Resin compositions, films, metal-clad laminates, and circuit boards

Abstract

Provided is a resin composition that has a low dielectric loss tangent at a high-frequency band and enables the formation of a film having reduced film thickness unevenness. The resin composition contains a thermoplastic liquid crystal polymer. The resin composition has a dielectric loss tangent at 5 GHz of no greater than 0.0015. When, after 12 minutes of measurement at a frequency of 1 rad / s using a rotary rheometer, the frequency is switched to 100 rad / s, the percentage of reduction in the complex viscosity η* 7 minutes after the switch is 20% or less.

Description

Related Application

[0001] This application claims the priority of Japanese Patent Application No. 2023-080082 filed on May 15, 2023, and the entire disclosure of which is incorporated herein by reference and made a part hereof.

Technical Field

[0002] The present invention relates to a resin composition containing a polymer capable of forming an optically anisotropic molten phase (hereinafter referred to as a thermoplastic liquid crystal polymer). The present invention also relates to a film containing the resin composition, a metal-clad laminate in which a metal layer is bonded to at least one surface of the film, and a circuit board including at least an insulating layer and a conductor layer containing the resin composition.

Background Art

[0003] In recent years, remarkable developments have taken place in the fields of information processing and communication equipment. Along with the increase in the transmission speed of signals in circuits used in these fields, the frequency of signals has been increasing. Along with this, the base materials used for circuit boards are required to have excellent dielectric properties in the high-frequency region.

[0004] As a material having excellent dielectric properties (high-frequency properties) in the high-frequency region, thermoplastic liquid crystal polymers have attracted attention. For example, Patent Document 1 (Japanese Patent No. 4639756) discloses an aromatic liquid crystal polyester having a repeating unit derived from 2-hydroxy-6-naphthoic acid in an amount of 40 to 74.8 mol%, a repeating unit derived from hydroquinone or 4,4'-dihydroxybiphenyl in an amount of 12.5 to 30 mol%, a repeating unit derived from 2,6-naphthalenedicarboxylic acid in an amount of 12.5 to 30 mol%, and a repeating unit derived from terephthalic acid or 4,4'-biphenyldicarboxylic acid in an amount of 0.2 to 15 mol%, wherein the number of moles of the repeating unit derived from terephthalic acid or 4,4'-biphenyldicarboxylic acid is not less than the number of moles of the repeating unit derived from 2,6-naphthalenedicarboxylic acid, and the flow start temperature is 300 to 400°C. Further, it is described that this aromatic liquid crystal polyester has a small dielectric loss and excellent processability into a film shape. rank The number of moles of the repeating unit derived from terephthalic acid or 4,4'-biphenyldicarboxylic acid is not less than the number of moles of the repeating unit derived from 2,6-naphthalenedicarboxylic acid, and the flow start temperature is 300 to 400°C. Further, it is described that this aromatic liquid crystal polyester has a small dielectric loss and excellent processability into a film shape. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 4639756 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, although the aromatic liquid crystal polyester described in the example of Patent Document 1 exhibits a low dielectric loss tangent in its film, the film made from such aromatic liquid crystal polyester has the problem of exhibiting uneven film thickness as an appearance defect.

[0007] Therefore, the object of the present invention is to provide a thermoplastic liquid crystal polymer resin composition that enables the molding of films with low dielectric loss tangent in the high-frequency band and reduced film thickness variations, which are appearance defects.

[0008] Another object of the present invention is to provide a circuit board comprising a film containing the resin composition, a metal-clad laminate in which a metal layer is bonded to at least one surface of the film, and an insulating layer containing a conductive layer and the resin composition. [Means for solving the problem]

[0009] The inventors of the present invention have conducted diligent studies to achieve the above objectives and have found that in a resin composition containing a thermoplastic liquid crystal polymer, the dielectric loss tangent at 5 GHz is within a specific range, and the complex viscosity η * We discovered that resin compositions with a reduction rate within a specific range can be used to form films with excellent dielectric properties in the high-frequency band while reducing film thickness variations, thus completing the present invention.

[0010] In other words, the present invention may be configured in the following embodiments. [Aspect 1] A resin composition comprising a thermoplastic liquid crystal polymer, wherein the dielectric loss tangent at 5 GHz is 0.0015 or less (preferably 0.0014 or less, more preferably 0.0013 or less, even more preferably 0.0012 or less, even more preferably 0.0011 or less, particularly preferably 0.0010 or less), and the complex viscosity η is measured 7 minutes after switching to a frequency of 100 rad / s after 12 minutes at a frequency of 1 rad / s using a rotary rheometer under the following measurement conditions. * A resin composition in which the rate of decrease is 20% or less (preferably 19% or less, more preferably 18% or less, even more preferably 15% or less, and even more preferably 10% or less). (Measurement conditions) • Parallel plate measurement • Gap distance: 0.9mm • Plate diameter: 25mm • Measurement temperature: Endothermic peak temperature Tm1 + 20°C derived from thermoplastic liquid crystal polymer, measured using a differential scanning calorimeter. ·Distortion: 3.0% Soak time for each measurement at frequencies of 1 rad / s and 100 rad / s: 0.0 seconds • Sampling interval during measurement at a frequency of 100 rad / s: 5.0 seconds / pt • Preheating time: 5 minutes [Aspect 2] The resin composition according to Embodiment 1, wherein, using a capillary rheometer, the capillary diameter is 1.0 mm, the capillary length is 20 mm, the endothermic peak temperature Tm1 + 20°C, and the shear rate is 1000 sec. -1 A resin composition having a melt viscosity of 30 to 120 Pa·s (preferably 35 to 80 Pa·s, more preferably 40 to 70 Pa·s, and even more preferably 42 to 65 Pa·s) as measured under conditions of a preheating time of 5 minutes. [Aspect 3] A resin composition according to embodiment 1 or 2, wherein, using a capillary rheometer, the capillary diameter is 1.0 mm, the capillary length is 20 mm, the endothermic peak temperature Tm1 + 20°C, and the shear rate is 1000 sec. -1A resin composition in which, under conditions of a preheating time of 5 minutes, the melt tension when pulled at a pull-up speed of 30 m / min with a distance of 200 mm from the capillary outlet to the center position of the tension pulley, is 0.002 N or more (preferably 0.003 N or more, more preferably 0.004 N or more). [Aspect 4] A resin composition according to any one of embodiments 1 to 3, wherein when heating and cooling cycles are repeated using a differential scanning calorimeter under the following heating and cooling conditions, the difference Tm1-Tm6 between the endothermic peak temperature Tm1 at the first heating cycle and the endothermic peak temperature Tm6 at the sixth heating cycle is 12°C or less (preferably 10°C or less, more preferably 9°C or less, and even more preferably 8°C or less). (Temperature increase / decrease conditions) • Heating conditions: Heat from 25°C to 400°C at a rate of 20°C / min, and hold at 400°C for 2 minutes after reaching the temperature. • Cooling conditions: Cool from 400°C to 25°C at a rate of 20°C / min, and hold at 25°C for 2 minutes after reaching 25°C. [Aspect 5] A resin composition according to any one of embodiments 1 to 4, wherein, using a capillary rheometer, the capillary diameter is 1.0 mm, the capillary length is 20 mm, the endothermic peak temperature Tm1 + 20°C, and the shear rate is 1000 sec. -1 A resin composition in which, when the melt viscosity measured under the condition of a preheating time of 5 minutes is X (Pa·s), and then the melt viscosity measured under the same temperature and shear rate conditions after standing in a barrel at the same temperature for 30 minutes is Y (Pa·s), the ratio Y / X between these two values ​​is 1.30 or less (preferably 1.25 or less, more preferably 1.20 or less). [Aspect 6] The resin composition according to any one of Aspects 1 to 5, wherein in the thermoplastic liquid crystal polymer, with respect to the total amount of all repeating units, the repeating unit represented by the following formula (1) is 0 to 25 mol% (preferably 0.1 to 25 mol%, more preferably 1 to 20 mol%), the repeating unit represented by the following formula (2) is 25 to 90 mol% (preferably 25 to 80 mol%, more preferably 30 to 75 mol%), the repeating unit represented by the following formula (3) is 0.1 to 40 mol% (preferably 0.1 to 37.5 mol%, more preferably 1 to 35 mol%, still more preferably 5 to 30 mol%), and the repeating unit represented by the following formula (4) is 0.1 to 40 mol% (preferably 0.1 to 37.5 mol%, more preferably 1 to 35 mol%, still more preferably 5 to 30 mol%). -O-Ar 1 -CO- (1) -O-Ar 2 -CO- (2) -CO-Ar 3 -CO- (3) -O-Ar 4 -O- (4) (In the formula, Ar 1 is a 1,4-phenylene group, Ar 2 is a 2,6-naphthylene group, Ar 3 is at least one selected from the group consisting of a 1,4-phenylene group, a 1,3-phenylene group, and a 2,6-naphthylene group, Ar 4 is at least one selected from the group consisting of a 1,4-phenylene group, a 1,3-phenylene group, and a 4,4'-biphenylene group, Ar 1 , Ar 2 , Ar 3 and Ar 4 The hydrogen atoms of the aromatic rings of may each independently be substituted with at least one selected from the group consisting of a C 1-3 alkyl group, a halogen atom, and a phenyl group). 〔Aspect 7〕 A resin composition according to embodiment 6, wherein the thermoplastic liquid crystal polymer has a total amount of repeating units containing 2,6-naphthylene groups of 40 mol% or more (preferably 50 mol% or more, more preferably 60 mol% or more) relative to the total amount of all repeating units. [Aspect 8] A resin composition according to any one of embodiments 1 to 7, comprising particulate matter. [Aspect 9] A resin composition according to any one of embodiments 1 to 8, comprising an additive material, wherein the additive material is at least one selected from the group consisting of thermoplastic resins, thermosetting resins, inorganic compounds, and liquid crystalline oligomers. [Aspect 10] A resin composition according to embodiment 9, wherein the thermoplastic resin comprises at least one selected from the group consisting of amorphous polyarylate resins, polyphenylene ether resins, polyphenylene sulfide resins, polyetherimide resins, polyethersulfone resins, polycarbonate resins, polyetheretherketone resins, and fluorine resins. [Aspect 11] A resin composition according to embodiment 9 or 10, wherein the inorganic compound comprises at least one selected from the group consisting of silica and titanium dioxide. [Aspect 12] A resin composition according to any one of embodiments 9 to 11, comprising two or more inorganic particles with different median diameters. [Aspect 13] A resin composition according to any one embodiment of embodiments 9 to 12, comprising two or more of the additive materials. [Aspect 14] A resin composition according to any one embodiment of embodiments 9 to 13, wherein the weight ratio of the thermoplastic liquid crystal polymer to the additive material (thermoplastic liquid crystal polymer / additive material) is in the range of 63.0 / 37.0 to 94.9 / 5.1 (preferably 66.0 / 34.0 to 94.5 / 5.5, more preferably 72.0 / 28.0 to 93.0 / 7.0). [Aspect 15] A film comprising the resin composition described in any one of embodiments 1 to 14. [Aspect 16] A film according to embodiment 15, wherein the film has a thickness of 5 to 200 μm (preferably 10 to 150 μm). [Aspect 17] A film according to embodiment 15 or 16, wherein the coefficient of variation of the thickness in the film width direction, as measured by a continuous thickness gauge, is 1.90% or less (preferably 1.80% or less, more preferably 1.75% or less, even more preferably 1.70% or less, even more preferably 1.40% or less, and particularly preferably 1.30% or less). [Aspect 18] A metal-clad laminate in which a metal layer is bonded to at least one surface of a film according to any one of embodiments 15 to 17. [Aspect 19] A circuit board comprising at least a conductive layer and an insulating layer containing the resin composition described in any one of embodiments 1 to 14.

