Styrene-based resin molding

Abstract

To provide a styrene-based resin molding comprising syndiotactic polystyrene resin, which exhibits low transmission loss, offers heat resistance, shows high tensile modulus and high strength, and has low coefficient of linear expansion.SOLUTION: A styrene-based resin molding comprises syndiotactic polystyrene resin, wherein the styrene-based resin molding includes 1 to 50 pts.mass of a filler surface-modified with a silane compound represented by formula (1), when the entire of the styrene-based resin molding is taken as 100 pts.mass.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a styrene-based resin molded article containing a syndiotactic polystyrene-based resin, and to a substrate which is a laminate of the styrene-based resin molded article and a metal film. [Background technology]

[0002] In recent years, high-frequency bands of 1 GHz or higher have been adopted in fields such as personal computers (PCs) and mobile phones to improve information processing speeds. Therefore, resin molded products used as circuit boards and other electronic components incorporated into personal computers and mobile phones are required to have low transmission loss in high-frequency bands. Transmission loss refers to the degree of degradation of electrical and optical signals traveling on communication lines. Transmission loss is undesirable because it is consumed as thermal energy and released as heat.

[0003] One way to reduce the transmission loss of a resin molded body is to use a low-dielectric polymer material with low dielectric loss. Known low-dielectric polymer materials include thermoplastic resins such as polyolefins and fluorine-based resins, and thermosetting resins such as unsaturated polyester resins, polyimide resins, epoxy resins, vinyl triazine resins (BT resins), crosslinked polyphenylene oxides, and curable polyphenylene ethers (see, for example, Patent Document 1).

[0004] Furthermore, when the above-mentioned circuit boards and other electronic components are incorporated into personal computers, mobile phones, etc. to create devices, a soldering process is always involved, so the above-mentioned low dielectric polymer materials also require heat resistance. Heat resistance requires that they do not deform during the soldering process, specifically, they must not deform even when heated at 260°C for 120 seconds.

[0005] One known method for improving the heat resistance of low-dielectric polymer materials is to add inorganic compounds such as glass fiber to the polymer material. However, to achieve sufficient heat resistance, a large amount of inorganic compound must be added to the polymer material, which raises the problem of increasing the dielectric constant of the resin molded product. In other words, since the dielectric constant of inorganic compounds is generally high, at 4 F / m or more, the greater the amount of inorganic compound added to the resin molded product, the higher the dielectric constant of the entire resin molded product.

[0006] Patent Document 2 describes a low dielectric and heat-resistant styrene resin composition that has low dielectric properties and high heat resistance. This styrene resin composition contains 1 to 10 parts by weight of an inorganic filler and 1 to 10 parts by weight of an intercalation agent for the inorganic filler, per 100 parts by weight of syndiotactic polystyrene resin. Clay is used as the inorganic filler, and N-phenylmaleimide is used as the intercalation agent.

[0007] Patent Document 3 describes a low dielectric and heat-resistant resin composition having low dielectric properties and high heat resistance, which comprises 100 parts by weight of a syndiotactic polystyrene resin and 1 to 10 parts by weight of an interlayer-modified clay, and which is obtained by intercalating distearyldimethylammonium chloride into the interlayer region.

[0008] Patent Document 4 describes a resin substrate that has excellent adhesive strength with a metal coating. The examples describe a laminate in which a polystyrene substrate obtained by applying 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide to a sheet-like resin molded product containing syndiotactic polystyrene as a main component is laminated with copper foil. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 11-60645 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-323650 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-213317 [Patent Document 4] Japanese Patent Application Publication No. 2023-61776 Summary of the Invention [Problem to be solved by the invention]

[0010] Meanwhile, resin molded articles used as materials for electronic devices or communication devices that operate in high frequency bands, for example, at frequencies of 1 GHz or higher, are required to have low dielectric properties and heat resistance, as well as high strength and low linear expansion.

[0011] An object of the present invention is to provide a styrene-based resin molded article containing a syndiotactic polystyrene-based resin, which has low transmission loss and heat resistance, and further has a high tensile modulus, high strength, and low linear expansion. [Means for solving the problem]

[0012] The present invention is as follows. [1] A styrene-based resin molded product containing a syndiotactic polystyrene-based resin, the styrene-based resin molded product containing 1 to 50 parts by mass of a filler surface-modified with a silane-based compound represented by the following formula (I) when the total amount of the styrene-based resin molded product is 100 parts by mass: [ka] [In formula (I), R 1 is an alkylene group having 1 to 10 carbon atoms. 2 ~R 4 are each independently a hydroxy group, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms, and R 2 ~R 4At least one of Q is a hydroxy group or an alkoxy group having 1 to 5 carbon atoms. Q is an azide group or -NR 5 R 6 and R 5 and R 6 are each independently H, a hydrocarbon group having 1 to 24 carbon atoms, or -R 7 -SiR 8 n (OA) 3-n and R 7 is a chain divalent hydrocarbon group having 1 to 12 carbon atoms, and R 8 is a chain hydrocarbon group having 1 to 4 carbon atoms, A is H or a chain hydrocarbon group having 1 to 4 carbon atoms, and n is an integer of 0 to 3. E is -NH-, -O-, -S-, or -NHCO-.] [2] The styrene-based resin molded article according to [1], having a tensile modulus in the MD direction of 3.0 GPa or more, a crystallization temperature under cooling of 260°C or less, and a crystallinity of 50% or more. [3] The styrene-based resin molded article according to [1] or [2], which has a linear expansion coefficient of 200 ppm or less. [4] The styrene resin molded article according to any one of [1] to [3], which has an L value of 70 or more and a gloss value of 30% or more. [5] The styrene-based resin molded article according to any one of [1] to [4], which is for use in electronic equipment or communication equipment used in a high frequency band of 1 GHz or more. [6] The styrene-based resin molded article according to any one of [1] to [5], wherein the filler is an inorganic filler. [7] The styrene resin molded article according to any one of [1] to [6], which is a film. [8] A substrate which is a laminate of the styrene-based resin molded product according to any one of [1] to [6], which is a film, and a metal film. [Effects of the Invention]

