Resin composition, molded article, kit, and method for manufacturing a molded article

Abstract

To provide a resin composition that can provide a molded article with high light transmittance, superior laser welding strength, and reduced surface irregularities, and a molded article, a kit, and a method for producing a molded article.SOLUTION: A resin composition contains a polyamide resin and also contains a total of 0.01-2.0 pts.mass of 1,2-phenylene benzimidazoperylene compounds relative to 100 pts.mass of the polyamide resin. The polyamide resin includes a xylylene diamine-based polyamide resin that includes diamine-derived constitutional units and dicarboxylic acid-derived constitutional units, wherein at least 70 mol% of the diamine-derived constitutional units are xylylene diamine-derived constitutional units.SELECTED DRAWING: None

Description

Technical Field

[0004] ,

[0001] The present invention relates to a resin composition, a molded product, a kit, and a method for manufacturing a molded product. The resin composition of the present invention is mainly used as a resin composition (light-transmissive resin composition) on the side that transmits light for laser welding.

Background Art

[0002] Polyamide resin, a typical engineering plastic, is easy to process and furthermore has excellent mechanical properties, electrical properties, heat resistance, and other physical and chemical properties. Therefore, it is widely used in vehicle parts, electrical and electronic equipment parts, and other precision equipment parts. Recently, parts with complex shapes have also come to be manufactured with polyamide resin. For example, for the adhesion of parts having a hollow portion such as an intake manifold, various welding techniques such as adhesive welding, vibration welding, ultrasonic welding, hot plate welding, injection welding, and laser welding techniques are used.

[0003] However, welding with an adhesive has problems such as environmental load problems such as pollution of the surroundings in addition to the time loss until curing. Ultrasonic welding, hot plate welding, etc. have been pointed out to have problems such as damage to the product due to vibration and heat, and the need for post-treatment due to the generation of abrasion powder and burrs. In addition, injection welding often requires special molds and molding machines, and furthermore, there are problems such as it cannot be used if the fluidity of the material is not good.

[0004] On the other hand, laser welding is a method of joining two resin members by bringing a resin member that is transparent to (also called non-absorbent or weakly absorbent of) laser light (hereinafter sometimes referred to as a "transparent resin member") into contact with a resin member that is absorbent to laser light (hereinafter sometimes referred to as an "absorbent resin member"). Specifically, it is a method in which laser light is irradiated onto the joining surface from the transparent resin member side, and the absorbing resin member forming the joining surface is melted by the energy of the laser light and joined. Laser welding does not generate wear particles or burrs, causes little damage to the product, and furthermore, since polyamide resin itself is a material with relatively high laser transmittance, the processing of polyamide resin products using laser welding technology has recently attracted attention.

[0005] The above-mentioned transparent resin member is usually molded from a light-transmitting resin composition. As such a light-transmitting resin composition, Patent Document 1 describes a polyamide resin composition containing 25 to 50% by mass of a semi-aromatic polyamide resin, 3 to 20% by mass of a brominated flame retardant, 1.5 to 10% by mass of zinc stagnate, and a light-transmitting dye. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-012093 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As mentioned above, light-transmitting resin compositions containing black dyes in polyamide resins have been investigated. However, such light-transmitting resin compositions may experience color transfer (also known as migration or color transfer) of the black dye depending on the material of the mating or adjacent components. To solve this problem, it is conceivable to use pigments instead of dyes to create light-transmitting resin compositions. However, it has been found that when pigments are incorporated into polyamide resin, the resulting molded products may have reduced light transmittance, surface defects, or reduced welding strength during laser welding. The present invention aims to solve the aforementioned problems and to provide a resin composition capable of producing molded articles with high light transmittance, excellent laser welding strength, and suppressed surface shrinkage, as well as molded articles, kits, methods for manufacturing molded articles, in-vehicle camera components, and in-vehicle cameras. [Means for solving the problem]

[0008] Based on the above problems, the inventors conducted investigations and found that the above problems can be solved by blending a 1,2-phenylenebenzimidazoperylene compound with a predetermined polyamide resin in a predetermined proportion. Specifically, the above problems were solved by the following means. <1> A resin composition comprising a xylylenediamine-based polyamide resin, wherein the polyamide resin contains a total of 0.01 to 2.0 parts by mass of a 1,2-phenylenebenzimidazoperylene compound per 100 parts by mass of polyamide resin, and the polyamide resin contains diamine-derived structural units and dicarboxylic acid-derived structural units, with 70 mol% or more of the diamine-derived structural units being derived from xylylenediamine. <2> In the xylylenediamine-based polyamide resin, 50 to 90 mol% of the diamine-derived structural units are derived from meta-xylylenediamine, and 50 to 10 mol% of the diamine-derived structural units are derived from para-xylylenediamine. <1> The resin composition described above. <3> In the xylylenediamine-based polyamide resin, 70 mol% or more of the dicarboxylic acid-derived constituent units are derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms. <1> or <2> The resin composition described above. <4> In the xylylenediamine-based polyamide resin, 70 mol% or more of the dicarboxylic acid-derived constituent units are derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 20 carbon atoms. <1> or <2> The resin composition described above. <5> In the xylylenediamine-based polyamide resin, 70 mol% or more of the constituent units derived from the dicarboxylic acid are derived from sebaciic acid. <1> or <2> The resin composition described above. <6> Furthermore, the mixture contains 10 to 250 parts by mass of reinforcing filler per 100 parts by mass of polyamide resin. <1> ~ <5> A resin composition as described in any one of the following. <7> The 1,2-phenylenebenzimidazoperylene compound is a mixture of compounds having the following skeleton: <1> ~ <6> A resin composition as described in any one of the following. [ka] <8> Furthermore, it includes at least one of copper iodide, potassium iodide, and cerium oxide. <1> ~ <7> A resin composition as described in any one of the following. <9> Furthermore, it contains green pigment, <1> ~ <8> A resin composition as described in any one of the following. <10> Furthermore, the compound contains 10 to 250 parts by mass of reinforcing filler per 100 parts by mass of polyamide resin, and the 1,2-phenylenebenzimidazoperylene compound is a mixture of compounds having the following skeleton, and further contains a green pigment. <1> ~ <8> A resin composition as described in any one of the following. [ka] <11> Laser welding is used. <1> ~ <10> A resin composition as described in any one of the following. <12> When the resin composition is molded into a test piece with a thickness of 1.5 mm, the light transmittance at a wavelength of 1060 nm is 5.0% or more. <1> ~ <11> A resin composition as described in any one of the following. <13> <1> ~ <12> A molded article formed from any one of the resin compositions described in that one. <14> <1> ~ <12> A kit comprising a resin composition described in any one of the above, and a light-absorbing resin composition comprising a thermoplastic resin and a light-absorbing dye. <15> <1> ~ <12> A method for manufacturing a molded article, comprising laser welding a molded article formed from any one of the resin compositions described in the previous article and a molded article formed from a light-absorbing resin composition containing a thermoplastic resin and a light-absorbing dye. <16> <1> ~ <12> An in-vehicle camera component formed from any one of the resin compositions described in that statement. <17> <16> Automotive cameras, including the automotive camera components listed above. [Effects of the Invention]

