KR20230116047A - Liquid Crystal Polymer Films, Polymer Films, and Laminates - Google Patents

Abstract

It includes a liquid crystal polymer layer containing a liquid crystal polymer, and a layer A disposed on at least one surface of the liquid crystal polymer layer, and between the liquid crystal polymer layer and the layer A, the liquid crystal polymer and a material constituting the layer A are included. A liquid crystal polymer film, in which a mixed region to be formed is formed, and a laminate using the liquid crystal polymer film.

Description

Liquid Crystal Polymer Films, Polymer Films, and Laminates

The present disclosure relates to a liquid crystal polymer film, a polymer film, and a laminate.

In recent years, frequencies used in communication devices tend to become very high. In order to suppress transmission loss in a high frequency band, it is required to lower the dielectric constant and dielectric tangent of insulating materials used for circuit boards.

Conventionally, as an insulating material used for circuit boards, polyimide has been widely used, but liquid crystal polymers with high heat resistance and low water absorption and low loss in a high frequency band are attracting attention.

As a conventional liquid crystal polymer film, for example, Japanese Unexamined Patent Publication No. 2020-26474 is a liquid crystal polyester film containing at least liquid crystal polyester, and the first orientation is defined as the main surface of the liquid crystal polyester film. When an orientation diagram in a first direction parallel to and a second orientation diagram in a second direction parallel to the main surface and orthogonal to the first direction, the first orientation diagram and the second orientation diagram The ratio of the first orientation / second orientation is 0.95 or more and 1.04 or less, and the third orientation of the liquid crystal polyester measured by the wide-angle X-ray scattering method in a direction parallel to the main surface is 60.0% or more, the liquid crystal polyester film This is listed. In addition, in order to improve the adhesion of the liquid crystal polymer film to other layers, plasma treatment (see, for example, Japanese Unexamined Patent Publication No. 2001-049002), UV treatment (see, for example, Japanese Unexamined Patent Publication No. 2000-233448) ) has also been proposed.

However, even if these methods were used, sufficient adhesiveness was not obtained.

According to an embodiment of the present invention, a liquid crystal polymer film excellent in adhesion to a layer formed on a liquid crystal polymer film is provided.

Further, according to an embodiment of the present invention, a laminate using the liquid crystal polymer film is provided.

Further, according to an embodiment of the present invention, a polymer film excellent in adhesion to a layer formed on a polymer film is provided.

Means for solving the above problems include the following aspects.

<1> A liquid crystal polymer layer containing a liquid crystal polymer, and a layer A disposed on at least one surface of the liquid crystal polymer layer, wherein between the liquid crystal polymer layer and the layer A, the liquid crystal polymer and the layer A are formed. A liquid crystal polymer film in which a mixed region containing a material is formed.

<2> The liquid crystal polymer film according to <1>, wherein the mixed region has an average thickness of 1 nm to 10 μm.

<3> The liquid crystal polymer film according to <1> or <2>, wherein the dielectric tangent is 0.005 or less.

<4> The liquid crystal polymer film according to any one of <1> to <3>, wherein the layer A is an adhesive layer containing an adhesive.

<5> The adhesive contains a compound having a functional group, and the functional group is at least one group selected from the group consisting of a group capable of covalent bonding, a group capable of ionic bonding, a group capable of hydrogen bonding, and a group capable of dipole interaction, The liquid crystal polymer film according to <4>.

<6> The liquid crystal polymer film according to <5>, wherein the functional group is a group capable of covalent bonding.

<7> The group capable of covalent bonding is an epoxy group, an oxetanyl group, an isocyanate group, an acid anhydride group, a carbodiimide group, an N-hydroxyester group, a glyoxal group, an imide ester group, a halogenated alkyl group, and at least one group selected from the group consisting of thiol groups, the liquid crystal polymer film according to <6>.

<8> The liquid crystal polymer film according to <5>, wherein the functional group is a group capable of ionic bonding, a group capable of hydrogen bonding, or a group capable of dipole interaction.

<9> The liquid crystal polymer film according to any one of <1> to <8>, wherein the liquid crystal polymer has a melting point of 280°C or higher.

<10> The liquid crystal polymer film according to any one of <1> to <9>, wherein the liquid crystal polymer includes a constituent unit derived from an aromatic hydroxycarboxylic acid.

<11> The liquid crystal polymer contains at least one structural unit selected from the group consisting of structural units derived from aromatic hydroxycarboxylic acids, structural units derived from aromatic diols, and structural units derived from aromatic dicarboxylic acids. The liquid crystal polymer film according to any one of <1> to <10>.

<12> The liquid crystal polymer film according to any one of <1> to <11>, wherein the liquid crystal polymer contains aromatic polyester amide.

<13> A laminate comprising the liquid crystal polymer film according to any one of <1> to <12>, and a metal layer or metal wiring disposed on at least one surface of the liquid crystal polymer film.

<14> The laminate according to <13>, wherein the metal layer or metal wiring has a group capable of interacting with the liquid crystal polymer film on a surface in contact with the liquid crystal polymer film.

<15> The laminate according to <14>, wherein the group capable of interacting with the liquid crystal polymer film is an amino group.

<16> The laminate according to any one of <13> to <15>, wherein the peel strength between the liquid crystal polymer film and the metal layer is 0.5 kN/m or more.

<17> at least one selected from the group consisting of fluorine-based polymers, polymers containing structural units derived from compounds having groups having cyclic aliphatic hydrocarbon groups and groups having ethylenically unsaturated bonds, polyphenylene ethers, and aromatic polyether ketones; A mixed region including a polymer layer containing a polymer of a species and a layer A disposed on at least one surface of the polymer layer, and between the polymer layer and the layer A containing the polymer and the material constituting the layer A. is formed, the polymer film.

According to one embodiment of the present invention, it is possible to provide a liquid crystal polymer film having excellent adhesion to a layer formed on the liquid crystal polymer film.

Further, according to another embodiment of the present invention, a laminate using the liquid crystal polymer film can be provided.

Further, according to another embodiment of the present invention, a polymer film excellent in adhesion to a layer formed on the polymer film is provided.

Below, the content of this indication is demonstrated in detail. The description of the constituent requirements described below may be made based on typical embodiments of the present disclosure, but the present disclosure is not limited to such embodiments.

In addition, in this specification, "-" which shows a numerical range is used by the meaning which includes the numerical value described before and after that as a lower limit value and an upper limit value.

In the numerical ranges described stepwise during the present disclosure, the upper limit or lower limit of one numerical range may be replaced with the upper limit or lower limit of another stepwisely described numerical range. In addition, in the numerical range described in this indication, you may replace the upper limit value or the lower limit value of the numerical range with the value shown in the Example.

In addition, in the notation of a group (atomic group) in this specification, the notation that does not describe substitution and unsubstitution includes those having a substituent as well as those having no substituent. For example, an "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

In this specification, "(meth)acryl" is a term used as a concept including both acryl and methacryl, and "(meth)acryloyl" refers to both acryloyl and methacryloyl. It is a term used as an inclusive concept.

In addition, the term "process" in this specification is included in this term, not only as an independent process, but also in cases where it cannot be clearly distinguished from other processes, provided that the intended purpose of the process is achieved. In addition, in the present disclosure, “mass%” and “weight%” have the same meaning, and “mass parts” and “weight parts” have the same meaning.

In addition, in this indication, the combination of two or more preferable aspects is a more preferable aspect.

In addition, the weight average molecular weight (Mw) and number average molecular weight (Mn) in the present disclosure are, unless otherwise specified, using columns of TSKgel GMHxL, TSKgel G4000HxL, and TSKgel G2000HxL (all are trade names of Tosoh Corporation). It is a molecular weight obtained by using a gel permeation chromatography (GPC) analyzer, detecting with a solvent THF (tetrahydrofuran) and a differential refractometer, and converting using polystyrene as a standard substance.

Hereinafter, the present disclosure will be described in detail.

[liquid crystal polymer film]

A liquid crystal polymer film according to the present disclosure includes a liquid crystal polymer layer containing a liquid crystal polymer and a layer A disposed on at least one surface of the liquid crystal polymer layer, between the liquid crystal polymer layer and the layer A, the liquid crystal polymer, and a mixed region containing the material constituting the layer A is formed.

The present inventors have found that conventional liquid crystal polymer films do not have sufficient adhesion to a layer formed on the liquid crystal polymer film.

As a result of intensive studies by the present inventors, it has been found that a liquid crystal polymer film excellent in adhesion to a layer formed on a liquid crystal polymer film can be provided by adopting the above configuration.

In the liquid crystal polymer film according to the present disclosure, in particular, since a mixed region containing the liquid crystal polymer and the material constituting the layer A is formed, separation between the liquid crystal polymer layer and the layer A is suppressed, and the liquid crystal polymer layer and the layer A are suppressed. adhesion is improved. In addition, the layer A is an adhesive comprising a compound having a functional group of at least one group selected from the group consisting of a covalent bond, an ionic bond, a hydrogen bond, and a group capable of dipole interaction with the surface of the layer formed on the liquid crystal polymer film. In the case of including as, it is presumed that the adhesion between the layer A and the layer formed on the liquid crystal polymer film is improved, so that the entire liquid crystal polymer film has excellent adhesion to the layer formed on the liquid crystal polymer film.

<Liquid Crystal Polymer Layer>

In the liquid crystal polymer film according to the present disclosure, the liquid crystal polymer layer includes a liquid crystal polymer.

