Liquid crystal polymer particles, thermosetting resin composition, and molded article

Abstract

The present invention provides liquid crystal polymer particles that, when added to a resin film, can suppress increases in the surface roughness and linear expansion coefficient of the resin film and reduce the dielectric loss tangent. The liquid crystal polymer particles of the present invention are characterized in that at least 80% by mass of the particles are flat, and the major diameter, minor diameter, and thickness of the flat liquid crystal polymer particles, as defined below, satisfy the following conditions (A) and (B): (A) the ratio of the major diameter to the minor diameter, i.e., the aspect ratio, is 1.2 to 5.0; and (B) the ratio of the minor diameter to the thickness, i.e., the flatness, is 1.2 or greater.

Description

Technical Field

[0001] The present invention relates to liquid crystal polymer particles, a thermosetting resin composition containing the liquid crystal polymer particles, and a molded article using the thermosetting resin composition. Background Art

[0002] In recent years, with the increase in the amount of information communication in the communication field, the use of signals with high-frequency bands has increased in electronic equipment, communication equipment, etc., especially signals with frequencies of 10 9 The use of signals with frequencies in the gigahertz (GHz) band above Hz is the most popular. However, as the frequency of the signal used becomes higher, it can lead to the misidentification of intelligence, the reduction of the quality of the output signal, that is, the transmission loss will become larger. The transmission loss is composed of the conductor loss caused by the conductor and the dielectric loss caused by the insulating resin composition of the electrical and electronic parts of the electronic circuit substrate in the electronic equipment and communication equipment. The conductor loss is proportional to the 0.5 power of the frequency used, and the dielectric loss is proportional to the 1 power of the frequency. Therefore, in the high frequency band, the so-called GHz band, the impact caused by the dielectric loss is very large. In this context, as the resin used in the circuit substrate, resins with excellent dielectric properties have been studied. For example, polyimide film has a low relative dielectric constant, so although it is also being studied and used, there is still room for improvement in terms of the reduction of dielectric loss tangent.

[0003] Since liquid crystal polymers are materials with excellent dielectric properties, liquid crystal polymer particles are added to resin films as additives to improve their dielectric properties. For example, Patent Documents 1 and 2 disclose approximately spherical liquid crystal polymer particles. Furthermore, Patent Documents 3 and 4 disclose fibrillar liquid crystal polymer particles.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6295013

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2019-001866

[0008] Patent Document 3: Japanese Patent Application No. 2005-501760

[0009] Patent Document 4: Japanese Patent No. 5904307 Summary of the Invention

[0010] However, although the roughly spherical liquid crystal polymer particles described in Patent Documents 1 and 2 have excellent handleability as powders, when used as additives, it is difficult to control the orientation in the resin film, resulting in a drawback that the linear expansion coefficient increases proportionally with the amount added. In addition, the fibrillar liquid crystal polymer particles described in Patent Documents 3 and 4 are prone to crosslinking between particles, making dispersibility and handling difficult and impractical. In addition, due to these properties, it is difficult to crush the fibrillar liquid crystal polymer particles to the cumulative distribution 50% diameter D in the particle size distribution. 50 If the surface roughness of the resin film is less than 20 μm, it may adversely affect the surface roughness of the resin film when added to the resin film. If the surface roughness of the resin film is large, when used in a copper foil laminate, the adhesion between the resin film and the copper plate is reduced, and the transmission loss caused by the rough surface of the copper plate increases.

[0011] Therefore, the present invention aims to provide a liquid crystal polymer particle that, when added to a resin film, can suppress the increase in the surface roughness and linear expansion coefficient of the resin film and reduce the dielectric loss tangent. In addition, the present invention aims to provide a thermosetting resin composition containing such liquid crystal polymer particles and a molded article formed using the thermosetting resin composition.

[0012] The present inventors conducted intensive research to address the above-mentioned issues and discovered that by controlling the shape of liquid crystal polymer particles to be flat (approximately disc-shaped), molded articles incorporating these liquid crystal polymer particles exhibit reduced surface roughness and reduced linear expansion coefficient, compared to molded articles incorporating spherical liquid crystal polymer particles, while also exhibiting superior dielectric properties. The present invention was completed based on this finding.

[0013] That is, according to one aspect of the present invention, it is possible to provide:

[0014] Liquid crystal polymer particles, characterized in that 80% by mass or more of the total particles are flat liquid crystal polymer particles.

[0015] The major axis, minor axis, and thickness of the flat liquid crystal polymer particles as defined below satisfy the following conditions (A) and (B):

[0016] (A) The ratio of the major diameter to the minor diameter, i.e., the aspect ratio, is 1.2 to 5.0;

[0017] (B) The ratio of the minor diameter to the thickness, that is, the flatness, is 1.2 or more.

[0018] In the embodiment of the present invention, it is preferred that the melting point of the liquid crystal polymer particles is 270° C. or higher.

[0019] Cumulative distribution 50% diameter D in particle size distribution 50 The diameter D of the cumulative distribution is less than 20 μm and the 90% diameter of the cumulative distribution is less than 20 μm.90 D 50 less than 2.5 times of the original value.

[0020] In the embodiment of the present invention, the liquid crystal polymer particles preferably have a dielectric loss tangent of 0.001 or less.

[0021] In the embodiment of the present invention, the liquid crystal polymer particles preferably include a structural unit (I) derived from a hydroxycarboxylic acid, a structural unit (II) derived from a diol compound, and a structural unit (III) derived from a dicarboxylic acid.

[0022] In the embodiment of the present invention, the structural unit (I) derived from a hydroxycarboxylic acid is preferably a structural unit derived from 6-hydroxy-2-naphthoic acid.

[0023] In the embodiment of the present invention, the composition ratio of the structural unit (I) is preferably 40 mol% to 80 mol% based on the structural units of the entire liquid crystal polymer particles.

[0024] In another aspect of the present invention, a thermosetting resin composition is provided, comprising the liquid crystal polymer particles and a thermosetting resin.

[0025] In another embodiment of the present invention, the content of the liquid crystal polymer particles is preferably 5 to 80 parts by mass based on 100 parts by mass of the thermosetting resin.

[0026] In another embodiment of the present invention, it is preferred that the thermosetting resin is at least one selected from the group consisting of epoxy resins, phenolic resins, polyimide resins, and bismaleimide triazine resins.

