Resin composition and resin molded article formed from the resin composition

Abstract

The present invention provides a resin composition for obtaining a resin molded product having low dielectric loss tangent and excellent mechanical strength such as toughness. The resin composition of the present invention is characterized in that: comprising a liquid crystal polyester resin (A) and a filler (B), the liquid crystal polyester resin (A) comprises a structural unit (I) from 6-hydroxy-2-naphthoic acid, a structural unit (II) from an aromatic diol compound, a structural unit (III) from an aromatic dicarboxylic acid compound, and the structural unit (III) comprises a structural unit (IIIA) from terephthalic acid and / or a structural unit (IIIB) from 2,6-naphthalenedicarboxylic acid, the composition ratio (mol %) of the structural unit satisfies the following conditions: 40 mol % ≤ structural unit (I) ≤ 75 mol %, 12 mol % ≤ structural unit (II) ≤ 30 mol %, 12 mol % ≤ structural unit (III) ≤ 30 mol %; the filler (B) is at least one selected from silica, mica and talc, and the dielectric loss tangent measured by the resonant cavity perturbation method at a measurement frequency of 10 GHz is 1.0 × 10 ‑3 the following.

Description

Technical Field

[0001] The present invention relates to a resin composition capable of producing a resin molded article having a low dielectric loss tangent and excellent mechanical strength such as toughness. Furthermore, the present invention relates to a resin molded article formed from the resin composition and an electric or electronic component including the resin molded article. Background Art

[0002] In recent years, the amount of information communication has continued to increase rapidly, and the frequency of the signals used has further increased, requiring a 9 Hz or more at a frequency in the gigahertz (GHz) band. For such a problem, patent document 1 discloses a liquid crystalline aromatic polyester, which is a liquid crystalline aromatic polyester showing a low dielectric loss tangent at a high bandwidth, and comprises two or more structural units from p- or m-hydroxybenzoic acid and a structural unit from hydroxynaphthoic acid. In addition, patent document 2 discloses a polyester resin, which is a fully aromatic polyester and comprises 1 to 6% of a structural unit from p-hydroxybenzoic acid, 40 to 60% of a structural unit from 6-hydroxy-2-naphthoic acid, 17.5 to 30% of a structural unit from an aromatic diol compound, and 17.5 to 30% of a structural unit from an aromatic dicarboxylic acid. However, the applicant found that even if the polyester resin proposed in patent document 1 was used, the required sufficiently low dielectric loss tangent was not shown at a high bandwidth. In addition, it was also found that even if the polyester resin proposed in patent document 2 was used, the required sufficiently low dielectric loss tangent was not shown at a high bandwidth.

[0003] Liquid crystal polyester resins are also widely used in surface-mount electronic components produced through injection molding due to their excellent heat resistance and thin-wall moldability. Furthermore, since liquid crystal polyester resins also exhibit low dielectric loss and excellent electrical properties, recent research has focused on methods for molding aromatic liquid crystal polyesters into films using methods such as T-die extrusion, inflation molding, and solution casting.

[0004] Furthermore, when using liquid crystal polyester resin to design components, etc., it will generally undergo high-temperature thermal processes such as processing using solder, so sufficient heat resistance is required. The applicant has found that the polyester resin proposed in patent document 1 cannot take into account both the sufficiently low dielectric loss tangent and sufficient heat resistance required under a high bandwidth of a measurement frequency of 10 GHz. Previously, the applicant proposed: by making the wholly aromatic liquid crystal polyester resin contain specific structural units and adjusting these structural units to a specific composition ratio, the following wholly aromatic liquid crystal polyester resin having an exceptionally low dielectric loss tangent and an excellent balance between heat resistance and processability can be obtained (see patent document 3).

[0005] In addition, as a material design method other than monomer design, it is known that fillers, other resins are mixed or blended with liquid crystal polyester resins to develop a method of developing materials with excellent properties. For example, it is proposed to mix a hollow glass bead filler with an air layer with a liquid crystal polyester resin (referring to patent documentation 4). Since air has an ultra-low dielectric constant of 1, it is possible to reduce the dielectric constant by blending with the resin. However, hollow glass beads can significantly hinder the liquid crystallinity of the liquid crystal polyester resin, and even if mixed in small quantities, the viscosity will rise significantly. Therefore, in order to significantly reduce the processability of the resin composition, in reality, only a very small amount of about 10% by mass of the entire resin composition can be mixed. In addition, since it is hollow, there is a problem that the material after mixing is brittle, and mechanical strength and heat resistance are reduced.

[0006] Furthermore, as a method for reducing the dielectric loss tangent, it is known to knead or blend liquid crystal polyester resin with ceramics such as magnesium oxide and boron nitride. However, the dielectric loss tangent of ceramic materials is as low as 10 -4 ~10 -5 The dielectric constant is above 8, and can be as high as about 80 depending on the situation. The dielectric constant of the mixed material will increase instead.