[0009] The present invention provides a resin composition capable of producing molded articles with high light transmittance, excellent laser welding strength, and suppressed surface shrinkage, as well as molded articles, kits, methods for manufacturing molded articles, automotive camera components, and automotive cameras. [Modes for carrying out the invention]

[0010] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). Note that the following embodiment is illustrative for explaining the present invention, and the present invention is not limited to this embodiment. In this specification, "~" is used to mean that the numbers before and after it are included as the lower and upper limits, respectively. In this specification, all physical properties and characteristic values ​​shall be those at 23°C unless otherwise specified. In this specification, the number-average molecular weight can be measured in accordance with the description in paragraph 0047 of Japanese Patent Application Publication No. 2018-165298, which is incorporated herein by reference. In this specification, the melting point (Tm) shall be the value measured according to differential scanning calorimetry (DSC) in accordance with ISO 11357. Specifically, it may be measured according to paragraph 0036 of International Publication No. 2016 / 084475, which is incorporated herein by reference. If the measurement methods, etc., described in the standards shown herein differ from year to year, unless otherwise specified, the standards as of January 1, 2022 shall apply.

[0011] The resin composition of this embodiment contains a total of 0.01 to 2.0 parts by mass of 1,2-phenylenebenzimidoperylene compound with respect to 100 parts by mass of the polyamide resin. The polyamide resin contains a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, and 70 mol% or more of the structural unit derived from diamine is a structural unit derived from xylylenediamine, and the resin composition contains a xylylenediamine-based polyamide resin. By adopting such a configuration, it is possible to provide a resin composition capable of providing a molded product with high light transmittance, excellent laser welding strength, and suppressed surface sink marks, as well as a molded product, a kit, a method for manufacturing a molded product, in-vehicle camera parts, and an in-vehicle camera. When the inventor conducted studies, it was found that when a 1,2-phenylenebenzimidoperylene compound is blended as a pigment in a polyamide resin, a higher transmittance can be achieved compared to the case of using a similar naphthalenebenzimidoperylene. However, when the inventor conducted more detailed studies, it was found that when the blending amount of the 1,2-phenylenebenzimidoperylene compound is increased, the welding strength deteriorates. In addition, it was found that when the 1,2-phenylenebenzimidoperylene compound is blended, sink marks may occur on the surface of the obtained molded product. In the present invention, by using a predetermined polyamide resin, it has been successful in achieving high laser transmittance, high welding strength, and suppressing the occurrence of sink marks on the surface of the molded product.

[0012] <Polyamide resin> The resin composition of this embodiment contains a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, and contains a xylylenediamine-based polyamide resin in which 70 mol% or more of the structural unit derived from diamine is a structural unit derived from xylylenediamine. By including such a polyamide resin, even when the content of the 1,2-phenylenebenzimidoperylene compound is reduced, it has been successful in increasing the welding strength and suppressing the occurrence of sink marks on the surface of the molded product.

[0013] The constituent units derived from diamine of the xylylenediamine-based polyamide resin are more preferably 75 mol% or more, still more preferably 80 mol% or more, even more preferably 90 mol% or more, yet even more preferably 95 mol% or more, and particularly even more preferably 99 mol% or more, and are derived from xylylenediamine (preferably p-xylylenediamine and / or m-xylylenediamine).

[0014] Xylylenediamine is preferably p-xylylenediamine and m-xylylenediamine. More specifically, it is preferable that 50 to 90 mol% of the constituent units derived from diamine are the constituent units derived from m-xylylenediamine, and 50 to 10 mol% of the constituent units derived from diamine are the constituent units derived from p-xylylenediamine. More preferably, 60 to 80 mol% of the constituent units derived from diamine are the constituent units derived from m-xylylenediamine, and 40 to 20 mol% of the constituent units derived from diamine are the constituent units derived from p-xylylenediamine. For the xylylenediamine-based polyamide resin, the total of the constituent units derived from p-xylylenediamine and the constituent units derived from m-xylylenediamine preferably accounts for 80 mol% or more, more preferably 85 mol% or more, still more preferably 90 mol% or more, even more preferably 95 mol% or more, yet even more preferably 98 mol% or more, and even more preferably 99 mol% or more of the constituent units derived from diamine. The upper limit of the total of the constituent units derived from p-xylylenediamine and the constituent units derived from m-xylylenediamine is 100 mol%.

