JP7627162B2 - Resin composition, resin molded article, and method for manufacturing plated resin molded article - Google Patents

Description

The present invention relates to a resin composition, a resin molded product, and a method for manufacturing a plated resin molded product.

In recent years, with the development of mobile phones, including smartphones, various methods of manufacturing antennas inside mobile phones have been considered. In particular, there is a demand for a method of manufacturing antennas that can be designed in three dimensions for mobile phones. As one of the techniques for forming such three-dimensional antennas, laser direct structuring (hereinafter sometimes referred to as "LDS") technology has attracted attention. LDS technology is a technology in which, for example, a laser is irradiated onto the surface of a resin molded product containing an LDS additive to activate it, and a metal is applied to the activated part to form plating. A feature of this technology is that it is possible to manufacture metal structures such as antennas directly on the surface of a resin molded product without using adhesives or the like. Such LDS technology is disclosed, for example, in Patent Documents 1 to 3.

JP 2013-144767 A JP 2014-043549 A International Publication No. 2017/102930

Here, as the use of LDS technology spreads, there is also a demand for resin compositions for LDS with low dielectric properties. In order to reduce the dielectric constant of a resin composition, it is possible to alloy a resin with relatively low dielectric properties with a thermoplastic resin. However, the present inventors conducted research and found that in resin compositions containing LDS additives, the relative dielectric constant or dielectric loss tangent may not decrease even if a resin with low dielectric properties is alloyed.
The present invention aims to solve these problems, and to provide a resin composition, a resin molded article, and a method for producing a plated resin molded article, which are capable of forming a plating and providing a low-dielectric resin molded article.

In view of the above-mentioned problems, the present inventors have conducted research and found that the above-mentioned problems can be solved by blending a polyolefin in a specified ratio together with an LDS additive with a specified thermoplastic resin. Specifically, the above-mentioned problems have been solved by the following means.
<1> A low dielectric resin composition for laser direct structuring, comprising a thermoplastic resin, a laser direct structuring additive, and a polyolefin, wherein the thermoplastic resin comprises at least one of a polycarbonate resin, a polyphenylene ether resin, a polyester resin, and a polyamide resin, and the polyolefin is contained in an amount of 4.0 to 30.0 parts by mass per 100 parts by mass of the thermoplastic resin.
<2> The resin composition according to <1>, wherein the thermoplastic resin comprises a polyamide resin.
<3> The resin composition according to <2>, wherein the polyamide resin contains a semi-aromatic polyamide resin.
<4> At least one of the polyamide resins contains a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. The resin composition according to <2>.
<5> The resin composition according to any one of <1> to <4>, wherein the laser direct structuring additive is contained in an amount of 1.0 to 30.0 parts by mass relative to 100 parts by mass of the thermoplastic resin.
<6> The resin composition according to any one of <1> to <5>, wherein the laser direct structuring additive contains at least one of copper, antimony, tin, aluminum, and zinc.
<7> The resin composition according to any one of <1> to <5>, wherein the laser direct structuring additive contains copper chromium copper oxide and/or an oxide containing antimony and tin.
<8> The resin composition according to any one of <1> to <7>, wherein the resistivity of the laser direct structuring additive is more than 5×10 ³ Ω·cm.
<9> The resin composition according to any one of <1> to <8>, wherein the polyolefin includes an acid-modified polyolefin.
<10> The resin composition according to any one of <1> to <9>, wherein the polyolefin includes polyethylene.
<11> The resin composition according to any one of <1> to <10>, further comprising 10.0 to 150.0 parts by mass of inorganic fibers relative to 100 parts by mass of the thermoplastic resin.
<12> The resin composition according to <11>, wherein the inorganic fibers have a relative dielectric constant of 7 or less.
<13> The resin composition according to <11> or <12>, wherein the inorganic fibers include glass fibers.
<14> The resin composition according to <13>, wherein the glass fiber is composed of 65 to 85 mass% SiO ₂ , 15 to 30 mass% B ₂ O ₃ , 0 to 4 mass% sodium oxide (Na ₂ O) and/or potassium oxide (K ₂ O), and 0 to 4 mass% other components.
<15> The resin composition according to any one of <11> to <14>, wherein the inorganic fibers are contained in an amount of 20.0 to 80.0 parts by mass relative to 100 parts by mass of the thermoplastic resin.
<16> The resin composition according to any one of <1> to <15>, further comprising 0.1 to 200.0 parts by mass of talc per 100.0 parts by mass of the laser direct structuring additive.
<17> The resin composition according to any one of <1> to <16>, wherein the resin composition has a relative dielectric constant of 3.60 or less at a frequency of 2.45 GHz.
<18> A resin molded product formed from the resin composition according to any one of <1> to <17>.
<19> The resin molded article according to <18>, wherein the surface of the resin molded article is plated.
<20> The resin molded product according to <19>, wherein the plating has antenna properties.
<21> The resin molded article according to any one of <18> to <20>, which is a part for a portable electronic device.
<22> A method for producing a plated resin molded product, comprising irradiating a surface of a resin molded product formed from the resin composition according to any one of <1> to <17> with a laser, and then applying a metal to form a plating.

The present invention makes it possible to provide a resin composition, a resin molded product, and a method for manufacturing a plated resin molded product that can form plating and provide a low-dielectric resin molded product.

FIG. 2 is a schematic diagram showing a process of plating the surface of a resin molded product.

Hereinafter, an embodiment of the present invention (hereinafter, simply referred to as the present embodiment) will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to the present embodiment.
In this specification, the word "to" is used to mean that the numerical values before and after it are included as the lower limit and upper limit.
In this specification, the number average molecular weight is a polystyrene equivalent value measured by GPC (gel permeation chromatography).
In this specification, various physical properties and characteristic values are those at 23° C. unless otherwise specified.
In cases where the standards shown in this specification differ depending on the year and the measurement methods, etc., they will be based on the standards as of January 1, 2021, unless otherwise specified.

The resin composition of the present embodiment contains a thermoplastic resin, a laser direct structuring additive, and a polyolefin, the thermoplastic resin containing at least one of a polycarbonate resin, a polyphenylene ether resin, a polyester resin, and a polyamide resin, and containing 4.0 to 30.0 parts by mass of the polyolefin per 100 parts by mass of the thermoplastic resin, the resin composition has low dielectric properties, and is used for laser direct structuring.
By blending a polyolefin and an LDS additive with at least one thermoplastic resin selected from the group consisting of polycarbonate resin, polyphenylene ether resin, polyester resin, and polyamide resin, it is possible to lower the dielectric properties of the resin composition while maintaining the plating properties of a resin molded product obtained from the resin composition.
It was thought that the dielectric properties of a resin composition could be lowered by blending a resin with relatively low dielectric properties with a thermoplastic resin. However, for example, when polyphenylene sulfide was blended with a polyamide resin, the dielectric tangent of the resin composition could be slightly lowered, but the relative dielectric constant remained almost unchanged, and plating could not be formed. Then, the inventors conducted research and found that by using a polyolefin as a resin for lowering the dielectric properties of a thermoplastic resin, it was possible to sufficiently lower the dielectric properties while maintaining plating properties.

<Thermoplastic resin>
The resin composition of the present embodiment contains at least one of a polycarbonate resin, a polyphenylene ether resin, a polyester resin, and a polyamide resin as a thermoplastic resin, and preferably contains a polyamide resin. By combining such a thermoplastic resin with a polyolefin, it becomes possible to form a plating on the obtained resin molded product while sufficiently reducing the dielectric properties.