[0013] According to the present invention, a styrene-based resin molded article containing a syndiotactic polystyrene-based resin can be realized that has low transmission loss, heat resistance, a high tensile modulus of elasticity, high strength, and low linear expansion by containing a predetermined amount of filler that has been surface-modified with a silane compound having a specific structure. DETAILED DESCRIPTION OF THE INVENTION

[0014] The styrene-based resin molded article according to the present invention is a styrene-based resin molded article containing a syndiotactic polystyrene-based resin, and contains 1 to 50 parts by mass of a filler surface-modified with a silane-based compound represented by the following formula (I) (hereinafter, sometimes referred to as a surface-modified filler) relative to 100 parts by mass of the entire styrene-based resin molded article. This makes it possible to realize a styrene-based resin molded article having low transmission loss, heat resistance, a high tensile modulus, high strength, and low linear expansion. This will be explained in detail below. [ka]

[0015] In formula (I), R 1 is an alkylene group having 1 to 10 carbon atoms. 2 ~R 4 are each independently a hydroxy group, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms, and R 2 ~R 4 At least one of Q is a hydroxy group or an alkoxy group having 1 to 5 carbon atoms. Q is an azide group or -NR 5 R 6 and R 5 and R 6 are each independently H, a hydrocarbon group having 1 to 24 carbon atoms, or -R 7 -SiR 8 n (OA) 3-n and R 7 is a chain divalent hydrocarbon group having 1 to 12 carbon atoms, and R 8is a chain hydrocarbon group having 1 to 4 carbon atoms, A is H or a chain hydrocarbon group having 1 to 4 carbon atoms, and n is an integer of 0 to 3. E is -NH-, -O-, -S-, or -NHCO-. Chain includes both linear and branched chains.

[0016] R 1 Among these, alkylene groups having 1 to 8 carbon atoms are preferred, alkylene groups having 1 to 5 carbon atoms are more preferred, and alkylene groups having 2 to 5 carbon atoms are even more preferred.

[0017] R 2 ~R 4 When the group represented by R is an alkoxy group, the number of carbon atoms constituting the alkoxy group is preferably 1 to 4, and more preferably 1 to 3. 2 ~R 4 When the group represented by R is an alkyl group, the number of carbon atoms constituting the alkyl group is preferably 1 to 4, and more preferably 1 to 3. 2 ~R 4 Among these, it is preferable that two of them are hydroxy groups or alkoxy groups having 1 to 5 carbon atoms, it is more preferable that three of them are hydroxy groups or alkoxy groups having 1 to 5 carbon atoms, and it is even more preferable that three of them are alkoxy groups having 1 to 5 carbon atoms.

[0018] The group represented by Q is -NR 5 R 6 and R 5 or R 6 The group represented by -R 7 -SiR 8 n (OA) 3-n If R 7 Among these, R is preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms, and even more preferably an alkylene group having 2 to 6 carbon atoms. 8Among these, R is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 1 to 2 carbon atoms. Among these, A is preferably H or an alkyl group having 1 to 4 carbon atoms, and more preferably H or an alkyl group having 1 to 3 carbon atoms. Among these, n is preferably 0, 1 or 2, more preferably 0 or 1, and most preferably 0. R 5 and R 6 Among these, Q is preferably H or a hydrocarbon group having 1 to 24 carbon atoms, more preferably H or an alkylene group having 1 to 8 carbon atoms, and even more preferably H. Among these, Q is preferably an azide group.

[0019] Among these, E is preferably —NH—, —O—, or —S—, and more preferably —NH—.

[0020] As the silane compound represented by formula (I), it is preferable to use 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide represented by the following formula (i). [ka]

[0021] Although the mechanism of interaction between syndiotactic polystyrene resin and filler is unknown, it is believed that bonding of silane groups to the filler coats the filler surface with the silane compound represented by formula (I), improving the dispersibility of the filler in the syndiotactic polystyrene resin. Furthermore, it is believed that the syndiotactic polystyrene resin bonds to the unsaturated group of the azide group of the silane compound represented by formula (I), and that the azide group exists in a reduced state to an amino group. In other words, when the 1,3,5-triazine and alkoxysilyl or silanol groups derived from the silane compound represented by formula (I) bond to the filler, the silane compound represented by formula (I) bonds to the syndiotactic polystyrene resin via the amino group, improving the strength (assessed by tensile modulus) and linear expansion properties. In this specification, the term "amino group" refers to a group represented by -NHR (where R is other than a hydrogen atom), and is used to encompass groups corresponding to the structure obtained by removing a hydrogen atom from a primary amine.

[0022] As the silane compound represented by formula (I), R 2 ~R 4 When a compound in which is a hydroxy group is used, the silane compound represented by formula (I) is present in the syndiotactic polystyrene resin as the following formula (II).

[0023] [ka]

[0024] In formula (II), R 1 ~R 4 The substituents of E and Q are the same as those in the compound of formula (I).

[0025] The silane compound represented by formula (I) may exist in any form as long as it can bond with the filler. For example, the component derived from the silane compound represented by formula (I) may be present without gaps over the entire surface of the filler to form a film structure.

[0026] (syndiotactic polystyrene resin) The resin molded article contains a syndiotactic polystyrene resin. The syndiotactic polystyrene resin refers to a resin in which the benzene rings contained in adjacent styrene units are arranged alternately (hereinafter referred to as syndiotacticity) with respect to the plane formed by the main chain of the polymer block at a high rate. This refers to polystyrene having a syndiotacticity of typically 75 mol % or more, preferably 85 mol % or more, in racemic diad (r), or typically 30 mol % or more, preferably 50 mol % or more, in racemic pentad (rrrr).

[0027] Whether the benzene rings are alternately arranged with respect to the plane formed by the main chain of the polymer block can be quantitatively identified, for example, by carbon isotope nuclear magnetic resonance (C-NMR).C-NMR can quantify the proportion of each of a plurality of consecutive structural units, for example, two consecutive monomer units as a dyad, three consecutive monomer units as a triad, and five consecutive monomer units as a pentad.