[0027] In another embodiment of the present invention, it is preferred that the ratio of the viscosity of the thermosetting resin composition to the viscosity of the thermosetting resin be 30 or less.

[0028] According to another aspect of the present invention, there is provided a molded article formed from the above-mentioned thermosetting resin composition.

[0029] The above-mentioned molded body is in the form of a film, sheet or plate.

[0030] The flat liquid crystal polymer particles have a ratio (a / b) of an average value a of Feret diameters in the longitudinal direction to an average value b of Feret diameters in a direction perpendicular to the longitudinal direction of the flat liquid crystal polymer particles of 1.2 or more.

[0031] In another embodiment of the present invention, the ratio (a / b) is preferably 1.2 to 10.0.

[0032] In another embodiment of the present invention, the molded article is preferably a resin film having a thickness of 25 μm or less.

[0033] In another aspect of the present invention, it is preferred that the resin film of the molded article have a surface roughness Ra of 1.0 μm or less.

[0034] By adding the flat (roughly disc-shaped) liquid crystal polymer particles of the present invention to a molded article, surface roughness can be suppressed and excellent dielectric properties can be achieved. In particular, in a film-like molded article to which the flat liquid crystal polymer particles are added, the long axis of the flat liquid crystal polymer particles is easily oriented along the transverse axis (MD direction) within the molded article, thereby minimizing the increase in the linear expansion coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a photograph of an ultrathin section in the longitudinal cross-section direction of a film obtained using the liquid crystal polymer particles of Example 1, taken using an optical microscope.

[0036] Figure 2 Schematic diagram showing the major axis, minor axis, and thickness of flat liquid crystal polymer particles.

[0037] Figure 3 Schematic diagram showing the Feret's diameter in the long-axis direction and the Feret's diameter in the direction perpendicular to the long-axis direction of flat liquid crystal polymer particles in a molded article. DETAILED DESCRIPTION

[0038] [Liquid Crystal Polymer Particles]

[0039] In the liquid crystal polymer particles of the present invention, 80% or more by mass, preferably 85% or more by mass, more preferably 90% or more by mass, and even more preferably 95% or more by mass of the total particles are flat. In the present invention, the flat liquid crystal polymer particles are characterized in that the major diameter, minor diameter, and thickness defined below satisfy the following conditions (A) and (B):

[0040] (A) The ratio of the major diameter to the minor diameter, i.e., the aspect ratio, is 1.2 to 5.0;

[0041] (B) The ratio of the minor diameter to the thickness, that is, the flatness, is 1.2 or more.

[0042] By adding such liquid crystal polymer particles to molded articles, surface roughness can be suppressed and excellent dielectric properties can be achieved. In particular, in film-like molded articles incorporating flat liquid crystal polymer particles, the long axis of the flat liquid crystal polymer particles tends to align along the transverse axis (MD) within the molded article, thereby minimizing the increase in the linear expansion coefficient.

[0043] Furthermore, the ratio of the major diameter to the minor diameter of the (A) flat liquid crystal polymer particles, i.e., the lower limit of the aspect ratio, is preferably 1.5 or more, more preferably 1.7 or more. The upper limit of the aspect ratio is preferably 4.0 or less, more preferably 3.0 or less, further preferably 2.8 or less, and further preferably 2.5 or less. In addition, the ratio of the minor diameter to the thickness of the (B) flat liquid crystal polymer particles, i.e., the lower limit of the flatness, is preferably 1.5 or more, more preferably 1.7 or more. The upper limit of the flatness is not particularly limited, for example, it can be 10.0 or less, 5.0 or less, or 3.0 or less.

[0044] <Method for measuring the major axis, minor axis, and thickness of liquid crystal polymer particles>

[0045] For the determination of the major diameter, minor diameter and thickness of the liquid crystal polymer particles, a film having a thickness of about 25 μm was prepared by adding liquid crystal polymer particles to a resin. The obtained film was cut along the cross-sectional direction using a freezing microtome to make ultrathin slices with a thickness of 0.5 to 2.5 μm. The cross section of the ultrathin slice can be observed using an optical microscope (optical microscope (manufactured by KEYENCE CORPORATION, model: VHX6000)), and the cross-sectional image can be analyzed to calculate the shape. In order to measure the shape of the liquid crystal polymer particles, in the manufacture of the film, general film-making conditions are sufficient, and conditions that cause a significant change in the shape of the liquid crystal polymer particles are not selected. When measuring the major diameter and minor diameter, observe the cross section at the position of 1 / 2 of the film thickness ( Figure 2 When measuring the short diameter and thickness, observe the longitudinal section of the film along the TD direction ( Figure 2 xz plane). 400μm×300μm is set as one field of view, and 3 fields of view in each of the cross section and the longitudinal section are observed at a magnification of 1000 times. The 3 fields of view in the cross section are all set in a manner that includes the center of the film in the TD direction and does not overlap with each other. As an example, it can be set to the 1 / 4 position, 2 / 4 position, and 3 / 4 position of the film in the MD direction. The 3 fields of view in the longitudinal section are all set in a manner that includes the center of the film in the thickness direction and does not overlap with each other. As an example, it can be set to the 1 / 4 position, 2 / 4 position, and 3 / 4 position of the film in the TD direction. In each field of view, the Feret diameter of the major axis, minor axis, and thickness of at least 100 or more liquid crystal polymer particles is measured. It should be noted that the major axis, minor axis, and thickness of the liquid crystal polymer particles can be adjusted according to the synthesis method of the liquid crystal polymer particles, the pulverization method, or the conditions of the sieve after pulverization.

[0046] In the present invention, the particle size distribution of the liquid crystal polymer particles can be measured using a laser diffraction / scattering particle size distribution measuring apparatus (manufactured by Beckman Coulter, Inc., LS 13 320 dry system equipped with a Tornado dry powder module). The cumulative distribution 50% diameter D in the particle size distribution is 50 (hereinafter referred to as "D 50 ”) represents the value of the particle size at which the cumulative distribution becomes 50% from the small particle size side, and the cumulative distribution 90% diameter D 90 (hereinafter referred to as "D 90 ”) indicates the value of the particle size at which the cumulative distribution becomes 90% from the smaller particle size side.

