JP2008112785A - Liquid crystal polyester resin composition and electromagnetic shielding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for an electromagnetic shield material having a high electromagnetic wave shield effect and electrical insulation properties, and to provide an electromagnetic shielding member in which the composition is formed. <P>SOLUTION: A liquid crystal polyester resin composition 1 contains a filler A1 made of a mineral containing silicon, a filler A2 containing magnetic metal, and liquid crystal polyester B as components. In a liquid crystal polyester resin composition 2 of 1, A1 is a filler made of ceramic or a filler made of a mineral. In a molding 3, one of the liquid crystal polyester resin compositions is formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electromagnetic wave shielding member.

  In recent years, with the explosive spread of mobile phones and the enhancement of the performance of OA devices such as personal computers, the operating frequency of such electronic devices has been increased. On the other hand, an electronic device that operates at such a high-frequency operating frequency has a problem that high-frequency electromagnetic waves are radiated from electronic components such as a processor or a communication cable in the electronic device, and the electronic device malfunctions due to the electromagnetic waves. Yes. In addition, the electromagnetic waves cause malfunctions to other electronic devices, and there are concerns about the influence on the human body, and countermeasures against the electromagnetic waves have become indispensable.

Conventionally, as a countermeasure against electromagnetic waves, an electromagnetic wave shielding method that suppresses the emission of electromagnetic waves by using a metal case or the like as an electromagnetic wave shielding member and covering the electronic components has been taken. However, it is difficult to reduce the size or weight of the metal case, and it is impossible to cope with the downsizing and portability of electronic devices. As an electromagnetic wave shielding material that solves this problem, Patent Document 1 discloses a composition in which a soft magnetic metal flat powder having iron as a base metal having a specific bulk density / true density ratio is mixed with a resin binder. Since the composition also uses conductive iron powder, as an electromagnetic wave shielding member for an electronic component (for example, between an internal element and a terminal of an electronic device) that requires insulation, like the metal case. Is unsuitable.
Thus, instead of the conventional electromagnetic wave shielding member, an electromagnetic wave shielding member that uses a resin material that is excellent in molding processability and light weight capable of forming a small part and has electrical insulation has been demanded.

JP 2003-209010 A (Claims)

  An object of the present invention is to provide a composition for an electromagnetic shielding member having a high degree of electromagnetic shielding effect and electrical insulation, and particularly to provide a resin composition that can be expected to have moldability and lightness.

  As a result of intensive studies to find an electromagnetic wave shielding member that can solve the above-mentioned problems, the present inventors have completed the present invention.

That is, the present invention provides the following liquid crystal polyester resin composition [1].
[1] A liquid crystal polyester resin composition containing the following component (A1), component (A2) and component (B).
(A1) a filler made of an inorganic substance containing silicon (A2) at least selected from the group consisting of a magnetic metal, a magnetic metal oxide (magnetic metal oxide) and a complex containing a magnetic metal as an ion (magnetic metal complex) 1 type of filler (B) liquid crystal polyester