In the present embodiment, a preferred example of the thermoplastic resin contains a polycarbonate resin, and 90% by mass or more (preferably 95% by mass or more) of the resin composition is a polycarbonate resin.
Another preferred example of the thermoplastic resin in the present embodiment is one that contains a polyphenylene ether resin, and 90 mass % or more (preferably 95 mass % or more) of the thermoplastic resin contained in the resin composition is a polyphenylene ether resin.
Another preferred example of the thermoplastic resin in this embodiment is one that contains a polyester resin (preferably, polybutylene terephthalate resin), and 90 mass % or more (preferably 95 mass % or more) of the thermoplastic resin contained in the resin composition is a polyester resin (preferably, polybutylene terephthalate resin).
Another preferred example of the thermoplastic resin in this embodiment is one that contains a polyamide resin (preferably, a xylylenediamine-based polyamide resin described later), and 90 mass % or more (preferably, 95 mass % or more) of the thermoplastic resin contained in the resin composition is a polyamide resin (preferably, a xylylenediamine-based polyamide resin described later).

<<Polycarbonate resin>>
The polycarbonate resin is not particularly limited, and any of aromatic polycarbonate resin, aliphatic polycarbonate resin, and aromatic-aliphatic polycarbonate resin can be used. Among them, aromatic polycarbonate resin is preferable, and further aromatic polycarbonate resin obtained by reacting aromatic dihydroxy compound with phosgene or carbonic acid diester is more preferable, bisphenol A type polycarbonate resin and/or bisphenol C type polycarbonate resin is preferable, and blend of bisphenol A type polycarbonate resin and bisphenol C type polycarbonate resin is more preferable.

Examples of aromatic dihydroxy compounds include 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc., preferably bisphenol A. Furthermore, for the purpose of preparing a resin composition with high flame retardancy, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compounds, or a polymer or oligomer having a siloxane structure and containing phenolic OH groups at both ends, etc. can be used.

There is no particular limitation on the method for producing the polycarbonate resin, and in this embodiment, polycarbonate resin produced by any method, such as the phosgene method (interfacial polymerization method) or the melting method (ester exchange method), can be used. In addition, in this embodiment, polycarbonate resin produced by a process for adjusting the amount of OH groups in the terminal groups after a general melting method production process may be used.

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

The molecular weight of the polycarbonate resin that can be used in this embodiment is preferably 10,000 or more, more preferably 15,000 or more, as calculated from the solution viscosity measured at 25° C. using methylene chloride as a solvent. The viscosity average molecular weight is preferably 32,000 or less, more preferably 28,000 or less. By setting the viscosity average molecular weight to be equal to or more than the lower limit, the mechanical properties of the molded product tend to be improved, and by setting the viscosity average molecular weight to be equal to or less than the upper limit, the processability during injection molding tends to be improved.
Two or more polycarbonate resins having different viscosity average molecular weights may be mixed and used. In this case, polycarbonates having a viscosity average molecular weight outside the above-mentioned preferred range may be mixed.
Here, the viscosity average molecular weight [Mv] means a value calculated from the Schnell viscosity formula, i.e., η = 1.23 × 10 ^-4 Mv ^0.83 , by determining the intrinsic viscosity [η] (unit: dL/g) at 25°C using methylene chloride as a solvent and an Ubbelohde viscometer. The intrinsic viscosity [η] is a value calculated from the specific viscosity [η _sp ] at each solution concentration [C] (g/dL) using the following formula:

For further information regarding the polycarbonate resin used in this embodiment, please refer to, for example, the description in paragraphs 0018 to 0066 of JP 2012-072338 A and the description in paragraphs 0011 to 0018 of JP 2015-166460 A, the contents of which are incorporated herein by reference.

<<Polyphenylene ether resin>>
In this embodiment, a known polyphenylene ether resin can be used, for example, a polymer having a structural unit represented by the following formula in the main chain (preferably a polymer in which the structural unit represented by the following formula accounts for 90 mol % or more of all structural units excluding terminal groups). The polyphenylene ether resin may be either a homopolymer or a copolymer.

（式中、２つのＲ^aは、それぞれ独立に、水素原子、ハロゲン原子、第１級もしくは第２級アルキル基、アリール基、アミノアルキル基、ハロゲン化アルキル基、炭化水素オキシ基、またはハロゲン化炭化水素オキシ基を表し、２つのＲ^bは、それぞれ独立に、水素原子、ハロゲン原子、第１級もしくは第２級アルキル基、アリール基、ハロゲン化アルキル基、炭化水素オキシ基、またはハロゲン化炭化水素オキシ基を表す。ただし、２つのＲ^aがともに水素原子になることはない。）

(In the formula, two R ^a's each independently represent a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, an aminoalkyl group, a halogenated alkyl group, a hydrocarbonoxy group, or a halogenated hydrocarbonoxy group; and two R ^b's each independently represent a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, a halogenated alkyl group, a hydrocarbonoxy group, or a halogenated hydrocarbonoxy group; however, two R ^a's cannot both be hydrogen atoms.)

R ^a and R ^b are each preferably independently a hydrogen atom, a primary or secondary alkyl group, or an aryl group. Suitable examples of the primary alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-amyl group, an isoamyl group, a 2-methylbutyl group, a 2,3-dimethylbutyl group, a 2-, 3-, or 4-methylpentyl group, or a heptyl group. Suitable examples of the secondary alkyl group include an isopropyl group, a sec-butyl group, or a 1-ethylpropyl group. In particular, R ^a is preferably a primary or secondary alkyl group having 1 to 4 carbon atoms, or a phenyl group. R ^b is preferably a hydrogen atom.

Suitable homopolymers of polyphenylene ether resins include, for example, polymers of 2,6-dialkylphenylene ethers such as poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene ether), poly(2,6-dipropyl-1,4-phenylene ether), poly(2-ethyl-6-methyl-1,4-phenylene ether), and poly(2-methyl-6-propyl-1,4-phenylene ether). Examples of copolymers include 2,6-dialkylphenol/2,3,6-trialkylphenol copolymers such as 2,6-dimethylphenol/2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol/2,3,6-triethylphenol copolymer, 2,6-diethylphenol/2,3,6-trimethylphenol copolymer, and 2,6-dipropylphenol/2,3,6-trimethylphenol copolymer; graft copolymers obtained by graft polymerizing styrene onto poly(2,6-dimethyl-1,4-phenylene ether); and graft copolymers obtained by graft polymerizing styrene onto 2,6-dimethylphenol/2,3,6-trimethylphenol copolymer.

In this embodiment, the polyphenylene ether resin is preferably poly(2,6-dimethyl-1,4-phenylene) ether or a 2,6-dimethylphenol/2,3,6-trimethylphenol random copolymer. In addition, polyphenylene ether resins with a specified number of terminal groups and copper content, as described in JP-A-2005-344065, can also be used.

The polyphenylene ether resin preferably has an intrinsic viscosity of 0.2 to 0.8 dL/g at 30°C measured in chloroform, more preferably 0.3 to 0.6 dL/g. By making the intrinsic viscosity 0.2 dL/g or more, the mechanical strength of the resin composition tends to be improved, and by making it 0.8 dL/g or less, the fluidity tends to be improved and molding processing tends to be easier. In addition, two or more polyphenylene ether resins with different intrinsic viscosities may be used in combination to achieve this intrinsic viscosity range.

