Polymer blend and molded article

Abstract

To provide a polymer blend that enables formation of a molded article exhibiting superior dielectric characteristics.SOLUTION: A polymer blend according to the present invention is a polymer blend comprising a polyphenylene ether having a number average molecular weight (Mn) of 10000 or more and a liquid crystal polymer, wherein the blending amount of the polyphenylene ether is 1 pt.mass or more and 50 pts.mass or less based on 100 pts.mass in total of the polyphenylene ether and the liquid crystal polymer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymer blend, more particularly to a polymer blend that can be used to obtain a molded article having excellent dielectric properties. The present invention also relates to a molded article containing the polymer blend. [Background technology]

[0002] Conventionally, liquid crystal polymers have been excellent in moldability, heat resistance, and dielectric properties, and therefore molded products (for example, injection molded products) made using liquid crystal polymers have been used in various electronic components.

[0003] In recent years, attempts have been made to improve various physical properties by mixing liquid crystal polymers with other resins such as polyphenylene ether. For example, Patent Document 1 proposes a polyphenylene ether resin composition comprising (A) 70 to 99 parts by weight of a polyphenylene ether resin and (B) 1 to 30 parts by weight of a liquid crystal polyester, wherein the melt viscosities of (A) and (B) at 300°C satisfy specific conditions. Patent Document 2 proposes a resin composition obtained by blending 0.01 to 10 parts by weight of (C) an organic compound containing an isocyanate group with 100 parts by weight of a resin component consisting of 1 to 70 parts by weight of (A) a polyphenylene ether resin and 30 to 99 parts by weight of (B) a liquid crystal polyester. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-317111 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-38003 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the resin composition described in Patent Document 1, the melt viscosity at 300°C of the polyphenylene ether and the liquid crystal polyester must satisfy specific conditions, which places restrictions on the design of the polymer blend and is insufficient for improving physical properties (especially dielectric properties). Furthermore, the resin composition described in Patent Document 2 requires the addition of a third component, (C) an organic compound containing an isocyanate group, which places restrictions on the design of the polymer blend and is insufficient for improving physical properties (particularly dielectric properties).

[0006] Polyphenylene ether generally has a higher dielectric loss tangent but a lower dielectric constant than liquid crystal polymers. Furthermore, when two polymers are blended, the resulting dielectric properties generally become the average of the two polymers used. Therefore, it has been difficult to obtain molded products with a well-balanced dielectric loss tangent and dielectric constant.

[0007] Therefore, an object of the present invention is to provide a polymer blend that can be used to obtain molded articles with excellent dielectric properties (significantly reducing the dielectric constant while suppressing an increase in the dielectric loss tangent compared to the liquid crystal polymer alone). Another object of the present invention is to provide molded articles with excellent dielectric properties. [Means for solving the problem]

[0008] The present inventors have discovered that when a liquid crystal polymer, which is the main component, is blended with a polyphenylene ether having a specific number average molecular weight Mn, the dielectric constant can be significantly reduced while suppressing an increase in the dielectric loss tangent.

[0009] That is, according to the present invention, the following inventions are provided. [1] A polymer blend consisting of polyphenylene ether having a number average molecular weight Mn of 10,000 or more and a liquid crystal polymer, The blended amount of the polyphenylene ether is 1 part by mass or more and 50 parts by mass or less per 100 parts by mass of the polyphenylene ether and the liquid crystal polymer combined. [2] The polymer blend according to [1], wherein the structural units derived from aromatic monomers account for 95 mol % to 100 mol % of all structural units in the liquid crystal polymer. [3] The polymer blend according to [2], wherein the composition ratio of the structural units derived from aromatic hydroxycarboxylic acid in the liquid crystal polymer is 45 mol % or more of all structural units. [4] The polymer blend has a dielectric constant of 3.45 or less and a dielectric loss tangent of 2.50 x 10 at 23°C measured by a 10GHz SPDR method. -3 The polymer blend according to any one of [1] to [3] below: [5] The polymer blend according to any one of [1] to [4], wherein the blending amount of the polyphenylene ether is 3 parts by mass or more and 45 parts by mass or less per 100 parts by mass of the total of the polyphenylene ether and the liquid crystal polymer. [6] The polymer blend according to any one of [1] to [5], wherein the upper limit of the number average molecular weight Mn of the polyphenylene ether is 50,000 or less. [7] The polymer blend is heated at 305°C or higher and 350°C or lower at a shear rate of 100 s -1 The polymer blend according to any one of [1] to [6], wherein the melt viscosity measured under the conditions below is 300 Pa·s or less. [8] The polymer blend according to any one of [1] to [7], wherein the polymer blend has a 1% mass loss temperature of 420°C or higher as measured by thermogravimetric analysis under a nitrogen atmosphere. [9] A molded article comprising the polymer blend according to any one of [1] to [8].

[10] An electric / electronic component comprising the molded article according to [9]. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a polymer blend that can be used to obtain a molded article with excellent dielectric properties (a significant reduction in dielectric constant while suppressing an increase in dielectric loss tangent compared to the liquid crystal polymer alone). Furthermore, according to the present invention, it is possible to provide a molded article with excellent dielectric properties.

[0011] [Polymer Blend] The polymer blend of the present invention comprises a liquid crystal polymer and a specific polyphenylene ether. The polymer blend of the present invention can significantly reduce the dielectric constant while suppressing an increase in the dielectric loss tangent compared to the liquid crystal polymer alone. Therefore, by using the polymer blend of the present invention, it is possible to provide a molded article with excellent dielectric properties (balance between the dielectric loss tangent and the dielectric constant).