[0011] As used herein, the singular forms, “a,” “an,” and “the,” are intended to include the plural form, including “at least one,” unless the context explicitly indicates otherwise. As used herein, the terms “and / or,” “at least one,” and “one or more” include any and all combinations of the related enumerated items.

[0012] Furthermore, any combination of at least two components disclosed in the claims and / or specification is included in the present invention. In particular, any combination of two or more claims described in the claims is included in the present invention. [Effects of the Invention]

[0013] The resin composition of the present invention has a low dielectric loss tangent in the high-frequency band and can be used to form films with reduced film thickness variations.

[0014] Films containing the resin composition of the present invention can be suitably used as circuit board materials and the like because they have a low dielectric loss tangent in the high-frequency band. [Modes for carrying out the invention]

[0015] [Thermoplastic liquid crystal polymer] The resin composition includes a thermoplastic liquid crystal polymer. The thermoplastic liquid crystal polymer is composed of a melt-mold liquid crystalline polymer (or a polymer capable of forming an optically anisotropic molten phase), and its chemical composition is not particularly limited as long as it is a melt-mold liquid crystalline polymer, but examples include thermoplastic liquid crystal polyester, or thermoplastic liquid crystal polyesteramide in which an amide bond is introduced thereto.

[0016] Furthermore, the thermoplastic liquid crystal polymer may be a polymer in which an aromatic polyester or aromatic polyesteramide is further modified by introducing isocyanate-derived bonds such as imide bonds, carbonate bonds, carbodiimide bonds, or isocyanurate bonds.

[0017] In this specification, the formation of an optically anisotropic molten phase can be determined, for example, by placing the sample on a hot stage, heating it in a nitrogen atmosphere, and observing the transmitted light of the sample.

[0018] Specific examples of thermoplastic liquid crystal polymers include known thermoplastic liquid crystal polyesters and thermoplastic liquid crystal polyesteramides derived from compounds classified as (1) to (4) below and their derivatives. However, it goes without saying that there is an appropriate range for the combination of various raw material compounds in order to form a polymer that can form an optically anisotropic molten phase.

[0019] (1) Aromatic or aliphatic diols (see Table 1 for representative examples) [Table 1]

[0020] (2) Aromatic or aliphatic dicarboxylic acids (see Table 2 for representative examples) [Table 2]

[0021] (3) Aromatic hydroxycarboxylic acids (see Table 3 for representative examples) [Table 3]

[0022] (4) Aromatic diamines, aromatic hydroxyamines, or aromatic aminocarboxylic acids (see Table 4 for representative examples) [Table 4]

[0023] Typical examples of thermoplastic liquid crystal polymers obtained from these raw material compounds include copolymers having repeating units, as shown in Tables 5 and 6.

[0024] [Table 5]

[0025] [Table 6]

[0026] Examples of copolymers constituting thermoplastic liquid crystal polymers include copolymers containing repeating units derived from two or more aromatic hydroxycarboxylic acids, and copolymers containing repeating units derived from at least one aromatic hydroxycarboxylic acid, at least one aromatic dicarboxylic acid, and at least one aromatic diol and / or aromatic hydroxyamine. For example, copolymers containing at least repeating units derived from p-hydroxybenzoic acid and / or 6-hydroxy-2-naphthoic acid are preferred as repeating units derived from aromatic hydroxycarboxylic acids. The resin composition may also contain a mixture of two or more copolymers from among these copolymers with different combinations of repeating units and their content.

[0027] The thermoplastic liquid crystal polymer in the resin composition preferably contains repeating units derived from at least one aromatic hydroxycarboxylic acid, repeating units derived from at least one aromatic dicarboxylic acid, and repeating units derived from at least one aromatic diol and / or aromatic hydroxyamine. In this specification, when the resin composition contains two or more copolymers with different combinations of repeating units and their content, the repeating units constituting the thermoplastic liquid crystal polymer in the resin composition are expressed as the total repeating units of all those copolymers. Furthermore, the content of each repeating unit constituting the thermoplastic liquid crystal polymer in the resin composition is expressed as an average value calculated considering the combination of repeating units of each of the two or more copolymers, their content, and molecular weight.

[0028] For example, the thermoplastic liquid crystal polymer in the resin composition may consist of 0 to 25 mol% of repeating units represented by the following formula (1) (hereinafter sometimes referred to as repeating unit (1)), 25 to 90 mol% of repeating units represented by the following formula (2) (hereinafter sometimes referred to as repeating unit (2)), 0.1 to 40 mol% of repeating units represented by the following formula (3) (hereinafter sometimes referred to as repeating unit (3)), and 0.1 to 40 mol% of repeating units represented by the following formula (4) (hereinafter sometimes referred to as repeating unit (4)), relative to the total amount of all repeating units. -O-Ar 1 -CO- (1) -O-Ar 2 -CO- (2) -CO-Ar 3 -CO- (3) -O-Ar 4 -O- (4) (In the formula, Ar 1 It is a 1,4-phenylene group, and Ar 2 It is a 2,6-naphthylene group, and Ar 3 is at least one selected from the group consisting of a 1,4-phenylene group, a 1,3-phenylene group, and a 2,6-naphthylene group, and Ar 4 is at least one selected from the group consisting of a 1,4-phenylene group, a 1,3-phenylene group, and a 4,4'-biphenylylene group, and Ar 1 Ar 2 Ar 3 and Ar 4 The hydrogen atoms of the aromatic ring are each independently of C 1-3 It may be substituted with at least one selected from the group consisting of alkyl groups, halogen atoms, and phenyl groups.