（式中、Ａｒ₁は、１，４−フェニレン基、２,６−ナフタレンジイル基又は４，４’−ビフェニリレン基を表す。Ａｒ₂、Ａｒ₃は、それぞれ独立に、１，４−フェニレン基、２,６−ナフタレンジイル基、１，３−フェニレン基又は４，４’−ビフェニリレン基を表す。また、Ａｒ₁、Ａｒ₂、Ａｒ₃は、その芳香環上の水素原子の一部又は全部が、ハロゲン原子、アルキル基、アリール基に置換されていてもよい。）
［１０］成分（Ｂ）が前記の（Ｂ３）の液晶ポリエステルを含む［９］の液晶ポリエステル樹脂組成物 Furthermore, the present invention provides the following [2] to [8] as preferred embodiments according to the above [1].
[2] The component (A2) is at least 1 selected from the group consisting of a magnetic metal having a relative permeability of 100 or more, a magnetic metal oxide having a relative permeability of 100 or more, and a magnetic metal complex having a relative permeability of 100 or more. [1] Liquid crystalline polyester resin composition [3], wherein component (A2) is iron, nickel, an alloy containing iron, an alloy containing nickel, an iron complex, and a nickel complex The liquid crystal polyester resin composition [4] component (A1), wherein the component (A1) is a filler comprising at least one selected from the group consisting of a filler containing silicon and / or silicon. The liquid crystal polyester resin composition [5] component (A1) of any one of [1] to [3], which is a filler composed of a mineral containing a flaky filler, is any one of [1] to [4] Liquid Crystalline Polyester Resin Composition [6] Component (A1) is a filler made of glass containing silicon and / or a filler made of mica [1] to [5] Liquid crystal polyester resin composition [7] Liquid crystal When the total amount of the polyester resin composition is 100% by volume, the liquid crystal polyester resin composition according to any one of [1] to [6], wherein the component (A1) is 5% by volume or more and 35% by volume or less [8] Liquid crystal polyester resin When the total amount of the composition is 100% by volume, the component (A2) is 5% by volume or more and 35% by volume or less [1] to [5] any one of the liquid crystal polyester resin compositions [9] component (B) The liquid crystal polyester resin composition according to any one of [1] to [8], which is at least one liquid crystal polyester selected from the following (B1), (B2) and (B3): (B1) (B2) Liquid Crystalline Polyester Consisting of Repeating Units Represented by (ii) and (iii) below (B3) Repeating Unit Represented by (i), (ii) and (iii) below Liquid crystalline polyester consisting of

(In the formula, Ar ₁ represents a 1,4-phenylene group, a 2,6-naphthalenediyl group, or a 4,4′-biphenylylene group. Ar ₂ and Ar ₃ are each independently a 1,4-phenylene group. 2,6-naphthalenediyl group, 1,3-phenylene group or 4,4′-biphenylylene group, and Ar ₁ , Ar ₂ , Ar ₃ are all or part of hydrogen atoms on the aromatic ring. May be substituted with a halogen atom, an alkyl group, or an aryl group.
[10] The liquid crystal polyester resin composition according to [9], wherein the component (B) includes the liquid crystal polyester of (B3).

In addition, the present invention provides the following [11] and [12] using any of the liquid crystal polyester resin compositions.
[11] Molded product obtained by molding any one of the above liquid crystal polyester resin compositions [12] Volume resistivity is 10 ⁸ Ωm or more, and electromagnetic wave shielding effect at a frequency of 1 GHz is 10 dB or more [11] Molded products

  The liquid crystal polyester resin composition of the present invention is excellent in moldability, and a molded product obtained by molding the liquid crystal polyester resin composition is excellent in electromagnetic shielding properties and electrical insulation properties, and is useful for members relating to electronic devices. .

Hereinafter, preferred embodiments of the present invention will be described.

<Filler>
The liquid crystal polyester resin composition of the present invention contains the following components (A1) and (A2) as fillers.
(A1) a filler made of an inorganic substance containing silicon (A2) at least selected from the group consisting of a magnetic metal, a magnetic metal oxide (magnetic metal oxide) and a complex containing a magnetic metal as an ion (magnetic metal complex) One kind of filler

  First, the component (A2) will be described. Component (A2) is a filler selected from the group consisting of magnetic metals, oxides of magnetic metals, and complexes containing magnetic metals as ions. Here, the magnetic metal means “high permeability and coercive force” described in page 112 of “Metal Glossary” (June 20, 1973, Maruzen), published by Nippon Metallurgy, edited by Nippon Metallurgy. The magnetic permeability is preferably a magnetic metal of 100 or more, more preferably a magnetic metal of 200 or more, expressed by the relative permeability divided by the permeability of vacuum.