[0028] Examples of syndiotactic polystyrene resins include polystyrene, poly(alkylstyrene), poly(halogenated styrene), poly(halogenated alkylstyrene), poly(alkoxystyrene), poly(vinyl benzoate ester), and hydrogenated polymers thereof, as well as mixtures of two or more selected from these, and copolymers containing these as the main component. Examples of poly(alkylstyrene)s include poly(methylstyrene), poly(ethylstyrene), poly(isopropylstyrene), poly(butylstyrene), poly(phenylstyrene), poly(vinylnaphthalene), and poly(vinylstyrene). Examples of poly(halogenated styrene)s include poly(chlorostyrene), poly(bromostyrene), and poly(fluorostyrene). Examples of poly(halogenated alkylstyrenes) include poly(chloromethylstyrene). Examples of poly(alkoxystyrenes) include poly(methoxystyrene) and poly(ethoxystyrene). Among these, preferred styrene-based polymers include polystyrene, poly(alkylstyrene) [e.g., poly(p-methylstyrene), poly(m-methylstyrene), poly(p- or t-butylstyrene)], poly(halogenated styrene) [e.g., poly(p-chlorostyrene), poly(m-chlorostyrene), poly(p-fluorostyrene)], hydrogenated polystyrene, and copolymers containing these structural units. Considering that the para-position of styrene is easily modified and an ion-exchange group is easily introduced, a styrene homopolymer (polystyrene) is particularly preferred. One or more types of syndiotactic polystyrene-based resins may be used.

[0029] The resin molded article preferably contains 50 to 90 parts by mass of syndiotactic polystyrene resin when the entire resin molded article is taken as 100 parts by mass. By making the content of syndiotactic polystyrene resin 50 parts by mass or more, both low dielectric constant and heat resistance can be achieved. The content of syndiotactic polystyrene resin is more preferably 55 parts by mass or more, and even more preferably 60 parts by mass or more. Furthermore, by making the content of syndiotactic polystyrene resin 90 parts by mass or less, transmission loss can be suppressed. The content of syndiotactic polystyrene resin is more preferably 85 parts by mass or less, and even more preferably 80 parts by mass or less.

[0030] The syndiotactic polystyrene resin can be produced by a known method. For example, "Zarek" manufactured by Idemitsu Kosan Co., Ltd. can be used as the syndiotactic polystyrene resin.

[0031] (surface-modified filler) The resin molded article contains a filler (filling agent) surface-modified with a silane-based compound represented by formula (I). The resin molded article must contain 1 to 50 parts by mass of the filler surface-modified with the silane-based compound represented by formula (I), based on 100 parts by mass of the entire resin molded article. By including the filler in an amount of 1 part by mass or more, the tensile modulus of the resin molded article can be increased, resulting in high strength, and low linear expansion. The filler content is more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more. However, if the filler content exceeds 50 parts by mass, the tensile modulus may be reduced and linear expansion may increase. Therefore, the filler content is more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less.

[0032] The raw filler to be surface-modified with the silane compound represented by formula (I) can be an inorganic filler and / or an organic filler, and it is preferable to use at least an inorganic filler. As the inorganic filler, for example, an inorganic filler containing boron nitride or an inorganic filler containing SiO2 is preferably used. As the organic filler, for example, a foamable resin can be used. A foamable resin is a resin that foams when heated, generating, for example, nitrogen gas, carbon dioxide gas, carbon monoxide gas, ammonia gas, or water vapor. For example, it is preferable to use a resin that foams when heated to 250°C or higher. By incorporating a small amount of a foamable resin, the dielectric constant of the resin molded product can be reduced. Examples of foaming agents that can be used include sodium bicarbonate and ammonium carbonate. Examples of resins that can be used include acrylic resins. Foamable resins can be produced, for example, by blending a foaming agent with a thermoplastic resin or by contacting a resin with nitrogen or carbon dioxide in a supercritical state. As the organic filler, for example, foam beads "Advancell EM501" manufactured by Sekisui Chemical Co., Ltd. can be used.

[0033] The raw filler may be a low dielectric filler, a high dielectric filler, or both a low dielectric filler and a high dielectric filler. It is preferable to use a low dielectric filler or a high dielectric filler alone, and it is more preferable to use a low dielectric filler. A low dielectric filler means a filler having a dielectric constant of 5.5 F / m or less at a frequency of 10 GHz. By blending a predetermined amount of low dielectric filler, it is possible to improve heat resistance without increasing transmission loss. The dielectric constant of the low dielectric filler at a frequency of 10 GHz is preferably 5.0 F / m or less, more preferably 4.8 F / m or less. The dielectric constant may be measured by a cavity resonance perturbation method.

[0034] The low dielectric filler may be an inorganic filler and / or an organic filler, and it is preferable to use at least an inorganic filler. For example, it is preferable to use an inorganic filler containing boron nitride or an inorganic filler containing SiO2.

[0035] When the low dielectric filler is an inorganic filler containing boron nitride, the low dielectric filler preferably contains 80% by mass or more of boron nitride, more preferably 90% by mass or more, even more preferably 95% by mass or more, and most preferably 100% by mass, when the entire low dielectric filler is taken as 100% by mass. Boron nitride has a dielectric constant of 4.5 F / m at a frequency of 10 GHz. As the boron nitride, for example, spherical nano-sized "BN" manufactured by Denka Co., Ltd. can be used.

[0036] When the low dielectric filler is an inorganic filler containing SiO2, when the entire low dielectric filler is taken as 100 mass%, the SiO2 content is preferably 45 to 99 mass%, more preferably 48 mass% or more, even more preferably 50 mass% or more, more preferably 95 mass% or less, even more preferably 90 mass% or less.

[0037] The shape of the low dielectric filler is not particularly limited, and it may have a hollow structure. By using a hollow low dielectric filler, the dielectric constant of the resin molded body can be reduced. The low dielectric filler may be surface-treated with a coupling agent. When the low dielectric filler is surface-treated with a coupling agent, the surface treated with the coupling agent may be further surface-modified with a silane compound represented by formula (I).

[0038] As the low dielectric filler, for example, low dielectric glass can be used. Low dielectric glass refers to glass with a dielectric constant of 5.5 F / m or less at a frequency of 10 GHz. When the entire low dielectric glass is taken as 100% by mass, the low dielectric glass preferably contains 45 to 90% by mass of SiO2. The SiO2 content is more preferably 48% by mass or more, even more preferably 50% by mass or more, and more preferably 85% by mass or less, even more preferably 80% by mass or less.