In the present disclosure, the type of liquid crystal polymer is not particularly limited, and a known liquid crystal polymer may be used.

Further, the liquid crystal polymer may be a thermotropic liquid crystal polymer exhibiting liquid crystallinity in a molten state or a lyotropic liquid crystal polymer exhibiting liquid crystallinity in a solution state. When the liquid crystal polymer is a thermotropic liquid crystal, it is preferable that the liquid crystal polymer melts at a temperature of 450°C or lower.

Examples of liquid crystal polymers include liquid crystal polyesters, liquid crystal polyester amides in which amide bonds are introduced into liquid crystal polyesters, liquid crystal polyester ethers in which ether bonds are introduced in liquid crystal polyesters, and liquid crystal polyesters in which carbonate bonds are introduced. Liquid crystal polyester carbonate etc. are mentioned.

Further, the liquid crystal polymer is preferably a polymer having an aromatic ring from the viewpoints of liquid crystallinity and thermal expansion coefficient, more preferably aromatic polyester or aromatic polyester amide, still more preferably aromatic polyester amide. .

Further, the liquid crystal polymer may be a polymer in which an isocyanate-derived bond such as an imide bond, a carbodiimide bond, or an isocyanurate bond is further introduced into an aromatic polyester or an aromatic polyester amide.

Further, the liquid crystal polymer is preferably a wholly aromatic liquid crystal polymer formed using only aromatic compounds as raw material monomers.

As an example of a liquid crystal polymer, the following is mentioned, for example.

1) formed by polycondensation of (i) aromatic hydroxycarboxylic acids, (ii) aromatic dicarboxylic acids, and (iii) at least one compound selected from the group consisting of aromatic diols, aromatic hydroxyamines, and aromatic diamines thing.

2) What is formed by polycondensing multiple types of aromatic hydroxycarboxylic acids.

3) Formed by polycondensation of (i) aromatic dicarboxylic acid and (ii) at least one compound selected from the group consisting of aromatic diols, aromatic hydroxyamines, and aromatic diamines.

4) What is formed by polycondensing (i) polyester, such as polyethylene terephthalate, and (ii) aromatic hydroxycarboxylic acid.

Here, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic hydroxyamines, and aromatic diamines may each independently use derivatives capable of polycondensation instead of part or all of them.

Examples of polymerizable derivatives of compounds having a carboxy group such as aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids are those obtained by converting a carboxy group to an alkoxycarbonyl group or aryloxycarbonyl group (ester), and those obtained by converting a carboxy group to a haloformyl group. (Acid halide), and what is formed by converting a carboxy group to an acyloxycarbonyl group (acid anhydride) is mentioned.

Examples of polymerizable derivatives of compounds having a hydroxyl group, such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxyamines, include those formed by acylating the hydroxyl group and converting it to an acyloxy group (acylated product).

Examples of polymerizable derivatives of compounds having an amino group, such as aromatic hydroxyamine and aromatic diamine, include those formed by acylating an amino group and converting to an acylamino group (acylated product).

The liquid crystal polymer preferably contains a constituent unit derived from an aromatic hydroxycarboxylic acid from the viewpoints of liquid crystallinity, dielectric tangent of the polymer film, and adhesion to metal.

In addition, from the viewpoint of liquid crystallinity, dielectric tangent of the polymer film, and adhesion to metal, the liquid crystal polymer is a structural unit derived from an aromatic hydroxycarboxylic acid, a structural unit derived from an aromatic diol, and an aromatic dicarboxylic acid. It is preferable to include at least 1 type of structural unit selected from the group which consists of derived structural units.

The liquid crystal polymer preferably has a structural unit represented by any of the following formulas (1) to (3) (hereinafter, the structural unit represented by formula (1) may be referred to as unit (1) or the like.) And it is more preferable to have a structural unit represented by the following formula (1), a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (2) It is particularly desirable to have

Formula (1) -O-Ar ¹ -CO-

Formula (2) -CO-Ar ² -CO-

Formula (3) -O-Ar ³ -O-

In Formulas (1) to (3), Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group, and Ar ² and Ar ³ are each independently a phenylene group, a naphthylene group, a biphenylylene group, or A group represented by the following formula (4) is shown, and the hydrogen atoms of the groups represented by Ar ¹ to Ar ³ may each independently be substituted with a halogen atom, an alkyl group, or an aryl group.

Formula (4) -Ar ⁴ -Z-Ar ⁵ -

In Formula (4), Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group, and Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylene group.

As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-hexyl group, 2-ethylhexyl group, n- An octyl group and an n-decyl group are mentioned, and the number of carbon atoms is preferably 1 to 10.

Examples of the aryl group include phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 1-naphthyl group and 2-naphthyl group, and the number of carbon atoms is preferably 6 to 20.

When the hydrogen atoms are substituted with these groups, the number is each independently, preferably two or less, more preferably one, per the group represented by Ar ¹ , Ar ² or Ar ³ .

Examples of the alkylene group include a methylene group, a 1,1-ethanediyl group, a 1-methyl-1,1-ethanediyl group, a 1,1-butanediyl group and a 2-ethyl-1,1-hexanediyl group. , and the number of carbon atoms is preferably 1 to 10.

Unit (1) is a structural unit derived from a predetermined aromatic hydroxycarboxylic acid.

As the unit (1), a structural unit in which Ar ¹ is a p-phenylene group (a structural unit derived from p-hydroxybenzoic acid) and a structural unit in which Ar ¹ is a 2,6-naphthylene group (6-hydroxy-2-naphthyl group) A structural unit derived from a native product) or a structural unit in which Ar ¹ is a 4,4'-biphenylylene group (a structural unit derived from 4'-hydroxy-4-biphenylcarboxylic acid), and Ar ¹ is A structural unit which is a p-phenylene group or a 2,6-naphthylene group is more preferable.

Unit (2) is a structural unit derived from a predetermined aromatic dicarboxylic acid.

As the unit (2), a structural unit in which Ar ² is a p-phenylene group (a structural unit derived from terephthalic acid), a structural unit in which Ar ² is a m-phenylene group (a structural unit derived from isophthalic acid), Ar ² is 2, A structural unit that is a 6-naphthylene group (a structural unit derived from 2,6-naphthalenedicarboxylic acid), or a structural unit in which Ar ² is a diphenylether-4,4'-diyl group (diphenylether-4, A structural unit derived from 4'-dicarboxylic acid) is preferable, and a structural unit in which Ar ² is a p-phenylene group or a 2,6-naphthylene group is more preferable.

Unit (3) is a structural unit derived from a predetermined aromatic diol.

As the unit (3), a structural unit in which Ar ³ is a p-phenylene group (a structural unit derived from hydroquinone), a structural unit in which Ar ³ is an m-phenylene group (a structural unit derived from isophthalic acid), or Ar ³ A structural unit (a structural unit derived from 4,4'-dihydroxybiphenyl) that is a 4,4'-biphenylylene group is preferable.

Among them, the liquid crystal polymer preferably contains at least one selected from the group consisting of structural units derived from p-hydroxybenzoic acid and structural units derived from 6-hydroxy-2-naphthoic acid. In addition, the liquid crystal polymer is composed of a structural unit derived from 6-hydroxy-2-naphthoic acid, a structural unit derived from an aromatic diol compound, a structural unit derived from terephthalic acid, and a structural unit derived from naphthalenedicarboxylic acid. It is preferable to include at least 1 sort(s) selected from the group.

The content of structural units derived from aromatic hydroxycarboxylic acids is determined by the total amount of all structural units (by dividing the mass of each structural unit constituting the liquid crystal polymer by the formula weight of each structural unit, the equivalent amount of the substance of each structural unit (mol) is calculated and the total value) is preferably 30 mol% or more, more preferably 30 mol% to 80 mol%, still more preferably 30 mol% to 60 mol%, particularly preferably It is 30 mol% - 40 mol%.

The content of constituent units derived from aromatic dicarboxylic acids is preferably 35 mol% or less, more preferably 10 mol% to 35 mol%, still more preferably 20 mol% to 35 mol%, based on the total amount of all constituent units. %, particularly preferably 30 mol% to 35 mol%.

The content of the constituent unit derived from the aromatic diol is preferably 35 mol% or less, more preferably 10 mol% to 35 mol%, still more preferably 20 mol% to 35 mol%, relative to the total amount of all the constituent units. %, particularly preferably 30 mol% to 35 mol%.

Heat resistance, strength and rigidity tend to improve as the content of the structural unit derived from aromatic hydroxycarboxylic acid increases.

The ratio of the content of structural units derived from aromatic dicarboxylic acids to the content of structural units derived from aromatic diols is [Content of structural units derived from aromatic dicarboxylic acids]/[Content of structural units derived from aromatic diols] It is represented by (mol/mol), and is preferably 0.9/1 to 1/0.9, more preferably 0.95/1 to 1/0.95, still more preferably 0.98/1 to 1/0.98.

Further, the liquid crystal polymer may each independently have two or more types of structural units derived from aromatic hydroxycarboxylic acids, structural units derived from aromatic dicarboxylic acids, and structural units derived from aromatic diols. Further, the liquid crystal polymer may have structural units other than the aforementioned structural units, but the content thereof is preferably 10 mol% or less, more preferably 5 mol% or less, with respect to the total amount of all the structural units.