[0047] In the liquid crystal polymer particles of the present invention, it is preferred that D 50 is less than 20 μm, and D 90 D 50 less than 2.5 times of the original value.

[0048] D 50 It is preferably 0.1 μm or more, more preferably 1 μm or more, further preferably 3 μm or more, and more preferably 5 μm or more. 50 It is preferably 15 μm or less, more preferably 12 μm or less, further preferably 10 μm or less, and even more preferably 6 μm or less.

[0049] D 90 Preferably D 50 The ratio of the total weight of the composite material to the composite material is 2.2 times or less, more preferably 2.0 times or less, and further preferably 1.8 times or less.

[0050] By using D as a parameter in the particle size distribution of liquid crystal polymer particles 50 and D 90 By adjusting the value of within the above range, it is possible to suppress the increase in the surface roughness and linear expansion coefficient of the resin film when added to the resin film, and to reduce the dielectric loss tangent. 50 and D 90 The value of can be adjusted by the synthesis method of the liquid crystal polymer particles, the pulverization method (pulverization pressure, supply conditions, etc.), and the classification conditions (size of the sieve after pulverization, air flow classification conditions, etc.).

[0051] The liquid crystallinity of a liquid crystal polymer can be confirmed by, for example, heating and melting the liquid crystal polymer on a microscope heating stage manufactured by Mettler using a polarizing microscope (trade name: BH-2) manufactured by Olympus Corporation equipped with a microscope heating stage (trade name: FP82HT) manufactured by Mettler, and then observing the presence or absence of optical anisotropy.

[0052] The melting point of the liquid crystal polymer particles is generally 270°C or higher, with a lower limit of preferably 280°C or higher, more preferably 290°C or higher, and even more preferably 300°C or higher. The upper limit is preferably 370°C or lower, 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, the heat resistance of the resin film obtained by adding the liquid crystal polymer particles of the present invention can be improved. It should be noted that in this specification, the melting point of the liquid crystal polymer can be measured using a differential scanning calorimeter (DSC) manufactured by Hitachi High-Tech Science Company, etc.

[0053] The dielectric loss tangent of the liquid crystal polymer particles (measured at 10 GHz) is 0.001 or less, preferably 0.0009 or less, more preferably 0.0008 or less, and even more preferably 0.0007 or less. This value is the measured value of the dielectric loss tangent in the in-plane direction of the injection-molded article of the liquid crystal polymer particles. It should be noted that the injection-molded article is a flat test piece measuring 30 mm × 30 mm × 0.4 mm (thickness).

[0054] The composition of the liquid crystal polymer used as the raw material of the liquid crystal polymer particles of the present invention is not particularly limited, but preferably includes a structural unit (I) derived from an aromatic hydroxycarboxylic acid, a structural unit (II) derived from an aromatic diol compound, and a structural unit (III) derived from an aromatic dicarboxylic acid. Furthermore, the liquid crystal polymer of the present invention may further include a structural unit (IV) as a structural unit other than structural units (I) to (III). The structural units contained in the liquid crystal polymer are described below.

[0055] (Structural unit (I) derived from hydroxycarboxylic acid)

[0056] The unit (I) constituting the liquid crystal polymer is a structural unit derived from a hydroxycarboxylic acid, preferably a structural unit derived from an aromatic hydroxycarboxylic acid represented by the following formula (I). The structural unit (I) may contain only one type or two or more types.

[0057] [Chemical Formula 1]

[0058]

[0059] In the above formula, Ar 1The desired group may be selected from phenyl, biphenyl, 4,4'-isopropenyldiphenyl, naphthyl, anthracenyl, and phenanthrenyl groups having a substituent. Of these, naphthyl is preferred. Examples of substituents include hydrogen, alkyl, alkoxy, and fluorine. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5. Furthermore, the alkyl group may be either linear or branched. The alkoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms.

[0060] Examples of monomers that provide the structural unit represented by the above formula (I) include 6-hydroxy-2-naphthoic acid (HNA, the following formula (1)), and acylates, ester derivatives, and acyl halides thereof.

[0061] [Chemical Formula 2]

[0062]

[0063] About the composition ratio (mol %) of the structural unit (I) relative to the structural unit of the entire liquid crystal polymer, as the lower limit, preferably 40 mol % or more, more preferably 45 mol % or more, further preferably 50 mol % or more, further preferably 55 mol % or more. The upper limit is preferably 80 mol % or less, more preferably 75 mol % or less, further preferably 70 mol % or less, further preferably 65 mol % or less. When comprising two or more structural units (I), their total molar ratio is within the range of the above-mentioned composition ratio.

[0064] (Structural unit (II) derived from diol compound)

[0065] The unit (II) constituting the liquid crystal polymer is a structural unit derived from a diol compound, preferably a structural unit derived from an aromatic diol compound represented by the following formula (II).

[0066] [Chemical Formula 3]

[0067]

[0068] In the above formula, Ar 2 The desired group may be selected from phenyl, biphenyl, 4,4'-isopropenyldiphenyl, naphthyl, anthracenyl, and phenanthrenyl groups having a substituent. Phenyl and biphenyl are preferred. Examples of substituents include hydrogen, alkyl, alkoxy, and fluorine. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5. Furthermore, the alkyl group may be either linear or branched. The alkoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms.

[0069] Examples of monomers forming structural unit (II) include 4,4-dihydroxybiphenyl (BP, following formula (2)), hydroquinone (HQ, following formula (3)), methylhydroquinone (MeHQ, following formula (4)), 4,4'-isopropenyldiphenol (BisPA, following formula (5)), and acylates, ester derivatives, and acyl halides thereof. Among these, 4,4-dihydroxybiphenyl (BP) and acylates, ester derivatives, and acyl halides thereof are preferably used.

[0070] [Chemical Formula 4]

[0071]

[0072] [Chemical Formula 5]

[0073]

[0074] [Chemical Formula 6]

[0075]

[0076] [Chemical Formula 7]

[0077]

[0078] About the composition ratio (mol %) of the structural unit (II) relative to the structural unit of the entire liquid crystal polymer, as the lower limit, preferably 10 mol % or more, more preferably 12.5 mol % or more, further preferably 15 mol % or more, further preferably 17.5 mol % or more. The upper limit is preferably 30 mol % or less, more preferably 27.5 mol % or less, further preferably 25 mol % or less, further preferably 22.5 mol % or less. When comprising two or more structural units (II), their total molar ratio is within the range of the above-mentioned composition ratio.