[0012] The dielectric constant of the polymer blend is preferably smaller than that of the liquid crystal polymer alone used in the polymer blend, for example, preferably 3.45 or less, more preferably 3.40 or less, even more preferably 3.35 or less, still more preferably 3.30 or less, and most preferably 3.25 or less. The dielectric loss tangent of the polymer blend is preferably not significantly higher than the dielectric loss tangent of the liquid crystal polymer used in the polymer blend. For example, the dielectric loss tangent of the polymer blend is preferably 2.50×10 -3 or less, and more preferably 2.30 × 10 -3 or less, and more preferably 2.00 × 10 -3 and even more preferably 1.80 x 10 -3 The following is the result. By setting the relative dielectric constant and dielectric loss tangent of the polymer blend within the above numerical ranges, a molded article having desired dielectric properties can be produced, and therefore, when used as a product, deterioration in the quality of output signals in electrical and electronic devices and communication devices that use high-frequency signals can be prevented. In this specification, the dielectric constant and dielectric loss tangent of the polymer blend can be measured using a flat test piece of 30 mm (flow direction) × 30 mm × 0.4 mm (thickness) obtained by heating and melting the polymer blend at a temperature between the melting point of the liquid crystal polymer and the melting point + 20°C (for example, 310°C). The dielectric constant and dielectric loss tangent can be measured by a cavity resonator method in accordance with IEC standard IEC62562, and the specific measurement conditions are as follows. The relative permittivity (Er) and dielectric loss tangent (tanδ) in the in-plane direction of the above-mentioned flat test specimen can be measured using a Keysight Technologies network analyzer M9805A by the split post dielectric resonator method (SPDR method) at 23°C, 55% humidity, and a frequency of 10 GHz.

[0013] (melt viscosity) Polymer blends at temperatures between 305°C and 350°C and a shear rate of 100 s -1 The lower limit of the melt viscosity measured under the above conditions is preferably 1 Pa s or more, more preferably 5 Pa s or more, and even more preferably 10 Pa s or more, and the upper limit is preferably 300 Pa s or less, more preferably 200 Pa s or less, even more preferably 150 Pa s or less, and even more preferably 120 Pa s or less. By setting the melt viscosity of the polymer blend within the above numerical range, moldability can be improved. In this specification, the melt viscosity of the polymer blend can be measured using a capillary rheometer viscometer in accordance with JIS K7199.

[0014] (thermal stability) In measurement by a thermogravimetric analyzer (TGA), the polymer blend is heated in a nitrogen atmosphere from room temperature (30°C) at a heating rate of 10°C / min up to 500°C, and the temperature at which the mass of the polymer blend at 30°C is reduced by 1% (1% mass loss temperature), assuming the mass of the polymer blend at 30°C as 100%, is preferably 420°C or higher, more preferably 425°C or higher, and even more preferably 430°C or higher, and may be 460°C or lower. If the 1% mass loss temperature is within the above range, the polymer blend will have excellent thermal stability and the practical heat resistance of molded articles can be improved.

[0015] (liquid crystal polymer) The liquid crystal polymer is not particularly limited, and conventionally known liquid crystal polymers can be used. In a preferred embodiment of the present invention, the liquid crystal polymer contains structural units derived from aromatic monomers, and the structural units derived from aromatic monomers preferably account for 95 mol% to 100 mol% of all structural units. In particular, the liquid crystal polymer preferably contains structural units (I) derived from aromatic hydroxycarboxylic acid, and may further contain structural units (II) derived from aromatic diols and structural units (III) derived from aromatic dicarboxylic acids, or may further contain structural units (IV) derived from aromatic monomers having two functional groups (excluding the structural units (I) to (III)). Each structural unit will be described in detail below.

[0016] The melting point of the liquid crystal polymer is not particularly limited, but considering heat resistance, it is generally required to be 250°C or higher. The lower limit of the melting point of the liquid crystal polymer is preferably 270°C or higher, more preferably 280°C or higher, even more preferably 300°C or higher, and even more preferably 310°C or higher. The upper limit of the melting point of the liquid crystal polymer is preferably 370°C or lower, more preferably 360°C or lower, and even more preferably 350°C or lower. By setting the melting point of the liquid crystal polymer within the above numerical range, it is possible to maintain moldability within a practical temperature range while improving the heat resistance of molded articles produced using a polymer blend containing the liquid crystal polymer against heat processing. In this specification, the melting point of the liquid crystal polymer is a value measured by a differential scanning calorimeter (DSC). Specifically, the temperature is raised from 30°C to 350-400°C at a rate of 10°C / min to completely melt the liquid crystal polymer, then the temperature is lowered to 30°C at a rate of 10°C / min, and then the temperature is raised again at a rate of 10°C / min to the same temperature as in the first cycle. The temperature at the apex of the endothermic peak in the second cycle of the temperature rise process is defined as Tm2, ​​and Tm2 is defined as the melting point (°C).

[0017] The liquid crystallinity of the liquid crystal polymer can be confirmed by using a polarizing microscope (product name: ECLIPSE E600 POL) manufactured by Nikon Corporation equipped with a large specimen cooling and heating stage for microscopes (product name: 10083L) manufactured by Japan High Tech Co., Ltd., to heat and melt the liquid crystal polymer on the microscope heating stage, and then observing whether or not it has optical anisotropy.

[0018] Each of the structural units contained in the liquid crystal polymer according to the present invention will be described in detail below.