[0015] Diamines other than meta-xylylenediamine and para-xylylenediamine that can be used as raw material diamine components for xylylenediamine-based polyamide resins include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine, as well as 1,3-bis( Examples include alicyclic diamines such as aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane, as well as aromatic ring-containing diamines such as bis(4-aminophenyl) ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. One or more of these can be used in combination.

[0016] On the other hand, of the xylylenediamine-based polyamide resin, the dicarboxylic acid-derived constituent units are preferably 70 mol% or more, more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and especially most preferably 99 mol% or more, derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms (preferably α,ω-linear aliphatic dicarboxylic acids having 9 to 20 carbon atoms, more preferably α,ω-linear aliphatic dicarboxylic acids having 9 to 14 carbon atoms, and even more preferably sebacic acid).

[0017] Preferred α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms for use as raw material dicarboxylic acid components in xylylenediamine-based polyamide resins include, for example, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanediic acid, and dodecanediic acid. One or more of these can be used in combination, but among these, adipic acid or sebacic acid is more preferred, and sebacic acid is even more preferred, as these allow the melting point of the polyamide resin to fall within a suitable range for molding. As a preferred embodiment of the xylylenediamine-based polyamide resin in this embodiment, an example is one in which 50 mol% or more (preferably 70 mol% or more, more preferably 90 mol% or more) of the constituent units derived from dicarboxylic acid are derived from sebacic acid.

[0018] Examples of dicarboxylic acid components other than the above-mentioned α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms include phthalate compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. One or more of these can be used in combination.

[0019] It should be noted that while xylylenediamine-based polyamide resins are mainly composed of diamine-derived and dicarboxylic acid-derived structural units, they do not completely exclude other structural units, and may also contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, "main component" refers to the structural unit in the xylylenediamine-based polyamide resin in which the total number of diamine-derived and dicarboxylic acid-derived structural units is the largest among all structural units. In this embodiment, it is preferable that the total of diamine-derived and dicarboxylic acid-derived structural units in the xylylenediamine-based polyamide resin accounts for 90% by mass or more of the total structural units, more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0020] The melting point of the xylylenediamine-based polyamide resin is preferably 150 to 350°C, more preferably 180 to 330°C, even more preferably 200 to 330°C, and even more preferably 200 to 320°C. The melting point is measured according to the method described in the examples below.

[0021] The xylylenediamine-based polyamide resin preferably has a lower limit of number average molecular weight (Mn) of 6,000 or more, more preferably 8,000 or more, even more preferably 10,000 or more, and also preferably 35,000 or less, more preferably 30,000 or less, even more preferably 25,000 or less, and even more preferably 20,000 or less. Within this range, heat resistance, elastic modulus, dimensional stability, and moldability are improved.

[0022] The content of xylylenediamine-based polyamide resin in the resin composition of this embodiment is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, even more preferably 50% by mass or more, and even more preferably 55% by mass or more. Setting it above the lower limit tends to increase the filler content such as glass fibers, making it easier to obtain high physical properties in terms of rigidity and strength. Furthermore, the content of xylylenediamine-based polyamide resin in the resin composition of this embodiment is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less, even more preferably 80% by mass or less, and even more preferably 75% by mass or less. Setting it below the upper limit tends to make it easier to adjust the fluidity balance by suppressing the reinforcing filler content to some extent. The resin composition of this embodiment may contain only one type of xylylenediamine-based polyamide resin, or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range. Furthermore, in the resin composition of this embodiment, it is preferable that the total of the polyamide resin and reinforcing filler accounts for 95% by mass or more of the resin composition, more preferably 96% by mass or more, even more preferably 97% by mass or more, and even more preferably 98% by mass or more.

[0023] The resin composition of this embodiment may contain other polyamide resins without departing from the spirit of the present invention. Other polyamide resins are not specifically defined, and any known polyamide resin can be used. The polyamide resin may be an aliphatic polyamide resin or a semi-aromatic polyamide resin. Examples of aliphatic polyamide resins include polyamide 4, polyamide 46, polyamide 6, polyamide 66, polyamide 666, polyamide 610, polyamide 11, and polyamide 12. Examples of semi-aromatic polyamide resins include terephthalic acid-based polyamide resins (polyamide 6T, polyamide 9T). If these other polyamide resins are included, they are preferably present in a proportion of 0.1 to 10% by mass of the resin composition.

[0024] <1,2-Phenylenebenzimidazoperylene compound> The resin composition of this embodiment contains a 1,2-phenylenebenzimidazoperylene compound. By including the 1,2-phenylenebenzimidazoperylene compound, a molded article that is colored and transmits light for laser welding can be obtained. Furthermore, even when a pigment is used in combination, a molded article that transmits light for laser welding can be obtained. The term 1,2-phenylenebenzimidazoperylene compound means a compound having a 1,2-phenylenebenzimidazoperylene skeleton, and may have substituents to the extent that it does not depart from the spirit of this embodiment. In this embodiment, the 1,2-phenylenebenzimidazoperylene compound is preferably a mixture of compounds having the following skeletons. [ka] The 1,2-phenylenebenzimidazoperylene compound is preferably 1,2-phenylenebenzimidazoperylene, and more preferably a mixture of the cis and trans isomers of the 1,2-phenylenebenzimidazoperylene compound.