[0079] (Structural unit (III) derived from aromatic dicarboxylic acid)

[0080] The unit (III) constituting the liquid crystal polymer is a structural unit derived from a dicarboxylic acid, preferably a structural unit derived from an aromatic dicarboxylic acid represented by the following formula (III). The structural unit (III) may contain only one type or two or more types.

[0081] [Chemical Formula 8]

[0082]

[0083] In the above formula, Ar 3The desired group may be selected from phenyl, biphenyl, 4,4'-isopropenyldiphenyl, naphthyl, anthracenyl, and phenanthrenyl groups having a substituent. Phenyl and naphthyl are preferred. Examples of substituents include hydrogen, alkyl, alkoxy, and fluorine. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5. Furthermore, the alkyl group may be either linear or branched. The alkoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms.

[0084] Examples of monomers providing structural unit (III) include terephthalic acid (TPA, formula (6) below), isophthalic acid (IPA, formula (7) below), 2,6-naphthalenedicarboxylic acid (NADA, formula (8) below), and acylates, ester derivatives, and acyl halides thereof.

[0085] [Chemical Formula 9]

[0086]

[0087] [Chemical Formula 10]

[0088]

[0089] [Chemical Formula 11]

[0090]

[0091] About the composition ratio (mol %) of the structural unit of structural unit (III) relative to the whole liquid crystal polymer, as the lower limit, preferably 10 mol % or more, more preferably 12.5 mol % or more, more preferably 15 mol % or more, more preferably 17.5 mol % or more. The upper limit is preferably 30 mol % or less, more preferably 27.5 mol % or less, more preferably 25 mol % or less, more preferably 22.5 mol % or less. In the case of comprising two or more structural units (II), their total molar ratio is within the range of the above-mentioned composition ratio. It should be noted that the composition ratio of structural unit (II) and the composition ratio of structural unit (III) are substantially equivalent ((structural unit (II) ≒ structural unit (III)).

[0092] (Structural unit (IV) derived from other monomers)

[0093] The liquid crystal polymer may further contain other structural units in addition to the above-mentioned structural units (I) to (III). The structural unit (IV) is derived from other monomers in addition to the monomers providing the above-mentioned structural units (I) to (III), and is not particularly limited as long as it is derived from a polymerizable monomer that can be polymerized with the monomers providing the above-mentioned structural units (I) to (III). Examples of polymerizable groups include: hydroxyl, carboxyl, amino and amide groups. The monomer providing the structural unit (IV) has one or more of these polymerizable groups, and preferably has two or more of these polymerizable groups. When containing two or more polymerizable groups, these polymerizable groups may be the same or different. The structural unit (IV) may contain only one type or two or more types.

[0094] Examples of the structural unit (IV) include the following structural units (IV-1):

[0095] [Chemical Formula 12]

[0096]

[0097] Examples of the monomer providing the structural unit (IV-1) include acetamidophenone (AAP, the following formula (9)), p-aminophenol, 4'-acetoxyacetanilide, and acylates, ester derivatives, and acyl halides thereof.

[0098] [Chemical Formula 13]

[0099]

[0100] In addition, examples of the structural unit (IV) include the following structural unit (IV-2):

[0101] [Chemical Formula 14]

[0102]

[0103] Examples of the monomer providing the structural unit (V-2) include 1,4-cyclohexanedicarboxylic acid (CHDA, the following formula (10)), and acylates, ester derivatives, and acyl halides thereof.

[0104] [Chemical Formula 15]

[0105]

[0106] The composition ratio (mol %) of the structural unit (IV) relative to the total structural units of the liquid crystal polymer can be appropriately set based on the composition ratio of the structural units (I) to (III). Specifically, the composition ratio of each structural unit can be appropriately set so that the monomer ratio (molar ratio) of the carboxyl group to the hydroxyl group and / or amino group in the monomer feed is within the range of approximately 1:1.

[0107] Preferred examples of the liquid crystal polymer include the following.

[0108] 45 mol%≤Structural unit (I) derived from 6-hydroxy-2-naphthoic acid≤75 mol%

[0109] 12 mol%≤Structural unit (II) derived from aromatic diol compound≤27.5 mol%

[0110] 3 mol%≤Structural units derived from terephthalic acid Structural units (IIIA)≤25 mol%

[0111] 2 mol%≤Structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid≤9 mol%.

[0112] Furthermore, as more preferable compounding of the liquid crystal polymer, the following compounds can be mentioned.

[0113] 50 mol%≤Structural unit (I) derived from 6-hydroxy-2-naphthoic acid≤70 mol%

[0114] 15 mol%≤Structural unit (II) derived from aromatic diol compound≤25 mol%

[0115] 9 mol%≤Structural units derived from terephthalic acid Structural units (IIIA)≤22 mol%

[0116] 3 mol %≤Structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid≤6 mol %.

[0117] Furthermore, as more preferable compounding of the liquid crystal polymer, the following compounding can be mentioned.

[0118] 54 mol%≤Structural unit (I) derived from 6-hydroxy-2-naphthoic acid≤66 mol%

[0119] 17 mol%≤Structural unit (II) derived from aromatic diol compound≤23 mol%

[0120] 11 mol%≤Structural units derived from terephthalic acid Structural unit (IIIA)≤20 mol%

[0121] 3 mol %≤Structural unit (IIIB) derived from 2,6-naphthalenedicarboxylic acid≤6 mol %.

[0122] When the content of each structural unit relative to the total structural unit content of the liquid crystal polymer is within the above-mentioned range, liquid crystal polymer particles having a low dielectric loss tangent can be obtained.

[0123] (Method for producing liquid crystal polymer)

[0124] Liquid crystal polymers can be produced by polymerizing monomers that provide structural units (I) to (III) as needed and monomers that provide structural unit (IV) as needed using conventionally known methods. In one embodiment, the liquid crystal polymer of the present invention can also be produced by two-stage polymerization, wherein a prepolymer is prepared by melt polymerization and the prepolymer is further solid-phase polymerized.