  Here, magnetic metals having a relative magnetic permeability of 100 or more are obtained from the relative magnetic permeability described in page 208 of Rika Chronology (Science and Technology Publications), Nonamiyuki Namba and Fumitaka Kaneko, “Electrical Materials-Dielectric Materials and Magnetic Materials”. More than 100 magnetic metals can also be selected. Preferred examples include cobalt, iron, and nickel, and particularly preferred is iron or nickel. In addition, the magnetic metal of the present invention is a concept including an alloy containing a hardly magnetic metal, and specific examples of the alloy include an Fe—Si alloy (silicon steel), an Fe—Al alloy (Alpalm). ), Fe—Ni alloy (permalloy), Fe—Co alloy, Fe—V alloy (permendur), Fe—Cr alloy, Fe—Si alloy (silicon steel), Fe—Al—Si alloy Fe-Cr-Al alloy, Fe-Cu-Nb-Si-B alloy, and Fe-Ni-Cr alloy called mu metal, and these alloys also have a relative permeability of 100 or more. Preferably used.

As the magnetic metal oxide, oxides generically referred to as ferrite containing iron oxide are preferable, and specific examples include manganese zinc ferrite and nickel zinc ferrite.
Furthermore, examples of the magnetic metal complex include carbonyl iron.
Such a magnetic metal oxide or a magnetic metal complex preferably has a relative permeability of 100 or more.

Any of the magnetic metals, oxides of magnetic metals, and complex complexes containing magnetic metals as ions can be preferably used because the relative permeability can be 100 or more, and the shape is particularly limited. Although not intended, it is preferable to use a powder that can be formed into a flat powder by physical or chemical treatment. When the filler of component (A2) is made of a magnetic metal, the surface of the filler may contain an oxide layer oxidized with oxygen in the air, but as component (A2) of the present invention Such can also be used.
Among the metal compounds exemplified above, from the viewpoint of operability, a magnetic metal (including an alloy thereof) is preferable, and iron, nickel, an iron alloy, or a nickel alloy is preferable.

Next, the component (A1) will be described.
The component (A1) is made of an inorganic substance containing silicon, and the inorganic substance is an inorganic substance selected from the group consisting of a ceramic containing silicon and a mineral containing silicic acid, and the shape thereof is a fiber. However, it is preferably in the form of short fibers or flakes having a fiber length of 10 mm or less, and more preferably in the form of flakes. Of such fillers made of ceramic or mineral, those that can be easily obtained from the market may be applied.

The filler made of ceramic is preferably a filler made of glass containing silicon, and examples of the glass include C glass and E glass. Such fillers are also easily obtained from the market.
The filler made of mineral is a filler obtained by processing a so-called naturally occurring ore, and particularly preferable filler made of mineral includes mica or talc from the viewpoint of availability, and particularly mica. Is preferred. Examples of mica include muscovite, biotite, and phlogopite, and any filler composed of mica selected from these can be used.

  Moreover, the filler made of the mineral or the filler made of the ceramic may be used as a component (A1) by mixing two or more kinds. The combination of the filler made of the mineral and the filler made of the ceramic, It can also be used as A1).

When the total amount of the liquid crystal polyester resin composition of the present invention is 100% by volume, the component (A1) is preferably 5% by volume or more and 35% by volume or less, and 10% by volume or more and 30% by volume or less. More preferably, it is 15 volume% or more and 25 volume% or less especially preferable.
On the other hand, the component (A2) is preferably 5% to 35% by volume, more preferably 10% to 30% by volume, and more preferably 15% to 25% by volume. And particularly preferred.
The total of the component (A1) and the component (A2) is preferably 10% by volume or more and 60% by volume or less, and 15% by volume or more and 50% by volume when the total amount of the liquid crystal polyester resin composition is 100% by volume. Or less, more preferably 20% by volume or more and 40% by volume or less.
When the total content of the component (A1) and the component (A2) is in the above range, a liquid crystal polyester resin composition having more excellent moldability is obtained, which is preferable.