The liquid crystal polymer is preferably produced by melt polymerization of raw material monomers corresponding to constituent units constituting the liquid crystal polymer. Melt polymerization may be carried out in the presence of a catalyst. Examples of the catalyst include magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, metal compounds such as antimony trioxide, 4- and nitrogen-containing heterocyclic compounds such as (dimethylamino)pyridine and 1-methylimidazole. Nitrogen-containing heterocyclic compounds are preferably used. In addition, melt polymerization may further solid-phase-polymerize as needed.

The liquid crystal polymer is preferably a liquid crystal polymer soluble in a specific organic solvent (hereinafter, also referred to as "soluble liquid crystal polymer").

Specifically, the soluble liquid crystal polymer in the present disclosure is N-methyl-2-pyrrolidone, N,N-dimethylacetamide, γ-butyrolactone, dimethylformamide, and ethylene at 25°C. It is preferably a liquid crystal polymer that dissolves 0.1 g or more in 100 g of at least one solvent selected from the group consisting of glycol monobutyl ether and ethylene glycol monoethyl ether.

-melting point Tm-

The liquid crystal polymer is preferably a liquid crystal polymer exhibiting liquid crystallinity in a molten state. The liquid crystal polymer has a melting point Tm of preferably 280°C or higher, more preferably 300°C or higher, still more preferably 315°C or higher, and particularly preferably 330°C to 400°C, from the viewpoint of dielectric tangent and breaking strength. do.

The melting point Tm is also called flow temperature or flow temperature. Using a capillary rheometer, melting the liquid crystal polymer while raising the temperature at a rate of 4°C/min under a load of 9.8 MPa (100 kg/cm ² ) to obtain an internal diameter of 1 mm and It is the temperature that shows the viscosity of 4,800 Pa·s (48,000 poise) when extruded from a nozzle with a length of 10 mm, and is a standard for the molecular weight of the liquid crystal polymer (Naoyuki Koide, “Liquid Crystal Polymer -Synthesis, Molding, Application-”) , CMC, Inc., June 5, 1987, p.95).

-Weight average molecular weight-

The liquid crystal polymer preferably has a weight average molecular weight of 13,000 or less, more preferably 3,000 to 13,000, still more preferably 5,000 to 12,000, and particularly preferably 5,000 to 10,000. When the weight average molecular weight of the liquid crystal polymer is within the above range, the thermal conductivity in the thickness direction, heat resistance, strength and rigidity of the film after heat treatment are excellent.

-genetic tangent-

The liquid crystal polymer preferably has a dielectric tangent of 0.005 or less, more preferably 0.004 or less, still more preferably 0.0035 or less, and particularly more than 0 and 0.003 or less from the viewpoint of the dielectric tangent of the liquid crystal polymer film and adhesion to metal. desirable.

The method of measuring the dielectric tangent in the present disclosure shall be measured by the following method.

The dielectric tangent is measured by the resonance perturbation method at a frequency of 10 GHz. A 10 GHz cavity resonator (Kanto Denshi Oyo Kaihatsu CP531) was connected to a network analyzer (“E8363B” manufactured by Agilent Technology), and a liquid crystal polymer or liquid crystal polymer film sample (width: 2.0 mm × length: CP531) was connected to the cavity resonator. 80 mm) was inserted, and the dielectric tangent of the liquid crystal polymer or liquid crystal polymer film was measured from the change in resonance frequency before and after the insertion for 96 hours in an environment of a temperature of 25° C. and a humidity of 60% RH.

The liquid crystal polymer film may contain only one type of liquid crystal polymer, or may contain two or more types of liquid crystal polymers.

The content of the liquid crystal polymer in the liquid crystal polymer layer is preferably 50% by mass or more, and preferably 70% by mass or more, with respect to the total mass of the liquid crystal polymer film, from the viewpoint of dielectric tangent of the liquid crystal polymer film and adhesion to metal. It is more preferable, and it is more preferable that it is 90 mass % or more. The upper limit of the content of the liquid crystal polymer is not particularly limited, and may be 100% by mass. That is, the liquid crystal polymer layer may be a layer made of a liquid crystal polymer.

The liquid crystal polymer layer may contain additives other than the liquid crystal polymer.

As other additives, known additives can be used. Specifically, a leveling agent, an antifoaming agent, an antioxidant, a ultraviolet absorber, a flame retardant, a coloring agent, a filler, etc. are mentioned, for example.

Further, the liquid crystal polymer layer may contain other resins other than the liquid crystal polymer as other additives.

Examples of other resins include thermoplastics such as polypropylene, polyamide, polyester, polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenylene ether and modified products thereof, and polyetherimide. profit; elastomers such as copolymers of glycidyl methacrylate and polyethylene; Thermosetting resins, such as a phenol resin, an epoxy resin, a polyimide resin, and a cyanate resin, are mentioned.

The total content of the other additives in the liquid crystal polymer layer is preferably 25 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5 parts by mass, based on 100 parts by mass of the liquid crystal polymer content. below The liquid crystal polymer layer may not contain other additives.

The average thickness of the liquid crystal polymer layer is not particularly limited, but is preferably 5 μm to 90 μm, more preferably 10 μm to 70 μm, and 10 μm to 50 μm from the viewpoint of dielectric tangent of the liquid crystal polymer film and adhesion to metal. is particularly preferred.

The method for measuring the average thickness of each layer in the liquid crystal polymer film according to the present disclosure is as follows.

The liquid crystal polymer film is cut on a plane perpendicular to the plane direction of the liquid crystal polymer film, and the thicknesses of five or more points are measured on the cross section, and the average value thereof is taken as the average thickness.

<Layer A>

A liquid crystal polymer film according to the present disclosure includes a layer A disposed on at least one surface of a liquid crystal polymer layer. Layer A may be disposed on only one surface of the liquid crystal polymer layer, or may be disposed on both surfaces of the liquid crystal polymer layer.

The material constituting the layer A is not particularly limited, and may be either an organic material or an inorganic material, or a combination of an organic material and an inorganic material may be used. Layer A is preferably an adhesive layer containing an adhesive from the viewpoint of adhesion to metal.

In the present disclosure, the type of adhesive is not particularly limited, and a known adhesive can be used.

As said adhesive, a thermosetting resin is mentioned suitably.

Examples of the thermosetting resin include epoxy resins, phenol resins, unsaturated imide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, A dicyclopentadiene resin, a silicone resin, a triazine resin, and a melamine resin etc. are mentioned. In addition, the thermosetting resin is not particularly limited to these, and a known thermosetting resin can be used. These thermosetting resins can be used individually or in combination of multiple types.

In addition, as the adhesive, a commercially available adhesive containing a thermosetting resin can also be used.

It is preferable that an adhesive agent contains the compound which has a functional group from an adhesive viewpoint with a metal. Further, the functional group is preferably at least one group selected from the group consisting of a group capable of covalent bonding, a group capable of ionic bonding, a group capable of hydrogen bonding, and a group capable of dipole interaction.

The number of functional groups in the compound having a functional group may be one or more, and may be two or more.

Moreover, the compound which has a functional group may have only 1 type of functional groups, and may have 2 or more types.

The compound having a functional group may be a low molecular compound or a high molecular compound. It is preferable that the compound which has a functional group is a high molecular compound from an adhesive viewpoint with a metal.

The compound having a functional group is preferably a polymer having a weight average molecular weight of 1,000 or more, more preferably a polymer having a weight average molecular weight of 2,000 or more, and still more preferably a polymer having a weight average molecular weight of 3,000 or more, from the viewpoint of adhesion to metal. and a polymer having a weight average molecular weight of 5,000 or more and 200,000 or less is particularly preferred.

<<functional group>>

The functional group in the compound having a functional group is preferably at least one group selected from the group consisting of a group capable of covalent bonding, a group capable of ionic bonding, a group capable of hydrogen bonding, and a group capable of dipole interaction.

From the viewpoint of adhesion to metal, the functional group is preferably a group capable of covalent bonding.

Moreover, from the viewpoint of storage stability and handling, the functional group is preferably a group capable of ionic bonding, a group capable of hydrogen bonding, or a group capable of dipole interaction.

-Group capable of covalent bonding-

The group capable of covalent bonding is not particularly limited as long as it is a group capable of forming a covalent bond, and examples thereof include an epoxy group, an oxetanyl group, an isocyanate group, an acid anhydride group, a carbodiimide group, an N-hydroxyester group, An imide ester group, a halogenated alkyl group, a thiol group, a hydroxyl group, a carboxy group, an amino group, an amide group, an isocyanate group, an aldehyde group, a sulfonic acid group, and the like. Among them, from the viewpoint of adhesion to metal, the group capable of covalent bonding is an epoxy group, an oxetanyl group, an isocyanate group, an acid anhydride group, a carbodiimide group, an N-hydroxyester group, a glyoxal group, and an imide ester. It is preferably at least one group selected from the group consisting of groups, halogenated alkyl groups, and thiol groups.

Moreover, as described later, it is preferable to have a group forming a pair with a functional group of a compound having a functional group on the surface of a metal to be bonded.

As a combination of groups capable of covalent bonding (a combination of a functional group of a compound having a functional group and a group having on the surface of a metal), specifically, when one is an epoxy group, the other is a hydroxyl group, an amino group, etc. can be heard

Moreover, when one is an N-hydroxyester group or an imide ester group, for example, an amino group etc. are mentioned for the other.

-Group capable of ionic bonding-

Examples of groups capable of ionic bonding include cationic groups and anionic groups.