[0025] The content of the 1,2-phenylenebenzimidazoperylene compound in the resin composition of this embodiment is 0.01 parts by mass or more, preferably 0.02 parts by mass or more, more preferably 0.03 parts by mass or more, and even more preferably 0.04 parts by mass or more, per 100 parts by mass of polyamide resin. By setting it above the lower limit, the transmittance can be improved while maintaining the black color of the resulting molded product. Furthermore, the upper limit of the content of the 1,2-phenylenebenzimidazoperylene compound is 2.0 parts by mass or less, preferably 1.5 parts by mass or less, more preferably 1.0 part by mass or less, even more preferably 0.7 parts by mass or less, even more preferably 0.5 parts by mass or less, even more preferably 0.3 parts by mass or less, and may also be less than 0.2 parts by mass, less than 0.15 parts by mass, less than 0.10 parts by mass, 0.08 parts by mass or less, or 0.07 parts by mass or less, per 100 parts by mass of polyamide resin. By setting the value below the aforementioned upper limit, laser transmittance improves, and laser welding performance tends to improve further. The resin composition of this embodiment may contain only one 1,2-phenylenebenzimidazoperylene compound, or it may contain two or more. When it contains two or more, it is preferable that the total amount is within the above range.

[0026] <Other pigments> The resin composition of this embodiment may also contain pigments other than 1,2-phenylenebenzimidazoperylene compounds, particularly green pigments. While there are no specific requirements regarding the type of green pigment, examples include phthalocyanine pigments and perylene pigments, with phthalocyanine pigments being preferred and copper phthalocyanine pigments being more preferred.

[0027] The content of the green pigment in the resin composition of this embodiment is preferably 0.01% by mass or more, preferably 0.3% by mass or less, and preferably 0.2% by mass or less. The present invention is extremely beneficial in that by incorporating such a small amount of green pigment, it is possible to enhance the appearance (blackness) of the resulting molded product while suppressing a decrease in light transmittance. The resin composition of this embodiment may contain only one type of green pigment, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0028] <Pigment content> Next, the pigment content in the resin composition of this embodiment will be described. In this embodiment, it is preferable that the total amount of pigment (1,2-phenylenebenzimidazoperylene compound, green pigment, and other pigments) is 0.1 to 5.0 parts by mass per 100 parts by mass of polyamide resin. The total amount of the pigment is preferably 4.0 parts by mass or less, more preferably 3.0 parts by mass or less, even more preferably 2.0 parts by mass or less, even more preferably 1.0 part by mass or less, even more preferably 0.8 parts by mass or less, even more preferably 0.6 parts by mass or less, especially more preferably 0.4 parts by mass or less, and even more especially preferably 0.3 parts by mass or less, based on 100 parts by mass of polyamide resin. By keeping the amount below the upper limit, the light transmittance of the resulting molded product tends to be higher. In the resin composition of this embodiment, the mass ratio of the 1,2-phenylenebenzimidazoperylene compound to the green pigment is preferably 1:0.1 to 5.0 when the green pigment is included. By using 0.1 or more of the green pigment relative to 1,2-phenylenebenzimidazoperylene compound, the light transmittance in the range of irradiated laser light wavelengths (for example, wavelengths of 900 nm to 1100 nm) tends to be further improved. Furthermore, by using 5.0 or less of the green pigment relative to 1,2-phenylenebenzimidazoperylene compound, a color close to black is tend to be obtained visually. The mass ratio of the 1,2-phenylenebenzimidazoperylene compound to the green pigment is more preferably 0.2 or more, more preferably 4.5 or less, even more preferably 4.0 or less, and even more preferably 3.5 or less, relative to 1,2-phenylenebenzimidazoperylene compound.

[0029] Furthermore, in this embodiment, it is preferable that the mixture is substantially free of pigments other than the 1,2-phenylenebenzimidazoperylene compound and the green pigment. Substantially free means that the amount of the 2-phenylenebenzimidazoperylene compound and the green pigment relative to the total amount of pigments is 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.1% by mass or less, and even more preferably 0.01% by mass or less. Furthermore, in this embodiment, it is preferable that the colorant is substantially free of colorants other than the 1,2-phenylenebenzimidazoperylene compound and the green pigment. Substantially free means that the amount of colorants other than the 2-phenylenebenzimidazoperylene compound and the green pigment relative to the total amount of colorants is 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.1% by mass or less, and even more preferably 0.01% by mass or less.

[0030] <Reinforcement Filler> The resin composition of this embodiment preferably contains a reinforcing filler in a ratio of 10 to 250 parts by mass per 100 parts by mass of polyamide resin. By including the reinforcing filler in the above ratio, high mechanical strength can be achieved in the resulting molded product. In this embodiment, the reinforcing filler does not include cerium oxide or nucleating agents, which will be described later. The reinforcing filler that can be included in the resin composition of this embodiment is one that has the effect of improving the mechanical properties of the resin composition obtained by compounding it with the resin, and commonly used plastic reinforcing materials can be used. The reinforcing filler may be organic or inorganic, but inorganic is preferred. Preferably, fibrous reinforcing fillers such as glass fibers, carbon fibers, basalt fibers, wollastonite, and potassium titanate fibers can be used. In addition, fillers such as granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organic clay, and glass beads; and flaky reinforcing materials such as glass flakes, mica, and graphite can also be used. Among these, fibrous fillers, especially glass fibers, are preferred in terms of mechanical strength, rigidity, and heat resistance. As for glass fibers, either a round cross-sectional shape or an irregular cross-sectional shape can be used. It is more preferable to use reinforcing fillers that have been surface-treated with a surface treatment agent such as a coupling agent. Glass fibers to which a surface treatment agent has been applied are preferable because they have excellent durability, resistance to humid heat, resistance to hydrolysis, and resistance to thermal shock.

[0031] The glass fibers consist of glass compositions such as A glass, C glass, E glass, S glass, R glass, M glass, and D glass, with E glass (alkali-free glass) being particularly preferred.