[0007] Furthermore, fluorine-based materials have been known as materials with extremely low dielectric loss tangent and dielectric constant. In particular, polytetrafluoroethylene (PTFE) is known to have a dielectric constant of approximately 2 and a dielectric loss tangent of approximately 10. -4 The PTFE of the present invention is a kind of PTFE with excellent electrical properties.On the other hand, the viscosity of known PTFE in molten state is extremely high, and it is impossible to carry out melt processing such as injection molding, melt extrusion film making.The only processing method is the cutting process that the compressed block is cut, but the high productivity and fine processing such as injection molding cannot be realized in this method.As the method for the processability of improved PTFE, fluorine materials such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) that change the structure of PTFE have been developed.Such material is compared to PTFE, and viscosity reduction can be processed into film etc., but on the other hand it is impossible to maintain the low dielectric loss tangent such as PTFE.Therefore, this is to sacrifice electrical physical property to improve processability, and now demand a kind of can under the state of heat resistance such as the heat resistance of the solder as product that processing is had suitable melt viscosity, guarantee, make the material that dielectric loss tangent reduces simultaneously.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-250620

[0011] Patent Document 2: Japanese Patent Application Laid-Open No. 2002-179776

[0012] Patent Document 3: Japanese Patent No. 6434195

[0013] Patent Document 4: Japanese Patent Application Laid-Open No. 2004-27021 Summary of the Invention

[0014] Therefore, the present inventors have developed a resin composition comprising a specific liquid crystal polyester resin and a fluororesin to provide a resin molded article comprising a liquid crystal polyester resin having a low dielectric loss tangent. However, the present inventors have discovered that while the resin composition containing the fluororesin exhibits a low dielectric loss tangent, it suffers from poor mechanical strength, such as toughness.

[0015] The present inventors have conducted intensive research to solve the above-mentioned problems and have further discovered that the above-mentioned problems can be solved by adding at least one of silica, mica, and talc as a filler to a specific liquid crystal polyester resin. The present invention has been completed based on this finding.

[0016] That is, according to one aspect of the present invention, it is possible to provide:

[0017] A resin composition comprising a liquid crystal polyester resin (A) and a filler (B),

[0018] The liquid crystal polyester resin (A) comprises a structural unit (I) derived from 6-hydroxy-2-naphthoic acid, a structural unit (II) derived from an aromatic diol compound, and a structural unit (III) derived from an aromatic dicarboxylic acid compound, wherein the structural unit (III) comprises a structural unit (IIIA) derived from terephthalic acid and / or a structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid.

[0019] The composition ratio (mol %) of the above structural units satisfies the following conditions:

[0020] 40 mol%≤Structural unit (I)≤75 mol%

[0021] 12 mol%≤Structural unit (II)≤30 mol%

[0022] 12 mol%≤structural unit (III)≤30 mol%;

[0023] The filler (B) is at least one selected from silica, mica and talc,

[0024] The dielectric loss tangent of the resin composition measured by the cavity perturbation method at a measurement frequency of 10 GHz is 1.0×10 -3 the following.

[0025] In one embodiment of the present invention, the amount of the liquid crystal polyester resin (A) is preferably 50 to 99 parts by mass, and the amount of the filler (B) is preferably 1 to 50 parts by mass, relative to 100 parts by mass of the total of the liquid crystal polyester resin (A) and the filler (B).

[0026] In one embodiment of the present invention, the melting point of the liquid crystal polyester resin (A) is preferably 300° C. or higher.

[0027] In one embodiment of the present invention, the liquid crystal polyester resin (A) is preferably -1 The melt viscosity is 5 Pa·s to 120 Pa·s.

[0028] In one embodiment of the present invention, the structural unit (II) is preferably represented by the following formula.

[0029] [Chemical Formula 1]

[0030]

[0031] (where Ar 1 is selected from phenyl, biphenyl, naphthyl, anthracenyl and phenanthrenyl groups which may have a substituent as desired.

[0032] In one embodiment of the present invention, it is preferred that the structural unit (III) comprises a structural unit (IIIA) derived from terephthalic acid and a structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid, and the composition ratio of the structural unit (IIIA) to the structural unit (IIIB) satisfies the following conditions:

[0033] 3 mol%≤Structural unit (IIIA)≤28 mol%

[0034] 2 mol%≤structural unit (IIIB)≤9 mol%.

[0035] According to another aspect of the present invention, there is provided a resin molded article formed from the above-mentioned resin composition.

[0036] In another embodiment of the present invention, the resin molded article is preferably in the form of a film.

[0037] In another embodiment of the present invention, the resin molded article is preferably in a fibrous form.

[0038] In another embodiment of the present invention, the resin molded article is preferably an injection molded article.

[0039] According to another aspect of the present invention, there is provided an electric or electronic component including the above-mentioned resin molded article.

[0040] According to the present invention, a resin composition can be provided that can produce a resin molded article having a low dielectric loss tangent and excellent mechanical strength such as toughness. In addition, a resin molded article formed from such a resin composition and an electric or electronic component including the resin molded article can be provided. DETAILED DESCRIPTION

[0041] [Resin composition]

[0042] The resin composition of the present invention comprises the following liquid crystal polyester resin (A) and filler (B). By using such a resin composition, a resin molded product having a low dielectric loss tangent and excellent mechanical strength such as toughness can be obtained. And then, the resin composition of the present invention can also have a heat resistance that is not inferior to that of the liquid crystal polyester resin.

[0043] The dielectric loss tangent of the resin composition measured by the cavity perturbation method at 10 GHz is 1.0×10 -3 Below, preferably 0.95×10 -3 Below, more preferably 0.9×10 -3 the following.

[0044] The resin composition preferably has a relative dielectric constant of 3.8 or less, more preferably 3.7 or less, further preferably 3.6 or less, and even more preferably 3.5 or less, as measured by a cavity perturbation method at 10 GHz.

[0045] The dielectric loss tangent and relative dielectric constant values ​​are average values ​​in the MD and TD directions of the injection-molded article of the resin composition. Note that the injection-molded article is a test piece obtained by cutting a 60 mm × 60 mm × 0.8 mm (thickness) flat plate into a 60 mm × 3 mm (width) piece.

[0046] In this specification, the dielectric loss tangent of a resin composition at 10 GHz can be measured using a network analyzer from Anritsu and a resonator from AET using the cavity perturbation method. Unless otherwise specified, dielectric loss tangent values ​​are measured at 23°C in an atmospheric environment.

[0047] Hereinafter, each component contained in the resin composition will be described.