（式中、Ａｒ₁は、１，４−フェニレン基、２,６−ナフタレンジイル基又は４，４’−ビフェニリレン基を表す。Ａｒ₂、Ａｒ₃は、それぞれ独立に、１，４−フェニレン基、２,６−ナフタレンジイル基、１，３−フェニレン基又は４，４’−ビフェニリレン基を表す。また、Ａｒ₁、Ａｒ₂、Ａｒ₃は、その芳香環上の水素原子の一部又は全部が、ハロゲン原子、アルキル基、アリール基に置換されていてもよい。） <Liquid crystal polyester>
The liquid crystal polyester (B) in the liquid crystal polyester resin composition of the present invention is a polyester that exhibits optical anisotropy when melted and forms an anisotropic melt at a temperature of 450 ° C. or lower.
Preferably, at least one liquid crystal polyester selected from the group consisting of the following (B1), (B2) and (B3) is preferable.
(B1) Liquid crystalline polyester composed of repeating units represented by the following (i) (B2) Liquid crystalline polyester composed of repeating units represented by the following (ii) and (iii) (B3) The following (i), (ii ) And (iii) liquid crystal polyesters composed of repeating units

(In the formula, Ar ₁ represents a 1,4-phenylene group, a 2,6-naphthalenediyl group, or a 4,4′-biphenylylene group. Ar ₂ and Ar ₃ are each independently a 1,4-phenylene group. 2,6-naphthalenediyl group, 1,3-phenylene group or 4,4′-biphenylylene group, and Ar ₁ , Ar ₂ , Ar ₃ are all or part of hydrogen atoms on the aromatic ring. May be substituted with a halogen atom, an alkyl group, or an aryl group.

Among the liquid crystal polyesters exemplified above, (B3) is particularly preferable, and the liquid crystal polyester resin composition using (B3) as the liquid crystal polyester has an excellent balance between moldability and heat resistance, that is, can apply normal molding conditions. In addition, there is an advantage that it has a wide range of application and high mechanical stability and chemical stability.
In the copolymerization ratio of the repeating unit of the liquid crystal polyester (B3), a preferable range is represented by (i) when the total of the above (i), (ii) and (iii) is 100 mol%. 30-80 mol% of repeating units derived from aromatic hydroxycarboxylic acid, 10-30 mol% of repeating units derived from aromatic dicarboxylic acid represented by (ii), aromatic diol represented by (iii) It is preferable that the repeating unit derived from is 10 to 35 mol%.

When the copolymerization ratio of the repeating unit derived from the aromatic hydroxycarboxylic acid is less than 30 mol%, the repeating unit derived from the aromatic dicarboxylic acid and the repeating unit derived from the aromatic dicarboxylic acid are 35 mol%. When exceeding, it exists in the tendency for resin obtained to become difficult to express liquid crystallinity.
On the other hand, when the repeating unit derived from the aromatic hydroxycarboxylic acid exceeds 80 mol%, or the repeating unit derived from the aromatic dicarboxylic acid and the repeating unit derived from the aromatic dicarboxylic acid are less than 10 mol%. Etc., the obtained liquid crystal polyester is difficult to melt and the processability tends to be lowered.

  Furthermore, the repeating unit derived from the aromatic hydroxycarboxylic acid is more preferably 40 to 70 mol%, and particularly preferably 45 to 65 mol%.

  On the other hand, the repeating unit derived from the aromatic dicarboxylic acid and the repeating unit derived from the aromatic diol are each preferably 15 to 30 mol%, more preferably 17.5 to 27.5 mol%, respectively. Especially preferred.

Examples of the monomer that forms the repeating unit represented by (i) include p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid or 4- (4-hydroxyphenyl) benzoic acid, and these benzenes. A monomer in which a hydrogen atom of a ring or a naphthalene ring is substituted with a halogen atom, an alkyl group or an aryl group is also included.
Furthermore, you may use for the ester-forming derivative mentioned later.

  Examples of the monomer that forms the repeating unit represented by (ii) include terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid or biphenyl-4,4′-dicarboxylic acid, and these benzene rings. Or the monomer by which the hydrogen atom of the naphthalene ring is substituted by the halogen atom, the alkyl group, or the aryl group is also mentioned. Further, it may be used as an ester-forming derivative described later.

  Examples of the monomer that forms the repeating unit represented by (iii) include hydroquinone, 2,6-naphthol, resorcin, or 4,4′-dihydroxybiphenyl. Furthermore, the hydrogen atom of these benzene ring or naphthalene ring is And a monomer substituted with a halogen atom, an alkyl group or an aryl group. Further, it may be used as an ester-forming derivative described later.