As said cationic group, it is preferable that it is an onium group. An ammonium group, a pyridinium group, a phosphonium group, an oxonium group, a sulfonium group, a selenium group, an iodonium group etc. are mentioned as an example of an onium group. Among them, from the viewpoint of adhesion to metal, an ammonium group, a pyridinium group, a phosphonium group, or a sulfonium group is preferable, an ammonium group or a phosphonium group is more preferable, and an ammonium group is particularly preferable.

The anionic group is not particularly limited, and examples thereof include a phenolic hydroxyl group, a carboxy group, -SO ₃ H, -OSO ₃ H, -PO ₃ H, -OPO ₃ H ₂ , -CONHSO ₂ -, -SO ₂ NHSO ₂ - etc. Among these, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, a sulfuric acid group, a sulfonic acid group, a sulfinic acid group or a carboxy group is preferable, a phosphoric acid group or a carboxy group is more preferable, and a carboxy group is still more preferable.

As a combination of groups capable of ionic bonding (combination of a functional group of a compound having a functional group and a group having on the surface of a metal), specifically, for example, when one has an acidic group, the other is a basic group. .

As said acidic group, a carboxy group, a sulfo group, a phosphoric acid group etc. are mentioned, for example, It is preferable that it is a carboxy group.

Moreover, when one is a carboxy group, for example, a tertiary amino group, a pyridyl group, and a piperidyl group are mentioned as a group capable of ionic bonding with a carboxy group.

-group capable of hydrogen bonding-

Examples of the group capable of hydrogen bonding include a group having a hydrogen bond-donating site and a group having a hydrogen-bonding accepting site.

The hydrogen bond-donating site may have a structure having an active hydrogen atom capable of hydrogen bonding, but is preferably a structure represented by X-H.

X represents a hetero atom, and is preferably a nitrogen atom or an oxygen atom.

The hydrogen bond-donating site, from the viewpoint of adhesion to the metal, is a hydroxy group, a carboxy group, a primary amide group, a secondary amide group, a primary amino group, a secondary amino group, or a primary sulfonamide. It is preferably at least one structure selected from the group consisting of a group, a secondary sulfonamide group, an imide group, a urea bond, and a urethane bond, and a hydroxyl group, a carboxy group, a primary amide group, It is more preferably at least one structure selected from the group consisting of a secondary amide group, a primary sulfonamide group, a secondary sulfonamide group, a maleimide group, a urea bond, and a urethane bond, At least one structure selected from the group consisting of a hydroxyl group, a carboxy group, a primary amide group, a secondary amide group, a primary sulfonamide group, a secondary sulfonamide group, and a maleimide group It is more preferable, and it is especially preferable that it is at least 1 sort(s) of structure selected from the group which consists of a hydroxyl group and a secondary amide group.

The hydrogen bond-accepting site is preferably a structure containing an atom having an unshared electron pair, more preferably a structure containing an oxygen atom having an unshared electron pair, and a carbonyl group (carboxy group, amide group, imide group, urea group). It is more preferably at least one structure selected from the group consisting of a carbonyl structure such as a bond or a urethane bond), and a sulfonyl group (including a sulfonyl structure such as a sulfonamide group). and a carbonyl group (including a carbonyl structure such as a carboxy group, an amide group, an imide group, a urea bond, or a urethane bond) is particularly preferred.

The group capable of hydrogen bonding is preferably a group having both the aforementioned hydrogen bond donating site and hydrogen bond accepting site, and having a carboxy group, amide group, imide group, urea bond, urethane bond, or sulfonamide group It is preferable, and what has a carboxy group, amide group, imide group, or sulfonamide group is more preferable.

As a combination of groups capable of hydrogen bonding (a combination of a functional group of a compound having a functional group and a group having a group on the surface of a metal), specifically, when one has a group having a hydrogen bond donating site, the other is hydrogen bond soluble Groups having sites are exemplified.

For example, when one is a carboxy group, an amide group, a carboxy group, etc. are mentioned.

Moreover, when one is a phenolic hydroxyl group, for example, phenolic hydroxyl etc. are mentioned for the other.

-group capable of dipole interaction-

As the group capable of dipole interaction, any group having a polarized structure other than the structure represented by X-H (X represents a hetero atom and a nitrogen atom or an oxygen atom) in the group capable of hydrogen bonding is sufficient. Groups in which atoms having different negative degrees are bonded are preferably exemplified.

As a combination of atoms having different electronegativity, a combination of at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom and a carbon atom is preferable, and an oxygen atom, a nitrogen atom, and A combination of at least one atom selected from the group consisting of sulfur atoms and a carbon atom is more preferred.

Among them, from the viewpoint of adhesion to metal, a combination of a nitrogen atom and a carbon atom, a combination of a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom are preferable, and specifically, a cyano group, a cyano group, a sulfonic acid An amide group is more preferable.

As the combination of groups capable of dipole interaction (combination of a functional group of a compound having a functional group and a group having on the surface of a metal), a combination of groups capable of the same dipole interaction is preferably mentioned.

When one is, for example, a cyano group, the other is a cyano group.

Moreover, when one is a sulfonic acid amide group, for example, the other is a sulfonic acid amide group.

Specific examples of the binding or interaction of the two functional groups are shown below, but the binding or interaction in the present disclosure is not limited thereto.

[Formula 1]

The compound having a functional group is preferably a polyfunctional epoxy compound or a polymer of a multifunctional epoxy compound, more preferably a bifunctional epoxy compound or a polymer of a bifunctional epoxy compound, from the viewpoint of adhesion to metal. , a polymer of a bifunctional epoxy compound is particularly preferred.

The adhesive layer may contain only one kind of adhesive, or may contain two or more kinds.

The content of the adhesive in the adhesive layer is preferably 50% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more with respect to the total mass of the liquid crystal polymer film, from the viewpoint of adhesion to metal. do. The upper limit of the content of the adhesive is not particularly limited, and may be 100% by mass. That is, the adhesive layer may be a layer made of an adhesive.

The adhesive layer may contain other additives other than the adhesive.

As other additives, known additives can be used. Specifically, a leveling agent, an antifoaming agent, an antioxidant, a ultraviolet absorber, a flame retardant, a coloring agent, a filler, etc. are mentioned, for example.

The average thickness of layer A is not particularly limited, but from the viewpoint of adhesion to metal, it is preferably 5 μm to 90 μm, more preferably 10 μm to 70 μm, and particularly preferably 15 μm to 30 μm.

<Mixed Area>

In the liquid crystal polymer film according to the present disclosure, a mixed region containing the liquid crystal polymer and the material constituting the layer A is formed between the liquid crystal polymer layer and the layer A.

Details of the liquid crystal polymer included in the mixed region and the material constituting the layer A are as described in the column of the liquid crystal polymer layer and layer A above.

Since the mixed region is formed, the liquid crystal polymer film according to the present disclosure has excellent adhesion to a layer formed on the liquid crystal polymer film.

Whether or not a mixed region is formed in the liquid crystal polymer film can be confirmed by the following method. The liquid crystal polymer film was cut obliquely, and the resulting cross-sectional sample was evaluated using TOF-SIMS (time-of-flight secondary ion mass spectrometry), and fragments derived from the liquid crystal polymer layer and fragments derived from layer A were simultaneously observed. This part is judged to be a mixed region. In addition, the presence of a fragment is judged to be above the detection limit.

The average thickness of the mixed region is preferably 1 nm to 10 μm, more preferably 100 nm to 5 μm, and still more preferably 300 nm to 2 μm, from the viewpoint of adhesion to metal.

The average thickness of the liquid crystal polymer film according to the present disclosure is preferably 6 μm to 200 μm, more preferably 12 μm to 100 μm, and 20 μm to 60 μm from the viewpoints of strength, dielectric tangent of the polymer film, and adhesion to metal. is particularly preferred.

The average thickness of the liquid crystal polymer film is measured at five arbitrary locations using an adhesive film thickness gauge, for example, an electronic micrometer (product name "KG3001A", manufactured by Anritsu Corporation), and taken as the average value thereof.

The dielectric tangent of the liquid crystal polymer film according to the present disclosure is preferably 0.005 or less, and more preferably greater than 0 and 0.003 or less, from the viewpoint of dielectric constant.

<Method for producing liquid crystal polymer film>

The method for producing the liquid crystal polymer film according to the present disclosure is not particularly limited, and known methods can be referred to.

The method for producing a liquid crystal polymer film according to the present disclosure includes, for example, a step of forming a film containing a liquid crystal polymer (hereinafter also referred to as a film forming step), and a material constituting layer A on the formed film. A step of applying a liquid (for example, an adhesive composition) to be applied (hereinafter also referred to as an application step), and a step of extending a film coated with a liquid containing the material constituting the layer A (hereinafter also referred to as an extending step) and a step of annealing the stretched film (hereinafter also referred to as an annealing step).

By providing the application step after the film forming step and before the stretching treatment, a liquid crystal polymer film in which a mixed region containing the liquid crystal polymer and the material constituting the layer A is formed between the liquid crystal polymer layer and the layer A is obtained. can

As a film forming method in the film forming step, for example, a casting method, a coating method, an extrusion method, etc. are preferably used. Among them, the film forming method is preferably a casting method.