[0125] Melt polymerization can be carried out in the presence of acetic anhydride under reflux of acetic acid. From the perspective of efficiently obtaining a liquid crystal polymer, melt polymerization is preferably carried out in the presence of 1.05 to 1.15 molar equivalents of acetic anhydride relative to all hydroxyl groups in the monomers constituting the liquid crystal polymer.

[0126] When the polymerization reaction is carried out in two stages, melt polymerization followed by solid-phase polymerization, the prepolymer obtained by melt polymerization is cooled and solidified, then pulverized into a powder or flake form, and then a known solid-phase polymerization method is selected. For example, a method such as heat-treating the prepolymer resin at a temperature range of 200-350°C for 1-30 hours under an inert atmosphere such as nitrogen or under vacuum is preferred. Solid-phase polymerization can be carried out with stirring or in a static state without stirring.

[0127] A catalyst may or may not be used in the polymerization reaction. As the catalyst used, a catalyst known as a catalyst for the polymerization of liquid crystal polymers can be used. Examples of the catalyst include metal salt catalysts such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide, nitrogen-containing heterocyclic compounds such as N-methylimidazole, and organic compound catalysts. The amount of the catalyst used is not particularly limited, but is preferably 0.0001 to 0.1 parts by weight relative to 100 parts by weight of the total amount of the monomers.

[0128] The polymerization reaction apparatus used in the melt polymerization is not particularly limited, but is preferably a reaction apparatus commonly used for high-viscosity fluid reactions. Examples of such reaction apparatuses include a stirring tank-type polymerization reaction apparatus having a stirring device with stirring blades of various shapes such as anchor-type, multi-stage-type, spiral ribbon-type, and screw shaft-type, or variations thereof; and a mixing apparatus commonly used for resin mixing, such as a kneader, a roll mill, and a Banbury mixer.

[0129] [Method for producing liquid crystal polymer particles]

[0130] The liquid crystal polymer particles of the present invention can be produced by pulverizing and classifying the liquid crystal polymer using a conventionally known pulverization and classification apparatus. It is known that liquid crystal polymer particles tend to exhibit shape anisotropy, such as fibrillation, when the pulverization temperature increases. Therefore, by adjusting the pulverization pressure of the pulverization apparatus or the airflow of the classification apparatus, for example, the balance between the frequency of particle collisions and the rate of heat removal generated by the collisions can be altered, thereby adjusting the aspect ratio, flatness, and particle size of the particles.

[0131] [Thermosetting resin composition]

[0132] The thermosetting resin composition of the present invention comprises the liquid crystal polymer particles of the present invention and a thermosetting resin. Examples of the thermosetting resin include epoxy resins, phenolic resins, polyimide resins, cyanate resins, acrylic resins, maleimide resins, and bismaleimide triazine resins, with polyimide resins being particularly preferred. These thermosetting resins may be present alone or in combination.

[0133] The content of the liquid crystal polymer particles in the thermosetting resin composition is preferably 5 to 80 parts by mass, more preferably 10 to 70 parts by mass, further preferably 15 to 60 parts by mass, and even more preferably 20 to 50 parts by mass, relative to 100 parts by mass of the thermosetting resin. If the content of the liquid crystal polymer particles is within the above range, the increase in the surface roughness and linear expansion coefficient of the resin film during the manufacture of the resin film can be suppressed, and the dielectric loss tangent can be reduced.

[0134] The thermosetting resin composition of present embodiment reduces dielectric loss tangent by containing liquid crystal polymer particles, but by adding liquid crystal polymer particles, thus the viscosity of thermosetting resin composition rises.By using the liquid crystal polymer particles of present embodiment, thus the viscosity of thermosetting resin composition can be suppressed to significantly rise, therefore in terms of manufacturing, it is preferred.The viscosity of the thermosetting resin composition comprising liquid crystal polymer particles of present embodiment is preferably below 30 relative to the ratio of the viscosity of thermosetting resin.The upper limit of the ratio of the viscosity of preferred thermosetting resin composition is 20,10,5,3 or 2.

[0135] (Method for producing thermosetting resin composition)

[0136] The manufacture method of the thermosetting resin composition of the present invention preferably at least includes the process of mixing the above-mentioned liquid crystal polymer particles with a thermosetting resin at a temperature less than the melting point of the liquid crystal polymer particles. By mixing at a temperature less than the melting point of the liquid crystal polymer particles, the thermosetting resin composition can be obtained under the condition that the particle size distribution of the liquid crystal polymer particles does not change as much as possible. As a mixing method, it can be carried out by existing known methods. For example, a Banbury mixer, kneader, single shaft or twin shaft extruder etc. can be used for mixing.

[0137] (Molding)

[0138] The molded article of the present invention can be obtained using the aforementioned thermosetting resin composition. The molded article of the present invention may contain other components in addition to the aforementioned liquid crystal polymer particles and thermosetting resin, as long as the effects of the present invention are not impaired. Examples of such other components include colorants, dispersants, plasticizers, antioxidants, curing agents, flame retardants, heat stabilizers, ultraviolet absorbers, antistatic agents, and surfactants.

[0139] The molded article is preferably in the form of a film, sheet, or plate. The thickness of the molded article is not particularly limited, but is generally 10 μm to 200 μm, preferably 150 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less. Even in the case of a film having a thickness of 200 μm or less, a molded article using the thermosetting resin composition containing liquid crystal polymer particles of the present invention can suppress surface roughness.

[0140] The average value b of the Feret's diameter in the vertical direction (TD direction) of the liquid crystal polymer particles in the molded body is preferably more than 1.2 relative to the average value a of the Feret's diameter in its major axis direction (MD direction), more preferably more than 1.5, further preferably more than 1.7. In addition, the upper limit of the above-mentioned ratio (a / b) is not particularly limited, for example, can be less than 5, or less than 3. If the above-mentioned ratio (a / b) is more than 1.2, the liquid crystal polymer particles are fully oriented along the major axis direction in the molded body, and dielectric loss tangent can be effectively reduced.