[0019] (Structural unit (I) derived from aromatic hydroxycarboxylic acid) The structural unit (I) derived from an aromatic hydroxycarboxylic acid is preferably a structural unit derived from an aromatic hydroxycarboxylic acid represented by the following formula (1): Only one type of structural unit (I) may be contained, or two or more types may be contained.

[0020] [ka] In the above formula, Ar 1 is a structure derived from an aromatic hydrocarbon, and may have a substituent or a hetero element as desired. Examples of the structure derived from an aromatic hydrocarbon include those having a skeleton derived from a monocyclic benzene, an aromatic polycyclic compound such as biphenyl or 4,4'-isopropylidenediphenyl, or a condensed compound such as naphthalene, anthracene, or phenanthrene. Examples of the substituent include a hydrogen atom, an alkyl group, an alkoxy group, and a fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. The alkyl group may be a linear or branched alkyl group. The alkoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms.

[0021] Examples of raw material monomers that provide the structural unit represented by formula (I) include 6-hydroxy-2-naphthoic acid (HNA), p-hydroxybenzoic acid (HBA), m-hydroxybenzoic acid (m-HBA), and acylated products, ester derivatives, and acid halides thereof.

[0022] From the viewpoint of dielectric properties, the composition ratio (mol %) of the structural unit (I) in the liquid crystal polymer has a lower limit of preferably 45 mol % or more, more preferably 50 mol % or more, and even more preferably 55 mol % or more, and an upper limit of preferably 100 mol % or less, more preferably 90 mol % or less, and even more preferably 80 mol % or less.

[0023] (Structural unit (II) derived from aromatic diol) The structural unit (II) derived from an aromatic diol is preferably a structural unit derived from an aromatic diol represented by the following formula (2): Only one type of structural unit (II) may be contained, or two or more types may be contained.

[0024] [ka] In the above formula, Ar 2 is a structure derived from an aromatic hydrocarbon, and may have a substituent or a hetero element as desired. Examples of the structure derived from an aromatic hydrocarbon include those having a skeleton derived from a monocyclic benzene, an aromatic polycyclic compound such as biphenyl or 4,4'-isopropylidenediphenyl, or a condensed compound such as naphthalene, anthracene, or phenanthrene. Examples of the substituent include a hydrogen atom, an alkyl group, an alkoxy group, and a fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. The alkyl group may be a linear or branched alkyl group. The alkoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms.

[0025] Examples of raw material monomers that provide the structural unit (II) include 4,4'-dihydroxybiphenyl (BP), hydroquinone (HQ), methylhydroquinone (MeHQ), 4,4'-isopropylidenediphenol (BisPA), and their acylated derivatives, ester derivatives, and acid halides.

[0026] From the viewpoint of dielectric properties, the composition ratio (mol %) of the structural unit (II) in the liquid crystal polymer has a lower limit of preferably 5 mol % or more, more preferably 10 mol % or more, and an upper limit of preferably 27.5 mol % or less, more preferably 25 mol % or less, and even more preferably 22.5 mol % or less.

[0027] (Structural unit (III) derived from aromatic dicarboxylic acid) The structural unit (III) derived from an aromatic dicarboxylic acid is preferably a structural unit derived from an aromatic dicarboxylic acid represented by the following formula (3): Only one type of structural unit (III) may be included, or two or more types may be included.

[0028] [ka] In the above formula, Ar 3 is a structure derived from an aromatic hydrocarbon, and may have a substituent or a hetero element as desired. Examples of the structure derived from an aromatic hydrocarbon include those having a skeleton derived from a monocyclic benzene, an aromatic polycyclic compound such as biphenyl or 4,4'-isopropylidenediphenyl, or a condensed compound such as naphthalene, anthracene, or phenanthrene. Examples of the substituent include a hydrogen atom, an alkyl group, an alkoxy group, and a fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. The alkyl group may be a linear or branched alkyl group. The alkoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms.

[0029] Examples of raw material monomers that provide the structural unit (III) include terephthalic acid (TPA), isophthalic acid (IPA), 2,6-naphthalenedicarboxylic acid (NADA), and acylated products, ester derivatives, and acid halides thereof.

[0030] From the viewpoint of dielectric properties, the composition ratio (mol %) of the structural unit (III) in the liquid crystal polymer has a lower limit of preferably 5 mol % or more, more preferably 10 mol % or more, and an upper limit of preferably 27.5 mol % or less, more preferably 25 mol % or less, and even more preferably 22.5 mol % or less.

[0031] (Structural unit (IV) derived from an aromatic monomer having two functional groups) In addition to the above-mentioned structural units (I) to (III), the liquid crystal polymer may also contain a structural unit (IV) derived from an aromatic monomer having two functional groups. The two functional groups in the structural unit (IV) are selected from the group consisting of a hydroxy group, a carboxy group, and an amino group, and preferably contain at least one amino group. Examples of aromatic monomers having two functional groups include aromatic hydroxy monoamines and aromatic diamines.

[0032] An example of a structural unit derived from an aromatic hydroxymonoamine is a structural unit represented by the following formula (4): Raw material monomers that provide this structural unit include acetaminophen (AAP), p-aminophenol, etc. [ka]

[0033] An example of a structural unit derived from an aromatic diamine is a structural unit represented by the following formula (5): Raw material monomers that provide this structural unit include 4,4'-diaminodiphenyl ether (ODA) and the like. [ka]

[0034] The composition ratio (mol%) of the structural unit (IV) in the liquid crystal polymer can be appropriately adjusted according to the composition ratios of the other structural units. The composition ratio (mol%) of the structural unit (IV) is preferably 10 mol% or less, more preferably 7 mol% or less, even more preferably 5 mol% or less, still more preferably 3 mol% or less, and may be 0 mol%.