As the solvent, for example, dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, 1-chlorobutane, chloro halogenated hydrocarbons such as benzene and o-dichlorobenzene; halogenated phenols such as p-chlorophenol, pentachlorophenol, and pentafluorophenol; ethers such as diethyl ether, tetrahydrofuran, and 1,4-dioxane; ketones such as acetone and cyclohexanone; esters such as ethyl acetate and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; amines such as triethylamine; nitrogen-containing heterocyclic aromatic compounds such as pyridine; nitriles such as acetonitrile and succinonitrile; amides such as N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, and urea compounds such as tetramethyl urea; nitro compounds such as nitromethane and nitrobenzene; sulfur compounds such as dimethyl sulfoxide and sulfolane; Phosphorus compounds, such as hexamethyl phosphate amide and tri-n-butyl phosphoric acid, etc. are mentioned, You may use 2 or more types of them.

As the solvent, from the viewpoint of low corrosiveness and ease of handling, an aprotic compound, particularly a solvent containing an aprotic compound having no halogen atom as a main component is preferable, and the ratio of the aprotic compound to the total solvent is It is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass. Further, as the aprotic compound, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, tetramethylurea, N-methylpyrrolidone, etc., from the viewpoint of dissolving the liquid crystal polymer easily; It is preferable to use esters such as γ-butyrolactone, and N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone are more preferable.

Further, as the solvent, a solvent containing a compound having a dipole moment of 3 to 5 as a main component is preferable from the viewpoint of easily dissolving the liquid crystal polymer, and the ratio of the compound having a dipole moment of 3 to 5 to the entire solvent is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass.

As the aprotic compound, it is preferable to use a compound having a dipole moment of 3 to 5.

In addition, as the solvent, from the viewpoint of easy removal, a solvent containing a compound having a boiling point of 220 ° C. or less at 1 atm as a main component is preferable, and the proportion of the compound with a boiling point of 220 ° C. or less at 1 atm occupied in the entire solvent is, It is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass.

As the aprotic compound, it is preferable to use a compound having a boiling point of 220°C or lower at 1 atmospheric pressure.

In the case of forming a film by the casting method, coating method, extrusion method or the like, a support may be used. Moreover, when using as a support body the metal layer (metal foil) etc. used for the laminated body mentioned later, you may use it as it is, without peeling.

As a support body, a glass plate, a resin film, or metal foil is mentioned, for example. Among them, a resin film is preferable, and in particular, a polyimide (PI) film is preferable because of its excellent heat resistance, easy application of the composition, and easy separation from the liquid crystal polymer.

Examples of commercially available polyimide (PI) films include Ube Industries Co., Ltd. U-Pilex S and U-Pilex R, Toray DuPont Co., Ltd. Kapton, and SKC Kolon PI Co., Ltd. IF30, IF70 and LV300. can be heard

Moreover, it is preferable that the surface treatment layer is formed on the surface of a support body so that it may peel easily. The surface treatment layer preferably contains a fluororesin.

The average thickness of the support is not particularly limited, but is preferably 25 μm or more and 75 μm or less, more preferably 50 μm or more and 75 μm.

In addition, as a method for removing at least a part of the solvent from the casted or coated film composition (casting film or coating film), there is no particular limitation, and a known drying method can be used.

The application step, the stretching step, and the annealing step are not particularly limited, and a commonly known method can be used.

-Usage-

The liquid crystal polymer film according to the present disclosure can be used for various purposes. Especially, it can use suitably for films for electronic parts, such as a printed wiring board, and can use suitably with a flexible printed circuit board.

In addition, the liquid crystal polymer film according to the present disclosure can be suitably used as a liquid crystal polymer film for metal bonding.

[Laminate]

The laminate according to the present disclosure may be any laminate comprising the liquid crystal polymer film according to the present disclosure. The liquid crystal polymer film according to the present disclosure has excellent adhesion to a layer formed on the liquid crystal polymer film. Therefore, the laminate according to the present disclosure preferably has the liquid crystal polymer film according to the present disclosure and a layer disposed on at least one surface of the liquid crystal polymer film. The layer disposed on at least one surface of the liquid crystal polymer film is not particularly limited, and examples thereof include a polymer layer and a metal layer. The layer disposed on at least one surface of the liquid crystal polymer film may be a coating layer.

Further, the layer disposed on at least one surface of the liquid crystal polymer film may be disposed on the entire surface of the liquid crystal polymer film or may be disposed on only a part of the liquid crystal polymer film.

Among them, the laminate according to the present disclosure preferably includes the liquid crystal polymer film according to the present disclosure and a metal layer or metal wiring disposed on at least one surface of the liquid crystal polymer film. In particular, it is preferable that the metal layer or metal wiring be disposed on the layer A (eg, adhesive layer) side of the liquid crystal polymer film.

Moreover, although the said metal layer or metal wiring should just be a well-known metal layer or metal wiring, it is preferable that it is a copper layer or copper wiring, for example.

The method for attaching the liquid crystal polymer film according to the present disclosure and the metal layer is not particularly limited, and a known laminating method can be used.

The peel strength between the liquid crystal polymer film and the metal layer is preferably 0.5 kN/m or more, more preferably 0.7 kN/m or more, still more preferably 0.7 kN/m to 2.0 kN/m, and 0.9 kN/m It is especially preferable that it is m - 1.5 kN/m.

In the present disclosure, the peel strength between the liquid crystal polymer film and the metal layer (eg, copper layer) is measured by the following method.

A test piece for peeling with a width of 1.0 cm is prepared from a laminate of a liquid crystal polymer film and a metal layer, the polymer film is fixed to a flat plate with double-sided adhesive tape, and according to JIS C 5016 (1994), by the 180 ° method, 50 mm / min. The strength (kN/m) when the polymer film is peeled off from the metal layer at a rate is measured.

It is preferable that a metal layer is a copper layer. As the copper layer, a rolled copper foil formed by a rolling method or an electrolytic copper foil formed by an electrolytic method is preferable, and a rolled copper foil is more preferable from the viewpoint of bending resistance.

The average thickness of the metal layer, preferably the copper layer, is not particularly limited, but is preferably 3 µm to 30 µm, and more preferably 5 µm to 20 µm. Copper foil with a carrier formed on the support body (carrier) so that exfoliation is possible may be sufficient as the copper foil. As the carrier, a known carrier can be used. The average thickness of the carrier is not particularly limited, but is preferably 10 µm to 100 µm, and more preferably 18 µm to 50 µm.

Further, the metal layer or the metal wiring preferably has a group capable of interacting with the liquid crystal polymer film on a surface in contact with the liquid crystal polymer film from the viewpoint of adhesion to the liquid crystal polymer film. In addition, when the adhesive contains a compound having a functional group, the group capable of interacting is preferably a group corresponding to a functional group of the compound having the functional group, such as, for example, an amino group and an epoxy group, a hydroxyl group and an epoxy group. do.

As a group which can interact, the group mentioned as a functional group in the compound which has the said functional group is mentioned.

Among them, from the viewpoint of adhesion and ease of treatment, the group capable of interaction is preferably a group capable of covalent bonding, more preferably an amino group or a hydroxyl group, and particularly preferably an amino group.

It is also preferable to process the metal layer in the laminate according to the present disclosure into a desired circuit pattern by, for example, etching to obtain a flexible printed circuit board. The etching method is not particularly limited, and a known etching method can be used.

[Polymer film]

The polymer film according to the present disclosure is a group consisting of a fluorine-based polymer, a polymer containing structural units derived from a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond, polyphenylene ether, and aromatic polyether ketone. A polymer layer containing at least one type of polymer selected from; and a layer A disposed on at least one surface of the polymer layer, between the polymer layer and the layer A, the polymer and the material constituting the layer A. A mixed region including is formed.

<Polymer layer>

In the polymer film according to the present disclosure, the polymer layer is a fluorine-based polymer, a polymer containing structural units derived from a compound having a group having a cyclic aliphatic hydrocarbon group and an ethylenically unsaturated bond, polyphenylene ether, and aromatic polyether. At least one polymer selected from the group consisting of ketones is included.

-Fluorine-based polymer-

As the fluorine-based polymer, for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, perfluoroalkoxy fluororesin, tetrafluoroethylene/hexafluoropropylene copolymer, ethylene/ Tetrafluorinated ethylene copolymer, ethylene/chlorotrifluoroethylene copolymer, etc. are mentioned.

Among them, polytetrafluoroethylene is preferred.

Further, the fluorine-based polymer is derived from a fluorinated α-olefin monomer, that is, an α-olefin monomer containing at least one fluorine atom, and, if necessary, a non-fluorinated ethylenically unsaturated monomer reactive with respect to the fluorinated α-olefin monomer. and homopolymers and copolymers containing structural units that are

As the fluorinated α-olefin monomer, CF ₂ =CF ₂ , CHF=CF ₂ , CH ₂ =CF ₂ , CHCl=CHF, CClF=CF ₂ , CCl ₂ =CF ₂ , CClF=CClF, CHF=CCl ₂ , CH ₂ =CClF, CCl ₂ =CClF, CF ₃ CF=CF ₂ , CF ₃ CF=CHF, CF ₃ CH=CF ₂ , CF ₃ CH=CH ₂ , CHF ₂ CH=CHF, CF ₃ CF=CF ₂ , perfluoro Rho(C2-C8 alkyl) vinyl ether (for example, perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, perfluorooctyl vinyl ether), etc. are mentioned. Among them, tetrafluoroethylene (CF ₂ =CF ₂ ), chlorotrifluoroethylene (CClF=CF ₂ ), (perfluorobutyl)ethylene, vinylidene fluoride (CH ₂ =CF ₂ ), and hexafluoro At least one monomer selected from the group consisting of lopropylene (CF ₂ =CFCF ₃ ) is preferred.

