 of the periodic table, zinc, aluminum, etc.

[0289] Elements that are in Group 1 of the periodic table include, for example, sodium and potassium.

[0290] Elements that are in Group 2 of the periodic table include, for example, calcium and magnesium.

[0291] Elements that are in Group 3 of the periodic table include, for example, scandium and yttrium.

[0292] The preferred elements are elements from Group 1 and Group 2 of the periodic table or aluminum, and more preferably sodium, potassium, calcium, magnesium or aluminum.

[0293] As higher fatty acid metal salts, specific examples include: calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium lignite, sodium lignite, calcium palmitate, etc.

[0294] Among them, the preferred metal salts are those of linalic acid or stearic acid, which are considered to be higher fatty acid metal salts.

[0295] (3) Higher fatty acid esters

[0296] Higher fatty acid esters refer to esterifications of higher fatty acids and alcohols.

[0297] As higher fatty acid esters, esters of aliphatic carboxylic acids with 8 or more and 40 or less carbon atoms and aliphatic alcohols with 8 or more and 40 or less carbon atoms are preferred.

[0298] Examples of aliphatic alcohols with 8 or more but less than 40 carbon atoms include stearyl alcohol, behenyl alcohol, and lauryl alcohol.

[0299] As higher fatty acid esters, specifically, examples include stearate stearate and behenate behenate.

[0300] (4) Higher fatty acid amides

[0301] Higher fatty acid amides refer to amide compounds of higher fatty acids.

[0302] Examples of high-grade fatty acid amides include: stearamide, oleamide, mustardamide, ethylene bis-stearamide, ethylene bis-oleamide, N-stearyl stearamide, N-stearyl mustardamide, etc.

[0303] These higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides can each be used alone or in combination of two or more.

[0304] (Deterioration inhibitor)

[0305] Degradation inhibitors are used to prevent thermal degradation and discoloration, and to improve heat resistance to aging.

[0306] As deterioration inhibitors, there are no particular restrictions. Examples include: copper compounds, phenolic stabilizers, phosphite stabilizers, hindered amine stabilizers, triazine stabilizers, benzotriazole stabilizers, benzophenone stabilizers, cyanoacrylate stabilizers, salicylate stabilizers, sulfur-containing stabilizers, etc.

[0307] Examples of copper compounds include copper acetate and cuprous iodide.

[0308] Examples of phenolic stabilizers include hindered phenolic compounds.

[0309] These degradation inhibitors can be used alone or in combination of two or more.

[0310] (Nucleating agent)

[0311] Nucleating agents are substances that, when added, can produce at least one of the following effects (1) to (3).

[0312] (1) The effect of increasing the crystallization peak temperature of the resin composition.

[0313] (2) The effect of reducing the difference between the extrapolation start temperature and the extrapolation end temperature of the crystallization peak.

[0314] (3) To achieve the effect of miniaturizing or homogenizing the size of the spherulites in the molded product.

[0315] Nucleating agents include, but are not limited to, talc, boron nitride, mica, kaolin, silicon nitride, carbon black, potassium titanate, and molybdenum disulfide.

[0316] Nucleating agents can be used alone or in combination of two or more.

[0317] Among them, talc or boron nitride are preferred as nucleating agents from the perspective of their effectiveness.

[0318] In addition, the number-average particle size of the nucleating agent is preferably 0.01 μm or more and 10 μm or less, because the nucleating agent has a high efficiency.

[0319] The number-average particle size of the nucleating agent can be determined using the following method. First, the molded article is dissolved in a solvent that can dissolve the resin composition, such as formic acid. Next, for example, more than 100 nucleating agents are arbitrarily selected from the obtained insoluble components. Then, the particle size is observed and measured using an optical microscope, scanning electron microscope, or the like, thereby determining the number-average particle size of the nucleating agent.

[0320] The nucleating agent content in the resin composition is preferably 0.001 parts by mass and 1 part by mass or less, more preferably 0.001 parts by mass and 0.5 parts by mass or less, and even more preferably 0.001 parts by mass and 0.09 parts by mass or less, relative to 100 parts by mass of thermoplastic resin (A).

[0321] When the nucleating agent content is above the lower limit mentioned above, the heat resistance of the molded product tends to be further improved. On the other hand, when the nucleating agent content is below the upper limit mentioned above, a molded product with better toughness can be obtained.

[0322] (Heat stabilizer)

[0323] Examples of heat stabilizers include, but are not limited to, phenolic heat stabilizers, phosphorus-containing heat stabilizers, amine heat stabilizers, and metal salts of elements in Groups 3, 4, and 11–14 of the periodic table.

[0324] (1) Phenolic heat stabilizers

[0325] Hindered phenolic compounds can be used as heat stabilizers for phenols, but are not limited to these. Hindered phenolic compounds possess properties that impart excellent heat and light resistance to resins and fibers such as polyamides.

[0326] Examples of hindered phenolic compounds include: N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)], pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoamide), triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 3,9-bis{2- [3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, etc., but not limited to these.

[0327] These hindered phenolic compounds can be used alone or in combination of two or more.

[0328] When using phenolic heat stabilizers, the content of phenolic heat stabilizers in the resin composition is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.05% by mass or more and 1% by mass or less, relative to the total mass of the resin composition.

[0329] By keeping the content of phenolic heat stabilizers within the above range, the heat aging resistance of the molded product can be further improved, and the gas production can be further reduced.

[0330] (2) Phosphorus-containing heat stabilizers

[0331] Examples of phosphorus-containing heat stabilizers include: pentaerythritol-type phosphite compounds, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, diphenyl octyl phosphite, triisodecyl phosphite, diisodecyl phosphite, di(tetrazyl) phosphite, isooctyl diphenyl phosphite, isodecyl diphenyl phosphite, triphenyl diphenyl phosphite, tri(nonylphenyl) phosphite, tri(2,4-di-tert-butylphenyl) phosphite, tri(2,4-di-tert-butyl-5-methylphenyl) phosphite, and tri(butoxy) phosphite. 4,4'-Butidene bis(3-methyl-6-tert-butylphenyl) diphosphite-tetra(tetrazyl) ester, 4,4'-Isopropylidene diphenyl diphosphite-tetra(C12-C15 mixed alkyl) ester, 4,4'-Isopropylidene bis(2-tert-butylphenyl) diphosphite-di(nonylphenyl) ester, tri(biphenyl) ester, 1,1,3-Tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane diphosphite-tetra(tetrazyl) ester, 4,4'-Butidene bis(3-methyl-6-tert-butylphenyl) ... '-Isopropylidene diphenyl ester-tetra(C1-C15 mixed alkyl) ester, tris(mono- and di-mixed nonylphenyl) phosphite, 4,4'-isopropylidene bis(2-tert-butylphenyl) ester-di(nonylphenyl) ester, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tris(3,5-di-tert-butyl-4-hydroxyphenyl) ester, hydrogenated 4,4'-isopropylidene diphenyl polyphosphite, bis(4,4'-butylidene bis(3-methyl-6-tert-butylphenyl))-1,6-hexanediol diphosphite di(octylphenyl) ester, 1,1,3-tris(2-methyl-4- Hydroxy-5-tert-butylphenyl)butane triphosphite hexa(tetrazyl) ester, tris(4,4'-isopropylidene bis(2-tert-butylphenyl)) ester, tris(1,3-distearyloxyisopropyl) ester, octyl ester of 2,2'-methylene bis(4,6-di-tert-butylphenyl) ester, 2-ethylhexyl ester of 2,2'-methylene bis(3-methyl-4,6-di-tert-butylphenyl) ester, tetra(2,4-di-tert-butyl-5-methylphenyl) ester, and 4,4'-biphenylene diphosphite tetra(2,4-di-tert-butylphenyl) ester, etc., but not limited to these.