[0032] The glass fibers used in the resin composition of this embodiment may be single fibers or multiple single fibers twisted together. The glass fibers can take any form, including single fibers, "glass roving" made by continuously winding multiple single fibers twisted together, "chopped strands" cut to a length of 1 to 10 mm, or "milled fibers" crushed to a length of 10 to 500 μm. Such glass fibers are readily available, commercially sold by Asahi Fiber Glass Co., Ltd. under the product names "Glasslon Chopped Strand" and "Glasslon Milled Fiber," and by Nippon Electric Glass Co., Ltd. under the product name "E Glass Fiber Chopped Strand." Different forms of glass fibers can also be used in combination.

[0033] Furthermore, the glass fibers used in this embodiment may have a circular or non-circular cross-section. By using glass fibers with a non-circular cross-section, warping of the resulting molded product can be suppressed more effectively. In addition, in this embodiment, even if glass fibers with a circular cross-section are used, warping can be effectively suppressed by using a polyamide resin that crystallizes sufficiently even at low mold temperatures.

[0034] The reinforcing filler content in the resin composition of this embodiment is preferably 10 parts by mass or more, more preferably 25 parts by mass or more, and even more preferably 40 parts by mass or more, per 100 parts by mass of polyamide resin. The upper limit is preferably 250 parts by mass or less, and may be 200 parts by mass or less, per 100 parts by mass of polyamide resin. The reinforcing filler content in the resin composition of this embodiment is preferably 20% by mass or more, and more preferably 25% by mass or more. The upper limit is preferably 75% by mass or less, and may be 65% by mass or less, 60% by mass or less, or 55% by mass or less. The resin composition of this embodiment may contain only one type of reinforcing filler, or it may contain two or more types. If it contains two or more types, the total amount will be within the above range. Note that the amount of reinforcing filler in this embodiment includes the amount of sizing agent and surface treatment agent.

[0035] <Copper iodide, potassium iodide, and cerium oxide> The resin composition of this embodiment preferably contains at least one of copper iodide, potassium iodide, and cerium oxide. The inclusion of copper iodide tends to further improve the heat resistance of the resulting molded article. Furthermore, the inclusion of potassium iodide facilitates the formation of complexes in the polyamide resin, thereby more effectively suppressing resin decomposition. Additionally, the inclusion of cerium oxide effectively suppresses color changes due to oxidation, and effectively inhibits color transfer after humid heat tests and hot water tests. In other words, by incorporating these components, it becomes possible to impart performance tailored to the application.

[0036] The proportion of copper iodide in the resin composition of this embodiment is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, preferably 2% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less. The resin composition of this embodiment may contain only one type of copper iodide or two or more types. When two or more types are included, it is preferable that the total amount is within the above range. The proportion of potassium iodide in the resin composition of this embodiment is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, preferably 2% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less. The proportion of cerium oxide in the resin composition of this embodiment is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, preferably 2% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less. The resin composition of this embodiment may contain only one type of cerium oxide or two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0037] <Release agent> The resin composition of this embodiment may contain a mold release agent. Examples of release agents include aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds with a number average molecular weight of 200 to 15,000, polysiloxane-based silicone oils, ketone waxes, and fatty acid amides. Aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, and fatty acid amides are preferred, with salts of aliphatic carboxylic acids and fatty acid amides being more preferred. Details of the release agent can be found in paragraphs 0055 to 0061 of Japanese Patent Publication No. 2018-095706, and these contents are incorporated herein by reference. If the resin composition of this embodiment contains a release agent, its content is preferably 0.05 to 3% by mass, more preferably 0.1 to 1% by mass, and even more preferably 0.2 to 0.8% by mass. The resin composition of this embodiment may contain only one type of release agent, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0038] <Nuclear agent> The resin composition of this embodiment may contain a nucleating agent. The nucleating agent is not particularly limited as long as it remains unmelted during the melting process and can act as a nucleus for crystals during the cooling process, but talc and calcium carbonate are preferred, with talc being more preferred. The number-average particle diameter of the nucleating agent is preferably 0.1 μm or more at the lower limit, more preferably 1 μm or more, and even more preferably 3 μm or more. The number-average particle diameter of the nucleating agent is preferably 40 μm or less at the upper limit, more preferably 30 μm or less, even more preferably 28 μm or less, even more preferably 15 μm or less, and still even more preferably 10 μm or less.

[0039] The proportion of the nucleating agent in the resin composition of this embodiment is preferably 0.01 to 1% by mass, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or less. The resin composition of this embodiment may contain only one nucleating agent or two or more. When two or more are included, it is preferable that the total amount is within the above range.

[0040] <Other ingredients> The resin composition of this embodiment may contain other components without departing from the spirit of the present invention. Examples of such additives include light stabilizers, antioxidants, ultraviolet absorbers, fluorescent whitening agents, anti-dripping agents, antistatic agents, anti-fogging agents, anti-blocking agents, flow improvers, plasticizers, dispersants, antibacterial agents, and flame retardants. Furthermore, the resin composition of this embodiment may contain copper compounds other than copper iodide, alkali metal halides other than potassium iodide, etc. These components may be used individually or in combination of two or more. In this embodiment, the resin composition is prepared such that the total amount of each component is 100% by mass, by adjusting the content of polyamide resin, 1,2-phenylenebenzimidazoperylene compound, reinforcing filler, at least one of copper iodide, potassium iodide, and cerium oxide, as well as a green pigment and other additives. In this embodiment, an example is given in which the total amount of xylylenediamine-based polyamide resin, 1,2-phenylenebenzimidazoperylene compound, reinforcing filler, copper iodide, potassium iodide, and release agent accounts for 99% by mass or more of the resin composition. In this embodiment, another example is given in which the total amount of xylylenediamine-based polyamide resin, 1,2-phenylenebenzimidazoperylene compound, reinforcing filler, green pigment, copper iodide, potassium iodide, and release agent accounts for 99% by mass or more of the resin composition.