[0039] The low dielectric glass preferably further contains B2O3, and the B2O3 content is preferably 10 to 30 mass% when the entire low dielectric glass is taken as 100 mass%. By containing B2O3 in this range, transmission loss can be reduced. When the entire low dielectric glass is taken as 100 mass%, the B2O3 content is more preferably 12 mass% or more, even more preferably 13 mass% or more, and more preferably 28 mass% or less, even more preferably 25 mass% or less.

[0040] The low dielectric glass preferably further contains CaO, and the CaO content is preferably 0.01 to 20% by mass when the entire low dielectric glass is taken as 100% by mass. By setting the CaO content to 0.01% by mass or more, costs can be reduced. The CaO content is more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more. On the other hand, if the mass of CaO is excessive, the dielectric constant of the resin molded product tends to increase. Therefore, the CaO content is preferably 20% by mass or less. The CaO content is more preferably 15% by mass or less, and even more preferably 13% by mass or less.

[0041] The low-dielectric glass may further contain SrO, but the SrO content is preferably 0.150% by mass or less when the entire low-dielectric glass is taken as 100% by mass. By setting the SrO content to 0.150% by mass or less, the dielectric constant of the resin molded body can be reduced. The SrO content is more preferably 0.120% by mass or less, and even more preferably 0.080% by mass or less. The SrO content is preferably as low as possible, but reducing it to less than 0.001% by mass reduces productivity. Therefore, the SrO content is preferably 0.001% by mass or more.

[0042] In the resin molded article, the mass ratio of the low dielectric filler to the syndiotactic polystyrene resin (low dielectric filler / syndiotactic polystyrene resin) preferably satisfies the range of 0.05 to 0.65. The mass ratio of the low dielectric filler to the syndiotactic polystyrene resin is more preferably 0.1 or more, even more preferably 0.15 or more, and more preferably 0.6 or less, even more preferably 0.55 or less.

[0043] A high dielectric filler means a filler having a dielectric constant of more than 5.5 F / m at a frequency of 10 GHz. The inclusion of a high dielectric filler can further improve heat resistance. The high dielectric filler preferably has a dielectric constant of 10 F / m or less at a frequency of 10 GHz. The dielectric constant may be measured by a cavity resonance perturbation method.

[0044] As the high dielectric filler, an organic filler may be used, but it is preferable to use an inorganic filler.

[0045] The highly dielectric inorganic filler preferably contains SiO2. When the highly dielectric inorganic filler contains SiO2, it preferably contains 45 to 90 mass% of SiO2 when the entire highly dielectric inorganic filler is taken as 100 mass%. The SiO2 content is more preferably 48 mass% or more, even more preferably 50 mass% or more, and more preferably 85 mass% or less, even more preferably 80 mass% or less.

[0046] The highly dielectric inorganic filler may further contain B2O3, but the B2O3 content is preferably less than 10% by mass, more preferably 9% by mass or less, and even more preferably 8% by mass or less, when the entire highly dielectric inorganic filler is taken as 100% by mass.

[0047] The highly dielectric inorganic filler may further contain CaO. The CaO content is 15% by mass or more, more preferably more than 20% by mass, and even more preferably 21% by mass or more, when the entire highly dielectric inorganic filler is taken as 100% by mass. The upper limit of the CaO content is, for example, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less.

[0048] The highly dielectric inorganic filler may further contain SrO. The content of SrO is preferably more than 0.150% by mass, more preferably 0.160% by mass or more, and even more preferably 0.170% by mass or more, when the entire highly dielectric inorganic filler is taken as 100% by mass.

[0049] As the highly dielectric inorganic filler, for example, "EPH80M-01N" manufactured by Nippon Electric Glass Co., Ltd. can be used.

[0050] When the resin molding contains both a low dielectric filler and a high dielectric inorganic filler, the mass ratio of the high dielectric inorganic filler to the low dielectric filler (high dielectric inorganic filler / low dielectric filler) is preferably 0.8 to 1.2. The mixing ratio of the high dielectric inorganic filler to the low dielectric filler is more preferably 0.9 or more, even more preferably 0.95 or more, and more preferably 1.1 or less, even more preferably 1.05 or less.

[0051] (Temperature-raised crystallization temperature (hereinafter sometimes referred to as Tc1)) The temperature-rising crystallization temperature (Tc1) of the resin molded body is preferably 200°C or lower. The temperature-rising crystallization temperature (Tc1) refers to the temperature at the maximum part of the exothermic peak observed during heating. By setting the temperature-rising crystallization temperature of the resin molded body to 200°C or lower, it is possible to improve the heat resistance (solder reflow heat resistance) and linear expansion characteristics. The temperature-rising crystallization temperature of the resin molded body is more preferably 195°C or lower, and even more preferably 190°C or lower. The temperature-rising crystallization temperature of the resin molded body is preferably as low as possible, but the lower limit is usually about 110°C. The temperature-rising crystallization temperature of the resin molded body can be calculated, for example, by measurement and analysis using a differential scanning calorimeter (hereinafter sometimes referred to as DSC).

[0052] (Crystallization temperature (hereinafter sometimes referred to as Tc2)) The temperature-reducing crystallization temperature (Tc2) of the resin molded body is preferably 260°C or lower. The temperature-reducing crystallization temperature (Tc2) refers to the temperature at the maximum of the exothermic peak observed during cooling. By setting the temperature-reducing crystallization temperature of the resin molded body to 260°C or lower, productivity can be improved. The temperature-reducing crystallization temperature of the resin molded body is more preferably 255°C or lower, and even more preferably 250°C or lower. The lower limit of the temperature-reducing crystallization temperature of the resin molded body is preferably 180°C or higher. By setting the temperature-reducing crystallization temperature of the resin molded body to 180°C or higher, heat resistance (solder reflow heat resistance) and linear expansion characteristics can be improved. The temperature-reducing crystallization temperature of the resin molded body is more preferably 190°C or higher, and even more preferably 200°C or higher. The temperature-reducing crystallization temperature of the resin molded body can be calculated, for example, by differential scanning calorimetry (DSC) measurement and analysis.