The method for producing the polyphenylene ether resin used in this embodiment is not particularly limited, and may be any known method, for example, a method in which a monomer such as 2,6-dimethylphenol is oxidatively polymerized in the presence of an amine copper catalyst, in which case the intrinsic viscosity can be controlled within a desired range by selecting the reaction conditions. The intrinsic viscosity can be controlled by selecting conditions such as the polymerization temperature, polymerization time, and catalyst amount.

<<Polyester Resin>>
As the polyester resin, a known thermoplastic polyester resin can be used, and it is preferable that the polyester resin contains a polyethylene terephthalate resin and/or a polybutylene terephthalate resin, and it is more preferable that the polyester resin contains at least a polybutylene terephthalate resin.
As is well known, polyethylene terephthalate resins and polybutylene terephthalate resins are produced on a large scale by reacting terephthalic acid or ester with ethylene glycol or 1,4-butanediol, and are distributed on the market. In this embodiment, these resins available on the market can be used. Some commercially available resins contain a copolymer component other than the terephthalic acid component and the ethylene glycol component or 1,4-butanediol component, but in this embodiment, resins containing preferably 3 to 40 mass %, more preferably 5 to 30 mass %, and even more preferably 10 to 25 mass % of the copolymer component can also be used.

The intrinsic viscosity of the polyethylene terephthalate resin is usually 0.4 to 1.0 dL/g, and preferably 0.5 to 1.0 dL/g. When the intrinsic viscosity is equal to or higher than the lower limit, the mechanical properties of the resin composition are less likely to deteriorate, and when the intrinsic viscosity is equal to or lower than the upper limit, the fluidity is easily maintained.
The intrinsic viscosity of the polybutylene terephthalate resin is usually 0.5 to 1.5 dL/g, and preferably 0.6 to 1.3 dL/g. If it is equal to or higher than the lower limit, it is easy to obtain a resin composition having excellent mechanical strength. If it is equal to or lower than the upper limit, the flowability of the resin composition is not lost, and the moldability tends to be excellent.
The intrinsic viscosity of each polyester resin was measured at 30° C. in a mixed solvent of phenol/tetrachloroethane (mass ratio 1/1).
The amount of terminal carboxyl groups of the polyester resin (preferably polybutylene terephthalate resin) is usually 60 eq/ton or less, preferably 50 eq/ton or less, and preferably 30 eq/ton or less. By making it 60 eq/ton or more, the alkali resistance and hydrolysis resistance are improved, and gas is less likely to be generated during melt molding of the resin composition. The lower limit of the amount of terminal carboxyl groups is not particularly determined, but is usually 10 eq/ton in consideration of the productivity of the production of the polyester resin.
The amount of terminal carboxyl groups in the polyester resin can be determined by dissolving 0.5 g of the resin in 25 mL of benzyl alcohol and titrating the solution with a 0.01 mol/L benzyl alcohol solution of sodium hydroxide.

The polybutylene terephthalate resin may be a polybutylene terephthalate resin modified by copolymerization, and specific preferred copolymers include polyester ether resins copolymerized with polyalkylene glycols, particularly polytetramethylene glycol, dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins. These copolymers refer to those in which the copolymerization amount is 1 mol% or more and less than 50 mol% of the total polybutylene terephthalate resin segments. In particular, the copolymerization amount is preferably 2 to 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%. For details of these, refer to paragraphs 0014 to 0022 of JP 2019-006866 A, the contents of which are incorporated herein by reference.

In addition to the above, the description of polyester resins can be found in paragraphs 0013 to 0016 of JP 2010-174223 A, the contents of which are incorporated herein by reference.

<<Polyamide resin>>
The type of polyamide resin used in this embodiment is not particularly limited, and may be an aliphatic polyamide resin or a semi-aromatic polyamide resin. For the polyamide resin, for example, the description in paragraphs 0011 to 0013 of JP 2011-132550 A can be referred to, and the contents thereof are incorporated herein by reference.
The polyamide resin used in this embodiment preferably contains a semi-aromatic polyamide resin. For example, it is more preferable that 90% by mass or more of the polyamide resin contained in the resin composition of this embodiment is a semi-aromatic polyamide resin. Here, the semi-aromatic polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 20 to 80 mol% of the total structural units of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit are structural units containing an aromatic ring. By using such a semi-aromatic polyamide resin, the mechanical strength of the obtained resin molded product can be increased. Examples of semi-aromatic polyamide resins include terephthalic acid-based polyamide resins (polyamide 6T, polyamide 9T, polyamide 10T) and xylylenediamine-based polyamide resins described later.

At least one of the polyamide resins used in the present embodiment contains diamine-derived structural units and dicarboxylic acid-derived structural units, and it is preferred that 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having a carbon number of 4 to 20. Hereinafter, such a polyamide resin may be referred to as a xylylenediamine-based polyamide resin.
The diamine-derived constituent units of the xylylenediamine-based polyamide resin are more preferably 75 mol % or more, even more preferably 80 mol % or more, still more preferably 85 mol % or more, even more preferably 90 mol % or more, and even more preferably 95 mol % or more derived from xylylenediamine. The dicarboxylic acid-derived constituent units of the xylylenediamine-based polyamide resin are more preferably 75 mol % or more, even more preferably 80 mol % or more, still more preferably 90 mol % or more, and even more preferably 95 mol % or more derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms.

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

Examples of α,ω-straight-chain aliphatic dicarboxylic acids having 4 to 20 carbon atoms that are suitable for use as the raw dicarboxylic acid component of xylylenediamine-based polyamide resins include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. One or more of these can be used in combination, but among these, adipic acid or sebacic acid are more preferred, and sebacic acid is even more preferred, since the melting point of the polyamide resin falls within a range suitable for molding.

Examples of dicarboxylic acid components other than the α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalene dicarboxylic acids such as 1,2-naphthalene dicarboxylic acid, 1,3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 1,6-naphthalene dicarboxylic acid, 1,7-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and 2,7-naphthalene dicarboxylic acid, and these can be used alone or in combination of two or more.

In the xylylenediamine-based polyamide resin of the present embodiment, 0 to 100 mol % of the diamine-derived structural units are derived from paraxylylenediamine, 100 to 0 mol % are derived from metaxylylenediamine, and 70 mol % or more (preferably 80 mol % or more, more preferably 90 mol % or more) of the dicarboxylic acid-derived structural units are derived from sebacic acid and/or adipic acid.
An example of a more preferred embodiment A of the xylylenediamine-based polyamide resin is one in which 70 mol % or more (preferably 80 mol % or more, more preferably 90 mol % or more, and even more preferably 95 mol % or more) of the diamine-derived structural units are derived from paraxylylenediamine, and 70 mol % or more (preferably 80 mol % or more, and more preferably 90 mol % or more) of the dicarboxylic acid-derived structural units are derived from sebacic acid.
Furthermore, a more preferred embodiment B of the xylylenediamine-based polyamide resin is, for example, a polyamide resin in which 30 to 90 mol % (preferably 60 to 80 mol %) of the diamine-derived structural units are derived from metaxylylenediamine, 70 to 10 mol % (preferably 40 to 20 mol %) are derived from paraxylylenediamine, and 70 mol % or more (preferably 80 mol % or more, more preferably 90 mol % or more) of the dicarboxylic acid-derived structural units are derived from sebacic acid.
As a more preferred embodiment C of the xylylenediamine-based polyamide resin, there can be mentioned one in which 70 mol % or more (preferably 80 mol % or more, more preferably 90 mol % or more, and even more preferably 95 mol % or more) of the diamine-derived structural units are derived from metaxylylenediamine, and 70 mol % or more (preferably 80 mol % or more, and more preferably 90 mol % or more) of the dicarboxylic acid-derived structural units are derived from adipic acid.
In the resin composition of this embodiment, embodiment A is particularly preferable.
In any of the above embodiments, the total amount of the constitutional units derived from diamines does not exceed 100 mol %, and the total amount of the constitutional units derived from dicarboxylic acids does not exceed 100 mol %.