[0332] These phosphorus-containing heat stabilizers can be used alone or in combination of two or more.

[0333] Examples of pentaerythritol-type phosphites include: pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-phenyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-methyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-2-ethylhexyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-isodecyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-lauryl ester, pentaerythritol diphosphite... 2,6-Di-tert-butyl-4-methylphenyl ester-isotridecyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-stearyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-cyclohexyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-benzyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-ethyl cellosolve ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-butylcarbidol Esters, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-octylphenyl ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-nonylphenyl ester, Pentaerythritol diphosphite di(2,6-di-tert-butyl-4-methylphenyl) ester, Pentaerythritol diphosphite di(2,6-di-tert-butyl-4-ethylphenyl) ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-2,6-di-tert-butylphenyl ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methyl Phenylacetyl ester-2,4-di-tert-butylphenyl ester, pentaerythritol diphosphite-2,6-di-tert-butyl-4-methylphenyl ester-2,4-di-tert-octylphenyl ester, pentaerythritol diphosphite-2,6-di-tert-butyl-4-methylphenyl ester-2-cyclohexylphenyl ester, pentaerythritol diphosphite-2,6-di-tert-pentyl-4-methylphenyl ester-phenyl ester, pentaerythritol diphosphite di(2,6-di-tert-pentyl-4-methylphenyl) ester, pentaerythritol diphosphite di(2,6-di-tert-octyl-4-methylphenyl) ester, etc., but not limited to these.

[0334] These pentaerythritol-type phosphite compounds can be used alone or in combination of two or more.

[0335] When using a phosphorus-containing heat stabilizer, the content of the phosphorus-containing heat stabilizer in the resin composition is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.05% by mass or more and 1% by mass or less, relative to the total mass of the resin composition.

[0336] By keeping the content of phosphorus-containing heat stabilizer within the above range, the heat aging resistance of the molded product can be further improved, and the gas production can be further reduced.

[0337] (3) Amine heat stabilizers

[0338] Examples of amine heat stabilizers include: 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(phenylacetoxy)-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, and 4-benzyloxy-2,2,6,6-tetramethylpiperidine. Methylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4-(ethylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(cyclohexylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(phenylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, di(2,2,6,6-tetramethyl-4-piperidinyl) carbonate, di(2,2,6,6-tetramethyl-4-piperidinyl) oxalate, di(2,2,6,6-tetramethyl-4-piperidinyl) malonate, di(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, hexyl Di(2,2,6,6-tetramethyl-4-piperidinyl) diacid, di(2,2,6,6-tetramethyl-4-piperidinyl) terephthalate, 1,2-bis(2,2,6,6-tetramethyl-4-piperidoxy)ethane, α,α'-bis(2,2,6,6-tetramethyl-4-piperidoxy)p-xylene, di(2,2,6,6-tetramethyl-4-piperidinyl) toluene-2,4-dicarbamate, di(2,2,6,6-tetramethyl-4-piperidinyl) hexamethylene-1,6-dicarbamate, tris(2,2,6,6-tetramethyl-4-piperidinyl)benzene-1,3,5-tricarbamate Condensations of 1-[2-{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy}butyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-2,2,6,6-tetramethylpiperidine, condensates of 1,2,3,4-butanetetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol and β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaziro(5,5)undecane]diethanol, etc., but not limited thereto.

[0339] These amine heat stabilizers can be used alone or in combination of two or more.

[0340] When using amine heat stabilizers, the content of amine heat stabilizers in the resin composition is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.05% by mass or more and 1% by mass or less, relative to the total mass of the resin composition.

[0341] By keeping the content of amine heat stabilizers within the above range, the heat aging resistance of the molded product can be further improved, and the gas production can be further reduced.

[0342] (4) Metal salts of elements in Groups 3, 4 and 11 to 14 of the periodic table

[0343] There are no restrictions on whether a metal salt is a salt of an element belonging to Group 3, Group 4, or Groups 11 to 14 of the periodic table.

[0344] From the viewpoint of further improving the heat aging resistance of the molded product, copper salts are preferred. Examples of such copper salts include, but are not limited to, copper acetate, copper propionate, copper benzoate, copper adipic acid, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, and copper complex salts formed by coordination of copper with a chelating agent.

[0345] Examples of chelating agents include ethylenediamine and ethylenediaminetetraacetic acid.

[0346] These copper salts can be used alone or in combination of two or more.

[0347] Copper acetate is preferred as the copper salt. When using copper acetate, a resin composition with better heat aging resistance and more effective suppression of metal corrosion (hereinafter sometimes simply referred to as "metal corrosion") of the screw and barrel during extrusion can be obtained.

[0348] When using copper salt as a heat stabilizer, the content of copper salt in the resin composition is preferably 0.01 parts by mass or more and 0.60 parts by mass or less, more preferably 0.02 parts by mass or more and 0.40 parts by mass or less, relative to 100 parts by mass of thermoplastic resin (A).

[0349] By keeping the copper salt content within the above range, the heat aging resistance of the molded product can be further improved, and the precipitation of copper and metal corrosion can be more effectively inhibited.

[0350] In addition, from the perspective of improving the heat aging resistance of molded products, compared to 10 6The thermoplastic resin (A) in parts by weight (1,000,000 parts by weight) preferably contains copper from the copper salt at a concentration of 10 parts by weight or more and 2,000 parts by weight or less, more preferably 30 parts by weight or more and 1,500 parts by weight or less, and even more preferably 50 parts by weight or more and 500 parts by weight or less.

[0351] The heat stabilizer components described above can be used alone or in combination of two or more.

[0352] [Method for manufacturing the resin composition]

[0353] There are no particular limitations on the method of manufacturing the resin composition, as long as it involves mixing the thermoplastic resin (A) with the filler (B), flame retardant (C), colorant (D), and other additives (E) as needed. It should be noted that the thermoplastic resin (A), filler (B), flame retardant (C), colorant (D), and other additives (E) will subsequently be referred to as component (A), component (B), component (C), component (D), and component (E), respectively.

[0354] As a method of mixing the above-mentioned component (A) with the required components (B) to (E), for example, the following methods (1) or (2) can be listed.

[0355] (1) A method of mixing the above-mentioned component (A) and the required components (B) to (E) using a Henschel mixer or the like, feeding the mixture into a single-screw or twin-screw extruder, and performing melt mixing.

[0356] (2) A method for preparing a mixture obtained by mixing the above-mentioned component (A) and the required components (C) to (E) in advance using a Henschel mixer or the like, feeding the mixture into a single-screw or twin-screw extruder for melt mixing, and then optionally feeding component (B) from the side feeder of the extruder.

[0357] The method of supplying the components constituting the resin composition to the melt mixer can either supply all the components at once to the same supply port, or supply the components separately from different supply ports.

[0358] When the polyamide (A1) contains aliphatic polyamide (A1-1), the melt mixing temperature is preferably a temperature that is about 1°C higher and about 100°C higher than the melting point of the aliphatic polyamide (A1-1), and more preferably a temperature that is about 10°C higher and about 50°C higher than the melting point of the aliphatic polyamide (A1-1).