[0048] (Liquid crystal polyester resin (A))

[0049] The liquid crystal polyester resin (A) used in the resin composition of the present invention comprises a structural unit (I) derived from 6-hydroxy-2-naphthoic acid, a structural unit (II) derived from a diol compound, and a structural unit (III) derived from a dicarboxylic acid. Each structural unit contained in the liquid crystal polyester resin (A) is described below.

[0050] (Structural unit (I) derived from 6-hydroxy-2-naphthoic acid)

[0051] The liquid crystal polyester resin (A) contains a structural unit (I) derived from 6-hydroxy-2-naphthoic acid represented by the following formula (I).

[0052] [Chemical Formula 2]

[0053]

[0054] Examples of the monomer providing the structural unit (I) include 6-hydroxy-2-naphthoic acid (HNA, the following formula (1)), acetylated products thereof, ester derivatives, and acid halides.

[0055] [Chemical Formula 3]

[0056]

[0057] With respect to the composition ratio (mol %) of the structural unit (I) in the liquid crystal polyester resin (A), from the viewpoint of reducing the dielectric loss tangent and increasing the melting point of the liquid crystal polyester resin (A), the lower limit is 40 mol % or more, preferably 45 mol % or more, more preferably 50 mol % or more, and the upper limit is 75 mol % or less, preferably 70 mol % or less, more preferably 65 mol % or less.

[0058] (Structural unit (II) derived from diol compound)

[0059] The unit (II) constituting the liquid crystal polyester resin (A) is a structural unit derived from a diol compound, preferably a structural unit derived from an aromatic diol compound represented by the following formula (II). The structural unit (II) may be comprised of only one type or two or more types.

[0060] [Chemical Formula 4]

[0061]

[0062] In the above formula, Ar 1 The desired group may be selected from phenyl, biphenyl, 4,4'-isopropenyldiphenyl, naphthyl, anthracenyl, and phenanthrenyl groups having a substituent. Of these, phenyl and biphenyl are more preferred. Examples of substituents include hydrogen, alkyl, alkoxy, and fluorine. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5. Furthermore, the alkyl group may be either linear or branched. The alkoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms.

[0063] Examples of monomers forming structural unit (II) include 4,4'-dihydroxybiphenyl (BP, following formula (2)), hydroquinone (HQ, following formula (3)), methylhydroquinone (MeHQ, following formula (4)), 4,4'-isopropenyldiphenol (BisPA, following formula (5)), and acylates, ester derivatives, and acyl halides thereof. Among these, 4,4'-dihydroxybiphenyl (BP) and acylates, ester derivatives, and acyl halides thereof are preferably used.

[0064] [Chemical Formula 5]

[0065]

[0066] [Chemical Formula 6]

[0067]

[0068] [Chemical Formula 7]

[0069]

[0070] [Chemical Formula 8]

[0071]

[0072] The composition ratio (mol %) of the structural unit (II) relative to the structural units of the entire polyester resin is:

[0073] The lower limit is 12 mol% or more, preferably 12.5 mol% or more, more preferably 15 mol% or more, and even more preferably 17.5 mol% or more, and the upper limit is 30 mol% or less, preferably 27 mol% or less, more preferably 25 mol% or less, and even more preferably 23 mol% or less. When two or more structural units (II) are included, their total molar ratio may be within the range of the above composition ratio.

[0074] (Structural unit (III) derived from aromatic dicarboxylic acid)

[0075] The unit (III) constituting the liquid crystal polyester resin (A) includes a structural unit (IIIA) derived from terephthalic acid represented by the following formula (IIIA) and / or a structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid represented by the following formula (IIIB), and preferably includes both the structural unit (IIIA) and the structural unit (IIIB).

[0076] [Chemical Formula 9]

[0077]

[0078] [Chemical Formula 10]

[0079]

[0080] Examples of monomers providing structural unit (IIIA) include terephthalic acid (TPA, formula (6) below) and its ester derivatives and acid halides. TPA and its derivatives are widely used as raw materials for general-purpose plastics such as polyethylene terephthalate. They are the most inexpensive aromatic dicarboxylic acid compounds. Therefore, by increasing the composition ratio of structural unit (IIIA) in structural unit (III), the cost advantage of the resin product can be improved.

[0081] [Chemical Formula 11]

[0082]

[0083] Examples of monomers providing structural unit (IIIB) include 2,6-naphthalene dicarboxylic acid (NADA, formula (7) below), and ester derivatives and acid halides thereof. NADA is relatively expensive compared to TPA and the like, so by reducing the composition ratio of structural unit (IIIB) in structural unit (III), the cost advantage of the resin product can be improved.

[0084] [Chemical Formula 12]

[0085]

[0086] The composition ratio (mol %) of the structural unit (III) relative to the structural units of the polyester resin (A) as a whole has a lower limit of 12 mol % or more, preferably 12.5 mol % or more, more preferably 15 mol % or more, and further preferably 17.5 mol % or more, and an upper limit of 30 mol % or less, preferably 27 mol % or less, more preferably 25 mol % or less, and further preferably 23 mol % or less.

[0087] The composition ratio (mol %) of the structural unit (IIIA) relative to the structural units of the polyester resin (A) as a whole has a lower limit of preferably 3 mol %, more preferably 6 mol % or more, further preferably 8 mol % or more, and further preferably 11 mol % or more, and an upper limit of preferably 28 mol % or less, more preferably 25 mol % or less, further preferably 23 mol % or less, and further preferably 21 mol % or less.