It should be noted that although the diamine-derived structural units and dicarboxylic acid-derived structural units are the main components, other structural units are not completely excluded, and it goes without saying that the resin may contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, the main component means that, among the structural units constituting the xylylenediamine-based polyamide resin, the total number of diamine-derived structural units and dicarboxylic acid-derived structural units is the largest among all structural units. In this embodiment, the total of the diamine-derived structural units and dicarboxylic acid-derived structural units in the xylylenediamine-based polyamide resin preferably accounts for 90% or more of the total structural units, more preferably 95% or more, and even more preferably 98% or more.

The melting point of the polyamide resin is preferably from 150 to 350°C, more preferably from 180 to 330°C, and even more preferably from 200 to 300°C.
The melting point can be measured by differential scanning calorimetry in accordance with JIS K7121 and K7122.

The 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, even more preferably 15,000 or more, even more preferably 20,000 or more, and even more preferably 22,000 or more. The upper limit of the Mn is preferably 35,000 or less, more preferably 30,000 or less, even more preferably 28,000 or less, and even more preferably 26,000 or less. Within such a range, the heat resistance, elastic modulus, dimensional stability, and moldability are improved.

The content of the thermoplastic resin in the resin composition of this embodiment is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, and even more preferably 45% by mass or more. By making it equal to or more than the lower limit, the mechanical strength of the molded article tends to be improved. The content of the thermoplastic resin in the resin composition of this embodiment is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less. By making it equal to or less than the upper limit, the mechanical strength of the molded article tends to be maintained.
The resin composition of the present embodiment may contain only one type of each thermoplastic resin, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is in the above range.

<Laser direct structuring additive>
The resin composition of the present embodiment contains a laser direct structuring additive (LDS additive). By containing the LDS additive, it becomes possible to form plating on the obtained resin molded article.
The LDS additive in this embodiment refers to a compound that can selectively form plating only in the laser irradiated portion when 10 parts by mass of an additive considered to be an LDS additive is added to 100 parts by mass of any of polycarbonate resin, polyphenylene ether resin, polyester resin, and polyamide resin, and irradiated with a YAG laser having a wavelength of 1064 nm at an output of 10 W, a frequency of 80 kHz, and a speed of 3 m/s, and then immersed in an electroless plating bath as a plating process. The LDS additive used in this embodiment may be a synthetic product or a commercially available product. In addition, the commercially available product may be a substance sold for other purposes, as long as it satisfies the requirements of the LDS additive in this embodiment, in addition to those sold commercially as LDS additives. Only one type of LDS additive may be used, or two or more types may be used in combination.

The LDS additive used in this embodiment preferably contains at least one of copper, antimony, tin, aluminum, and zinc, more preferably contains copper chromium copper oxide and/or an oxide containing antimony and tin, and even more preferably contains copper chromium copper oxide.
Moreover, the LDS additive used in this embodiment preferably has a resistivity of more than 5×10 ³ Ω·cm. By using an LDS additive having such a high resistivity, a resin composition having lower dielectric properties can be obtained.

More specifically, the first embodiment of the LDS additive used in this embodiment is a compound containing copper and chromium. The LDS additive of the first embodiment preferably contains 10 to 30 mass% copper. Also, it is preferable that the LDS additive contains 15 to 50 mass% chromium. The LDS additive in the first embodiment is preferably an oxide containing copper and chromium (copper chromium oxide).

The copper and chromium are preferably contained in a spinel structure, which is one of the typical crystal structures found in AB ₂ O ₄ type compounds (A and B are metal elements) in double oxides.

The LDS additive of the first embodiment may contain trace amounts of other metals in addition to copper and chromium. Examples of other metals include antimony, tin, lead, indium, iron, cobalt, nickel, zinc, cadmium, silver, bismuth, arsenic, manganese, magnesium, and calcium, with manganese being preferred. These metals may be present as oxides.
A preferred example of the LDS additive of the first embodiment is an LDS additive having a content of metal oxides other than copper chromium oxide of 10 mass % or less.

A second embodiment of the LDS additive used in this embodiment is an oxide containing at least one of antimony and phosphorus and tin, preferably an oxide containing antimony and tin.

In the second embodiment, the LDS additive preferably has a tin content greater than the phosphorus and antimony contents, and more preferably has an amount of tin relative to the total amount of tin, phosphorus, and antimony of 80 mass% or more.

In particular, as the LDS additive of the second embodiment, an oxide containing antimony and tin is preferable, an oxide in which the tin content is greater than the antimony content is more preferable, and an oxide in which the amount of tin relative to the total amount of tin and antimony is 80 mass% or more is even more preferable.
More specifically, examples of the LDS additive of the second embodiment include antimony-doped tin oxide, antimony oxide-doped tin oxide, phosphorus-doped tin oxide, and phosphorus oxide-doped tin oxide, with antimony oxide-doped tin oxide and antimony oxide-doped tin oxide being preferred, and antimony oxide-doped tin oxide being more preferred.

The number average particle size of the LDS additive used in this embodiment is preferably 0.01 to 100 μm, more preferably 0.05 to 30 μm, and even more preferably 0.05 to 15 μm. By setting the number average particle size to such a range, the plating surface can be made more uniform.

The content of the LDS additive in the resin composition of this embodiment is preferably 1.0 parts by mass or more, more preferably 2.0 parts by mass or more, even more preferably 3.0 parts by mass or more, even more preferably 4.0 parts by mass or more, and even more preferably 5.0 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin. By making it equal to or more than the lower limit, plating property tends to be further improved. In addition, the content of the LDS additive in the resin composition of this embodiment is preferably 30.0 parts by mass or less, more preferably 25.0 parts by mass or less, even more preferably 20.0 parts by mass or less, even more preferably 15.0 parts by mass or less, and even more preferably 10.0 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin. By making it equal to or less than the upper limit, the resin composition tends to exhibit lower dielectric constant.
The resin composition of the present embodiment may contain only one type of LDS additive, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

<Polyolefin>
The resin composition of the present embodiment contains 4.0 to 30.0 parts by mass of polyolefin per 100 parts by mass of thermoplastic resin. By containing polyolefin, it is possible to impart plating properties to the obtained resin molded product while also achieving low dielectric constant.
As the polyolefin, homopolymers and/or copolymers of α-olefins such as ethylene, propylene, and butene are preferred.