Examples of the non-fluorinated monoethylenically unsaturated monomer include ethylene, propylene, butene, ethylenically unsaturated aromatic monomers (for example, styrene and α-methylstyrene), and the like.

Fluorinated α-olefin monomers may be used individually by 1 type, or may use 2 or more types together.

Moreover, a non-fluorinated ethylenically unsaturated monomer may be used individually by 1 type, and may use 2 or more types together.

As the fluorine-based polymer, polychlorotrifluoroethylene (PCTFE), poly(chlorotrifluoroethylene-propylene), poly(ethylene-tetrafluoroethylene) (ETFE), poly(ethylene-chlorotrifluoroethylene) (ECTFE) ), poly(hexafluoropropylene), poly(tetrafluoroethylene) (PTFE), poly(tetrafluoroethylene-ethylene-propylene), poly(tetrafluoroethylene-hexafluoropropylene) (FEP), poly (tetrafluoroethylene-propylene) (FEPM), poly(tetrafluoroethylene-perfluoropropylene vinyl ether), poly(tetrafluoroethylene-perfluoroalkyl vinyl ether) (PFA) (e.g. , poly(tetrafluoroethylene-perfluoropropylvinylether)), polyvinylfluoride (PVF), polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-chlorotrifluoroethylene), purple Fluoropolyether, perfluorosulfonic acid, perfluoropolyoxetane, etc. are mentioned.

A fluorine-type polymer may be used individually by 1 type, and may use 2 or more types together.

The fluorine-based polymer is preferably at least one of FEP, PFA, ETFE, or PTFE. FEP is available from DuPont under the trade name of TEFLON (registered trademark) FEP, or from Daikin Kogyo Co., Ltd. under the trade name of NEOFLON FEP; PFA is a trade name of NEOFLON PFA from Daikin Kogyo Co., Ltd., a trade name of TEFLON (registered trademark) PFA from DuPont, or Solvay Solesis ( It is available under the trade name of HYFLON PFA from Solvay Solexis.

The fluorine-based polymer preferably contains PTFE. PTFE may include a PTFE homopolymer, a partially modified PTFE homopolymer, or a combination containing one or both of these. The partially modified PTFE homopolymer preferably contains less than 1% by mass of constituent units derived from a comonomer other than tetrafluoroethylene based on the total mass of the polymer.

The fluorine-based polymer may be a crosslinkable fluoropolymer having a crosslinkable group. A crosslinkable fluoropolymer can be crosslinked by a conventionally known crosslinking method. One of the representative crosslinkable fluoropolymers is a fluoropolymer having a (meth)acryloxy group. For example, a crosslinkable fluoropolymer has the formula:

H ₂ C=CR'COO-(CH ₂ ) _n -R-(CH ₂ ) _n -OOCR'=CH ₂

In the formula, R is a fluorine-based oligomer chain having two or more structural units derived from a fluorinated α-olefin monomer or a non-fluorinated monoethylenically unsaturated monomer, R' is H or -CH ₃ , and n is 1 to 4. R may be a fluorine-based oligomer chain containing a structural unit derived from tetrafluoroethylene.

In order to initiate a radical crosslinking reaction via a (meth)acryloxy group on a fluorine-based polymer, a crosslinked fluoropolymer network structure can be formed by exposing the fluoropolymer having a (meth)acryloxy group to a free radical source. The free radical source is not particularly limited, but a radical photopolymerization initiator or an organic peroxide is preferably used. Suitable photoradical polymerization initiators and organic peroxides are well known in the art. Crosslinkable fluoropolymers are commercially available, and examples thereof include Viton B manufactured by DuPont.

-Polymers Containing Constituent Units Derived from Compounds Having a Group Having a Cycloaliphatic Hydrocarbon Group and an Ethylenically Unsaturated Bond-

Examples of the polymer containing a structural unit derived from a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond include, for example, structural units formed from monomers composed of cyclic olefins such as norbornene or polycyclic norbornene-based monomers. The thermoplastic resin which has is mentioned, It is also called a thermoplastic cyclic olefin resin.

The polymer containing a structural unit derived from a compound having a cycloaliphatic hydrocarbon group and a group having an ethylenically unsaturated bond may be a hydrogenated product of a ring-opened polymer of the above cyclic olefin or a ring-opened copolymer using two or more cyclic olefins, or may be a cyclic olefin and an aromatic compound having an ethylenically unsaturated bond such as a chain olefin or a vinyl group. Moreover, a polar group may be introduced into the polymer containing a structural unit derived from a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond.

A polymer containing a structural unit derived from a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond may be used alone or in combination of two or more.

The ring structure of the cyclic aliphatic hydrocarbon group may be a monocyclic ring, a condensed ring in which two or more rings are condensed, or a bridged exchange.

As a ring structure of a cyclic aliphatic hydrocarbon group, a cyclopentane ring, a cyclohexane ring, a cyclooctane ring, an isophorone ring, a norbornane ring, a dicyclopentane ring, etc. are mentioned.

The compound having a group having an ethylenically unsaturated bond with a cyclic aliphatic hydrocarbon group may be a monofunctional ethylenically unsaturated compound or a polyfunctional ethylenically unsaturated compound.

The number of cycloaliphatic hydrocarbon groups in the compound having a cycloaliphatic hydrocarbon group and a group having an ethylenically unsaturated bond may be 1 or more, and may have 2 or more.

The polymer containing a structural unit derived from a compound having a group having a cycloaliphatic hydrocarbon group and an ethylenically unsaturated bond may be a polymer obtained by polymerizing a compound having at least one cycloaliphatic hydrocarbon group and a group having an ethylenically unsaturated bond. , It may be a polymer obtained by polymerizing a compound having a group having two or more types of cyclic aliphatic hydrocarbon groups and an ethylenically unsaturated bond, or a copolymer of another ethylenically unsaturated compound having no cyclic aliphatic hydrocarbon group.

Moreover, it is preferable that the polymer containing the structural unit derived from the compound which has a group which has a cycloaliphatic hydrocarbon group and an ethylenically unsaturated bond is a cycloolefin polymer.

-Polyphenylene ether-

The weight average molecular weight (Mw) of polyphenylene ether is preferably 500 to 5,000, and preferably 500 to 3,000, from the viewpoint of heat resistance and film formation, when thermally cured after film formation. Moreover, when it is not thermosetted, although it does not specifically limit, it is preferable that it is 3,000-100,000, and it is preferable that it is 5,000-50,000.

As polyphenylene ether, the average number of phenolic hydroxyl groups at the molecular terminals per molecule (number of terminal hydroxyl groups) is preferably 1 to 5, and preferably 1.5 to 3, from the viewpoint of dielectric tangent and heat resistance. it is more preferable

The number of hydroxyl groups or phenolic hydroxyl groups of polyphenylene ether can be known from, for example, standard values of polyphenylene ether products. The number of terminal hydroxyl groups or the number of terminal phenolic hydroxyl groups is, for example, a numerical value showing the average value of hydroxyl groups or phenolic hydroxyl groups per molecule of all polyphenylene ethers present in 1 mole of polyphenylene ether. can

Polyphenylene ether may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyphenylene ether include polyphenylene ether composed of 2,6-dimethylphenol, at least one of bifunctional phenol and trifunctional phenol, or poly(2,6-dimethyl-1). , 4-phenylene oxide), etc. which have polyphenylene ether, such as as a main component, are mentioned. More specifically, it is preferable that it is a compound which has a structure represented by Formula (PPE), for example.

[Formula 2]

In the formula (PPE), X represents an alkylene group having 1 to 3 carbon atoms or a single bond, m represents an integer of 0 to 20, n represents an integer of 0 to 20, and the sum of m and n is , represents an integer from 1 to 30.

As said alkylene group in said X, a dimethylmethylene group etc. are mentioned, for example.

-Aromatic polyether ketone-

It does not specifically limit as aromatic polyether ketone, A well-known aromatic polyether ketone can be used.

The aromatic polyether ketone is preferably a polyether ether ketone.

Polyether ether ketone is a type of aromatic polyether ketone, and is a polymer in which bonds are arranged in the order of an ether bond, an ether bond, and a carbonyl bond (ketone). It is preferable that each bond is connected by a divalent aromatic group.

Aromatic polyether ketone may be used individually by 1 type, and may use 2 or more types together.

Examples of the aromatic polyether ketone include polyether ketone (PEEK) having a chemical structure represented by the following formula (P1) and polyether ketone (PEK) having a chemical structure represented by the following formula (P2). , polyether ether ketone ketone (PEKK) having a chemical structure represented by the following formula (P3), polyether ether ketone ketone (PEEKK) having a chemical structure represented by the following formula (P4), represented by the following formula (P5) polyether ketone ether ketone ketone (PEKEKK) having a chemical structure.

[Formula 3]

From the viewpoint of mechanical properties, each n of the formulas (P1) to (P5) is preferably 10 or more, and more preferably 20 or more. On the other hand, from the viewpoint of easily producing aromatic polyether ketone, n is preferably 5,000 or less, and more preferably 1,000 or less. That is, 10-5,000 are preferable and, as for n, 20-1,000 are more preferable.

<Layer A>

A polymer film according to the present disclosure includes a layer A disposed on at least one surface of a polymer layer. Layer A may be disposed on only one surface of the polymer layer, or may be disposed on both surfaces of the liquid crystal polymer layer. A preferable aspect of the layer A is the same as that of the layer A in the above liquid crystal polymer film.