[0088] The composition ratio (mol %) of the structural unit (IIIB) relative to the total structural units of the polyester resin (A) has a lower limit of preferably 2 mol % or more, more preferably 3 mol % or more, and even more preferably 4 mol % or more, and an upper limit of preferably 9 mol % or less, more preferably 8 mol % or less. The composition ratio of the structural unit (II) and the composition ratio of the structural unit (III) (the combined composition ratio of the structural units (IIIA) and (IIIB)) are substantially equivalent ((structural unit (II) ≒ structural unit (III)).

[0089] As particularly preferred compositions of the polyester resin (A) of the present invention, the following compositions can be mentioned.

[0090] 45 mol%≤Structural unit (I) derived from 6-hydroxy-2-naphthoic acid≤75 mol%

[0091] 12 mol%≤Structural unit (II) derived from aromatic diol compound≤27.5 mol%

[0092] 3 mol%≤Structural units derived from terephthalic acid Structural units (IIIA)≤25 mol%

[0093] 2 mol%≤Structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid≤9 mol%.

[0094] When the content of each structural unit relative to the total structural units of the polyester resin (A) is within the above range, a polyester resin having a low dielectric loss tangent can be obtained.

[0095] The liquid crystallinity of the liquid crystalline polyester resin (A) can be confirmed by heating and melting the liquid crystalline polyester resin (A) on a microscope hot stage using a polarizing microscope (trade name: BH-2) manufactured by Olympus Corporation equipped with a Mettler microscope hot stage (trade name: FP82HT), and then observing the presence or absence of optical anisotropy.

[0096] The lower limit of the melting point of the liquid crystal polyester resin (A) is preferably 300°C or higher, more preferably 305°C or higher, and even more preferably 310°C or higher. The upper limit is preferably 360°C or lower, preferably 350°C or lower, and even more preferably 340°C or lower. By setting the melting point of the liquid crystal polyester resin (A) to the above numerical range, the processing stability of the resin composition containing the liquid crystal polyester resin (A) within the range shown in the present invention can be improved. Specifically, the stability of the melt molding processability after shearing and the melt processing stability in the non-shearing state can be improved. In addition, from the perspective of solder heat resistance, the heat resistance of the material of the molded article produced using the liquid crystal polyester resin (A) can be maintained in a good range.

[0097] The dielectric loss tangent of the liquid crystal polyester resin (A) measured by the cavity perturbation method at 10 GHz is preferably 1.0×10 -3 Below, preferably 0.9×10 -3 Below, more preferably 0.8×10 -3 Below, more preferably 0.7×10 -3 The dielectric loss tangent value is the average value of the in-plane TD and MD directions of an injection-molded article of a liquid crystal polyester resin (A). The injection-molded article is a test piece obtained by cutting a 60 mm × 60 mm × 0.8 mm (thickness) flat plate into a 60 mm × 3 mm width.

[0098] The melt viscosity of the liquid crystal polyester resin (A) is preferably 0.0547 W / m from the viewpoint of melt molding processability at a temperature of 20°C or higher above the melting point of the liquid crystal polyester resin (A) and a shear rate of 1000 s. -1 Under the conditions, the lower limit is preferably 5 Pa·s or more, more preferably 10 Pa·s or more, further preferably 20 Pa·s or more, and the upper limit is preferably 120 Pa·s or less, more preferably 110 Pa·s or less, further preferably 100 Pa·s or less.

[0099] (Method for producing liquid crystal polyester resin (A))

[0100] The liquid crystal polyester resin (A) is produced by polymerizing monomers forming structural units (I) to (III) according to a conventionally known method. In one embodiment, the liquid crystal polyester resin (A) of the present invention can be produced by a second polymerization step of melt polymerization to prepare a prepolymer and then solid phase polymerization of the prepolymer.

[0101] From the viewpoint of more efficiently obtaining the polyester compound according to the present invention, melt polymerization is preferably carried out by reflux of acetic acid in the presence of 1.05 to 1.15 molar equivalents of acetic anhydride relative to all hydroxyl groups possessed by the monomers, with the monomers forming the structural units (I) to (III) being combined in a predetermined formulation as desired to be 100 mol%.

[0102] When the polymerization reaction is carried out in two stages, melt polymerization followed by subsequent solid-phase polymerization, the prepolymer obtained by melt polymerization can be cooled and solidified, then pulverized to form a powder or flakes. A known solid-phase polymerization method is then preferably used, for example, heat-treating the prepolymer resin at a temperature range of 200-350°C for 1-30 hours under an inert atmosphere such as nitrogen or under vacuum. Solid-phase polymerization can be carried out with stirring or in a static state without stirring.

[0103] A catalyst may or may not be used in the polymerization reaction. The catalyst used may be any known polyester polymerization catalyst, including metal salt catalysts such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide; and organic compound catalysts such as nitrogen-containing heterocyclic compounds such as N-methylimidazole. The amount of catalyst used is not particularly limited, but is preferably 0.0001 to 0.1 parts by weight relative to 100 parts by weight of the total amount of the monomers.

[0104] The polymerization reaction apparatus used in the melt polymerization is not particularly limited, but is preferably a reaction apparatus commonly used for high-viscosity fluid reactions. Examples of such reaction apparatuses include a stirring tank-type polymerization reaction apparatus having a stirring device with stirring blades of various shapes such as anchor-type, multi-stage-type, spiral ribbon-type, and screw shaft-type, or variations thereof; and a mixing apparatus commonly used for resin mixing, such as a kneader, a roll mill, and a Banbury mixer.

[0105] (Filler (B))

[0106] As the filler (B) used for the resin composition of the present invention, silicon dioxide, mica and talc can be mentioned. One filler (B) can be used alone, or two or more fillers can be used in combination. By adding the filler (B) to the liquid crystal polyester resin (A), a resin molded product having excellent mechanical strength such as dielectric properties and toughness that does not damage the liquid crystal polyester resin (A) can be obtained.