[0029] If the thermoplastic liquid crystal polymer in the resin composition contains repeating units (1), the content of repeating units (1) may preferably be 0.1 to 25 mol%, and more preferably 1 to 20 mol%, relative to the total amount of all repeating units.

[0030] The content of repeating units (2) in the thermoplastic liquid crystal polymer in the resin composition may preferably be 25 to 80 mol%, and more preferably 30 to 75 mol%, relative to the total amount of all repeating units.

[0031] The content of repeating units (3) in the thermoplastic liquid crystal polymer in the resin composition is preferably 0.1 to 37.5 mol%, more preferably 1 to 35 mol%, and even more preferably 5 to 30 mol%, based on the total amount of all repeating units.

[0032] The content of repeating units (4) in the thermoplastic liquid crystal polymer in the resin composition is preferably 0.1 to 37.5 mol%, more preferably 1 to 35 mol%, and even more preferably 5 to 30 mol%, based on the total amount of all repeating units.

[0033] From the viewpoint of increasing the molecular weight of the thermoplastic liquid crystal polymer and improving its mechanical properties, the molar ratio of repeating unit (3) to repeating unit (4) in the thermoplastic liquid crystal polymer in the resin composition may be 95 / 100 to 100 / 95, preferably 98 / 100 to 100 / 98, more preferably 99 / 100 to 100 / 99, and even more preferably 100 / 100.

[0034] From the viewpoint of reducing dielectric loss tangent, the thermoplastic liquid crystal polymer in the resin composition preferably has a naphthalene skeleton as a repeating unit. For example, the total amount of repeating units containing 2,6-naphthylene groups in the thermoplastic liquid crystal polymer in the resin composition may be 40 mol% or more, preferably 50 mol% or more, and more preferably 60 mol% or more, based on the total amount of all repeating units. Furthermore, from the viewpoint of adjusting the melting point and improving melt moldability, it may be 95 mol% or less, preferably 90 mol% or less, and more preferably 85 mol% or less. Examples of repeating units containing 2,6-naphthylene groups include repeating unit (2) (a repeating unit derived from 6-hydroxy-2-naphthoic acid) and Ar3 A repeating unit (3) (a repeating unit derived from 2,6-naphthalenedicarboxylic acid) in which is a 2,6-naphthylene group is preferred.

[0035] In the thermoplastic liquid crystal polymer in the resin composition, each repeating unit (1) to (4) may contain two or more types. The above content of each repeating unit represents the content of all repeating units corresponding to each repeating unit. For example, in the thermoplastic liquid crystal polymer in the resin composition, repeating unit (3) may be Ar 3 If the repeating unit contains two types of repeating units, one being a 1,4-phenylene group and the other being a 2,6-naphthylene group, the content of repeating unit (3) represents the total content of these two types.

[0036] The thermoplastic liquid crystal polymer in the resin composition may contain two or more repeating units (3) and / or two or more repeating units (4).

[0037] The thermoplastic liquid crystal polymer in the resin composition may have repeating units other than repeating units (1) to (4), but the total content of repeating units (1) to (4) may be, for example, 95 mol% or more, preferably 98 mol% or more, more preferably 99 mol% or more, and even more preferably 100 mol% of the total amount of all repeating units.

[0038] Thermoplastic liquid crystal polymers can be synthesized by known polycondensation methods. Various aromatic diols, aromatic dicarboxylic acids, aromatic hydroxycarboxylic acids, aromatic hydroxyamines, etc., may be used as monomers for polycondensation, or carboxylic acid derivatives such as acylated hydroxyl groups with activated monomer ends, carboxyl group esters, acid halides, and acid anhydrides may be used.

[0039] Polycondensation may be carried out in the presence of various polymerization catalysts, such as organotin catalysts (dialkyltin oxides, etc.), antimony catalysts (antimony trioxide, etc.), titanium catalysts (titanium dioxide, etc.), alkali metal salts or alkaline earth metal salts of carboxylic acids (potassium acetate, etc.), Lewis salts (BF3, etc.), and organic compound catalysts (N,N-dimethylaminopyridine, 1-methylimidazole, etc.).

[0040] Polycondensation may be performed by melt polymerization, followed by solid-phase polymerization. Solid-phase polymerization can be carried out by extracting the polymer obtained in the melt polymerization step, crushing it into a powder or flake, or granulating it into pellets using an extruder, and then heat-treating it in a solid state under vacuum or an inert atmosphere such as nitrogen.

[0041] [Resin composition] The resin composition has a dielectric loss tangent of 0.0015 or less at 5 GHz, and a complex viscosity η * The reduction rate is 20% or less. Such resin compositions make it possible to form films with reduced film thickness unevenness while possessing excellent dielectric properties in the high-frequency band.

[0042] In this invention, the inventors found that when conventional thermoplastic liquid crystal polymers with low dielectric loss tangent in the high-frequency range are formed into films, the resulting films tend to exhibit uneven film thickness. This is thought to be because conventional thermoplastic liquid crystal polymers with low dielectric loss tangent tend to have weak polarization in the molecular chain direction. The liquid crystal domains, which are regions where the orientation and arrangement of molecular chains in such thermoplastic liquid crystal polymers are aligned, become less stable under shear during film formation, resulting in uneven film thickness as a defect in the appearance of the formed film. Thus, a trade-off relationship was found where the characteristic of thermoplastic liquid crystal polymers exhibiting low dielectric loss tangent in the high-frequency range works unfavorably in film formation. The inventors found that the stability of the liquid crystal domains under shear in thermoplastic liquid crystal polymers is related to the complex viscosity η * We found that the rate of decrease of complex viscosity η correlates with the complex viscosity of resin compositions containing thermoplastic liquid crystal polymers.* By controlling the rate of reduction to a specific range, we have discovered a resin composition that exhibits low dielectric loss tangent in the high-frequency band, high stability of liquid crystal domains even under shear conditions, and enables the molding of films with reduced film thickness unevenness.

[0043] The dielectric loss tangent of the resin composition at 5 GHz is preferably 0.0014 or less, more preferably 0.0013 or less, even more preferably 0.0012 or less, even more preferably 0.0011 or less, particularly preferably 0.0010 or less, and particularly more preferably 0.0009 or less. Furthermore, a lower dielectric loss tangent at 5 GHz is preferable, and its lower limit is not particularly limited, but for example, it may be 0.0001 or more. In this specification, the dielectric loss tangent of the resin composition is measured on a film-shaped (or sheet-shaped) sample, measured in one direction within the plane (X direction) and in a direction orthogonal to that direction within the plane (Y direction), and is calculated as the average value of the X and Y directions. Specifically, it is the value measured by the method described in the examples later. If the target is not in film shape, the sample can be prepared by molding it into a film shape (for example, by hot pressing, etc.), and the dielectric loss tangent of the resin composition can be measured.

[0044] The resin composition has a complex viscosity η * The rate of decrease may preferably be 19% or less, more preferably 18% or less, even more preferably 15% or less, and even more preferably 10% or less. Also, complex viscosity η * The lower limit of the rate of decrease is not particularly limited and may be, for example, 0.1% or more, or 0.2% or more. In this specification, complex viscosity η *The rate of decrease is measured using a rotary rheometer in parallel plate measurements with a plate diameter of 25 mm and a gap distance of 0.9 mm, under the following conditions: measurement temperature: endothermic peak temperature Tm1 + 20°C derived from the thermoplastic liquid crystal polymer contained in the resin composition, strain: 3.0%, soak time: 0.0 seconds for each measurement at frequencies of 1 rad / s and 100 rad / s, and sampling interval: 5.0 seconds / pt for measurement at a frequency of 100 rad / s. The value is measured by the following procedure: first, the device is preheated for 5 minutes after the temperature inside reaches the above measurement temperature, then the complex viscosity η is measured at a frequency of 1 rad / s for 12 minutes, and then the frequency is switched to 100 rad / s. * X , and the complex viscosity η 7 minutes after switching * Y By measuring the complex viscosity η * The rate of decrease is (η * X -η * Y ) / η * X This value is calculated by multiplying by 100.

[0045] Furthermore, the endothermic peak temperature Tm1 refers to the temperature of the endothermic peak originating from the thermoplastic liquid crystal polymer contained in the resin composition, which appears when the resin composition is heated from 25°C to 400°C at a rate of 20°C / min during differential scanning calorimetry of the resin composition. Note that "endothermic peak temperature" refers to the temperature at the peak of the endothermic peak. If multiple endothermic peaks originating from thermoplastic liquid crystal polymers are observed in a sample, Tm1 shall be the endothermic peak temperature originating from the thermoplastic liquid crystal polymer with the largest weight ratio in the sample. Also, if multiple endothermic peaks originating from thermoplastic liquid crystal polymers are observed in a sample, and the weight ratios of the multiple thermoplastic liquid crystal polymers to which each endothermic peak belongs are equal, Tm1 shall be the endothermic peak temperature with the lowest temperature. The endothermic peak temperature Tm1 may be in the range of 260 to 370°C, preferably in the range of 280 to 360°C, and more preferably in the range of 290 to 350°C.