  As described above, any of the structural units represented by (i), (ii) or (iii) may have a substituent on the aromatic ring (benzene ring or naphthalene ring), and these substituents For example, the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and the alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, or a propyl group. , A butyl group, a hexyl group, an octyl group, and a decyl group, which may be linear or branched, and may be an alicyclic group. Examples of the aryl group include aryl groups having 6 to 20 carbon atoms represented by phenyl group and naphthyl group.

  As the monomer that forms the repeating unit represented by (i), (ii), or (iii), an ester-forming derivative is preferably used in order to facilitate polymerization in the process of producing a polyester. The ester-forming derivative refers to a monomer having a group that promotes an ester formation reaction. Specifically, an ester formation in which a carboxylic acid group in a monomer molecule is converted into an acid halide or an acid anhydride. And highly reactive derivatives such as ester-forming derivatives in which the hydroxyl group in the monomer molecule is a lower carboxylic acid ester group.

  As a method for producing the liquid crystal polyester, it can be produced by a known method. Particularly preferably, the ester-forming derivative is a derivative obtained by converting a hydroxyl group in a monomer molecule into a lower carboxylic acid ester group. Preferably, the lower carboxylic acid group is particularly preferably an acyl group. Acylation can usually be achieved by reacting a monomer having a hydroxyl group with acetic anhydride. These ester-forming derivatives by acylation can be polymerized by deacetic acid polycondensation, and polyesters can be easily produced.

  As the liquid crystal polyester production method, for example, a known method such as the method described in JP-A No. 2002-146003 can be applied. That is, after the monomer corresponding to the structural unit represented by (i), (ii) and (iii) is acylated, preferably acylated with acetic anhydride to produce an ester-forming derivative, And a polymer having a relatively low molecular weight (hereinafter abbreviated as “prepolymer”) to obtain a relatively low molecular weight aromatic liquid crystalline polyester, and then subjecting the prepolymer to powder and heating to solid phase polymerization. It is done. In such solid phase polymerization, the polymerization proceeds further, and the molecular weight can be increased.

<Other additives>
The liquid crystal polyester resin composition of the present invention can also contain a filler (hereinafter referred to as “other filler”) other than the components (A1) and (A2). The other filler is preferably a long fiber filler from the viewpoint of improving the mechanical strength of the obtained molded article, and examples thereof include glass fiber, asbestos fiber, silica fiber, asbestos fiber, and silica alumina fiber.

<Method for adjusting liquid crystal polyester resin composition>
The adjustment method of the liquid crystalline polyester resin composition of this invention can be manufactured by a well-known method. In general, the above-mentioned component (A1), component (A2) and component (B), and a long fibrous filler added as necessary may be mixed using a Henschel mixer, a tumbler, etc. The component (B) may be preheated and melted in an extruder, and then the components (A1) and (A2), and the long fibrous filler added as necessary may be added and kneaded to form pellets. Moreover, after mixing previously the said component (A1), a component (A2), a component (B), and the long fibrous filler added as needed, the mixture is obtained using an extruder. It may be melt-kneaded to form pellets. The liquid crystalline polyester resin composition of the present invention is preferably formed into pellets because it becomes easy to handle in a later molding method.

<Molding method>
The molding method according to the liquid crystal polyester resin composition of the present invention is not particularly limited. It can be molded into various shapes by a general molding method in the field of thermoplastic resins, such as injection molding, extrusion molding, transfer molding, blow molding, press molding, injection press molding, extrusion injection molding. A plurality of these molding methods may be combined. In particular, when obtaining a molded body to be applied to an electronic component that is required to be downsized, injection molding is preferable from the viewpoint that a thin-wall moldability and a component having a complicated shape can be molded.

<Molding>
By optimizing the molding method of the liquid crystalline polyester resin composition of the present invention, the obtained molded product can be a molded product suitable as an electromagnetic wave shielding member in an electronic component. Specifically, when the electrical insulation is represented by volume resistivity, it is 10 ⁸ Ωm or more, and as the electromagnetic wave shielding property, a molded product (electromagnetic wave shielding member) of 10 dB or more when represented by a shielding effect against a high frequency of 1 GHz. Can be obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these Examples.