[0053] (crystallinity) The crystallinity of the resin molded body is preferably 20% or more. The crystallinity is a value calculated from the ratio of the latent heat at the melting point to the latent heat at the crystallization temperature (Tc2) upon cooling. By making the crystallinity of the resin molded body 20% or more, the heat resistance (solder reflow heat resistance) and linear expansion characteristics can be improved. The crystallinity of the resin molded body is more preferably 25% or more, even more preferably 50% or more, and particularly preferably 80% or more. The crystallinity of the resin molded body is preferably as high as possible, and may be 100%. The crystallinity of the resin molded body can be calculated, for example, by differential scanning calorimetry (DSC) measurement and analysis.

[0054] The temperature-rising crystallization temperature, temperature-decreasing crystallization temperature, and crystallinity of the resin molded body can be controlled, for example, by adjusting the amount of low-dielectric filler contained in the resin molded body or by adjusting the temperature of the cooling touch roll used in the production process. By adjusting the temperature of the cooling touch roll to 150°C or less, the resin molded body can be rapidly cooled, thereby lowering the temperature-rising crystallization temperature, temperature-decreasing crystallization temperature, and crystallinity of the resin molded body. Furthermore, excessive softening of the resin molded body can be prevented, thereby improving productivity. The temperature of the cooling touch roll is preferably 120°C or less, more preferably 100°C or less. The lower limit of the temperature of the cooling touch roll is preferably 10°C or higher. By setting the temperature of the cooling touch roll to 10°C or higher, water droplets can be prevented from adhering to the cooling touch roll, thereby improving the appearance of the resin molded body. The temperature of the cooling touch roll is more preferably 15°C or higher, and even more preferably 25°C or higher.

[0055] The resin molded article thus obtained has sufficient heat resistance as it is, but it may also be subjected to a heat treatment. By subjecting the resin molded article to a heat treatment, the heat resistance of the resin molded article can be further improved. In addition, by subjecting the resin molded article to a heat treatment, the linear expansion coefficient of the resin molded article can be reduced.

[0056] The heat treatment conditions are, for example, preferably performed in a temperature range of 80°C to 240°C, more preferably 100°C or higher, even more preferably 150°C or higher, more preferably 220°C or lower, and even more preferably 210°C or lower. By setting the heat treatment temperature to 80°C or higher, the heat resistance of the resin molded body can be further improved. In addition, the linear expansion coefficient of the resin molded body can be reduced. However, if the heat treatment temperature is too high, the resin molded body may be deformed, so the heat treatment temperature is preferably 240°C or lower.

[0057] The method for subjecting the resin molded body to heat treatment is not particularly limited, and examples thereof include heat setting and electron beam irradiation, with heat setting being preferred. When heat setting is performed, for example, a method of heat treatment by heating in a dryer is mentioned.

[0058] (MD tensile modulus) The resin molded article preferably has a tensile modulus in the MD of 3.0 GPa or more. MD refers to the flow direction. A tensile modulus in the MD of 3.0 GPa or more can increase the strength of the resin molded article. The tensile modulus in the MD of the resin molded article is more preferably 3.1 GPa or more, and even more preferably 3.2 GPa or more. There is no particular upper limit to the tensile modulus in the MD of the resin molded article, but it is preferably, for example, 4 GPa or less, more preferably 3.8 GPa or less, and even more preferably 3.6 GPa or less. The tensile modulus in the MD of the resin molded article can be calculated, for example, by performing a tensile test using a tension-compression tester and calculating it from the slope of the SS curve in the strain range of 0.05 to 0.25%. The tensile modulus in the MD of the resin molded article can be controlled by adjusting the amount of surface-modified filler contained in the resin molded article.

[0059] The resin molded body preferably has a tensile modulus in the MD direction of 3.0 GPa or more, a cooling crystallization temperature of 260° C. or less, and a crystallinity of 50% or more.

[0060] The resin molded product preferably has a linear expansion coefficient of 200 ppm or less. When the resin molded product has a linear expansion coefficient of 200 ppm or less, it is less likely to deform due to heat. The linear expansion coefficient of the resin molded product is more preferably 190 ppm or less, and even more preferably 180 ppm or less. The lower limit of the linear expansion coefficient of the resin molded product is, for example, preferably 80 ppm or more, more preferably 90 ppm or more, and even more preferably 100 ppm or more. The linear expansion coefficient of the resin molded product can be measured, for example, using a thermomechanical analyzer. The linear expansion coefficient of the resin molded product can be controlled by adjusting the amount of surface-modifying filler contained in the resin molded product or the temperature during heat treatment.

[0061] It is preferable that the resin molded body has a good appearance, specifically, an L value of 70 or more or a gloss value of 30% or more, and more preferably an L value of 70 or more and a gloss value of 30% or more.

[0062] (L value) The L value (color L value) of the resin molded product is preferably 65 or more. The L value is a scale indicating brightness, and a larger value means less darkening and higher brightness, resulting in a better appearance of the resin molded product and improved product value. The L value of the resin molded product is more preferably 68 or more, and even more preferably 70 or more. There is no particular upper limit for the L value of the resin molded product, and it may be 100 or 90 or less. The L value can be measured using a color difference meter (such as the "TC-1500MC-88" manufactured by Tokyo Denshoku Corporation) and irradiating the center of the test piece with standard light using a C light source to determine the L value in the Lab display system.

[0063] (gloss value) The gloss value of the resin molded product is preferably 25% or more. By making the gloss value of the resin molded product 25% or more, the appearance of the resin molded product becomes good and the product value is improved. The gloss value of the resin molded product is more preferably 30% or more, even more preferably 35% or more, and particularly preferably 50% or more. The upper limit of the gloss value of the resin molded product is not particularly limited, but is, for example, about 90%. The gloss value of the resin molded product can be measured and analyzed using a gloss meter.

[0064] The L value and gloss value of the resin molded product can be controlled, for example, by adjusting the amount of surface-modifying filler contained in the resin molded product or by adjusting the surface roughness Rz of the cooling touch roll used in the manufacturing process. The surface roughness Rz of the cooling touch roll used in the manufacturing process is preferably adjusted to 110 μm or less, more preferably 100 μm or less, even more preferably 80 μm or less, and particularly preferably 50 μm or less.