[0107] Silica that is known in the art can be used. The shape of the silica is not particularly limited and may be any of spherical, plate-like, and flaky. The silica may be either amorphous or crystalline, or a mixture thereof. Commercially available silica may be used, for example, SC2500-SPJ (spherical silica) manufactured by Yaduma Co., Ltd., KSE625 (spherical silica), KSE2045 (spherical silica), FHD05 (fused silica), and FCS12 (fused silica) manufactured by Kinsei Kogyo Co., Ltd.

[0108] As mica, existing well-known mica can be used. As mica, either wet-crushed mica powder or dry-crushed mica powder can be used, or a mixture thereof can be used. In addition, mica can be a natural product or a synthetic product. Commercially available mica can also be used, for example, the trade name AB-25S (Muscovite (wet)) manufactured by Yamaguchi Mica Co., Ltd. of Japan, the trade name A-21S (Muscovite (wet)), the trade name Y-1800 (Muscovite (wet)), the trade name S-30 (Muscovite (dry)), the trade name S-325 (Phlogopite (dry)) manufactured by Repco Mica Co., Ltd., the trade name MK-300 (synthetic mica) manufactured by Katakura & Co-op Agri Co., Ltd., etc.

[0109] As the talc, conventionally known talc can be used. As the talc, commercially available products can be used, for example, MS-KY manufactured by Nippon Talc Co., Ltd. can be mentioned.

[0110] Filler (B) may further comprise a fiber-filled material in addition to the above. The fiber-filled material may be selected from inorganic fibrous materials and organic fibrous materials. As inorganic fibrous materials, carbon fiber, silicon carbide fiber, ceramic fiber, glass fiber, asbestos fiber, aluminum oxide fiber, zirconium oxide fiber, boron nitride fiber, silicon nitride fiber, boron fiber, wollastonite, whisker, potassium titanate fiber and metal fiber etc. may be mentioned, preferably carbon fiber, silicon carbide fiber, ceramic fiber, glass fiber, wollastonite, whisker and metal fiber, more preferably carbon fiber and glass fiber. In addition, as organic fibrous materials, high melting point organic fibrous materials such as aramid fiber may be mentioned. The fiber-filled material may be in the form of nanofibers.

[0111] In the resin composition of the present invention, relative to the total 100 mass parts of liquid crystal polyester resin (A) and filler (B), the lower limit of the amount of liquid crystal polyester resin (A) is preferably more than 50 mass parts, more preferably more than 55 mass parts, more preferably more than 60 mass parts, more preferably more than 65 mass parts, and the upper limit is preferably less than 99 mass parts, more preferably less than 95 mass parts, more preferably less than 90 mass parts. In addition, relative to the total 100 mass parts of liquid crystal polyester resin (A) and filler (B), the lower limit of the amount of filler (B) is preferably more than 1 mass part, more preferably more than 5 mass parts, more preferably more than 10 mass parts, the upper limit is preferably less than 50 mass parts, more preferably less than 45 mass parts, more preferably less than 40 mass parts, more preferably less than 35 mass parts. If the proportion of liquid crystal polyester resin (A) and filler (B) is about the above-mentioned numerical range, a resin molded product having low dielectric loss tangent and excellent mechanical strength such as toughness can be obtained. And then, a resin composition having more excellent melt molding processability and heat resistance can be obtained.

[0112] (Other additives)

[0113] The resin composition of the present invention may further contain other additives such as colorants, dispersants, plasticizers, antioxidants, curing agents, flame retardants, heat stabilizers, ultraviolet absorbers, antistatic agents, and surfactants without departing from the scope of the present invention.

[0114] (Resin molded products)

[0115] The resin molded article of the present invention is formed from the above-mentioned resin composition. The resin molded article of the present invention has a low dielectric loss tangent and excellent mechanical strength such as toughness. Furthermore, the resin molded article preferably has excellent heat resistance. The shape of the resin molded article of the present invention is not particularly limited and can be plate-shaped, film-shaped, fibrous, etc.

[0116] (Method for producing resin molded article)

[0117] In the present invention, a resin composition comprising the liquid crystal polyester resin (A) and the filler (B), or other additives used as desired, can be molded by conventionally known methods to obtain a resin molded article. The resin composition can be obtained by melt-kneading the entire liquid crystal polyester resin (A) and the filler (B), etc., using a Banbury mixer, a kneader, a single-screw or twin-screw extruder, or the like.

[0118] The molding method of the resin molded article is not particularly limited, and examples thereof include press molding, foam molding, injection molding, extrusion molding, punching molding, etc. The molded article produced in the above manner can be processed into various shapes depending on the intended use.

[0119] Specifically, the film-shaped resin molded article can be obtained by conventionally known methods, such as extrusion molding such as inflation molding, melt extrusion molding, and solution casting. The film thus obtained may be a single-layer film composed solely of the resin composition of the present invention, or a multilayer film composed of different types of materials.

[0120] It should be noted that films produced by extrusion or solution casting can also be stretched using a single screw or twin screw extruder to improve dimensional stability and mechanical properties. In addition, they can also be heat treated to remove anisotropy or improve heat resistance of these films.

[0121] In addition, fibrous resin molded products can be obtained by conventionally known methods, such as melt spinning, solution spinning, etc. The fibers may be composed solely of the resin composition of the present invention or may be mixed with other resins.

[0122] (Electrical and electronic components)

[0123] The electrical and electronic components of the present invention are formed by the above-mentioned resin composition. Examples of such components include antennas used in electronic devices such as ETC, GPS, wireless LAN, and mobile phones, high-speed transmission connectors, CPU sockets, circuit boards, flexible printed circuit boards (FPCs), laminated circuit boards, millimeter-wave and quasi-millimeter-wave radars such as collision avoidance radars, RFID tags, capacitors, inverter components, insulating films, cable coatings, insulating materials for secondary batteries such as lithium-ion batteries, and speaker diaphragms.