<Mixed Area>

In the polymer film according to the present disclosure, a mixed region containing the polymer and the material constituting the layer A is formed between the polymer layer and the layer A.

Details of the polymer included in the mixed region and the material constituting the layer A are as described in the column of the polymer layer and layer A above.

Since the mixed region is formed, the polymer film according to the present disclosure has excellent adhesion to a layer formed on the polymer film.

Whether or not the mixed region is formed in the polymer film can be confirmed by the same method as the mixed region in the liquid crystal polymer film.

The average thickness of the mixed region is preferably 1 nm to 10 μm, more preferably 100 nm to 5 μm, and still more preferably 300 nm to 2 μm, from the viewpoint of adhesion to metal.

The average thickness of the polymer film according to the present disclosure is preferably 6 μm to 200 μm, more preferably 12 μm to 100 μm, and 20 μm to 60 μm, from the viewpoints of strength, dielectric tangent of the polymer film, and adhesion to metal. is particularly preferred.

From the viewpoint of dielectric constant, the dielectric tangent of the polymer film according to the present disclosure is preferably 0.005 or less, and more preferably greater than 0 and 0.003 or less.

The polymer film according to the present disclosure can be made into a laminate in the same way as the above liquid crystal polymer film.

Example

Hereinafter, the present disclosure will be described in more detail by way of examples. Materials, amount of use, ratio, processing content, processing procedure, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present disclosure. Therefore, the scope of the present disclosure is not limited to the specific examples shown below.

<<measurement method>>

[genetic tangent]

The dielectric tangent was measured by the resonance perturbation method at a frequency of 10 GHz. A 10 GHz cavity resonator (Kanto Denshi Oyo Kaihatsu CP531) was connected to a network analyzer (“E8363B” manufactured by Agilent Technology), a film sample (width: 2.0 mm × length: 80 mm) was inserted into the cavity resonator, and , The dielectric tangent of the film was measured from the change in resonance frequency before and after insertion for 96 hours under a temperature of 25°C and a humidity of 60%RH.

[Peel strength]

A test piece for peeling with a width of 1.0 cm was prepared from the laminate of the liquid crystal polymer film and the copper layer, the liquid crystal polymer film was fixed to a flat plate with a double-sided adhesive tape, and according to JIS C 5016 (1994), by the 180 ° method, 50 mm / The strength (kN/m) when the copper layer was peeled off from the liquid crystal polymer film at a rate of one minute was measured.

<<Production Example>>

<liquid crystal polymer>

LC-A: liquid crystal polymer prepared according to the following manufacturing method

LC-B: liquid crystal polymer prepared according to the following manufacturing method

-Preparation of LC-A-

To a reactor equipped with a stirrer, torque meter, nitrogen gas inlet pipe, thermometer and reflux condenser, 940.9 g (5.0 mol) of 6-hydroxy-2-naphthoic acid, 377.9 g (2.5 mol) of 4-hydroxyacetaminophen, After putting 415.3 g (2.5 mol) of isophthalic acid and 867.8 g (8.4 mol) of acetic anhydride, substituting the gas in the reactor with nitrogen gas, stirring under a nitrogen gas stream, from room temperature (23 ° C.) to 140 ° C. for 60 minutes The temperature was raised over and refluxed at 140 ° C. for 3 hours.

Next, while distilling off by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 150 ° C. to 300 ° C. over 5 hours, and after holding at 300 ° C. for 30 minutes, the contents were taken out of the reactor and then brought to room temperature. Cooled down. The obtained solid material was pulverized with a pulverizer to obtain a powdery liquid crystal polyester (B1). The flow initiation temperature of this liquid crystal polyester (B1) was 193.3°C.

The liquid crystal polyester (B1) obtained above was heated from room temperature to 160°C over 2 hours and 20 minutes under a nitrogen atmosphere, then heated from 160°C to 180°C over 3 hours and 20 minutes, and heated at 180°C for 5 hours. After carrying out solid state polymerization by holding|maintaining, it cooled and then grind|pulverized with a grinder, and powdery liquid crystal polyester (B2) was obtained. The flow initiation temperature of this liquid crystal polyester (B2) was 220°C.

The liquid crystal polyester (B2) obtained above was heated from room temperature (23° C.) to 180° C. over 1 hour and 25 minutes under a nitrogen atmosphere, and then from 180° C. to 255° C. over 6 hours 40 minutes. After carrying out solid phase polymerization by holding|maintaining at °C for 5 hours, it cooled and obtained powdery liquid crystal polyester (LC-A). The flow initiation temperature of the liquid crystal polyester (LC-A) was 302°C. Moreover, it was 311 degreeC as a result of measuring the melting|fusing point of this liquid crystal polyester (LC-A) using a differential scanning calorimetry apparatus.

-Preparation of LC-B-

1034.99 g (5.5 mol) of 2-hydroxy-6-naphthoic acid and 378.33 g (1.75 mol) of 2,6-naphthalenedicarboxylic acid were placed in a reactor equipped with a stirring device, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser. , 83.07 g (0.5 mol) of terephthalic acid, 272.52 g (2.475 mol) of hydroquinone, 0.225 mol excess relative to the total molar amount of 2,6-naphthalenedicarboxylic acid and terephthalic acid, 1226.87 g (12 mol) of acetic anhydride, and 1- 0.17 g of methylimidazole was added. After replacing the gas in the reactor with nitrogen gas, the temperature was raised from room temperature to 145°C over 15 minutes while stirring under a nitrogen gas stream, and refluxed at 145°C for 1 hour.

Then, while distilling off by-produced acetic acid and unreacted acetic anhydride, the temperature was raised from 145 ° C to 310 ° C over 3 hours and 30 minutes, maintained at 310 ° C for 3 hours, and solid liquid crystal polyester (LC-B ) was taken out, and the liquid crystal polyester (LC-B) was cooled to room temperature. The flow onset temperature of this polyester (LC-B) was 265°C.

<Polymer>

P-1:

An aqueous dispersion of commercially available polytetrafluoroethylene (PTFE) particles (Polyfreon PTFE D-711, average particle diameter 0.30 μm, solid content concentration 60%, manufactured by Daikin Kogyo Co., Ltd.) was prepared in the amount of solid content shown in Table 1. used as much as possible.

<Additives>

F-1: Commercially available low dielectric tangent filler with an average particle diameter of 600 nm (specially treated fused spherical silica, manufactured by Denka Co., Ltd.)

<Composition for adhesive layer>

M-1: Commercially available low dielectric adhesive (SLK (manufactured by Shin-Etsu Chemical Co., Ltd.) varnish mainly containing a polymer type curable compound

M-2: Commercially available low-dielectric adhesive (thermoplastic polyimide varnish PIAD 100H, manufactured by Arakawa Chemical Industry Co., Ltd.)

(Example 1 - Example 3, Example 5 - Example 8)

In Examples 1 to 3 and Examples 5 to 8, film formation was performed using a casting method (solution film forming method).

-Preparation of liquid crystal polymer solution-

In Examples 1 to 3 and Examples 6 to 8, the liquid crystal polymer was added to N-methylpyrrolidone and stirred at 140°C for 4 hours under a nitrogen atmosphere to obtain a liquid crystal polymer solution. Solid content concentration was 8 mass %.

In Example 5, the above liquid crystal polymer and the above additives were added to N-methylpyrrolidone and stirred at 140°C for 4 hours under a nitrogen atmosphere to obtain a liquid crystal polymer solution. The additive was added so that the content of the additive in the liquid crystal polymer layer was in the amount shown in Table 1. Solid content concentration was 11 mass %.

Next, the solution was passed through a sintered fiber metal filter having a nominal pore diameter of 10 μm and further passed through a sintered fiber filter having a nominal pore diameter of 10 μm to obtain a liquid crystal polymer solution.

-Film forming process-

The obtained liquid crystal polymer solution was fed to a casting die and casted on a stainless steel belt (support). When the amount of residual solvent reached 25% by mass, it was peeled from the support, conveyed while applying 10% draw to the web, and a film was obtained.

-Formation of adhesive layer 1-

The adhesive layer composition described in Table 1 was applied to the resulting film so that the thickness of the adhesive layer was 1/10 of the thickness described in Table 1, and dried to form adhesive layer 1.

-Stretching process, annealing process-

The film on which the adhesive layer 1 was formed was held by a tenter and stretched by 15% in the transverse direction. Thereafter, a heat treatment was performed in which the temperature was raised from room temperature to 270°C at 1°C/minute under a nitrogen atmosphere and maintained at that temperature for 2 hours.

-Formation of adhesive layer 2-

The composition for an adhesive layer described in Table 1 was further applied onto the adhesive layer 1 so that the thickness of the adhesive layer became the thickness described in Table 1, and dried to obtain a liquid crystal polymer film.

Next, a copper clad laminate was produced using the obtained liquid crystal polymer film. The manufacturing method is as follows.

-Copper Clad Laminate Precursor Process-

Copper foil (Fukuda Kinzoku Hakuhun Kogyo Co., Ltd., CF-T9DA-SV-18, thickness 18 μm, surface roughness Rz 0.85 μm of the sticking surface (treated surface)) is bonded to the surface on which the adhesive layer of the liquid crystal polymer film is formed and laminating for 1 minute using a laminator (“Vacuum Laminator V-130” manufactured by Nikko Materials) under conditions of 140° C. and a laminating pressure of 0.4 MPa, to obtain a copper-clad laminate precursor. got it

-This thermocompression bonding process-

A copper clad laminate was produced by thermally compressing the obtained copper clad laminated board precursor under conditions of 300°C and 4.5 MPa for 10 minutes using a thermocompression bonding machine ("MP-SNL" manufactured by Toyo Seiki Seisakusho Co., Ltd.).