[0065] The resin molded article can be suitably used as a material for electronic devices or communication devices used in high frequency bands of 1 GHz or higher, because transmission loss can be kept low even when used in high frequency bands.

[0066] The resin molded body preferably has a dielectric constant (εr) of 3.4 F / m or less at a frequency of 10 GHz, as determined by the cavity resonance perturbation method. If the dielectric constant in the high frequency band is too high, it will be difficult to use in applications such as 5G communication equipment and automotive radar. The dielectric constant (εr) is more preferably 3.2 F / m or less.

[0067] The shape of the resin molded product is not particularly limited, but examples include a film, a sheet, a plate, etc., and a film is preferred. The thickness of the film is, for example, preferably 0.1 mm to 1 mm, more preferably 0.15 mm or more, even more preferably 0.2 mm or more, more preferably 0.9 mm or less, and even more preferably 0.8 mm or less.

[0068] The present invention also includes a substrate that is a laminate of a film that is the resin molded article of the present invention and a metal film. This substrate can be suitably used as a material for electronic devices or communication devices used in high frequency bands with frequencies of 1 GHz or higher.

[0069] Examples of metal films include films of copper, aluminum, iron, stainless steel, nickel, etc., and alloy films of these materials, with copper films being most preferred.

[0070] The styrene resin molded article according to the present invention can be produced by molding a styrene resin composition containing a syndiotactic polystyrene resin and a filler whose surface has been modified with a silane compound represented by formula (I). The surface-modified filler is blended in an amount of 1 to 50 parts by mass relative to 100 parts by mass of the entire styrene resin composition.

[0071] The filler surface-modified with the silane compound represented by formula (I) may be produced by coating a commercially available filler (raw material filler) with the silane compound represented by formula (I). When the commercially available filler has been surface-treated with, for example, a coupling agent, the surface of the surface treatment film may be coated with the silane compound represented by formula (I), or the surface treatment film may be removed and then coated with the silane compound represented by formula (I).

[0072] The substrate according to the present invention, which is a laminate of a film that is a resin molded article and a metal film, can be produced by laminating a film obtained by molding the styrene-based resin composition and a metal film. [Example]

[0073] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples, and it is of course possible to carry out the invention by making modifications within the scope that is compatible with the above-mentioned and below-mentioned aims, and all such modifications are included in the technical scope of the present invention.

[0074] The following materials were used in the examples and comparative examples.

[0075] As the syndiotactic polystyrene resin, "Zarek 130ZC" manufactured by Idemitsu Kosan Co., Ltd. was used.

[0076] As the filler surface-modified with the silane compound represented by formula (I), an inorganic filler was prepared as the raw filler, and the surface of the inorganic filler was coated with 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide as the silane compound represented by formula (I) to form a filler (surface-modified filler). As the inorganic filler, a low-dielectric filler or a high-dielectric inorganic filler was prepared. A specific description is given below.

[0077] Low dielectric filler Low-dielectric glass "HTD-09100T" manufactured by Tochu Corporation was prepared as the inorganic filler material. "HTD-09100T" is a round glass with a dielectric constant of 4.2 F / m at a frequency of 10 GHz. "HTD-09100T" contains 51% by mass of SiO2, 24% by mass of B2O3, 8.7% by mass of CaO, and 0.02% by mass of SrO. "HTD-09100T" had a silane-based surface treatment on its glass surface. Next, the silane-based coating formed on the surface of "HTD-09100T" was removed to produce "HTD-09100T without surface treatment." Specifically, "HTD-09100T" was baked in an oven at 400°C for 5 hours, cooled, washed with acetone, further washed with ion-exchanged water, filtered, and dried at 120°C to produce "HTD-09100T surface treatment-removed product." Next, the surface of the "HTD-09100T surface treatment-removed product" was coated with 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide to produce "HTD-09100T resurface-modified product." Specifically, the "HTD-09100T surface treatment-removed product" was immersed in an ethanol solution containing 0.1% by mass of 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide manufactured by Io Chemical Research Institute, filtered, and dried at 120°C for 30 minutes to produce "HTD-09100T resurface-modified product." The resulting "HTD-09100T resurface-modified product" corresponds to the surface-modified filler.

[0078] Highly dielectric inorganic filler Nippon Electric Glass Co., Ltd.'s "EPH80M-01N" was prepared as the inorganic filler material. "EPH80M-01N" was a round glass with a dielectric constant of 6.5 F / m at a frequency of 10 GHz. "HTD-09100T" contained 56% by mass of SiO2, 5.7% by mass of B2O3, 21% by mass of CaO, and 0.18% by mass of SrO. "EPH80M-01N" had a silane-based surface treatment applied to its glass surface. Next, the silane-based coating formed on the surface of "EPH80M-01N" was removed to produce "EPH80M-01N without surface treatment." Specifically, "EPH80M-01N" was baked in an oven at 400°C for 5 hours, cooled, washed with acetone, further washed with ion-exchanged water, filtered, and dried at 120°C to produce an "EPH80M-01N surface treatment-removed product." Next, the surface of the "EPH80M-01N surface treatment-removed product" was coated with 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide to produce an "EPH80M-01N resurface-modified product." Specifically, the "EPH80M-01N surface treatment-removed product" was immersed in an ethanol solution containing 0.1% by mass of 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide manufactured by Io Chemical Research Institute, filtered, and dried at 120°C for 30 minutes to produce an "EPH80M-01N resurface-modified product." The resulting "EPH80M-01N resurface-modified product" corresponds to the surface-modified filler.

[0079] Example 1 78 parts by mass of "Zarek 130ZC" syndiotactic polystyrene resin and 22 parts by mass of "HTD-09100T surface-modified product" were mixed to obtain resin composition 1. Resin composition 1 was fed into a 50 mm screw diameter co-rotating twin-screw extruder, extruded, water-cooled, and granulated to produce resin pellets. The resulting resin pellets were fed into a 50 mm screw diameter single-screw extruder and cooled using a cooling touch roll to produce rod-shaped test specimens (0.3 mmΦ x 300 mm) and sheet-shaped test specimens (length 130 mm x width 100 mm x thickness 0.3 mm) as styrene resin molded bodies. The cooling touch roll used had a surface roughness Rz of 30 μm, and the temperature of the cooling touch roll was set to 25 °C.