[0141] <Measurement method of ratio (a / b)>

[0142] The ratio (a / b) can be measured by observing the cross section of the liquid crystal polymer particles in the above-mentioned <Method for measuring the major axis, minor axis and thickness of liquid crystal polymer particles>. Specifically, the cross section ( Figure 3) and analyze the resulting image to calculate. A field of view of 400 μm × 300 μm is set as one field of view, and three fields of view in the cross section are observed at a magnification of 1000x. The three fields of view in the cross section are all set so as to include the center of the film in the TD direction and not overlap with each other. As an example, the three fields of view can be set to the 1 / 4 position, the 2 / 4 position, and the 3 / 4 position of the film in the MD direction. In each field of view, the Feret diameters of at least 100 or more liquid crystal polymer particles are measured, and the ratio of their average values ​​is calculated.

[0143] (resin film)

[0144] The resin film of the present invention, by using the liquid crystal polymer particles, can suppress increases in the surface roughness and linear expansion coefficient of the resin film and reduce the dielectric loss tangent. The surface roughness Ra of the resin film is preferably 1.0 μm or less, more preferably 0.9 μm or less, and even more preferably 0.8 μm or less.

[0145] The thickness of the resin film is preferably 25 μm or less, more preferably 20 μm or less, and may be 10 μm or more. By using the liquid crystal polymer particles, the surface roughness Ra can be suppressed even when such a thin film is produced.

[0146] (Method for producing molded article)

[0147] In the present invention, the above-mentioned thermosetting resin composition can be obtained by molding using existing known methods. As molding methods, for example, compression molding, foam molding, injection molding, extrusion molding, stamping molding, etc. can be cited. The molded body manufactured in the above manner can be processed into various shapes according to the application. The shape of the molded body is not limited, for example, it is film-like, sheet-like or plate-like. In particular, by using the liquid crystal polymer particles of the present invention, the surface roughness of the molded body can be reduced even if it is a thin film, and therefore it is suitable for a film-like molded body.

[0148] (Electronic circuit board)

[0149] The electronic circuit substrate of the present invention can be obtained using the above-mentioned thermosetting resin composition. In addition, the electronic circuit substrate of the present invention includes the above-mentioned molded body. As the electronic circuit substrate, even if it is formed into a film-like shape of a thin film, the surface roughness can be suppressed and the dielectric loss tangent can be reduced, so it is preferably a flexible circuit substrate.

[0150] (Other forms)

[0151] It should be noted that the liquid crystal polymer particles of the present invention can be used as molded articles, in addition to the above-mentioned films or electronic circuit substrates, as bonding sheets, prepregs, coverlays, etc. Furthermore, they are not limited to molded articles and can be used, for example, as paste compositions, in which case they can also be used as adhesives, interlayer insulating materials, sealing materials, etc.

[0152] Example

[0153] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0154] <Synthesis of Liquid Crystal Polymers>

[0155] (Synthesis example 1)

[0156] In a polymerization vessel equipped with a stirring blade, 60 mol% of 6-hydroxy-2-naphthoic acid (HNA), 20 mol% of 4,4-dihydroxybiphenyl (BP), 15.5 mol% of terephthalic acid (TPA), and 4.5 mol% of 2,6-naphthalenedicarboxylic acid (NADA) were added as catalysts, and potassium acetate and magnesium acetate were added. The polymerization vessel was decompressed and nitrogen injected three times to carry out nitrogen substitution. Then, acetic anhydride (1.08 molar equivalents relative to the hydroxyl group) was further added, the temperature was raised to 150°C, and an acetylation reaction was carried out under reflux for 2 hours.

[0157] After the acetylation was completed, the polymerization vessel, still distilling acetic acid, was heated at 0.5°C / min. When the melt temperature in the vessel reached 310°C, the polymer was removed and cooled to solidify. The resulting polymer was pulverized to a size that would pass through a 2.0 mm mesh sieve to obtain a prepolymer.

[0158] Next, the prepolymer obtained above was heated in an oven manufactured by Yamato Scientific Co., Ltd., raising the temperature from room temperature to 295°C over 14 hours, and then maintaining the temperature at 295°C for 1 hour to perform solid-phase polymerization. Afterwards, the heat was naturally dissipated at room temperature to obtain liquid crystal polymer A. Using a polarizing microscope (trade name: BH-2) manufactured by Olympus Corporation equipped with a microscope hot stage (trade name: FP82HT) manufactured by Mettler, liquid crystal polymer A was heated and melted on the microscope hot stage, and the presence or absence of optical anisotropy was then confirmed to determine whether the liquid crystallinity was present.

[0159] <Production of Liquid Crystal Polymer Particles>

[0160] (Example 1)

[0161] Liquid crystal polymer A powder was pulverized using a collision plate sonic jet mill (built-in classifier (adjustment ring: 60 mm, center navel: Φ60 mm, blower setting: -45 kPa), manufactured by Nippon Pneumatic Kogyo Co., Ltd., model: SPK-12+UFS10) at a pulverization pressure of 0.70 MPa and a rate of 10 kg / h. As a result, flat liquid crystal polymer A1 was obtained.

[0162] (Example 2)

[0163] The flat liquid crystal polymer A1 obtained in Example 1 was further classified using a classifier (adjustment ring height 30 mm, distance ring height 15 mm, guide blade gap 4 mm, center hole diameter Φ40 mm, light shielding body opening 1 mm, manufactured by Nippon Pneumatic Kogyo Co., Ltd., model: DXF2) to obtain flat liquid crystal polymer particles A2.

[0164] (Example 3)

[0165] The pulverization was carried out in the same manner as in Example 1 except that the pulverization pressure was set to 0.75 MPa. As a result, a flat liquid crystal polymer A3 was obtained.

[0166] (Comparative Example 1)

[0167] Liquid crystal polymer A powder was finely pulverized by the method described in Example 1 of Japanese Patent No. 6697644 to obtain a true spherical liquid crystal polymer A4.