[0359] The preferred shearing speed in the mixer is approximately 100 seconds. -1That's all. Additionally, the average residence time during mixing is preferably between about 0.5 minutes and about 5 minutes.

[0360] The apparatus for performing melt mixing can be a known apparatus, such as a single-screw or twin-screw extruder, a Banbury internal mixer, a melt mixing mill (mixing rollers, etc.), etc.

[0361] The proportions of each component in the resin composition are the same as the contents of each component in the above-mentioned resin composition.

[0362] [Physical Properties of the Resin Composition]

[0363] The glass transition temperature (Tg) of the resin composition is preferably 75°C or higher, more preferably 75°C or higher and 220°C or lower, even more preferably 80°C or higher and 210°C or lower, particularly preferably 85°C or higher and 200°C or lower, and most preferably 90°C or higher and 150°C or lower.

[0364] When the glass transition temperature (Tg) of the resin composition is within the above-mentioned range, the gloss of the molded article and the clarity of the mark formed by laser marking are superior.

[0365] The glass transition temperature (Tg) of the resin composition can be determined, for example, using a dynamic viscoelasticity measuring device.

[0366] Specifically, for example, when measuring at an applied frequency of 8 Hz while heating from -100°C to 250°C at a heating rate of 3°C / min, the peak temperature at which the storage modulus significantly decreases and the loss modulus reaches its maximum is taken as the glass transition temperature Tg. Specifically, the ratio of loss modulus E2 to storage modulus E1 (E2 / E1) is set as tanδ, and the temperature at which tanδ reaches its maximum is taken as the glass transition temperature Tg. In the case of two or more loss modulus peaks, the peak temperature of the highest temperature peak is taken as the glass transition temperature Tg. To improve measurement accuracy, the measurement frequency is set to at least once every 20 seconds.

[0367] Furthermore, there are no particular restrictions on the preparation method of the sample for testing, and it can be prepared according to JIS-K7139. From the viewpoint of eliminating the influence of molding strain, it is preferable to use slices of hot-pressed articles. In addition, from the viewpoint of heat conduction, it is preferable that the size (width and thickness) of the slices be as small as possible.

[0368] The crystallization peak temperature of the resin composition is preferably below 240°C, more preferably above 120°C and below 235°C, even more preferably above 130°C and below 230°C, and particularly preferably above 140°C and below 225°C.

[0369] When the crystallization peak temperature of the resin composition is within the above-mentioned range, the gloss of the molded product and the clarity of the marking formed by laser marking are superior.

[0370] The crystallization peak temperature of the resin composition can be determined, for example, by DSC.

[0371] Specifically, for example, the temperature is increased from 50°C to 350°C at a rate of 20°C / min, held at 350°C for 3 minutes, then cooled from 350°C to 50°C at a rate of 20°C / min, held at 50°C for 3 minutes, and then increased again from 50°C to 350°C at a rate of 20°C / min, held at 350°C for 3 minutes, and then cooled again from 350°C to 50°C at a rate of 20°C / min. The peak temperature of the endothermic peak that appears at this point is taken as the crystallization peak temperature. If more than two endothermic peaks appear, the peak temperature of the endothermic peak at the highest temperature is taken as the crystallization peak temperature.

[0372] The enthalpy of the endothermic peak at this point is preferably 10 J / g or higher, more preferably 20 J / g or higher. Furthermore, during the determination, it is preferable to use a sample obtained by temporarily heating the sample to a temperature of 20°C or higher above its melting point to melt the resin, and then cooling it to 23°C at a cooling rate of 10°C / min.

[0373] <Manufacturing Method of Molded Articles>

[0374] The aforementioned molded articles can be manufactured, for example, by the methods shown below.

[0375] That is, the method for manufacturing a molded article with laser marking in this embodiment (hereinafter, sometimes simply referred to as the "manufacturing method of this embodiment") includes a step of laser marking a molded article obtained by molding a resin composition containing thermoplastic resin (A) (hereinafter referred to as the "laser marking step").

[0376] In the above process, laser marking is performed such that the unfolded area ratio Sdr of the laser-marked portion of the molded article, as specified by ISO25178, is 0.10 or more and 1.00 or less, and the raised height of the laser-marked portion of the molded article is 6.6 μm or more and 100.0 μm or less.

[0377] The manufacturing method of this embodiment, by having the above-described configuration, enables the production of molded products with clearly defined markings formed by laser marking.

[0378] That is, the manufacturing method of this embodiment can also be called a laser marking method for giving a clear mark formed by laser marking to a molded article.

[0379] [Laser marking process]

[0380] Examples of lasers used in laser marking processes include: carbon dioxide lasers, Nd-YAG lasers, YAG lasers, ruby ​​lasers, semiconductor lasers, argon lasers, and excimer lasers. From a marking performance perspective, Nd-YAG lasers, YAG lasers, or semiconductor lasers are preferred.

[0381] The wavelength of the laser used is typically above 193nm and below 1100nm, preferably a three-band wavelength of above 220nm and below 250nm, above 520nm and below 550nm, or above 900nm and below 1100nm, more preferably a two-band wavelength of above 520nm and below 550nm or above 900nm and below 1100nm, and even more preferably a wavelength of above 1050nm and below 1070nm.

[0382] By processing in these wavelengths, the laser is effectively absorbed by the colorant and resin, the unevenness of the foamed part becomes finer, and the Sdr and bulge height become larger.

[0383] From the perspective of shortening production cycle time, the scanning speed of laser marking is usually above 10 mm / s and below 5000 mm / s, preferably above 100 mm / s and below 4000 mm / s, and more preferably above 500 mm / s and below 2500 mm / s.

[0384] By setting the scanning speed above the lower limit mentioned above, it is possible to prevent the Sdr and ridge height from decreasing due to reduced laser absorption, thus more effectively preventing the marking from becoming unclear. On the other hand, by setting the scanning speed below the upper limit mentioned above, it is possible to prevent excessive laser absorption, thus more effectively preventing carbonization due to heating and the resulting inability to read the marking.

[0385] The processing output power of laser marking is usually above 1.0W and below 30.0W, preferably above 1.0W and below 20.0W, and more preferably above 1.0W and below 15.0W.

[0386] By processing the output power at or above the aforementioned lower limit, it is possible to prevent the Sdr and ridge height from decreasing due to reduced laser absorption, thus more effectively preventing the marking from becoming unclear. On the other hand, by processing the output power at or below the aforementioned upper limit, it is possible to prevent excessive laser absorption, thus more effectively preventing carbonization due to heating and the resulting inability to read the marking.

[0387] The frequency of laser marking is typically above 1 kHz and below 1000 kHz, preferably above 5 kHz and below 750 kHz, and more preferably above 10 kHz and below 500 kHz.

[0388] By using a frequency above the aforementioned lower limit, marking can be performed without gaps, thus preventing a decrease in Sdr and elevation height due to reduced laser absorption, and more effectively preventing the marking from becoming unclear. On the other hand, by using a frequency below the aforementioned upper limit, it is possible to suppress excessive marking density, and more effectively prevent carbonization due to heating, which would render the marking unreadable.

[0389] The spacing of laser marking is typically 0.1 μm or more and 500 μm or less, preferably 1 μm or more and 250 μm or less, and more preferably 5 μm or more and 250 μm or less.

[0390] By setting the spacing above the lower limit, excessive laser absorption can be prevented, thus more effectively preventing carbonization due to heating and the resulting unreadable markings. On the other hand, by setting the spacing below the upper limit, reduced Sdr and ridge height due to decreased laser absorption can be prevented, thus more effectively preventing the markings from becoming unclear.