[0080] (Comparative Example 1) Resin composition 2 was obtained under the same conditions as in Example 1, except that the "HTD-09100T surface treatment removed product" was used instead of the "HTD-09100T re-surface modified product" in Example 1. Next, using resin composition 2 under the same conditions as in Example 1, a rod-shaped test material (0.3 mmΦ×300 mm) and a sheet-shaped test material (length 130 mm×width 100 mm×thickness 0.3 mm) were produced as styrene-based resin molded articles.

[0081] Example 2 78 parts by mass of "Xarek 130ZC" as a syndiotactic polystyrene resin and 22 parts by mass of "EPH80M-01N resurface-modified product" were mixed to obtain Resin Composition 3. Next, using Resin Composition 3, a rod-shaped test material (0.3 mmΦ×300 mm) and a sheet-shaped test material (length 130 mm × width 100 mm × thickness 0.3 mm) were produced under the same conditions as in Example 1.

[0082] (Comparative Example 2) Resin composition 4 was obtained under the same conditions as in Example 2, except that "EPH80M-01N surface treatment removed product" was used instead of "EPH80M-01N re-surface modified product" in Example 2. Next, using resin composition 4, a rod-shaped test material (0.3 mmΦ×300 mm) and a sheet-shaped test material (length 130 mm×width 100 mm×thickness 0.3 mm) were produced under the same conditions as in Example 1.

[0083] Example 3 Using the resin composition 1 obtained in Example 1, a rod-shaped test material (0.3 mmΦ×300 mm) and a sheet-shaped test material (length 130 mm × width 100 mm × thickness 0.3 mm) were produced under the same conditions as in Example 1, except that a cooling touch roll with a surface roughness Rz of 110 μm was used.

[0084] (Comparative Example 3) Using the resin composition 2 obtained in Comparative Example 1, a rod-shaped test material (0.3 mmΦ×300 mm) or a sheet-shaped test material (length 130 mm × width 100 mm × thickness 0.3 mm) was produced under the same conditions as in Example 1, except that a cooling touch roll with a surface roughness Rz of 110 μm was used.

[0085] Example 4 The rod-shaped test material and the sheet-shaped test material produced in Example 1 were heat-set in a dryer at 200°C for 1 hour.

[0086] Comparative Example 4 The rod-shaped test material and the sheet-shaped test material produced in Comparative Example 1 were heat-set in a dryer at 200°C for 1 hour.

[0087] Example 5 The rod-shaped test material and the sheet-shaped test material produced in Example 1 were heat-set in a dryer at 170°C for 1 hour.

[0088] (Comparative Example 5) The rod-shaped test material and the sheet-shaped test material produced in Comparative Example 1 were heat-set in a dryer at 170°C for 1 hour.

[0089] Example 6 The rod-shaped test material and the sheet-shaped test material produced in Example 1 were heat-set in a dryer at 150°C for 1 hour.

[0090] (Comparative Example 6) The rod-shaped test material and the sheet-shaped test material produced in Comparative Example 1 were heat-set in a dryer at 150°C for 1 hour.

[0091] (Comparative Example 7) Resin composition 5 was obtained under the same conditions as in Example 1, except that "HTD-09100T" was used instead of "HTD-09100T resurface-modified product" in Example 1. Next, using resin composition 5, a rod-shaped test material (0.3 mmΦ×300 mm) and a sheet-shaped test material (length 130 mm×width 100 mm×thickness 0.3 mm) were produced under the same conditions as in Example 1.

[0092] The temperature-rising crystallization temperature, temperature-falling crystallization temperature, and degree of crystallinity of the obtained rod-shaped test material were calculated by DSC measurement analysis. The dielectric constant of the obtained rod-shaped test material at a frequency of 10 GHz was measured to evaluate the dielectric properties. The dielectric loss tangent of the obtained rod-shaped test material at a frequency of 10 GHz was also measured. The film-forming properties of the resin pellets made of the resin compositions obtained in the Examples and Comparative Examples when processed into sheet-shaped test material were also evaluated. The heat resistance of the obtained sheet-shaped test material was also evaluated. The tensile modulus in the MD direction of the obtained sheet-shaped test material was also measured to evaluate its strength, and the linear expansion coefficient was also measured to evaluate its linear expansion properties. The L value and gloss value of the obtained sheet-shaped test material were also measured to evaluate its appearance.

[0093] (Temperature-raising crystallization temperature (Tc1), temperature-falling crystallization temperature (Tc2), crystallinity) The heating crystallization temperature, cooling crystallization temperature, and crystallinity of rod-shaped specimens were measured using a TA Instruments TAS100 differential scanning calorimeter (DSC). A 4.0±0.3 mg specimen cut from the rod-shaped specimen was placed in an aluminum pan and heated from room temperature to 320°C at a heating rate of 20°C / min. The heating crystallization temperature (Tc1) was measured. After reaching 320°C, the specimen was held for 5 minutes and then cooled at a rate of 20°C / min. The cooling crystallization temperature (Tc2) was measured. The heating crystallization temperature (Tc1) and cooling crystallization temperature (Tc2) were determined as the maximum temperatures of their respective peaks. The crystallinity was calculated from the ratio of the latent heat of the melting point to the latent heat of the cooling crystallization temperature (Tc2). The calculated results are shown in Table 1 below.

[0094] (Dielectric properties) A 0.3mmΦ x 100mm test piece was cut from a rod-shaped test material (0.3mmΦ x 300mm), and the permittivity (εr) and dielectric loss tangent (Df) at a frequency of 10GHz were measured using the cavity resonance perturbation method. An Agilent Technologies Precision LCR Meter was used to measure the permittivity and dielectric loss tangent. The measurement results are shown in Table 1 below. Furthermore, based on the measured permittivity (εr), the dielectric properties were evaluated according to the following criteria. The evaluation results are shown in Table 1 below. Good dielectric properties (○): Dielectric constant (εr) is 3.0 F / m or less Dielectric properties are slightly inferior but within the acceptable range (△): Dielectric constant (εr) is greater than 3.0 F / m and less than 3.4 F / m

[0095] (Film forming property) The obtained resin pellets were fed into a single-screw extruder to produce a sheet-shaped test material measuring 130 mm in length, 100 mm in width, and 0.3 mm in thickness. If a sheet-shaped test material could be produced, it was evaluated as passing film-forming properties (○), and if a sheet-shaped test material could not be produced, it was evaluated as failing film-forming properties (×). If the film-forming properties were unacceptable, the subsequent measurements and evaluations of physical properties were not carried out.