As homopolymers, polyethylene and polypropylene are preferred, with polyethylene being more preferred.
On the other hand, as the copolymer, a polymer of at least two of ethylene, propylene and butene, or a copolymer of at least one of ethylene, propylene and butene with a monomer that can be copolymerized therewith can be used. Examples of the monomer that can be copolymerized with at least one of ethylene, propylene and butene include α-olefins, styrenes, dienes, cyclic compounds, oxygen atom-containing compounds, etc. Particularly preferred copolymers include ethylene/butene copolymers and ethylene/propylene copolymers, with ethylene/butene copolymers being preferred.
For details of α-olefins, styrenes, dienes, cyclic compounds, and oxygen-containing compounds, please refer to paragraph 0044 of WO 2017/094564, the contents of which are incorporated herein by reference.
The copolymer may be any of an alternating copolymer, a random copolymer, and a block copolymer.

As polyethylene, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), etc. can be used, with HDPE being preferred.

In this embodiment, the polyolefin is preferably an acid-modified polyolefin. The acid-modified polyolefin is preferably a polyolefin acid-modified with a carboxylic acid and/or a derivative thereof, or a polyolefin acid-modified with a carboxylic acid and/or a derivative thereof and further grafted with a polyamide via a functional group introduced into the molecule by the acid modification. By using an acid-modified polyolefin, a functional group having affinity for the thermoplastic resin can be introduced into the molecule, which tends to further improve the dispersibility of the polyolefin in the thermoplastic resin. This is particularly effective when a polyamide resin is used as the thermoplastic resin.

Compounds that can modify polyolefins with acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methylfumaric acid, mesaconic acid, citraconic acid, glutaconic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, endobicyclo[2.2.1]-5-heptene-2,3-dicarboxylic acid, and metal salts of these carboxylic acids, monomethyl maleate, monomethyl itaconate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, and methyl methacrylate. Preferred examples of the above include 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo-[2.2.1]-5-heptene-2,3-dicarboxylic anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, acrylamide, methacrylamide, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, and glycidyl citraconate. These may be used alone or in combination of two or more. Of these, maleic anhydride is preferred from the viewpoint of melt mixability with other resins.

In this embodiment, examples of acid-modified polyolefins that are particularly suitable for use include maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, and maleic anhydride-modified ethylene/butene copolymers, from the viewpoints of elastic modulus, flexibility, and impact resistance. Among these, maleic anhydride-modified polyethylene and maleic anhydride-modified polypropylene are particularly preferably used.

For further details about polyolefins, please refer to paragraphs 0042 to 0056 of International Publication No. 2017/094564, the contents of which are incorporated herein by reference.

The content of the polyolefin in the resin composition of this embodiment is 4.0 parts by mass or more, preferably 6.0 parts by mass or more, more preferably 8.0 parts by mass or more, more preferably 10.0 parts by mass or more, even more preferably 12.0 parts by mass or more, and even more preferably 14.0 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin. By making it equal to or more than the lower limit, the dielectric properties of the resin composition tend to be lowered. In addition, the content of the polyolefin in the resin composition of this embodiment is 30.0 parts by mass or less, preferably 28.0 parts by mass or less, even more preferably 26.0 parts by mass or less, even more preferably 24.0 parts by mass or less, and even more preferably 22.0 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin. By making it equal to or less than the upper limit, it is possible to suppress a significant decrease in the mechanical properties and thermal properties inherent to the thermoplastic resin.
The resin composition of the present embodiment may contain only one type of polyolefin, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

In the resin composition of this embodiment, the mass ratio of polyolefin to LDS additive (LDS/polyolefin) is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more, and is preferably 1.5 or less, more preferably 1.3 or less, even more preferably 1.1 or less, and even more preferably 0.9 or less. By setting it in such a range, the effects of the present invention tend to be more effectively exhibited.

<Inorganic fibers>
The resin composition of the present embodiment may further contain 10.0 to 150.0 parts by mass of inorganic fibers per 100 parts by mass of the thermoplastic resin. By containing the inorganic fibers, the mechanical strength of the obtained resin molded article can be further improved.
Examples of inorganic fibers include carbon fibers and glass fibers, and it is preferable to include glass fibers.

In the present embodiment, the inorganic fiber means a fibrous inorganic material, and more specifically, it is preferable for the inorganic fiber to have a chopped shape in which 1,000 to 10,000 inorganic fibers are bundled together and cut to a predetermined length.
In the present embodiment, the inorganic fibers preferably have a number average fiber length of 0.5 to 10 mm, and more preferably 1 to 5 mm. By using inorganic fibers with such a number average fiber length, the mechanical strength can be further improved. The number average fiber length is calculated from the measured value obtained by randomly extracting inorganic fibers to be measured for fiber length from an image obtained by observation with an optical microscope and measuring the long side of the fibers. The observation is performed at a magnification of 20 times, and the number of fibers measured is 1,000 or more. It roughly corresponds to the cut length.
The cross section of the inorganic fiber may be any shape, such as a circle, an ellipse, an oval, a rectangle, a shape in which both short sides of a rectangle are joined by semicircles, a cocoon shape, etc., but a circle is preferable. Here, the circle includes not only a circle in the mathematical sense, but also what is usually called a circle in the technical field of this embodiment.
The number average fiber diameter of the inorganic fibers is preferably 4.0 μm or more, more preferably 4.5 μm or more, and even more preferably 5.0 μm or more. The upper limit of the number average fiber diameter of the inorganic fibers is preferably 15.0 μm or less, and more preferably 12.0 μm or less. By using inorganic fibers having a number average fiber diameter in such a range, a resin molded product with excellent plating properties can be obtained even after wet heat treatment. Furthermore, even if the resin molded product is stored for a long period of time or heat treated for a long period of time, high plating properties can be maintained. The number average fiber diameter of the inorganic fibers is calculated from the measured values obtained by randomly extracting glass fibers to be measured for fiber diameter from an image obtained by observation with an electron microscope, measuring the fiber diameter near the center. The magnification of the observation is 1,000 times, and the number of fibers measured is 1,000 or more. The number average fiber diameter of glass fibers having a cross section other than a circle is the number average fiber diameter when converted into a circle having the same area as the cross section.

Next, the glass fiber preferably used in this embodiment will be described.
The glass fiber is a fiber obtained by melt spinning a glass such as commonly supplied E glass (electrical glass), C glass (chemical glass), A glass (alkaline glass), S glass (high strength glass), D glass, R glass, and alkali-resistant glass. A preferred example of this embodiment is E glass, and D glass is also preferred to achieve a lower dielectric constant.

In order to lower the dielectric properties of the resin composition, the inorganic fibers in this embodiment are preferably low-dielectric inorganic fibers, and more preferably low-dielectric glass fibers.
The term "low dielectric inorganic fiber" refers to an inorganic fiber having a low dielectric constant and dielectric loss tangent, and is exemplified by an inorganic fiber having a dielectric constant of 7 or less. The dielectric constant here is a value measured in accordance with ASTM D 150.
An example of such low dielectric glass fiber is glass fiber composed of 65-85% _{by mass} of SiO2, 15-30% by _mass of _B2O3 , 0-4% by mass of sodium oxide ( _Na2O ) and/or potassium oxide ( _K2O ), and 0-4% by mass of other components (the total amount here does not exceed 100% by mass, and preferably the total is 100% by mass). Glass fibers with a high _amount of _B2O3 are known as glass fibers with a low relative dielectric constant.