[0391] [Molding Process]

[0392] The manufacturing method of this embodiment may include a forming process before the laser marking process.

[0393] In the molding process, the above-mentioned resin composition is molded to obtain an intermediate molded product that does not have a marking portion formed by laser marking.

[0394] There are no particular restrictions on the method for obtaining intermediate molded products, and known molding methods can be used.

[0395] Commonly known molding methods include, for example: extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, heterogeneous material molding, gas-assisted injection molding, foam injection molding, low-pressure molding, ultra-thin wall injection molding (ultra-high speed injection molding), and in-mold composite molding (insert molding, injection molding on substrate), etc.

[0396] <Applications of Molded Products>

[0397] The laser-marked markings on the molded articles of this embodiment are clear, thus enabling them to be used for various purposes.

[0398] As for the use of the molded articles of this embodiment, they can be appropriately used in the automotive, electrical and electronic, machinery and industrial, office equipment, and aerospace fields.

[0399] The molded article of this embodiment is particularly suitable for use as an electrical and electronic component in electrical and electronic fields such as magnetic switch housings, circuit breaker housings, various switch components, and connector molded articles, and is even more suitable for use in magnetic switch housings, circuit breaker housings, or connector molded articles.

[0400] Electromagnetic contactors that use electromagnets to open and close circuits, thermal relays that cut off circuits when overloaded, electromagnetic switches (including magnetic switches, air circuit breakers, and other names) obtained by combining these, safety circuit breakers that cut off power when a specified current flows through or when abnormalities such as shaking or overheating are detected, and residual current circuit breakers (hereinafter, sometimes collectively referred to as "circuit breakers") are all electrical and electronic components assembled in electrical wiring, and are indispensable for ensuring the safety of electrical wiring.

[0401] These electrical and electronic components require product identification, connection markings to prevent incorrect installation, and markings related to product safety. Previously, these markings were achieved by affixing seals containing the markings, but this method has limitations, such as requiring a smooth surface on the molded part. Therefore, a shift from affixing seals to laser marking is underway for these products, requiring clear marking characteristics.

[0402] That is, the molded article of this embodiment can be appropriately used in the above-mentioned electrical and electronic components that require clear marking characteristics.

[0403] Example

[0404] The present invention will now be described in detail with specific embodiments and comparative examples, but the present invention is not limited to the following embodiments.

[0405] The components of the resin compositions used in the molded articles of the Examples and Comparative Examples are described.

[0406] <Components>

[0407] [Aliphatic polyamide (A1-1)]

[0408] A1-1-1: Polyamide 66

[0409] A1-1-2: Polyamide 66 / 6 copolymer

[0410] [Semi-aromatic polyamide (A1-2)]

[0411] A1-2-1: Polyamide 6I

[0412] A1-2-2: Polyamide 6I / 6T (manufactured by EMS, model: G21, the content of isophthalic acid units in all dicarboxylic acid units is 70 mol%, molecular weight: 27000)

[0413] A1-2-3: Polyamide 66 / 6I

[0414] [Packaging (B)]

[0415] B-1: Glass fiber (GF) (manufactured by Nippon Electric Glass Co., Ltd., trade name "ECS03T275H", average fiber diameter 10μmφ, cut length 3mm)

[0416] [Flame retardant (C)]

[0417] C-1: Phosphine-based flame retardant, aluminum diethylphosphinate (manufactured by Clariant, trade name: "ExolitOP1230")

[0418] [Coloring agent (D)]

[0419] D1: Carbon black (primary particle size 27nm)

[0420] [Other Additives (E)]

[0421] E-2: Titanium oxide (particle size 210nm)

[0422] <Manufacturing of Polyamides>

[0423] The manufacturing methods for aliphatic polyamide A1-1-1, semi-aromatic polyamide A1-2-1, and semi-aromatic polyamide A1-2-3 are described in detail below. It should be noted that the aliphatic polyamide A1-1-1, semi-aromatic polyamide A1-2-1, and semi-aromatic polyamide A1-2-3 obtained by the manufacturing methods described below are dried in a nitrogen stream to adjust the moisture content to approximately 0.2% by mass, and then used as raw materials for the resin compositions used in the molded articles of the examples and comparative examples described later.

[0424] [Synthesis example 1]

[0425] (Synthesis of aliphatic polyamide A1-1-1 (polyamide 66))

[0426] The polymerization reaction of polyamide was carried out by the "thermal melt polymerization method" as described below.

[0427] First, 1500g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1500g of distilled water to prepare an equimolar 50% by mass homogeneous aqueous solution of the raw material monomers. This aqueous solution was then transferred to a 5.4L autoclave and purged with nitrogen. Next, while stirring at a temperature above approximately 110°C and below approximately 150°C, water vapor was slowly extracted to concentrate the solution to a concentration of 70% by mass. The internal temperature was then raised to 220°C. At this point, the autoclave was pressurized to 1.8 MPa. This pressure was maintained for 1 hour until the internal temperature reached 245°C, and the reaction continued for 1 hour while slowly extracting water vapor and maintaining the pressure at 1.8 MPa. The pressure was then reduced over 1 hour. Finally, the autoclave was maintained at a reduced pressure of 650 Torr (86.66 kPa) for 10 minutes using a vacuum device. At this point, the final internal temperature of the polymerization was 265°C. Next, nitrogen gas is used to pressurize the filaments, which are then formed into a filament from the lower spinneret (nozzle). The filaments are then water-cooled, cut, and discharged as granules. The granules are then dried at 100°C in a nitrogen atmosphere for 12 hours to obtain aliphatic polyamide Al-1-1 (polyamide 66).

[0428] [Synthesis example 2]

[0429] (Synthesis of aliphatic polyamide A1-1-2 (polyamide 66 / 6 copolymer))

[0430] 30 kg of a 50% by mass aqueous solution of the polymerization components (equimolar salts of hexamethylenediamine and adipic acid and ε-caprolactam) for forming a polyamide 66 / 6 (90% by mass / 10% by mass) copolymer was prepared. This solution was then added to a 40-liter high-pressure reactor equipped with a stirrer and a bottom extraction nozzle, and stirred thoroughly at 50°C. The reactor was then completely purged with nitrogen, and the temperature was increased from 50°C to approximately 270°C while stirring. At this point, the pressure inside the high-pressure reactor was approximately 1.8 MPa (gauge pressure). Water was removed from the system to prevent the pressure from exceeding 1.8 MPa. The polymerization time was adjusted to achieve the target relative viscosity. The polymer was discharged in a linear fashion from the bottom nozzle, water-cooled, and cut to obtain polyamide 66 / 6 copolymer particles. These particles were then vacuum-dried at 80°C for 24 hours.

[0431] [Synthesis example 3]

[0432] (Synthesis of semi-aromatic polyamide A1-2-1 (polyamide 6I))

[0433] The polymerization reaction of polyamide was carried out by the "thermal melt polymerization method" as described below.