[0041] <Physical properties of resin compositions> The resin composition of this embodiment preferably has a high light transmittance at a wavelength of 1060 nm. For example, when the resin composition of this embodiment is molded into a test piece with a thickness of 1.5 mm, the light transmittance at a wavelength of 1060 nm is preferably 5.0% or more, more preferably 8.0% or more, and even more preferably 10.0% or more. The upper limit of the light transmittance at a wavelength of 1060 nm of the 1.5 mm thick test piece may be, for example, 90% or less, or 70% or less. Such high light transmittance is achieved by incorporating a 1,2-phenylenebenzimidazoperylene compound, and furthermore, by using a green pigment in combination.

[0042] <Method for producing resin compositions> The method for producing the resin composition of this embodiment is not particularly limited, but a method using a single-screw or twin-screw extruder equipped with a vent for evaporation is preferred. The xylylenediamine-based polyamide resin, the 1,2-phenylenebenzimidazoperylene compound, and other additives as needed may be supplied to the kneader all at once, or the polyamide resin component may be supplied first, followed by the other additives sequentially. The reinforcing filler is preferably supplied partway through the extruder process to suppress crushing during kneading. Alternatively, two or more components selected from each component may be pre-mixed and kneaded. In this embodiment, the pigment may be a polyamide resin or the like, which may be prepared in advance as a masterbatch and then kneaded with other components to obtain the resin composition of this embodiment.

[0043] The method for manufacturing molded articles using the resin composition of this embodiment is not particularly limited, and molding methods commonly used for thermoplastic resins, such as injection molding, hollow molding, extrusion molding, and press molding, can be applied. In this case, injection molding is a particularly preferred molding method due to its good fluidity. When performing injection molding, it is preferable to control the resin temperature to 250 to 310°C.

[0044] <Kit> The resin composition of this embodiment and the light-absorbing resin composition containing a thermoplastic resin and a light-absorbing dye are preferably used as a kit for manufacturing molded products by laser welding. In other words, the resin composition of this embodiment included in the kit acts as a light-transmitting resin composition, and a molded product formed from such a light-transmitting resin composition becomes a resin component that transmits laser light during laser welding. On the other hand, a molded product formed from a light-absorbing resin composition becomes a resin component that absorbs laser light during laser welding.

[0045] <<Light-absorbing resin composition>> The light-absorbing resin composition used in this embodiment comprises a thermoplastic resin and a light-absorbing dye. It may also contain other components such as reinforcing fillers. Examples of thermoplastic resins include polyamide resins, olefin resins, vinyl resins, styrene resins, acrylic resins, polyphenylene ether resins, polyester resins, polycarbonate resins, and polyacetal resins. Polyamide resins, polyester resins, and polycarbonate resins are particularly preferred due to their good compatibility with the light-transmitting resin composition (the resin composition of this embodiment), and polyamide resins are even more preferred. Furthermore, there may be one thermoplastic resin or two or more types. While there is no specific type of polyamide resin to be used in the light-absorbing resin composition, the xylylenediamine-based polyamide resin described above is preferred. Examples of reinforcing fillers include laser-absorbing fillers such as glass fibers, carbon fibers, silica, alumina, carbon black, and inorganic powders coated with laser-absorbing materials, with glass fibers being preferred. Glass fibers are synonymous with glass fibers that may be incorporated into the resin composition of this embodiment. The content of the reinforcing filler is preferably 20 to 70% by mass, more preferably 25 to 60% by mass, and even more preferably 30 to 55% by mass. The light-absorbing dyes include dyes having absorption wavelengths in the range of the irradiated laser light wavelength, for example, in this embodiment, in the range of 900 nm to 1100 nm. Furthermore, the light-absorbing dyes include, for example, dyes that, when blended in an amount of 0.3 parts by mass per 100 parts by mass of xylylenediamine-based polyamide resin and measured using the measurement method described in the examples below, have a transmittance of less than 30%, and even less than 10%. Specific examples of light-absorbing dyes include inorganic pigments (black pigments such as carbon black (e.g., acetylene black, lamp black, thermal black, furnace black, channel black, Ketjen black, etc.), red pigments such as iron oxide red, orange pigments such as molybdate orange, and white pigments such as titanium dioxide), and organic pigments (yellow pigments, orange pigments, red pigments, blue pigments, green pigments, etc.). Among these, inorganic pigments are generally preferred due to their strong opacity, and black pigments are even more preferred. Two or more of these light-absorbing dyes may be used in combination. The content of the light-absorbing dye is preferably 0.01 to 30 parts by mass per 100 parts by mass of xylylenediamine-based polyamide resin.

[0046] In the above kit, it is preferable that 80% or more of the components excluding the light-transmitting dye and reinforcing filler in the resin composition and the components excluding the light-absorbing dye and reinforcing filler in the light-absorbing resin composition are common, more preferably 90% or more by mass, and even more preferably 95-100% by mass.

[0047] <<Laser welding method>> Next, the laser welding method will be described. In this embodiment, a molded product (laser-welded body) can be manufactured by laser welding a molded product (transparent resin member) formed from the resin composition of this embodiment and a molded product (absorbing resin member) formed from the above-mentioned light-absorbing resin composition. By laser welding, the transparent resin member and the absorbing resin member can be firmly welded together without the use of adhesive. The shape of the components is not particularly limited, but since the components are joined together by laser welding, they typically have a shape that includes at least surface contact points (flat or curved surfaces). In laser welding, the laser light that passes through the transparent resin component is absorbed by the absorbent resin component, melts, and the two components are welded together. The molded product formed from the resin composition of this embodiment has high transmittance to laser light and can therefore be preferably used as a transparent resin component. Here, the thickness of the component through which the laser light passes (the thickness in the laser transmission direction in the portion through which the laser light passes) can be appropriately determined considering the application, the composition of the resin composition, and other factors, but for example, it is 5 mm or less, and preferably 4 mm or less.