The glass fiber used in this embodiment is preferably surface-treated with a surface treatment agent such as a silane coupling agent, for example, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, etc. The amount of the surface treatment agent attached is preferably 0.01 to 1 mass % of the glass fiber. Furthermore, if necessary, it is also possible to use glass fibers that have been surface-treated with a lubricant such as a fatty acid amide compound or silicone oil, an antistatic agent such as a quaternary ammonium salt, a resin having a film-forming ability such as an epoxy resin or urethane resin, or a mixture of a resin having a film-forming ability with a heat stabilizer, a flame retardant, etc.

The content of inorganic fibers (preferably glass fibers) in the resin composition of this embodiment is preferably 10.0 parts by mass or more, more preferably 20.0 parts by mass or more, even more preferably 30.0 parts by mass or more, and even more preferably 40.0 parts by mass or more, particularly 50.0 parts by mass or more, relative to 100 parts by mass of thermoplastic resin. By making it equal to or more than the lower limit, the mechanical strength of the obtained resin molded product tends to be further improved. In addition, the content of inorganic fibers (preferably glass fibers) in the resin composition of this embodiment is preferably 150.0 parts by mass or less, more preferably 120.0 parts by mass or less, even more preferably 100.0 parts by mass or less, even more preferably 80.0 parts by mass or less, and even more preferably 70.0 parts by mass or less, relative to 100 parts by mass of thermoplastic resin. By making it equal to or less than the upper limit, the dielectric properties of the resin composition tend to be lowered.
In addition, the content of inorganic fibers (preferably glass fibers) in the resin composition of this embodiment is preferably 10.0% by mass or more in the resin composition, more preferably 15.0% by mass or more, and even more preferably 18.0% by mass or more. By making it equal to or more than the lower limit, the mechanical strength of the obtained resin molded product tends to be further improved. In addition, the content of inorganic fibers (preferably glass fibers) in the resin composition of this embodiment is preferably 50.0% by mass or less in the resin composition, more preferably 45.0% by mass or less, even more preferably 40.0% by mass or less, even more preferably 35.0% by mass or less, and even more preferably 34.0% by mass or less. By making it equal to or less than the upper limit, the dielectric properties of the resin composition tend to be lowered.
The resin composition of the present embodiment may contain only one type of inorganic fiber, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

<Talc>
The resin composition of the present embodiment may further contain 0.1 to 200.0 parts by mass of talc relative to 100 parts by mass of the laser direct structuring additive. By containing talc, it is possible to improve the dimensional stability and the appearance of the product, and also to increase the plating growth rate. Furthermore, by containing talc, it is possible to improve the plating properties of the resin molded product even if the content of the LDS additive is reduced.
The talc may be surface-treated with at least one compound selected from polyorganohydrogensiloxanes and organopolysiloxanes. In this case, the amount of the siloxane compound attached to the talc is preferably 0.1 to 5% by mass of the talc.
The number average particle size of talc is preferably 1 to 50 μm, and more preferably 2 to 25 μm. Talc is usually scaly, and the length of the longest part is taken as the average particle size. The number average particle size of talc is calculated from the measured values obtained by randomly extracting talc particles to be measured for particle size from an image obtained by observation with an electron microscope, measuring the particle size of the sample, and then the number of particles is measured. The magnification of observation is 1,000 times, and the number of particles measured is 1,000 or more.

The content of talc in the resin composition of this embodiment is preferably 0.1 parts by mass or more, more preferably 1.0 parts by mass or more, even more preferably 10.0 parts by mass or more, even more preferably 60.0 parts by mass or more, and even more preferably 100.0 parts by mass or more, relative to 100.0 parts by mass of the laser direct structuring additive. By making it equal to or more than the lower limit, plating property tends to be further improved. In addition, the content of talc in the resin composition of this embodiment is preferably 200.0 parts by mass or less, more preferably 180.0 parts by mass or less, even more preferably 170.0 parts by mass or less, even more preferably 160.0 parts by mass or less, and even more preferably 150.0 parts by mass or less, relative to 100 parts by mass of the laser direct structuring additive. By making it equal to or less than the upper limit, the mechanical properties of the obtained molded product can be more effectively improved.
In addition, when blended, the content of talc in the resin composition of this embodiment is preferably 0.1 parts by mass or more, more preferably 1.0 parts by mass or more, and even more preferably 4.5 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin, and is preferably 20.0 parts by mass or less, more preferably 15.0 parts by mass or less, and even more preferably 12.0 parts by mass or less.
The resin composition of the present embodiment may contain only one type of talc, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

<Release Agent>
The resin composition of the present embodiment may further contain a release agent. The release agent is mainly used to improve the productivity during molding of the resin composition. Examples of the release agent include aliphatic carboxylic acid amides, aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils.

For details about the release agent, please refer to the descriptions in paragraphs 0037 to 0042 of JP 2016-196563 A and paragraphs 0048 to 0058 of JP 2016-078318 A, the contents of which are incorporated herein by reference.

When the release agent is added, the lower limit of the content of the release agent relative to the resin composition is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and the upper limit is preferably 2.0% by mass or less, more preferably 1.5% by mass or less. By setting the content within such a range, it is possible to improve the releasability when molding using a mold such as injection molding, and also to effectively suppress mold contamination. The release agent may be used alone or in combination of two or more types. When two or more types are used, it is preferable that the total amount is within the above range.

<Other additives>
The resin composition of the present embodiment may contain other components in addition to the above. Examples of other components include light stabilizers, heat stabilizers, alkalis, elastomers, titanium oxide, antioxidants, hydrolysis resistance improvers, matting agents, UV absorbers, nucleating agents, plasticizers, dispersants, antistatic agents, coloring inhibitors, gelling inhibitors, colorants, and flame retardants. For details of these, refer to paragraphs 0130 to 0155 of Japanese Patent No. 4894982, the contents of which are incorporated herein by reference. It is preferable that these components are 20% by mass or less in total of the resin composition. Each of these components may be used alone or in combination of two or more.
In the resin composition of the present embodiment, the total amount of the thermoplastic resin, the polyolefin, the LDS additive, and, optionally, the inorganic fibers, the release agent, and the talc is preferably 95% by mass or more, more preferably 98% by mass or more, and even more preferably 99% by mass or more of the resin composition.
In addition, the resin composition of the present embodiment preferably does not contain calcium copper titanate.

<Method of producing resin composition>
As a method for producing the resin composition of the present embodiment, any method may be adopted.
For example, a method in which a thermoplastic resin, a polyolefin, an LDS additive, inorganic fibers, etc. are mixed using a mixing means such as a V-type blender to prepare a lump-sum blend, which is then melt-kneaded in a vented extruder and pelletized. Alternatively, a two-stage kneading method in which components other than inorganic fibers are thoroughly mixed in advance, which is then melt-kneaded in a vented extruder to produce pellets, which are then mixed with a reinforcing filler, and the pellets are then melt-kneaded in a vented extruder.
Furthermore, a method can be mentioned in which components other than the inorganic fibers are thoroughly mixed in advance using a V-type blender or the like, and the mixture is fed from a first chute of a vented twin-screw extruder, while the inorganic fibers are fed from a second chute midway through the extruder, followed by melt-kneading and pelletization.

The screw configuration of the kneading zone of the extruder is preferably such that an element that promotes kneading is disposed on the upstream side and an element capable of increasing pressure is disposed on the downstream side.
Examples of elements that promote kneading include a progressive kneading disc element, an orthogonal kneading disc element, a wide kneading disc element, and a progressive mixing screw element.