[0434] First, 1500 g of an equimolar salt of isophthalic acid and hexamethylenediamine, 1.5 mol% excess of adipic acid relative to the total equimolar salt composition, and 0.5 mol% acetic acid relative to the total equimolar salt composition were dissolved in 1500 g of distilled water to prepare a homogeneous aqueous solution of the raw material monomers at 50% by mass. Next, while stirring at a temperature above approximately 110°C and below approximately 150°C, water vapor was slowly extracted to concentrate the solution to a concentration of 70% by mass. Then, the internal temperature was raised to 220°C. At this point, the autoclave was pressurized to 1.8 MPa. This pressure was maintained for 1 hour until the internal temperature reached 245°C, and the reaction continued for 1 hour while slowly extracting water vapor and maintaining the pressure at 1.8 MPa. Then, the pressure was reduced over 30 minutes. Next, the autoclave was maintained at a reduced pressure of 650 Torr (86.66 kPa) for 10 minutes using a vacuum device. At this point, the final internal temperature of the polymerization was 265°C. Next, nitrogen gas is used to pressurize the material, forming it into a filament from the lower spinneret (nozzle). This filament is then water-cooled, cut, and discharged as granules. The granules are then dried at 100°C under a nitrogen atmosphere for 12 hours to obtain semi-aromatic polyamide Al-2-1 (polyamide 6I).

[0435] [Synthesis example 4]

[0436] (Synthesis of semi-aromatic polyamide A1-2-3 (polyamide 66 / 6I))

[0437] 2.00 kg of an equimolar salt of adipic acid and hexamethylenediamine, 0.50 kg of an equimolar salt of isophthalic acid and hexamethylenediamine, and 2.5 kg of pure water were added to a 5 L autoclave and stirred thoroughly. Nitrogen purging was performed completely, and then the temperature was raised from room temperature to 220°C over approximately one hour while stirring. At this point, the internal pressure, measured by the natural pressure gauge generated by the steam inside the autoclave, reached 18 kg / cm². 2 G, remove water from the reaction system to prevent it from reaching 18 kg / cm³. 2 The pressure was increased to above G, and heating continued. Heating was stopped after 2 hours when the internal temperature reached 260°C, the autoclave's discharge valve was closed, and it was cooled to room temperature for approximately 8 hours. After cooling, the autoclave was opened, approximately 2 kg of polymer was removed, and pulverized. The pulverized polymer was placed in a 10L evaporator and solid-state polymerized at 200°C for 10 hours under a nitrogen atmosphere. Then, under nitrogen pressure, the polymer was formed into a filament from the lower spinneret (nozzle), water-cooled, cut, and discharged as granules. The granules were then dried at 100°C under a nitrogen atmosphere for 12 hours to obtain semi-aromatic polyamide Al-2-3 (polyamide 66 / 6I).

[0438] <Preparation of Resin Composition>

[0439] [Manufacturing Example 1]

[0440] (Preparation of resin composition PA-1)

[0441] Using a TEM35mm twin-screw extruder (set temperature: 280°C, screw speed: 300 rpm) manufactured by Toshiba Machine Co., Ltd., a material pre-blended with aliphatic polyamide A1-1-1, semi-aromatic polyamide A1-2-1, and carbon black D1 was fed from a top feed inlet located at the very top of the extruder. The molten compound extruded from the die was then linearly cooled and granulated to obtain granules of the resin composition. The formulation amounts are shown in Table 1.

[0442] [Manufacturing Examples 2-19]

[0443] (Preparation of resin compositions PA-2 to PA-19)

[0444] The proportions of components (A) to (E) were set as shown in Tables 1 to 3, and filler B-1 was supplied from the side feed port on the downstream side of the extruder (in a state where the resin supplied from the top feed port is fully molten). Otherwise, each resin composition was manufactured using the same method as that shown in Manufacturing Example 1.

[0445] The compositions of the obtained resin compositions PA-1 to PA-19 are shown in Tables 1 to 3.

[0446] [Table 1]

[0447]

[0448] [Table 2]

[0449]

[0450] [Table 3]

[0451]

[0452] <Physical Properties and Evaluation>

[0453] First, the particles of each resin composition obtained in Manufacturing Examples 1 to 19 were dried in a nitrogen gas stream to adjust the water content in the resin composition to 500 ppm by mass or less. Next, various physical properties of the particles of each resin composition with adjusted water content were measured using the method described below. Furthermore, various physical properties were measured and various evaluations were performed on the molded articles described later.

[0454] [Physical properties 1]

[0455] (Glass transition temperature Tg)

[0456] For the granules of each resin composition obtained in Manufacturing Examples 1 to 18, a PS40E injection molding machine manufactured by Nissei Kogyo Co., Ltd. was used. The barrel temperature was set to 290°C and the mold temperature was set to 80°C. Under the injection molding conditions of 10 seconds of injection and 10 seconds of cooling, molded articles according to JIS-K7139 were produced.

[0457] For the granules of the resin composition obtained in Manufacturing Example 19, a PS40E injection molding machine manufactured by Nissei Kogyo Co., Ltd. was used. The barrel temperature was set to 265°C and the mold temperature was set to 80°C. Under the injection molding conditions of 10 seconds of injection and 10 seconds of cooling, a molded article according to JIS-K7139 was produced.

[0458] The molded articles of these manufacturing examples 1 to 19 were measured using a dynamic viscoelasticity evaluation device (GABO EPLEXOR 500N) under the following conditions.

[0459] (Measurement conditions)

[0460] Measurement mode: Tension

[0461] Measurement frequency: 10Hz

[0462] Heating rate: 3℃ / minute

[0463] Temperature range: above -100℃ and below 250℃

[0464] The ratio of loss modulus E2 to energy storage modulus E1 (E2 / E1) is set as tanδ, and the temperature at which tanδ reaches its maximum is taken as the glass transition temperature Tg.

[0465] [Physical Properties 2]

[0466] (Crystallization peak temperature)

[0467] The crystallization peak temperature was determined according to JIS-K7121 using a Diamond-DSC manufactured by PerkinElmer, as described below. The determination was performed under a nitrogen atmosphere.

[0468] First, approximately 10 mg of the resin composition was heated from 50°C to 350°C at a heating rate of 20°C / min. Then, it was held at 350°C for 3 minutes, followed by cooling from 350°C to 50°C at a cooling rate of 20°C / min. This was repeated, holding at 50°C for 3 minutes, and then heating again from 50°C to 350°C at a heating rate of 20°C / min. The crystallization peak temperature was then measured.

[0469] [Physical Properties 3]

[0470] (The unfolded area of ​​the interface of the marked part formed by laser marking is greater than Sdr)

[0471] Using a laser microscope (measurement unit: VK-X210, controller: VK-X200) manufactured by Keyence Corporation, the unfolded area ratio Sdr of the interface of the laser-marked part of each molded product was measured according to ISO 25178 at 20x objective magnification and expert mode.

[0472] [Physical Properties 4]

[0473] (The height of the raised area formed by laser marking)

[0474] Using a laser microscope (measurement unit: VK-X210, controller: VK-X200) manufactured by Keyence Corporation, with objective magnification of 20x and expert mode, the average height of the laser-marked part and its vicinity on each molded product was measured by average height difference measurement.

[0475] [Rating 1]

[0476] (Glossiness)

[0477] The gloss level (%) at 60 degrees was measured on the central part of each molded part (the part not marked by laser marking) according to JIS-K7150 using a gloss meter (HORIBA, IG320). The higher the measured value, the better the gloss. A measured value of 55% or higher was considered to have good gloss.

[0478] [Rating 2]

[0479] (Color difference)

[0480] For each molded product, the colorimetric values ​​of the laser-marked areas and the nearby unmarked areas (unprocessed areas) were measured using a colorimeter SC-50μ manufactured by Suga Testing Machine Co., Ltd. under D65 light and 10° conditions. The color difference ΔE* between the laser-marked areas and the nearby unmarked areas (unprocessed areas) was calculated. The larger the color difference ΔE*, the better the clarity of the laser-marked area. A color difference ΔE* of 35 or higher was considered to indicate good clarity of the laser-marked area.