[0046] From the viewpoint of melt moldability, the resin composition was measured using a capillary rheometer with a capillary diameter of 1.0 mm, a capillary length of 20 mm, an endothermic peak temperature Tm1 + 20°C, and a shear rate of 1000 sec. -1 The melt viscosity measured under the condition of a preheating time of 5 minutes may be 30 to 120 Pa·s. Furthermore, the melt viscosity of the resin composition may preferably be 35 to 80 Pa·s, more preferably 40 to 70 Pa·s, and even more preferably 42 to 65 Pa·s. If this value is too high, stagnation of the molten resin may occur in the melt molding process, and if it is too low, sufficient melt tension may not be achieved during film formation. The melt viscosity is a value measured by the method described in the examples below.

[0047] From the viewpoint of melt moldability, the resin composition was measured using a capillary rheometer with a capillary diameter of 1.0 mm, a capillary length of 20 mm, an endothermic peak temperature Tm1 + 20°C, and a shear rate of 1000 sec. -1 If the melt viscosity measured under the condition of a preheating time of 5 minutes is X (Pa·s), and then the melt viscosity measured under the same temperature and shear rate conditions after standing in the barrel at the same temperature for 30 minutes is Y (Pa·s), then the ratio Y / X may be 1.30 or less. If the ratio of melt viscosities Y / X is too large, the resin composition will thicken when heated, causing the molten resin composition to accumulate during melt molding, resulting in poor melt moldability. The ratio Y / X of the melt viscosity of the resin composition may preferably be 1.25 or less, more preferably 1.20 or less. Furthermore, the lower limit of the ratio Y / X of the melt viscosity of the resin composition is not particularly limited, but for example, it may be 1.00 or more.

[0048] The resin composition was measured using a capillary rheometer with a capillary diameter of 1.0 mm, a capillary length of 20 mm, a distance of 200 mm from the capillary outlet to the center of the tension pulley, an endothermic peak temperature Tm1 + 20°C, and a shear rate of 1000 sec. -1The melt tension may be 0.002 N or higher when pulled at a take-up speed of 30 m / min under the condition of a preheating time of 5 minutes. If the melt tension is too low, it may lead to film formation problems in melt molding, such as draw resonance occurring when forming films using a T-die or instability of bubbles during inflation molding. The melt tension of the resin composition may preferably be 0.003 N or higher, more preferably 0.004 N or higher. Furthermore, there is no particular upper limit to the melt tension of the resin composition, but for example, it may be 0.01 N or lower.

[0049] From the viewpoint of heat resistance, the resin composition may have a difference of 12°C or less between the endothermic peak temperature Tm1 during the first heating cycle and the endothermic peak temperature Tm6 during the sixth heating cycle, as measured using a differential scanning calorimeter. These endothermic peak temperatures are determined by repeating a heating and cooling cycle six times in differential scanning calorimeter measurements of the resin composition, where the temperature is raised from 25°C to 400°C at a rate of 20°C / min and held for 2 minutes after reaching 400°C, and then cooled from 400°C to 25°C at a rate of 20°C / min and held for 2 minutes after reaching 25°C. The endothermic peak temperature during the first heating cycle is defined as Tm1 (°C), and the endothermic peak temperature during the sixth heating cycle is defined as Tm6 (°C). The difference in endothermic peak temperatures Tm1-Tm6 is an indicator of how much the endothermic peak temperature, which represents the melting point of the thermoplastic liquid crystal polymer, has decreased due to the thermal history caused by the heating and cooling cycle. If this difference is too large, it is expected that transesterification of the thermoplastic liquid crystal polymer is occurring due to heating, and the heat resistance tends to be poor due to the thermal history. The difference in endothermic peak temperatures Tm1-Tm6 may preferably be 10°C or less, more preferably 9°C or less, and even more preferably 8°C or less.

[0050] The resin composition has dielectric loss tangent and complex viscosity η. *The reduction rate is not limited as long as it is within a certain range, but for example, it may contain particulate matter. In this specification, particulate matter refers to components that are dispersed in a matrix of a thermoplastic liquid crystal polymer having a predetermined composition (combination of repeating units and its content) contained as a main component in the resin composition, and are not miscible at room temperature. The shape of the particulate matter is not particularly limited and may exist in any particle shape such as spherical, cylindrical, honeycomb, fibrous, or irregular shape. It is sufficient that the particulate matter is dispersed in the matrix of the thermoplastic liquid crystal polymer contained as a main component, and for example, the average particle diameter of the particulate matter may be 50 μm or less, preferably 30 μm or less, more preferably 10 μm or less, and the lower limit is not particularly limited, but for example it may be 0.01 μm or more. The average particle diameter of the particulate matter is calculated as the average value of the maximum diameter of the particulate matter dispersed in the matrix by image analysis method using an electron microscope (e.g., SEM). Particulate matter may include not only the additive materials described later, but also particulate thermoplastic liquid crystal polymers with a different composition from the thermoplastic liquid crystal polymer contained as the main component. In this specification, "main component" refers to the component that is present in the highest concentration in the resin composition. Furthermore, even when thermoplastic liquid crystal polymers are included as particulate matter, as described above, the repeating units and their content in the thermoplastic liquid crystal polymers in the resin composition are expressed as the average value of all repeating units and their content in all thermoplastic liquid crystal polymers contained in the resin composition, without distinguishing between the main component and the particulate matter.

[0051] The resin composition has dielectric loss tangent and complex viscosity η. * The rate of decrease is not limited as long as it is within a certain range, but for example, it may include additive materials. The additive material is a component other than the thermoplastic liquid crystal polymer and may be at least one selected from the group consisting of thermoplastic resins, thermosetting resins, inorganic compounds, and liquid crystalline oligomers. Preferably, the additive material is at least one selected from the group consisting of thermoplastic resins and inorganic compounds.

[0052] The thermoplastic resin is not particularly limited as long as it is a thermoplastic resin other than the thermoplastic liquid crystal polymers mentioned above, but examples include amorphous polyarylate resins, polyphenylene ether resins, polyphenylene sulfide resins, polyetherimide resins, polyethersulfone resins, polyetheretherketone resins, polycarbonate resins, and fluorine resins. Amorphous polyarylate resins refer to amorphous aromatic polyesters obtained by polycondensation of divalent phenol and aromatic dicarboxylic acid, and examples include copolymers of bisphenol A with terephthalic acid and isophthalic acid. Fluorine resins refer to polymers having fluorine atoms in their molecular chains, and examples include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and copolymers of tetrafluoroethylene and perfluoroalkoxyethylene (PFA). Among these thermoplastic resins, amorphous polyarylate resins, polyphenylene ether resins, and fluorine resins are preferred.

[0053] Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, thermosetting polyimide resins, bismaleimide resins, phenolic resins, melamine resins, and thermosetting polyurethane resins.

[0054] Examples of inorganic compounds include silica (silicon oxide), alumina (aluminum oxide), titanium oxide, zirconium oxide, silicon carbide, aluminum nitride, boron nitride, barium titanate, glass, mica, and talc. Of these inorganic compounds, at least one may be selected from the group consisting of silica and titanium oxide, and silica is more preferable.

[0055] Furthermore, it is preferable that the inorganic compound is included as inorganic particles. The median diameter of the inorganic particles may be 0.01 to 10 μm, preferably 0.03 to 5 μm, and more preferably 0.05 to 1 μm. In this specification, the median diameter of the inorganic particles refers to the particle diameter that corresponds to 50% of the integrated value in the particle size distribution measured by laser diffraction-scattering.

[0056] The resin composition may contain two or more inorganic particles with different median diameters. The inorganic particles with different median diameters may be of the same type but with different median diameters, or they may be of different types but with different median diameters.

[0057] Liquid crystalline oligomers refer to oligomers of 10-mer or less that are composed of repeating units selected from the various repeating units exemplified in the thermoplastic liquid crystalline polymers described above, and are produced by known polymerization methods such as polycondensation of the raw material compounds (monomers) described above. "10-mer or less" means that the total number of repeating units in one molecule is 10 or less.

[0058] The resin composition may contain two or more additive materials. Two or more additive materials with different chemical structures may be used. For example, two or more may be used from each of thermoplastic resins, thermosetting resins, inorganic compounds, or liquid crystalline oligomers (for example, two or more thermoplastic resins and two or more inorganic compounds), or at least two or more may be used from the group consisting of thermoplastic resins, thermosetting resins, inorganic compounds, and liquid crystalline oligomers (for example, one or more thermoplastic resins and one or more inorganic compounds, or one or more thermoplastic resins and one or more thermosetting resins).