[0168] <Evaluation of Liquid Crystal Polymers>

[0169] (Determination of aspect ratio and flatness of particles)

[0170] Prepare polyamic acid varnish in a glass container equipped with a stirring device, add a solution obtained by dispersing the liquid crystal polymer particles obtained above in a dispersion medium, stir, and thus obtain a suspension. At this time, the concentration of the liquid crystal polymer particles is adjusted to 10 to 20 parts by mass relative to 100 parts by mass of polyamic acid. The obtained suspension is applied to a glass substrate, dried, and solidified at 300°C to produce a film with a thickness of about 25 μm. Use a freezing microtome to cut the obtained film along the cross-sectional direction to make ultrathin sections with a thickness of 0.5 to 2.5 μm. About the adjustment of thickness, according to the number average diameter of the observed particles, it is set in a manner that more than 100 particles can be observed and do not overlap in the microscope field under the magnification described later. For particles with a volume average diameter of about 5 μm, 0.5 μm thick is more suitable. According to the above-mentioned <Method for measuring the major axis, minor axis and thickness of liquid crystal polymer particles>, the cross section of the obtained ultrathin slice was observed using an optical microscope (manufactured by KEYENCE CORPORATION, model: VHX6000), and the ratio of minor axis / thickness was defined as the flatness of the particle. Figure 1 This is a photograph of an ultrathin section in the cross-sectional direction of a film obtained using the liquid crystal polymer particles of Example 1, taken using an optical microscope.

[0171] Next, the film was sliced ​​horizontally using a cryostat to prepare ultrathin sections with a thickness of 0.5 to 2.5 μm. The obtained ultrathin sections were observed under an optical microscope, and the ratio of major axis to minor axis was defined as the aspect ratio of the particles.

[0172] (Measurement of Particle Size Distribution)

[0173] The particle size distribution of each liquid crystal polymer particle obtained above was measured using a laser diffraction and scattering particle size distribution measuring apparatus (manufactured by Beckman Coulter, Inc., LS13320 dry system equipped with a tornado dry powder module). 50 and D 90 The calculation results were obtained from the measurement data and are shown in Table 1.

[0174] (Determination of Melting Point)

[0175] The melting point of each liquid crystal polymer obtained above was measured using a differential scanning calorimeter (DSC) manufactured by Hitachi High-Tech Science Company. The temperature was raised from room temperature to 360-380°C at a rate of 10°C / min until the polymer was completely melted. The temperature was then lowered to 30°C at a rate of 10°C / min, and then raised to 380°C at a rate of 10°C / min. The peak of the endothermic peak obtained at this time was defined as the melting point (Tm2). The measurement results are shown in Table 1.

[0176] (Measurement of Dielectric Loss Tangent (10 GHz))

[0177] Each liquid crystal polymer obtained above was heated and melted at a temperature between its respective melting point and its melting point + 30°C, and injection molded using a 30 mm × 30 mm × 0.4 mm (thickness) mold to produce a flat test piece. Next, the flat test piece was used to measure the dielectric loss tangent at a frequency of 10 GHz using a network analyzer N5247A from Keysight Technologies using a split dielectric resonator (SPDR method). It should be noted that each type of sample was measured with N = 4, and the average value of the four measurements is shown in Table 1.

[0178] [Table 1]

[0179]

[0180] <Film Production>

[0181] (Example 4)

[0182] 60% of m-toluidine (tol), 40% of 4,4'-diaminodiphenyl ether (DDE), and N,N-dimethylacetamide added in a manner to a specific concentration are added to a glass container equipped with a stirring device, and stirred at 25 ° C under a nitrogen environment to obtain a solution. 100% of pyromellitic dianhydride (PMDA) is added to the solution several times and stirred at 25 ° C under a nitrogen environment to obtain a polyamic acid varnish. 30 parts by mass of liquid crystal polymer particles A1 are added to the obtained polyamic acid varnish relative to 100 parts by mass of polyamic acid in the varnish to obtain a suspension. The obtained suspension is applied to a glass substrate, dried, and then cured at 300 ° C to produce a film with a thickness of 25 μm.

[0183] (Example 5)

[0184] A film having a thickness of 25 μm was produced in the same manner as in Example 4 except that the amount of the liquid crystal polymer particles A1 added was 50 parts by mass relative to 100 parts by mass of the polyamic acid.

[0185] (Example 6)

[0186] A film having a thickness of 25 μm was produced in the same manner as in Example 4 except that 30 parts by mass of the liquid crystal polymer particles A2 were added instead of the liquid crystal polymer particles A1 relative to 100 parts by mass of the polyamic acid.

[0187] (Example 7)

[0188] A film having a thickness of 25 μm was produced in the same manner as in Example 4 except that 50 parts by mass of the liquid crystal polymer particles A2 were added instead of the liquid crystal polymer particles A1 relative to 100 parts by mass of the polyamic acid.

[0189] (Example 8)

[0190] A film having a thickness of 25 μm was produced in the same manner as in Example 4 except that 30 parts by mass of the liquid crystal polymer particles A3 were added instead of the liquid crystal polymer particles A1 relative to 100 parts by mass of the polyamic acid.

[0191] (Example 9)

[0192] A film having a thickness of 25 μm was produced in the same manner as in Example 4 except that 50 parts by mass of the liquid crystal polymer particles A3 were added instead of the liquid crystal polymer particles A1 relative to 100 parts by mass of the polyamic acid.

[0193] (Comparative Example 2)

[0194] A film having a thickness of 25 μm was produced in the same manner as in Example 3 except that 50 parts by mass of liquid crystal polymer particles A4 were added instead of the liquid crystal polymer particles A1 relative to 100 parts by mass of the polyamic acid.

[0195] (Reference example)

[0196] A film having a thickness of 25 μm was produced in the same manner as in Example 4 except that the liquid crystal polymer particles A1 were not added.

[0197] Performance Evaluation

[0198] (Determination of Orientation)

[0199] Each of the films produced above was cut along the cross-section using a cryostat to produce ultrathin sections with a thickness of 0.5 μm. The resulting ultrathin sections were observed cross-sectionally and the Feret's diameters of the polymer particles in the longitudinal direction and perpendicular directions were measured using an optical microscope (Keyence Corporation, Model: VHX6000) according to the "Ratio (a / b) Measurement Method" described above. The ratio (a / b) of the average Feret's diameter in the longitudinal direction (a) to the average Feret's diameter in the perpendicular direction (b) was calculated, and the results are shown in Table 2.