[0481] <Manufacturing of Molded Products>

[0482] [Examples 1-17 and Comparative Examples 1-2]

[0483] For the granules of each resin composition obtained in Manufacturing Examples 1 to 18, an injection molding machine [IS150E: manufactured by Toshiba Machine Co., Ltd.] was used. The cooling time was set to 25 seconds, the screw speed was set to 200 rpm, the barrel temperature was set to 290°C, and the mold temperature was set to 80°C. The injection pressure and injection speed were appropriately adjusted so that the filling time was within the range of 1.0 seconds ± 0.1 seconds. Flat sheets (9cm × 6cm, 2mm thick) were made from the granules of each resin composition.

[0484] For the resin composition particles obtained in Manufacturing Example 19, an injection molding machine [IS150E: manufactured by Toshiba Machine Co., Ltd.] was used. The cooling time was set to 25 seconds, the screw speed was set to 200 rpm, the barrel temperature was set to 265°C, and the mold temperature was set to 80°C. The injection pressure and injection speed were appropriately adjusted so that the filling time was within the range of 1.0 seconds ± 0.1 seconds. Flat sheet (9cm × 6cm, thickness 2mm) was made from the resin composition particles.

[0485] Next, each of the obtained flat molded sheets was marked with a 3mm × 3mm square using a Keyence MD-V9920 or MD-S9910 laser marking machine, thereby obtaining each molded product. The laser marking conditions were set to 1064nm (Examples 1-15 and Comparative Examples 1-2) or 532nm (Examples 16-17), the scanning speed was set to 2000mm / sec (Examples 1-15 and Comparative Examples 1-2) or 1000mm / sec (Examples 16-17), and the output power was set to 7.8W or 9.1W.

[0486] For each molded product, the results of the physical property determination and evaluation obtained by the above method are shown in Tables 4 to 6.

[0487] [Table 4]

[0488]

[0489] [Table 5]

[0490]

[0491] [Table 6]

[0492]

[0493] As shown in Tables 4 to 6, the molded articles M-a1 to M-a17 (Examples 1 to 17) with an Sdr of 0.12 or higher and 0.68 or lower and a raised height of 6.6 μm or higher and 42.8 μm or lower have good gloss and clarity of the marked parts formed by laser marking.

[0494] On the other hand, although the molded product M-b1 (Comparative Example 1), with an Sdr of less than 0.10 for the marked portion, had good gloss, the clarity of the marked portion formed by laser marking was poor. Similarly, although the molded product M-b2 (Comparative Example 2), with an Sdr of less than 0.10 for the marked portion and a raised height of less than 6.6 μm for the marked portion, also had good gloss, the clarity of the marked portion formed by laser marking was poor.

[0495] Therefore, it can be seen that the markings formed by laser marking on molded products with Sdr and bulge height within a specific numerical range have excellent clarity.

[0496] Industrial practicality

[0497] According to the molded article and manufacturing method of this embodiment, it is possible to obtain a molded article with clear markings formed by laser marking. The molded article of this embodiment can be appropriately used in, for example, the automotive industry, the electrical and electronic industry, the machinery and industrial industry, the office equipment industry, and the aerospace industry.

Claims

1. A molded article obtained by molding a resin composition containing a thermoplastic resin (A), wherein, The molded article has a foam identification part. The unfolded area ratio (Sdr) of the interface of the foaming identification part, as specified by ISO 25178, is 0.10 or higher and 1.00 or lower. The height of the foam recognition part is between 6.6 μm and 100.0 μm. The thermoplastic resin (A) comprises a polyamide resin (A1), wherein the polyamide resin (A1) is a semi-aromatic polyamide (A1-2) containing an aromatic ring in its skeleton; or the polyamide resin (A1) is an alloy of the semi-aromatic polyamide (A1-2) and an aliphatic polyamide (A1-1).

2. The molded article as described in claim 1, wherein, The foaming recognition part is a marking part formed by laser marking.

3. The molded article as described in claim 1, wherein, The unfolded area ratio Sdr of the interface of the foaming identification part as specified by ISO25178 is 0.15 or higher and 0.90 or lower.

4. The molded article as described in claim 1, wherein, The unfolded area ratio Sdr of the interface of the foam identification part as specified by ISO25178 is 0.20 or more and 0.80 or less.

5. The molded article as described in claim 1, wherein, The unfolded area ratio Sdr of the interface of the foam identification part as specified by ISO25178 is 0.30 or more and 0.70 or less.

6. The molded article as claimed in claim 1, wherein, The height of the foam recognition part is 10.0 μm or more and 90.0 μm or less.

7. The molded article as claimed in claim 1, wherein, The height of the foam recognition part is above 14.0 μm and below 80.0 μm.

8. The molded article as claimed in claim 1, wherein, The height of the foam recognition part is 17.0 μm or more and 70.0 μm or less.

9. The molded article as claimed in claim 1, wherein, The content of the semi-aromatic polyamide (A1-2) is 5.0 parts by weight or more and 100.0 parts by weight or less, relative to a total of 100.0 parts by weight of the aliphatic polyamide (A1-1) and the semi-aromatic polyamide (A1-2).

10. The molded article as claimed in claim 1, wherein, The content of the semi-aromatic polyamide (A1-2) is 5.0 parts by weight or more and 95.0 parts by weight or less, relative to a total of 100.0 parts by weight of the aliphatic polyamide (A1-1) and the semi-aromatic polyamide (A1-2).

11. The molded article as claimed in claim 1, wherein, The content of the semi-aromatic polyamide (A1-2) is 10.0 parts by weight or more and 80.0 parts by weight or less, relative to a total of 100.0 parts by weight of the aliphatic polyamide (A1-1) and the semi-aromatic polyamide (A1-2).

12. The molded article as claimed in claim 1, wherein, The content of the semi-aromatic polyamide (A1-2) is 15.0 parts by weight or more and 70.0 parts by weight or less, relative to a total of 100.0 parts by weight of the aliphatic polyamide (A1-1) and the semi-aromatic polyamide (A1-2).

13. The molded article as claimed in claim 1, wherein, The content of aliphatic polyamide (A1-1) is more than 0.0 parts by weight and less than 95.0 parts by weight relative to a total of 100.0 parts by weight of the aliphatic polyamide (A1-1) and the semi-aromatic polyamide (A1-2).

14. The molded article as claimed in claim 1, wherein, The content of aliphatic polyamide (A1-1) is 5.0 parts by weight or more and 95.0 parts by weight or less, relative to a total of 100.0 parts by weight of the aliphatic polyamide (A1-1) and the semi-aromatic polyamide (A1-2).

15. The molded article as claimed in claim 1, wherein, The content of aliphatic polyamide (A1-1) is 7.0 parts by weight or more and 80.0 parts by weight or less, relative to a total of 100.0 parts by weight of aliphatic polyamide (A1-1) and semi-aromatic polyamide (A1-2).

16. The molded article as claimed in claim 1, wherein, The content of aliphatic polyamide (A1-1) is 9.0 parts by weight or more and 70.0 parts by weight or less, relative to a total of 100.0 parts by weight of the aliphatic polyamide (A1-1) and the semi-aromatic polyamide (A1-2).

17. The molded article as claimed in claim 1, wherein, The semi-aromatic polyamide (A1-2) contains more than 10 mol% aromatic dicarboxylic acid units relative to 100 mol% of all dicarboxylic acid units.