[0048] The laser light source used for laser welding can be determined according to the transmission wavelength of the light-transmitting dye, and a laser in the wavelength range of 900 to 1100 nm is preferred. For example, a semiconductor laser or a fiber laser can be used.

[0049] More specifically, for example, when welding a transparent resin member and an absorbent resin member, first, the areas to be welded are brought into contact with each other. At this time, surface contact is desirable for the welding areas, and this can be flat surfaces, curved surfaces, or a combination of flat and curved surfaces. Next, a laser beam is irradiated from the transparent resin member side. At this time, if necessary, a lens may be used to focus the laser beam at the interface between the two. The focused beam passes through the transparent resin member and is absorbed near the surface of the absorbent resin member, generating heat and melting it. Next, this heat is transferred to the transparent resin member by thermal conduction, causing it to melt as well, forming a molten pool at the interface between the two, and after cooling, the two are joined together. Molded products formed by welding a permeable resin member and an absorbent resin member in this manner have high welding strength. In this embodiment, the term "molded product" includes not only finished products and parts, but also components that make up a part of them.

[0050] The molded product obtained by laser welding in this embodiment can be applied to various uses, for example, various storage containers, electrical and electronic equipment parts, office automation (OA) equipment parts, household appliance parts, mechanical mechanism parts, vehicle mechanism parts, and the like. In particular, it can be suitably used for food containers, medicine containers, oil and fat product containers, vehicle hollow parts (various tanks, intake manifold parts, camera housings, etc.), vehicle electrical parts (various control units, ignition coil parts, etc.), motor parts, various sensor parts, connector parts, switch parts, breaker parts, relay parts, coil parts, transformer parts, lamp parts, and the like. In particular, the in-vehicle camera parts formed from the resin composition or kit of this embodiment are suitable for in-vehicle cameras.

Examples

[0051] The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not depart from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. When the measuring instruments and the like used in the examples are difficult to obtain due to obsolescence or the like, measurements can be made using other devices having equivalent performance.

[0052] <Polyamide resin> MP10: The molar ratio of meta-xylylenediamine / para-xylylenediamine (M / P) = 7:3, and it was synthesized according to the following synthesis example. <<Synthesis example of MP10 (M / P molar ratio = 7:3)>> Sebacic acid was heated and dissolved in a reaction vessel under a nitrogen atmosphere, and then, while stirring the contents, a mixed diamine with a molar ratio of para-xylylenediamine (manufactured by Mitsubishi Gas Chemical Company) and meta-xylylenediamine (manufactured by Mitsubishi Gas Chemical Company) of 3:7 was gradually dropped under pressure (0.35 MPa) so that the molar ratio of diamine to sebacic acid became about 1:1, and the temperature was raised to 235°C. After the dropping was completed, the reaction was continued for 60 minutes to adjust the amount of components having a molecular weight of 1,000 or less. After the reaction was completed, the contents were taken out in a strand shape and pelletized with a pelletizer to obtain a polyamide resin (MP10).

[0053] PA66: Polyamide 66, Invista, Part Number U4800 PA6: Polyamide 6, UBE Corporation, Part Number 1013B

[0054] <Talc> #5000S: Manufactured by Hayashi Chemical Co., Ltd., Micron White <Yokadaiichido (CuI)> Cuprous iodide, manufactured by Nippon Chemical Industries, Ltd. <Potassium iodide> Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. <Release agent> (1) Zinc(II) stearate: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. (2) WH255: Light amide WH-255: Manufactured by Kyoeisha Chemical Co., Ltd., high-grade fatty acid amide

[0055] <Reinforcement Filler> ECS03T-756H: Manufactured by Nippon Electric Glass Co., Ltd., glass fiber

[0056] <Pigments> Spectrasence Black K0087: Manufacturer: Color & Effect Japan Co., Ltd., perylene pigment, mixture of the following compounds [ka] Heliogen Green K8730 (Green): Manufacturer: Color & Effect Japan Co., Ltd., Copper Phthalocyanine Pigment Spectrasence Black K0088: Manufacturer: Color & Effect Japan Co., Ltd., Perylene pigment, 1,8-Naphthylenebenzimidazoperylene, Cistrans mixture

[0057] Examples 1-4, Comparative Examples 1-5 <Compound> To obtain the composition shown in Table 1 or Table 2 below (each component in Tables 1 and 2 is expressed in parts by mass), all components except glass fiber were weighed, dry-blended, and then fed into a twin-screw extruder (Shibaura Machine Co., Ltd., TEM26SS) from the screw root using a twin-screw cassette weighing feeder (Kubota Corporation, CE-W-1-MP). The glass fiber was fed into the twin-screw extruder from the side using a vibrating cassette weighing feeder (Kubota Corporation, CE-V-1B-MP), where it was melt-kneaded with the resin components to obtain resin composition pellets. The extruder temperature was set to 280°C when MP10 was used as the polyamide resin.

[0058] <Light transmittance> The resin composition pellets obtained above were dried at 120°C for 4 hours, and then test specimens for light transmittance measurement (ASTM D638 standard No. 4 dumbbell specimens, 1.5 mm thick) were prepared using an injection molding machine (Japan Steel Works, Ltd., J-50ADS). The cylinder temperature was 260°C and the mold surface temperature was 110°C. Light transmittance was measured on the non-gate side of the above test specimen using a visible-ultraviolet spectrophotometer, and the light transmittance at a wavelength of 1060 nm (unit: %) was measured. A visible / ultraviolet spectrophotometer, specifically the LMT F1LC PA manufactured by Tsubosaka Electric, was used.