[0035] (Method of manufacturing liquid crystal polymer) The liquid crystal polymer can be produced, for example, by polymerizing the raw material monomers of the liquid crystal polymer described above by a conventionally known method. In a preferred embodiment of the present invention, the liquid crystal polymer can be produced only by melt polymerization. The liquid crystal polymer can also be produced by a method (two-stage polymerization) including a step of obtaining a polymer by melt polymerization and a step of obtaining a liquid crystal polymer by solid-state polymerization of the polymer.

[0036] From the viewpoint of efficiently obtaining a liquid crystal polymer, the melt polymerization is preferably carried out under reflux of acetic acid in the presence of 1.03 to 1.15 molar equivalents of acetic anhydride relative to the total hydroxyl groups possessed by all raw material monomers of the liquid crystal polymer.

[0037] The reaction temperature for melt polymerization is preferably in the range of the melting point to (melting point + 70)°C, more preferably in the range of (melting point + 20)°C to (melting point + 50)°C.

[0038] The melt polymerization is preferably carried out in the presence of a catalyst without a solvent. As the catalyst, a conventionally known catalyst for polymer polymerization can be used. Examples of the catalyst include metal salt catalysts such as potassium acetate, magnesium acetate, stannous acetate, lead acetate, sodium acetate, tetrabutyl titanate, and antimony trioxide, nitrogen-containing heterocyclic compounds such as N-methylimidazole, and organic compound catalysts. The amount of catalyst used is not particularly limited, but is preferably the total number of moles of monomers × (10 to 100) mg / mol.

[0039] When performing solid-state polymerization, the polymer obtained by melt polymerization may be cooled and solidified, and then pulverized into powder or flakes. Alternatively, the polymer strands obtained by melt polymerization may be pelletized. The reaction temperature for solid-state polymerization is preferably the melting point or lower, and is preferably (melting point - 30)°C to (melting point - 10)°C. Solid-state polymerization may be performed with stirring, or may be performed in a stationary state without stirring.

[0040] The polymerization reactor is not particularly limited, but a reactor generally used for reactions of high-viscosity fluids is preferably used. Examples of such reactors include stirred tank-type polymerization reactors having stirrers with stirring blades of various shapes, such as anchor-type, multi-stage-type, spiral belt-type, and spiral shaft-type, or modified versions of these, as well as mixing devices generally used for kneading resins, such as kneaders, roll mills, and Banbury mixers.

[0041] (Polyphenylene ether) Polyphenylene ether (PPE) is a compound having a polyphenylene ether chain in the molecule. In the present invention, conventionally known polyphenylene ethers can be used as the polyphenylene ether. The polyphenylene ether of the present invention also includes its modified product, modified polyphenylene ether (m-PPE). The modified polyphenylene ether of the present invention also includes an alloy of polyphenylene ether (PPE) with other synthetic resins. Examples of other synthetic resins include polystyrene (PS), polyphenylene sulfide (PPS), polypropylene (PP), polyamide (PA), and polyacetal (POM).

[0042] The lower limit of the number average molecular weight Mn of the polyphenylene ether is 10,000 or more, preferably 12,000 or more, more preferably 14,000 or more, and even more preferably 16,000 or more, and the upper limit may be 50,000 or less, 40,000 or less, 30,000 or less, or 20,000 or less. When the number average molecular weight Mn of the polyphenylene ether is within the above numerical range, a polymer blend having excellent thermal stability can be provided. The lower limit of the weight average molecular weight Mw of the polyphenylene ether is preferably 20,000 or more, preferably 25,000 or more, more preferably 30,000 or more, and even more preferably 35,000 or more, and the upper limit may be 100,000 or less, 90,000 or less, 80,000 or less, or 70,000 or less. When the weight average molecular weight Mw of the polyphenylene ether is within the above numerical range, a polymer blend having excellent thermal stability can be provided. In this specification, the number average molecular weight Mn and weight average molecular weight Mw of polyphenylene ether can be measured by gel permeation chromatography (GPC) and are values ​​calculated in terms of styrene.

[0043] The amount of polyphenylene ether in the polymer blend, relative to 100 parts by mass of the total of polyphenylene ether and liquid crystal polymer, has a lower limit of 1 part by mass or more, preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more, and an upper limit of 50 parts by mass or less, preferably 45 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 35 parts by mass or less. When the amount of polyphenylene ether in the polymer blend is within the above numerical range, it becomes easier to impart desired physical properties to the polymer blend.

[0044] [Method of manufacturing polymer blends] The method for producing the polymer blend according to the present invention is not particularly limited, but for example, the polymer blend according to the present invention can be produced by kneading a liquid-crystalline polymer and a polyphenylene ether by a conventionally known method. In particular, the polymer blend according to the present invention is preferably produced by kneading a liquid-crystalline polymer and a polyphenylene ether using an extruder equipped with a twin-screw kneader. Conditions such as the kneading temperature and time may be appropriately adjusted depending on the types of liquid-crystalline polymer and polyphenylene ether.

[0045] [Molded products] The molded article of the present invention contains the above-described polymer blend. By including the above-described polymer blend, the molded article has excellent dielectric properties, such as a low dielectric loss tangent comparable to that of liquid crystal polymers and a lower dielectric constant than conventional liquid crystal polymers. In addition, the molded article has practical heat resistance equal to or higher than that of liquid crystal polymers, which are highly heat-resistant polymers.