[0096] (Heat resistance) Test pieces measuring 35 mm long, 5 mm wide, and 0.3 mm thick were cut from a sheet of test material (130 mm long, 100 mm wide, and 0.3 mm thick), and the resulting test pieces were immersed in a solder bath heated to 260°C for 120 seconds. The shape of the test pieces was visually observed before and after immersion to check for deformation. If no deformation was observed before and after immersion, the test pieces were rated as passing heat resistance (◎); if slight deformation but still usable, they were rated as passing heat resistance (◎ to ○); if slight deformation but still usable, they were rated as passing heat resistance (○); and if obvious deformation was observed and the test pieces were unusable, they were rated as failing heat resistance (×). The evaluation results are shown in Table 1 below.

[0097] (strength) Test pieces measuring 130mm long x 10mm wide x 0.3mm thick were cut from the sheet-like test material (130mm long x 100mm wide x 0.3mm thick). Tensile tests were performed in the MD direction using a MinebeaMitsumi NMB TG-2kN THCHNOGRAPH tension-compression testing machine at 23°C and 50% RH, with an initial chuck distance of 40mm and a tensile speed of 20mm / min. The tensile modulus was calculated from the slope of the SS curve in the strain range of 0.05 to 0.25%, and strength was evaluated. The calculated tensile modulus and the results of strength evaluation based on the tensile modulus are shown in Table 1 below. Passed strength (○): MD tensile modulus of elasticity is 3.0 GPa or more Strength failure (×): MD tensile modulus less than 3.0 GPa

[0098] (Linear expansion characteristics) Test pieces measuring 50 mm long, 50 mm wide, and 0.3 mm thick were cut out from a sheet of test material (130 mm long, 100 mm wide, and 0.3 mm thick). The linear expansion coefficient of the resulting test pieces was measured using a thermomechanical analyzer (Hitachi High-Tech Science Corporation's "TM7000" film adapter). The measurement temperature range was 30°C to 200°C. The measurement results are shown in Table 1 below. A linear expansion coefficient of 200 ppm or less was evaluated as passing the linear expansion characteristics (○), and a linear expansion coefficient of more than 200 ppm was evaluated as failing the linear expansion characteristics (×). The evaluation results are shown in Table 1 below.

[0099] (L value) A test piece measuring 50 mm long x 50 mm wide x 0.3 mm thick was cut out from a sheet-like test material (130 mm long x 100 mm wide x 0.3 mm thick), and the L value of the Lab display system was measured for the obtained test piece using a color difference meter, "TC-1500MC-88 Model" manufactured by Tokyo Denshoku Co., Ltd., using a C light source and irradiating light onto the center of the test piece. The measurement results are shown in Table 1 below.

[0100] (gloss value) A test piece measuring 70 mm long x 70 mm wide x 0.3 mm thick was cut out from a sheet-like test material (130 mm long x 100 mm wide x 0.3 mm thick). The gloss value of the obtained test piece was measured using a gloss meter "VG-2000" manufactured by Nippon Denshoku Industries Co., Ltd., at a surface angle of 60°. The measurement results are shown in Table 1 below.

[0101] [Table 1-1]

[0102] [Table 1-2]

[0103] The following can be concluded from Table 1. The styrene-based resin molded articles obtained in Examples 1 to 6 satisfy the requirements defined by the present invention, having low transmission loss and heat resistance, as well as high tensile modulus, high strength, and low linear expansion. In particular, the styrene-based resin molded articles obtained in Examples 1 and 4 to 6 had large L values ​​and gloss values ​​and good appearances. On the other hand, the styrene-based resin molded articles obtained in Comparative Examples 1 to 7 had low transmission loss and heat resistance, but low tensile modulus and low strength. In particular, the styrene-based resin molded articles obtained in Comparative Examples 1 and 2 had high linear expansion coefficients and were unable to achieve low linear expansion.

Claims

1. A styrene-based resin molded product containing a syndiotactic polystyrene-based resin, When the entire styrene-based resin molded body is taken as 100 parts by mass, A styrene-based resin molded article containing 1 to 50 parts by mass of a filler whose surface has been modified with a silane-based compound represented by the following formula (I): 【Chemical 1】 [In formula (I), R １ is an alkylene group having 1 to 10 carbon atoms. R ２ ~R ４ are each independently a hydroxy group, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms, and R ２ ~R ４ At least one of the groups is a hydroxy group or an alkoxy group having 1 to 5 carbon atoms. Q is an azide group or -NR ５ R ６ and R ５ and R ６ are each independently H, a hydrocarbon group having 1 to 24 carbon atoms, or -R ７ -SiR ８ ｎ (OA) ３－ｎ and R ７ is a chain divalent hydrocarbon group having 1 to 12 carbon atoms, and R ８ is a chain hydrocarbon group having 1 to 4 carbon atoms; A is H or a chain hydrocarbon group having 1 to 4 carbon atoms; and n is an integer of 0 to 3. E is —NH—, —O—, —S—, or —NHCO—.]

2. 2. The styrene resin molded article according to claim 1, which has a tensile modulus in the machine direction of 3.0 GPa or more, a crystallization temperature upon cooling of 260°C or less, and a crystallinity of 50% or more.

3. 2. The styrene resin molded article according to claim 1, which has a linear expansion coefficient of 200 ppm or less.

4. 2. The styrene resin molded article according to claim 1, which has an L value of 70 or more and a gloss value of 30% or more.

5. 2. The styrene resin molded article according to claim 1, which is used in electronic equipment or communication equipment for use in a high frequency band of 1 GHz or more.

6. 2. The styrene resin molded article according to claim 1, wherein the filler is an inorganic filler.

7. The styrene resin molded article according to any one of claims 1 to 6, which is a film.

8. A substrate which is a laminate of the styrene resin molded article according to any one of claims 1 to 6, which is a film, and a metal film.

Images