[0059] The dielectric loss tangent and complex viscosity η of the resin composition depend on the additive materials used and their content. * The rate of decrease can be adjusted, for example, the weight ratio of thermoplastic liquid crystal polymer to additive material (thermoplastic liquid crystal polymer / additive material) may be in the range of 63.0 / 37.0 to 94.9 / 5.1, preferably 66.0 / 34.0 to 94.5 / 5.5, and more preferably 72.0 / 28.0 to 93.0 / 7.0. In this specification, if the resin composition contains two or more additive materials, this weight ratio is calculated by the total amount of all additive materials.

[0060] In one embodiment, the resin composition may include a thermoplastic liquid crystal polymer and an inorganic compound. The inorganic compound can be one of the inorganic compounds described above, and it is preferable to use inorganic particles, for example, at least one selected from the group consisting of silica particles and titanium oxide particles. Furthermore, two or more types of inorganic particles with different median diameters may be used, for example, the resin composition may contain silica particles and titanium oxide particles with different median diameters, or it may contain two or more types of silica particles with different median diameters.

[0061] In another embodiment, the resin composition may include a thermoplastic liquid crystal polymer and a thermoplastic resin. The thermoplastic resin can be one of the thermoplastic resins described above, and it is preferable to use at least one selected from the group consisting of amorphous polyarylate resins, polyphenylene ether resins, and fluororesins.

[0062] Furthermore, the resin composition may also contain thermoplastic resin as thermoplastic resin particles, for example, it may contain fluororesin particles.

[0063] In another embodiment, the resin composition may include a thermoplastic liquid crystal polymer, a thermoplastic resin, and an inorganic compound. For example, the resin composition may include at least one selected from the group consisting of amorphous polyarylate resins and polyphenylene ether resins as the thermoplastic resin, and silica as the inorganic compound.

[0064] The resin composition may contain two or more thermoplastic liquid crystal polymers with different compositions. For example, the resin composition may contain thermoplastic liquid crystal polymers in particulate form as components other than the thermoplastic liquid crystal polymer as the main component.

[0065] When the resin composition contains a thermoplastic liquid crystal polymer and an inorganic compound, the weight ratio of the thermoplastic liquid crystal polymer to the inorganic compound (thermoplastic liquid crystal polymer / inorganic compound) may be in the range of 66.0 / 34.0 to 96.0 / 4.0, preferably 80.0 / 20.0 to 94.9 / 5.1, and more preferably 90.0 / 10.0 to 94.0 / 6.0.

[0066] The content of inorganic compounds in the resin composition may be 0 to 30% by weight, preferably 1 to 15% by weight, and more preferably 4.5 to 9.5% by weight, relative to the weight of solids in the resin composition.

[0067] When the resin composition contains a thermoplastic liquid crystal polymer and a thermoplastic resin, the weight ratio of the thermoplastic liquid crystal polymer to the thermoplastic resin (thermoplastic liquid crystal polymer / thermoplastic resin) may be in the range of 60.0 / 40.0 to 96.0 / 4.0, preferably 63.0 / 37.0 to 94.9 / 5.1, and more preferably 65.0 / 35.0 to 94.0 / 6.0.

[0068] The content of thermoplastic resin in the resin composition may be 0 to 37% by weight, preferably 3 to 30% by weight, and more preferably 5 to 28% by weight, relative to the weight of solids in the resin composition.

[0069] The total content of inorganic compounds and thermoplastic resins in the resin composition may be 4 to 37% by weight, preferably 5 to 30% by weight, and more preferably 6 to 20% by weight, relative to the solid content weight of the resin composition.

[0070] [Method for producing resin composition] The resin composition can be produced by mixing the above-mentioned thermoplastic liquid crystal polymer and additive materials by known methods. The resin composition may also be produced by mixing two or more thermoplastic liquid crystal polymers with different compositions. Alternatively, these thermoplastic liquid crystal polymers may be obtained by melt polymerization and then mixed with thermoplastic liquid crystal polymers whose degree of polymerization has been adjusted by solid-phase polymerization.

[0071] The resin composition may be manufactured by melt-kneading the above-mentioned thermoplastic liquid crystal polymer and additive materials in an extruder. There are no particular restrictions on the extruder used for melt-kneading, but examples include single-screw extruders, twin-screw extruders, and multi-screw extruders. Among these, a twin-screw extruder is preferred from the viewpoint of uniformly dispersing the minor components (e.g., additive materials) in the resin composition.

[0072] The L / D ratio of the extruder is preferably 10 to 100, more preferably 15 to 80, and even more preferably 20 to 60, from the viewpoint of uniformly mixing the raw material components. When the L / D is 10 or higher, it becomes easier to obtain an even better kneading state. Furthermore, when the L / D is 100 or lower, shear heat generation during kneading can be reduced, and the thermal decomposition of each component in the resin composition can be suppressed. Hereinafter, L [unit: mm] is the length of the cylinder of the extruder, and D [unit: mm] is the inner diameter of the cylinder of the extruder.

[0073] The extruder is preferably equipped with one or more open vents. By using such an extruder, decomposition products and volatile components can be aspirated from the open vents, thereby improving the quality of the resulting resin composition. To aspirate decomposition products and the like from the open vents, it is preferable to reduce the pressure in the open vents, for example. When reducing the pressure, it is preferable that the pressure be 0.1 to 90 kPa, more preferably 0.3 to 80 kPa, even more preferably 0.5 to 50 kPa, and particularly preferably 0.7 to 10 kPa. By keeping the pressure in the open vents at 90 kPa or less, the amount of residual decomposition products and volatile components can be reduced. Furthermore, by keeping the pressure in the open vents at 0.1 kPa or more, the productivity of the resin composition can be improved.

[0074] A known die can be connected to the extruder according to the desired shape of the resin composition. For example, by connecting a strand die and cutting the extruded resin composition to the desired length, a granular or columnar resin composition can be obtained.

[0075] The method of supplying the raw materials for the resin composition to the extruder is not particularly limited. All materials may be supplied together from a weight feeder to a raw material supply hopper, or individual or partial raw materials may be supplied together from two or more weight feeders to the raw material supply hopper. When some or all of the raw materials are mixed to produce a premix, there are no particular restrictions on the manufacturing method. For example, mixing can be done using a known mixer such as a tumbler mixer or a Henschel mixer.

[0076] An example of an extruder screw configuration includes a conveying section equipped with a full-flight screw segment for conveying the raw materials or kneaded material of the resin composition, and a kneading section equipped with a kneading disc (forward, neutral, reverse, etc.) for kneading the raw materials of the resin composition, and a screw segment in the opposite direction of molten resin feeding (a screw segment with the spiral winding direction reversed, reverse flight). From the viewpoint of uniformly dispersing auxiliary components (e.g., additive materials) in the resin composition, it is preferable to have one or more kneading sections. Furthermore, in order to avoid an increase in resin pressure at the twin-screw extruder head, it is preferable that the conveying section be located behind the kneading section that conveys the kneaded material of the resin composition to the die section, etc.

[0077] From the viewpoint of preventing deterioration of the resin composition, the extruder may be melt-kneaded while passing an inert gas through it.

[0078] A polymer filter may be installed at the rear of the extruder to remove foreign matter. Examples of polymer filters include candle-type polymer filters and leaf-disc-type polymer filters.

[0079] [film] The resin compositions described above can be suitably used for molding films. Films can be manufactured by extruding the resin compositions. Any extrusion method can be used, but well-known methods such as the T-die method and the inflation method are industrially advantageous. In particular, with the inflation method, stress is applied not only in the mechanical axis direction of the film (hereinafter abbreviated as the MD direction) but also in the direction perpendicular to it (hereinafter abbreviated as the TD direction), allowing for uniform stretching in both the MD and TD directions. As a result, films with controlled molecular orientation and dielectric properties in the MD and TD directions can be obtained.

[0080] Furthermore, the film may be stretched after extrusion molding as needed. The stretching method itself is well known, and either biaxial stretching or uniaxial stretching may be used, but biaxial stretching is preferred because it is easier to control the degree of molecular orientation. In addition, known uniaxial stretchers, simultaneous biaxial stretchers, sequential biaxial stretchers, etc., can be used for stretching.

[0081] In extrusion molding, a stretching process may be performed to control orientation. For example, in extrusion molding using the T-die method, the molten sheet extruded from the T-die may be stretched not only in the MD direction of the thermoplastic liquid crystal polymer film, but also simultaneously in both the MD and TD directions to form the film. Alternatively, the molten sheet extruded from the T-die may be stretched first in the MD direction, and then stretched in the TD direction to form the film.