[0059] <Presence or absence of surface sink marks> The resin composition pellets obtained above were dried at 120°C for 4 hours, and then 1.5 mm thick No. 4 dumbbell pieces (permeable resin components) conforming to ASTM D638 standard were fabricated using an injection molding machine (J-50ADS, manufactured by Japan Steel Works, Ltd.). The cylinder temperature was 260°C and the mold surface temperature was 110°C. Furthermore, for the light-absorbing resin components, the pigments (Spectrasence K0087, Heliogen Green K8730, Spectrasence K0088) were removed from the resin compositions of each example or comparative example, and instead, a carbon black masterbatch was added so that the amount of carbon black was 0.6% by mass relative to the resin composition. The rest of the process was carried out similarly to produce ASTM D638 standard 1.5 mm thick No. 4 dumbbell pieces (light-absorbing resin components). The non-gate sides of the absorbent resin member and the transparent resin member obtained above were overlapped and welded using a diode laser welding machine manufactured by Fine Devices. The welding conditions were: laser output: 30W, number of scans: 5, feed rate: 70 (mm / s), total energy input: 34.3 (J). The presence or absence of sink marks on the surface of the transparent resin member welded under these conditions was checked.

[0060] <Tensile welding strength> The tensile welding strength of welded joints fabricated using an Instron 5544 (load cell 2kN) manufactured by Instron Japan Company Limited was measured, with the presence or absence of surface shrinkage being considered. The tensile test speed was set to 5 mm / min. The unit is indicated in Newtons (N).

[0061] [Table 1]

[0062] [Table 2]

[0063] As is clear from the above results, molded articles formed from the resin composition of the present invention exhibited high light transmittance, high tensile welding strength, and no sink marks were observed on the surface (Examples 1-4). In contrast, even with perylene pigments, when 1,8-naphthylenebenzimidazoperylene was used (Comparative Examples 1 and 4), shrinkage was observed on the surface, and the tensile welding strength was low. Furthermore, even when a 1,2-phenylenebenzimidazoperylene compound was used as a pigment, if the polyamide resin was not a xylylenediamine-based polyamide resin, the light transmittance was low, the tensile welding strength was low, and shrinkage was observed on the surface (Comparative Examples 2, 3, and 4).

Claims

1. The polyamide resin contains a total of 0.01 to 2.0 parts by mass of 1,2-phenylenebenzimidazoperylene compounds per 100 parts by mass of polyamide resin. The polyamide resin includes a xylylenediamine-based polyamide resin in which the polyamide resin contains diamine-derived structural units and dicarboxylic acid-derived structural units, and 70 mol% or more of the diamine-derived structural units are derived from xylylenediamine. The content of the xylylenediamine-based polyamide resin is 30% by mass or more and 95% by mass or less in the resin composition. A resin composition wherein the content of the nucleating agent is 0 or 0.01 to 1% by mass in the resin composition.

2. The resin composition according to claim 1, wherein in the xylylenediamine-based polyamide resin, 50 to 90 mol% of the diamine-derived constituent units are derived from meta-xylylenediamine, and 50 to 10 mol% of the diamine-derived constituent units are derived from para-xylylenediamine.

3. The resin composition according to claim 1 or 2, wherein in the xylylenediamine-based polyamide resin, 70 mol% or more of the constituent units derived from the dicarboxylic acid are constituent units derived from α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms.

4. The resin composition according to claim 1 or 2, wherein in the xylylenediamine-based polyamide resin, 70 mol% or more of the constituent units derived from the dicarboxylic acid are constituent units derived from α,ω-linear aliphatic dicarboxylic acids having 9 to 20 carbon atoms.

5. The resin composition according to claim 1 or 2, wherein in the xylylenediamine-based polyamide resin, 70 mol% or more of the constituent units derived from the dicarboxylic acid are constituent units derived from sebacic acid.

6. Furthermore, the resin composition according to claim 1 or 2, further comprising 10 to 250 parts by mass of a reinforcing filler per 100 parts by mass of polyamide resin.

7. The resin composition according to claim 1 or 2, wherein the 1,2-phenylenebenzimidazoperylene compound is a mixture of compounds having the following skeleton. 【Chemistry 1】

8. Furthermore, the resin composition according to claim 1 or 2 further comprises at least one of copper iodide, potassium iodide, and cerium oxide.

9. Furthermore, the resin composition according to claim 1 or 2, further comprising a green pigment.

10. Furthermore, the material contains 10 to 250 parts by mass of reinforcing filler per 100 parts by mass of polyamide resin. The 1,2-phenylenebenzimidazoperylene compound is a mixture of compounds having the following skeleton: Furthermore, the resin composition according to claim 1 or 2, further comprising a green pigment. 【Chemistry 2】

11. The resin composition according to claim 1 or 2, wherein the application method is laser welding.

12. The resin composition according to claim 1 or 2, wherein when the resin composition is molded into a test piece with a thickness of 1.5 mm, the light transmittance at a wavelength of 1060 nm is 5.0% or more and 90% or less.

13. A molded article formed from the resin composition according to claim 1 or 2.

14. A kit comprising the resin composition according to claim 1 or 2, and a light-absorbing resin composition comprising a thermoplastic resin and a light-absorbing dye.

15. A method for manufacturing a molded article, comprising laser welding a molded article formed from a resin composition according to claim 1 or 2 and a molded article formed from a light-absorbing resin composition containing a thermoplastic resin and a light-absorbing dye.

16. An in-vehicle camera component formed from the resin composition according to claim 1 or 2.

17. An in-vehicle camera including the in-vehicle camera component described in claim 16.

Images