[0124] Example

[0125] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0126] <Production of Liquid Crystal Polyester Resin (A)>

[0127] (Synthesis example 1)

[0128] In a polymerization vessel equipped with a stirring blade, 50 mol% of 6-hydroxy-2-naphthoic acid (HNA), 25 mol% of 4,4'-dihydroxybiphenyl (BP), 17 mol% of terephthalic acid (TPA), and 8 mol% of 2,6-naphthalenedicarboxylic acid (NADA) were added as catalysts, and potassium acetate and magnesium acetate were added. The polymerization vessel was decompressed and nitrogen injected three times to perform nitrogen substitution. Then, acetic anhydride (1.08 molar equivalents relative to the hydroxyl group) was further added, the temperature was raised to 150°C, and an acetylation reaction was carried out under reflux for 2 hours.

[0129] After the acetylation was completed, the polymerization vessel, still distilling acetic acid, was heated at 0.5°C / min. When the melt temperature in the vessel reached 310°C, the polymer was removed and cooled to solidify. The resulting polymer was pulverized to a size that would pass through a 2.0 mm mesh sieve to obtain a prepolymer.

[0130] Next, the prepolymer obtained above was heated in an oven manufactured by Yamato Scientific Co., Ltd., raising the temperature from room temperature to 300°C over 14 hours, and then maintaining the temperature at 300°C for 2 hours to perform solid-phase polymerization. Afterwards, the prepolymer was allowed to naturally dissipate heat at room temperature to obtain liquid crystal polyester resin A1. Using a polarizing microscope (trade name: BH-2) manufactured by Olympus Corporation equipped with a Mettler microscope hot stage (trade name: FP82HT), the liquid crystal polyester resin sample was heated and melted on the microscope hot stage, and the presence or absence of optical anisotropy was then used to confirm whether the sample exhibited liquid crystallinity.

[0131] (Synthesis example 2)

[0132] Liquid crystal polyester resin A2 was obtained in the same manner as in Synthesis Example 1, except that the monomer amounts were changed to 55 mol% HNA, 22.5 mol% BP, 16.5 mol% TPA, and 6 mol% NADA. Subsequently, the same procedure was performed as above to confirm that the obtained liquid crystal polyester resin A2 exhibited liquid crystallinity.

[0133] (Synthesis example 3)

[0134] Liquid crystal polyester resin A3 was obtained in the same manner as in Synthesis Example 1, except that the monomer amounts were changed to 60 mol% HNA, 20 mol% BP, 15.5 mol% TPA, and 4.5 mol% NADA. Subsequently, the same procedure was performed as above to confirm that the obtained liquid crystal polyester resin A3 exhibited liquid crystallinity.

[0135] (Synthesis Example 4)

[0136] Liquid crystal polyester resin A4 was obtained in the same manner as in Synthesis Example 1, except that the monomer amounts were changed to 65 mol% HNA, 17.5 mol% BP, 15.5 mol% TPA, and 2 mol% NADA. Subsequently, the same procedure was performed as above to confirm that the obtained liquid crystal polyester resin A4 exhibited liquid crystallinity.

[0137] (Synthesis Example 5)

[0138] Liquid crystal polyester resin A5 was obtained in the same manner as in Synthesis Example 1, except that the monomer amounts were changed to 70 mol% HNA, 15 mol% BP, 6 mol% TPA, and 9 mol% NADA. Subsequently, the same procedure was performed as above to confirm that the obtained liquid crystal polyester resin A5 exhibited liquid crystallinity.

[0139] Performance Evaluation

[0140] The structural units (monomer compositions) of the liquid crystal polyester resins A1 to A5 obtained above are shown in Table 1. Next, performance evaluations were performed on the liquid crystal polyester resins A1 to A5 obtained above.

[0141] (Determination of Melting Point)

[0142] The melting points of the liquid crystal polyester resins A1 to A5 obtained above were measured using a differential scanning calorimeter (DSC) manufactured by Hitachi High-Tech Science Company in accordance with the test methods of ISO 11357 and ASTM D3418. The temperature was raised from room temperature to 360 to 380°C at a rate of 10°C / min until the polymer was completely melted. The temperature was then lowered to 30°C at a rate of 10°C / min, and then raised to 380°C at a rate of 10°C / min. The peak of the endothermic peak obtained at this time was defined as the melting point (Tm2). The measurement results are shown in Table 1.

[0143] (Dielectric loss tangent measurement (10 GHz))

[0144] The liquid crystal polyester resins A1 to A5 obtained above were heated and melted at the melting point to the melting point + 30 ° C, respectively, and injection molded using a 60 mm × 60 mm × 0.8 mm (thickness) mold to produce a flat test piece. Next, the produced flat test piece was cut into 60 mm × 3 mm (width), and the network analyzer MS46122B manufactured by Anritsu and the resonator manufactured by AET were used to measure the relative dielectric constant and dielectric loss tangent in the flow direction at a frequency of 10 GHz by the resonant cavity perturbation method. It should be noted that the dielectric loss tangent in the TD direction and the MD direction of each test piece was measured, and its average value is shown in Table 1.

[0145] (Determination of Melt Viscosity)

[0146] The liquid crystal polyester resins A1 to A5 obtained above were measured at a shear rate of 1000 s using a capillary rheometer (Toyo Seiki Seisakusho Co., Ltd., Capillograph 1D) and a capillary with an inner diameter of 1 mm in accordance with JIS K7199. -1The melt viscosity (Pa·s) at the melting point of the resin composition + 20° C. is shown in Table 1. The measurement results are shown in Table 1. Before the measurement, the resin composition was dried at 150° C. under reduced pressure for 4 hours.