[0082] Furthermore, in extrusion molding by the inflation method, a cylindrical sheet extruded from a ring die may be stretched at a predetermined draw ratio (corresponding to the stretching ratio in the MD direction) and blow ratio (corresponding to the stretching ratio in the TD direction) to form a film.

[0083] The film thus obtained is composed of the resin composition described above. The resin composition described above has a complex viscosity η *Because the rate of decrease is low within a specific range, the stability of the liquid crystal domains under shear is high, making it possible to form a film with reduced film thickness unevenness. For example, the film may have a coefficient of variation of thickness of 1.90% or less in the film width direction as measured by a continuous thickness gauge, preferably 1.80% or less, more preferably 1.75% or less, even more preferably 1.70% or less, even more preferably 1.40% or less, and particularly preferably 1.30% or less. In this specification, the coefficient of variation of thickness is calculated by thickness standard deviation / mean thickness × 100 using measured thickness data in the film width direction, and is measured by the method described in the examples below.

[0084] The film thickness can be set appropriately depending on the application. For example, it can be selected from a wide range of 1 to 500 μm, but when considering its use as an insulating layer material for circuit boards, it is preferably 5 to 200 μm, and more preferably 10 to 150 μm.

[0085] The film may have a melting point (Tm) in the range of 260 to 370°C, preferably in the range of 280 to 360°C, and more preferably in the range of 285 to 350°C. The melting point of the film is defined as the temperature of the endothermic peak derived from the thermoplastic liquid crystal polymer that appears when the film sample is heated from 25°C at a rate of 20°C / min using a differential scanning calorimeter.

[0086] [Metal-clad laminate] The above-described film can be used in a metal-clad laminate in which a metal layer is bonded to at least one of its surfaces. The metal-clad laminate may be a single-sided metal-clad laminate having a metal layer on one side of the film, or a double-sided metal-clad laminate having metal layers on both sides of the film. In the metal-clad laminate, the film and the metal layer may be laminated with an adhesive layer (e.g., an adhesive) in between, but from the viewpoint of reducing the thickness as a material for manufacturing circuit boards, it is preferable that the film and the metal layer are directly laminated without an adhesive layer.

[0087] The metal-clad laminate may be manufactured by bonding a metal foil to the aforementioned film by thermocompression to form a metal layer, by forming a metal layer by sputtering, vapor deposition, electroless plating, etc., or by casting a resin composition onto a metal foil.

[0088] There are no particular restrictions on the metal that forms the metal layer; for example, it may be gold, silver, copper, iron, tin, nickel, aluminum, chromium, or alloys thereof. These metals may also contain other metal species in amounts of 2000 ppm or less by mass, and unavoidable impurities may be present.

[0089] When using metal foil as the metal layer, for example, it may be a metal foil formed from the above-mentioned metals, and copper foil or stainless steel foil is preferred from the viewpoint of conductivity, ease of handling, and cost. Copper foil can be manufactured by rolling or electrolytic methods. Furthermore, the metal foil may be subjected to surface treatments such as roughening treatments that are normally applied, as long as they do not impair the high-frequency characteristics of the metal-clad laminate of the present invention.

[0090] In sputtering or vapor deposition, a process is carried out to bring metal parts into contact and bond them together by sputtering or vapor deposition of metal. Sputtering and vapor deposition are well-known methods in the field of circuit board manufacturing. Examples of metals used for sputtering or vapor deposition include copper, aluminum, gold, tin, and chromium.

[0091] In electroless plating, a process is carried out in which metal is deposited from a solution containing metal ions, thereby bonding the two materials together. Electroless plating is a well-known method in the field of manufacturing plated products on non-conductive materials (such as plastics and ceramics), and examples of metals used include copper, nickel, cobalt, gold, tin, and chromium.

[0092] Metal-clad laminates can be effectively used as components in fields such as electrical and electronics, office equipment and precision machinery, and power semiconductors, for example, as circuit board materials.

[0093] [Circuit board] The above-described resin composition can be used in a circuit board comprising at least an insulating layer and a conductive layer containing it. For example, a circuit board can be manufactured by forming a conductive pattern on the surface of the above-described film. Alternatively, a circuit board can be manufactured by processing a metal layer on the above-described metal-clad laminate to form a wiring circuit. Known methods can be used for circuit processing; for example, circuits may be formed by etching the metal layer on the film using a subtractive method.

[0094] The conductive layer is formed, for example, from at least a conductive metal, and a circuit is formed on this conductive layer using a known circuit processing method. The conductor forming the conductive layer may be various conductive metals, such as gold, silver, copper, iron, tin, nickel, aluminum, chromium, or alloys thereof.

[0095] The circuit board can be used as various high-frequency circuit boards. Furthermore, the circuit board may be a circuit board (or semiconductor element mounting board) on which semiconductor elements (e.g., IC chips) are mounted. Also, because the circuit board has a low and controlled dielectric loss tangent, it can be used in various transmission lines, such as coaxial lines, strip lines, microstrip lines, coplanar lines, and parallel lines, as well as in antennas (e.g., microwave or millimeter-wave antennas). The circuit board can also be used in antenna devices where the antenna and transmission line are integrated. For example, it can be used in various sensors, particularly in automotive radar.

[0096] Examples of antennas include waveguide slot antennas, horn antennas, lens antennas, printed antennas, triplate antennas, microstrip antennas, and patch antennas, which utilize millimeter waves or microwaves. [Examples]

[0097] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples. In the following examples and comparative examples, various physical properties were measured by the methods described below.

[0098] [Endothermic peak temperature] Using a differential scanning calorimeter (DSC Q2000, manufactured by T.A. Instruments Japan Co., Ltd.), 5.0 mg of the resin composition was placed in a sample container, and the heating and cooling cycle was repeated six times under the following heating and cooling conditions. The temperature of the endothermic peak originating from the thermoplastic liquid crystal polymer during the first heating cycle was defined as Tm1 (°C), and the endothermic peak originating from the thermoplastic liquid crystal polymer during the sixth heating cycle was defined as Tm6 (°C). Tm1-Tm6 (°C) was calculated from these values. (Temperature increase / decrease conditions) • Heating conditions: Heat from 25°C to 400°C at a rate of 20°C / min, and hold at 400°C for 2 minutes after reaching the temperature. • Cooling conditions: Cool from 400°C to 25°C at a rate of 20°C / min, and hold at 25°C for 2 minutes after reaching 25°C.

[0099] [Film melting point] Using a differential scanning calorimeter (DSC Q2000, manufactured by T.A. Instruments Japan Co., Ltd.), a sample of a predetermined size was taken from the films obtained in the examples and comparative examples, placed in a sample container, and the temperature of the endothermic peak that appeared when the temperature was increased from 25°C to 400°C at a rate of 20°C / min was defined as the melting point Tm of the film.

[0100] [Dielectric Loss Tangent] The films obtained in the examples and comparative examples were cut in the MD direction to obtain sample pieces 8 cm long and 2 mm wide. Similarly, samples were cut in the TD direction to obtain sample pieces 8 cm long and 2 mm wide. Dielectric loss tangent measurements were performed using the cavity resonator perturbation method at a frequency of 5 GHz. A 5 GHz cavity resonator (manufactured by Kanto Electronics Applied Development Co., Ltd.) was connected to a network analyzer (Agilent Technology "E8362B"), the above sample pieces were inserted into the cavity resonator, and measurements were taken at 25°C to measure the dielectric loss tangents in the MD and TD directions. The average value of these values ​​was calculated as the dielectric loss tangent.

[0101] [complex viscosity η] * [Decrease rate] (Sample preparation method) The resin compositions obtained in the examples and comparative examples were subjected to testing at Tm1+15 to Tm1+30°C (Tm1 represents the endothermic peak temperature derived from the thermoplastic liquid crystal polymer during the first heating cycle, as measured above) and a pressure of 100 kg / cm². 2 A heat press was used to obtain a 10cm square sheet with a thickness of 0.9mm and dimensions of 10cm in length and 10cm in width. Next, the obtained sheet was punched out into a circular disc shape with a diameter of 25mm to obtain a sample for measurement.