(Example 4)

In Example 4, it formed into a film using the extrusion method (melt film forming method).

-Production of Resin Pellets-

After drying the liquid crystal polymer in a nitrogen flow atmosphere at 80°C, it was pelletized in a nitrogen atmosphere using a twin-screw extruder. The obtained pellets were used after drying with dry air at 80°C.

-Film forming process-

The obtained pellets were supplied into a cylinder from the same supply port of a twin screw extruder with a screw diameter of 50 mm, and kneaded by heating at 340°C to 350°C to obtain a kneaded product. Subsequently, the kneaded material was fed to a T die, the film-like kneaded material in a molten state was discharged, and pulled out with a chill roll while applying a draw of 10% to solidify to obtain a film.

-Formation of adhesive layer 1-

The adhesive layer composition M-1 was applied to the resulting film so that the thickness of the adhesive layer was 1/10 of the thickness shown in Table 1, and dried to form adhesive layer 1.

-Stretching process, annealing process-

The film on which the adhesive layer was formed was held by a tenter and stretched by 15% in the transverse direction. Thereafter, a heat treatment was performed in which the temperature was raised from room temperature to 270°C at 1°C/minute under a nitrogen atmosphere and maintained at that temperature for 2 hours.

-Formation of adhesive layer 2-

The composition for an adhesive layer described in Table 1 was further applied onto the adhesive layer 1 so that the thickness of the adhesive layer became the thickness described in Table 1, and dried to obtain a liquid crystal polymer film.

Using the obtained liquid crystal polymer film, a copper clad laminate was produced in the same manner as in Example 1.

(Example 9)

In Example 9, it formed into a film using the coating method.

-Film forming process-

The dispersion was applied onto the treated surface of copper foil (CF-T4X-SV-18 manufactured by Fukuda Kinzoku Hakuhun Kogyo Co., Ltd., thickness 18 μm) by reverse gravure method, dried at 120° C. for 10 minutes, and formed into a film. precursor was obtained.

-Formation of adhesive layer 1-

The adhesive layer composition described in Table 2 was applied to the obtained film precursor so that the thickness of the adhesive layer was 1/10 of the thickness described in Table 2, and dried to form adhesive layer 1.

-Annealing process-

The film precursor on which the adhesive layer 1 was formed was heated at 380°C for 5 minutes in a nitrogen atmosphere.

-Formation of adhesive layer 2-

On adhesive layer 1, the composition for adhesive layer described in Table 2 was further applied and dried so that the thickness of the adhesive layer became the thickness described in Table 2, and a laminate of copper foil/polymer film was obtained.

A copper clad laminate was produced in the same manner as in Example 1 using the obtained copper foil/polymer film laminate.

(Comparative Example 1)

In Comparative Example 1, after performing the film forming step, a stretching step and an annealing step were subsequently performed, and an adhesive layer was formed after the annealing step. Each process was carried out in the same manner as in Example 1 to obtain a liquid crystal polymer film. Using the obtained liquid crystal polymer film, a copper clad laminate was produced in the same manner as in Example 1.

(Comparative Example 2)

In Comparative Example 2, after performing the film forming step, a stretching step and an annealing step were subsequently performed, and an adhesive layer was formed after the annealing step. Each process was carried out in the same manner as in Example 4 to obtain a liquid crystal polymer film. Using the obtained liquid crystal polymer film, a copper clad laminate was produced in the same manner as in Example 1.

Table 1 shows the measurement results of the dielectric tangent of the liquid crystal polymer film and the peel strength of the copper-clad laminate. In Table 1, regarding the liquid crystal polymer film, the type and thickness of the liquid crystal polymer, the type, formation timing and thickness of the adhesive layer, and the film forming method are described. The formation timing of the adhesive layer was described as "A" when the formation of the adhesive layer was performed immediately after the film forming step and "B" when performed immediately after the annealing step. Further, in Examples 1 to 8, since it was confirmed that a mixed region containing the liquid crystal polymer and an adhesive was formed in the liquid crystal polymer film, the thickness of the mixed region was described. In Example 9, since it was confirmed that a mixed region containing a polymer and an adhesive was formed in the polymer film, the thickness of the mixed region was described.

In addition, in the liquid crystal polymer film and the liquid crystal polymer film, as to whether or not a mixed region is formed, the liquid crystal polymer film is cut in an oblique direction, and the cross-sectional sample obtained is subjected to TOF-SIMS (time-of-flight secondary ion mass spectrometry). It was evaluated using a liquid crystal polymer layer, and a portion where fragments derived from the liquid crystal polymer layer and fragments derived from the layer A were observed at the same time was judged to be a mixed region.

[Table 1]

[Table 2]

As shown in Table 1, in Examples 1 to 8, a liquid crystal polymer layer containing a liquid crystal polymer and a layer A disposed on at least one surface of the liquid crystal polymer layer are included, and the liquid crystal polymer layer and the layer A are included. Since a mixed region containing the liquid crystal polymer and the material constituting the layer A was formed in between, it was found that the adhesion between the liquid crystal polymer film and the metal was excellent.

As shown in Table 2, in Example 9, a polymer layer containing a polymer and a layer A disposed on at least one surface of the polymer layer are included, and between the polymer layer and the layer A, a liquid crystal polymer, and Since the mixed region containing the material constituting the layer A was formed, it was found that the adhesion between the polymer film and the metal was excellent.

On the other hand, in Comparative Example 1 and Comparative Example 2, it was found that the mixed region containing the liquid crystal polymer and the material constituting the layer A was not formed, and the adhesion between the liquid crystal polymer film and the metal was poor.

In addition, as for the indication of Japanese Patent Application No. 2021-024494 for which it applied on February 18, 2021, the whole is used in this specification by reference. In addition, all documents, patent applications, and technical standards described in this specification are incorporated by reference in this specification to the same extent as when each document, patent application, and technical standard is specifically and individually recorded. is used by

Claims (17)

A liquid crystal polymer layer comprising a liquid crystal polymer;
A layer A disposed on at least one side of the liquid crystal polymer layer,
The liquid crystal polymer film, wherein a mixed region containing the liquid crystal polymer and a material constituting the layer A is formed between the liquid crystal polymer layer and the layer A. The method of claim 1,
The average thickness of the mixed region is 1 nm to 10 μm, a liquid crystal polymer film. According to claim 1 or claim 2,
A liquid crystal polymer film having a dielectric tangent of 0.005 or less. The method according to any one of claims 1 to 3,
The layer A is an adhesive layer containing an adhesive, a liquid crystal polymer film. The method of claim 4,
The adhesive includes a compound having a functional group,
The functional group is at least one group selected from the group consisting of a group capable of covalent bonding, a group capable of ionic bonding, a group capable of hydrogen bonding, and a group capable of dipole interaction, liquid crystal polymer film. The method of claim 5,
The functional group is a group capable of covalent bonding, a liquid crystal polymer film. The method of claim 6,
The covalently bondable group is an epoxy group, an oxetanyl group, an isocyanate group, an acid anhydride group, a carbodiimide group, an N-hydroxyester group, a glyoxal group, an imide ester group, a halogenated alkyl group, and, A liquid crystal polymer film comprising at least one group selected from the group consisting of thiol groups. The method of claim 5,
The functional group is a group capable of ionic bonding, a group capable of hydrogen bonding, or a group capable of dipole interaction, a liquid crystal polymer film. The method according to any one of claims 1 to 8,
The liquid crystal polymer film having a melting point of 280 ° C. or higher. The method according to any one of claims 1 to 9,
The liquid crystal polymer film, wherein the liquid crystal polymer includes a constituent unit derived from an aromatic hydroxycarboxylic acid. The method according to any one of claims 1 to 9,
The liquid crystal polymer includes at least one structural unit selected from the group consisting of a structural unit derived from an aromatic hydroxycarboxylic acid, a structural unit derived from an aromatic diol, and a structural unit derived from an aromatic dicarboxylic acid. liquid crystal polymer film. According to any one of claims 1 to 11,
The liquid crystal polymer film comprising an aromatic polyester amide. A laminate comprising the liquid crystal polymer film according to any one of claims 1 to 12, and a metal layer or metal wiring disposed on at least one surface of the liquid crystal polymer film. The method of claim 13,
wherein the metal layer or metal wiring has a group capable of interacting with the liquid crystal polymer film on a surface in contact with the liquid crystal polymer film. The method of claim 14,
The group capable of interacting with the liquid crystal polymer film is an amino group. The method according to any one of claims 13 to 15,
A laminate wherein a peel strength between the liquid crystal polymer film and the metal layer is 0.5 kN/m or more. At least one polymer selected from the group consisting of fluorine-based polymers, polymers containing constitutional units derived from compounds having cyclic aliphatic hydrocarbon groups and groups having ethylenically unsaturated bonds, polyphenylene ethers, and aromatic polyether ketones A polymer layer comprising a;
A layer A disposed on at least one side of the polymer layer,
The polymer film according to claim 1 , wherein a mixed region containing the polymer and a material constituting the layer A is formed between the polymer layer and the layer A.