[0046] (filler) The molded article may further contain a filler. Examples of fillers include carbon fiber, graphite, glass fiber, talc, mica, glass flakes, clay, sericite, calcium carbonate, calcium sulfate, calcium silicate, silica, alumina, aluminum hydroxide, calcium hydroxide, graphite, potassium titanate, titanium oxide, fluorocarbon resin fiber, fluorocarbon resin, barium sulfate, and various whiskers. These fillers may be used alone or in combination of two or more.

[0047] The content of the filler in the molded article is preferably 1% by mass or more and 70% by mass or less, more preferably 5% by mass or more and 60% by mass or less, even more preferably 10% by mass or more and 50% by mass or less, and even more preferably 15% by mass or more and 45% by mass or less, based on the total amount of the molded article. When two or more fillers are contained, it is preferable that the total content thereof is within the above range. If the content of the filler in the molded article is within the above range, it is preferable because a molded article with excellent dielectric properties can be obtained.

[0048] (other resins) The molded article may further contain other resins in addition to the polymer blends described above, provided that the resin does not deviate from the spirit of the present invention. Examples of such resins include polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polyarylate, polycyclohexylene dimethylene terephthalate, and polybutylene terephthalate; polyolefin resins such as polyethylene and polypropylene; cycloolefin polymers; vinyl resins such as polyvinyl chloride; (meth)acrylic resins such as polyacrylate, polymethacrylate, and polymethyl methacrylate; imide resins such as polyacetal resins, polyamide resins, polyimides, and polyetherimides; polystyrene resins such as polystyrene, high-impact polystyrene, AS resin, and ABS resin; thermosetting resins such as epoxy resins; cellulose resins, polyether ether ketone resins, fluororesins, and polycarbonate resins. These resins may be used alone or in combination of two or more.

[0049] The content of resins other than the polymer blend in the molded article is preferably 1 part by mass or more and preferably 10 parts by mass or less, based on 100 parts by mass of the polymer blend.

[0050] (Other additives) The molded article may contain other additives, such as colorants, dispersants, plasticizers, antioxidants, curing agents, flame retardants, heat stabilizers, ultraviolet absorbers, antistatic agents, and surfactants, within the scope of the present invention.

[0051] The shape of the molded product is not particularly limited and may be changed appropriately depending on the application, and may be, for example, a plate, sheet, film, fiber, powder, or the like.

[0052] Molded articles can be produced by a conventional molding method using a mixture containing the above-mentioned polymer blend and, if desired, a filler, other resins, other additives, etc. The mixture can be obtained by melt-kneading the above-mentioned polymer blend, etc. using a Banbury mixer, kneader, single-screw or twin-screw extruder, etc. Examples of molding methods for molded articles include press molding, foam molding, injection molding, melt spinning, solution spinning, calendar molding, and punch molding.

[0053] [Electrical and electronic components] The electric / electronic component according to the present invention comprises a molded article (e.g., a fibrous molded article or an injection-molded article) containing the polymer blend. Examples of electric / electronic components comprising the molded article include antennas used in electronic devices and communication 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 prevention radars, RFID tags, capacitors, inverter components, insulating films, cable covering materials, insulating materials for secondary batteries such as lithium-ion batteries, and speaker diaphragms. [Example]

[0054] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0055] <Production example of liquid crystal polymer A> A polymerization vessel equipped with a stirring blade was charged with 27 mol% 6-hydroxy-2-naphthoic acid (HNA) and 73 mol% p-hydroxybenzoic acid (HBA) as raw monomers, and magnesium acetate and potassium acetate as catalysts. The vessel was then subjected to three cycles of vacuum and nitrogen injection, after which acetic anhydride (1.05 molar equivalents relative to the hydroxyl groups) was added, and the temperature was raised to 160°C, at which point the acetylation reaction was carried out under reflux for 1.5 hours.

[0056] After the acetylation was completed, the polymerization vessel, which had been in a state of acetic acid distillation, was heated to 320°C at a rate of 0.5°C / min. During this time, acetic acid as a by-product was distilled off as the esterification reaction progressed. After reaching 320°C, the vessel was stirred for 20 minutes, and then the system was depressurized while maintaining the temperature at 320°C to promote the distillation of acetic acid as a by-product. In this state, the pressure was gradually reduced to 200 hPa over 20 minutes. After that, the viscosity of the polymer was measured based on the power consumption and torque of the agitator. -1 When the viscosity reached approximately 20 Pa·s, the polymer was extracted and cooled to solidify. If the target viscosity was not reached after maintaining the pressure at 200 hPa for more than an hour, the pressure was further reduced to 10 hPa. After the reaction, the amount of acetic acid distilled was measured and found to be 99-100% of the theoretical reaction standard. The obtained polymer was allowed to cool naturally at room temperature, and then crushed to a size that could pass through a sieve with 2.0 mm openings, yielding liquid crystal polymer A.

[0057] The obtained polymer was heated and melted on the heating stage of a polarizing microscope (product name: ECLIPSE E600 POL) manufactured by Nikon Corporation equipped with a large cooling and heating stage for microscopes (product name: 10083L) manufactured by Japan High Tech Co., Ltd., and the liquid crystallinity was confirmed based on the presence or absence of optical anisotropy.