[0147] [Table 1]

[0148]

[0149] <Preparation of filler (B)>

[0150] The following resin was prepared as filler (B).

[0151] Silica 1: Spherical silica, manufactured by Yaduma Co., Ltd., trade name SC2500-SPJ

[0152] Silica 2: Spherical silica, manufactured by Kinsei Kogyo Co., Ltd., trade name KSE625

[0153] Silica 3: Spherical silica, manufactured by Kinsei Kogyo Co., Ltd., trade name KSE2045

[0154] Silica 4: Fused silica, manufactured by Kinsei Kogyo Co., Ltd., trade name FHD05

[0155] Silica 5: Fused silica, manufactured by Kinsei Kogyo Co., Ltd., trade name FCS12

[0156] Mica 1: Muscovite (wet type), manufactured by Yamaguchi Mica Co., Ltd., Japan, trade name AB-25S

[0157] Mica 2: Muscovite (wet type), manufactured by Yamaguchi Mica Co., Ltd., Japan, trade name A-21S

[0158] Mica 3: Muscovite (wet type), manufactured by Yamaguchi Mica Co., Ltd., Japan, trade name Y-1800

[0159] Mica 4: Muscovite (dry type), manufactured by Yamaguchi Mica Co., Ltd., Japan, trade name S-30

[0160] Mica 5: Muscovite (dry type), manufactured by Repco Mica Co., Ltd., trade name M-325

[0161] Mica 6: Phlogopite (dry type), manufactured by Repco Mica Co., Ltd., trade name S-325

[0162] Mica 7: Synthetic mica, manufactured by Katakura & Co-op Agri Co., Ltd., trade name MK-300

[0163] Talc 1: manufactured by Nippon Talc Co., Ltd., trade name MS-KY

[0164] <Preparation of other additives>

[0165] The following additives were prepared as other additives.

[0166] Polytetrafluoroethylene resin (PTFE): manufactured by Kitamura Co., Ltd., trade name KT-400M

[0167] Insulating glass (GB): manufactured by 3M, trade name S-60HS

[0168] Glass fiber (CGF): manufactured by Nippon Electric Glass Co., Ltd., trade name T-786H

[0169] [Test Example 1]

[0170] The following test was conducted to confirm that a resin composition obtained by blending silica, mica, or talc into a liquid crystal polyester resin can produce a resin molded article having a low dielectric loss tangent and excellent mechanical strength such as toughness, compared to a resin composition obtained by blending other additives into a liquid crystal polyester resin.

[0171] <Manufacturing of resin composition>

[0172] (Example 1)

[0173] 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the silica 1 above were dry-blended, and then kneaded using a twin-screw kneader (manufactured by Ikegai Co., Ltd., PCM 30) at a temperature of Tm2+20 to 50°C of the liquid crystal polyester resin A3, and granulated by strand cutting to obtain a granular resin composition.

[0174] (Example 2)

[0175] A pelletized resin composition was obtained in the same manner as in Example 1 except that 75 parts by mass of the liquid crystal polyester resin A3 obtained above and 25 parts by mass of the mica 1 were dry-blended.

[0176] (Example 3)

[0177] A pelletized resin composition was obtained in the same manner as in Example 1 except that 80 parts by mass of the liquid crystal polyester resin A3 obtained above and 20 parts by mass of the talc 1 were dry-blended.

[0178] (Comparative Example 1)

[0179] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the PTFE were dry-blended.

[0180] (Comparative Example 2)

[0181] A pelletized resin composition was obtained in the same manner as in Example 1 except that 95 parts by mass of the liquid crystal polyester resin A3 obtained above and 5 parts by mass of the GB were dry-blended.

[0182] (Comparative Example 3)

[0183] A pelletized resin composition was obtained in the same manner as in Example 1 except that 85 parts by mass of the liquid crystal polyester resin A3 obtained above and 15 parts by mass of the GB above were dry-blended.

[0184] (Comparative Example 4)

[0185] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the CGF were dry-blended.

[0186] Performance Evaluation

[0187] The composition of the resin composition obtained above is shown in Table 2. Next, the performance of the resin composition obtained above was evaluated.

[0188] (Measurement of dielectric loss tangent and relative dielectric constant (10 GHz))

[0189] Using a small injection molding machine, the resin composition obtained above is heated and melted under the conditions of the melting point + 20 to the melting point + 30 ℃ of the liquid crystal polyester A3, and injection molding is performed using a mold of 60mm×60mm×0.8mm (thickness) to produce a flat test piece. Next, the produced flat test piece is cut into 60mm×3mm (width), and the network analyzer MS46122B manufactured by Anritsu and the resonator manufactured by AET are used to measure the dielectric loss tangent and relative dielectric constant of the flow direction at a frequency of 10GHz by the resonant cavity perturbation method. It should be noted that the dielectric loss tangent and relative dielectric constant of the TD direction and the MD direction of each test piece are measured, and their average values ​​are shown in Table 2.

[0190] (Determination of Izod impact strength)

[0191] The resin composition obtained above was injection molded using an injection molding machine (SE30DUZ, manufactured by Sumitomo Heavy Industries, Ltd.) at a maximum cylinder temperature of 340°C and a mold temperature of 80°C to prepare a bending test piece in accordance with ASTM D790. Next, the Izod impact strength (kJ / m²) was measured using the prepared bending test piece in accordance with ASTM D256. 2 The higher the Izod impact strength value, the better the toughness of the resin molded product.