[Electromagnetic shielding value measurement method]
The electromagnetic shielding value at a frequency of 1 GHz was measured by the Advantest method.

[Volume resistivity measurement method]
Volume resistivity was obtained with SM-10E type super insulation meter manufactured by Toa Denpa Kogyo Co., Ltd.

Production Example 1
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 828.7 g (6.0 mol) of p-hydroxybenzoic acid and 372.4 g of 4,4′-dihydroxybiphenyl ( 2.0 mol), 249.2 g (1.5 mol) of terephthalic acid, 83.1 g (0.5 mol) of isophthalic acid, 1223.0 (11.0 mol) of acetic anhydride and 0. 1-methylimidazole as a catalyst. After adding 16 g and stirring at room temperature for 15 minutes, the temperature was raised while stirring. When the internal temperature reached 145 ° C., the mixture was stirred for 1 hour while maintaining the same temperature.
Next, the temperature was raised from 145 ° C. to 320 ° C. over 3 hours while distilling off distilling by-product acetic acid and unreacted acetic anhydride. The mixture was kept at the same temperature for 40 minutes to obtain a liquid crystal polyester. The obtained liquid crystal polyester was cooled to room temperature and pulverized with a pulverizer to obtain liquid crystal polyester powder (particle size: about 0.1 mm to about 1 mm).
It was 260 degreeC when the flow start temperature was measured about this powder (liquid crystal polyester) using the flow tester (CFT-500 type | mold Shimadzu Corp. make).
The obtained powder was heated from 25 ° C. to 250 ° C. over 1 hour, then heated from the same temperature to 300 ° C. over 8 hours, and then kept at that temperature for 5 hours for solid phase polymerization. Thereafter, the powder after solid-phase polymerization was cooled to obtain liquid crystal polyester 1. The liquid crystal polyester obtained had a flow initiation temperature of 325 ° C.

Example 1
Mica, permalloy (T3 powder manufactured by Mitsubishi Materials, Ni: 79-80% by weight, Fe: 19-20%, containing a small amount of Mo) and liquid crystal polyester powder 1, respectively, mica / permalloy / liquid crystal polyester powder 1 = 10% by volume / 20% by volume / 70% by volume was mixed and granulated at a cylinder temperature of 340 ° C. using a twin-screw extruder (IKEMAI PCM30 HS) to obtain pellets 1. The obtained pellet 1 was injection-molded using a UH1000 injection molding machine manufactured by Nissei Plastic Industry Co., Ltd., injection-molded at a cylinder temperature of 350 ° C. and a mold temperature of 130 ° C., and was 64 mm × 64 mm × 1 mm. A substantially rectangular parallelepiped molded product 1 having dimensions was obtained. As a result of measuring the electromagnetic wave shield and the volume resistivity of the obtained molded product 1, they were 23 dB and 1.12 × 10 ¹⁰ Ωm, respectively.

Comparative Example 1
Mica and liquid crystalline polyester powder 1 were mixed so that mica / liquid crystalline polyester powder 1 = 30% by volume / 70% by volume, and using a twin screw extruder (PCM30 HS manufactured by IKEGAI) at a cylinder temperature of 340 ° C. Pellet 2 was obtained by granulation. The obtained pellet 2 was injection-molded using a UH1000 injection molding machine manufactured by Nissei Plastic Industry Co., Ltd., injection-molded at a cylinder temperature of 350 ° C. and a mold temperature of 130 ° C., and was 64 mm × 64 mm × 1 mm. An approximately rectangular parallelepiped molded product 2 having dimensions was obtained. As a result of measuring the electromagnetic wave shield and the volume resistivity of the obtained molded product 2, they were 0 dB and 7.67 × 10 ¹³ Ωm, respectively.