[0058] The melting point of the liquid crystal polymer A was measured using a differential scanning calorimeter (DSC). Specifically, the liquid crystal polymer A was heated from 30°C to 350-400°C at a rate of 10°C / min until completely melted, then cooled to 30°C at a rate of 10°C / min, and heated again at a rate of 10°C / min to the same temperature as in the first cycle. The temperature at the apex of the endothermic peak in the second cycle of the heating process was taken as Tm2, ​​and Tm2 was taken as the melting point (°C). As a result of the measurement, the melting point of the liquid crystal polymer A was 285°C.

[0059] <Production example of liquid crystal polymer B> Liquid crystal polymer B was obtained in the same manner as in the production example of liquid crystal polymer A, except that the raw material monomers were changed to 60 mol% HNA, 20 mol% 4,4'-dihydroxybiphenyl (BP), 15.5 mol% terephthalic acid (TPA), and 4.5 mol% 2,6-naphthalenedicarboxylic acid (NADA), and the final temperature of the melt polymerization was changed to 350°C. The liquid crystallinity of the polymer was confirmed in the same manner as above. The melting point of liquid crystal polymer B was measured in the same manner as above, and was found to be 320°C.

[0060] <Production example of liquid crystal polymer C> Liquid crystal polymer C was obtained in the same manner as in the production example of liquid crystal polymer B, except that the raw material monomers were changed to HBA 70 mol%, HNA 2 mol%, hydroquinone (HQ) 14 mol%, and NADA 14 mol%. The liquid crystallinity of the polymer was confirmed in the same manner as above. The melting point of liquid crystal polymer C was measured in the same manner as above and was found to be 323 ° C.

[0061] The monomer compositions of the liquid crystal polymers A, B, and C (LCP-A, LCP-B, and LCP-C) produced above are shown in Table 1. [Table 1]

[0062] <Polymer Blend Production Example 1> (Example 1-1) 95 parts by mass of the liquid crystal polymer A produced above and 5 parts by mass of poly(2,6-dimethyl-1,4-phenylene ether) (PPE, Mw: 47600, Mn: 17300, manufactured by SABIC Corporation, trade name: NORYL PPO630) were mixed using an extruder equipped with a twin-screw mixer (Toyo Seiki Co., Ltd., Labo Plastomill Micro, small extrusion segment 2D15W) at a heating temperature of 340°C and a screw rotation of 40 rpm to obtain a polymer blend.

[0063] (manufacturing of molded products) The resulting polymer blend was heated and melted at 310°C using an injection molding machine and injected into a mold at 80°C to prepare a flat test piece measuring 30 mm (flow direction) x 30 mm x 0.4 mm (thickness).

[0064] (Example 1-2) A polymer blend was obtained in the same manner as in Example 1-1, except that the blending amount of the liquid crystal polymer A was changed to 85 parts by mass and the blending amount of the PPE was changed to 15 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 1-1.

[0065] (Examples 1-3) A polymer blend was obtained in the same manner as in Example 1-1, except that the blending amount of the liquid crystal polymer A was changed to 75 parts by mass and the blending amount of the PPE was changed to 25 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 1-1.

[0066] (Examples 1-4) A polymer blend was obtained in the same manner as in Example 1-1, except that the blending amount of the liquid crystal polymer A was changed to 69 parts by mass and the blending amount of the PPE was changed to 31 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 1-1.

[0067] (Examples 1-5) A polymer blend was obtained in the same manner as in Example 1-1, except that the blending amount of the liquid crystal polymer A was changed to 60 parts by mass and the blending amount of the PPE was changed to 40 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 1-1.

[0068] (Comparative Example 1-1) A polymer blend was obtained in the same manner as in Example 1-1, except that PPE was not added in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 1-1.

[0069] (Comparative Example 1-2) A polymer blend was obtained in the same manner as in Example 1-1, except that the blending amount of liquid crystal polymer A was changed to 47.1 parts by mass and the blending amount of PPE was changed to 52.9 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 1-1.

[0070] <Performance evaluation of polymer blends 1> <Measurement of relative permittivity and dielectric loss tangent (10GHz)> The dielectric constant and dielectric loss tangent of each of the flat test specimens prepared above were measured using the cavity resonator method in accordance with IEC standard IEC62562. Specifically, the in-plane dielectric constant (Er) and dielectric loss tangent (tanδ) of the above flat test specimens were measured using a Keysight Technologies network analyzer N5247A by the split post dielectric resonator method (SPDR method) at 23°C, 55% humidity, and a frequency of 10 GHz. Each type of sample was measured in quadruplicate, and the average values ​​for the four measurements are shown in Table 2.

[0071] <Measurement of mass loss rate> The mass loss rate of each polymer blend obtained above was measured using a thermogravimetric analyzer (TGA) manufactured by Hitachi High-Tech Science Corporation. Specifically, a sample of each polymer blend was heated from room temperature (30°C) at a rate of 10°C / min under a nitrogen atmosphere until it reached 500°C. The initial mass of the sample was taken as 100%, and the temperature at which the mass had decreased by 1% was taken as the 1% mass loss temperature (Td1%). The measurement results are shown in Table 2.

[0072] <Melt viscosity measurement> Each polymer blend obtained above was subjected to a shear rate of 100 s at 305 °C. -1The melt viscosity (Pa s) under these conditions was measured in accordance with JIS K7199 using a capillary rheometer viscometer (Capillograph 1D, Toyo Seiki Seisakusho Co., Ltd.) and a capillary with an inner diameter of 1 mm and a length of 40 mm. The measurement results are shown in Table 2.