[0192] (Determination of tensile strength and tensile elastic modulus)

[0193] The resin composition obtained above was injection molded using an injection molding machine (SE30DUZ, manufactured by Sumitomo Heavy Industries, Ltd.) at a maximum cylinder temperature of 340°C and a mold temperature of 80°C to produce tensile test specimens in accordance with ASTM D638. The tensile strength (MPa) and tensile modulus (MPa) of the prepared tensile test specimens were then measured in accordance with ASTM D638.

[0194]

[0195] [Test Example 2]

[0196] The following test was conducted to confirm that a resin molded article having a low dielectric loss tangent and excellent mechanical strength such as toughness can be obtained even when the types of silica and mica added to the liquid crystal polyester resin are changed.

[0197] <Manufacturing of resin composition>

[0198] (Example 4)

[0199] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the silica 2 were dry-blended.

[0200] (Example 5)

[0201] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the silica 3 were dry-blended.

[0202] (Example 6)

[0203] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the silica 4 were dry-blended.

[0204] (Example 7)

[0205] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the silica 5 were dry-blended.

[0206] (Example 8)

[0207] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the mica 2 were dry-blended.

[0208] (Example 9)

[0209] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the mica 3 were dry-blended.

[0210] (Example 10)

[0211] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the mica 4 were dry-blended.

[0212] (Example 11)

[0213] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the mica 5 were dry-blended.

[0214] (Example 12)

[0215] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the mica 6 were dry-blended.

[0216] (Example 13)

[0217] A pelletized resin composition was obtained in the same manner as in Example 1 except that 90 parts by mass of the liquid crystal polyester resin A3 obtained above and 10 parts by mass of the mica 7 were dry-blended.

[0218] Performance Evaluation

[0219] The composition of the resin composition obtained above is shown in Table 3. Hereinafter, the performance evaluation of the resin composition obtained above was performed in the same manner as in [Test Example 1].

[0220]

[0221] [Test Example 3]

[0222] The following test was conducted to confirm that a resin molded article having a low dielectric loss tangent and excellent mechanical strength such as toughness can be obtained even when the concentrations of silica and mica added to the liquid crystal polyester resin are changed.

[0223] <Manufacturing of resin composition>

[0224] (Example 14)

[0225] A pelletized resin composition was obtained in the same manner as in Example 1 except that 70 parts by mass of the liquid crystal polyester resin A3 obtained above and 30 parts by mass of the mica 1 were dry-blended.

[0226] (Example 15)

[0227] A pelletized resin composition was obtained in the same manner as in Example 1 except that 75 parts by mass of the liquid crystal polyester resin A3 obtained above and 25 parts by mass of the mica 1 were dry-blended.

[0228] (Example 16)

[0229] A pelletized resin composition was obtained in the same manner as in Example 1 except that 80 parts by mass of the liquid crystal polyester resin A3 obtained above and 20 parts by mass of the mica 1 were dry-blended.

[0230] (Example 17)

[0231] A pelletized resin composition was obtained in the same manner as in Example 1 except that 80 parts by mass of the liquid crystal polyester resin A3 obtained above and 20 parts by mass of the silica 4 were dry-blended.

[0232] Performance Evaluation

[0233] The composition of the resin composition obtained above is shown in Table 4. Hereinafter, the performance evaluation of the resin composition obtained above was performed in the same manner as in [Test Example 1].

[0234]

Claims

1. A resin composition, characterized in that Containing a liquid crystal polyester resin (A) and a filler (B), The liquid crystal polyester resin (A) comprises a structural unit (I) derived from 6-hydroxy-2-naphthoic acid, a structural unit (II) derived from 4,4'-dihydroxybiphenyl, and a structural unit (III) derived from an aromatic dicarboxylic acid compound, wherein the structural unit (III) comprises a structural unit (IIIA) derived from terephthalic acid and a structural unit (IIIB) derived from 2,6-naphthalene dicarboxylic acid. The composition ratio (mol %) of the structural units (I), (II) and (III) satisfies the following conditions: 40 mol%≤Structural unit (I)≤75 mol% 12 mol%≤Structural unit (II)≤30 mol% 12 mol%≤structural unit (III)≤30 mol%; The composition ratio (mol %) of the structural unit (IIIA) and the structural unit (IIIB) satisfies the following conditions: 3 mol%≤Structural unit (IIIA)≤28 mol% 2 mol%≤structural unit (IIIB)≤9 mol%; The filler (B) is at least one selected from silica, mica and talc, The dielectric loss tangent of the resin composition measured by the cavity perturbation method at a measurement frequency of 10 GHz is 1.0×10 -3 the following.

2. The resin composition according to claim 1, wherein The amount of the liquid crystal polyester resin (A) is 50 to 99 parts by mass, and the amount of the filler (B) is 1 to 50 parts by mass, per 100 parts by mass of the total of the liquid crystal polyester resin (A) and the filler (B).

3. The resin composition according to claim 1 or 2, wherein The melting point of the liquid crystal polyester resin (A) is 300° C. or higher.

4. The resin composition according to claim 1 or 2, wherein The liquid crystal polyester resin (A) is heated at a temperature of 20°C above the melting point and a shear rate of 1000s -1 The melt viscosity is 5 Pa·s to 120 Pa·s.

5. The resin composition according to claim 1 or 2, wherein The composition ratio of the structural unit (IIIA) and the structural unit (IIIB) satisfies the following conditions: 6 mol%≤Structural unit (IIIA)≤28 mol% 2 mol%≤structural unit (IIIB)≤9 mol%. 6 . A resin molded article formed from the resin composition according to claim 1 . The resin molded article according to claim 6 , which is in a film form. The resin molded article according to claim 6 , which is in a fibrous form. 9 . The resin molded article according to claim 6 , which is an injection molded article. 10 . An electric or electronic component comprising the resin molded article according to claim 1 .

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