The heating temperature during melt kneading can usually be selected appropriately from the range of 180 to 360°C. If the temperature is too high, decomposition gases are likely to be generated, which may cause extrusion defects such as strand breakage. Therefore, it is desirable to select a screw configuration that takes into account shear heat generation, etc. The use of antioxidants and heat stabilizers is desirable to suppress decomposition during kneading and subsequent molding processes.

<Physical Properties of Resin Composition>
The resin composition of the present embodiment preferably has low dielectric properties, and in particular, preferably has a low relative dielectric constant. For example, when the resin composition of the present embodiment is compared with a resin composition obtained by removing polyolefin from the resin composition of the present embodiment, if the resin composition of the present embodiment has a lower relative dielectric constant, it can be said that the dielectric constant is low.
For example, the relative dielectric constant of the resin composition of this embodiment at a frequency of 2.45 GHz can be 3.60 or less, and can also be 3.50 or less. The lower limit of the relative dielectric constant is ideally 0, but the required performance is also satisfied even if it is, for example, 1.00 or more, or even 2.80 or more. In particular, it is preferable that the above range is satisfied when a polyamide resin is used as the thermoplastic resin.
The resin composition of the present embodiment preferably has a low dielectric tangent.
For example, the specific dielectric tangent at a frequency of 2.45 GHz of the resin composition of this embodiment can be 0.020 or less, and can also be 0.015 or less. The lower limit is ideally 0, but the required performance is satisfied even if it is, for example, 0.001 or more, or even 0.008 or more. In particular, it is preferable that the above range is satisfied when a polyamide resin is used as the thermoplastic resin.

The resin composition of this embodiment preferably has a bending strength of 140 MPa or more, more preferably 145 MPa or more, and even more preferably 150 MPa or more, according to ISO 178, when molded to a thickness of 4 mm. The upper limit of the bending strength is not particularly specified, but is practically, for example, 270 MPa or less, further 260 MPa or less, and particularly 250 MPa or less. In particular, it is preferable that the bending strength is within the above range when a polyamide resin is used as the thermoplastic resin.
The resin composition of this embodiment has a flexural modulus of 5.0 GPa or more, more preferably 5.5 GPa or more, and even more preferably 6.0 GPa or more, according to ISO 178, when molded to a thickness of 4 mm. The upper limit of the flexural modulus is not particularly specified, but is practically, for example, 15 GPa or less, further 14 GPa or less, and particularly 13 GPa or less. In particular, it is preferable that the above range is satisfied when a polyamide resin is used as the thermoplastic resin.

The resin composition of the present embodiment preferably has a notched Charpy impact strength of 2 kJ/ ^m2 or more according to ISO 179 when molded to a thickness of 4 mm. The upper limit of the notched Charpy impact strength is not particularly set, but for example, 15 kJ/m2 ^or less is practical. In particular, it is preferable that the above range is satisfied when a polyamide resin is used as the thermoplastic resin.

The above-mentioned dielectric constant, dielectric tangent, flexural strength, flexural modulus, and notched Charpy impact strength are each measured according to the method described in the Examples below.

<Resin molded products>
This embodiment also discloses a resin molded article formed from the resin composition of this embodiment.
In the present embodiment, the manufacturing method of the resin molded product is not particularly limited, and any molding method generally used for resin compositions can be used. Examples of such methods include injection molding, ultra-high speed injection molding, injection compression molding, two-color molding, gas-assisted hollow molding, molding using a heat-insulating mold, molding using a rapid heating mold, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, etc. Also, a molding method using a hot runner system can be used.

The resin molded article formed from the resin composition of this embodiment is preferably used as a resin molded article having plating on the surface of the resin molded article. It is preferable that the plating in the resin molded article of this embodiment has antenna performance.

<Method of manufacturing plated resin molded product>
Next, a method for producing a plated resin molded article will be disclosed, which includes irradiating a laser onto the surface of a resin molded article formed from the resin composition of this embodiment, and then applying a metal to form a plating.
Fig. 1 is a schematic diagram showing a process of forming a plating on the surface of a resin molded product 1 by the laser direct structuring technique. In Fig. 1, the resin molded product 1 is a flat substrate, but it does not necessarily have to be a flat substrate, and may be a resin molded product that is partially or entirely curved. In addition, the obtained plated resin molded product is not limited to a final product, but also includes various parts.

Returning to Fig. 1, a resin molded product 1 is irradiated with a laser 2. The laser here is not particularly limited and can be appropriately selected from known lasers such as a YAG laser, an excimer laser, and an electromagnetic ray, with a YAG laser being preferred. The wavelength of the laser is also not particularly limited. A preferred wavelength range is 200 nm to 1200 nm, and more preferably 800 to 1200 nm.
When the laser is irradiated, the resin molded article 1 is activated only at the portion 3 irradiated with the laser. In this activated state, the resin molded article 1 is applied to the plating liquid 4. The plating liquid 4 is not particularly specified, and a wide variety of known plating liquids can be used. As the metal component, a plating liquid (particularly, an electroless plating liquid) consisting of one or more of copper, nickel, silver, gold, and palladium is preferable, a plating liquid (particularly, an electroless plating liquid) consisting of one or more of copper, nickel, silver, and gold is more preferable, and a plating liquid (particularly, an electroless plating liquid) containing copper is even more preferable. That is, in the plating in this embodiment, the metal component is preferably at least one of the above metals.
The method for applying the resin molded article 1 to the plating liquid 4 is not particularly limited, but may be, for example, a method of immersing the resin molded article in a liquid containing the plating liquid. After the plating liquid is applied to the resin molded article, plating 5 is formed only on the portions irradiated with the laser.
In the method of this embodiment, it is possible to form a plating (circuit) having a gap of 1 mm or less, or even 150 μm or less (the lower limit is not particularly specified, but for example, 30 μm or more). In order to prevent corrosion or deterioration of the formed plating (circuit), the plating can be further protected with nickel or gold, for example, after electroless plating. Similarly, it is also possible to form a required film thickness in a short time by using electrolytic plating after electroless plating.
The above-mentioned method for producing a plated resin molded product is also preferably used as a method for producing a portable electronic device part having an antenna, including the above-mentioned method for producing a plated resin molded product.

The resin molded products obtained from the resin composition of this embodiment can be used for various applications, such as electronic components such as sensors, connectors, switches, relays, conductive circuits, and antennas (particularly portable electronic device components, communication base stations, and computer peripherals).

In addition, the descriptions in JP 2011-219620 A, JP 2011-195820 A, JP 2011-178873 A, JP 2011-168705 A, and JP 2011-148267 A may be referred to without departing from the spirit of this embodiment.

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

In this example, the following raw materials were used:

In Table 1 above, MAH stands for maleic anhydride, HDPE stands for high density polyethylene, PP stands for polypropylene, LDPE stands for low density polyethylene, PTFE stands for polytetrafluoroethylene, and PPS stands for polyphenylene sulfide.

Examples 1 to 10, Comparative Examples 1 to 4
<Compound>
Each component was weighed so as to obtain the composition shown in Tables 2 to 4 below (each component in Tables 2 to 4 is in parts by mass), and the components except for the inorganic fiber (glass fiber) were blended in a tumbler and fed into a twin-screw extruder (Shibaura Machine Co., Ltd., TEM26SS) from the base. After melting, the inorganic fiber (glass fiber) was side-fed to produce a resin composition (pellets). The temperature of the twin-screw extruder was set to 300°C. Each component in Tables 2 to 4 is shown in mass ratio.