[0073] [Table 2]

[0074] The results in Table 2 show that blending an appropriate amount of polyphenylene ether into the liquid crystal polymer suppresses the increase in the dielectric dissipation factor, keeping it at 2.50 × 10, which is the same as the ordinary liquid crystal polymer alone. -3 While maintaining the dielectric constant at or below 100%, the dielectric constant could be significantly reduced compared to the liquid crystal polymer alone (Comparative Example 1-1).

[0075] <Polymer Blend Production Example 2> Example 2-1 A polymer blend was obtained in the same manner as in Example 1-1, except that the blending amount of liquid crystal polymer B was changed to 85 parts by mass, the blending amount of PPE was changed to 15 parts by mass, and the heating temperature was changed to 350°C. Next, using the obtained polymer blend, flat plate test pieces were prepared in the same manner as in Example 1-1, except that the heating temperature during injection molding was set to 340°C.

[0076] (Example 2-2) A polymer blend was obtained in the same manner as in Example 2-1, except that the blending amount of liquid crystal polymer B was changed to 75 parts by mass and the blending amount of PPE was changed to 25 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 2-1.

[0077] (Example 2-3) A polymer blend was obtained in the same manner as in Example 2-1, except that the blending amount of liquid crystal polymer B was changed to 69 parts by mass and the blending amount of PPE was changed to 31 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 2-1.

[0078] (Examples 2-4) A polymer blend was obtained in the same manner as in Example 2-1, except that the blending amount of liquid crystal polymer B was changed to 59 parts by mass and the blending amount of PPE was changed to 41 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 2-1.

[0079] (Comparative Example 2-1) A polymer blend was obtained in the same manner as in Example 2-1, except that no PPE was added in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 2-1.

[0080] <Performance evaluation of polymer blends 2> <Measurement of relative permittivity and dielectric loss tangent (10GHz)> The dielectric constant and dielectric loss tangent of each of the flat test pieces prepared above were measured in the same manner as in Polymer Blend Performance Evaluation 1. Each type of sample was measured four times, and the average values ​​of the four measurements are shown in Table 3.

[0081] [Table 3]

[0082] From the results in Table 3, it can be seen that blending an appropriate amount of polyphenylene ether into the liquid crystal polymer suppresses the increase in the dielectric loss tangent, and the loss tangent is 2.50 × 10 -3 While maintaining the dielectric constant at or below 100%, the dielectric constant could be significantly reduced compared to the liquid crystal polymer alone (Comparative Example 2-1).

[0083] <Polymer Blend Production Example 3> Example 3-1 A polymer blend was obtained in the same manner as in Example 2-1, except that the blending amount of liquid crystal polymer C was changed to 85 parts by mass and the blending amount of PPE was changed to 15 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 2-1.

[0084] (Example 3-2) A polymer blend was obtained in the same manner as in Example 3-1, except that the blending amount of liquid crystal polymer C was changed to 75 parts by mass and the blending amount of PPE was changed to 25 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 3-1.

[0085] (Example 3-3) A polymer blend was obtained in the same manner as in Example 3-1, except that the blending amount of liquid crystal polymer C was changed to 69 parts by mass and the blending amount of PPE was changed to 31 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 3-1.

[0086] (Examples 3-4) A polymer blend was obtained in the same manner as in Example 3-1, except that the blending amount of liquid crystal polymer C was changed to 60 parts by mass and the blending amount of PPE was changed to 40 parts by mass in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 3-1.

[0087] (Comparative Example 3-1) A polymer blend was obtained in the same manner as in Example 3-1, except that PPE was not added in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 3-1.

[0088] <Performance evaluation of polymer blends 3> <Measurement of relative permittivity and dielectric loss tangent (10GHz)> The dielectric constant and dielectric loss tangent of each of the flat test pieces prepared above were measured in the same manner as in Polymer Blend Performance Evaluation 1. Each type of sample was measured four times, and the average values ​​of the four measurements are shown in Table 4.

[0089] [Table 4]

[0090] From the results in Table 4, it can be seen that blending an appropriate amount of polyphenylene ether into the liquid crystal polymer suppresses the increase in the dielectric tangent, and the dielectric tangent is 2.50 × 10 -3 While maintaining the dielectric constant at or below 100%, the dielectric constant could be significantly reduced compared to the liquid crystal polymer alone (Comparative Example 3-1).

[0091] <Polymer Blend Production Example 4> (Example 4-1) A polymer blend was obtained in the same manner as in Example 1-2, except that 15 parts by mass of poly(2,6-dimethyl-1,4-phenylene ether) (PPE, Mw: 56200, Mn: 19900, manufactured by SABIC Corporation, trade name: NORYL PPO640) was used as the PPE in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 1-2.

[0092] (Comparative Example 4-1) A polymer blend was obtained in the same manner as in Example 4-1, except that 15 parts by mass of poly(2,6-dimethyl-1,4-phenylene ether) (PPE, Mw: 6300, Mn: 2350, manufactured by SABIC Corporation, trade name: SA120) was used as the PPE in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 4-1.

[0093] (Comparative Example 4-2) A polymer blend was obtained in the same manner as in Example 2-1, except that 15 parts by mass of poly(2,6-dimethyl-1,4-phenylene ether) (PPE, Mw: 6300, Mn: 2350, manufactured by SABIC Corporation, trade name: SA120) was used as the PPE in the production of the polymer blend. Next, the obtained polymer blend was used to prepare a flat test piece in the same manner as in Example 4-1.