[0102] (Measurement method) Using a rotary rheometer (ARES-G2, manufactured by T.A. Instrument Japan Co., Ltd.), the sample for measurement was set on a parallel plate with a plate diameter of 25 mm. Under the following conditions, with a gap distance of 0.9 mm, a measurement temperature of the endothermic peak temperature Tm1 + 20°C of the resin composition obtained above, a strain of 3.0%, a soak time of 0.0 seconds for each measurement at frequencies of 1 rad / s and 100 rad / s, and a sampling interval of 5.0 seconds / pt for measurement at a frequency of 100 rad / s, the measurement was performed using the following procedure. First, the apparatus was preheated for 5 minutes after the temperature reached the above measurement temperature. Next, measurements were taken at a frequency of 1 rad / s for 12 minutes, then the frequency was switched to 100 rad / s and the measurement was continued. The complex viscosity at the time of switching to a frequency of 100 rad / s was measured η * X Then, the complex viscosity η after 7 minutes of switching was calculated.* Y The complex viscosity η was determined to be... * The rate of decrease (%) is (η * X -η * Y ) / η * X It was calculated by multiplying by 100.

[0103] [Melting viscosity] The resin compositions obtained in the examples and comparative examples were dried in a vacuum dryer at 140°C and a reduced pressure of 1.4 kPa for 16 hours. Using a capillary rheometer (Toyo Seiki Seisakusho Co., Ltd. "Capillograph® F-2"; barrel diameter 15 mm), the resin composition was placed in the barrel, and measurements were performed under the following conditions: capillary diameter: 1.0 mm, capillary length: 20 mm, and measurement temperature: endothermic peak temperature Tm1 + 20°C of the resin composition obtained above. After preheating the barrel for 5 minutes after the barrel temperature reached the measurement temperature, the measurement temperature and shear rate were set to 1000 sec. -1 The melt viscosity was measured under the specified conditions, and this melt viscosity was defined as X (Pa·s).

[0104] After measuring the melt viscosity X as described above, the piston was stopped and the molten resin was allowed to stand in the barrel for 30 minutes. Then, the melt viscosity was measured again under the same temperature and shear rate conditions, and this melt viscosity was defined as Y (Pa·s). The ratio of melt viscosities Y / X was calculated.

[0105] [Melt Tension] The resin compositions obtained in the examples and comparative examples were dried in a vacuum dryer at 140°C and a reduced pressure of 1.4kPa for 16 hours. Using a capillary rheometer (Toyo Seiki Seisakusho Co., Ltd. "Capillograph® F-2"; barrel diameter 15mm), the resin composition was placed in the barrel, and measurements were performed under the following conditions: capillary diameter: 1.0mm, capillary length: 20mm, measurement temperature: endothermic peak temperature Tm1 + 20°C of the resin composition obtained above, and distance from capillary outlet to the center of the tension pulley: 200mm. The following procedure was followed: After preheating the barrel for 5 minutes after the barrel temperature reached the measurement temperature, the measurement temperature and piston speed were set to 33.33mm / min (shear rate 1000sec). -1 Under the conditions, the pickup speed is changed from 25 m / min to an acceleration of 0.02778 m / s². 2 The melt tension was measured when the material was pulled up to 50 m / min while being raised, and the melt tension (N) was read when it was pulled at a pull speed of 30 m / min.

[0106] [Film thickness] Five sample pieces with a width of 210 mm in the TD direction and a width of 30 mm in the MD direction were cut from the films obtained in the examples and comparative examples. Using a desktop thickness gauge (RC-1W, manufactured by Meisan Co., Ltd.), the thickness of the five sample pieces was measured at 0.5 mm intervals while transporting them in the TD direction at a transport speed of 60 mm / sec. First, the average thickness measured in the transport direction was calculated for each sample piece. Then, the average thickness of the five sample pieces was used as the thickness data, and the average value from these five thickness data points was calculated as the thickness (μm). In addition, the standard deviation from the five thickness data points was calculated as the thickness standard deviation (μm), and the coefficient of variation (%) of the thickness was calculated using the following formula. Coefficient of variation of thickness = Standard deviation of thickness / Mean thickness × 100

[0107] (Reference example 1) In a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer and reflux condenser, 1034.99 g of 6-hydroxy-2-naphthoic acid (HNA; 5.5 mol), 83.07 g of terephthalic acid (TPA; 0.5 mol), 378.33 g of 2,6-naphthalenedicarboxylic acid (NDCA; 1.75 mol), 272.52 g of hydroquinone (HQ; 2.475 mol, with an excess of 0.225 mol), and acetic anhydride were added. 1214.87g (11.9 mol) and 0.17 g of 1-methylimidazole as a catalyst were added. The mixture was stirred at room temperature for 15 minutes under a nitrogen atmosphere, then the temperature was increased while stirring and held at 145°C for 1 hour. Next, the temperature was increased from 145°C to 310°C over 3 hours and 30 minutes while distilling off the distilled by-product acetic acid and unreacted acetic anhydride. The mixture was held at 310°C for 3 hours, then cooled to room temperature and ground in a pulverizer to obtain a thermoplastic liquid crystal polymer powder.

[0108] The obtained powder was heated in a heated atmosphere. The temperature was increased from 25°C to 250°C over 1 hour, and then increased from 250°C to 315°C over 5 hours. It was then held at 315°C, and the endothermic peak temperature was 320.5°C, with a shear rate of 1000 s at 340.5°C. -1 Solid-phase polymerization was carried out until the melt viscosity reached 54 Pa·s. The solid-phase polymerized powder was then cooled, and the cooled powder was granulated at 340°C using a twin-screw kneading extruder to obtain pellets of thermoplastic liquid crystal polymer A.

[0109] (Reference example 2) In a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser, 20.19 g of 6-hydroxy-2-naphthoic acid (HNA; 0.1073 mol ), 2,6-naphthalenedicarboxylic acid 7.73g (NDCA; 0.0358 mol ), hydroquinone 1.97g (HQ; 0.0179 mol ), 4,4'-dihydroxybiphenyl 3.33g (BP; 0.0179 mol ), acetic anhydride 20.08g ( 0.1967 mol), and 3.77 mg of potassium acetate as a catalyst were added. The mixture was heated from room temperature under a nitrogen atmosphere with stirring, and held at 160°C for approximately 2 hours. Then, the temperature was increased to 280°C for 0.5 hours, 320°C for 1 hour, and 360°C for 1 hour. Next, a reduced pressure treatment (100 Pa) was performed until it was confirmed that the foaming had subsided (30-120 minutes), after which the mixture was purged with nitrogen, cooled to room temperature, and ground in a pulverizer to obtain a thermoplastic liquid crystal polymer powder. The cooled powder had an endothermic peak temperature of 291.1°C and a shear rate of 1000 s at 311.1°C. -1 The melt viscosity was 55 Pa·s. The cooled powder was granulated at 315°C using a twin-screw kneading extruder to obtain pellets of thermoplastic liquid crystal polymer B.

[0110] (Reference example 3) In a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser, 660.5 g of 6-hydroxy-2-naphthoic acid (HNA; 3.51 mol), 248.3 g of terephthalic acid (TPA; 1.49 mol), 14.3 g of hydroquinone (HQ; 0.13 mol), and 254.2 g of 4,4'-dihydroxybiphenyl (BP; 1.37 mol) were added. Then, 1.03 times the amount of acetic anhydride relative to the total amount of hydroxyl groups (mol) of monomers was added. Under a nitrogen atmosphere, the mixture was heated from room temperature to 150°C over 1 hour with stirring, and held at 150°C for 1 hour. Next, the mixture was heated to 350°C over 7 hours while distilling off the by-product acetic acid, and then the pressure was reduced to 1333 Pa over 90 minutes. The polymerization reaction was terminated when the desired torque was reached, the mixture was cooled to room temperature, and pulverized to obtain a thermoplastic liquid crystal polymer powder.

[0111] The obtained powder was heated under a heating atmosphere. The temperature was increased from 25°C to 250°C over 1 hour, and then increased from 250°C to 325°C over 2 hours. It was then held at 325°C, and the shear rate at which the endothermic peak temperature was 340.0°C and 360.0°C was 1000 s. -1 Solid-phase polymerization was carried out until the melt viscosity reached 55 Pa·s. The cooled powder was granulated at 360°C using a twin-screw kneading extruder to obtain pellets of thermoplastic liquid crystal polymer C.

[0112] (Reference example 4) A thermoplastic liquid crystal polymer (A920RX, manufactured by Polyplastics Co., Ltd.; HBA / HNA = 73 / 27 (mol)) was heated from 25°C to 240°C over 1 hour. It was then held at 240°C, with an endothermic peak temperature of 295.0°C and a shear rate of 1000 s at 315.0°C. -1 Solid-phase polymerization was carried out until the melt viscosity reached 53 Pa·s. The cooled powder was granulated at 315°C using a twin-screw kneading extruder to obtain pellets of thermoplastic liquid crystal polymer D.