[0200] (Determination of Linear Expansion Coefficient)

[0201] Each of the films produced above was cut into strips of about 4 mm in width to obtain a short strip of sample for measurement. A thermomechanical analyzer (manufactured by Hitachi High-Tech Science Company, model: TMA7000) was used to measure the linear expansion coefficient (CTE) of the sample in tension mode. During the measurement, the distance between measurements was set to 15 mm, and the temperature was raised and lowered at a rate of 10°C / min within a temperature range of 30°C to 230°C, and the measurement was performed for two cycles. The CTE was measured in the temperature range above the glass transition temperature of 170°C to 230°C in the second cycle. The measurement results are shown in Table 2.

[0202] (Measurement of surface roughness)

[0203] Each of the films produced above was cut into 3 mm × 80 mm strips to obtain film samples. The surface roughness of the film samples was then measured using an OLS5000 laser microscope manufactured by Olympus Corporation. The measurement results are shown in Table 2.

[0204] (Determination of dielectric constant and dielectric loss tangent)

[0205] The dielectric constant and dielectric loss tangent of each film sample produced above were measured at 10 GHz using a measurement device consisting of a cavity resonator manufactured by AET Corporation and a spectrum network analyzer MS46122B manufactured by Anritsu Corporation. The measurement results are shown in Table 2.

[0206] [Table 2]

[0207]

[0208] Generally, when mixing liquid crystal polymer particle powder with polyamic acid, a precursor of a polyimide, the calcination conditions are appropriately adjusted to 300°C or higher to achieve a sufficiently high imidization rate of the polyimide. Based on the above results, by using the flat liquid crystal polymer particles of the present invention, even with such adjustments, the adverse effects on the dielectric loss tangent, relative dielectric constant, and surface roughness of the film can be minimized.

[0209] (Determination of viscosity)

[0210] For the liquid crystal polymer particles A1 to A3 manufactured above, the viscosity when added to the varnish is measured by the following method. Relative to 100 parts by mass of polyamic acid in the polyamic acid varnish, 30 parts by mass of liquid crystal polymer particles are added to a solution prepared by diluting the varnish U-Varnish A (polyamic acid concentration 18%) manufactured by Ube Industries, Ltd. with N-methyl-2-pyrrolidone to 2 / 3, thereby obtaining a suspension. For the obtained suspension, an SP-4 type spindle is installed in a B-type viscometer (IKA Co., Ltd., device name: ROTAVISC lo-vi Complete), and the viscosity is measured under the conditions of a rotation speed of 100 rpm and a temperature of 25 ° C. In addition, for the polyamic acid varnish to which no liquid crystal polymer particles are added, the viscosity is also measured in the same manner.

[0211] The measurement results are shown in Table 3. The varnish containing the flat liquid crystal polymer particles of the present invention did not show a significant increase in viscosity to such an extent that flowability became difficult compared to the varnish containing no liquid crystal polymer particles, and was suitable for film production in the production process.

[0212] [Table 3]

[0213]

[0214] Explanation of symbols

[0215] 1: Resin film

[0216] 2: Flat liquid crystal polymer particles

[0217] 3: Long diameter

[0218] 4: Short diameter

[0219] 5: Thickness

[0220] T:TD direction

[0221] M:MD direction

[0222] 6: Molded body

[0223] 7: Feret diameter in the long axis direction (MD direction)

[0224] 8: Feret diameter in the direction perpendicular to the long axis (TD direction)

Claims

1. A liquid crystal polymer particle, characterized in that: The liquid crystal polymer particles contain 80% or more of the particles by mass in a flat shape. Cumulative distribution 50% diameter D in particle size distribution 50 0.1μm~10μm, and the cumulative distribution 90% diameter D 90 D 50 Less than 2.5 times of The major axis, minor axis, and thickness of the flat liquid crystal polymer particles as defined below satisfy the following conditions (A) and (B): (A) The ratio of the major diameter to the minor diameter, i.e., the aspect ratio, is 1.7 to 2.5; (B) The ratio of the minor diameter to the thickness, i.e., the flatness, is 1.7 to 3.

0.

2. The liquid crystal polymer particles according to claim 1, wherein Cumulative distribution 50% diameter D in particle size distribution 50 1μm~6μm. 3 . The liquid crystal polymer particles according to claim 1 , which have a melting point of 270° C. or higher.

4. The liquid crystal polymer particles according to claim 1 or 2, wherein The liquid crystal polymer particles have a dielectric loss tangent of 0.001 or less.

5. The liquid crystal polymer particles according to claim 1 or 2, wherein The liquid crystal polymer particles include a structural unit (I) derived from a hydroxycarboxylic acid, a structural unit (II) derived from a diol compound, and a structural unit (III) derived from a dicarboxylic acid. The liquid crystal polymer particles according to claim 5 , wherein The structural unit (I) derived from a hydroxycarboxylic acid is a structural unit derived from 6-hydroxy-2-naphthoic acid.

7. The liquid crystal polymer particles according to claim 5, wherein The composition ratio of the structural unit (I) is 40 mol% to 80 mol% based on the structural units of the entire liquid crystal polymer particles.

8. A thermosetting resin composition comprising: The liquid crystal polymer particles according to any one of claims 1 to 7, and Thermosetting resin.

9. The thermosetting resin composition according to claim 8, wherein The ratio of the viscosity of the thermosetting resin composition to the viscosity of the thermosetting resin is 30 or less.

10. The thermosetting resin composition according to claim 8 or 9, wherein The content of the liquid crystal polymer particles is 5 to 80 parts by mass relative to 100 parts by mass of the thermosetting resin.

11. The thermosetting resin composition according to claim 8 or 9, wherein The thermosetting resin is at least one selected from the group consisting of epoxy resin, phenolic resin, polyimide resin, and bismaleimide triazine resin.

12. A molded product formed from the thermosetting resin composition according to any one of claims 8 to 11, The formed body is in the form of a film, sheet or plate, The flat liquid crystal polymer particles have a ratio (a / b) of an average value a of Feret's diameters in the long axis direction to an average value b of Feret's diameters in a direction perpendicular to the long axis direction of the flat liquid crystal polymer particles of 1.2 or more.

13. The molded article according to claim 12, wherein The ratio (a / b) is 1.2 to 10.

0.

14. The molded article according to claim 12 or 13, wherein The molded body is a resin film having a thickness of 25 μm or less.

15. The molded article according to claim 12 or 13, wherein The resin film has a surface roughness Ra of 1.0 μm or less.

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