Comparative Example 2
Permalloy (Mitsubishi Materials T3 powder, Ni: 79 to 80% by weight, Fe: 19 to 20%, containing a small amount of Mo) and liquid crystal polyester powder 1 are permalloy / liquid crystal polyester powder 1 = 30% by volume / 70 Pellet 3 was obtained by mixing so as to have a volume% and granulating the mixture at a cylinder temperature of 340 ° C. using a twin-screw extruder (PCM30 HS manufactured by IKEGAI). The obtained pellet 3 was injection molded using a UH1000 injection molding machine manufactured by Nissei Plastic Industry Co., Ltd., injection molded at a cylinder temperature of 350 ° C. and a mold temperature of 130 ° C., and was 64 mm × 64 mm × 1 mm. A substantially rectangular parallelepiped molded product 3 having dimensions was obtained. As a result of measuring the electromagnetic wave shield and the volume resistivity of the obtained molded product 3, they were 68 dB and 1.51 × 10 ³ Ωm, respectively.

It has been found that the molded product obtained from the liquid crystal polyester resin composition of the present invention has an electromagnetic shielding effect and further maintains electrical insulation.

Claims (12)

A liquid crystal polyester resin composition containing the following component (A1), component (A2) and component (B).
(A1) a filler made of an inorganic substance containing silicon (A2) at least selected from the group consisting of a magnetic metal, a magnetic metal oxide (magnetic metal oxide) and a complex containing a magnetic metal as an ion (magnetic metal complex) 1 type of filler (B) liquid crystal polyester   Component (A2) comprises at least one selected from the group consisting of a magnetic metal having a relative permeability of 100 or more, a magnetic metal oxide having a relative permeability of 100 or more, and a magnetic metal complex having a relative permeability of 100 or more. The liquid crystal polyester resin composition according to claim 1, wherein the liquid crystal polyester resin composition is a filler.   The component (A2) is a filler comprising at least one selected from the group consisting of iron, nickel, an iron-containing alloy, a nickel-containing alloy, an iron complex, and a nickel complex. The liquid crystal polyester resin composition as described.   The liquid crystal polyester resin composition according to any one of claims 1 to 3, wherein the component (A1) is a filler made of a ceramic containing silicon and / or a filler made of a mineral containing silicon.   A component (A1) is a flaky filler, The liquid-crystal polyester resin composition in any one of Claims 1-4.   The liquid crystal polyester resin composition according to any one of claims 1 to 5, wherein the component (A1) is a filler made of glass containing silicon and / or a filler made of mica.   The liquid crystal polyester resin composition according to any one of claims 1 to 6, wherein the component (A1) is 5% by volume or more and 35% by volume or less when the total amount of the liquid crystal polyester resin composition is 100% by volume.   The liquid crystal polyester resin composition according to any one of claims 1 to 7, wherein when the total amount of the liquid crystal polyester resin composition is 100% by volume, the component (A2) is 5% by volume or more and 35% by volume or less. The liquid crystal polyester resin composition according to any one of claims 1 to 8, wherein the component (B) is at least one liquid crystal polyester selected from the group consisting of the following (B1), (B2) and (B3).
(B1) Liquid crystalline polyester composed of repeating units represented by the following (i) (B2) Liquid crystalline polyester composed of repeating units represented by the following (ii) and (iii) (B3) The following (i), (ii) And a liquid crystal polyester comprising a repeating unit represented by (iii)

(In the formula, Ar ₁ represents a 1,4-phenylene group, a 2,6-naphthalenediyl group, or a 4,4′-biphenylylene group. Ar ₂ and Ar ₃ are each independently a 1,4-phenylene group. 2,6-naphthalenediyl group, 1,3-phenylene group or 4,4′-biphenylylene group, and Ar ₁ , Ar ₂ , Ar ₃ are all or part of hydrogen atoms on the aromatic ring. May be substituted with a halogen atom, an alkyl group, or an aryl group.   The liquid crystal polyester resin composition according to claim 9, wherein the component (B) contains the liquid crystal polyester of (B3).   The molded article obtained by shape | molding the liquid-crystal polyester resin composition in any one of Claims 1-10. The molded article according to claim 11, wherein the volume resistivity is 10 ⁸ Ωm or more, and the shielding effect against electromagnetic waves having a frequency of 1 GHz is 10 dB or more.