[0113] The following additives were used: • Silica particles A (Admatex Co., Ltd.'s "Surface-treated Adma Fine Silica SC2500-SQ", median diameter 0.5 μm) • Silica particles B (manufactured by Admatex Co., Ltd., median diameter 0.3 μm) • Polyphenylene ether (PPE; "Zylon S201A" manufactured by Asahi Kasei Corporation) • Amorphous polyarylate (PAR; "U-100" manufactured by Unitika Ltd.)

[0114] (Example 1) A resin composition was prepared by melt-kneading 90.9% by weight of thermoplastic liquid crystal polymer A and 9.1% by weight of silica particles A, obtained in Reference Example 1, using a twin-screw compounding extruder at a cylinder setting temperature of 330°C. The analysis results of the obtained resin composition are shown in Table 7.

[0115] Using the obtained resin composition, a film was prepared by melt extrusion using a cyclic inflation die (die diameter 46.0 mm, die slit spacing 900 μm) with a draw ratio of 2.0 and a blow ratio of 4.2. The analysis results of the obtained film are shown in Table 7.

[0116] (Examples 2-9, Comparative Examples 1-5) Resin compositions and films were prepared in the same manner as in Example 1, except that each component was used in the weight ratios shown in Table 7. The analysis results of the obtained resin compositions and films are shown in Table 7.

[0117] [Table 7]

[0118] As shown in Table 7, the resin compositions of Examples 1 to 9 have dielectric loss tangent and complex viscosity η at 5 GHz. * Because the rate of decrease is within a specific range, the film obtained by molding such a resin composition has a small coefficient of variation in thickness.

[0119] On the other hand, in Comparative Examples 1 and 2, although the dielectric loss tangent of the thermoplastic liquid crystal polymer at 5 GHz was low, the complex viscosity η * Due to the high rate of decrease, films obtained by molding such thermoplastic liquid crystal polymers have a large coefficient of variation in thickness, resulting in uneven film thickness as an appearance defect.

[0120] Although the resin compositions of Comparative Examples 3 and 5 have low dielectric loss tangents at 5 GHz, their complex viscosity η * Due to the high rate of decrease, films obtained by molding such resin compositions have a large coefficient of variation in thickness, resulting in uneven film thickness as an appearance defect.

[0121] The resin composition of Comparative Example 4 has a complex viscosity η * Because the rate of decrease is low, the film obtained by molding this has a small coefficient of variation in thickness, but because the dielectric loss tangent at 5 GHz is high, the dielectric properties in the high-frequency range required for various circuit boards are not sufficient. [Industrial applicability]

[0122] The resin composition of the present invention has a low dielectric loss tangent in the high-frequency band and can form films with reduced film thickness variations. Therefore, the films obtained by forming the resin composition can be suitably used as high-frequency circuit board materials in fields such as electrical and electronics, office equipment and precision machinery, and power semiconductors.

[0123] As described above, preferred embodiments of the present invention have been explained, but those skilled in the art will readily anticipate various changes and modifications within the obvious scope by reviewing this specification. Therefore, such changes and modifications shall be construed as falling within the scope of the invention as defined by the claims.

Claims

1. A resin composition containing a thermoplastic liquid crystal polymer, wherein the dielectric loss tangent at 5 GHz is 0.0015 or less, and the complex viscosity η is measured 7 minutes after switching to a frequency of 100 rad / s, using a rotary rheometer under the following measurement conditions. ＊ The rate of decrease is less than 20%, The thermoplastic liquid crystal polymer has a total amount of repeating units containing 2,6-naphthylene groups of 40 mol% or more relative to the total amount of all repeating units. The material includes an additive, wherein the additive is at least one selected from the group consisting of thermoplastic resins, thermosetting resins, inorganic compounds, and liquid crystalline oligomers. A resin composition in which the weight ratio of the thermoplastic liquid crystal polymer to the additive material (thermoplastic liquid crystal polymer / additive material) is in the range of 63.0 / 37.0 to 94.9 / 5.

1. (Measurement conditions) Parallel plate measurement Gap distance: 0.9 mm Plate diameter: 25 mm • Measurement temperature: Endothermic peak temperature Tm originating from thermoplastic liquid crystal polymer, measured using a differential scanning calorimeter. １ +20℃ ・Distortion: 3.0% Soak time for each measurement at frequencies of 1 rad / s and 100 rad / s: 0.0 seconds Sampling interval during measurement at a frequency of 100 rad / s: 5.0 seconds / pt Preheating time: 5 minutes

2. The resin composition according to claim 1, wherein, using a capillary rheometer, the capillary diameter is 1.0 mm, the capillary length is 20 mm, and the endothermic peak temperature Tm is measured. １ +20°C, shear rate 1000 sec －１ A resin composition having a melt viscosity of 30 to 120 Pa·s, measured under the condition of a preheating time of 5 minutes.

3. The resin composition according to claim 1, wherein, using a capillary rheometer, the capillary diameter is 1.0 mm, the capillary length is 20 mm, and the endothermic peak temperature Tm is measured. １ +20°C, shear rate 1000 sec －１ A resin composition in which, under the conditions of a preheating time of 5 minutes, the melt tension is 0.002 N or more when pulled at a pull-up speed of 30 m / min with a distance of 200 mm from the capillary outlet to the center of the tension pulley.

4. The resin composition according to claim 1, wherein when a cycle of temperature increase and decrease is repeated under the following temperature increase and decrease conditions using a differential scanning calorimeter, the endothermic peak temperature Tm during the first temperature increase １ and the endothermic peak temperature Tm during the sixth temperature increase ６ The difference Tm １ -Tm ６ is 12°C or less. The resin composition. (Temperature rise and fall conditions) • Heating conditions: Heat from 25°C to 400°C at a rate of 20°C / min, and hold at 400°C for 2 minutes after reaching the temperature. • Cooling conditions: Cool from 400°C to 25°C at a rate of 20°C / min, and hold at 25°C for 2 minutes after reaching 25°C.

5. The resin composition according to claim 1, wherein, using a capillary rheometer, the capillary diameter is 1.0 mm, the capillary length is 20 mm, and the endothermic peak temperature Tm is measured. １ +20°C, shear rate 1000 sec －１ A resin composition in which, when the melt viscosity measured under the condition of a preheating time of 5 minutes is X (Pa·s), and then the melt viscosity measured under the same temperature and shear rate conditions after standing in a barrel at the same temperature for 30 minutes is Y (Pa·s), the ratio Y / X between these two values ​​is 1.30 or less.

6. A resin composition according to claim 1, wherein the thermoplastic liquid crystal polymer comprises, with respect to the total amount of all repeating units, 0 to 25 mol% of repeating units represented by the following formula (1), 25 to 90 mol% of repeating units represented by the following formula (2), 0.1 to 40 mol% of repeating units represented by the following formula (3), and 0.1 to 40 mol% of repeating units represented by the following formula (4). -O-Ar １ -CO- (1) -O-Ar ２ -CO- (2) -CO-Ar ３ -CO- (3) -.-�2 ４ -O- (4) (In the formula, Ar １ The group is a 1,4-phenylene group, Ar ２ It is a 2,6-naphthylene group, and Ar ３ is at least one selected from the group consisting of a 1,4-phenylene group, a 1,3-phenylene group, and a 2,6-naphthylene group, and Ar ４ is at least one selected from the group consisting of a 1,4-phenylene group, a 1,3-phenylene group, and a 4,4'-biphenylene group, and Ar １ Ar ２ Ar ３ and Ar ４ The hydrogen atoms of the aromatic ring are, independently, C １－３ (May be substituted with at least one selected from the group consisting of alkyl groups, halogen atoms, and phenyl groups.)

7. A resin composition according to claim 1, comprising particulate matter having an average particle diameter of 50 μm or less.

8. A resin composition according to claim 1, wherein the thermoplastic resin comprises at least one selected from the group consisting of amorphous polyarylate resins, polyphenylene ether resins, polyphenylene sulfide resins, polyetherimide resins, polyethersulfone resins, polycarbonate resins, polyetheretherketone resins, and fluorine resins.

9. A resin composition according to claim 1, wherein the inorganic compound comprises at least one selected from the group consisting of silica and titanium dioxide.

10. A resin composition according to claim 1, comprising two or more inorganic particles having different median diameters.

11. A resin composition according to claim 1, comprising two or more of the additive materials.

12. A film comprising the resin composition according to any one of claims 1 to 11.

13. A film according to claim 12, wherein the film has a thickness of 5 to 200 μm.

14. A film according to claim 12, wherein the coefficient of variation of the thickness in the film width direction, as measured by a continuous thickness gauge, is 1.90% or less.

15. A metal-clad laminate having a metal layer bonded to at least one surface of the film according to claim 12.

16. A circuit board comprising at least a conductive layer and an insulating layer containing the resin composition described in any one of claims 1 to 11.

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