[0094] <Performance evaluation of polymer blends 4> <Measurement of relative permittivity and dielectric loss tangent (10GHz)> The dielectric constant and dielectric loss tangent of each of the flat test pieces prepared above were measured in the same manner as in Polymer Blend Performance Evaluation 1. Each type of sample was measured four times, and the average values ​​of the four measurements are shown in Table 5.

[0095] <Measurement of mass loss rate> For each of the polymer blends obtained above, the mass loss rate was measured in the same manner as in Polymer Blend Performance Evaluation 1. The measurement results are shown in Table 5.

[0096] In Table 5, the results of Examples 1-2 and 2-1 are also shown for reference. [Table 5]

[0097] The results in Table 5 show that blending a liquid crystal polymer with polyphenylene ether having a number average molecular weight Mn of 10,000 or more could improve the dielectric tangent and thermal stability.

[0098] <Performance evaluation of polymer blends 5> <Measurement of tensile fracture temperature> Each flat plate specimen prepared in Examples 1-1 to 1-5 and Comparative Examples 1-1 and 1-2 was cut to a size of 30 mm x 8 mm (with the long side in the TD direction) to obtain a measurement sample. The obtained samples were evaluated for practical heat resistance using a dynamic viscoelasticity analyzer (DMA, Hitachi High-Tech Science Corporation, Model No. DMS6100). Specifically, measurements were performed in tensile mode at 1 Hz, with a heating rate of 6°C / min and a starting temperature of 30°C. The end point of the measurement was the point at which the sample was thermally deformed or fractured during the heating process, or the point at which the loss modulus decreased to one-hundredth of the value at the start of the measurement. In the measurement data, the loss modulus graph showed a flat section showing a stable change in physical properties relative to temperature above 200°C, which is higher than the glass transition point, and the intersection of the tangents to the section just before the measurement ended due to an inelastic change or breakage, where the material's liquid behavior suddenly intensified with further heating, was determined, and the temperature at this intersection was taken as the tensile breakage temperature, at which the material could no longer withstand the specified stress of the DMA device and broke. The measurement results are shown in Table 6.

[0099] [Table 6]

[0100] The results in Table 6 show that by blending an appropriate amount of polyphenylene ether into the liquid crystal polymer, it is possible to maintain the same level of tensile break temperature as the liquid crystal polymer alone, and to provide high enough heat resistance for practical use as a high heat resistant material.

[0101] <Performance evaluation of polymer blends 6> <Measurement of deflection temperature under load (DTUL)> Using an injection molding machine, the polymer blends obtained in Example 2-1 and Comparative Example 4-2 were heated and melted at 310°C and injected into a mold at 80°C to prepare bending test specimens measuring 80 mm (flow direction) x 12 mm x 2 mm (thickness). Next, the bending test specimens prepared above were subjected to edgewise testing in accordance with ISO 75 using a load deflection temperature measuring instrument (manufactured by Yasuda Seiki Seisakusho Co., Ltd., model number: No. 148-HD500), in which a load was applied to an 80 mm x 2.0 mm surface. The specific measurement conditions were as follows: In a nitrogen atmosphere, a load of 1.80 MPa was applied to the center of the bending test piece with a support distance of 64 mm, and the measurement starting temperature was 100°C, with a heating rate of 120°C / hr. The temperature at which the specified deflection of 0.11 mm was reached was taken as the deflection temperature under load (°C) (DTUL). Measurements were performed on N=3 samples, and the average values ​​of the three measurements are shown in Table 7.

[0102] [Table 7]

[0103] The results in Table 7 show that blending a liquid crystal polymer with polyphenylene ether having a number average molecular weight Mn of 10,000 or more increases the deflection temperature under load (DTUL) and improves practical heat resistance.

Claims

1. A polymer blend comprising a polyphenylene ether having a number average molecular weight Mn of 10,000 or more and a liquid crystal polymer, The blended amount of the polyphenylene ether is 1 part by mass or more and 50 parts by mass or less per 100 parts by mass of the polyphenylene ether and the liquid crystal polymer combined.

2. 2. The polymer blend according to claim 1, wherein in the liquid crystal polymer, structural units derived from aromatic monomers account for 95 mol % or more and 100 mol % or less of all structural units.

3. 3. The polymer blend according to claim 2, wherein the composition ratio of the structural units derived from aromatic hydroxycarboxylic acid in the liquid crystal polymer is 45 mol % or more of all structural units.

4. The polymer blend has a relative dielectric constant of 3.45 or less and a dielectric loss tangent of 2.50×10 at 23° C. as measured by a 10 GHz SPDR method. －３ 2. The polymer blend of claim 1, wherein:

5. 2. The polymer blend according to claim 1, wherein the blending amount of the polyphenylene ether is 3 parts by mass or more and 45 parts by mass or less per 100 parts by mass of the total of the polyphenylene ether and the liquid crystal polymer.

6. 2. The polymer blend according to claim 1, wherein the upper limit of the number average molecular weight Mn of the polyphenylene ether is 50,000 or less.

7. The polymer blend was subjected to a shear rate of 100 s －１ 2. The polymer blend of claim 1, wherein the melt viscosity measured under the conditions of

8. 2. The polymer blend of claim 1, wherein the polymer blend has a 1% mass loss temperature of 420°C or higher as measured by thermogravimetric analysis under a nitrogen atmosphere.

9. A molded article comprising the polymer blend of any one of claims 1 to 8.

10. An electric / electronic component comprising the molded article according to claim 9.

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