18. The molded article as claimed in claim 17, wherein, The semi-aromatic polyamide (A1-2) contains more than 30 mol% aromatic dicarboxylic acid units relative to 100 mol% of all dicarboxylic acid units.

19. The molded article as claimed in claim 17, wherein, The semi-aromatic polyamide (A1-2) contains more than 50 mol% aromatic dicarboxylic acid units relative to 100 mol% of all dicarboxylic acid units.

20. The molded article as claimed in claim 17, wherein, The semi-aromatic polyamide (A1-2) contains more than 70 mol% aromatic dicarboxylic acid units relative to 100 mol% of all dicarboxylic acid units.

21. The molded article as claimed in claim 1, wherein, The semi-aromatic polyamide (A1-2) contains more than 10 mol% isophthalic acid units relative to 100 mol% of all dicarboxylic acid units constituting the semi-aromatic polyamide (A1-2).

22. The molded article as claimed in claim 1, wherein, The polyamide resin (A1) is selected from one or more of the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 611, polyamide 612, polyamide 66 / 6I, polyamide 6T, polyamide 6I, polyamide 6I / 6T, polyamide 9T and polyamide MXD6.

23. The molded article as claimed in claim 1, wherein, The aliphatic polyamide (A1-1) is polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 611, polyamide 612, or a copolymer of polyamide 66 / 6. The semi-aromatic polyamide (A1-2) is polyamide 66 / 6I, polyamide 6T, polyamide 6I, polyamide 6I / 6T, polyamide 9T or polyamide MXD6.

24. The molded article as claimed in claim 1, wherein, The aliphatic polyamide (A1-1) is polyamide 66 or a polyamide 66 / 6 copolymer. The semi-aromatic polyamide (A1-2) is polyamide 6I, polyamide 6I / 6T, or polyamide 66 / 6I.

25. The molded article as claimed in claim 1, wherein, The aliphatic polyamide (A1-1) is polyamide 66.

26. The molded article as claimed in claim 1, wherein, The glass transition temperature of the resin composition is above 75°C.

27. The molded article as claimed in claim 26, wherein, The glass transition temperature of the resin composition is above 75°C and below 220°C.

28. The molded article as claimed in claim 26, wherein, The glass transition temperature of the resin composition is above 80°C and below 210°C.

29. The molded article as claimed in claim 26, wherein, The glass transition temperature of the resin composition is above 85°C and below 200°C.

30. The molded article as claimed in claim 26, wherein, The glass transition temperature of the resin composition is above 90°C and below 150°C.

31. The molded article as claimed in claim 1, wherein, The crystallization peak temperature of the resin composition is below 240°C.

32. The molded article as claimed in claim 31, wherein, The crystallization peak temperature of the resin composition is above 120°C and below 235°C.

33. The molded article as claimed in claim 31, wherein, The crystallization peak temperature of the resin composition is above 130°C and below 230°C.

34. The molded article as claimed in claim 31, wherein, The crystallization peak temperature of the resin composition is above 140°C and below 225°C.

35. The molded article as claimed in claim 1, wherein, The resin composition also contains filler (B).

36. The molded article as claimed in claim 35, wherein, The resin composition contains, relative to 100 parts by weight of the thermoplastic resin (A), more than 0 parts by weight and less than or equal to 150.0 parts by weight of the filler (B).

37. The molded article as claimed in claim 35, wherein, The resin composition contains 10.0 parts by weight and 140.0 parts by weight of the filler (B) relative to 100 parts by weight of the thermoplastic resin (A).

38. The molded article as claimed in claim 35, wherein, The resin composition contains 20.0 parts by weight and 135.0 parts by weight of the filler (B) relative to 100 parts by weight of the thermoplastic resin (A).

39. The molded article as claimed in claim 35, wherein, The resin composition contains 25.0 parts by weight and 130.0 parts by weight of the filler (B) relative to 100 parts by weight of the thermoplastic resin (A).

40. The molded article as claimed in claim 35, wherein, The resin composition contains 30.0 parts by weight and 100.0 parts by weight of the filler (B) relative to 100 parts by weight of the thermoplastic resin (A).

41. The molded article as claimed in claim 35, wherein, The filler (B) is selected from one or more of the group consisting of glass fiber, calcium carbonate, talc, mica, wollastonite and ground fiber.

42. The molded article as claimed in claim 1, wherein, The resin composition also contains a flame retardant (C).

43. The molded article as claimed in claim 42, wherein, The flame retardant (C) is selected from one or more of the group consisting of phosphonates and diphosphonates.

44. The molded article as claimed in claim 43, wherein, The phosphonate is a compound represented by the following general formula (I). The secondary phosphonate is a compound represented by the following general formula (II). (In general formula (1), R) 11 and R 12 Each is independently an alkyl group having 1 or more but less than 6 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; M n11+ It is a metal ion with an n11 valence; M is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum; n11 is 2 or 3; multiple Rs exist. 11 and multiple R 12 They can be the same or different. In general formula (2), R 21 and R 22 Each is independently an alkyl group having 1 or more but less than 6 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; Y 21 It is an alkylene group having 1 or more but less than 10 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; M' m21+ M' is a metal ion with a valence of m21; M' is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum; n21 is an integer greater than or equal to 1 and less than or equal to 3; when n21 is 2 or 3, multiple R's exist. 21 Multiple R 22 and multiple Y 21 Each can be the same or different; m21 is 2 or 3; x is 1 or 2; when x is 2, there are multiple M's that can be the same or different; n21, x and m21 are integers that satisfy the relation 2 × n21 = m21 × x).

45. The molded article as claimed in claim 43, wherein, The flame retardant (C) is selected from calcium dimethyl phosphine, magnesium dimethyl phosphine, aluminum dimethyl phosphine, zinc dimethyl phosphine, calcium ethyl methyl phosphine, magnesium ethyl methyl phosphine, aluminum ethyl methyl phosphine, zinc ethyl methyl phosphine, calcium diethyl phosphine, magnesium diethyl phosphine, aluminum diethyl phosphine, zinc diethyl phosphine, calcium methyl propyl phosphine, magnesium methyl propyl phosphine, aluminum methyl propyl phosphine, zinc methyl propyl phosphine, calcium methyl phenyl phosphine, magnesium methyl phenyl phosphine, etc. One or more of the group consisting of aluminum diphenylphosphine, zinc diphenylphosphine, calcium diphenylphosphine, magnesium diphenylphosphine, aluminum diphenylphosphine, zinc diphenylphosphine, calcium dimethylphosphine, magnesium dimethylphosphine, aluminum dimethylphosphine, zinc dimethylphosphine, calcium phenyl-1,4-dimethylphosphine, magnesium phenyl-1,4-dimethylphosphine, aluminum phenyl-1,4-dimethylphosphine, and zinc phenyl-1,4-dimethylphosphine.

46. ​​The molded article as claimed in claim 42, wherein, The flame retardant (C) is aluminum diethylphosphinate.

47. The molded article as claimed in claim 42, wherein, The content of the flame retardant (C) is 5.0 parts by weight or more and 90.0 parts by weight or less relative to 100 parts by weight of the thermoplastic resin (A).

48. The molded article as claimed in claim 42, wherein, The content of the flame retardant (C) is 10.0 parts by weight or more and 80.0 parts by weight or less relative to 100 parts by weight of the thermoplastic resin (A).

49. The molded article as claimed in claim 42, wherein, The content of the flame retardant (C) is 15.0 parts by weight or more and 70.0 parts by weight or less relative to 100 parts by weight of the thermoplastic resin (A).