<Flexural strength and flexural modulus>
The pellets obtained by the above manufacturing method were dried at 120°C for 4 hours, and then injection molded into ISO tensile test pieces (4 mm thick) using an injection molding machine (manufactured by Shibaura Machine Co., Ltd., "EC75SX") under conditions of a cylinder temperature of 300°C, a mold temperature of 130°C, and a molding cycle of 50 seconds.
The flexural strength (unit: MPa) and flexural modulus (unit: GPa) were measured at a temperature of 23° C. in accordance with ISO 178.

<Notched Charpy impact strength>
The pellets obtained by the above manufacturing method were dried at 120°C for 4 hours, and then injection molded into ISO tensile test pieces (4 mm thick) using an injection molding machine (manufactured by Shibaura Machine Co., Ltd., "EC75SX") under conditions of a cylinder temperature of 300°C, a mold temperature of 130°C, and a molding cycle of 50 seconds.
Using the ISO tensile test pieces (4 mm thick) obtained above, Charpy impact strength (notched) was measured at a temperature of 23° C. in accordance with ISO 179 standard.
The unit is kJ/ ^m2 .

<Deflection temperature under load (DTUL)>
The pellets obtained by the above manufacturing method were dried at 120°C for 4 hours, and then injection molded into ISO multipurpose test pieces (4 mm thick) using an injection molding machine (manufactured by Shibaura Machine Co., Ltd., "EC75SX") under conditions of a cylinder temperature of 300°C, a mold temperature of 130°C, and a molding cycle of 50 seconds.
The ISO multipurpose test piece (4 mm thick) obtained above was processed into a shape based on ISO 75-1 and ISO 75-2, and the deflection temperature under load (unit: ° C.) was measured at a load of 1.80 MPa based on ISO 75-1 and ISO 75-2.

<Dielectric constant/dielectric tangent>
The relative dielectric constant and the dielectric loss tangent were measured at a frequency of 2.45 GHz by a cavity resonator perturbation method using a 100 mm×100 mm×2 mm flat plate-shaped test piece formed from the resin composition.
Specifically, the pellets obtained by the above manufacturing method were dried at 120°C for 4 hours, and then injection molded in an injection molding machine (manufactured by Shibaura Machine Co., Ltd., "EC75SX") under conditions of a cylinder temperature of 300°C, a mold temperature of 130°C, and a molding cycle of 50 seconds to mold flat test pieces of 100 mm x 100 mm x 2 mm.
From the obtained flat test piece, a flat test piece of 100 mm×1 mm×2 mm was obtained by cutting in the longitudinal direction of the flow direction, and the relative dielectric constant and dielectric loss tangent at a set frequency were measured by a cavity resonator perturbation method.
For the measurement, a network analyzer manufactured by KEYSIGHT and a cavity resonator manufactured by Kanto Electronics Application Development Co., Ltd. were used.

<Plating ability>
A 10×10 mm area of the ISO multipurpose test piece (4 mm thick) obtained above was irradiated with a laser using a Trumpf VMc1 laser irradiation device (YAG laser with a wavelength of 1064 nm and a maximum output of 15 W) at a power of 10 W, a frequency of 80 kHz, and a speed of 2 m/s. The subsequent plating process involved treatment for 10 minutes in a 65° C. plating tank (set temperature 68° C.) of a MacDermid electroless Copper 100XB.
A: Plating was formed. B: Plating was not formed.

As is clear from the above results, the resin composition of the present invention was able to achieve low dielectric properties, in particular a low relative dielectric constant, while maintaining plating properties (Examples 1 to 10).
In contrast, when no polyolefin was blended (Comparative Example 1), the relative dielectric constant did not decrease.Also, when a resin other than polyolefin was alloyed (Comparative Examples 2 and 3), the relative dielectric constant did not decrease.
On the other hand, when no LDS additive was added (Comparative Example 4), the relative dielectric constant was low, but no plating could be formed.

1 resin molded product 2 laser 3 laser irradiated part 4 plating solution 5 plating

Claims (20)

A thermoplastic resin;
Laser direct structuring additives;
and a polyolefin,
The thermoplastic resin includes at least one of a polycarbonate resin, a polyphenylene ether resin, a polyester resin, and a polyamide resin;
The thermoplastic resin contains 4.0 to 30.0 parts by mass of polyolefin relative to 100 parts by mass of the thermoplastic resin,
The mass ratio of the polyolefin to the laser direct structuring additive (laser direct structuring additive/polyolefin) is 0.1 or more and 1.3 or less;
The polyolefin is an acid-modified polyolefin obtained by modifying a homopolymer and/or copolymer of an olefin selected from the group consisting of ethylene, propylene, and butene with maleic anhydride .
Low dielectric resin composition for laser direct structuring. The resin composition according to claim 1, wherein the thermoplastic resin comprises a polyamide resin. The resin composition according to claim 2, wherein the polyamide resin comprises a semi-aromatic polyamide resin. The resin composition according to claim 2, wherein at least one of the polyamide resins contains diamine-derived structural units and dicarboxylic acid-derived structural units, 70 mol% or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol% or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. The resin composition according to any one of claims 1 to 4, comprising 1.0 to 30.0 parts by mass of the laser direct structuring additive per 100 parts by mass of the thermoplastic resin. The resin composition according to any one of claims 1 to 5, wherein the laser direct structuring additive contains at least one of copper, antimony, tin, aluminum and zinc. The resin composition according to any one of claims 1 to 5, wherein the laser direct structuring additive comprises copper chromium copper oxide and/or an oxide containing antimony and tin. The resin composition according to any one of claims 1 to 7, wherein the resistivity of the laser direct structuring additive is greater than 5 x 10 ³ Ω·cm. The resin composition according to any one of claims 1 to 8 , further comprising 10.0 to 150.0 parts by mass of inorganic fibers per 100 parts by mass of the thermoplastic resin. The resin composition according to claim 9 , wherein the inorganic fibers have a relative dielectric constant of 7 or less. The resin composition according to claim 9 or 10 , wherein the inorganic fibers include glass fibers. The resin composition according to claim 11, wherein the glass fiber is composed of 65-85% by weight of SiO ₂ , 15-30% by weight of B ₂ O ₃ , 0-4% by weight of sodium oxide (Na ₂ O) and/or potassium oxide (K ₂ O), and 0-4% by weight of other components. The resin composition according to any one of claims 9 to 12 , wherein the inorganic fibers are contained in an amount of 20.0 to 80.0 parts by mass per 100 parts by mass of the thermoplastic resin. The resin composition according to any one of claims 1 to 13 , further comprising 0.1 to 200.0 parts by mass of talc per 100.0 parts by mass of the laser direct structuring additive. The resin composition according to any one of claims 1 to 14 , wherein the resin composition has a relative dielectric constant of 3.60 or less at a frequency of 2.45 GHz. A resin molded product formed from the resin composition according to any one of claims 1 to 15 . The resin molded article according to claim 16 , wherein the surface of the resin molded article is plated. The resin molded product according to claim 17 , wherein the plating has a function as an antenna. The resin molded product according to any one of claims 16 to 18 , which is a portable electronic device part. A method for producing a plated resin molded product, comprising: irradiating a surface of a resin molded product formed from the resin composition according to any one of claims 1 to 15 with a laser, and then applying a metal to form a plating.

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