50. The molded article as claimed in claim 42, wherein, The content of the flame retardant (C) is 20.0 parts by weight or more and 60.0 parts by weight or less relative to 100 parts by weight of the thermoplastic resin (A).

51. The molded article as claimed in claim 1, wherein, The resin composition also contains a colorant (D) that is black, gray, or colored.

52. The molded article as claimed in claim 51, wherein, The colorant (D) contains carbon black (D1), and The content of carbon black (D1) is 0.001 parts by mass or more and 5.00 parts by mass or less relative to 100 parts by mass of the thermoplastic resin (A).

53. The molded article as claimed in claim 52, wherein, The content of carbon black (D1) is 0.005 parts by mass and 2.5 parts by mass or less relative to 100 parts by mass of the thermoplastic resin (A).

54. The molded article as claimed in claim 52, wherein, The content of carbon black (D1) is 0.01 parts by mass or more and 1.00 parts by mass or less relative to 100 parts by mass of the thermoplastic resin (A).

55. The molded article as claimed in claim 1, wherein, The resin composition also contains other additives (E) selected from molding modifiers, degradation inhibitors, nucleating agents and heat stabilizers.

56. The molded article as claimed in claim 2, wherein, The color difference ΔE* between the marked portion formed by laser marking and the nearby unmarked portion of the molded article is 35 or more.

57. The molded article as claimed in claim 1, wherein, The molded article is a magnetic switch housing, a circuit breaker housing, or a connector molded article.

58. A method for manufacturing a molded article subjected to laser marking, wherein, The manufacturing method includes a step of laser marking a molded article obtained by molding a resin composition containing thermoplastic resin (A). In the aforementioned process, laser marking is performed such that the unfolded area ratio (Sdr) of the laser-marked portion of the molded article, as specified by ISO 25178, is 0.10 or more and 1.00 or less, and the raised height of the laser-marked portion of the molded article is 6.6 μm or more and 100.0 μm or less. The thermoplastic resin (A) comprises a polyamide resin (A1), wherein the polyamide resin (A1) is a semi-aromatic polyamide (A1-2) containing an aromatic ring in its skeleton; or the polyamide resin (A1) is an alloy of the semi-aromatic polyamide (A1-2) and an aliphatic polyamide (A1-1).

59. The manufacturing method as described in claim 58, wherein, The unfolded area ratio Sdr of the interface specified by ISO 25178 is greater than 0.15 and less than 0.

90.

60. The manufacturing method as described in claim 58, wherein, The unfolded area ratio Sdr of the interface specified by ISO 25178 is greater than 0.20 and less than 0.

80.

61. The manufacturing method as described in claim 58, wherein, The unfolded area ratio Sdr of the interface specified by ISO 25178 is greater than 0.30 and less than 0.

70.

62. The manufacturing method as described in claim 58, wherein, The height of the bulge is above 10.0 μm and below 90.0 μm.

63. The manufacturing method as described in claim 58, wherein, The height of the bulge is above 14.0 μm and below 80.0 μm.

64. The manufacturing method as described in claim 58, wherein, The height of the bulge is above 17.0 μm and below 70.0 μm.

65. The manufacturing method as described in claim 58, wherein, The wavelength of the laser used in the laser marking process is above 193nm and below 1100nm.

66. The manufacturing method as described in claim 65, wherein, The wavelength of the laser used in the laser marking process is above 220nm and below 250nm, above 520nm and below 550nm, or above 900nm and below 1100nm.

67. The manufacturing method as described in claim 65, wherein, The wavelength of the laser used in the laser marking process is above 1050nm and below 1070nm.

68. The manufacturing method as described in claim 58, wherein, The scanning speed of the laser marking is above 10 mm / s and below 5000 mm / s.

69. The manufacturing method as described in claim 68, wherein, The scanning speed of the laser marking is above 100 mm / s and below 4000 mm / s.

70. The manufacturing method as described in claim 68, wherein, The scanning speed of the laser marking is above 500 mm / s and below 2500 mm / s.

71. The manufacturing method as described in claim 58, wherein, The laser marking process output power is above 1.0W and below 30.0W.

72. The manufacturing method as described in claim 71, wherein, The laser marking process output power is above 1.0W and below 20.0W.

73. The manufacturing method as described in claim 71, wherein, The laser marking process output power is above 1.0W and below 15.0W.

74. The manufacturing method as described in claim 58, wherein, The resin composition is the resin composition used in the molded article according to any one of claims 9 to 57.

75. A laser marking method, wherein, The laser marking method includes a step of laser marking a molded article obtained by molding a resin composition containing thermoplastic resin (A). In the laser marking process, laser marking is performed such that the unfolded area ratio (Sdr) of the laser-marked portion of the molded article, as specified in ISO 25178, is 0.10 or higher and 1.00 or lower. The thermoplastic resin (A) comprises a polyamide resin (A1), wherein the polyamide resin (A1) is a semi-aromatic polyamide (A1-2) containing an aromatic ring in its skeleton; or the polyamide resin (A1) is an alloy of the semi-aromatic polyamide (A1-2) and an aliphatic polyamide (A1-1).

76. The laser marking method as described in claim 75, wherein, The unfolded area ratio Sdr of the interface specified by ISO 25178 is greater than 0.15 and less than 0.

90.

77. The laser marking method as described in claim 75, wherein, The unfolded area ratio Sdr of the interface specified by ISO 25178 is greater than 0.20 and less than 0.

80.

78. The laser marking method as described in claim 75, wherein, The unfolded area ratio Sdr of the interface specified by ISO 25178 is greater than 0.30 and less than 0.

70.

79. The laser marking method as described in claim 75, wherein, In the laser marking process, the laser marking is performed such that the raised height of the laser-marked portion of the molded article is 6.6 μm or more and 100.0 μm or less.

80. The laser marking method as described in claim 79, wherein, The height of the bulge is above 10.0 μm and below 90.0 μm.

81. The laser marking method as described in claim 79, wherein, The height of the bulge is above 14.0 μm and below 80.0 μm.

82. The laser marking method as described in claim 79, wherein, The height of the bulge is above 17.0 μm and below 70.0 μm.

83. The laser marking method as described in claim 75, wherein, The wavelength of the laser used in the laser marking process is above 193nm and below 1100nm.

84. The laser marking method as described in claim 83, wherein, The wavelength of the laser used in the laser marking process is above 220nm and below 250nm, above 520nm and below 550nm, or above 900nm and below 1100nm.

85. The laser marking method as described in claim 83, wherein, The wavelength of the laser used in the laser marking process is above 1050nm and below 1070nm.

86. The laser marking method as described in claim 75, wherein, The scanning speed of the laser marking is above 10 mm / s and below 5000 mm / s.

87. The laser marking method as described in claim 86, wherein, The scanning speed of the laser marking is above 100 mm / s and below 4000 mm / s.

88. The laser marking method as described in claim 86, wherein, The scanning speed of the laser marking is above 500 mm / s and below 2500 mm / s.

89. The laser marking method as described in claim 75, wherein, The laser marking process output power is above 1.0W and below 30.0W.

90. The laser marking method as described in claim 89, wherein, The laser marking process output power is above 1.0W and below 20.0W.

91. The laser marking method as described in claim 89, wherein, The laser marking process output power is above 1.0W and below 15.0W.

92. The laser marking method as described in claim 75, wherein, The resin composition is the resin composition used in the molded article according to any one of claims 9 to 57.

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